SC140 DSP Core
Reference Manual
Revision 4.1, September 2005
This document contains information on a new product.
Specifications and information herein are subject to
change without notice.
(c) Freescale Semiconductor, Inc. 2005, All rights
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changes without further notice to any products included and covered hereby. LICENSOR makes
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incidental, consequential, reliance, exemplary, or any other similar such damages, by way of
illustration but not limitation, such as, loss of profits and loss of business opportunity. "Typical"
parameters which may be provided in LICENSOR data sheets and/or specifications can and do
vary in different applications and actual performance may vary over time. All operating
parameters, including "Typicals" must be validated for each customer application by customer’s
technical experts. LICENSOR does not convey any license under its patent rights nor the rights of
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systems intended for surgical implant into the body, or other applications intended to support life,
or for any other application in which the failure of the LICENSOR product could create a situation
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SC140 DSP Core Reference Manual
Table of Contents
About This Book
Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi
Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxii
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv
Chapter 1
Introduction
1.1
Target Markets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2
Architectural Differentiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3
Core Architecture Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.3.1
Typical System-On-Chip Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.3.2
Variable Length Execution Set (VLES) Software Model . . . . . . . . . . . . . . . . 1-5
Chapter 2
Core Architecture
2.1
Architecture Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.1
Data Arithmetic Logic Unit (DALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.1.1.1
Data Register File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.1.2
Multiply-Accumulate (MAC) Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.1.3
Bit-Field Unit (BFU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.1.4
Shifter/Limiters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.2
Address Generation Unit (AGU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.1.2.1
Stack Pointer Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
2.1.2.2
Bit Mask Unit (BMU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
2.1.3
Program Sequencer Unit (PSEQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
2.1.4
Enhanced On-Chip Emulator (EOnCE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
2.1.5
Instruction Set Accelerator Plug-in (ISAP) Interface . . . . . . . . . . . . . . . . . . . . 2-5
2.1.6
Memory Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
2.2
DALU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
2.2.1
DALU Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
2.2.1.1
Data Registers (D0–D15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
2.2.1.2
Multiply-Accumulate (MAC) Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
2.2.1.3
Bit-Field Unit (BFU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.2.1.4
Data Shifter/Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.2.1.5
Scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.2.1.6
Limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.2.1.7
Scaling and Arithmetic Saturation Mode Interactions . . . . . . . . . . . . . . . 2-16
2.2.2
DALU Arithmetic and Rounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
SC140 DSP Core Reference Manual
iii
2.2.2.1
Data Representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
2.2.2.2
Data Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.2.3
Multiplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
2.2.2.4
Division. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
2.2.2.5
Unsigned Arithmetic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
2.2.2.6
Rounding Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21
2.2.2.7
Arithmetic Saturation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.2.2.8
Multi-Precision Arithmetic Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
2.2.2.9
Viterbi Decoding Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30
2.3
Address Generation Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31
2.3.1
AGU Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31
2.3.2
AGU Programming Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
2.3.2.1
Address Registers (R0–R15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
2.3.2.2
Stack Pointer Registers (NSP, ESP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
2.3.2.3
Offset Registers (N0–N3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
2.3.2.4
Base Address Registers (B0–B7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
2.3.2.5
Modifier Registers (M0–M3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
2.3.2.6
Modifier Control Register (MCTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
2.3.3
Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
2.3.3.1
Register Direct Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
2.3.3.2
Address Register Indirect Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
2.3.3.3
PC Relative Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
2.3.3.4
Special Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41
2.3.3.5
Memory Access Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42
2.3.3.6
Memory Access Misalignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42
2.3.3.7
Addressing Modes Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
2.3.4
Address Modifier Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
2.3.4.1
Linear Addressing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
2.3.4.2
Reverse-carry Addressing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
2.3.4.3
Modulo Addressing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
2.3.4.4
Multiple Wrap-Around Modulo Addressing Mode . . . . . . . . . . . . . . . . . 2-47
2.3.5
Arithmetic Instructions on Address Registers . . . . . . . . . . . . . . . . . . . . . . . . 2-48
2.3.6
Bit Mask Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-49
2.3.6.1
Bit Mask Test and Set (Semaphore Support) Instruction . . . . . . . . . . . . . 2-50
2.3.6.2
Semaphore Hardware Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-51
2.3.7
Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-51
2.4
Memory Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-55
2.4.1
SC140 Endian Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-56
2.4.1.1
SC140 Bus Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-56
2.4.1.2
Memory Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-57
2.4.1.3
Data Moves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58
2.4.1.4
Multi-Register Moves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-60
2.4.1.5
Instruction Word Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62
2.4.1.6
Memory Access Behavior in Big/Little Endian Modes . . . . . . . . . . . . . . 2-64
iv
SC140 DSP Core Reference Manual
Chapter 3
Control Registers
3.1
Core Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1.1
Status Register (SR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1.2
Exception and Mode Register (EMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.1.2.1
Clearing EMR Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
3.2
PLL and Clock Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Chapter 4
Emulation and Debug (EOnCE)
4.1
Debugging System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.2
Overview of the Combined JTAG and EOnCE Interface. . . . . . . . . . . . . . . . . . . . 4-2
4.2.1
Cascading Multiple SC140 EOnCE Modules in a SoC . . . . . . . . . . . . . . . . . . 4-2
4.2.2
JTAG Scan Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.2.3
Activating the EOnCE Through the JTAG Port . . . . . . . . . . . . . . . . . . . . . . . . 4-6
4.2.4
Enabling the EOnCE Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
4.2.5
DEBUG_REQUEST and ENABLE_EONCE Commands. . . . . . . . . . . . . . . . 4-7
4.2.6
Reading/Writing EOnCE Registers Through JTAG. . . . . . . . . . . . . . . . . . . . . 4-7
4.3
Main Capabilities of the EOnCE Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
4.3.1
EOnCE Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
4.3.2
EOnCE Dedicated Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
4.3.3
Debug State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
4.3.4
Debug Exception. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
4.3.5
Executing an Instruction while in Debug State . . . . . . . . . . . . . . . . . . . . . . . 4-12
4.3.6
Software Downloading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
4.3.7
EOnCE Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
4.3.8
EOnCE Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
4.3.9
Event and Action Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
4.4
EOnCE Enabling and Power Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
4.5
EOnCE Module Internal Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
4.5.1
EOnCE Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
4.5.2
Event Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
4.5.3
Event Detection Unit (EDU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
4.5.3.1
Address Event Detection Channel (EDCA) . . . . . . . . . . . . . . . . . . . . . . . 4-22
4.5.3.2
Data Event Detection Channel (EDCD) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
4.5.3.3
Optional External Event Detection Address Channels . . . . . . . . . . . . . . . 4-25
4.5.4
Event Selector (ES). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25
4.5.5
Trace Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26
4.5.5.1
Change of Flow and Interrupt Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
4.5.5.2
Writing to the Trace Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29
4.5.5.3
Reading the Trace Buffer (TB_BUFF) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29
4.5.5.4
Trace Unit Programming Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29
4.6
EOnCE Register Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-30
4.6.1
Reading or Writing EOnCE Registers Using Core Software . . . . . . . . . . . . . 4-33
4.6.2
Real-Time JTAG Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
4.6.3
Real-Time Data Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
SC140 DSP Core Reference Manual
v
4.6.4
General EOnCE Register Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
4.7
EOnCE Controller Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
4.7.1
EOnCE Command Register (ECR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
4.7.2
EOnCE Status Register (ESR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37
4.7.3
EOnCE Monitor and Control Register (EMCR). . . . . . . . . . . . . . . . . . . . . . . 4-41
4.7.4
EOnCE Receive Register (ERCV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43
4.7.5
EOnCE Transmit Register (ETRSMT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43
4.7.6
EE Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44
4.7.6.1
EE Signals as Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44
4.7.6.2
EE Signals as Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45
4.7.6.3
EE Signals Control Register (EE_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . 4-45
4.7.7
Core Command Register (CORE_CMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48
4.7.8
PC of the Exception Execution Set (PC_EXCP) . . . . . . . . . . . . . . . . . . . . . . 4-49
4.7.9
PC of the Next Execution Set (PC_NEXT) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-49
4.7.10
PC of Last Execution Set (PC_LAST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-49
4.7.11
PC Breakpoint Detection Register (PC_DETECT) . . . . . . . . . . . . . . . . . . . . 4-49
4.8
Event Counter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-50
4.8.1
Event Counter Control Register (ECNT_CTRL) . . . . . . . . . . . . . . . . . . . . . . 4-50
4.8.2
Event Counter Value Register (ECNT_VAL) . . . . . . . . . . . . . . . . . . . . . . . . 4-52
4.8.3
Extension Counter Value Register (ECNT_EXT) . . . . . . . . . . . . . . . . . . . . . 4-53
4.8.4
EC Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
4.9
Event Detection Unit (EDU) Channels and Registers . . . . . . . . . . . . . . . . . . . . . 4-54
4.9.1
Address Event Detection Channel (EDCA) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-54
4.9.1.1
EDCA Control Registers (EDCAi_CTRL). . . . . . . . . . . . . . . . . . . . . . . . 4-54
4.9.1.2
EDCA Reference Value Registers A and B
(EDCAi_REFA, EDCAi_REFB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-57
4.9.1.3
EDCA Mask Register (EDCAi_MASK) . . . . . . . . . . . . . . . . . . . . . . . . . 4-57
4.9.2
Data Event Detection Channel (EDCD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
4.9.2.1
EDCD Control Register (EDCD_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
4.9.2.2
EDCD Reference Value Register (EDCD_REF) . . . . . . . . . . . . . . . . . . . 4-61
4.9.2.3
EDCD Mask Register (EDCD_MASK) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-61
4.10 Event Selector (ES) Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-61
4.10.1
Event Selector Control Register (ESEL_CTRL) . . . . . . . . . . . . . . . . . . . . . . 4-61
4.10.2
Event Selector Mask Debug State Register (ESEL_DM) . . . . . . . . . . . . . . . 4-63
4.10.3
Event Selector Mask Debug Exception
Register (ESEL_DI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-64
4.10.4
Event Selector Mask Enable Trace Register (ESEL_ETB) . . . . . . . . . . . . . . 4-64
4.10.5
Event Selector Mask Disable Trace Register (ESEL_DTB) . . . . . . . . . . . . . 4-65
4.11 Trace Unit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-65
4.11.1
Trace Buffer Control Register (TB_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-65
4.11.2
Trace Buffer Read Pointer Register (TB_RD) . . . . . . . . . . . . . . . . . . . . . . . . 4-69
4.11.3
Trace Buffer Write Pointer Register (TB_WR) . . . . . . . . . . . . . . . . . . . . . . . 4-69
4.11.4
Trace Buffer Register (TB_BUFF). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-69
vi
SC140 DSP Core Reference Manual
Chapter 5
Program Control
5.1
Pipeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1.1
Instruction Pipeline Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.1.1.1
Instruction Pre-Fetch and Fetch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.1.1.2
Instruction Dispatch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.1.1.3
Address Generation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.1.1.4
Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
5.2
Instruction Grouping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
5.2.1
Grouping Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
5.2.1.1
Serial Grouping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
5.2.1.2
Prefix Grouping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
5.2.2
Prefix Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
5.2.2.1
Two-Word Prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
5.2.2.2
One-Word Low Register Prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
5.2.3
Conditional Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
5.2.4
Prefix Selection Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
5.2.5
Instruction Reordering Within an Execution Set . . . . . . . . . . . . . . . . . . . . . . 5-12
5.3
Instruction Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
5.3.1
Sequential Instruction Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
5.3.1.1
DALU Instruction Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
5.3.1.2
Move Instruction Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
5.3.1.3
Bit Mask Instruction Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
5.3.2
Change-Of-Flow Instruction Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
5.3.2.1
Direct, PC-Relative, and Conditional COF . . . . . . . . . . . . . . . . . . . . . . . 5-18
5.3.2.2
Delayed COF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
5.3.2.3
COF Execution Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
5.3.3
Memory Access Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
5.3.3.1
Memory Access Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
5.3.3.2
Implicit Push/Pop Memory Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
5.3.3.3
Memory Stall Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
5.4
Hardware Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
5.4.1
Loop Programming Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
5.4.1.1
Loop Start Address Registers (SAn). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
5.4.1.2
Loop Counter Registers (LCn) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
5.4.1.3
Status Register (SR) Loop Flag Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
5.4.2
Loop Notation and Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
5.4.3
Loop Initiation and Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
5.4.4
Loop Nesting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
5.4.5
Loop Iteration and Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
5.4.6
Loop Control Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
5.4.7
Loop Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
5.5
Stack Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
5.5.1
SC140 Single Stack Memory Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
5.5.2
SC140 Dual Stack Memory Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
5.5.3
Stack Support Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34
5.5.4
Shadow Stack Pointer Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
SC140 DSP Core Reference Manual
vii
5.5.5
Fast Return from Subroutines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-36
5.6
Working Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
5.6.1
Normal Working Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
5.6.2
Exception Working Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
5.6.3
Typical Working Mode Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
5.6.3.1
Dual-stack RTOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
5.6.3.2
Single-stack RTOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39
5.6.4
Working Mode Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39
5.6.4.1
From Exception to Normal mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39
5.6.4.2
From Normal to Exception mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39
5.7
Processing States. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41
5.7.1
Processing State Change Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41
5.7.2
Processing State Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-42
5.7.3
Execution State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
5.7.4
Reset Processing State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
5.7.5
Debug State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
5.7.6
Wait Processing State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
5.7.7
Stop Processing State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45
5.8
Exception Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-46
5.8.1
Interrupt Vector Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48
5.8.1.1
Vector Base Address Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48
5.8.1.2
Programming Exception Routine Addresses . . . . . . . . . . . . . . . . . . . . . . 5-48
5.8.2
Return From Exception Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-49
5.8.3
Maskable Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
5.8.3.1
Interrupt Priority Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
5.8.3.2
Controlling All Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
5.8.4
Non-Maskable Interrupts (NMI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
5.8.5
Internal Exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
5.8.5.1
Illegal Exception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
5.8.5.2
DALU Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
5.8.5.3
TRAP Exception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
5.8.5.4
Debug Exception. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
5.8.6
Exception Interface to the Pipeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
5.8.6.1
Exception Routine Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
5.8.6.2
Exception Mode Execution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
5.8.7
Exception Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Chapter 6
Instruction Set Accelerator Plug-In
6.1
6.2
6.2.1
6.2.2
6.3
6.4
6.5
6.6
viii
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
ISAP - SC140 Schematic Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Single ISAP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Multiple ISAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59
ISAP instructions and instruction encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
ISAP Memory Access. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
ISAP-core register transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-61
Immediate Data Transfer to ISAP registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
SC140 DSP Core Reference Manual
6.7
Core Assembly Syntax with an ISAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
6.7.1
Identification of ISAP instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
6.7.1.1
Working with One ISAP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
6.7.1.2
Working with Multiple ISAPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-64
6.7.2
An Example of the Definition Flexibility of an ISAP . . . . . . . . . . . . . . . . . . 6-65
6.7.3
Conditional Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-66
6.8
Programming Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
6.8.1
ISAP Functions that Interact With the Core . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
6.8.2
Grouping rules for explicit ISAP instructions . . . . . . . . . . . . . . . . . . . . . . . . 6-68
6.8.3
Rules for implicit AGU instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-68
6.8.4
Sequencing rules for T bit update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69
Chapter 7
Programming Rules
7.1
VLES Sequencing Semantics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.2
VLES Grouping Semantics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.3
SC140 Pipeline Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.4
Programming Rule Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.4.1
Grouping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.4.1.1
Prefix Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.4.1.2
Conditional Subgroups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.4.1.3
Assembler Reordering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.4.2
Sequencing Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.4.2.1
Cycle Counts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.4.2.2
Conditional Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.4.2.3
Simulator Execution Counts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.4.3
Register Read/Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.4.3.1
Register Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.4.3.2
B Register Aliasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
7.4.4
Status Bit Updates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
7.4.5
Instruction Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
7.4.6
MOVE-like Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
7.4.6.1
Address/Data Operands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
7.4.7
AGU Arithmetic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
7.4.8
Change-Of-Flow Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
7.4.8.1
COF Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
7.4.9
Delayed COF Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
7.4.9.1
Delay Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
7.4.10
Hardware Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
7.4.10.1
Enabled Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
7.4.10.2
Enveloping Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
7.5
Static Programming Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
7.5.1
Hardware Loop Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
7.5.2
General Grouping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
7.5.3
Prefix Grouping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
7.5.4
AGU Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
7.5.5
Delayed COF Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19
SC140 DSP Core Reference Manual
ix
7.5.6
Status Bit Rules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22
7.5.7
Loop Nesting Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28
7.5.8
Loop LA Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-31
7.5.9
Loop Sequencing Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-33
7.5.10
Loop COF Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-36
7.5.11
General Looping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-40
7.6
Dynamic Programming Rules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-41
7.6.1
AGU Dynamic Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-41
7.6.2
Memory Access Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-42
7.6.3
RAS Rules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-43
7.6.4
Loop Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-43
7.6.5
Rule Detection Across COF Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-44
7.6.5.1
Cycle-Based COF Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-44
7.6.5.2
VLES-Based COF Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-45
7.6.6
Rule Detection Across Exception Boundaries . . . . . . . . . . . . . . . . . . . . . . . . 7-46
7.7
Programming Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-48
7.7.1
Rules Not Detected Across COF Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
7.7.2
Good Programming Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
7.7.2.1
Source Code Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
7.7.2.2
Binary Code Practices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-50
7.7.2.3
Software Development Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51
7.8
LPMARK Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51
7.8.1
LPMARK Instruction Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51
7.8.2
Static Programming Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
7.8.2.1
General Grouping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
7.8.2.2
Prefix Grouping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
7.8.3
Dynamic Programming Rules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
7.8.3.1
LPMARK Notation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
7.8.3.2
Loop Nesting Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53
7.8.3.3
Loop LA Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53
7.8.3.4
Loop Sequencing Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55
7.8.3.5
Loop COF Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-56
7.8.3.6
General Looping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-59
7.8.3.7
Rule Detection Across Exception Boundaries . . . . . . . . . . . . . . . . . . . . . 7-59
7.8.4
LPMARK Programming Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-59
7.9
NOP Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-60
7.9.1
Grouping Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-61
Appendix A
SC140 DSP Core Instruction Set
A.1
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.1.1
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.1.1.1
Brackets as ISAP indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.1.1.2
Brackets as address indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.1.2
Addressing Mode Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.1.3
Data Representation in Memory for the Examples. . . . . . . . . . . . . . . . . . . . .
A.1.4
Encoding Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
x
A-1
A-2
A-4
A-4
A-5
A-6
A-6
SC140 DSP Core Reference Manual
A.1.5
Prefix Word Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
A.1.5.1
One-Word Low Register Prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8
A.1.5.2
Two-Word Prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-9
A.1.6
Instruction Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
A.1.6.1
Instruction Sub-types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
A.2
Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-19
A.2.1
Instruction Definition Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-19
Appendix B
StarCore Registry
B.1
Using the StarCore Registry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
SC140 DSP Core Reference Manual
xi
xii
SC140 DSP Core Reference Manual
List of Figures
1-1
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23
2-24
2-25
3-1
3-2
4-1
4-2
4-3
4-4
4-5
4-6
Block Diagram of a Typical SoC Configuration with the SC140 Core . . . . . . . 1-5
Block Diagram of the SC140 Core . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
DALU Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
DALU Data Representations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
Fractional and Integer Multiplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
Convergent Rounding (No Scaling) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Two’s Complement Rounding (No Scaling) . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24
DMAC Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
Fractional Double-Precision Multiplication . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
Fractional Mixed-Precision Multiplication. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28
Signed Integer Double-Precision Multiplication . . . . . . . . . . . . . . . . . . . . . . . 2-29
Unsigned Integer Double-Precision Multiplication . . . . . . . . . . . . . . . . . . . . . 2-30
AGU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32
AGU Programming Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
Modifier Control Register (MCTL) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
Modulo Addressing Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-46
Integer Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53
Fractional Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-54
Bit Allocation in MOVE.L D0.e:D1.e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-55
Endian Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-56
Basic Connection between SC140 Core and Memory . . . . . . . . . . . . . . . . . . . 2-57
Memory Organization of Big and Little Endian Mode. . . . . . . . . . . . . . . . . . . 2-57
Data Transfer in Big and Little Endian Modes. . . . . . . . . . . . . . . . . . . . . . . . . 2-59
Multi-Register Transfer in Big and Little Endian Modes. . . . . . . . . . . . . . . . . 2-61
Program Memory Organization in Big and Little Endian Modes . . . . . . . . . . 2-62
Instruction Moves in Big and Little Endian Modes . . . . . . . . . . . . . . . . . . . . . 2-63
Status Register -SR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Exception and Mode Register (EMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
JTAG and EOnCE Multi-core Interconnection . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
TAP Controller State Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Cascading Multiple EOnCE Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Reading and Writing EOnCE Registers Via JTAG . . . . . . . . . . . . . . . . . . . . . . 4-8
Accessing EOnCE registers through JTAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Typical Debugging System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
SC140 DSP Core Reference Manual
xiii
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
6-1
6-2
xiv
Software Downloading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
EOnCE Controller Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Event Counter Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Event Detection Unit Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
EDCA Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
EDCD Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Event Selector Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26
Trace Unit Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
EOnCE Command Register (ECR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
EOnCE Status Register (ESR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
EOnCE Monitor and Control Register (EMCR). . . . . . . . . . . . . . . . . . . . . . . . 4-41
EE Signals Control Register (EE_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45
Injected Instruction Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48
Event Counter Register (ECNT_CTRL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
EDCA Control Register (EDCAi_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-54
EDCD Control Register (EDCD_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
Event Selector Control Register (ESEL_CTRL) . . . . . . . . . . . . . . . . . . . . . . . 4-62
Event Selector Mask Debug State (ESEL_DM). . . . . . . . . . . . . . . . . . . . . . . . 4-63
Event Selector Mask Debug Exception (ESEL_DI). . . . . . . . . . . . . . . . . . . . . 4-64
Event Selector Mask Enable Trace (ESEL_ETB) . . . . . . . . . . . . . . . . . . . . . . 4-64
Event Selector Mask Disable Trace (ESEL_DTB). . . . . . . . . . . . . . . . . . . . . . 4-65
Trace Buffer Control Register (TB_CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-67
Instruction Pipeline Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Instruction Grouping Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Low Register Prefix Selection Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Hardware Loop Programming Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
Loop Nesting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
SC140 Memory Use with a Single Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . 5-32
SC140 Memory Use with Dual Stack Pointers. . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Working mode Transitions - Unprotected Dual-stack RTOS. . . . . . . . . . . . . . 5-38
Working mode Transitions - Unprotected Single-stack RTOS . . . . . . . . . . . . 5-39
Core State Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-42
Core-PIC Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-47
Flowchart for Exception Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-55
Core to Single ISAP Connection Schematic. . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Core to Multiple ISAP Connection Schematic . . . . . . . . . . . . . . . . . . . . . . . . . 6-59
SC140 DSP Core Reference Manual
List of Tables
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23
2-24
2-25
2-26
2-27
2-28
2-29
2-31
2-30
3-1
3-2
4-1
DALU Programming Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Write to Data Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Read from Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Data Registers Access Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
DALU Arithmetic Instructions (MAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
DALU Logical Instructions (BFU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Scaling Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Ln Bit Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
Limiting Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Scaling and Limiting Interactions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Saturation and Rounding Interactions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
Two’s Complement Word Representations . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
Rounding Position in Relation to Scaling Mode . . . . . . . . . . . . . . . . . . . . . . . 2-21
Arithmetic Saturation Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Fractional Signed and Unsigned Two’s Complement Multiplication . . . . . . . 2-26
Integer Signed and Unsigned Two’s Complement Multiplication . . . . . . . . . . 2-28
Address Modifier (AM) Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
Access Width Support for Address and Register Update Calculations . . . . . . 2-42
Memory Address Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Addressing Modes Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Modulo Register Values for Modulo Addressing Mode . . . . . . . . . . . . . . . . . 2-47
Modulo Register Values for Wrap-Around Modulo Addressing Mode . . . . . . 2-48
AGU Arithmetic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-48
AGU Bit Mask Instructions (BMU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-50
AGU Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52
Data Representation in Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58
Move Instructions in Big and Little Endian Modes . . . . . . . . . . . . . . . . . . . . . 2-64
Stack Support Instructions in Big and Little Endian Modes . . . . . . . . . . . . . . 2-67
Bit Mask Instructions in Big and Little Endian Modes . . . . . . . . . . . . . . . . . . 2-67
Control Instructions in Big and Little Endian Modes. . . . . . . . . . . . . . . . . . . . 2-68
Non-Loop Change-of-Flow Instructions in Big and Little Endian Modes . . . . 2-68
Status Register Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
EMR Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
JTAG Interface Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
SC140 DSP Core Reference Manual
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4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
xvi
JTAG Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
JTAG Scan Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
EOnCE Event Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
EOnCE Event and Action Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
EOnCE Controller Register Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Event Counter Register Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
EDCA Register Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
EDCD Register Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Event Selector Register Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26
Trace Buffer Register Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-30
EOnCE Register Addressing Offsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31
ECR Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
ESR Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
EMCR Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
EE_CTRL Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
Length Control Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48
ECNT_CTRL Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
EDCA_CTRL Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-54
EDCD_CTRL Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
ESEL_CTRL Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-62
Allowed tracing mode combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-66
TB_CTRL Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-67
Pipeline Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Pipeline Stages Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Prefix Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Conditional IFc Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Instruction Categories Timing Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Non-Loop Change-of-Flow Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Loop Change-Of-Flow Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
Number of Cycles Needed by Change-of-Flow Instructions . . . . . . . . . . . . . . 5-20
LPMARKA and LPMARKB Bits in Short and Long Loops . . . . . . . . . . . . . . 5-27
Loop Control Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
Stack Push/Pop Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34
Even and Odd Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34
Stack Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
Stack Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
Working Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
Processing State Change Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41
Processing State Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
SC140 DSP Core Reference Manual
5-18
5-19
5-20
5-21
6-1
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-11
A-12
A-13
A-14
A-15
A-16
A-17
B-1
Exit Wait Processing State due to an Interrupt or NMI . . . . . . . . . . . . . . . . . . 5-45
Exception Vector Address Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-49
Exception Pipeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Pipeline Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
ISAP Encoding Fields. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
Instruction Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Operations Syntax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Register Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Assembler Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Addressing Mode Notation for the EA Operand . . . . . . . . . . . . . . . . . . . . . . . . A-5
Addressing Mode Notation for the ea Operand . . . . . . . . . . . . . . . . . . . . . . . . . A-5
DALU Arithmetic Instructions (MAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-13
DALU Logical Instructions (BFU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-14
AGU Arithmetic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-15
AGU Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-15
AGU Stack Support Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-16
AGU Bit-Mask Instructions (BMU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
AGU Non-Loop Change-of-Flow Instructions. . . . . . . . . . . . . . . . . . . . . . . . . A-17
AGU Loop Control (Including Loop COF) Instructions . . . . . . . . . . . . . . . . . A-18
AGU Program Control Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-18
Prefix Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-18
Combinations of LPMARKx Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-221
SCID Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
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SC140 DSP Core Reference Manual
List of Examples
3-1
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
7-1
7-2
7-3
7-4
7-5
7-6
Clearing an EMR Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Four SC140 Instructions in an Execution Set . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Grouping Six SC140 Instructions in an Execution Set. . . . . . . . . . . . . . . . . . . . 5-5
Execution Set with Three One-word and Two Two-word Instructions . . . . . . 5-13
Conditional VLES Having Two Subgroups . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Set of 2 Two-word Instructions Requiring a NOP . . . . . . . . . . . . . . . . . . . . . . 5-13
Delayed Change-of-Flow and Its Delay Slot . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Subroutine Call Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
Parallel Execution of Two Move Instructions . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Execution Set Containing a Bit Mask and a Move Instruction. . . . . . . . . . . . . 5-23
Execution Set Containing One Bit Mask Instruction . . . . . . . . . . . . . . . . . . . . 5-23
Execution Set Containing a Bit Mask and a Pop Instruction . . . . . . . . . . . . . . 5-24
Long Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Long Loop Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Short Loop, Two Execution Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Short Loop, One Execution Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Nested Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Basic Exception Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
ISAP memory access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-61
ISAP-Core register transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
ISAP-Core register transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Single ISAP coding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
Multiple ISAP coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-65
Conditional Execution Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-66
Conditional Execution Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-66
MOVE rules with an implicit MOVE instruction from ISAP . . . . . . . . . . . . . 6-68
B Register Aliasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Delayed COF Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
VLES Word Count Exceeds Eight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Too Many AGU Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Duplicate PC Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9
Duplicate Address Pointer Register Destinations . . . . . . . . . . . . . . . . . . . . . . . . 7-9
SC140 DSP Core Reference Manual
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7-7
7-8
7-9
7-10
7-11
7-12
7-13
7-14
7-15
7-16
7-17
7-18
7-19
7-20
7-21
7-22
7-23
7-24
7-25
7-26
7-27
7-28
7-29
7-30
7-31
7-32
7-33
7-34
7-35
7-36
7-37
7-38
7-39
7-40
7-41
7-42
7-43
xx
Duplicate Stack Pointer Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9
Duplicate Register Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Duplicate SR/EMR Register Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Duplicate Status Bit Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Dual Stack Pointer Destination Exception . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Mutually Exclusive Register Destination Exception . . . . . . . . . . . . . . . . . . . . 7-11
Mutually Exclusive Status Bit Destination Exception . . . . . . . . . . . . . . . . . . . 7-11
Multiple C, S and DOVF Status Bit Destination Exception. . . . . . . . . . . . . . . 7-11
DALU Register Use Exceeds Four Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
VLES Extension Words Exceed Two. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Two-Word Instructions Exceed Two . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
VLES Has Mutually Exclusive Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13
RTE Uses Both AAU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13
Data Source Use of Nn and Mn Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
IFc Having Two Subgroups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
IFA Subgroup Must Be Last Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Core AGU instructions on same VLES as ISAP instructions . . . . . . . . . . . . . 7-15
ISAP instructions in same IFc group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
MCTL Write to R0-R7 Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
Rn, Nn, Mn Write to AGU Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17
Rn or Nn Write to MOVE-like Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18
LCn Write to MOVE-like Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18
NMID Update to EMR Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19
Instructions in a Delay Slot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19
Instructions in a RTED Delay Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20
RTE/D with SR Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20
PC Read in a Return Delay Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
SR Write with a Subroutine Call . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
SR Write in BSRD or JSRD Delay Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
SP Use in Return Delay Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
SR Read in a CONTD Delay Slot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22
EMR Use in Return Delay Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22
T Bit Update to IFT/IFF AGU Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22
T Bit Update by ISAP and COF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23
T Bit Update by ISAP and MOVET/MOVEF . . . . . . . . . . . . . . . . . . . . . . . . . 7-23
T Bit Update by ISAP and IFT/IFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23
SR Write to SR Status Bit Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-25
SC140 DSP Core Reference Manual
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7-45
7-46
7-47
7-48
7-49
7-50
7-51
7-52
7-53
7-54
7-55
7-56
7-57
7-58
7-59
7-60
7-61
7-62
7-63
7-64
7-65
7-66
7-67
7-68
7-69
7-70
7-71
7-72
7-73
7-74
7-75
7-76
7-77
7-78
7-79
7-80
SR Write to SR Status Bit Update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOVF Update to SR Read or Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOVF Update grouped with Move-like SR updates . . . . . . . . . . . . . . . . . . . .
Status Bit Update with SR Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nested Loops with the Same LA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nested Loops with Ordered Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nested DOENn/DOENSHn Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOENn instruction following DOENSHn Instruction . . . . . . . . . . . . . . . . . . .
LOOPEND between DOEN and LOOPEND . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing a loop type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instructions at the End of Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCn Write at the End of Long Loop n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instructions in Short Loops. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Short Loop LA at the End of a Long Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCn Write to SKIPLS Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCn Write at the End of Long Loop n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCn Write at the Start of Short Loop n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCn Write to CONT/D Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SAn Write at the End of Long Loop n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SAn Write to CONT/D Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCn Read at the Start of Short Loop n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COF Destination to Loop Delay Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COF Instructions at LA-2 of a Long Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bc/Jc at SA-1 of a Short Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bc/Jc at LA-3 of a Long Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop COF Destination in the Same Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop COF at End of Nested Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subroutine Call to End of Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Delayed COF at LA-3 of a Long Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Delayed COF at SA-1 of a Short Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SR Read to LA of Any Long Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SR Read to SA of Any Short Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enabling Short and Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bn, Mn Write to AGU Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiple Memory Writes to the Same Location . . . . . . . . . . . . . . . . . . . . . . . .
Pre-Calculated Memory Accesses to the Same Location . . . . . . . . . . . . . . . . .
Memory Write to Stack in a Return Delay Slot . . . . . . . . . . . . . . . . . . . . . . . .
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Illegal use of RAS value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SR.2 Across a COF Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2 from a Delay Slot to a COF Destination . . . . . . . . . . . . . . . . . . . . . . . . . .
Set condition during a COF, and use it at the destination (T.1) . . . . . . . . . . . .
EMR access at the start of an exception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MCTL Write to R0-R7 Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Invalid COF Destination Cannot be Detected . . . . . . . . . . . . . . . . . . . . . . . . .
COF Destination in the Middle of a VLES. . . . . . . . . . . . . . . . . . . . . . . . . . . .
COF Destination in a Delay Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LFn Enabled During Loop Body n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LFn Enabled at LPA or LPB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instructions at the End of Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Active LCn Write at the End of Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . .
Instructions in Short Loops. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Active LCn Write at the Start of a Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Active SAn Write at the End of Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . .
Active LCn Read at the Start of a Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COF Instructions at LPB of a Long Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bc/Jc at the Start of a Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop COF at End of Nested Long Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subroutine Call to End of Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Delay Slot at LPA or LPB of a Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SR Read to LPA or LPB of a Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COF Destination to Loop Delay Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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SC140 DSP Core Reference Manual
About This Book
This manual provides reference information for the StarCore SC140 digital signal processor (DSP) core.
Specifically, this book describes the instruction set architecture and programming model for the SC140
core as well as corresponding register details, debug capabilities, and programming rules.
An appendix provides a detailed instruction reference for the SC140 instruction set, describing the
operation, mnemonics, instruction fields, and encoding for each instruction. Instruction examples are also
provided.
The resulting system-on-chip devices designed around the SC140 core will usually include additional
functional blocks such as on-chip memory, an external memory interface, peripheral accelerators, and
coprocessor devices. The specification of these functional blocks is customer-specific as well as
application-specific. Therefore, this information is not covered in this manual.
Audience
This manual is intended for systems software developers, hardware designers, and application developers.
Organization
This book is organized into six chapters and one appendix as follows:
•
Chapter 1, “Introduction”, describes key features of the SC140 architecture. This chapter also
illustrates a typical system using the SC140 core.
•
Chapter 2, “Core Architecture”, describes the main functional blocks and data paths of the SC140
core.
•
Chapter 3, “Control Registers”, details the core’s control registers.
•
Chapter 4, “Emulation and Debug (EOnCE)”, describes the hardware debug capabilities of the core.
•
Chapter 5, “Program Control”, details program control features such as the pipeline, instruction
grouping, instruction timing, hardware loops, stack support, processing states, protection model, and
exception processing.
•
Chapter 6, “Instruction Set Accelerator Plug-In”, describes how the SC140 core and SW developer
can work with a an Instruction Set Accelerator Plug-In.
•
Chapter 7, “Programming Rules”, details the VLES semantics, static programming rules, dynamic
programming rules, and programming guidelines for correct code construction.
•
Appendix A, “SC140 DSP Core Instruction Set,” references the SC140 instruction set.
•
Appendix B, “StarCore Registry,” shows how to access the core version
SC140 DSP Core Reference Manual
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Abbreviations
The abbreviations used in this manual are listed below:
Table 1. Abbreviations
Abbreviation
xxiv
Description
AAU
Address arithmetic unit
ADM
Application development module
AGU
Address generation unit
ALU
Arithmetic logic unit
Bn
AGU base address register n
BFU
Bit-field unit
BMU
Bit mask unit
DALU
Data arithmetic and logic unit
DSP
Digital signal processor
ECR
EOnCE control register
EDU
Event detection unit, with respect to the EOnCE
EE
EOnCE event pins
EMCR
EOnCE monitor and control register
EMR
Exception and mode register
EOnCE
Enhanced on-chip emulator
ERCV
EOnCE receive register
ES
Event selector, with respect to the EOnCE
ESP
Exception mode stack pointer
ESR
EOnCE status register
ETRSMT
EOnCE transmit register
EXT
Extension portion of a data register
FC
Fetch counter
FIFO
First-in first-out
FFT
Fast Fourier transform
HP
High portion of a data register
IPL
Interrupt priority level
ISAP
Instruction Set Accelerator Plug-in
SC140 DSP Core Reference Manual
Table 1. Abbreviations (Continued)
Abbreviation
Description
ISR
Interrupt service routine
JTAG
Joint test action group
LA
Last address
LCn
Loop counter register n
Ln
Limit tag bit n
LP
Low portion of a data register
LSB
Least significant bits
LSP
Least significant portion
Mn
AGU modifier register
MAC
Multiply-accumulate
MCTL
Modifier control register
MIPS
Million instructions per second
MMACS
Million multiply and accumulate operations per second
MSB
Most significant bits
MSP
Most significant portion
Nn
AGU offset register n
NMI
Non-maskable interrupt
NSP
Normal mode stack pointer
OS
Operating system
PAB
Program address bus
PAG
Program address generator
PC
Program counter register
PCU
Program control unit
PDB
Program data bus
PDU
Program dispatch unit
PIC
Programmable interrupt controller
PLL
Phase locked loop
PSEQ
Program sequencer unit
Rn
AGU address register n
SC140 DSP Core Reference Manual
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Table 1. Abbreviations (Continued)
Abbreviation
Description
RAS
Return address register
RTOS
Real-time operating system
SAn
Start address register n
SF
Signed fractional
SI
Signed integer
SM
Saturation mode
SoC
System-on-chip
SP
Stack pointer
SR
Status register
T
True bit
UI
Unsigned integer
VBA
Interrupt vector base address register
VLES
Variable length execution set instruction grouping
XABA
Data memory address bus A
XABB
Data memory address bus B
XDBA
Data memory data bus A
XDBB
Data memory data bus B
Revision History
Table 2. Revision History
Revision
Date
Description
4.0
31 Aug, 2004
Fourth release of SC140
4.1
20 Sep, 2005
Misc. corrections (restored missing IADDNC.W instruction)
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SC140 DSP Core Reference Manual
Chapter 1
Introduction
The StarCore SC140 digital signal processing (DSP) core, a new member of the SC100 architecture,
addresses key market needs of next-generation DSP applications. It is especially suited for wireline and
wireless communications, including infrastructure and subscriber communications. It is a flexible
programmable DSP core which enables the emergence of computational-intensive communication
applications by providing exceptional performance, low power consumption, efficient compilability, and
compact code density. The SC140 core efficiently deploys a variable-length execution set (VLES)
execution model which utilizes maximum parallelism by allowing multiple address generation and data
arithmetic logic units to execute multiple instructions in a single clock cycle.
This chapter describes key features of the SC140 core architecture.
1.1 Target Markets
The design of the SC140 architecture aims to provide a DSP software platform that fulfills the constantly
increasing computational requirements of DSP applications due to:
•
New communication standards and services
•
Wideband channels and data rates
•
New user interfaces and media
Currently, software-configurable wireless terminals are already required to accommodate multiple air
interfaces and frequency bands for cellular phones, PCs, paging devices, cordless phones, wireless LAN
systems, and modems. In addition, multiple voice, messaging, internet, and video services must also be
supported. These terminals must be flexible and upgradable so that they can be personalized for each user
(such as permitting the dynamic download of applets). Finally, these terminals must be able to process
baseband data using software to implement a range of functions previously carried out by hardware.
Target markets for the SC140 architecture include:
•
Wireless software configurable handset terminals (radios)
•
Third generation wireless handset systems with wideband data services
•
Wireless and wireline base stations as well as the corresponding infrastructure
•
Speech coding, synthesis, and voice recognition
•
Wireless internet and multimedia
•
Network and data communication
SC140 DSP Core Reference Manual
1-1
Architectural Differentiation
1.2 Architectural Differentiation
The SC140architecture differentiates itself in the market with the following capabilities:
•
High-level Abstraction of the Application Software
— DSP applications and kernels can currently be developed in the C programming language. An
optimizing compiler generates parallel instructions while maintaining a high code density.
— An orthogonal instruction set and programming model along with single data space and byte
addressability enable the compiler to generate efficient code.
— Hardware supported integer and fractional data types enable application developers to choose
their own style of code development, or to use coding techniques derived from an
application-specific standard.
•
Scalable Performance
— The number of execution units is independent of the instruction set, and can be tailored to the
application’s performance requirement. The SC140 contains four arithmetic logic units (ALUs)
and two address arithmetic units (AAUs).
— A high frequency of operation is achieved at low voltage, providing four million multiply and
accumulate (MAC) operations per second (4 MMACS) for each megahertz of clock frequency.
— Support exists for application-specific accelerators, providing a performance boost and
reduction in power consumption.
•
High Code Density for Minimized Cost
— 16-bit wide instruction encoding.
— A rich and orthogonal instruction set, major portions of which focus on control code that can
often occupy most of the application code.
— Variable length execution set (VLES) for DSP kernel operations.
•
Improved Support for Multi-tasking Applications
— Dual stack pointer support in HW.
•
Optimized Power Management Control
— Very low power consumption.
— Low voltage operation.
— Power saving modes.
•
Efficient Memory and I/O Interface
—
—
—
—
—
•
Very large on-chip zero-wait state static random access memory (SRAM) capability.
Support for slower on-chip memory via wait-states.
32-bit address space for both program and data (byte-addressable).
Unified data and program memory space.
Decoupled external memory timing with independent clock.
Core Organization and Design
— Supports flexible system-on-a-chip (SoC) configurations.
— Portable across fabrication lines and foundries.
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SC140 DSP Core Reference Manual
Core Architecture Features
1.3 Core Architecture Features
The SC140 core consists of the following:
•
Data arithmetic logic unit (DALU) that contains four instances of an arithmetic logic unit (ALU) and
a data register file
•
Address generation unit (AGU) that contains two address arithmetic units (AAU) and an address
register file
•
Program sequencer and control unit (PSEQ)
Key features of the SC140 core include the following:
•
Up to four million multiply-accumulate (MAC) operations per second (4 MMACS) for each
megahertz of clock frequency
•
Up to 10 RISC MIPS (million instruction words per second) for each megahertz of clock frequency
(a MAC operation is counted as two RISC instructions)
•
Four ALUs comprising MAC and bit-field units
•
A true (16 ∗ 16) + 40 to 40-bit MAC unit in each ALU
•
A true 40-bit parallel barrel shifter in each ALU
•
Sixteen 40-bit data registers for fractional and integer data operand storage
•
Sixteen 32-bit address registers, eight of which can be used as 32-bit base address registers
•
Four address offset registers and four modulo address registers
•
Hardware support for fractional and integer data types
•
Up to six instructions executed in a single clock cycle
•
Very rich 16-bit wide orthogonal instruction set
•
Support for application specific instruction set enhancements with an interface to an ISAP
(Instruction Set Accelerator Plug-in)
•
VLES execution model
•
Two AAUs with integer arithmetic capabilities
•
A bit mask unit (BMU) for bit and bit-field logic operations
•
Unique DSP addressing modes
•
32-bit unified data and program address space
•
Zero-overhead hardware loops with up to four levels of nesting
•
Byte-addressable data memory
•
Position independent code utilizing change-of-flow instructions that are relative to the
program counter (PC)
•
Enhanced on-chip emulation (EOnCE) module with real-time debug capabilities
•
Low power wait standby mode
•
Very low power complementary metal-oxide semiconductor (CMOS) design
•
Fully static logic
SC140 DSP Core Reference Manual
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Core Architecture Features
1.3.1 Typical System-On-Chip Configuration
The SC140 is a high-performance general-purpose fixed-point DSP core, allowing it to support many
system-on-chip (SoC) configurations. A library of modules containing memories, peripherals, accelerators,
and other processor cores makes it possible for a variety of highly integrated and cost-effective SoC
devices to be built around the SC140. Figure 1-1 shows a block diagram of a typical SoC chip made up of
the SC140 core and associated SoC components (described below). In a typical system the SC140 core is
enveloped in a platform that includes the core and supporting zero wait-state memories. This platform is
integrated as a unit in the SoC. Although not indicated in this configuration, an SoC can contain more than
one SC140 core platform.
An on-platform instruction set accelerator plug-in can be used as part of the SC140 core platform to
provide additional instructions for unique application solutions such as video processing, which require
specific arithmetic instructions in addition to the main instruction set.
•
SC140 DSP core platform — Includes the DSP core and the immediate supporting blocks that
typically run at the full core frequency. The DSP platform typically includes:
— SC140 DSP core
— Instruction Set Accelerator Plug-in (ISAP) - for expanding the instruction set with
application-specific instructions.
— L1 caches - data and instruction caches, operating with zero wait states in case of cache hit
— Unified M1 memory - supporting both program and data, and hence connected to both the
program and data buses of the core. The M1 memory operates with no wait states. It could be
either RAM or ROM, or a mix of both. The RAM, depending on its’ size, may be connected as
a slave to an external DMA.
— Program interrupt controller (PIC)
— Interfaces - translate the core data and program fetch requests to the bus protocol supported by
the system, usually in reduced frequency.
•
DSP Expansion Area — This area includes the functional units that interface between the core and
the DSP application, most importantly the functions that send and receive data from external
input/output sources, under the control of the software running on the DSP core. In addition, this area
includes accelerators that execute portions of the application, in order to boost performance and
decrease power consumption. This area is application-specific and may or may not include various
functional units such as:
— Synchronous serial interface
— Serial communication interface
— Viterbi accelerator
— Filter coprocessors
•
System Expansion Area — This area includes the SoC functional units that are not tightly coupled
with the DSP core. Typically it may include other processors with their support platform as well.
This area is application-specific, and may include various functional units such as:
— External memory interface
— Direct memory access (DMA) controller
— L2 Cache controller for either data or program
— Chip-level Interrupt control unit
— On-chip Level 2 (M2) memory expansion modules
— Other processor cores with their supporting platforms
1-4
SC140 DSP Core Reference Manual
Core Architecture Features
SoC
DSP expansion area
System expansion area
External memory interface
PLL
Standard I/O Peripherals
Level-2 caches
DMA
Application specific accelerators
On-chip RAM and ROM
Host interface
General purpose programmable
accelerators
Other micro-controllers
SC140 platform
Bus switch & interfaces
Trace
buffer
Unified M1
prog. & data
memory
PIC
JTAG
Instruction
cache
EOnCE
Data
cache
RAM ROM
ISAP
SC140 core
P
XA
XB
Figure 1-1. Block Diagram of a Typical SoC Configuration with the SC140 Core
1.3.2 Variable Length Execution Set (VLES) Software Model
The VLES software model is the instruction grouping used by the SC140 to address the requirements of
DSP kernels. Using an orthogonal compiler-friendly instruction set, this model maintains a compact code
density for applications.
All SC140 instruction words are 16 bits wide. Most instructions are encoded with one word. Each SC140
instruction encodes an atomic (lowest-level) operation. For example, MAC and store (move) instructions
are encoded in 16 bits. Since atomic operations need fewer bits to encode, the 16-bit instruction set
becomes fully orthogonal and very rich in the functionality it supports.
In order to execute signal processing kernels, a set of SC140 instructions can be grouped to be executed in
parallel. The PSEQ performs this automatically with up to four DALU instructions and two AGU
instructions executed at the same time.
SC140 DSP Core Reference Manual
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Core Architecture Features
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SC140 DSP Core Reference Manual
Chapter 2
Core Architecture
This chapter provides an overview of the SC140 core architecture. It describes the main functional blocks
and data paths of the core.
2.1 Architecture Overview
The SC140 core provides the following main functional units:
•
Data arithmetic and logic unit (DALU)
•
Address generation unit (AGU)
•
Program sequencer unit (PSEQ)
To provide data exchange between the core and the other on-chip blocks, the following buses are
implemented:
•
Two data memory buses (address and data pairs: XABA and XDBA, XABB and XDBB) that are
used for all data transfers between the core and memory.
•
Program data and address buses (PDB and PAB) for carrying program words from the memory to
the core.
•
Special buses to support tightly coupled external user-definable instruction set accelerators.
A block diagram of the SC140 core is shown in Figure 2-3.
SC140 DSP Core Reference Manual
2-1
Architecture Overview
.
32
64
XDBB
32
XDBA
32
XABB
XABA
128
PAB
PDB
Unified
Data/Program Memory
64
StarCore
SC140
Core
Program
Sequencer
Address Generator
Register File
DALU
Register File
DALU
AGU
EOnCE
ISAP
25
2 AAUs
JTAG
controller
BMU
4 ALUs
Instruction Bus
Figure 2-1. Block Diagram of the SC140 Core
2.1.1 Data Arithmetic Logic Unit (DALU)
The DALU performs arithmetic and logical operations on data operands in the SC140 core. The
components of the DALU are as follows:
•
A register file of sixteen 40-bit registers
•
Four parallel ALUs, each ALU containing a multiply-accumulate (MAC) unit and
a bit-field unit (BFU)
•
Eight data bus shifter/limiters
All the MAC units and BFUs can access all the DALU registers. Each register is partitioned into three
portions: two 16-bit registers (low and high portion of the register) and one 8-bit register (extension
portion). Accesses to or from these registers can be in widths of 8 bits, 16 bits, 32 bits, or 40 bits,
depending on the instruction.
The two data buses between the DALU register file and the memory are each 64 bits wide. This enables a
very high data transfer speed between memory and registers by allowing two data moves in parallel, each
up to 64 bits in width. The move instructions vary in access width from 8 bits to 64 bits, and can transfer
multiple words within the 64 bit constraint. With every MOVE instruction affecting the memory, one of
four signals to the memory interface is asserted, defining the access width.
2-2
•
MOVE.B loads or stores bytes (8-bit).
•
MOVE.W or MOVE.F loads or stores integer or fractional words (16-bit).
•
MOVE.2W, MOVE.2F or MOVE.L loads or stores two integers, two fractions and long words
respectively (32-bit).
•
MOVE.4W or MOVE.4F loads or stores four integers or four fractions, respectively (64-bit).
SC140 DSP Core Reference Manual
Architecture Overview
•
MOVE.2L loads or stores two long words (64-bit).
2.1.1.1 Data Register File
The DALU registers can be read or written over the data buses (XDBA and XDBB). A DALU register can
be the source for up to four simultaneous instructions, but simultaneous writes of a destination register are
illegal. The source operands for DALU arithmetic instructions usually originate from DALU registers. The
destination of every arithmetic operation is a DALU register, and each such destination can be used as a
source operand for the operation immediately following, without any time penalty.
2.1.1.2 Multiply-Accumulate (MAC) Unit
The MAC unit comprises the main arithmetic processing unit of the SC140 core and performs the
arithmetic operations. The MAC unit has a 40-bit input and outputs one 40-bit result in the form of
[Extension:High Portion:Low Portion] (EXT:HP:LP).
The multiplier executes 16-bit by 16-bit fractional or integer multiplication between two’s complement
signed, unsigned, or mixed operands (16-bit multiplier and multiplicand). The 32-bit product is
right-justified, sign-extended, and may be added to the 40-bit contents of one of the 16 data registers.
2.1.1.3 Bit-Field Unit (BFU)
The BFU contains a 40-bit parallel bidirectional shifter with a 40-bit input and a 40-bit output, a mask
generation unit, and a logic unit. The BFU is used in the following operations:
•
Multi-bit left/right shift (arithmetic or logical)
•
One-bit rotate (right or left)
•
Bit-field insert and extract
•
Count leading bits (ones or zeros)
•
Logical operations
•
Sign or zero extension operations
2.1.1.4 Shifter/Limiters
Eight shifter/limiters provide scaling and limiting on 32-bit transfers from the data register file to memory.
Scaling up or down by one bit is programmable as is limiting to the maximum values provided in 32 bits.
For more detailed information, see Section 2.2.1.4, “Data Shifter/Limiter,” Section 2.2.1.5, “Scaling,” and
Section 2.2.1.6, “Limiting.”
2.1.2 Address Generation Unit (AGU)
The AGU contains address registers and performs address calculations using integer arithmetic necessary
to address data operands in memory. It implements four types of arithmetic: linear, modulo, multiple
wrap-around modulo, and reverse-carry. The AGU operates in parallel with other core resources to
minimize address generation overhead.
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Architecture Overview
The AGU in the SC140 core has two address arithmetic units (AAU) to allow two address generation
operations at every clock cycle. The AAU has access to:
•
Sixteen 32-bit address registers (R0–R15), of which R8–R15 can also be used as base address
registers for modulo addressing.
•
Four 32-bit offset registers (N0–N3).
•
Four 32-bit modulo registers (M0–M3).
The two AAUs are identical. Each contains:
•
A 32-bit full adder, used for offset calculations.
•
A second 32-bit full adder, used for modulo calculations.
Each AAU can update one address register in the address register file in one instruction cycle.
The AGU also contains a 32-bit modulo control register (MCTL). This control register is used to specify
the addressing mode of the R registers: linear, reverse-carry, modulo, or multiple wrap-around modulo.
When modulo addressing mode is selected, the MCTL register is used to specify which of the four modulo
registers is assigned to a specific R register.
Explicit instructions in the SC140 instruction set are used to execute arithmetic operations on the address
pointers. This capability can also be used for general data arithmetic. In addition, the AGU generates
change-of-flow program addresses and updates the stack pointers as needed.
2.1.2.1 Stack Pointer Registers
Two special registers with special addressing modes are used for software stacks. These are the Normal
mode stack pointer (NSP) and the Exception mode stack pointer (ESP). Both the ESP and the NSP are
32-bit read/write address registers with pre-decrement and post-increment updates. Both are offset with
immediate values to allow random access to a software stack.
The ESP is used by stack instructions when the SC140 is in the Exception mode of operation, which is
entered when exceptions occur. The NSP is used in Normal mode when there are no exceptions. The
existence of two stack pointers enables separate allocation of stack space by the operating system and each
application task, which optimizes memory use in multi-tasking systems.
2.1.2.2 Bit Mask Unit (BMU)
The BMU provides an easy way of setting, clearing, inverting, or testing a selected, but not necessarily
adjacent, group of bits in a register or memory location.
The BMU supports a set of bit mask instructions that operate on:
•
All AGU pointers (R0–R15)
•
All DALU registers (D0–D15)
•
All control registers (EMR, VBA, SR, MCTL)
•
Memory locations
Only a single bit mask instruction is allowed in any single execution set since only one execution unit
exists for these instructions.
A subgroup of the bit mask instructions (BMTSET) provides hardware support of semaphoring, providing
one instruction for read-modify-write.
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Architecture Overview
2.1.3 Program Sequencer Unit (PSEQ)
The PSEQ performs instruction fetch, instruction dispatch, hardware loop control, and exception
processing. The PSEQ controls the different processing states of the SC140 core. The PSEQ consists of
three hardware blocks:
•
Program dispatch unit (PDU)—Responsible for detecting the execution set out of a one or two fetch
set, and dispatching the execution set’s various instructions to their appropriate execution units
where they are decoded.
•
Program control unit (PCU)—Responsible for controlling the sequence of the program flow.
•
Program address generator (PAG)—Responsible for generating the program counter (PC) for
instruction fetch operations, including hardware looping.
The PSEQ implements its functions using the following registers:
•
PC—Program counter register
•
SR—Status register
•
SA0-3—Four start address registers (SA0–SA3)
•
LC0-3—Four loop counter registers (LC0–LC3)
•
EMR—Exception and mode register
•
VBA—Interrupt vector base address register
2.1.4 Enhanced On-Chip Emulator (EOnCE)
The EOnCE module provides a non-intrusive means of interacting with the SC140 core and its peripherals
so that a user can examine registers, memory, or on-chip peripherals as well as define various breakpoints
and read the trace-FIFO. The EOnCE module greatly aids the development of hardware and software on
the SC140 core processor, EOnCE interfacing with the debugging system through on-chip JTAG TAP
controller pins. Refer to Chapter 4, “Emulation and Debug (EOnCE),” for details.
2.1.5 Instruction Set Accelerator Plug-in (ISAP) Interface
A user-defined instruction set accelerator plug-in (ISAP) module provides a means of enhancing the
SC140 basic instruction set with additional instructions. These additional instructions are executed in an
external module connected to the core. The new instructions are added to the SC140 Assembler and
Compiler via intrinsic libraries making application-specific or general-purpose functions available to the
user. A 25-bit instruction bus from the SC140 core to the ISAP enables the definition and support of a very
rich instruction set. The ISAP is also connected to the two 64-bit data buses, providing a large data
bandwidth to the main memory system.
2.1.6 Memory Interface
The SC140 core uses a unified memory space. Each address can contain either program information or
data. The exact memory configuration is customizable for each chip containing an SC140 core. Memory
space typically consists of on-chip RAM and ROM that can be expanded off-chip. The memory system
must support two parallel data accesses. However, it may issue stalls due to its specific implementation.
Refer to Section 2.4, “Memory Interface,” for further details.
Both internal and external memory configurations are specific to each member of the SC140 family.
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DALU
2.2 DALU
This section describes the architecture and operation of the DALU, the block where most of the arithmetic
and logical operations are performed on data operands. In addition, this section details the arithmetic and
rounding operations performed by the DALU as well as its programming model.
2.2.1 DALU Architecture
The DALU performs most of the arithmetic and logical operations on data operands in the SC140 core.
The data registers can be read from or written to memory over the XDBA and the XDBB as 8-bit, 16-bit,
or 32-bit operands. The 64-bit wide data buses, XDBA and XDBB, support the transfer of several operands
in a single access. The source operands for the DALU, which may be 16, 32, or 40 bits, originate either
from data registers or from immediate data. The results of all DALU operations are stored in the data
registers.
All DALU operations are performed in one clock cycle. Up to parallel arithmetic operations can be
performed in each cycle. The destination of every arithmetic operation can be used as a source operand for
the operation immediately following without any time penalty.
The components of the DALU are as follows:
•
A register file of sixteen 40-bit registers
•
Four parallel ALUs, each containing a MAC unit and a BFU with a 40-bit barrel shifter
•
Eight data bus shifter/limiters that allow scaling and limiting of up to four 32-bit operands
transferred over each of the XDBA and XDBB buses in a single cycle
Figure 2-2 shows the architecture of the DALU.
Memory Data Bus 1 (XDBA)
Memory Data Bus 2 (XDBB)
64
64
64
64
(8) Shifter/Limiters
40
40
40
40
40
40
40
40
Data Registers D0–D15
40
40
ALU
40
40
40
ALU
40
40
40
ALU
40
40
40
40
ALU
Figure 2-2. DALU Architecture
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DALU
The DALU programming model is shown in Table 2-1. Register D0 refers to the entire 40-bit register,
whereas D0.e, D0.h, and D0.l refer to the extension: high portion and low portion of the D0 register,
respectively. In addition, one limit tag bit is associated with each data register. L0–L15 are concatenated to
D0–D15, respectively.
Table 2-1. DALU Programming Model
LIMIT
EXT
HP
LP
L0
D0.e
D0.h
D0.l
L1
D1.e
D1.h
D1.l
L2
D2.e
D2.h
D2.l
L3
D3.e
D3.h
D3.
L5
D5.e
D5.h
D5.l
L6
D6.e
D6.h
D6.l
L7
D7.e
D7.h
D7.l
L8
D8.e
D8.h
D8.l
L9
D9.e
D9.h
D9.l
L10
D10.e
D10.h
D10.l
L11
D11.e
D11.h
D11.l
L12
D12.e
D12.h
D12.l
L13
D13.e
D13.h
D13.l
L14
D14.e
D14.h
D14.l
L15
D15.e
D15.h
D15.l
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DALU
2.2.1.1 Data Registers (D0–D15)
In this section, the D0–D15 data registers are referred to as Dn. They can be used as:
•
Source operands
•
Destination operands
•
Accumulators
The registers can serve as input buffer registers between XDBA or XDBB and the ALUs. The registers are
used as DALU source operands, allowing new operands to be loaded for the next instruction while the
register contents are used by the current arithmetic instruction.
Each data register Dn has a limit tag bit (Ln) which is used to signify whether the extension portion of the
register is in use. The limit tag bit Ln is coupled to the extension portion Dn.e, which forms a 9-bit operand
for the purpose of storing these bits to memory. See Section 2.2.1.6, “Limiting,” for further details.
The data registers can be accessed over XDBA and XDBB with three data widths:
•
A long-word access, writing or reading 32-bit operands
•
A word access, writing or reading 16-bit operands
•
A byte access, writing or reading 8-bit operands
For move instructions of fractional data, the transfer of a Dn register to memory over XDBA and XDBB is
protected against overflow by substituting a limiting constant for the data that is being transferred. The
content of Dn is not affected should limiting occur. Only the value transferred over XDBA or XDBB is
limited. This process is commonly referred to as transfer saturation and should not be confused with the
arithmetic saturation mode as described in Section 2.2.2.7, “Arithmetic Saturation Mode.”
Limiting is performed after the contents of the register have been shifted according to the scaling mode.
Shifting and limiting are performed only for MOVES instructions when a fractional operand is specified as
the source for a data move over XDBA or XDBB. When an integer operand is specified as the source for a
data move, shifting and limiting are not performed.
Automatic sign extension (or zero extension of the data values into the 40-bit registers) is provided when
an operand is transferred from memory to a data register. Sign extension can occur when loading the Dn
register from memory. If a fractional word operand is to be written to a data register, the high portion (HP)
of the register is written with the word operand. The low portion (LP) is zero-filled. The EXT portion is
sign-extended from the HP, and the limit tag bit (Ln) is cleared.
When an integer word operand is to be written to a data register, the LP portion of the register is written
with the word operand. The HP and EXT portions are either zero-extended or sign-extended from the LP.
Long-word operands are written into the HP:LP portions of the register. The EXT portion is zero-extended
or sign-extended, and the limit tag bit (Ln) is cleared.
When a byte operand is to be written to a data register, the register’s first 8-bit portion of the LP
(Dn.1[7:0]) is written with the byte operand. The following eight bits of the LP (Dn.1[15:8]), the high
portion, and the EXT are either zero-extended or sign-extended from the LP lower byte. The limit tag bit
(Ln) is cleared.
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DALU
A special case of the MOVE.L instruction is used for reading from or writing to the EXT portion of a data
register. Six variations of this instruction save (restore) the extension bits and Ln bit of data registers to
(from) memory. One of the variations writes to memory the Ln bit and extension bits of an even and an odd
pair of registers. Another variation reads bits 8:0 from memory to the extension bits and the Ln bit of an
even register. Another variation reads bits 24:16 to the extension bits and the Ln bit of an odd register.
Memory writes are done from the even/odd pair of registers. Memory reads are done to a single register.
An extension saved to memory from an even numbered register must be restored to an even register,
likewise for odd registers.
All move instructions are described in detail in Appendix A, “SC140 DSP Core Instruction Set.”
Table 2-2 summarizes the various types of data bus write access to the data registers.
Note:
When an unsigned long operand is written to a data register, Dn.e is zero-extended.
Table 2-2. Write to Data Registers
Operand Type
Ln
Dn.e
Dn.h
Dn.l
Fractional word
Zero-extended
Sign-extended
Operand
Zero-filled
Integer Byte
Zero-extended
Zero-extended/
Sign-extended
Zero-filled/
Sign-extended
Upper byte - Sign-extended/zero-extended
Lower byte - Operand
Integer Word
Zero-extended
Zero-extended/
Sign-extended
Zero-filled/
Sign-extended
Operand
Long
Zero-extended
Zero-extended/
Sign-extended
Operand
Operand
2 Extensions - Long
Operand
Operand
Unchanged
Unchanged
Table 2-3 summarizes the various types of data bus read accesses from the data registers.
Table 2-3. Read from Data Registers
Operand Type
Memory Data Bus.h
Memory Data Bus.l
Limiting/Scaling
Fractional Word
-
Dn.h
Yes/No (See Note)
Fractional Long
Dn.h
Dn.l
Yes/No (See Note)
Integer Word
-
Dn.l
No
Integer Long
Dn.h
Dn.l
No
Integer Byte
-
Low byte - Dn.l[7:0]
No
2 Extensions - Long
EXT word: {7 zero bits, Ln+1,
Dn+1.e}
EXT word: {7 zero bits, Ln,
Dn.e}
No
Note:
A fractional word or fractional long word can be written to memory with or without limiting and
shifting. See MOVE.F and MOVES.F in Appendix A, “SC140 DSP Core Instruction Set.”
The register file architecture and the 64-bit wide data buses XDBA and XDBB support wide data transfers
between the memory and the data registers. Up to four 16-bit words or two 32-bit long words can be
transferred between the register file and the memory in a single move operation on each data bus, XDBA
or XDBB.
Table 2-4 summarizes the various data widths for data moves from/to the data register file.
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DALU
.
Table 2-4. Data Registers Access Width
Operand Type
Data Width (Bits)
Byte
8
Word
16
Long
32
Two word
32
Four byte
32
Two long word
64
Four word
64
2.2.1.2 Multiply-Accumulate (MAC) Unit
The MAC unit is the arithmetic part of the ALU containing both a multiplier and an adder. It also performs
other operations such as rounding, saturation, comparisons, and shifting. Inputs to the MAC unit are from
data registers or from immediate data programmed into the instruction. As many as three operands may be
inputs. The destination for MAC instructions is always a data register in the 40-bit form EXT:HP:LP. The
multiplier executes 16 by 16 parallel multiplication of two’s complement data, signed or unsigned,
fractional or integer. The multiplier output can be accumulated with 40-bit data in a destination register. A
detailed description of each multiplication operation is given in Section 2.2.2.3, “Multiplication.” The
adder executes addition and subtraction of two 40-bit operands. All MAC instructions are executed in one
clock cycle.
Table 2-5 lists the arithmetic instructions that are executed in the MAC unit. A more detailed description of
each instruction is given in Appendix A, “SC140 DSP Core Instruction Set.”
Table 2-5. DALU Arithmetic Instructions (MAC)
Instruction
ABS
Absolute value
ADC
Add long with carry
ADD
Add
ADD2
Add two words
ADDNC.W
2-10
Description
Add without changing the carry bit in the SR
ADR
Add and round
ASL
Arithmetic shift left by one bit
ASR
Arithmetic shift right by one bit
CLR
Clear
CMPEQ
Compare for equal
CMPGT
Compare for greater than
CMPHI
Compare for higher (unsigned)
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DALU
Table 2-5. DALU Arithmetic Instructions (MAC) (Continued)
Instruction
Description
DECEQ
Decrement a data register and set T (the true bit) if zero
DECGE
Decrement a data register and set T if greater than or equal to zero
DIV
Divide iteration
DMACSS
Multiply signed by signed and accumulate with data register
right-shifted by word size
DMACSU
Multiply signed by unsigned and accumulate with data register
right-shifted by word size
IADDNC.W
IMAC
IMACLHUU
40-bit non-saturating add integers with immediate, no carry update
Multiply-accumulate integers
Multiply-accumulate unsigned integers:
first source from low portion, second from high portion
IMACUS
Multiply-accumulate unsigned integer and signed integer
IMPY.W
Multiply integer
IMPYHLUU
Multiply unsigned integer and unsigned integer:
first source from high portion, second from low portion
IMPYSU
Multiply signed integer and unsigned integer
IMPYUU
Multiply unsigned integer and unsigned integer
INC
Increment a data register
INC.F
Increment a data register (as fractional data)
MAC
Multiply-accumulate signed fractions
MACR
Multiply-accumulate signed fractions and round
MACSU
Multiply-accumulate signed fraction and unsigned fraction
MACUS
Multiply-accumulate unsigned fraction and signed fraction
MACUU
Multiply-accumulate unsigned fraction and unsigned fraction
MAX
Transfer maximum signed value
MAX2
Transfer two 16-bit maximum signed values
MAX2VIT
MAXM
Transfer two 16-bit maximum signed values, update Viterbi flags
Transfer maximum magnitude value
MIN
Transfer minimum signed value
MPY
Multiply signed fractions
MPYR
Multiply signed fractions and round
MPYSU
Multiply signed fraction and unsigned fraction
MPYUS
Multiply unsigned fraction and signed fraction
MPYUU
Multiply unsigned fraction and unsigned fraction
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DALU
Table 2-5. DALU Arithmetic Instructions (MAC) (Continued)
Instruction
Description
NEG
Negate
RND
Round
SAT.F
Saturate fractional value in data register to fit in high portion
SAT.L
Saturate value in data register to fit in 32 bits
SBC
Subtract long with carry
SBR
Subtract and round
SUB
Subtract
SUB2
Subtract two words
SUBL
Shift left and subtract
SUBNC.W
Subtract with no carry bit generation
TFR
Transfer data register to a data register
TFRF
Transfer data register to a data register if T bit is false
TFRT
Transfer data register to a data register if T bit is true
TSTEQ
TSTEQ.L
Test for equal to zero
32-bit compare for equal to zero
TSTGE
Test for greater than or equal to zero
TSTGT
Test for greater than zero
2.2.1.3 Bit-Field Unit (BFU)
The BFU is the logic part of the ALU. It contains a 40-bit parallel bidirectional shifter (with a 40-bit input
and a 40-bit output) mask generation unit and logic unit. The BFU is used in the following operations:
•
Multi-bit left/right shift (arithmetic or logical)
•
One-bit rotate (right or left)
•
Bit-field insert and extract
•
Count leading bits (ones or zeros)
•
Logical operations
•
Sign or zero extension operations
Table 2-6 lists the instructions which are executed in the BFU. A more detailed description of each
instruction is given in Appendix A, “SC140 DSP Core Instruction Set.”
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DALU
Table 2-6. DALU Logical Instructions (BFU)
Instruction
Description
AND
Logical AND
ASLL
Multi-bit arithmetic shift left
ASLW
Word arithmetic shift left (16-bit shift)
ASRR
Multi-bit arithmetic shift right
ASRW
Word arithmetic shift right (16-bit shift)
CLB
Count leading bits (ones or zeros)
EOR
Bit-wise exclusive OR
EXTRACT
Extract signed bit-field
EXTRACTU
INSERT
Extract unsigned bit-field
Insert bit-field
LSLL
Multi-bit logical shift left
LSR
Logical shift right by one bit
LSRR
Multi-bit logical shift right
LSRW
Word logical shift right (16-bit shift)
NOT
One’s complement (inversion)
OR
Bit-wise inclusive OR
ROL
Rotate one bit left through the carry bit
ROR
Rotate one bit right through the carry bit
SXT.B
Sign extend byte
SXT.L
Sign extend long
SXT.W
Sign extend word
ZXT.B
Zero extend byte
ZXT.L
Zero extend long
ZXT.W
Zero extend word
2.2.1.4 Data Shifter/Limiter
The data shifters/limiters provide special post-processing on data written from a Dn register to the XDBA
or XDBB buses. There are eight independent shifters/limiters, four for the XDBA bus and four for the
XDBB bus, allowing transfers to memory of up to four words per MOVES instruction with scaling and
limiting. Each consists of a shifter for scaling followed by a limiter. Note that arithmetic saturation from
DALU operations is a different function. Saturation occurs in the DALU before data is written to a
destination register.
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DALU
2.2.1.5 Scaling
The data shifters in the shifter/limiter unit can perform the following data shift operations:
•
Scale up—Shift data one bit to the left
•
Scale down—Shift data one bit to the right
•
No scaling—Pass the data unshifted
The eight shifters permit direct dynamic scaling of fixed-point data without additional program steps. For
example, this permits straightforward block floating-point implementation of Fast Fourier Transforms
(FFTs).
Scaling occurs if programmed in the scaling mode bits S0 and S1 (bits 4 and 5 in the SR). Scaling of
operands only occurs with the MOVES.F, MOVES.2F, MOVES.4F, and MOVES.L instructions, moving
data from a DALU register (or registers) to memory. The data in the register is not changed, only the data
that is transferred. The scaling mode also affects the Ln bit calculation and the rounding function for a set
of DALU instructions. Scaling is disabled when the arithmetic saturation mode is set. See Section 3.1.1,
“Status Register (SR),” and below for further details. An example of scaling is provided in Table 2-7.
Table 2-7. Scaling Example
Instruction
Memory/
Register
New Value
Comments
move.w #$0030,r0
r0
$0000 0030
R0 initialized for first memory write
moveu.w #$0200,d0.h
d0
$0200 0000
D0 written
bmset #$10,sr.l
sr
$0000 0010
Scale down set in SR
moves.f d0,(r0)+
$0030
$0100
Memory written with scaled down value
move.l #$00e40020,sr
sr
$00e4 0020
Scale up set in SR
moves.f d0,(r0)
$0032
$0400
Memory written with scaled up value
2.2.1.6 Limiting
The limiting capability is enabled only for the MOVES.F, MOVES.2F, MOVES.4F, and MOVES.L
instructions, and not for any other fractional moves such as MOVE.F. These instructions move data from
DALU register(s) to memory. The limiting operation takes place in two steps: first, calculating the Ln bit
when a previous ALU instruction wrote to a register, and second, transferring the data from that register
with a MOVES instruction. The transferred data is limited if the Ln bit is set.
2.2.1.6.1 Calculating the Ln Bit
The Ln bit can be affected by ALU instructions which are capable of using the extension portion of a data
register. The only use of the Ln bit is to set up or prepare for a subsequent MOVES instruction. The Ln bit
is calculated based on the effective extension bits shown in Table 2-8. These are the bits to the left of the
implied decimal point after scaling. If the bits are not all zeros or all ones, the extension is effectively in
use and the Ln bit will be set. The Ln bit is cleared as data is written to a DALU register if the defining bits
below are all zeros or all ones.
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DALU
Table 2-8. Ln Bit Calculation
S1
S0
Scaling Mode
Bits Defining the Ln bit Calculation
0
0
No Scaling
Bits 39, 38..............32, 31
0
1
Scale Down
Bits 39, 38..............33, 32
1
0
Scale Up
Bits 39, 38..............31, 30
The Ln bit is calculated (and set or cleared) for the following saturable instructions: ABS, ADC, ADR,
ADD, ADDNC, ASL, ASR, DIV, INC, MAC, MACR, MPY, MPYR, NEG, RND, SBC, SBR, SUB,
SUBL, SUBNC, and TFRx. The Ln bit is cleared if arithmetic saturation mode is set, except for these
instructions: ADC, DIV, SBC, TFR, TFRT, and TFTF. For the latter six, the Ln bit calculation is done,
even if arithmetic saturation mode is set. However, no scaling is considered in the Ln bit calculation if the
arithmetic saturation mode is set, even if a scaling mode bit is set.
The Ln bit is always cleared as a result of the execution of one of the following instructions: CLR,
DECEQ, DECGE, MAX, MAXM, MIN, ADD2, SUB2, MAX2, MAX2VIT, DMACsu, DMACss,
MACsu, MACuu, MACus, MPYsu, MPYuu, MPYus, IADDNC, SAT, all integer multiplication
operations, all BFU operations (as listed in Table 2-6 on page 2-13), and all MOVE instructions except for
the specialized MOVE instruction that restores (pops the stack) the extension and Ln bits from memory. If
the result of these instructions is required to be limited by a following move operation (a TFR Dn), the Dn
instruction should be executed after the original instruction in order to validate the Ln bit before the value
is written to memory using a MOVES.x operation.
2.2.1.6.2 Limiting with the MOVES Instructions
The second stage of limiting occurs with the execution of a MOVES instruction. A limited value is
substituted for the transferred data if the Ln bit of that register was set. The data in the register is not
changed, only the data transferred.
Having four limiters for each bus allows eight operands to be limited independently in the same instruction
cycle. The four data limiters per bus can also be combined to form two 32-bit data limiters per bus for
long-word operands.
If limiting occurs, the data limiter substitutes a limited data value having maximum magnitude (saturated)
and the same sign as the 40-bit source register content:
•
$7FFF for 16-bit positive numbers
•
$7FFF FFFF for 32-bit positive numbers
•
$8000 for 16-bit negative numbers
•
$8000 0000 for 32-bit negative numbers
This substitution process is sometimes called transfer saturation. The value in the register is not shifted or
limited, and can be reused by subsequent instructions. If the arithmetic saturation mode is set in the SR,
scaling is not considered in the calculation of the Ln bit. An example of limiting is provided in Table 2-9.
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DALU
Table 2-9. Limiting Example
Memory/
Register
New Value
Comments
move.w #$0030,r0
r0
$0000 0020
R0 holds the address for the first move to memory
moveu.w #$7fff,d0.h
d0
$7fff 0000
d0.h set with the most positive 2’s complement number
moveu.w #$7fff,d1.h
d1
$7fff 0000
d1.h set with the most positive 2’s complement number
add d0,d1,d3
d3
$1:00:fffe 0000
move.f d3,(r0)+
$0020
$fffe
No limiting from the move instruction
moves.f d3,(r0)
$0022
$7fff
Limiting occurs with the moves instruction
Instruction
L3 bit set from overflow
Note that in the unusual case where arithmetic saturation mode is set between a DALU instruction and a
subsequent moves instruction, scaling with the moves instruction is inhibited. However, limiting will occur
if the Ln bit is already set.
2.2.1.7 Scaling and Arithmetic Saturation Mode Interactions
The following table shows the scaling and limiting operations for the four possible cases of scaling/no
scaling with arithmetic saturation mode on/off. Note that the mode of both scaling and arithmetic
saturation selected is not a normal mode of operation for the core. The “Special Six” instructions referred
to in Table 2-10 and Table 2-11 are ADC, DIV, SBC, TFR, TFRT, and TFTF.
Table 2-10. Scaling and Limiting Interactions
Ln Bit Calculation
Scaling
Selected
Limiting
with MOVES
instructions
Saturable
DALU
Instructions
Special Six
Instructions
Other DALU
Instructions
(see note below)
Scaling with
MOVES
Instructions
None
Off
Calculated,
no scaling
Calculated,
no scaling
Cleared
Yes
No
Up/down
Off
Calculated,
with scaling
Calculated,
with scaling
Cleared
Yes
Yes
Off
On
Cleared
Calculated,
no scaling
Cleared
Yes
No
Up/down
On
Cleared
Calculated,
no scaling
Cleared
Yes
No
Note:
2-16
Arithmetic
Saturation
Mode
Limiting will occur if the Ln bit is set.
SC140 DSP Core Reference Manual
DALU
The following table (Table 2-11) shows the arithmetic saturation and rounding operations for the four
possible cases of scaling, no scaling, and arithmetic saturation mode on/off.
Table 2-11. Saturation and Rounding Interactions
Scaling
Selected
Arithmetic
Saturation
Mode
Arithmetic Saturation
Rounding
Saturable DALU
Instructions
Special Six Instructions
None
Off
None
None
Rounding with no scaling
Up/down
Off
None
None
Rounding with scaling
considered
None
On
Saturation can occur
None
Rounding with no scaling
Up/down
On
Saturation can occur, no
scaling considered
None
Rounding with no scaling
2.2.2 DALU Arithmetic and Rounding
The following paragraphs describe the DALU data representation, rounding modes, and arithmetic
methods.
2.2.2.1 Data Representation
The SC140 core uses either a fractional or integer two’s complement data representation for all DALU
operations. The main difference between fractional and integer representations is the location of the
decimal (or binary) point. For fractional arithmetic, the decimal (or binary) point is always located
immediately to the right of the most significant bit of the high portion. For integer values, it is always
located immediately to the right of the least significant bit (LSB) of the value. Figure 2-3 shows the
location of the decimal point (binary point) bit weighting and operand alignment for different fractional
and integer representations supported on the SC140 architecture.
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DALU
16-bit word operand
D0.h—D15.h,
16-bit memory
40-bit registers
D0—D15
–28
– 20
2–15
20
2–15
2–16
2–31
Signed Fractional Two’s Complement Representations
16-bit word operand
D0.l—D15.l,
16-bit memory
40-bit registers
D0—D15
–215
214
20
.
–239
231
216
215
20
.
Signed Integer Two’s Complement Representations
Figure 2-3. DALU Data Representations
2.2.2.2 Data Formats
Three types of two’s complement data formats are supported by the SC140 core:
•
Signed fractional (SF)
•
Signed integer (SI)
•
Unsigned integer (UI)
The ranges for each of these formats, described below, apply to all data stored in memory as well as data
stored in the data registers. The extension associated with each register allows word growth so that the
most positive fractional number that can be represented in a register is almost 256.0 with the most negative
fractional number being exactly -256.0. When the register extension is in use, the data contained in the
register cannot be stored exactly in memory or in other registers in a single move. In these cases, the
storage error can be minimized by limiting the data to the most positive or most negative number
consistent with the size of the destination, the sign of the register and the MSB of the extension.
2.2.2.2.1 Signed Fractional
In this format, without extension bits 39-32, the N-bit operand is represented using the 1.[N-1] bit format
(1 sign bit, N-1 fractional bits). Signed fractional numbers lie in the following range:
-1.0 ≤ SF ≤+1.0 - 2-[N-1]
For words and long-word signed fractions, the most negative number that can be represented is exactly
–1.0, of which the internal representation is $8000 and $8000 0000, respectively. The most positive word
is $7FFF or 1.0–2-15, and the most positive long word is $7FFF FFFF or 1.0–2-31.
If the extension bits are in use, the most positive number is 256 – 2–31 represented by $7F FFFF FFFF, and
the most negative number is –256, represented by $80 0000 0000.
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DALU
2.2.2.2.2 Signed Integer
This format is used when processing data as integers. Using this format, the N-bit operand is represented
using the N.0 bit format (N integer bits). Signed integer numbers lie in the following range:
-2[N-1] ≤ SI ≤ [2[N-1]-1]
For words and long-word signed integers, the most negative word that can be represented is -32768
($8000) and the most negative long word is -2147483648 ($8000 0000). The most positive word is 32767
($7FFF) and the most positive long word is 2147483647 ($7FFF FFFF).
If the extension bits are in use, N becomes 40, and the most positive number is 239 – 1 represented by
$7F FFFF FFFF. The most negative number is –239, represented by $80 0000 0000.
2.2.2.2.3 Unsigned Integer
Unsigned integer numbers may be thought of as positive only. The unsigned numbers have nearly twice
the magnitude of a signed number of the same length. Unsigned integer numbers lie in the following range:
0 ≤ UI ≤ [2N-1]
The binary word is interpreted as having a binary point immediately to the right of the LSB. The most
positive 16-bit unsigned integer is 65535 ($FFFF). The most positive 32-bit unsigned integer is 232-1
($FFFF FFFF). The smallest unsigned number is zero ($0000).
If the extension bits are in use, the range is from zero to +240 – 1.
Table 2-12. Two’s Complement Word Representations
Signed Fractional
Signed Integer
Unsigned Integer
$7FFF
1.0 – 2 – 15
$7FFF
2 15 – 1
$FFFF
2 16 – 1
l
l
l
l
$FFFE
2 16 – 2
l
l
l
l
l
l
$0001
2 –15
$0001
+1
l
l
$0000
0
$0000
0
l
l
$FFFF
– 2 – 15
$FFFF
–1
l
l
l
l
l
l
l
l
l
l
l
l
$0001
1
$8000
– 1.0
$8000
– 2 15
$0000
0
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DALU
2.2.2.3 Multiplication
Most of the operations are performed identically in fractional and integer arithmetic. However, the
multiplication operation is not the same for integer and fractional arithmetic. As illustrated in Figure 2-4,
fractional and integer multiplication differ by a 1-bit shift. Any binary multiplication of two N-bit signed
numbers gives a signed result that is 2N-1 bits in length. This 2N-1 bit result must then be correctly placed
into a field of 2N-bits to correctly fit into the on-chip registers. For correct fractional multiplication, an
extra 0-bit is placed at the LSB to give a 2N-bit result. For correct integer multiplication, an extra sign bit
is placed at the MSB to give a 2N-bit result.
Signed Multiplication: N x N --> 2N – 1 Bits
Integer
S
Fractional
S
S
S
X
X
Signed Multiplier
S
S
HP
LP
2N – 1 product
Signed Multiplier
S
HP
LP
0
2N – 1 product
sign extension
zero fill
2N bits
2N bits
Figure 2-4. Fractional and Integer Multiplication
The MPY, MAC, MPYR, and MACR instructions perform fractional multiplication and fractional
multiply-accumulation. The IMPY and the IMAC instructions perform integer multiplication.
2.2.2.4 Division
Fractional division of both positive and signed values is supported using the DIV instruction. The dividend
(numerator) is a 32-bit fraction and the divisor (denominator) is a 16-bit fraction. For a detailed description
of the DIV instruction, see Appendix A, “SC140 DSP Core Instruction Set.”
2.2.2.5 Unsigned Arithmetic
Unsigned arithmetic can be performed on the SC140 core architecture. Most of the unsigned arithmetic
instructions are performed the same as the signed instructions. However, some operations require special
hardware and are implemented as separate instructions.
2.2.2.5.1 Unsigned Multiplication
Unsigned multiplication (MPYUU, MACUU) and mixed unsigned-signed multiplication (MPYSU,
MACSU) are used to support double precision, as described in Section 2.2.2.8, “Multi-Precision
Arithmetic Support.” These instructions can be used for unsigned arithmetic multiplication.
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DALU
2.2.2.5.2 Unsigned Comparison
When performing an unsigned comparison, the condition code computation is different from signed
comparisons. The most significant bit of the unsigned operand has a positive weight, while in signed
representation it has a negative weight. Special instructions are implemented to support unsigned
comparison such as CMPHI (compare greater).
2.2.2.6 Rounding Modes
The SC140 DALU performs rounding of the full register to single precision if requested in the instruction.
The high portion of the register is rounded according to the contents of the low portion of the register.
Then the low portion is cleared. The boundary between the low portion and the high portion is determined
by the scaling mode bits (S0 and S1) in the SR. Two types of rounding are implemented, convergent
rounding and two’s complement rounding. The type of rounding is selected by the rounding mode (RM)
bit in the SR.
Table 2-13 shows the boundary between the high portion and the low portion depending on scaling. The
scaling adjustment is disabled if arithmetic saturation mode is selected.
Table 2-13. Rounding Position in Relation to Scaling Mode
S1
S0
Scaling Mode
High Portion
Low Portion
0
0
No Scaling
39–16
15–0
0
1
Scale Down
39–17
16–0
1
0
Scale Up
39–15
14–0
2.2.2.6.1 Convergent Rounding
Convergent rounding (also called round-to-nearest even number) is the default rounding mode. It is
selected when the rounding mode (RM) bit in the SR is cleared. The traditional rounding method rounds up
any value greater than one-half, and rounds down any value less than one-half. However, the question
arises as to which way one-half should be rounded. If it is always rounded one way, the results are
eventually biased in that direction. Convergent rounding, however, removes the bias by rounding down if
the high portion is even (LSB = 0) and rounding up if the high portion is odd (LSB = 1).
For no scaling, the higher portion (HP) of the register is bits 39:16; the low portion (LP) is bits 15:0. The
HP is incremented by one bit if the LP was > 1/2, or if the LP = 1/2 and bit 16 was 1 (odd). The HP is left
alone if the LP was <1/2, or if LP = 1/2 and bit 16 was 0 (even). After rounding, the LP is cleared. If
scaling down is selected, the HP is bits 39:17 and the LP is bits 16:0. If scaling up is selected, the HP is bits
39:15 and the LP is bits 14:0.
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DALU
Figure 2-5 shows the four cases for rounding a number in the Dn.h register. If scaling is set in the SR, the
rounding position is updated to reflect the alignment of the result when it is put on the data bus. However,
the contents of the register are not scaled.
Case I: If D0.l < $8000 (1/2), then round down (add nothing)
Before Rounding
After Rounding
0
D0.e
D0.h
D0.l
XX..XX XXX...XXX0100 011XXX....XXX
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0100 000.........000
39
32 31
16 15
0
Case II: If D0.l > $8000 (1/2), then round up (add 1 to D0.h)
Before Rounding
After Rounding
1
D0.e
D0.h
D0.l
XX..XX XXX...XXX0100 1110XX....XXX
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0101 000.........000
39
32 31
16 15
0
Case III: If D0.l = $8000 (1/2), and the LSB of D0.h= 0, then round down (add nothing)
Before Rounding
After Rounding
0
D0.e
D0.h
D0.l
XX..XX XXX...XXX0100 1000........000
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0100 000.........000
39
32 31
16 15
0
Case IV: If D0.l = $8000 (1/2), and the LSB of Do.h = 1, then round up (add 1 to D0.h)
After Rounding
Before Rounding
1
D0.e
D0.h
D0.l
XX..XX XXX...XXX0101 1000........000
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0110 000.........000
39
32 31
16 15
0
*D0.l is always clear, performed during RND, MPYR, and MACR.
Figure 2-5. Convergent Rounding (No Scaling)
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DALU
2.2.2.6.2 Two’s Complement Rounding
When two’s complement rounding is selected by setting the rounding mode (RM) bit in the SR, all values
greater than or equal to one-half are rounded up, and all values less than one-half are rounded down.
Therefore, a small positive bias is introduced.
For no scaling, the higher portion (HP) of the register is bits 39:16; the low portion (LP) is bits 15:0. The
HP is incremented by one bit if the LP was ≥ 1/2. The HP is left alone if the LP was <1/2. After rounding,
the LP is cleared. If scaling down is selected, the HP is bits 39:17 and the LP is bits 16:0. If scaling up is
selected, the HP is bits 39:15 and LP is bits 14:0.
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DALU
Figure 2-6 shows the four cases for rounding a number in the Dn.h register. If scaling is set in the SR, the
rounding position is updated to reflect the alignment of the result when it is transferred to the data bus.
However, the contents of the register are not scaled.
Case I: If D0.l < $8000 (1/2), then round down (add nothing)
Before Rounding
After Rounding
0
D0.e
D0.h
D0.e
D0.l
XX..XX XXX...XXX0100 011XXX....XXX
39
32 31
16 15
0
D0.h
D0.l*
XX..XX XXX...XXX0100 000.........000
39
32 31
16 15
0
Case II: If D0.l > $8000 (1/2), then round up (add 1 to D0.h)
Before Rounding
After Rounding
1
D0.e
D0.h
D0.l
XX..XX XXX...XXX0100 1110XX....XXX
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0101 000.........000
39
32 31
16 15
0
Case III: If D0.l = $8000 (1/2), and the LSB of D0.h = 0, then round up (add 1 to D0.h)
Before Rounding
After Rounding
1
D0.e
D0.h
D0.l
XX..XX XXX...XXX0100 1000........000
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0101 000.........000
39
32 31
16 15
0
Case IV: If D0.l = $8000 (1/2), and the LSB of D0.h = 1, then round up (add 1 to D0.h)
Before Rounding
After Rounding
1
D0.e
D0.h
D0.l
XX..XX XXX...XXX0101 1000........000
39
32 31
16 15
0
D0.e
D0.h
D0.l*
XX..XX XXX...XXX0110 000.........000
39
32 31
16 15
0
*D0.l is always cleared, performed during RND, MPYR, and MACR.
Figure 2-6. Two’s Complement Rounding (No Scaling)
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DALU
2.2.2.7 Arithmetic Saturation Mode
By setting the arithmetic saturation mode (SM) bit in the SR, the arithmetic unit’s result is limited to 32
bits (high portion and low portion). The dynamic range of the DALU is therefore reduced to 32 bits. The
purpose of this bit is to provide a saturation mode for algorithms that do not recognize or cannot take
advantage of the extension bits.
Arithmetic saturation operates by checking whether bits 39–31 of a relevant DALU instruction result in all
ones or all zeros. If they are not, and if bit 39 is one, the result receives the negative saturation constant
$FF 8000 0000. If bit 39 is zero, the result receives the positive saturation constant $00 7FFF FFFF. If
saturation occurs, the DOVF bit in the EMR register is set.1
The calculation for saturation is not affected by the scaling mode. In the same way, the rounding of the
saturation constant during execution of MPYR, MACR and RND instructions is independent of the scaling
mode: $00 7FFF FFFF is rounded to $00 7FFF 0000 and $FF 8000 0000 is unchanged.
The instructions that are affected by arithmetic saturation mode are: MAC, MPY, MACR, MPYR, SUB,
ADD, NEG, ABS, RND, INC, ADR, SBR, SUBL, ASR, SUBNC, ADDNC, and ASL.
When the arithmetic saturation mode is set, for most of the instructions, the scaling mode bits are ignored
for the calculation of the Ln bit, and the Ln bit cannot be set. For instructions ADC, DIV, SBC, TFR,
TFRT, and TFRF, however, the arithmetic saturation mode is ignored, and the Ln bit will be calculated.
These six are dependent on arithmetic saturation mode to the extent that scaling is not considered in the Ln
bit calculation if arithmetic saturation mode is on. See Section 2.2.1.7, “Scaling and Arithmetic Saturation
Mode Interactions,” on page 2-16 for more information.
The arithmetic saturation mode is always disabled during the execution of the following instructions:
TFR, TFRT, TFRF, MAX, MAXM, MIN, ADD2, SUB2, DIV, SBC, ADC, MAX2, MAX2VIT,
DMACSU, DMACSS, MACSU, MACUS, MACUU, MPYSU, MPYUU, MPYUS, IADDNC, CMPHI,
DECEQ, DECGE all integer multiplication operations, and all BFU operations as described in Table 2-6
on page 2-13. If the result of these instructions should be saturated, a SAT.L Dn instruction must be
executed following the original instruction.
If the arithmetic saturation mode is set and data saturation occurs, the sticky data overflow bit (DOVF) in
the EMR is set to signify that the arithmetic result before saturation cannot be represented in 32 bits. Note
that if arithmetic saturation mode is not set, the DOVF bit is set when overflow from 40 bits occurs.
Table 2-14 provides an example of the arithmetic saturation mode.
Table 2-14. Arithmetic Saturation Example
Memory/
Register
New Value
Comments
bmset #$0004,sr.l
sr
$00e4 0004
Arithmetic saturation mode set
moveu.w #$7fff,d0.h
d0
$7fff 0000
d0.h set with the most positive 2’s complement number
moveu.w #$7fff,d1.h
d1
$7fff 0000
d1.h set with the most positive 2’s complement number
add d0,d1,d3
d3
$0:00:7fff ffff
Max positive constant loaded in D3. L3 bit not set from
overflow
emr
$0000 0004
DALU overflow bit set
Instruction
1. In case of a 40-bit overflow which takes place in conjunction with arithmetic saturation, the constant being chosen is undefined, and it can
be either the negative or positive constant.
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DALU
2.2.2.8 Multi-Precision Arithmetic Support
The SC140 DALU supports multi-precision arithmetic for fractional and integer operations.
2.2.2.8.1 Fractional Multi-Precision Arithmetic
A set of DALU instructions is provided for fractional multi-precision multiplications. When these
instructions are used, the multiplier accepts some combinations of two’s complement signed and unsigned
formats. Table 2-15 lists these instructions.
Table 2-15. Fractional Signed and Unsigned Two’s Complement Multiplication
Instruction
Description
MPYSU/MACSU
Fractional multiplication and multiply-accumulate with signed × unsigned operands
MPYUS/MACUS
Fractional multiplication and multiply-accumulate with unsigned × signed operands
MPYUU/MACUU
Fractional multiplication and multiply-accumulate with unsigned × unsigned operands
DMACSS
Fractional multiplication with signed × signed operands and 16-bit arithmetic right shift
of the accumulator before accumulation
DMACSU
Fractional multiplication with signed × unsigned operands and 16-bit arithmetic right
shift of the accumulator before accumulation
Figure 2-7 shows how the DMAC instruction is implemented.
16-bit Operand
>> 16
Register Shifter
16-bit Operand
Multiply
+
40-bit Accumulate
Figure 2-7. DMAC Implementation
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DALU
Figure 2-8 illustrates the use of these instructions in the case of a double-precision multiplication of
32-bit x 32-bit operands. The “Unsigned x Unsigned” operation is used to multiply or multiply-accumulate
the unsigned low portion of one double-precision number with the unsigned low portion of the other
double-precision number. The “Signed x Unsigned” and “Unsigned x Signed” operations are used to
multiply or multiply-accumulate the signed high portion of one double-precision number with the unsigned
low portion of the other double-precision number. The “Signed x Signed” operation is used to multiply or
multiply-accumulate the two signed high portions of two signed double-precision numbers. The TFRx
instructions in parentheses are optional instructions that are used only in case all 64 bits of the result are
needed. Otherwise, the result is truncated to a 32-bit fraction.
32 bits
D0.h
D0.l
×
D1.h
D1.l
=
Unsigned × Unsigned
mpyuu
(tfr
D0,D1,D2
D2,D3)
dmacsu
D0,D1,D2
D1.l × D0.l
Signed × Unsigned
+
D0.h × D1.l
+
Unsigned × Signed
macus
(tfr
D0,D1,D2
D2,D4)
D1.h × D0.l
+
Signed × Signed
dmacss
D1.h × D0.h
D0,D1,D2
S Ext
D2.e
D2.h
D2.l
D4.l
D3.l
64 bits
Figure 2-8. Fractional Double-Precision Multiplication
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DALU
Figure 2-9 illustrates the use of the fractional multiplication and multiply-accumulate instructions in the
case of a mixed double-precision multiplication of 16-bit by 32-bit signed operands. The “Signed x
Unsigned” operation is used to multiply the signed high portion of one single-precision number with the
unsigned low portion of the other double-precision number. The “Signed x Signed” DMAC operation is
used to multiply-accumulate the two signed high portions of the two signed operands. The TFRx
instruction in parentheses is an optional instruction that is used only in case all 48 bits of the result are
needed. Otherwise, the result is truncated to a 32 bit fraction.
D0.h
×
D1.h
D1.l
=
Signed × Unsigned
mpysu
(tfr
D0,D1,D2
D2,D3)
dmacss
D0,D1,D2
D0.h × D1.l
Signed × Signed
+
D1.h × D0.h
S Ext
D2.e
D2.h
D2.l
D3.l
48 bits
Figure 2-9. Fractional Mixed-Precision Multiplication
2.2.2.8.2 Integer Multi-Precision Arithmetic
A set of DALU operations is provided for integer multi-precision multiplications. When these instructions
are used, the multiplier accepts some combinations of two’s complement signed and unsigned formats.
Both signed and unsigned multi-precision multiplication are supported. Table 2-16 lists these instructions.
Table 2-16. Integer Signed and Unsigned Two’s Complement Multiplication
Instruction
Description
IMPYSU/IMACSU
Integer multiplication and multiply-accumulate with signed x unsigned operands
IMPYUU
Integer multiplication with unsigned x unsigned operands
IMPYHLUU
Integer multiply unsigned x unsigned:
first source from high portion, second from low portion
IMACLHUU
Integer multiply-accumulate unsigned x unsigned:
first source from low portion, second from high portion
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DALU
Figure 2-10 illustrates the use of these instructions in the case of a signed integer double-precision
multiplication of 32-bit by 32-bit signed operands. In this example, only a 32-bit result is generated. The
most significant 32 bits are shifted out.The “Unsigned x Unsigned” operation is used to multiply or
multiply-accumulate the unsigned low portion of one double-precision number with the unsigned low
portion of the other double-precision number. The “Signed x Unsigned” and “Unsigned x Signed”
operations are used to multiply or multiply-accumulate the signed high portion of one double-precision
number with the unsigned low portion of the other double-precision number. This example generates only
a 32-bit integer.
32 bits
D0.h
D0.l
×
D1.h
D1.l
=
Unsigned × Unsigned
impyuu
D1.l × D0.l
D0,D1,D2
Signed × Unsigned
impysu
D0,D1,D3
D0.h × D1.l
+
Unsigned × Signed
imacus
D0,D1,D3
D1.h × D0.l
+
0
D3.l
aslw
D3
add
D2,D3
D3.h
D3.l
32 bits
AA0551
Figure 2-10. Signed Integer Double-Precision Multiplication
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DALU
Figure 2-11 illustrates the use of these instructions in the case of an unsigned integer double-precision
multiplication of 32-bit by 32-bit unsigned operands. In this example, only a 32-bit result is generated. The
most significant 32-bits are shifted out. All multiplications are of the “Unsigned x Unsigned” type using
different combinations of high and low portions.
D0.h
D0.l
×
D1.h
D1.l
=
Unsigned × Unsigned
impyuu d0,d1,d2
D1.l × D0.l
Unsigned × Unsigned
impyhluu d0,d1,d3
D0.h × D1.l
imaclhuu d0,d1,d3
D1.h × D0.l
+
+
aslw d3
0
D3.l
add d2,d3
D3.h
D3.l
32 bits
Figure 2-11. Unsigned Integer Double-Precision Multiplication
2.2.2.9 Viterbi Decoding Support
A set of DALU and AGU operations is provided for Viterbi decoding kernels. A special MAX2VIT
operation is defined. This instruction functions as a regular MAX2 instruction and is used to transfer two
16-bit maximum signed values. In addition, the MAX2VIT instruction updates two Viterbi flags (VFs)
which reside in the status register as described in Section 3.1.1, “Status Register (SR),” on page 3-1.
Complementary AGU move operations are provided (VSL instructions). For a full description of the
Viterbi instructions, see Appendix A, “Viterbi Shift Left Move (AGU) VSL,” on page A-422.
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Address Generation Unit
2.3 Address Generation Unit
The AGU is one of the execution units in the SC140 core. The AGU performs effective address
calculations using the integer arithmetic necessary to address data operands in memory. It also contains the
registers used to generate the addresses. The AGU implements four types of arithmetic: linear, modulo,
multiple wrap-around modulo, and reverse-carry. It operates in parallel with other chip resources to
minimize address generation overhead. The AGU also generates change-of-flow program addresses as
well as updates the stack pointer (SP), whenever needed.
2.3.1 AGU Architecture
The major components of the AGU are listed below:
•
Eight low bank address registers (R0–R7)
•
Eight high bank address registers (R8–R15), or alternatively, eight base address registers (B0–B7)
•
Two stack pointers (NSP, ESP), only one of which is active at a time (SP)
•
Four offset registers (N0–N3)
•
Four modifier registers (M0–M3)
•
A modifier control register (MCTL)
•
Two address arithmetic units (AAU)
•
One bit mask unit (BMU)
In this section, the registers are referred to as:
•
Rn for any of the R0–R15 address registers
•
Bn for any of the B0–B7 base address registers
•
Ni for any of the N0–N3 offset registers
•
Mj for any of the M0–M3 modifier registers
All the Rn, Bn, SP, Ni, and Mj registers are referred to as AGU registers. All of the AGU registers are
32-bits.
Figure 2-12 shows a block diagram of the AGU.
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Address Generation Unit
R8/B0
M0
N0
R9/B1
M1
N1
R10/B2
M2
N2
R11/B3
M3
N3
R12/B4
XABA
XABB
32
32
PAB
32
R0
Address
Arithmetic
Unit (AAU)
R1
R2
R3
R4
MCTL
R13/B5
R5
R14/B6
R6
R15/B7
R7
NSP
ESP
Bit
Mask
Unit
(BMU)
Program Counter (PC) Address
Memory Data Bus 1 (XDBA)
64
Memory Data Bus 2 (XDBB)
64
Figure 2-12. AGU Block Diagram
All sixteen address registers (R0–R15) as well as the NSP or ESP are used for generating addresses in the
register indirect addressing modes. All four offset registers (N0–N3) can be used by all sixteen address
registers. The four modifier registers (M0–M3) can only be used by the low bank of eight address registers
(R0–R7).
The base address (Bn) registers are uniquely associated with the low bank of Rn registers such that B0 is
used with R0, B1 with R1, and so on.
The BMU is used to perform bit mask operations such as setting, clearing, changing, or testing bits in a
destination according to an immediate mask operand. Data is loaded into the BMU over the data memory
buses XDBA or XDBB. The result is written back over XDBA or XDBB to the destinations in the next
cycle. All bit mask instructions are typically executed in two cycles and work on 16-bit data. This data can
be a memory location or a portion (high or low) of a register. For more information, see Section 2.3.6, “Bit
Mask Instructions.”
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During every instruction cycle, the two AAUs can generate one 32-bit program memory address on the
PAB (in case of change of flow) or two 32-bit data memory addresses (one on each of the XABA and
XABB). Each AAU can generate an address to access a byte, a 16-bit word, a 32-bit long word, or a 64-bit
two-word long operand in memory to feed into the DALU in a single cycle.
Each AAU can update one address register during one instruction cycle. The modifier control register
(MCTL) specifies the type of arithmetic to be used in the address register update calculation. The address
arithmetic instructions provide arithmetic operations for address calculations or for general purpose
calculations.
The two AAUs are identical. Each contains a 32-bit full adder, called an offset adder, which can perform
the following:
•
Add or subtract two AGU registers
•
Add an immediate value
•
Increment or decrement an AGU register
•
Add the PC
•
Add with reverse-carry
The offset adder can also perform compare or test operations as well as arithmetic and logical shifts. The
offset values added in this adder can be pre-shifted left by 1, 2, or 3 bits according to the access width. In
reverse-carry mode, the carry propagates in the opposite direction.
A second full adder, called a modulo adder, adds the summed result of the first full adder to a modulo
value, M or minus M, where M is stored in the selected modifier register. In modulo mode, a modulo
comparator tests whether the result is inside the buffer by comparing the results to the B register, choosing
the correct result from the offset adder or the modulo adder.
For more information, see Section 2.3.5, “Arithmetic Instructions on Address Registers.”
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Address Generation Unit
2.3.2 AGU Programming Model
The programming model of the AGU is shown in Figure 2-13.
The address registers can be programmed for linear addressing, modulo addressing (regular or multiple
wrap-around), and reverse-carry addressing. Automatic updating of address registers is available when
using address register indirect addressing.
31
0
31
0
R0
N0
R1
N1
R2
N2
R3
N3
R4
31
0
R5
M0
R6
M1
R7
M2
SP (NSP, ESP)
M3
ADDRESS REGISTERS
MCTL
31
0
OFFSET, MODIFIER, and MCTL REGISTERS
R8 / B0
R9 / B1
R10 / B2
R11 / B3
R12 / B4
R13 / B5
R14 / B6
R15 / B7
ADDRESS REGISTERS / BASE ADDRESS REGISTERS
Figure 2-13. AGU Programming Model
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Address Generation Unit
2.3.2.1 Address Registers (R0–R15)
The sixteen 32-bit address registers R0–R15 can contain addresses or general-purpose data. These are
32-bit read/write registers. The 32-bit address in a selected address register is used in calculating the
effective address of an operand. The contents of an address register can point directly to data, or can be
used as an index.
The sixteen address registers R0–R15 are composed of two separate banks, a low bank (R0–R7) and a high
bank (R8–R15). The high bank can be used alternatively as a base address register bank (B0–B7). Each
address register Rn of the high bank can serve as an address register on condition that the corresponding
Bn-8 register is not used. Both Rn and Bn-8 are mapped to the same physical register. For example, R8 is
available only if R0 is not being used in modulo addressing since this requires the base address register B0.
Use of both Rn and Bn-8 notations as source and destination of move-like instructions is permitted,
regardless of the use of the physical register as Base modulo or as a pointer. For example:
MOVE.L #ADDRESS, B0
...
MOVE.W (R8), D0
See Section 2.3.2.6, “Modifier Control Register (MCTL),” for further information. The high bank of
registers can only be used as pointers in the linear mode of addressing since the other modes of addressing
are only encoded for the low bank in the MCTL register.
In addition, an address register can be post-updated according to the addressing mode selected. If an
address register is updated, one of the modifier registers (Mj) can be used to specify the type of update
arithmetic. Offset registers (Ni) are used for post-incrementing and indexing by offset.
The address register modification can be performed by either of the two AAUs. Most addressing modes
modify the selected address register in a read-modify-write fashion. The address register is read, its
contents are modified by the associated modulo arithmetic unit, and the register is written with the
appropriate output of the AAU. The form of address register modification performed by the address
arithmetic unit is controlled by the contents of the offset and modifier registers described in the following
sections.
2.3.2.2 Stack Pointer Registers (NSP, ESP)
The SC140 core has two stack pointer registers: the normal stack pointer (NSP) and the exception stack
pointer (ESP). These 32-bit registers are used implicitly in all PUSH and POP instructions. Only one stack
pointer is active at one time according to the mode:
•
In Normal working mode, the NSP is used.
•
In Exception working mode, the ESP is used.
The EXP bit in the status register (SR) determines the active working mode. The active stack pointer (SP)
is used explicitly for memory references when used with the address register indirect modes. The stack
pointers point to the next unoccupied location in the stacks. They are post-incremented on all the implicit
PUSH operations and pre-decremented on all the implicit POP operations.
Note:
Both stack pointer registers must be initialized explicitly by the programmer after reset.
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2.3.2.2.1 Shadow Stack Pointer Registers
Both stack pointers have shadow registers which contain a decremented value of the stack pointers. When
the shadow register is not valid, the POP instruction is executed in two cycles. The first cycle is used to
decrement the stack pointer. When the shadow register is valid, the POP instruction is executed in only one
cycle.
When an SP is written by the AAU register transfer (TFRA), its shadow register automatically becomes
invalid. When a PUSH/POP instruction is executed, the shadow register of the active SP becomes valid. As
a result, during consecutive POPs, even in the worst case, only the first POP requires an additional cycle.
2.3.2.2.2 Initializing ESP
ESP should be initialized using the AAU register transfer (TFRA) instruction. This guarantees a valid ESP
value even if execution of this instruction is interrupted by an exception. The TFRA instruction is
considered an address arithmetic operation. The ESP is updated at the address generation pipeline stage,
avoiding pipeline conflicts.
2.3.2.3 Offset Registers (N0–N3)
The four 32-bit read/write offset registers N0–N3 can contain offset values used to increment or decrement
address registers in address register update calculations. These registers can also be used for 32-bit general
purpose storage. For example, the contents of an offset register can specify the offset into a table or the
base of the table for indexed addressing, or can be used to step through a table at a specified rate (for
example, five locations per step for waveform generation). Each address register can be used with each
offset register. For example, R0 can be used with N0, N1, N2, or N3 for offset address calculations. The
signed value in an offset register is pre-shifted to the left by 0, 1, 2, or 3 bits to align to the access width.
2.3.2.4 Base Address Registers (B0–B7)
The eight 32-bit read/write base address registers B0–B7 are used in modulo calculations. Each B register
is associated with an R register (B0 with R0, and so on). When activating the modulo addressing mode, the
B register contains the lower boundary value of the modulo buffer. The upper boundary of the modulo
buffer is calculated by B+M-1, where M is the modifier register associated with the R register by MCTL.
When not used for modulo addressing, these registers can be used as high bank address registers
(R8–R15). Both Rn and Bn-8 share the same physical register. For example, if R0 is not programmed for
modulo addressing, the base address register B0 can serve as an additional address register R8.
2.3.2.5 Modifier Registers (M0–M3)
The four 32-bit read/write modifier registers M0–M3 can contain the value of the modulus modifier. These
registers can also be used for general-purpose storage. When activating the modulo arithmetic, the contents
of Mj specify the modulus. Each low address register can be used with each modifier register as
programmed in the MCTL register.
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Address Generation Unit
2.3.2.6 Modifier Control Register (MCTL)
The MCTL register is a 32-bit read/write register. This control register is used to program the address
mode (AM) for each of the eight low address registers (R0–R7). The addressing mode of the high address
register file (R8–R15) cannot be programmed and functions in linear addressing mode only. The format of
MCTL is shown in Figure 2-14.
Bit 31
30
29
28
27
R7 AM[3:0]
Bit 15
14
26
25
24
23
R6 AM[3:0]
13
12
11
R3 AM[3:0]
10
9
21
20
19
R5 AM[3:0]
8
R2 AM[3:0]
22
7
6
5
18
17
Bit 16
R4 AM[3:0]
4
3
R1 AM[3:0]
2
1
Bit 0
R0 AM[3:0]
Figure 2-14. Modifier Control Register (MCTL) Format
The AM bits (AM3, AM2, AM1, AM0) associated with each address register (R0-R7) reflect the address
modifier mode of this address register as shown in Table 2-17. Each of the Rn registers can use M0, M1,
M2, or M3 as their associated modulo register either in modulo addressing mode, or in multiple
wrap-around modulo addressing mode. When activating the modulo addressing mode, the corresponding
B register is used to define the lower boundary value (B0 with R0, and so on). The linear or the
reverse-carry addressing modes can also be used, freeing the B register to be used as an additional linear
address register.
The high bank of the address register file (R8–R15) can only be used in linear addressing mode. Each Rn
(n = 8:15) is available only if the corresponding Bn-8 register is not used since both Rn and Bn-8 are mapped
to the same physical register.
Table 2-17. Address Modifier (AM) Bits
AM3
AM2
AM1
AM0
Address Modifier Modes
0
0
0
0
Linear addressing
0
0
0
1
Reverse-carry addressing
1
0
0
0
M0 used—Modulo addressing
1
0
0
1
M1 used—Modulo addressing
1
0
1
0
M2 used—Modulo addressing
1
0
1
1
M3 used—Modulo addressing
1
1
0
0
M0 used—Multiple wrap-around modulo addressing
1
1
0
1
M1 used—Multiple wrap-around modulo addressing
1
1
1
0
M2 used—Multiple wrap-around modulo addressing
1
1
1
1
M3 used—Multiple wrap-around modulo addressing
MCTL is initialized to zero at reset, setting a default linear mode for all Rn registers. All other AM field
combinations are reserved and should not be used.
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2.3.3 Addressing Modes
The SC140 core provides four types of addressing modes:
•
Register direct
•
Address register indirect
•
PC relative
•
Special
The addressing modes are related to where the operands are to be found and how the address calculations
are to be made. These modes are described in the following sections:
2.3.3.1 Register Direct Modes
The register direct addressing modes specify that the operand is in one or more of the DALU registers,
AGU registers, or control registers, and are classified as register references.
•
Data or Control Register Direct — The operand is in one, two, or four DALU registers as specified
in a portion of the data bus movement field in the instruction. An example is: mac d4,d5,d6,
which uses data registers d4, d5, and d6 as sources for the multiply-accumulate operation. This
addressing mode is also used to specify a control register operand for special instructions.
•
Address Register Direct — The operand is in one of the twenty-seven AGU registers (R0–R7,
R8–R15/B0–B7, N0–N3, M0–M3, MCTL, N/ESP) specified by a field in the instruction. An
example is addl1a r0,r1, which performs a 1-bit arithmetic left shift on the data in R0, and adds the
result to the data in R1.
2.3.3.2 Address Register Indirect Modes
The address register indirect modes specify that the address register is used to point to a memory location.
The term indirect is used because the register contents are not the operand itself, but rather the operand
address. These addressing modes specify that an operand is in a memory location and specify the effective
address of that operand. These references are classified as memory references. The term “index” refers to
an offset stored in a register. The term “displacement” refers to an offset from an immediate in the
instruction.
•
No Update, (Rn) — The operand address is in the address register. The contents of the address
register are unchanged by executing the instruction. For R0-R7, the contents of the modifier control
register (MCTL) are ignored. An example is: bmclr.w #$004f,(r4). A word is read from
memory location stored in r4, operated on, and written back to the same location. The address in r4
is unchanged.
•
Post-increment, (Rn)+ — The operand address is in the address register. After the operand address
is used, it is incremented by the access width (1, 2, 4, or 8 bytes) and stored in the same address
register. The access width is the number of bytes used by the active instruction on the memory data
bus. Incrementing the operand address by the access width places the next available byte address in
the register. The type of arithmetic used for updating R0-R7 is determined by programming the
MCTL register. An example is: move.f (r3)+,d2. The data in the location identified by the
value in r3 is moved to data register d2. Then the value in r3 is incremented by two.
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•
Post-decrement, (Rn)- —The operand address is in the address register. After the operand address
is used, it is decremented by the access width (1, 2, 4, or 8 bytes) and stored in the same address
register. The type of arithmetic used for updating R0-R7 is determined by programming the
MCTL register. An example is: move.l (r3)-,d2. In this case, the value in r3 is decremented
by four after the move has taken place.
•
Post-increment by Offset Ni, (Rn) + Ni — The operand address is in the address register. After the
operand address is used, it is incremented or decremented by an amount determined by the signed
contents of the Ni register pre-shifted to the left by 0, 1, 2, or 3 bits according to the access width.
The result is stored in the same address register. The type of arithmetic used for updating R0-R7 is
determined by programming the MCTL register. The contents of the Ni register are unchanged. An
example is: move.w d3,(r2)+n3. The access width is two, so the increment is twice the value
in the n3 register.
•
Indexed By Offset N0, (Rn + N0) — The operand address is the sum of the contents of the address
register and the signed contents of the N0 register, pre-shifted to the left by 0, 1, 2, or 3 bits according
to the access width. The type of arithmetic used for updating R0-R7 is determined by programming
the MCTL register. The contents of the Rn and N0 registers are unchanged. For example:
move.b d6,(r3+n0). The access width is one, so the contents of the n0 register are used
directly to modify the address before the move is done.
Note that only the N0 offset register can be used in this addressing mode.
•
Indexed by Address Register Rm, (Rn + Rm) — The operand address is the sum of the contents
of the address register Rn and the contents of the address register Rm, pre-shifted to the left by 0, 1,
2, or 3 bits according to the access width. The type of arithmetic used for updating R0-R7 is
determined by programming the MCTL register. The contents of the Rn and Rm registers are
unchanged. An example is: move.l (r0+r2),d6. Here, the access width is four, so the value in
r2 is shifted left two bits before adding to the address in r0.
Note that only address registers (R0–R7) can be used as Rm.
•
Short Displacement, (Rn + x) — The operand address is the sum of the contents of the address
register Rn and a short displacement x that occupies three bits in the instruction word. The
displacement (unsigned) is first shifted to the left by 0, 1, 2, or 3 bits according to the access width.
It is then zero-extended to 32 bits and added to Rn to obtain the operand address. Thus, the
displacement can range from [0] to [+7] bytes, words, long words, or two long words according to
the access width. The contents of the Rn register are unchanged. The type of arithmetic used for
updating R0-R7 is determined by programming the MCTL register. An example is: move.l
d4,(r3+$1c). The access width is four, and the displacement encoded in the instruction is seven
(4 x 7 = 28 = $1c).
•
Word Displacement, (Rn + xxxx) — The operand address is the sum of the contents of the address
register Rn and an immediate displacement. The displacement is a signed 15-bit word that requires
a second instruction word. It is sign-extended to 32 bits and then added to Rn to obtain the operand
address. Thus, the displacement can range from [-16,384] to [+16,383] bytes, [-8192] to [+8191]
words, [-4096] to [+4095] long words, or [-2048] to [+2047] two long words according to the access
width. The contents of the Rn register are unchanged. The type of arithmetic used for updating
R0-R7 is determined by programming the MCTL register.
•
SP Short Displacement, (SP – xx) — The instruction word contains a 5-bit or 6-bit short unsigned
immediate index field. This field is first shifted to the left by 1 or 2 bits according to the access width,
then zero-extended to form a 32-bit offset and subtracted from the active stack pointer (NSP in
Normal mode, ESP in Exception mode) to obtain the operand address. Thus, the displacement can
range from [0] to [31/63] words or long words according to the access width. The contents of the
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Address Generation Unit
active SP register are unchanged. The type of arithmetic used is always linear. An example is:
move.w #$ffff,(sp–$3e). The encoded displacement is 31,the maximum value of five bits,
and the actual displacement is 62 ($3e), since the access width is two.
•
SP Word Displacement, (SP + xxxx)—The operand address is the sum of the contents of the active
stack pointer (SP) and an immediate displacement. The displacement is a signed 15-bit word that
requires a second instruction word. It is sign-extended to 32 bits and added to the active stack pointer
(NSP in Normal mode, ESP in Exception mode) to obtain the operand address. Thus, the
displacement can range from [-16,384] to [+16,383] bytes, [-8192] to [+8191] words, [-4096] to
[+4095] long words, or [-2048] to [+2047] two long words according to the access width. The
contents of the active SP register are unchanged. The type of arithmetic used is always linear. An
example is: move.l (sp+$2000),d2.e. Here, the positive value $2000 is added to the active
stack pointer before the memory access.
2.3.3.3 PC Relative Mode
The PC relative address mode is used to calculate the program destination of change-of-flow instructions
such as branches (BRA). In the PC relative addressing mode, the instruction encoding contains a signed
displacement operand. The operand address is obtained by left-shifting (multiplying by two) the
displacement and adding the result to the value of the program counter (PC). The operand is left-shifted
because the addresses of the program instructions are word-aligned, and memory addressing is in units of
bytes. The arithmetic used is always linear. For example, bra _label2. Assume that PC=$0010 and that
_label2 is at location $0020. The encoded displacement will be ($0020 – $0010)/2 = $0008.
The number of bits occupied by the displacement in the instruction differs with the different kinds of PC
relative instructions. In all cases, the displacement is first sign-extended to 32 bits, then multiplied by two,
and added to the PC to obtain the operand address.
In the one-word conditional branch instructions, the displacement occupies 8 bits of the instruction word
and can range from [-256] to [254] words. In the one-word unconditional branch instructions, the
displacement occupies 10 bits of the instruction word and can range from [-1024] to [1022] words. In the
two-word branch instructions, the displacement occupies 20 bits and can range from [-1,048,576] to
[1,048,574] words. In the DOSETUP instruction, the displacement occupies 16 bits of the instruction. The
displacement for the start address (SA) can range from [-65,536] to [65,534] words.
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2.3.3.4 Special Addressing Modes
The special addressing modes do not use an address register when specifying an effective address. They
either use an immediate value that is included in the instruction for the data value, such as the data value
address, or they use a register that is implicitly referenced by the instruction for the data value.
•
Immediate Short Data — A 5-bit, 6-bit, or 7-bit operand is part of the instruction operation word.
The 5-bit zero-extended operand is used for DALU and AGU arithmetic instructions. The 6-bit
zero-extended operand is used for DALU instructions to move short immediate data to an LCn
register. The 7-bit sign-extended operand is used for immediate moves to a register. This reference
is classified as a program reference. An example is: doen2 #$3f. The value $3f, 63, is loaded to
loop counter 2.
•
Immediate Word Data — This addressing mode requires a one-word instruction extension. The
immediate data is a 16-bit operand. This reference is classified as a program reference. An example
is: doen2 #$40. The value 64 is loaded to loop counter 2. The value exceeds the 6-bit limit for
immediate short data, so an extra word is needed for the encoding.
•
Immediate Long Data — This addressing mode requires a two-word instruction extension. The
immediate data is a 32-bit operand. This reference is classified as a program reference. An example
is: move.l #$f00d0d01,n0. The 32-bit unsigned value is moved to the general register n0.
•
Absolute Word Address — This addressing mode requires a one-word instruction extension. The
operand address occupies 16 bits in the instruction operation words, and is zero-extended to form a
32-bit address. This reference is classified as a memory reference. An example is: move.w
($8a20),d0.
•
Absolute Long Address — This addressing mode requires a two-word instruction extension. A
32-bit address is contained in the instruction words. This reference is classified as a memory
reference. An example is: move.w ($34008a20),d0.
•
Absolute Jump Address — The operand occupies 32 bits in the instruction operation words. It
requires a two-word instruction extension. This reference is classified as a program reference. An
example is: jmp lbl4, where the instruction is encoded with the program memory address of lbl4.
•
Implicit Reference — Some instructions make implicit reference to the PC, normal or exception
stack, loop registers (SA0, SA1, SA2, SA3, LC0, LC1, LC2, LC3), or status register (SR). These
registers are implied by the instruction, and their use is defined by the individual instruction
descriptions. An example is: tfra osp,r2, which transfers the 32-bit word stored at the other
(non-active) stack pointer to address register R2.
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2.3.3.5 Memory Access Width
The SC140 core supports variable width access to data memory. With every memory access, the core sends
one of four signals to the memory interface to designate whether the access width is 8 bits, 16 bits, 32 bits,
or 64 bits wide. The access width is determined by the type of MOVE instruction being used. For example,
MOVE.B is used for byte access. MOVE.W is used for word access. For long-word access, MOVE.L,
MOVE.2F, and MOVE.2W are used. And, for two long-word access, MOVE.2L, MOVE.4F, and
MOVE.4W are used.
The memory addresses are always in units of bytes. For example, addresses for two-word MOVE
operations to/from memory are available in multiples of four in order to best align the data with the byte
addressing.
Address calculations and register update calculations are performed according to the memory access width
as shown in Table 2-18.
Table 2-18. Access Width Support for Address and Register Update Calculations
Memory Access Width
Addressing Mode
Calculation
Byte
Word
Long
Two Long
1
2
4
8
Ni*1
Ni*2
Ni*4
Ni*8
Post-increment (Rn) +
Post-decrement (Rn) -
Rn register post-increment or
post-decrement by —>
Post-increment by
Offset (Rn)+Ni
Rn register post-increment by ->
Indexed by Offset N0
(Rn + N0)
Actual address offset
N0
2*N0
4*N0
8*N0
Indexed by Address
Register Rm (Rn + Rm)
Actual address offset
Rm
2*Rm
4*Rm
8*Rm
Short Displacement
(Rn + x)
Actual address displacement
x
x
x
x
Word Displacement
(Rn + xxxx)
Actual address displacement
xxxx
xxxx
xxxx
xxxx
SP update in Push/Pop
SP post-increment or
pre-decrement by —>
8
8
8
8
SP Short Displacement
(SP - xx)
Actual address displacement
NA
xx
xx
NA
SP Word Displacement
Actual address displacement
xxxx
xxxx
xxxx
xxxx
2.3.3.6 Memory Access Misalignment
Each access to the memory generated by the core should be aligned according to the access type. If the
alignment rule is violated, erroneous data may be fetched from the memory. In addition, an exception may
be generated to identify that an unaligned access occurred. For more information, see Section 5.8,
“Exception Processing,” on page 5-46.
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Address Generation Unit
Table 2-19 summarizes the memory address alignment rule for each type of memory access.
Table 2-19. Memory Address Alignment
Access Type
Aligned Address
Byte access
Any address
Word access
Multiple of 2
Long-word access
Multiple of 4
Two long-word access
Multiple of 8
2.3.3.7 Addressing Modes Summary
Table 2-20 provides a summary of the addressing modes described in the previous sections. The Operand
Reference columns are abbreviated as follows:
•
S = Software Stack Reference in data memory (uses NSP or ESP according to mode)
•
C = Program Control Unit Register Reference
•
D = DALU Register Reference
•
A = AGU Register Reference
•
P = Program Memory Reference
•
X = Data Memory Reference
Table 2-20. Addressing Modes Summary
Addressing Modes
R0-R7
Uses
MCTL
Operand Reference
Assembler Syntax
S
C
D
√
√
A
P
X
Register Direct
Data or Control Register
—
Address Register (Rn)
—
√
Rn
Address Modifier Register (Mj)
—
√
Mj
Base Address Register (Bn)
—
√
Bn
Address Offset Register (Ni)
—
√
Ni
Stack Pointer
—
√
SP
SC140 DSP Core Reference Manual
Dn
Dn Dm
Dn Dm Di Dj
MCTL
SR, EMR, VBA
LC0, LC1
LC2, LC3
SA0, SA1
SA2, SA3
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Address Generation Unit
Table 2-20. Addressing Modes Summary (Continued)
Addressing Modes
R0-R7
Uses
MCTL
Operand Reference
Assembler Syntax
S
C
D
A
P
X
Address Register Indirect
No Update, (Rn)
No
√
(Rn)
Post-increment, (Rn)+
Yes
√
(Rn)+
Post-decrement, (Rn)–
Yes
√
(Rn)–
Post-increment by Offset Ni, (Rn)+Ni
Yes
√
(Rn) + Ni
Indexed by offset N0, (Rn+N0)
Yes
√
(Rn + N0)
Indexed by Address Register Rm,
(Rn+Rm)
Yes
√
(Rn + Rm)
Short Displacement, (Rn+x)
Word Displacement, (Rn+xxxx)
Yes
√
(Rn + x)
(Rn + xxxx)
SP Short Displacement, (SP-xx)
—
√
√
(SP - xx)
SP Word Displacement, (SP+xxxx)
—
√
√
(SP + xxxx)
PC Relative
PC Relative with Displacement
—
√
#xx (8 bits)
#xxx (10 bits)
#xxxx (16 bits)
#xxxxx (20 bits)
√
#xx (5, 6, or 7bits)
#xxxx (16 bits)
#xxxxxxxx(32 bits)
Special
Note:
2-44
Immediate Short Data
Immediate Word Data
Immediate Long Data
—
Absolute Word Address
Absolute Long Address
—
Absolute Jump Address
—
Implicit Reference
—
√
√
√
√
xxxx (16 bits)
xxxxxxxx (32 bits)
xxxxxxxx (32 bits)
√
The “—” that appears in the “R0-R7 Uses MCTL” heading means that it is not applicable for that
addressing mode.
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Address Generation Unit
2.3.4 Address Modifier Modes
The AAU supports linear, reverse-carry, modulo, and multiple wrap-around modulo arithmetic types for
address register indirect modes operating on R0-R7. These arithmetic types allow the easy creation of data
structures in memory for First-In/First-Out (FIFO) queues, delay lines, circular buffers, stacks, and
reverse-carry Fast Fourier Transform (FFT) buffers.
Data is manipulated by updating address registers (Rn) used as pointers rather than moving large blocks of
data. The contents of the modifier control register MCTL define the type of arithmetic to be performed for
address calculations. For modulo arithmetic, the address modifier register Mj specifies the modulus. Each
of the address register lower banks (R0–R7) can be used with any of the modifier registers (M0–M3) as
programmed in the MCTL register.
2.3.4.1 Linear Addressing Mode
Linear addressing is useful for general-purpose addressing such as stacks. In linear addressing mode, the
address is calculated using standard binary arithmetic. The entire memory space is addressable. Linear
addressing mode is selected by setting the AM3–0 bits to 0000 in the MCTL register. This is the default
state.
2.3.4.2 Reverse-carry Addressing Mode
Reverse-carry addressing is useful for 2k point FFT addressing. This mode is selected for R0-R7 by setting
the AM3-0 bits to 0001 in the MCTL register. Address modification is performed in the hardware by
propagating the carry from each pair of added bits in the reverse direction (from the MSB end toward the
LSB end). For the +Ni addressing mode, reverse-carry is equivalent to:
•
Bit-reversing the contents of Rn (redefining the MSB as the LSB, the next MSB as bit 1, and so on)
•
Shifting the offset value in Ni left by 0, 1, 2, or 3 according to the access width
•
Bit-reversing the shifted Ni
•
Adding normally
•
Bit-reversing the result
This address modification is useful for addressing the twiddle factors in 2k point FFT addressing as well as
to unscramble 2k point FFT data. The range of values for Ni is 0 to 232-1, which allows reverse-carry
addressing for FFTs up to 4,294,967,296 points.
Note:
To achieve correct reverse-carry accessing for access widths of 2, 4, or 8, the last 1, 2, or 3 least
significant bits (respectively) of the address calculation result are forced to zero.
2.3.4.3 Modulo Addressing Mode
Modulo address modification is useful for creating circular buffers for FIFO queues, delay lines, and
sample buffers up to 231 bytes long.
Modulo addressing is selected by writing the MCTL AM3-0 bits of the MCTL register (as shown in
Table 2-10) as well as writing the desired modulus to the corresponding Mj register. Address modification
is performed in modulo M, where M ranges from 1 to +231-1. Modulo M arithmetic causes the address
register values to remain within an address range of size M, thus defining a buffer with a lower and an
upper address boundary.
Each base address register (Bn register) is associated with an Rn register (B0 with R0, and so on). Each
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Address Generation Unit
register Rn has one Mj register assigned to it by encoding in the MCTL. The lower boundary value of the
buffer resides in the Bn register, and the upper boundary is calculated as Bn+Mj-1. Mj must be smaller
than 231 - 1 (Mj < 231 - 1).
The modulo addressing definition, using a base register (Bn) and a modulo register (Mj), enables the
programmer to locate the modulo buffer at any address. The buffer start address is only required to be
aligned to the access width.
The address pointer Rn is not required to start at the lower address boundary, nor to end on the upper
address boundary. Rn can initially point anywhere (aligned to its access width) within the defined modulo
address range, Bn ≤ Rn < B+Mj. Assuming the (Rn)+ indirect addressing mode, if the address register
pointer increments past the upper boundary of the buffer (base address + Mj-1), it wraps around through
the base address (lower boundary). Alternatively, assuming the (Rn)- indirect addressing mode, if the
address decrements past the lower boundary (base address), it wraps around through the base address +
Mj-1 (upper boundary).
The following constraints apply:
1. For proper modulo addressing, if an offset Ni is used in the address calculation, the 32-bit
absolute effective value |Ni| must be less than or equal to Mj, where “effective” means the
programmed Ni is multiplied by the access width. For example, move.w (r0)+n0,d0 translates
to the restriction 2*n0 ≤ Μj, and move.l (r0)+,d0 translates to 4 ≤ Mj. If effective Ni > Mj, the
result of the address calculation is undefined. Multiple wrap-around modulo addressing
supports the situation of effective Ni greater than Mj.
2. Mj must be aligned to the access width used. For example, if the buffer is used with a
MOVE.2L instruction, Mj must be aligned to 8 (be a multiple of 8). If the modulus is less
than the access width, the data accessed as well as the address calculations are undefined.
3. When Bn is used as a base address register, the use of Rn+8 as a pointer is illegal since this
is the same physical register.
Modulo addressing is illustrated in Figure 2-15. Addresses will be kept within the eleven addresses shown.
For the instruction, move.w (r0+$000e),d0, the access will be made from $26 (38), if the base address
is $20, the modulus is $c, and r0 is $24. The operation is 36+14=50=38 in modulus 12, base address 32
(50–44 + 32 = 38).
32
$0020 = B
36
M = 12
38
$002c = B + M – 1
44
Figure 2-15. Modulo Addressing Example
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Address Generation Unit
Table 2-21 describes the modulo register values and the corresponding address calculation.
Table 2-21. Modulo Register Values for Modulo Addressing Mode
Modifier Mj
Address Calculation Arithmetic
$0000 0000
Unused
$0000 0001
Modulo 1
$0000 0002
Modulo 2
$7FFF FFFE
Modulo 231-2
$7FFF FFFF
Modulo 231-1
2.3.4.4 Multiple Wrap-Around Modulo Addressing Mode
Multiple wrap-around addressing is useful for decimation, interpolation, and waveform generation. The
multiple wrap-around capability can be used for argument reduction. In multiple wrap-around modulo
addressing mode, the modulus M is a power of 2 in the range of 21 to 231. The value M-1 is stored in the
modifier register (Mj). The B registers B0 to B7 are not used for multiple wrap-around modulo addressing;
therefore, their corresponding R8–R15 registers can be used for linear addressing.
The lower and upper boundaries are derived from the contents of Mj. The lower boundary (base address)
value has zeros in the k LSBs where M = 2k and therefore must be a multiple of M. The Rn register
involved in the memory access is used to set the MSBs of the base address. The base address is set so that
the initial value in the Rn register is within the lower and upper boundaries. The upper boundary is the
lower boundary plus the modulo size minus one (base address + M–1).
The size of the modulo buffer must be aligned to (be a multiple of) the access width. If the modulus is less
than the access width, the data accessed as well as the address calculations are undefined.
If an offset Ni is used in the address calculations, it is not required to be less than or equal to M for proper
modulo addressing. The multiple wrap-around modulo addressing mode supports unlimited boundary
wraps.
When using the (Rn)+ and (Rn)- addressing modes with a modulus 2k ≥ 8, there is no functional difference
between the multiple wrap-around and normal modulo modes since the address can only be wrapped
around once.
As an example, consider the instruction move.w (r0 + $0042),d0. If the mctl is set to $000c, and m0
is set to $000f, then M0 = 16. If r0 is initially $24 (36), the lower boundary is $20 (32) and the upper
boundary is $2f (47). The memory access is done from address $26 (38), calculated by 36 + 66 = 102,
102–48=54, 54–3x16=6, 6+32=38.
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Address Generation Unit
Table 2-22 describes the modulo register Mj values and the corresponding multiple wrap-around address
calculation.
Table 2-22. Modulo Register Values for Wrap-Around Modulo Addressing Mode
Modifier Mj
Address Calculation Arithmetic
$0000 0001
Multiple Wrap-around Modulo 2
$0000 0003
Multiple Wrap-around Modulo 4
$0000 0007
Multiple Wrap-around Modulo 8
$7FFF FFFF
Multiple Wrap-around Modulo 231
$FFFF FFFF
Linear
2.3.5 Arithmetic Instructions on Address Registers
The SC140 core provides arithmetic instructions on the address registers (R0–R15), offset registers
(N0–N3), the stack pointer (SP), and the program counter (PC).
Address modification modes can affect the arithmetic results stored in R0-R7 using instructions ADDA,
SUBA, ADDL1A, or ADDL2A. In addition, an address calculation that increments or decrements address
register R0-R7 is affected by the modifier mode. When updating R0-R7 in modulo addressing mode, the
modulo registers hold the modulus.
Table 2-23 lists the arithmetic instructions that are executed in the AGU unit. A more detailed description
of the operations is provided in Appendix A, “SC140 DSP Core Instruction Set.”
Table 2-23. AGU Arithmetic Instructions
2-48
Instruction
Description
ADDA
AGU Add (affected by the modifier mode)
ADDL2A
AGU Add with 2-bit left shift of source operand (affected by the
modifier mode)
ADDL1A
AGU Add with 1-bit left shift of source operand (affected by the
modifier mode)
ASL2A
AGU Arithmetic shift left by 2 bits (32-bit)
ASLA
AGU Arithmetic shift left (32-bit)
ASRA
AGU Arithmetic shift right (32-bit)
CMPEQA
AGU Compare for equal
CMPGTA
AGU Compare for greater than
CMPHIA
AGU Compare for higher (unsigned)
DECA
AGU Decrement register (affected by the modifier mode)
DECEQA
AGU Decrement and set T if result is zero
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Address Generation Unit
Table 2-23. AGU Arithmetic Instructions (Continued)
Instruction
Description
DECGEA
AGU Decrement and set T if result is equal to or greater than zero
INCA
AGU Increment register (affected by the modifier mode)
LSRA
AGU Logical shift right (32-bit)
SUBA
AGU Subtract (affected by the modifier mode)
SXTA.B
AGU Sign-extend byte
SXTA.W
AGU Sign-extend word
TFRA
AGU Register transfer
TSTEQA
AGU Test for equal to zero
TSTEQA.W
AGU Test for equal to zero on lower 16 bits
TSTGEA
AGU Test for greater than or equal to zero
TSTGTA
AGU Test for greater than zero
ZXTA.B
AGU Zero-extend byte
ZXTA.W
AGU Zero-extend word
2.3.6 Bit Mask Instructions
The SC140 core provides bit mask instructions on all address registers (R0–R15), all DALU registers
(D0–D15), all control registers (EMR, VBA, SR, MCTL), and all memory locations.
Bit mask instructions provide an easy way of setting, clearing, inverting, or testing a selected but not
necessarily adjacent group of bits in a register or memory location.
All bit mask instructions work on 16-bit data. This data can be the contents of a memory location or a
portion (high or low) of a register.
Only a single bit mask instruction is allowed in one execution set since only one execution unit exists for
these instructions. A subgroup of the bit mask instructions (BMTSET) supports hardware semaphores. For
more information, see Section 2.3.6.1, “Bit Mask Test and Set (Semaphore Support) Instruction.”
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Address Generation Unit
Table 2-24 lists the arithmetic instructions that are executed in the BMU.
Table 2-24. AGU Bit Mask Instructions (BMU)
Instruction
Description
AND.W
Logical AND on a 16-bit operand
BMCHG
Bit mask change
Inverts every bit in the destination (register or memory) that has the value 1 in the mask.
BMCLR
Bit mask clear
Clears every bit in the destination (register or memory) that has the value 1 in the mask.
BMSET
Bit mask set
Sets every bit position in the destination (register or memory) that has the value 1 in the mask.
BMTSET
Bit mask test (if set) and set
Sets the T bit if every bit that has the value 1 in the mask is 1 in the destination (register or
memory). Sets (writes) every bit in the destination (register or memory) that has the value 1 in
the mask, and sets the T-bit if the set (write) failed. See Section 2.3.6.1, “Bit Mask Test and Set
(Semaphore Support) Instruction.”
BMTSTC
Bit mask test if clear
Sets the T-bit, if every bit position that has the value 1 in the mask is 0 in an operand.
BMTSTS
Bit mask test if set
Sets the T bit if every bit position that has the value 1 in the mask is 1 in an operand.
EOR.W
Logical exclusive OR on a 16-bit operand
NOT.W
Binary inversion of a 16-bit operand
OR.W
Logical OR on a 16-bit operand
2.3.6.1 Bit Mask Test and Set (Semaphore Support) Instruction
The bit mask test and set instruction (BMTSET) provides support for hardware semaphores. A semaphore
is a signal which can be set to indicate whether a program resource can be accessed or not. The destination
of this instruction can be a register or a memory location in either internal or external memory. If the
semaphore indicates that the resource is available, the T bit has the value 0. If the semaphore indicates that
the resource is not available (T = 1), a jump can be made to skip the resource code.
This instruction performs the following tasks:
1. Reads the destination register, tests the data, and sets the T bit, if every bit that has the value
1 in the mask is 1 in the destination.
2. Writes back to the destination a word with ones for the masked bits, and the original
destination bits for the unmasked bits.
3. Sets the T bit if the set (write) failed.
Normally, the BMTSET consists of three indivisible operations: read, update the T bit, and
write. A set (write) failed condition occurs if the destination failed to be written indivisibly
from the previous read operation of that BMTSET instruction. The memory subsystem
signals the core of a write failure if a memory access that is initiated by another master
source intervenes between the read and the write accesses of the BMTSET operation. As a
result of the non-exclusive write indication, the T bit is set, signalling that the resource may
not be available, thereby avoiding a hazard condition.
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Address Generation Unit
2.3.6.1.1 Example of Normal Usage of the Semaphoring Mechanism
The following sequence accesses a resource controlled by a semaphore.
label : BMTSET.W #mask,(R0)
JT label
Normally, the mask enables only one bit. In this case, the memory destination pointed to by (R0) is read,
and the enabled bit is tested. The enabled bit is then set, and the memory destination is written back.
The T bit is set if the enabled bit was originally 1 (meaning that it was semaphore-occupied), or that the
write-back failed. A T bit value of TRUE indicates to the conditional jump that the attempt to obtain the
resource has failed, and that the jump should be taken. The T bit is cleared if the enabled bit was originally
zero. This means that the semaphore was not allocated. Therefore, the resource was available, and the
instruction was successful in setting the semaphore exclusively. A successful allocation writeback results.
When the destination is a register, the write is always successful.
2.3.6.2 Semaphore Hardware Implementation
During the address phase of the read and write accesses associated with the BMTSET instruction, an
output of the core is asserted. This assertion indicates that the read and the following write are part of a
read-modify-write sequence.
During the data phase of the write access, a core input provides the core with the result of the access
(de-asserted = write failed).
2.3.7 Move Instructions
The SC140 instruction set supports various types of move instructions which differ in the following
properties:
•
Access width — Byte (8 bits), word (16 bits), long-word (32 bits), and two long words (64 bits)
•
Data type — Signed integer, unsigned integer, fractional (with or without limiting)
•
Multi-register moves — Some move operations split data between two or four registers
•
Addressing mode — For example, absolute, relative to an address pointer (with various offset and
post-update options), and relative to the stack pointer
The move instructions perform data movement over the XDBA and XDBB buses (for data moves). Move
instructions do not affect the status register with the exception of the sticky scaling bit in reading a DALU
register.
Table 2-25 lists the move instructions. The suffix just before the period in the MOVE nomenclature
indicates the following:
•
None = Signed
•
U = Unsigned
•
S = Scaling and limiting (saturation) enabled
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The suffix just after the period in the MOVE nomenclature indicates the following:
•
B = Byte
•
W = Integer word (16 bits)
•
L = Long word (32 bits)
•
F = Fractional word (16 bits)
Either a two or four may modify the last suffix.
Table 2-25. AGU Move Instructions
2-52
Instruction
Description
MOVE.2F
Move two fractional words from memory to a register pair
MOVE.2L
Move two longs to/from a register pair
MOVE.2W
Move two integer words to/from memory and a register pair
MOVE.4F
Move four fractional words from memory to a register quad
MOVE.4W
Move four integer words to/from memory and a register quad
MOVE.B
Move byte to/from memory
MOVE.F
Move fractional word to/from memory
MOVE.L
Move long
MOVE.W
Move integer word to/from memory, or immediate to register or
memory
MOVEc
Conditional move between address registers
MOVES.2F
Move two fractional words to memory with scaling and limiting enabled
MOVES.4F
Move four fractional words to memory with scaling and limiting enabled
MOVES.F
Move fractional word to memory with scaling and limiting enabled
MOVES.L
Move long to memory with scaling and limiting enabled
MOVEU.B
Move unsigned byte from memory
MOVEU.L
Move unsigned long from immediate
MOVEU.W
Move unsigned integer word from memory or from immediate
VSL.2F
Viterbi shift left—specialized move to support Viterbi kernel
VSL.2W
Viterbi shift left—specialized move to support Viterbi kernel
VSL.4F
Viterbi shift left—specialized move to support Viterbi kernel
VSL.4W
Viterbi shift left—specialized move to support Viterbi kernel
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Address Generation Unit
Integer moves from memory (byte, word, long, two long) are right-aligned in the destination register, and
by default are sign-extended to the left. Unsigned moves are marked with “U” (for example, MOVEU.B),
and zero extended in the destination register. A schematic representation of integer moves from memory
into a 40-bit register is shown in Figure 2-16. Moves from registers to memory use the appropriate portion
from the source register. Moves to registers of less than 40 bits behave the same as in Figure 2-16 up to
their bit length.
39
MOVE.B (signed byte move)
8
0
8
0
sign extension
39
MOVEU.B (unsigned byte move)
zero extension
39
16
0
16
0
zero extension
MOVEU.W (unsigned word move)
39
MOVE.W (signed word move)
sign extension
32
sign
extension
MOVE.L (signed long move)
MOVEU.L (unsigned long move)
39
0
39
0
32
zero
extension
39
16
0
sign extension
MOVE.2W (signed two word move)
sign extension
32
sign
extension
sign
extension
39
MOVE.2L (signed two long move)
39
0
16
0
sign extension
MOVE.4W (signed four-word move)
sign extension
sign extension
sign extension
Figure 2-16. Integer Move Instructions
Fractional moves are supported only to DALU registers. Moves from memory are put in the high portion
of the data register, sign-extended to the extension, and zero-filled in the low portion. MOVE.L and
MOVE.2L may also be considered fractional moves since alignment in the destination register is the same
for integer long moves and fractional long moves. A schematic representation of fractional moves from
memory to 40-bit data registers is shown in Figure 2-17.
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Address Generation Unit
.
39
32
sign
extension
MOVE.F (fractional move)
39
MOVE.2F (fractional double move)
32
sign
extension
sign
extension
39
MOVE.4F (fractional quad-move)
32
sign
extension
sign
extension
sign
extension
sign
extension
16
0
zero-fill
16
0
zero-fill
zero-fill
0
16
zero-fill
zero-fill
zero-fill
zero-fill
Figure 2-17. Fractional Move Instructions
The four instructions MOVES.F, MOVES.2F, MOVES.4F, and MOVES.L move data from data registers
to the memory with scaling and limiting. The first three operate on 16-bit data. The MOVES.L instruction
performs 32-bit scaling and limiting before the move.
For all moves on the SC140, the syntax requires that the source of the data be specified first followed by
the destination (SRC, DST). The source and destination are separated by a comma with no spaces either
before or after the comma.
Multi-register move instructions originate or update several registers. Registers that are accessed as part of
the same move instruction are specified with a colon separator. For example, a MOVE.4F from a memory
location pointed by R0 to the registers D0, D1, D2, and D3 is written as:
MOVE.4F (R0),D0:D1:D2:D3
In this case, let the address in R0 be noted as A0. The fractional word in location A0 then goes to D0, the
word in A0 + 2 goes to D1, the word in A0 + 4 goes to D2, and the word in A0 + 6 goes to D3. The
addresses increment by two since the addressing unit is always a byte. Moves to or from more than one
register are treated according to the same principle.
A special MOVE.L instruction supports moving data to and from data register extensions (Dn.e). In order
to support full saving and restoring of the machine state, extension moves also include the limit bit Ln of
the register, and are therefore nine bits wide. In one case of the MOVE.L instruction, two extensions
belonging to two consecutive data registers are moved concurrently from the registers to the memory as
part of a 32-bit access.
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Memory Interface
The extension bits of the even data register occupy bits 0 to 8 (bit 8 is the limit bit). The extension bits of
the odd register occupy bits 16 to 24 (bit 24 is the limit bit) as described in Figure 2-18.
31
24
16
0
39
32
8
0
0
16
Memory Long Word
0
L0
+ extension
D0
L1
+ extension
D1
Figure 2-18. Bit Allocation in MOVE.L D0.e:D1.e
Moves from memory to an extension are only to single registers. However, they are also 32-bit wide and
implicitly assume the bit allocation described above according to the register number (odd or even). For
example, move.l $4F42,d3.E is the instruction for moving bits 24:16 from the memory location addressed
by $4F42 to the limit bit and extension bits of the odd register d3. See Appendix A, “Move Long Word
(AGU) MOVE.L,” , for more information about the moves to and from extension registers.
2.4 Memory Interface
The SC140 core interfaces to memory via the following:
•
32-bit program memory address bus (PAB) and 128-bit program memory data bus (PDB)
•
32-bit data memory address bus A (XABA) and 64-bit data memory data bus A (XDBA)
•
32-bit data memory address bus B (XABB) and 64-bit data memory data bus B (XDBB)
•
Control signals such as read and write access strobes as well as access width control
The SC140 does not specify a memory subsystem architecture, only the minimum requirements for correct
execution of SC140 code. Listed below are requirements for all memory designs that interface with the
SC140 core.
•
The SC140 core supports only unified memory designs. Memory is regarded as a single space. There
is no distinction between program memory locations and data memory locations. Each memory
location possesses a unique address that can be accessible from either the program or data buses.
From the core’s perspective, there is only one memory address “a,” which can hold either data or
program information.
•
Data must be byte-addressable and accessible by the two data memory buses.
•
All data width accesses used by the SC140 core must be supported by the memory such as byte
(8 bits), word (16 bits), long word (32 bits), or double-long word and four-word (64 bits). One of
four control signals will indicate to the memory which access width is needed for each access.
•
Multi-byte memory accesses must support both endian modes.
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Memory Interface
•
Memory must resolve access ordering on a cycle by cycle basis. All accesses on a given cycle must
be completed before proceeding to accesses in the next cycle. Note that a conflict acces may occur
when there are multiple requests to access the same memory module, in the same cycle. An access
conflict is resolved by a stall cycle (per conflict), which serializes the multiple request.
•
Multiple access rules in a given cycle are as follows:
— Multiple read or write accesses to different memory locations execute without any
predetermined sequence.
— In cases where multiple accesses to the same memory location occur, the access sequence is
program fetch, data read, and data write.
— If two write operations access the same byte in memory in the same cycle, the operation is illegal
and the result is undefined. The same byte may be written by different but overlapping words or
long words. The memory subsystem should be able to detect these cases and issue an imprecise
interrupt to the core. The use of this interrupt is optional. Refer to Section 5.3.3.2, “Implicit
Push/Pop Memory Timing,” on page 5-24 for more details.
•
Accesses to non-existent memory locations are illegal and the result is undefined. The memory
subsystem can issue an imprecise interrupt to the core. The use of this interrupt is optional.
2.4.1 SC140 Endian Support
The term “little endian” is defined as a computer architecture such that given a multi-byte operand
representation, bytes at lower addresses have lower numeric significance. Each word is stored little end
first. In little endian mode, the MOVE.W D0,(R0) instruction (for example) stores bits 7–0 of D0 into
address (R0), and bits 15–8 into address (R0 + 1).
In “big endian” architectures, the most significant byte has the lowest address, and each word is stored big
end first. In big endian mode, the MOVE.W D0,(R0) instruction stores bits 15–8 of D0 into address (R0),
and bits 7–0 into address (R0 + 1).
The SC140 supports both big and little endian architectures through the big endian memory (BEM) mode
bit in the EMR. This bit samples a core input signal when exiting the reset state, and cannot be changed
during normal operation.
Figure 2-19 shows an example how data is transferred from a register to memory in the two endian modes.
Big Endian
15
8 7
Little Endian
0
REGISTER
7
15
8 7
0
MEMORY
0
REGISTER
7
A0
7
0
A0+1
0
A0
7
0
MEMORY
A0+1
Figure 2-19. Endian Example
2.4.1.1 SC140 Bus Structure
The entire memory space of the SC140 core is unified. The memory supports two parallel 64-bit data
accesses and one 128-bit program fetch. All can occur in parallel.
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Memory Interface
The two data buses that connect between the core and the memory are each 64 bits wide. Instructions such
as load to registers and store to memory utilize the bus according to the application requirement. Different
versions of the instructions are used for different bandwidths such that:
•
MOVE.B loads or stores bytes (8 bits).
•
MOVE.W and MOVE.F load or store integer or fractional words (16 bits).
•
MOVE.2W, MOVE.2F, and MOVE.L load or store double-integers, double-fractions, and long
words respectively (32 bits).
•
MOVE.4W, MOVE.4F, and MOVE.2L load or store quad-integers, quad-fractions, and double-long
words respectively (64 bits).
Figure 2-20 shows the data busses between the SC140 core and the memory.
SC140 Core
128-bit PDB-bus
Unified
Memory
Space
64-bit XDBA-bus
64-bit XDBB-bus
Figure 2-20. Basic Connection between SC140 Core and Memory
2.4.1.2 Memory Organization
Different types of data are stored differently in memory for each of the two endian modes. However, the
data retains the same meaning. For example, 64 bits of data can be represented by any of the following:
•
Eight 8-bit bytes
•
Four 16-bit numbers
•
Two 32-bit numbers
Figure 2-21 shows how data is organized in memory in the two endian modes. Each data unit is a byte
made of two hexadecimal numbers.
Little Endian
Big Endian
0
1
2
3
4
5
6
7
0a 0b 0c 0d 0e 0f
01 02 03 04 05 06 07 08
16 ($10) 11 22 33 44 cc dd ee ff
0
8
7
6
5
4
3
2
1
0
0f 0e 0d 0c 0b 0a
0
07 08 05 06 03 04 01 02 8
cc dd ee ff 11 22 33 44 16 ($10)
Figure 2-21. Memory Organization of Big and Little Endian Mode
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Memory Interface
Table 2-26 describes the data representation for each 64-bit row in Figure 2-21.
Table 2-26. Data Representation in Memory
Representation Type
Value
Eight 8-bit bytes
A0 = $0a, A1 = $0b, A2 = $0c, A3 = $0d, A4 = $0e, A5 = $0f
Four 16-bit numbers
A8 = $0102, A10 = $0304, A12 = $0506, A14 = $0708
Two 32-bit numbers
A16 = $11223344, A20 = $ccddeeff
2.4.1.3 Data Moves
Data moves are executed by moving core registers to and from memory over one of the data buses (XDBA
or XDBB).
The data registers can be accessed with three types of data:
•
Long type access, writing or reading 32-bit operands.
•
Word type access, writing or reading 16-bit operands.
•
Byte type access, writing or reading 8-bit operands.
Figure 2-22 shows an example of data transfer in big and little endian modes.
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Memory Interface
Memory
Big Endian
0
1
Little Endian
7
2 3 4 5 6 7
0 0a 0b 0c 0d 0e 0f
8 01 02 03 04 05 06 07 08
6
5
4
3
2
1
0
0f 0e 0d 0c 0b 0a
07 08 05 06 03 04 01 02
cc dd ee ff 11 22 33 44
16 ($10) 11 22 33 44 cc dd ee ff
24 ($18)
0
8
16 ($10)
24 ($18)
32 ($20)
32 ($20)
xxxx xxxx xxxx xx0a
xxxx xxxx xxxx xx0c
xxxx xxxx xxxx 0102
xxxx xxxx 1122 3344
64-bit XB-BUS
Data Bus Contents
MOVE.B (A0), D0
MOVE.B (A2), D0
MOVE.W (A8), D0
MOVE.L (A16), D0
64-bit XA-BUS
Instructions
SC140 Core
Figure 2-22. Data Transfer in Big and Little Endian Modes
For single-register moves, assuming an equivalent memory map in big and little endian modes, the byte
organization on the buses is identical in both modes. However, the memory subsystem must route the data
bus bytes to different memory addresses for each supported endian mode.
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Memory Interface
2.4.1.4 Multi-Register Moves
For accesses involving more than one register, such as with MOVE.2W or MOVE.4F instructions, the
SC140 ensures that data originating from a specific register reaches the same address in memory in both
little and big endian modes (and the other way round). The memory system does not distinguish between
MOVE.L and MOVE.2W transfers that have the same data width. Memory treats them both like a long
word transfer. If the data bus were the same for both endian modes in a two-register transfer, the data from
the two registers would end up in different addresses. To correct for this, the byte order on the buses for
multi-register transfers is adjusted for the little endian mode. The memory also does not distinguish
between transfers of four words or two long words. It treats them both like a string of eight bytes. The bus
structure for the little endian mode corrects for both cases to ensure that register data is stored at the same
address for both modes.
As an example of the problem that arises if a correction is not made, consider the following case:
The instruction move.2w d0:d1,(a8) transfers two integer words from data registers d0 and d1 to
memory at address a8. For d0 = $0102 and d1 = $0304, the data bus would be $01020304, and the memory
would be accessed for a width of 32 bits. For big endian mode, the memory would look like:
Address
Data
a8
01
a9
02
a10
03
a11
04
For little endian mode, the memory would be accessed for a width of 32 bits (like a long word), and then it
would write the data little end first such that the memory would look like:
Address
Data
a8
04
a9
03
a10
02
a11
01
Note that the data word from d0, $0102, is at a different address for the two modes. If the data bus were
modified by the core to $03040102, then the memory for little endian mode would look like:
2-60
Address
Data
a8
02
a9
01
a10
04
a11
03
SC140 DSP Core Reference Manual
Memory Interface
This is the desired result. This effect is achieved in little endian mode through logic in the core, which
modifies the data on the data bus to the memory for both reads and writes.
Figure 2-23 shows examples of multi-register data transfers in big and little endian modes.
Memory
Big Endian
0
1
2
3
4
5
6
Little Endian
7
7
0 0a 0b 0c 0d 0e 0f
8 01 02 03 04 05 06 07 08
6
5
4
3
2
1
0
0f 0e 0d 0c 0b 0a
07 08 05 06 03 04 01 02
cc dd ee ff 11 22 33 44
16 ($10) 11 22 33 44 cc dd ee ff
24 ($18)
0
8
16 ($10)
24 ($18)
32 ($20)
32 ($20)
xxxx xxxx 0304 0102
0708 0506 0304 0102
ccdd eeff 1122 3344
64-bit XB-BUS
64-bit XB-BUS
Data Bus Contents
(a) MOVE.2W (A8), D0:D1
(b) MOVE.4W (A8), D0:D1:D2:D3
(c) MOVE.2L (A16), D0:D1
64-bit XA-BUS
Instructions
xxxx xxxx 0102 0304
0102 0304 0506 0708
1122 3344 ccdd eeff
64-bit XA-BUS
Data Bus Contents
SC140 Core
D0
(a)
0102
D1
D2
D3
0304
–
–
(b)
0102
0304
0506
0708
(c)
11223344
ccddeeff
–
–
Figure 2-23. Multi-Register Transfer in Big and Little Endian Modes
Note:
The only exceptions to the behavior described above are the VSL instructions. These instructions
cause source data words from the core to be written to different memory locations in big and little
endian modes. For more information about the VSL instructions, refer to Table 2-27 on page 2-64,
and Appendix A, “Viterbi Shift Left Move (AGU) VSL,” on page A-422..
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Memory Interface
2.4.1.5 Instruction Word Transfers
Instruction words are transferred to the core from memory over the program data bus (PDB) to special
instruction registers in the program dispatch unit (PDU).
The instruction registers can be accessed only with aligned access of 128-bit width (8 instruction words).
Figure 2-24 shows the program memory organization in big and little endian modes. Note that program
data consists of a series of 16-bit instructions. In this example the assembler determines the instructions to
be:
word address $00 instruction $a0b0
word address $02 instruction $c0d0
word address $04 instruction $e0f0
word address $06 instruction $a1b1
word address $08 instruction $c1d1
word address $0a instruction $e1f1
word address $0c instruction $a2b2
word address $0e instruction $c2d2
word address $10 instruction $e2f2
.....
These are to be placed in memory as shown in the following figure.
Big Endian
0
1
a0b0
2
3
c0d0
4
5
e0f0
Little Endian
6
7
7
6
5
4
3
2
1
0
a1b1
0
a1b1
e0f0
c0d0
a0b0
0
c1d1
e1f1
a2b2
c2d2
8
c2d2
a2b2
e1f1
c1d1
8
e2f2
a3b3
c3d3
e3f3
16 ($10)
e3f3
c3d3
a3b3
e2f2
16 ($10)
24 ($18)
24 ($18)
Figure 2-24. Program Memory Organization in Big and Little Endian Modes
The assembler outputs a byte stream to the loader and therefore corrects for the byte address reversal inside
each 16-bit instruction to achieve the memory results above.
Big Endian Assembler OutputLittle Endian Assembler Output
byte address $00 data $a0byte address $00 data $b0
byte address $01 data $b0byte address $01 data $a0
byte address $02 data $c0byte address $02 data $d0
byte address $03 data $d0byte address $03 data $c0
byte address $04 data $e0byte address $04 data $f0
.....
.....
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Memory Interface
Figure 2-25 shows the memory accesses to the same memory area by both program fetches as well as data
accesses in big and little endian modes.
Memory
Big Endian
0
1
2
3
4
5
6
7
Little Endian
7
6
5
4
3
2
1
0
a0b0
c0d0
e0f0
a1b1
0
c1d1
e1f1
a2b2
c2d2
8
c2d2
a2b2
e1f1
c1d1
8
e2f2
a3b3
c3d3
e3f3
16 ($10)
e3f3
c3d3
a3b3
e2f2
16 ($10)
a1b1
e0f0
c0d0
a0b0
0
MOVE.4W from address $00
a1b1_e0f0_c0d0_a0b0
xxxx_xxxx_c1d1_e1f1
MOVE.L from address $08
xxxx_xxxx_e1f1_c1d1
xxxx_xxxx_xxxx_c1d1
MOVE.W from address $08
xxxx_xxxx_xxxx_c1d1
xxxx_xxxx_xxxx_xxc1
MOVE.B from address $08
xxxx_xxxx_xxxx_xxd1
128-bit P-BUS
FETCH (always 128 aligned) from address A0
Program Bus Contents (for both Endian cases)
Memory System Changes Big Endian to Little
c2d2_a2b2_e1f1_c1d1_a1b1_e0f0_c0d0_a0b0
64-bit XB-BUS
a0b0_c0d0_e0f0_a1b2
64-bit XA-BUS
Data Bus Contents
64-bit XB-BUS
Instructions
64-bit XA-BUS
Data Bus Contents
SC140 Core
Figure 2-25. Instruction Moves in Big and Little Endian Modes
The Program Bus contents always appear as eight 16-bit little endian packed instructions, the memory
system performing a word (instruction) reversal in the case of big endian (program bus only).
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Memory Interface
2.4.1.6 Memory Access Behavior in Big/Little Endian Modes
Table 2-27 shows the representation of the move instructions in big and little endian modes. In the
examples shown in this table, it is assumed that R0 points to address A0. Each alphanumeric A–H
represents one byte. Also, the memory contents may not exactly equal the register contents. For example,
in VSL instructions, the memory word (16 bits) is the register word shifted left by one bit. See Appendix A
for more detailed information.
Table 2-27. Move Instructions in Big and Little Endian Modes
Instruction
MOVE.B
MOVEU.B
Register Operands
Example: MOVE.B D0,(R0)
39
8
D0 =
MOVE.W
MOVEU.W
39
A
A0 = A
A0 = A
A1 = B
A0 = B
A1 = A
A0 = A
A1 = B
A2 = C
A3 = D
A0 = B
A1 = A
A2 = D
A3 = C
A0 = A
A1 = B
A2 = C
A3 = D
A4 = E
A5 = F
A6 = G
A7 = H
A0 = B
A1 = A
A2 = D
A3 = C
A4 = F
A5 = E
A6 = H
A7 = G
A0 = A
A1 = B
A2 = C
A3 = D
A0 = D
A1 = C
A2 = B
A3 = A
B
Example: MOVE.2W D0:D1, (R0)
16
0
D0 =
A
B
D1 =
C
D
Example: MOVE.4W D0:D1:D2:D3, (R0)
0
16
D0 =
A
B
D1 =
C
D
D2 =
E
F
D3 =
G
H
Example: MOVE.L D0, (R0)
39
D0 =
2-64
0
16
39
MOVE.L
MOVEU.L
MOVES.L
A0 = A
0
Example: MOVE.W D0, (R0)
39
MOVE.4W
Little
Endian
A
D0 =
MOVE.2W
Big Endian
32
0
A
B
C
D
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Memory Interface
Table 2-27. Move Instructions in Big and Little Endian Modes (Continued)
Instruction
Register Operands
MOVE.L
(Extension)
Example: MOVE.L D0.E:D1.E, (A0)
39
MOVE.2L
D0 = L0 +
A
D1 = L1 +
B
MOVE.4F
MOVES.4F
0
32
0
D0 =
A
B
C
D
D1 =
E
F
G
H
Example: MOVE.F D0, (R0)
39
32
D0 =
MOVE.2F
MOVES.2F
16
Example: MOVE.2L D0:D1, (R0)
39
MOVE.F
MOVES.F
32
16
A
0
32
16
D0 =
A
B
D1 =
C
D
0
Example: MOVE.4F D0:D1:D2:D3, (R0)
39
32
16
D0 =
A
B
D1 =
C
D
D2 =
E
F
D3 =
G
H
SC140 DSP Core Reference Manual
Little
Endian
A0 = L1
A1 = B1
A2 = L0
A3 = A1
A0 = A1
A1 = L0
A2 = B1
A3 = L1
A0 = A
A1 = B
A2 = C
A3 = D
A4 = E
A5 = F
A6 = G
A7 = H
A0 = D
A1 = C
A2 = B
A3 = A
A4 = H
A5 = G
A6 = F
A7 = E
A0 = A
A1 = B
A0 = B
A1 = A
A0 = A
A1 = B
A2 = C
A3 = D
A0 = B
A1 = A
A2 = D
A3 = C
A0 = A
A1 = B
A2 = C
A3 = D
A4 = E
A5 = F
A6 = G
A7 = H
A0 = B
A1 = A
A2 = D
A3 = C
A4 = F
A5 = E
A6 = H
A7 = G
B
Example: MOVE.2F D0:D1, (R0)
39
Big Endian
0
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Memory Interface
Table 2-27. Move Instructions in Big and Little Endian Modes (Continued)
Instruction
VSL.4W
16
A
B
D6 =
C
D
Note 1
E
F
Note 2
G
H
A0 = B
A1 = A
A2 = D
A3 = C
A4 = F
A5 = E
A6 = H
A7 = G
A0 = C
A1 = D
A2 = A
A3 = B
A4 = G
A5 = H
A6 = E
A7 = F
A0 = B
A1 = A
A2 = D
A3 = C
A4 = F
A5 = E
A6 = H
A7 = G
0
A0 = C
A1 = D
A2 = A
A3 = B
A0 = B
A1 = A
A2 = D
A3 = C
0
A0 = C
A1 = D
A2 = A
A3 = B
A0 = B
A1 = A
A2 = D
A3 = C
Example: VSL.4F D2:D6:D1:D3, (R0) + N0
32
16
D2 =
A
B
D6 =
C
D
Note 3
E
F
Note 4
G
H
0
Example: VSL.2W D1:D3, (R0) + N0
39
VSL.2F
A0 = C
A1 = D
A2 = A
A3 = B
A4 = G
A5 = H
A6 = E
A7 = F
0
D2 =
39
VSL.2W
Little
Endian
Example: VSL.4W D2:D6:D1:D3, (R0) + N0
39
VSL.4F
Big Endian
Register Operands
16
Note 1
A
B
Note 2
C
D
Example: VSL.2F D1:D3, (R0) + N0
39
32
16
Note 3
A
B
Note 4
C
D
Notes:
1. Data selected according to VF0 bit in SR, selects D3.l<<1 if VF0=1, D1.L<<1 if VF0=0
2. Data selected according to VF2 bit in SR, selects D3.l<<1 if VF2=1, D1.L<<1 if VF2=0
3. Data selected according to VF1 bit in SR, selects D3.H<<1 if VF1=1, D1.H<<1 if VF1=0
4. Data selected according to VF3 bit in SR, selects D3.H<<1 if VF3=1, D1.H<<1 if VF3=0
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Memory Interface
Table 2-28 shows the representation of the stack support instructions in big and little endian modes. In the
examples shown in this table, it is assumed that the stack access is to address A0. The stack instructions
treat the register data like a 32-bit long word move.
Table 2-28. Stack Support Instructions in Big and Little Endian Modes
Instruction
Register Operands
Single
POP
POPN
PUSH
PUSHN
Example: PUSH D0
Double
POP
POPN
PUSH
PUSHN
Example: PUSH D0 PUSH D1
31
D0 =
0
A
B
C
D
31
0
D0 =
A
B
C
D
D1 =
E
F
G
H
Big Endian
Little
Endian
A0 = A
A1 = B
A2 = C
A3 = D
A0 = D
A1 = C
A2 = B
A3 = A
A0 = A
A1 = B
A2 = C
A3 = D
A4 = E
A5 = F
A6 = G
A7 = H
A0 = D
A1 = C
A2 = B
A3 = A
A4 = H
A5 = G
A6 = F
A7 = E
Table 2-29 shows the representation of the bit mask instructions in big and little endian modes.
Table 2-29. Bit Mask Instructions in Big and Little Endian Modes
Instruction
BMCHG.W
BMCLR.W
BMSET.W
BMTSTS.W
BMTSTC.W
BMTSET.W
NOT.W
AND.W
OR.W
EOR.W
Register Operands
Example: BMSET.W #$1234, (A0)
15
0
Data =
A
B
Mask =
12
34
SC140 DSP Core Reference Manual
Big Endian
Little
Endian
A0 = A
A1 = B
A0 = B
A1 = A
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Memory Interface
Table 2-30 shows the representation of the change-of-flow instructions in big and little endian modes. In
this table, it is assumed that the stack access is to address A0. This shows how the contents of the PC and
SR are transferred to/from memory like 32-bit long words.
Table 2-30. Non-Loop Change-of-Flow Instructions in Big and Little Endian Modes
Instruction
Register Operands
BSR
BSRD
JSR
JSRD
RTE
RTED
31
RTS
RTSD
RTSTK
RTSTKD
0
PC =
A
B
C
D
SR =
E
F
G
H
31
PC =
0
A
B
C
D
Big
Endian
Little
Endian
A0 = A
A1 = B
A2 = C
A3 = D
A4 = E
A5 = F
A6 = G
A7 = H
A0 = D
A1 = C
A2 = B
A3 = A
A4 = H
A5 = G
A6 = F
A7 = E
A0 = A
A1 = B
A2 = C
A3 = D
A0 = D
A1 = C
A2 = B
A3 = A
Table 2-31 shows the representation of the control instructions in big and little endian modes. In this table,
it is assumed that the stack access is to address A0.
Table 2-31. Control Instructions in Big and Little Endian Modes
Instruction
Register Operands
TRAP
ILLEGAL
Interrupt Service
31
0
PC =
A
B
C
D
SR =
E
F
G
H
Big
Endian
Little
Endian
A0 = A
A1 = B
A2 = C
A3 = D
A4 = E
A5 = F
A6 = G
A7 = H
A0 = D
A1 = C
A2 = B
A3 = A
A4 = H
A5 = G
A6 = F
A7 = E
.
2-68
SC140 DSP Core Reference Manual
Chapter 3
Control Registers
This chapter describes the core control registers for the SC140 core.
Several bits in these registers are not used, and are marked as reserved. These bits are initialized with a
zero value and should be written with a zero value for future compatibility.
3.1 Core Control Registers
The SC140 programming model contains two 32-bit core control registers: a status register (SR) and an
exception and mode register (EMR). These registers include dedicated bits for reflecting and controlling
different operating modes of the core as well as various status flags.
3.1.1 Status Register (SR)
The SR contains 32 bits. It reflects and controls the following:
•
Core working mode ( Normal or Exception)
•
State of the four hardware loops and type of the currently executing loop
•
Current interrupt priority level (IPL) of the core
•
Overflow exceptions enabled or disabled
•
Interrupts enabled or disabled
•
Viterbi flags
•
Scaling, rounding, and arithmetic saturation modes
•
Numeric range of moved data after scaling
•
Result (true or false) of a condition test
•
Existence of a carry/borrow generated from the last addition/subtraction operation
•
Value of last shifted bit during a DALU shift operation
When a subroutine or exception is serviced, the status register is pushed onto the stack. The following
instructions implicitly push the SR onto the stack:
•
JSR/D
•
BSR/D
Any exception or interrupt implicitly pushes the SR onto the stack, including exceptions that are triggered
by the following instructions:
•
TRAP
SC140 DSP Core Reference Manual
3-1
Core Control Registers
•
ILLEGAL
•
DEBUG, DEBUGEV (if configured in the EOnCE to generate an exception)
The following instructions implicitly pop the SR from the stack:
•
RTE/D
Refer to Appendix A, “SC140 DSP Core Instruction Set,” for a full description of these instructions.
The pipeline imposes certain programming rules relating to the minimum distance between writing the SR
and when the change takes effect. For further details, refer to Chapter 7, “Programming Rules.”
Figure 3-1 shows the bits that make up the status register
.
BIT 31
30
29
28
27
26
25
SLF
LF3
LF2
LF1
LF0
TYPE
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
BIT 15
14
13
12
11
24
23
22
21
20
19
18
17
16
I2
I1
I0
OVE
DI
EXP
rw
rw
rw
rw
rw
rw
rw
rw
rw
0
0
1
1
1
0
0
1
0
0
10
9
8
7
6
5
4
3
2
1
BIT 0
VF3
VF2
VF1
VF0
S
S1
S0
RM
SM
T
C
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 3-1. Status Register -SR
Table 3-1 describes the various SR bits.
Table 3-1. Status Register Description
Name
Description
Settings
SLF
Bit 31
Short Loop Flag — Indicates (when set)
that the active loop is a short loop, which
means that it contains only one or two
execution sets.
At the start of an interrupt service routine
(ISR), the SR (including the SLF bit) is
pushed onto the software stack and the
SLF bit is cleared.
This bit is cleared at core reset.
0 = Active loop length is three or more execution sets
1 = Active loop length is one or two execution sets
LF3
Bit 30
Loop Flag 3 — Indicates (when set) that
hardware loop #4 is enabled. At the start
of an ISR, the SR (including the LF3 bit)
is pushed onto the software stack and
the LF3 bit is cleared.
This bit is cleared at core reset.
0 = Hardware loop #4 not enabled
1 = Hardware loop #4 enabled
3-2
SC140 DSP Core Reference Manual
Core Control Registers
Table 3-1. Status Register Description (Continued)
Name
Description
Settings
LF2
Bit 29
Loop Flag 2 — When set, indicates that
hardware loop #3 is enabled. At the start
of an ISR, the SR (including the LF2 bit)
is pushed onto the software stack and
the LF2 bit is cleared.
This bit is cleared at core reset.
0 = Hardware loop #3 not enabled
1 = Hardware loop #3 enabled
LF1
Bit 28
Loop Flag 1 — When set, indicates that
hardware loop #2 is enabled. At the start
of an ISR, the SR (including the LF1 bit)
is pushed onto the software stack and
the LF1 bit is cleared.
This bit is cleared at core reset.
0 = Hardware loop #2 not enabled
1 = Hardware loop #2 enabled
LF0
Bit 27
Loop Flag 0 — When set, indicates that
hardware loop #1 is enabled. At the start
of an ISR, the SR (including the LF0 bit)
is pushed onto the software stack and
the LF0 bit is cleared.
This bit is cleared at core reset.
0 = Hardware loop #1 not enabled
1 = Hardware loop #1 enabled
R
Bits
26–24
Reserved
I2–I0
Bits
23–21
Interrupt Mask Bits — Reflect the
current interrupt priority level (IPL) of the
core. Only non-maskable interrupts or
interrupts with an IPL higher than the
current interrupt mask value can
interrupt the core. The current IPL of the
core can be changed under software
control.
At the start of an ISR, the SR (including
the interrupt mask bits) is pushed onto
the software stack. The interrupt mask
bits are changed to the IPL of the
interrupt being serviced.
The interrupt mask bits are set at core
reset.
For a detailed description of interrupt
service, refer to Section 5.8, “Exception
Processing,” on page 5-46.
I2
I1
I0
Exceptions
Permitted
Exceptions
Masked
0
0
0
IPL 1–7
IPL 0
0
0
1
IPL 2–7
IPL 0–1
0
1
0
IPL 3–7
IPL 0–2
0
1
1
IPL 4–7
IPL 0–3
1
0
0
IPL 5–7
IPL 0–4
1
0
1
IPL 6–7
IPL 0–5
1
1
0
IPL 7
IPL 0–6
1
1
1
NMI
IPL 0–7
An IPL0 exception is always masked.
SC140 DSP Core Reference Manual
3-3
Core Control Registers
Table 3-1. Status Register Description (Continued)
Name
Description
Settings
OVE
Bit 20
Overflow Exception Enable Bit —
Enables or disables the generation of an
exception caused by an overflow. The
DOVF bit in EMR is always set when an
overflow occurs. If the OVE bit is set and
the DOVF bit is already set, no exception
is generated until the DOVF bit is cleared
and set again.
See Section 3.1.2, “Exception and Mode
Register (EMR),” for more information.
This bit is cleared at core reset.
0 = Overflow exception generation is disabled
1 = Overflow exception generation is enabled, unless DOVF
bit in EMR is already 1
DI
Bit 19
Disable Interrupts Bit — When this bit
is set, no maskable interrupts are
serviced, regardless of the IPL values,
which remain unchanged.
This bit can be set with the DI instruction,
which ensures that interrupts are
masked immediately, and can be cleared
with the EI instruction.
This bit is cleared at core reset.
0 = Interrupts enabled
1 = Interrupts disabled
EXP
Bit 18
Exception Mode Bit — Selects the
active stack pointer and working mode of
the core.
This bit is set at core reset.
0 = Normal working mode, active SP is NSP
1 = Exception working mode, active SP is ESP
R
Bits
17–12
Reserved
VF3–VF0
Bits 11–8
Viterbi Flags — Reflect the status of the
two parallel conditional transfers in the
MAX2VIT instruction. These flags are
generally used in conjunction with the
VSL instructions. Two Viterbi flags can
be independently set or cleared
according to the MAX2VIT result.
For more information, see MAX2VIT and
VSL in Appendix A, “SC140 DSP Core
Instruction Set.”
These bits are cleared at core reset.
R
Bit 7
Reserved
3-4
0 = Appropriate 16-bit portion transferred
1 = Appropriate 16-bit portion not transferred
SC140 DSP Core Reference Manual
Core Control Registers
Table 3-1. Status Register Description (Continued)
Name
Description
S
Bit 6
Scaling Bit — Set when moving a result
from a data register (D0–D15) to
memory using a MOVES (saturated
move) instruction. The scaling bit is set
when the absolute value of the data that
is moved to memory (after scaling and
limiting) is greater than or equal to 0.25
and less than 0.75.
The logical equations of this bit, if viewed
as functions of the data in the register,
are dependent on the scaling mode.
If limiting occurs during a data register
transfer to memory, the scaling bit is not
affected. This bit is a sticky bit and it
remains set until explicitly cleared.
This bit is cleared at core reset.
S1–S0
Bits 5–4
RM
Bit 3
Scaling Mode Bits — Specify the
scaling to be performed in the DALU
shifter/limiter as well as the rounding
position in the DALU MAC unit.
The shifter/limiter scaling mode affects
data read from the D0–D15 registers out
to the data memory bus using a MOVES
instruction. The scaling mode also
affects the calculation of the Ln bit for a
class of DALU instructions. See
Section 2.2.1.5, “Scaling,” and
Section 2.2.1.6, “Limiting,” for more
information.
The scaling mode also affects the MAC
rounding bit position. Correct rounding is
maintained when different portions of the
registers are read out to the data
memory buses. For more information,
see Section 2.2.2.6, “Rounding Modes.”
During arithmetic saturation mode, the
scaling bits are ignored for most DALU
instructions. See Section 2.2.2.7,
“Arithmetic Saturation Mode.”
These bits are cleared at the start of an
exception service routine as well as at
core reset.
Rounding Mode Bit — Selects the type
of rounding performed by the DALU
during arithmetic operations that involve
rounding. SeeSection 2.2.2.6, “Rounding
Modes.”
This bit is cleared at core reset.
SC140 DSP Core Reference Manual
Settings
S1
S0
Scaling
Mode
0
0
No scaling
S = (D30 XOR D29)
OR S (previous)
0
1
Scale down
S = (D31 XOR D30)
OR S (previous)
1
0
Scale up
S = (D29 XOR D28)
OR S (previous)
1
1
Reserved
S = Undefined
S Equation
S1
S0
Rounding
Bit
Scaling Mode
0
0
15
No scaling
0
1
16
Scale down
(1-bit Arithmetic Right
Shift)
1
0
14
Scale up
(1-bit Arithmetic Left Shift)
1
1
—
Reserved
0 = Convergent rounding selected
1 = Two’s complement rounding selected
3-5
Core Control Registers
Table 3-1. Status Register Description (Continued)
Name
Description
Settings
SM
Bit 2
Arithmetic Saturation Mode — Selects
automatic saturation on 32 bits for data
arithmetic and logic unit (DALU) results.
This bit provides an arithmetic saturation
mode for algorithms that do not
recognize or cannot take advantage of
the extension register. When the
arithmetic saturation mode is set, the
scaling mode bits are ignored for most
instructions. No scaling is performed.
Refer to Section 2.2.2.7, “Arithmetic
Saturation Mode,” on page 2-25, for
details of arithmetic saturation, including
the list of instructions affected by
arithmetic saturation with or without
scaling.
Each individual instruction in
Appendix A, “SC140 DSP Core
Instruction Set,” lists arithmetic
saturation as a condition, if appropriate.
This bit is cleared at core reset.
0 = Arithmetic saturation mode not selected
1 = Arithmetic saturation mode selected
T
Bit 1
True Bit — Indicates whether the
condition being tested by a compare or
test instruction is true or false.
The T-bit is affected by all instructions
that check a condition, such as CMPxx,
TSTxx, and BMTSTx. The BMTSET.W
instruction also sets this bit if a write to
memory fails. Conditional instructions
(such as JT, JF, BT, BF, IFT, and others)
test the T-bit, and execute accordingly.
This bit is cleared during core reset as
well as at the start of an exception
service routine.
0 = Condition tested by compare or test instruction is false
1 = Condition tested by compare or test instruction is true
3-6
SC140 DSP Core Reference Manual
Core Control Registers
Table 3-1. Status Register Description (Continued)
Name
Description
Settings
C
Bit 0
Carry Bit — Indicates whether a carry is
generated from the resulting most
significant bits (MSB) of the last addition
operation or a borrow generated in the
last subtraction operation. The carry or
borrow is generated from bit 39 of the
result. The carry bit is also affected by
DALU bit manipulation as well as rotate
and shift instructions. The carry bit
usually holds the value of the last shifted
bit.
If more than one instruction in an
execution set affects the carry bit
(according to the instruction definition),
then the carry bit is updated by the last
instruction (in assembly source order)
that actually executes, while the other
instructions do not affect the carry bit. If
no carry-affecting instructions execute,
the carry bit is not affected.
This bit is cleared during core reset as
well as at the start of an exception
service routine.
0 = No carry or borrow generated
1 = Carry generated from last addition, or borrow generated
from last subtraction
3.1.2 Exception and Mode Register (EMR)
The purpose of the EMR is to reflect and control exception situations in the core. EMR bits reflect memory
configuration as well as the servicing of non-maskable interrupts. EMR bits also reflect exception
conditions such as:
•
DALU overflow
•
EOnCE and software debugging access and control
•
Illegal execution set
•
Illegal instruction opcode
Figure 3-2 displays the bit configuration of the execution and mode register.
BIT 31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
GP6
GP5
GP4
GP3
GP2
GP1
GP0
BEM
TYPE
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
RESET
0
0
0
0
0
0
0
0
IO
IO
IO
IO
IO
IO
IO
IO
BIT 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
BIT 0
NMID
DOVF
ILST
ILIN
TYPE
r
r
r
r
r
r
r
r
r
r
r
r
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 3-2. Exception and Mode Register (EMR)
SC140 DSP Core Reference Manual
3-7
Core Control Registers
Table 3-2 describes the EMR fields.
Table 3-2. EMR Description
Name
Description
R
Bits 31–24
Reserved
GP6–GP0
Bits 23–17
General Purpose Flags — Use of these bits is
dependent on the state of external pins. Their
function is specific to the SoC.
BEM
Bit 16
Big Endian Memory Bit — Indicates big endian
or little endian memory configuration. See
Section 2.4.1, “SC140 Endian Support,” for more
information.
Settings
0 = Little endian configuration
1 = Big endian configuration
This bit is dependent on the state of an external
pin. This pin is sampled at core reset.
R
Bits 15–4
Reserved
NMID
Bit 3
Non-maskable Interrupt (NMI) Disable Bit —
Set when an NMI service routine enters execution
such as when the NMI vector is fetched. While this
bit is set, no pending NMI requests are serviced.
The bit is cleared by an RTE instruction, or by
writing back 1 to it as explained in Section 3.1.2.1,
“Clearing EMR Bits.”
0 = No NMI service executing
1 = NMI service executing
The NMI bit cannot be set by the user. It is cleared
at reset.
DOVF
Bit 2
3-8
DALU Overflow Bit — Indicates that an overflow
from 40 bits occurred during a DALU operation, or
that arithmetic saturation occurred in arithmetic
saturation mode (overflow from 32 bits).
Whenever there is an overflow, an exception is
generated if the OVE bit is set in the SR. Until the
bit is cleared, no new exceptions are generated.
The DOVF bit is a sticky bit. The bit is set if the
appropriate exception occurred. It can only be
cleared by writing back 1 to it as explained in
Section 3.1.2.1, “Clearing EMR Bits.”
The DOVF bit cannot be set by the user, only by
the hardware. It is cleared at reset.
If the OVE bit is set, the clearing operation should
only be performed during the overflow exception
service routine.
Due to pipeline effects, the overflow exception is
not serviced immediately after the instruction that
caused the overflow condition.
0 = No overflow or arithmetic saturation occurred
1 = Overflow or arithmetic saturation occurred
SC140 DSP Core Reference Manual
Core Control Registers
Table 3-2. EMR Description (Continued)
Name
Description
Settings
ILST
Bit 1
Illegal Execution Set — Indicates whether an
execution set grouping rule has been violated (for
example, more than one opcode dispatched to an
execution unit). The ILST bit is a sticky bit. The bit
is set if the appropriate exception occurred, and it
can only be cleared by the programmer. The
clearing operation should only be performed
during the illegal exception service routine. This
bit is cleared by writing back 1 to it as explained in
Section 3.1.2.1, “Clearing EMR Bits.”
0 = No execution set rule violated
1 = Execution set rule violated
Whenever an illegal set is detected, an illegal
exception is generated. The conditions that set
this bit when violated are listed in
Section 5.8.5.1.2, “Illegal Execution Set.”
ILST is cleared at reset.
ILIN
Bit 0
Illegal Instruction — Indicates that one or more
of the instruction opcodes received from program
memory are not in the SC140 instruction set.
“Holes” in operand tables are detected as illegal.
Both opcodes for instructions considered reserved
and holes in operand tables are determined to be
illegal. Whenever an illegal instruction is detected,
an illegal exception is generated.
0 = No instruction set violation
1 = One or more opcodes received are not part of
the SC140 instruction set
The ILIN bit is a sticky bit. It is set if the
appropriate exception occurred, and can only be
cleared by the user. The bit is cleared by writing
back 1 to it, as explained in Section 3.1.2.1,
“Clearing EMR Bits.” This clearing operation
should only be performed during the illegal
exception service routine.
ILIN is cleared at reset.
SC140 DSP Core Reference Manual
3-9
PLL and Clock Registers
3.1.2.1 Clearing EMR Bits
The ILIN, ILST, DOVF, and NMID bits can only be set by the hardware. These events should be regarded
as asynchronous to the program flow given the complex relationship between the events that set these bits
and the program flow. These bits are typically cleared by the SW during an exception service routine.
DOVF can be cleared outside of an exception service routine for polling usage.
As a programming guideline, the EMR bits should be cleared with great care, to ensure that no information
about new events is lost. An EMR bit is cleared by writing back 1 to it using the BMCLR instruction
typically inside an exception service routine. Example 3-1 illustrates the use of the BMCLR instruction in
the interrupt service routine of an overflow exception, which is activated when DOVF is set.
Example 3-1. Clearing an EMR Bit
BMCLR #$fffb,EMR.L
This instruction writes back a zero to every bit in EMR.L except for DOVF, which is written with the same
value it contained when it was read. Because DOVF was set to begin with, it is now cleared. Other bits set
in EMR.L are not affected. Due to this special behavior, the EMR should not be stored to the stack during
a context switch. This ensures that no bits are cleared unintentionally when the EMR is restored.
3.2 PLL and Clock Registers
The SC140 core provides a programming interface to an on-chip phase-locked loop (PLL). The core has
two registers that control settings for the PLL as well as clocks, named PCTL0 and PCTL1. The definition
and usage of these registers is chip specific. In systems where the PLL is controlled without these registers,
they cannot be used as general purpose registers.
3-10
SC140 DSP Core Reference Manual
Chapter 4
Emulation and Debug (EOnCE)
The SC140 core provides board and chip-level testing capability through two on-chip modules:
•
Enhanced on-chip emulation (EOnCE) module
•
Joint test action group (JTAG) test access module
These modules are accessed through the JTAG or EOnCE port.
The EOnCE module provides a means of non-intrusive interfacing with the SC140 core and its peripherals,
enabling users to examine registers, memory, or on-chip peripherals. Special circuits and dedicated signals
on the core are defined, which avoid sacrificing user-accessible on-chip resources. With respect to
developing applications for the SC140, the EOnCE provides application developers the following:
•
Breakpoints on address ranges
•
Breakpoints on data bus values
•
Detection of events, which can initiate a number of different actions determined by a developer
•
Non-destructive access to the core and its peripherals
•
Various means of profiling
•
Program tracing
4.1 Debugging System
With the JTAG or EOnCE interface, the user can insert the SC140 core into a target system while retaining
debug control. The EOnCE module is used in DSP devices that are based on the SC140 to debug
application software in real time. EOnCE is a separate on-chip block that allows non-intrusive interaction
with the core. It is accessible through the contents of the JTAG interface signals as well as from the
software. The EOnCE module makes it possible to examine the contents of registers, memory, or on-chip
peripherals in a special debug environment. This avoids sacrificing user-accessible on-chip resources to
perform debugging.
The EOnCE module provides system-level debugging for real-time systems with the ability to:
•
Maintain a running log and trace when tasks and interrupts are executed.
•
Debug the operation of real-time operating systems (RTOS).
SC140 DSP Core Reference Manual
4-1
Overview of the Combined JTAG and EOnCE Interface
In addition, the EOnCE:
•
Reduces system intrusion when debugging in real time.
•
Reduces the use of general-purpose peripherals for debugging I/O activities.
•
Standardizes the process of system-level debugging across multiple target platforms.
•
Provides a rich set of watchpoint features with real-time operation.
•
Provides non-intrusive access capability to peripheral registers (for read and write) while in debug
state.
•
Supports a trace buffer for program flow tracing.
•
Provides a programming model accessible during real time by either software or debugging system.
4.2 Overview of the Combined JTAG and EOnCE
Interface
The JTAG and EOnCE blocks are tightly coupled. All EOnCE registers are JTAG compliant. Three
different programming models are available when using the JTAG and EOnCE interface:
•
EOnCE programming model through a host on the JTAG port
•
EOnCE programming model through a host from the core software
•
JTAG programming model through a host on the JTAG port
Table 4-1 lists the JTAG or EOnCE interface signals.
Table 4-1. JTAG Interface Signal Descriptions
Signal Name
Signal Description
TDI
Test Data Input — Provides a serial input data stream to the JTAG and EOnCE module. It
is sampled on the rising edge of the test clock input (TCK), and has an on-chip pull-up
resistor.
TDO
Test Data Output — Provides a serial tri-state capable output data stream from the JTAG
and EOnCE modules. It is driven in the Shift-IR and Shift-DR controller states of the JTAG
state machine. The signal changes on the falling edge of TCK (see below).
TCK
Test Clock Input — Provides a gated clock to synchronize the test logic and shift serial
data to and from the JTAG or EOnCE module.
TMS
Test Mode Select Input — Sequences the JTAG controller's state machine. It is sampled
on the rising edge of TCK and has an on-chip pull-up resistor.
TRST
Test Reset
— Provides a reset signal to the JTAG TAP controller.
4.2.1 Cascading Multiple SC140 EOnCE Modules in a SoC
A typical SC140SoC uses the JTAG TAP controller for standard defined testing compatibilities and for
single/multi-core EOnCE control and EOnCE interconnection control. In a multi-core device the EOnCE
modules interconnect in a chain and are configured and controlled by the JTAG port (see Figure 4-1).
4-2
SC140 DSP Core Reference Manual
Overview of the Combined JTAG and EOnCE Interface
tdi
EOnCE1
EOnCE2
choose_tdi
EOnCEn-1
EOnCEn
choose_clock_dr
eonce_reset
tck
tdo
tdi
JTAG TAP Controller
Figure 4-1. JTAG and EOnCE Multi-core Interconnection
To access the EOnCE module of each of the cores through the JTAG port, it is important to know the
following:
•
The JTAG scan paths
•
The JTAG instructions
•
The EOnCE control register value
4.2.2 JTAG Scan Paths
The host controller communicates with SoC via the Test Access Port (TAP) controller using the following
scan paths:
•
Select-IR JTAG scan path. Used when the host sends the JTAG instructions shown in Table 4-2 to
the SoC.
•
Select-DR JTAG scan path. used for data transfer between the HOST and the SoC, which
corresponds to the current JTAG instruction exist in the Jtag IR register.
Table 4-2. JTAG Instructions
B4
B3
B2
B1
B0
Instruction
0
0
0
0
0
EXTEST
Selects the Boundary Scan Register. Forces a predictable internal
state while performing external boundary scan operations.
0
0
0
0
1
SAMPLE/PRELOAD
Selects the Boundary Scan Register. Provides a snapshot of
system data and control signals on the rising edge of TCK in the
Capture-DR controller state. Initializes the BSR output cells prior
to selection of EXTEST or CLAMP.
0
0
0
1
0
IDCODE
Selects the ID Register. Allows the manufacturer, part number
and version of a component to be identified.
0
0
0
1
1
CLAMP
Selects the Bypass Register. Allows signals driven from the
component pins to be determined from the Boundary Scan
Register.
SC140 DSP Core Reference Manual
Description
4-3
Overview of the Combined JTAG and EOnCE Interface
Table 4-2. JTAG Instructions (Continued)
B4
B3
B2
B1
B0
Instruction
Description
0
0
1
0
0
HIGHZ
Selects the Bypass Register. Disables all device output drivers
and forces the output to high impedance (tri-state) as per the
IEEE specification.
0
0
1
1
0
ENABLE_EONCE
Selects the EOnCE registers. Allows to perform system debug
functions. Before this instruction is selected, the
CHOOSE_EONCE instruction should be activated to define
which EOnCE is going to be activated.
0
0
1
1
1
DEBUG_REQUEST
Selects the EOnCE registers. Forces the chosen cores EOnCE
modules into Debug state or generate a Debug exception. Before
this instruction, the ENABLE_EONCE and the
CHOOSE_EONCE instructions should be performed.
0
1
0
0
0
RUNBIST
Selects the BIST registers. Allows you to generate a built-in
self-test for checking the system circuitry.
0
1
0
0
1
CHOOSE_EONCE
Selects the EOnCE registers. Allows to select EOnCE targets in
devices with multiple EOnCE modules. This instruction is
activated before the ENABLE_EONCE and
DEBUG_REQUEST instructions.
0
1
1
0
0
ENABLE_SCAN
Selects the DFT registers. Allows the DFT chain registers to be
loaded by a known value or examined in the Shift_DR controller
state.
0
1
1
0
1
LOAD_GPR
Allows the component manufacturer to gain access to test
features of the device.
0
1
1
1
0
LOAD_SPR
Allows the component manufacturer to gain access to test
features of the device.
1
1
1
1
1
BYPASS
Selects the Bypass register. Creates a shift register path from TDI
to the Bypass Register and to TDO. Enhances test efficiency
when a component other than the current device becomes the
device under test.
Figure 4-2 shows the TAP controller state machine, and Table 4-3 shows the states associated with each
scan path. The Test Mode Select (TMS) pin determines whether an instruction register scan or a data
register scan is performed.
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SC140 DSP Core Reference Manual
Overview of the Combined JTAG and EOnCE Interface
TMS=1
Test-Logic-Reset
TMS=0
TMS=0
TMS=1
TMS=1
Select-DR-Scan
Run-Test/Idle
TMS=0
TMS=1
TMS=0
TMS=1
Capture-DR
TMS=0
Capture-IR
TMS=0
TMS=0
Shift-DR
TMS=0
Shift-IR
TMS=1
TMS=1
Exit1-DR
Exit1-IR
TMS=0
TMS=0
TMS=0
Pause-DR
TMS=0
Pause-IR
TMS=1
TMS=1
TMS=0
TMS=1
Select-IR-Scan
Exit2-DR
TMS=1
TMS=0
TMS=1
Update-DR
TMS=1
Exit2-IR
TMS=1
TMS=1
Update-IR
TMS=1
TMS=0
TMS=0
Figure 4-2. TAP Controller State Machine
Table 4-3. JTAG Scan Paths
Select-DR Scan Path
Select-IR Scan Path
Select-DR_SCAN
Select-IR_SCAN
Capture-DR
Capture-IR
Shift-DR
Shift-IR
Exit1-DR
Exit1-IR
Update-DR
Update-IR
At power-up or during normal operation of the host, the TAP is forced into the Test-Logic-Reset state
when the TMS signal is driven high for five or more Test Clock (TCK) cycles.
When test access is required, TMS is set low to cause the TAP to exit the Test-Logic-Reset and move
through the appropriate states. From the Run-Test/Idle state, an instruction register scan or a data register
scan can be issued to transition through the appropriate states.
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Overview of the Combined JTAG and EOnCE Interface
The first action that occurs when either block is entered is a Capture operation. The Capture-DR state
captures the data into the selected serial data path, and the Capture-IR state captures status information into
the instruction register. The Exit state follows the Shift state when shifting of instructions or data is
complete. The Shift and Exit states follow the Capture state so that test data or status information can be
shifted out and new data shifted in. Registers in the selected scan path hold their present state during the
Capture and Shift operations. The Update state causes the registers to update with the new data that is
shifted into the selected scan path.
4.2.3 Activating the EOnCE Through the JTAG Port
Each of the on chip EOnCE modules has an interface to a JTAG port (via the TAP controller). The
interface is active even when a reset signal to the SC140 core is asserted. However, the system reset must
be de-asserted to allow proper interface with the cores. This interface is synchronized with internal clocks
derived from the JTAG TCK clock. Through the JTAG-EOnCE interface, the JTAG TAP controller can
perform the following actions:
•
Choose one or more EOnCE blocks (CHOOSE_EONCE instruction)
•
Issue a debug request to the EOnCE (DEBUG_REQUEST instruction)
•
Enable the chosen EOnCE modules.
•
Write an EOnCE command to the EOnCE Command Register.
•
Read and write internal EOnCE registers.
4.2.4 Enabling the EOnCE Module
The CHOOSE_EONCE mechanism allows integration of multiple SC140 cores and thus multiple EOnCE
modules on the same device. Using the CHOOSE_EONCE instruction, you can selectively activate one or
more of the EOnCE modules on the device. The EOnCE modules selected by the CHOOSE_EONCE
instruction are cascaded as shown in Figure 4-3. Only selected EOnCE modules respond to
ENABLE_EONCE and DEBUG_REQUEST instructions from the JTAG. In Motorola implementations, if
the DEBUG_REQUEST instruction is asserted during core reset, until reset de-assertion, all EOnCE
modules respond to the instruction and enter debug state when the core leaves reset. However, for driver
compatibility with non-Motorola implementations, the JTAG driver should perform CHOOSE_EONCE
also during reset for Motorola parts as well. The CHOOSE_EONCE instruction in this case will have no
effect. All EOnCE modules are deselected after reset. Since all the EOnCE modules are cascaded, the
selection procedure when not in reset is performed serially. The sequence is as follows:
1. Select the CHOOSE_EONCE instruction.
2. At Shift_DR state, enter the serial stream that specifies the modules to be selected.
The number of bits in the serial stream, that is, the number of clocks in this state, is equal to the
number of SC140 cores in the cascade. This state is indicated by the CHOOSE_CLOCK_DR signal.
To activate the n-th core in the cascade, which is the closest to TDO and the farthest from TDI, the
data is 1,0,0,0,...,0 (first a one, then n-1 zeros). If the data is 1,0,1,0,0....0 then both the n-th and the
n-2th cells are selected.
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SC140 DSP Core Reference Manual
Overview of the Combined JTAG and EOnCE Interface
SC140
CORE 1
CORE n
EOnCE
EOnCE
Choose
Choose
~
~
TDI
SC140
to TDO mux
JTAG
Controls
Figure 4-3. Cascading Multiple EOnCE Modules
4.2.5 DEBUG_REQUEST and ENABLE_EONCE Commands
After the CHOOSE_EONCE instruction completes, DEBUG_REQUEST and ENABLE_EONCE
instructions can be executed. More than one such instruction can execute, and other instructions can be
placed between them and also between them and the CHOOSE_EONCE instruction. The EOnCE modules
selected in the CHOOSE_EONCE instruction remain selected until the next CHOOSE_EONCE
instruction. The DEBUG_REQUEST or ENABLE_EONCE instruction is shifted in during the Shift-IR
state, as are all JTAG instructions.
4.2.6 Reading/Writing EOnCE Registers Through JTAG
An external host can read or write almost every EOnCE register through the JTAG interface, using the
following steps (see Figure 4-4):
1. Execute the CHOOSE_EONCE command in the JTAG.
2. Send the data showing which EOnCE is chosen. This command enables the JTAG to manage
multiple EOnCE modules in a device.
3. Execute the ENABLE_EONCE command in the JTAG.
4. Write the EOnCE command into the EOnCE Command register (ECR).
That is, the host enters the JTAG TAP state machine into the shift-dr state and then gives the required
command on the TDI input signal. After the command is shifted in, the JTAG TAP state machine
must enter the update-dr state. The data shifted via the TDI is sampled into the ECR. For example, if
the command written into the ECR is “Write EDCA0_CTRL,” then the host must again enter the
JTAG into shift-dr and shift the required data, which is to be written into the EDCA0_CTRL, via
TDI. If the command is “read some register,” then the DR chain must be passed again and the
contents of the register are shifted out through the TDO output.
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Overview of the Combined JTAG and EOnCE Interface
Execute CHOOSE_EONCE instruction in JTAG
Write JTAG data in order to choose the EOnCE
Execute ENABLE_EONCE instruction in JTAG
EOnCE is connected to the TDO.
EOnCE is ready to get command in ECR.
.
Write command into ECR register via shift-dr - update-dr
Bits 0-6 = offset of the chosen register.
Bits 7-8 = 00
Bit 9 = 0 when write command, and 1 when read command
The chosen register is selected.
Write/read data into the chosen register via shift-dr or update-dr.
The chosen register is written/read.
Figure 4-4. Reading and Writing EOnCE Registers Via JTAG
The SC140 EOnCE has several shift registers to interface with the JTAG controller, one shift register per
functional unit. Each such shift register is used to interface with all the EOnCE registers in that unit. The
length of the each shift register is therefore equal to the length of the longest register in that unit. The list of
registers and the shift length is listed in Table 4-12. Figure 4-5 describes how to access a register whose
length is shorter than the shift register’s length (8 bits versus 32 bits, in this example). In write operations,
the last bits to be shifted in the shift register are written to the EOnCE register, the rest have no effect. In
read operations, the first bits shifted out of the shift register hold the read data. The rest of the bits are read
as zeros.
This organization shortens the access time to the EOnCE registers if the access is only to those registers,
and no other devices on the JTAG chain are accessed on that transaction. In such a case, reads and writes
can be done only to the actual register length. In case other devices participate in the transaction, the full
shift register length should be used, using the convention outlined in Figure 4-5. From the IEEE 1149.1
standard point of view, some of the EOnCE registers have different “read” and “write” views.
4-8
SC140 DSP Core Reference Manual
Overview of the Combined JTAG and EOnCE Interface
(A) EOnCE register write operation through JTAG
7
0
EOnCE register
TDI
(relevant bits)
(don’t care bits)
TDO
internal shift register
(B) EOnCE register read (capture) operation through JTAG
23
0 7
EOnCE register
24 zeros
TDI
0
(bits captured as zero)
(relevant bits)
TDO
internal shift register
Figure 4-5. Accessing EOnCE registers through JTAG
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4-9
Main Capabilities of the EOnCE Module
4.3 Main Capabilities of the EOnCE Module
While the JTAG port provides board test capability, the EOnCE module provides emulation and debug
capability. The EOnCE module permits full-speed, real-time, and non-intrusive emulation for a target
system or a SC140 development board. This section describes the environment in which the EOnCE
module is used for debugging a real-time embedded application. Figure 4-6 shows a typical debug
environment where the core resides in a target DSP system.
Host
Computer
Target DSP
Memory
Debugging
Software
Control
Data
EOnCE
EE
Debugging
Hardware
7
SC140
Core
JTAG
Interface
TRST
TMS
TCK
TDO
TDI
EOnCE Signals
JTAG Signals
Figure 4-6. Typical Debugging System
4.3.1 EOnCE Signals
The JTAG signals TCK, TDI, and TDO are used to shift data and instructions in and out (see Table 4-1 on
page 4-2 for a description of the JTAG signals). For emulation of specific functions, six dedicated EOnCE
event signals (EE0–EE5) are available as well as one data event (EED) signal and two event counter (EC)
signals.
The two event counter signals EC0 and EC1 allow the event counter to count off-core events such as cache
hits/misses, memory contention, external wait-states, etc. These inputs are assumed synchronous to the
core clock and support a counting rate up to the core frequency. EC0 and EC1 use is derivative-dependent.
The EE signals can be connected to any on-chip peripheral block such as DMA or TIMER as well as
off-chip. This enables an external device to intervene asynchronously in the SC140 debugging process, or
to serve as an indication of the events occurring inside the DSP device. Some of these signals have
multiple functions programmed by the EE Signals Control Register (EE_CTRL). See Section 4.7.6, “EE
Signals,” for further information.
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Main Capabilities of the EOnCE Module
4.3.2 EOnCE Dedicated Instructions
The instruction set of the SC140 core architecture includes three instructions which are dedicated to the
EOnCE module and available for debugging purposes:
•
DEBUG — Upon decoding by the core, if the SDD bit in EMR is clear, the core enters the debug
processing state.
•
DEBUGEV — This instruction indicates to the EOnCE that a debug event has occurred. The
EOnCE handles the instruction according the settings of the event selector control registers.
•
MARK — Upon execution by the core when the TMARK bit in the TB_CTRL register is set, its
program counter (PC) value is put into the trace buffer. This enables it to mark the different parts of
application code that can be executed by different threads. See Section 4.11.1, “Trace Buffer Control
Register (TB_CTRL),” for further details.
4.3.3 Debug State
Debug state is a special core processing state in which the pipeline is stalled, waiting for commands from
the EOnCE through the JTAG port. All the execution units are ready to operate, but the PSEQ dispatcher
module does not dispatch any new execution sets to the execution units. Peripherals can include control
bits that determine whether they continue to operate in debug state.
Two actions are possible in debug state:
•
Execute a Single Step — The core leaves debug state for one cycle. The currently fetched
execution set is executed, after which the core then returns to debug state and the PSEQ proceeds to
the next execution set.
•
Insert an Instruction from the JTAG port or EOnCE — A MOVE, JMP, or BRA instruction can be
inserted and executed without the core leaving debug state.
The core can be put into debug state by a request from the EOnCE when:
•
The DEBUG instruction is issued.
•
The EE0 signal is asserted at the exit from reset.
•
The EE0 signal is asserted when configured as a debug request (default behavior).
•
The JTAG DEBUG_REQUEST instruction is issued at any time, including when the core is exiting
reset.
•
Assertion a debug request input, to be used for system requests. The usage of this input is SoC
specific.
•
The trace buffer is full and the TBFDM bit is set in the EOnCE monitor and control register
(EMCR).
•
The event selector (ES) is programmed to enter the core into debug state upon the detection of an
appropriate event.
When the EE0 signal causes the core to enter debug state, the signal must be asserted until the user receives
debug acknowledgement.
Asserting the EE0 pin or the JTAG DEBUG_REQUEST instruction signal during reset until getting debug
acknowledge will place the core into debug processing state before the first VLES fetch.
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Main Capabilities of the EOnCE Module
If the core is in execution state or in a power-saving state (stop or wait) when a debug request is issued, the
core enters debug state. In special cases where the core is frozen (for example, during external access) the
core enters debug state after restart of the core clock.
To exit debug state, set the EX bit in the EOnCE command register (ECR) by the EOnCE command
shifted through the JTAG port. See Section 4.7.1, “EOnCE Command Register (ECR),” for more details.
Debug state is also exited upon a reset.
4.3.4 Debug Exception
Debug exception is a non-maskable core exception, except for the action of the PICINT bit. The PICINT
bit in the EMCR register acts as a mode/state switch. If PICINT = 1, a debug event that would otherwise
have caused a debug exception asserts instead an EOnCE output to an off-core interrupt controller. If
PICINT = 0, the debug event generates a debug exception. This bit is for the use of the system engineer.
Exception vectors and priorities are described in Section 5.8, “Exception Processing,” on page 5-46.
Debug exceptions are generated upon the following:
•
The event selector (ES) is programmed to generate a debug exception when an appropriate event
occurs.
•
The ERCV register is written, and the RCVINT bit in the EMCR register is set.
•
The ETRSMT register is read by JTAG, and the TRSINT bit in the EMCR register is set.
•
The IME bit in the EMCR register is set, enabling any of the cases that cause the core to enter debug
state.
4.3.5 Executing an Instruction while in Debug State
When the core is in debug state, the host connected to the JTAG port can execute a subgroup of the SC140
instruction set in the core. This is done by eliminating the fetch and dispatch stages from the pipeline, and
performing only decoding and execution of the instruction directly by an AGU execution unit. The host
system writes an instruction to be executed into the core command register (CORE_CMD) together with
the GO command. For more information, see Section 4.7.1, “EOnCE Command Register (ECR).”
The subgroup of the instructions that can be executed includes:
•
All move instructions with all possible addressing modes
•
All types of jump and branch instructions with all possible addressing modes (with the exception of
delayed jumps and branches)
•
AGU arithmetic instructions
Changes in the state of the core resulting from executing instructions using EOnCE in debug state are the
same as when executing the same instructions using core software.
4.3.6 Software Downloading
The JTAG interface along with the EOnCE can be used to download a program into any core-addressable
memory. To do this, the CHOOSE_EONCE and DEBUG_REQUEST instructions must have already been
executed through the JTAG port, thereby enabling the EOnCE, entering the core into debug state.
Figure 4-7 shows a possible flow for software downloading.
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SC140 DSP Core Reference Manual
Main Capabilities of the EOnCE Module
Execute CHOOSE_EOnCE and DEBUG_REQUEST instructions using the JTAG port.
EOnCE is in debug state and ready to receive a command in the ECR register.
Write a command into the ECR register with the address of the ERCV register.
The ERCV register is selected.
Write the program data to be transferred into the
memory of the ERCV register.
The ERCV register is written with the program data.
Write a command into the ECR register with the address of the CORE_CMD register.
The CORE_CMD register is selected.
Write into the CORE_CMD register with a MOVE instruction from the ERCV
register to a core register.
The core register is written with the program data.
Write a command into the ECR register with the address of the CORE_CMD register.
The CORE_CMD register is selected.
Write into the CORE_CMD register with a MOVE instruction from the core
register to a memory location.
The memory location is written with the program data.
Figure 4-7. Software Downloading
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Main Capabilities of the EOnCE Module
4.3.7 EOnCE Events
An emulator event is an occurrence that the emulator can count or trace, or that can cause the emulator to
perform an action.
Examples: A core clock cycle is an example of an event because the emulator can count core clock cycles.
The execution of a DEBUGEV instruction is another example of an event because the emulator can
perform an action—such as placing the core in debug state—whenever the core executes a DEBUGEV
instruction.
Table 4-4 below lists EOnCE event types.
Table 4-4. EOnCE Event Types
Event type
DEBUG
DEBUGEV
JTAG
DEBUG_REQ
EE
Counter
The core executes a DEBUG instruction
The core executes a DEBUGEV instruction
execution of the DEBUG_REQUEST command from the host through the JTAG port
An EE signal (EE0–EE5 or EED) is asserted (when programmed as an input)
The 31-bit event counter reaches zero
EDCD
The data event-detection channel (EDCD) detects specified values on the data-memory
data buses
EDCA
An address event-detection channel (EDCA0–EDCA5) detects specified values on the
data-memory address buses or in the program counter
External EDCA
Trace Buffer Full
ERCV
ETRSMT
Data address detection events detected by two optional external EDCA channels
(EDCA6, EDCA7)
The trace buffer is full
The host writes the most-significant half of the ERCV register
The host reads the most-significant half of the ETRSMT register
VLES
The core executes a VLES
Clock
A new core clock cycle begins
Trace Transaction
The emulator writes a record to the trace buffer
EC
An EC signal (EC0 or EC1) is asserted
MARK
The core executes a MARK instruction
COF
4-14
Occurs when
A change of flow occurs during program execution
SC140 DSP Core Reference Manual
Main Capabilities of the EOnCE Module
4.3.8 EOnCE Actions
An emulator action is something that the EOnCE does as a result of an emulator event.
Example: Action Placing the core in debug state is an example of an action.
The EOnCE can perform the following actions:
•
Place the core in debug state.
•
Generate a debug exception or external interrupt request
•
Enable program tracing.
•
Disable program tracing.
•
Enable the counter.
•
Enable the EDCD.
•
Enable EDCAs.
4.3.9 Event and Action Summary
Table 4-5 summarizes the events and their possible actions they may cause, depending on the EOnCE
programming.
Table 4-5. EOnCE Event and Action Summary
Event type
Counted
trace
trigger
Debug
state
Debug
exception
Enable
tracing
Disable
tracing
DEBUG
-
-
+
+
-
-
DEBUGEV
+
-
+
+
+
+
JTAG
DEBUG_REQ
-
-
+
+
-
-
EE
-
-
+
+
+
+
Other actions
•
•
Controls when corresponding
EDCD and EDCAs are enabled
Enable the counter
Counter
-
-
+
+
+
+
•
•
Enable one or more EDCAs
Enable the EDCD
EDCD
+
-
+
+
+
+
•
•
•
Enable one or more EDCAs
Enable the counter
EDCA
+
-
+
+
+
+
•
•
•
Enable other EDCAs
Enable the EDCD
Enable the counter
External EDCA
+
-
+
+
+
+
•
•
•
Enable other EDCAs
Enable the EDCD
Enable the counter
Trace Buffer Full
-
-
+
+
-
-
ERCV
-
-
-
+
-
-
ETRSMT
-
-
-
+
-
-
VLES
+
+
-
-
-
-
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EOnCE Enabling and Power Considerations
Table 4-5. EOnCE Event and Action Summary
Event type
Counted
trace
trigger
Debug
state
Debug
exception
Enable
tracing
Disable
tracing
Clock
+
-
-
-
-
-
Trace Transaction
+
-
-
-
-
-
EC
+
-
-
-
-
-
MARK
-
+
-
-
-
-
COF
-
+
-
-
-
-
Other actions
4.4 EOnCE Enabling and Power Considerations
Except for the EOnCE controller, modules are disabled until one of the following occurs:
•
Write access is made to one of the EOnCE registers by the core software.
•
Execution of either ENABLE_EONCE or DEBUG_REQUEST instructions by the host
These events enable all the EOnCE modules, which will result in increased power consumption.
4.5 EOnCE Module Internal Architecture
The EOnCE module is composed of five main sub-units, which performs the following main tasks:
•
EOnCE Controller: Controls the overall behavior of the EOnCE and allows the JTAG port and core
software to read and write the EOnCE registers
•
Event Counter: Counts various events
•
Event Detection Unit (EDU): Generates events when it detects predefined values on
— the data-memory address buses
— the program counter
— the data-memory data buses
•
Event Selector: Controls what action is taken when events or a combination of simultaneous events
occurs
•
Trace Unit: Performs non-intrusive program tracing during program execution
The various EOnCE units include a number of registers. The units, the tasks they perform, and the
corresponding registers are described in the sections that follow.
4.5.1 EOnCE Controller
The EOnCE controller performs the following functions:
•
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Reading and writing EOnCE registers through JTAG
SC140 DSP Core Reference Manual
EOnCE Module Internal Architecture
•
Reading and writing EOnCE registers from the software
•
Real-time JTAG port access
•
Real-time data transfer
•
Executing instructions while in debug state
•
Samples core PC information in various states
Figure 4-8 displays the EOnCE controller block diagram.
TCK
Command Register
6
0
Address
TDI
Status Register
Monitor and Control Register
Address
Decoder
Control
Logic
Receive Register
Transmit Register
TDO
Update Signal from the TAP Controller
Figure 4-8. EOnCE Controller Block Diagram
The EOnCE controller register set is shown in Table 4-6.
Table 4-6. EOnCE Controller Register Set
Register Name
Description
ECR
EOnCE command register
ESR
EOnCE status register
EMCR
EOnCE monitor and control register
ERCV
EOnCE receive register
ETRSMT
EOnCE transmit register
EE_CTRL
EE signals control register
CORE_CMD
PC_EXCP
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EOnCE core command register
PC of the execution set causing illegal or overflow exception
4-17
EOnCE Module Internal Architecture
Table 4-6. EOnCE Controller Register Set
Register Name
Description
PC_NEXT
PC of the next execution set
PC_LAST
PC of the last execution set
PC_DETECT
PC breakpoint address register
The functionality of the EOnCE controller registers is described in Section 4.7, “EOnCE Controller
Registers.”
4.5.2 Event Counter
The 64-bit event counter is used to count one of the following possible events:
•
System clock
•
Instruction execution
•
Event detection by an event detection channel
•
Tracing into the trace buffer
•
Execution of the DEBUGEV instruction
•
Off-core events from the EC input signals
When the core is in debug state, the event counter does not count core clocks.
The event counter programming model includes three registers:
•
Event counter register (ECNT_CTRL)
•
Downcount event counter value register (ECNT_VAL)
•
Extension counter value register (ECNT_EXT)
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SC140 DSP Core Reference Manual
EOnCE Module Internal Architecture
Figure 4-9 shows a block diagram of the event counter.
Count Value
31-bit
Event
Counter
System Clock
Inst Execution
ECNT_VAL
Event0-5
EventD
Count Event
Count
Selector
Trace
DEBUGEV
EC0-1
External EDCA6,7 event
31-bit
Extension
Counter
Control Register
ECNT_CTRL
ECNT_EXT
Figure 4-9. Event Counter Block Diagram
ECNT_VAL and ECNT_EXT are 32-bit registers, but their values are limited to 31 bits; their MSB is
always zero. Their range is from zero to $7FFF FFFF. The counter counts down, while the extension
counter counts up. The event counter has two counting modes:
•
Single count: The counter counts down to zero, and then disables. Upon reaching zero, an EOnCE
event is generated (the outcome depends on the event selector).
•
Extended count: When the counter reaches zero, it wraps around to $7FFF FFFF and continues to
count. The extension counter is incremented. No EOnCE event is generated.
Table 4-7 shows the event counter register set.
Table 4-7. Event Counter Register Set
Register Name
ECNT_CTRL
Description
Event counter control register
ECNT_VAL
Event counter value register (32-bit)
ECNT_EXT
Extension counter value register (32-bit)
The functionality of the event counter registers is described in Section 4.8, “Event Counter Registers.”
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EOnCE Module Internal Architecture
4.5.3 Event Detection Unit (EDU)
The EOnCE EDU capabilities are:
•
Event detection on program and data memory address bus range or value
•
Event detection on data memory and data bus range or value
•
Detection of data written or read to/from a certain data memory address
•
Generating an EOnCE event upon event detection
The EOnCE EDU includes six instances of an Address Event Detection Channel (EDCA), one Data Event
Detection Channel (EDCD), and an event selector (ES). In addition, the EDU has an interface that supports
adding two additional EDCAs as external modules outside the EOnCE, thus enabling to expand the
EOnCE address detection capabilities.
The possible events generated by the EDU are:
•
Signal to the event selector (entry to debug state, debug exception, enable or disable tracing) - see
Section 4.5.4, “Event Selector (ES).”
•
Enable another EDCA or EDCD
•
Enable the counter
•
Generate a counter event
•
Toggle an EE pin (one EE pin assigned to each EDCA or EDCD)
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EOnCE Module Internal Architecture
In the case of read-modify-write commands, the EDU generates an event even if the read-modify-write
command failed. Figure 4-10 shows the event detection unit block diagram.
EED
EE[5..0]
PC, XABA, XABB
Address Buses
Data Buses
XDBxx
EDCA#0
EDCA#1
EDCA#2
EDCA#5
EDCD
EventD
Event0
Event1
Event2
Event5
Count event
from EDCA6,7 (ext.)
Event6,7 (external)
Count event (from Counter)
Debug State
Event
Selector
Debug Exceptio
Enable Trace
Disable Trace
Figure 4-10. Event Detection Unit Block Diagram
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EOnCE Module Internal Architecture
4.5.3.1 Address Event Detection Channel (EDCA)
One of the main elements of the EDU is the EDCA. An EDCA has all the logic required to detect address
values according to a user-programmable configuration.
There is no support for breakpoints on the PC of an instruction that is not the first instruction of the
execution set. All PC detections are done at execution set level.
XABB
XABA
PC
Figure 4-11 shows the EDCA block diagram.
EEi
MUX
Memory Bus and
Access Type Select
MASK Register
>=<
Comparator A
>=<
Reference Value Register A
Comparator B
Reference Value Register B
Event[i+1 mod 6]
Event[i+2 mod 6]
Event[i+3 mod 6]
Event[i+4 mod 6]
Event
Event[i+5 mod 6]
Selection
Eventi
External Event 6
External Event 7
EventD
Count Event
Control Register
Figure 4-11. EDCA Block Diagram
Two 32-bit comparators are used to compare the core address buses and the reference values programmed
into the reference value registers EDCAi _REFA and EDCAi _REFB. Each comparator is capable of
detecting one of the following four conditions:
•
Equal
•
Not equal
•
Less than
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EOnCE Module Internal Architecture
•
Greater than
Each EDCA includes four registers, as shown in Table 4-8.
Table 4-8. EDCA Register Set
Register Name
Description
EDCAi_CTRL
EDCA control register
EDCAi_REFA
EDCA reference value register A
EDCAi_REFB
EDCA reference value register B
EDCAi_MASK
EDCA mask register
The functionality of the EDCA registers is described in Section 4.9.1, “Address Event Detection Channel
(EDCA).”
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EOnCE Module Internal Architecture
4.5.3.2 Data Event Detection Channel (EDCD)
The EDCD is one of the main elements of the EDU. It has all the logic required to detect data values
according to a user-programmable configuration.
XDBAR
XDBAW
XDBBR
XDBBW
Figure 4-12 shows the EDCD block diagram.
MUX
Access Type Select
EED
Event 0..5
EDCD MASK Register
External Event 6,7
Count Event
Two Comparators
EventD
Reference Value Register
Control Register
Figure 4-12. EDCD Block Diagram
The EDCD register set is shown below.
Table 4-9. EDCD Register Set
Register Name
Description
EDCD_CTRL
EDCD control register
EDCD_MASK
EDCD mask register
EDCD_REF
EDCD reference value register
The functionality of the EDCD registers is described in Section 4.9.2, “Data Event Detection Channel
(EDCD).”
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EOnCE Module Internal Architecture
4.5.3.3 Optional External Event Detection Address Channels
The EDU has two ports to optional external event detection channels named EDCA6 and EDCA7. If
needed, the system designer may add additional event detection capabilities to the EOnCE using these
ports. These outcomes of EDCA6/7 events could include the following:
— Placing the core in debug state
— Generating a core debug exception
— Enabling the trace logic
— Disabling the trace logic
— Generating a counter event
— Combinations with other events in the event selector
— Setting the debug reason bits in ESR and the event status bits in EMCR
EDCA6 and EDCA7 do not have an EE pin associated with them.
4.5.4 Event Selector (ES)
The ES selects the source for various debugging operations. The possible sources that can be selected are:
•
Outputs of EDCA instances
•
Outputs of optional external EDCA events
•
Output of the EDCD
•
Output of the event counter
•
EE signals
•
DEBUGEV instruction
Each of these source events could be programmed1 in the event selector to cause some or all of the
following actions:
•
Entry into Debug state
•
Execution of a Debug exception
•
Enable or disable program tracing
1. They can be programmed individually or combined with other simultaneous events
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EOnCE Module Internal Architecture
Event0..Event5
External Event6, Event7
EventD
Count event
Debug State
Debug Exception
Enable Trace
Disable Trace
DEBUGEV
EE[4:0]
ES
The ES block diagram is shown in Figure 4-13.
Figure 4-13. Event Selector Block Diagram
The ES can be used to detect reading or writing data from/to a certain data address by using the EDCD to
detect the data, an EDCA to detect the address (on XABA, XABB, or both), and the ES to generate an
EOnCE event if both events occur. In this case, when both EDCA and EDCD events are selected, only
address and data values on the same bus (A or B) can cause an EOnCE event.
Table 4-10 shows the register set of the ES.
Table 4-10. Event Selector Register Set
Register Name
ESEL_CTRL
Description
ES control register
ESEL_DM
ES mask debug state register
ESEL_DI
ES mask debug exception register
ESEL_ETB
ES mask enable trace register
ESEL_DTB
ES mask disable trace register
The functionality of the event selector registers is described in Section 4.10, “Event Selector (ES)
Registers.”
4.5.5 Trace Unit
The trace unit is used to store information about a running application without halting its execution. The
user can select the addresses to be stored in the trace unit from a wide selection that includes:
•
Change-of-flow instructions
— All Change-of-flow instructions
— Call/return from subroutine instructions
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EOnCE Module Internal Architecture
— Return from exception instructions
•
Other change of flow events:
— Interrupts
— Hardware loops
•
Any execution set
•
Mark instructions
For each change-of-flow event, a package of information is stored in the trace buffer, including the PC of
the source, the PC of the destination, and, optionally, the value of the event counter and the counter
extension.
The EOnCE trace unit:
•
Supports a circular hardware trace buffer external to the core. Each entry is 32-bit long. The number
of entries is derivative-specific.
•
Traces change-of-flow instructions, normal execution, hardware loops, and interrupts.
•
Operates during real-time processing.
•
Can be read by the debugging hardware during execution state as well as debug state when the trace
buffer is disabled.
The trace buffer can be enabled by the host, core software, or by an EOnCE event generated by various ES
configurations.
The following addresses can be traced:
•
The PC of an execution set containing a taken change-of-flow instruction, followed by its target
address.
•
The PC of the last execution set executed before servicing an interrupt, followed by the address of
the interrupt. See more on interrupt tracing in Section 4.5.5.1, “Change of Flow and Interrupt
Tracing,” )
•
The PC of every execution set issued.
•
The last address for short hardware loops and the last address followed by the start address for long
hardware loops.
•
The PC of each execution set that includes the MARK instruction.
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EOnCE Module Internal Architecture
Figure 4-14 displays a block diagram of the trace unit.
Trace Unit
Trace Unit
PC
Controller
Hardware Loops
MARK
Change of Flow
Interrupts
Normal Execution Set
Enable Trace
Control Register
Read Pointer
Disable Trace
Strobes
Data
Address
Write Pointer
Trace Buffer (TB)
Off-Core
Figure 4-14. Trace Unit Block Diagram
4.5.5.1 Change of Flow and Interrupt Tracing
The trace logic can be configured to trace change of flow instructions. Upon execution of such an
instruction, the source and destination addresses of the change of flow event are traced. In case of a
delayed change of flow instruction, the source address is also that of the change of flow instruction.
The following change of flow instructions are those that can be traced:
— BT, BF, BTD, BFD
— BRA, BRAD
— JMP JMPD
— JT, JF, JTD, JFD
— JSR, JSRD
— BSR, BSRD
— RTS, RTSD
— RTSTK, RTSTKD
— RTE, RTED
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EOnCE Module Internal Architecture
— BREAK
— CONT, CONTD
— SKIPLS
Note that TRAP, and ILLEGAL are traced as interrupts, not as change of flow instructions.
When tracing interrupts, a source destination address pair is also traced. The source address normally
reflects the PC of the last executed execution set, and the destination address reflects the PC of the
interrupt vector.
There is one exception to this rule: If the interrupt occurred while the core is executing certain instructions
(mainly change of flow instructions), it may be that the PC of the execution set including this instruction is
traced although not actually executed. This situation is termed “PC KILL”. The debugger SW can identify
this case by noting that the return PC upon returning from the exception is that of the killed PC and not that
of the following execution set.
4.5.5.2 Writing to the Trace Buffer
The trace buffer is a circular buffer. A write pointer (TB_WR) points to the next free location. The pointer
is incremented circularly after every trace, and cleared whenever the trace buffer is enabled.
A flag is set every time the trace buffer is full. The flag is cleared whenever the trace buffer is enabled.
4.5.5.3 Reading the Trace Buffer (TB_BUFF)
The content of the trace buffer is read either through the JTAG interface or from software using the
location pointed to by the TB_RD register. The TB_RD pointer is incremented after every read access to
the trace buffer, and is cleared when the trace buffer is enabled.
Due to a pre-fetch mechanism, when the user reads the location pointed to by the TB_RD register (by
reading the TB_BUFF register), the TB_RD pointer is already three stages ahead. As a result of this
pre-fetch mechanism, there is a restriction on reading the trace buffer. A three clock cycle delay must take
place from disabling the trace buffer or writing to the read pointer until the first read access is issued to the
trace buffer.
The TBFULL bit in the ESR indicates that the buffer is full, and that the contents of the trace buffer should
be read. The TBFULL bit of the ESR is set when entry size minus 15 is written. When it reaches the end of
the memory, the trace buffer wraps around to address zero and continues until stopped. See the description
of the TBFULL bit in Section 4.7.2, “EOnCE Status Register (ESR).”
If the TBFDM in the EMCR is set, and TBFULL is being set, a debug event is generated. If the IME bit in
EMCR is clear then the core enters into debug state. If the IME bit is set, a debug exception is generated.
This exeption can be used by a software routine to empty the trace buffer to an external memory or device.
See Section 4.7.3, “EOnCE Monitor and Control Register (EMCR),” and Section 4.6.1, “Reading or
Writing EOnCE Registers Using Core Software,” for further details.
4.5.5.4 Trace Unit Programming Model
The trace unit contains the following registers, as shown in Table 4-11.
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EOnCE Register Addressing
Table 4-11. Trace Buffer Register Set
Register Name
TB_CTRL
Description
Trace buffer control register
TB_RD
Trace buffer read pointer register
TB_WR
Trace buffer write pointer register
TB_BUFF
Trace buffer virtual register
The functionality of the trace unit registers is described in Section 4.11, “Trace Unit Registers.”
4.6 EOnCE Register Addressing
The various units described above use a large number of registers. The EOnCE registers can be read or
written when the core is running, or when the core is in debug state.
All the EOnCE registers accessible from the core (either for read or write operations) are memory mapped.
This means that each register has its own address in the memory space. The memory address of an EOnCE
register is defined by adding four times the register address offset from Table 4-12 on page 4-31 to the
EOnCE register base address defined for each SoC derivative. For example, the memory address for the
LSB part of register ERCV is $8 + rba_via, where rba_via is the derivative dependent register base
address.
Most EOnCE memory-mapped registers allow only 32-bit accesses except the status, monitor, and control
registers (ESR, EMCR, EE_CTRL, EDCA[0-5]_CTRL, EDCD_CTRL, ECNT_CTRL, ESEL_CTRL, and
TB_CTRL). The latter support 16-bit accesses, which enable the use of bit-mask operations. There is only
one access per execution set for all EOnCE registers. When a 16-bit access is used on the 32-bit long ESR
and EMCR registers, the software address offset to the MSB part of the registers is equal to the software
address offset of the LSB part + 2.
Registers longer than 32 bits are accessed as two registers.
As described in Section 4.2.6, “Reading/Writing EOnCE Registers Through JTAG,” each EOnCE unit has
a shift register supporting the EOnCE registers of this unit. In some cases, the “shift width” of the EOnCE
register is longer than its actual width.
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EOnCE Register Addressing
Table 4-12 displays the EOnCE register addressing offsets.
Table 4-12. EOnCE Register Addressing Offsets
EOnCE
Register
Offset
Software
Access
Width
Shift
width
00
R
32
01
R/W
02
R
03
R
04
W
05
W
06
R/W
16
64
EE_CTRL
EE signals control register
07
R
32
32
PC_EXCP
PC of VLES causing Illegal or Overflow
exception
08
NO
32
32
PC_NEXT
PC of next execution set
09
NO
32
32
PC_LAST
PC of last execution set
0A
R
32
32
PC_DETECT
PC breakpoint detection register
..........
..........
10
R/W
16
32
EDCA0_CTRL
EDCA0 control register
11
R/W
16
32
EDCA1_CTRL
EDCA1 control register
12
R/W
16
32
EDCA2_CTRL
EDCA2 control register
13
R/W
16
32
EDCA3_CTRL
EDCA3 control register
14
R/W
16
32
EDCA4_CTRL
EDCA4 control register
15
R/W
16
32
EDCA5_CTRL
EDCA5 control register
Register Name
Description
64
ESR
EOnCE status register
32
64
EMCR
Monitor and control register
64
64
ERCV
EOnCE receive register - least significant
part
EOnCE receive register - most significant
part
64
64
ETRSMT
EOnCE transmit register - least
significant part
EOnCE transmit register - most
significant part
Reserved addresses
16
Reserved address
17
Reserved address
..........
18
R/W
32
32
EDCA0_REFA
EDCA0 reference value A
19
R/W
32
32
EDCA1_REFA
EDCA1 reference value A
1A
R/W
32
32
EDCA2_REFA
EDCA2 reference value A
1B
R/W
32
32
EDCA3_REFA
EDCA3 reference value A
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EOnCE Register Addressing
Table 4-12. EOnCE Register Addressing Offsets (Continued)
EOnCE
Register
Offset
Software
Access
Width
Shift
width
Register Name
Description
1C
R/W
32
32
EDCA4_REFA
EDCA4 reference value A
1D
R/W
32
32
EDCA5_REFA
EDCA5 reference value A
1E
Reserved Address
1F
Reserved Address
20
R/W
32
32
EDCA0_REFB
EDCA0 reference value B
21
R/W
32
32
EDCA1_REFB
EDCA1 reference value B
22
R/W
32
32
EDCA2_REFB
EDCA2 reference value B
23
R/W
32
32
EDCA3_REFB
EDCA3 reference value B
24
R/W
32
32
EDCA4_REFB
EDCA4 reference value B
25
R/W
32
32
EDCA5_REFB
EDCA5 reference value B
..........
..........
30
R/W
32
32
EDCA0_MASK
EDCA0 mask register
31
R/W
32
32
EDCA1_MASK
EDCA1 mask register
32
R/W
32
32
EDCA2_MASK
EDCA2 mask register
33
R/W
32
32
EDCA3_MASK
EDCA3 mask register
34
R/W
32
32
EDCA4_MASK
EDCA4 mask register
35
R/W
32
32
EDCA5_MASK
EDCA5 mask register
Reserved addresses
36
Reserved address
37
Reserved address
..........
38
R/W
16
32
EDCD_CTRL
EDCD control register
39
R/W
32
32
EDCD_REF
EDCD reference value
3A
R/W
32
32
EDCD_MASK
EDCD mask register
..........
..........
40
R/W
16
32
ECNT_CTRL
Counter control register
41
R/W
32
32
ECNT_VAL
Counter value register
42
R/W
32
32
ECNT_EXT
Extension counter value
..........
..........
48
R/W
4-32
Reserved addresses
Reserved addresses
8
16
ESEL_CTRL
..........
..........
Selector control register
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EOnCE Register Addressing
Table 4-12. EOnCE Register Addressing Offsets (Continued)
EOnCE
Register
Offset
Software
Access
Width
Shift
width
49
R/W
16
4A
R/W
16
Register Name
Description
16
ESEL_DM
Selector DM mask
16
ESEL_DI
Selector DI mask
4B
Reserved address
4C
R/W
16
16
ESEL_ETB
Selector enable TB mask
4D
R/W
16
16
ESEL_DTB
Selector disable TB mask
4E
Reserved address
4F
Reserved address
50
R/W
16
32
TB_CTRL
Trace buffer control register
51
R/W
16
32
TB_RD
Trace buffer read pointer
52
R/W
16
32
TB_WR
Trace buffer write pointer
53
R
32
32
TB_BUFF
Trace buffer
..........
..........
7E
NO
7F
NO
Reserved addresses
48
48
CORE_CMD
Core command register
NOREG
No register selected
4.6.1 Reading or Writing EOnCE Registers Using Core
Software
The core can read or write most EOnCE registers from the software. Software access can be disabled by
the SWDIS bit in the EMCR register. For more information, see Section 4.7.3, “EOnCE Monitor and
Control Register (EMCR).”
In cases where the core is being accessed by the software and the JTAG port at the same time, the JTAG
access has priority over the software access.
4.6.2 Real-Time JTAG Access
The EOnCE registers could be read or written to by the host through the JTAG port, as described in
Section 4.2.6, “Reading/Writing EOnCE Registers Through JTAG.”
When the core is not in debug state and the host is accessing the EOnCE registers from the JTAG port,
there is a possibility that an EOnCE command may be lost due to a long core stall. To ensure correct
execution of a command, the user should read a special ACK bit by shifting out the JTAG IR register
together with the core status bits. If the bit is set, this indicates that the last EOnCE command was
successfully executed. This bit is reset each time a new command is shifted from the JTAG port to the
EOnCE.
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EOnCE Register Addressing
The ACK bit could be checked on TDO by executing a “neutral” JTAG EOnCE command such as
“ENABLE_EONCE”. Only after it was verified with the ACK bit that the previous access was accepted by
the core, the next register could be accessed. This check should be performed also for accessing the ECR.
4.6.3 Real-Time Data Transfer
The EOnCE controller enables the core software to transmit data from the core to the host as well as to
receive data sent from the host to the core. This is done by means of a simple receive or transmit
mechanism while the core is running.
For transmitting data to the host, the core writes to the transmit register ETRSMT by means of a move
instruction using the memory-mapped address of the ETRSMT register. The TRSMT status bit in the ESR
is asserted by the EOnCE (see Section 4.7.2, “EOnCE Status Register (ESR),” for more details). The host
can poll the TRSMT status bit to see when the data in the ETRSMT register is available. Or alternatively,
the host can program the EE4 signal to reflect this status bit externally for interrupt-like transfers, and then
read the ETRSMT through TDO using the mechanism described in Section 4.7.1, “EOnCE Command
Register (ECR).” The TRSMT bit is cleared by the EOnCE automatically after the ETRSMT register is
read by the host. A debug exception can be generated to notify the core that the register can be written
again.
The ERCV register can be used for receiving data from the host. The host writes to the ERCV register
through the TDI input signal. The EOnCE automatically sets the status bit RCV in the ESR. For more
information, see Section 4.7.2, “EOnCE Status Register (ESR).” This bit can be polled by the core to see
when the data is ready in the ERCV register, or the application can configure EOnCE to generate a debug
exception when the data is ready in the ERCV register. See Section 4.7.4, “EOnCE Receive Register
(ERCV),” for more information. The RCV bit is automatically cleared by the EOnCE after the ERCV
register is read by the core.
4.6.4 General EOnCE Register Issues
During core reset, the following takes place:
•
The selector mask registers are written with zeros.
•
All others mask registers are written with ones.
•
The EE_CTRL register is written with ones.
•
All the remaining registers in the EOnCE programming model are written with zeros.
Only one EOnCE register could be accessed per VLES. It is not allowed to group together a read access
from the EOnCE in parallel with an instruction that performs a memory write.
Reserved or unused bits in all registers should be written as zero and the read value should be masked.
Writing to unimplemented registers has no effect in the current implementation, but should be avoided for
future software compatibility. Reading from unimplemented or write-only registers as well as reading the
most significant bits (MSBs) of an 8-bit or 16-bit register with a 32-bit MOVE instruction are both illegal
and produces undefined results.
Software write access is possible only if the SWDIS bit in the EMCR register is cleared. The only
exception is the ETRSMT register that can always be written by software. When the SWDIS bit is set,
read-only access is enabled except reading from the trace buffer.
If the software writes and then reads a given EOnCE register, a NOP or other instruction must be inserted
before the read instruction in order to read back the value just written.
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EOnCE Register Addressing
Accessibility of the registers through JTAG is the same as from software with the following exceptions:
•
The ETRSMT register is only readable only using the JTAG port.
•
The ERCV registers are only writable using the JTAG port.
•
PC_LAST and PC_NEXT can only be read by the JTAG port.
•
The CORE_CMD register can only be written by the JTAG port in debug state.
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EOnCE Controller Registers
4.7 EOnCE Controller Registers
A list of the EOnCE controller registers is given in Table 4-6 on page 4-17. The sections that follow
describe these registers.
4.7.1 EOnCE Command Register (ECR)
The ECR is a write-only 16-bit shift register that receives its serial data from the TDI input signal. This
register is accessed only using JTAG.
Figure 4-15 displays the bit configuration of the ECR.
BIT 15
14
13
12
11
10
9
8
7
R/W
GO
EX
6
5
4
3
2
1
BIT 0
REGSEL
TYPE
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The shaded bits are reserved and should be initialized with zeros for future software compatibility.
Figure 4-15. EOnCE Command Register (ECR)
Table 4-13 describes the ECR fields.
Table 4-13. ECR Description
Name
Description
R
Bits 15-10
Reserved
R/W
Bit 9
Read/Write Command — Specifies the
direction of data transfer.
4-36
Settings
0 = Write the data associated with the command into
the register specified by REGSEL.
1 = Read the data contained in the register specified
by REGSEL.
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EOnCE Controller Registers
Table 4-13. ECR Description (Continued)
Name
Description
Settings
GO
Bit 8
Go Command — If this bit is set, there are
two possible modes of execution:
• When used together with writing or
reading a register (except for
CORE_CMD), this register is first written
or read, and then the next instruction in
the pipeline is executed. When used
together with the NOREG register, only
the next instruction in the pipeline is
executed. In this single-step mode, the
core leaves debug state for one
instruction cycle in order to execute the
instruction. If the EX bit is also set, the
core continues normal operation after
executing the instruction.
• When used together with writing to the
CORE_CMD register, the instruction
written to the CORE_CMD register is
executed, and the core remains in debug
state. If the EX bit is set as well, debug
state is exited after the instruction is
executed.
0 = Inactive (no action taken)
1 = Execute one instruction
EX
Bit 7
Exit Command — If this bit is set, then after
executing any associated write or read
command, the core leaves debug state and
resumes normal operation. When used
together with the write or read NOREG
command, the exit command is executed
without writing or reading any register.
0 = Remain in debug state.
1 = Exit debug state.
REGSEL
Bits 6–0
Register Select — Define which register is
the source or destination for the read or write
operation. See Table 4-12 on page 4-31 for
the EOnCE register offsets.
4.7.2 EOnCE Status Register (ESR)
The ESR is a 32-bit register. The status bits of the register indicate the status of the core as well as the
reason for entering debug state or for issuing a debug exception. All bits are read-only.
Debug reason bits are set to show what caused the core to enter debug state or execute a debug exception.
These bits are reset when the core leaves debug state or if the DIS bit in EMCR is reset by an interrupt
service routine. After entering debug state, the appropriate bit is set when a new event occurs that could
cause the core to enter debug state.
Figure 4-16 displays the bit configuration of the ESR.
BIT 31
30
29
CORES
28
27
PCKILL RCV
26
25
24
23
TRSMT TBFULL NOCHOF
22
21
20
19
REVNO
18
17
CORETP
16
DRTBFULL
TYPE
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
RESET
0
0
0
0
0
0
0
0
x
x
x
0
x
x
x
0
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EOnCE Controller Registers
BIT 15
DRSW
14
13
12
11
10
9
8
7
6
5
4
3
2
1
BIT 0
DREE DREE DREE DREE DREE DRCOUNDRED DRED DRED DRED DRED DRED DRED DRED
DREDCD
4
3
2
1
0
TER
CA7
CA6
CA5
CA4
CA3
CA2
CA1
CA0
TYPE
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The shaded bits are reserved and should be initialized with zeros for future software compatibility. The
reset values for REVNO and CORETP (shown as x) are derivative-dependent.
Figure 4-16. EOnCE Status Register (ESR)
Table 4-14 describes the ESR fields.
Table 4-14. ESR Description
Name
Description
CORES
Bits 31-30
Core Status — Provides core status information. Indicates whether the core has
entered debug state and the reason. These bits are also reflected in the JTAG
instruction shift register, which allows for the polling of core status information at
the JTAG level. This is useful in case the core software executes a STOP
instruction so there are no clocks for reading the core status. The settings for these
bits are as follows:
• 00 = Core is executing instructions.
• 01 = Core is in wait or stop mode.
• 10 = Core is waiting for a bus.
• 11 = Core is in debug state.
The “waiting for a bus” state indicates that the core is waiting for data on the bus to
be transferred, or that the core is disabled by the external system (for example
during memory BIST).
The core could be waiting for a bus in any of the processing states. In such a case
the CORES field will show “waiting for a bus”.
R
Bit 29
Reserved
PCKILL
Bit 28
PC Killed — This bit signifies that the last executed VLES was aborted by a
pending exception. It is set by the EOnCE when the last execution set has been
aborted, and cleared when starting to perform the next single step. This bit is valid
only in debug state, and is useful particularly while single stepping.
RCV
Bit 27
Receive — Set by the EOnCE when the host has finished writing to the ERCV
register. The bit is cleared by EOnCE when both halves of the ERCV register
contents are read by the core. The two halves are read in a specific order with the
LSB read first. The RCV bit is cleared when the MSB has been read without
checking if the LSB part has been read.
TRSMT
Bit 26
Transmit — Set by the EOnCE when both halves of the ETSMT register are
written by the core. The two halves are written in a specific order with the LSB
written first. The TRSMT bit is set when the MSB has been written without
checking if the LSB part has been written. The bit is cleared by EOnCE when the
host has finished reading the content of the ETRSMT register.
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EOnCE Controller Registers
Table 4-14. ESR Description (Continued)
Name
Description
TBFULL
Bit 25
Trace Buffer Full — Indicates that the trace buffer of EOnCE is full. In order not to
lose addresses when TBFDM and IME bits in the EMCR register are set (when TB
is full), the bit causes a debug exception. The TBFULL bit is set when the TB write
pointer equals TB-size minus 15, where TB-size is defined for each SoC
derivative. TB-size is the size of the off-core trace buffer memory and is defined by
the value of 16 core external signals. The TBFULL bit is reset when the trace
buffer is enabled. For more information, see Section 4.5.5.3, “Reading the Trace
Buffer (TB_BUFF).”
NOCHOF
Bit 24
No Change-of-Flow (COF) in Debug State — If this read-only status bit is set by
EOnCE upon entering debug state, users cannot inject a change-of-flow
instruction through the EOnCE to the core. This occurs when the core is in the
following locations:
• Immediately after executing a delayed change of flow instruction (see
Section 7.4.9)
• At the end of a long loop, right after executing LA-2 or LA-1 (see
Section 5.4.2)
• During a short loop.
Single-step operations can be used in order to exit this state. When debug state is
entered in the middle of a short loop, the loop counter (LC) should be reset and
some single-step operations should be executed before injecting a JMP
instruction.
If this bit is set right before intended return to execution (with the EX bit in ECR),
one single-step should be performed before exiting debug state.
REVNO
Bits 23–21
Revision Number — The REVNO field generally identifies the basic instruction
set revision of the core. It identifies the availability of new instructions and
corrections to existing instructions along a binary upward compatible roadmap.
Changes in REVNO imply a software tools switch, different software simulator and
different host debugger. Cores of different revisions can differ in their EOnCE
programming model.
R
Bit 20
Reserved
CORETP
Bits 19–17
Core Type — The CORETP field identifies the architecture member within the
SC100 family. It identifies the availability of new execution units and VLES
grouping capabilities. Note that execution units and VLES can scale up or down
without altering the basic instruction set. Changes in CORETP imply a software
tools switch, different software simulator, and different host debugger.
DRTBFULL
Bit 16
Debug Reason is Trace Buffer — Set when the core enters debug state or
executes a debug exception as a result of the EOnCE trace buffer being full
(TBFULL set). It is cleared by EOnCE when the core exits debug state, or when
the DIS bit in EMCR is reset by the user.
DRSW
Bit 15
Debug Reason is Software Debug — Set when the core enters debug state or
executes a debug exception as a result of the execution of a debug instruction in
the core. DRSW is also set when an execution of the DEBUGEV instruction puts
the DSP into debug state. It is cleared by EOnCE when the core exits debug state,
or when the DIS bit in EMCR is reset by the user.
DREE4
Bit 14
Debug Reason is EE4 — Set when the core enters debug state or executes a
debug exception as a result of EE4 assertion. It is cleared by the EOnCE when the
core exits debug state, or when the DIS bit in EMCR is reset by the user.
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EOnCE Controller Registers
Table 4-14. ESR Description (Continued)
Name
Description
DREE3
Bit 13
Debug Reason is EE3 — Set when the core enters debug state or executes a
debug exception as a result of EE3 assertion. It is cleared by the EOnCE when the
core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREE2
Bit 12
Debug Reason is EE2 — Set when the core enters debug state or executes a
debug exception as a result of EE2 assertion. It is cleared by the EOnCE when the
core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREE1
Bit 11
Debug Reason is EE1 — Set when the core enters debug state or executes a
debug exception as a result of the EE1 assertion. It is cleared by the EOnCE when
the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREE0
Bit 10
Debug Reason is EE0 — Set when the core enters debug state or executes a
debug exception as a result of EE0 assertion. It is cleared by the EOnCE when the
core exits debug state, or when the DIS bit in EMCR is reset by the user.
DRCOUNTER
Bit 9
Debug Reason is Counter — Set when the core enters debug state or executes a
debug exception as a result of a count event. It is cleared by the EOnCE when the
core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCAD
Bit 8
Debug Reason is EDCD — Set when the core enters debug state or executes a
debug exception as a result of detection by the EDCD. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCA7
Bit 7
Debug Reason is EDCA7 — Set when the core enters debug state or executes a
debug exception as a result of detection by the optional external EDCA7. It is
cleared by the EOnCE when the core exits debug state, or when the DIS bit in
EMCR is reset by the user.
DREDCA6
Bit 6
Debug Reason is EDCA6 — Set when the core enters debug state or executes a
debug exception as a result of detection by the optional external EDCA6. It is
cleared by the EOnCE when the core exits debug state, or when the DIS bit in
EMCR is reset by the user.
DREDCA5
Bit 5
Debug Reason is EDCA5 — Set when the core enters debug state or executes a
debug exception as a result of detection by EDCA5. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCA4
Bit 4
Debug Reason is EDCA4 — Set when the core enters debug state or executes a
debug exception as a result of detection by EDCA4. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCA3
Bit 3
Debug Reason is EDCA3 — Set when the core enters debug state or executes a
debug exception as a result of detection by EDCA3. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCA2
Bit 2
Debug Reason is EDCA2 — Set when the core enters debug state or executes a
debug exception as a result of detection by EDCA2. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCA1
Bit 1
Debug Reason is EDCA1 — Set when the core enters debug state or executes a
debug exception as a result of detection by EDCA1. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
DREDCA0
Bit 0
Debug Reason is EDCA0 — Set when the core enters debug state or executes a
debug exception as a result of detection by EDCA0. It is cleared by the EOnCE
when the core exits debug state, or when the DIS bit in EMCR is reset by the user.
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EOnCE Controller Registers
4.7.3 EOnCE Monitor and Control Register (EMCR)
The EMCR is a 32-bit register. Bits 31–16 are read/write control bits. Bits 15–0 are sticky status bits and
can only be written with zeros. Writing them with a one has no effect. The sticky status bits of the register
indicate an event generated by the EOnCE EDU.
Figure 4-17 displays the configuration of EMCR.
BIT
31
30
29
28
27
26
25
24
23
22
21
PICINT TRSINT TBFDM RCVINT
20
19
18
DEBUGERST
17
16
SWDIS
IME
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
14
13
12
11
10
9
2
1
BIT 0
BIT 15
8
7
6
5
4
3
EDCD EDCA EDCA EDCA EDCA EDCA EDCA EDCA EDCA
ST
ST7
ST6
ST5
ST4
ST3
ST2
ST1
ST0
DIS
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The shaded bits are reserved and should be initialized with zeros for future software compatibility.
Figure 4-17. EOnCE Monitor and Control Register (EMCR)
Table 4-15 describes the EMCR fields.
Table 4-15. EMCR Description
Name
Description
R
Bits 31–26
Reserved
PICINT
Bit 25
PIC interrupt - When set, and there is a condition that would have caused a
debug exception, the EOnCE will assert an external pin to an external interrupt
controller. When reset, the core generates an internal debug exception for the
same event. This bit is for the use of the system engineer.
TRSINT
Bit 24
Transmit Interrupt — Can be set for interrupt driven data messaging. If this bit is
set and the TRSMT bit is reset by the EOnCE, a debug exception is issued. The
core ISR determines the reason for the interrupt and writes the new data to the
ETRSMT register.
TBFDM
Bit 23
Enter Debug on Trace Buffer Full — When TBFDM is cleared, the trace buffer
wraps around when full and does not affect core execution. After write pointer
wrap-around, the trace buffer over-writes the oldest entries like a modulo buffer.
When TBFDM is set, the trace buffer almost-full condition affects core execution
according to the IME bit. For this condition, IME cleared causes the core to enter
debug state and IME set causes the core to take the debug exception. TBFDM is
cleared on RESET
RCVINT
Bit 22
Receive Interrupt — Can be set by the user for interrupt driven data messaging
from the host to the target. If this bit is set and the RCV bit is set by the EOnCE, a
debug exception is issued. The core interrupt service routine (ISR) determines the
reason for the interrupt and reads the content of the ERCV register.
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EOnCE Controller Registers
Table 4-15. EMCR Description (Continued)
Name
Description
DEBUGERST
Bits 21–18
Debugger Status Information — If several applications (debugger processes) try
to connect to the core, unaware of each other, DEBUGERST bits serve as flags.
Reset once the core is powered, they can be set/reset by the application as an
occupy signal. The debugger may use these bits to reserve the core for its use.
In case the host disconnects from the core or goes down, when the host
(debugger) tries to regain control on the core, it can use the DEBUGERST bits to
find out at when the host disconnected. This is extremely useful when the host is
connected to the core through a network rather than direct cables.
SWDIS
Bit 17
Software Access Disable — Enables the debug host to lock the EOnCE. When
the bit is set, software write access is denied to all the EOnCE registers except the
ETRSMT register. Software read access is denied from the trace buffer.
IME
Bit 16
Interrupt Mode Enable — When set, this bit causes the core to execute a debug
exception instead of entering debug state for any of the source events that would
have put the core in debug state. This bit can only be changed when all debug
request sources are disabled, specifically when there are no debug requests from
the external source (JTAG port, EE pin or system debug request), trace buffer,
event selector or from the execution of a debug instruction.
Debug request signals from external sources should not normally be used as a
source for debug exceptions. If they are used, the interrupt request should be kept
asserted until the core acknowledges it to the driver by some agreed SW protocol.
The core then must acknowledge that the interrupt was de-asserted before the
driver may assert it again.
DIS
Bit 15
Debug Interrupt Status — Sticky bit that is set by the EOnCE when a debug
exception is generated. When a user resets this bit, all the debug reason bits of the
ESR are reset.
R
Bits 14–9
Reserved
EDCDST
Bit 8
EDCD Status — Sticky bit that is set by the EOnCE upon event detection by the
EDCD. Should be cleared by the user.
EDCAST7
Bit 7
EDCA7 Status — Sticky bit that is set by the EOnCE upon event detection by the
optional external EDCA7. It should be cleared by the user.
EDCAST6
Bit 6
EDCA6 Status — Sticky bit that is set by the EOnCE upon event detection by the
optional external EDCA6. It should be cleared by the user.
EDCAST5
Bit 5
EDCA5 Status — Sticky bit that is set by the EOnCE upon event detection by
EDCA5. It should be cleared by the user.
EDCAST4
Bit 4
EDCA4 Status — Sticky bit that is set by the EOnCE upon event detection by
EDCA4. It should be cleared by the user.
EDCAST3
Bit 3
EDCA3 Status — Sticky bit that is set by the EOnCE upon event detection by
EDCA3. It should be cleared by the user.
EDCAST2
Bit 2
EDCA2 Status — Sticky bit that is set by the EOnCE upon event detection by
EDCA2. It should be cleared by the user.
EDCAST1
Bit 1
EDCA1 Status — Sticky bit that is set by the EOnCE upon event detection by
EDCA1. It should be cleared by the user.
EDCAST0
Bit 0
EDCA0 Status — Sticky bit that is set by the EOnCE upon event detection by
EDCA0. It should be cleared by the user.
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EOnCE Controller Registers
4.7.4 EOnCE Receive Register (ERCV)
ERCV is a 64-bit shift register that can be written from the TDI input signal. The register can be read by
the software as two 32-bit registers. The ERCV register has to be read in a specific order with the Least
Significant Part first. The Least Significant Part read is optional, but the Most Significant Part read is
required to clear the RCV bit in the ESR.
ERCV is used to transfer data from the host. This can be done in the following sequence:
1. The host issues a write command to the ERCV register.
2. The host transmits 64 bits through TDI into the ERCV register.
3. The RCV bit in the ESR is set by the EOnCE.
4. If the RCVINT bit in the EMCR is set, the core is interrupted by a debug exception.
Otherwise, the core must poll the RCV status bit to know when the data is ready in the
ERCV register.
5. The core reads the ERCV register using move instructions.
6. The RCV bit in ESR is cleared by EOnCE. The EE3 signal can be programmed to reflect the
value of the RCV bit, informing the host when further data can be transmitted.
4.7.5 EOnCE Transmit Register (ETRSMT)
ETRSMT is a 64-bit shift register that can be read by the TDO output signal. The register can be written by
software as two 32-bit registers. The ETRSMT register must be written in a specific order, with the Least
Significant Part first. The Least Significant Part write is optional, but the Most Significant Part write is
required to set the TRSMT status bit.
The ETRSMT register can transmit data from the core to an external host while the core is running. This
can be done in the following sequence:
1. The core writes data to be transmitted into the ETRSMT register.
2. The TRSMT bit in the ESR is set automatically by the EOnCE.
3. The host polls the TRSMT bit in the ESR to detect that the data in the ETRSMT register is
available. Alternatively, the host can program the EE4 signal to be set when the TRSMT bit
is set.
4. The host issues a read command to the ETRSMT register and reads the register serially
through the TDO line.
5. The TRSMT bit is cleared on completion of the read by the host debugger. If the TRSINT
bit in the EMCR is set, the core is interrupted by a debug exception, informing the core that
further data can be transmitted.
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EOnCE Controller Registers
4.7.6 EE Signals
EE signals are general-purpose core interfaces which serve as input or output to the EOnCE. They can be
connected off-chip or to a specific on-chip peripheral. This connection is defined by the SoC derivative. In
some systems, the EE signals are not connected to an external signal.
4.7.6.1 EE Signals as Outputs
EE signals can be used to indicate internal EOnCE events to devices outside the core. The internal signals
which can be indicated are:
•
Detection by the event detection channels
•
Detection of entry into debug state
•
Status bit of the ERCV register
•
Status bit of the ETRSMT register
4.7.6.1.1 Detection by the Event Detection Channels
Each EE signal can be configured to serve as an off-core indication of an event detected by the
corresponding EDCA or by EDCD. The EE signals in this case work as a toggle. This capability can be
used in the following manner:
•
One or more event detection channels of the EOnCE can be programmed to detect certain events.
•
Each event detection channel toggles its EE signal when the detection of the desired event occurs.
•
The time elapsed between the two detected events can be measured by connecting the EE signals to
a logic analyzer.
If the EE pin is connected to an I/O pad of the chip, there may be limitations on the frequency of events
that could be reflected on these pins due to the fact that I/O pad frequency is usually substantially lower
then the core frequency. The logic definition of the behavior of the EE pins outputs assumes that the
frequency of the I/O pad is no less than 4 times slower than the core frequency. In order to support this, a
toggle cannot occur in two consecutive cycles. A toggle can occur in a cycle only if there was no toggle in
the preceding cycle. If the frequency of the core is more than 4 times the I/O pad maximum supported
frequency, then not all event sequences could be properly reflected on the pads, and some extra logic may
be required between the EOnCE EE pin outputs and the I/O pads to buffer or compress events.
4.7.6.1.2 Detecting Entry into Debug State
The EE1 signal can be configured as an indication of debug state. Each time the core enters debug state,
the EE1 signal is asserted. On exiting debug state, the EE1 signal is negated. This technique can be used as
a debug acknowledge.
4.7.6.1.3 Status Bit of the ERCV Register
The EE3 signal can be programmed to serve as an indication that the ERCV register (read by the core) is
empty. This capability provides interrupt driven transfers to the host debugger. If the EE3 signal is
programmed in this way, it is asserted when the host has finished writing to the ERCV register through the
JTAG. It is negated when the core finishes reading the Most Significant Part of the ERCV register.
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EOnCE Controller Registers
4.7.6.1.4 Status Bit of the ETRSMT Register
The EE4 signal can be programmed to serve as an indication of data availability in the ETRSMT register.
This capability provides interrupt driven transfers to the host debugger. If the EE4 signal is programmed in
this way, each time the core performs the transfer (and writes to the ETRSMT register), the EE4 signal is
asserted and the host is interrupted. The EE4 signal is negated when the host has finished reading the
ETRSMT register through the JTAG.
4.7.6.2 EE Signals as Inputs
EE signals can be programmed to enable event detection channels or to generate one of the EOnCE events.
After reset, the EE signals are set as inputs. When programmed as an input, an EE signal must be driven
with zero or one. EE assertion can be programmed to perform several functions. For example, EE2 can
enable both EDCA2 and the event counter as well as generate any of the EOnCE events at the same time.
4.7.6.2.1 Using EE Signals to Enable Event Detection Channels
Each EE signal can be programmed to enable the corresponding address detection channel or the data
detection channel. The user can configure EE0 to enable EDCA0, EE1 to enable EDCA1, EE2 to enable
EDCA2, and so on. EED can also be configured to enable EDCD. For a description of how address event
detection channels can be configured to be enabled upon an appropriate EE assertion, see Section 4.9.1.1,
“EDCA Control Registers (EDCAi_CTRL),” and Section 4.9.2.1, “EDCD Control Register
(EDCD_CTRL).”
4.7.6.2.2 Using EE Signals to Cause EOnCE Events
If programmed by the user, EE signal assertion can cause any of the following EOnCE events:
•
Place the core in debug state.
•
Cause a debug exception.
•
Enable trace buffer.
•
Disable trace buffer.
4.7.6.2.3 Using EE Signals to Enter Debug State
The EE0 signal by default can cause the core to enter debug state right after core reset. It can also cause the
core to leave a wait or stop state and enter debug state.
4.7.6.3 EE Signals Control Register (EE_CTRL)
This 16-bit register defines the behavior of the EE signals.
Figure 4-18 displays the bit configuration of the EE signals control register. Shaded bits are reserved and
should be initialized with zeros for future software compatibility.
BIT 15
14
13
12
11
EEDDEF
10
EE5DEF
9
8
7
6
5
4
3
2
1
BIT 0
EE4DEF
EE3DEF
EE2DEF
EE1DEF
EE0DEF
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Figure 4-18. EE Signals Control Register (EE_CTRL)
SC140 DSP Core Reference Manual
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EOnCE Controller Registers
The functionality of EE signals when programmed as an input depends on the programming of the EDU
and the ES. See Section 4.9, “Event Detection Unit (EDU) Channels and Registers,” for further details.
Table 4-16 describes the EE_CTRL fields.
Table 4-16. EE_CTRL Description
Name
Description
Settings
EEDDEF
Bit 15
EED Definition — Programs the EED signal.
As an output of the EED, the EEDDEF bit can
indicate detection by the EDCD, working as a
toggle. As an input to the EOnCE, EED can be
programmed to enable the EDCD. EED
cannot disable EDCD.
0 = Output, detection by EDCD
1 = Input, enables EDCD
R
Bits
14–11
Reserved
EE5DEF
Bit 10
EE5 Definition — Programs the EE5 signal.
Programmed as an output of the EOnCE, EE5
can indicate detection by EDCA5, working as
a toggle. Programmed as an input to the
EOnCE, EE5 can be programmed to enable
EDCA5. EE5 cannot disable EDCA5.
0 = Output, detection by EDCA5
1 = Input, enables EDCA5
EE4DEF
Bits 9–8
EE4 Definition — Programs the EE4 signal.
Programmed as an output of the EOnCE, EE4
can indicate detection by EDCA4, working as
a toggle. It can also indicate that the ETRSMT
register was written by the core. Programmed
as an input to the EOnCE according to the
programming of the EDU and the ES, EE4 can
be programmed to enable EDCA4 or to
generate one of the EOnCE events. EE4
cannot disable EDCA4.
00 = Output, detection by EDCA4
01 = Output, data in ETRSMT register ready
10 = Reserved
11 = Input, enables EDCA4 or generates an EOnCE
event
EE3DEF
Bits 7–6
EE3 Definition — Programs the EE3 signal.
Programmed as an output of the EOnCE, EE3
can indicate detection by EDCA3, working as
a toggle. It can also indicate that the ERCV
register is full. Programmed as an input to the
EOnCE according to the programming of the
EDU and the ES, EE3 can be programmed to
enable EDCA3 or to generate one of the
EOnCE events. EE3 cannot disable EDCA3.
00 = Output, detection by EDCA3
01 = ERCV register full
10 = Reserved
11 = Input, enables EDCA3 or generates an EOnCE
event
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EOnCE Controller Registers
Table 4-16. EE_CTRL Description (Continued)
Name
Description
Settings
EE2DEF
Bits 5–4
EE2 Definition — Programs the EE2 signal.
Programmed as an output of the EOnCE, EE2
can indicate detection by EDCA2, working as
a toggle.
Programmed as an input to the EOnCE
according to the programming of the ECNT,
EDU, and ES, EE2 can be programmed to:
• Enable the ECNT together with the
ECNTEN bits
• Enable the EDCA2 together with the
EDCAEN bits
• Generate one of the EOnCE events
together with the ES
EE2 cannot disable EDCA2 or ECNT.
00 = Output, detection by EDCA2
01 = Reserved
10 = Reserved
11 = Input, enables EDCA2 or ECNT, or generates an
EOnCE event
EE1DEF
Bits 3–2
EE1 Definition — Programs the EE1 signal.
Programmed as an output of the EOnCE, EE1
can indicate detection by EDCA1, working as
a toggle. It can also indicate that the core has
entered debug state (debug acknowledge). In
the case of debug acknowledge, when
single-stepping, EE1 does not toggle.
Programmed as an input to the EOnCE
according to the programming of the EDU and
the ES, EE1 can be programmed to enable
EDCA1 or to generate one of the EOnCE
events.
00 = Output, detection by EDCA1
01 = Debug acknowledgement
10 = Reserved
11 = Input, enables EDCA1 or generates an EOnCE
event
EE0DEF
Bits 1–0
EE0 Definition — Programs the EE0 signal.
Programmed as an output of the EOnCE, EE0
can indicate detection by the EDCA0, working
as a toggle.
Programmed as an input to the EOnCE
according to the programming of the EDU and
the ES, the EE0 can be programmed to enable
EDCA0 together with the EDCAEN bits, or
generate one of the EOnCE events together
with the ES.
EE0 can also be programmed to force the core
into debug state. This default state enables
entry into debug state directly after core reset.
Holding EE0 at logic value 1 during and after
the reset enters the core into debug state
before the first dispatch occurs. In this mode,
asserting EE0 also causes an exit from stop or
wait processing states of the core, as specified
in Section 5.7, “Processing States,” on page
5-41.
When programmed as a debug request, EE0
can also enable EDCA0 or generate an
EOnCE event if EDCA0 or the ES are
programmed in this manner.
00 = Output, detection by EDCA0
01 = Reserved
10 = Input, enables EDCA0 or generates an EOnCE
event
11 = Input, debug request (also enables EDCA0 or
generates an EOnCE event)
SC140 DSP Core Reference Manual
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EOnCE Controller Registers
4.7.7 Core Command Register (CORE_CMD)
The CORE_CMD register is used to execute instructions in the core while in debug state. The external host
writes the instruction into the CORE_CMD register as described in Section 4.2.6, “Reading/Writing
EOnCE Registers Through JTAG.” The EOnCE commands written into the ECR must be Write
CORE_CMD and GO. After writing the instruction into the CORE_CMD register, the core executes it
without leaving debug state. If the EX bit in ECR is also set, debug state is exited after the instruction is
performed.
The format of the injected command is shown in Figure 4-19 below.
Bit
47
34 33
ImmB
14 bits
bits [0:13]
20 19
ImmA
14 bits
bits [0:13]
4
3
Opcode
16 bits
bits [0:15]
2
Ext.
Prefix
2 bits
1
0
Length
Control
2 bits
CORE_CMD
{Prefix1[5], Prefix1[7]}
Instruction Bus (IB)
Prefix1
Prefix2
Opcode
ImmA
ImmB
[15:0]
[15:0]
[15:0]
[15:0]
[15:0]
Figure 4-19. Injected Instruction Format
The length control bits are described in Table 4-17, below:
Table 4-17. Length Control Bits
Length Control Bits
Description
0
0
Not supported
0
1
One word instruction
1
0
Two word instruction
1
1
Three word instruction
The two prefix bits allow the instruction to use the high bank of registers. Bits 15 and 14 in the second and
third words encode the grouping/word partition used by the core for execution set parsing. In the case of a
single instruction, they do not need to be part of the CORE_CMD word. For further details, see
Appendix A, “SC140 DSP Core Instruction Set.”
In general, core commands should not perform illegal operations. In case a core command generated an
exception (such as an illegal exception), the exception will be serviced only after the core exits debug state.
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EOnCE Controller Registers
4.7.8 PC of the Exception Execution Set (PC_EXCP)
PC_EXCP enables the user to determine exactly which execution set caused an imprecise internal Illegal
or DALU overflow exception. It is a read-only register that is accessed through the JTAG port or by core
software.
In the case of an illegal instruction, illegal execution set or DALU overflow, the PC of the execution set is
saved in the PC_EXCP register. In this way, users can determine the address of the execution set that
caused the internal exception. It is best done in the illegal exception service routine, which is serviced right
after the exception event has occurred. For a list of internal exceptions, see Section 5.8, “Exception
Processing,” on page 5-46.
Multiple exception events may occur between the first event and its exception service routine. For multiple
exception types (illegal or DALU overflow), the PC_EXCP register will capture the VLES address of the
first occurrence of the last exception type, regardless of whether the exception type is serviced or not. For
multiple events of the same type (including the different reasons of the illegal exception), only the first
event will be sampled in PC_EXCP.
4.7.9 PC of the Next Execution Set (PC_NEXT)
PC_NEXT is a 32-bit register that stores the address of the execution set to be executed next. Although the
PC_NEXT register can also be read while the device is running and not in debug state, the register contents
are not defined. This register is not affected by the operations performed during debug state. When single
stepping, the value of PC_NEXT is valid after every step. PC_NEXT will sample data only if the EOnCE
is enabled (see Section 4.4, “EOnCE Enabling and Power Considerations.” ) If the EOnCE enters debug
state without being enabled first, the value of PC_NEXT is undefined.
PC_NEXT is read-only and read through JTAG.
4.7.10 PC of Last Execution Set (PC_LAST)
PC_LAST contains the PC of the last executed execution set. It is used in debug state to define which PC
triggered a PC breakpoint. If the PC_LAST register is read while the device is running and not in debug
state, the register contents are not defined. PC_LAST will sample data only if the EOnCE is enabled (see
Section 4.4, “EOnCE Enabling and Power Considerations.” ) If the EOnCE enters debug state without
being enabled first, the value of PC_LAST is undefined. In case of a killed PC (when PCKILL in ESR is
asserted), the value of PC_LAST is not updated to that of the killed PC, and still reflects the last execution
set.
PC_LAST is read-only and read through JTAG.
4.7.11 PC Breakpoint Detection Register (PC_DETECT)
PC_DETECT captures the PC value of the first execution set that caused an entry into debug state based on
a data memory event in EDCA or EDCD. For data breakpoint detection, only the first event will be
sampled into PC_DETECT because the core has already executed a few more execution sets by the time it
enters debug state.
PC_DETECT captures the correct PC of the VLES that triggered the entry into debug state if all the
following conditions are met:
•
An event was detected on XABA/B and/or XDBA/B by an enabled EDCA/D channel.
SC140 DSP Core Reference Manual
4-49
Event Counter Registers
•
This event was programmed in ESEL_DM.
•
The debug reason bits (DREDCA0-5, DREDCD) in ESR indicate that the data detection event was
part of the reason to enter debug state. ESR should be checked because ESEL_DM may be
programmed to enter debug state for other reasons that do not cause sampling into PC_DETECT.
This ESR check should match the way the data memory events were programmed to combine to a
debug entry condition in ESEL_CTRL. For example, several conditions could be ANDed or ORed,
requiring a different ESR check in each case.
Once sampled, PC_DETECT will not be re-sampled again until the core enters and then exits debug state.
PC_DETECT is read-only and read through JTAG or by core software. PC_DETECT should be read only
in debug state. If PC_DETECT is read when the core is not in debug state, its value is undefined.
4.8 Event Counter Registers
The event counter (ECNT) contains three registers:
•
Event Counter Register (ECNT_CTRL)
•
Event Counter Value Register (ECNT_VAL)
•
Extension Counter Value Register (ECNT_EXT)
These three registers are described in the following sections.
4.8.1 Event Counter Control Register (ECNT_CTRL)
The ECNT_CTRL register selects the event to be counted by the event counter. It also determines the
enabled source of the event counter.
Two modes of event counter operation are determined by the ECNT_CTRL register:
1. In the regular mode of operation, the extension counter is disabled. Thus, when the event
counter reaches zero, the count event is generated and the counter stops its operation. The
maximum value that can be counted before generating the count event is $8000 0000. This
can be achieved by writing $0000 0000 to the ECNT_VAL register. The event counter can be
used as a watchdog timer provided that the counter is programmed to count the DSP cycles
(internal clock), and that the debug exception in the ES event is set to generate an EOnCE
event upon count event (when the counter comes to zero).
2. In the extended mode of operation, when the event counter reaches zero, it does not generate
the count event and wraps around to $7FFF FFFF. The event counter continues to count
down, and the number of transitions from 1 to 0 is counted by the extension counter. This
creates a virtual 62-bit counter. When the extension counter (ECNT_VAL) reaches $7FFF
FFFF, the next count wraps around to $0000 0000. Overflow of the extension counter
register does not generate a count event.
For information on events 0–5, see Section 4.9.1, “Address Event Detection Channel (EDCA).” For
information on event D, see Section 4.9.2, “Data Event Detection Channel (EDCD).” Like EDU, the event
counter can be enabled explicitly by writing 1111 to the ECNTEN bits of the control register. It can also be
enabled by specifying an event. The profiler can exploit this capability for cycle count operations to
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SC140 DSP Core Reference Manual
Event Counter Registers
ascertain the number of cycles needed by a device to get from a starting address to an ending address, in
the following manner:
1. Write $7FFF FFFF to the ECNT_VAL register.
2. Configure ECNT to count the internal clock.
3. Program ECNT to be enabled upon EDCAi detection.
4. Program EDCAi to detect the starting address.
5. Program EDCAj to detect the ending address.
6. Program ES to generate a debug exception upon EDCAj detection.
The following stages are:
1. Detection of the start address which enables the counter and to start counting.
2. Detection of the final address which generates a debug exception.
3. ISR of the debug exception which disables the counter, reads the counter contents
(ECNT_VAL register), and subtracts the cycles of the interrupt service routine overhead.
This value gives the cycle count between the count enabling and the ending address.
When the trace buffer operates in counter mode, each destination address that is put into the trace buffer is
followed by the value of the counter register. The trace buffer can also be configured to write both the
values of the counter and extension counter with each trace package. For more information, see
Section 4.11.1, “Trace Buffer Control Register (TB_CTRL).”
The counter can be configured to count the number of traced entries. In case the tracing includes the
counter values themselves, they are counted as well.
Figure 4-20 displays the configuration of ECNT_CTRL. The shaded bits are reserved and should be
initialized with zeros for future software compatibility.
BIT 15
14
13
12
11
10
9
8
7
TEST
EXT
6
5
4
3
ECNTEN
2
1
BIT 0
ECNTWHAT
TYPE
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rw
rw
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rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 4-20. Event Counter Register (ECNT_CTRL)
Table 4-18 describes the ECNT_CTRL fields.
Table 4-18. ECNT_CTRL Description
Name
Description
R
Bits 15–10
Reserved
TEST
Bit 9
Reserved for Test
0 = Normal operation
1 = Reserved for test
EXT
Bit 8
Extended Mode of Operation Bit —
See Section 4.5.2, “Event Counter,” on
page 4-18.
0 = ECNT operates in regular mode
1 = ECNT operates in extended mode
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Settings
4-51
Event Counter Registers
Table 4-18. ECNT_CTRL Description (Continued)
Name
Description
Settings
ECNTEN
Bits 7–4
Event Counter Enable — Used to
enable the ECNT operation. When
ECNTEN is set to 1111, ECNT is
operational and will count events
according to ECNTWHAT bits, which
select the source for that count. If bits
ECNTEN are set to enable the operation
of the event counter when an event is
detected or signal EE2 is asserted, the
EOnCE overwrites these bits to 1111
one cycle after the appearance of the
event.
0000 =.The event is disabled.
0001 =.The event counter is disabled, but is enabled
when an event is detected by the EDCA0.
0010 =.The event counter is disabled, but is enabled
when an event is detected by the EDCA1.
0011 =.The event counter is disabled, but is enabled
when an event is detected by the EDCA2.
0100 =.The event counter is disabled, but is enabled
when an event is detected by the EDCA3.
0101 =.The event counter is disabled, but is enabled
when an event is detected by the EDCA4.
0110 =.The event counter is disabled, but is enabled
when an event is detected by the EDCA5.
0111 =.The event counter is disabled, but is enabled
when an event is detected by the optional external
EDCA6.
1000 =.The event counter is disabled, but is enabled
when an event is detected by the optional external
EDCA7.
1001 =.The event counter is disabled, but is enabled
when an event is detected by EDCD.
1010 =.The event counter is disabled, but is enabled
when signal EE2 is asserted and EE2 is
programmed in the EE_CTRL register as an input.
1011 =.Reserved
1100 =.Reserved
1101 =.Reserved
1110 =.Reserved
1111 =.The event counter is enabled.
When the event counter is programmed
to be enabled by the same event that it
has to count, the first such event enables
the event counter and is counted as the
first event.
When the event counter is enabled by a
given event, but is programmed to count
a different event, the counter does not
include the enabling event in the count.
ECNTWHAT
Bits 3–0
Events to be Counted — Determines
what is to be counted by ECNT.
0000 =.Count event0 occurrence.
0001 =.Count event1 occurrence.
0010 =.Count event2 occurrence.
0011 =.Count event3 occurrence.
0100 =.Count event4 occurrence.
0101 =.Count event5 occurrence.
0110 =.Count optional external event6 occurrence
0111 =.Count optional external event7 occurrence
1000 =.Count eventD occurrence.
1001 =.Count executions of DEBUGEV instruction.
1010 =.Count trace events (data moved to the buffer).
1011 =.Count executed execution sets.
1100 =.Count core clocks.
1101 =.Count off-core event 0
1110 =.Count off-core event 1
1111 = Reserved
4.8.2 Event Counter Value Register (ECNT_VAL)
This 32-bit register is used to determine how many events the event counter should count before it
generates the count event signal. ECNT_VAL is a down-counter. The MSB is always zero, so the range is
from $7FFF FFFF to $0000 0000. When the register is written, the MSB should be written to zero for
software compatibility.
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SC140 DSP Core Reference Manual
Event Counter Registers
4.8.3 Extension Counter Value Register (ECNT_EXT)
This is a 32-bit register that is used in the extended mode of operation to count the number transitions from
1 to 0 in the ECNT_VAL register. See Section 4.5.2, “Event Counter,” for further details. The ECNT_EXT
register counts up. Reset writes zeros to this register. Software can write the register when new counting is
started. The MSB is always zero, so the count is from $0000 0000 to $7FFF FFFF. When the register is
written, the MSB should be written to zero for software compatibility.
4.8.4 EC Signals
The two event counter signals EC0 and EC1 allow the event counter to count off-core events such as cache
hits/misses, memory contention, external wait states, etc. These inputs are assumed to be synchronized to
the core clock and support a counting rate up to the core frequency. EC0 and EC1 use is
derivative-dependent.
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Event Detection Unit (EDU) Channels and Registers
4.9 Event Detection Unit (EDU) Channels and
Registers
The various event detection channels and corresponding registers are described in the sections that follow.
4.9.1 Address Event Detection Channel (EDCA)
The EDCA can be used to detect the following:
•
Program breakpoint, specified on a specific PC value or range
•
Data address breakpoint, specified on a specific data address or range.
The functionality of these registers is described in the following sections.
4.9.1.1 EDCA Control Registers (EDCAi_CTRL)
EDCAi_CTRL is a 16-bit register used to control the behavior of the corresponding EDCA. The following
sections describe the functionality of each bit in the EDCAi_CTRL register.
Figure 4-21 displays the configuration of the EDCAi_CTRL register.
BIT 15
14
13
12
11
10
9
EDCAEN
8
7
CS
6
5
CBCS
4
3
CACS
2
1
ATS
BIT 0
BS
TYPE
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rw
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rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 4-21. EDCA Control Register (EDCAi_CTRL)
Table 4-19 describes the EDCAi_CTRL fields.
Table 4-19. EDCA_CTRL Description
Name
Description
R
Bits
14-15
Reserved
4-54
Settings
SC140 DSP Core Reference Manual
Event Detection Unit (EDU) Channels and Registers
Table 4-19. EDCA_CTRL Description (Continued)
Name
Description
Settings
EDCAEN
Bits
13–10
Event Detection Channel (EDCAi)
Enable — Used to enable or disable
event detection channels. When it is
enabled, it continues to operate until it is
explicitly disabled by writing 0000 into
EDCAEN bits, or EDCAEN bits are
changed for another enabling condition.
The channel remains disabled until a
new enabling condition occurs.
0000 =.EDCAi is disabled.
0001 =.EDCAi is disabled, but is enabled when an event is
detected by EDCA0.
0010 =.EDCAi is disabled, but is enabled when an event is
detected by EDCA1.
0011 =.EDCAi is disabled, but is enabled when an event is
detected by EDCA2.
0100 =.EDCAi is disabled, but is enabled when an event is
detected by EDCA3.
0101 =.EDCAi is disabled, but is enabled when an event is
detected by EDCA4.
0110 =.EDCAi is disabled, but is enabled when an event is
detected by EDCA5.
0111 =.EDCAi is disabled, but is enabled when an event is
detected by the optional external EDCA6...
1000 =.EDCAi is disabled, but is enabled when an event is
detected by the optional external EDCA7.
1001 =.EDCAi is disabled, but is enabled when an event is
detected by EDCD.
1010 =.EDCAi is disabled, but is enabled when a count
event is detected.
1011 =.EDCAi is disabled, but is.enabled when a signal EEi
is asserted and EEi in the EE_CTRL register is
programmed to be an input.
1100 =.EDCAi is enabled but will be disabled when EEi is
negated, in both cases and EEi is programmed as an
input in the EE_CTRL register. This state can only be
reached by previously being in the 1011 state and
asserting the EEi pin.
1101 =.Reserved
1110 =.Reserved
1111 =.EDCA is enabled.
When bits EDCAEN are set to enable
the operation of EDCAi upon detection
of an event, the EOnCE overwrites
these bits to 1111 one cycle after the
appearance of the event.
When the event detection channel is
programmed to detect PC, the PC of the
first instruction cycle after the channel
has been enabled is not yet detected.
The latency for enabling a channel is
one cycle.
CS
Bits 9–8
Comparators Selection — Used to
select the desired combination of
comparator A and comparator B results.
An event detection can be generated in
the following cases:
• Only comparator A condition is
detected.
• Only comparator B condition is
detected.
• Both comparator A and comparator
B conditions are detected.
• Either comparator A or comparator
B conditions are detected.
SC140 DSP Core Reference Manual
00 =
01 =
10 =
11 =
Comparator A only
Comparator B only
Comparator A AND Comparator B
Comparator A OR Comparator B
4-55
Event Detection Unit (EDU) Channels and Registers
Table 4-19. EDCA_CTRL Description (Continued)
Name
Description
Settings
CBCS
Bits 7–6
Comparator B Condition Selection —
Used to select one of these four results
from comparator B:
• Equal to
• Not equal to
• Greater than
• Less than
00 = Equal to EDCA_REFB
01 = Not equal to EDCA_REFB
10 = Greater than EDCA_REFB
11 = Less than EDCA_REFB
CACS
Bits 5–4
Comparator A Condition Selection —
Used to select one of these four results
from comparator A:
• Equal to
• Not equal to
• Greater than
• Less than
00 =
01 =
10 =
11 =
ATS
Bits 3–2
Access Type Selection — These bits
are used to select the type of memory
access that should be detected by the
event detection channel. The possible
memory access types are:
• Read access
• Write access
• Read or write access
00 = Read access
01 = Write access
10 = Read or write access
11 = Reserved
BS
Bits 1–0
Bus Selection — Used to select which
address bus or buses should be
sampled for comparison by comparator
A and/or by comparator B. The possible
buses that can be chosen by these bits
are PC, XABA, and XABB.
00 =
01 =
10 =
11 =
Equal to EDCA_REFA
Not equal to EDCA_REFA
Greater than EDCA_REFA
Less than EDCA_REFA
XABA
XABB
XABA and XABB
PC
If XABA and/or XABB are the selected
buses, bus XABA is compared to the
EDCA_REFA register while XABB is
compared to the EDCA_REFB register.
If CS bits are set to 11, then setting BS
bits to 10 enables the user to set a
watchpoint on an address when it is not
known whether the address to be used
for accessing memory is on XABA or
XABB. In this case, the user must set
both reference value registers with the
address to be detected.
If the BS bits are set to 10, then the CS
bits must be set to either 10 or 11.
In order to detect a watchpoint on a PC range, one EDCA is enough. In order to detect a watchpoint on a
data address range, two EDCAs are required. When configuring two EDCAs to detect a watchpoint to an
address range, one EDCA should be configured to detect the range on bus A, and the other EDCA to detect
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SC140 DSP Core Reference Manual
Event Detection Unit (EDU) Channels and Registers
the range on bus B, and the two EDCA events should be OR-ed in the event selector. The apparent
alternative of detecting the upper range boundary on both buses and the other EDCA to detect the lower
range boundary on both buses (AND-ing them in the event selector) may produce erroneous results, for
example if two unrelated parallel accesses match the conditions by chance.
When used for data address detection, the EDCA takes into account the access width in order to identify an
access to an address that is part of a wide access. Hence, when the data access is 16-bit wide, the LSB of
the address does not participate in the comparison.
In a similar way, the following holds true:
— for 16-bit accesses - the LSB of the address is not compared
— for 32-bit accesses (including MOVE.2W) - the 2 LSBs of the address are not compared
— for 64-bit accesses (including MOVE.4W, MOVE.2W) - the 3 LSBs of the address are not
compared.
For example, this feature allows setting a watchpoint on address 0x101, in which case the EDCA will also
identify it when the core is performing a MOVE.W, MOVE.L, etc. to address $100.
When detection occurs, status bit EDCASTi is set by the EOnCE in the EMCR register. Refer to
Table 4-15 on page 4-41.
4.9.1.2 EDCA Reference Value Registers A and B (EDCAi_REFA,
EDCAi_REFB)
EDCAi_REFA and EDCAi_REFB are 32-bit registers used to hold reference values that are to be
compared by the event detection channel comparators. EDCAi_REFA is used by the event detection
channel comparator A. EDCAi_REFB is used by the event detection channel comparator B.
4.9.1.3 EDCA Mask Register (EDCAi_MASK)
The EDCAi_MASK is a 32-bit register that allows masking of any one of a sample address’ bits. The
sampled address is ANDed with the mask value.
•
Mask bits with a value of one stored in them allow the corresponding bit of the selected address to
participate in the comparison.
•
Mask bits with a value of zero stored in them cause the corresponding bit of the selected address to
always match the corresponding bits in the reference value.
The masked address value is then compared to the EDCAi_REFA and EDCAi_REFB registers. For
example, the EDCAi_MASK register can be used to detect accesses to a memory region with several
address aliases.
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Event Detection Unit (EDU) Channels and Registers
4.9.2 Data Event Detection Channel (EDCD)
In order to set a watchpoint on a given data value, the user should:
•
Write the watched value into the EDCD_REF.
•
Enter a write mask into the EDCD_MASK.
•
Specify the type of access (read or write) in the EDCD_CTRL.
•
Specify the data type (byte/word/long) in the EDCD_CTRL.
•
Enable the event detection unit in EDCD_CTRL, as the last action.
The following sections describe the functionality of these registers.
4.9.2.1 EDCD Control Register (EDCD_CTRL)
Figure 4-22 displays the configuration of EDCD_CTRL.
BIT 15
14
13
12
11
10
9
8
7
6
AWS
5
4
3
2
EDCDEN
1
CCS
BIT 0
ATS
TYPE
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rw
rw
rw
rw
rw
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rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The shaded bits are reserved and should be initialized with zeros for future software compatibility.
Figure 4-22. EDCD Control Register (EDCD_CTRL)
Table 4-20 describes the EDCD_CTRL fields.
Table 4-20. EDCD_CTRL Description
Name
Description
R
Bits
14-15
Reserved
R
Bits
13–10
Reserved
4-58
Settings
SC140 DSP Core Reference Manual
Event Detection Unit (EDU) Channels and Registers
Table 4-20. EDCD_CTRL Description (Continued)
Name
Description
Settings
AWS
Bits 9–8
Access Width Selection —
Determines the width of the data access
that should be watched. The different
width types are summarized in the
settings column.
00 = Byte
01 = Word
10 = Long
11 = Reserved
In byte access mode, only the eight LSB
bits of the masked data are compared
with the eight LSB bits of the
EDCD_REF register. One or four
comparisons are performed with logical
OR among them, depending on the
access resolution (byte or quad-byte).
When word access width is chosen, the
sixteen LSB bits of the EDCD_REF
register are compared with each of the
sixteen bits of the masked data. One,
two, or four comparisons are performed
with logical OR among them, depending
on the access resolution (word,
double-word, or quad-word).
When long access width is chosen, then
the 32 LSB bits of the EDCD_REF
register are compared with each of the
32 bits of the masked data. One or two
comparisons are performed with logical
OR among them, depending on the
access resolution (long or double-long).
R
Bit 7
Reserved
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4-59
Event Detection Unit (EDU) Channels and Registers
Table 4-20. EDCD_CTRL Description (Continued)
Name
Description
Settings
EDCDEN
Bits 6–3
EDCD Enable — Used to enable or
disable the EDCD. When enabled,
EDCD continues to operate until it is
explicitly disabled by writing 0000 into
EDCDEN bits, or when EDCDEN bits
are changed for another enabling
condition. The channel remains disabled
until a new enabling condition occurs.
0000 =.EDCD is disabled.
0001 = EDCD is disabled, but is.enabled when an event is
detected by EDCA0.
0010 = EDCD is disabled, but is.enabled when an event is
detected by EDCA1.
0011 =.EDCD is disabled, but is.enabled when an event is
detected by EDCA2.
0100 =.EDCD is disabled, but is enabled when an event is
detected by EDCA3.
0101 =.EDCD is disabled, but is.enabled when an event is
detected by EDCA4.
0110 =.EDCD is disabled, but is.enabled when an event is
detected by EDCA5.
0111 =.EDCD is disabled, but is enabled when an event is
detected by the optional external EDCA6.
1000 =.EDCD is disabled, but is enabled when an event is
detected by the optional external EDCA7.
1001 =.EDCD is disabled, but is enabled when a count event
is.detected.
1010 = EDCD is disabled, but is enabled when EED is
asserted and EED is programmed as input in the
EE_CTRL register.
1011 = EDCD is enabled but will be disabled when EED is
negated, in both cases EED is programmed as an input
in the EE_CTRL register. This state can only be reached
by previously being in the 1010 state and asserting the
EED pin.
1100 = Reserved
1101 = Reserved
1110 = Reserved
1111 = EDCD is enabled.
When the EDCDEN bits are set to
enable the operation of the EDCD upon
event occurrence, the EOnCE
overwrites these bits to 1111 one clock
cycle after the appearance of the event.
The latency for enabling the channel is
one cycle.
CCS
Bits 2–1
ATS
Bit 0
4-60
Comparator Condition Selection —
These bits select one of these four
results from the comparator:
• Equal to
• Not equal to
• Greater than
• Less than
00 = Equal to EDCD_REF
01 = Not equal to EDCD_REF
10 = Greater than EDCD_REF
11 = Less than EDCD_REF
Access Type Selection — The ATS bit
determines whether the memory access
is read or write.
0 = Read
1 = Write
In case of multi-operand data accesses (such as MOVE.2W
etc.) the compare result will be true if the condition is fulfilled
for any of the individual operands (one byte, word etc.).
However for the “not equal” condition – all operands must
be not equal in order for the condition to be fulfilled.
SC140 DSP Core Reference Manual
Event Selector (ES) Registers
4.9.2.2 EDCD Reference Value Register (EDCD_REF)
EDCD_REF is a 32-bit register used to hold a reference value to be compared by the EDCD comparator.
EDCD_REF is used by the EDCD comparator. If a byte (8 bits) or a word (16 bits) is to be written into the
EDCD_REF, it should be LSB-aligned.
4.9.2.3 EDCD Mask Register (EDCD_MASK)
EDCD_MASK is a 32-bit register that allows the masking of any of the bits in the data bus value that is
compared. If bit i in the EDCD_MASK is zero, then it does not participates in the comparison. The data on
the bus is ANDed with the EDCD_MASK value, and is then compared with the EDCD_REF register
according to the access width. Hence the masked bits must also be zero in the EDCD_REF.
In case that the reference value is 16 or 8 bits long, the mask value must be duplicated 2 or 4 times
(respectively) to fill the mask register.
Since data buses are 64 bits, the 32-bit EDCD_MASK register is masked on both 32 LSB and 32 MSB bits
of the sampled bus value.
EDCD_MASK is initialized to all ones at reset.
4.10 Event Selector (ES) Registers
ES selects the source for various operations used by the EOnCE. It contains the following registers:
•
Event selector control register (ESEL_CTRL)
•
Event selector mask debug state register (ESEL_DM)
•
Event selector mask debug exception register (ESEL_DI)
•
Event selector mask enable trace register (ESEL_ETB)
•
Event selector mask disable trace register (ESEL_DTB)
The following sections describe these registers.
4.10.1 Event Selector Control Register (ESEL_CTRL)
The 8-bit control register ESEL_CTRL controls the operation of the ES, which is programmed in the
following order:
1. Reset the event selector mask registers.
2. Program the ESEL_CTRL register.
3. Program the appropriate event selector mask registers.
SC140 DSP Core Reference Manual
4-61
Event Selector (ES) Registers
Figure 4-23 displays the bit configuration of ESEL_CTRL.
BIT 7
6
5
4
3
SELDTB
SELETB
2
1
BIT 0
SEDLDI
SELDM
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
The shaded bits are reserved and should be initialized with zeros for future software compatibility.
Figure 4-23. Event Selector Control Register (ESEL_CTRL)
The ESEL_CTRL fields are described in Table 4-21.
Table 4-21. ESEL_CTRL Description
Name
Description
Settings
R
Bits 7–5
Reserved
SELDTB
Bit 4
Selection Bit for Trace Disable —
Determines how the enabled sources
disable trace.
0 = Trace is disabled upon detection of the event by any one
of the sources (ORed) selected on the ESEL_DTB
register.
1 = Trace is disabled upon detection of the event by all the
sources (ANDed) selected on the ESEL_DTB register.
SELETB
Bit 3
Selection Bit for Trace Enable —
Determines how the enabled sources
enable trace.
0 = Trace is enabled upon detection of the event by any one
of the sources (ORed) selected on the ESEL_ETB
register.
1 = Trace is enabled upon detection of the event by all the
sources (ANDed) selected on the ESEL_ETB register.
R
Bit 2
Reserved
SELDI
Bit 1
Selection Bit for Debug Exception —
Determines how the enabled sources
cause a debug exception.
0 = A debug exception is reached upon detection of the
event by any one of the sources (ORed) selected on the
ESEL_DI register.
1 = A debug exception is reached upon detection of the
event by all the sources (ANDed) selected on the
ESEL_DI register.
SELDM
Bit 0
Selection Bit for Debug state —
Determines how the enabled sources
cause the core to enter into debug state.
0 = Core enters debug state upon detection of the event by
any one of the sources (ORed) selected on the
ESEL_DM register.
1 = Core enters debug state upon detection of the event by
all the sources (ANDed) selected on the ESEL_DM
register.
Each of the following event selector registers can enable the system to configure what debug events
(EDCA event, EE event etc.) will cause the outcome controlled by that register (entry into debug state,
debug exception etc.).
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SC140 DSP Core Reference Manual
Event Selector (ES) Registers
For each outcome, the individual events could be AND-ed or OR-ed as specified in ESEL_CTRL. When
the ESEL_CTRL is configured as “OR” for a certain outcome, all events could be enabled as needed.
However, AND-ing events is more restricted, since the respective events that are AND-ed have to be
related so that the combination will be meaningful. For example, there is no meaning to AND an EE pin
assertion (a transient event) with an EDCA event because there is no practical way to synchronize them.
Combining events with an AND condition in the ESEL_CTRL register is allowed only for the following
options:
— EDCA0-5 events all configured to detect a PC
meaning: the events relate to the same execution set
— One EDCA0-5 event configured to detect data accesses with an EDCD event
meaning: a matching address-data pair of the same access.
The interface for the optional external EDCA6 and EDCA7 has the same timing as data address events.
This means that if the external EDCAs were implemented with the same detection timing as the internal
ones, they could be used in the event selector with other events in same way as the internal EDCAs.
In general, the options for combining external EDCA events in the event selector are as follows:
— OR-ed with other EOnCE events, as asynchronous events with respect to core activity.
— AND-ed with other EOnCE events, if used as an enabling event that is asserted continuously for
extended periods. In this case the assertion and de-assertion transitions of EDCA6/7 events
should be controlled by the system (in SW or HW) since the transition edge cases could be
problematic to detect.
— AND-ed with an EDCD event, intended to detect an address/data pair on the same bus.
In case the event selector is configured to have some events cause entry into debug state and other events
to cause a debug exception (ESEL_DM and ESEL_DI are both enabled at the same time), then the events
configured in each of them cannot be with an AND condition in ESEL_CTRL.
4.10.2 Event Selector Mask Debug State Register (ESEL_DM)
This 16-bit register has one bit for each source of event selection. Setting the appropriate bit configures the
related source to cause entry into debug state.
Figure 4-24 displays the bit configuration of ESEL_DM.
BIT 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
BIT 0
DEBUGE
V
EE4
EE3
EE2
EE1
EE0
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
COUN
EDCA EDCA EDCA EDCA EDCA EDCA EDCA EDCA
EDCD
T
5
4
3
2
1
0
7
6
Figure 4-24. Event Selector Mask Debug State (ESEL_DM)
If multiple sources are configured to cause entry into debug state, they are ANDed or ORed according to
the value of the SELDM bit in the ESEL_CTRL. For more information, see Section 4.10.1, “Event
Selector Control Register (ESEL_CTRL),” on page 4-61. If all the bits are set to zero, the ES does not
enter debug state.
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4-63
Event Selector (ES) Registers
4.10.3 Event Selector Mask Debug Exception
Register (ESEL_DI)
This 16-bit register has one bit for each source of event selection. Setting the appropriate bit enables the
related source to cause a debug exception.
Figure 4-25 displays the bit configuration of ESEL_DI.
BIT 15
14
DEBUGE
EE4
V
13
12
11
EE3
EE2
EE1
10
9
8
EE0 COUNT EDCD
7
6
5
4
3
2
1
BIT 0
EDCA EDCA EDCA EDCA EDCA EDCA EDCA EDCA
5
4
3
2
1
0
7
6
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 4-25. Event Selector Mask Debug Exception (ESEL_DI)
If multiple sources are configured to cause a debug exception, they are ANDed or ORed according to the
value of the SELDI bit in the ESEL_CTRL. For more information, see Section 4.10.1, “Event Selector
Control Register (ESEL_CTRL).” If all the bits are set to zero, the ES does not issue a debug exception.
4.10.4 Event Selector Mask Enable Trace Register
(ESEL_ETB)
This 16-bit register has one bit for every source of the ES. Setting the appropriate bit configures the related
source to enable trace.
Figure 4-26 displays the bit configuration of ESEL_ETB.
BIT 15
14
DEBUGE
EE4
V
13
12
11
10
EE3
EE2
EE1
EE0
9
8
7
6
5
4
3
2
1
BIT 0
COUN
EDCA EDCA EDCA EDCA EDCA EDCA EDCA EDCA
EDCD
T
5
4
3
2
1
0
7
6
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 4-26. Event Selector Mask Enable Trace (ESEL_ETB)
If multiple sources are configured to enable trace, they are ANDed or ORed according to the value of the
SELETB bit in the ESEL_CTRL. If all the bits are set to zero, the ES does not enable trace.
The same event cannot be configured to both enable and disable tracing.
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SC140 DSP Core Reference Manual
Trace Unit Registers
4.10.5 Event Selector Mask Disable Trace Register
(ESEL_DTB)
This 16-bit register has one bit for every source of the ES. Setting the appropriate bit configures the related
source to cause a disable trace.
Figure 4-27 displays the bit configuration of ESEL_DTB.
BIT 15
14
DEBUGE
EE4
V
13
12
11
10
EE3
EE2
EE1
EE0
9
8
7
6
5
4
3
2
1
BIT 0
COUN
EDCA EDCA EDCA EDCA EDCA EDCA EDCA EDCA
EDCD
T
5
4
3
2
1
0
7
6
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 4-27. Event Selector Mask Disable Trace (ESEL_DTB)
If multiple sources are configured to disable trace, they are ANDed or ORed according to the value of the
SELDTB bit in the ESEL_CTRL. See Section 4.10.1, “Event Selector Control Register (ESEL_CTRL),”
for further details. If all the bits are set to zero, the ES does not issue a disable trace.
The same event cannot be configured to both enable and disable tracing.
4.11 Trace Unit Registers
The trace unit includes the following registers:
•
Trace Buffer Control Register (TB_CTRL)
•
Trace Buffer Read Pointer Register (TB_RD)
•
Trace Buffer Write Pointer Register (TB_WR)
•
Trace Buffer Virtual Register (TB_BUFF)
4.11.1 Trace Buffer Control Register (TB_CTRL)
The TB_CTRL register controls the operation of the trace unit. The following tracing modes are possible,
all which trace the PC of execution sets that answer some conditions:
•
TEXEXT -
trace the PC of every execution set
•
TMARK -
trace the PC of execution sets that includes the MARK instruction
•
TCHOF -
trace the source and destination PC of execution set that includes
a taken COF instruction (listed in Table A-13 in Appendix A, not including
TRAP, but including the BREAK, CONT/D instructions)
•
TLOOP -
trace the exection of HW loops.
For long loops, the PC of the last address (LA) and start address (SA) are traced.
For short loops, only the PC of LA is traced.
•
TINT -
trace the interrupt point and destination PC of interrupts and exceptions
(including the TRAP, and ILLEGAL instructions)
TEXEC and TMARK can only be activated on their own, without other tracing options enabled.
SC140 DSP Core Reference Manual
4-65
Trace Unit Registers
In addition, the counter values could be added to the trace package of each trace event, thereby allowing to
monitor the elapsed cycles between trace events. The possible counter tracing modes are:
•
TCOUNT
upon a trace event, trace the counter value (ECNT_VAL)
•
TCNTEXT
upon a trace event, trace the extension counter value (ECNT_EXT).
This mode is usefull only with the TCOUNT mode.
Activating the TCOUNT mode adds a 32-bit entry to the traced package upon each trace event. Activating
the TCNTEXT mode in addition to the TCOUNT mode adds two 32-bit entries to the trace package upon
each trace event.
Both the counter modes cannot be activated with the TEXEC and TMARK mode, in order not to create
situations of tracing overflow.
The tracing mode combinations that are allowed are summarized in Table 4-22.
Table 4-22. Allowed tracing mode combinations
Allowed with
TCOUNT or
TCHOF
TLOOP
TINT
TEXEC
TMARK
Trace mode
TCOUNT & TCNTEXT
+
TCHOF
+
-
-
+
+
-
-
+
-
-
+
-
-
TLOOP
+
TINT
+
+
TEXEC
-
-
-
TMARK
-
-
-
-
-
When the TB_CTRL register is configured for multiple trace data writes, there is a potential for data loss.
This is because each write to the trace buffer requires one core clock cycle. Requesting multiple trace
buffer actions such as setting TLOOP, TCOUNT and TCNEXT in TB_CTRL will require a core clock
cycle for each write - in this case, four clocks. If a long loop with only three execution sets is encountered
with the above TB_CTRL configuration, there are not enough cycles to write all the data. The value of the
extension counter register will be lost.
In TB_CTRL configurations where there are not enough core clock cycles to write all requested trace data,
the priority for writing data is as follows:
1. Destination and source address
2. Counter value
3. Extension counter value
When using the supported modes, source or destination addresses could not be lost.
When tracing in all modes except TMARK and TEXEC, the LSB of the PC of the source execution set is
always 1, while the LSB of all other words in a package is 0. This allows decoding the trace buffer contents
when the trace buffer is set to trace different cases, when all programmed information could not be written
to the trace buffer at the same time.
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SC140 DSP Core Reference Manual
Trace Unit Registers
In order to ensure that the LSB value of the trace data is always valid according to this convention, the
values of the 31-bit event counter and event counter extension are traced shifted one position to the left,
occupying positions [31:1] of the traced 32-bit value. Hence for example a counter value of 0x8 will be
traced as 0x10. The debugger SW should account for this shift when interpreting trace data.
When tracing in TEXEC mode, the LSB of the trace buffer entry is written with the valid T-bit value from
the SR. The value is potentially set by the previous execution set, which is the previous trace buffer entry.
The T bit value in a trace entry relates to the predicated DALU instructions (IFc on DALU instructions) in
the current execution set , and relates to the predicated AGU instructions (IFc on AGU instructions) in the
next execution set .
The tracing modes in the TB_CTRL register can only be changed when the trace buffer is disabled.
Tracing could be enabled again after no less than 5 VLES from when it has been disabled.
Figure 4-28 displays the bit configuration of TB_CTRL. Shaded areas are reserved.
BITS 15-8
7
6
5
TCNTEXT TCOUNT TLOOP
4
3
2
1
BIT 0
TEN
TMARK
TEXEC
TINT
TCHOF
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
Figure 4-28. Trace Buffer Control Register (TB_CTRL)
The TB_CTRL fields are described in the following table.
Table 4-23. TB_CTRL Description
Name
Description
Settings
TCNTEXT
Bit 7
Trace Buffer Extension Counter
Mode — Enables a special mode of the
trace unit where each destination
address put into the trace buffer is
followed by the value of the extension
counter register.
0 = Tracing of the extension counter is disabled
1 = Tracing of the extension counter is enabled
TCOUNT
Bit 6
Trace Buffer Counter Mode —
Enables a special mode of the trace unit
where each destination address put into
the trace buffer is followed by the value
of the event counter register. When both
counter mode bits (TCOUNT and
TCNTEXT) are set, the event counter
register is first written followed by the
extension counter register.
0 = Tracing of the counter is disabled
1 = Tracing of the counter is enabled
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Trace Unit Registers
Table 4-23. TB_CTRL Description (Continued)
Name
Description
Settings
TLOOP
Bit 5
Trace Loops Mode — Enables tracing
the addresses of hardware loops. When
the bit is set, every change of flow
resulting from a loop puts the last
address of loop (LA) into the trace
buffer. In the case of a long loop, the
start address of loop (SA) is put into the
trace buffer after LA. If the loop has a
number of iterations N, the LA and SA of
the loop are written to the trace buffer
(N-1) times. The last iteration of the loop
is executed in normal flow. If LC = 0 or
LC = 1, LA and SA are not written to the
trace buffer.
0 = Loop tracing is disabled.
1 = Loop tracing is enabled.
TEN
Bit 4
Trace Buffer Enable Mode — Enables
tracing. The TEN bit can be set or
cleared directly. It can also be set when
TB is enabled by the ES_ETB. It is
cleared when disabled by the ES_DTB.
0 = Tracing is disabled.
1 = Trace is enabled.
TMARK
Bit 3
Trace Mark Instruction Mode —
Enables the trace of MARK instruction
execution.
0 = MARK instruction is not traced.
1 = PC of MARK instruction is traced.
TEXEC
Bit 2
Trace Issue of Execution Sets Enable
Mode — Enables tracing the addresses
of every issued execution set.
0 = Execution set tracing is disabled.
1 = Execution set tracing is enabled. All other mode bits
should be cleared.
Tracing includes the PC of every issued execution set.
TINT
Bit 1
Trace Interrupts Enable Mode — Used
to enable tracing the addresses of
interrupt vectors. When the bit is set,
each service of an interrupt puts the
address of the last executed or aborted
execution set (before the interrupt) into
the trace buffer as well as the address of
the interrupt vector.
0 = Interrupt tracing is disabled.
1 = Interrupt tracing is enabled.
Tracing includes source PC of interrupt point, the PC
of the interrupt vector, and optional counter values
TCHOF
Bit 0
Trace Addresses of Change-of-Flow
(COF) Instructions Enable Mode —
Used to enable the tracing of addresses
for execution sets containing
change-of-flow instructions. When the
bit is set, every execution of an
execution set containing change-of-flow
instructions (even if the change-of-flow
instruction is executed together with
other instructions in the execution set)
puts into the trace buffer the address of
that execution set (the address of the
first instruction in the execution set) and
the target address of the change-of-flow
instruction.
0 = Tracing of COF instructions is disabled .
1 = Tracing of COF instructions is enabled.
Tracing includes source PC, destination PC and
optional counter value.
4-68
For long loops, tracing includes LA, SA and optional
counter values.
For short loops, tracing includes only the PC of the loop LA
SC140 DSP Core Reference Manual
Trace Unit Registers
4.11.2 Trace Buffer Read Pointer Register (TB_RD)
TB_RD is a 16-bit register that points to the location in the RAM buffer from which the next value is read.
The register is reset when the trace buffer is enabled.
4.11.3 Trace Buffer Write Pointer Register (TB_WR)
TB_WR is a 16-bit register that points to the next location available for writing into the buffer. The register
is reset when the trace buffer is enabled.
4.11.4 Trace Buffer Register (TB_BUFF)
This 32-bit register is used to read the contents of the trace buffer. For details, see Section 4.5.5.3,
“Reading the Trace Buffer (TB_BUFF).” It is a pipeline register inside the core, not the off-core trace
buffer.
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Trace Unit Registers
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SC140 DSP Core Reference Manual
Chapter 5
Program Control
This chapter describes the program control features for the SC140 including:
•
Pipeline
•
Instruction grouping
•
Instruction timing
•
Hardware loops
•
Stack support
•
Processing states
•
Exception processing
The SC140 core, being a multiple ALU processor, has special hardware that can issue up to two AGU and
four DALU instructions at the same time. When two or more instructions are being issued to two or more
execution units in the same clock cycle, these instructions are defined as grouped. The C compiler or the
assembly programmer can specify in the source code which instructions are grouped together according to
the SC140 programming rules. When the assembler compiles the DSP code, it specifies in the encoding
whether an instruction stands alone, or whether it is grouped with other instructions. In each clock cycle,
the dispatch logic detects how many instructions are grouped. Each group of instructions issued to the
execution units on a given clock cycle is called an execution set. Each line of eight words read from the
program memory and associated with an address is called a fetch set.
5.1 Pipeline
This section describes how instructions are processed in the SC140 core pipeline. The SC140 pipeline
consists of five stages:
•
Pre-fetch stage
•
Fetch stage
•
Dispatch stage
•
Address generation stage
•
Execution stage
The first three stages are implemented in the program sequencer unit (PSEQ). The last two stages are
implemented in the AGU and DALU, respectively.
SC140 DSP Core Reference Manual
5-1
Pipeline
To support parallel execution, the core uses a variable length execution set (VLES) architecture with a
static grouping mechanism. Several instructions can be grouped together to form an execution set, which is
dispatched to the execution units in parallel. The core contains four ALUs and two AAUs and thus
execution set can contain up to four DALU instructions and two AGU instructions with a maximum of
eight words. For many instructions, an execution set takes only one clock cycle. For a detailed description
of SC140 core instruction timing, see Section 5.3, “Instruction Timing,” on page 5-14.
5.1.1 Instruction Pipeline Stages
Figure 5-1 illustrates the five instruction pipeline stages.
Pre-fetch
Fetch
Dispatch
Address
Generation
Execution
Figure 5-1. Instruction Pipeline Stages
5-2
SC140 DSP Core Reference Manual
Pipeline
Table 5-1 shows a typical pipeline flow. For the machine to advance to the next instruction cycle, all of the
five operations at the current cycle must be completed.
Table 5-1. Pipeline Example
Instruction Cycle
Operation
Pre-fetch
1
2
3
4
5
6
i1
i2
i3
i4
i5
i6
i1
i2
i3
i4
i5
i6
i1
i2
i3
i4
i5
i6
i1
i2
i3
i4
i5
i6
i1
i2
i3
i4
i5
Fetch
Decode
Address
Generation
Execution
7
8
9
10
11
12
i6
Table 5-2 provides an overview of the operations performed at each stage of the pipeline.
Table 5-2. Pipeline Stages Overview
Pipeline Stage
Description
Pre-fetch
•
•
Generate addresses for program fetch
Update fetch counter (FC)
Fetch
•
Read fetch set from memory
Dispatch
•
•
Dispatch instructions
Decode AGU instructions
Address Generation
•
•
•
•
•
Decode DALU instructions
Generate addresses for data load and store operations
Perform address calculations: normal and change-of-flow
Perform AGU arithmetic instructions
Update AGU registers
Execution
•
•
•
•
•
Read source operands to DALU
Read source register for memory store operations
Perform data calculations (multiply and add)
Write DALU results to destination registers
Write destination register for memory load operations
SC140 DSP Core Reference Manual
5-3
Pipeline
5.1.1.1 Instruction Pre-Fetch and Fetch
The first two stages of the pipeline are the pre-fetch and fetch stages. These two stages combined are
responsible for the program memory read of the fetch set. Each fetch set contains eight instruction words.
In the pre-fetch stage, the address of the fetch set is driven into the program address bus (PAB) along with
the read strobe. This enables the memory read process. While the address is issued to memory, the fetch
counter (FC) in the PSEQ is updated for the next program memory read. Both of these operations occur in
parallel. The address can be generated by the PSEQ for:
•
Normal program flow
•
Exception program flow
•
Hardware loops
•
Change-of-flow instructions in the AGU
The fetch stage, which follows the pre-fetch stage, is dedicated to waiting for the memory access to be
completed. Memory access is completed when the PSEQ samples the program memory value from the
128-bit wide program data bus (PDB).
Since an execution set can overlap to a second fetch set, more than one fetch set is stored in a buffer.
However, the instructions in an execution set need to be dispatched together.
The SC140 core in the current implementation holds an internal fetch buffer of 4 fetch sets (128 bits each).
VLES are dispatched form this buffer to the execution units, emptying the buffer. Dispatching is unrelated
to fetching, and only the actual number of instruction words needed for execution are dispatched. Hence a
single fetch set can be "consumed" anywhere between 1 cycle (in case the VLES is 8 words long) and 8
cycles (in case it contains 8 VLES of 1 word each). The fetch unit tries to keep this buffer full as much as it
can. After reset and after every change of flow (COF), a series of 4 fetch requests is issued to the memory.
Upon dispatch of the last instruction in the fetch set, another fetch request is issued to the memory. In serial
code it means that a fetch is issued between once per cycle and once every 8 cycles, depending on the
width of the VLES that are executed. Hence the main factors that affect the density of fetches on the
program bus are the width of the execution set (number of instructions per set - affects the rate the buffer is
emptied) and the frequency of COF instructions (which trigger a fetch buffer flush and re-fill).
5.1.1.2 Instruction Dispatch
After the fetch set is read from memory to the PSEQ, the PSEQ detects which instructions are grouped into
an execution set. These instructions will be dispatched in parallel such that the number of cycles taken by
the longest instruction will determine the number of cycles for the whole execution set. The PSEQ detects
the type of instructions (such as DALU or AGU), and the AGU instructions are decoded.
5.1.1.3 Address Generation
The address generation pipeline stage is implemented in the AGU and DALU. In the DALU, the address
generation stage includes decoding the DALU instructions. However, in the AGU, the address generation
stage includes updating the address pointers as well as the actual memory accesses (driving the address and
the read/write strobes). The AGU is also responsible for address calculation when a change-of-flow
operation takes place.
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5.1.1.4 Execution
During the execution stage, all DALU arithmetic calculations are performed by:
•
Reading the data operands from source registers
•
Performing arithmetic operations on the data
•
Writing the results to destination registers
5.2 Instruction Grouping
The SC140 instruction set architecture is built around a 16-bit instruction set for optimal code density and
performance. The core contains two AAUs and four ALUs that enable two instructions to the AAUs and
four instructions to the ALUs per clock cycle. The grouping of these instructions is specified explicitly in
the assembly source code and encoded by the assembler, subject to the encoding rules described later in
this section.
Example 5-1 shows an execution set containing the following four SC140 instructions: a MAC, an AND, a
memory read, and an AAU calculation. All four instructions execute independently in a single cycle.
Example 5-1. Four SC140 Instructions in an Execution Set
MACR -D0,D1,D7
AND D4,D5
MOVE.L (R0)+N0,R6
ADDA R2,R3
DALU Instr
DALU Instr
AGU Instr
AGU Instr
In the execution set above, the four SC140 instructions are grouped. When executed, the following occurs:
1. The contents of the D0 and D1 registers are multiplied fractionally. The result is subtracted
from the D7 data register. The final result is then rounded and stored in the D7 data register.
2. The contents of the D4 and D5 registers are ANDed together. The result is stored in the
D5 data register.
3. The contents of the 32-bit memory location (pointed to by the R0 register) are moved into
the R6 register.
4. The address in the R0 register is incremented by the contents of the N0 register.
5. The contents of R2 are added to the R3 register. This result is stored back in the R3 register.
A second case is illustrated in Example 5-2, which shows a six-instruction execution set that executes in
one clock cycle.
Example 5-2. Grouping Six SC140 Instructions in an Execution Set
MAC D0,D1,D7
MAC D3,D4,D6
MACR D0,D2,D5
DALU
Instr
DALU
Instr
DALU
Instr
SC140 DSP Core Reference Manual
ADR D3,D4 MOVE.W(R0)+N3,D2 MOVE.L D0,R1
DALU
Instr
AGU
Instr
AGU
Instr
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Instruction Grouping
In the execution set described above, six SC140 instructions are grouped together. When executed, the
following occurs:
1. The contents of the D0 and D1 registers are multiplied fractionally. The result is added to the
content of the D7 data register. The final result is then stored in the D7 data register.
2. The contents of the D3 and D4 registers are multiplied fractionally. The result is added to
the content of the D6 data register. The final result is then stored in the D6 data register.
3. The contents of the D0 and D2 registers are multiplied fractionally. The result is added to
the content of the D5 data register. The final result is then rounded and stored in the D5 data
register.
4. The contents of the D3 and D4 registers are added together. The result is rounded and stored
in the D4 data register.
5. The contents of the 16-bit memory location pointed to by the R0 register is sign extended
and moved into the D2 register.
6. The content of the N3 register is added to the content of the R0 register. The result is stored
back in the R0 register.
7. The 32 least significant bits of the D0 register are moved to the R1 register.
5.2.1 Grouping Types
The SC140 grouping includes two types of encoding:
•
Serial (non-prefix) grouping, which encodes in the two most significant bits (MSB) of instructions.
•
Prefix grouping, which encodes a one-word or two-word prefix at the start of the execution set.
The Program Dispatch Unit (PDU) in the PSEQ determines which instructions in each clock cycle should
be issued to the execution units. It does this by decoding the grouping information.
In serial grouping, the value 00 in the two most significant bits (MS) of an instruction word indicates that
this word is to be grouped with the next instruction word. An instruction with a value other than 00 in its
two MS bits is considered the last instruction in the set, and marks the execution set boundary.
In prefix grouping, if a prefix exists at the beginning of an execution set, the PDU uses it to determine the
grouping information, including the number of instruction words grouped in the execution set.
Figure 5-2 illustrates the serial and prefix methods for the SC140 grouping mechanism:
Inst. #1
Serial grouping
00
Prefix word(s)
Prefix grouping
Inst. #1
Inst. #2
00
Inst. #3
01
Inst. #2
Inst. #3
011
Figure 5-2. Instruction Grouping Methods
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Prefix grouping can group together any instructions that have available execution units. However, the
prefix method requires one additional instruction word per execution set. Serial grouping is more compact,
but only supports a subset of instructions. The assembler automatically selects serial or prefix grouping
based on the instructions in each execution set so that the encoding length is minimized. The grouping
method selection algorithm is described in Figure 5-3.
5.2.1.1 Serial Grouping
In the serial grouping method, the two most significant bits of each instruction in the execution set provide
the core with the necessary information to perform instruction grouping.
Each SC140 instruction belongs to one of the following four types:
•
Type 1 — Basic DALU and move instructions, which are frequently used single-word
instructions.
•
Type 2 — Additional DALU, move, and AGU arithmetic instructions that are also single-word
instructions, but not used as frequently as Type 1 instructions.
•
Type 3 — Two-word and three-word DALU, move, and AGU arithmetic instructions.
•
Type 4 — All other instructions, which may be one or two words long.
The serial grouping options for an execution set are:
•
One to six Type 1 instructions.
•
One Type 2 instruction grouped with up to five Type 1 instructions, on condition that a Type 2
instruction can be the last in VLES. Refer to Section 7.4.1.3, “Assembler Reordering,” on page
7-3.
•
One Type 3 instruction grouped with up to five Type 1 instructions, on condition that a Type 3
instruction can be the last in VLES. Refer to Section 7.4.1.3, “Assembler Reordering,” on page
7-3.
•
One Type 4 instruction.
The two MS bit combinations that characterize serially grouped Type 1 instructions are:
•
00 for instructions grouped with the next instruction.
•
01 to indicate the last Type 1 instruction in the set.
In serial grouping (by definition), Type 2, 3, and 4 instructions terminate an execution set. Type 4
instructions cannot be grouped with any other instruction.
5.2.1.2 Prefix Grouping
The SC140 architecture uses prefix words to encode architecture extensions for an entire execution set.
The prefix word is a part of the execution set but is not issued directly to any of the execution units.
The grouping information encoded in the prefix includes the number of words to be grouped (including the
number of prefix words) minus one. Valid values are from 0 to 7. A value of 0 corresponds to a NOP
instruction that is not dispatched.
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Instruction Grouping
5.2.2 Prefix Types
The SC140 architecture supports 2 types of prefix instructions, each is used to convey a subset or all of the
following information about the VLES:
•
The number of instructions that are grouped together in the execution set.
•
Conditional execution of the whole set or a subgroup of the set (encoding the IFT/IFF/IFA prefix
instructions).
•
Looping information for supporting hardware loops (encoding the LPMARKA and LPMARKB
bits).
•
Encoding extensions for high register banks (D8-D15, R8-R15).
The prefix instructions use either one or two instruction words. Since the fetch set is eight words long, and
the maximum issue width is six (four DALU instructions and two AGU instructions), there is usually room
for two prefix words without affecting performance. However, in order to save code size, 3 prefix
instruction types were defined. Two one-word prefix types have a subset of the mentioned functionality. A
two-word prefix has all of the listed functionality. The selection of the right prefix type is done by the
assembler which automatically chooses the smallest prefix type (or no prefix at all); see Figure 5-3.
The detailed encoding for prefix words is specified in Appendix A.1.5, “Prefix Word Encoding.”
5.2.2.1 Two-Word Prefix
The two-word prefix includes all information that could be specified in a prefix:
•
Number of instructions in the VLES
•
Mark hardware loop information
•
Specify conditional execution of the VLES or sub-groups of the VLES
•
Encode high register banks (D8-D15, R8-R15)
The SC140 16-bit instruction encoding has a three bit field for specifying each data register or address
pointer register. On their own, these instructions can encode eight DALU registers (D0–D7) and
eight address pointers (R0–R7). In order to specify operands that belong to the high register banks
(D8–D15, and R8–R15), additional register field bits are encoded in a second prefix word.
The two-word prefix includes a register field for each execution unit in the core (namely, four fields for
DALU instructions and two fields for AGU instructions). At most, DALU instructions have three operands
(for example, ADD D0,D1,D2). Therefore, each DALU field is three bits, so that each operand can be
independently specified to be in the high bank. Most AGU instructions have two operands (for example,
MOVE (R0)+,D0). Therefore, each AGU field has two bits.
A register extension bit is added for each possible operand in each execution unit. If this bit is set, it
signifies that the respective operand uses a register from the high bank. If this bit is cleared, or if the
respective set does not include a two-word prefix, the operand uses a register from the low bank. A
two-word prefix is generated by the assembler if at least one of the instructions in the execution set uses a
register from the high bank.
For a description of what conditional execution options are available, see Section 5.2.3, “Conditional
Execution.”
For a description about the function of HW loop support with LPMARK, see Section 5.4, “Hardware
Loops.”
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5.2.2.2 One-Word Low Register Prefix
The One-Word Low register prefix encodes all information of the two-word prefix, except for encoding for
high registers. It is used whenever no instruction in the VLES uses a high register, and a prefix is needed
for one of the other reasons: instruction grouping that cannot be done with serial grouping, conditional
execution of the whole VLES or a sub-group, and encoding for HW loop support.
5.2.3 Conditional Execution
Certain instructions are executed conditional on the state of the T-bit in the status register (SR). For
example, JT (Jump if True) is executed only if the T-bit is set. The SC140 also supports conditional
execution of a group or subgroup of instructions in an execution set. A group or subgroup represents the
instructions that may be conditionally executed depending upon a single condition encoded in the prefix.
The single condition is specified by the following prefix instructions:
Table 5-3. Prefix Instructions
Instruction
Description
IFT (if true)
Execute the group or subgroup if the T bit is set
IFF (if false)
Execute the group or subgroup if the T bit is clear
IFA (if always)
Execute the group or subgroup unconditionally
For example:
IFT
ADD D0,D1,D2
MOVE.L (R0)+,D0
The set as a whole (including the ADD and MOVE instructions) is executed only if the T-bit is set. The
instructions in the subgroups may themselves be conditional. For example, using MOVEc, TFRc and Jc
can add further conditional control. However, the subgroups themselves may not contain another IFc
instruction.
If no IFc instructions exist in the execution set, the default is the unconditional execution of the whole set.
For finer control, it is possible to split the instructions in the execution set into two subgroups 1 and 2,
conditionally controlling the execution of each subgroup independently. Refer to Section 5.2.5,
“Instruction Reordering Within an Execution Set,” for information about how the assembler reorders
instructions for encoding conditional execution sets.
Table 5-4 displays the conditional IFc syntax. In the table, [inst] represents optional additional instructions.
Refer to Section 7.5.3, “Prefix Grouping Rules,” on page 7-11 for the IFc programming rules.
Table 5-4. Conditional IFc Syntax
Assembly Syntax
Meaning
[IFA] inst [inst]
Unconditional execution of the VLES
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Table 5-4. Conditional IFc Syntax
Assembly Syntax
Meaning
IFT inst [inst] IFF inst [inst]
Execution of subgroup1 if T==1
Execution of subgroup2 if T==0
IFT inst [inst]
Execution of the whole group if T==1
IFF inst [inst]
Execution of the whole group if T==0
IFT inst [inst] IFA inst [inst]
Execution of subgroup1 if T==1; always execute subgroup2
IFF inst [inst] IFA inst [inst]
Execution of subgroup1 if T==0; always execute subgroup2
5.2.4 Prefix Selection Algorithm
The grouping method (or encoding of prefix words) is not specified by the programmer. The assembler
analyzes each execution set and attempts to group the instructions in a way that minimizes the number of
instruction words. If possible, serial grouping is chosen. However, if extra grouping information is
necessary, a one-word prefix is generated. A two-word prefix is generated only when high register banks
are used in the execution set. The assembler encodes the execution set according to these principles, as
shown in Figure 5-3.
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Instruction Grouping
Yes
Are registers D8-D15 or
R8–R15 used in the
execution set?
Use a two-word
prefix.
No
Continue
Is the set conditionally
executed (IFc), or does it
convey looping
information?
Yes
Use a one-word
low-register prefix.
No
Continue
Yes
Does the execution set
contain only one
instruction?
No prefix is
needed.
No
Continue
Does the set contain all
Type 1 instructions, except for
a single Type 2 or Type 3
instruction?
Yes
Can a Type 2 or a Type 3
instruction be the last in
VLES?
Yes
No
No
Continue
Use a one-word
low-register prefix.
No prefix is
needed.
Figure 5-3. Low Register Prefix Selection Algorithm
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5.2.5 Instruction Reordering Within an Execution Set
The SC140 can execute up to four DALU instructions and up to two AGU instructions concurrently. These
instructions are grouped together in an execution set and dispatched in parallel to the execution units by the
PDU. Since the execution units of each type are identical (in principle), any ALU can receive any DALU
instruction. As well, any AAU can receive any AGU instruction. The hardware takes advantage of this fact
to reduce internal routing from the PDU to the execution units. As a result of this reduction, some
reordering may be necessary concerning instruction positions within an execution set.
In general, execution set reordering is transparent to application developers. The assembler appropriately
reorders the instruction encoding in an execution set. However, the assembler’s behavior may become
apparent upon disassembly of the binary code when the order of instructions in the set may be different
from the source code. In some rare cases, the assembler may add a NOP instruction in order to accomplish
the reordering.
An execution set can include up to eight instruction words, occupying positions 0 through 7 within the set.
The position of a multi-word instruction is defined as the position of its first word. Example 5-3 shows the
positions occupied by 3 one-word (1w) instructions and 2 two-word (2w) instructions grouped with a
one-word prefix:
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Example 5-3. Execution Set with Three One-word and Two Two-word Instructions
Position 0
1w prefix
1
2
2w - - ext
3
1w
4
5
2w - - ext
6
1w
7
1w
The instruction reordering by the assembler operates as follows:
•
Instruction words of an execution set must be encoded contiguously. No encoding gaps are
allowed.
•
Up to two AGU instructions may appear in an execution set. One must encode in an even position.
The other must encode in an odd position. If there is only one AGU instruction, it can be encoded
anywhere.
•
Up to four DALU instructions may appear in an execution set. These DALU instructions must
encode in different positions in modulo 4 arithmetic. For example, two DALU instructions in the
same set cannot be encoded in positions 0 and 4, positions 1 and 5, and so on.
•
An execution set with a prefix can contain up to 2 two-word instructions. One two-word
instruction must encode in an even position and the other in an odd position. Thus, the 2 two-word
instructions of an execution set must be encoded with an odd number of instruction words between
them.
•
Some execution sets contain two conditional subgroups using IFT/IFF/IFA instructions:
Example 5-4. Conditional VLES Having Two Subgroups
IFT ADD D0,D1,D2 RND D2,D3 IFF SUB D0,D1,D2 ADDA R0,R1
Instructions within a conditional VLES are assigned to two subgroups as follows:
— Subgroup1 — Instructions encode in the even word positions.
— Subgroup2 — Instructions encode in the odd word positions.
This means that in any subgroup one cannot have more then one two-word instruction. (since
according to the previous bullet one two-word instruction should be in even place and the other in
odd).
In this example, instructions of the IFT subgroup encode in subgroup1 (even word positions) while
instructions of the IFF subgroup encode in subgroup2 (odd word positions) of the VLES. The
assembly syntax completely hides this interleaved encoding from the programmer.
•
In cases where more than one DALU instruction in the execution set affects the carry bit C in SR
(according to the instruction definition), the last (right or bottom in the assembly source code)
carry-updating instruction that actually executes updates the carry bit while the other instructions
do not affect the carry bit. If no carry-affecting instructions execute, the carry bit is not affected.
The assembler keeps the last carry-affecting instruction as the last (highest position)
carry-affecting instruction in the VLES encoding. For two IFc subgroups, this encoding rule
applies independently to each subgroup encoding.
In some cases, the assembler adds a NOP instruction during the encoding process. For example, if 2
two-word instructions are grouped, they must be separated by an odd number of instruction words. If no
one-word instructions are included in the set, the assembler inserts a NOP instruction. Example 5-5
illustrates such a case.
Example 5-5. Set of 2 Two-word Instructions Requiring a NOP
MOVE #xxxx,D0 MOVE #xxxx,D1
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Instruction Timing
Given the execution set in Example 5-5, the assembler adds a NOP to the object code for correct encoding.
5.3 Instruction Timing
Most of the instructions used for DSP algorithms take one cycle to execute. They can be grouped together
and executed simultaneously. Other instructions, such as those used in the control portion of the
application, may take more than one cycle to execute. Some of these multi-cycle instructions are
change-of-flow (COF) instructions. Other control-oriented instructions use special addressing modes, or
perform read-modify-write operations on memory.
Most sequential (non-change-of-flow) instructions take one cycle to execute. They include DALU, AGU
arithmetic, and data moves with simple addressing modes. Data moves with address pre-calculation take
two cycles, and atomic read-modify-write BMU instructions take two or three cycles.
Change-of-flow (COF) instructions take three or more cycles to execute. They include direct, PC-relative,
conditional, delayed jumps and branches, and loop control instructions.
Parallel execution takes place when two or more instructions (grouped into an execution set) execute
simultaneously. Instructions belonging to an execution set always start execution concurrently. A set of
instructions start execution only after all the instructions belonging to previous execution sets are
completed. Therefore, an execution set’s execution time is determined by the instruction in the set that has
the longest execution time.
This section describes the time needed to execute SC140 instructions as measured in clock cycles. In the
discussion below, it is assumed that memory accesses are zero wait-state and contention-free, unless
explicitly stated otherwise. This timing is for the current SC140 implementation, and may change with
future implementations.
Interrupt timing and memory access timing is also discussed in this section.
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Table 5-5 summarizes the timing of the various categories of SC140 instructions.
Table 5-5. Instruction Categories Timing Summary
Basic Instruction Category
Example/Condition
DALU
MAC D0, D1, D2
1
Data move with simple addressing
MOVE.W (R0)+N2, D3
1
Data move with address pre-calculation
MOVE.W (R5+N0), D4
2
BMU with simple addressing
BMSET.W #$1010, (R0)
2
BMU with address pre-calculation
BMSET.W #$1010,(SP+$10)
3
Direct change-of-flow
JMP dest
3
PC-relative change-of-flow
BRA dest
4
Conditional change-of-flow
If condition is true
4
If condition is false
1
Delayed change-of-flow
Number of Clock Cycles
Direct
3 (some cycles used by the
execution set in the delay slot)
PC-relative
4 (some cycles used by the
execution set in the delay slot)
5.3.1 Sequential Instruction Timing
This section describes the timing of non-COF instructions:
•
All DALU instructions take one clock cycle to execute.
•
All AGU arithmetic instructions take one cycle to execute.
•
All memory MOVE instructions (zero-wait-states without contention) take one clock cycle to
execute, unless the addressing mode needs to perform a pre-calculation, in which case, the move
executes in two cycles. For example, the move instructions below take two cycles:
—
—
—
—
•
MOVE.L
MOVE.L
MOVE.L
MOVE.L
d0,(Rn
d0,(Rn
d0,(Rn
d0,(SP
+
+
+
+
N0)
$5)
Rm)
$100)
All bit mask (BMU) instructions execute in two cycles on registers and memory (zero-wait-states
without contention) with simple addressing modes. However, if a pre-calculation is required, such
as an SP offset, a third cycle is added.
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5.3.1.1 DALU Instruction Timing
DALU instructions are the most timing-critical instructions in the DSP algorithm kernels, taking only one
cycle to execute. DALU instructions consist, among others, of the following:
•
Multiply-accumulate (MAC)
•
Multiply (MPY)
•
ADD
•
SUB
•
Compare
•
Shift
•
Test
5.3.1.2 Move Instruction Timing
Most of the move instructions take one cycle to execute, assuming a zero-wait-state, contention-free
memory. The exception is for the addressing modes requiring an arithmetic calculation of a new address:
(Rn + N0), (Rn + Rm), (Rn + x), (Rn + xxxx), (SP – xx) and (SP + xxxx). These addressing modes require
one additional clock cycle to calculate the address of the memory access. All the other versions of data
moves are one cycle, including the versions for byte, word, two-word, long-word, four-word, and two
long-word operands (signed or unsigned). Data can be moved between memory and register, or between
registers.
5.3.1.3 Bit Mask Instruction Timing
The SC140 core includes various instructions for bit mask operations. These instructions are helpful when
several bits need to be changed or tested at the same time. The bit mask instructions include the following:
•
Bit mask set (BMSET)
•
Bit mask clear (BMCLR)
•
Bit mask change (BMCHG)
•
Bit mask test (BMTSTS, BMTSTC)
•
Bit mask test and set (BMTSET)
Bit mask instructions are a read-modify-write instruction. This means they have three steps:
1. Read the operand.
2. Change (set, clear, or change) selected bits.
3. Write the operand back to the original location.
This type of instruction takes two clock cycles to execute for the simple addressing modes, and three clock
cycles for the addressing modes that require pre-calculation of the address.
Refer to Appendix A, “SC140 DSP Core Instruction Set,” for a full description of the bit mask instructions.
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5.3.2 Change-Of-Flow Instruction Timing
The change-of-flow (COF) instructions include branches, jumps, traps, returns, conditional branches,
conditional jumps, and loop control instructions that affect the program counter and/or software stack.
Program control instructions may affect or be affected by status register bits as specified in the instruction.
In the SC140 instruction set naming convention, “jump” signifies instructions using a direct destination
address (either absolute or in a register), while “branch” signifies instructions that use a PC-relative offset
to specify the destination address.
Jumps and branches to subroutines (JSR/BSR) include implicit push operations to the stack. Similarly,
returns from subroutines or exceptions (RTS/RTSTK/RTE) include implicit pop operations from the stack.
COF instructions usually take longer to execute because the pipeline is disrupted during their execution.
They are usually most affected by the access time to memory as well as the number of stages in the
pipeline. In order to use time more efficiently, most of the COF instructions have a delayed version that
enables the execution of one execution set while the pipeline is filling up. The delayed instruction
effectively saves one or more cycles over the non-delayed version. The suffix D indicates the delayed
version of an instruction, as in JMP and JMPD. For example, JMPD is the delayed version of the JMP
instruction.
In Example 5-6, the MOVE.W instruction is logically executed before the delayed jump. The delayed COF
instruction JMPD as well as the execution set in the delay slot are a non-interruptible sequence.
Example 5-6. Delayed Change-of-Flow and Its Delay Slot
JMPD
MOVE.W
destination_label
(R0+N0),D0
;delayed COF
;delay slot
COF instructions are of two types - non-loop COF shown in Table 5-6, and loop COF shown in Table 5-7.
Table 5-6. Non-Loop Change-of-Flow Instructions
Instruction
BF
Description
Branch if false
BFD
Branch if false (delayed)
BRA
Branch
BRAD
BSR
BSRD
BT
BTD
JF
Branch (delayed)
Branch to subroutine
Branch to subroutine (delayed)
Branch if true
Branch if true (delayed)
Jump if false
JFD
Jump if false (delayed)
JMP
Jump
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Table 5-6. Non-Loop Change-of-Flow Instructions (Continued)
Instruction
JMPD
JSR
JSRD
JT
Description
Jump (delayed)
Jump to subroutine
Jump to subroutine (delayed)
Jump if true
JTD
Jump if true (delayed)
RTE
Return from exception
RTED
RTS
Return from exception (delayed)
Return from subroutine
RTSD
Return from subroutine (delayed)
RTSTK
Restore PC from the stack, updating SP
RTSTKD
TRAP
Restore PC from the stack, updating SP (delayed)
Execute a precise software exception
Table 5-7. Loop Change-Of-Flow Instructions
Instruction
Description
BREAK
Terminate the loop and branch to an address
CONT
Jump to the start of the loop to start the next iteration
CONTD
Jump to the start of the loop to start the next iteration (delayed)
SKIPLS
Test the active LC and skip the loop if it is equal or smaller than zero
5.3.2.1 Direct, PC-Relative, and Conditional COF
The SC140 core implements a five-stage pipeline with two stages dedicated to memory access. This results
in the addition of two clock cycles for unconditional COF instructions that use immediate values as well as
the addition of three clock cycles for the PC-relative COF instructions. Conditional change-of-flow
instructions, where the condition is true (meaning the change-of-flow operation is taken), always take an
additional three cycles. When a conditional change-of-flow is determined as not taken (meaning the
condition is false), there are no additional cycles.
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Instruction Timing
5.3.2.2 Delayed COF
When a change-of-flow instruction is executed, the core must wait for the pipeline to fill, starting with a
new pre-fetch from memory. A delay slot is the next VLES after a delayed change-of-flow instruction.
Since it is possible to use the delay slots of the change-of-flow operation to continue the execution of the
previously fetched instructions, special delayed instructions are added to the instruction set. These
instructions use part or all of the delay cycles to execute one additional execution set. This effectively
reduces the penalty for utilizing a change-of-flow operation. If the additional execution set in the delay slot
is included in the cycle count, the number of cycles for the change-of-flow instruction are effectively
reduced. Refer to Section 5.3.2, “Change-Of-Flow Instruction Timing,” on page 5-17 for further details.
5.3.2.3 COF Execution Cycles
The basic change-of-flow JMP instruction takes three cycles to execute. However, the number of cycles is
different for the following change-of-flow instructions:
•
PC-relative instructions such as BRA require an additional cycle to calculate the destination.
•
Delayed instructions such as JMPD effectively require the same cycle count as the non-delayed
version (in this example JMP) minus the execution cycle count of the set in the delay slot. This is
the case because the pipeline fill-up time is used to execute a useful execution set. The actual time
taken to jump to the new address is the same for the delayed or non-delayed version. However, the
effective cycle count is less for the delayed version since the execution of the instructions in the
delay slot would be extra counts if the non-delayed version was used.
The delay slot lasts for the full execution time of the set in the delay slot, which may be more than
one cycle. The minimum execution time of a delayed instruction is one cycle. For example:
JMPD dest;
takes 1 cycle (3-2=1), because the next instruction
MOVE.W d0,(sp + xxx) ; takes 2 cycles
Stalls that originate in delay slot instructions, and are caused by a memory access wait-state or
contention, stall the whole core, and are not deducted from the cycle count.
•
Conditional change-of-flow instructions (JT/JF/BT/BF) require four cycles to execute (if taken),
and one cycle to execute (if not taken).
•
The core implements a mechanism for fast return from subroutine. The return address of
subroutines is kept in a hidden return address stack (RAS) register in addition to being pushed to
the stack. This saves the need to read it from the stack in memory upon return. However, this
hidden register is not valid if there was another jump to a subroutine before the return, in which
case, the core adds two cycles to the RTS instruction to read the return address from the stack.
Refer to Section 5.5.5, “Fast Return from Subroutines,” for a more detailed description of the fast
return mechanism.
•
The core keeps a “shadow” version of SP-8 to save pre-calculation time in case of a POP. If SP
was explicitly changed by a TFRA or an AGU arithmetic instruction, the shadow SP is not valid
and another cycle is needed for the first POP pre-calculation (or equivalent, such as RTE). Refer to
Section 5.5.4, “Shadow Stack Pointer Registers,” for a more detailed description of the shadow SP
mechanism.
•
A change-of-flow instruction (jump, branch, interrupt, or long loop iteration) made to an execution
set destination that is spread over two fetch sets, requires an additional cycle for memory access.
An execution set is not necessarily aligned to a fetch set, and can overlap two fetch sets. The core
keeps two fetch sets in a buffer, so this is not normally a problem. However, when a
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Instruction Timing
change-of-flow occurs to a new execution set spread over two fetch sets, two new fetches must be
read from memory.
•
The subroutine call instructions (JSR, JSRD, BSR, and BSRD) need one free cycle in order to
push the return PC and SR onto the stack. Normally, a subroutine call instruction uses one of the
idle cycles while the pipeline is filling up so that no stall occurs. However, one stall cycle is added
if the instructions that execute in parallel with the subroutine CALL need more cycles than a
specific number. In essence, an additional cycle is added to a subroutine call instruction when
(Cjn + Cd) ≥ Cj where:
— Cjn Highest cycle count of instructions grouped with CALL
— Cj
Cycle count of the non-delayed version of CALL (for example, BSR and BSRD, Cj = 4)
— Cd
Cycle count of the set in the delayed slot (if CALL is not a delayed instruction, Cd = 0)
Example 5-7 shows a case when a stall cycle is added.
Example 5-7. Subroutine Call Timing
JSRD _subr
ADDA R0,R1
MOVE.W (R0+2),D0
; Cj = 3, Cjn = 2
; Cd = 1
Table 5-8 summarizes the cycle count for change-of-flow instructions. In the Number of Cycles column,
Cd represents the length of the delay slot in cycles. The technique of subtracting the cycles of the delay slot
instructions from the cycle count of the delayed change-of-flow instruction assumes that the delay slot
instructions’ cycles are counted separately. The net count should be zero since the instructions are
“hidden” in the delay slot. The minimum number of cycles is specified for the delayed instructions, but
only when the number of cycles is small enough for the minimum number of cycles to actually occur. If no
number appears in the Minimum Number of Cycles column, the equation in the Number of Cycles column
applies, with no minimum.
Table 5-8. Number of Cycles Needed by Change-of-Flow Instructions
Instruction
Number of
Cycles
JMP
3
JMPD
3 – Cd
JSR
3
4
JSRD
1+ Cjn
BRA, BSR
4
BRAD
4 – Cd
1
BSRD
4 – Cd
2
1+ Cjn
Condition
1
Cjn < 3
Cjn ≥ 3
Cjn+Cd < 4
Cjn+Cd ≥ 4
Jc/Bc
4
1
Jump is taken.
Jump is not taken.
JcD/BcD
4 – Cd
Jump is taken.
Jump is not taken.
1
5-20
Minimum Number
of Cycles
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Table 5-8. Number of Cycles Needed by Change-of-Flow Instructions (Continued)
Instruction
Number of
Cycles
Minimum Number
of Cycles
Condition
RTE
5
6
Shadow SP is valid.
Shadow SP is not valid.
RTED
5 – Cd
Shadow SP is valid.
Shadow SP is not valid.
6 – Cd
RTS
3
5
6
RTSD
3 – Cd
3 – Cd
RAS is valid.
RAS is not valid and shadow SP is valid.
RAS is not valid and shadow SP is not valid.
1
2
5 – Cd
6 – Cd
RAS is valid and shadow SP is valid.
RAS is valid and shadow SP is not valid.
RAS is not valid and shadow SP is valid.
RAS is not valid and shadow SP is not valid.
RTSTK
5
6
Shadow SP is valid.
Shadow SP is not valid.
RTSTKD
5 – Cd
Shadow SP is valid.
Shadow SP is not valid.
6 – Cd
SKIPLS
4
1
BREAK
4
CONT
3
4
CONTD
3 – Cd
4 – Cd
TRAP
Jump is taken.
Jump is not taken.
SA is taken.
Destination is taken.
1
1
SA is taken.
Destination is taken.
5
5.3.3 Memory Access Timing
The SC140 core executes up to one execution set per cycle. The programmer can specify up to two
memory MOVE instructions per execution set. Since the memory interface has one program and two data
buses, up to three simultaneous memory accesses can occur as described in Section 2.4, “Memory
Interface.”
The memory organization determines when memory contention occurs for simultaneous accesses. There is
likely contention if the same byte-addressed location is accessed. However, there could be a contention in
other cases, due to the memory internal structure. Because memory is not implemented to provide true
multi-port access, accessing of two different addresses in the same memory block may cause a contention.
The intent of the following section is to describe the timing for memory accesses generated by instructions
in the same execution set. In some examples, no problems arise since the memory accesses fall into
different cycles. In other examples, memory contention can occur.
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Instruction Timing
The read or write for each memory access can be mapped to the execution cycle in which they operate
as follows:
•
Cycle 1
— Move read or write without address pre-calculation.
— Bit mask read without address pre-calculation.
— Pop read with shadow SP valid.
•
Cycle 2
— Move read or write with address pre-calculation.
— Bit mask read with address pre-calculation.
— Bit mask write without address pre-calculation.
— Pop read with shadow SP invalid.
•
Cycle 3
— Bit mask write with address pre-calculation.
Contention may occur when two instructions in an execution set attempt to access the same physical
memory module in the same cycle. The memory system evaluates contention on a cycle-by-cycle basis, not
for the execution set as a whole.
The following conventions apply to the execution of memory access operations:
•
Each AGU access operation is performed in its cycle number, independent of any other access.
•
Operations that execute in different cycles are performed in cycle sequence without contention.
•
Bit mask instructions (such as BMSET, BMCLR, and BMCHG) are read-modify-write
instructions. These instructions each generate two memory accesses in sequence.
•
Pop instruction timing depends on the validity of the stack pointer (SP) shadow register that holds
a pre-decremented value of the SP in order to avoid the need for pre-calculation. If shadow SP is
not valid (for example, after an explicit SP update), another cycle is needed for the first pop in
order to perform the pre-calculation.
The following rules apply to cases of contention due to dual access to the same physical memory module
by two instructions in the same cycle:
•
A memory read instruction executes before a memory write instruction.
•
For two memory writes to different locations, the order is undefined, meaning that it is
implementation-specific. The program algorithm should not assume any specific behavior of the
memory system for the memory writes.
•
Two memory writes to the same location in the same execution set is not allowed by the SC140
programming rules. If this occurs, the memory results are undefined.
5.3.3.1 Memory Access Examples
This section describes the contention cases of two memory access instructions grouped in a VLES. If two
memory writes are grouped in a VLES, it is assumed that the two write addresses contend for the same
physical memory module but do not access the same memory locations. Two memory writes to the same
location are not allowed per Section 7.6, “Dynamic Programming Rules.” The following description is
assumes a simple memory without write buffers, where the memory system executes all accesses on a
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cycle-by-cycle basis. Accesses issued on the same cycle may cause a contention. The cases where
contentions will occur and how many stall cycles will be introduced depends on the definition of the
memory system, which may be different than that described below.
Example 5-8 provides an execution set that does not cause contention since the instructions execute in
different cycles.
Example 5-8. Parallel Execution of Two Move Instructions
MOVE.L D0,(R0)
MOVE.B (R1+1),D1;
;Cycle 1: write to memory
;Cycle 2: read from memory, cycle 2 required by the pre-calculation of (R1+1)
Example 5-9 provides two cases of parallel execution by a bit mask and write instruction. In the example,
it is assumed that the memory accesses are made to addresses that cause contention. In Case A, the read
and write operations scheduled for Cycle 1 will cause contention. In Case B, the two write operations in
Cycle 2 will cause contention.
Example 5-9. Execution Set Containing a Bit Mask and a Move Instruction
A)
BMSET.W #$0008,(R1)
MOVE.W D0,($8200);
;Cycle 1: read from (R1); ;write to ($8200)
;Cycle 2: write to (R1)
B)
BMSET.W #$0010,(R1)
MOVE.W D1,(R0+2)
;Cycle 1: read from (R1);
;Cycle 2: write to (R1)
;write to (R0+2)
Example 5-10 shows the parallel execution of a bit mask instruction and a move instruction that does not
cause contention. The write operation from the MOVE instruction occurs at Cycle 1. The BMU read
operation occurs at Cycle 2. The BMU write operation that accesses the same location in memory takes
place at Cycle 3.
Example 5-10. Execution Set Containing One Bit Mask Instruction
BMSET.W #$0080,(SP-2)
MOVE.W D2,($8200)
;Cycle 1: write to ($8200)
;Cycle 2: read from (SP-2)
;Cycle 3: write to (SP-2)
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Instruction Timing
Example 5-11 shows the parallel execution of a bit mask and a pop instruction. The example distinguishes
the cases of a valid and invalid shadow SP (see Section 5.5.4, “Shadow Stack Pointer Registers.” )
If the shadow SP is not valid as in Case A (meaning the address of the stack pointer was overwritten), the
address of the stack pointer (SP–8) must be pre-calculated from the value in SP. There is no contention
since the two read operations occur at different cycles.
If the shadow SP is valid as in Case B, the address of the stack pointer that was saved in the shadow SP is
readily available. Cycle 1 now includes two reads that may access the same location and may cause
contention.
Example 5-11. Execution Set Containing a Bit Mask and a Pop Instruction
A)
BMTSTS.W #$0800,(R0)
POP D0
;Shadow SP is not valid, R0==SP-8
;Cycle 1: read from (R0)
;Cycle 2: read from (SP-8)
B)
BMTSTS.W #$0800,(R0)
POP D0
;Shadow SP is valid
;Cycle 1: read from (R0); read from (SP-8)
5.3.3.2 Implicit Push/Pop Memory Timing
Instructions with implicit push/pop memory access (such as JSR and RTE) execute the memory access
after all other accesses in the execution set have been performed.
Delayed instructions with implicit push memory access (such as JSRD) access memory after all other
accesses in the delay slot have been performed. Delayed instructions with implicit pop memory access
(such as RTSD and so on) access memory before accesses in the delay slot are performed.
Consequently, these instructions do not cause contention when they are executed in parallel with other
instructions that access memory.
5.3.3.3 Memory Stall Conditions
The SC140 can generate up to three memory accesses per cycle consisting of one program fetch and two
data accesses. The extent to which the specific memory configuration can support various kinds of
simultaneous accesses to memory modules may vary from chip to chip. The memory system identifies
access combinations (usually by means of a bus controller) that cannot be supported simultaneously. The
memory system stalls the SC140, which results in the serialization of the contending accesses. For
example, a stall occurs when a memory unit that can support only one access at a time receives a
simultaneous request for two data accesses (or for one program access and one data access). Stalls can also
occur if the memory itself is not zero-wait-states, which may be a characteristic of the memory technology
(such as flash or DRAM), or may occur with off-chip memory.
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Hardware Loops
5.4 Hardware Loops
One of the most important features of a DSP algorithm is efficient loop execution. The SC140 core has a
fully optimized looping mechanism, which enables loop execution with up to four levels of loop nesting.
The loop programming model is part of the PSEQ programming model, and includes four pairs of registers
that specify the start address of the loop as well as the number of times the loop is to be executed.
5.4.1 Loop Programming Model
There are four pairs of loop registers with two registers in each pair:
•
Loop start address registers (SA0, SA1, SA2, SA3)
•
Loop counter registers (LC0, LC1, LC2, LC3)
Each pair is responsible for a single hardware loop. The functionality of each register pair is described in
the sections that follow.
Figure 5-4 shows the hardware loop programming model. This programming model holds the full loop
state and can be saved and restored for exception service routines, context switches, or spill/fill operations
to support additional nesting levels.
31
0
31
0
31
0
31
0
31
0
LC0
SA0
31
0
LC1
SA1
31
0
LC2
SA2
31
0
LC3
SA3
LOOP START
ADDRESS REGISTERS
LOOP COUNTER
REGISTERS
SR
31
30
29
28
27
SLF
LF3
LF2
LF1
LF0
STATUS
REGISTER
Figure 5-4. Hardware Loop Programming Model
5.4.1.1 Loop Start Address Registers (SAn)
The SAn registers are 32-bit read/write registers that are used to define the address of the first execution set
in each loop. The DOSETUPn label instruction initializes the SAn register with the start address. The
LOOPSTARTn assembly directive also marks the start address and must be placed at the same address as
the label of the DOSETUPn instruction.
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Hardware Loops
5.4.1.2 Loop Counter Registers (LCn)
The LCn registers are 32-bit read/write registers used to define the number of times each loop is to be
executed. LCn always holds a 32-bit signed value. This means that the largest number of loop iterations is
231-1. The DOENn or DOENSHn instructions initialize the LCn register.
5.4.1.3 Status Register (SR) Loop Flag Bits
Certain status bits in the SR are associated with hardware loop initiation and execution. These bits are set
and cleared by special loop instructions such as DOENn as well as various loop conditions. Although not
recommended, they can also be set and cleared by explicitly writing the SR register. It is not recommended
to explicitly change these bits while a loop is active. The bits are:
•
Loop Flag Bits — Four loop flag bits (LF0, LF1, LF2, LF3) are defined in the SR, one for each
hardware loop. The bit is set when the loop is initiated by either the DOENn or the DOENSHn
instruction. It is cleared when the loop terminates.
•
Short Loop Flag Bit — This bit (SLF) is set when the loop is initiated by the DOENSHn
instruction. It is cleared when the loop terminates. The short loop can only be used in the
inner-most nesting level.
5.4.2 Loop Notation and Encoding
The notation used in the loop definitions is as follows:
5-26
•
Loop Body — The execution sets that are iterated during loop execution.
•
Long Loop — A loop body that consists of three or more execution sets.
•
Short Loop — A loop body that consists of one or two execution sets.
•
Start address (SA) — The address of the first execution set in a loop body. Do not confuse this
with SA0, SA1, SA2, and SA3, which are register names used to hold SA values. The start address
is defined by the DOSETUPn label instruction and the LOOPSTARTn assembly directive. These
two redundant definitions of the start address must be consistent.
•
Last address (LA) — The address of the last execution set in a loop body. LA is defined by the
LOOPENDn assembly directive. In the case of a loop with only one execution set, SA is also the
last address.
•
SA+1 — Address of the execution set following SA (similarly SA+2, and so on).
•
LA-2 — Address of the execution set that comes two execution sets before the execution set at LA
(similarly LA-1, and so on).
•
LPMARKA and LPMARKB — Two marker bits in the prefix words that identify different
looping conditions. The LPMARK bits are set automatically by the assembler based on the
LOOPSTARTn and LOOPENDn assembly directives, and are not written by the programmer.
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Table 5-9 illustrates the location of these marker bits and their functionality in both short and long loops.
Refer to Appendix A, “SC140 DSP Core Instruction Set,” for further details.
Table 5-9. LPMARKA and LPMARKB Bits in Short and Long Loops
LPMARKA
LPMARKB
Loop Type
Location
Functionality
Location
Functionality
Short loop
SA
Identifies a single-execution
set loop. Causes no timing
overhead.
SA
Identifies a two-execution
set loop. Causes no timing
overhead.
Long loop
LA
Identifies a jump to SA after
executing the set at LA, if the
loop is repeated. Causes a
timing overhead.
LA-2
Identifies a jump to SA
after executing the sets at
LA-2, LA-1, and LA, if the
loop is repeated. Causes
no timing overhead.
5.4.3 Loop Initiation and Execution
The following steps are required to initiate a hardware loop:
1. Execute a DOSETUPn instruction at some stage before the loop starts (except in the case of
a short loop). This instruction writes the start address of the loop to the corresponding SAn
register.
2. Execute a DOENn or DOENSHn instruction to load the corresponding LCn register with the
number of iterations for the loop. The corresponding loop flag bit is implicitly set when LCn
is loaded with the loop iteration value. The SLF is set if the loop is initialized by a
DOENSHn instruction.
3. Execute a SKIPLS instruction before entering the loop to check the value of LCn. If the
value of LCn is less than or equal to zero, then the loop is skipped and the program counter
(PC) is loaded with the address specified in the SKIPLS instruction. If it is guaranteed that
LCn is greater than zero (for example, if the loop is initialized by an immediate value), the
SKIPLS instruction can be omitted. The SKIPLS instruction provides the additional
flexibility of skipping the steps in the loop completely if the loop count is zero initially.
After the LCn is loaded and the LFn bit is set with the DOENn or DOENSHn instruction, the hardware
loop is ready for operation. In long loops, whenever the program reaches the execution set marked by
LPMARKB [which appears two execution sets before the last execution set of the loop (LA-2)], LCn is
compared to the value one in order to detect loop termination. If the value of LCn is greater than one, the
program effectively jumps to the start address while executing the two execution sets at LA-1 and LA. The
LCn is decremented by one and the loop is repeated. If the value of LCn is equal or less than one, the loop
terminates and the loop flag bit is cleared. Execution of instructions continues in sequence.
In short loops, one or two execution sets are stored in internal buffers and repeated the appropriate number
of times according to the value stored in LCn. No program fetches are required for short loops.
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5.4.4 Loop Nesting
The core has four hardware loops (LOOP0, LOOP1, LOOP2 and LOOP3) to execute up to four levels of
loop nesting. A loop can only be nested within a loop that has a lower index. In a nested loop structure,
more than one loop can be enabled at one time. A loop is enabled when its corresponding LFn is set. The
LF3–LF0 bits indicate which of the loops are enabled. The enabled loop with the highest index is defined
as the “active loop”. Only one loop can be active at a time.
Figure 5-5 shows an example of the loop nesting structure.
Loop 0
Loop 2
Loop 3
Figure 5-5. Loop Nesting
In Figure 5-5, all three loops are initially disabled. Loop 3 has the highest index, Loop 2 has the next
highest index, and Loop 0 has the lowest index of the three. In the normal program flow through the loops,
Loop 0 is enabled and its first iteration takes it to Loop 2, which is enabled. Loop 2 has a higher index than
Loop 0, so Loop 2 is the active loop. In the first iteration of Loop 2, Loop 3 is enabled and now becomes
the active loop. Loop 3 is active until it has finished repeating, at which time Loop 2 becomes active. When
Loop 2 stops repeating (including further complete cycles of Loop 3), Loop 0 becomes the active loop.
When Loop 0 stops repeating, no loops are active.
5.4.5 Loop Iteration and Termination
The CONT instruction causes the active loop iteration to conditionally terminate before reaching the last
execution set of the loop. If the value of LCn is greater than one, then the CONT instruction causes the
program to jump to the address stored in SAn. The LCn is decremented by one and the loop is repeated. If
the value of LCn is less than or equal to one, then the CONT instruction causes the program to branch to
the address specified by the CONT instruction. The LCn is cleared and the loop terminates (LFx is
cleared).
The BREAK instruction also causes the active loop to terminate. The program address bus is loaded with
the address specified by the BREAK instruction. The loop terminates (LFx is cleared) regardless of the
value of LCn, which is not changed.
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5.4.6 Loop Control Instructions
Table 5-10 lists the loop instructions.
Table 5-10. Loop Control Instructions
Instruction
Operation
DOSETUPn <label>
Initialize register SAn with <label> address.
Used only in long loops.
DOENn (reg or imm)
Activate loop n as a long loop. Performs the
following operations:
• Initializes LCn
• Sets LFn in the SR
DOENSHn (reg or imm)
Activate loop n as a short loop. Performs the
following operations:
• Initializes LCn
• Sets LFn and SLF in the SR
SKIPLS <label>
If LCn <= 0, jumps to <label>, clearing LFn.
CONT <label>
Within an active loop, if LC > 1, jumps to SAn and
decrements LCn. If LC <= 1 jumps to <label> and
clears the LCn register as well as LFn.
CONTD <label>
Provides a delayed version of the CONT
instruction.
BREAK <label>
Within an active loop, jumps to <label> and clears
LFn.
The instructions that activate the loop are either DOENn or DOENSHn. In nested loops, DOENn or
DOENSHn must be re-executed in order to re-activate the inner loops. In other words, the DOENn or
DOENSHn instruction for an inner loop must be contained in its corresponding outer loop. DOSETUPn is
only used to initialize SAn in long loops and need not be re-executed if the value of the SAn register is
unchanged. In short loop initialization, DOSETUPn is not needed at all. The instructions SKIPLS, CONT,
and BREAK (along with their variants) are optional, to be used only if needed.
The above instructions are assembled from source mnemonics in the conventional way. They are also
disassembled normally. In addition, looping bits are encoded in the instruction prefix. When coding a
hardware loop in assembly, two loop-related assembly directives must be used to set the LPMARKA and
LPMARKB bits as follows:
•
LOOPSTARTn — Placed immediately before SA.
•
LOOPENDn — Placed immediately after LA.
By definition, a loop body n is enveloped by the LOOPSTARTn and LOOPENDn directives.
In disassembled code, the LOOPSTART and LOOPEND directives are not available. The start address
information is encoded as an offset in the DOSETUPn instruction for long loops, or in the LPMARK
prefix bits for short loops. The last address information is encoded in the LPMARK prefix bits for long
loops. The assembler normally places the LPMARKB bit at LA-2. For special cases, such as a SKIPLS
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instruction to the last address, the LPMARKA bit will be placed at LA in addition to the LPMARKB bit at
LA-2. In nested loops, if the LPMARKA and LPMARKB bits occur in the same execution set, the
LPMARKA bit belongs to the inner loop, and the LPMARKB bit belongs to the outer loop.
The following is an example of a long loop.
Example 5-12. Long Loop
dosetup0
_start0
doen0 #$10
move.w
(r3)+,d1
skipls
_end0
loopstart0
SA
Initializes SA0 with address
corresponding to _start0
Activates loop0, puts 16 into LC0,
sets LF0
Puts data into d1
Skips loop if LC0 = 0
Assembler directive denoting loopstart
_start0
LA
mac
d0,d1,d2
add
d5,d6,d4
sub
d3,d2,d4
mac
d0,d1,d6
sub
d5,d4,d4
loopend0
move.w (r0)+,d0
move.w (r1)+,d5
inc d5
move.w (r0)+,d7
inc d7
Loop body
LPMARKB
_end0
Example 5-13 shows the disassembly of the long loop in Example 5-12.
Example 5-13. Long Loop Disassembly
p:$00380000
p:$00380004
p:$00380006
p:$00380008
p:$0038000c
p:$00380010
p:$00380014
p:$0038001a
p:$0038001e
2803
9050
511b
2103
2111
2e5a
94d0
2311
2e35
800c
801a
5018
5519
6e3d 66ef
5718
67ef
=
=
=
=
=
=
=
=
=
dosetup0 *+$c
doen0 #<$10
move.w (r3)+,d1
skipls >*+$1a
mac d0,d1,d2 move.w (r0)+,d0
add d5,d6,d4 move.w (r1)+,d5
lpmarkb sub d3,d2,d4 inc d5
mac d0,d1,d6 move.w (r0)+,d7
sub d5,d4,d4 inc d7
The following is an example of a short loop in two execution sets.
Example 5-14. Short Loop, Two Execution Sets
SA
LA
5-30
doensh0#$10
...
loopstart0
mac
d0,d1,d2
add
d5,d6,d4
loopend0
move.w (r0)+,d0
move.w (r1)+,d5
LPMARKB
Loop body
SC140 DSP Core Reference Manual
Hardware Loops
The following is an example of a short loop in one execution set.
Example 5-15. Short Loop, One Execution Set
doensh0#$10
...
loopstart0
mac
d0,d1,d2
loopend0
SA, LA
move.w (r0)+,d0
Loop body
LPMARKA
The following is an example of a nested loop.
Example 5-16. Nested Loop
dosetup0 _start0
dosetup1 _start1
doen0
#$10
...
loopstart0
_start0
SA
loop 0
SA
LA
LA
loop 1
loop 1
loop 0
bmset
#$ff01,d0
doen1
d7
clr
d2
skipls
_end1
loopstart1
_start1
mac d0,d1,d2 move.w (r0)+,d0
add d5,d6,d4 move.w (r1)+,d5
sub d3,d2,d4 inc d5
mac d4,d5,d6 move.w (r0)+,d4
add d3,d4,d6 move.w (r1)+,d3
loopend1
_end1 inc
d0
loopend0
_end0
Loop body 0
Loop
body
1
loop 1
loop 0
loop 0
LPMARKB
LPMARKB
LPMARKA
In Example 5-16, the LPMARKA bit of loop 0 is set because the SKIPLS instruction can skip over the
LPMARKB bit of loop 0.
The assembler sets the appropriate LPMARK bits, adding a prefix word with the loopstart or loopend
information, if necessary. In disassembly, these LPMARK bits (if used) appear preceding the normal
disassembled mnemonics of the set.
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Stack Support
5.4.7 Loop Timing
If the loop starting address is not aligned (meaning that the first execution set is spread over two fetch sets),
one stall cycle is added to the loop execution on each iteration of the loop. In every other case, no stall
cycles are added to the loop execution time. A loop may be aligned with the assembler directive FALIGN,
which when placed just before the LOOPSTART, will cause the assembler to insert NOP instructions in
order to align the first execution set of the loop.
At the end of a long loop having LCn greater than one, decoding a LPMARKB bit does not cause a stall.
Whereas decoding a LPMARKA bit in the same situation, adds the change-of-flow stall cycles.
5.5 Stack Support
Multitasking creates the impression that the DSP is executing several tasks concurrently, when in reality it
is only executing a single task at any given time. The SC140 core has many features that help software
designers implement a software stack, and more efficiently support a multitasking real time operating
system (RTOS). These features include:
•
Two stack pointers: one for the normal stack (NSP) and one for the exception stack (ESP), only
one of which is active at a time (referenced as SP)
•
Separate user/normal and exception working modes
•
Push and pop instructions
•
Stack-oriented addressing modes
5.5.1 SC140 Single Stack Memory Use
Task
SP
Task
SP
Extra space allocated for RTOS
Task Stack
SP
Task Stack
Task
Task Stack
In a single stack pointer system, each task stack must allocate memory for RTOS function calls and
interrupts. Thus, extra memory is allocated on each task stack as shown in Figure 5-6.
Extra space allocated for interrupts
Figure 5-6. SC140 Memory Use with a Single Stack Pointer
The memory space for interrupts is replicated on each task stack since any task can be interrupted. The
interrupt functions can use the stack for subroutines, local variables, and so on. So each task stack must be
increased by the size of the maximal interrupt memory use.
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Stack Support
Memory space is required for interrupts because any task may be active when an interrupt occurs. The ISR
pushes registers on the current stack and may also allocate local variables on the current stack. Since it is
not known which task is being executed when an interrupt occurs, each task stack must be increased by the
maximum ISR memory use. In both situations, the memory is used only once, but it is allocated in more
than one location. RTOS functions return without switching tasks. In addition, RTOS calls are not
preemptable, although they are interruptible. Interrupts have the same behavior as RTOS functions in that
they return without switching tasks.
5.5.2 SC140 Dual Stack Memory Use
The solution to excessive stack memory use is to separate tasks from the RTOS and interrupts. This is done
by using the user/normal and exception working modes. The programming model has two stack pointers:
NSP and ESP. The NSP is used by tasks when the core is in the user or normal working modes. The ESP is
used in the exception working mode by the RTOS and interrupts. Since the RTOS and interrupts have their
own stack pointer, memory for the RTOS and interrupts can be allocated separately. Thus, the RTOS and
interrupt code can be modified independently of the tasks.
Task
Stack
Task
NSP
Task
NSP
ESP
Exception
Stack
NSP
Space allocated for interrupts
Space allocated for RTOS calls
Task
Stack
Task
Task
Stack
Figure 5-7 shows the stack structure.
Figure 5-7. SC140 Memory Use with Dual Stack Pointers
The core uses the exception working mode whenever it is processing an exception. When an exception
occurs, the core switches to the ESP, saves the PC and SR, and uses the exception stack later for saving
registers and allocating local variables and subroutine calls.
RTOS calls are performed by executing a TRAP instructions, which generates a software interrupt. Since
the processor is now in exception working mode, all stack memory use is on the exception stack.
As the core enters the exception working mode, the RTOS usually needs to save the current context by
storing registers other than the SR and PC in the normal stack. For this purpose, specialized push and pop
instructions (PUSHN/POPN) are provided that always access the normal stack, regardless of the mode.
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Stack Support
5.5.3 Stack Support Instructions
The core provides push and pop instructions that reference the active stack pointer (NSP or ESP).
Table 5-11 describes these instructions.
Table 5-11. Stack Push/Pop Instructions
Instruction
POP
Description
Pre-decrement the stack by eight and restore one 32-bit register
POPN
Same as POP, but using the NSP regardless of the working mode
PUSH
Push a single 32-bit register onto the active stack and increment the pointer by
eight
PUSHN
Same as PUSH, but using the NSP regardless of the working mode
In addition, the stack can be accessed with move or bit mask instructions that use short and word
displacement addressing with the stack pointer as a base pointer. However, these instructions do not
change the value of the stack pointer. Generally, the stack pointer points to the next unoccupied location.
While using the pop/push instructions, all SC140 registers are viewed as two separate banks, an even
register file bank and an odd register file bank (as shown in Table 5-12).
Table 5-12. Even and Odd Registers
Even Register (De) File
Odd Register (Do) File
D0 D2 D4 D6 D8 D10 D12 D14
D0.e D2.e D4.e D6.e
D8.e D10.e D12.e D14.e
D0.e:D1.e D2.e:D3.e D4.e:D5.e D6.e:D7.e
D8.e:D9.e D10.e:D11.e D12.e:D13.e D14.e:D15.e
R0 R2 R4 R6 R8 R10 R12 R14
B0 B2 B4 B6
N0 N2 M0 M2
SA0 SA1 SA2 SA3
D1 D3 D5 D7 D9 D11 D13 D15
D1.e D3.e D5.e D7.e
D9.e D11.e D13.e D15.e
R1 R3 R5 R7 R9 R11 R13 R15
B1 B3 B5 B7
N1 N3 M1 M3
LC0 LC1 LC2 LC3
VBA SR MCTL
Up to two push instructions are supported in a single execution set. If two push instructions are included in
a single execution set, one push instruction must use an even register operand, and the other push
instruction must use an odd register operand. A push instruction always pushes one 32-bit register into the
stack. Any execution set that includes one or two push instructions increments the stack pointer by eight. In
the case of a single push, a single operand is written to the memory while the adjacent memory location
remains unchanged.
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Stack Support
Table 5-13 describes the stack memory map while performing a single or a dual push access.
Table 5-13. Stack Memory Map
Type
Memory Location X+4
Memory Location X
Single push - even register
Unused
Even operand
Single push - odd register
Odd operand
Unused
Dual push
Odd operand
Even operand
Up to two pop instructions are supported in a single execution set. If two pop instructions are included in a
single execution set, one pop instruction must use an even register operand and the other pop instruction
must use an odd register operand.
An execution set that includes one or two pop instructions restores De from SP–8 and/or Do from SP–4
(See Table 5-12 for the definition of De and Do). The execution set decrements the original stack pointer
by eight as specified by the operands. Note that if the stack is popped with one register only, the data from
the other pushed register may be lost.
Pushing and popping the data extension register (Dx.e + Lx tag bit) are unique operations. It is possible to
push two extensions that are coupled together to form a single operand, or to push a single extension. The
single extensions are divided between the even and odd tables. In both cases, the push operation occupies
32 bits. For more information, see Table 5-12, as well as the PUSH and POP instructions in Appendix A.
For correct operation, the stack should be popped in reverse order with exactly the same register pairing as
it was pushed. When dual push instructions are used in an execution set, the corresponding pop instructions
should be dual. The pop operands should match the corresponding push operands.
In addition to the push and pop instructions, the stack can be accessed directly with move or bit-mask
instructions. The available addressing modes are shown in Table 5-14. The two addressing modes differ in
the instruction word count. Note that the user cannot use addressing modes that update SP during the
access, but only short or word displacement addressing modes that leave the SP unchanged.
Table 5-14. Stack Move Instructions
Addressing Mode
Description
(SP - xx)
Subtract offset by a shifted unsigned 5-bit or
6-bit immediate value. The SP remains
unchanged.
(SP + xxxx)
Add a signed 15-bit immediate offset. The SP
remains unchanged.
5.5.4 Shadow Stack Pointer Registers
The stack normally grows by incrementing SP and shrinks by decrementing SP. Both stack pointers have
shadow registers that contain a decremented value of the stack pointers. When the shadow register is not
valid, the pop instruction is executed in two cycles where the first cycle is used to decrement the stack
pointer. When the shadow register is valid, the pop instruction is executed in only one cycle.
When an NSP or ESP is written (by TFRA), then its shadow register automatically becomes invalid. In this
situation, the first pop instruction takes an additional cycle. When a push/pop instruction is executed, then
the shadow register of the active NSP or ESP becomes valid.
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Stack Support
5.5.5 Fast Return from Subroutines
The SC140 supports a mechanism for speeding up the execution of the return from subroutine (RTS)
instruction, using a return address stack (RAS) register. The RAS is updated with the return address during
the execution of a JSR or BSR instruction.
Normal execution of an RTS takes five to six execution cycles. If the routine performing the RTS is a leaf
routine (meaning that no other RTS has been executed between the jump to this subroutine and the
execution of the RTS), then RTS executes in three cycles. Upon RTS, the RAS is invalidated until the next
JSR or BSR instruction.
The user is not allowed to create a situation where upon using RTS, the RAS is valid but the return address
does not match the one that is stored in the stack. This situation may occur if the user explicitly changed
the return address in the stack. See Rule J.4 in Chapter 7, “Programming Rules.”
The RTSTK instruction can be used to bypass the special logic that implements this fast RTS mechanism.
This instruction retrieves the return address from the stack also when the RAS is valid. RTSTK is typically
used when the return address from subroutine is explicitly changed in the stack.
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Working Modes
5.6 Working Modes
The working mode is determined by the EXP bit in theStatus Register (SR), as shown in the table below:
Table 5-15. Working Modes
Working Mode
EXP bit
Active SP
Normal
0
NSP
Exception
1
ESP
The SC140 can operate in one of two working modes.
Normal mode -
Typically intended for task-related services. Works with NSP as the stack pointer.
Exception mode - Typically intended for RTOS kernels, exception routines and peripheral device
drivers. Works with the ESP as the stack pointer.
5.6.1 Normal Working Mode
This mode uses the Normal Stack Pointer (NSP). This mode is intended for application tasks that were
each allocated a distinct stack area. It could also be used for RTOS services that are tightly related to a
specific task, and hence would work more efficiently if they could reference the NSP with SP. Example for
such tasks are memory allocation and management tasks, or RTOS messaging services that need
observability into the task data structures.
The core stays in this mode unless:
•
An exception is encountered, as described in
•
A hardware reset occurs, as described in Section 5.7.4, “Reset Processing State.”
•
An RTE-like instruction (RTE/D) is issued,.
5.6.2 Exception Working Mode
This mode uses the Exception Stack Pointer (ESP). It is intended for the RTOS kernel, interrupt service
routines, peripheral device drivers, etc. Also, application code for single stack systems runs in this mode.
The SC140 core can enter the exception working mode in any of the following ways:
•
An external hardware interrupt request is issued to the core, for example by an off-chip device or
an on-chip peripheral.
•
A software exception request (TRAP) is issued by the program itself.
•
An internal exception such as an illegal opcode, illegal execution set, or DALU overflow occurs.
•
A debug exception request is issued by the EOnCE.
This is the default state of the core after exiting the reset state. Refer to Section 5.8, “Exception
Processing,” for a detailed description of the different exception types, and of the way an exception is
serviced.
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Working Modes
5.6.3 Typical Working Mode Usage Scenarios
The core changes its working modein different ways, depending on the protection and stack paradigm in
use. The sections immediately below illustrate two common task management paradigms supported by the
SC140 core, that may be used by an RTOS: Dual-stack, and Single-stack
The terms “single” or “dual” stack refer to the number of stack pointer registers that are used by the
system. When using a dual stack-pointer configuration, the RTOS can implement what is termed a
multi-stack system. In such configurations, the stack pointer allocated for user tasks can be changed at each
task switch to point to a different memory location for each task.
5.6.3.1
Dual-stack RTOS
Figure 5-8 illustrates the working mode transitions for dual-stack operating systems.
Reset
nested exceptions
and external interrupt
requests
Exception Mode
EXP SP
1
ESP
return from exception via
RTE/D
RTOS call (via TRAP),
or exception,
or external interrupt
request
Normal Mode
EXP SP
0
NSP
Figure 5-8. Working mode Transitions - Unprotected Dual-stack RTOS
The dual-stack operating system kernel executes in the Exception working mode. User task context is
initialized while in the Exception working mode. User task invocation occurs when an RTE/D instruction
is executed that restores EXP=0 in the SR. The user task executes in the Normal working mode until it
requests operating system services using a TRAP instruction, or an exception or external interrupt request
occurs. When the working mode changes from Normal to Exception mode, EXP is set by the core, and the
previous SR is pushed on the exception stack.
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Working Modes
5.6.3.2
Single-stack RTOS
Figure 5-9 illustrates state transitions for a single-stack-based operating system.
Reset
exception
or external interrupt
request
Exception Mode
EXP SP
1
ESP
return from exception via
RTE/D
Figure 5-9. Working mode Transitions - Unprotected Single-stack RTOS
Existing single-stack operating systems operate exclusively in the Exception working mode. The EXP bit
is always set, making ESP the active SP for all operating system and user tasks. Transfer of control
between the operating system and user tasks is typically made via change-of-flow (COF) instructions (JSR,
RTS/D and RTSTK/D). If an exception is taken, the exception service routine returns control via RTE/D.
5.6.4 Working Mode Transitions
5.6.4.1 From Exception to Normal mode
The core leaves the Exception mode and enters the Normal mode by either explicitly changing the EXP bit
in the SR (for example with the instruction: BMCLR #4,SR.H), or executing a Return From Exception
(RTE/D) instruction. If this transition is to be taken to a new task that is not on the stack, the stack must be
pre-loaded with suitable values before performing the RTE. The following explicit actions must be taken:
•
The address of the first VLES for the task must be stored in the memory location representing the
PC on the active (ESP) stack.
•
The memory location representing SR on the active (ESP) stack must be set with EXP=0.
•
An RTE/D instruction restores the PC and SR from the active (ESP) stack.
From the core’s point of view, the difference between Exception and Normal modes is only the identity of
the active stack pointer (NSP vs. ESP).
5.6.4.2 From Normal to Exception mode
The core leaves the Normal mode and enters the Exception mode upon taking an exception, either via a
TRAP instructions, or via an imprecise exception or interrupt request. It can also enter the Exception mode
by explicitly setting the EXP in the SR (directly using an instruction or indirectly using RTE where in the
restored SR EXP=1). Upon an exception, the following implicit actions occur:
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Working Modes
•
The EXP bit in the SR is set(if not already), thereby enabling the Exception Stack Pointer (ESP) as
the active SP.
•
The PC and previous SR are pushed on the active (ESP) stack.
•
The PC jumps to the Vector Base Address (VBA) + Exception Offset Address. For example,
executing a TRAP instruction causes the core to enter an Exception state and begin executing
instructions at VBA + 0x00, since the TRAP instruction has an exception offset address of 0x00.
If choosing to prepare the return values on the stack explicitly to perform this transition, the programmer
should be aware that in Normal mode RTE uses the active stack (NSP).
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Processing States
5.7 Processing States
The SC140 core is always in one of the five processing states:
•
Execution
•
Debug
•
Reset
•
Wait
•
Stop
These states are described in the sections that follow. In some states, the operation of peripherals and other
blocks is affected.
Note:
The descriptions of the change in operation given here may be different for certain products that
utilize a SC140 core. Consult the product-specific manuals for details of actions in each processing
state.
5.7.1 Processing State Change Instructions
Processing state changes can be initiated by hardware or software means. Table 5-16 lists the instructions
that can initiate a processing state change.
Table 5-16. Processing State Change Instructions
Instruction
DEBUG
DEBUGEV
Description
Enter debug state
Signal a debug event
STOP
Stop processing (lowest power stand-by)
WAIT
Wait for interrupt (low power stand-by)
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Processing States
5.7.2 Processing State Transitions
The transitions between the states are summarized in the following figure.
EXECUTION
14
11
8
4
5
10
DEBUG
RESET
3
13
9
12
7
6
WAIT
2
1
STOP
Figure 5-10. Core State Diagram
Table 5-17 describes the processing state transitions shown in Figure 5-10.
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Processing States
Table 5-17. Processing State Transitions
Processing State Transitions
1, 2, 3, 4
5
6, 7
Description
Assertion of one of the core hardware reset
input signals.
De-assertion of reset if EE0 or a JTAG debug
command is asserted during reset
Entering debug state through an external
request (JTAG, EE pin or system input).
8
Entering debug state through execution of
debug/debugev, or occurrence of EOnCE
events as programmed in the activated
EOnCE, or an external request ((JTAG, EE pin
or system input)
9
Executing the STOP instruction.
10
Executing the WAIT instruction.
11
De-assertion of the reset signal, assuming
EE0 not asserted.
12
Assertion of one of the exit from STOP signals.
13
Assertion of an unmasked interrupt request.
14
Programming change to the EOnCE control
registers through the JTAG.
5.7.3 Execution State
The execution state is where instructions are repeatedly fetched and executed. All software runs in the
execution state.
5.7.4 Reset Processing State
The reset processing state is entered when an external core hardware reset occurs. Upon entering the reset
state, the following registers are updated with their reset values:
•
SR
•
EMR
•
VBA
•
MCTL
Refer to Chapter 3, “Control Registers,” for details on the reset of the various bits of the above registers.
The core remains in the reset state until the end of hardware reset. Upon leaving the reset state, the core
enters the exception working mode, as part of the execution state, and program execution begins at a
derivative-dependent program memory address.
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Processing States
5.7.5 Debug State
The debug state is a special core processing state in which the pipeline is stalled and waits for user
commands from the JTAG or EOnCE. The core can enter the Debug state in the following cases:
•
JTAG issues a debug request is asserted, in all states.
•
The EE0 EOnCE signal is asserted during reset.
•
The EE0 EOnCE signal is asserted anytime, if programmed as a debug request input in the
EE_CTRL register.
•
An EOnCE Debug state event occurs.
•
A DEBUG instruction is executed, if the SDD in EMR is not set, and the EOnCE is programmed
so that it will generate a Debug state event.
•
A DEBUGEV instruction is executed, and the EOnCE is programmed so that it will generate a
Debug state event.
If EE0 or the JTAG debug request are asserted during reset and continue to be asserted when reset is
de-asserted, the core enters the debug state without executing any instruction.
The debug state is exited by setting the exit bit in the EOnCE command register by JTAG. Refer to
Chapter 4, “Emulation and Debug (EOnCE),” for a detailed description of the user commands in the
debug state.
5.7.6 Wait Processing State
The wait processing state is a low-power consumption state entered by the execution of the WAIT
instruction. After a system-specific delay of some cycles from the issue of the WAIT instruction, the core’s
global clock is turned off. Peripherals can continue to operate, but all internal processing is halted until one
of the following actions occurs:
•
An interrupt, with enabled priority, is issued1.
•
A non-maskable interrupt (NMI) request is issued.
•
A low-level is applied to the RESET signal (RESET asserted).
•
The JTAG issues a debug request.
•
The EOnCE EE0 signal (programmed as a debug request input) is asserted.
Debug request from the EOnCE may also exit from Wait Processing State, if it occur a few cycles after the
WAIT instruction execution (exact time may vary according to the specific clock scheme implemented).
If an exit from the Wait Processing State is caused by assertion of the EE0 signal or a debug request, the
core either enters the debug state immediately, or the debug exception is serviced according to the EOnCE
configuration. Refer to Chapter 4, “Emulation and Debug (EOnCE),” , for further details.
If the Wait Processing State is exited by assertion of the RESET signal, the core enters the reset processing
state.
Table 5-18 describes exit from Wait Process State, due to interrupt and NMI, under various core
conditions.
1. i.e. IPL of the interrupt is greater than the core IPL, as determined by bits I2-I0 of the SR. See Table 5-18 for more information.
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Processing States
Table 5-18. Exit Wait Processing State due to an Interrupt or NMI
Disable Interrupts
(DI)
Disable NMI
(NMID)
Maskable Request with IPL > core IPL
as determined by the I2–I0 bits of the
SR
Clear (interrupts
enabled)
Clear or set
Exit the wait processing state.
Jump to the Interrupt Service
Routine (ISR).
Maskable Request with IPL > core IPL
as determined by the I2–I0 bits of the
SR
Set (interrupts
disabled)
Clear or set
Exit the wait processing state.
Enter execution state and
continue program execution,
following the WAIT instruction.
No jump to the ISR.
Maskable Request with IPL <= core IPL
as determined by the I2–I0 bits of the
SR
Clear or set
Clear or set
Remain in the wait processing
state.
Non-maskable request
Clear or set
Clear
Exit the wait processing state.
Jump to the ISR.
Non-maskable request
Clear or set
Set
Exit the wait processing state.
Enter execution state and
continue program execution,
following the WAIT instruction.
No jump to the ISR.
Interrupt Request
Wait Process
5.7.7 Stop Processing State
The stop processing state is the lowest power consumption state and is entered by the execution of the
STOP instruction. After the STOP instruction has been issued, it takes a system-specific number of clock
cycles to enter the stop state and turn off the global clocks to the entire core and peripherals. The core exits
from the stop processing state when one of the following occurs:
•
A dedicated core “wake from stop” input signal is asserted.
•
The RESET signal is asserted.
•
The JTAG controller issues a debug request.
•
The EE0 signal (programmed as a debug request input) is asserted.
Debug request from the EOnCE may also exit from Stop Processing State, if it occurs few cycles after the
STOP instruction execution (exact time may vary according to the specific clock scheme implemented).
If an exit from the stop processing state is caused by assertion of the EE0 signal or a debug request, the
core either enters the debug state immediately, or the debug exception is serviced according to the EOnCE
configuration.Refer to the EOnCE Reference Manual, for further details.
If the Stop Processing State is exited by assertion of the RESET signal, the core enters the reset processing
state.
If the stop processing state is exited during the assertion of an external interrupt request, the core enters the
exception mode and services the highest priority pending interrupt. If no interrupt is pending, the core
enters the execution state and executes the instruction following the STOP instruction that caused the entry
into the stop state.
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Exception Processing
5.8 Exception Processing
Exceptions are events that interfere with the normal operation of the core and the system in which it works.
The Exception working mode was designed to deal with situations such as these. In general, the
prioritizing and arbitrating between all the exception sources is performed in the programmable interrupt
controller (PIC), which is not part of the SC140 core. This section describes the exception handling after
the PIC has determined which interrupt request is issued to the core.
A distinction is made between the terms “exception” and “interrupt” in this section. “Exception” is used as
a general term for all the cases that interfere with normal program execution, whether generated by
hardware or software, internal or external. “Interrupt” is used only for external (off-core) hardware
interrupt sources.
There are three categories of exceptions as listed below:
•
Internal Exceptions — These have the highest priority, ranging from 0 to 3, with 0 the highest.
Each of these three, TRAP, ILLEGAL, and DEBUG, has a separate priority and a separate offset
address vector. The offset address vector forms part of the address to which the program jumps to
perform a particular routine in response to the exception.
•
Non-Maskable External Interrupts — These have the next highest priority level, four. A
non-maskable external interrupt is driven from the external interrupt controller. Its offset address
vector is either the AUTO-VEC (0x180) or the value on the 6-bit Interrupt Offset bus.
•
Maskable External Interrupts — These have the lowest priority level, five (in comparison to the
above exceptions). Each occurrence of a maskable external interrupt has an interrupt priority level
(IPL) associated with it, driven on the IPL bus. This IPL value is compared to the internal masking
threshold defined in the SR. If the IPL exceeds the threshold, it can be serviced. The offset address
value is either the AUTO-VEC (0x1c0) or the value on the 6-bit Interrupt Offset bus.
Note that two types of priority terms are in use here. One is the priority among the three major types above,
including the four levels in type 1. The second is the interrupt priority level, from 0 to 7, which only
applies within the maskable external interrupts. The first priority type, with values from 0 to 5, determines
which exception is to be taken if two or more exceptions are pending on the same clock cycle. The second
priority type, the interrupt priority level, determines whether a maskable external interrupt is taken or not.
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Figure 5-11 below depicts the core interface to an external interrupt controller.
INTERRUPT OFFSET
6
6
NMI_REQ
20
IREQ
VBA
6
AUTO_VEC
3
IPL
Program
Sequencer
PSEQ
PAB
Internal
Exceptions
SC140
Figure 5-11. Core-PIC Interface
The interface signals (inputs to the core from an external interrupt controller) are described in the
following list.
•
Maskable Interrupt Request Signal (IREQ) — Asserted to inform the core of a pending
maskable interrupt request.
•
Interrupt Request Priority Level (IPL) — This 3-bit bus defines the priority level of the
maskable interrupt request. If this value exceeds the value encoded in the SR bits I[2:0], the
interrupt can be serviced. Otherwise, it is masked.
•
Non-maskable Interrupt Request (NMI_REQ) — Assertion of this signal initiates an interrupt
independent of the value on the IPL bus or the SR priority level. This input can be inhibited by the
non-masked interrupt disable (NMID) bit in the Exception and Mode Register (EMR).
•
Enable Auto-vector (AUTO_VEC) — This signal selects the source for the offset part of the
interrupt vector address: either the default offset or the value driven by the user on the 8-bit
INTERRUPT OFFSET bus. This selection affects both maskable and non-maskable interrupts.
•
INTERRUPT OFFSET — This 6-bit value can be the offset address applied to the interrupt
vector address table. It is selected if the AUTO_VEC (above) does not select the default offset.
The complete address of the interrupt vector is defined by a number of fields. For more details, see
Section 5.8.1.2, “Programming Exception Routine Addresses.”
The following list outlines how exceptions are processed by the SC140:
1. The hardware interrupt request is synchronized with the core clock. The interrupt pending
request signal for that particular hardware interrupt is set. An internal exception (such as an
illegal instruction) is processed in the PSEQ internally as a non-maskable exception request.
An exception source can have only one exception pending at any given time.
2. The PSEQ in the core automatically ignores any interrupt request with an IPL lower than or
equal to the interrupt mask level in the SR. NMIs and internal exceptions are serviced
regardless of the current IPL.
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Exception Processing
3. The PSEQ services an exception request when ready, typically in five cycles. It may
postpone an exception while a change-of-flow is executing (up to 16 cycles latency). After
fetching an exception service routine base address, the core enters the exception working
mode. The next PC value (namely, the address of the execution set where execution should
be resumed upon the return from the exception) is pushed onto the exception stack together
with the SR. The instruction set at the exception vector address associated with the selected
exception is fetched. This address is formed as follows:
— Bits 31:12 from the Vector Base Address Register (VBA)
— Bits 11:6 from either the exception and interrupt address offset table (Table 5-19) or the external
Interrupt Offset Bus as enabled by the AUTO_VEC signal and an external interrupt. External
interrupts with a default vector address (indicated by the AUTO_VEC signal) refer to the
AUTO-NMI and AUTO-IR vectors in Table 5-19.
— Bits 5:0 of an exception vector base address are always zero, allowing 16 bytes at each vector.
— The first three execution sets from the fetched exception vector enter execution. Only then can
a new exception request be serviced.
5.8.1 Interrupt Vector Address
5.8.1.1 Vector Base Address Register
The Vector Base Address Register (VBA) is a 32-bit register with the lower 12 bits always zero. The upper
twenty bits [31:12] are automatically used to form the base address (bits [31:12] of the exception vector
address). The upper twenty bits of VBA are initialized at reset with a derivative-dependent address
pointing to the initial Vector Address Table. After reset, VBA may be programmed to relocate the Vector
Address Table anywhere in memory. Care must be taken that interrupts are disabled (either in the core or
in the system) when changing the VBA register, otherwise an interrupt serviced during the change process
may use either the old or new VBA value.
5.8.1.2 Programming Exception Routine Addresses
Each exception vector address is formed from a base address and an offset. The base address bits [31:12]
come from the VBA register. Bits 11:6 of the offset are from either the exception vector address table
(Table 5-19) or the external Interrupt Offset Bus as enabled by the AUTO_VEC signal and an external
interrupt. External interrupts with a default vector address (indicated by the AUTO_VEC signal) refer to
the AUTO-NMI and AUTO-IR vectors in Table 5-19. Bits [5:0] are zero since the distance between two
exception vectors is 16 bytes (one full execution set). There are 64 possible exception vector locations in
the table.
Table 5-19 shows the exception vector address offsets. The last row in the table is for offsets from 0x200 to
0xFC0. These can be accessed by either the non-maskable interrupt or the (maskable) external interrupt,
since the user-driven Interrupt Offset bus determines this address for either type.
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Table 5-19. Exception Vector Address Table
Exception Address
Offset
Priority
(0 - highest)
Type
Description
0x00
0
TRAP
TRAP instruction
0x40
-
Reserved
0x80
1
ILLEGAL
ILLEGAL instruction, and illegal
instruction set
0xC0
2
DEBUG
DEBUG exception from EOnCE
0x100
3
Overflow
DALU overflow
0x140
-
Reserved
0x180
5
Auto-NMI
NMI default vector
0x1C0
6
Auto-IR
Interrupt default vector
5
NMI
NMI
External interrupts
External interrupts
0x200-0xFC0
5.8.2 Return From Exception Instructions
Return from exception should be done with dedicated Return from Exception instructions (RTE, RTED, termed collectively “RTE-like” instructions). These instructions pop from the active stack two values: The
return PC, form which execution resumes, and SR value. The SR value sets (among other things) the
working mode of the core. The RTE-like instructions are used to automatically enable resuming the task
that was interrupted (by restoring the next PC to be executed and the SR, including the working mode). It
could also be manipulated by the RTOS to change the task that is restored.
For maximum efficiency on return from an exception, the SC140 instruction set provides a delayed return
from the exception instruction. This takes five or six cycles to execute, but allows the usage of some of
these cycles to execute instructions. Refer to Appendix A, “SC140 DSP Core Instruction Set,” for details
on return-from-exception usage in the RTE and RTED instructions.
The RTE/D instructions do not affect the shadow return address of subroutines, see Section 5.5.5, “Fast
Return from Subroutines.” In this way, the interrupts interfere less with the interrupted task, allowing it to
continue and enjoy the reduced cycle count when performing an RTS, if applicable. However, if during the
ISR, the task was switched, the RAS may hold content from the previous task that may corrupt the
execution of the restored task. In such a case, the user should clear the RAS by performing, in the ISR that
switches the tasks, a dummy jump to subroutine (JSR) and return (RTS). .
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Exception Processing
5.8.3 Maskable Interrupts
5.8.3.1 Interrupt Priority Level
An external maskable interrupt is given a request IPL (between 1 and 7) by driving a 3-bit input along with
the request. The core IPL is held in the I2–I0 bits of the SR. Only interrupts with a request IPL greater than
the core IPL are serviced. Refer to Section 3.1.1, “Status Register (SR),” on page 3-1, for further
information.
Upon entry to execution, the core priority level is set to be equal to the interrupt priority level of the
serviced interrupt. This prevents interrupts with lower and equal priority level from entering execution.In
particular it prevents the same interrupt, which usually is still asserted, from entering execution again. In
the Interrupt Service Routine the user should typically include an access to the interrupt source to de-assert
the interrupt request, after which the previous interrupt priority level could be lowered, either explicitly or
by executing the RTE instruction which restores the original SR.
5.8.3.2 Controlling All Interrupt Sources
All maskable interrupts can be disabled with the DI instruction, which sets the DI bit in the SR. No
interrupts are serviced after the DI instruction is executed. As a result, the code following the DI
instruction does not need to take into account any possible pipeline effects caused by interrupts.
Non-maskable exceptions are not blocked by the DI instruction. The EI instruction clears the DI bit in the
SR, thus enables all interrupts that are not masked by the IPL bits. The DI and EI instructions do not affect
the IPL bits.
5.8.4 Non-Maskable Interrupts (NMI)
An NMI request is serviced regardless of the current IPL and DI bit values. The only time an NMI request
remains pending is when another NMI is already being serviced. When an NMI service routine enters
execution (namely, the NMI vector is fetched), the NMI disable (NMID) bit in the EMR is set. Refer to
Section 3.1.2, “Exception and Mode Register (EMR),” for a detailed description of the EMR. While this
bit is set, any pending NMI request is not serviced if the core is in normal or exception modes. This bit is
cleared by an RTE or RTED instruction (while the core is in normal or exception mode), or by writing 1 to
it. It cannot be set by the user.
5.8.5 Internal Exceptions
This section describes exceptions generated by conditions inside the core. The internal exceptions (except
the TRAP instruction) are imprecise. These exceptions occur asynchronously after detecting the exception
condition. Thus, they are unable to identify the precise location of the offending instruction. They are used
mostly for diagnostics during program debugging.
In order to aid in the debugging process, a dedicated register in the EOnCE (PC_EXCP) holds the address
of the VLES that caused internal, imprecise exceptions (the Illegal and Overflow exceptions). For multiple
exception types (illegal instruction, illegal execution set, or DALU overflow), the PC_EXCP register will
retrieve the VLES address of the first occurrence of the last exception type. For multiple events of the same
type, only the first event will be sampled in PC_EXCP. For more information on the PC_EXCP register,
see Section 4.7.8, “PC of the Exception Execution Set (PC_EXCP).”
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If two or more exceptions are pending on the same clock cycle, the one with the higher priority (as defined
in Table 5-19 on page 5-49) is taken.
Due to the imprecise nature of these exceptions, there may be additional exception events between the first
event and its exception service routine. Additional exception events will set their associated EMR bits and
be serviced according to their exception priority, not necessarily according to the order of the execution
sets that caused them.
5.8.5.1 Illegal Exception
The illegal exception is generated by any of several conditions, described in the following sections. To
enable application developers to debug applications and avoid illegal conditions and errors, the SC140
core provides exception bits in the EMR, which are set when an exception is detected. The EMR is
described in detail in Section 3.1.2, “Exception and Mode Register (EMR).” the address of the execution
set that caused the last Illegal exception is written to the PC_EXCP register of the EOnCE.
5.8.5.1.1 Illegal Instruction
An illegal instruction exception is generated when one or more of the instruction opcodes coming from the
program memory do not belong to the SC140 instruction set. This exception can also be generated by the
ILLEGAL instruction. To prevent the system from entering a deadlock state whenever there is an illegal
instruction, an internal exception request is generated, and the ILIN bit in the EMR is set. The execution
flow continues until the exception is serviced. Execution of the original program is undefined.
The ILIN bit does not block subsequent illegal instruction exceptions. Multiple illegal instructions will
cause multiple illegal exceptions, regardless of the ILIN state. However, illegal instructions that occur
close together may share the same illegal exception. In particular, additional illegal events that occur
between the first event and its illegal exception service routine will share the same exception. If an illegal
execution set also occurred during this period, the ILST bit in EMR will be set to indicate multiple causes
for this illegal exception. If the illegal exception service routine has an illegal instruction, nested illegal
exceptions will occur.
5.8.5.1.2 Illegal Execution Set
An illegal execution set exception is generated whenever one of the following execution set grouping rules
is violated:
•
A maximum of four DALU instructions per set can occupy different modulo four positions within
the set.
•
A maximum of two AGU instructions per set can occupy different modulo two positions within
the set.
•
A maximum of two extension words per set can occupy different modulo two positions within the
set.
•
A maximum of one ISAP instruction is allowed per set.
Whenever an illegal set occurs, an exception request is generated. The ILST bit in the EMR is set, and
instruction execution continues until the exception is serviced. Execution of the original program code is
undefined after this exception occurs.
The ILST bit does not block subsequent illegal execution set exceptions. Multiple illegal execution sets
will cause multiple illegal exceptions, regardless of the ILST state. However, illegal execution sets that
occur close together may share the same illegal exception. In particular, additional illegal events that occur
between the first event and its illegal exception service routine will share the same exception. If an illegal
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Exception Processing
instruction also occurred during this period, the ILIN bit in EMR will be set to indicate multiple causes for
this illegal exception. If the illegal exception service routine has an illegal execution set, nested illegal
exceptions will occur.
5.8.5.2 DALU Overflow
The DALU overflow exception is generated whenever an overflow occurs as a result of a DALU
operation. Whenever there is an overflow, an exception is generated and the DOVF bit in the EMR is set, if
the exception enable bit OVE in the SR is set. The DOVF bit blocks subsequent DALU overflow
exceptions. Once the DOVF bit is set, no additional DALU overflow exceptions will occur until the DOVF
bit is cleared. Although useful for algorithm debugging, the overflow exception routine may be unable to
take corrective action due to the imprecise nature of this exception.
The PC of the execution set causing the overflow exception is saved in the PC_EXCP register of the
EOncE.
5.8.5.3 TRAP Exception
Immediately after executing a TRAP instruction, the core enters the exception mode. Both the PC and SR
values are pushed onto the exception stack. The IPL is set to its maximum value and the exception mode is
entered. This exception is precise. It occurs immediately after the execution set that contains the TRAP
instruction.
The TRAP instructionis typically used for RTOS calls.
5.8.5.4 Debug Exception
A debug exception can be initiated as a result of a debug event, as configured in the EOnCE. It is also
possible to configure the DEBUG and DEBUGEV instructions to generate a debug exception. This
exception is not precise. Please refer to Chapter 4, “Emulation and Debug (EOnCE),” for further details.
5.8.6 Exception Interface to the Pipeline
When an interrupt request signal is asserted or an internal exception is triggered, the PSEQ finds the first
possible time slot to interrupt the current program flow and start servicing the exception. The PSEQ will
delay an exception service when the current pipeline state cannot be interrupted safely without damaging
the running task. In most cases, only one cycle is consumed for the exception servicing (for pushing the
return address and the SR onto the exception software stack). From this point on, the exception handling
routine is treated like any normal flow code. The sections that follow describe the exception process.
5.8.6.1 Exception Routine Fetch
When the PSEQ acknowledges an exception request for service, the exception vector address is driven
onto the program address bus. The core then enters exception mode, fetching instructions starting at the
exception vector address.
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5.8.6.2 Exception Mode Execution
An exception mode execution is performed in exactly the same way as a normal program flow. There is no
constraint on the length of an exception routine. Table 5-20 shows the flow for the pipeline changing from
normal execution to exception execution.
Table 5-20. Exception Pipeline
Instruction Cycle
Operation
Pre-fetch
Fetch
1
2
3
4
5
n1
n2
n3
i1
i2
n1
n2
n3
i1
i2
n1
n2
push
i1
i2
n1
n2
push
i1
i2
n1
n2
push
i1
Decode
Address
Generation
Execute
6
7
8
9
10
11
12
i2
n = normal or user execution set
i1, i2 = exception execution sets 1 and 2
5.8.7 Exception Timing
When an unmasked exception is taken, the core breaks the normal execution flow and adds a cycle. The
return PC and SR are pushed onto the stack, and the core then resumes execution at the exception vector
address. After the exception request is asserted, the exact point at which the normal execution flow is
interrupted is not fixed. It is dependent on the properties of the instructions being executed in the vicinity
of the exception request as well as any core stalls that may occur in parallel. For example, a delayed
instruction and its delay slot constitute an uninterruptable sequence.
Example 5-17 describes the exception servicing for a simple case that does not include delayed
instructions or core stalls, but does include exceptions occurring near change-of-flow instructions. In this
example, the JUMP instruction represents all change-of-flow instructions in Table 5-8, excluding delayed
instructions and TRAP. It also represents the DI (disable interrupt) instruction.
Example 5-17. Basic Exception Timing
Let ES0 -> ... -> ES4 ... be a sequence of execution sets such that if ES0 is a JUMP instruction, then ES1 is
an instruction from the target address (ES0 -> ES1 -> ES2 -> ES3 -> ES4). In addition, assume that an
exception request arises on the same cycle that ES0 starts its AGU execution stage.
If (ES1 is not JUMP) and (ES2 is not JUMP):
Then
•
The execution set from the target of the exception vector is executed after ES2, and the address of
ES3 is pushed as a return address to the stack.
•
1 cycle is added, which is needed to push the return address to the stack.
Else, if (ES1 is not JUMP) and (ES2 is JUMP):
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Then
— The execution set from the target of the exception vector is executed after ES1, and the address
of ES2 is pushed as a return address to the stack.
— 2 cycles are added.
Else, if (ES1 is JUMP):
Then
– The execution set from the target of the exception vector is executed after ES0, and the
address of ES1 is pushed as a return address to the stack.
– 3 cycles are added.
End
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Exception Processing
Figure 5-12 provides a flow chart for Example 5-17.
Is ES1 a JUMP?
Yes
Execute ES0.
Store ES1 address.
Add three cycles.
Execute exception vector.
No
No
Is ES2 a JUMP?
Execute ES2.
Store ES3 address.
Add one cycle.
Execute exception vector.
Yes
Yes
Execute ES1.
Store ES2 address.
Add two cycles.
Execute exception vector.
Figure 5-12. Flowchart for Exception Timing
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The following pipeline table shows the first case in Example 5-17. ES0 is a JMP with a minimum cycle
count of three. ES1 and ES2 are not change-of-flow instructions. And, I1 is the first instruction at the
exception vector address. The exception request is initiated in cycle 4.
Table 5-21. Pipeline Example
Instruction Cycle
Operation
Pre-fetch
Fetch
Decode
Address
Generation
Execute
5-56
1
2
3
ES0
4
5
ES1
ES2
ES0
ES1
ES0
6
ES0
8
9
10
11
12
I1
ES2
ES1
ES0
7
I1
ES2
push
I1
ES1
ES2
push
I1
ES1
ES2
push
I1
SC140 DSP Core Reference Manual
Chapter 6
Instruction Set Accelerator Plug-In
This chapter describes the ISAP capability of the SC140 core, and how to incorporate an ISAP when using
the SC140 core as part of a larger system.
6.1 Introduction
An ISAP is an Instruction Set Accelerator Plug-in - a unit external to the core that the SC140 core controls
using dedicated instructions that are incorporated into the SC140 program. The SC140 has an interface and
dedicated encoding space that enables defining and integrating such a unit.
The ISAP enables you to enhance the core instruction set with additional application-specific instructions
that are not part of the original SC140 instruction set. For example, ISAPs could enhance the SC140 to
support floating-point arithmetic, image processing capabilities, etc.
ISAP support is integral to the SC140 development tools, so the SC140 assembler, simulator and compiler
can all be modularly configured to support the specific ISAP(s) definition. This enables the programmer to
effectively use ISAP instructions in the source code like any other SC140 instruction (with minor
modifications). However, the specific ISAP instruction set and programming rules are specific to each
ISAP and are out of the scope of this document.
Single or multiple ISAPs can be connected to a single SC140 core. The normal configuration is of
instructions being dispatched to one ISAP at a time. 1
An ISAP normally has its own set of registers, by which it can exchange data with the core or data
memory, as well as execute data processing instructions.
1. However, using the SIMD (single instruction, multiple data) approach, more complex configurations that enable dispatching
an instruction to more than one ISAP at a time are possible. For details, see the Integration Guide.
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ISAP - SC140 Schematic Connection
6.2 ISAP - SC140 Schematic Connection
The ISAP-SC140 connection actually involves an external data memory bank as well. Two connection
schemes are shown: SC140 to single ISAP, and SC140 to multiple ISAPs.
6.2.1 Single ISAP
Connection with the ISAP is illustrated in Figure 6-1 below:
Address buses (A, B)
Data Memory
2
Read buses (A,B)
SC140Core
2
ISAP - Core
Register channel
2 Write buses (A, B)
ISAP
Core to ISAP
instruction dispatch
Figure 6-1. Core to Single ISAP Connection Schematic
The ISAP receives instructions from the core via a dedicated ISAP instruction dispatch bus, up to once per
execution set.
The ISAP is connected to the data memory via the same two data buses XDBA and XDBB as the core, in
both read and write directions. The SC140 core is the only address generating master of the data buses. The
ISAP does not send address information to the Data memory, hence the ISAP does not need an AGU. A
data access to or from the ISAP requires a parallel core AGU MOVE instruction that generates the access
on the address and control lines to the memory. The ISAP then drives or samples the data buses
accordingly. The way the ISAP memory access is shared between the core and the ISAP is described in
Section 6.4, “ISAP Memory Access.” .
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ISAP - SC140 Schematic Connection
6.2.2 Multiple ISAP
Connection between the core and multiple ISAPs is illustrated in Figure 6-2, below:
ISAP
SC140Core
ISAP
ISAP selection encoding
Core to ISAP
instruction dispatch
ISAP
Enable bits
ISAP Controller
Figure 6-2. Core to Multiple ISAP Connection Schematic
In a multiple ISAP configuration, some of the ISAP instruction encoding bits should be dedicated in
advance for encoding the ISAP selection. For each dispatched ISAP instruction, an ISAP controller
decodes the ISAP select bits and enables the respective ISAP. The other ISAPs are therefore disabled, for
this cycle. The system designer must put these bits in the MSB of the opcode of the ISAP instruction.
Further operation is similar to a single ISAP:
The connections of the ISAPs with the data memory are not shown in Figure 6-2. Proper muxing should be
implemented according to the same principle as shown in Figure 6-1.
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ISAP instructions and instruction encoding
6.3 ISAP instructions and instruction encoding
This section presents an overview of the concept of programming the ISAP from the SC140 assembly
code.
The SC140 core can dispatch one ISAP opcode per VLES. This opcode uses the 2-word prefix encoding,
and is recognized as an ISAP opcode if it is not the first opcode in the VLES. The SC140 core encoding
rules allow this situation only with prefix grouping, hence it follows that an ISAP opcode can only appear
as part of a prefixed VLES.
The 2-word prefix encoding is shown in Table 6-1: ISAP Encoding Fields below:
Table 6-1. ISAP Encoding Fields
Binary Encoding
0011 _ _ _ _ _ _ _ _ _ _ _ _ _
101_ _ _ _ _ _ _ _ _ _ _ _ _ _
Words
Bits
2
25
This encoding allows the ISAP 25 bits as its encoding space. The ISAP architect can freely allocate these
bits. The only constraint is that in case the ISAP is intended to be used as part of a multi-ISAP
configuration, some of the Most Significant Bits of the 25 bits should be reserved for ISAP selection
encoding. The number of such bits that are to be left aside is also the decision of the ISAP architect.
An ISAP opcode can specify one or more ISAP instructions. An ISAP could be defined as a VLIW
processor, encoding more than one instruction in one ISAP opcode.
ISAP instructions can be of two main kinds:
•
ALU instructions: ISAP instructions that execute with a pipeline similar to the core DALU, without
activation of simultaneous core AGU instructions.
•
Data move instructions: Instructions that transfer data between the ISAP and its environment
(external Data memory or SC140 core). The core has the capability of providing the ISAP with data
addressing, so that the ISAP designer need not incorporate an AGU in the ISAP. This requires certain
conventions, which are detailed in Section 6.4, “ISAP Memory Access,” .
ISAP instructions must obey the same VLES semantics as other SC140 instructions (dependency of
operands between VLES, etc.). At the instruction level, the syntax should be as close as possible to existing
SC140 conventions (source and destination order, data width specifiers, etc.). The individual ISAP
instruction syntax should be defined in the particular ISAP specification.
The term “ISAP instruction” can be used both to specify the assembly mnemonic, or to the specific
sub-opcode in the ISAP opcode related to the source mnemonic. Differentiation is according to context source code or assembly level context, or encoding context.
6.4 ISAP Memory Access
The ISAP accesses data via the XDBA and the XDBB busses, in addition to core-ISAP buses for register
transfer.
The ISAP should not be designed with an AGU, leaving the addressing duties to the core. This allows the
ISAP to enjoy the full addressing and modulo capabilities of the core AGU, and the ISAP design to
concentrate on the specific ISAP specialty.
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ISAP-core register transfers
However, this feature requires some assembler support (core and ISAP) when using such instructions.
When the ISAP must either write or retrieve data from the data memory via the data busses, the core
assembler must create a parallel AGU MOVE instruction in the same VLES as the ISAP instruction.
This method works as follows:
When the assembler encounters an ISAP data move instruction, the core assembler creates an AGU
MOVE instruction that will generate the required address to the data memory.
Example 6-1. ISAP memory access
To understand this, look at the following lines of code:
core_ins {move_special k0,(r1)}
In this example, two parallel instructions are used:
1st - core_ins = a generic core instruction
2nd - {move_special k0, (r1)} = a fictional ISAP instruction (for illustration purposes only), whose
intent is to take the data in k0 (an ISAP register), and place it in the address whose value is found
in the core register r1
The core assembler translates the above line of code (at the opcode level) to read, in effect, the following:
core_ins move.l d0,(r1) {move_special k0,data bus}
In order for this to work, the core must not drive d0 to the memory. The core hardware achieves this in the
following way: A memory MOVE instruction that uses a DALU register (D0 to D15) in parallel to any
ISAP instruction simply will not drive or sample the D register. In effect, the d0 in this instruction becomes
a dummy source which the core therefore ignores, and in our case only the address found in r1 is driven to
on the data address bus. In a complementary manner, the ISAP move_special instruction only drives
the data in k0 on the appropriate data bus, and not handle the addressing of the access.
In this manner, the data memory receives data from the ISAP, and the address from the AGU of the core.
There are some ramifications of this method of memory access, that are mentioned in Section 6.8.4,
“Sequencing rules for T bit update.” .
The ISAP must support both big and little endian byte order conventions in the same manner as the core
supports these conventions (see Section 2.4.1, “SC140 Endian Support,” ).
6.5 ISAP-core register transfers
The ISAP architect can define ISAP instructions that exchange data between core and ISAP registers.
These instructions are treated in a similar manner to MOVE instructions. That is, the core assembler
translates the ISAP instructions into two equivalent instructions: one core instruction that drives or samples
the core register, and an ISAP instruction that samples or drives the ISAP register.
The assembler uses the core instruction “MOVE.L C4<->Db” (See Appendix A, Appendix , “MOVE.L,”
on page A-275). When executed in parallel with an ISAP instruction, the core does not drive or sample the
“Db” (DALU) register. This enables the core to perform data transfers between the C4 registers (D, R, N,
B, M) and ISAP registers.
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Immediate Data Transfer to ISAP registers
Example 6-2. ISAP-Core register transfers
The following line of code,
core_ins {move_special d1,k0}
That uses these instructions,
1st - core_ins = a generic core instruction
2nd - {move_special d1, k0} = a fictional ISAP instruction (for illustration purposes only), whose
intent is to take the data in d1 (a core register), and place it in the k0 ISAP register.
Is translated by the core assembler (at the opcode level) to read, in effect, the following:
core_ins move.l d1,d0 {move_special bus,k0}
The core does not take the data in d1 and place it in d0, but it takes the data in d1, and drives it on the
core-ISAP register bus. In a complementary manner, the ISAP move_special instruction should only
sample the data from the core-ISAP bus, and place it in the k0 ISAP register.
6.6 Immediate Data Transfer to ISAP registers
The ISAP architect can define ISAP instructions that write immediate data to ISAP registers. These
instructions are treated in a similar manner like memory moves instructions: the assembler translate the
ISAP instructions into two instructions: one core instruction that writes an immediate value to a dummy
core register, and an ISAP instruction that samples the data to an ISAP register.
The assembler can use any move-immediate core instruction to a DALU register, for example “MOVE.L
#s32,D0” (See Appendix , “MOVE.L,” on page A-272). When executed in parallel with an ISAP
instruction, the core does not sample the data to a DALU register. This enables performing immediate data
transfers to ISAP registers.
Example 6-3. ISAP-Core register transfers
The following line of code,
core_ins {move_special #$1234,k0}
That uses these instructions,
1st - core_ins = a generic core instruction
2nd - {move_special #$1234, k0} = a fictional ISAP instruction (for illustration purposes only),
whose intent is to take the number $1234 and place it in the k0 ISAP register.
Is translated by the core assembler (at the opcode level) to read, in effect, the following:
core_ins move.l #$1234,d0 {move_special bus,k0}
The core does not take the number $1234 and place it in d0, but it takes the number $1234, and drives it on
the core-ISAP register bus. In a complementary manner, the ISAP move_special instruction should
only sample the data from the core-ISAP bus, and place it in the k0 ISAP register.
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Core Assembly Syntax with an ISAP
6.7 Core Assembly Syntax with an ISAP
This section describes aspects of the core assembly syntax, supported by the software tools, that relate to
the presence of an ISAP and to ISAP assembly instructions.
6.7.1 Identification of ISAP instructions
ISAP specific commands are included in brackets: {}, for example:
add d0,d1,d2 {...ISAP instructions..}
The instructions outside the brackets are core instructions, while the instructions inside the brackets are
ISAP instructions. The mnemonics used for the ISAP instructions are defined by the ISAP architect, and
assembled by an assembler extension module that is modularly linked with the standard core assembler.
ISAP instructions can be combined in one bracket pair or could be split in two pairs with different
predication, for example:
IFT {ISAP instruction} add d0,d1,d2 IFF {ISAP instruction}
See more details on predication of ISAP instructions in Section 6.7.3, “Conditional Execution.”
When using an ISAP, the core assembler should be informed which ISAP is to be used so that it can verify
that it is using the correct assembler extension. The core assembler supports two methods to do this:
Setting a default ISAP name, and prefixing the ISAP brackets with the ISAP name.
6.7.1.1 Working with One ISAP
When working with a single ISAP, we recommend defining a default ISAP name. An assembly directive is
used to do this. The following syntax is used:
ISAP_ID_default “ISAP_ID1”
...
{ .. ISAP instructions .. }
The assembler directive “ISAP_ID_default” defines the default ISAP name (in this case) to be
“ISAP_ID1”. The specific ISAP designation is to be determined by the ISAP architect. Until set to another
value, the core assembler will assume this ISAP ID string for any ISAP instructions that are not prefixed
by an explicit ID string.
This method is preferred when a single ISAP is used in an assembly code section. In this way the overhead
of prefixing every ISAP instruction is avoided.
Example 6-4. Single ISAP coding
A VLES that uses an implicit ISAP ID string:
nop {tsteq k0} abs d0
In this example, three parallel instructions are used:
1st - nop = a core instruction
2nd - {tsteq k0} = a fictional ISAP instruction (for illustration purposes only), written in the syntax
of the appropriate ISAP.
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Core Assembly Syntax with an ISAP
3rd - abs d0 = a core instruction
The syntax defines that the string between the brackets is sent to the ISAP assembler.
One ISAP in a Single-Line VLES
mac d0,d1,d3 {isap_instruction k0,k1,k2 move_special.l k2,(r0)+}
In this example, the MAC instruction is executed by the core and the instructions delimited by the brackets
are executed by the ISAP.
One ISAP in a Multi-Line VLES
A VLES spanning multiple lines (parallel execution specified by square bracket delimiters and ISAP
instructions specified by curly bracket delimiters):
1
2
3
4
[ mac d0,d2,d4
mac d1,d3,d5
{isap_instruction k0,k1,k2
move_special.l k2,(r1)+}
move.l (r0)+,r2]
In this example, five parallel instruction are executed - three instructions are executed by the core,
and two instruction by the ISAP.
line 1: Two MAC instructions executed by the core
line 2: An ISAP instruction with ISAP registers k0,k1 and k2 as arguments
line 3: An ISAP move instruction, storing ISAP register k2 to a memory location pointed by core register
r1. The assembler generates an implicit AGU instruction: “move.l d0,(r1)+”. As
explained in Section 6.4 ISAP Memory Access, the d0 register is a dummy register which is not
driven on the memory data bus, rather the ISAP stores its k2 register by driving the k2 register data
on the data bus, and the address is set by the core as (r1).
line 4: A Core move instruction, loading core register r2 from a memory location. Note that loading of R
registers in parallel to an ISAP instruction is allowed (unlike D registers).
6.7.1.2 Working with Multiple ISAPs
In this case, each ISAP instruction should be specified by prefixing it with a unique label written before the
brackets. This label overrides the default value set with the ISAP_ID_default directive.
The following syntax is used:
ISAP_ID1{ .. ISAP1 instructions .. }
ISAP_ID2{ .. ISAP2 instructions .. }
This method is preferred when multiple ISAP modules are used with the core, and are used
interchangeably in the same code section.
In the following example, the two ISAPs that are connected in parallel are a Floating Point ISAP (FP) and
an Image Processing ISAP (IP):
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Example 6-5. Multiple ISAP coding
Two VLES lines that use an explicit ISAP ID string, for two different ISAPs:
mac d0,d1,d3 IP{isap_instruction k0,k1,k2}
mac d0,d1,d3 FP{isap_instruction k0,k1,k2}
In this example, three parallel instructions are used for each line:
1st - mac = a core instruction
2nd - IP or FP = instructs the ISAP controller to which ISAP the following instruction belongs
3rd - isap_instruction = a fictional ISAP instruction, used here for illustration purposes only
Note that the ISAP’s registers names could have the same indication (k0,k1,k2), but are actually different
registers because they belong to different ISAPs.
Multiple ISAPs in a Multi-Line VLES
In this example, there are multiple ISAPs connected to the core, therefore each ISAP has a unique ID
string. The two ISAPs that are connected in parallel are a Floating Point ISAP (FP) and an Image
Processing ISAP (IP):
[
mac d0,d1,d3
IP{isap_instruction k0,k1,k2}
]
[
mac d0,d1,d3
FP{isap_instruction k0,k1,k2}
]
In this example, in the first execution set the core performs a parallel MAC instruction and the Floating
Point ISAP executes its own instruction. In the second execution set, the core performs a MAC instruction,
and the Image Processing ISAP executes its own instruction.
6.7.2 An Example of the Definition Flexibility of an ISAP
When assembling a data move instruction to the ISAP, the assembler generates a parallel AGU instruction
that will handle the address generation (for memory moves), immediate value generation or core register
drive/sample. The ISAP portion of the instruction is responsible for ISAP register activation. These ISAP
instructions are normally designated with MOVE mnemonics, as described in Section 6.4, “ISAP Memory
Access,” on page 6-60.
However, the ISAP architect can define special move instructions that involve additional processing of the
data before or after a memory accesses which is related to it. This example shows how flexible and
powerful the ISAP can be, and demonstrates a MOVE instruction that includes other tasks in the same
opcode:
nop {permute_lsb_set.2l (r0)+,k0} abs d0
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This is similar example to that shown in Section 6.7.1, “Identification of ISAP instructions,” but instead of
the ISAP tsteq instruction, a special move from a memory location to ISAP register k0 is used. The
special ISAP move instruction (called permute_lsb_set.2l in this case) can read 64-bit data, permute
the bytes according to a certain definition, set the LSB, and write the result to register k0.
In this case, the ISAP assembler translates its move instruction to a core move instruction with dummy
core registers d0,d1 - move.2l (r0)+,d0:d1. This example is aimed to show how complex some
specialized ISAP instructions may get, and why it is not desirable to constrain their syntax.
6.7.3 Conditional Execution
ISAP instructions can be conditionally executed by using the core IFc prefix instruction. By definition, the
IFc mnemonics imply prefix predication. A VLES can have up to two IFc groups.
The following syntax conventions and limitations apply to conditionally executing ISAP instructions (See
also Rule G.P.9):
•
IFc mnemonic must be outside any ISAP clause (predication is the property of the core syntax, even
if predicating only an ISAP clause as in the case of the iff in the above example)
•
There can be two ISAP clauses per VLES, each belonging to a different IFc group.
•
ISAP ALU instructions must all be in the same IFc group
•
Implicit Core AGU instructions generated to support ISAP move instructions are subject to the same
limitations as other core AGU instructions. This means for example:
— If the VLES includes two IFc groups, and there are two ISAP move instructions, then the each
ISAP move must be in a different IFc group.
The IFc predication convention is supported by ISAP interface signals that inform the ISAP of the
predication status for each AGU instruction (associated with a data bus).
According to Rule G.P.9, it is not allowed to have two ISAP ALU instructions in two IFc groups.
However, ISAP move instructions will cause the assembler to generate implicit core MOVE instruction,
which could be in different IFc groups. For more details on how this works, see Section 6.4, “ISAP
Memory Access,” on page 6-60.
Example 6-6. Conditional Execution Example
ift inc d0 {move.w (r0),k0} iff {tfra k0,k1 move.l (r1),k5}
The move instructions inside the ISAP brackets translates into an implicit core MOVE instructions, each
conditioned by a different IFc condition.
Example 6-7. Conditional Execution Example
1
2
3
4
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[ ift mac d0,d2,d4 mac d1,d3,d5
iff {alu_instruction k0,k1,k2
move_special.w k2,(r1)+}
move.l (r0)+,r2]
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line 1: The ift (if true) prefix instruction indicates that the core MAC instructions will be executed only if
the T bit is set.
lines2,3,4: The iff (if false) prefix instruction indicates that the ISAP instructions on lines 2,3 (including
the implicit MOVE generated for the move_special ISAP instruction) and the core MOVE.L instruction
on line 4 will be executed if the T bit is cleared.
6.8 Programming Rules
This section overviews all SC140 programming rules that relate to ISAP instructions. These programming
rules also appear in Chapter 7, “Programming Rules,” but are briefly summarized here as well.
ISAP-specific programming rules depend on the specific ISAP application should be described in the
specific ISAP specification document, and are out of the scope of this document.
6.8.1 ISAP Functions that Interact With the Core
The functionality of ISAP instructions is in principle free to be defined as the ISAP architect wishes.
However, some ISAP functions use core resources or affect core state. These functions usually have
limitations associated with them, as will be described in the following sections:
•
Read data from the data memory to ISAP register(s). An implicit SC140 AGU MOVE instruction is
needed for this function.
•
Write data from to ISAP register(s) to the data memory. An implicit SC140 AGU MOVE instruction
is needed for this function.
•
Exchange data between core registers and ISAP register(s). An implicit SC140 AGU MOVE
instruction is needed for this function.
•
Accept immediate data from the core into ISAP register(s). An implicit SC140 AGU MOVE
instruction is needed for this function.
•
Change the value of the SC140 core T bit in SR
•
ISAP instructions could be predicated with the IFT/IFF prefix instructions like other core
instructions.
In addition, there are other guidelines, as follows:
•
ISAP instructions must have the same semantics of parallel execution like core instructions (for
example destination operands do not affect source operands in the same VLES, etc.). In general, the
guidelines as written in Sections 7.1 VLES Sequencing Semantics through 7.3 SC140 Pipeline
Exposure must be adhered to.
•
The ISAP’s pipeline should be coupled to the SC140 core, which means that instructions that
perform data memory accesses or data processing should have similar pipeline behavior like
respective SC140 core AGU or DALU instructions. For a description on the SC140 pipeline, see
Chapter 5.1, “Pipeline.”
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6.8.2 Grouping rules for explicit ISAP instructions
G.G.2: up to 8 instruction words per VLES
G.G.3: One ISAP encoding word per VLES
G.G.4: A destination operand can only be updated by one source per VLES. In the context of the ISAP, it
means the following limitations:
•
The same core register being updated by the ISAP and another core or ISAP instruction
•
A core address register updated by an implicit AGU instruction generated for supporting and ISAP
instruction, and the same address register being updated by another instruction.
•
The T bit being updated by the ISAP and another core or ISAP instruction
G.P.8: It is not allowed to group AGU instructions that use or update a data register (D0-D15) in the same
VLES with an ISAP instruction.
G.P.9: ISAP ALU instructions must belong to the same IFc condition group.
6.8.3 Rules for implicit AGU instructions
As mentioned in Section 6.4, “ISAP Memory Access,” on page 6-60, when a data transfer instruction
between the ISAP and the memory or core register is written inside the ISAP brackets, the core assembler
creates an implicit MOVE instruction that will send the required address to the data memory.
The ramification of this is that when there is a MOVE-like instruction inside the ISAP brackets, all the
rules that apply for “original core” MOVE-like instructions apply for the implicit MOVE-like instructions
as well.
An example from Rule A.2, for an ISAP instruction, is shown below:
Example 6-8. MOVE rules with an implicit MOVE instruction from ISAP
The original rule requires (among other cases) a cycle difference between a MOVE-like instruction to an R
register and it’s use as an AAU operand (see Rule A.2 on page 7-17):
core_ins {move.l k0,r0}
adda r0,r1
;core instruction, with ISAP move instruction
;not allowed
This is so because the core assembler generates the implicit MOVE instruction. In the example above, the
effective assembler code for the first line will look like:
core_ins move.l d0,r0 {move.l k0,bus}
jmp
r0
;not allowed
Where the core ignores its own d0 part of the implicit move instruction. As can be seen, Rule A.2 prohibits
this.
In a manner similar to the one shown, the following rules are relevant also to implicit AGU instructions:
G.G.5, G.P.1, G.P.4, G.P.5, G.P.6, A.1, A.2, A.4, T.1, SR.2, A.2a, A.5, A.6, D.7, A.1a.
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6.8.4 Sequencing rules for T bit update
The ISAP has the ability to change the T bit as a destination of it’s instructions. The ISAP is less tightly
coupled with the core, hence there the required dependency distance between The update of the T bit by
the ISAP and usage by conditional core instructions is larger for non-DALU instructions.
T.2a: One VLES required between an ISAP instruction that updates the T bit and a conditional COF
instruction
T.2b: 2 VLES required between an ISAP instruction that updates the T bit and a MOVET/F instruction
T.2c: 2 VLES required between an ISAP instruction that updates the T bit and an AGU instruction
conditioned by IFT/F.
In addition, ISAP instructions that change the T bit or depend on it (via IFc) are subject to the same rules as
are other core instructions:
T.1, D.2, D.3.
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Chapter 7
Programming Rules
The SC140 has programming rules for correct construction and execution of assembly language code.
These rules define the ability to group or sequence instructions that activate various execution units,
because of their use of shared resources. This chapter describes the SC140 programming rules and
guidelines for correct code construction. These programming rules must be followed to ensure that
software applications produce expected results, and are compatible with future processor implementations.
The SC140 assembler and simulator assist the programmer in conforming to these programming rules.
7.1 VLES Sequencing Semantics
The SC140 VLES execute in sequence according to the following semantics1:
•
One VLES finishes execution before the next VLES begins execution, with one exception being
delayed change-of-flow instructions finish execution after the delay slot. This means:
— The results of one VLES are immediately available to the next sequential VLES.
— The latency of various SC140 instructions is not exposed in the assembly source code.
— The number of cycles for a VLES is the number of cycles taken by its longest instruction.
•
Even though the SC140 pipeline overlaps the execution of several VLES, the assembly source order
for sequential VLES execution is enforced.
7.2 VLES Grouping Semantics
The SC140 instructions grouped in a VLES are executed according to the following semantics:
•
Instructions to be executed together are explicitly grouped in a VLES by the programmer. This
means:
— The SC140 does not make any grouping decisions. However, it will take an illegal execution set
exception if it decodes a grouping error.
— Grouped instructions are placed on the same assembly source line, or on one or more lines
surrounded by brackets [...].
1. Semantics is the meaning of language. In this context, the function of instructions, the relationship between instructions in a VLES, and the
relationship between VLES in a program.
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VLES Grouping Semantics
•
All instructions in a VLES execute in parallel. This means:
— The assembly source order of instructions and labels within an unconditional VLES does not
change the results, with one exception being the assembly source order determines which
instruction (if any) updates the carry bit. Because source order within an unconditional VLES is
not required for correct code execution, the assembler sometimes reorders instructions in the
VLES during the encoding process.
— All instruction source registers and memory locations are read in parallel when the VLES starts
execution. That is, the order that multiple reads occur does not change the results.
— After all sources are read, all grouped instructions operate on them in parallel.
— All instruction results are written to registers and memory locations in parallel when the VLES
finishes execution. Parallel memory writes must write to different locations so the order that
multiple writes occur does not change the results.
•
Instructions in a VLES can execute conditionally. This means:
— A VLES without conditional instructions executes all instructions unconditionally.
— A VLES can have conditional instructions (such as Bc, Jc, MOVEc, TFRc, where c is the
execution condition). The conditional instruction executes if its condition is true. If its condition
is false, the instruction does not execute (becomes a NOP).
— The IFc instruction conditionally executes all instructions that follow it (in assembly source
order) until the next IFc instruction or the end of the VLES. Multiple IFc instructions in a VLES
form subgroups of instructions that are conditionally executed based on their associated IFc
condition. Multiple IFc subgroups having the same condition are in the same subgroup.
— Each unconditional instruction in an IFc group or subgroup executes if its IFc condition is true.
If its IFc condition is false, the instruction does not execute (becomes a NOP).
— Each conditional instruction in an IFc group or subgroup executes if the instruction’s condition
and its IFc condition are both true. If either condition is false, the instruction does not execute
(becomes a NOP).
•
Only one carry-affecting instruction in a VLES may update the carry bit. This means:
— A VLES can have multiple carry-affecting instructions that execute in parallel.
— The carry-affecting instructions can execute unconditionally, or conditionally in an IFc group or
subgroup.
— The last (in assembly source order) carry-affecting instruction whose execution condition is true
updates the carry bit, while the other instructions in the VLES do not affect the carry bit.
— If no carry-affecting instructions execute, the carry bit is not affected.
•
7-2
Even though the SC140 may execute instructions grouped in a VLES during different pipeline
stages, the assembly source grouping for parallel instruction execution is enforced.
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7.3 SC140 Pipeline Exposure
The SC140 has no hardware interlocks, so the pipeline is fully exposed during VLES execution. This is in
direct contrast with the VLES sequencing and grouping semantics presented above, and is the motivation
for the SC140 programming rules that follow. The programming rules hide the short pipeline latencies so
they are not exposed in the assembly source code, saving hardware complexity and making SC140 code
portable across different pipelines.
The SC140 software development tools (assembler and simulator) replace hardware interlocks with
software detection of equivalent programming rules. This allows the programmer to write software that
conforms to the VLES sequencing and grouping semantics defined above. The compiler code generation
conforms to the programming rules by definition, since it always produces correct SC140 code.
7.4 Programming Rule Notation
Programming rules in this chapter use the following notation:
7.4.1 Grouping Rules
Grouping rules enforce the VLES grouping semantics within the same VLES by specifying that instruction
“A” and instruction “B” cannot be “grouped in a VLES”. That is, “A” and “B” cannot execute in parallel.
Some grouping rules specify that instruction “A” cannot be in a VLES at a specific location. They use the
notation that “A” cannot be “in a delay slot,” “in a short loop,” “at LA of the same long loop n,” or “in the
first VLES of an exception service routine,” and so on.
7.4.1.1 Prefix Instructions
Prefix instructions are a unique instruction type, because they are encoded in a VLES prefix and are not
dispatched to execution units. Any unique rule application is specifically noted in the rule definition.
7.4.1.2 Conditional Subgroups
Unless stated otherwise, the grouping rules in this chapter apply to the VLES as a whole regardless of any
conditional instructions, IFc groups, or subgroups. Some rules apply independently to each IFc subgroup,
and are specifically noted in the rule definitions. In this manual, the term “mutually exclusive subgroups”
refers only to VLES having the IFT/IFF subgroups. IFT/IFA and IFF/IFA are not mutually exclusive
subgroups.
7.4.1.3 Assembler Reordering
The assembler reorders instructions within a VLES for encoding efficiency. If more than one instruction in
the VLES affects the carry bit C in SR, the assembler must keep the last (in assembly source order)
carry-affecting instruction in each group or subgroup as last (highest word position) in its respective VLES
encoding. This reordering conforms to the carry-update semantics described in Section 7.2, “VLES
Grouping Semantics,” and is described in Section 5.2.5, “Instruction Reordering Within an Execution Set.”
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7.4.2 Sequencing Rules
Sequencing rules enforce the VLES sequencing semantics by specifying the minimum distance between
different VLES having instructions “A” and “B”. They use the notation “at least n VLES are required
between” or “the minimum number of VLES between” instructions “A” and “B”. For a minimum VLES
distance between “A” and “B”, the VLES having “A” and “B” are not included in this count.
7.4.2.1 Cycle Counts
Rules A.1 and A.2 specify a minimum cycle distance between “A” and “B” events. They use the notation
“at least n cycles are required between when A and when B” occur. This takes into account the exact
pipeline stages when “A” and “B” occur. By grouping a multiple cycle instruction with “A”, the minimum
cycle distance may be met without scheduling additional VLES between “A” and “B”. For a minimum
cycle distance between “A” and “B”, the cycles when “A” and “B” occur are not included in this count.
7.4.2.2 Conditional Execution
If instructions “A” or “B” are conditional or conditioned by an IFc instruction, they will execute only if
their execution condition is true. If “A” and “B” have mutually exclusive execution conditions, their
execution cannot violate a sequencing rule. The simulator knows if “A” and “B” execute from its
simulation trace, and detects programming rules considering their conditional execution. However, the
assembler cannot know the T bit state when “A” or “B” execute. So the assembler detects sequencing rules
independent of conditional execution. That is, it assumes all conditional instructions always execute.
7.4.2.3 Simulator Execution Counts
A conditional VLES that is not executed (becomes a NOP) is counted by the simulator as one VLES for
VLES-based sequencing rules. For cycle-based sequencing rules, a conditional VLES that is not executed
(becomes a NOP) is counted by the simulator as one cycle.
7.4.3 Register Read/Write
In this chapter the programming rules use the notation “read” and “write” to refer to whole register sources
and destinations, respectively. This notation applies to instruction source and destination operands, both
explicit and implicit (implied), as specified in each instruction definition in Appendix A.2, “Instructions,”
on page A-19.
7.4.3.1 Register Names
Some rules apply to selected registers — address, data, or program control. The rules specify the registers
using the names given in Table A-3: Register Abbreviations on page A-3.
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7.4.3.2 B Register Aliasing
The B0-7 base registers are the same registers as the R8-15 address registers in the AGU. For example, B0
and R8 have different source syntax and instruction encoding, but they are aliases to the same physical
register. The rules always specify the Rn registers. The assembler and simulator detect the programming
rules using either alias.
Example 7-1. B Register Aliasing
move.l d0,r8 move.l d1,b0 ;not allowed by G.G.4 - r8 and b0 are the same reg.
7.4.4 Status Bit Updates
In this chapter the programming rules use the notation “affected by” or “affect(s)” to refer to individual
status bit sources and destinations, respectively. This notation applies to individual status bits as explicitly
stated in each instruction definition in Appendix A.2, “Instructions.” The rules treat status bits as 1-bit
registers.
7.4.5 Instruction Words
SC140 instructions can be one, two or three words long. All SC140 instructions have a base size of one
word (16-bits). The second and third words of an instruction are called “extension words”.
7.4.6 MOVE-like Instructions
Instructions that access data during the Execute pipeline stage, including:
— All explicit MOVE instructions listed in Table A-10: AGU Move Instructions on page A-16
— VSL instructions listed in Table A-10: AGU Move Instructions on page A-16
— Pop/push instructions listed in Table A-11: AGU Stack Support Instructions on page A-16
— Bit mask instructions listed in Table A-12: AGU Bit-Mask Instructions (BMU) on page A-17
COF instructions that have implicit push/pop operations are not considered MOVE-like instructions.
In this chapter, a subset of this list is relevant if the rule applies to register sources only (POP is not
relevant) or register destinations only (PUSH and BMTSTx are not relevant).
7.4.6.1 Address/Data Operands
In this chapter, MOVE-like instructions use pipeline-specific operand notation. “Data” operands refer to
actual data being read from a source and written to a destination during the Execute pipeline stage.
“Address” operands are read during the Address Generation pipeline stage to determine the address of a
data operand in memory, and written during the Address Generation pipeline stage if an address register
update is specified by the MOVE-like instruction. Address operands are not written for the (Rn) No
Update and address pre-calculation addressing modes. When a programming rule applies to only one
operand type, it will be stated in the rule definition. If not stated, the rule applies to both address and data
operands of the MOVE-like instruction.
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Programming Rule Notation
7.4.7 AGU Arithmetic Instructions
“AGU arithmetic instructions” are those instructions that execute during the Address Generation pipeline
stage. This includes all instructions in Table A-9: AGU Arithmetic Instructions on page A-15. All SC140
instructions in this category end with the letter A (such as CMPEQA, ADDA, TFRA) with the following
exceptions: IFA (a prefix instruction) and BRA (a non-loop COF instruction) are excluded.
7.4.8 Change-Of-Flow Destinations
A “change-of-flow (COF) destination” is any non-sequential change in the program counter (PC) register.
COF destinations can be caused by COF instructions, hardware loop LA to SA iterations, and exceptions.
Exceptions include instruction exceptions and hardware interrupts as described in Section 5.8, “Exception
Processing.”
7.4.8.1 COF Instructions
A “COF instruction” specifies a (usually non-sequential) destination address that may implicitly write the
program counter (PC) register. The COF result may be conditional on the T bit. All references to “COF
instructions” in this manual include both the non-loop COF instructions listed in Table A-13: AGU
Non-Loop Change-of-Flow Instructions on page A-17 and the loop COF instructions (BREAK, CONT,
CONTD, and SKIPLS) from Table A-14: AGU Loop Control (Including Loop COF) Instructions on page
A-18.
7.4.9 Delayed COF Instructions
A “delayed COF instruction” is a COF instruction that also executes the next sequential VLES. All COF
instructions in this category end with the letter D.
Example 7-2. Delayed COF Instructions
BFD
BRAD
BSRD
BTD
CONTD
JFD
JMPD
JSRD
JTD
RTED
RTSD
RTSTKD
7.4.9.1 Delay Slot
A “delay slot” is the next sequential VLES after a VLES having a “delayed COF instruction.”
7-6
SC140 DSP Core Reference Manual
Static Programming Rules
7.4.10 Hardware Loops
The loop count “LCn” and start address “SAn” registers are described in Section 5.4.1, “Loop
Programming Model,” on page 5-25.
The VLES addresses “LA, LA-1, LA-2” (relative to the loop end (last) address) and “SA, SA-1, SA-2”
(relative to the loop start address) are defined in Section 5.4.2, “Loop Notation and Encoding,” on page
5-26. The minus “-” notation adjusts the VLES address earlier in the source code order.
The term “active loop” is defined in Section 5.4.4, “Loop Nesting,” on page 5-28.
All references to “in a loop” in this manual refer to both long and short loops, unless explicitly stated.
7.4.10.1 Enabled Loop
In a nested loop structure, more than one loop can be enabled at the same time. A loop n is enabled when
its LFn bit in SR is set, where n is the loop index. The assembler’s static rule detection assumes loop n is
enabled from the VLES after the VLES having the DOENn/DOENSHn instruction to LA of loop n (as
specified by the LOOPENDn directive).
7.4.10.2 Enveloping Loop
In a nested loop structure, a loop “B” is nested inside another loop “A”. For this pair of loops, loop “B” is
called a “nested loop” and loop “A” is called an “enveloping loop”. That is, loop “A” envelopes (surrounds
or contains) loop “B”. This definition is relative to each loop pair. If another loop “C” is nested inside loop
“B”, loop “C” becomes the nested loop and loop “B” becomes the enveloping loop for this loop pair.
Loops “A” and “B” are required to have ordered (but not adjacent) loop indexes. The assembler’s static
rule detection assumes the boundaries of loop n are from the VLES after the VLES having the
DOENn/DOENSHn instruction to LA of loop n (as specified by the LOOPENDn directive).
7.5 Static Programming Rules
Static programming rules are detected by examining the mnemonic/symbolic source code within the
visibility of the assembler. Generally the assembler has visibility over a single source file with its
INCLUDE files and MACRO expansions. The assembler detects all static rules in sequential VLES within
its visibility.
7.5.1 Hardware Loop Detection
The assembler detects static rules for hardware loop iterations (LA to SA sequences) when all loop source
code including the DOENn/DOENSHn instruction, LOOPSTARTn and LOOPENDn assembler directives
for all nesting levels are within its visibility. The assembler rule detection makes the following
assumptions:
•
The loop flags (LFn and SLF) in SR are not changed within an active loop.
•
Each loop n has one SA and one LA specified by the LOOPSTARTn and LOOPENDn directives,
respectively.
•
Loops enter at SA and exit from LA, except for exits using loop control instructions: BREAK and
CONT/CONTD.
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Static Programming Rules
•
The SAn register contains the starting address of the first VLES of long loop n.
These assumptions ensure the LOOPSTARTn and LOOPENDn directives are consistent with the hardware
loop state machine’s decoding of the LPMARKx bits. The assembler may not detect hardware loop rules if
these assumptions are violated.
7.5.2 General Grouping Rules
Rule G.G.1
Up to 6 instructions can be grouped in a VLES. Prefix instructions (IFc, LPMARKx, and NOP) are not
counted for this rule.
Rule G.G.2
Up to eight instruction words (including prefix words) can be grouped in a VLES.
Example 7-3. VLES Word Count Exceeds Eight
jmpd r5 adr d0,d12
adr d1,d2
adr d2,d3
adr d5,d6
move.l #$12345678,r0
This example is not allowed. There are six instruction words plus two MOVE extension words and two
prefix words.
Rule G.G.3
Instructions grouped in a VLES cannot exceed the available execution units. The maximum number of
instructions in a VLES is:
•
DALU instructions listed in Table A-7: DALU Arithmetic Instructions (MAC) on page A-13 and
Table A-8: DALU Logical Instructions (BFU) on page A-14.
•
Two AGU instructions, including:
— All AGU arithmetic instructions listed in Table A-9: AGU Arithmetic Instructions on page
A-15.
— All AGU move instructions listed in Table A-10: AGU Move Instructions on page A-16.
— All AGU stack support instructions listed in Table A-11: AGU Stack Support Instructions on
page A-16
— All control instructions listed in Table A-13: AGU Non-Loop Change-of-Flow Instructions on
page A-17, Table A-14: AGU Loop Control (Including Loop COF) Instructions on page A-18,
and Table A-15: AGU Program Control Instructions on page A-18.
•
One bit-mask (BMU) instruction listed in Table A-12: AGU Bit-Mask Instructions (BMU) on page
A-17. This instruction is also counted as an AGU instruction.
•
One ISAP opcode (2-w prefix encoding) per VLES. An ISAP can be defined to support more than
one instruction per ISAP opcode, Section 6.3, “ISAP instructions and instruction encoding.”
•
This rule does not apply to prefix instructions listed in Table A-16: Prefix Instructions on page A-18
because they do not allocate execution units.
Example 7-4
Too Many AGU Instructions
bmtsts #$eb22,d5.h move.w r2,(r0)+
7-8
move.w r2,(r5)
;not allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule G.G.4
Instructions grouped in a VLES cannot write to the same register or affect the same status bit.
For mutually exclusive IFc subgroups in a VLES, this rule applies independently to each subgroup unless
explicitly stated.
The less obvious cases are:
•
Multiple COF instructions that implicitly write the PC register cannot be grouped in a VLES. This
case applies to the whole VLES, independent of the T bit state.
Example 7-5
Duplicate PC Destinations
jmp _lbl3
bt _label1
btd _label1
jt r1
jtd r1
ift bra _label1
ift brad _label1
ift jmp r1
ift jmpd r1
ift jmp r0
ift bra _label1
ift bra _label1
ift jmp r1
ift bra _label1
ift jmpd r1
•
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed
Duplicate Address Pointer Register Destinations
move.w (r0)+,d0
move.w (r0)+,r0
move.l d0,r0
move.l d0,r8
pop r0
move.w
move.w
move.w
move.w
move.w d1,(r0)+
move.l (r0)+,d1
move.l d1,b0
move.l (r0)+,d0
(r0+$6),r0
(r0+n0),r0
(r0),r0
(r0),d0
move.w
(r0)+,d1
;not
;not
;not
;not
;not
allowed
allowed
allowed
allowed - B register alias
allowed
;allowed
;allowed
;allowed
;allowed
-
no
no
no
no
update
update
update
update
mode
mode
mode
mode
Multiple writes of the ESP or NSP stack pointer registers (implicitly using SP and OSP) cannot be
grouped in a VLES. This rule applies independent of the EXP status bit.
Example 7-7
•
;not
;not
;not
;not
;not
;not
;not
;not
;not
;not
;not
;not
;not
;not
;not
Multiple writes of the same address pointer register Rn cannot be grouped in a VLES. The no update
addressing mode (Rn) is not considered an address register write.
Example 7-6
•
bsr _lbl6
bf _label2
bfd _label2
jf r2
jfd r2
iff bra _label2
iff brad _label2
iff jmp r2
iff jmpd r2
iff rts
iff rts
iff break
ifa jf r2
iff brad _label2
iff jmp r2
Duplicate Stack Pointer Destinations
pop d2
pushn d0
pop d1
rts
tfra r1,osp
tfra r0,sp
;not allowed
;not allowed
;not allowed
tfra r0,sp
tfra r1,osp
;allowed - writes different regs.
Multiple instructions that write different portions of the same register cannot be grouped in a VLES.
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Static Programming Rules
Example 7-8
Duplicate Register Destinations
move.w #$1234,d0.h move.w #$5678,d0.l
bmset #3,sr.h
bmset #4,sr.l
;not allowed
;not allowed
Note that BMSET #$3,SR.H reads and writes the 32-bit SR register.
•
MOVE-like instructions that write the SR or EMR register cannot be grouped in a VLES with
instructions that affect individual status bits in the same register.
Example 7-9
pop
ift
pop
add
add
Duplicate SR/EMR Register Destinations
sr
pop sr
sr
d0,d1,d2
d0,d1,d2
add d0,d1,d2
iff add d0,d1,d2
bmtstc #$3,d0.l
bmset #$0040,emr.l
bmset #$0040,emr.h
;not allowed
;allowed
;not allowed
;not allowed
;not allowed
- C bit is written twice
- T bit is written twice
- DOVF is written twice
- DOVF is written twice
Note that BMSET #$3,SR.H reads and writes the 32-bit SR register, while BMTSTC #$3,D0.L
affects only the T status bit in SR.
•
Multiple instructions that affect the same status bit (T, VF0-3, DI, LF0-3, or SLF bits in SR) cannot
be grouped in a VLES.
Example 7-10
Duplicate Status Bit Destinations
cmpeq d0,d1
cmpeq d0,d1
tstgea.l r0
bmtstc #$3,d0.l
;not allowed - multiple T bit updates
;not allowed - multiple T bit updates
Note that BMSET #$3,SR.H reads and writes the 32-bit SR register, while BMTSTC #$3,D0.L
affects only the T status bit in SR.
•
Rule G.G.4 also applies to core vs. ISAP instructions in addition to ISAP vs. ISAP instructions. For
the latter case, the ISAP assembler is responsible for detecting the violation.
Rule G.G.4 Exceptions
•
Two push or pop instructions that both implicitly write the SP register can be grouped in a VLES if
they access different, De (even) and Do (odd), register fields. For the following groupings, the
SC140 ensures that the SP register is written correctly. This case applies to the whole VLES.
Example 7-11
Dual Stack Pointer Destination Exception
push
pushn
pop
popn
De
De
De
De
field
field
field
field
ift push De field
•
7-10
push
pushn
pop
popn
Do
Do
Do
Do
field
field
field
field
ifa push Do field
;allowed
;allowed
;allowed
;allowed
;allowed
Two mutually exclusive writes to the same register (except the PC register) can be grouped in a
VLES.
SC140 DSP Core Reference Manual
Static Programming Rules
Example 7-12
Mutually Exclusive Register Destination Exception
ift
movet
tfrt
ift
ift
ift
[ift
add #1,d0
iff
add #2,d0
r0,r1
movef r2,r1
d0,d1
tfrf d5,d1
add #1,d0
ifa
tfrf d1,d0
adda #1,r0
iff
adda #2,r0
move.w (r0)+,d0
iff
move.w (r0)-,d0
move.w (r0)+,d0
iff
{move_special (r0)-,d0)} ]
tfra r1,r0
iff
tfra r2,r0
push d0
iff
push d1
movet r1,r0 movef r2,r0
ift
ift
ift
•
;allowed
;allowed
;allowed
;allowed
Instructions that affect different status bits can be grouped in a VLES. These include the C, T, S,
VF0-3, DI, LF0-3, and SLF status bits in SR, and the DOVF bit in EMR. The G.G.4 rule treats
instructions that affect these status bits as writing 1-bit destinations.
Example 7-13
Mutually Exclusive Status Bit Destination Exception
cmpeq d0,d1
di
doen0 #5
•
;allowed
;allowed
;allowed
;allowed
;allowed
;allowed
add d0,d1,d2
moves.f d0,(r0)+
max2vit d4,d2
;allowed - T and C bit updates
;allowed - DI and S updates
;allowed - LF and VF updates
Multiple instructions that affect the C or S status bits in SR or the DOVF status bit in EMR can be
grouped in a VLES. S and DOVF are “sticky” status bits are set by the logical OR of all executed
instructions in a VLES that affect them. C is updated by only one instruction in a VLES - the last (in
the assembly source order) carry-affecting instruction that actually executes in the VLES. This case
applies to the whole VLES.
Example 7-14
Multiple C, S and DOVF Status Bit Destination Exception
add d0,d1,d2
asrr #4,d0
[
[moves.4f d0:d1:d2:d3,(r0)+
moves.2f d4:d5,(r1)+ ]
;allowed -last instruction (asrr)
;affects the C status bit in SR
;allowed - d0-d5
;data affects S bit
Rule G.G.5
A data register Dn can be used as a source operand up to four times in a VLES. This includes all implicit
sources, such as the accumulator source of a MAC instruction.
Example 7-15. DALU Register Use Exceeds Four Times
mac d2,d2,d2
add d2,d2,d3 ;not allowed - d2 used 5 times as a source
7.5.3 Prefix Grouping Rules
The following rules only apply to prefix-grouped VLES.
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7-11
Static Programming Rules
Rule G.P.1
Up to two extension words can be grouped in a VLES. This means:
•
A three-word instruction can only be grouped in a VLES with one-word instructions.
Example 7-16
VLES Extension Words Exceed Two
[
bmset #$ab34,d3.l
move.l #$f0d0,vba
]
•
; 1st extension word
; not allowed - 2nd & 3rd extension word
A two-word instruction can only be grouped in a VLES with one other two-word instruction and/or
one-word instructions.
Example 7-17
Two-Word Instructions Exceed Two
[
move.f #$1234,d0
extract #8,#16,d0,d2
extractu #8,#24,d0,d3
zxt.b d0,d0
]
; 1st extension word
; 2nd extension word
; not allowed - 3rd extension word
The second and third words of an instruction are called “extension words.” An extension word can occur in
the following cases:
•
Some immediate values
•
Some absolute addresses or offsets
•
Bit mask instructions listed in Table A-16: Prefix Instructions on page A-18
•
INSERT or EXTRACT/U instructions
•
Integer double precision instructions such as IMACxx, IMACxxxx, IMPYxx, IMPYxxxx and
IMPY.W
7-12
SC140 DSP Core Reference Manual
Static Programming Rules
Rule G.P.3
The following instructions in each line are mutually exclusive, and cannot be grouped in a VLES. For
mutually exclusive IFc subgroups in a VLES, this rule applies independently to each subgroup.
•
MARK
•
DEBUG and DEBUGEV
•
DI and EI
•
BREAK, CONT, CONTD, DOENn, DOENSHn, and SKIPLS
STOP, WAIT, and any COF instruction cannot be grouped in a VLES. This applies also to a VLES having
two mutually exclusive IFc subgroups.
Example 7-18. VLES Has Mutually Exclusive Instructions
stop
mark
wait
mark
;not allowed
;not allowed
stop
mark
ift doen1 #5 iff doen2 #4
ift debug
iff debugev
;allowed
;allowed
;allowed
ift stop
ift wait
;not allowed
;not allowed
iff wait
iff bra _label
Rule G.P.4
An RTE/D instruction cannot be:
•
Grouped in a VLES with another AGU instruction.
•
In a VLES having two IFc subgroups.
Example 7-19. RTE Uses Both AAU
rted
ift clr d0
inca r3
ifa rte
;not allowed
;not allowed - two IFc subgroups
ift rte
impy d0,d1,d2
;allowed - one IFc group
Rule G.P.5
The same Nn or Mn register can be used as a data source operand of a MOVE-like instruction only once in
a VLES. For mutually exclusive IFc subgroups in a VLES, this rule applies independently to each
subgroup.
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7-13
Static Programming Rules
Example 7-20. Data Source Use of Nn and Mn Registers
move.l n0,d0
ift move.l n0,d0
move.l n0,d1
iff move.l n0,d1
;not allowed
;allowed
move.l
move.l
move.l
move.l
move.l
move.l
move.l
move.l n1,d1
suba n0,r0
move.l (r0)+n0,d1
move.l (r0+n0),d1
move.l (r1)+n0,d1
move.l (r1+n0),d1
move.l (r1+n0),d1
;allowed
;allowed
;allowed
;allowed
;allowed
;allowed
;allowed
n0,d0
n0,d0
n0,d0
n0,d0
(r0)+n0,d0
(r0)+n0,d0
(r0+n0),d0
move.l n0,d0
adda n0,n0
adda n0,n0
vsl.2f d1:d3,(r0)+n0;allowed
move.l (r0)+n0,d1 ;allowed
move.l (r0+n0),d1 ;allowed
Rule G.P.6
In a VLES having two IFc subgroups, each subgroup can have up to one AGU instruction and two DALU
instructions. Prefix instructions (IFc, LPMARKx, NOP, and ISAP instructions) are not counted for this
rule. However, if the core assembler adds implicit AGU instructions to support ISAP memory accesses and
register transfers, this rule does apply to these implicit AGU instructions. For more details on how this
works, see Section 6.4, “ISAP Memory Access,” on page 6-60.
Note that the overall number of DALU instructions in the entire VLES is restricted by Section , “Rule
G.G.3,” .
Example 7-21. IFc Having Two Subgroups
ift add d0,d2,d3
ift move.w d3,(r4)
iff move.w d3,(r4)
iff add d0,d2
move.w d4,($8)
clr d4
;not allowed
;allowed
ift move.l d2,(r1)
iff add d3,d4
{isap_ins}
;allowed
Rule G.P.7
Up to two IFc subgroups (different conditions) can be grouped in a VLES. An IFc group or subgroup must
have at least one instruction. An IFA subgroup (if present) must be the last (in the assembly source order)
instructions in a VLES.
Example 7-22. IFA Subgroup Must Be Last Instructions
7-14
ift add d0,d1,d2
iff add d3,d4,d5
ift
iff inc d0
;not allowed
inc d0
ift add d0,d1,d2
;not allowed
ifa inc d0
ift add d0,d1,d2
;not allowed
ift add d0,d1,d2
ifa inc d0
;allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule G.P.8
It is not allowed to group AGU instructions that use or update a data register (D0-D15) in the same VLES
with an ISAP instruction.
This rule relates to independent AGU instructions, not to instructions that are implicitly generated by the
assembler from ISAP instructions to support ISAP memory accesses and register transfers. For more
details on how this works, see Section 6.4, “ISAP Memory Access,” on page 6-60.
Example 7-23. Core AGU instructions on same VLES as ISAP instructions
move.l (r0)+,d0 {INC K0}
add d0,d1,d2 {INC K0}
{MOVE.L D0,K0}
;
;
;
;
not allowed {INC K0} is an ISAP instruction
allowed, “add” is not an AGU instruction
allowed. The core assembler generates an
implicit AGU move from d0
Rule G.P.9
All ISAP ALU instructions in a VLES must belong to the same IFc group. ISAP instructions that generate
implicit AGU instructions are subject to Rule G.P.6. See more on conditionally executed ISAP
instructions in Section 6.7.3, “Conditional Execution.”
Example 7-24. ISAP instructions in same IFc group
ift {isap_one}
ift move.w d3,(r4)
ift move.l d2,(r1)
SC140 DSP Core Reference Manual
iff {isap_two}
iff {move_special} {isap_two}
iff add d3,d4
{isap_ins}
;not allowed
;allowed
;allowed
7-15
Static Programming Rules
7.5.4 AGU Rules
Rule A.1
At least two cycles are required between when an instruction writes the MCTL register and when an AGU
instruction reads the R0-R7 registers with an address register update or address pre-calculation, or as an
operand affected by a MCTL modifier field. This rule does not apply to R8-R15, or to R0-R7 using the no
update (Rn) addressing mode.
Example 7-25. MCTL Write to R0-R7 Use
7-16
move.l
move.w
#$12345678,mctl
(r0)+,d0
;change MCTL
;use MCTL, not allowed
move.l
nop
move.w
#$12345678,mctl
;change MCTL
(r0)+,d0
;use MCTL, not allowed
move.l
nop
nop
move.w
#$12345678,mctl
;change MCTL
(r0)+,d0
;use MCTL, allowed
move.l
adda
d0,mctl
r0,r1
;change MCTL
;use MCTL, not allowed
move.l
move.w
d0,mctl
d1,(r0+n0)
;change MCTL
;use MCTL, not allowed
bmclr
move.w
#0,mctl.l
(r0)+,d0
;change MCTL
;use MCTL, not allowed
bmclr
move.w
#0,mctl.l
(r1)+,d0
;change MCTL
;use MCTL, not allowed
bmclr
move.w
#0,mctl.l
(r5)+,d0
;change MCTL
;use MCTL, not allowed
move.l
adda
d0,mctl
r8,r1
;change MCTL
;use MCTL, not allowed
move.l
adda
d0,mctl
r1,r8
;change MCTL
;no modifier mode, allowed
move.l
adda
d0,mctl
#$1234,r8,r1
;change MCTL
;use MCTL, allowed
move.l
adda
d0,mctl
#$1234,r1,r8
;change MCTL
;no modifier mode, not allowed
move.l
move.w
d0,mctl
(r0),d0
;change MCTL
;no update mode, allowed
move.l
move.w
d0,mctl
(r8)+,d0
;change MCTL
;no modifier mode, allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule A.2
At least one cycle is required between a MOVE-like instruction writing to an address register (Rn or Nn) as
a data operand and when the same register is used in the following manner with the following instructions:
•
An address operand of a MOVE-like instruction.
•
A source operand of an AGU arithmetic instruction.
•
An operand holding a target of a COF instruction 1.
This rule does not apply when a MOVE-like instruction writes Bn or Mn and used for modulo calculation
on Rn, by either MOVE or an AGU arithmetic instruction is the instruction immediately following the
MOVE-like instruction (even in the case that Bn is referred to as Rn+8)2. The rule does apply to writing to
Rn (for n = 8÷15), using Bn-8 representation3.
Example 7-26. Rn, Nn, Mn Write to AGU Use
move.l
jmp
d0,r0
r0
;not allowed
move.l
move.w
d0,r0
(r0),d1
;not allowed
move.l
move.w
d0,b0
(r8),d1
;not allowed (b0 is alias of r8)
move.l
move.w
d0,b0
(r0)+,d1
;allowed - (but may contradict Rule A.2a due to r0 post inc)
move.l d0,r0
bmclr.w #4,(r0)
;not allowed
move.l
move.w
d0,b0
(r0),d1
;allowed - no Rn write
move.l
adda
d0,b0
r9,d0
;not allowed
move.l
adda
d0,b3
r11,d2
;not allowed - (b3 is alias of r11)
move.l
move.w
d0,m0
(r0),d1
;allowed - no Rn write
move.l
move.l
d0,m1
d1,(r0)+
;allowed (but may contradict Rule A.2a due to r0 post inc)
move.l d0,n0
move.b (r0+n0),d1
;not allowed
Rule A.3
A VLES having a JT/JF or BT/BF or TRAP instruction must be followed by another VLES. The last VLES
in a program section cannot contain a JT/JF or TRAP instruction.
1. i.e. JMP Rn, JMPD Rn, JSR Rn, JSRD Rn, JT Rn, JTD Rn, JF Rn and JFD Rn, DOENn Rn or DOENSHn Rn
2. Writing to Bn and Mn is covered by dynamic rule A.2a.
3. B and R aliasing is applicable for other rule exceptions as well. See Chapter 7.4.3.2, “B Register Aliasing,” for more details.
SC140 DSP Core Reference Manual
7-17
Static Programming Rules
If the VLES having a JT/JF or TRAP instruction is at the end of a program section, the following VLES
must be a NOP. It cannot be data tables or uninitialized memory.
Rule A.4
An AGU arithmetic instruction that writes a Rn or Nn register, or a MOVE-like instruction that writes a Rn
or Nn register as an address operand, cannot be grouped in a VLES with a MOVE-like instruction that
reads the same register as a data operand. For mutually exclusive IFc subgroups in a VLES, this rule
applies independently to each subgroup.
Example 7-27. Rn or Nn Write to MOVE-like Use
adda #$5,r0
move.w r0,($100)
move.w (r0)+,d0
bmtsts #$1234,r0.l
tfra r1,r0
push r0
tfra r1,n0
move.l n0,d0
tfra osp,r0
move.l r0,d0
move.w r0,(r0)+
move.w d0,(r8)+
move.l r8,d1
move.w d0,(r8)+
move.l b0,d1
vsl.2w d1:d3,(r0)+n0 move.l r0,d0
;not
;not
;not
;not
;not
;not
;not
;not
;not
move.w (r2),r0
move.w r0,(r0)
adda #>28,r6,r0
adda #>28,r6,r0
adda #>5,n0
adda #>5,n0
adda #>5,n0
adda #>5,n0
ift adda #<1,r0
iff adda #<1,r0
;allowed
;allowed - no Rn write
;allowed
;allowed
;allowed
;allowed
;allowed
;allowed
;allowed
;allowed
move.w r0,(r1)
move.l (r0),r2
move.l r2,(r0)
move.l d0,(r0)+n0
move.l (r0)+n0,d0
move.l d0,(r0+n0)
move.l (r0+n0),d0
iff move.l r0,d0
ifa movet r0,r7
allowed
allowed
allowed
allowed
allowed
allowed
allowed
allowed - b0 alias
allowed
A DOENn or DOENSHn, CONT, or CONTD instruction that writes an LCn register cannot be grouped in
a VLES with a MOVE-like instruction that reads the same register. For mutually exclusive IFc subgroups
in a VLES, this rule applies independently to each subgroup.
Example 7-28. LCn Write to MOVE-like Use
doen0 r0
doensh0 #5
cont
contd
7-18
move.l lc0,d0
push lc0
move.l lc1,d3
push lc2
;not
;not
;not
;not
allowed
allowed
allowed
allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule A.7
A RTSTK or RTSTKD instruction cannot be grouped in a VLES with a MOVE-like instruction that reads
the EMR register. For mutually exclusive IFc subgroups in a VLES, this rule applies independently to each
subgroup.
Example 7-29. NMID Update to EMR Read
rtstk
move.l emr,d0
;not allowed
7.5.5 Delayed COF Rules
Rule D.1
The following instructions are not allowed in a delay slot:
•
COF instructions
•
STOP and WAIT
•
DI
•
DEBUG
Example 7-30. Instructions in a Delay Slot
jmpd r1
jmp r2
;not allowed
SC140 DSP Core Reference Manual
7-19
Static Programming Rules
Rule D.2
Core or ISAP instructions that read or write the SR register, affect status bits in SR, or are affected by
status bits in SR are not allowed in a RTED delay slot.
This rule applies to instructions that use the stack pointer SP (implicitly or explicitly) and other stack
pointer OSP, since SR affects which stack pointer is used (EXP status bit).
Example 7-31. Instructions in a RTED Delay Slot
rted
move.l d0,sr
;not allowed
rted
move.l sr,d0
;not allowed
rted
bmset #1,sr.l
;not allowed
rted
rol
d0
;not allowed, affected by SR[C]
rted
push
d0
;not allowed, affected by SR[EXP]
rted
bmclr.w #64,(sp-8)
;not allowed, affected by SR[EXP]
rted
bmtsts.w #64,(r0)
;not allowed, affects SR[T]
rted
tfra
r0,osp
;not allowed, affected by SR[EXP]
rted
tfra
sp,r0
;not allowed, affected by SR[EXP]
rted
ift
clr d0
;not allowed, affected by SR[T]
rted
tfra
r0,r1
;allowed
rted
{tsteq k0}
;changes T bit based on ISAP register - not allowed
rted
bmclr.w
;allowed
#64,(r0)
Rule D.3
Core or ISAP instructions that write the SR register or affect status bits in SR cannot be grouped in a VLES
with a RTE/RTED instruction.
Example 7-32. RTE/D with SR Updates
rte
rte
7-20
add d0,d1,d2
{tsteq k0}
;not allowed - affects the carry bit in SR
;not allowed - affects the T bit in SR
SC140 DSP Core Reference Manual
Static Programming Rules
Rule D.4
Instructions that read the PC register (implicitly or explicitly) as a source operand are not allowed in a
RTED/RTSD/RTSTKD delay slot. This rule does not apply to the MARK instruction that reads the PC
register for the EOnCE trace buffer.
Example 7-33. PC Read in a Return Delay Slot
rted
adda pc,r0
;not allowed
rtsd
dosetup0 _label
;not allowed
Rule D.5
A MOVE-like instruction that writes the SR register cannot be grouped in a VLES with a BSR, BSRD,
JSR or JSRD instruction. For mutually exclusive IFc subgroups in a VLES, this rule applies independently
to each subgroup.
Example 7-34. SR Write with a Subroutine Call
pop sr
jsr r0
;not allowed
Rule D.5a
A MOVE-like instruction that writes the SR register is not allowed in the delay slot of a BSRD or JSRD
instruction.
Example 7-35. SR Write in BSRD or JSRD Delay Slot
bsrd _label
pop sr
;not allowed
Rule D.6
Instructions that read or write the SP register are not allowed in the delay slot of delayed return (RTSD,
RTED, , and RTSTKD) instructions. This rule also applies to implicit SP register writes (push and pop
instructions).
Example 7-36. SP Use in Return Delay Slots
rtsd
tfra r0,sp
;not allowed
rted
tfra sp,r0
;not allowed
rtsd
tfra
;allowed
r0,osp
rtstkd
tfra osp,r0
;allowed
rtstkd
pop d0
;not allowed
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7-21
Static Programming Rules
Rule D.8
A MOVE-like instruction that reads the SR register is not allowed in the delay slot of a CONTD
instruction.
Example 7-37. SR Read in a CONTD Delay Slot
contd _label
move.l sr,d0
;not allowed
Rule D.9
Instructions that read the EMR register are not allowed in the delay slot of a RTED, or RTSTKD
instruction.
Example 7-38. EMR Use in Return Delay Slots
rtstkd
move.l emr,d0
;not allowed
rted
bmclr #$fffb,emr.l ;not allowed
7.5.6 Status Bit Rules
Rule T.1
At least one VLES is required between an instruction that affects the T status bit in SR and an AGU
instruction in an IFT/IFF group or subgroup. This rule does not apply to AGU instructions in an IFA
subgroup.
Example 7-39. T Bit Update to IFT/IFF AGU Use
tsteq d0
ift move.l r0,d1
; not allowed
tsteq d0
nop
ift move.l r0,d1
; allowed
tsteq d0
ift mac d0,d1,d2
; allowed
tsteq d0
ift mac d0,d1,d2
7-22
ifa move.l r0,d1
; allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule T.2.a
At least one VLES is required between an ISAP instruction that affects the T status bit in SR and a
conditional COF instruction.
Example 7-40. T Bit Update by ISAP and COF
{tsteq k0}
jt r0
; tsteq is an ISAP instruction that
updates the T bit
; not allowed
{tsteq k0}
nop
jf _destination
; allowed
Rule T.2.b
At least two VLES are required between an ISAP instruction that affects the T status bit in SR and a
MOVET/MOVEF instruction.
Example 7-41. T Bit Update by ISAP and MOVET/MOVEF
{tsteq k0}
movet r0,r1
; tsteq is an ISAP instruction that
updates the T bit
; not allowed
{tsteq k0}
nop
nop
movet r1,r2
; allowed
Rule T.2.c
At least two VLES are required between an ISAP instruction that affects the T status bit in SR and an AGU
instruction in an IFT/IFF group or subgroup. This rule does not apply to AGU instructions in an IFA
subgroup.
Example 7-42. T Bit Update by ISAP and IFT/IFF
{tsteq k0}
ift move.l d0,d1
; tsteq is an ISAP instruction that
updates the T bit
; not allowed
{tsteq k0}
nop
nop
ift move.l d1,d2
; allowed
Rule SR.2
At least two VLES are required between a MOVE-like instruction that writes the SR register and an
instruction affected by a status bit in SR.
SC140 DSP Core Reference Manual
7-23
Static Programming Rules
This rule applies to instructions that use the stack pointer (implicitly or explicitly), since SR affects which
stack pointer is used (EXP status bit).
A MOVE-like instruction that writes the SR register may be followed by a MOVE-like instruction that
reads the SR register, if not affected by a SR status bit.
The assembler-mapped instruction CLR Dn is never affected by SR status bits, even though it is
implemented as SUB Da,Da,Dn. Therefore, this rule applies to the SUB instruction, but not to CLR (SUB
Da,Da,Dn is taken as CLR in this context).
7-24
SC140 DSP Core Reference Manual
Static Programming Rules
Example 7-43. SR Write to SR Status Bit Use
bmclr #$ffff,sr.h
move.w #$1234,d0
;change SR
;allowed, not affected by SR
bmclr
rol
#$ffff,sr.h
d0
;change SR
;not allowed, affected by SR[C]
bmclr
nop
rol
#$ffff,sr.h
;change SR
d0
;not allowed, affected by SR[C]
bmclr
nop
nop
rol
#$ffff,sr.h
;change SR
d0
;allowed
bmclr
nop
push
#<1,sr.l
;change SR
d0
;not allowed, affected by SR[EXP]
bmclr #<1,sr.h
nop
ift clr d0
;change SR
bmtstc #$0001,sr.l
add
d1,d5,d1
;read SR, affects SR[T], not a SR write
;allowed
pop
bmset
;allowed
sr
#$a,sr.l
;not allowed, affected by SR[T]
move.l d0,sr
move.l sr,d5
;allowed
bmset #$a,sr.h
and.w #$1234,(sp-8)
;not allowed
bmset #$a,sr.l
and.w #$1234,(sp-8)
;not allowed
bmset
bmset
;allowed
#$a,sr.l
#$b,sr.h
move.l
move.l
d1,sr
d0,(sp+4)
;not allowed
move.l
move.l
d1,sr
d0,(r0+4)
;allowed
move.l d1,sr
nop
clr d0
;change SR
move.l d1,sr
nop
sub d1,d2,d3
;change SR
move.l d1,sr
nop
sub d1,d1,d3
SC140 DSP Core Reference Manual
;allowed, clear not effected by SR
;not allowed, sub effected by S0,S1
;change SR
;allowed, this is a CLR
7-25
Static Programming Rules
Rule SR.3
At least one VLES is required between a MOVE-like instruction that writes the SR register and the
following instructions that affect status bits in SR:
•
DI and EI
•
DOENn and DOENSHn
•
CONT/D, BREAK, and SKIPLS
Example 7-44. SR Write to SR Status Bit Update
move.l #<1,sr
di
; not allowed
bmclr
doen0
#$ffff,sr.h
#<10
; not allowed
pop
cont
sr
_next
; not allowed
Rule SR.4
At least two VLES are required between an instruction that affects the DOVF status bit in EMR and a
MOVE-like instruction that reads or writes the EMR register.
The assembler-mapped instruction CLR Dn never affects the DOVF status bit, even though it is
implemented as SUB Da,Da,Dn. Therefore, this rule applies to the SUB instruction, but not to CLR (SUB
Da,Da,Dn is taken as CLR in this context).
7-26
SC140 DSP Core Reference Manual
Static Programming Rules
Example 7-45. DOVF Update to SR Read or Write
bmset #$4,emr.l
move.l emr,d2
;allowed
move.l #$4,emr
move.l emr,d0
;allowed
move.l #$4,emr
move.l d0,emr
;allowed
move.l d1,emr
move.l emr,d0
;allowed
add d0,d1,d2
nop
move.l emr,d3
;overflow may set DOVF bit
adr
nop
move.l
d3,d4
;overflow may set DOVF bit
d0,emr
;not allowed
bmset
nop
move.l
#$01,emr.l
;read and write EMR register
d0,emr
;allowed
;not allowed
sub d0,d1,d2
nop
move.l emr,d3
;overflow may set DOVF bit
clr d0
move.l emr,d3
;DOVF bit not affected
;allowed
sub d1, d1, d0
move.l emr, d3
;This is a CLR. The DOVF bit is not affected
;allowed
;not allowed
Rule SR.4a
Instructions that affect the DOVF status bit in EMR can’t be grouped with a MOVE-like instruction to SR
or with an RTE-like instruction (RTE/D ).
The only exception for this rule is for Bit-Mask instructions on SR for which it is ensured that the
value of the OVE bit in SR is not changed.
Example 7-46. DOVF Update grouped with Move-like SR updates
bmclr #$0010,sr.h
bmchg #$0010,sr.h
bmclr #$0001,sr.h
bmchg #$0010,sr.l
move.l #$100000,sr
move.l d0,sr
pop sr
rted
mac
mac
mac
mac
mac
mac
mac
mac
SC140 DSP Core Reference Manual
d1,d2,d3
d1,d2,d3
d1,d2,d3
d2,d2,d3
d0,d1,d2
d0,d1,d2
d0,d1,d2
d0,d1,d2
;
;
;
;
;
;
;
;
Not allowed
Not allowed
Allowed (OVE not changed)
Allowed (OVE not changed)
Not allowed
Not allowed
Not allowed
Not allowed
7-27
Static Programming Rules
Rule SR.7
The following instructions that affect status bits in SR cannot be grouped in a VLES with a MOVE-like
instruction that reads the SR register:
•
BREAK
•
CONT/CONTD
•
DI and EI
•
DOENn and DOENSHn
•
SKIPLS
For mutually exclusive IFc subgroups in a VLES, this rule applies independently to each subgroup.
Example 7-47. Status Bit Update with SR Read
doen0 #5
di
skipls _dest
move.l sr,d0
push sr
bmtsts #4,sr.h
;not allowed
;not allowed
;not allowed
7.5.7 Loop Nesting Rules
Rule L.N.1
Nested loops cannot have the same LA.
Example 7-48. Nested Loops with the Same LA
...
move.w r3,(r4)
loopend1
loopend0
7-28
;LA
;not allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule L.N.2
A loop body n must be surrounded by the LOOPSTARTn and LOOPENDn assembly directives, and can
only be nested inside a loop body having a smaller index.
Example 7-49. Nested Loops with Ordered Index
doen1
move.w
move.l
move.w
#count1
#num,d1
#mem_l,r1
#offset,n0
loopstart1
label1
inc
dosetup0
doen0
move.w
d1
label2
#count2
#num,d2
loopstart0
;not allowed
label2
inc
d2
impyuu
d1,d2,d3
move.w
d3,(r1)+
loopend0
nop
loopend1
Rule L.N.3
A DOENn/DOENSHn instruction having a different loop index and any LOOPEND directive cannot come
between the DOENn/DOENSHn instruction and LOOPSTARTn directive of loop n.
Also, it is not allowed to place a DOENSH instruction with any index between the DOENn and its
respective LOOPSTARTn directive, or a DOEN instruction with any index between the DOENSHn
instruction and its respective LOOPSTARTn directive.
Example 7-50. Nested DOENn/DOENSHn Instructions
count2 equ 5
...
move.w #count2,d6
dosetup0 label2
doen0 d6
doen1 #2
; not allowed
loopstart0
doen1 #5
doen1 #6
; allowed
loopstart1
SC140 DSP Core Reference Manual
7-29
Static Programming Rules
Example 7-51. DOENn instruction following DOENSHn Instruction
doensh0 #3
doen0 #3 dosetup0 _loop_start
nop
nop
_loop_start
loopstart0
move.l #0,d0
move.l #1,d0
move.l #2,d0
loopend0
; not allowed (SLF isn't reset)
;instruction should be in the loop, but isn't!
Example 7-52. LOOPEND between DOEN and LOOPEND
doen2 #3
dosetup2 L_1
nop
L_1
loopstart2
nop
nop
doen3 #3
dosetup3 L_2
nop
nop
nop
loopend2
nop
;not allowed: problem created here
;problem becomes apparent here
L_2
loopstart3
nop
nop
nop
loopend3
Example 7-53. Changing a loop type
doensh0 #3
doen0 #3
dosetup0 _loop_start
nop
nop
_loop_start
loopstart0
move.l #0,d0
move.l #1,d0
move.l #2,d0
loopend0
7-30
; not allowed to change loop type
SC140 DSP Core Reference Manual
Static Programming Rules
7.5.8 Loop LA Rules
Rule L.L.1
The following instructions are not allowed at LA-1 or LA of a long loop:
•
COF instructions
•
STOP and WAIT
•
DI
•
DEBUG
Example 7-54. Instructions at the End of Long Loops
move.w #count2,d6
dosetup0 label2
doen0 d6
move.w #1,d1
move.w #2,d2
move.w #3,d3
move.w #4,d4
loopstart0
label2 inc d1
inc d2
inc d3
inc d4
wait
loopend0
;not allowed
Rule L.L.2
A DOENn or MOVE-like instruction that writes a LCn register is not allowed at LA-2, LA-1, or LA of the
same long loop n.
Example 7-55. LCn Write at the End of Long Loop n
doen1 #5
move.w d3,(r1)+
loopend1
SC140 DSP Core Reference Manual
;not allowed
7-31
Static Programming Rules
Rule L.L.3
The following instructions are not allowed in a short loop:
•
COF instructions
•
STOP and WAIT
•
DI
•
DEBUG
•
DOENn/DOENSHn
•
MOVE-like instructions that read any LCn register
•
MOVE-like instructions that write any LCn register
•
MOVE-like instructions that read the SR register
•
MOVE-like instructions that write the SR register
This rule does not apply to other instructions that affect status bits in SR.
Example 7-56. Instructions in Short Loops
doensh0 #$10
nop
loopstart0
jmp end
loopend0
doensh1 #count2
move.w #num,d2
loopstart1
doen1 #5
loopend1
;not allowed
;not allowed
Rule L.L.4
The LA of a short loop cannot be at LA-1 of a long loop.
Example 7-57. Short Loop LA at the End of a Long Loop
dosetup0 label1
doen0
#count1
move.w #num,d1
nop
nop
loopstart0
nop
nop
label1 inc d1
doensh1 #count2
move.w
#num1,d2
loopstart1
label2 inc d2
impyuu d1,d2,d3
loopend1
nop
loopend0
7-32
;not allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule L.L.5
A MOVE-like instruction that writes the SR register is not allowed at LA-4, LA-3, LA-2, LA-1, or LA of a
long loop.
Rule L.L.6
A MOVE-like instruction that writes the SR register is not allowed at SA-2 or SA-1 of a short loop.
7.5.9 Loop Sequencing Rules
Rule L.D.1
At least one VLES is required between the following instructions that write any LCn register and the
SKIPLS instruction:
•
Any DOENn Dn (data register)
•
Any DOENSHn Dn (data register)
•
MOVE-like instruction that writes any LCn register
Example 7-58. LCn Write to SKIPLS Instruction
doen0 d2
skipls label4
; not allowed
Rule L.D.2
The minimum number of VLES between the following instructions that write a LCn register and LA of the
same long loop n is:
•
DOENn Rn or #x: three VLES (address register or immediate value)
•
DOENn Dn: four VLES (data register)
•
MOVE-like instruction that writes a LCn register: four VLES
Example 7-59. LCn Write at the End of Long Loop n
move.w #3,d8
dosetup1 label1
doen1 d8
nop
loopstart1
label1 inc d3
inc d4
inc d5
loopend1
SC140 DSP Core Reference Manual
;not allowed
7-33
Static Programming Rules
Rule L.D.3
The minimum number of VLES between the following instructions that write a LCn register and SA of the
same short loop n is:
•
DOENSHn Rn or #x: one VLES (address register or immediate value)
•
DOENSHn Dn: two VLES (data register)
•
MOVE-like instruction that writes a LCn register: two VLES
Example 7-60. LCn Write at the Start of Short Loop n
move.w #3,r0
doensh0 r0
move.l d1,lc0
move.w #2,d2
loopstart0
inc d1
loopend0
;allowed
;not allowed
Rule L.D.5
The minimum number of VLES between an instruction that writes any LCn register and a CONT/CONTD
instruction is:
•
Any DOENn Rn or #x : one VLES (address register or immediate value)
•
Any DOENn Dn: two VLES (data register)
•
MOVE-like instruction that writes any LCn register: two VLES
Example 7-61. LCn Write to CONT/D Instruction
doen1 #5
...
loopstart1
loop1 nop
move.l d0,lc1
nop
cont label
nop
nop
loopend1
;not allowed
Rule L.D.6
A MOVE-like instruction that writes a SAn register is not allowed at (LA-3), (LA-2), (LA-1), and LA of
the same long loop n.
7-34
SC140 DSP Core Reference Manual
Static Programming Rules
Example 7-62. SAn Write at the End of Long Loop n
loopstart0
...
doen1 #5
...
loopstart1
...
dosetup0 _addr
loopend1
nop
loopend0
;not allowed
Rule L.D.7
At least one VLES is required between an instruction that writes any SAn register and a CONT/CONTD
instruction.
Example 7-63. SAn Write to CONT/D Instruction
doen1 #5
dosetup1 label1
loopstart1
label1 cont label2
inc d0
move.w #$23,d2
move.w #$beef,d3
loopend1
label2 inc d1
;not allowed
Rule L.D.8
A MOVE-like instruction that reads a LCn register is not allowed at the (LA-3), (LA-2), (LA-1), and LA of
the same long loop.
Rule L.D.9
At least one VLES is required between a MOVE-like instruction that reads a LCn register and SA of the
same short loop n.
Example 7-64. LCn Read at the Start of Short Loop n
doensh0 #$10
push lc0
loopstart0
inc
d0
loopend0
doensh0 #$10
push lc1
loopstart0
inc
d0
loopend0
SC140 DSP Core Reference Manual
;not allowed
;allowed
7-35
Static Programming Rules
7.5.10 Loop COF Rules
Rule L.C.1
A COF instruction cannot have a COF destination that is LA-1 or LA of a long loop, or LA of a 2-VLES
short loop. This rule does not apply to loop COF instructions (BREAK, CONT, CONTD and SKIPLS) in a
nested loop having a COF destination that is LA-1 or LA of an enveloping loop.
Example 7-65. COF Destination to Loop Delay Slots
doensh1 #5
...
cmpeq.w #3,d0
jf _dest
inc d0
loopstart1
inc d0
_dest add d1,d2,d3
loopend1
;not allowed
Rule L.C.2
COF instructions, WAIT and STOP are not allowed at LA-2 of a long loop.
Example 7-66. COF Instructions at LA-2 of a Long Loop
dosetup1 label1
doen1 #n2
move.l #mem_l1,r1
move.l #mem_l2,r0
loopstart1
label1 inc d1
jsr r1
add d1,d2,d3
move.w d3,(r0)
loopend1
bra label2
;LA-2, not allowed
;LA-1
;LA
Rule L.C.3
A Bc or Jc instruction is not allowed at SA-1 of a short loop.
Example 7-67. Bc/Jc at SA-1 of a Short Loop
cmpgt d4,d3
nop
iff doensh3 #count2
bt _dest
;SA-1, not allowed
loopstart3
inc d2
loopend3
...
_dest inc d2
7-36
SC140 DSP Core Reference Manual
Static Programming Rules
Rule L.C.5
A Bc or Jc instruction is not allowed at LA-3 of a long loop.
Example 7-68. Bc/Jc at LA-3 of a Long Loop
dosetup1 label7
move.w #0,d1
doen1 #5
loopstart1
label7 inc d1
bf label6
inc d2
inc d3
inc d4
loopend1
SC140 DSP Core Reference Manual
;LA-3, not allowed
7-37
Static Programming Rules
Rule L.C.7
A loop COF instruction (BREAK, CONT, CONTD, or SKIPLS) in an enabled loop n cannot have a COF
destination in the same loop n.
Example 7-69. Loop COF Destination in the Same Loop
dosetup3 label1
doen3 #5
loopstart3
label1 inc d1
inc d2
break label2
inc d3
inc d4
label2 inc d5
loopend3
dosetup3 label1
doen3 d0
nop
skipls label2
loopstart3
label1 inc d1
inc d2
inc d3
inc d4
inc d5
loopend3
label2 nop
dosetup2 label1
doen2 #6
nop
loopstart2
label1 cont next
nop
inc d0
dosetup3 label2
doen3 #5
loopstart3
label2 inc d1
next
inc d2
inc d3
inc d4
inc d5
loopend3
nop
loopend2
nop
7-38
;not allowed
;allowed
;not allowed
SC140 DSP Core Reference Manual
Static Programming Rules
Rule L.C.9
A loop COF instruction (BREAK, CONT, CONTD, or SKIPLS) cannot have a COF destination that is one
VLES before two consecutive VLES that are both LA of long loops.
Example 7-70. Loop COF at End of Nested Long Loops
doen0 #5
...
loopstart0
...
doen1 #10
...
loopstart1
...
doen2 d0
...
skipls _dest
loopstart2
...
loopend2
...
; not allowed
_dest
nop
nop
loopend1
nop
loopend0
; last address of long loop 1
; last address of long loop 0
Rule L.C.10
A BSR, BSRD, JSR, or JSRD instruction cannot have a COF destination that is LA-2 of a long loop or SA
of a short loop.
Example 7-71. Subroutine Call to End of Loops
dosetup0 label1
doen0 d1
nop
nop
loopstart0
label1 nop
nop
jsr label2
nop
nop
inca r1
label2 inca r7
add d1,d2,d3
move.w d3,(r0)
loopend0
SC140 DSP Core Reference Manual
;not allowed
;LA-2
;LA-1
;LA
7-39
Static Programming Rules
Rule L.C.11
A delayed COF instruction is not allowed at LA-3 of a long loop.
Example 7-72. Delayed COF at LA-3 of a Long Loop
jmpd_dest
nop
nop
nop
loopend0
;not allowed
Rule L.C.12
A delayed COF instruction is not allowed at SA-1 of a short loop.
Example 7-73. Delayed COF at SA-1 of a Short Loop
jmpd _dest
loopstart0
nop
loopend0
;not allowed
7.5.11 General Looping Rules
Rule L.G.3
A MOVE-like instruction that reads the SR register is not allowed at the (LA-3), (LA-2), (LA-1), and LA
of any long loop.
Example 7-74. SR Read to LA of Any Long Loop
dosetup1 label1
doen1
#5
loopstart1
label1
inc d1
move.l sr,d0
inc d2
move.l #mem_l1,r1
move.l #mem_l2,r0
loopend1
;not allowed
Rule L.G.4
At least one VLES is required between a MOVE-like instruction that reads the SR register and SA of any
short loop.
Example 7-75. SR Read to SA of Any Short Loop
doensh0 #$10
push sr
loopstart0
inc d0
loopend0
7-40
;not allowed
SC140 DSP Core Reference Manual
Dynamic Programming Rules
Rule L.G.5
A loop having one or two VLES must be enabled by a DOENSHn instruction. A loop having three or more
VLES must be enabled by a DOENn instruction.
Example 7-76. Enabling Short and Long Loops
doen1 #5
dosetup1 label1
skipls
label2
loopstart1
; not allowed
label1
move.l d1,(r1)+
addnc.w #1,d1,d1
loopend1
label2 nop
7.6 Dynamic Programming Rules
Dynamic programming rules cannot be detected by the assembler examining the source code, because they
depend on the run-time execution trace. These rules can be detected by the simulator examining the SC140
visible and hidden registers and simulation trace. The simulator detects all dynamic rules that occur during
its execution. The simulator cannot detect programming rules in binary encodings that were not executed.
Dynamic rule detection depends on the test coverage of the programmer’s test suite. Programmers should
exercise all COF destinations, exception service routines, and system configurations (such as conditional
assembly directives) in the simulation trace so the simulator detects all dynamic programming rules. The
simulation trace should also exercise all data dependencies of conditional COF instructions (such as Bc
and Jc), conditional instructions (MOVEc and TFRc) and conditional groups or subgroups (IFc).
7.6.1 AGU Dynamic Rules
Rule A.2a
At least one cycle is required between when a MOVE-like instruction writes Bn or Mn register as a data
operand and a MOVE or an AGU arithmetic instruction using the same register for a modulo calculation
(even in the case that Bn is referred to as Rn+8). This rule applies only if these registers are actually used in
a modulo calculation as determined by the actual value in MCTL.
Example 7-77. Bn, Mn Write to AGU Use
move.l #$000000f, MCTL
move.l d0,b0
move.w (r0)+,d1
pop d0,m1
adda r9,r1
SC140 DSP Core Reference Manual
; r0 only has modulo addressing
; Not allowed
; Allowed
7-41
Dynamic Programming Rules
7.6.2 Memory Access Rules
Rule A.5
Only one memory write instruction to the same location can be grouped in a VLES. Multiple memory
write instructions grouped in a VLES must write to different locations, so the order that multiple writes
occur does not change the memory results. If this is not done, the memory contents of the accessed
locations are undefined. For mutually exclusive IFc subgroups in a VLES, this rule applies independently
to each subgroup.
Example 7-78. Multiple Memory Writes to the Same Location
move.l
move.l
move.l
move.l
move.l
move.l
d0,(r0)
d0,(r0+n0)
d0,$100
d0,(r0)
d0,(r0)
d0,(r0)
move.l d1,(r0)
move.l d1,(r0+n0)
move.b d1,$103
move.l d1,(r1)
move.b d1,(r0+n0)
move.w d1,(r1+$6)
;not
;not
;not
;not
;not
;not
allowed
allowed
allowed
allowed if addresses overlap
allowed if addresses overlap
allowed if addresses overlap
Rule A.6
A memory read instruction having a pre-calculated address cannot be grouped in a VLES with a memory
write instruction not having a pre-calculated address to the same memory location. These memory accesses
must write to different locations, so the order that multiple accesses occur does not change the memory
results. If this is not done, the memory contents of the accessed locations are undefined. For mutually
exclusive IFc subgroups in a VLES, this rule applies independently to each subgroup.
Example 7-79. Pre-Calculated Memory Accesses to the Same Location
move.w (r0+$3),d0 move.l d1,(r0)
move.b (r0+n0),d0 move.l d1,(r0)
move.w (r0+$6),d0 move.b d1,(r1)
bmset.w #$123,(sp+$10) move.w d0,(r0)
;not
;not
;not
;not
allowed
allowed if addresses overlap
allowed if addresses overlap
allowed if addresses overlap
pop d0
move.l d1,(r0)
rts
move.w d0,(r0)
;not allowed
; and shadow
;not allowed
; and shadow
if
SP
if
SP
addresses overlap
is not valid
addresses overlap
is not valid
Rule D.7
Instructions in the delay slot of delayed return instructions (RTED, RTSD, RTSTKD) cannot write to a
memory address in the range (SP−8 ≤ address < SP), where SP is the value of the active stack pointer
register at the beginning of the VLES having the RTED, RTSD or RTSTKD instruction.
Example 7-80. Memory Write to Stack in a Return Delay Slot
tfra
sp,r0
move.l d1,(r0-8)
rtsd
move.l d2,(r0-8)
7-42
;allowed
;not allowed
SC140 DSP Core Reference Manual
Dynamic Programming Rules
7.6.3 RAS Rules
Rule J.4
Upon execution of the RTS or RTSD instruction, if the RAS is valid, the value of the RAS (used to restore
the PC) must be equal to the value in the stack, pointed to by the SP, that would have been used if the RAS
was not valid.
The following case manipulates the SP and builds on the return address using RAS:
Example 7-81. Illegal use of RAS value
move.l d6,(sp-8) adda #<8,sp
rts move.l d7,(sp-$c)
; not allowed since RAS may be valid
7.6.4 Loop Rules
The loop COF instructions produce undefined results if all loops are disabled. Since the assembler cannot
know the LFn state when these instructions execute, the simulator detects this programming rule. Good
loop programming practices can ensure that rule L.N.6 is enforced.
Rule L.N.6
Loop COF instructions (BREAK, CONT, CONTD, and SKIPLS) cannot be used if all loops are disabled.
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7-43
Dynamic Programming Rules
7.6.5 Rule Detection Across COF Boundaries
Some sequencing rules may be violated across COF boundaries — between instructions that are before the
COF instruction or grouped in a VLES with the COF instruction (or its delay slot), and instructions at or
after the COF destination. The assembler does not analyze this control flow and lacks the run-time
execution trace to detect these cases. In addition, the code segments containing the COF instruction and the
COF destination may be in two independently assembled source files, thus outside the visibility of the
assembler. However, the simulator can detect most rule violations across COF boundaries by examining
the simulation trace.
For example, the assembler cannot detect SR.2 across a COF boundary, but the simulator can detect it from
the simulation trace.
Example 7-82. SR.2 Across a COF Boundary
pop
bra
...
sr
fred
add
d1,d2,d3
fred
;not allowed by SR.2
The assembler cannot detect the A.2 violation between the delay slot and the COF destination shown
below, but the simulator can detect it from the simulation trace.
Example 7-83. A.2 from a Delay Slot to a COF Destination
jmpd _dest
bmset #3,r0.l
...
;2-cycle instruction
move.l (r0),d0
;not allowed by A.2
_dest
7.6.5.1 Cycle-Based COF Rules
Cycle-based COF rules calculate the COF cycle count to determine if the sequence is allowed or not.
Cycle-based rule violations across COF boundaries are relatively rare because the COF instruction, taking
multiple cycles, creates a “cycle barrier” between the VLES having the COF instruction and the VLES at
the COF destination. However, this cycle barrier is reduced when the instructions are grouped in a VLES
with the COF instruction (or its delay slot).
The relevant cycle-based rules that the simulator detects across COF boundaries are:
•
A.1
•
A.2
•
A.2a
7-44
SC140 DSP Core Reference Manual
Dynamic Programming Rules
7.6.5.2 VLES-Based COF Rules
VLES-based COF rules are detected like static rules, except the rule is detected from the simulation trace,
not the source code order. A VLES having a COF instruction is counted like any other VLES. Exceptions
to the above are JSR/D and BSR/D instructions, guaranteeing an inherent one VLES distance between the
instructions in the source execution flow (including the delay slot), and the instructions in the destination
flow.
The relevant VLES-based rules that the simulator detects across COF boundaries are:
•
Non-loop COF rules
— T.1
— SR.2
— SR.4
•
Loop COF rules
— L.L.5
— L.L.6
— L.D.1
— L.D.2
— L.D.3
— L.D.5
— L.D.6
— L.D.7
— L.D.8
— L.D.9
— L.C.10
— L.G.3
— L.G.4
Example 7-84. Set condition during a COF, and use it at the destination (T.1)
bt _des1cmpeq d0,d1
...
_des1 ift tfra r0,r1
;Not allowed
btd _des2cmpeq d0,d1
nop
...
_des2 ift tfra r0,r1
; Allowed
bt _des3
cmpeq d0,d1
...
_des3 ift tfra r0,r1
; Not allowed
jsrd _des4
cmpeq d0,d1
...
_des4 ift tfra r0,r1
SC140 DSP Core Reference Manual
; Allowed (1 extra VLES calculated between cmpeq and
ift)
7-45
Dynamic Programming Rules
7.6.6 Rule Detection Across Exception Boundaries
The SC140 can take an exception at most VLES boundaries in a program, and return using a RTE//RTED/
instruction after completing the exception service routine. The programming rules ensure that the
transition from the program to the exception service routine, and the return back to the program are correct.
The return back to the program is covered by the RTE//RTED/ programming rules in this chapter.
The following rules cover the transition from the program to the exception service routine. They apply to
the first 1-2 VLES of the exception service routine, and do not apply to the program that was interrupted:
Rule SR.2a
Instructions that are affected by the C, T, S0, S1, or VF0-VF3 status bits in SR are not allowed in the first
two VLES of an exception service routine. This rule does not apply to instructions that are affected by the
EXP status bit in SR.
The assembler-mapped instruction CLR Dn is never affected by the SR status bits, even though it is
implemented as SUB Da,Da,Dn. Therefore, this rule applies to the SUB instruction, but not to CLR (SUB
Da,Da,Dn is taken as CLR in this context).
Rule SR.4b
MOVE-like instructions that reads or writes the EMR register are not allowed at the first two VLES of an
exception service routine. The exception to this rule is any bit mask instruction(s) that does not have a zero
value to the corresponding position of DOVF bit in the mask or that accesses the high portion of the EMR.
Example 7-85. EMR access at the start of an exception
; ISR Start
move.l emr.l,d0
; Not allowed
; ISR Start
bmclr #$0004,emr.l
; Not allowed
; ISR Start
bmclr #$fff0,emr.l
; Allowed
; ISR Start
bmtstc #$0020,emr.l
; Allowed
; ISR Start
move #$00000004,sr
; Not allowed
Rule SR.6
The following instructions are not allowed in the first two VLES of an exception service routine:
•
DOENn/DOENSHn
•
CONT/CONTD
•
BREAK
•
SKIPLS
7-46
SC140 DSP Core Reference Manual
Dynamic Programming Rules
Rule A.1a
AGU instructions that read the R0-R7 registers with an address register update or address pre-calculation,
or as an operand affected by a MCTL modifier field are not allowed at the first 2 cycles of an exception
service routine. This rule does not apply to R8-R15, or to R0-R7 using the no update (Rn) addressing
mode.
Example 7-86. MCTL Write to R0-R7 Use
; ISR Start
move.w (r0)+,d0
;use MCTL, not allowed
; ISR Start
nop
move.w (r0)+,d0
;use MCTL, not allowed
; ISR Start
nop
nop
move.w (r0)+,d0
;use MCTL, allowed
; ISR Start
adda r0,r1
;use MCTL, not allowed
; ISR Start
move.w d1,(r0+n0)
;use MCTL, not allowed
; ISR Start
move.w (r0)+,d0
;use MCTL, not allowed
; ISR Start
move.w (r1)+,d0
;use MCTL, not allowed
; ISR Start
move.w (r5)+,d0
;use MCTL, not allowed
; ISR Start
adda r8,r1
;use MCTL, not allowed
; ISR Start
adda r1,r8
;no modifier mode, allowed
; ISR Start
adda #$1234,r8,r1
;use MCTL, not allowed
; ISR Start
adda #$1234,r1,r8
;no modifier mode, allowed
; ISR Start
move.w (r0),d0
;no update mode, allowed
; ISR Start
move.w (r8)+,d0
;no modifier mode, allowed
SC140 DSP Core Reference Manual
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Programming Guidelines
7.7 Programming Guidelines
The rules in this section cannot be detected within the visibility of the assembler and simulator. For
example, the assembler and simulator cannot determine if the computed JMP below has a valid COF
destination.
Example 7-87. Invalid COF Destination Cannot be Detected
jmp r0
;assembler and simulator cannot determine
; if COF destination is the start of a VLES
The following rules must be detected by the programmer, and can be avoided by good programming
practices. In addition to these rules, some good programming practices are presented below to assist the
programmer in writing robust, compatible SC140 code.
Rule J.1
A COF destination must be the start (lowest) address of a VLES. A COF destination cannot jump into the
middle of a VLES. This rule applies to all types of COF destinations described in Section 7.4.8,
“Change-Of-Flow Destinations.”
Example 7-88. COF Destination in the Middle of a VLES
jmp _dest+2
...
_dest mac d0,d1,d2
;not allowed
mac d3,d4,d5
The assembler evaluates the address of a VLES label as the start (lowest) address of a VLES, regardless of
its source position in the VLES. Good programming practice always places COF destination labels before
or at the start of a VLES. Programmers should be careful that computed COF destinations are the start of a
VLES. This will ensure that rule J.1 is enforced.
Rule J.2
A COF destination cannot be a delay slot.
Example 7-89. COF Destination in a Delay Slot
move.l #_dest,r0
...
jmp r0
jmpd _dest2
;not allowed - COF delay slot
_dest
add d0,d1,d2
Good programming practice never places COF destination labels before or inside a delay slot VLES.
Programmers should be careful that computed COF destinations are not a delay slot. This will ensure that
rule J.2 is enforced.
Rule J.3
Code should not be written to rely on the fact that delayed COF instructions and their delay slots are
non-interruptible. In order to create non-interruptible sequences, the user should use other mechanisms
such as the BMTSET.W instruction or encapsulating the code with the DI and EI instructions. Complying
with this rule will help to insure compatibility with future StarCore architectures.
7-48
SC140 DSP Core Reference Manual
Programming Guidelines
Rule J.5
A program section that ends near a border of reserved memory must end with a non-conditional change of
flow (COF) instruction(s) followed by 4 aligned fetch sets (64 bytes) of NOPs or un-allocated memory. If
the last meaningful instruction is not aligned with an end of a fetch set, some more NOPs are needed (up to
7) before 4 mentioned fetch sets. This is needed so that memory systems that generate an exception when
reserved memory is accessed will not get an exception due to the pre-fetching of the core into the reserved
memory.
Rule L.N.5
The LFn status bit (and SLF for a short loop) in SR must be set when executing loop body n (between the
LOOPSTARTn and LOOPENDn directives).
Example 7-90. LFn Enabled During Loop Body n
dosetup1 label1
doen1 #5
pop sr
...
loopstart1
;not allowed if pop disables LF1
label1
nop
nop
nop
loopend1
Good programming practice uses the loop control instructions listed in Table A-14: AGU Loop Control
(Including Loop COF) Instructions on page A-18 for enabling and terminating loops. The programmer
should not change the LFn and SLF status bits in SR while a loop is enabled. This will ensure that rule
L.N.5 is enforced.
7.7.1 Rules Not Detected Across COF Boundaries
The simulator cannot detect all rules across COF boundaries. This may be due to limited analysis of the
execution trace, or missing information in the binary encoding input to the simulator. The following rules
must be detected by the programmer across COF boundaries:
— L.G.5
7.7.2 Good Programming Practices
Good programming practices assist the assembler and simulator in detecting programming rule violations.
They also help the programmer write robust, compatible SC140 code. Some are generic to all software,
and others are specific to the SC140 . They are organized in several categories.
7.7.2.1 Source Code Practices
•
Use symbolic COF destination labels and symbol arithmetic (not absolute addresses). Let the
assembler resolve the label to a COF destination address.
•
Use symbolic data labels (not absolute addresses). Use symbolic labels and symbol arithmetic for
offsets into data structures. Let the assembler resolve the label to a data element address.
SC140 DSP Core Reference Manual
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Programming Guidelines
•
Observe the immediate operand ranges as specified within the braces { } in Appendix A.2,
“Instructions,” on page A-19. Operand values outside these ranges are undefined. Some specific
examples are:
—
—
•
ADD #u5,Dn {0 < u5 < 32}
ASLL Da,Dn {-40 < Da[6:0] < 40}
Observe address pointer alignments on memory accesses as specified in Table 2-19: Memory
Address Alignment and within the braces { } in Appendix A.2, “Instructions.” Misaligned memory
accesses are undefined. Some specific examples are:
—
MOVE.L (a32),DR {0 £ a32 < 232,L}, meaning long word aligned (address is a multiple
of 4).
—
•
MOVE.4F (EA),Da:Db:Dc:Dd {0 £ EA < 232,Q}, meaning quad word aligned (address is
a multiple of 8).
Observe SP and OSP stack pointer quad alignment. The ESP and NSP registers have their three least
significant bits hard-wired to zero. So SP arithmetic results that are not a multiple of 8 cannot be
represented in the ESP and NSP registers. Note that MOVE-like instructions using SP with an offset
to access the stack allow more general alignment based on the memory access size.
•
Observe the word alignment requirement for COF destinations. Computed COF destinations (such
as JMP R0) that are not a multiple of 2 are in error. Misaligned program fetches are undefined. Note
that the PC register has its least significant bit hard-wired to zero.
•
Observe modifier mode parameter constraints on size and offset discussed in Section 2.3.4,
“Address Modifier Modes.” Using out-of-range or reserved parameter values may produce
undefined results. Also observe address pointer alignments specific to the selected modifier mode.
•
MOVES should be preceded by an instruction that updates the Ln-bit based on the data. Otherwise,
the data moved may be modified by a Ln-bit not associated with the data.
•
Do not explicitly modify the SR register to change the loop flags LFn and SLF in SR. Use the loop
control instructions in Table A-14: AGU Loop Control (Including Loop COF) Instructions on page
A-18.
•
The SR register contains local task context such as the loop flags, T bit, etc. Always save and restore
the SR register on exceptions and OS context switches.
•
The EMR register contains global, not local, status bits. Do not use EMR status bits for local task
context. Do not save and restore EMR on exceptions and OS context switches.
•
Do not return from a subroutine with RTE/D, and do not return from an exception with RTS/D.
•
If the return address on the memory stack is changed to effect a task switch, use RTSTK to bypass
the RAS mechanism. Otherwise, the SC140 will return to the previous caller location if RAS is
valid.
•
Do not use VSL for anything other than the Viterbi algorithm. It violates the endian rules.
•
Do not use “reserved” bits in registers for data storage. Always write “reserved” bits with their initial
reset value (usually zero). This maintains software compatibility if a “reserved” bit is defined in the
future.
7.7.2.2 Binary Code Practices
•
Do not write self-modifying code (replacing portions of an application binary at run-time). It cannot
be checked for errors by the assembler. It is also difficult to debug, and may not be compatible with
future processor implementations.
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SC140 DSP Core Reference Manual
LPMARK Rules
•
Do not write explicit binary encodings using DC (declare constant) assembler directives. It cannot
be checked for errors by the assembler.
•
Do not use “reserved” or “--” operand field values in instruction encodings. This maintains software
compatibility if a “reserved” or “--” field is defined in the future.
7.7.2.3 Software Development Practices
•
Programmers should not disable programming rule detection by the assembler and simulator.
•
Programmers should have an application test suite that provides good dynamic rule test coverage
using the simulator.
•
The assembler cannot detect rule violations across source file boundaries. Partition the application
program into separate source files at logical points, using COF instructions to pass program control
between source files to avoid possible rule violations.
•
The linker does not detect programming rules. Do not link several object files into sequential binary
code. Use COF instructions to pass program control between linked object files to avoid possible
rule violations.
•
Static detection of hardware loop iterations (LA to SA sequences) requires all of loop body n
including the DOENn/DOENSHn instructions, LOOPSTARTn and LOOPENDn directives to be in
the same source file. Follow the static detection assumptions given in Section 7.5.1, “Hardware
Loop Detection,” on page 7-7.
•
Do not reassemble disassembled code. The disassembled code may contain hardware loop
LPMARKx prefix instructions that are not supported in SC140 source code. Use one
LOOPSTARTn and LOOPENDn directive to mark the hardware loop body n in the assembly source
code.
•
Write endian-independent code wherever possible. Document code that is endian-specific.
•
Document status bit assumptions (such as 32-bit arithmetic saturation mode, SR[SM]) in application
programs.
7.8 LPMARK Rules
The SC140 encodes LPMARK bits in the first prefix word to mark the end of hardware loops. The
LPMARK bits are automatically encoded by the assembler based on the LOOPSTARTn and LOOPENDn
assembly directives. The encoding procedure is defined in the LPMARKx (LPMARKA and LPMARKB)
instruction definitions in Appendix A.2, “Instructions.”
Generally, the LPMARKA and LPMARKB instructions are disassembler syntax only for host debugging.
The assembler flags their use in source code as a fatal error. However, the LPMARKA and LPMARKB
instructions can be used in source code for hardware testing, enabled by an assembler switch.
The LPMARK rules in this section are defined for two purposes - 1) how to construct correct test code
using the LPMARKA and LPMARKB instructions, and 2) how the LPMARK bits encoded in the prefix
are used by the simulator to detect some SC140 programming rules.
7.8.1 LPMARK Instruction Type
LPMARK is classified as a prefix instruction type for all SC140 programming rules.
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LPMARK Rules
7.8.2 Static Programming Rules
This section defines new SC140 LPMARK programming rules for correct LPMARKA and LPMARKB
instruction use in a VLES, when enabled by an assembler switch. When enabled, these rules apply in
addition to the other programming rules.
7.8.2.1 General Grouping Rules
LPMARK Rule G.G.1
The LPMARKA and LPMARKB instructions are not counted for this rule.
7.8.2.2 Prefix Grouping Rules
LPMARK Rule G.P.3
Multiple LPMARKA instructions cannot be grouped in a VLES. Multiple LPMARKB instructions cannot
be grouped in a VLES. This LPMARK rule applies to the whole VLES.
LPMARK Rule G.P.6
The LPMARKA and LPMARKB instructions are not counted for this rule.
LPMARK Rule G.P.7
IFc instructions do not affect the LPMARKA and LPMARKB instructions. The LPMARKA and
LPMARKB instructions always execute unconditionally, and can be placed anywhere in the assembly
source order.
7.8.3 Dynamic Programming Rules
The LPMARK rules in this section are alternate forms of SC140 programming rules detectable from the
prefix encoding. Source code that complies with the assembly notation rules is by definition compliant
with LPMARK rules. These LPMARK rules allow the simulator to detect dynamic programming rules that
are not detectable by the assembler.
7.8.3.1 LPMARK Notation
The LPMARK rules use the VLES address notation “LPA-2, LPA-1, and LPA” (relative to the VLES
having LPMARKA set) and “LPB, LPB+1 and LPB+2” (relative to the VLES having LPMARKB set).
The minus “-” notation adjusts the VLES address earlier in the object code order.
7.8.3.1.1 Active Loop
In a nested loop structure, more than one loop can be enabled at the same time. A loop is enabled when its
LFn bit in SR is set, where n is the loop index. The enabled loop with the highest index is defined as the
“active loop”. This definition is dynamic and follows the SC140 loop state machine. The SC140 loop
state machine and simulator determine the “active loop” from the LFn bits in SR when a VLES having an
LPMARK bit set is executed.
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LPMARK Rules
7.8.3.1.2 Active SAn Register
“Active SAn register” is defined as the SAn register where n = the active loop index. This definition is
dynamic and follows the SC140 loop state machine.
7.8.3.1.3 Active LCn Register
“Active LCn register” is defined as the LCn register where n = the active loop index. This definition is
dynamic and follows the SC140 loop state machine.
7.8.3.2 Loop Nesting Rules
LPMARK Rule L.N.5
At least one LFn status bit in SR must be set at LPA or LPB of a loop.
Example 7-91. LFn Enabled at LPA or LPB
dosetup1 label1
doen1 #5
pop sr
...
;pop clears all LFn
label1
nop
nop
nop
{lpmarkb set}
;not allowed
7.8.3.3 Loop LA Rules
LPMARK Rule L.L.1
The following instructions are not allowed at LPB+1 or LPB+2 of a long loop:
•
COF instructions
•
STOP and WAIT
•
DI
•
DEBUG
Example 7-92. Instructions at the End of Long Loops
move.w #count2,d6
dosetup0 label2
doen0 d6
move.w #1,d1
move.w #2,d2
move.w #3,d3
move.w #4,d4
label2 inc d1
inc d2
inc d3
inc d4
wait
{lpmarkb set}
SC140 DSP Core Reference Manual
;not allowed
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LPMARK Rules
LPMARK Rule L.L.2
A DOENn or MOVE-like instruction that writes the active LCn register is not allowed at LPB, LPB+1, or
LPB+2 of a long loop.
Example 7-93. Active LCn Write at the End of Long Loops
doen1 #3
move.l #$12345678,r1
inc d0
{lpmarkb set}
doen1 #5
;not allowed
move.w d3,(r1)+
LPMARK Rule L.L.3
The following instructions are not allowed at LPA, LPB, or LPB+1 of a short loop:
•
COF instructions
•
STOP and WAIT
•
DI
•
DEBUG
•
DOENn/DOENSHn
•
MOVE-like instructions that read any LCn register
•
MOVE-like instructions that write any LCn register
•
MOVE-like instructions that read the SR register
•
MOVE-like instructions that write the SR register
This rule does not apply to other instructions that affect status bits in SR.
Example 7-94. Instructions in Short Loops
move.w #count2,r6
doensh0 r6
move.w #3,d3
inc d3
wait
{lpmarkb set}
;not allowed
doensh0 #$10
nop
jmp end
{lpmarka set}
;not allowed
doensh1 #count2
move.w #num,d2
doen1 #5
{lpmarka set}
;not allowed
LPMARK Rule L.L.5
A MOVE-like instruction that writes the SR register is not allowed at LPB-2, LPB-1, LPB, LPB+1, or
LPB+2 of a long loop.
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LPMARK Rules
LPMARK Rule L.L.6
A MOVE-like instruction that writes the SR register is not allowed at LPA-2, LPA-1, LPB-2 or LPB-1 of a
short loop.
7.8.3.4 Loop Sequencing Rules
LPMARK Rule L.D.2 + L.D.3
The minimum number of VLES between the following instructions that write the active LCn register and
LPA or LPB of a loop is:
•
DOENn/DOENSHn Rn or #x: one VLES (address register or immediate value)
•
DOENn/DOENSHn Dn: two VLES (data register)
•
MOVE-like instruction that writes the active LCn register: two VLES
Example 7-95. Active LCn Write at the Start of a Loop
move.w
doensh0
move.l
move.w
inc
d1
#3,d0
d0
d1,lc0
#2,d2
{lpmarka set}
move.w #3,r8
dosetup1 label1
doen1 r8
label1 inc
inc
inc
d3
d4
d5
;allowed
;not allowed
;not allowed
{lpmarkb set}
LPMARK Rule L.D.6
At least one VLES is required between an instruction that writes the active SAn register and LPA or LPB
of a long loop.
Example 7-96. Active SAn Write at the End of Long Loops
doen0 #5
dosetup0 label
label inc d2
{lpmarkb set}
inc d1
inc d0
;not allowed
LPMARK Rule L.D.8 + L.D.9
At least one VLES is required between a MOVE-like instruction that reads the active LCn register and
LPA or LPB of a loop.
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LPMARK Rules
Example 7-97. Active LCn Read at the Start of a Loop
doensh0 #$10
push lc0
inc
d0
;not allowed
{lpmarka set}
doensh0 #$10
push lc1
inc
d0
;allowed
{lpmarka set}
move.w #count2,d6
dosetup0 label2
doen0 d6
move.w #1,d1
move.w #2,d2
move.w #3,d3
move.w #4,d4
label2 inc d1
move.l lc0,d0
;not allowed
inc d2
{lpmarkb set}
inc d3
inc d4
move.w #count2,d6
dosetup0 label2
doen0 d6
move.w #1,d1
move.w #2,d2
move.w #3,d3
move.w #4,d4
label2 inc d1
move.l lc1,d0
;allowed
inc d2
{lpmarkb set}
inc d3
inc d4
7.8.3.5 Loop COF Rules
LPMARK Rule L.C.2
COF instructions are not allowed at LPB of a long loop.
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LPMARK Rules
Example 7-98. COF Instructions at LPB of a Long Loop
dosetup1 label1
doen1 #n2
move.l #mem_l1,r1
move.l #mem_l2,r0
label1 inc d1
jsr r1
{lpmarkb set}
add d1,d2,d3
move.w d3,(r0)
;not allowed
LPMARK Rule L.C.3 + L.C.5
A Bc or Jc instruction is not allowed at LPA-1 or LPB-1 of a loop.
Example 7-99. Bc/Jc at the Start of a Loop
cmpgt d4,d3
nop
iff doensh3 #count2
bt _dest
;not allowed
inc d2
...
_dest inc d2
{lpmarka set}
dosetup1 label7
move.w #0,d1
doen1 #5
move.w #10,d2
label7 inc d1
bf label6
inc d2
inc d3
inc d4
;not allowed
{lpmarkb set}
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LPMARK Rules
LPMARK Rule L.C.9
A loop COF instruction (BREAK, CONT, CONTD, or SKIPLS) cannot have a COF destination that is at
LPB of a long loop if immediately followed by LPA.
Example 7-100. Loop COF at End of Nested Long Loops
doen0 #5
...
doen1 #10
...
doen2 d0
nop
skipls _dest
nop
ift break label
nop
nop
{lpmarkb set}
nop
nop
...
nop
{lpmarkb set}
;not allowed
_dest
nop
label nop
nop
{lpmarkb set}
{lpmarka set}
;last address of long loop 1
;last address of long loop 0
LPMARK Rule L.C.10
A BSR, BSRD, JSR, or JSRD instruction cannot have a COF destination that is at LPA or LPB of a loop.
Example 7-101. Subroutine Call to End of Loops
dosetup0 label1
doen0 d1
nop
nop
label1 nop
nop
jsr label2
;not allowed
nop
nop
inca r1
label2 inca r7
{lpmarkb set};LA-2
add d1,d2,d3
;LA-1
move.w d3,(r0)
;LA
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LPMARK Rules
LPMARK Rule L.C.11 + L.C.12
A delayed COF instruction is not allowed at LPA-1 or LPB-1 of a loop.
Example 7-102. Delay Slot at LPA or LPB of a Loop
jmpd_dest
nop
nop
nop
jmpd
;not allowed
{lpmarkb set}
_dest
nop
;not allowed
{lpmarka set}
7.8.3.6 General Looping Rules
LPMARK Rule L.G.3 + L.G.4
At least one VLES is required between a MOVE-like instruction that reads the SR register and LPA or
LPB of a loop.
Example 7-103. SR Read to LPA or LPB of a Loop
dosetup1 label1
doen1
#5
label1
inc d1
move.l sr,d0
inc d2
{lpmarkb set}
move.l #mem_l1,r1
move.l #mem_l2,r0
doensh0 #$10
push sr
inc d0
;not allowed
;not allowed
{lpmarka set}
7.8.3.7 Rule Detection Across Exception Boundaries
LPMARK Rule SR.6
LPA or LPB cannot be the first two VLES of an exception service routine.
7.8.4 LPMARK Programming Guidelines
The rules in this section cannot be detected by the simulator from its execution trace. The following rules
must be detected by the programmer, and can be avoided by good programming practices.
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NOP Definition
LPMARK Rule L.C.1
A COF instruction cannot have a COF destination that is LPB+1 or LPB+2 of a long loop or LPB+1 of a
short loop. This rule does not apply to loop COF instructions (BREAK, CONT, CONTD and SKIPLS) in a
nested loop having a COF destination that is LPA-1 or LPA of an enveloping loop.
Example 7-104. COF Destination to Loop Delay Slots
doensh1 #5
...
cmpeq.w #3,d0
jf _dest
inc d0
;not allowed
inc d0
{lpmarkb set}
_dest add d1,d2,d3
Good programming practice never places COF destination labels before or inside a loop delay slot VLES,
unless the label is the destination of a loop COF instruction as described above. Programmers should be
careful that computed COF destinations are not a loop delay slot. This will ensure that LPMARK rule
L.C.1 is enforced.
7.9 NOP Definition
Programmers use NOP as a deterministic way to control word padding within a VLES, and cycle padding
in a program. The architecture definition of NOP and its assembler encoding follows:
1. A “baseline VLES” is defined as the source code and binary encoding of the VLES without
NOPs in the source code. The baseline VLES has a “baseline size” in words (“W”, a 16-bit
unit). It may or may not include prefixes, reordered encoding, or modulo alignment padding.
The “baseline encoding” may pad a word for modulo alignment, but it should not be called
a NOP in the Tools document or the CRM. In this discussion, an assembler-generated NOP
encoding not present in the source code will be called a “PAD”.
2. A “NOP” is defined in the CRM Appendix A as a source syntax having a 1W prefix
encoding that can be used in a standalone NOP-only VLES or embedded in a baseline VLES
having a prefix. The binary encoding of the standalone NOP is a 1W prefix having the VLES
size in the aaa field, and the embedded NOP is a 1W prefix having aaa=0, as specified in the
CRM Appendix. A. The NOP definition is to increase the baseline size by 1 word for
each source NOP added to the baseline VLES. This means that NOPs are not compressed
or absorbed into baseline VLES encodings already having prefixes. They are concatenated
as higher addressed words with the baseline VLES encoding occupying the lower addresses.
3. Prefix grouped VLES already have a prefix, and each NOP adds one 1W embedded NOP
prefix having aaa=0 to the baseline VLES encoding. Serially (non-prefixed) grouped VLES
are encoded without a prefix, so the first NOP is added differently. The first NOP encodes
as a standalone 1W prefix having the VLES size in the aaa field, and corrects the serial
grouping field of the baseline instructions. Any additional NOPs are encoded as in prefix
grouping.
4. When NOPs are used in a standalone VLES, the baseline size is zero. A VLES containing
only N NOPs in the source code has a size of N words. It is implemented by a standalone
1W NOP prefix having the VLES size in the aaa field followed by N-1 embedded 1W NOP
prefixes having aaa=0. This is the only guaranteed way to pad N consecutive words.
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NOP Definition
5. Source syntax order in a VLES generally has no effect on the baseline size, as parallel
semantics define no instruction serialization within a VLES. The baseline size is determined
by the encoding rules in the assembler. There are two cases where source order matters for
the programmer - 1) for multiple conditional subgroups in a VLES, any IFA subgroup must
be the last (right-most) subgroup in the source syntax, and 2) if multiple instructions in the
same VLES affect SR[C], the last (right-most) instruction in the source syntax that actually
executes updates SR[C]. This source order syntax affects the encoding order of the VLES
and can affect the baseline size, but not the size increase due to NOPs in the source VLES.
6. Conditional (IFc) syntax requires special rules to provide deterministic NOP word padding
when the two subgroups are used. If a conditional group or subgroup contains only NOPs,
it should be assembler mapped as follows (a colon “:” is the concatenation operation):
IFT NOP --> IFT (prefix ccc=010):NOP
IFF NOP --> IFF (prefix ccc=011):NOP
IFT NOP IFA subgroup2 --> IFA (prefix ccc=000) group2:NOP (same as group2:NOP)
IFF NOP IFA subgroup2 --> IFA (prefix ccc=000) group2:NOP (same as group2:NOP)
IFT subgroup1 IFA NOP --> IFT (prefix ccc=010) group1:NOP
IFF subgroup1 IFA NOP --> IFF (prefix ccc=011) group1:NOP
IFT subgroup1 IFF NOP --> IFT (prefix ccc=010) group1:NOP
IFT NOP IFF subgroup2 --> IFF (prefix ccc=011) group2:NOP
This mapping converts each NOP-only conditional group or subgroup to embedded NOPs
concatenated with a conditional group (no subgroups). This is necessary to ensure that each NOP
adds exactly one word to the baseline size. Some of these are not useful cases, but are legal source
syntax for the assembler.
If a conditional group or subgroup has a NOP with other instructions, the NOPs should ignore their
subgroup when concatenating with the baseline VLES encoding. In other word, NOP padding can
be added to either subgroup as shown in the examples.
7. The FALIGN assembler directive should assemble the VLES source code including existing
source NOPs, determine the VLES address boundaries, and add the minimum number of
PADs to achieve the desired fetch address alignment. The assembler can spread PADs across
several VLES (including conditional VLES) to avoid a cycle penalty, or add them as a
standalone VLES if the alignment cannot be achieved without a cycle penalty.
7.9.1 Grouping Examples
Assume there are N NOP instructions in the source VLES (including PADs added by the FALIGN
directive).
1. If a baseline VLES does not require a prefix, the first source NOP is encoded as a 1W VLES
prefix. For example:
[INC D0NOP]
is encoded as:
[1W prefix, INC]
and
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NOP Definition
[INC D0NOP
NOP]
is encoded as:
[1W prefix, INC, NOP]
and
[NOPNOP
INC D0]
is encoded as:
[1W prefix, INC, NOP]
2. If a baseline VLES has a 1W or 2W prefix, a 1W embedded NOP is encoded for each source
NOP. For example:
[LPMARKAINC D0
NOP]
is encoded as:
[1W prefix, INC, NOP]
and
[INC D8NOP]
is encoded as:
[2W prefix, INC, NOP]
3. If a baseline VLES requires assembler padding for modulo alignment, a 1W embedded NOP
is encoded for each source NOP. For example:
[MOVE.W #s16,d0MOVE.W #s16,d1NOP
NOP]
is encoded as:
[1W prefix, 2W MOVE, PAD, 2W MOVE, NOP, NOP]
4. If a VLES has only NOPs, the first source NOP is encoded as the VLES prefix. For example:
[NOPNOP
NOP]
is encoded as:
[1W prefix, NOP, NOP]
5. If a baseline VLES has a NOP as the only instruction in a conditional subgroup, a 1W
embedded NOP is encoded for each source NOP. For example:
[IFT CLR D0IFF NOP]
is assembler mapped to the IFT prefix and encoded as:
[1W IFT prefix, CLR, NOP]
and
[IFT NOPIFF CLR D0
IFF INC D1
IFF MOVE.W (R0),D2]
is assembler mapped to the IFF prefix and encoded as:
[1W IFF prefix, CLR, INC, MOVE, NOP]
6. If a baseline VLES has a NOP with other instructions in a conditional subgroup, a 1W
embedded NOP is encoded for each source NOP in either subgroup. For example:
[IFT CLR D8IFF INC D1
IFF NOP]
is encoded as:
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NOP Definition
[2W IFT-IFF prefix, INC, CLR, NOP]
and
[IFF CLR D8IFT INC D1
IFT NOP]
is encoded (ignoring the NOP subgroup) as:
[2W IFT-IFF prefix, CLR, INC, NOP]
7. If a baseline VLES has multiple NOPs in a conditional subgroup, a 1W embedded NOP is
encoded for each source NOP. For example:
[IFT CLR D0IFT NOP
IFT NOP]
is encoded as:
[1W IFT prefix, CLR, NOP, NOP]
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Appendix A
SC140 DSP Core Instruction Set
A.1 Introduction
This appendix describes in detail the SC140 instruction set, its encoding, and its syntax. The first pages of
this appendix contain information common to all of the instructions such as the conventions, notation, and
syntax used in the Appendix. Next, the encoding for the prefix words is given. Then, the names and simple
descriptions of the instructions are listed in functional groups. At the end of the introductory section, a
single page describes the format of the instruction descriptions, which are listed in alphabetical order
through the bulk of the Appendix.
Each non-prefix instruction activates one functional unit in the SC140 architecture. The architecture can be
viewed as several functional units operating in parallel:
•
Four arithmetic logic units (ALUs)
•
Two address arithmetic units (AAUs)
•
One bit mask unit (BMU)
•
One program controller (PSEQ)
Several instructions can be grouped together for parallel execution.
The instruction set has been designed to enable efficient parallel execution of DSP algorithms and control
code, using high-level language compilers, achieving maximum speed and minimum power consumption.
This extensive range of instruction capabilities also provides a very powerful assembly language for DSP
algorithms and general-purpose computing. Certain programming rules apply regarding the ability to
group instructions that activate the various units, because of their use of shared resources.
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DSP Core Instruction Set
A.1.1 Conventions
Table A-1 lists the conventions used in this appendix to define the instructions.
Table A-1. Instruction Conventions
Convention
Definition
()
aa
Cn
Da
Da:Db
De.E; Do.E
De.E:Do.E
Db
De
Dn
Do
DR
Ea
HP
Ln
LP
rc
Rn
rx
Rx
{}
Indirect address
Absolute address
Control registers
Single source/destination data register
Source/destination data register pair
Data register extension (bits 39:32 + Ln bit)
Data register extension pair (e.g., D4.E:D5.E)
Single source data register
Even numbered data/core register
Destination data register
Odd numbered data/core register
Data or address register
Effective address
High portion (bits [31:16]) of a register
Limit tag bit
Low portion (bits [15:0]) of a register
Rounding constant
Address register
AGU source register
AGU source/destination register
If used at the end of a line, the intent is merely for clarity purposes,
and this is not part of the assembler syntax.
However, note that if this is used in assembler code, the contents
will be understood as ISAP instructions.
Bit range a to b in a register or memory
Bit number a in a register or memory
[b:a]
[a]
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DSP Core Instruction Set
Table A-2 describes the operators and operations syntax for each instruction.
Table A-2. Operations Syntax
Operator
Description
+
Add
–
Subtract
*
Multiply
/
Divide
||
Absolute value
&
Logical AND
|
Logical OR
⊕
Exclusive OR
~
Bitwise complement
==
Test for equality, 1 if equal, 0 if not equal
→
Transfer left to right
↔
Indicates either right or left transfers, but not both at once
>>
Arithmetic right shift (sign bits shifted right)
<<
Arithmetic or logical left shift (functionally the same)
>>>
Logical right shift
>
Compare for greater than
Rnd( )
Rounding function
x:y
Concatenation of x and y
Table A-3 describes the abbreviations used for the core registers.
Table A-3. Register Abbreviations
Abbreviation
Register Name
D0-D15
General purpose data register
R0-R15
General purpose address register
EMR
Exception and mode register
VBA
Vector base address register
SP
Stack pointer registers: normal (NSP) and exception (ESP)
PC
Program counter
SR
Status register
MCTL
Modifier control register
SA0-SA3
Start address registers
LC0-LC3
Loop counter registers
B0-B7
Modulo base registers
N0-N3
Offset registers
M0-M3
Modulo registers
OSP
Other stack pointer
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A-3
DSP Core Instruction Set
Table A-4 lists special syntax used in this appendix to define an instruction’s assembler syntax. Note that
the assembler syntax is case insensitive.
Table A-4. Assembler Syntax
#
Prefix for an immediate value (for example, #u5 means an immediate 5-bit unsigned number and #s16 is an
immediate 16-bit signed number).
$
Prefix to a hexadecimal value (for example, #$1A4F as an immediate value or $2FC as an address offset).
>
Prefix for long addressing, forces the assembler to use an extra word to encode the displacement/offset.
<
Prefix for short addressing, forces the assembler to use the smallest instruction when encoding the displacement/offset.
label
Replace the word “label” in an instruction with the label name of an execution set in code. The instruction
determines if the assembler substitutes an absolute address or a relative displacement in the opcode.
*
Assembler variable containing the address of the current execution set.
{}
Used to include ISAP instructions, OR - i
If the contents are not ISAP instruction, then these brackets are merely for illustrative purposes only, and can
be used to define the range of addressing of the previous instruction
A.1.1.1 Brackets as ISAP indicators
The SC140 core can dispatch one ISAP opcode per VLES. This opcode uses the 2-word prefix encoding,
and is recognized as an ISAP opcode if it is not the first opcode in the VLES. The assembly syntax uses
brackets to identify a mnemonic as an ISAP instruction, for example:
ADD D0,D1,D2 {move_spacial (r0)+,K0}
For more details about working with an ISAP, see Chapter 6, “Instruction Set Accelerator Plug-In.”
A.1.1.2 Brackets as address indicators
The ranges for addresses are included in the assembly syntax sections. These are not part of the assembly
syntax, but are shown there for clarity. They are enclosed in curly brackets {}. For example, in MOVE.L
the following is found:
MOVE.L (Rn+u3),DR {0 ≤u3 < 32,L}
In this example, u3 is an unsigned immediate offset to the value in pointer register Rn. In addition, u3 is
aligned to long word addressing. Its values are in multiples of four. Addressing is in units of bytes, and
there are four bytes to a 32-bit long word. With only every fourth address required, u3 is encoded with
three bits to encode: 0, 4, 8, ---, 28. The notation for these numbers is {0 ≤u3 < 25, L}. The values for
u3 in the source code and disassembled code will be multiples of four from 0 to 28. The 3-bit encoded
values in the instruction will be zero to seven. Other notations for address alignment are:
•
W for word (multiples of two)
•
Q for quad (multiples of eight)
The ranges shown in the brackets are always for the source code addressing. The ranges may or may not
reflect the number of bits used in the encoding, depending on whether a left shift is applied to the encoded
value.
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A.1.2 Addressing Mode Notation
Table A-5 and Table A-6 define the fields in the address offset or post increment tables, which are found in
the instruction field section of an instruction definition. EA stands for effective address. A different field in
the opcode (RRR) determines what register is used for Rn.
EA
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
11
(Rn)
Table A-5. Addressing Mode Notation for the EA Operand
Addressing Mode Definition
Notation in the Instruction Field
Indexed by offset in N0
(Rn + N0)
Post decrement
(Rn)–
No update
(Rn)
Post increment
(Rn)+
Post update by offset in N0
(Rn) + N0
Post update by offset in N1
(Rn) + N1
Post update by offset in N2
(Rn) + N2
Post update by offset in N3
(Rn) + N3
Note:
Rn is taken from the Rn (RRR) table found in the instruction definition.
ea
MM
Effective Address Notation
00
(Rn)+
01
(Rn)–
10
(Rn+N0)
Table A-6. Addressing Mode Notation for the ea Operand
Addressing Mode Definition
Notation in Instruction Field
Indexed by offset in N0
(Rn + N0)
Post decrement
(Rn)–
No update
(Rn)
Post increment
(Rn)+
Note:
Rn is taken from the Rn (RRR) table found in the instruction definition.
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A.1.3 Data Representation in Memory for the Examples
For the examples in this appendix, the convention for the representation of data in memory is to show the
same order in memory as is in the source register for a write. For example, a 32-bit write from a register
containing $12345678 to address $100 will be shown as: ($100) = $12345678. The exact order of
multi-byte operands in memory depends on the endian mode, and is described in Section 2.4.1, “SC140
Endian Support,” on page 2-56.
A.1.4 Encoding Notation
The instruction encoding is defined for each instruction under Instruction Formats and Opcodes and
Instruction Fields. Each instruction field may not be contiguous in the opcode, but the order of the bits in
each field is consistent from the opcode to the definition of the field. For example, in the MOVE.B
instruction, the encoding for the opcode is
15
MOVE.B (a16),DR
8
7
0
0
0
0
1 H H H H A A A 0
1
1
1
0
1
0
0 A A A A A A A A A A A A A
The order of bits for a16 (AAA---A) is the MSB in the first bit at the left-most position in word 1. The LSB
is the right-most position in word 2. If written out fully, the encoding would be:
15
MOVE.B (a16),DR
8
0
0
0
1
0
0
1
H
H
7
0
H
H
A15 A14 A13
A12 A11 A10 A9
A8
A7
A6
A5
0
1
1
1
0
A4
A3
A2
A1
A0
A more complicated example is for BSR, where two fields are intermixed. The order for each field is
maintained, monotonically decreasing from left to right.
BSR >label
0
0
1
0
a
0
1
1 A A A 1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
The definition for the field is:
displacement
20-bit signed PC relative displacement
aaaaaAAAAAAAAAAAAAAA0
(>label)
If the field was written out in the encoding table, it would appear as follows:
BSR >label
A-6
0
0
1
1
0
0
0
a20
0
1
A12 A11 A10 A9
1
A8
A15 A14 A13
A7
A6
A5
1
1
A4
A3
a19 a18 a17
A2
A1
a16
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A.1.5 Prefix Word Encoding
Each execution set can be associated with a one-word (low or high register) or two-word prefix that is
placed at the beginning of the set. A prefix conveys additional information about the set such as:
•
Conditional execution of an execution set or a subgroup (originating in the IFT/IFF/IFA
instructions).
•
The number of instructions that are grouped together in the execution set.
•
Looping information to support hardware loops (lpmarkA and lpmarkB bits).
•
Encoding extension for high register banks (D8–D15, R8–R15).
There are two prefix formats: a one-word low register prefix, and a two-word prefix. A one-word low
register prefix encodes information concerning the first three items above. A two-word prefix includes
information on all items above.
The basic 16-bit instruction encoding of the SC140 has three bits allocated to specify a data or pointer
register. Therefore, these encodings alone can specify only eight DALU registers (D0–D7) and eight
address pointers (R0–R7). In order to specify operands that belong to the high register banks (D8–D15,
R8–R15), additional encoding bits are needed. These bits are allocated in the two-word prefix. A two-word
prefix includes a field for each execution unit in the SC140: four fields for DALU instructions and two
fields for AGU instructions.
DALU instructions have a maximum of three operands, so each DALU field is 3 bits wide. AGU
instructions have a maximum of two operands, so each AGU field is two bits wide. This provides an
encoding extension bit for each possible operand in each execution unit. If a bit is set, it signifies that the
respective operand uses a high-bank register. If the associated bit is clear, the operand uses a register from
the low bank. A two-word prefix is generated by the assembler if at least one of the instructions in the
execution set that uses a register from the high banks has 3 operands, and/or is conditionally executed or is
in a loop.
Prefix words are optional, generated by the assembler if needed. The rules used by the assembler to
determine if a prefix is needed are described in Section 5.2.4, “Prefix Selection Algorithm.” :
Note:
Use of a prefix reduces the space available for instructions in the eight-word execution set by the
size of the prefix. For example, if an instruction that references a high-bank register causes the
assembler to generate a two-word prefix,only six words are left available in that execution set for
instructions.
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A.1.5.1 One-Word Low Register Prefix
Includes information on grouping, looping, and IFc (conditional execution).
Instruction Formats and Opcodes
Prefix
Words Cycles Type
Opcode
15
1W LOW REG
PREFIX
1
0
4
1
0
0
1
a
a
a
8
7
0
1
0
1
0
p
j
c
c
c
Instruction Fields
aaa:
Number of instruction words being grouped, including the prefix word minus one. If aaa
equals zero, this is a NOP instruction that is not dispatched for either a single, stand-alone
NOP, or an intra-set NOP [0 ≤ aaa ≤ 7].
ccc:
Conditional execution of the entire execution set.
In the following table, true/false relates to the state of the T bit in SR. D0, D1, D2, and D3 are
DALU instructions. A0 and A1 are AGU instructions. The numbers relate to the relative word
offset of the instruction from the beginning of the set.
000—Unconditionally executed
001—If true (D0, D2, A0) If false (D1, D3, A1)
010—If true, all the set
011—If false, all the set
100—Reserved
101—Reserved
110—If true (D0, D2, A0), always (D1, D3, A1)
111—If false (D0, D2, A0), always (D1, D3, A1)
p:
lpmarkB bit
In the case of a loop with three or more execution sets, the lpmarkB bit is a one in the
execution set that is two before the last execution set in the loop.
Example:
lpmarkB
_last
;(set LA – 2)
;(set LA – 1)
;(set LA)
In the case of a loop with two execution sets such as SA mark, the lpmarkB bit is set in the first
execution set of the loop.
Example:
_start execution_setlpmarkb
_last execution_set
;(this is a loop on two execution sets)
j:
lpmarkA bit
In case of a loop with more than three execution sets, the lpmarkA bit is set in the prefix of the
execution set which is at _last only if there are any SKIPLS, BREAK, CONT, CONTD to
_last, or to _last-1.
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Example:
skipl _last
;(there is a skipl to _last in the program)
.
.
.
execution_set
execution_set
_last
execution_setlpmarkA
In the case of the loop having just one execution, the lpmarkA bit is set in the prefix of this
single execution set of the loop.
A.1.5.2 Two-Word Prefix
Includes information on grouping, looping, IFc (conditional execution), and high-register banks (D8-D15,
R8-R15).
Instruction Formats and Opcodes
Prefix
Words Cycles Type
Opcode
15
2
2W PREFIX
0
4
8
0
0
1
1
a
a
a
1
0
1
b B e E T
7
0 H
0
t
h
p
j
c
c
c
b B e E b B e E
Note: The order of the register bank encoding fields is, for example, E1 E2 E3, with E1 occupying the most significant bit
position in the table.
Instruction Fields
aaa:
Number of instruction words being grouped, including the prefix word minus one (for
example, 2-w prefix + 2 grouped instruction words, aaa = 3).
For a 2-w prefix at the beginning of the execution set, aaa = 000 and aaa = 001 are reserved as
escape codes to signify that more prefix words are concatenated to support architectures with 3
or more prefix words. Use of a 2-w prefix in the middle of the set is reserved for future
encoding (such as accelerator or predication instructions) and should not be placed as a NOP.
ccc:
Conditional execution of the entire execution set.
In the following table, true/false relates to the state of the T bit in SR. D0, D1, D2, and D3 are
DALU instructions, A0 and A1 are AGU or BMU instructions. The numbers relate to the
relative offset of the instruction from the beginning of the set.
000—Unconditionally executed
001—If true (D0, D2, A0), if false (D1, D3, A1)
010—If true, all the set
011—If false, all the set
100—Reserved
101—Reserved
110—If true (D0, D2, A0), always (D1, D3, A1)
111—If false (D0, D2, A0), always (D1, D3, A1)
p:
lpmarkB bit
In the case of a loop with three or more execution sets, the lpmarkB bit is a one in the
execution set that is two before the last execution set in the loop.
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Example:
lpmarkB;(set LA – 2)
;(set LA – 1)
_last
;(set LA)
In the case of a loop with two execution sets such as SA mark, the lpmarkB bit is set in the first
execution set of the loop.
Example:
_start execution_set lpmarkB
_last execution_set
;(this is a loop on two execution sets)
j:
lpmarkA bit
In case of a loop with more than three execution sets, the lpmarkA bit is set in the prefix of the
execution set, which is at _last only if there were any SKIPLS, BREAK, CONT, CONTD to
_last, or to _last-1.
Example:
skipl _last
;(there is a skipl to _last in the program)
.
.
.
execution_set
execution_set
_last
execution_set lpmarkA
In the case of the loop having just one execution set, the lpmarkA bit is set in the prefix of the
first execution set of the loop.
EEE:
Data register expansion for DALU execution unit 0 (bit names: E1, E2, E3). This includes all
DALU instructions. For three-operand instructions (inst op1,op2,op3):
––1:
–1–:
1––:
high data register is used for the op3 field (E3 is set)
high data register is used for the op1 field (E2 is set)
high data register is used for the op2 field (E1 is set)
In case of two-operand MAC unit instructions, only E1 and E3 are used. In case of
one-operand MAC unit instructions, only ––E3 is used.
In case of four-operand instructions with data registers defined as third and fourth operands,
E1 and E3 used similarly to two-operand instructions.
Each of the E bits serves as a fourth register field encoding bit, effectively turning
FFF → FFFF, etc. For example, the D0-7 registers are expanded to D0-15. Each E bit selects
the low or high bank of registers for that field.
Fields representing multiple registers in DALU instructions could be scaled up independantly.
For instance, the register pair encoding in the instruction MAX D0,D4 can be expanded to
MAX D8,D4.
eee:
The same as EEE, but for DALU execution unit 1.
BBB:
The same as EEE, but for DALU execution unit 2.
bbb:
The same as EEE, but for DALU execution unit 3.
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Hh:
High register expansion encoding for AGU execution unit 0. This includes all AGU and BMU
instructions. R0-7 registers are expanded up to R0-15.
The two bits Hh controls the expansion of R0-R7 registers to R8-R15 registers in one or two
AGU instruction’s operands according to the following rules:
The H bit is used for all of the operands from the types:
- Rn operand defined with RRR field (e.g. Rn in MOVE like instruction, or ADDA
instructions, EA or ea in MOVE like instructions).
- Rx operand defined with RRRR field.
- Df operand defined with hhh field of MOVE.L Df,C4 and MOVE.L C4.Df instructions.
The h bit is used for all the operands other then the above.
The expansion encoding have no effect if the register decoded in the instruction is not R0-R7
(e.g. SP in RRRR field for Rx decoding).
Fields representing multiple registers (used in some MOVE-like instructns) are affected
together. For example, the register pair encoding for D0:D1 can be expanded to D8:D9 (not
each register independently).
Note that Rr register in (Rn+Rr) addressing mode, is limited to R0-R7 and thus not effected by
both H and h bits.
Tt:
The same as Hh, but for AGU execution unit 1.
Note the special position of the T bit (bit 8 in the second word).
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A.1.6 Instruction Types
The SC140 instruction set is organized into the following instruction types, specified at the top of every
instruction definition in this Appendix:
DALU Instructions- perform operations on the data registers D0-D15 using the DALU execution units
(MAC and BFU). All DALU instructions are listed in Table A-7 and Table A-8. The architecture is
described in Section 2.2.1, “DALU Architecture,” on page 2-6.
AGU Instructions- perform operations using the AGU execution units (AAU and BMU) and the program
sequencer unit. All the AGU instructions are listed in Table A-9 through Table A-15. The architecture is
described in Section 2.3.1, “AGU Architecture,” on page 2-31.
BMU Instructions - are a subset of AGU instructions that perform atomic read-modify-write operations
on registers or memory locations. They execute in the BMU. All BMU instructions are listed in
Table A-12. The architecture is described in Section 2.3.6, “Bit Mask Instructions,” on page 2-49.
Although the BMU instructions are a subset of AGU instructions, they are presented in this Appendix with
the other types for greater visibility, and to make them easier to find.
PREFIX Instructions - support conditional execution of other instructions and NOP insertion for time
and space padding. They have unique properties since their binary form is a prefix encoding. They are
decoded by the dispatcher, but are not dispatched to an execution unit. All PREFIX instructions are listed
in Table A-16.
A.1.6.1 Instruction Sub-types
The instruction types can be further divided into sub-types as follows:
DALU Instruction Sub-types
•
Data arithmetic (including multiply-accumulate) instructions are listed in Table A-7 and described
in Section 2.2.1.2, “Multiply-Accumulate (MAC) Unit,” on page 2-10.
•
Logical (including bit-field) instructions are listed in Table A-8 and described in Section 2.2.1.3,
“Bit-Field Unit (BFU),” on page 2-12.
AGU Instruction Sub-types
•
Address arithmetic instructions (AAU) are listed in Table A-9 and described in Section 2.3.1, “AGU
Architecture,” on page 2-31.
•
Move instructions are listed in Table A-10 and described in Section 2.3.7, “Move Instructions,” on
page 2-51.
•
Stack Support instructions are listed in Table A-11 and described in Section 5.5, “Stack Support,” on
page 5-32.
•
Bit-Mask (BMU) instructions are listed in Table A-12 and described in Section 2.3.6, “Bit Mask
Instructions,” on page 2-49.
•
Non-loop change-of-flow (non-loop COF) instructions are listed in Table A-13 and described in
Section 5.3.2, “Change-Of-Flow Instruction Timing,” on page 5-17.
•
Loop control instructions are listed in Table A-14 and described in Section 5.4.6, “Loop Control
Instructions,” on page 5-29.
— Loop change-of-flow instructions are also listed in Table A-14 and are described in
Section 5.3.2, “Change-Of-Flow Instruction Timing,” on page 5-17.
•
A-12
Program control instructions are listed in Table A-15 and described in Section 5.7.1, “Processing
State Change Instructions,” on page 5-41.
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Table A-7. DALU Arithmetic Instructions (MAC)
Instruction
Description
ABS
Absolute value
ADC
Add long with carry
ADD
Add
ADD2
Add two words
ADDNC.W
Add without changing the carry bit in the SR
ADR
Add and round
ASL
Arithmetic shift left by one bit
ASR
Arithmetic shift right by one bit
CLR
Clear
CMPEQ
Compare for equal
CMPGT
Compare for greater than
CMPHI
Compare for higher (unsigned)
DECEQ
Decrement a data register and set T if zero
DECGE
Decrement a data register and set T if greater than or equal to zero
DIV
Divide iteration
DMACSS
Multiply signed by signed and accumulate with data register right shifted by word size
DMACSU
Multiply signed by unsigned and accumulate with data register right shifted by word size
IADDNC.W
Add integers, 40-bit, non-saturating, immediate, no-carry update
IMAC
Multiply-accumulate integers
IMACLHUU
Multiply-accumulate unsigned integers;
first source from low portion, second from high portion
IMACUS
Multiply-accumulate unsigned integer and signed integer
IMPY
Multiply signed integers in data registers
IMPY.W
Multiply signed immediate and signed integer in data register
IMPYHLUU
Multiply unsigned integer and unsigned integer;
first source from high portion, second from low portion
IMPYSU
Multiply signed integer and unsigned integer
IMPYUU
Multiply unsigned integer and unsigned integer
INC
Increment a data register (as integer data)
INC.F
Increment a data register (as fractional data)
MAC
Multiply-accumulate signed fractions
MACR
Multiply-accumulate signed fractions and round
MACSU
Multiply-accumulate signed fraction and unsigned fraction
MACUS
Multiply-accumulate unsigned fraction and signed fraction
MACUU
Multiply-accumulate unsigned fraction and unsigned fraction
MAX
Transfer maximum signed value
MAX2
Transfer two 16-bit maximum signed values
MAX2VIT
Special MAX2 version for Viterbi kernel
MAXM
Transfer maximum magnitude value
MIN
Transfer minimum signed value
MPY
Multiply signed fractions
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Table A-7. DALU Arithmetic Instructions (MAC) (Continued)
Instruction
Description
MPYR
Multiply signed fractions and round
MPYSU
Multiply signed fraction and unsigned fraction
MPYUS
Multiply unsigned fraction and signed fraction
MPYUU
Multiply unsigned fraction and unsigned fraction
NEG
Negate
RND
Round
SAT.F
Saturate fractional value in data register to fit in high portion
SAT.L
Saturate value in data register to fit in 32 bits
SBC
Subtract long with carry
SBR
Subtract and round
SUB
Subtract
SUB2
Subtract two words
SUBL
Shift left and subtract
SUBNC.W
Subtract without changing the carry bit in the status register
TFR
Transfer data register to a data register
TFRF
Conditional data register transfer, if the T bit is clear
TFRT
Conditional data register transfer, if the T bit is set
TSTEQ
Test for equal to zero
TSTGE
Test for greater than or equal to zero
TSTGT
Test for greater than zero
Table A-8. DALU Logical Instructions (BFU)
Instruction
Description
AND
Logical AND
ASLL
Multi-bit arithmetic shift left
ASLW
Word arithmetic shift left (16 bit shift)
ASRR
Multi-bit arithmetic shift right
ASRW
Word arithmetic shift right (16 bit shift)
CLB
Count leading bits (ones or zeros)
EOR
Logical exclusive OR
EXTRACT
Extract signed bit field
EXTRACTU
Extract unsigned bit field
INSERT
Insert bit field
LSLL
Multi-bit logical shift left
LSR
Logical shift right by one bit
LSRR
Multi-bit logical shift right
LSRW
Word logical shift right (16-bit shift)
NOT
One’s complement (inversion)
OR
Logical inclusive OR
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Table A-8. DALU Logical Instructions (BFU) (Continued)
Instruction
Description
ROL
Rotate one bit left through the carry bit
ROR
Rotate one bit right through the carry bit
SXT.B
Sign extend byte
SXT.L
Sign extend long
SXT.W
Sign extend word
ZXT.B
Zero extend byte
ZXT.L
Zero extend long
ZXT.W
Zero extend word
Table A-9. AGU Arithmetic Instructions
Instruction
Description
ADDA
ADDL1A
ADDL2A
ASL2A
ASLA
ASRA
CMPEQA
CMPGTA
CMPHIA
DECA
DECEQA
DECGEA
INCA
LSRA
SUBA
SXTA.B
SXTA.W
TFRA
TFRA (OSP)
TSTEQA.L
TSTEQA.W
TSTGEA
TSTGTA
ZXTA.B
ZXTA.W
Add (affected by the modifier mode)
Add with 1-bit left shift of source operand (affected by the modifier mode)
Add with 2-bit left shift of source operand (affected by the modifier mode)
Arithmetic shift left by 2 bits (32-bit)
Arithmetic shift left (32-bit)
Arithmetic shift right (32-bit)
Compare for equal
Compare for greater than
Compare for higher (unsigned)
Decrement register
Decrement and set T if zero
Decrement and set T if equal or greater than zero
Increment register
Logical shift right (32-bit)
Subtract (affected by the modifier mode)
Sign extend byte
Sign extend word
Register transfer
Move the “other” stack pointer to/from a register, inversely defined by the exception mode
Test for equal
Test for equal on lower 16 bits
Test for greater than or equal
Test for greater than
Zero extend byte
Zero extend word
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Table A-10. AGU Move Instructions
Instruction
Description
MOVE.2F
Move two fractional words from memory to a register pair
MOVE.2L
Move two longs to/from a register pair
MOVE.2W
Move two integer words to/from memory and a register pair
MOVE.4F
Move four fractional words from memory to a register quad
MOVE.4W
Move four integer words to/from memory and a register quad
MOVE.B
Move byte to/from memory
MOVE.F
Move fractional word to/from memory
MOVE.L
Move long to/from memory
MOVE.W
Move integer word to/from memory, or immediate to register or memory
MOVEc
Move address register to address register, depending on T bit of SR
MOVES.2F
Move two fractional words to memory with scaling and limiting enabled
MOVES.4F
Move four fractional words to memory with scaling and limiting enabled
MOVES.F
Move fractional word to memory with scaling and limiting enabled
MOVES.L
Move long to memory with scaling and limiting enabled
MOVEU.B
Move unsigned byte from memory
MOVEU.L
Move unsigned long from immediate
VSL.2F
Viterbi shift left: special move for Viterbi kernel
VSL.2W
Viterbi shift left: special move for Viterbi kernel
VSL.4F
Viterbi shift left: special move for Viterbi kernel
VSL.4W
Viterbi shift left: special move for Viterbi kernel
Table A-11. AGU Stack Support Instructions
Instruction
Description
POP
POPN
PUSH
PUSHN
Pop a register from the software stack
Pop a register from the software stack using the normal stack pointer
Push a register onto the software stack
Push a register onto the software stack using the normal stack pointer
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Table A-12. AGU Bit-Mask Instructions (BMU)
Instruction
Description
AND
Logical AND on a 16-bit operand
BMCHG
Bit-mask change a 16-bit operand
BMCHG.W
Bit-mask change a 16-bit operand in memory
BMCLR
Bit-mask clear a 16-bit operand
BMCLR.W
Bit-mask clear a 16-bit operand in memory
BMSET
Bit-mask set a 16-bit operand
BMSET.W
Bit-mask set a 16-bit operand in memory
BMTSET
Bit mask test and set a 16-bit operand
BMTSET.W
Bit mask test and set a 16-bit operand in memory
BMTSTC
Bit mask test if clear
Sets the T-bit, if every bit position that has the value 1 in the mask is 0 in an operand.
BMTSTC.W
Bit mask test if clear in memory
Sets the T-bit, if every bit position that has the value 1 in the mask is 0 in an operand.
BMTSTS
Bit mask test if set
Sets the T-bit, if every bit position that has the value 1 in the mask is 1 in an operand.
BMTSTS.W
Bit mask test if set in memory
Sets the T-bit, if every bit position that has the value 1 in the mask is 1 in an operand.
EOR
Logical Exclusive OR on a 16-bit operand
NOT
Binary inversion of a 16-bit operand
OR
Logical OR on a 16-bit operand
Table A-13. AGU Non-Loop Change-of-Flow Instructions
Instruction
Description
BF
Branch if false
BFD
Branch if false (delayed)
BRA
Branch
BRAD
Branch (delayed)
BSR
Branch to subroutine
BSRD
Branch to subroutine (delayed)
BT
Branch if true
BTD
Branch if true (delayed)
JF
Jump if false
JFD
Jump if false (delayed)
JMP
Jump
JMPD
Jump (delayed)
JSR
Jump to subroutine
JSRD
Jump to subroutine (delayed)
JT
Jump if true
JTD
Jump if true (delayed)
RTE
Return from exception
SC140 DSP Core Reference Manual
A-17
DSP Core Instruction Set
Table A-13. AGU Non-Loop Change-of-Flow Instructions
Instruction
Description
RTED
Return from exception (delayed)
RTS
Return from subroutine
RTSD
Return from subroutine (delayed)
RTSTK
Force restore PC from the stack, updating SP
RTSTKD
Force restore PC from the stack, updating SP (delayed)
TRAP
Execute a precise software exception
Table A-14. AGU Loop Control (Including Loop COF) Instructions
Instruction
Description
BREAK
Terminate the loop and branch to an address
CONT
Jump to the start of the loop to start the next iteration
CONTD
Jump to the start of the loop to start the next iteration (delayed)
DOENn
Do enable - set loop counter n and enable loop n as a long loop
DOENSHn
Do enable short - set loop counter n and enable loop n as a short loop
DOSETUPn
Setup loop start address n
SKIPLS
Test the active LC and skip the loop if LCn is equal or smaller than zero
Table A-15. AGU Program Control Instructions
Instruction
Description
DEBUG
Enter debug mode
DEBUGEV
Signal debug event
DI
Disable interrupts (sets the DI bit in the status register)
EI
Enable interrupts (clears the DI bit in the status register)
ILLEGAL
Trigger an imprecise illegal instruction exception
MARK
Push the PC into the trace buffer
STOP
Stop processing (lowest power stand-by)
WAIT
Wait for interrupt (low power stand-by)
Table A-16. Prefix Instructions
Instruction
Description
IFA
Execute current execution set or subgroup unconditionally
IFF
Execute current execution set or subgroup if the T bit is clear
IFT
Execute current execution set or subgroup if the T bit is set
NOP
No operation
A-18
SC140 DSP Core Reference Manual
DSP Core Instruction Set
A.2 Instructions
The following pages list all of the SC140 instructions and provide specific details about each instruction’s
operation and encoding.
A.2.1 Instruction Definition Layout
INST
Description (type)
Instruction type
(AGU, DALU, etc.)
A brief description of the instruction
INST
Instruction name, the same as in the mnemonic
Operation
Assembler Syntax
The fields under this header describe the
operations carried out by the various forms
of this instruction.
The fields under this header illustrate the assembler syntax for
the various forms of this instruction. The field in curly brackets
to the right of an instruction defines the range of a constant used
as an operand, and its alignment (B = byte, W = word,
L = long word/2 words, Q = quad word/4 words) if used
as an address or in an address calculation.
Description
The paragraphs under this header provide a detailed description of the various forms of this instruction.
Status and Conditions that Affect or are Changed by Instruction
The paragraphs under this header explain how status bits and condition codes affect the execution of the instruction
and how the instruction affects clearing or setting particular condition codes and status bits.
Example
inst
(The instruction as it would be entered by a programmer.)
(Optional section added when examples make the instruction definition clearer.)
The first column of the example lists the registers or memory addresses affected in the example.
The second column illustrates those registers, immediates, and memory locations BEFORE execution takes place.
The third column illustrate those registers and memory locations AFTER execution takes place.
The examples show the effects on the programmer’s model (registers and memory), and do not reflect the pipeline
timing of the updates.
Instruction Formats and Opcodes
The fields under this header define the instruction:
Instruction
The instruction in assembler
syntax.
Words
Number of words in memory
used by this instruction.
Cycles
Type
Opcode
One to three words (16 bits per word) of bits defining
the opcode as the core decodes it.
The instruction’s type relevant to non-prefix grouping. See
Section 5.2.2.1, Serial Grouping, for details.
The number of cycles used in execution of this instruction. Addressing modes and the machine’s state
can affect the cycle count of instructions. See Section 5.3, "Instruction Timing" for more details.
Instruction Fields
(Optional section added when the instruction has one or more operands.)
Each field shows how the operand appears in the Mnemonic and Opcode fields of the
Instruction Formats and Opcodes section. A field contains a table of registers or the definition
of an immediate value, an absolute address displacement/offset, or an absolute address.
A table of registers lists single register groups, register pair groups, address offset/post increment
definition groups, or register quad groups.
SC140 DSP Core Reference Manual
A-19
ABS
A
ABS
ABS
Absolute Value (DALU)
Operation
Assembler Syntax
⏐Dn⏐ → Dn
ABS Dn
Description
ABS Dn
Replaces the value in a data register (Dn) with its absolute value.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the Ln
bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic saturation
mode (SR [SM] = 1), clears the Ln bit in the destination register.
Example
abs d0
Register/Memory Address
SR
L0:D0
EMR
Before
After
$00E0 0000
$0:FF FFFF FFF6
$0:00 0000 000A
$0000 0000
$FFF6 = -10, $000A = 10
A-20
SC140 DSP Core Reference Manual
ABS
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ABS Dn
Note:
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
0
1
1
0
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-21
ADC
ADC
Add Long With Carry (DALU)
Operation
Assembler Syntax
Dc + Dd + C → Dd
ADC Dc,Dd
ADC
Description
ADC Dc,Dd
Adds two source data registers (Dc, Dd) plus the carry bit and stores the result in the second data register
(Dd). This instruction can be used in multiple precision addition as illustrated in the example, which is a
64-bit addition.
Note:
The carry bit is set correctly for multiple precision arithmetic using long word operands if the
extension of the destination data register is the sign-extension of bit 31.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[0]
C
Added as a carry bit to the LSB.
SR[5:4]
S[1:0]
The scaling mode bits determine which bits in the result are used in
the Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Calculates and updates the Ln bit in the destination register.
SR[0]
C
Calculates and updates the C bit in the status register.
Example
add d0,d1,d1 ;sets the carry bit
adc d4,d5 ;add with the carry bit
Register/Memory Address
D0
L1:D1
Before
After
$FF 8000 0008
$0:$FF 8000 0005
$0:$FF 0000 000D
SR
$00E4 0000
$00E4 0001
D4
$00 0000 0005
L5:D5
SR
A-22
$0:$00 0000 0001
$0:$00 0000 0007
$00E4 00001
$00E0 0000
SC140 DSP Core Reference Manual
ADC
Register/Memory Address
Before
After
EMR
$0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ADC Dc,Dd
Note:
1
1
0
*
1
0
1
1
e
8
7
e
0
0
1
1
1
1
0
1
0
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
D0,D1
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-23
ADD
ADD
ADD
Add (DALU)
Operation
Assembler Syntax
#u5 + Dn → Dn
ADD #u5,Dn {0 ≤ u5 < 32}
Da + Db → Dn
ADD Da,Db,Dn
Description
These operations add two source operands and store the result in a destination data register (Dn).
ADD #u5,Dn
The five bits of the unsigned immediate are right-aligned and the upper bits are zero-extended to form a
40-bit source operand. That operand is then added to a data register (Dn) and the result stored in the
destination data register (Dn).
ADD Da,Db,Dn
Adds two source data registers (Da and Db) and stores the result in a destination data register (Dn).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the Ln bit
calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates and updates the C bit in the status register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result saturates
to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and updates
the Ln bit in the destination register. If in arithmetic saturation mode (SR
[SM] = 1), clears the Ln bit in the destination register.
Example 1
add d0,d1,d2
Register/Memory Address
Before
After
SR
$00E0 0000
D0
$00 0000 0005
D1
$00 0000 0002
A-24
SC140 DSP Core Reference Manual
ADD
Register/Memory Address
Before
After
L2:D2
$0:$00 0000 0007
EMR
$0000 0000
Example 2
add d1,d0,d2
Register/Memory Address
Before
After
SR
$00E0 0000
D1
$00 72E3 8F2A
D0
$00 7216 EE3C
L2:D2
$1:$00 E4FA 7D66
EMR
$0000 0000
The L2 bit is set from the 32-bit overflow. Note that the extension bits are in use in the sum, bit 32 =0, bit
31 = 1.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
ADD #u5,Dn
1
1
1
0
8
*
1
1
1
0
15
ADD Da,Db,Dn
1
1
1
0
8
*
1
0
1
1
15
ADD Da,Da,Dn
Note:
1
1
1
0
1
0
0
0
0
1
0
i
i
i
i
7
F F F
8
*
7
F F F
0
1
0
J
J
J
J
7
F F F
i
J
0
1
1
0
0
0
j
j
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-25
ADD
Instruction Fields
Da,Db
JJJJJ
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
00111
Notes:
1.
2.
3.
Da,Da
jj
Data Register Pairs
00
Note:
Dn
A-26
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#u5
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be reversed for clarity because the order of operation is not
important for add operations.
The JJJJJ encoding does not include the pairs: D1,D1; D3,D3; D5,D5; D7,D7. These are
covered in the jj encoding.
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
5-bit unsigned immediate data
SC140 DSP Core Reference Manual
ADD2
ADD2
Add Two 16-Bit Values (DALU)
Operation
Assembler Syntax
Da.H + Dn.H → Dn.H
Da.L + Dn.L → Dn.L
ADD2 Da,Dn
ADD2
Description
ADD2 Da,Dn
Performs a 32-bit addition of source registers Da and Dn with carry disabled between bits 15 and 16, so
that the high and low words of each register are added separately. The result is stored back in Dn. The
extension byte of the result is undefined.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example 1
add2 d0,d1
Register/Memory Address
Before
D0
After
$00 1100 1100
L1:D1
$0:$00 2200 3300
$0:$00 3300 4400
Example 2
add2 d0,d1
Register/Memory Address
Before
D0
L1:D1
SC140 DSP Core Reference Manual
After
$00 1101 F011
$0:$00 0020 2002
$0:$00 1121 1013
A-27
ADD2
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ADD2 Da,Dn
1
2
1
8
1
0
1
0
0
7
F F F
0
1
0
0
0
J
J
J
Instruction Fields
Dn
FFF
000
001
Note:
Da
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-28
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
ADDA
ADDA
Add (AGU)
ADDA
Operation
Assembler Syntax
#u5 + Rx → Rx
ADDA #u5,Rx {0 ≤ u5 < 32}
#s16 + rx → Rn
ADDA #s16,rx,Rn {–215 ≤ s16 < 215}
rx + Rx → Rx
ADDA rx,Rx
Description
These operations add an immediate signed 16-bit integer to the contents of a source AGU register and store
the result in a destination address register. If the second source operand (rx) uses R0-R7, the operation is
affected by the modifier mode selected in the modifier control register (MCTL).
ADDA #u5,Rx
Adds an immediate unsigned 5-bit integer to a source AGU register, Rx, (address or offset register,
program counter, or active stack pointer) and stores the result in the destination register (Rx). The five bits
of the unsigned integer are right-aligned and the upper bits are zero-extended to form a 32-bit source
operand. For R0-R7, the operation is affected by the modifier mode selected in MCTL. If the stack pointer
is the destination operand, then the immediate value must be a multiple of eight as its three LSBs are forced
to zero.
ADDA #s16,rx,Rn
Adds an immediate signed 16-bit integer and the contents of a source AGU register (rx) and stores the
result in a destination address register (Rn). The 16 bits of the signed integer are right-aligned and the
upper bits are sign-extended to form a 32-bit operand. If the second source operand (rx) uses R0-R7, the
operation is affected by the modifier mode selected in MCTL.
ADDA rx,Rx
Adds the contents of two source AGU registers (rx, Rx) and stores the result in the destination (second
source) register (Rx). If the second source operand (Rx) uses R0-R7, the operation is affected by the
modifier mode selected in MCTL. If the stack pointer is the destination operand, then the value in rx must
be a multiple of eight as its three LSBs are forced to zero.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
Status and Conditions Changed by Instruction
None.
SC140 DSP Core Reference Manual
A-29
ADDA
Example 1
adda r0,r1
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$0000 1100
R1
$0000 2200
$0000 3300
Example 2
move.l #$8,mctl ;assigns m0 to r0, modulo arithmetic
move.l #$10,m0 ;puts modulo 16 in m0
move.w #$c,r0 ;initializes 12 to r0
nop
adda #$8,r0,r1 ; 8 + 12 = 20 or 4 modulo 16
Register/Memory Address
Before
After
MCTL
$0000 0008
R0
$0000 000c
R1
$0000 0000
$0000 0004
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ADDA #u5,Rx
1
2
1
8
1
1
15
ADDA #s16,rx,Rn
2
1
4
8
1
1
2
0
1
0
i
i
i
i
7
i
0
0
0
1
0
r
r
r
r
i
i
i
0
1 R R R
1
0
0
i
i
i
i
i
i
i
i
i
i
8
7
15
ADDA rx,Rx
7
0 R R R R 0
1
1
1
0 R R R R 0
i
i
i
0
0
0
1
r
r
r
r
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-30
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
ADDA
rx
rrrr
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
AGU Source Register
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
#u5
#s16
iiiii
5-bit unsigned immediate data
iiiiiiiiiiiiiiii
16-bit signed immediate data
SC140 DSP Core Reference Manual
A-31
ADDL1A
ADDL1A
Add With One-Bit Arithmetic Shift Left
of Source Operand (AGU)
Operation
Assembler Syntax
(rx<<1) + Rx → Rx
ADDL1A rx,Rx
ADDL1A
Description
ADDL1A rx,Rx
Performs a one-bit arithmetic shift left on the data from source AGU register (rx) and adds the result to a
second source AGU register (Rx). The sum is stored back in Rx. For R0-R7 destinations, the operation is
affected by the modifier mode selected in MCTL.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
Example
addl1a r0,r1
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$0000 0055
R1
$0000 0011
$0000 00BB
In binary:
R0
0101 0101
R0 shifted left
1010 1010
R1
0001 0001
Sum
1011 1011
A-32
SC140 DSP Core Reference Manual
ADDL1A
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ADDL1A rx,Rx
1
2
1
8
1
1
7
0 R R R R 0
0
0
0
0
r
r
r
r
Instruction Fields
rx
rrrr
0000
N0
0100
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
AGU Source Register
—
1000
R0
1100
R4
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-33
ADDL2A
ADDL2A
Add With Two-Bit Arithmetic Shift Left
of Source Operand (AGU)
Operation
Assembler Syntax
(rx<<2) + Rx → Rx
ADDL2A rx,Rx
ADDL2A
Description
ADDL2A rx,Rx
Performs a two-bit arithmetic shift left on the data from AGU source register (rx), adds the result to another
AGU source register (Rx), and stores the sum in the destination (second) register (Rx). For R0-R7
destinations, the operation is affected by the modifier mode selected in MCTL.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
Status and Conditions Changed by Instruction
None.
Example
addl2a r0,r1
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$0000 0055
R1
$0000 0011
$0000 0165
In binary:
R0
R0 shifted left two
R1
Sum
A-34
0101 0101
1 0101 0101
0001 0001
1 0110 0101
SC140 DSP Core Reference Manual
ADDL2A
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ADDL2A rx,Rx
1
2
1
8
1
1
7
0 R R R R 0
0
0
1
0
r
r
r
r
Instruction Fields
rx
rrrr
0000
N0
0100
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
AGU Source Register
—
1000
R0
1100
R4
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-35
ADDNC.W
ADDNC.W
ADDNC.W
Add Without Changing
the Carry Bit (DALU)
Operation
Assembler Syntax
#s16 + Da → Dn
ADDNC.W #s16,Da,Dn {–215 ≤ s16 < 215}
Description
ADDNC.W #s16,Da,Dn
Sign-extends the 16-bit immediate value to 40 bits and adds it to the source data register Da. The sum is
stored in destination register Dn. The carry bit is not affected by this instruction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
The scaling mode bits determine which bits in the result are used in
the Ln bit calculation.
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
EMR[3]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic saturation
mode (SR [SM] = 1), clears the Ln bit in the destination register.
Example
addnc.w #$ca3e,d1,d2
Register/Memory Address
Before
After
immediate operand
$FF FFFF CA3E
D1
$FF FFFF CA3E
L2:D2
SR
EMR
$0:$FF FFFF 947C
$00E0 0000
$00E0 0000
$0000 0000
An add with a carry allowed would result in setting the carry bit as a result of an overflow from bit 39.
A-36
SC140 DSP Core Reference Manual
ADDNC.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
ADDNC #s16,Da,Dn
2
1
4
8
7
0
0
0
1
1
J
J
J
1
i
i
i
0
0
F F F
1
0
0
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#s16
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit signed immediate data
A-37
ADR
ADR
ADR
Add and Round (DALU)
Operation
Assembler Syntax
Rnd(Da + Dn) → Dn
ADR Da,Dn
Description
ADR Da,Dn
Adds one source data register (Da) to another (Dn) and rounds the sum. The result is stored in the
destination data register (Dn). Rounding adjusts the LSB of the high part of the destination register
according to the value of the low part of the register and then zeros the low part. The boundary between the
high part and the low part changes with scaling. The two modes of the round function, Rnd(), are described
on page A-359.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[3]
RM
Rounding mode
SR[5:4]
S[1:0]
The scaling mode bits determine which bits in the result are used in
the Ln bit calculation, and which bits are used in rounding.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Example
adr d3,d4
Register/Memory Address
D3
L4:D4
SR
EMR
A-38
Before
After
$00 0034 A216
$0:$00 2000 0000
$0:$00 2035 0000
$00E0 0000
$0000 0000
SC140 DSP Core Reference Manual
ADR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ADR Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
F F F
0
1
0
0
0
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-39
AND
AND
AND
Bitwise AND (DALU)
Operation
Assembler Syntax
#0u16 • Da → Dn
AND #0{u16},Da,Dn {0 ≤ u16 < 216}
#u16$0000 • Da → Dn
AND #{u16}$0000,Da,Dn {0 ≤ u16 < 216}
Da • Dn → Dn
AND Da,Dn
Description
These operations perform a "logical and" between the two source operands, and store the result in the
destination operand.
AND #0{u16},Da,Dn
The immediate unsigned word is zero-extended in bits [40:16] to form a 40-bit immediate operand. This
operand is then ANDed with the contents of a source data register (Da), and the result stored in a
destination data register (Dn). The HP and extension (bits [40:16]) of the destination register are cleared as
a result of this instruction.
The { } are not part of the assembler syntax, they are used here for clarity. For example, given an
immediate value of $27A6, using D0 as the source data register, and using D1 as the destination data
register, this instruction would be written as:
and #$027a6,d0,d1
AND #{u16}$0000,Da,Dn
A 40-bit operand is formed with zeros in bits [15:0], the immediate word in bits [31:16], and bit 31 copied
to bits [39:32] (sign-extended). This operand is then ANDed with the contents of a source data register
(Da), and the result stored in a destination data register (Dn). The LP of the destination register is cleared
as a result of this instruction.
The { } are not part of the assembler syntax, they are used here for clarity. For example, given an
immediate value of $27A6, using D0 as the source data register, and using D1 as the destination data
register, this instruction would be written as:
and #$27a60000,d0,d1
AND Da,Dn
Performs a bitwise AND on the contents of two source data registers (Da, Dn) and stores the result in the
destination (second) data register (Dn).
Status and Conditions that Affect Instruction
None.
A-40
SC140 DSP Core Reference Manual
AND
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example 1
and d2,d1
Register/Memory Address
Before
D2
After
$FF CE66 47F2
L1:D1
$0:$FF D859 6705
$0:$FF C840 4700
Example 2
and #$0ff2e,d2,d1
Register/Memory Address
Before
After
immediate
$00 0000 FF2E
D2
$00 27A6 98FB
L1:D1
$0:$00 0000 982A
Example 3
and #$ff2e0000,d2,d1
Register/Memory Address
Before
After
immediate
$FF FF2E 0000
D2
$F0 27A6 98FB
L1:D1
Note:
$0:$F0 2726 0000
The value of the immediate $ff2e0000 is extended to $ffff2e0000 before the AND operation with D2.
SC140 DSP Core Reference Manual
A-41
AND
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
AND #0{u16},Da,Dn
1
4
2
1
4
1
1
2
0
0
1
1
J
J
J
1
i
i
i
1
1
F F F
1
0
0
i
i
i
i
i
i
i
i
i
i
i
8
7
i
i
0
0
0
1
1
J
J
J
1
i
i
i
0
1
F F F
1
0
0
i
i
i
i
i
i
i
i
i
i
i
8
7
15
AND Da,Dn
7
0
15
AND #{u16}$0000,Da,Dn
8
1
1
0
1
1
1
F F F
i
i
0
0
0
0
0
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
001
Note:
Dn
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
#0(u16)
0000000000000000
iiiiiiiiiiiiiiii
16-bit unsigned immediate data in lower word,
upper word zeroed
#(u16)$0000
iiiiiiiiiiiiiiii
0000000000000000
16-bit unsigned immediate data in upper word,
lower word zeroed
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
#u16
A-42
SC140 DSP Core Reference Manual
AND
AND
Bitwise AND with 16-Bit Immediate (BMU)
Operation
Assembler Syntax
#u16 • DR.L → DR.L
AND #u16,DR.L
#u16 • DR.H → DR.H
AND #u16,DR.H
AND
Description
AND #u16,DR.L
Performs a bitwise AND on an immediate unsigned word and the contents of the LP of a source data or
address register (DR). Stores the result in the LP of the data or address register (DR). The HP of the register
is unaffected.
Note:
This instruction is assembler-mapped to BMCLR #~u16,DR.L where #~u16 is the bitwise
complement of #u16.
AND #u16,DR.H
Performs a bitwise AND on an immediate unsigned word and the contents of the HP of a data or address
register (DR). Stores the result in the HP of the data or address register (DR). The LP of the register is
unaffected.
Note:
This instruction is assembler-mapped to BMCLR #~u16,DR.H.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
and #$a70e,d1.h
Register/Memory Address
Before
After
immediate
$A70E
D1.H
$57AF
In binary, $A70E
1010 0111 0000 1110
$57AF
0101 0111 1010 1111
and = $070E
0000 0111 0000 1110
SC140 DSP Core Reference Manual
$070E
A-43
AND
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
AND #u16,DR.L
2
2
3
2
2
3
7
0
0
0
0
0
1
0
0
0
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
AND #u16,DR.H
8
i
i
i
i
0
0
0
0
0
1
0
0
0
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
DR
HHHH
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u16
A-44
Data/Address Register
This instruction can specify D8-D15 or R8-R15 as operands by using a a prefix prefix.
~iiiiiiiiiiiiiiii
One’s complement of 16-bit
unsigned immediate data
SC140 DSP Core Reference Manual
AND.W
AND.W
Bitwise AND with 16-Bit Immediate (BMU)
AND.W
Operation
Assembler Syntax
#u16 • (R) → (R)
AND.W #u16,(Rn){0 ≤ u16 < 216}
#u16 • (SP – u5) → (SP – u5)
AND.W #u16,(SP–u5){0 ≤ u16 < 216}{0 ≤ u5 < 64,W}
#u16 • (a16) → (a16)
AND.W #u16,(a16){0 ≤ u16 < 216}{0 ≤ a16 < 216,W}
#u16 • (SP + s16) → (SP + s16)
AND.W #u16,(SP+s16){0 ≤ u16 < 216}{–215 ≤ s16 < 215,W}
Description
These operations read from memory, modify the retrieved value, and write the new value back to that
memory address, resulting in two memory accesses. The absolute addresses, offsets, and address register
values must be word-aligned.
AND.W #u16,(Rn)
Performs a bitwise AND on a 16-bit unsigned immediate value and the contents of a memory address,
pointed to by the contents of an address register (Rn). Stores the result in the same memory address.
Note:
This instruction is assembler-mapped to BMCLR.W #~u16,(Rn) where #~u16 is the one’s
complement of #u16.
AND.W #u16,(SP–u5)
Performs a bitwise AND on a 16-bit unsigned immediate value and the contents of a memory address,
pointed to by a 5-bit unsigned offset subtracted from SP. Stores the result in the same memory address. The
address offset must be even.
Note:
This instruction is assembler-mapped to BMCLR.W #~u16,(SP-u5).
AND.W #u16,(a16)
Performs a bitwise AND on a 16-bit unsigned immediate value and the contents of a 16-bit absolute
memory address. Stores the result in the same memory address.
Note:
This instruction is assembler-mapped to BMCLR.W #~u16, (a16).
AND.W #u16,(SP+s16)
Performs a bitwise AND on a 16-bit unsigned immediate value and the contents of a memory address,
pointed to by a 15-bit signed offset added to SP. Stores the result in the same memory address.
Note:
This instruction is assembler-mapped to BMCLR.W #~u16,(SP+s16).
SC140 DSP Core Reference Manual
A-45
AND.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
Example
and.w #$54a1,(r7)
Register/Memory Address
immediate
R7
($50)
Before
After
$54A1
$50
$15AF
In binary, $54A1
0101 0100 1010 0001
$15AF
0001 0101 1010 1111
and = $14A1
0001 0100 1010 0001
A-46
$14A1
SC140 DSP Core Reference Manual
AND.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
AND.W #u16,(Rn)
2
3
2
3
3
3
2
3
0
1
0
0
0
0
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
3
3
3
i
i
i
0
0
0
0
0
0
0
0
0
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
1
1
i
i
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
i
i
0
i
0
i
0
i
0
i
15
AND.W #u16,(SP+s16)
0
0
15
AND.W #u16,(a16)
7
0
15
AND.W #u16,(SP–u5)
8
1
1
i
8
7
i
i
i
i
i
0
i
0
i
1
i
0
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
i
i
0
i
i
0
i
0
0 A A A
i
0 A A A
i
i
i
i
i
i
i
i
0
i
1
i
1
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
#u16
u5
s16
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
~iiiiiiiiiiiiiiii
One’s complement of unsigned 16-bit
immediate data
AAAAA0
Unsigned 5-bit SP address offset
AAAAAAAAAAAAAAAA
Signed 16-bit SP address offset
SC140 DSP Core Reference Manual
A-47
ASL
ASL
ASL
Arithmetic Shift Left
By One Bit (DALU)
Operation
Assembler Syntax
Da << 1→ Dn
ASL Da,Dn
Description
ASL Da,Dn
Shifts a source data register (Da) left one bit and stores the result in a destination data register (Dn). If the
source and destination registers are the same, the original value is destroyed, leaving the shifted value in
the register.
C
39
32 31
16 15
0
0
Note:
The ASL instruction is mapped by the assembler to ADD Da,Db,Dn if Da is an even numbered data
register and ADD Da,Da,Dn if Da is an odd numbered data register.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Bit Da[39] is stored in the carry bit.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Example
asl d0,d1
Register/Memory Address
D0
L1:D1
A-48
Before
After
$ff f001 0001
$0:$ff e002 0002
SC140 DSP Core Reference Manual
ASL
Register/Memory Address
Before
After
SR
$00E0 0000
$00E0 0001
EMR
$0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
ASL Da,Dn
1
1
1
ASL Da,Dn
1
1
1
0
8
1
0
1
1
F F F
*
1
0
0
0
F F F
15
Note:
0
7
*
8
0
1
0
J
J
J
J
1
1
0
0
0
j
7
J
0
j
** indicates serial grouping encoding.
Instruction Fields
Da,Db
JJJJJ
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
2.
3.
Da,Da
jj
Data Register Pairs
00
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix. Each register of a pair
can be separately encoded as the higher register. For example, D0,D4 can be changed to
D8,D4 by use of a prefix.
Register pair order can be reversed for clarity because the order of operation is not
important for add operations.
The JJJJJ encoding does not include the pairs: D1,D1; D3,D3; D5,D5; D7,D7. These are
covered in the jj encoding.
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-49
ASL2A
ASL2A
ASL2A
Arithmetic Shift Left
By Two Bits (AGU)
Operation
Assembler Syntax
Rx<<2 → Rx
ASL2A Rx
Description
ASL2A Rx
Shifts an AGU register (Rx) left two bits. Bits [29:0] are copied into bits [31:2]. Bits [1:0] are cleared.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
Example
asl2a r0
Register/Memory Address
Before
After
R0
$e001 0002
$8004 0008
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASL2A Rx
1
2
1
8
1
1
7
0 R R R R 1
0
1
1
1
1
1
1
0
Instruction Fields
Rx
RRRR
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
A-50
AGU Source/Destination Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
ASLA
ASLA
ASLA
Arithmetic Shift Left
By One Bit (AGU)
Operation
Assembler Syntax
Rx<<1 → Rx
ASLA Rx
Description
ASLA Rx
Shifts an AGU (Rx) register left one bit. Bits [30:0] are copied into bits [31:1]. Bit 0 is cleared.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
Example
asla r0
Register/Memory Address
Before
After
R0
$e001 0002
$c002 0004
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASLA Rx
1
2
1
8
1
1
7
0 R R R R 1
0
1
1
1
1
1
0
0
Instruction Fields
Rx
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-51
ASLL
ASLL
ASLL
Multiple-Bit Arithmetic Shift Left (DALU)
Operation
Assembler Syntax
Dn << #u5 → Dn
ASLL #u5,Dn {0 ≤ u5 < 32}
If Da[6:0] > 0, then Dn << Da[6:0] → Dn
ASLL Da,Dn {–40 ≤ Da[6:0] ≤ 40}
else Dn >> |Da[6:0]| → Dn
Description
These operations shift the contents of Dn by the amount in #u5 or in Da. Bits shifted out of Dn are lost
except for the last bit, which is stored in the C bit.
ASLL #u5,Dn
Shifts left by #u5, an immediate unsigned 5-bit integer. The vacated positions to the right are zero-filled.
C
39
32 31
16 15
0
0
ASLL Da,Dn
Performs a bidirectional arithmetic shift of Dn by Da[6:0] bits and stores the result in Dn. If Da[6:0] is
positive, the shift is left. If shifting left, the vacated positions to the right are zero-filled. If Da[6:0] is
negative, the shift is right. If shifting right, the MSB of the source is copied into the vacated positions,
creating a sign-extension.
C
39
32 31
16 15
0
Da[6:0] > 0
0
39
39
32 31
16 15
0
C
Da[6:0] < 0
Status and Conditions that Affect Instruction
None.
A-52
SC140 DSP Core Reference Manual
ASLL
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates and updates the carry bit in the status register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Clears the Ln bit in the destination register.
Example 1
asll d0,d1
Register/Memory Address
Before
D0
After
$00 0000 0003
L1:D1
$0:$FF A572 A572
$0:$FD 2B95 2B90
$00E0 0000
$00E0 0001
SR
EMR
$0000 0000
3
9
3
2
1
6
0
1111111110100101011100101010010101110010
C
1
1111110100101011100101010010101110010000
Example 2
asll d0,d1
Register/Memory Address
Before
D0
After
$FF FFFF FFFD
L1:D1
$0:$FF A572 A572
$0:$FF F4AE 54AE
$00E4 0000
$00E4 0000
SR
EMR
$0000 0000
3
9
3
2
1
6
0
1111111110100101011100101010010101110010
1111111111110100101011100101010010101110
SC140 DSP Core Reference Manual
C
0
A-53
ASLL
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
ASLL #u5,Dn
1
1
1
ASLL Da,Dn
1
1
2
0
8
*
1
1
1
1
F F F
1
0
1
0
1
F F F
15
Note:
1
7
8
0
1
0
i
i
i
i
i
0
0
1
0
J
J
J
7
0
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
001
Note:
Dn
A-54
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#u5
D0
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
5-bit unsigned immediate data
SC140 DSP Core Reference Manual
ASLW
ASLW
Word Arithmetic Shift Left 16 Bits (DALU)
Operation
Assembler Syntax
Da<<16 → Dn
ASLW Da,Dn
ASLW
Description
ASLW Da,Dn
Shifts the source register Da left by 16 bits and stores it in the destination register Dn. Bit 24 of the source
register is copied into the C bit. Bits [23:0] of the source register are copied into bits [39:16] of the
destination register. Bits [15:0] of the destination register are cleared.
C
39
32 31
16 15
0
0
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Bit Da[24] is stored in the carry bit.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Clears the Ln bit in the destination register.
Example
aslw d0,d1
Register/Memory Address
Before
D0
After
$FF A572 A572
L1:D1
$0:$00 0000 0000
$0:$72 A572 0000
$00E0 0000
$00E0 0001
SR
EMR
$0000 0004
3
9
3
2
1
6
0
1111111110100101011100101010010101110010
C
1
0 1 1 1 0 0 1 0 1 0 1 0 0 1 0 1 0 1 1 1 0 0 1 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
SC140 DSP Core Reference Manual
A-55
ASLW
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASLW Da,Dn
1
2
1
8
1
0
1
1
0
7
F F F
0
0
0
1
0
J
J
J
Instruction Fields
Dn
FFF
000
001
Note:
Da
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-56
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
ASR
ASR
ASR
Arithmetic Shift Right
By One Bit (DALU)
Operation
Assembler Syntax
Da>>1 → Dn
ASR Da,Dn
Description
ASR Da,Dn
Performs an arithmetic right shift by one bit on the source register Da, and stores it in the destination
register Dn. The LSB (bit 0) of the source register is copied into the status register carry (C) bit. Bits [39:1]
of the source register are copied into bits [38:0] of the destination register. Bit 39 of the source register is
copied into bit 39 of the destination register.
39
39
32 31
16 15
0
C
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Da[0] is stored in the carry bit.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Example
asr d5,d3
Register/Memory Address
Before
D5
L3:D3
SC140 DSP Core Reference Manual
After
$00 0000 7903
$0:$00 0000 3C81
A-57
ASR
Register/Memory Address
Before
SR
After
$00E4 0000
$00E4 0001
EMR
$0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASR Da,Dn
Note:
1
1
0
8
*
1
1
0
1
7
F F F
0
1
0
0
0
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-58
Single Source Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
ASRA
ASRA
ASRA
Arithmetic Shift Right
By One Bit (AGU)
Operation
Assembler Syntax
Rx>>1 → Rx
ASRA Rx
Description
ASRA Rx
Performs an arithmetic right shift by one bit on the AGU register (Rx). Moves bits [31:1] into bits [30:0].
Bit 31 remains the same, creating a sign-extension.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
Example
asra r2
Register/Memory Address
Before
After
$8002 0002
R2
$C001 0001
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASRA Rx
1
2
1
8
1
1
7
0 R R R R 1
0
1
1
1
1
1
0
1
Instruction Fields
Rx
RRRR AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-59
ASRR
ASRR
Multiple-Bit Arithmetic Shift Right (DALU)
Operation
Assembler Syntax
Dn >> #u5 → Dn
ASRR #u5,Dn {0 ≤ u5 < 32}
If Da[6:0] > 0, then Dn >> Da[6:0]→ Dn
else Dn << |Da[6:0]| → Dn
ASRR Da,Dn
ASRR
Description
This operation shifts the contents of Dn by N bits. Bits shifted out of Dn are lost except for the last bit,
which is stored in the C bit.
ASRR #u5,Dn
Performs an arithmetic right shift by N, an immediate unsigned 5-bit integer. The MSB is copied into the
vacated positions.
39
32 31
16 15
0
C
ASRR Da,Dn
Performs a bidirectional arithmetic shift of Dn by Da[6:0] bits and stores the result in Dn. If Da[6:0] is
positive, the shift is right. If shifting right, the MSB is copied into the vacated positions. If shifting left, the
vacated positions to the right are zero-filled. N is obtained from Da[6:0].
39
32 31
16 15
0
39
32 31
16 15
0
C
Da[6:0] > 0
C
Da[6:0] < 0
0
Status and Conditions that Affect Instruction
None.
A-60
SC140 DSP Core Reference Manual
ASRR
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Set to the value of the last bit out.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits
(possible only for ASRR Da,Dn)
Ln
L
Clears the Ln bit in the destination register.
Example 1
asrr #$3,d5
Register/Memory Address
Before
After
D3
$3
L5:D5
$0:$00 0000 7C09
$0:$00 0000 0F81
$00E4 0000
$00E4 0000
SR
EMR
$0000 0000
3
9
3
2
1
6
0
0000000000000000000000000111110000001001
0000000000000000000000000000111110000001
C
0
Example 2
asrr d3,d5
Register/Memory Address
Before
D3
After
$FF FDDD DDDC
L5:D5
$0:$00 0000 7C09
$0:$00 0007 C090
$00E4 0000
$00E4 0001
SR
EMR
$0000 0000
3
9
3
2
1
6
0
1111111110100101011100101010010101110010
C
1
1111110100101011100101010010101110010000
SC140 DSP Core Reference Manual
A-61
ASRRS
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASRR #u5,Dn
1
1
0
8
*
1
1
1
1
15
1
ASRR Da,Dn
Note:
1
2
1
0
1
0
1
0
F F F
8
1
7
1
1
i
i
i
i
7
i
0
F F F
0
0
1
1
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
A-62
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#u5
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
5-bit unsigned immediate data
SC140 DSP Core Reference Manual
ASRW
ASRW
Word Arithmetic Shift Right 16 Bits (DALU)
Operation
Assembler Syntax
Da>>16 → Dn
ASRW Da,Dn
ASRW
Description
ASRW Da,Dn
Performs an arithmetic right shift of 16 bits on the source register Da and stores the result in the destination
register Dn. It copies bit 39 of the source register to bits [39:24] of the destination register, bit 15 of the
source register to the C bit, and bits [39:16] of the source register to bits [23:0] of the destination register.
39
32 31
16 15
0
C
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Da[15] is stored in the carry bit.
Ln
L
Clears the Ln bit in the destination register.
Example
asrw d5,d0
Register/Memory Address
Before
D5
L0:D0
SR
SC140 DSP Core Reference Manual
After
$80 1234 8765
$0:$00 0000 0000
$0:$ff ff80 1234
$00E0 0000
$00E0 0001
A-63
ASRW
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ASRW Da,Dn
1
2
1
8
1
0
1
1
0
7
F F F
0
0
0
1
1
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
001
Note:
Dn
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-64
D0
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
BF
B
BF
BF
Branch If False (AGU)
Operation
Assembler Syntax
If T==0, then PC + displacement → PC
BF <label
BF >label
Description
BF <label
BF >label
Branches to label if the true bit is cleared. If the T bit is cleared, the program continues executing at
location PC + displacement. If the T bit is set, the PC is updated to point to the next execution set, and the
program continues executing sequentially. The displacement, calculated by the assembler and linker, is a
two’s complement integer that represents the relative distance from the current PC to the destination label.
The assembler determines if the PC relative displacement is a short branch (<label [–28 ≤ displacement <
28, W]) or a long branch (>label [–220 ≤ displacement < –28, W and 28 ≤ displacement < 220, W]).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
BF lbl
Instruction
Result
cmpeq.w #$35,d1
Not equal, so T bit in SR cleared.
bf lbl move.w #$29,d1
Branch taken, move.w executed.
inc d1
Skipped over.
move.w #$47,d2
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
lbl move.w #$16,d4
Execution continues here at lbl.
Register/Memory Address
Before
After
SR
$00E4 0000
d1
$0000
SC140 DSP Core Reference Manual
$0029
A-65
BF
Register/Memory Address
Before
After
d2
$0000
$0000
pc
$0006
$0016
Instruction Formats and Opcodes
Words Cycles1 Type
Instruction
Opcode
15
BF <label
1
1/4
4
1
8
0
0
0
0
1
2
1/4
4
8
0
a
1
0
0 A A A A A A A A 1
15
BF >label
7
1
7
1 A A A 1
0
0
0
1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles.
Instruction Fields
displacement (<label)
displacement
(>label)
A-66
AAAAAAAA0
8-bit signed PC relative displacement
aaaaaAAAAAAAAAAAAAA
A0
20-bit signed PC relative displacement
SC140 DSP Core Reference Manual
MOVES.4F
BFD
Branch If False Using a Delay Slot (AGU)
Operation
Assembler Syntax
If T==0, then PC + displacement → PC
BFD <label
BFD >label
BFD
Description
BFD <label
BFD >label
Branches to label if the true bit is cleared. If the T bit is cleared, the program continues executing at
location PC + displacement. If the T bit is set, the PC is updated to point to the next execution set, and the
program continues executing sequentially. The displacement, calculated by the assembler and linker, is a
two’s complement integer that represents the relative distance from the current PC to the destination label.
The assembler determines if the PC relative displacement is a short branch (<label [–28 ≤ displacement <
28, W]) or a long branch (>label [–220 ≤ displacement < –28, W and 28 ≤ displacement < 220, W]). The
execution set in the delay slot immediately following the BFD instruction is executed unconditionally after
the execution set containing the BFD instruction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
BFD lbl
Instruction
Result
cmpeq.w #$35,d1
Not equal, so T bit in SR cleared.
bfd lbl move.w #$29,d1
Branch taken, move.w executed.
inc d1
Increment executed in the delay slot.
move.w #$47,d2
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
lbl move.w #$1A,d4
Execution continues here at lbl.
Register/Memory Address
Before
SR
SC140 DSP Core Reference Manual
After
$00E0 0000
A-67
MOVES.4F
Register/Memory Address
Before
After
d1
$0000
$002A
d2
$0000
$0000
d4
$0000
$001A
pc
$0006
$0016
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
BFD <label
1
1/4
4
1
8
0
0
0
0
1
2
1/4
4
8
0
a
1
0
0 A A A A A A A A 0
15
BFD >label
7
1
7
0
0
0
1
0 A A A 1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles minus the time used
by the execution set in the delay slot. The cycle count for this instruction cannot be less than 1 cycle.
Instruction Fields
displacement
(<label)
AAAAAAAA0
8-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAA
A0
20-bit signed PC relative displacement
(>label)
A-68
SC140 DSP Core Reference Manual
BMCHG
BMCHG
Bit-Masked Change a
BMCHG
16-Bit Operand (BMU)
Operation
Assembler Syntax
~C1.Hi → C1.Hi (i denotes bits=1 in #u16)
BMCHG #u16,C1.H {0 ≤ u16 < 216}
~C1.Li → C1.Li
BMCHG #u16,C1.L {0 ≤ u16 < 216}
~DR.Hi → DR.Hi
BMCHG #u16,DR.H {0 ≤ u16 < 216}
~DR.Li → DR.Li
BMCHG #u16,DR.L {0 ≤ u16 < 216}
Description
These operations use an unsigned 16-bit immediate data mask to invert selected bits in the
destination operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding
destination operand’s bit position is inverted. Bits that are not selected as well as bits in the other
part of the register are unaffected. These operations read from a register, modify the retrieved
value, and write the new value back to that register. The operation is equivalent to the
exclusive-or function.
Note:
Special care must taken when using this instruction to clear bits on the EMR register due to this
register’s special functionality. See Chapter 3 for a description of this behavior.
BMCHG
#u16,C1.H
Inverts selected bits in the contents of the HP of a control register (C1).
BMCHG
#u16,C1.L
Inverts selected bits in the contents of the LP of a control register (C1).
BMCHG
#u16,DR.H
Inverts selected bits in the contents of the HP of a data or address register (DR).
BMCHG
#u16,DR.L
Inverts selected bits in the contents of the LP of a data or address register (DR).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode for instructions that have these
registers as an operand.
SC140 DSP Core Reference Manual
A-69
BMCHG.W
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination data register.
Example
bmchg #$f0f0,d1.h
Register/Memory Address
Before
After
immediate
$F0F00000
L1:D1
$0:$FFF0F07B22
$0:$FF00007B22
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMCHG #u16,C1.H
2
2
3
2
2
3
2
2
3
0
1
0
0
1
0
i
i
i
1
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
2
2
3
i
i
i
0
0
0
0
1
0
0
1
0
i
i
i
0
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
i
i
i
0
0
0
0
0
1
0
1
0
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
BMCHG #u16,DR.L
0
0
15
BMCHG #u16,DR.H
7
0
15
BMCHG #u16,C1.L
8
i
i
i
i
0
0
0
0
0
1
0
1
0
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
C1
DR
CCC
EMR
010
-
100
—
110
—
001
VBA
011
-
101
SR
111
MCTL
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
A-70
Control Registers
000
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
SC140 DSP Core Reference Manual
BMCHG.W
#u16
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit unsigned immediate data
A-71
BMCHG.W
BMCHG.W
Bit-Masked Change a
16-Bit Operand in Memory (BMU)
BMCHG.W
Operation
Assembler Syntax
~(SP-u5)i → (SP-u5)i
BMCHG.W #u16,(SP–u5){0 ≤ u16 < 216}{0 ≤ u5 < 64,W}
(i denotes bits=1 in #u16)
~(SP+s16)i → (SP+s16)i
BMCHG.W #u16,(SP+s16){0 ≤ u16 < 216}{–215 ≤ s16 < 215,W}
~(Rn)i → (Rn)i
BMCHG.W #u16,(Rn) {0 ≤ u16 < 216}
~(a16)i → (a16)i
BMCHG.W #u16,(a16) {0 ≤ u16 < 216}{0 ≤ a16 < 216,W}
Description
These operations use an unsigned 16-bit immediate data mask to invert selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination
operation’s bit position is inverted. These operations read from memory, modify the retrieved value, and
write the new value back to that memory address, resulting in two memory accesses. The absolute
addresses, offsets, and address register values must be word-aligned.
BMCHG.W #u16,(SP–u5)
Inverts selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with an
unsigned 5-bit offset.
BMCHG.W #u16,(SP+s16)
Inverts selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with a
signed 16-bit offset.
BMCHG.W #u16,(Rn)
Inverts selected bits in the contents of a memory address pointed to by an address register (Rn).
BMCHG.W #u16,(a16)
Inverts selected bits in the contents of a memory address pointed to by an absolute 16-bit address.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
A-72
SC140 DSP Core Reference Manual
BMCHG.W
Example
bmchg.w #$661f,<$800c
Register/Memory Address
Before
After
immediate
$661F
$800C
$ACE1
In binary, $661F
0110 0110 0001 1111
$ACE1
1010 1100 1110 0001
$CAFE
1100 1010 1111 1110
$CAFE
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
BMCHG.W #u16,(SP–u5)
3
3
3
3
3
2
0
0
0
0
0
1
0
i
i
i
A A A A A
0
1
i
i
i
i
i
i
i
i
i
8
7
0
3
1
1
0
1
2
3
i
i
i
i
0
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
i
i
i
i
i
i
8
7
0
0
0
1
0
0
1
0
1
0
1
i
i
i
i
0
0
1
1
1
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
15
3
BMCHG.W #u16,(a16)
0
1
15
2
BMCHG.W #u16,(Rn)
7
0
15
BMCHG.W #u16,(SP+s16)
8
i
i
i
i
0 A A A
i
i
0
i
i
i
i
i
i
0
1 R R R
i
i
i
i
i
i
i
i
i
8
7
0 A A A
i
i
0
0
1
i
i
1
i
i
i
1
i
0
0
i
i
i
i
i
i
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
#u16
u5
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
SC140 DSP Core Reference Manual
A-73
BMCHG.W
s16
A-74
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
BMCLR;Instruction Set:BMCLR
BMCLR
Bit-Masked Clear a 16-Bit Operand (BMU)
BMCLR
Operation
Assembler Syntax
0 → C1.Hi (i denotes bits=1 in #u16)
BMCLR #u16,C1.H {0 ≤ u16 < 216}
0 → C1.Li
BMCLR #u16,C1.L {0 ≤ u16 < 216}
0 → DR.Hi
BMCLR #u16,DR.H {0 ≤ u16 < 216}
0 → DR.Li
BMCLR #u16,DR.L {0 ≤ u16 < 216}
Description
These operations use an unsigned 16-bit immediate data mask to clear selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination operand’s
bit position is cleared. Bits that are not selected as well as bits in the other part of the register are
unaffected. These operations read from a register, modify the retrieved value, and write the new value back
to that register.
Note:
Special care must be taken when using this instruction to clear bits on the EMR register due to this
register’s special functionality. See Chapter 3 for a description of this behavior.
BMCLR #u16,C1.H
Clears selected bits in the HP contents of a control register (C1).
BMCLR #u16,C1.L
Clears selected bits in the LP contents of a control register (C1).
BMCLR #u16,DR.H
Clears selected bits in the HP contents of a data or address register (DR).
BMCLR #u16,DR.L
Clears selected bits in the LP contents of a data or address register (DR).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode for instructions that have these
registers as an operand.
SC140 DSP Core Reference Manual
A-75
BMCLR
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
bmclr #$b646,d7.l
Register/Memory Address
Before
After
immediate
$B646
L7:D7
$0:$0050006C5A
$0:$0050004818
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMCLR #u16,C1.H
2
2
3
2
2
3
2
2
3
0
1
0
0
0
0
i
i
i
1
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
2
2
3
i
i
i
0
0
0
0
1
0
0
0
0
i
i
i
0
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
i
i
i
0
0
0
0
0
1
0
0
0
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
BMCLR #u16,DR.L
0
0
15
BMCLR #u16,DR.H
7
0
15
BMCLR #u16,C1.L
8
i
i
i
i
0
0
0
0
0
1
0
0
0
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
C1
DR
CCC
EMR
010
-
100
—
110
—
001
VBA
011
-
101
SR
111
MCTL
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
A-76
Control Registers
000
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
SC140 DSP Core Reference Manual
BMCLR
#u16
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit unsigned immediate data
A-77
BMCLR.W
BMCLR.W
Bit-Masked Clear a
16-Bit Operand in Memory (BMU)
BMCLR.W
Operation
Assembler Syntax
0 → (SP–u5)i
BMCLR.W #u16,(SP–u5){0 ≤ u16 < 216<{0 ≤ u5 < 64,W}
(i denotes bits=1 in #u16)
0 → (SP+s16)i
BMCLR.W #u16,(SP+s16){0 ≤ u16 < 216}{–215 ≤ s16 < 215,W}
0 → (Rn)i
BMCLR.W #u16,(Rn){0 ≤ u16 < 216}
0 → (a16)i
BMCLR.W #u16,(a16){0 ≤ u16 < 216}{0 ≤ a16 < 216,W}
Description
These operations use an unsigned 16-bit immediate data mask to clear selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination operand’s
bit position is cleared. These operations read from memory, modify the retrieved value, and write the new
value back to that memory address, resulting in two memory accesses. The absolute addresses, offsets, and
address register values must be word-aligned.
BMCLR.W #u16,(SP–u5)
Clears selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with an
unsigned 5-bit offset.
BMCLR.W #u16,(SP+s16)
Clears selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with a
16-bit signed offset.
BMCLR.W #u16,(Rn)
Selected bits in the contents of a memory address pointed to by an address register (Rn).
BMCLR.W #u16,(a16)
Clears selected bits in the contents of a memory address pointed to by an absolute 16-bit address.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
A-78
SC140 DSP Core Reference Manual
BMCLR.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMCLR.W #u16,(SP–u5)
2
3
3
3
3
3
2
2
0
0
0
0
0
0
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
0
3
1
3
2
3
i
0
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
0
i
1
i
1
i
0
i
0 A A A
i
i
8
7
i
i
i
i
i
i
0
i
1
i
1
i
0
0
0
0
1
0
0
0
0
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
15
BMCLR.W #u16,(a16)
0
0
15
BMCLR.W #u16,(Rn)
7
0
15
BMCLR.W #u16,(SP+s16)
8
1
0
0
1
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
0
i
0
i
1
i
i
0 A A A
i
i
i
i
i
i
i
i
0
i
0
i
1
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
#u16
u5
s16
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
A-79
BMSET
BMSET
Bit-Masked Set a 16-Bit Operand (BMU)
BMSET
Operation
Assembler Syntax
1→ C1.Hi (i denotes bits=1 in #u16)
BMSET #u16,C1.H {0 < u16 < 216}
1 → C1.Li (selected bits)
BMSET #u16,C1.L {0 < u16 < 216}
1 → DR.Hi (selected bits)
BMSET #u16,DR.H {0 < u16 < 216}
1 → DR.Li (selected bits)
BMSET #u16,DR.L {0 < u16 < 216}
Description
These operations use an unsigned 16-bit immediate data mask to set selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination operand’s
bit position is set. Bits that are not selected as well as the other part of the register are unaffected. These
operations read from the register, modify the retrieved value, and write the new value back to that register.
BMSET #u16,C1.H
Sets selected bits in the HP contents of a control register (C1).
BMSET #u16,C1.L
Sets selected bits in the LP contents of a control register (C1).
BMSET #u16,DR.H
Sets selected bits in the HP contents of a data or address register (DR).
BMSET #u16,DR.L
Sets selected bits in the LP contents of a data or address register (DR).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode for instructions that have these
registers as an operand.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
A-80
SC140 DSP Core Reference Manual
BMSET
bmset #$2436,d1.l
Register/Memory Address
Before
After
$2436
L1:D1
$0:$0043A1243C
$0:$0043A1243E
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMSET #u16,C1.H
2
2
3
2
2
3
2
2
3
0
0
1
0
0
0
1
i
i
i
1
0 C C C
0
1
i
i
i
i
i
i
i
i
i
i
8
7
2
2
3
i
i
i
0
0
0
0
1
0
0
0
1
i
i
i
0
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
i
i
i
0
0
0
0
0
1
0
0
1
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
BMSET #u16,DR.L
0
1
15
BMSET #u16,DR.H
7
0
15
BMSET #u16,C1.L
8
i
i
i
i
0
0
0
0
0
1
0
0
1
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
C1
DR
CCC
000
EMR
010
-
100
—
110
—
001
VBA
011
-
101
SR
111
MCTL
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u16
Control Registers
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit unsigned immediate data
A-81
BMSET
BMSET.W
Bit-Masked Set a
16-Bit Operand in Memory (BMU)
Operation
BMSET.W
Assembler Syntax
1 → (SP–u5)i (i denotes bits=1 BMSET.W #u16,(SP–u5){0 ≤ u16< 216}{0 ≤ u5 < 64,W}
in #u16)
1 → (SP+s16)i (selected bits)
BMSET.W #u16,(SP+s16){0 ≤ u16 < 216}{–215 ≤ s16 < 215,W}
1 → (Rn)i (selected bits)
BMSET.W #u16,(Rn){0 ≤ u16 < 216}
1 → (a16)i (selected bits)
BMSET.W #u16,(a16){0 ≤ u16 < 216}{0 ≤ a16 < 216,W}
Description
These operations use an unsigned 16-bit immediate data mask to set selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination operand’s
bit position is set. These operations read from memory, modify the retrieved value, and write the new value
back to that memory address, resulting in two memory accesses. The absolute addresses, offsets, and
address register values must be word-aligned.
BMSET.W #u16,(SP–u5)
Sets selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with an
unsigned 5-bit offset.
BMSET.W #u16,(SP+s16)
Sets selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with a
16-bit signed offset.
BMSET.W #u16,(Rn)
Sets selected bits in the contents of a memory address pointed to by an address register (Rn).
BMSET.W #u16,(a16)
Sets selected bits in the contents of a memory address pointed to by an absolute 16-bit address.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
A-82
SC140 DSP Core Reference Manual
BMSET
Example
bmset.w #$f111,<$800c
Register/Memory Address
Before
After
immediate
$F111
($800C)
$C642
$F753
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMSET.W #u16,(SP–u5)
2
3
3
3
3
3
2
3
0
0
0
0
0
0
1
i
i
i
A A A A A
0
1
i
i
i
i
i
i
i
i
i
8
7
1
1
0
0
3
2
3
i
i
i
i
0
0
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
i
i
i
i
i
i
8
7
0
0
0
1
0
0
0
1
1
0
1
i
i
i
i
0
0
1
1
1
0
0
0
0
1 A A A A A A A A A A A A A
1
0
i
15
BMSET.W #u16,(a16)
0
1
15
2
BMSET.W #u16,(Rn)
7
0
15
BMSET.W #u16,(SP+s16)
8
i
i
i
i
1 A A A
i
i
0
i
i
i
i
i
i
0
1 R R R
i
i
i
i
i
i
i
i
i
8
7
1 A A A
i
i
0
0
1
i
i
1
i
i
i
1
i
0
0
i
i
i
i
i
i
i
Instruction Fields
Rn
RRR
000
001
Note:
a16
#u16
u5
s16
Address Register
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
A-83
BMTSET
BMTSET
BMTSET
Bit-Masked Test and Set a
16-Bit Operand (BMU)
Operation
Assembler Syntax
1 → DR.Hi (i denotes bits=1 in #u16)
if (all selected bits were set), then 1 → T, else 0 → T
BMTSET #u16,DR.H {0 ≤ u16 < 216}
1 → DR.Li (selected bits)
if (all selected bits were set), then 1 → T, else 0 → T
BMTSET #u16,DR.L {0 ≤ u16 < 216}
Description
These operations use an unsigned 16-bit immediate data mask to test and set selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination operand’s
bit position is set. Unselected bits are unaffected. If all selected bits were set when the data was read, the T
bit is set. If at least one of the selected bits was not set, the T bit is cleared. This operation reads from a
register, modifies the retrieved value, and writes the new value back to that register.
BMTSET #u16,DR.H
Tests and sets selected bits in the HP contents of a data or address register (DR).
BMTSET #u16,DR.L
Tests and sets selected bits in the LP contents of a data or address register (DR).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if all the bits selected by the mask were set, cleared otherwise.
Ln
L
Clears the Ln bit in the destination data register.
Example 1
bmtset #$111f,d1.l
Register/Memory Address
SR
immediate
d1
A-84
Before
After
$00E4 0000
$00E4 0000
$111F
$00 1234 5678
$00 1234 577F
SC140 DSP Core Reference Manual
BMTSET
Example 2
bmtset #$4238,d4.l
Register/Memory Address
Before
After
SR
$00E4 0000
immediate
$00E4 0002
$4238
d4
$00 1234 5678
$00 1234 5678
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMTSET #u16,DR.H
2
2
3
2
2
3
7
0
0
0
0
0
1
1
1
0
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
BMTSET #u16,DR.L
8
i
i
i
i
0
0
0
0
0
1
1
1
0
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
DR
HHHH
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
D3
0111
D7
1011
R3
1111
R7
0011
Note:
#u16
Data/Address Register
0000
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit unsigned immediate data
A-85
BMTSET.W
BMTSET.W
BMTSET.W
Bit-Masked Test and Set a
16-Bit Operand in Memory (BMU)
Operation
Assembler Syntax
BMTSET.W #u16,(SP–u5){0 ≤ u16 < 216}
1 → (SP–u5)i (i denotes bits=1 in #u16)
if (all selected bits were set), then 1 → T, else 0 → T {0 ≤ u5 < 64,W}
BMTSET.W #u16,(SP+s16){0 ≤ u16 < 216}
1 → (SP+s16)i
15
15
if (all selected bits were set), then 1 → T, else 0 → T {–2 ≤ s16 < 2 ,W}
BMTSET.W #u16,(Rn){0 ≤ u16 < 216}
1 → (Rn)i
if (all selected bits were set), then 1 → T, else 0 → T
BMTSET.W #u16,(a16){0 ≤ u16 < 216}
1 → (a16)i
{0
≤ a16 < 216,W}
if (all selected bits were set), then 1 → T, else 0 → T
Description
These operations use an unsigned 16-bit immediate data mask to test and set selected bits in the destination
operand. For each bit i that is set (selected) in the mask, the bit i in the destination operand’s corresponding
bit position is set. Unselected bits are unaffected. These operations read from memory, modify the
retrieved value, and attempt to write the new value back to that memory address. These operations result in
two memory accesses.
This instruction is intended for semaphore support in a multi-process shared memory environment.
Typically, the process that wants to get exclusive control of a semaphore tries to set bits in the memory
using this instruction. This action can fail if all of the bits are already set. It can also fail in case of
protection violation, or if another process has locked the bus or written to the same memory address
between the read and write cycles of this instruction. It is the responsibility of the memory system to
inform the core of failures due to the latter case. Both failures cause the T bit to be set. The process
attempting to set the semaphore should test the T bit after the instruction is executed in order to determine
if the semaphore is set or not. The absolute addresses, offsets, and address register values must be
word-aligned.
Although this instruction is designed with semaphores in mind, it can be used for other applications.
BMTSET.W #u16,(SP–u5)
Tests and sets selected bits in the contents of a memory address pointed to by the active stack pointer (SP)
with an unsigned 5-bit offset.
BMTSET.W #u16,(SP+s16)
Tests and sets selected bits in the contents of a memory address pointed to by the active stack pointer (SP)
with a 16-bit signed offset.
BMTSET.W #u16,(Rn)
Tests and sets selected bits in the contents of a memory address pointed to by an address register (Rn).
BMTSET.W #u16,(a16)
Tests and sets selected bits in the contents of a memory address pointed to by an absolute 16-bit address.
A-86
SC140 DSP Core Reference Manual
BMTSET.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if all the bits selected by the mask are set, or the memory access
fails; cleared otherwise.
Example
bmtset.w #$4328,($c)
Register/Memory Address
Before
After
immediate
$4238
($C)
$5678
$5678
$00E4 0000
$00E4 0002
SR
SC140 DSP Core Reference Manual
A-87
BMTSET.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
BMTSET.W #u16,(SP–u5)
3
3
3
3
3
2
2
0
0
0
1
1
0
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
0
3
1
3
2
3
i
0
0
1 A A A A A A A A A A A A A
1
0
i
i
1
i
0
i
1
i
1
i
1
i
0
i
0 A A A
i
i
8
7
i
i
i
i
i
0
i
i
1
i
1
i
0
0
0
0
1
0
1
1
0
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
15
BMTSET.W #u16,(a16)
0
0
15
BMTSET.W #u16,(Rn)
7
0
15
BMTSET.W #u16,(SP+s16)
8
1
0
0
1
0
1 A A A A A A A A A A A A A
1
0
i
i
1
i
0
i
1
i
0
i
1
i
i
0 A A A
i
i
i
i
i
i
i
0
i
i
0
i
1
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
#u16
u5
s16
A-88
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
BMTSTC
BMTSTC
Bit-Masked Test a
16-Bit Operand If Clear (BMU)
BMTSTC
Operation
Assembler Syntax
if (#u16 & C1.H) == $0000, then 1 → T, else 0 → T
BMTSTC #u16,C1.H {0 ≤ u16 < 216}
if (#u16 & C1.L) == $0000, then 1 → T, else 0 → T
BMTSTC #u16,C1.L {0 ≤ u16 < 216}
if (#u16 & DR.H) == $0000, then 1 → T, else 0 → T BMTSTC #u16,DR.H {0 ≤ u16 < 216}
if (#u16 & DR.L) == $0000, then 1 → T, else 0 → T BMTSTC #u16,DR.L {0 ≤ u16 < 216}
Description
These operations use an unsigned 16-bit immediate data mask to determine if all selected bits in an
operand are cleared. If all the selected bits are cleared, the T bit is set; if not, the T bit is cleared.
BMTSTC #u16,C1.H
Tests selected bits in the HP contents of a control register (C1).
BMTSTC #u16,C1.L
Tests selected bits in the LP contents of a control register (C1).
BMTSTC #u16,DR.H
Tests selected bits in the HP contents of a data or address register (DR).
BMTSTC #u16,DR.L
Tests selected bits in the LP contents of a data or address register (DR).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines working mode, and which SR or EMR is used for
instructions that have these registers as an operand.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if all the bits selected by the mask are clear, cleared otherwise.
Example
bmtstc #$8a59,d7.h
Register/Memory Address
Before
immediate
SC140 DSP Core Reference Manual
After
$8A590000
A-89
BMTSTC
Register/Memory Address
Before
L7:D7
After
$0:$0024A60000
SR
$00E40000
$00E40002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMTSTC #u16,C1.H
2
2
3
8
7
0
0
0
1
0
1
0
0
i
i
i
1
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
0
0
0
1
0
1
0
0
i
i
i
0
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
0
0
0
0
1
1
0
0
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
0
0
0
0
1
1
0
0
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
15
BMTSTC #u16,C1.L
2
2
3
15
BMTSTC #u16,DR.H
2
2
3
15
BMTSTC #u16,DR.L
2
2
3
0
i
i
i
0
i
i
i
0
i
i
i
i
0
i
i
i
i
Instruction Fields
C1
DR
CCC
000
EMR
010
-
100
—
110
—
001
VBA
011
-
101
SR
111
MCTL
HHHH
A-90
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u16
Control Registers
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
SC140 DSP Core Reference Manual
BMTSTC.W
BMTSTC.W
BMTSTC.W
Bit-Masked Test a
16-Bit Operand in Memory If Clear (BMU)
Operation
Assembler Syntax
if (#u16 & (SP-u5)) == $0000, then 1→T else 0→T
BMTSTC.W #u16,(SP–u5){0 ≤ u16 < 216}
{0 ≤ u5 < 64,W}
if (#u16 & (SP+s16)) == $0000, then 1→T else 0→T
BMTSTC.W #u16,(SP+s16){0 ≤ u16 < 216}
{–215 ≤ s16 < 215,W}
if (#u16 & (Rn)) == $0000, then 1→T else 0→T
BMTSTC.W #u16,(Rn){0 ≤ u16 < 216}
if (#u16 & (a16)) == $0000, then 1→T else 0→T
BMTSTC.W #u16,(a16){0 ≤ u16 < 216}
{0 ≤ a16 < 216,W}
Description
These operations use an unsigned 16-bit immediate data mask to determine if all selected bits in an
operand are cleared. If all the selected bits are cleared, the T bit is set; if not, the T bit is cleared. The
absolute addresses, offsets, and address register values must be word-aligned.
BMTSTC.W #u16,(SP–u5)
Tests selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with an
unsigned 5-bit offset.
BMTSTC.W #u16,(SP+s16)
Tests selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with a
signed 16-bit offset.
BMTSTC.W #u16,(Rn)
Tests selected bits in the contents of a memory address pointed to by an address register (Rn).
BMTSTC.W #u16,(a16)
Tests selected bits in the contents of a memory address pointed to by an absolute 16-bit address.
SC140 DSP Core Reference Manual
A-91
BMTSTC.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if all the bits selected by the mask are clear, cleared otherwise.
Example
bmtstc.w #$8A59,(r0)
Register/Memory Address
immediate
Before
After
$8A59
R0
$0000 0002
$0000 0002
($0002)
$0000 24A6
$0000 24A6
SR
$00E4 0000
$00E4 0002
$24A6 --0010 0100 1010 0110
mask $8A59 --1000 1010 0101 1001
A-92
SC140 DSP Core Reference Manual
BMTSTC.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
BMTSTC.W #u16,(SP–u5)
3
3
3
3
3
2
2
0
0
0
1
0
0
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
0
3
1
3
2
3
i
0
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
1
i
1
i
1
i
0
i
0 A A A
i
i
8
7
i
i
i
i
i
0
i
i
1
i
1
i
0
0
0
0
1
0
1
0
0
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
15
BMTSTC.W #u16,(a16)
0
0
15
BMTSTC.W #u16,(Rn)
7
0
15
BMTSTC.W #u16,(SP+s16)
8
1
0
0
1
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
1
i
0
i
1
i
i
0 A A A
i
i
i
i
i
i
i
0
i
i
0
i
1
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
#u16
u5
s16
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
A-93
BMTSTS
BMTSTS
Bit-Masked Test a
16-Bit Operand If Set (BMU)
BMTSTS
Operation
Assembler Syntax
if (#u16 & ~C1.H = $0000), then 1 → T, else 0 → T
BMTSTS #u16,C1.H {0 ≤ u16 < 216}
if (#u16 & ~C1.L = $0000), then 1 → T, else 0 → T
BMTSTS #u16,C1.L {0 ≤ u16 < 216}
if (#u16 & ~DR.H = $0000), then 1 → T, else 0 → T
BMTSTS #u16,DR.H {0 ≤ u16 < 216}
if (#u16 & ~DR.L = $0000), then 1 → T, else 0 → T
BMTSTS #u16,DR.L {0 ≤ u16 < 216}
Description
These operations use an unsigned 16-bit immediate data mask to determine if all selected bits in an
operand are set. If all the selected bits are set, the T bit is set; if not, the T bit is cleared.
BMTSTS #u16,C1.H
Tests selected bits in the HP contents of a control register (C1).
BMTSTS #u16,C1.L
Tests selected bits in the LP contents of a control register (C1).
BMTSTS #u16,DR.H
Tests selected bits in the HP contents of a data or address register (DR).
BMTSTS #u16,DR.L
Tests selected bits in the LP contents of a data or address register (DR).
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if all the bits selected by the mask are set, cleared otherwise.
A-94
SC140 DSP Core Reference Manual
BMTSTS
Example
bmtsts #$24a6,d7.h
Register/Memory Address
Before
After
immediate
$24A60000
L7:D7
$0:$0024A60560
SR
$00E40000
$00E40002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BMTSTS #u16,C1.H
2
2
3
2
2
3
2
2
3
0
0
1
0
1
0
1
i
i
i
1
0 C C C
0
1
i
i
i
i
i
i
i
i
i
i
8
7
2
2
3
i
i
i
0
0
0
0
1
0
1
0
1
i
i
i
0
0 C C C
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
i
i
i
0
0
0
0
0
1
1
0
1
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
BMTSTS #u16,DR.L
0
1
15
BMTSTS #u16,DR.H
7
0
15
BMTSTS #u16,C1.L
8
i
i
i
i
0
0
0
0
0
1
1
0
1
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
C1
DR
CCC
EMR
010
-
100
—
110
—
001
VBA
011
-
101
SR
111
MCTL
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u16
Control Registers
000
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit unsigned immediate data
A-95
BMTSTS.W
BMTSTS.W
BMTSTS.W
Bit-Masked Test a
16-Bit Operand in Memory (BMU)
Operation
Assembler Syntax
if (#u16 & ~(SP–u5) = $0000), then 1→ T,
else 0 → T
BMTSTS.W #u16,(SP–u5){0 ≤ u16 < 216}
{0 ≤ u5 < 64,W}
if (#u16 & ~(SP+s16) = $0000), then 1→ T,
else 0 → T
BMTSTS.W #u16,(SP+s16){0 ≤ u16 < 216}
{–215 ≤ s16 < 215,W}
if (#u16 & ~(Rn) = $0000), then 1→ T, else 0 → T
BMTSTS.W #u16,(Rn){0 ≤ u16 < 216}
if (#u16 & ~(a16) = $0000), then 1→ T, else 0 → T
BMTSTS.W #u16,(a16){0 ≤ u16 < 216}
{0 ≤ a16 < 216,W}
Description
These operations use an unsigned 16-bit immediate data mask to determine if all selected bits in an
operand are set. If all the selected bits are set, the T bit is set; if not, the T bit is cleared. The absolute
addresses, offsets, and address register values must be word-aligned.
BMTSTS.W #u16,(SP–u5)
Tests selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with an
unsigned 5-bit offset.
BMTSTS.W #u16,(SP+s16)
Tests selected bits in the contents of a memory address pointed to by the active stack pointer (SP) with a
16-bit signed offset.
BMTSTS.W #u16,(Rn)
Tests selected bits in the contents of a memory address pointed to by an address register (Rn).
BMTSTS.W #u16,(a16)
Tests selected bits in the contents of a memory address pointed to by an absolute 16-bit address.
A-96
SC140 DSP Core Reference Manual
BMTSTS.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if all the selected bits in the mask are set, or the memory access
fails; cleared otherwise.
Example
bmtsts.w #$0428,(r0)
Register/Memory Address
Before
After
immediate
$0428
(r0)
$16FC
$16FC
$00E4 0000
$00E4 0002
sr
In binary, $0428
0000 0100 0010 1000
$16FC
0001 0110 1111 1100
SC140 DSP Core Reference Manual
A-97
BMTSTS.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
BMTSTS.W #u16,(SP–u5)
3
3
3
3
3
2
2
0
0
0
1
0
1
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
0
3
1
3
2
3
i
0
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
1
i
1
i
1
i
0
i
1 A A A
i
i
8
7
i
i
i
i
i
0
i
i
1
i
1
i
0
0
0
0
1
0
1
0
1
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
15
BMTSTS.W #u16,(a16)
0
0
15
BMTSTS.W #u16,(Rn)
7
0
15
BMTSTS.W #u16,(SP+s16)
8
1
0
0
1
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
1
i
0
i
1
i
i
1 A A A
i
i
i
i
i
i
i
0
i
i
0
i
1
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
#u16
u5
s16
A-98
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
BRA
BRA
Branch (AGU)
Operation
Assembler Syntax
PC + displacement → PC
BRA <label
BRA >label
BRA
Description
BRA >label
BRA <label
Causes program execution to continue at location PC + displacement. The displacement, calculated by the
assembler and linker, is a two’s complement integer that represents the relative distance from the current
PC to the destination label. The assembler determines if the PC relative displacement is a short branch
(<label [–210 ≤ displacement < 210, W]) or a long branch (>label [–220 ≤ displacement < –210, W and 210 ≤
displacement < 220, W]).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
SC140 DSP Core Reference Manual
A-99
BRA
Example
bra _label2
nop
nop
; disassembled: bra >*+$8
_label2
Register/Memory Address
Before
After
_label (displacement)
$0000 000A
PC
$0000 0002
$0000 000A
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BRA <label
1
4
4
1
8
0
0
0
2
4
4
8
0
0
1 A A A A A A A A A A 1
15
BRA >label
7
a
0
0
7
0
0
0
1
1 A A A 1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Instruction Fields
displacement
(<label)
AAAAAAAAAA0
10-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAAA0
20-bit signed PC relative displacement
(>label)
A-100
SC140 DSP Core Reference Manual
BRAD
BRAD
Branch Using a Delay Slot (AGU)
Operation
Assembler Syntax
PC + displacement → PC
BRAD <label
BRAD >label
BRAD
Description
BRAD <label
BRAD >label
Causes program execution to continue at location PC + displacement after executing the execution set
immediately following the execution set containing the BRAD instruction (called the delay slot). The
displacement, calculated by the assembler and linker, is a two’s complement integer that represents the
relative distance from the current PC to the destination label. The assembler determines if the PC relative
displacement is a short branch (<label [–210 ≤ displacement < 210, W]) or a long branch (>label [–220 ≤
displacement < –210, W and 210 ≤ displacement < 220, W]).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
Source Code
Comments
move.l #$1234,d0.l ;loads d0
brad lbl3
; disassembled code - brad >*+a; p:lbl3
add d0,d1,d7
; executes, d7 = $1234, pc then branches to $e, address of lbl3
nop
nop
lbl3 add d0,d7,d7
; executes, d7 = $2468
SC140 DSP Core Reference Manual
A-101
BRAD
Register/Memory Address
Before
After
lbl3 (displacement)
$0000 000A
PC
$0000 0004
$0000 000E
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BRAD <label
1
1
4
4
1
8
0
0
0
41
2
4
8
0
0
1 A A A A A A A A A A 0
15
BRAD >label
7
a
0
0
7
0
0
0
1
0 A A A 1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Note 1: The branch uses 4 cycles minus the execution time used by execution set in the delay slot. The cycle
count for this instruction cannot be less than 1 cycle.
Instruction Fields
displacement
(<label)
AAAAAAAAAA0
10-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAAA
0
20-bit signed PC relative displacement
(>label)
A-102
SC140 DSP Core Reference Manual
BREAK
BREAK
Terminate the Loop and Branch
to an Address (AGU)
Operation
Assembler Syntax
PC + displacement → PC
0 → LFn
BREAK label
BREAK
Description
BREAK label
Exits the active loop n unconditionally before the active loop counter (LCn) equals one, and clears the
active loop flag. The program execution continues at “label.” The displacement, calculated by the
assembler and linker, is a two’s complement integer that represents the relative distance from the current
PC to the destination label. Some programming rules apply to the use of this instruction. If no loops are
enabled, this instruction is undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Determines which loop is active.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Clear active loop flag.
Example
break _label
Register/Memory Address
Before
After
_label (displacement)
$0000 000C
PC
$0000 0014
$0000 0020
SR
$40E0 0000
$00E0 0000
Note:
The assembler has calculated the displacement $C to increment the program counter from its value
at the BREAK ($0000 0014) to its value at _label ($0000 0020). LF3 is cleared by the break.
SC140 DSP Core Reference Manual
A-103
BREAK
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BREAK label
2
4
4
8
0
0
0
0
7
0
0
0
1
0 A A A 0
0
0
1
1
1
0
0 A A A A A A A A A A A A a
Instruction Fields
displacement
A-104
aAAAAAAAAAAAAAAA0
16-bit signed PC relative displacement.
The encoding is the displacement with bit
0 stripped and replaced by the sign bit.
SC140 DSP Core Reference Manual
BSR
BSR
BSR
Branch to Subroutine (AGU)
Operation
Assembler Syntax
(Next PC) → (SP); SR → (SP + 4); SP + 8 → SP;
PC + displacement → PC; (Next PC)→ RAS
BSR <label
BSR >label
Description
BSR <label
BSR >label
Pushes the next PC and SR onto the stack and causes program execution to continue at location PC +
displacement. The displacement, calculated by the assembler and linker, is a two’s complement integer that
represents the relative distance from the current PC to the destination label. The assembler determines if
the PC relative displacement is a short branch (<label [–28 ≤ displacement < 28, W]) or a long branch
(>label [–220 ≤ displacement < –28, W and 28 ≤ displacement < 220, W]). In addition to being pushed onto
the stack, the next PC is stored in the return address from subroutine register (RAS) and RAS becomes
valid.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines the stack pointer used in instructions that have a stack
pointer as an operand.
Status and Conditions Changed by Instruction
None.
Example
bsr _label
Register/Memory Address
Before
After
SR
$00E0 0000
_label (displacement)
$0000 0014
PC
$0000 0002
$0000 0016
$30
$38
NSP
($30)
$0000 0006
($34)
$00E0 0000
SC140 DSP Core Reference Manual
A-105
BSR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
BSR <label
1
4
4
BSR >label
2
4
4
1
8
7
0
0
0
0
0
0
1 A A A A A A A A 1
0
0
1
0
a
0
1
1
0
0 A A A A A A A A A A A A a
15
8
7
0
1 A A A 1
1
a
a
a
Instruction Fields
displacement
(<label)
AAAAAAAA0
8-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAA
A0
20-bit signed PC relative displacement
(>label)
A-106
SC140 DSP Core Reference Manual
BSRD
BSRD
Branch to Subroutine Using a Delay Slot (AGU)
Operation
Assembler Syntax
(next* PC) → (SP); SR → (SP + 4); SP + 8 → SP;
PC + displacement → PC, (next* PC)→RAS
BSRD <label
BSRD >label
BSRD
Description
BSRD <label
BSRD >label
Executes the execution set in the delay slot, then pushes the next* PC (the PC of the execution set after the
delay slot) and SR onto the stack, and causes program execution to continue at location PC + displacement.
The displacement, calculated by the assembler and linker, is a two’s complement integer that represents the
relative distance from the current PC to the destination label. The assembler and linker determines if the PC
relative displacement is a short branch (<label [–28 ≤ displacement < 28, W]) or a long branch (>label [–220
≤ displacement < –28, W and 28 ≤ displacement < 220, W]). In addition to being pushed onto the stack, the
next* PC is stored in the RAS register, and RAS becomes valid.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines the stack pointer used in instructions that have a stack
pointer as an operand.
Status and Conditions Changed by Instruction
None.
Example
Source Code
Comments
move.l #$30,r0
;loads r0 to later initialize sp
move.l #$40,r1
; loads r1 to later initialize osp
tfra r0,sp
; initializes sp, sp is esp in this example
tfra r1,osp
; initializes osp, osp is nsp
nop
bsrd lbl3
; branch to lbl3
move.w #$1234,r0 ; execute before the branch
nop
lbl3 add d0,d1,d2
SC140 DSP Core Reference Manual
A-107
BSRD
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
BSRD <label
1
4/5
4
1
8
0
0
0
0
0
2
4/5
4
8
0
a
0
0
1 A A A A A A A A 0
15
BSRD >label
7
1
7
0
0
0
1
0 A A A 1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Note 1: The branch uses 4 cycles minus the execution time used by the execution set in the delay slot. The cycle
count for this instruction cannot be less than 2 cycles. The branch uses 5 cycles, minus the execution time
used by the execution set in the delay slot, if the total of the largest cycle time of the instructions grouped
with the BSRD and the execution time of the delay slot set is ≥ 4. One cycle is used by the core to push the
return address onto the stack.
Instruction Fields
displacement
(<label)
AAAAAAAA0
8-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAA
A0
20-bit signed PC relative displacement
(>label)
A-108
SC140 DSP Core Reference Manual
BT
BT
BT
Branch If True (AGU)
Operation
Assembler Syntax
If T==1, then PC + displacement → PC
BT <label
BT >label
Description
BT <label
BT >label
Branches to label if the true bit is set. If the T bit is set, the program continues executing at location
PC + displacement. If the T bit is cleared, the PC is updated to point to the next execution set, and the
program continues executing sequentially. The displacement, calculated by the assembler and linker, is a
two’s complement integer that represents the relative distance from the current PC to the destination label.
The assembler determines if the PC relative displacement is a short branch (<label [–28 ≤ displacement <
28, W]) or a long branch (>label [–220 ≤ displacement < –28, W and 28 ≤ displacement < 220, W]).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
BT lbl
Instruction
Result
cmpeq.w #$35,d1
Equal, so T bit in SR set.
bt lbl move.w #$29,d1
Branch taken, move.w executed, d1=$29.
inc d1
Skipped over.
move.w #$47,d2
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
lbl move.w #$16,d4
Execution continues here at lbl, d4=$16.
Register/Memory Address
Before BT
After
SR
$00E4 0002
d1
$0035
SC140 DSP Core Reference Manual
$0029
A-109
BT
Register/Memory Address
Before BT
After
d2
$0000
$0000
pc
$0006
$0016
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
BT <label
1
1/4
4
1
8
0
0
0
0
0
2
1/4
4
8
0
a
1
0
0 A A A A A A A A 1
15
BT >label
7
0
7
1 A A A 1
0
0
0
1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles.
Instruction Fields
displacement
(<label)
AAAAAAAA0
8-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAA
A0
20-bit signed PC relative displacement
(>label)
A-110
SC140 DSP Core Reference Manual
BTD
BTD
Branch If True Using a Delay Slot (AGU)
Operation
Assembler Syntax
If T==1, then PC + displacement → PC
BTD <label
BTD >label
BTD
Description
BTD <label
BTD >label
Branches to label if the true bit is set. If the T bit is set, the program continues executing at location
PC + displacement. If the T bit is cleared, the PC is updated to point to the next execution set, and the
program continues executing sequentially. The displacement, calculated by the assembler and linker, is a
two’s complement integer that represents the relative distance from the current PC to the destination label.
The assembler determines if the PC relative displacement is a short branch(<label [–28 ≤ displacement < 28,
W]) or a long branch (>label [–220 ≤ displacement < –28, W and 28 ≤ displacement < 220, W]). The
execution set in the delay slot immediately following the BTD instruction is executed unconditionally after
the execution set containing the BTD instruction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
BTD lbl
Instruction
Result
cmpeq.w #$35,d1
Equal, so T bit in SR set.
btd lbl move.w #$29,d1
Branch taken, move.w executed, d1=$29.
inc d1
Increment executed in the delay slot, d1=$2A.
move.w #$47,d2
Skipped over.
----
Skipped over.
----
Skipped over.
----
Skipped over.
lbl move.w #$1A,d4
Register/Memory Address
Execution continues here at lbl.
Before BTD
SR
SC140 DSP Core Reference Manual
After
$00E0 0002
A-111
BTD
Register/Memory Address
Before BTD
After
d1
$0035
$002A
d2
$0000
$0000
d4
$0000
$001A
pc
$0006
$0016
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
BTD
<label
1
1/4
4
1
8
0
0
0
0
0
>label
2
1/4
4
8
0
a
1
0
0 A A A A A A A A 0
15
BTD
7
0
7
0 A A A 1
0
0
0
1
1
a
a
a
1
0
0 A A A A A A A A A A A A a
Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles minus the time used by
the execution set in the delay slot. The cycle count for this instruction cannot be less than 1 cycle.
Instruction Fields
displacement
(<label)
AAAAAAAA0
8-bit signed PC relative displacement
displacement
aaaaaAAAAAAAAAAAAAA
A0
20-bit signed PC relative displacement
(>label)
A-112
SC140 DSP Core Reference Manual
CLB
C-D
CLB
Count Leading Bits (DALU)
CLB
Operation
Assembler Syntax
If Da[39] == 0,
then 9 – (number of consecutive leading zeros in Da[39:0]) → Dn
else 9 – (number of consecutive leading ones in Da[39:0]) → Dn
CLB Da,Dn
Description
CLB Da,Dn
Counts the leading 0s or 1s according to bit 39 of source Da. It scans bits [39:0] of Da starting from bit 39.
The operation loads nine minus the number of consecutive leading 0s or 1s into destination Dn. The result
is sign-extended. The range of the result is +8 to –31. This instruction can be used in conjunction with the
instruction ASRR for performing fast normalization of the operand. If Da equals zero, then Dn is set to
zero.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clear the Ln bit in the destination data register.
Example
clb d3,d7
Register/Memory Address
Before
D3
After
$00000 F7434
L7:D7
$0:$FF FFFF FFF5
The number of consecutive zeros is 20, 9 - 20 = -11 ($FFF5)
SC140 DSP Core Reference Manual
A-113
CLB
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CLB Da,Dn
1
2
1
8
1
0
1
0
0
7
F F F
0
0
0
1
0
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
001
Note:
Dn
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-114
D0
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
CLR
CLR
CLR
Clear a Data Register (DALU)
Operation
Assembler Syntax
0 → Dn
CLR Dn
Description
CLR Dn
Clears a data register (Dn).
Note:
CLR Dn is assembler mapped to SUB Da,Da,Dn where Dn is the register being cleared and Da is
an arbitrary register assigned by the assembler for programming rule G.G.5. Any (Da-Da) results in
zero being stored in Dn. Da assignment uses the low data registers (D0-D7) where possible to avoid
using a prefix.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
SR[0]
C
Clears the carry bit.
Example
clr d1
Register/Memory Address
Before
After
SR
L1:D1
$00E0 0001
$00E0 0000
$0:$00 0000 0040
$0:$00 0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
8
7
0
CLR Dn (Da even)
1
1
1
0
*
1
0
1
1
F F F
0
0
J
J
J
J
J
CLR Dn (Da odd)
1
1
1
0
*
1
0
0
0
F F F
1
1
0
0
1
j
j
Note:
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-115
CLR
Instruction Fields
Dn
FFF
Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
11110
D6
11
D7
Note:
Da
JJJJJ
10000
Note:
Da
Source Data Register
D0
11100
D2
10100
D4
This instruction can specify D8-D15 as operands by using a prefix.
jj
Source Data Register
00
Note:
A-116
This instruction can specify D8-D15 as operands by using a prefix.
D1
01
D3
10
D5
If registers D8–D15 are accessed instead of D0–D7, a prefix is used.
SC140 DSP Core Reference Manual
CMPEQ
CMPEQ
CMPEQ
Compare for Equal (DALU)
Operation
Assembler Syntax
If Da == Dn, then 1→ T, else 0 → T
CMPEQ Da,Dn
Description
CMPEQ Da,Dn
Compares the 40-bit contents of two data registers (Da and Dn), setting the T bit if they are equal, and
clearing the T bit if they are not.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets T bit if equal, otherwise cleared.
Example
cmpeq d2,d3
Register/Memory Address
Before
After
D2
$00 0000 0005
D3
$00 0000 0005
SR
$00E4 0000
$00E4 0002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CMPEQ Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
F F F
0
1
1
0
0
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-117
CMPEQ
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-118
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
CMPEQ.W
CMPEQ.W
Compare for Equal (DALU)
CMPEQ.W
Operation
Assembler Syntax
If #u5 == Dn, then 1 → T, else 0 → T
CMPEQ.W #u5,Dn {0 ≤ u5 < 32}
If #s16 == Dn, then 1 → T, else 0 → T
CMPEQ.W #s16,Dn {–215 ≤ s16 < 215}
Description
CMPEQ.W #u5,Dn
Compares an immediate unsigned 5-bit value (range 0–31) with a data register (Dn) for equality. The
immediate value is right-aligned and zero-extended.
CMPEQ.W #s16,Dn
Compares an immediate signed 16-bit value that has been right-aligned and sign-extended to 40 bits with a
data register (Dn) for equality.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets T bit if equal, otherwise cleared.
Example
cmpeq.w #$5,d3
Register/Memory Address
Before
immediate
After
$0000 0005
D3
$00 0000 0005
SR
$00E4 0000
SC140 DSP Core Reference Manual
$00E4 0002
A-119
CMPEQ.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
CMPEQ.W #u5,Dn
1
1
2
CMPEQ.W #s16,Dn
2
1
4
1
8
7
1
0
1
0
0
F F F
8
7
0
0
1
1
0
1
0
0
1
0
0
i
i
i
i
i
15
0
0
1
i
i
i
i
i
i
i
i
1
0
F F F
i
i
i
i
i
i
0
i
i
Instruction Fields
Dn
FFF
000
001
Note:
#u5
#s16
A-120
Single Source/Destination Data Register
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
5-bit unsigned immediate data
iiiiiiiiiiiiiiii
16-bit signed immediate data
SC140 DSP Core Reference Manual
CMPEQA
CMPEQA
Compare for Equal (AGU)
Operation
Assembler Syntax
If rx == Rx, then 1 → T, else 0 → T
CMPEQA rx,Rx
CMPEQA
Description
CMPEQA rx,Rx
Compares two AGU registers (rx and Rx) for equality. Note that a register cannot be compared to itself
using this instruction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets T bit if equal, otherwise cleared.
Example
cmpeqa r1,r2
Register/Memory Address
Before
After
R1
$0000 0005
R2
$0000 0005
SR
$00E4 0000
SC140 DSP Core Reference Manual
$00E4 0002
A-121
CMPEQA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CMPEQA rx,Rx
1
2
1
8
1
1
7
0 R R R R 1
0
0
1
0
r
r
r
r
Instruction Fields
rx
rrrr
0000
N0
0100
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
—
1000
R0
1100
R4
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
A-122
AGU Source Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
CMPGT
CMPGT
CMPGT
Compare for Greater Than (DALU)
Operation
Assembler Syntax
Dn > Da → T
CMPGT Da,Dn
Description
CMPGT Da,Dn
Compares two data registers (Da and Dn). The T bit is set if the signed value in the second data register
(Dn) is greater than the signed value in the first (Da); T is cleared otherwise.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets T bit if Dn > Da, otherwise cleared.
Example
cmpgt d2,d3
Register/Memory Address
Before
After
D2
$0000 35FA
D3
$0000 35FB
SR
$00E4 0000
$00E4 0002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CMPGT Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
F F F
0
1
1
1
0
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-123
CMPGT
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-124
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
CMPGT.W
CMPGT.W
Compare for Greater Than
(DALU)
CMPGT.W
Operation
Assembler Syntax
Dn > #u5 → T
CMPGT.W #u5,Dn {0 ≤ u5 < 32}
Dn > #s16 → T
CMPGT.W #s16,Dn {–215 ≤ s16 < 215}
Description
These instructions set the T bit if the content of a signed data register (Dn) is greater than the immediate
value, or clear the T bit if the content of the data register is not greater than the immediate value.
CMPGT.W #u5,Dn
Compares if a data register is greater than an immediate unsigned 5-bit value that has been right-aligned
and zero-extended to 40 bits.
CMPGT.W #s16,Dn
Compares if a data register is greater than an immediate signed 16-bit value that has been right-aligned and
sign-extended to 40 bits.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets T bit if Dn > an immediate, otherwise cleared.
Example
cmpgt.w #$8002,d2
Register/Memory Address
Before
After
immediate
$FF FFFF 8002
D2
$FF FFFF 8004
SR
$00E4 0000
SC140 DSP Core Reference Manual
$00E4 0002
A-125
CMPGT.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
CMPGT.W #u5,Dn
1
1
2
CMPGT.W #s16,Dn
2
1
4
1
8
7
1
0
1
0
1
F F F
8
7
0
0
1
1
0
1
1
0
1
0
0
i
i
i
i
i
15
0
0
1
i
i
i
i
i
i
i
i
1
0
F F F
i
i
i
i
i
i
0
i
i
Instruction Fields
Dn
FFF
000
001
Note:
#u5
#s16
A-126
Single Source/Destination Data Register
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
5-bit unsigned immediate data
iiiiiiiiiiiiiiii
16-bit signed immediate data
SC140 DSP Core Reference Manual
CMPGTA
CMPGTA
Compare for Greater Than (AGU)
Operation
Assembler Syntax
Rx > rx → T
CMPGTA rx,Rx
CMPGTA
Description
CMPGTA rx,Rx
Compares two signed AGU registers (rx and Rx) and sets the T bit if the second AGU register is greater
than the first, or clears the T bit if the second AGU register is not greater than the first. Note that a register
cannot be compared to itself using this instruction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets the T bit if Rx > rx, otherwise cleared.
Example
cmpgta r2,r3
Register/Memory Address
Before
After
R2
$0000 35FA
R3
$0000 34EA
SR
$00E4 0002
SC140 DSP Core Reference Manual
$00E4 0000
A-127
CMPGTA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CMPGTA rx,Rx
1
2
1
8
1
1
7
0 R R R R 1
0
0
0
1
r
r
r
r
Instruction Fields
rx
rrrr
0000
N0
0100
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
—
1000
R0
1100
R4
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
A-128
AGU Source Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
CMPHI
CMPHI
CMPHI
Unsigned Compare for Higher (DALU)
Operation
Assembler Syntax
Dn > Da → T
CMPHI Da,Dn
Description
CMPHI Da,Dn
Compares the unsigned value in bits 31:0 of two data registers (Da and Dn) to determine which is greater.
It sets the T bit if the unsigned value of Dn[31:0] is greater than the unsigned value of Da[31:0]. Otherwise,
it clears the T bit.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets the T bit if 32-bit unsigned Dn > Da, otherwise cleared.
Example
cmphi d1,d0
Register/Memory Address
Before
After
D1
$00 26A2 44F3
D0
$00 2781 21A2
SR
$00E4 0000
$00E4 0002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CMPHI Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
F F F
0
1
1
1
1
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-129
CMPHI
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-130
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
CMPHIA
CMPHIA
Unsigned Compare for Higher (AGU)
Operation
Assembler Syntax
Rx > rx → T
CMPHIA rx,Rx
CMPHIA
Description
CMPHIA rx,Rx
Compares the unsigned value in two AGU registers (rx and Rx) to determine which is greater. It sets the T
bit if the unsigned value of Rx is greater than the unsigned value of rx. It clears the T bit if the unsigned
value of Rx is not greater than the unsigned value of rx. Note that a register cannot be compared to itself
using this instruction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
SR[1]
T
Sets the T bit if unsigned Rx > rx, otherwise cleared.
Example
cmphia r0,r1
Register/Memory Address
Before
After
R0
$FFFF 8002
R1
$FFFF FFFF
SR
$00E4 0000
SC140 DSP Core Reference Manual
$00E4 0002
A-131
CMPHIA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
CMPHIA rx,Rx
1
2
1
8
1
1
7
0 R R R R 1
0
0
0
0
r
r
r
r
Instruction Fields
rx
rrrr
0000
N0
0100
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
—
1000
R0
1100
R4
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
A-132
AGU Source Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
CONT
CONT
Continue to the Next Loop Iteration (AGU)
Operation
If LCn > 1,
CONT
Assembler Syntax
then SAn → PC, LCn-1 → LCn
else PC + displacement → PC
0 → LFn,
0 → LCn
CONT label
Description
CONT label
Continues the active loop n from the start address of the loop (SAn) if its loop counter (LCn) is greater than
one. Otherwise, it clears the active loop flag (LFn) and branches to an address determined by a 16-bit
signed displacement [–216 ≤ displacement < 216,W] added to the PC. In either case, the active loop counter
is decremented by one. Some programming rules apply to the use of this instruction. If no loops are
enabled, this instruction is undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Read loop flags to determine active loop.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Clear active loop flag if the active loop counter is less than or equal to
one.
Example
cont _label
Register/Memory Address
Before
After
_label (displacement)
$C
LC3
$1
$0
SR
$40E4 0000
$00E4 0000
PC
$0000 0014
$0000 0020
Loop count 3 (LC3) is 1, so loop count is decremented to 0, loop flag 3 (SR26) is cleared, and program
continues at _label, address $0000 0020.
SC140 DSP Core Reference Manual
A-133
CONT
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
CONT label
2
3/4
4
8
0
0
0
1
7
1 A A A 0
0
0
0
1
1
0
0 A A A A A A A A A A A A a
0
0
1
1
Note 1: If LC > 1, CONT uses 3 cycles. If LC ≤ 1, CONT uses 4 cycles.
Instruction Fields
displacement
A-134
aAAAAAAAAAAAAAAA0
16-bit signed PC relative displacement. The
encoding is the displacement with bit 0
stripped and replaced by the sign bit.
SC140 DSP Core Reference Manual
CONTD
CONTD
Continue to Next Loop Iteration
Using a Delay Slot (AGU)
Operation
If LCn > 1,
CONTD
Assembler Syntax
then SAn → PC, LCn-1 → LCn
else PC + displacement → PC
0 → LFn,
0 → LCn
CONTD label
Description
CONTD label
Continues the active loop n from the start address of the loop (SAn) if its loop counter (LCn) is greater than
one. Otherwise, it clears the active loop flag (LFn), and branches to an address determined by a 16-bit
signed displacement [–216 ≤ displacement < 216,W] added to the PC. In either case, the active loop counter
is decremented by one, and the execution set immediately following the execution set containing the
CONTD is executed. Some programming rules apply to the use of this instruction. If no loops are enabled,
this instruction is undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Read loop flags to determine active loop.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Clear active loop flag if the active loop counter is less than or equal to
one.
Example
contd lbl3
Instruction
dosetup strt0
Result
; defines start address for loop 0
doen0 #$10
; activates loop 0 with a count of 16
loopstart0
; assembler directive defining starting address SA
strt0 mac d0,d1,d2
; DALU instruction at start address
add d5,d6,d7
contd lbl3
; PC returns to strt0 until LC = 1
inc d1
; executes in the delay slot each time, PC jumps to lbl3 when LC = 1
nop
nop
SC140 DSP Core Reference Manual
A-135
CONTD
loopend0
lbl3 add d0,d1,d2
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
CONTD label
2
3/4
4
8
0
0
0
1
7
0 A A A 0
0
0
0
1
1
0
0 A A A A A A A A A A A A a
0
0
1
1
Note 1: If LC > 1, CONTD uses 3 cycles. If LC = 1, CONTD uses 4 cycles. In both cases, the cycles are decreased
by the time used for the execution set in the delay slot. The cycle count for this instruction cannot be less than 1
cycle.
Instruction Fields
displacement
A-136
aAAAAAAAAAAAAAAA0
16-bit signed PC relative displacement. The
encoding is the displacement with bit 0
stripped and replaced by the sign bit.
SC140 DSP Core Reference Manual
DEBUG
DEBUG
DEBUG
Enter Debug Mode (AGU)
Operation
Assembler Syntax
DEBUG
Description
DEBUG
Causes the device to enter the debug state. It is an Enhanced On-chip Emulator (EOnCE)
dedicated instruction that is used for debugging. This instruction cannot be grouped with another
debug instruction.
Status and Conditions that Affect Instruction
None
Status and Conditions Changed by Instruction
None.
Example
debug
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DEBUG
1
2
SC140 DSP Core Reference Manual
4
1
0
0
1
1
1
1
8
7
0
0
0
1
1
1
0
0
0
0
A-137
DEBUGEV
DEBUGEV
DEBUGEV
Signal a Debug Event (AGU)
Operation
Assembler Syntax
DEBUGEV
Description
DEBUGEV
Generates a debug event. It is an EOnCE dedicated instruction. If the EOnCE has not been enabled since
reset, issuing DEBUGEV has no effect. If the EOnCE is enabled, the effect of this instruction depends on
the programming of EOnCE control registers. Receipt of an EOnCE event can cause the core to enter the
debug mode, generate an exception, or enable the trace buffer. The delay from the DEBUGEV instruction
to entering debug mode or generating an exception is not precise; it could be a few execution sets. Events
can also be counted before an action takes place.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DEBUGEV
A-138
1
2
4
1
0
0
1
1
1
1
8
7
0
0
0
1
1
1
0
0
0
1
SC140 DSP Core Reference Manual
DECA
DECA
DECA
Decrement a Register (AGU)
Operation
Assembler Syntax
Rx – 1 → Rx
DECA Rx
Description
DECA Rx
Subtracts one from an AGU register (Rx). SP cannot be used as a destination of this instruction.
Note:
The assembler maps this instruction to SUBA #u5,Rx; where #u5 = 1.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
Status and Conditions Changed by Instruction
None.
Example
deca r0
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$074F 312A
$074F 3129
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
DECA Rx
1
2
1
8
1
1
7
0 R R R R 0
0
1
1
i
i
i
i
i
Instruction Fields
Rx
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-139
DECA
#u5
A-140
iiiii
5-bit unsigned immediate data = 1, set by the assembler
SC140 DSP Core Reference Manual
DECEQ
DECEQ
DECEQ
Decrement and Set T If Equal Zero (DALU)
Operation
Assembler Syntax
Dn – 1 → Dn; if Dn==0, then 1→ T, else 0 → T
DECEQ Dn
Description
DECEQ Dn
Decrements a data register (Dn) and sets the T bit if the result is equal to zero.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates and updates the carry bit in the status register.
SR[1]
T
Set if result = 0, cleared otherwise.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Clears the Ln bit in the destination register.
Example
deceq d7
Register/Memory Address
Before
L7:D7
After
$0:$00 0000 0001
$0:$00 0000 0000
$00E4 0000
$00E4 0002
SR
EMR
$0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DECEQ Dn
Note:
1
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
1
1
0
1
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-141
DECEQ
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-142
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
DECEQA
DECEQA
DECEQA
Decrement and Set T If Equal Zero
(AGU)
Operation
Assembler Syntax
Rx – 1 → Rx; if Rx==0, then 1 → T, else 0 → T
DECEQA Rx
Description
DECEQA Rx
Decrements an AGU register (Rx) and sets the T bit if the result is zero. SP cannot be used as an operand of
this instruction.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if result = 0, cleared otherwise.
Example
deceqa r0
Register/Memory Address
Before
After
R0
$0000 0001
$0000 0000
SR
$00E4 0000
$00E4 0002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
DECEQA Rx
1
2
1
8
1
1
7
0 R R R R 1
0
1
1
1
0
1
1
0
Instruction Fields
Rx
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note: This instruction can specify R8-R15 as operands by using a high register prefix. SP cannot be
used as an operand for this instruction.
SC140 DSP Core Reference Manual
A-143
DECGE
DECGE
DECGE
Decrement and Set T
If Greater Than or Equal to Zero (DALU)
Operation
Assembler Syntax
Dn – 1 → Dn; Dn≥0 → T
DECGE Dn
Description
DECGE Dn
Decrements a data register (Dn) and sets the T bit if the result is greater than or equal to zero. In the case of
an arithmetic overflow (DECGE on the value $80 0000 0000), the T bit will not be set.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates and updates the carry bit in the status register.
SR[1]
T
Set if result ≥ 0, cleared otherwise.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Clears the Ln bit in the destination register.
Example
decge
Instruction
SR
d3
move.w #$1,d3 ;$00E4 0000
$00 0000 0001
decge d3
;$00E4 0002 T-bit set
$00 0000 0000
decge d3
;$00E4 0001 T-bit cleared, carry bit set $FF FFFF FFFF
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DECGE Dn
Note:
A-144
1
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
1
1
0
0
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
DECGE
Instruction Fields
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-145
DECGEA
DECGEA
Decrement and Set T
If Greater Than or Equal to Zero (AGU)
Operation
Rx – 1 → Rx;
DECGEA
Assembler Syntax
Rx ≥ 0 → T
DECGEA Rx
Description
DECGEA Rx
Decrements an AGU register (Rx) and sets the T bit if the result is greater than or equal to zero. In case
there is an arithmetic overflow (DECGEA on the value of $80000000), the T bit will not be set by this
instruction. SP cannot be used as an operand of this instruction.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[1]
T
Set if result ≥ 0, cleared otherwise.
Example 1
decgea r4
Register/Memory Address
Before
After
R4
$0010 E438
$0010 E437
SR
$00E4 0000
$00E4 0002
Example 2
decgea r4
Register/Memory Address
Before
After
R4
$8000 0000
$7FFF FFFF
SR
$00E4 0002
$00E4 0000
A-146
SC140 DSP Core Reference Manual
DECGEA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
DECGEA Rx
1
2
1
8
1
1
7
0 R R R R 1
0
1
1
1
0
1
1
1
Instruction Fields
Rx
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note: This instruction can specify R8-R15 as operands by using a high register prefix. SP cannot be
used by this instruction.
SC140 DSP Core Reference Manual
A-147
DI
DI
DI
Disable Interrupts (AGU)
Operation
Assembler Syntax
1 → DI
DI
Description
DI
Sets the DI bit in the status register in order to disable interrupts. The effect is immediate, so the
instructions that execute in the same execution set as well as later execution sets are not interruptible by
maskable interrupts. Non-maskable interrupts and exceptions are not disabled by this bit.
The DI instruction and its counterpart, the EI instruction, can be used to delimit a code segment that needs
to be protected from interruption. For example, a non-interruptible read-modify-write sequence of
execution sets could be written like this:
DI read
modify
EI write
Where read, modify, and write stand for instruction(s). If using this instruction, no allowance is necessary
for a pipeline delay of updating SR by the DI instruction. This instruction can appear only once in an
execution set.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[19]
DI
Set disable interrupt bit.
Example 1
di
Register/Memory Address
Before
After
SR
$0000 0000
$0008 0000
EMR
$0000 0000
$0000 0000
Instruction Formats and Opcodes
Instruction
A-148
Words Cycles Type
Opcode
SC140 DSP Core Reference Manual
DI
15
DI
1
1
SC140 DSP Core Reference Manual
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
1
1
0
1
A-149
DIV
DIV
DIV
Divide Iteration (DALU)
Operation
Assembler Syntax
If Dn[39] ⊕ Da[39] = 1,
then 2 * Dn + C + (Da & $FF FFFF 0000) → Dn
else 2 * Dn + C – (Da & $FF FFFF 0000) → Dn
where ⊕ denotes the bitwise exclusive OR operator.
DIV Da,Dn
Description
DIV Da,Dn
This instruction is used iteratively to divide the destination operand Dn by the source operand Da and store
the result in the destination operand Dn. The 32-bit dividend must be a positive fraction which has been
sign-extended to 40-bits and stored in the full 40-bit Dn. The 16-bit divisor is a signed fraction and is stored
in Da.
Each DIV iteration calculates one quotient bit using a non-restoring fractional division algorithm (see
description below). After the execution of the first DIV instruction, Dn holds both the partial remainder
and the formed quotient. The partial remainder occupies the high portion of Dn and is a signed fraction.
The formed quotient occupies the low portion of Dn and is a positive fraction. One bit of the formed
quotient is shifted into bit 0 of Dn at the start of each DIV iteration. The formed quotient is the true quotient
if the true quotient is positive. If the true quotient is negative, the formed quotient must be negated. Valid
results are obtained only when |Dn| < |Da| and the operands are interpreted as fractions. This condition
ensures that the magnitude of the quotient is less than one (i.e., is fractional) and precludes division by
zero.
The DIV instruction calculates one quotient bit based on the divisor and the previous partial remainder. To
produce an N-bit quotient, the DIV instruction is executed N times, where N is the number of bits of
precision desired in the quotient, 1≤N≤16. Thus, for a full-precision (16 bit) quotient, 16 DIV iterations are
required. In general, executing the DIV instruction N times produces an N-bit quotient and a 32-bit
remainder that has (32–N) bits of precision and whose N most significant bits are zeros. The partial
remainder is not a true remainder and must be corrected (due to the non-restoring nature of the division
algorithm) before it can be used. Therefore, once the divide is complete, it is necessary to reverse the last
DIV operation, and restore the remainder to obtain the true remainder.
The DIV instruction uses a non-restoring fractional division algorithm that consists of the following
operations (see the previous Operation definition):
1. Compare the source and destination operand sign bits: An exclusive OR operation is
performed on bit 39 of Dn and bit 39 of Da.
2. Shift the partial remainder and the quotient: Dn is shifted one bit to the left. The carry
bit C is moved into bit 0 of Dn. The carry bit represents the quotient bit generated by the
previous DIV iteration.
A-150
SC140 DSP Core Reference Manual
DIV
3. Calculate the next quotient bit and the new partial remainder: The 16-bit signed divisor
in Da.H is either added to or subtracted from Dn.H, and the result is stored back into Dn.H.
If the result of the exclusive OR operation previously described was a “1” (i.e., the sign bits
were different), Da.H is added to Dn.H. If the result of the exclusive OR operation was a “0”
(i.e., the sign bits were the same), Da.H is subtracted from Dn.H. Because of the
sign-extension of the 16-bit signed divisor, the addition or subtraction operation correctly
sets the carry bit C of the condition code register with the next quotient bit.
For extended precision division (i.e., for N-bit quotients where N>16), the DIV instruction is no longer
applicable, and a user-defined N-bit division routine is required.
For further information on division algorithms, refer to pages 524–530 of Theory and Application of
Digital Signal Processing by Rabiner and Gold (Prentice-Hall, 1975), pages 190–199 of Computer
Architecture and Organization by John Hayes (McGraw-Hill, 1978), pages 213–223 of Computer
Arithmetic: Principles, Architecture, and Design by Kai Hwang (John Wiley and Sons, 1979), or other
references as required.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[0]
C
Carry bit is copied into Dn[0].
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the Ln
bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Bit is set if bit 39 of the result is cleared.
EMR[2]
DOVF
Set if the MS bit of the result cannot be represented in 40 bits, or is
changed as a result of the instruction’s left shift operation.
Ln
L
Calculates and updates the Ln bit in the destination register.
Example
div d2,d1
Register/Memory Address
Before
D2
L1:D1
SR
EMR
SC140 DSP Core Reference Manual
After
$00 2311 5A3B
$0:$00 6666 0A57
$0:$00 A9BB 14AE
$00E4 0000
$00E4 0001
$0000 0000
A-151
DIV
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
DIV Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
F F F
0
1
0
1
0
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Da
This instruction can specify D8-D15 as operands by using a prefix.
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-152
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
DMACSS
DMACSS
DMACSS
Multiply Signed By Signed and
Accumulate With Right Shifted Data Register (DALU)
Operation
Assembler Syntax
[Dn>>16] + Dc.H * Dd.H → Dn
(Dc signed, Dd signed)
DMACSS Dc,Dd,Dn
Description
DMACSS Dc,Dd,Dn
Shifts Dn 16 bits to the right with bit 39 sign-extended into bits [39:24]. Adds the result to the product of
signed fractions in Dc.H and Dd.H. Places the result into Dn.
Dc and Dd are a data register pair. The operands are in the HP of each register.
This instruction is optimized for multi-precision-multiplication support.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
dmacss d2,d3,d5
Register/Memory Address
Before
After
D2
$00 0002 0000
D3
$00 0003 0000
L5:D5
$0:$00 0050 0000
EMR
$0:$00 0000 005C
$0000 0000
$00 0002 0000
-14
2
x $00 0003 0000
2-14 + 2-15
$00 0000 000C
2-28 + 2-29
+ $00 0000 0050
$00 0000 005C
SC140 DSP Core Reference Manual
A-153
DMACSS
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DMACSS Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
1
1
7
F F F
0
1
1
1
0
1
e
e
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-154
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
DMACSU
DMACSU
DMACSU
Multiply Signed By Unsigned and
Accumulate With Right Shifted Data Register (DALU)
Operation
Assembler Syntax
[Dn>>16] + Dc.H * Dd.L → Dn
(Dc signed, Dd unsigned)
DMACSU Dc,Dd,Dn
Description
DMACSU Dc,Dd,Dn
Shifts Dn 16 bits to the right with bit 39 sign-extended into bits [39:24]. Adds the result to the product of a
signed fraction in Dc.H and an unsigned fraction in Dd.L. Places the result into Dn.
Dc and Dd are a data register pair. The operands are in the HP and LP of each register, respectively.
This instruction is optimized for multi-precision multiplication support.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
dmacsu d2,d3,d5
Register/Memory Address
Before
After
D2
$FF F002 0000
D3
$00 0000 00D1
L5:D5
$0:$00 0001 0000
$0:$FF FFE5 E345
EMR
$0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DMACSU Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
1
1
7
F F F
0
1
1
1
0
0
e
e
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-155
DMACSU
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-156
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
DOENn
DOENn
DO Enable Long Loop (AGU)
Operation
Assembler Syntax
#u6 → LCn; 1 → LFn
DOENn #u6 {0 ≤ u6 < 64}
#u16 → LCn; 1 → LFn
DOENn #u16 {0 ≤ u16 < 216}
DR → LCn; 1 → LFn
DOENn DR
DOENn
Description
This instruction initializes the selected loop as a long loop by loading the iteration count into the respective
loop counter and setting the respective loop flag in the SR. After this instruction is executed, the loop
becomes active. There can be other instructions between this instruction and the actual body of the loop. If
the loop is nested, the DOEN instruction must be placed inside the enclosing loop in order to re-activate
the inner loop each iteration. Various programming rules apply concerning the minimum distance between
this instruction and the loop body or other loop instructions.
DOENn #u6
Moves an unsigned 6-bit immediate value into the loop counter (LCn) and enables the chosen loop flag.
DOENn #u16
Moves an unsigned 16-bit immediate value into the loop counter (LCn) and enables the chosen loop flag.
DOENn DR
Moves the 32 lower bits of data or address register into the loop counter (LCn) and enables the chosen loop
flag.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Sets active loopflag.
Example
doen2 d0
Register/Memory Address
Before
D0
After
$00 0000 000F
LC2
SR
SC140 DSP Core Reference Manual
$0000 000F
$00E4 0000
$20E4 0000
A-157
DOENn
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DOENn #u6
1
1
4
DOENn #u16
2
1
4
1
0
1
0
0
n
n
0
8
7
0
0
1
0
0
0
n
n
1
0
0
i
i
i
i
i
8
7
0
0
1
1
0
n
n
0
15
1
1
4
7
0
15
DOENn DR
8
1
0
1
i
i
i
i
i
i
i
i
i
0
0
1
0
0
i
i
i
i
i
i
i
i
1
0
0 H H H H
0
0
Instruction Fields
n
Loop Identifier
00
DR
Loop 0
01
0000
D0
0100
D4
0001
D1
0101
0010
D2
D3
0011
Note:
#u6
#u16
A-158
Loop 2
11
Loop 3
1000
R0
1100
R4
D5
1001
R1
1101
R5
0110
D6
1010
R2
1110
R6
0111
D7
1011
R3
1111
R7
HHHH
Loop 1
10
Data/Address Register
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
iiiiii
6-bit unsigned immediate data
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
SC140 DSP Core Reference Manual
DOENSHn
DOENSHn
Do Enable Short Loop (AGU)
Operation
#u6 → LCn;
Assembler Syntax
1 → LFn;
#u16 → LCn;
DR → LCn;
DOENSHn
1 → SLF
1 → LFn;
1 → LFn;
DOENSHn #u6 {0 ≤ u6 < 64}
1 → SLF
DOENSHn #u16 {0 ≤ u16 < 216}
1 → SLF
DOENSHn DR
Description
This instruction initializes the selected loop as a short loop by loading the iteration count to the respective
loop counter and setting the SLF and respective loop flag in the SR. After this instruction is executed, the
loop becomes active. There can be a distance between this instruction and the actual body of the loop. In
case the loop is nested, the DOENSH instruction must be placed inside the enveloping loop in order to
re-activate the inner loop each iteration. Various programming rules apply concerning the minimum
distance between this instruction and the loop body or other loop instructions.
DOENSHn #u6
Moves an unsigned 6-bit immediate value into the loop counter (LCn) and enables the chosen loop flag and
short loop flag.
DOENSHn #u16
Moves an unsigned 16-bit immediate value into the loop counter (LCn) and enables the chosen loop flag
and short loop flag.
DOENSHn DR
Moves the 32 lower bits of a data or address register into the loop counter (LCn) and enables the chosen
loop flag and short loop flag.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Sets active loopflag.
SR[31]
SLF
Sets short loopflag.
Example
doensh2 d0
Register/Memory Address
Before
D0
LC2
SC140 DSP Core Reference Manual
After
$00 0000 000F
$0000 000F
A-159
DOENSHn
Register/Memory Address
Before
After
SR
$00E4 0000
$A0E4 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DOENSHn #u6
1
1
4
DOENSHn #u16
2
1
4
8
7
0
0
1
0
1
n
n
0
8
7
0
0
1
0
0
1
n
n
1
0
0
i
i
i
i
i
8
7
0
0
1
1
1
n
n
0
1
15
15
1
DOENSHn DR
1
4
1
0
1
i
i
i
i
i
i
i
i
i
0
0
1
0
0
i
i
i
i
i
i
i
i
1
0
0 H H H H
0
0
Instruction Fields
n
Loop Identifier
00
DR
#u16
A-160
01
HHHH
Loop 1
10
Loop 2
11
Loop 3
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u6
Loop 0
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
iiiiii
6-bit unsigned immediate data
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
SC140 DSP Core Reference Manual
DOSETUPn
DOSETUPn
DOSETUPn
Setup Long Loop
Start Address (AGU)
Operation
Assembler Syntax
PC + displacement → SAn
DOSETUPn label
Description
DOSETUPn label
This instruction is required for initialization of a long loop, not short loops. In case the loop is nested, the
DOSETUPn instruction can be placed outside the enveloping loop as long as SA (Start Address) is not
changed by instructions in the loop. DOSETUPn loads a loop start address register (SAn). The label is
placed at the beginning of the loop. The encoded value in the DOSETUP instruction is a PC relative
displacement calculated by the assembler and linker from the label. The start address placed in SAn is the
absolute address of the label. The DOSETUPn instruction is redundant with the LOOPSTART assembler
directive, both of which define SA. In case of a conflict between the two, SA is defined by DOSETUPn.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
dosetup1 _label
Register/Memory Address
Before
(displacement)
PC
SA1
SC140 DSP Core Reference Manual
After
$101E
$0000 0002
$0000 1020
A-161
DOSETUPn
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
DOSETUPn label
2
1
4
8
0
1
0
n
7
0
0
0
1
n A A A 0
0
0
1
1
1
0
0 A A A A A A A A A A A A a
Instruction Fields
n
Loop Identifier
00
displacement
A-162
Loop 0
01
aAAAAAAAAAAAAAAA0
Loop 1
10
Loop 2
11
Loop 3
16-bit signed PC relative displacement.
The encoding is the displacement with
bit 0 stripped and replaced by the
sign bit.
SC140 DSP Core Reference Manual
EI
E-J
EI
EI
Enable Interrupts (AGU)
Operation
Assembler Syntax
0 → DI
EI
Description
EI
Clears the DI bit in the status register to enable interrupts. The EI instruction and its counterpart, the DI
instruction, can be used to delimit a non-interruptible code sequence. For example, a non-interruptible
read-modify-write sequence of execution sets can be written like this:
DI read
modify
EI write
Where read, modify, and write represent instruction(s). This instruction can appear only once in an
execution set. The effect of EI may not be immediate. That is, a pending interrupt may not be serviced as
the first execution set immediately after this instruction because of pipeline effects.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[19]
DI
Clears disable interrupt bit.
Example
ei
Register/Memory Address
Before
After
SR
$EC0000
$E40000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
EI
1
1
SC140 DSP Core Reference Manual
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
1
1
0
0
A-163
EI
A-164
SC140 DSP Core Reference Manual
EOR
EOR
Bitwise Exclusive OR (DALU)
Operation
Assembler Syntax
Da ⊕ Dn → Dn
EOR Da,Dn
EOR
Description
EOR Da,Dn
Performs a bitwise exclusive OR between two data registers (Da and Dn) and stores the result in a
destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
eor d4,d5
Register/Memory Address
Before
D4
After
$FF FFFF FFFB
L5:D5
$0:$00 0000 0003
B
1011
⊕3
0011
8
1000
SC140 DSP Core Reference Manual
$0:$FF FFFF FFF8
A-165
EOR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
EOR Da,Dn
1
2
1
8
1
0
1
1
1
7
F F F
0
0
0
1
0
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
001
Note:
Dn
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-166
D0
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
EOR
EOR
Bitwise Exclusive OR on a 16-Bit Operand (BMU)
Operation
Assembler Syntax
#u16 ⊕ DR.L → DR.L
EOR #u16,DR.L {0 ≤ u16 < 216}
#u16 ⊕ DR.H → DR.H
EOR #u16,DR.H {0 ≤ u16 < 216}
EOR
Description
EOR #u16,DR.L
Performs a bitwise exclusive OR between a 16-bit unsigned immediate value and the LP of an address
register or data register (DR). Stores the result in the destination register (DR). This instruction is
assembler-mapped to BMCHG #u16,DR.L with the immediate value. The HP of the register is unaffected.
EOR #u16,DR.H
Performs a bitwise exclusive OR between a 16-bit unsigned immediate value and the HP of an address
register or data register (DR). Stores the result in the destination register (DR). This instruction
assembler-mapped to BMCHG #u16,DR.H with the immediate value. The LP of the register is unaffected.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
eor #$5,d5.l
Register/Memory Address
Before
After
immediate
d5
$0005
$0000 0003
5
0101
⊕3
0011
6
0110
SC140 DSP Core Reference Manual
$0000 0006
A-167
EOR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
EOR #u16,DR.L
2
2
3
2
2
3
7
0
0
0
0
0
1
0
1
0
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
EOR #u16,DR.H
8
i
i
i
i
0
0
0
0
0
1
0
1
0
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
DR
HHHH
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u16
A-168
Data/Address Register
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
SC140 DSP Core Reference Manual
EOR.W
EOR.W
Bitwise Exclusive OR on
a 16-Bit Operand in Memory (BMU)
EOR.W
Operation
Assembler Syntax
#u16 ⊕ (R) → (R)
EOR.W #u16,(Rn){0 ≤ u16 < 216}
#u16 ⊕ (SP–u5) → (SP–u5)
EOR.W #u16,(SP-u5){0 ≤ u16 < 216}{0 ≤ u5 < 64,W}
#u16 ⊕ (SP + s16) → (SP + s16)EOR.W #u16,(SP+s16){0 ≤ u16 < 216}{-215 ≤ s16 < 215,W}
#u16 ⊕ (a16) → (a16)
EOR.W #u16,(a16){0 ≤ u16 < 216}{0 ≤ a16 < 216,W}
Description
These operations read from memory, modify the retrieved value, and write the new value back to the same
memory address, resulting in two memory accesses. The absolute addresses, offsets, and address register
values must be word-aligned.
EOR.W #u16,(Rn)
Performs a bitwise exclusive OR between an immediate unsigned word and the contents of a memory
address, pointed to by the contents of an address register (Rn). Stores the result in the same memory
address. This instruction is assembler-mapped to BMCHG.W #u16,(Rn) with the immediate value.
EOR.W #u16,(SP–u5)
Performs a bitwise exclusive OR between an immediate unsigned word and the contents of a memory
address. Stores the result in the same memory address. The memory address is calculated as the active
stack pointer (SP) minus a 5-bit unsigned offset value. This instruction is assembler-mapped to
BMCHG.W #u16,(SP–u5) with the immediate value.
EOR.W #u16,(SP+s16)
Performs a bitwise exclusive OR between an immediate unsigned word and the contents of a memory
address. Stores the result in the same memory address. The memory address is calculated as the active
stack pointer (SP) plus a 16-bit signed offset value. This instruction is assembler-mapped to
BMCHG.W #u16,(SP+s16) with the immediate value.
EOR.W #u16,(a16)
Performs a bitwise exclusive OR between an immediate unsigned word and the contents of an absolute
memory address. Stores the result in the same memory address. This instruction is assembler-mapped to
BMCHG.W #u16,(a16) with the immediate value.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
SC140 DSP Core Reference Manual
A-169
EOR.W
Example
eor.w #$aaaa,(r0)
Register/Memory Address
Before
After
immediate
$AAAA
(r0)
$0000 5555
$0000 FFFF
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
EOR.W #u16,(Rn)
2
3
2
3
3
3
3
3
0
0
1
0
0
1
0
i
i
i
0
1 R R R
0
1
i
i
i
i
i
i
i
i
i
i
8
7
2
3
i
i
i
0
0
0
0
0
0
0
1
0
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
1
1
0
1
i
i
i
i
0
0
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
i
i
i
i
i
i
i
i
i
i
i
i
8
7
0
0
1
1
1
0
1
0 A A A
i
i
0
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
15
3
EOR.W #u16,(a16)
0
1
15
EOR.W #u16,(SP+s16)
7
0
15
EOR.W #u16,(SP–u5)
8
i
i
i
i
0 A A A
i
i
i
i
i
0
1
1
0
i
i
i
i
i
i
i
Instruction Fields
Rn
RRR
000
001
Note:
a16
#u16
u5
s16
A-170
Address Register
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAA0
5-bit unsigned SP address offset
AAAAAAAAAAAAAAAA
16-bit signed SP address offset
SC140 DSP Core Reference Manual
EXTRACT
EXTRACT
Extract Signed Bit Field (DALU)
Operation
EXTRACT
Assembler Syntax
Db[(offset + width – 1):offset] → Dn[(width – 1):0]
Db[offset + width – 1] → Dn[39:width] (sign-extension)
width = #U6; offset = #u6
EXTRACT #U6,#u6,Db,Dn
{0 ≤ U6 ≤ 40}{0 ≤ u6 ≤ 40}
{#U6+#u6 ≤ 40}
width = Da[13:8]; offset = Da[5:0]
EXTRACT Da,Db,Dn
{0 ≤ Da[13:8] ≤ 40}
{0 ≤ Da[5:0] ≤ 40}
{Da[13:8]+Da[5:0] ≤ 40}
Description
These operations extract a bit field from a source data register (Db) and place it in a destination data
register (Dn), right-aligned and sign-extended from the MSB of the extracted bit field. The extracted field
is a signed integer. If the offset is zero, this instruction can be used to sign-extend an arbitrary width signed
integer.
EXTRACT #U6,#u6,Db,Dn
Uses two immediate unsigned 6-bit integers for the width (#U6) and offset (#u6).
EXTRACT Da,Db,Dn
Uses a supplemental data register (Da) for the width (bits 13–8) and the offset (bits 5–0).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
extract #$c,#$e,d2,d4
Register/Memory Address
Before
After
immediate (width)
$C
immediate (offset)
$E
D2
L4:D4
SC140 DSP Core Reference Manual
$FF 8665 4321
$0:$00 0000 0000
$0:$FF FFFF F995
A-171
EXTRACT
3
9
D2
3
2
1
6
0
1111111110000110011001010100001100100001
WIDTH = 12
D4
OFFSET = 14
1111111111111111111111111111100110010101
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
EXTRACT #U6,#u6,Db,Dn
2
1
4
2
1
4
7
0
0
0
1
1
j
j
j
0
1
1
0
0
1
F F F
1
0
0
1
I
I
I
I
I
I
i
i
i
i
8
7
15
EXTRACT Da,Db,Dn
8
i
i
0
0
0
1
1
j
j
j
0
1
0
0
0
1
F F F
1
0
0
1
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Db
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
jjj
Single Source/Destination Data Register
000
001
Note:
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
#u16
iiiiii
Unsigned 6-bit integer
#U16
IIIIII
Unsigned 6-bit integer
A-172
SC140 DSP Core Reference Manual
EXTRACTU
EXTRACTU
Extract Unsigned Bit Field
(DALU)
Operation
EXTRACTU
Assembler Syntax
Db[(offset + width – 1):offset] → Dn[(width – 1):0]
0 → Dn[39:width]
width = #U6; offset = #u6
EXTRACTU #U6,#u6,Db,Dn
{0 ≤ U6 ≤ 40}
{0 ≤ u6 ≤ 40}
{#U6+#u6 ≤ 40}
width = Da[13:8]; offset = Da[5:0]
EXTRACTU Da,Db,Dn
{0 ≤ Da[13:8] ≤ 40}
{0 ≤ Da[5:0] ≤ 40}
{Da[13:8]+Da[5:0] ≤ 40}
Description
These operations extract a bit field from a source data register (Db) and place it in a destination data
register (Dn), right-aligned and zero-extended. The extracted field is an unsigned integer. If the offset is
zero, this instruction can be used to zero-extend an arbitrary width unsigned integer.
EXTRACTU #U6,#u6,Db,Dn
Uses two immediate unsigned 6-bit integers for the width (#U6) and offset (#u6).
EXTRACTU Da,Db,Dn
Uses a supplemental data register (Da) for the width (bits 13:8) and the offset (5:0).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
extractu #$c,#$e,d2,d4
Register/Memory Address
Before
After
immediate (width)
$C
immediate (offset)
$E
D2
L4:D4
SC140 DSP Core Reference Manual
$FF 8665 4321
$0:$00 0000 0000
$0:$00 0000 0995
A-173
EXTRACTU
3
9
D6
3
2
1
6
0
1111111110000110011001010100001100100001
WIDTH = 12
D7
OFFSET = 14
0000000000000000000000000000100110010101
Instruction Formats and Opcodes
Instruction
Words
Cycles Type
Opcode
15
2
EXTRACTU #U6,#u6,Da,Dn
1
4
2
1
4
7
0
0
0
1
1
j
j
j
0
1
1
0
0
1
F F F
1
0
0
0
I
I
I
I
I
I
i
i
i
i
8
7
15
EXTRACTU Da,Db,Dn
8
i
i
0
0
0
1
1
j
j
j
0
1
0
0
0
1
F F F
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Db
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
#u16
iiiiii
unsigned 6-bit integer
#U16
IIIIII
unsigned 6-bit integer
A-174
SC140 DSP Core Reference Manual
IADDNC.W
IADDNC.W
IADDNC.W
Integer Addition
Without Changing the Carry Bit
Not Affected by Saturation (DALU)
Description
IADDNC.W #s16,Dn
Sign-extends the 16-bit immediate value to 40 bits and adds it to the destination data register Dn. The
result is not affected by the arithmetic saturation mode. The carry bit is not affected by this instruction.
This instruction is an integer (non-saturating) version of ADDNC.W.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Clears the L bit in the destination register.
Example
iaddnc.w #$a002,d2
Register/Memory Address
Before
L2:D2
After
$1:$FFFFFFCA3E
$0:$FFFFFF6A40
EMR
$00000000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IADDNC.W #s16,Dn
2
1
4
8
7
0
0
1
1
1
0
1
0
i
i
i
1
0
F F F
0
1
0
0
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#s16
Single Source/Destination Data Register
If registers D8–D15 are accessed instead of D0–D7, a prefix is used.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit signed immediate data
A-175
IFc
IFc
Conditionally Execute a Group or Subgroup (PREFIX)
Operation
IFc
Assembler Syntax
If T == 0,
then execute group/subgroup
else treat as NOP
IFF group or subgroup of instructions
If T == 1,
then execute group/subgroup
else treat as NOP
IFT group or subgroup of instructions
execute group/subgroup unconditionally
IFA group or subgroup of instructions
Description
These instructions add conditional control over a group or subgroup of instructions in a VLES.
IFF
Execute the group or subgroup if T is equal to zero (condition is false). If T is equal to one (condition is
true), the group or subgroup is treated as a NOP. This instruction can be used in conjunction with IFT to
form an if/else clause.
IFT
Execute the group or subgroup if T is equal to one (condition is true). If T is equal to zero (condition is
false), the group or subgroup is treated as a NOP. This instruction can be used in conjunction with IFF to
form an if/else clause.
IFA
Always execute the group or subgroup. This instruction may be used in conjunction with IFT or IFF to split
a VLES group into conditional and unconditional subgroups, where IFA must be the last subgroup in the
VLES.
The following combinations of these instructions can be used:
IFT
group
; execute group if T is set
IFF
group
; execute group if T is clear
IFA
group
; execute group unconditionally
IFT
subgroup1
IFA
subgroup2
; execute subgroup1 if T is set,
; execute subgroup2 unconditionally
IFF
subgroup1
IFA
subgroup2
; execute subgroup1 if T is clear,
; execute subgroup2 unconditionally
IFT
subgroup1
IFF
subgroup2
; execute subgroup1 if T is set,
; execute subgroup2 if T is clear
Notes: 1. The instructions in the subgroups can be conditional (e.g., TFRT, JF), which adds finer
control.
2. The “IFA group” is the same as not using IFc. That is, unconditional execution of the VLES.
3. The detailed use of IFc is defined by Section 7.2, “VLES Grouping Semantics,” and
programming rule G.P.7 in Section 7.5.3, “Prefix Grouping Rules.”
A-176
SC140 DSP Core Reference Manual
IFc
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
ift move.w #>$ffff,d0
Register/Memory Address
Before
SR
After
$00E4 0002
immediate
$00E4 0002
$FFFF
L0:D0
$0:$FF FFFF FFFF
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IFc
1
1
4
1
0
0
1
a
a
a
15
IFc
Note:
2
1
4
a
a
a
8
7
0
1
8
7
0
0
1
1
0 H
1
0
1
b B e E T
0
1
0
p
j
c
c
c
0
t
h
p
j
c
c
c
b B e E b B e E
These instructions are encoded into either a one-word or two-word prefix.
Instruction Fields
ccc:
Conditional execution of the entire execution set
In the following table, true/false relates to the state of the T bit in SR: D0, D1, D2, and D3 are DALU
instructions. A0 and A1 are AGU instructions. The numbers relate to the relative offset of the instruction
from the beginning of the set, as encoded. For example, a full execution set might be D0, D1, D2, D3, A0,
A1.
000—Unconditionally executed
001—If true (D0,D2,A0), if false (D1,D3,A1)
010—If true, all the set
011—If false, all the set
100—Reserved
101—Reserved
110—If true (D0,D2,A0), always (D1,D3,A1)
111—If false (D0,D2,A0), always (D1,D3,A1)
SC140 DSP Core Reference Manual
A-177
ILLEGAL
ILLEGAL
Generate an Illegal Exception
Request (AGU)
ILLEGAL
Operation
Assembler Syntax
upon service: PC → (ESP); SR → (ESP + 4);
SP + 8 → SP; VBA[31:12]: illegal_vector → PC;
1 → EXP
111→ I[2:0]
1 → ILIN
0→C
0→T
00 → S[1:0]
0 → SLF
0000 → LF[3:0]
ILLEGAL {illegal vector = $080}
Description
ILLEGAL
Generates an imprecise non-maskable illegal exception request. The exact place in the execution
flow that the request is serviced depends on the machine state. Imprecise means that the exception
timing is not guaranteed, being asynchronous with the instruction execution. Users should not rely
on any timing between the ILLEGAL instruction execution and the start of exception processing.
In the most common case, the exception vector is executed after four more execution sets are
executed following the illegal instruction. In other cases, it can be the set immediately after or
delayed by another execution set. Thus, it should be realized that in the exception routine, the
machine state cannot be reconstructed to the exact state before or after the ILLEGAL instruction
is executed. It is possible, however, to know at which PC the request was raised by reading the
PC_EXCP register in the EOnCE (see the EOnCE section for a description of this register).
The AGU sets the EXP bit in SR to switch the active stack pointer to the exception stack pointer. .
A-178
SC140 DSP Core Reference Manual
ILLEGAL
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Sets EXP to switch active stack pointer to exception stack pointer.
SR[23:21]
I[2:0]
Set interrupt priority level to 111.
EMR[0]
ILIN
Sets illegal instruction bit.
SR[0]
C
Cleared
SR[1]
T
Cleared
SR[5:4]
S[1:0]
Cleared
SR[31]
SLF
Cleared
SR[30:27]
LF[3:0]
Clear loop flags.
Example
illegal
Register/Memory Address
Before
After
SR
$18E0 0003
$00E4 0000
EMR
$0000 0000
$0000 0001
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
ILLEGAL
1
4
5
1
0
0
1
1
1
1
8
7
0
0
0
1
1
1
1
1
0
0
Note 1: Cycle count is dependant on the machine state. Typically, five cycles is the service time for an illegal
request.
SC140 DSP Core Reference Manual
A-179
IMAC
IMAC
Integer Multiply-Accumulate (DALU)
Operation
Assembler Syntax
Dn ± (Da.L * Db.L) → Dn
IMAC ±Da,Db,Dn
IMAC
Description
IMAC ±Da,Db,Dn
Performs signed integer-multiplication on the LP contents of two source data registers (Da and Db) and
adds or subtracts the product to or from a destination data register (Dn). The default operation is the
addition of the product to the destination register.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Example 1
imac d4,d5,d6
Register/Memory Address
Before
After
D4
$FF FFFF FFFB
D5
$00 0000 0003
L6:D6
EMR
A-180
$0:$00 0000 0008
$0:$FF FFFF FFF9
$0000 0000
$0000 0000
SC140 DSP Core Reference Manual
IMAC
–5
x 3
–15
+8
–7
$FFFB
$0003
$000F
$0008
$FFF9
Example 2
imac -d4,d5,d6
Register/Memory Address
Before
After
D4
$00 1022 002A
D5
$FF FF3A 000B
L6:D6
$0:$00 0000 1000
$0:$00 0000 0E32
$0000 0000
$0000 0000
EMR
–42
x 11
–462
+4096
3,634
$002A
$000B
$FE32
$1000
$0E32
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMAC ±Da,Db,Dn
1
1
1
IMAC ±Da,Da,Dn
1
1
1
0
8
*
1
0
1
0
F F F
*
1
0
1
0
F F F
15
Note:
0
7
8
0
k
0
J
J
J
J
1
1
0
k
1
j
7
J
0
j
** indicates serial grouping encoding.
Instruction Fields
k
Accumulation Notation
0
add
SC140 DSP Core Reference Manual
1
subtract
A-181
IMAC
Da,Db
JJJJJ
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
2.
3.
Da,Da
jj
Data Register Pairs
00
Note:
Dn
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-182
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be inverted for clarity because the order of operation is not important
for multiply operations.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, and D7–D7. These
are covered in the jj encoding.
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
IMACLHUU
IMACLHUU
IMACLHUU
Integer Multiply-Accumulate
Lower Unsigned By Upper Unsigned (DALU)
Operation
Assembler Syntax
Dn + (Da.L * Db.H) → Dn
IMACLHUU Da,Db,Dn
Description
IMACLHUU Da,Db,Dn
Performs an unsigned integer multiplication of the 16-bit LP of one source data register (Da) with the
16-bit HP of another source data register (Db). It then adds the zero-extended 32-bit product to a
destination data register (Dn). This instruction is optimized for multi-precision-multiplication support.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Example
imaclhuu d3,d4,d0
Register/Memory Address
Before
After
D3
$00 0000 0002
D4
$FF FFC0 0000
L0:D0
$0:$00 0000 0001
EMR
$0:$00 0001 FF81
$0000 0000
–65,472$FFC0
x 2
$0002
–130,944$FF80
+1
$0001
-130,943$FF81
SC140 DSP Core Reference Manual
A-183
IMACLHUU
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMACLHUU Da,Db,Dn
2
1
4
8
7
0
0
0
1
1
1
0
0
0
j
j
j
0
0
F F F
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Db
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-184
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
IMACUS
IMACUS
Integer Multiply Accumulate
Unsigned By Signed (DALU)
Operation
Assembler Syntax
Dn + (Da.L * Db.H) → Dn
IMACUS Da,Db,Dn
IMACUS
Description
IMACUS Da,Db,Dn
Performs a signed integer multiplication of the unsigned 16-bit LP of one source data register (Da) with the
signed 16-bit HP of another source data register (Db). It then adds the sign-extended 32-bit product to a
destination data register (Dn). This instruction is optimized for multi-precision-multiplication support.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Example
imacus d3,d4,d0
Register/Memory Address
Before
After
D3
$00 7CE8 0002
D4
$FF FFC0 F0D0
L0:D0
EMR
SC140 DSP Core Reference Manual
$0:$00 0000 0000
$0:$FF FFFF FF80
$0000 0000
A-185
IMACUS
2
x –64
–128
+0
-128
$0002
$FFC0
$FF80
$0000
$FF80
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMACUS Da,Db,Dn
2
1
4
8
7
0
0
1
1
0
0
0
0
j
j
j
0
0
F F F
0
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
jjj
Single Source/Destination Data Register
000
001
Note:
Db
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
Single Source Data Register
001
Note:
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-186
010
JJJ
000
Dn
D0
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
IMPY
IMPY
IMPY
Integer Multiply (DALU)
Operation
Assembler Syntax
Da.L * Db.L → Dn
IMPY Da,Db,Dn
Description
IMPY Da,Db,Dn
Performs a signed integer multiplication on the low portions of two signed source data registers (Da, Db)
and stores the product in a destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
impy d3,d4,d0
Register/Memory Address
Before
After
D3
$FF FFFF 0202
D4
$00 0000 FFFE
L0:D0
$0:$FF FFFF FBFC
514
$0202
x –2 $FFFE
–1028 $FBFC
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMPY Da,Da,Dn
1
1
1
IMPY Da,Db,Dn
1
1
1
0
8
*
1
0
1
0
F F F
*
1
0
1
0
F F F
15
Note:
0
7
8
0
1
1
1
0
1
j
j
0
1
J
J
J
J
J
7
0
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-187
IMPY
Instruction Fields
Da,Da
jj
Data Register Pairs
00
Note:
Da,Db
D1,D1
10
D5,D5
11
D7,D7
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
00111
1.
2.
3.
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be inverted for clarity because the order of operation is not important
for multiply operations.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, D7–D7. These are
covered in the jj encoding.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-188
D3,D3
This instruction can specify D8-D15 as operands by using a prefix.
JJJJJ
Notes:
Dn
01
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
IMPY.W
IMPY.W Signed Immediate Integer Multiply (DALU) IMPY.W
Operation
Assembler Syntax
#s16 * Dn.L → Dn
IMPY.W #s16,Dn {–215 ≤ s16 < 215}
Description
IMPY.W #s16,Dn
Performs a signed integer multiplication on the low portion of a source data register (Dn) and an immediate
signed 16-bit word. It then stores the result in a destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
impy.w #$fffe,d3
Register/Memory Address
Before
immediate
d3
SC140 DSP Core Reference Manual
After
$FFFE
$00 7FFF FFF8
$00 0000 0010
A-189
IMPY.W
–8
x –2
+16
$FFF8
$FFFE
$0010
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMPY.W #s16,Dn
2
1
4
8
7
0
0
0
1
1
1
1
1
0
i
i
i
1
0
F F F
1
0
0
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#s16
A-190
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
iiiiiiiiiiiiiiii
16-bit signed immediate data
SC140 DSP Core Reference Manual
IMPYHLUU
IMPYHLUU
Integer Multiply Upper
Unsigned By Lower Unsigned
(DALU)
IMPYHLUU
Operation
Assembler Syntax
Da.H * Db.L → Dn
IMPYHLUU Da,Db,Dn
Description
IMPYHLUU Da,Db,Dn
Performs an unsigned integer multiplication on the 16-bit HP of one source data register (Da) and the
16-bit LP of another source data register (Db). It then stores the zero-extended 32-bit result in a destination
data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example 1
impyhluu d4,d3,d0
Register/Memory Address
Before
After
D3
$00 0002 FFFF
D4
$FF FFFF FFFE
L0:D0
$0:$00 FFFE 0001
Example 2
impyhluu d4,d3,d0
Register/Memory Address
Before
After
D3
$00 0000 FFFF
D4
$FF FFFF FFFE
L0:D0
SC140 DSP Core Reference Manual
$0:$00 FFFE 0001
A-191
IMPYHLUU
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMPYHLUU Da,Db,Dn
2
1
4
8
7
0
0
0
1
1
1
0
1
0
j
j
j
0
0
F F F
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Db
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-192
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
IMPYSU
IMPYSU
Integer Multiply
Signed By Unsigned (DALU)
Operation
Assembler Syntax
Da.H * Db.L → Dn
IMPYSU Da,Db,Dn
IMPYSU
Description
IMPYSU Da,Db,Dn
Performs a signed integer multiplication on the signed 16-bit HP of one source data register (Da) and the
unsigned 16-bit LP of a second source data register (Db). It then stores the sign-extended 32-bit result in a
destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register
Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
impysu d3,d5,d1
Register/Memory Address
Before
After
D5
$00 0000 0122
D3
$FF FFFF FFFF
L1:D1
SC140 DSP Core Reference Manual
$0:$FF FFFF FEDE
A-193
IMPYSU
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMPYSU Da,Db,Dn
2
1
4
8
7
0
0
0
1
1
0
1
0
0
j
j
j
0
0
F F F
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Db
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-194
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
IMPYUU
IMPYUU
IMPYUU
Integer Multiply
Unsigned By Unsigned (DALU)
Operation
Assembler Syntax
Da.L * Db.L → Dn
IMPYUU Da,Db,Dn
Description
IMPYUU Da,Db,Dn
Performs an unsigned integer multiplication on the 16-bit LP (Da) of one data register and the16-bit LP of
another data register (Db). It then stores the zero-extended 32-bit result in a data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
impyuu d5,d3,d1
Register/Memory Address
Before
After
D5
$00 0000 0002
D3
$FF FFFF FFFC
L1:D1
$0:$00 0001 FFF8
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
IMPYUU Da,Db,Dn
2
1
4
8
7
0
0
0
1
1
0
1
1
0
j
j
j
0
0
F F F
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
jjj
Single Source/Destination Data Register
000
001
Note:
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-195
IMPYUU
Db
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-196
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
INC
INC
Increment a Data Register By One (DALU)
Operation
Assembler Syntax
Dn + 1 → Dn
INC Dn
INC
Description
INC Dn
Adds one to a data register (Dn).
Note:
The assembler maps this instruction to ADD #u5,Dn, where #u5 = 1.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates and updates the carry bit in the status register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Example 1
inc d0
Register/Memory Address
Before
L0:D0
SR
EMR
SC140 DSP Core Reference Manual
After
$0:$FF FFFF FFFF
$0:$00 0000 0000
$00E4 0000
$00E4 0001
$0000 0000
A-197
INC
Example 2
inc d15
Register/Memory Address
Before
SR
L15:D15
After
$00E0 0004
$00E0 0004
$0:$00 7FFF FFFF
$0:$00 7FFF FFFF
EMR
$0000 0004
Arithmetic saturation mode set, SR[2], 32-bit overflow indicated in
EMR[2].
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
INC Dn
Note:
1
1
0
8
*
1
1
1
0
7
F F F
0
1
0
0
0
0
0
1
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-198
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
INC.F
INC.F
Increment HP of a Data Register by One (DALU)
Operation
Assembler Syntax
Dn + $00:00010000 → Dn
INC.F Dn
INC.F
Description
INC.F Dn
Adds one to the HP of a data register (Dn). Can be used to increment a 16-bit fraction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates and updates the carry bit in the status register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Example
inc.f d15
Register/Memory Address
Before
L0:D15
SR
EMR
SC140 DSP Core Reference Manual
After
$0:$FF FFFF FFFF
$0:$00 0000 FFFF
$00E4 0000
$00E4 0001
$0000 0000
A-199
INC.F
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
INC.F Dn
Note:
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
0
1
1
1
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-200
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
INCA
INCA
Increment Register (AGU)
Operation
Assembler Syntax
Rx + 1 → Rx
INCA Rx
INCA
Description
INCA Rx
Adds one to an AGU register (Rx). The stack pointer (SP) cannot be used as an operand by this instruction.
Note:
The assembler maps this instruction to ADDA #u5,Rx, where #u5 = 1.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
Status and Conditions Changed by Instruction
None.
Example 1
inca r0
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$074F 312A
$074F 312B
Example 2
inca r0
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$FFFF FFFF
SC140 DSP Core Reference Manual
$0000 0000
A-201
INCA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
INCA Rx
1
2
1
8
1
1
7
0 R R R R 0
0
1
0
i
i
i
i
i
Instruction Fields
Rx
RRRR
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
#u5
A-202
AGU Source/Destination Register
This instruction can specify R8-R15 as operands by using a high register prefix.
iiiii
5-bit unsigned immediate data = 1, set by the assembler
SC140 DSP Core Reference Manual
INSERT
INSERT
INSERT
Insert Bit Field (DALU)
Operation
Assembler Syntax
Db[(width – 1):0] → Dn[(offset + width – 1):offset]
width = #U6; offset = #u6
INSERT #U6,#u6,Db,Dn {0 ≤ U6 ≤ 40}
{0 ≤ u6 ≤ 40}[#U6 + #u6 ≤ 40]
width = Da[13:8]; offset = Da[5:0]
INSERT Da,Db,Dn {0 ≤ Da[5:0] ≤ 40}
{0 ≤ Da[13:8] ≤ 16}{Da[13:8] + Da[5:0]
≤ 40}
Description
These operations insert a bit field from a source data register (Db) into the destination data register (Dn).
The bits outside of the inserted field in the destination register are unchanged. In addition, the source
register is unchanged.
INSERT #U6,#u6,Db,Dn
Uses two immediate unsigned 6-bit integers for the width (#U6) and offset (#u6).
INSERT Da,Db,Dn
Uses a supplemental data register Da for the width (bits 13:8) and the offset (bits 5:0).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
insert #12,#22,d6,d7
Register/Memory Address
Before
D6
After
$FF AF6C 3465
L7:D7
$0:$00 0000 000F
3
9
D6
3
2
$0:$01 1940 000F
1
6
0
1111111110101111011011000011010001100101
WIDTH = 12
OFFSET = 22
D7
0000000100011001010000000000000000001 111
SC140 DSP Core Reference Manual
A-203
INSERT
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
INSERT #U6,#u6,Db,Dn
2
1
4
2
1
4
7
0
0
0
1
1
j
j
j
0
1
1
1
0
1
F F F
1
0
0
0
I
I
I
I
I
I
i
i
i
i
8
7
15
INSERT Da,Db,Dn
8
i
i
0
0
0
1
1
j
j
j
0
1
0
1
0
1
F F F
1
0
0
0
0
0
0
0
0
0
0
0
0
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
001
D1
011
D3
101
D5
Note: This instruction can specify D8-D15 as operands by using a prefix.
Db
jjj
FFF
110
111
D6
D7
110
111
D6
D7
Single Source/Destination Data Register
000
D0
010
D2
100
D4
001
D1
011
D3
101
D5
Note: This instruction can specify D8-D15 as operands by using a prefix.
#u6
iiiiii
unsigned 6-bit integer
#U6
IIIIII
unsigned 6-bit integer
A-204
D6
D7
Single Source/Destination Data Register
000
D0
010
D2
100
D4
001
D1
011
D3
101
D5
Note: This instruction can specify D8-D15 as operands by using a prefix.
Dn
110
111
SC140 DSP Core Reference Manual
JF
JF
Jump If False (AGU)
Operation
Assembler Syntax
If T==0, then label → PC
JF label {0 ≤ label < 232,W}
If T==0, then Rn → PC
JF Rn
JF
Description
If the T bit is cleared, program execution continues at a specified 32-bit memory destination address. If the
T bit is set, the PC is updated to point to the next execution set. Program execution continues sequentially.
The destination address cannot be in the middle of an execution set.
JF label
Jumps to the absolute memory address specified by a label. The assembler and linker calculate an absolute
address from the label.
JF Rn
Jumps to the memory address specified in an address register (Rn). The value of Rn must be word-aligned.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
JF lbl
Instruction
Result
cmpeq.w #$35,d1
Not equal, so T bit in SR cleared.
jf lbl move.w #$29,d1
Jump to lbl, move.w executed.
inc d1
Skipped over.
move.w #$47,d2
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
lbl move.w #$1A,d4
Register/Memory Address
Execution continues here at lbl.
Before
SR
SC140 DSP Core Reference Manual
After
$00E0 0000
A-205
JF
Register/Memory Address
Before
After
d1
$00 0000 0000
$00 0000 0029
d2
$00 0000 0000
$00 0000 0000
d4
$00 0000 0000
$00 0000 001A
pc
$0000 0006
$0000 0016
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
3
JF label
1/4
3
0
8
0
1
1
0
1
1
1
1/4
4
0
1 A A A a
a
1
0
0
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
15
JF Rn
7
1
0
0
1
a
a
8
7
1 R R R 0
a
a
a
a
a
a
a
0
1
1
0
0
1
1
1
Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles.
Instruction Fields
Rn
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
label
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
Note:
A-206
This instruction can specify R8-R15 as operands by using a high register prefix.
32-bit absolute long address
Label must be word-aligned, LSBit = 0.
SC140 DSP Core Reference Manual
JFD
JFD
Jump If False Using a Delay Slot (AGU)
Operation
Assembler Syntax
If T==0, then label → PC
JFD label [0 ≤ label < 232,W]
If T==0, then Rn → PC
JFD Rn
JFD
Description
If the T bit is cleared, program execution continues at a specified 32-bit memory destination address after
executing the execution set in the delay slot. If the T bit is set, the PC is updated to point to the next
execution set and program execution continues sequentially. The destination address cannot be in the
middle of an execution set.
JFD label
Jumps to the absolute memory address specified by a label after executing the set in the delay slot. The
assembler and linker calculate the destination address from the label.
JFD Rn
Jumps to the memory address specified in an address register (Rn) after executing the execution set in the
delay slot.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions changed by Instruction
None.
Example
JFD R0
Instruction
Result
cmpeq.w #$35,d1
Not equal, so T bit in SR cleared.
move.w #adr,r0
Places the numerical address of adr in r0.
nop
Delay needed after write to pointer.
jfd r0 move.w #$29,d1
Jump to adr, move.w executed.
inc d1
Increment d1 to $2A.
move.w #$47,d2
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
adr move.w #$1A,d4
Execution continues here at lbl.
SC140 DSP Core Reference Manual
A-207
JFD
Register/Memory Address
Before
After
SR
$00E0 0000
D1
$00 0000 0000
$00 0000 002A
D2
$00 0000 0000
$00 0000 0000
D4
$00 0000 0000
$00 0000 001A
PC
$0000 0006
$0000 0016
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
3
JFD label
1/4
3
0
8
0
1
1
0
1
1
1
1/4
4
0
0 A A A a
a
1
0
0
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
15
JFD Rn
7
1
0
0
1
a
a
8
7
1 R R R 0
a
a
a
a
a
a
a
0
1
1
0
0
1
1
0
Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles minus the time used
by the execution set in the delay slot. The cycle count for this instruction cannot be less than 1 cycle.
Instruction Fields
Rn
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
label
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
Note:
A-208
This instruction can specify R8-R15 as operands by using a high register prefix.
32-bit absolute long address
Label must be word-aligned, LSBit = 0.
SC140 DSP Core Reference Manual
JFD
JMP
JMP
Jump (AGU)
Operation
Assembler Syntax
label → PC
JMP label {0 ≤ label < 232,W}
Rn → PC
JMP Rn
Description
These operations continue program execution at a specified 32-bit memory destination address. The
destination address cannot be in the middle of an execution set.
JMP label
Jumps to an absolute memory address specified by a label. The assembler and the linker calculate the
destination address from the label.
JMP Rn
Jumps to a memory address specified by an address register (Rn). The value in Rn must be word-aligned.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
jmp _label
Register/Memory Address
Before
After
_label (absolute)
$0000 000A
PC
$0000 0002
SC140 DSP Core Reference Manual
$0000 000A
A-209
JFD
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
3
JMP label
3
3
0
8
0
1
1
1
3
4
0
0
0
1 A A A a
a
1
0
0
0
0
1 A A A A A A A A A A A A A
1
0
a
a
15
JMP Rn
0
7
1
0
0
1
a
a
a
a
a
8
7
1 R R R 0
a
a
a
a
a
a
a
0
1
1
0
0
0
0
1
Instruction Fields
Rn
RRR
Address Register
000
R0
010
R2
100
R4
110
001
R1
011
R3
101
R5
111
Note: This instruction can specify R8-R15 as operands by using a high register prefix.
label
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
Note:
A-210
R6
R7
32-bit absolute long address
Label must be word-aligned, LSBit = 0.
SC140 DSP Core Reference Manual
JMPD
JMPD
Jump Using a Delay Slot (AGU)
JMPD
Operation
Assembler Syntax
label → PC
JMPD label {0 ≤ label < 232,W}
Rn → PC
JMPD Rn
Description
JMPD label
Jumps to an absolute memory destination address specified by a label after executing the execution set in
the delay slot. The assembler and the linker calculate the destination address from the label. The
destination address cannot be in the middle of an execution set.
JMPD Rn
Jumps to a memory address specified by an address register (Rn) after executing the execution set in the
delay slot. The value in Rn must be word-aligned.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
jmpd lbl
Instruction
Comment
move.w #$35,d0
Places $35 in d0.
jmpd lbl move.w #$29,d1
Jump to lbl, move.w executed.
inc d1
Increment executed in the delay slot, d1 = $2A.
move.w #$20,d3
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
lbl move.w #$16,d4
SC140 DSP Core Reference Manual
Execution continues here at lbl.
A-211
JMPD
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
3
JMPD label
31
3
0
8
0
1
1
0
0
0
1
JMPD Rn
4
0
0 A A A a
a
1
0
0
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
15
31
7
1
0
0
1
a
a
8
7
1 R R R 0
a
a
a
a
a
a
a
0
1
1
0
0
0
0
0
Note 1: The jump uses 3 cycles minus the execution time used by execution set in the delay slot. The cycle
count for this instruction cannot be less than 1 cycle.
Instruction Fields
label
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAAA
Note:
Rn
Label must be word-aligned, LSBit = 0.
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-212
32-bit absolute long address
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
JSR
JSR
Jump to Subroutine (AGU)
JSR
Operation
Assembler Syntax
(Next PC) → (SP); SR → (SP + 4); SP + 8 → SP; label → PC
JSR label {0 ≤ label < 232,W}
(Next PC) → (SP); SR → (SP + 4); SP + 8 → SP; Rn → PC
JSR Rn
Description
These operations jump to the subroutine location in program memory that is given by the instruction’s
effective address. The operation includes an implicit push of the status register (SR) and the program
counter (PC) onto the stack. The value of PC stored on the stack is that of the execution set following the
current execution set. In addition, the value of the next PC is stored in the RAS shadow register. The
destination address cannot be in the middle of an execution set.
JSR label
Jumps to a memory location specified by the label. The assembler and linker calculate the 32-bit absolute
destination address from the label.
JSR Rn
Jumps to a memory location contained in an address register (Rn). The value in Rn must be word-aligned.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used.
Status and Conditions Changed by Instruction
None.
Example
jsr r6
Register/Memory Address
Before
After
R6
$0000 0012
PC
$0000 0004
$0000 0012
SP
$0000 0100
$00000108
SR
$00E0 0000
($00000100)
$0000 000A
($00000104)
$00E0 0000
SC140 DSP Core Reference Manual
A-213
JSR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
3/41
3
JSR label
3
8
1
0
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
0
a
1
a
15
3/41
1
JSR Rn
4
0
0
a
0
7
1
0
0
1
1 A A A a
a
a
8
7
a
a
a
a
a
1
a
0
a
0
a
0
1 R R R 0
1
1
0
0
0
1
1
Note 1: The cycle time is 4 if the largest execution time of the other instructions grouped with JSR is ≥ 3.
Instruction Fields
label
Note:
Rn
Label must be word-aligned, LSBit = 0.
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-214
absolute long address
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
JSRD
JSRD
Jump to a Subroutine Using a Delay Slot (AGU)
JSRD
Operation
Assembler Syntax
(Next* PC) → (SP); SR → (SP + 4); SP + 8 → SP;
(Next* PC) →RAS; label → PC
JSRD label {0 ≤ label < 232,W}
(Next* PC) → (SP); SR → (SP + 4); SP + 8 → SP;
(Next* PC) → RAS; Rn → PC
JSRD Rn
Description
Executes the execution set in the delay slot, then pushes the next* PC (the PC of the execution set after the
delay slot) and SR onto the stack, and causes program execution to continue at the address defined by label
or Rn. In addition, the next* PC is stored in the RAS register, and RAS becomes valid. The destination
address cannot be in the middle of an execution set.
JSRD label
Jumps to a memory location specified by an immediate 32-bit absolute address.
JSRD Rn
Jumps to a memory location contained in an address register (Rn). The value in Rn must be word-aligned.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used.
Status and Conditions Changed by Instruction
None.
Example
jsrd r6
Instruction
Comment
move.w #subroutine,r6
Places subroutine label in r6.
move.w #$35,d0
Places $35 in d0.
jsrd r6 move.w #$29,d1
Jump to subroutine, place $29 in d1.
inc d1
Increment executed in the delay slot, d1=$2A.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
subroutine
Execution continues here at subroutine.
move.w #$16,d4
SC140 DSP Core Reference Manual
A-215
JSRD
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
3
JSRD label
1
2/3
3
8
1
0
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
0
a
15
1
JSRD Rn
1
2/3
4
1
0
0
1
1
0
0
a
0
7
a
0 A A A a
a
a
8
7
1 R R R 0
a
a
a
a
a
1
a
0
0
a
a
0
1
1
0
0
0
1
0
Note 1: The jump uses three cycles if the largest cycle time of the instructions grouped with JSRD is 3 or greater.
The cycle count of two or three is reduced by the execution time used by the execution set in the delay
slot. The cycle count for this instruction cannot be less than one cycle.
Instruction Fields
label
Note:
Rn
Label must be word-aligned, LSBit = 0.
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-216
absolute long address
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
JT
JT
JT
Jump If True (AGU)
Operation
Assembler Syntax
If T=1, then label → PC
JT label {0 ≤ label < 232,W}
If T=1, then Rn → PC
JT Rn
Description
If the T bit is set, these operations continue program execution at a specified 32-bit memory destination
address. If the T bit is cleared, the PC is updated to point to the next execution set. Program execution
continues sequentially. The destination address cannot be in the middle of an execution set.
JT label
Jumps to the memory location specified by the label. The assembler and linker calculate the 32-bit
absolute address from the label.
JT Rn
Jumps to the memory location contained in an address register (Rn). The value in Rn must be
word-aligned.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
jt r0
Register/Memory Address
Before
After
R0
$0000 0010
SR
$00E4 0002
PC
$0000 0006
SC140 DSP Core Reference Manual
$0000 0010
A-217
JT
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
3
JT label
1
1/4
3
8
1
0
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
1
a
0
a
15
1
JT Rn
1/41
4
0
0
a
0
7
1
0
0
1
1 A A A a
a
a
8
7
1 R R R 0
a
a
a
a
a
1
a
0
a
0
a
0
1
1
0
0
1
0
1
Note 1: If not taken, the jump uses 1 cycle. If taken, the jump uses 4 cycles.
Instruction Fields
label
Note:
Rn
Label must be word-aligned, LSBit = 0.
RRR
000
001
Note:
A-218
absolute long address
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
Address Register
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
JTD
JTD
Jump If True Using Delay Slot (AGU)
JTD
Operation
Assembler Syntax
If T=1, then label → PC
JTD label {0 ≤ label < 232,W}
If T=1, then Rn → PC
JTD Rn
Description
If the T bit is set, this instruction continues program execution at a specified 32-bit memory destination
address after executing the execution set in the delay slot. If the T bit is cleared, the PC is updated to point to
the next execution set. Program execution continues sequentially. The destination address cannot be in the
middle of an execution set.
JTD label
Jumps to the memory location specified by the label. The assembler and linker calculate the 32-bit absolute
address from the label.
JTD Rn
Jumps to the memory location contained in an address register (Rn). The value in Rn must be
word-aligned.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
jtd r0
Instruction
Comment
move.w #ADRES,r0
Load ADRESS into r0.
move.w #$5,d3
Load 5 into d3.
cmpeq.w#$5,d3
Set the true bit in the status register.
jtd r0 move.w #$45,d0
Jump to ADRESS stored in r0, execute the move.w.
inc d1
Increment executed in the delay slot.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
ADRESS
Execution continues here at ADRESS.
move.w #$16,d4
SC140 DSP Core Reference Manual
A-219
JTD
Instruction Formats and Opcodes
Instruction
Words
Cycles
Type
Opcode
15
3
JTD label
1
1/4
3
8
1
0
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
1
a
0
a
15
1
JTD Rn
1/41
4
0
0
a
0
7
1
0
0
1
0 A A A a
a
a
8
7
1 R R R 0
a
a
a
a
a
1
a
0
a
0
a
0
1
1
0
0
1
0
0
Note 1: If the jump is not taken, it uses 1 cycle. If the jump is taken, it uses 4 cycles minus the time used by the
execution set in the delay slot. The cycle count for this instruction cannot be less than 1 cycle.
Instruction Fields
label
Note:
Rn
Label must be word-aligned, LSBit = 0.
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-220
absolute long address
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
LPMARKx
L-M
LPMARKx
End-of-Loop Mark (PREFIX)
Operation
If LCn > 1,
LPMARKx
Disassembler Syntax Only
then SAn → PC
LCn – 1 → LCn
LPMARKB (long loop)
else next PC → PC
0 → LCn
0 → LFn
If LCn > 1,
then SAn → PC
LCn – 1 → LCn
LPMARKA (external of nested loops)
else next PC → PC
0 → LCn
0 → LFn
If LCn > 1,
then SAn → PC
LCn – 1 → LCn
LPMARKB (short loop of 2 sets)
else next PC → PC
0 → LCn
0 → LFn
0 → SLF
If LCn > 1,
then SAn → PC
LCn – 1 → LCn
LPMARKA (short loop of 1 set)
else next PC → PC
0 → LCn
0 → LFn
0 → SLF
Description
The LPMARK prefix bits are used for hardware loops and perform the operations associated with ending a
loop iteration: a conditional jump to the start of the loop (based on the value of LCn) and a decrement of
LCn. In the case where LCn indicates the last iteration, these bits disable the active loop and do not jump.
The LPMARK bits use the SAn/LCn register of the active loop as specified by the LF bits in SR.
The LPMARK bits are encoded in the prefix words, and are not independent instructions. They are
generated automatically by the assembler at the correct positions based on the LOOPSTART and
LOOPEND assembly directives inserted by the programmer. The assembler does not allow the
programmer to use LPMARKx.
SC140 DSP Core Reference Manual
A-221
LPMARKx
LPMARKB
For long loops (SLF=0), this prefix bit is placed at LA-2 (two sets before the last set of the loop). It
instructs the active loop to decrement LCn and issue a jump delayed operation (with 2 delay slots) to SAn,
if LCn is greater than one. If LCn is less than or equal to one, then the LCn register and the LFn bit are
cleared. For short loops (SLF=1) of two execution sets, this prefix bit is placed at the first set of the loop
(SA).
LPMARKA
For long loops (SLF=0), this prefix bit is placed at LA (the last set of the loop) and is used in special cases.
It instructs the active loop machine to decrement LCn and jump to SAn if LCn is greater than one. If LCn
is less than or equal to one, then the LCn register and the LFn bit are cleared. This prefix bit is used only in
cases where there is a possibility that the loop machine might not be able to identify LPMARKB, which is
normally used in long loops. An example is the case of nested loops where the inner loop may be skipped
with SKIPLS directly to the LA of the enveloping loop. In case of short loops (SLF=1) of one execution
set, LPMARKA is always placed at the first set of the loop (SA).
Table A-17. Combinations of LPMARKx Use
LPMARKA
LPMARKB
LFn
SLF
LCn
Description
no
LPMARKB
set
clear
>1
LCn decrements by one and a jump with two delay slots
to SAn occurs. LPMARKs appearing in the delay slots
are ignored.
≤1
LCn and LFn are cleared. The active loop is terminated.
Every LPMARKA that appears in the next two delay slots
is ignored.
>1
LCn decrements by one and a jump to SAn occurs.
≤1
LCn, LFn, and SLF are cleared. The active loop is terminated.
>1
LCn decrements by one and LPMARKs appearing in the
next execution set are ignored. A jump with one delay
slot to SAn occurs.
≤1
LCn, LFn, and SLF are cleared. The active loop is terminated. LPMARKs appearing in the next execution set are
treated.
>1
LCn decrements by one and a jump to SAn occurs.
≤1
LCn, LFn, and SLF are cleared. The active loop is terminated.
If LPMARKA and LPMARKB appear together,
LPMARKA belongs to the inner loop and LPMARKB
belongs to the outer loop.
If the inner LCn > 1, the LPMARKB is ignored and the
LPMARKA is executed.
If the inner LCn ≤ 1, the inner LCn and the inner LFn are
cleared. The active inner loop is terminated and the
LPMARKB is executed.
LPMARKA
no
LPMARKA
no
LPMARKB
no
set
set
set
clear
set
set
LPMARKA
LPMARKB
set
clear
>1
LPMARKA
LPMARKB
set
set
>1
Status and Conditions that Affect LPMARK Execution
The loop flag (LFn), short loop flag (SLFn), and loop counters (LCn) affect the response as described in
the description above.
A-222
SC140 DSP Core Reference Manual
LPMARKx
Status and Conditions Changed by LPMARK Execution
The loop flag (LFn) and short loop flag (SLFn) are cleared as described in the operation field.
Example
Insertion of lpmarkb by assembler.
Instruction
Disassembled Instruction
Comments
dosetup0 _lab
dosetup0 *+e
Sets up loop 0 with a start address at _lab.
doen0 d6
doen0 d6
Initializes a long loop with the iteration count from d6.
move.w #1,d1
move.w #<$1,d1
Puts the number one into d1.
move.w #2,d2
move.w #<$2,d2
Puts the number two into d2.
move.w #3,d3
move.w #<$3,d3
Puts the number three into d3.
move.w #4,d4
move.w #<$4,d4
Puts the number four into d4.
An assembler directive that defines the start of the loop.
loopstart0
_lab inc d1
inc d1
Increments d1 each pass through the loop.
inc d2
lpmarkb inc d2
lpmarkb bit placed in the prefix by the assembler. Increments d2 each pass through the loop.
inc d3
inc d3
Increments d3 each pass through the loop.
inc d4
inc d4
Increments d4 each pass through the loop.
An assembler directive that defines the end of the loop.
loopend0
add d1,d2,d0
Places the sum of d1and d2 into d0. If two iterations were
selected in d6, d1=3, d2=4, and d0=7.
add d1,d2,d0
Prefix Formats and Opcodes
End-of-Loop Mark Words Cycles Type
Opcode
15
LPMARKx
1
1
4
1
0
0
1
a
a
a
15
LPMARKx
2
1
4
a
a
a
8
7
0
1
8
7
0
0
1
1
0 H
1
0
1
b B e E T
0
1
0
p
j
c
c
c
0
t
h
p
j
c
c
c
b B e E b B e E
Note: If LPMARKA is present, j = 1. If LPMARKB is present, p = 1. The other bits shown in the encoding table are
independent of LPMARKx.
SC140 DSP Core Reference Manual
A-223
LSLL
LSLL
LSLL
Multiple-Bit Bitwise Shift Left (DALU)
Operation
Assembler Syntax
If Da[6:0] > 0, then Dn << Da[6:0] → Dn
else Dn >>> ⏐Da[6:0]⏐ → Dn
LSLL Da,Dn {–40 ≤ Da[6:0] ≤ 40}
Description
LSLL Da,Dn
Logically shifts a 40-bit data register (Dn) left or right N bits. N is a signed 6-bit integer contained in
Da[6:0].
If N is positive, Dn is shifted left. Bit (40 – N) is stored in the C bit. Bits [(39 – N):0] are copied to bits
[39:N]. Bits [(N – 1):0] are cleared.
If N is negative, Dn is shifted right. Bit (|N| – 1) of Dn is stored in the C bit. Bits [39:|N|] are copied to bits
[(39 – |N|):0]. Bits [39:(40 – |N|)] are cleared.
C
39
32 31
16 15
0
Da[6:0] > 0
0
39
Da[6:0] ≤ 0
32 31
16 15
0
C
0
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Bit (40 – N) of Dn is stored in the C bit for a left shift. Or, bit (|N| – 1)
of Dn is stored in the C bit for a right shift.
Ln
L
Clears the Ln bit in the destination register.
Example 1
lsll d4,d2
Register/Memory Address
Before
After
D4
$00 0000 0002
SR
$00E4 0000
$00E4 0001
$0:$FF 8765 4321
$0:$FE 1D95 0C84
L2:D2
A-224
SC140 DSP Core Reference Manual
LSLL
3
9
3
2
1
6
0
1111111110000111011001010100001100100001
C
1
1111111000011101100101010000110010000100
Example 2
lsll d4,d2
Register/Memory Address
Before
After
D4
$FF FFFF FFFE
SR
$00E4 0000
$00E4 0000
$0:$FF 8765 4321
$0:$3F E1D9 50C8
L2:D2
3
9
3
2
1
6
0
1111111110000111011001010100001100100001
0011111111100001110110010101000011001000
C
0
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
LSLL Da,Dn
Note:
1
2
1
8
1
0
1
0
1
7
0
F F F
0
0
0
0
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-225
LSR
LSR
LSR
Bitwise Shift Right One Bit (DALU)
Operation
Assembler Syntax
(Dn>>>1) → Dn; 0 → Dn[39]
LSR Dn
Description
LSR Dn
Shifts the contents of a data register (Dn) right one bit. The LSB (bit 0) is shifted into the carry (C) bit in
the status register. Bits [39:1] are copied to bits [38:0]. Bit 39 is cleared.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Dn[0] is stored in the C bit.
Ln
L
Clears the Ln bit in the destination register.
Example
lsr d4
Register/Memory Address
Before
SR
L4:D4
After
$00E4 0000
$00E4 0001
$0:$FF CCCC CCCD
$0:$7F E666 6666
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
LSR Dn
Note:
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
1
1
1
0
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-226
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
LSRA
LSRA
LSRA
Bitwise Shift Right By One Bit (AGU)
Operation
Assembler Syntax
(Rx>>>1) → Rx; 0 → Rx[31]
LSRA Rx
Description
LSRA Rx
Shifts the contents of an AGU register (Rx) right one bit. Bits [31:1] are copied to bits [30:0]. Bit 31 is
cleared.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
Example
lsra r2
Register/Memory Address
Before
R2
After
$AAAA AAAA
$5555 5555
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
LSRA Rx
1
1
2
1
8
1
1
7
0 R R R R 1
0
1
1
1
1
1
1
1
Instruction Fields
Rx
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
N3
0111
SP
1011
R3
1111
R7
0011
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-227
LSRR
LSRR
Multiple-Bit Bitwise Shift Right (DALU)
LSRR
Operation
Assembler Syntax
If Da[6:0] > 0, then Dn>>>Da→ Dn
else Dn << ⏐Da⏐→ Dn
LSRR Da,Dn {–40 ≤ Da[6:0] ≤ 40}
Dn >>> #u5 → Dn
LSRR #u5,Dn {0 ≤ u5 < 32}
|Description
LSRR Da,Dn
Logically shifts the contents of a 40-bit data register (Dn) left or right N bits. N is a signed 6-bit integer
contained in Da bits [6:0].
If N is positive, Dn is shifted right. Bit (N – 1) is stored in the C bit. Bits [39:N] are copied to bits [(39 –
N):0]. Bits [39:(40 – N)] are cleared.
If N is negative, Dn is shifted left. Bit (40 – |N|) is stored in the C bit. Bits [(39 – |N|):0] are copied to bits
[39:|N|]. Bits [(|N| – 1):0] are cleared.
Da[6:0] > 0
39
32 31
16 15
0
39
32 31
16 15
0
C
0
C
Da[6:0] ≤ 0
0
LSRR #u5,Dn
Shifts the contents of a 40-bit data register (Dn) right the number of bits designated in #u5. #u5 is an
unsigned 5-bit integer immediate. Bit (N – 1) is stored in the C bit. Bits[ 39:N] are copied to bits [(39 –
N):0]. Bits [39:(40 – N)] are cleared.
39
32 31
16 15
0
C
0
Status and Conditions that Affect Instruction
None.
A-228
SC140 DSP Core Reference Manual
LSRR
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Bit (N – 1) of Dn is stored in the C bit for a right shift. Or, bit
(40 – |N|) of Dn is stored in the C bit for a left shift.
Ln
L
Clears the Ln bit in the destination register.
Example 1
lsrr d4,d2
Register/Memory Address
Before
After
D4
$FF FFFF FFFE
SR
$00E4 0000
$00E4 0001
$0:$FF 8765 4321
$0:$FE 1D95 0C84
L2:D2
3
9
3
2
1
6
0
1111111110000111011001010100001100100001
C
1
1111111000011101100101010000110010000100
Example 2
lsrr d4,d2
Register/Memory Address
Before
After
D4
$00 0000 0002
SR
$00E4 0000
$00E4 0000
$0:$FF 8765 4321
$0:$3F 1ED9 50C8
L2:D2
3
9
3
2
1
6
0
1111111110000111011001010100001100100001
0011111111100001110110010101000011001000
SC140 DSP Core Reference Manual
C
0
A-229
LSRR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
LSRR Da,Dn
1
1
2
LSRR #u5,Dn
1
1
2
1
8
1
0
1
0
1
F F F
1
0
1
1
1
F F F
15
1
7
8
0
0
0
0
1
J
J
0
1
i
i
i
i
7
J
0
i
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
000
001
Note:
#u5
A-230
This instruction can specify D8-D15 as operands by using a prefix.
Single Source/Destination Data Register
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
5-bit unsigned immediate data
SC140 DSP Core Reference Manual
LSRW
LSRW
Word Bitwise Shift Right (DALU)
Operation
Assembler Syntax
Da>>>16 → Dn
LSRW Da,Dn
LSRW
Description
LSRW Da,Dn
Copies a source data register (Da) to the destination data register (Dn), logically shifted right 16 bits. Bit 15
of the source register is copied to the C bit. Bits [39:16] of the source register are copied to bits [23:0] of
the destination register. Bits [39:24] of the destination register are cleared.
39
32 31
39
32 31
16 15
0
16 15
0
Da
Dn
0
23
C
0
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Dn[15] is copied into the C bit.
Ln
L
Clears the Ln bit in the destination register.
Example
lsrw d4,d2
Register/Memory Address
Before
D4
After
$FF 8765 4321
L2:D2
SR
SC140 DSP Core Reference Manual
$0:$00 00FF 8765
$00E4 0000
$00E4 0000
A-231
LSRW
3
9
3
2
1
6
0
1111111110000111011001010100001100100001
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 11 0 0 0 0 1 1 1 0 1 1 0 0 1 0 1
C
0
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
LSRW Da,Dn
1
2
1
8
1
0
1
1
0
7
F F F
0
0
0
0
1
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-232
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MAC
MAC
Signed Fractional Multiply-Accumulate (DALU)
MAC
Operation
Assembler Syntax
Dn + (#s16 * Da.H) → Dn
MAC #s16,Da,Dn {–215 ≤ s16 < 215}
Dn ± (Da.H * Db.H) → Dn
MAC ±Da,Db,Dn
Description
These operations perform signed fractional multiplication of two 16-bit signed operands (Da.H and Db.H).
They then add or subtract the product to or from a data register (Dn). One operand is the HP of a data
register. The other operand is either the HP of a data register or an immediate 16-bit signed data.
MAC #s16,Da,Dn
Adds the product of an immediate 16-bit word and a data register (Da) to the destination register (Dn).
MAC ±Da,Db,Dn
Multiplies the HP contents of two data registers (Da, Db) and adds or subtracts the product to or from a
destination data register (Dn). The default is to add the product to the destination register.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Example 1
mac d4,d5,d6
Register/Memory Address
Before
After
SR
$00E0 0000
D4
$00 1000 0000
SC140 DSP Core Reference Manual
A-233
MAC
Register/Memory Address
Before
D5
After
$00 3000 0000
L6:D6
$0:$00 4000 0000
$0:$00 4600 0000
EMR
$0000 0000
0.001 $1000
x 0.011$3000
0.0000110$0600
+0.1000000$4000
0.1000110$4600
Example 2
mac #$1000,d5,d6
Register/Memory Address
Before
After
SR
$00E0 0000
D5
$00 3000 261F
L6:D6
$0:$00 4000 0000
$0:$00 4600 0000
EMR
$0000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
MAC #s16,Da,Dn
1
4
1
1
1
Note:
1
1
1
0
0
1
1
J
J
J
1
i
i
i
1
0
F F F
1
0
0
i
i
i
i
i
i
i
i
i
i
i
8
7
0
*
1
0
0
0
15
MAC ±Da,Da,Dn
7
0
15
MAC ±Da,Db,Dn
8
0
F F F
8
*
1
0
1
0
i
0
k
0
J
J
J
J
7
F F F
i
J
0
1
1
0
k
0
j
j
** indicates serial grouping encoding.
Instruction Fields
k
Accumulation Notation
0
A-234
add
1
subtract
SC140 DSP Core Reference Manual
MAC
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Da,Db
This instruction can specify D8-D15 as operands by using a prefix.
JJJJJ
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
2.
3.
Da,Da
jj
Data Register Pairs
00
Note:
Dn
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#s16
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be inverted for clarity because the order of operation is not important
for add and multiply operations.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, and D7–D7. These
are covered in the jj encoding.
This instruction can specify D8-D15 as operands by using a prefix.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit signed immediate data
A-235
MACR
MACR
Signed Fractional Multiply-Accumulate
and Round (DALU)
Operation
Assembler Syntax
Rnd(Dn ± (Da.H * Db.H)) → Dn
MACR ±Da,Db,Dn
MACR
Description
MACR ±Da,Db,Dn
This instruction performs signed fractional multiplication of two 16-bit signed operands (Da.H and Db.H).
It then adds or subtracts the product to or from a destination data register (Dn) and rounds the final result.
Rounding adjusts the LSB of the high part of the destination register according to the value of the low part
of the register, and then zeros the low part. The two modes of the round function Rnd (), are described on
page A-359.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[3]
RM
Rounding mode
SR[5:4]
S[1:0]
The scaling mode bits determine which bits in the result are used in
the Ln bit calculation and which bits are used in rounding.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Example
macr d4,d5,d6
Register/Memory Address
Before
After
SR
$00E0 0000
D4
$00 0080 0000
D5
$00 0080 0000
L6:D6
A-236
$0:$00 0007 0000
$0:$00 0008 0000
SC140 DSP Core Reference Manual
MACR
Register/Memory Address
Before
After
EMR
$0000 0000
0.000 0000 1000$0080
x 0.000 0000 1000$0080
0.000 0000 0000 0000 1000$000080000
+0.000 0000 0000 0111 0000$0007
rnd0.000 0000 0000 0111 1000$00078
0.000 0000 0000 1000 0000
$0008
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MACR ±Da,Db,Dn
1
1
1
MACR ±Da,Da,Dn
1
1
1
0
8
*
1
0
0
1
F F F
*
1
0
1
0
F F F
15
Note:
0
7
8
0
k
0
J
J
J
J
1
1
1
1
k
j
7
J
0
j
** indicates serial grouping encoding.
Instruction Fields
k
Accumulation Notation
0
Da,Db
add
1
JJJJJ
subtract
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
2.
3.
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be inverted for clarity because the order of operation is not important
for multiply operations.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, and D7–D7. These
are covered in the jj encoding.
SC140 DSP Core Reference Manual
A-237
MACR
Da,Da
jj
Data Register Pairs
00
Note:
Dn
FFF
000
001
Note:
A-238
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
Single Source/Destination Data Register
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MACSU
MACSU
Fractional Multiply-Accumulate
Signed By Unsigned (DALU)
MACSU
Operation
Assembler Syntax
Dn + (Dc.H * Dd.L) → Dn
MACSU Dc,Dd,Dn
Description
MACSU Dc,Dd,Dn
Performs signed fractional multiplication of the signed 16-bit HP of one data register (Dc) in a register pair
(Dc and Dd) by the unsigned 16-bit LP of the other data register (Dd). It then adds the sign-extended 32-bit
product to a destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Example
macsu d0,d1,d4
Register/Memory Address
Before
After
D0
$FF C000 0000
D1
$00 0000 0001
L4:D4
EMR
SC140 DSP Core Reference Manual
$0:$00 0000 0000
$0:$FF FFFF 8000
$0000 0000
A-239
MACSU
1.100 $C000
x 0.000 0000 0000 0001$0001 (2–15)
1.111 1111 1111 1111 1000
$FFFF 8000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MACSU Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
0
0
7
F F F
0
1
1
1
0
0
e
e
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-240
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MACUS
MACUS
Fractional Multiply-Accumulate
Unsigned By Signed (DALU)
MACUS
Operation
Assembler Syntax
Dn + (Dc.L * Dd.H) → Dn
MACUS Dc,Dd,Dn
Description
MACUS Dc,Dd,Dn
Performs signed fractional multiplication of the unsigned 16-bit LP of one data register (Dc) in a register
pair by the signed 16-bit HP of the other data register (Dd). It then adds the sign-extended 32-bit product to
a data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Example
macus d0,d1,d4
Register/Memory Address
Before
After
D0
$00 0000 0001
D1
$FF C000 0000
L4:D4
$0:$00 3FFF 8000
EMR
$0:$00 3fff 0000
$0000 0000
2–15
$0001
x 1.100 $C000
1.111 1111 1111 1111 1000$FFFF 8000
0.011 1111 1111 1111 1000$3FFF 8000
0.011 1111 1111 1111 0000$3FFF
SC140 DSP Core Reference Manual
A-241
MACUS
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MACUS Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
1
1
7
F F F
0
1
1
0
0
0
e
e
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-242
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MACUU
MACUU
Fractional Multiply-Accumulate
Unsigned By Unsigned (DALU)
MACUU
Operation
Assembler Syntax
Dn + (Dc.L * Dd.L) → Dn
MACUU Dc,Dd,Dn
Description
MACUU Dc,Dd,Dn
Performs unsigned fractional multiplication of the unsigned 16-bit LP of one data register (Dc) by the
unsigned 16-bit LP of the other data register (Dd). It then adds the zero-extended 32-bit product to a data
register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Example
macuu d2,d3,d1
Register/Memory Address
Before
After
D2
$00 0000 FFFF
D3
$00 0000 FFFF
L1:D1
$0:$00 7FFF FFFF
EMR
$0:$02 7FFC 0001
$0000 0000
1.111 1111 1111 1111$FFFF
x 1.111 1111 1111 1111$FFFF
1 1.111 1111 1111 1100 0000 0000 0000 0001$01 FFFC 0001
+ 0.111 1111 1111 1111 1111 1111 1111 1111$00 7FFF FFFF
10 0.111 1111 1111 1100 0000 0000 0000 0001$02 7FFC 0001
SC140 DSP Core Reference Manual
A-243
MACUU
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MACUU Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
1
1
7
F F F
0
1
1
0
0
1
e
e
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-244
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MARK
MARK
MARK
Push the PC into the Trace Buffer (AGU)
Operation
Assembler Syntax
PC → trace buffer
MARK
Description
MARK
Writes PC (the address of the MARK instruction) to the trace buffer if the trace buffer is enabled (TMARK
bit in the TB_CTRL register is set). It is an EOnCE dedicated instruction used for debugging. This
instruction can appear only once in an execution set.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MARK
1
1
SC140 DSP Core Reference Manual
4
1
0
0
1
1
1
1
8
7
0
0
0
1
1
1
0
0
1
0
A-245
MAX
MAX
MAX
Transfer Maximum Signed Value (DALU)
Operation
Assembler Syntax
If Dg > Dh, then Dg → Dh
MAX Dg,Dh
Description
MAX Dg,Dh
Writes the larger of two signed values in a data register pair (Dg and Dh) to the second of the two registers
(Dh). If the first register is greater than the second, the value of the first register is written to the second.
Otherwise, the second register is unchanged. Only certain pairs of registers are allowed; see Instruction
Fields below.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
max d0,d4
Register/Memory Address
Before
D0
After
$FF FFFF FFF5
L4:D4
$0:$FF FFFF 8000
$0:$FF FFFF FFF5
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MAX Dg,Dh
Note:
1
1
0
8
*
1
0
1
7
1 G G 0
0
1
1
1
1
1
0
0
** indicates serial grouping encoding.
Instruction Fields
Dg,Dh
GG
Data Register Pairs
00
Note:
A-246
D0,D4
01
D1,D5
10
D2,D6
11
D3,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MAX2
MAX2
MAX2
Transfer Two 16-Bit
Maximum Signed Values (DALU)
Operation
Assembler Syntax
If Dg.H > Dh.H, then Dg.H → Dh.H
MAX2 Dg,Dh
If Dg.L > Dh.L, then Dg.L → Dh.L
Description
MAX2 Dg,Dh
Writes the larger of each of the corresponding portions in a data register pair (Dg and Dh) to the second of
the two registers (Dh). The high and low portions of the two registers are compared independently as 16-bit
signed values and written (or not written) based on the comparison. If the high portion of the first register is
greater than the high portion of the second, the value of the high portion of the first register is written to the
high portion of the second. Otherwise, the high portion of the second register is unchanged. The same
process is applied to the low portions of the two registers with the low portion only being affected. The
extension byte is undefined. Only certain pairs of registers are allowed; see Instruction Fields below.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
max2 d0,d4
Register/Memory Address
Before
D0
After
$00 0F43 0023
L4:D4
$0:$00 0FE4 8F22
$0:$00 0FE4 0023
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MAX2 Dg,Dh
Note:
1
1
1
0
8
*
1
0
1
7
1 G G 0
0
1
1
1
1
1
1
1
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-247
MAX2
Instruction Fields
Dg,Dh
GG
Data Register Pairs
00
Note:
A-248
D0,D4
01
D1,D5
10
D2,D6
11
D3,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MAX2VIT
MAX2VIT
MAX2
for Viterbi Kernel (DALU)
MAX2VIT
Operation
Assembler Syntax
If Da.L > Db.L, then 0 → VFn, Da.L → Db.L
else 1 → VFn
MAX2VIT Da,Db
Da
Db
VFn
D4.L
D2.L
VF0
D4.H
D2.H
VF1
D0.L
D6.L
VF2
D0.H
D6.H
VF3
D12.L
D10.L
VF0
D12.H
D10.H
VF1
D8.L
D14.L
VF2
D8.H
D14.H
VF3
Description
These operations independently compare the 16-bit contents of the HP and LP of a data register pair to find
the larger value. They copy the larger value to the corresponding portion in the second data register and set
or clear Viterbi flags (VF0–VF3 in SR) to indicate which portions are larger. The HP and LP of the two
registers are compared separately as 16-bit signed values and the Viterbi flags are set or cleared
accordingly. These instructions are similar to MAX2, except they also set Viterbi flags. The MAX2VIT
instructions are intended to optimize implementation of the Viterbi decoder algorithm. The MAX2VIT
instruction is used with conjunction with the VSL instruction (see page A-423).
MAX2VIT Da,Db
For the low portion comparison, the instruction clears VFn (n=0, 2) if the LP of Da is greater than the LP of
Db. It then copies the contents of the LP of Da to the LP of Db. It sets VFn (n=0, 2) if the LP of Da is not
greater than the LP of Db. For the high portion comparison, this instruction clears VFn (n=1, 3) if the HP of
Da is greater than the HP of Db. It then copies the contents of the HP of Da to the HP of Db. It sets VFn
(n=1, 3) if the HP of Da is not greater than the HP of Db. The high bank of registers can also be used: D12
and D8 substituted for Da, and D10 and D14 substituted for Db. The encoding for the substitution is done
with a prefix.
Status and Conditions that Affect Instruction
None.
SC140 DSP Core Reference Manual
A-249
MAX2VIT
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[8]
VF0
Updated by MAX2VIT D4,D2 and MAX2VIT D12,D10.
SR[9]
VF1
Updated by MAX2VIT D4,D2 and MAX2VIT D12,D10.
SR[10]
VF2
Updated by MAX2VIT D0,D6 and MAX2VIT D8,D14.
SR[11]
VF3
Updated by MAX2VIT D0,D6 and MAX2VIT D8,D14.
Ln
L
Clears the Ln bit in the destination register.
Example
max2vit d4,d2
Register/Memory Address
Before
After
D4
$00 0643 1023
D2
$00 0564 1F22
$00 0643 1F22
SR
$00E4 0000
$00E4 0100
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MAX2VIT D4,D2
1
1
2
1
1
0
1
0
1
0
15
MAX2VIT D0,D6
Note:
A-250
1
1
2
1
1
0
1
0
1
0
8
7
0
0
8
7
0
0
0
1
0
1
1
0
0
0
0
1
0
1
1
0
0
1
This instruction can specify D12, D10, D8, and D14 instead of D4, D2, D0, and D6 by using a prefix.
SC140 DSP Core Reference Manual
MAXM
MAXM
MAXM
Transfer Maximum Absolute Value (DALU)
Operation
Assembler Syntax
If⏐Dg⏐ > ⏐Dh⏐, then Dg → Dh
MAXM Dg,Dh
If Dg == –Dh, then ⏐Dg⏐→ Dh
Description
MAXM Dg,Dh
Compares the absolute values of a data register pair (Dg and Dh). If the absolute value of the first register
(Dg) is greater than the absolute value of the second (Dh), the value of the first register is written to the
second (Dh). Otherwise, the second register is unchanged. In case Dg and Dh have equal magnitudes but
opposite signs, the destination register Dh is written with the positive value.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
maxm d2,d6
Register/Memory Address
Before
D2
After
$FF FFFF FFDD
L6:D6
$0:$00 0000 0022
$0:$FF FFFF FFDD
$FFDD = –35, $0022 = +34
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MAXM Dg,Dh
Note:
1
1
1
0
8
*
1
0
1
7
1 G G 0
0
1
1
1
1
1
1
0
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-251
MAXM
Instruction Fields
Dg,Dh
GG
Data Register Pairs
00
Note:
A-252
D0,D4
01
D1,D5
10
D2,D6
11
D3,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MIN
MIN
MIN
Transfer Minimum Signed Value (DALU)
Operation
Assembler Syntax
If Dg < Dh, then Dg → Dh
MIN Dg,Dh
Description
MIN Dg,Dh
Writes the smaller of two signed values in a data register pair (Dg and Dh) to the second of the two
registers (Dh). If the first register is less than the second, the value of the first register is written to the
second. Otherwise, the second register is unchanged.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
min d1,d5
Register/Memory Address
Before
D1
After
$00 36AE 3FB4
L5:D5
$0:$00 48FE 4A68
$0:$00 36AE 3FB4
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MIN Dg,Dh
Note:
1
1
8
*0 *
1
0
1
7
1 G G 0
0
1
1
1
1
1
0
1
** indicates serial grouping encoding.
Instruction Fields
Dg,Dh
GG
Data Register Pairs
00
Note:
D0,D4
01
D1,D5
10
D2,D6
11
D3,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-253
MIN2
MOVE.2F
Move Two Fractional Words from
Memory to a Register Pair (AGU)
MOVE.2F
Operation
Assembler Syntax
(EA) → Da:Db
MOVE.2F (EA),Da:Db {0 ≤ EA < 232,L}
Description
MOVE.2F (EA),Da:Db
Moves two signed fractional words from memory to a data register pair (Da:Db). The effective memory
address of the two words is contained in an address register with an optional offset or post-increment (EA).
Each word is written in the HP of its respective data register, sign-extended, and the LP is zero-filled. The
reverse operation (moving from a register pair to memory) is done with saturation. It is described in
MOVES.2F.
The first operand (Da) will be moved from the lower memory address (EA). The second operand (Db) will
be moved from memory address (EA + 2). In order to maintain this behavior in both big endian and little
endian modes, the core will interpret the data bus differently in each mode. See Section 2.4.1, “SC140
Endian Support,” on page 2-56, for more detail on bus and memory behavior for each mode.
The address register values used with this instruction must be a multiple of 4, long aligned.
39
32
16
SIGN
EXTENSION
SIGN
EXTENSION
Da
Db
0
(EA) OPERAND
ZERO FILL
(EA+2) OPERAND
ZERO FILL
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
move.2f (r7),d2:d3
Register/Memory Address
Before
After
MCTL
$0000 0000
R7
$0000 0050
A-254
SC140 DSP Core Reference Manual
MOVE.2F
Register/Memory Address
Before
After
$0050
$6000
$0052
$2000
L2:D2
$0:$00 6000 0000
L3:D3
$0:$00 2000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MOVE.2F (EA),Da:Db
Notes:
1.
2.
12
1
0
*
0
1
1
h
h
8
7
0
1
0
1 M M M R R R
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
Da:Db
hh
Data Register Pairs
00
D0:D1
01
D2:D3
10
D4:D5
11
D6:D7
Note: This instruction can specify D8-D15 as operands by using a prefix. In such a case, all the registers
in the group will be high registers.
EA
Rn
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-255
MOVE.2L
MOVE.2L
Move Two Integer Longs
to/from a Register Pair (AGU)
MOVE.2L
Operation
Assembler Syntax
Da,Db ↔ (EA)
MOVE.2L Da:Db,(EA){0 ≤ EA < 232,Q}
MOVE.2L (EA),Da:Db {0 ≤ EA < 232,Q}
Description
These operations move two long words from registers to memory, or from memory to registers.
MOVE.2L Da:Db,(EA)
MOVE.2L (EA),Da:Db
Move two long signed integer words from a data register pair (Da:Db) to memory, or from memory to a
data register pair. The effective memory address of the two long words is obtained from an address register
with an optional offset or post-increment (EA).
The first operand (Da) will be moved to or from the lower memory address (EA). The second operand (Db)
will be moved to or from memory address (EA + 4). In order to keep this behavior in both big endian and
little endian modes, the core will drive or interpret the data bus differently in each mode. See Section 2.4.1,
“SC140 Endian Support,” on page 2-56, for more detail on bus and memory behavior for each mode.
The address register values used with this instruction must be a multiple of 8, quad word-aligned.
39
32
SIGN
EXTENSION
SIGN
EXTENSION
Da
Db
0
(EA)
(EA + 4)
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
move.2l d0:d1,(r0)
Register/Memory Address
MCTL
A-256
Before
After
$0000 0000
SC140 DSP Core Reference Manual
MOVE.2L
Register/Memory Address
Before
After
R0
$0000 0050
L0:D0
$0:$00 12345 678
L1:D1
$0:$00 5432 9876
$0050
$1234 5678
$0054
$5432 9876
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MOVE.2L Da:Db,(EA)
11
2
1
8
1
0
0
0
h
7
0
h w 0
0 M M M R R R
MOVE.2L (EA),Da:Db
Note 1: When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
w
Read/Write Notation
0
Da:Db
write
1
hh
read
Data Register Pairs
00
D0:D1
01
D2:D3
10
D4:D5
11
D6:D7
Note: This instruction can specify D8-D15 as operands by using a prefix. In such a case, all the registers
in the group will be high registers.
EA
Rn
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-257
MOVE.2W
MOVE.2W
Move Two Integer Words
to/from a Register Pair (AGU)
MOVE.2W
Operation
Assembler Syntax
(EA) ↔ Da:Db
MOVE.2W (EA),Da:Db {0 ≤ EA < 232,L}
MOVE.2W Da:Db,(EA) {0 ≤ EA < 232,L}
Description
MOVE.2W (EA),Da:Db
MOVE.2W Da:Db,(EA)
Moves two signed integer words from memory to a data register pair (Da:Db), or from the registers to
memory. The effective memory address of the two words is obtained from an address register with an
optional offset or post-increment (EA). Each word is stored in the LP of its respective data register.
The first operand (Da) will be moved to or from the lower memory address (EA) and the second operand
(Db) will be moved to or from memory address (EA + 2). In order to keep this behavior in both big endian
and little endian modes, the core will drive or sample the data bus differently in each mode. See
Section 2.4.1, “SC140 Endian Support,” on page 2-56, for more detail on bus and memory behavior for
each mode.
The address register values used with this instruction must be a multiple of 4, long word-aligned.
39
16
0
Da
SIGN EXTENSION
(EA)
Db
SIGN EXTENSION
(EA + 2)
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
move.2w d0:d1,(r0)
Register/Memory Address
MCTL
A-258
Before
After
$0000 0000
SC140 DSP Core Reference Manual
MOVE.2W
Register/Memory Address
Before
After
D0
$FF FFFF AF44
D1
$00 0000 2377
R0
$0000 0050
$0050
$AF44
$0052
$2377
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MOVE.2W (EA),Da:Db
12
1
0
*
0 w 1
h
h
8
7
0
0
0
1 M M M R R R
MOVE.2W Da:Db,(EA)
Notes:
1.
2.
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
w
Read/Write Notation
0
Da:Db
write
1
hh
read
Data Register Pairs
00
D0:D1
01
D2:D3
10
D4:D5
11
D6:D7
Note: This instruction can specify D8-D15 as operands by using a prefix. In such a case, all the registers
in the group will be high registers.
EA
Rn
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-259
MOVE.4F
MOVE.4F
Move Four Fractional Words from
Memory to a Register Quad (AGU)
MOVE.4F
Operation
Assembler Syntax
(EA) → Da:Db:Dc:Dd
MOVE.4F (EA),Da:Db:Dc:Dd {0 ≤ EA < 232,Q}
Description
MOVE.4F (EA),Da:Db:Dc:Dd
Reads four signed fractional words from memory to a data register quad (Da:Db:Dc:Dd). The effective
memory address of the four words is contained in an address register with an optional offset or
post-increment (EA). Each word is written into the HP of its respective data register, is sign-extended, and
the LP is zero-filled. The reverse operation (moving from a register quad to memory) is done with
saturation as described by MOVES.4F.
The first operand (Da) will be moved from the lower memory address (EA). The second operand (Db) will
be moved from memory address (EA + 2). The third operand (Dc) will be moved from memory address
(EA + 4). And, the fourth operand (Dd) will be moved from memory address (EA + 6). In order to keep this
behavior in both big endian and little endian modes, the core will interpret the data bus differently in each
mode. See Section 2.4.1, “SC140 Endian Support,” on page 2-56, for more detail on bus and memory
behavior for each mode.
The address register values used with this instruction must be a multiple of 8, quad word-aligned
39
Da
Db
Dc
Dd
32
SIGN
EXTENSION
SIGN
EXTENSION
SIGN
EXTENSION
SIGN
EXTENSION
16
0
(EA)
ZERO FILL
(EA + 2)
ZERO FILL
(EA + 4)
ZERO FILL
(EA + 6)
ZERO FILL
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
A-260
SC140 DSP Core Reference Manual
MOVE.4F
move.4f (r0),d0:d1:d2:d3
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$0000 0100
$0100
$943C
$0102
$5AB1
$0104
$33E4
$0106
$A7AC
L0:D0
$0:$FF 943C 0000
L1:D1
$0:$00 5AB1 0000
L2:D2
$0:$00 33E4 0000
L3:D3
$0:$FF A7AC 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.4F(EA),Da:Db:Dc:Dd
Notes:
1.
2.
1
12
1
0
*
0
0
1
k
0
8
7
0
1
1
1 M M M R R R
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
Da:Db:Dc:Dd
k
Data Register Quad
0
D0:D1:D2:D3
1
D4:D5:D6:D7
Note: This instruction can specify D8-D15 as operands by using a prefix. In
such a case, all the registers in the group will be high registers.
EA
Rn
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-261
MOVE.4W
MOVE.4W
Move Four Integer Words
to/from a Register Quad (AGU)
MOVE.4W
Operation
Assembler Syntax
(EA) ↔ Da:Db:Dc:Dd
MOVE.4W (EA),Da:Db:Dc:Dd {0 ≤ EA < 232,Q}
MOVE.4W Da:Db:Dc:Dd,(EA){0 ≤ EA < 232,Q}
Description
MOVE.4W (EA),Da:Db:Dc:Dd
MOVE.4W Da:Db:Dc:Dd,(EA)
Moves four signed integer words from memory to a data register quad (Da:Db:Dc:Dd), or from the register
quad to memory. The effective memory address of the four words is obtained from an address register with
an optional offset or post-increment (EA). Each word is stored in the LP of its respective data register.
The first operand (Da) will be moved to or from the lower memory address (EA). The second operand (Db)
will be moved to or from memory address (EA + 2). The third operand (Dc) will be moved to or from
memory address (EA + 4). And, the fourth operand (Dd) will be moved to or from memory address (EA +
6). In order to keep this behavior in both big endian and little endian modes, the core will drive or interpret
the data bus differently in each mode. See Section 2.4.1, “SC140 Endian Support,” on page 2-56, for more
detail on bus and memory behavior for each mode.
The address register values used with this instruction must be a multiple of 8, quad word-aligned.
39
16
0
Da
SIGN EXTENSION
(EA)
Db
SIGN EXTENSION
(EA + 2)
Dc
SIGN EXTENSION
(EA + 4)
Dd
SIGN EXTENSION
(EA + 6)
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
A-262
SC140 DSP Core Reference Manual
MOVE.4W
move.4w d0:d1:d2:d3,(r0)
Register/Memory Address
Before
After
MCTL
$0000 0000
R0
$0000 0050
L0:D0
$0:$00 0000 1FEC
L1:D1
$0:$00 0000 2354
L2:D2
$0:$00 0000 38C0
L3:D3
$0:$00 0000 4151
$0050
$1FEC
$0052
$2354
$0054
$38C0
$0056
$4151
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.4W (EA),Da:Db:Dc:Dd
11
1
2
1
8
1
0
0
1
k
7
0
0 w 0
0 M M M R R R
MOVE.4W Da:Db:Dc:Dd,(EA)
Note 1: When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
w
Read/Write Notation
0
Da:Db:Dc:Dd
write
1
k
read
Data Register Quad
0
D0:D1:D2:D3
1
D4:D5:D6:D7
Note: This instruction can specify D8-D15 as operands by using a prefix. In
such a case, all the registers in the group will be high registers.
EA
Rn
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
RRR
Note:
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-263
MOVE.B
MOVE.B
MOVE.B
Byte Move (AGU)
Operation
Assembler Syntax
(aa) ↔ DR
MOVE.B (a16),DR {0 ≤ a16 < 216}
MOVE.B DR,(a16) {0 ≤ a16 < 216}
DR → (aa)
MOVE.B DR,(a32) {0 ≤ a32 < 232}
DR→(Rn+s15)
MOVE.B DR,(Rn+s15) {–214 ≤ s15 < 214}
(ea) ↔ DR
MOVE.B (ea),DR
MOVE.B DR,(ea)
(SP+s15) ↔ DR
MOVE.B (SP+s15),DR {–214 ≤ s15 < 214}
MOVE.B DR,(SP+s15) {–214 ≤ s15 < 214}
Description
These operations move 8-bit data from memory to a data or address register, or from a register to memory.
31
8
0
8
0
SIGN EXTENSION
39
SIGN EXTENSION
MOVE.B (a16),DR
Reads a byte from a 16-bit absolute memory address, sign-extending it into a register.
MOVE.B DR,(a16)
Writes a byte to a 16-bit absolute memory address.
MOVE.B DR,(a32)
Writes a byte to a 32-bit absolute memory address.
MOVE.B DR,(Rn+s15)
Writes a byte to memory from a register. The effective memory address is obtained from an address
register with a signed 15-bit offset.
MOVE.B (ea),DR
Reads a byte from memory, sign-extending it into a register. The effective memory address is obtained
from an address register with an optional offset or post-increment.
A-264
SC140 DSP Core Reference Manual
MOVE.B
MOVE.B DR,(ea)
Writes a byte to memory. The effective memory address is obtained from an address register with an
optional offset or post-increment.
MOVE.B (SP+s15),DR
Reads a byte from memory, sign-extending it into a register. The effective memory address is obtained
from the active stack pointer (SP) with a signed 15-bit offset.
MOVE.B DR,(SP+s15)
Writes a byte to memory. The address is obtained from the stack pointer with a signed 15-bit offset.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
move.b d3,(r7+$3)
Register/Memory Address
Before
MCTL
After
$0000 0000
D3
$FF FFFF FFF8
R7
$0000 0050
$00000053
SC140 DSP Core Reference Manual
$F8
A-265
MOVE.B
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
MOVE.B (a16),DR
1
3
8
2
1
3
0
0
1 H H H H A A A 0
1
0
0 A A A A A A A A A A A A A
8
3
1
3
2
2
1
MOVE.B DR,(ea)
1
11
4
MOVE.B (SP+s15),DR
2
2
3
MOVE.B (ea),DR
4
0 A A A A A A A A A A A A A
8
0
0
1
0
0
0
a
0
0
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
a
a
8
7
a
a
a
a
a
a
a
0
0
0
0
0 H H H H 0
s
s
1
0 R R R
1
0
0
s
s
s
s
s
1
1
3
1
7
0 H H H H A A A a
s
s
s
0
0
s
s
8
7
1 H H H H 1
8
s
s
0
1 H H H H 1
0
0
0
1
0
0
1
s
0
1
1 M M R R R
7
0
0
0
0 M M R R R
1 H H H H 0
s
s
1
1
1
1
0
0
s
s
s
s
s
s
s
s
0
0
0 H H H H 0
s
s
1
1
1
0
0
0
0
s
s
s
s
s
s
s
s
8
s
s
s
15
2
0
0
15
2
0
1
15
MOVE.B DR,(SP+s15)
7
0 H H H H A A A 0
15
11
1
0
0
3
1
0
15
MOVE.B DR,(Rn+s15)
1
0
15
MOVE.B DR,(a32)
0
0
15
MOVE.B DR,(a16)
7
s
s
s
7
s
s
8
7
s
s
0
0
Note 1: When the form (Rn + N0) is used in ea, the cycle count is increased by 1.
Instruction Fields
DR
HHHH
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
A-266
Data/Address Register
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
MOVE.B
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
ea
This instruction can specify R8-R15 as operands by using a high register prefix.
MM
Effective Address Notation
00
a16
Address Register
(Rn)+
01
(Rn)–
10
(Rn+N0)
11
(Rn)
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
a32
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
s15
sssssssssssssss
Signed 15-bit offset
SC140 DSP Core Reference Manual
A-267
MOVE.F
MOVE.F
MOVE.F
Move Fractional Word
to/from Memory (AGU)
Operation
Assembler Syntax
#s16 → Db
MOVE.F #s16,Db {–215 ≤ s16 < 215}
(aa) → Db
MOVE.F (a16),Db {0 ≤ a16 < 216,W}
(aa) → Db
MOVE.F (a32),Db {0 ≤ a32 < 232,W}
(EA) → Db
MOVE.F (EA),Db {0 ≤ EA < 232,W}
(Rn+s15) → Db
MOVE.F (Rn+s15),Db {–214 ≤ s15 < 214,W}
(SP+s15) → Db
MOVE.F (SP+s15),Db {–214 ≤ s15 < 214,W}
Db → (ea)
MOVE.F Db,(ea){0 ≤ ea < 232,W}
Description
These operations read a fractional word from memory into the high portion of a destination data register
Db, sign-extended and zero-filled.
This instruction also moves data from a register to memory without saturation. However, moving
fractional data from register to memory is generally done with saturation. These instructions are described
in MOVES.F.
The address of the access must be word-aligned.
39
Db
32
16
SIGN
EXTENSION
0
ZERO FILL
MOVE.F #s16,Db
Loads a 16-bit immediate fractional value into a data register.
MOVE.F (a16),Db
Reads a fractional word from a 16-bit unsigned absolute address into a data register.
MOVE.F (a32),Db
Reads a fractional word from a 32-bit absolute address into a data register.
MOVE.F (EA),Db
Reads a fractional word from memory into a data register. The effective memory address is obtained from
an address register with an optional offset or post-increment.
MOVE.F (Rn+s15),Db
Reads a fractional word from memory into a data register. The effective memory address is obtained from
an address register with a signed 15-bit offset.
A-268
SC140 DSP Core Reference Manual
MOVE.F
MOVE.F (SP+s15),Db
Reads a fractional word from memory. The effective memory address is obtained from the active stack
pointer (SP) with a signed 15-bit offset.
MOVE.F Db,(ea)
Writes an unsaturated fractional word to memory without being affected by the scaling mode. This is the
only instruction available for moving the HP of a data register to memory without saturation. The effective
memory address is obtained from an address register with an optional offset or post-increment.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
move.f ($54),d10
Register/Memory Address
Before
$00000054
L10:D10
SC140 DSP Core Reference Manual
After
$6000
$0:$00 6000 0000
A-269
MOVE.F
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
MOVE.F #s16,Db
1
4
2
1
3
3
1
3
1
0
0
j
j
j
i
i
i
0
0
0
0
1
1
0
0
i
i
i
i
i
i
i
i
i
i
i
i
i
8
7
j
A A A 0
0
0
j
j
1
MOVE.F (EA),Db
1
0
0
1
0
0 A A A A A A A A A A A A A
0
0
0
0
1
j
j
2
2
3
2
2
3
MOVE.F Db,(ea)
Notes:
1.
2.
1
4
j
A A A a
0
1
0
a
0
1
1
0
1 A A A A A A A A A A A A A
0
a
a
a
a
a
0
*
0
1
0
j
j
a
a
a
a
a
a
a
a
a
8
7
0
j
0
1 M M M R R R
8
7
0
0
0
0
0
1
j
j
j
1
s
s
1
0 R R R
1
0
0
s
s
s
s
s
s
s
s
s
s
8
7
s
s
s
0
0
0
0
0
0
j
j
j
1
s
s
1
1
1
0
0
1
0
0
s
s
s
s
s
s
s
s
s
s
s
s
s
8
7
j
0
15
12
7
1
1
15
MOVE.F (SP+s15),Db
8
1
0
15
MOVE.F (Rn+s15),Db
0
0
15
12
0
0
15
MOVE.F (a32),Db
7
0
15
MOVE.F (a16),Db
8
1
0
0
1 M
j
j
0
0
1 M 1 R R R
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA or ea, the cycle count is increased by 1.
Instruction Fields
Db
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
EA
A-270
This instruction can specify D8-D15 as operands by using a prefix.
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
SC140 DSP Core Reference Manual
MOVE.F
ea
MM
Effective Address Notation
00
Rn
(Rn)+
RRR
(Rn)–
10
(Rn+N0)
11
(Rn)
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix.
#s16
a16
01
iiiiiiiiiiiiiiii
16-bit signed immediate data
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
a32
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
s15
sssssssssssssss
Signed 15-bit offset
SC140 DSP Core Reference Manual
A-271
MOVE.L
MOVE.L
MOVE.L
Move Long Word (AGU)
Operation
Assembler Syntax
#s32 → C4
MOVE.L #s32,C4 {–231 ≤ s32 < 231}
#u32 → C1
MOVE.L #u32,C1 {0 ≤ u32 < 232}
C4 ↔ Db
MOVE.L C4,Db
MOVE.L Db,C4
C2 ↔ Db
MOVE.L C2,Db
MOVE.L Db,C2
Description
These operations move an immediate long word (32-bit data) into a register, or move a long word between
registers. MOVE.L instructions that write to a data register clear the destination register’s limit tag bit (Ln
bit).
39
32
SIGN
Db
EXTENSION
0
MOVE.L #s32,C4
Loads an immediate signed long word into a general register.
MOVE.L #u32,C1
Loads an immediate unsigned long word into a control register.
MOVE.L C4,Db
MOVE.L Db,C4
Moves a long word between a selected data register and a selected general register.
MOVE.L C2,Db
MOVE.L Db,C2
Moves a long word between a selected data register and a selected general register.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.L #s32,C4
A-272
3
1
3
0
0
1
8
7
1 D D D D
i
0
i
i
I
I
0 D 0
SC140 DSP Core Reference Manual
MOVE.L
0
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
1
0
I
I
I
I
I
I
I
I
I
I
I
I
I
I
8
7
0
0
1
1
0 C C C
i
i
i
I
I
0
1
1
0
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
1
0
I
I
I
I
I
I
I
I
I
I
I
I
I
I
8
7
1
0
0 D D D D 0
1
0 D w
j
j
15
MOVE.L #u32,C1
3
1
3
15
1
MOVE.L C4,Db
1
2
1
0
0
j
MOVE.L Db,C4
15
1
MOVE.L C2,Db
1
2
1
8
1
0
7
0 C C C C 0
0
1
1
0 w
j
j
j
MOVE.L Db,C2
Instruction Fields
C1
C2
C4
CCC
000
EMR
010
-
100
—
110
—
001
VBA
011
-
101
SR
111
MCTL
CCCC
General Registers
0000
EMR
0100
—
1000
SA0
1100
SA2
0001
VBA
0101
SR
1001
LC0
1101
LC2
0010
-
0110
—
1010
SA1
1110
SA3
0011
-
0111
MCTL
1011
LC1
1111
LC3
DDDDD
00000
General Registers
D0
01000
D4
10000
R0
11000
R4
00001
B0
00010
D1
01001
B4
10001
N0
11001
M0
01010
D5
10010
R1
11010
R5
00011
B1
01011
B5
10011
N1
11011
M1
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
D3
01110
D7
10110
R3
11110
R7
00111
B3
01111
B7
10111
N3
11111
M3
Note:
Db
Control Registers
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
If registers D8–D15 are accessed instead of D0–D7, a prefix is used.
SC140 DSP Core Reference Manual
A-273
MOVE.L
w
Read/Write Notation
0
write
1
read
#s32
(31)IIIIIIIIIIIIIIII(16)
(15)iiiiiiiiiiiiiiii (0)
32-bit signed immediate data
#u32
(31)IIIIIIIIIIIIIIII(16)
(15)iiiiiiiiiiiiiiii (0)
32-bit unsigned immediate data
A-274
SC140 DSP Core Reference Manual
MOVE.L
MOVE.L
Move Long Register Extensions (AGU)
MOVE.L
Operation
Assembler Syntax
((SP+s15)[8:0]) → De.E
MOVE.L (SP+s15),De.E {–214 ≤ s15 < 214,L}
Da.E:Db.E → (SP+s15)
MOVE.L Da.E:Db.E,(SP+s15) {–214 ≤ s15 < 214,L}
((SP+s15)[24:16]) → Do.E
MOVE.L (SP+s15),Do.E {–214 ≤ s15 < 214,L}
(aa[8:0]) → De.E
MOVE.L (a32),De.E {0 ≤ a32 < 232,L}
Da.E:Db.E → (aa)
MOVE.L Da.E:Db.E,(a32) {0 ≤ a32 < 232,L}
(aa[24:16]) → Do.E
MOVE.L (a32),Do.E {0 ≤ a32 < 232,L}
Description
These six operations save (restore) the extension bits and Ln bit of data registers to (from) memory. One of
the operations writes to memory the Ln bit and extension bits of an even and odd pair of registers, as
shown below. Another operation reads bits 8:0 from memory to the extension bits and Ln bit of an even
register. Another operation reads bits 24:16 to the extension bits and Ln bit of an odd register. The memory
address can be specified as an offset to the stack pointer, or as an absolute address.
Writes to memory are done from the even/odd pair of registers. Reads from memory are done to a single
register. An extension saved to memory from an even numbered register must be restored to an even
register, likewise for odd registers.
The address of the access must be long word-aligned.
31
24
0
39
Note:
32
16
Db.E
ODD
8
0
16
0
Da.E
EVEN
MEMORY LONG WORD
0
La + EXTENSION
Da EVEN
Lb + EXTENSION
Db ODD
Moves of extensions into data registers restore the corresponding limit tag bit (Ln bit) in the
destination register.
MOVE.L (SP+s15),De.E
Reads from a memory address pointed to by the stack pointer and a signed 15-bit offset into the extension
and Ln bit of an even numbered data register.
MOVE.L Da.E:Db.E,(SP+s15)
SC140 DSP Core Reference Manual
A-275
MOVE.L
Stores the L and extension bits from one even and one odd data register into a 32-bit memory address that
is pointed to by the active stack pointer (SP) and a signed 15-bit offset.
MOVE.L (SP+s15),Do.E
Reads from a memory address pointed to by the active stack pointer (SP) and a signed 15-bit offset into the
extension and Ln bit of an odd numbered data register.
MOVE.L (a32),De.E
Reads from a 32-bit absolute memory address into the extension and Ln bit of an even numbered data
register.
MOVE.L Da.E:Db.E,(a32)
Stores the L and extension bits from one even and one odd data register into a 32-bit absolute memory
address.
MOVE.L (a32),Do.E
Reads from a 32-bit absolute memory address into the extension and Ln bit of an odd numbered data
register.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is
an operand. Otherwise, the instruction is not affected by SR.
Ln
L
Register to memory moves read the Ln bit with the extension from
the source register.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Memory to register moves write the Ln bit in the destination
register.
Example
move.l d0.e:d1.e,($1224)
Register/Memory Address
Before
L0:D0
$1:$FF FEDC BA98
L1:D1
$0:$00 1234 5678
$1224
A-276
After
$0000 01FF
SC140 DSP Core Reference Manual
MOVE.L
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.L (SP+s15),De.E
2
2
3
MOVE.L Da.E:Db.E,(SP+s15)
2
2
3
MOVE.L (SP+s15),Do.E
2
2
3
MOVE.L (a32),De.E
3
1
3
MOVE.L Da.E:Db.E,(a32)
3
1
3
MOVE.L (a32),Do.E
3
1
3
0
1
8
0
0
0 0 1 f f 0 1 A A 1 1 1 0 0
0 A A A A A A A A A A A A A
0
0
0 0 1 q q 1 1 A A 1 1 1 1 0
0 A A A A A A A A A A A A A
0
0
0
0 1 1 Q Q 0 A A A a a 0 0 0
1 A A A A A A A A A A A A A
a a a a a a a a a a a a a a
0
0
0
0 1 0 f f 0 A A A a a 0 0 0
1 A A A A A A A A A A A A A
a a a a a a a a a a a a a a
0
0
0
0 1 1 q q 1 A A A a a 0 0 0
1 A A A A A A A A A A A A A
a a a a a a a a a a a a a a
8
15
0
1
8
15
0
0
1
8
15
0
0
1
8
15
0
0
1
0
0 0 1 Q Q 0 1 A A 1 1 1 1 0
0 A A A A A A A A A A A A A
15
0
1
7
0
0
8
7
0
7
0
7
0
7
0
7
0
Instruction Fields
De
QQ
Data Register
00
D0
01
D2
10
D4
11
D6
Note: This instruction can specify D8, D10, D12, or D14 as operands instead of D0, D2, D4, or D6 by
using a prefix.
Do
qq
Data Register
00
D1
01
D3
10
D5
11
D7
Note: This instruction can specify D9, D11, D13, or D15 as operands instead of D1, D3, D5, or D7 by
using a prefix.
Da.E:Db.E ff
Data Register Extension Pair
00
Note:
s15
D0.E:D1.E
01
D2.E:D3.E
10
D4.E:D5.E
11
D6.E:D7.E
This instruction can specify D8-D15 as operands by using a prefix.
AAAAAAAAAAAAAAA
SC140 DSP Core Reference Manual
Signed 15-bit offset
A-277
MOVE.L
a32
A-278
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
SC140 DSP Core Reference Manual
MOVE.L
MOVE.L
Move Long (AGU)
MOVE.L
Operation
Assembler Syntax
(aa) ↔ DR
MOVE.L (a32),DR {0 ≤ a32 < 232,L}
MOVE.L DR,(a32)
(aa) ↔ C4
MOVE.L (a16),C4 {0 ≤ a16 < 216,L}
MOVE.L C4,(a16)
(Rn + u3) ↔ DR
MOVE.L (Rn+u3),DR {0 ≤ u3 < 32,L}
MOVE.L DR,(Rn+u3)
(Rn + s15) ↔ DR
MOVE.L (Rn+s15),DR {–214 ≤ s15 < 214,L}
MOVE.L DR,(Rn+s15)
(Rn + Rr) ↔ DR
MOVE.L (Rn+Rr),DR
MOVE.L DR,(Rn+Rr)
(EA) ↔ DR
MOVE.L (EA),DR
MOVE.L DR,(EA)
(Rn) ↔ C3
MOVE.L (Rn),C3
MOVE.L C3,(Rn)
(SP – u6) ↔ DR
MOVE.L (SP–u6),DR {0 ≤ u6 < 256,L}
MOVE.L DR,(SP–u6)
(SP + s15) ↔ C4
MOVE.L (SP+s15),C4 {–214 ≤ s15 < 214,L}
MOVE.L C4,(SP+s15)
Description
These operations move a signed long word (32-bit data) from memory to a register, or from a register to
memory. Absolute addresses, offsets, and address register values must be long word-aligned (the address
must be a multiple of 4). The programmer should ensure that the effective address resides on a long word
boundary.
31
39
D
SC140 DSP Core Reference Manual
32
SIGN
EXTENSION
0
0
A-279
MOVE.L
MOVE.L (a32),DR
MOVE.L DR,(a32)
Moves a 32-bit long word between a data or address register and a memory address pointed to by a 32-bit
absolute address.
MOVE.L (a16),C4
MOVE.L C4,(a16)
Moves a 32-bit long word between a general register and a memory address pointed to by a 16-bit
unsigned absolute address.
MOVE.L (Rn+u3),DR
MOVE.L DR,(Rn+u3)
Moves a 32-bit long word between a data or address register and a memory address pointed to by an
address register plus a 3-bit unsigned offset that is preshifted right by 2 bits. The offset u3, defined by the
programmer, must be a multiple of four from 0:28. It is encoded by the assembler with 3 bits, thus
creating a 3-bit offset, which is coded in the instruction. The core, when decoding the instruction,
post shifts left the 3-bit offset to reconstruct the real offset. This feature enables condensed code
size when short immediates are needed.
MOVE.L (Rn+s15),DR
MOVE.L DR,(Rn+s15)
Moves a 32-bit long word between a data or address register and a memory address pointed to by an
address register plus a 15-bit signed offset.
MOVE.L (Rn+Rr),DR
MOVE.L DR,(Rn+Rr)
Moves a 32-bit long word between a data or address register and a memory address pointed to by an
address register plus the contents of a second address register as an offset. The second address register (Rr)
is shifted left by 2 bits prior to being added. The modifier mode of this instruction is determined by Rn in
MCTL. Rr is limited to R0–R7.
MOVE.L (EA),DR
MOVE.L DR,(EA)
Moves a 32-bit long word between a data or address register and a memory address pointed to by an
address register with optional offset or post-increment.
MOVE.L (Rn),C3
MOVE.L C3,(Rn)
Moves a 32-bit long word between a control, offset, or modifier register and a memory address pointed to
by an address register.
MOVE.L (SP–u6),DR
MOVE.L DR,(SP–u6)
Moves a 32-bit long word between a data or address register and a memory address pointed to by the active
stack pointer minus a 6-bit unsigned offset.
A-280
SC140 DSP Core Reference Manual
MOVE.L
MOVE.L (SP+s15),C4
MOVE.L C4,(SP+s15)
Moves a 32-bit long word between a general register and a memory address pointed to by the active stack
pointer plus a 15-bit signed offset.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3-AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is
an operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
move.l d0,(r0)
Register/Memory Address
Before
MCTL
After
$0000 0000
D0
$FF FFFF FFFA
R0
$0000 0084
$0084
$FFFF FFFA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.L (a32),DR
3
1
3
MOVE.L DR,(a32)
8
2
1
3
MOVE.L C4,(a16)
0
0
0
1 A A A A A A A A A A A A A
1
0
a
1
SC140 DSP Core Reference Manual
2
4
0 H H H H A A A a
a
a
a
a
a
a
8
7
a
a
a
a w 1
a
a
a
0
a
0
0
0
0 w D D D D A A A 0
1
0
0 A A A A A A A A A A A A A
15
MOVE.L (Rn+u3),DR
0
0
15
MOVE.L (a16),C4
7
0
1
8
0
1
1
0 D 1
7
1 H H H H w 1 R R R s
0
s
s
A-281
MOVE.L
MOVE.L DR,(Rn+u3)
15
MOVE.L (Rn+s15),DR
2
2
3
MOVE.L DR,(Rn+s15)
8
1
2
4
0
0
0
0 w H H H H 1
s
s
0
0 R R R
1
0
0
s
s
s
s
s
s
s
s
15
MOVE.L (Rn+Rr),DR
7
1
0
1
s
s
8
7
s
s
s
0
0 H H H H w 1 R R R
r
r
r
MOVE.L DR,(Rn+Rr)
15
MOVE.L (EA),DR
1
1
1
1
0
8
*
Note:
MOVE.L DR,(EA)
7
0
0 w H H H H 1
0 M M M R R R
** indicates serial grouping encoding.
15
MOVE.L (Rn),C3
1
1
4
1
8
0
0
7
1 D D D D 0
0
0
0
1 w R R R
MOVE.L C3, (Rn)
15
MOVE.L (SP–u6),DR
1
2
2
1
8
1
1
7
0
1 H H H H w 1
s
s
s
s
s
s
MOVE.L DR,(SP–u6)
15
MOVE.L (SP+s15),C4
MOVE.L C4,(SP+s15)
2
2
3
8
7
0
0
0
0 w D D D D 1
s
s
1
1
0 D 0
1
0
0
s
s
s
s
s
s
s
s
s
s
s
s
s
Note 1: When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
A-282
SC140 DSP Core Reference Manual
MOVE.L
Instruction Fields
C3
C4
DDDD
B0
0100
B4
1000
N0
1100
M0
0001
B1
0101
B5
1001
N1
1101
M1
0010
B2
0110
B6
1010
N2
1110
M2
0011
B3
0111
B7
1011
N3
1111
M3
DDDDD
00000
01000
D4
10000
R0
11000
R4
00001
B0
00010
D1
01001
B4
10001
N0
11001
M0
01010
D5
10010
R1
11010
R5
00011
B1
01011
B5
10011
N1
11011
M1
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
D3
01110
D7
10110
R3
11110
R7
00111
B3
01111
B7
10111
N3
11111
M3
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
D3
0111
D7
1011
R3
1111
R7
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
RRR
Address Register
Note:
Rr
Data/Address Register
0000
0011
Rn
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
HHHH
Note:
EA
General Registers
D0
Note:
DR
General Registers
0000
This instruction can specify R8-R15 as operands by using a high register prefix.
rrr
Address Register
000
R0
010
R2
001
R1
011
R3
Note: The Rr operand is limited to R0–R7.
w
100
101
R4
R5
110
111
R6
R7
Read/Write Notation
0
write
SC140 DSP Core Reference Manual
1
read
A-283
MOVE.L
a16
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
a32
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
s15
sssssssssssssss
Signed 15-bit offset
u3
sss00
Unsigned 3-bit offset
u6
ssssss00
Unsigned 6-bit SP offset
A-284
SC140 DSP Core Reference Manual
MOVE.W
MOVE.W
Move Immediate Integer Word (AGU)
MOVE.W
Operation
Assembler Syntax
#s7 → DR
MOVE.W #s7,DR {–64 ≤ s7 < 64}
#s16 → C4
MOVE.W #s16,C4 {–215 ≤ s16 < 215}
#s16 → (aa)
MOVE.W #s16,(a16) {–215 ≤ s16 < 215}{0 ≤ a16 < 216,W}
#s16 → (SP–u5)
MOVE.W #s16,(SP–u5) {–215 ≤ s16 < 215}{0 ≤ u5 < 64,W]
#s16 → (Rn)
MOVE.W #s16,(Rn) {–215 ≤ s16 < 215}
#s16 → (SP+sa16)
MOVE.W #s16,(SP+sa16) {–215 ≤ s16 < 215}{–215≤ sa16 < 215,W}
Description
These operations move a signed immediate integer word to a register or a memory address. The address of
the access must be word-aligned.
31
16
0
16
0
SIGN EXTENSION
39
D
SIGN EXTENSION
MOVE.W #s7,DR
Loads an immediate signed 7-bit value into the LP of a data or address register and sign-extends it.
MOVE.W #s16,C4
Loads an immediate signed 16-bit value into the LP of a general register and sign-extends it.
MOVE.W #s16,(a16)
Writes an immediate signed 16-bit value to an absolute 16-bit address.
MOVE.W #s16,(SP–u5)
Writes an immediate signed 16-bit value to a memory address pointed to by the active stack pointer (SP)
minus an unsigned 5-bit offset that is preshifted left 1 bit.
MOVE.W #s16,(Rn)
Writes an immediate signed 16-bit value to a memory address pointed to by an address register.
MOVE.W
#s16,(SP+sa16)
Writes a 16-bit signed immediate value to a memory address pointed to by the active stack pointer (SP)
plus a signed 16-bit offset.
SC140 DSP Core Reference Manual
A-285
MOVE.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is
an operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
move.w #$0050,r7
Register/Memory Address
immediate
R7
A-286
Before
After
$0000 0050
$0000 0050
SC140 DSP Core Reference Manual
MOVE.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.W #s7,DR
1
1
2
MOVE.W #s16,C4
2
1
4
1
8
0
0 H H H H 1
8
7
0
0
1
0 D D D D
1
0
0
i
i
i
i
0
0
1
1
1
0
0
0
0
1 A A A A A A A A A A A A A
1
0
i
15
3
1
3
i
i
i
i
15
MOVE.W #s16,(SP–u5)
2
2
3
2
1
3
3
2
3
i
i
i
i
i
i
i
0
0
0 D 0
i
i
i
i
i
i
i
i
i
8
7
0 A A A
i
i
1
0
0
i
i
8
7
i
i
0
0
i
i
i
i
i
i
i
0
0
0
1
1
0
0
0
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
i
i
i
i
0
0
0
0
1
1
0
0
1
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
15
MOVE.W #s16,(SP+sa16)
i
0
15
MOVE.W #s16,(Rn)
0
1
15
MOVE.W #s16,(a16)
7
1
0
1
0
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
0
i
0
i
0
i
1
i
i
0 A A A
i
i
i
i
i
i
i
1
i
i
0
i
1
i
Instruction Fields
C4
DDDDD
General Registers
00000
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
D1
01010
D5
10010
R1
11010
R5
00011
B1
01011
B5
10011
N1
11011
M1
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
D3
01110
D7
10110
R3
11110
R7
00111
B3
01111
B7
10111
N3
11111
M3
Note:
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-287
MOVE.W
DR
HHHH
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
Rn
#s16
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
#s7
Data/Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
iiiiiii
7-bit signed immediate data
iiiiiiiiiiiiiiii
16-bit signed immediate data
a16
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
sa16
AAAAAAAAAAAAAAAA
Signed 16-bit offset
AAAAA0
Unsigned 5-bit SP offset
u5
A-288
SC140 DSP Core Reference Manual
MOVE.W
MOVE.W
Move Integer Word (AGU)
MOVE.W
Operation
Assembler Syntax
(aa) ↔ DR
MOVE.W (a32),DR {0 ≤ a32 < 232,W}
MOVE.W DR,(a32)
(aa) ↔ C4
MOVE.W (a16),C4 {0 ≤ a16 < 216,W}
MOVE.W C4,(a16)
(Rn+u3) ↔ DR
MOVE.W (Rn+u3),DR {0 ≤ u3 < 16,W}
MOVE.W DR,(Rn+u3)
(Rn+s15) ↔ DR
MOVE.W (Rn+s15),DR {–214 ≤ s15 < 214,W}
MOVE.W DR,(Rn+s15)
(Rn+Rr) ↔ DR
MOVE.W (Rn+Rr),DR
MOVE.W DR,(Rn+Rr)
(EA) ↔ DR
MOVE.W (EA),DR
MOVE.W DR,(EA)
(Rn) ↔ C3
MOVE.W (Rn),C3
MOVE.W C3,(Rn)
(SP-u6) ↔ DR
MOVE.W (SP–u6),DR {0 ≤ u6 < 128,W}
MOVE.W DR,(SP–u6)
(SP+s15) ↔ C4
MOVE.W (SP+s15),C4 {–214 ≤ s15 < 214,W}
MOVE.W C4,(SP+s15)
Description
These operations either read a signed integer word from memory into the LP of a register and sign-extend
it, or write a signed integer word from the LP of a register to a memory address.
The address of the access must be word-aligned.
31
16
0
16
0
SIGN EXTENSION
39
D
SIGN EXTENSION
MOVE.W (a32),DR
MOVE.W DR,(a32)
Moves a signed word between a data or address register (DR) and an absolute 32-bit address.
MOVE.W (a16),C4
MOVE.W C4,(a16)
Moves a signed word between a general register (C4) and an absolute 16-bit address.
SC140 DSP Core Reference Manual
A-289
MOVE.W
MOVE.W (Rn+u3),DR
MOVE.W DR,(Rn+u3)
Moves a signed word between a data or address register (DR) and a memory address pointed to by an
address register (Rn) with an unsigned 3-bit offset that is preshifted right by 1 bit. The offset u3, defined by
the programmer, must be an even integer from 0–14. It is encoded by the assembler with 3 bits, thus
creating a 3-bit offset, which is coded in the instruction. The core, when decoding the instruction, post
shifts left the 3-bit offset to reconstruct the real offset. This feature enables condensed code size when short
immediates are needed.
MOVE.W (Rn+s15),DR
MOVE.W DR,(Rn+s15)
Moves a signed word between a data or address register (DR) and a memory address pointed to by an
address register (Rn) with a signed 15-bit offset.
MOVE.W (Rn+Rr),DR
MOVE.W DR,(Rn+Rr)
Moves a signed word between a data or address register (DR) and a memory address pointed to by an
address register (Rn) with an offset contained in another address register (Rr). The second address register
(Rr) is shifted left by one bit prior to being added. The modifier mode of this instruction is determined by
Rn in MCTL. Rr is limited to R0–R7.
MOVE.W (EA),DR
MOVE.W DR,(EA)
Moves a signed word between a data or address register (DR) and a memory address pointed to by (EA) an
address register with an optional offset or post-increment.
MOVE.W (Rn),C3
MOVE.W C3,(Rn)
Moves a signed word between a control, offset, or modifier register (C3) and a memory address pointed to
by an address register (Rn).
MOVE.W (SP–u6),DR
MOVE.W DR,(SP–u6)
Moves a signed word between a data or address register (DR) and a memory address pointed to by the
active stack pointer (SP) minus a 6-bit unsigned offset.
MOVE.W (SP+s15),C4
MOVE.W C4,(SP+s15)
Moves a signed word between a general register (C4) and a memory address pointed to by the active stack
pointer (SP) with a signed 15-bit offset.
A-290
SC140 DSP Core Reference Manual
MOVE.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
move.w d1,(r7+4)
Register/Memory Address
Before
MCTL
After
$0000 0000
d1
$FF FFFF FFF1
R7
$0000 000A
$000E
SC140 DSP Core Reference Manual
$0000 000A
$FFF1
A-291
MOVE.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVE.W (a32),DR
3
1
3
MOVE.W DR,(a32)
0
8
0
0
2
1
3
MOVE.W C4,(a16)
1
2
4
a w 0
0
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
a
a
8
7
a
a
a
a
a
a
a
0
0
0
0 w D D D D A A A 0
1
0
0 A A A A A A A A A A A A A
15
MOVE.W (Rn+u3),DR
0
0 H H H H A A A a
15
MOVE.W (a16),C4
7
1
8
0
1
1
0 D 0
7
0
1 H H H H w 0 R R R s
s
s
MOVE.W DR,(Rn+u3)
15
MOVE.W (Rn+s15),DR
2
2
3
MOVE.W DR,(Rn+s15)
8
1
2
4
0
0
0
0 w H H H H 0
s
s
0
0 R R R
1
0
0
s
s
s
s
s
s
s
s
15
MOVE.W (Rn+Rr),DR
7
1
0
1
s
s
8
7
s
s
s
0
0 H H H H w 0 R R R
r
r
r
MOVE.W DR,(Rn+Rr)
15
MOVE.W (EA),DR
1
12
1
0
8
*
7
0
0 w H H H H 0
0 M M M R R R
MOVE.W DR,(EA)
Notes:
1.
2.
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
0
MOVE.W (Rn),C3
1
1
4
1
0
0
1 D D D D 0
0
0
0 w R R R
MOVE.W C3,(Rn)
15
MOVE.W (SP+s15),C4
2
2
3
MOVE.W C4,(SP+s15)
8
1
2
2
0
0
0
0 w D D D D 0
s
s
1
1
0 D 0
1
0
0
s
s
s
s
s
15
MOVE.W (SP–u6),DR
7
1
1
1
s
s
s
s
s
s
8
7
1 H H H H w 0
s
s
0
s
s
s
s
s
s
MOVE.W DR,(SP–u6)
A-292
SC140 DSP Core Reference Manual
MOVE.W
Instruction Fields
w
Read/Write Notation
0
C3
C4
Rn
General Registers
B0
0100
B4
1000
N0
1100
M0
0001
B1
0101
B5
1001
N1
1101
M1
0010
B2
0110
B6
1010
N2
1110
M2
0011
B3
0111
B7
1011
N3
1111
M3
DDDDD
General Registers
00000
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
D1
01010
D5
10010
R1
11010
R5
00011
B1
01011
B5
10011
N1
11011
M1
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
D3
01110
D7
10110
R3
11110
R7
00111
B3
01111
B7
10111
N3
11111
M3
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
Rr
read
0000
Note:
EA
1
DDDD
Note:
DR
write
This instruction can specify R8-R15 as operands by using a high register prefix.
rrr
Address Register
000
001
Note:
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
The Rr register file is limited to the lower bank R0–R7.
SC140 DSP Core Reference Manual
A-293
MOVE.W
a16
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
a32
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
s15
sssssssssssssss
Signed 15-bit offset
u3
sss0
Unsigned 3-bit offset
u6
ssssss0
Unsigned 6-bit SP offset
A-294
SC140 DSP Core Reference Manual
MOVEc
MOVEc
Conditional Address Register Move (AGU)
Operation
Assembler Syntax
If T=1, then Rq → Rn
MOVET Rq,Rn
If T=0, then Rq → Rn
MOVEF Rq,Rn
MOVEc
Description
This instruction conditionally copies the value of one address register to another, depending on the value of
the T bit in SR. These operations have the same timing as other move instructions. MOVEc is performed in
the execution stage of the pipeline, unlike TFRA, which is performed in the address generation stage.
MOVET Rq,Rn
Copies one address register to another if the T bit is set.
MOVEF Rq,Rn
Copies one address register to another if the T bit is cleared.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[1]
T
True bit
Status and Conditions Changed by Instruction
None.
Example
movet r0,r1
Register/Memory Address
Before
After
SR
$00E4 0002
R0
$0000 0010
R1
Note:
$0000 0010
$00E4 0002 in the status register indicates that the true bit is set.
SC140 DSP Core Reference Manual
A-295
MOVEc
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MOVET Rq,Rn
1
4
1
8
0
0
1
1 R R R 0
15
1
MOVEF Rq,Rn
1
4
1
8
0
0
1
7
0
1
0
1
0
q
q
7
1 R R R 0
q
0
1
0
1
1
q
q
q
Instruction Fields
Rq
qqq
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
Rn
This instruction can specify R8-R15 as operands by using a high register prefix.
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-296
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
MOVES.2F
MOVES.2F
Move Two Fractional Words to
Memory With Scaling and
Saturation (AGU)
MOVES.2F
Operation
Assembler Syntax
Da:Db → (EA)
MOVES.2F Da:Db,(EA)
Description
The data that is moved from each register to memory is scaled according to the scaling mode. If the Ln bit
is set, the moved data is also saturated. The address register values must be long aligned. This instruction is
affected by by SM (Saturation Mode bit - SR[2]). When SM is set, scaling is not performed, and the scale
bits S[1:10] have no effect.
MOVES.2F Da:Db,(EA)
Moves two signed fractional words from a data register pair to a memory address pointed to by an address
register with an optional offset or post-increment.
The first operand (Da) will be moved to the lower memory address (EA). The second operand (Db) will be
moved to memory address (EA + 2). In order to keep this behavior in both big endian and little endian
modes, the core will interpret the data bus differently in each mode. See Section 2.4.1, “SC140 Endian
Support,” on page 2-56, for more detail on bus and memory behavior for each mode.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[5:4]
S[1:0]
Scaling mode bits choose: no scaling, scale up one bit, or scale down
one bit.
Ln
L
Limited values are written to the destination if the Ln bit is set.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[6]
S
Scaling bit, set when the absolute value of either or both of the
words moved (after scaling and limiting) is greater than or equal to
0.25 and less than 0.75.
Example
moves.2f d0:d1,(r0)
Register/Memory Address
Before
MCTL
SC140 DSP Core Reference Manual
After
$0000 0000
A-297
MOVES.2F
Register/Memory Address
Before
After
SR
$00E0 0000
d0
$1:$00 8000 0000
d1
$0:$00 7EAC F00D
R0
$0000 0054
$00E0 0000
$0054
$7FFF
$0056
$7EAC
The Ln bit is set in d0, and the number in d0 is positive (bit 39 = 0), so the saturated value $7FFF is written
to memory.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MOVES.2F Da:Db,(EA)
Notes:
1.
2.
12
1
0
*
0
0
1
h
h
8
7
0
1
0
1 M M M R R R
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
Da:Db
hh
Data Register Pairs
00
Note:
EA
Rn
01
D2:D3
10
D4:D5
11
D6:D7
This instruction can specify D8-D15 as operands by using a prefix.
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
Address Register
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
A-298
D0:D1
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
MOVES.4F
MOVES.4F
MOVES.4F
Move Four Fractional Words to
Memory With Scaling and Saturation (AGU)
Operation
Assembler Syntax
Da:Db:Dc:Dd → (EA)
MOVES.4F Da:Db:Dc:Dd,(EA)
Description
The data that is moved from each register to memory is scaled according to the scaling mode. If the Ln bit
is set, it is also saturated. The address register values must be quad word-aligned (a multiple of 8). This
instruction is affected by by SM (Saturation Mode bit - SR[2]). When SM is set, scaling is not performed,
and the scale bits S[1:10] have no effect.
MOVES.4F Da:Db:Dc:Dd,(EA)
Writes four signed fractional words from a data register quad to memory addresses pointed to by an address
register with an optional offset or post-increment.
The first operand (Da) will be moved to the lower memory address (EA). The second operand (Db) will be
moved to memory address (EA + 2). The third operand (Dc) will be moved to memory address (EA + 4).
And, the fourth operand (Dd) will be moved to memory address (EA + 6). In order to keep this behavior in
both big endian and little endian modes, the core will drive the data bus differently in each mode. See
Section 2.4.1, “SC140 Endian Support,” on page 2-56, for more detail on bus and memory behavior for
each mode.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[5:4]
S[1:0]
Scaling mode bits choose: no scaling, scale up one bit, or scale
down one bit.
Ln
L
Limited values are written to the destination if the Ln bit is set.
EMR[16]
BEM
Set if big endian mode, cleared if little endian mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[6]
S
Scaling bit, set when the absolute value of any one of the words
moved (after scaling and limiting) is greater than or equal to 0.25
and less than 0.75.
Example
moves.4f d0:d1:d2:d3,(r0)
Register/Memory Address
Before
SR
SC140 DSP Core Reference Manual
After
$00E0 0000
A-299
MOVES.4F
Register/Memory Address
Before
After
R0
$0000 0050
L0:D0
$1:$0 08000 0000
L1:D1
$0:$00 7FFF FFFF
L2:D2
$1:$87 6543 2100
L3:D3
$0:$FF 8765 4321
$0050
$7FFF
$0052
$7FFF
$0054
$8000
$0056
$8765
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
MOVES.4F
12
1
0
*
0
0
1
k
0
8
7
0
0
1
1 M M M R R R
Da:Db:Dc:Dd,(EA)
Notes:
1.
2.
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
Da:Db:Dc:Dd
k
Data Register Quad
0
Note:
EA
Rn
1
D4:D5:D6:D7
This instruction can specify D8-D15 as operands by using a prefix.
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
000
001
Note:
A-300
D0:D1:D2:D3
Address Register
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
This instruction can specify R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
MOVES.F
MOVES.F
MOVES.F
Move Fractional Word to
Memory With Scaling and Saturation (AGU)
Operation
Assembler Syntax
Db → (aa)
MOVES.F Db,(a16) {0 ≤ a16 < 216,W}
Db → (aa)
MOVES.F Db,(a32) {0 ≤ a32 < 232,W}
Db → (Rn + s15)
MOVES.F Db,(Rn+s15) {–214 ≤ s15 < 214,W}
Db → (EA)
MOVES.F Db,(EA)
Db → (SP + s15)
MOVES.F Db,(SP+s15) {–214 ≤ s15 < 214,W}
Description
This operation moves a fractional word from a data register to memory. The data is scaled according to the
scaling mode and is saturated if the Ln bit is set. The address register values must be word-aligned. This
instruction is affected by by SM (Saturation Mode bit - SR[2]). When SM is set, scaling is not performed,
and the scale bits S[1:10] have no effect. The address of the access must be word-aligned.
MOVES.F Db,(a16)
Writes the HP of a data register (Db) to an absolute 16-bit memory address.
MOVES.F Db,(a32)
Writes the HP of a data register (Db) to an absolute 32-bit memory address.
MOVES.F Db,(Rn+s15)
Writes the HP of a data register (Db) to a memory address pointed to by an address register (Rn) with a
signed 15-bit offset.
MOVES.F Db,(EA)
Writes the HP of a data register (Db) to a memory address pointed to by an address register (EA) with an
optional offset or post-increment.
MOVES.F Db,(SP+s15)
Writes the HP of a data register (Db) to a memory address pointed to by the active stack pointer (SP) with
a signed 15-bit offset.
SC140 DSP Core Reference Manual
A-301
MOVES.4F
Status and Conditions that Affect Instruction
Register
Address
Bit Name
MCTL[31:0]
AM3–AM0 Address modification bits for R0–R7.
SR[5:4]
S[1:0]
Scaling mode bits choose: no scaling, scale up one bit, or scale
down one bit.
Ln
L
Limited values are written to the destination if the Ln bit is set.
SR[18]
EXP
Determines the stack pointer used in instructions that have a stack pointer
as an operand.
Description
Status and Conditions Changed by Instruction
Register
Address
Bit Name
Description
SR[6]
S
Scaling bit, set when the absolute value of the data moved (after
scaling and limiting) is greater than or equal to 0.25 and less than
0.75.
Example
moves.f d0,(r0)
Register/Memory Address
Before
After
SR
$00E0 0000
R0
$0000 0050
L0:D0
($0050)
$00E0 0000
$1:$00 8000 0000
$7FFF
The Ln bit is set in d0, and the number in d0 is positive (bit 39 = 0), so the saturated value $7FFF is written
to memory.
A-302
SC140 DSP Core Reference Manual
MOVES.4F
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
MOVES.F Db,(a16)
1
3
0
0
j
j
3
1
3
2
2
1
MOVES.F Db,(EA)
Notes:
1.
2.
1
A A A 0
1
0
0 A A A A A A A A A A A A A
0
0
0
0
j
j
8
7
j
A A A a
1
1
1
1
0
a
0
1
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
a
a
8
7
a
a
a
a
a
a
a
0
0
0
0
0
0
j
j
j
1
s
s
1
0 R R R
1
0
0
s
s
s
s
s
s
s
s
s
s
8
7
0
j
0
1 M M M R R R
8
7
0
15
12
j
0
0
3
0
0
15
MOVES.F Db,(Rn+s15)
7
0
15
MOVES.F Db,(a32)
8
0
*
0
0
0
j
j
s
s
s
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
15
2
MOVES.F Db,(SP+s15)
2
3
0
0
0
0
0
j
j
j
1
s
s
1
1
1
1
0
1
0
0
s
s
s
s
s
s
s
s
s
s
s
s
s
Instruction Fields
Db
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
EA
Rn
MMM
a32
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
RRR
Note:
a16
This instruction can specify D8-D15 as operands by using a prefix.
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
SC140 DSP Core Reference Manual
32-bit absolute long address
A-303
MOVES.4F
s15
A-304
sssssssssssssss
Signed 15-bit offset
SC140 DSP Core Reference Manual
MOVES.L
MOVES.L
MOVES.L
Move Long to
Memory With Scaling and Saturation (AGU)
Operation
Assembler Syntax
Db → (EA)
MOVES.L Db,(EA)
Description
The data is scaled according to the scaling mode, and saturated if the Ln bit is set. The address register
values must be long word-aligned. This instruction is affected by by SM (Saturation Mode bit - SR[2]).
When SM is set, scaling is not performed, and the scale bits S[1:10] have no effect
MOVES.L Db,(EA)
Moves a saturated long word from a data register (Db) to a memory address pointed to by an address
register with an optional offset or post-increment.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[5:4]
S[1:0]
Scaling mode bits choose: no scaling, scale up one bit, or
scale down one bit.
Ln
L
Limited values are written to the destination if the Ln bit is set.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[6]
S
Scaling bit, set when the absolute value of the data moved (after
scaling and limiting) is greater than or equal to 0.25 and less than
0.75.
Example
moves.l d0,(r0)
Register/Memory Address
Before
After
SR
$00E0 0000
R0
$0000 0054
L0:D0
$00000054
SC140 DSP Core Reference Manual
$00E0 0000
$1:$00 8000 0000
$7FFF FFFF
A-305
MOVES.L
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVES.L Db,(EA)
Notes:
1.
2.
1
1
2
1
0
*
0
0
0
j
j
8
7
0
j
1
1 M M M R R R
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
Db
A-306
This instruction can specify R8-R15 as operands by using a high register prefix.
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
EA
Address Register
This instruction can specify D8-D15 as operands by using a prefix.
MMM
Effective Address Notation
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
SC140 DSP Core Reference Manual
MOVEU.B
MOVEU.B
Move Unsigned Byte from
Memory (AGU)
MOVEU.B
Operation
Assembler Syntax
(aa) → DR
MOVEU.B (a16),DR {0 ≤ a16 < 216}
(aa) → DR
MOVEU.B (a32),DR {0 ≤ a32 < 232}
(Rn + s15) → DR
MOVEU.B (Rn+s15),DR {–214 ≤ s15 < 214}
(ea) → DR
MOVEU.B (ea),DR
(SP + s15) → DR
MOVEU.B (SP+s15),DR {–214 ≤ s15 < 214}
Description
These operations move an unsigned byte from memory into a data or address register (DR). Data is placed
in bits 7:0 of the destination register (DR) and zero-extended.
31
8
0
8
0
ZERO EXTENSION
39
D
ZERO EXTENSION
MOVEU.B (a16),DR
Reads an unsigned byte from a 16-bit unsigned absolute address in memory into a data or address register
(DR).
MOVEU.B (a32),DR
Reads an unsigned byte from an absolute 32-bit address in memory into a data or address register (DR).
MOVEU.B (Rn+s15),DR
Reads an unsigned byte from a memory address pointed to by an address register with a signed 15-bit
offset into a data or address register (DR).
MOVEU.B (ea),DR
Reads an unsigned byte from a memory address pointed to by an address register with an optional offset or
post-increment into a data or address register (DR).
MOVEU.B (SP+s15),DR
Reads an unsigned byte from a memory address pointed to by the active stack pointer with a signed 15-bit
offset into a data or address register (DR).
SC140 DSP Core Reference Manual
A-307
MOVEU.B
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
moveu.b ($0053),d10
Register/Memory Address
($0053)
D10
A-308
Before
After
$F8
$0:$00 0000 00F8
SC140 DSP Core Reference Manual
MOVEU.B
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
MOVEU.B (a16),DR
1
3
8
3
1
3
0
0
1 H H H H A A A 0
1
0
0 A A A A A A A A A A A A A
0
8
0
0
2
2
3
1
MOVEU.B (ea),DR
4
2
2
0
0
a
1
0
1
0
1 A A A A A A A A A A A A A
0
a
a
a
a
a
a
a
8
7
a
a
a
a
a
a
a
0
0
0
0
1 H H H H 0
s
s
1
0 R R R
1
0
0
s
s
s
s
s
1
3
0
1
s
s
s
0
0
s
s
8
7
1 H H H H 1
15
MOVEU.B (SP+s15),DR
1
0
15
11
1
7
0 H H H H A A A a
15
MOVEU.B (Rn+s15),DR
0
0
15
MOVEU.B (a32),DR
7
8
s
s
s
0
0
1 M M R R R
7
0
0
0
0
1 H H H H 0
s
s
1
1
1
0
0
1
0
0
s
s
s
s
s
s
s
s
s
s
s
s
s
Note 1: When the form (Rn + N0) is used in ea, the cycle count is increased by 1.
Instruction Fields
DR
HHHH
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
ea
Effective Address Notation
(Rn)+
01
RRR
000
001
Note:
a16
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
MM
00
Rn
Data/Address Register
(Rn)–
10
(Rn+N0)
11
(Rn)
Address Register
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
SC140 DSP Core Reference Manual
A-309
MOVEU.B
a32
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
s15
sssssssssssssss
Signed 15-bit offset
A-310
SC140 DSP Core Reference Manual
MOVEU.L
MOVEU.L
Move Unsigned Immediate Long
to a Data Register (AGU)
MOVEU.L
Operation
Assembler Syntax
#u32 → Db
MOVEU.L #u32,Db {0 ≤ u32 < 232}
Description
MOVEU.L #u32,Db
Loads an unsigned long word (32-bit) immediate value into a data register (Db), zero-extending it.
39
32
ZERO
EXTENSION
Db
0
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
moveu.l #$fffffff8,d3
Register/Memory Address
Before
Immediate
D3
SC140 DSP Core Reference Manual
After
$FFFF FFF8
$0:$00 FFFF FFFF8
A-311
MOVEU.L
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MOVEU.L #u32,Db
3
1
3
0
1
0
j
j
8
7
j
i
0
0
1
i
i
I
I
0
0
1
0
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
1
0
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Instruction Fields
Db
jjj
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#u32
A-312
This instruction can specify D8-D15 as operands by using a prefix.
(31)IIIIIIIIIIIIIIII(16)
(15)iiiiiiiiiiiiiiii (0)
32-bit unsigned immediate data
SC140 DSP Core Reference Manual
MOVEU.W
MOVEU.W
Move Unsigned Immediate Word
to a Register Portion (AGU)
MOVEU.W
Operation
Assembler Syntax
#u16 → Db[31:16]
MOVEU.W #u16,Db.H {0 ≤ u16 < 216}
#u16 → Db[15:0]
MOVEU.W #u16,Db.L {0 ≤ u16 < 216}
Description
These operations move an immediate unsigned word to a high/low part of a data register (Db) without
changing the other bits in the data register (Db).
MOVEU.W #u16,Db.H
Loads an immediate unsigned word into the HP of a data register (Db). The other bits in the register are
unchanged.
39
32
UNCHANGED
Db
16
0
UNCHANGED
MOVEU.W #u16,Db.L
Loads an immediate unsigned word into the LP of a data register (Db). The other bits in the register are
unchanged.
39
16
0
UNCHANGED
Db
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
moveu.w #$2345,d10.l
Register/Memory Address
Before
Immediate
D10
SC140 DSP Core Reference Manual
After
$2345
$0:$00 ABCD EFFF
$0:$00 ABCD 2345
A-313
MOVEU.W
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
MOVEU.W #u16,Db.H
1
3
2
1
3
7
0
0
0
0
1
1
0
0
1
i
i
i
1
0
j
j
j
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
8
7
15
MOVEU.W #u16,Db.L
8
0
0
0
0
1
1
0
0
1
i
i
i
0
0
j
j
j
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
Db
jjj
Single Source/Destination Data Register
000
001
Note:
#u16
A-314
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
SC140 DSP Core Reference Manual
MOVEU.W
MOVEU.W
Move Unsigned Word from
Memory to a Register (AGU)
MOVEU.W
Operation
Assembler Syntax
(aa) → C4
MOVEU.W (a16),C4 {0 ≤ a16 < 216}
(aa) → DR
MOVEU.W (a32),DR {0 ≤ a32 < 232}
(Rn + s15) → DR
MOVEU.W (Rn+s15),DR {–214 ≤ s15 < 214}
(EA) → DR
MOVEU.W (EA),DR
(SP + s15) → C4
MOVEU.W (SP+s15),C4 {–214 ≤ s15 < 214}
Description
These operations move an unsigned word from memory to the LP of a register and zero-extend it. The
address of the access must be word-aligned.
31
R/C4
39
D
16
0
16
0
ZERO EXTENSION
ZERO EXTENSION
MOVEU.W (a16),C4
Reads an unsigned word from an 16-bit unsigned absolute address, places the data in the LP of a general
register (C4), and zero-extends the upper bits.
MOVEU.W (a32),DR
Reads an unsigned word from an absolute 32-bit address, places the data in the LP of a data or address
register (DR), and zero-extends the upper bits.
MOVEU.W (Rn+s15),DR
Reads an unsigned word from a memory address pointed to by an address register (Rn) with a signed 15-bit
offset, places the data in the LP of a data or address register (DR), and zero-extends the upper bits.
MOVEU.W (EA),DR
Reads an unsigned word from a memory address pointed to by an address register with an optional offset or
post-increment, places the data in the LP of a data or address register (DR), and zero-extends the upper
bits.
MOVEU.W (SP+s15),C4
Reads an unsigned word from a memory address pointed to by the active stack pointer (SP) with a signed
15-bit offset, places the data in the LP of a general register (C4), and zero-extends the upper bits.
SC140 DSP Core Reference Manual
A-315
MOVEU.W
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
MCTL[31:0]
AM3–AM0 Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
moveu.w (r7+2),d10
Register/Memory Address
Before
After
MCTL
$0000 0000
R7
$0000 0050
(R7+2)
D10
A-316
$FFF8
$00 1010 0000
$00 0000 FFF8
SC140 DSP Core Reference Manual
MOVEU.W
Instruction Formats and Opcodes
Instructions
Words Cycles Type
Opcode
15
2
MOVEU.W (a16),C4
1
3
8
3
1
3
0
0
1 D D D D A A A 0
1
0
0 A A A A A A A A A A A A A
0
8
0
0
2
2
3
1
MOVEU.W (EA),DR
Notes:
1.
2.
1
1 D 1
0
a
1
1
1
0
0
1 A A A A A A A A A A A A A
1
0
a
a
a
a
a
a
a
8
7
a
a
a
a
a
a
a
0
0
0
0
1 H H H H 1
s
s
1
0 R R R
1
0
0
s
s
s
s
s
s
s
s
s
s
8
7
0
1 H H H H 1
1 M M M R R R
15
12
1
7
0 H H H H A A A a
15
MOVEU.W (Rn+s15),DR
0
0
15
MOVEU.W (a32),DR
7
0
*
0
s
s
s
** indicates serial grouping encoding.
When the form (Rn + N0) is used in EA, the cycle count is increased by 1.
15
MOVEU.W (SP+s15),C4
2
2
3
8
7
0
0
0
0
1 D D D D 1
s
s
1
1
1 D 0
1
0
0
s
s
s
s
s
s
s
s
s
s
s
s
s
Instruction Fields
C4
DDDDD
00000
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
D1
01010
D5
10010
R1
11010
R5
00011
B1
01011
B5
10011
N1
11011
M1
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
D3
01110
D7
10110
R3
11110
R7
00111
B3
01111
B7
10111
N3
11111
M3
Note:
DR
General Registers
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-317
MOVEU.W
EA
Rn
MMM
000
(Rn+N0)
010
(Rn)
100
(Rn)+N0
110
(Rn)+N2
001
(Rn)–
011
(Rn)+
101
(Rn)+N1
111
(Rn)+N3
RRR
000
001
Note:
a16
Effective Address Notation
Address Register
R0
010
R2
100
R4
110
R6
R1
011
R3
101
R5
111
R7
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
a32
aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA
32-bit absolute long address
s15
sssssssssssssss
Signed 15-bit offset
A-318
SC140 DSP Core Reference Manual
MPY
MPY
Signed Fractional Multiply (DALU)
Operation
Assembler Syntax
Da.H * Db.H → Dn
MPY Da,Db,Dn
MPY
Description
MPY Da,Db,Dn
Performs signed fractional multiplication of the high portions of two data registers (Da, Db) and stores the
product in a destination data register (Dn).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling bits determine which bits in the result are used in the Ln bit
calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic saturation
mode (SR [SM] = 1), clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in saturation mode.
Example 1
mpy d4,d5,d6
Register/Memory Address
Before
After
SR
$00E0 0000
D4
$FF C000 0000
D5
$00 2000 0000
L6:D6
EMR
SC140 DSP Core Reference Manual
$0:$FF F000 0000
$0000 0000
A-319
MPY
0.010 $2000 1/4
x 1.100$C000 –1/2
1.111 $F000 –1/8
Example 2
mpy d6,d6,d7
Register/Memory Address
Before
After
D6
$FF C000 0000
L7:D7
$0:$00 2000 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MPY Da,Da,Dn
1
1
1
MPY Da,Db,Dn
1
1
1
0
8
1
0
1
0
F F F
*
1
0
0
0
F F F
15
Note:
0
7
*
8
0
1
1
1
0
0
j
0
1
J
J
J
J
7
j
0
J
** indicates serial grouping encoding.
Instruction Fields
Da,Da
jj
Data Register Pairs
00
Note:
Da,Db
D1,D1
JJJJJ
D3,D3
10
D5,D5
11
D7,D7
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
2.
3.
A-320
01
This instruction can specify D8-D15 as operands by using a prefix.
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be inverted for clarity because the order of operation is not important
for multiply operations.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, and D7–D7. These
are covered in the jj encoding.
SC140 DSP Core Reference Manual
MPY
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-321
MPYR
MPYR
MPYR
Signed Fractional Multiply
and Round (DALU)
Operation
Assembler Syntax
Rnd((Da.H * Db.H)) → Dn
MPYR Da,Db,Dn
Description
MPYR Da,Db,Dn
Performs signed fractional multiplication of the high portions of a data register pair (Da, Db), rounds the
product, and stores the result in a destination data register (Dn). Rounding adjusts the LSB of the high part
of the destination register according to the value of the low part of the register and then zeros the low part.
The two modes of the round function, Rnd(), are described on page A-359.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[3]
RM
Rounding mode
SR[5:4]
S[1:0]
Scaling bits determine which bits in the result are used in the Ln bit
calculation and which bits are used in rounding.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in saturation mode.
Example
mpyr d4,d5,d6
Register/Memory Address
Before
After
SR
$00E0 0000
D4
$00 4001 0000
D5
$00 4002 0000
A-322
SC140 DSP Core Reference Manual
MPYR
Register/Memory Address
Before
After
L6:D6
$0:$00 2002 0000
EMR
$0000 0000
0.100 0000 0000 0001$4001
x 0.100 0000 0000 0010$4002
0.010 0000 0000 0001 1000 0000 0000 0000$2001 8000
rounded 0.010 0000 0000 0010$2002
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MPYR Da,Db,Dn
1
1
1
MPYR Da,Da,Dn
1
1
1
0
8
1
0
0
1
F F F
*
1
0
0
0
F F F
15
Note:
0
7
*
8
0
0
1
J
J
J
J
1
1
0
1
0
j
7
J
0
j
** indicates serial grouping encoding.
Instruction Fields
Da,Db
JJJJJ
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
2.
3.
Da,Da
jj
Data Register Pairs
00
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
Register pair order can be inverted for clarity because the order of operation is not important
for multiply operations.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, and D7–D7. These
are covered in the jj encoding.
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-323
MPYR
A-324
SC140 DSP Core Reference Manual
MPYSU
MPYSU
MPYSU
Fractional Multiply
Signed By Unsigned (DALU)
Operation
Assembler Syntax
Dc.H * Dd.L → Dn
MPYSU Dc,Dd,Dn
Description
MPYSU Dc,Dd,Dn
Performs signed fractional multiplication between the signed 16-bit HP of the first register (Dc) of a data
register pair with the unsigned 16-bit LP of the second register (Dd). It then stores the sign-extended 32-bit
product in a destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
mpysu d4,d5,d6
Register/Memory Address
Before
After
D4
$FF C000 0001
D5
$FF E000 0002
L6:D6
$0:$FF FFFF 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MPYSU Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
1
1
7
F F F
0
1
1
0
1
0
e
e
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
D0,D1
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-325
MPYSU
Dn
FFF
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-326
Single Source/Destination Data Register
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MPYUS
MPYUS
MPYUS
Fractional Multiply
Unsigned By Signed (DALU)
Operation
Assembler Syntax
Dc.L * Dd.H → Dn
MPYUS Dc,Dd,Dn
Description
MPYUS Dc,Dd,Dn
Performs signed fractional multiplication between the unsigned 16-bit LP of the first register (Dc) of a data
register pair with the signed 16-bit HP of the second register (Dd). It then stores the sign-extended 32-bit
product in a destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
mpyus d2,d3,d4
Register/Memory Address
Before
After
D2
$FF FF00 0002
D3
$FF C000 0042
L4:D4
$0:$FF FFFF 0000
1.100 $C000 (–2–1)
x 0.000 0000 0000 0010$0002 (2–14)
1.111 1111 1111 1111$FFFF (–2–15)
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MPYUS Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
0
0
7
F F F
0
1
1
1
0
1
e
e
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-327
MPYUS
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-328
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
MPYUU
MPYUU
MPYUU
Fractional Multiply
Unsigned By Unsigned (DALU)
Operation
Assembler Syntax
Dc.L * Dd.L → Dn
MPYUU Dc,Dd,Dn
Description
MPYUU Dc,Dd,Dn
Performs unsigned fractional multiplication between the unsigned 16-bit LP of the first register (Dc) of a data register
pair with the unsigned 16-bit LP of the second register (Dd). It then stores the sign-extended 32-bit product in a
destination data register (Dn).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
mpyuu d4,d5,d6
Register/Memory Address
Before
After
D4
$00 4000 2000
D5
$FF E000 4000
L6:D6
$0:$00 1000 0000
0.010 $2000 (2–2)
x 0.100$4000 (2–1)
0.001 $1000 (2–3)
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
MPYUU Dc,Dd,Dn
Note:
1
1
1
0
8
*
1
0
1
1
7
F F F
0
1
1
0
1
1
e
e
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
A-329
MPYUU
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
Dn
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-330
D0,D1
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
NEG
N-R
NEG
NEG
Negate (DALU)
Operation
Assembler Syntax
0 – Dn → Dn
NEG Dn
Description
NEG Dn
Negates the contents of a source data register (Dn) and stores the 40-bit two’s complement result in a
destination data register (Dn).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in saturation mode.
Example
neg d3
Register/Memory Address
Before
SR
After
$00E0 0000
L3:D3
$0:$00 0765 1235
$0:$FF F89A EDCB
EMR
$0000 0000
0000 0111 0110 0101 0001 0010 0011 0101
invert 1111 1000 1001 1010 1110 1101 1100 1010
add one 1111 1000 1001 1010 1110 1101 1100 1011
SC140 DSP Core Reference Manual
A-331
NEG
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
NEG Dn
Note:
1
1
0
8
*
1
0
0
1
7
0
F F F
1
1
0
0
1
0
0
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-332
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
NOP
NOP
NOP
No Operation (PREFIX)
Operation
Assembler Syntax
no operation
NOP
Description
NOP
This instruction is encoded as a one-word prefix inside the set, or alone. If the NOP is the only instruction
in the execution set, it takes one cycle to execute although no operation is done. This is useful in case
delays are needed in a program for various reasons (for example, to account for pipeline delays). The NOP
instruction is not dispatched to any execution unit. As a prefix, it is identified by the dispatcher and is not
dispatched further.
If grouped with other instructions (as an intra-group NOP), it functions as a program place-holder.
In a few isolated cases, the assembler adds this instruction inside an execution set to help arrange the
instructions within that set for proper dispatching. These cases are implementation-dependent. The
assembler issues a warning to make the user aware of the event.
Status and conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
nop
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
NOP
1
1
SC140 DSP Core Reference Manual
4
1
0
0
1
0
0
0
8
7
0
1
0
1
0
0
0
0
0
0
A-333
NOT
NOT
NOT
Bitwise Complement (DALU)
Operation
Assembler Syntax
~Da → Dn
NOT Da,Dn
Description
NOT Da,Dn
Replaces the contents of the destination data register (Dn) with the 40-bit one’s complement of the source
data register (Da).
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example
not d4,d5
Register/Memory Address
Before
D4
After
$FF FFFF FFFB
L5:D5
$0:$00 0000 0004
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
NOT Da,Dn
1
2
1
8
1
0
1
1
0
7
F F F
0
0
0
0
0
J
J
J
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-334
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
NOT
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-335
NOT
NOT
Binary Inversion of a 16-Bit Operand (BMU)
Operation
Assembler Syntax
~DR.L → DR.L
NOT DR.L
~DR.H→ DR.H
NOT DR.H
NOT
Description
NOT DR.L
Inverts the LP of a source data or address register (DR). The other bits are unchanged. This instruction is
assembler-mapped to BMCHG DR.L with the full mask enabled.
NOT DR.H
Inverts the HP of a source data or address register (DR). The other bits are unchanged. This instruction is
assembler-mapped to BMCHG DR.H with the full mask enabled.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
not D0.L
Register/Memory Address
L0:D0
A-336
Before
$1:$00 3FF2 FFFB
After
$0:$00 3FF2 0004
SC140 DSP Core Reference Manual
NOT
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
NOT DR.L
2
2
3
2
2
3
7
0
0
0
0
0
1
0
1
0
1
1
1
0 H H H H
1
0
1
1
1
1
1
1
1
1
1
1
8
7
15
NOT DR.H
8
1
1
1
1
0
0
0
0
0
1
0
1
0
1
1
1
1 H H H H
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Instruction Fields
DR
HHHH
Data/Address Register
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
SC140 DSP Core Reference Manual
A-337
NOT.W
NOT.W
Binary Inversion of a 16-Bit Operand
in Memory (BMU)
NOT.W
Operation
Assembler Syntax
~(R) → (R)
NOT.W (Rn)
~(SP–u5) → (SP–u5)
NOT.W (SP–u5) {0 ≤ u5 < 64,W]
~(SP+s16) → (SP+s16)
NOT.W (SP+s16) {–215 ≤ s16 < 215,W}
~(a16) → (a16)
NOT.W (a16) {0 ≤ a16 < 216,W}
Description
These operations read from memory, invert the retrieved value, and write the new value back to the same
memory address, resulting in two memory accesses.
The absolute addresses, offsets, and address register values must be word-aligned.
NOT.W (Rn)
Replaces the contents of a memory address pointed to by an address register (Rn) with its complement.
This instruction is assembler-mapped to BMCHG.W #$FFFF,(Rn). The full mask is enabled.
NOT.W (SP–u5)
Replaces the contents of a memory address pointed to by the active stack pointer (SP) minus a 5-bit
unsigned immediate value with its complement. This instruction is assembler-mapped to
BMCHG.W #$FFFF,(SP–u5). The full mask is enabled.
NOT.W (SP+s16)
Replaces the contents of a memory address pointed to by the active stack pointer (SP) offset by a 16-bit
signed immediate value with its complement. This instruction is assembler-mapped to
BMCHG.W #$FFFF,(SP+s16). The full mask is enabled.
NOT.W (a16)
Replaces the contents of a memory address pointed to by a 16-bit unsigned absolute address with its
complement. This instruction is assembler-mapped to BMCHG.W #$FFFF,(a16). The full mask is enabled.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
A-338
SC140 DSP Core Reference Manual
NOT.W
Example
not.w (r1)
Register/Memory Address
Before
After
R1
$0000 0050
($50)
$FFFB
$0004
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
NOT.W (Rn)
2
3
2
3
3
3
3
3
0
1
0
0
1
0
1
1
1
0
1 R R R
1
0
1
1
1
1
1
1
1
1
1
1
1
8
7
3
2
1
1
0
0
0
0
0
0
1
0
1
1
1 A A A A A
1
0
1
1
1
1
1
1
1
1
1
8
7
0
3
1
0
0
1
1
1
0
1
1
1
1
1
1
0
0 A A A 1
1
0
1
1
0
0
1 A A A A A A A A A A A A A
1
0
1
1
1
1
1
15
NOT.W (a16)
0
0
15
NOT.W (SP+s16)
7
0
15
NOT.W (SP–u5)
8
1
7
1
1
1
1
1
1
0
0
1
0
1 A A A A A A A A A A A A A
1
0
1
1
1
8
1
0
1
0
1
0
1
1
1
1
0 A A A 1
1
1
1
1
1
1
1
0
1
0
1
1
1
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
a16
u5
s16
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
AAAAAAAAAAAAAAAA 16-bit unsigned absolute address
AAAAA0
Unsigned 5-bit address offset
AAAAAAAAAAAAAAAA
Signed 16-bit SP address offset
SC140 DSP Core Reference Manual
A-339
OR
OR
OR
Bitwise Inclusive OR (DALU)
Operation
Assembler Syntax
Da ⏐ Dn → Dn
OR Da,Dn
Description
OR Da,Dn
Performs a bitwise inclusive OR of two data registers (Da and Dn) and stores the result in the second data
register (Dn). This is a full 40-bit operation.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
or d3,d0
Register/Memory Address
Before
D3
After
$E0 0007 0005
L0:D0
$0:$50 0003 0008
$0:$F0 0007 000F
1110 ---- 0111 ---- 0101
or 0101 ---- 0011 ---- 1000
1111 ---- 0111 ---- 1111
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
OR Da,Dn
1
2
1
8
1
0
1
1
1
7
F F F
0
0
0
1
1
J
J
J
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
A-340
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
OR
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
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A-341
OR
OR
Bitwise OR on a 16-Bit Operand (BMU)
Operation
Assembler Syntax
#u16 ⏐ DR.L → DR.L
OR #u16,DR.L {0 ≤ u16 < 216}
#u16 ⏐ DR.H → DR.H
OR #u16,DR.H {0 ≤ u16 < 216}
OR
Description
OR #u16,DR.L
Performs a bitwise inclusive OR of an immediate value with the LP of a data or address register (DR). It
then stores the result in the LP of the destination data or address register (DR). The other register bits are
not affected. This instruction is assembler-mapped to BMSET #u16,DR.L with the immediate value.
OR #u16,DR.H
Performs a bitwise inclusive OR of an immediate value with the HP of a data or address register (DR). It
then stores the result in the HP of the destination data or address register (DR). The other register bits are
not affected. This instruction is assembler-mapped to BMSET #u16,DR.H with the immediate value.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination registers.
Example
or #$0f0a,d0.l
Register/Memory Address
Before
Immediate
D0
After
$0F0A
$1:$00 ACBD F065
$0:$00 ACBD FF6F
0000 1111 0000 1010
or 1111 0000 0110 0101
1111 1111 0110 1111
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OR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
OR #u16,DR.L
2
3
2
2
3
7
0
0
0
0
0
1
0
0
1
i
i
i
0 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
8
7
15
OR #u16,DR.H
8
i
i
i
i
0
0
0
0
0
1
0
0
1
i
i
i
1 H H H H
1
0
1
i
i
i
i
i
i
i
i
i
i
i
i
i
Instruction Fields
DR
HHHH
0000
D0
0100
D4
1000
R0
1100
R4
0001
D1
0101
D5
1001
R1
1101
R5
0010
D2
0110
D6
1010
R2
1110
R6
0011
D3
0111
D7
1011
R3
1111
R7
Note:
#u16
Data/Address Register
This instruction can specify D8-D15 or R8-R15 as operands by using a high register prefix.
iiiiiiiiiiiiiiii
SC140 DSP Core Reference Manual
16-bit unsigned immediate data
A-343
OR.W
OR.W Bitwise OR on a 16-Bit Operand in Memory (BMU) OR.W
Operation
Assembler Syntax
#u16 ⏐ (R) → (R)
OR.W #u16,(Rn) {0 ≤ u16 < 216}
#u16 ⏐ (SP–u5) → (SP–u5)
OR.W #u16,(SP–u5) {0 ≤ u16 < 216} {0 ≤ u5 < 64,W]
#u16 ⏐ (SP+s16) → (SP+s16) OR.W #u16,(SP+s16) {0 ≤ u16 < 216} {–215 ≤ s16 < 215,W}
#u16 ⏐ (a16) → (a16)
OR.W #u16,(a16) {0 ≤ u16 < 216} {0 ≤ a16 < 216,W}
Description
These operations read from memory, modify the retrieved value, and write the new value back to the same
memory address, resulting in two memory accesses.
The absolute addresses, offsets, and address register values must be word-aligned.
OR.W #u16,(Rn)
Performs a bitwise inclusive OR of an immediate unsigned word with the contents of a memory address
pointed to by an address register (Rn). It then stores the result in that memory address. This instruction is
assembler-mapped to BMSET.W #u16,(Rn) with the immediate value.
OR.W #u16,(SP–u5)
Performs a bitwise inclusive OR of an immediate unsigned word with the contents of a memory address
pointed to by the active stack pointer (SP) minus an unsigned 5-bit offset. It then stores the result in the
memory address. This instruction is assembler-mapped to BMSET.W #u16,(SP–u5) with the immediate
value.
OR.W #u16,(SP+s16)
Performs a bitwise inclusive OR of an immediate unsigned word with the contents of a memory address
pointed to by the active stack pointer (SP) plus by a signed 16-bit offset. It then stores the result in the
memory address. This instruction is assembler-mapped to BMSET.W #u16,(SP+s16) with the immediate
value.
OR.W #u16,(a16)
Performs a bitwise inclusive OR of an immediate unsigned word with the contents of a 16-bit absolute
memory address. It then stores the result in the memory location. This instruction is assembler-mapped to
BMSET.W #u16,(a16) with the immediate value.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
Status and Conditions Changed by Instruction
None.
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OR.W
Example
or.w #$f01a,(r1)
Register/Memory Address
Before
After
Immediate
$F01A
R1
$0000 0050
($0050)
$1235
$F23F
1111 0000 0001 1010
or 0001 0010 0011 0101
1111 0010 0011 1111
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
2
OR.W #u16,(Rn)
2
3
2
3
3
3
3
3
0
1
0
0
0
1
i
i
i
0
1 R R R
1
0
1
i
i
i
i
i
i
i
i
i
i
8
7
3
2
3
i
i
i
0
0
0
0
0
0
0
0
1
i
i
i
A A A A A
1
0
1
i
i
i
i
i
i
i
i
i
8
7
1
i
0
0
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
1
i
0
i
0
i
1
i
0
i
15
OR.W #u16,(a16)
0
0
15
OR.W #u16,(SP+s16)
7
0
15
OR.W #u16,(SP–u5)
8
1
8
7
i
i
i
i
0
i
1
i
1
i
0
0
1
0
1 A A A A A A A A A A A A A
1
0
i
i
0
i
i
0
i
0
i
i
0
i
1
1 A A A
i
1 A A A
i
i
i
i
i
i
i
i
0
i
0
i
1
i
Instruction Fields
Rn
RRR
000
R0
010
R2
100
R4
110
R6
001
R1
011
R3
101
R5
111
R7
Note:
#u16
a16
u5
Address Register
This instruction can specify R8-R15 as operands by using a high register prefix.
iiiiiiiiiiiiiiii
16-bit unsigned immediate data
AAAAAAAAAAAAAAAA
16-bit unsigned absolute address
AAAAA0
Unsigned 5-bit SP address offset
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A-345
OR.W
s16
A-346
AAAAAAAAAAAAAAAA
Signed 16-bit SP address offset
SC140 DSP Core Reference Manual
POP
POP
Pop a Register from the Software Stack (AGU)
Operation
Assembler Syntax
(SP – 8) → De; SP – 8 → SP
POP De
(SP – 4) → Do; SP – 8 → SP
POP Do
POP
Description
These operations read the memory address pointed to by the active stack pointer (SP) into an even or odd
register (De or Do) and adjust SP. All memory accesses are 32-bit long words. The registers are divided
into two groups (even and odd) which determines the memory offset relative to the SP of the data being
read. It is important to pop registers in the same register grouping by which they were pushed. For
example, after the sequence "push d1" and "pop d3," d3 will hold the data originally in d1. However, "push
d0" and "pop d1" will not do the same because d0 and d1 are not in the same register group.
One or two POP instructions can appear in an execution set. In both cases, SP is decremented only once by
8. When two POP instructions are grouped together in an execution set, each must be in a different register
group.
If the register is a DALU register, bits [39:32] of the destination are sign-extended from bit 31 and the Ln
bit is cleared. Hence, in order to restore a full data register, the extension should be popped last.
Extensions of data registers (with the associated Ln bits) are special. Extensions of even and odd registers
are read from bits [8:0] and [24:16] of the long data word, respectively, both for single register and register
pair operations (see the figure below).
Note:
For proper data register restoration, extensions that were pushed as a pair should be popped as a
pair. Extensions pushed as single registers should be popped as single registers.
31
24
0
39
32
16
8
0
Do
16
0
De
MEMORY LONG WORD
0
La + EXTENSION
De (even)
Lb + EXTENSION
Do (odd)
POP De
Restores data register extension pairs, even registers, and loop start registers from the stack. Data register
extension pairs are popped the same as even numbered registers.
POP Do
Restores modifier control, odd registers, and loop counter registers from the stack.
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POP
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer used, and which execution working
mode .
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
Ln
L
Pops of extensions restore the Ln bit in the destination register. Pops to
data registers clear the Ln bit.
Example
pop d3
Register/Memory Address
Before
After
SR
$00E00000
NSP
$00000010
$0000000C
$2E03FF4E
$00000008
L3:D3
$0:$002E03FF4E
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
1
1
4
Opcode
15
POP De
1
0
0
8
7
1 E E E 0
0
8
7
1
0
15
POP Do
1
1
4
1
0
0
1
e
e
e
0
0
1 E 0
0 E 1
0
0
1
e
0
0
e
1
Note 1: An extra cycle is added if the shadow SP is not valid when the POP instruction is executed. See
Section 5.5.4, “Shadow Stack Pointer Registers,”
Instruction Fields
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SC140 DSP Core Reference Manual
POP
De
EEEEE
00000
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
—
01010
—
10010
SA0
11010
SA2
00011
D0.E
01011
D4.E
10011
D0.E:D1.E
11011
D4.E:D5.E
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
-
01110
—
10110
SA1
11110
SA3
00111
D2.E
01111
D6.E
10111
D2.E:D3.E
11111
D6.E:D7.E
Note:
Do
Extension Pairs, Even Registers, and Loop Start Registers
eeeee
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
Modifier Control, Odd Registers, and Loop Counter Registers
00000
D1
01000
D5
10000
R1
11000
R5
00001
B1
01001
B5
10001
N1
11001
M1
00010
VBA
01010
SR
10010
LC0
11010
LC2
00011
D1.E
01011
D5.E
10011
—
11011
—
00100
D3
01100
D7
10100
R3
11100
R7
00101
B3
01101
B7
10101
N3
11101
M3
00110
-
01110
MCTL
10110
LC1
11110
LC3
00111
D3.E
01111
D7.E
10111
—
11111
—
Note:
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
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POPN
POPN
Pop a Register from the Software Stack
Using the Normal Stack Pointer (AGU)
Operation
Assembler Syntax
(NSP – 8) → De; NSP – 8 → ΝSP
POPN De
(NSP – 4) → Do; NSP – 8 → ΝSP
POPN Do
POPN
Description
These operations read the memory address pointed to by the normal stack pointer (NSP) into an even or
odd register (De or Do) and adjust NSP regardless of the state of the exception (EXP) bit. All memory
accesses are 32-bit long words. The registers are divided into two groups (even and odd) which determines
the memory offset relative to NSP of the data being read. It is important to pop registers in the same
register grouping by which they were pushed. For example, after the sequence "pushn d1" and "popn d3,"
d3 will hold the data originally in d1. However, "pushn d0" and "popn d1" will not do the same because d0
and d1 are not in the same register group.
One or two POP instructions can appear in an execution set. In both cases, NSP is decremented only once
by 8. When two POP instructions are grouped together in an execution set, each must be in a different
register group.
If the register is a DALU register, bits [39:32] of the destination are sign-extended from bit 31 and the Ln
bit is cleared. Hence, in order to restore a full data register, the extension should be popped last.
Extensions of data registers (with the associated Ln bits) are special. Extensions of even and odd registers
are read from bits [8:0] and [24:16] of the long data word, respectively, both for single register and register
pair operations (see the figure below).
Note:
For proper data register restoration, extensions that were pushed as a pair should be popped as a
pair. Extensions pushed as single registers should be popped as single registers.
31
24
0
39
A-350
32
16
Do
8
0
16
0
De
MEMORY LONG WORD
0
La + EXTENSION
De (even)
Lb + EXTENSION
Do (odd)
SC140 DSP Core Reference Manual
POPN
POPN De
Restores data register extension pairs, even registers, and loop start registers from the normal stack. Data
register extension pairs are popped the same as even numbered registers.
POPN Do
Restores modifier control, odd registers, and loop counter registers from the normal stack.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode.
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
Ln
L
Pops of extensions restore the Ln bit in the destination register. Pops to
data registers clear the Ln bit.
Example
popn d6.e:d7.e
Register/Memory Address
Before
After
NSP
$00000010
$00000008
$000000FF
$00000008
L6:D6
$0:$FF00000000
L7:D7
$0:$0000000000
Instruction Formats and Opcodes
Words
Cycles1
Type
POPN De
1
1
4
POPN Do
1
1
4
Instruction
Opcode
15
1
8
7
0
0
1 E E E 0
0
0
0
1
15
1
e
e
e
8
7
1
0
0
0
1 E 0
1 E 1
0
1
1
0
e
0
e
1
Note 1: An extra cycle is added if the shadow SP is not valid when the POP instruction is executed. See
Section 5.3.3, “Shadow Stack Pointer Registers.”
Instruction Fields
SC140 DSP Core Reference Manual
A-351
POPN
De
EEEEE
00000
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
—
01010
—
10010
SA0
11010
SA2
00011
D0.E
01011
D4.E
10011
D0.E:D1.E
11011
D4.E:D5.E
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
-
01110
—
10110
SA1
11110
SA3
00111
D2.E
01111
D6.E
10111
D2.E:D3.E
11111
D6.E:D7.E
Note:
Do
eeeee
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
Modifier Control, Odd Registers, and Loop Counter Registers
00000
D1
01000
D5
10000
R1
11000
R5
00001
B1
01001
B5
10001
N1
11001
M1
00010
VBA
01010
SR
10010
LC0
11010
LC2
00011
D1.E
01011
D5.E
10011
—
11011
—
00100
D3
01100
D7
10100
R3
11100
R7
00101
B3
01101
B7
10101
N3
11101
M3
00110
-
01110
MCTL
10110
LC1
11110
LC3
00111
D3.E
01111
D7.E
10111
—
11111
—
Note:
A-352
Extension Pairs, Even Registers, and Loop Start Registers
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
SC140 DSP Core Reference Manual
PUSH
PUSH
Push a Register onto the Software Stack (AGU)
Operation
Assembler Syntax
De → (SP); SP + 8 → SP
PUSH De
Do → (SP + 4); SP + 8 → SP
PUSH Do
PUSH
Description
These operations move an even or odd register (De or Do) to the active stack in memory and adjust SP. All
memory accesses are 32-bit long words. The registers are divided into two groups (even and odd) which
determines the memory offset relative to SP of the data being written. It is important to pop registers in the
same register grouping by which they were pushed. For example, after the sequence "push d1" and "pop
d3," d3 will hold the data originally in d1. However, "push d0" and "pop d1" will not do the same because
d0 and d1 are not in the same register group.
One or two PUSH instructions can appear in an execution set. In both cases, SP is incremented only once
by 8. When two PUSH instructions are grouped together in an execution set, each must be in a different
register group.
Extensions of data registers (with the associated Ln bits) are special. Extensions of even and odd registers
are written to bits [8:0] and [24:16] of the long data word, respectively, both for single register and register
pair operations (see the figure below).
Note:
For proper data register restoration, extensions that were pushed as a pair should be popped as a
pair. Extensions pushed as single registers should be popped as single registers.
31
24
0
39
32
16
Do
8
0
16
0
De
MEMORY LONG WORD
0
La + EXTENSION
De (even)
Lb + EXTENSION
Do (odd)
PUSH De
Pushes data register extension pairs, even registers, and loop start registers onto the current stack. Data
register extension pairs are pushed the same as even numbered registers.
PUSH Do
Pushes modifier control, odd registers, and loop counter registers onto the current stack.
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A-353
PUSH
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer used, and execution working mode.
Status and Conditions Changed By Instruction
None
Example
push d0.e:d1.e
Register/Memory Address
Before
After
SR
$00E40000
ESP
$00000000
$00000008
($00000000)
$00000000
$000000FF
L0:D0
$0:$FF89ABCDEF
L1:D1
$0:$0001234567
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
PUSH De
1
1
4
1
0
0
8
7
1 E E E 0
0
8
7
1
0
15
PUSH Do
A-354
1
1
4
1
0
0
1
e
e
e
0
0
1 E 0
0 E 0
0
0
1
e
0
0
e
0
SC140 DSP Core Reference Manual
PUSH
Instruction Fields
De
EEEEE
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
—
01010
—
10010
SA0
11010
SA2
00011
D0.E
01011
D4.E
10011
D0.E:D1.E
11011
D4.E:D5.E
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
-
01110
—
10110
SA1
11110
SA3
D2.E
01111
D6.E
10111
D2.E:D3.E
11111
D6.E:D7.E
00111
Note:
Do
Extension Pairs, Even Registers, and Loop Start Registers
00000
eeeee
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
Modifier Control, Odd Registers, and Loop Counter Registers
00000
D1
01000
D5
10000
R1
11000
R5
00001
B1
01001
B5
10001
N1
11001
M1
00010
VBA
01010
SR
10010
LC0
11010
LC2
00011
D1.E
01011
D5.E
10011
—
11011
—
00100
D3
01100
D7
10100
R3
11100
R7
00101
B3
01101
B7
10101
N3
11101
M3
00110
-
01110
MCTL
10110
LC1
11110
LC3
00111
D3.E
01111
D7.E
10111
—
11111
—
Note:
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
SC140 DSP Core Reference Manual
A-355
PUSHN
PUSHN
Push a Register onto the Software Stack
Using the Normal Stack Pointer (AGU)
Operation
Assembler Syntax
De → (NSP); NSP + 8 → ΝSP
PUSHN De
Do → (NSP + 4); NSP + 8 → ΝSP
PUSHN Do
PUSHN
Description
These operations move an even or odd register (De or Do) to the normal stack in memory and adjusts the
NSP, regardless of the state of the exception (EXP) bit. All memory accesses are 32-bit long words. The
registers are divided into two groups (even and odd) which determines the memory offset relative to NSP
of the data being written. It is important to pop registers in the same register grouping by which they were
pushed. For example, after the sequence "pushn d1" and "popn d3," d3 will hold the data originally in d1.
However, "pushn d0" and "popn d1" will not do the same because d0 and d1 are not in the same register
group.
One or two PUSHN instructions can appear in an execution set. In both cases, NSP is incremented only
once by 8. When two PUSHN instructions are grouped together in an execution set, each must be in a
different register group.
Extensions of data registers (with the associated Ln bits) are special. Extensions of even and odd registers
are written to bits [8:0] and [24:16] of the long data word, respectively, both for single register and register
pair operations (see the figure below).
Note:
For proper data register restoration, extensions that were pushed as a pair should be popped as a
pair. Extensions pushed as single registers should be popped as single registers
31
24
0
39
32
16
Do
8
0
16
0
De
MEMORY LONG WORD
0
La + EXTENSION
De (even)
Lb + EXTENSION
Do (odd)
PUSHN De
Pushes data register extension pairs, even registers, and loop start registers onto the current stack. Data
register extension pairs are pushed the same as even numbered registers.
PUSHN Do
Pushes modifier control, odd registers, and loop counter registers onto the current stack.
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SC140 DSP Core Reference Manual
PUSHN
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode.
Status and Conditions Changed By Instruction
Register Address
Bit Name
Description
Ln
L
Pops of extensions restore the Ln bit in the destination register. Pops to
data registers clear the Ln bit.
Example
pushn d0.e:d1.e
Register/Memory Address
Before
NSP
After
$00000008
L0:D0
$0:$FF89ABCDEF
L1:D1
$0:$0001234567
($000008)
SC140 DSP Core Reference Manual
$000000010
$000000FF
A-357
PUSHN
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
PUSHN De
1
1
4
PUSHN Do
1
1
4
1
7
0
0
0
1 E E E 0
0
0
1
15
1
8
e
e
e
8
7
1
0
0
0
1 E 0
1 E 0
0
1
1
0
e
0
e
0
Instruction Fields
De
EEEEE
00000
D0
01000
D4
10000
R0
11000
R4
00001
B0
01001
B4
10001
N0
11001
M0
00010
—
01010
—
10010
SA0
11010
SA2
00011
D0.E
01011
D4.E
10011
D0.E:D1.E
11011
D4.E:D5.E
00100
D2
01100
D6
10100
R2
11100
R6
00101
B2
01101
B6
10101
N2
11101
M2
00110
-
01110
—
10110
SA1
11110
SA3
00111
D2.E
01111
D6.E
10111
D2.E:D3.E
11111
D6.E:D7.E
Note:
Do
eeeee
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
Modifier Control, Odd Registers, and Loop Counter Registers
00000
D1
01000
D5
10000
R1
11000
R5
00001
B1
01001
B5
10001
N1
11001
M1
00010
VBA
01010
SR
10010
LC0
11010
LC2
00011
D1.E
01011
D5.E
10011
—
11011
—
00100
D3
01100
D7
10100
R3
11100
R7
00101
B3
01101
B7
10101
N3
11101
M3
00110
-
01110
MCTL
10110
LC1
11110
LC3
D3.E
01111
D7.E
10111
—
11111
—
00111
Note:
A-358
Extension Pairs, Even Registers, and Loop Start Registers
If registers D8–D15 or R8–R15 are accessed instead of D0–D7 or R0–R7, a prefix is used.
SC140 DSP Core Reference Manual
RND
RND
RND
Round (DALU)
Operation
Assembler Syntax
Rnd(Da) → Dn
RND Da,Dn
Description
RND Da,Dn
Rounds the 40-bit value in the source data register (Da) and stores the result in the destination data register
(Dn). In the round function, the contribution of the least significant bits is rounded into the HP of the
destination data register by adding a rounding constant RC to the LS bits of the source data register. The
boundary between the LP and HP is determined by the scaling mode bits S0 and S1 in SR. The LSBs of the
result are cleared. The number of LSBs cleared is determined by the scaling mode bits in SR. All bits to the
right of (including the rounding position) are cleared in the result.
Two types of rounding can be used: convergent rounding (round to the nearest even number) or two’s
complement rounding. The type of rounding is selected by the rounding mode bit (RM) in SR. The default
mode is convergent rounding (SR[3] = 0).
In both rounding modes, a rounding constant (RC) is first added to the source data. The value of the
rounding constant added is determined by the scaling mode bits S0 and S1 in SR. A 1 is positioned in the
rounding constant aligned with the MSB of the scaled LP. The rounding constant weight is actually equal
to half the weight of the scaled HP’s LSB.
For two’s complement rounding, the scaled LP bits are then truncated. Numbers with an original value of
1/2 in the scaled LP are rounded up, resulting in a small positive bias.
If convergent rounding is used, the result of the addition is tested. If all the bits of the result to the right of
(including the rounding position) are cleared, then the bit to the left of the rounding position is cleared in
the result, ensuring that the result is even. An even result eliminates the two’s complement bias where 1/2
is always rounded up.
See Section 2.2.2.6, “Rounding Modes,” on page 2-21 for more detailed information.
The following table shows the rounding position (LP MSB) and rounding constant (RC) as determined by
the scaling mode bits:
Rounding Constant
(RC) Bits
Rounding
S1
S0
Scaling Mode
Position
39–17
16
15
14
13–0
0
0
No Scaling
15
0...0
0
1
0
0...0
0
1
Scale Down
16
0...0
1
0
0
0...0
1
0
Scale Up
14
0...0
0
0
1
0...0
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A-359
RND
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[3]
RM
Rounding mode
SR[5:4]
S[1:0]
Scaling bits determine which bits in the result are used in the Ln bit
calculation and which bits are used in rounding.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and updates
the Ln bit in the destination register. If in arithmetic saturation mode (SR
[SM] = 1), clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if the result is not representable in 40 bits, or if the result saturates to
32 bits in saturation mode.
Example 1
rnd d1,d5
Register/Memory Address
Before
After
SR
$00E0 0000
D1
$00 0000 FFFF
L5:D5
$0:$00 0001 0000
EMR
$0000 0000
Example 2
rnd d2,d1
Register/Memory Address
Before
After
SR
$00E0 0028
D2
$00 CAFE 4000
L1:D1
EMR
$0:$00 CAFE 8000
$0000 0000
$CAFE 40001100 1010 1111 1110 0100 0000 0000 0000
After rounding $CAFE 80001100 1010 1111 1110 1000 0000 0000 0000
Scaling up is selected in SR[4-5], and 2’s complement rounding is selected in SR[3]. Bit 15 is rounded up
because bit 14 = 1.
A-360
SC140 DSP Core Reference Manual
RND
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
RND Da,Dn
Note:
1
1
0
8
*
1
1
0
1
7
0
F F F
1
0
0
1
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Da
Single Source/Destination Data Register
000
This instruction can specify D8-D15 as operands by using a prefix.
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
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A-361
ROL
ROL
Rotate One Bit Left Through the Carry Bit (DALU)
Operation
Assembler Syntax
(Dn[38:0]<<1) → Dn[39:1]
ROL Dn
ROL
Dn[39] → C
C → Dn[0]
Description
ROL Dn
Rotates the contents of a data register (Dn) one bit to the left. The carry bit C is shifted to bit 0, bit 39 is
copied to the carry bit, and bits [38:0] are copied to bits [39:1].
C
39
32 31
16 15
0
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[0]
C
The carry bit is copied into Dn[0].
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Set if bit 39 in the data register was one before rotation. Cleared if
bit 39 in the data register was zero before rotation.
Ln
L
Clears the Ln bit in the destination register.
Example
rol d5
Register/Memory Address
SR
L5:D5
A-362
Before
After
$00E4 0000
$00E4 0001
$0:$FF A000 0005
$0:$FF 4000 000A
SC140 DSP Core Reference Manual
ROL
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ROL Dn
Note:
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
0
0
1
0
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
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A-363
ROR
ROR
Rotate One Bit Right Through the Carry Bit (DALU)
Operation
Assembler Syntax
(Dn[39–1]>>>1) → Dn[38–0]
ROR Dn
ROR
C → Dn[39]
Dn[0] → C
Description
ROR Dn
Rotates the contents of a data register (Dn) one bit to the right. The carry bit C is shifted to bit 39, bit 0 is
copied to the carry bit, and bits [39:1] are copied to bits [38:0].
C
39
32 31
16 15
0
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[0]
C
The carry bit is copied into Dn[39].
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Set if bit 0 in the data register was one before rotation. Cleared if bit
0 in the data register was zero before rotation.
Ln
L
Clears the Ln bit in the destination register.
Example
ror d15
Register/Memory Address
SR
L15:D15
A-364
Before
After
$00E0 0000
$00E0 0001
$0:$FF A000 0005
$0:$7F D000 0002
SC140 DSP Core Reference Manual
ROR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
ROR Dn
Note:
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
0
0
1
1
** indicates serial grouping encoding.
Instruction Fields
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
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A-365
ROR
RTE
Return From Exception (AGU)
Operation
Assembler Syntax
(SP – 8) → PC
(SP – 4) → SR
SP – 8 → SP
0 → NMID
RTE
RTE
Description
RTE
Returns from an exception routine. The program counter and status register are popped from the active
stack in memory, and program execution continues at the address specified in the PC. This instruction
cannot appear in an execution set with another AGU instruction or a set that uses IFT and IFF, IFT and
IFA, or IFF and IFA because RTE uses both AGUs. RTE does two simultaneous 32-bit long-word memory
accesses. Instructions that change SR cannot appear in the same set with this instruction.
Note:
Because RTE does not use RAS, returning from a subroutine using RTE is illegal. The result is
undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer used and execution working mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
SR[31:0]
EMR[3]
A-366
Description
Restores SR from stack.
NMID
Enables NMI.
SC140 DSP Core Reference Manual
ROR
Example
rte
Register/Memory Address
Before
After
ESP
$00000010
($000C)
$00E00000
($0008)
$0000000A
$00000008
PC
$0000000A
SR
$00E40000
$00E00000
EMR
$00000000
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
1
5/6
4
Opcode
15
RTE
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
0
0
1
1
Note 1: The shadow SP is valid or not valid. RTE uses 5 cycles if the shadow SP is valid. RTE uses 6 cycles if
the shadow SP is not valid.
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A-367
RTED
RTED
Return From Exception With a Delay Slot (AGU)
Operation
Assembler Syntax
(SP – 8) → PC
(SP – 4) → SR
SP – 8 → SP
0 → NMID
RTED
RTED
Description
RTED
Returns from an exception routine after executing the execution set in the delay slot. The program counter
and status register are popped from the active stack in memory, and program execution continues at the
address specified in PC. This instruction cannot appear in an execution set with another AGU instruction
or a set that uses IFT and IFF, IFT and IFA, or IFF and IFA because RTED uses both AGUs. RTED does
two simultaneous 32-bit long-word memory accesses. Instructions that change SR cannot appear in the
same set with this instruction or in the delay slot following the instruction.
Note:
Because RTED does not use RAS, returning from a subroutine using RTED is illegal. The result is
undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer used and execution working mode.
Status and Conditions Changed by Instruction
Register Address
Bit Name
SR[31:0]
EMR[3]
A-368
Description
Restores SR from stack.
NMID
Enables NMI.
SC140 DSP Core Reference Manual
RTED
Example
rted
Instruction
Comment
move.w #$2000,vba
Load the vector base address register.
trap
Issue a software interrupt and enter the exception state.
- - -
Instructions in the trap routine located at the address found
at $2000 and trap_vector offset.
rted not d4,d2
inc d1
Execute the not instruction and the inc d1 instruction in the
delay slot. Return to the original working mode (see example for RTE).
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
RTED
1
5/6
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
0
0
1
0
Note 1: The shadow SP is valid or not valid. RTED uses 5 cycles if the shadow SP is valid. RTED uses 6 cycles
if the shadow SP is not valid. To get the correct cycle count for this instruction, subtract the execution time
used by the execution set in the delay slot. The cycle count for this instruction cannot be less than 2 cycles.
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A-369
RTS
RTS
Return From Subroutine (AGU)
Operation
Assembler Syntax
If (RAS valid), then RAS → PC;
else (SP – 8) → PC;
RTS
RTS
always SP – 8 → SP
Description
RTS
Returns from a subroutine. If the RAS is valid, the PC is restored from the RAS. Otherwise, the PC is
popped from the active stack in memory as a 32-bit long word. The stack pointer always decrements by 8,
RAS becomes invalid, and program execution continues at the address specified in the PC.
Note:
Because RTS uses the RAS mechanism, returning from an exception using RTS is illegal. The result
is undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used.
Status and Conditions Changed by Instruction
None.
Example
rts
Register/Memory Address
Before
After
SR
$00E4 0000
ESP
$0000 2008
($2000)
$0000 0018
RAS
$0000 0018
PC
$0000 0026
A-370
$0000 2000
$0000 0018
SC140 DSP Core Reference Manual
RTS
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
RTS
1
3/5/6
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
0
0
0
1
Note 1: RTS uses 3 cycles if the RAS is valid. RTS uses 5 cycles if the RAS is not valid and the shadow SP is
valid. RTS uses 6 cycles if neither the RAS nor the shadow SP are valid.
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A-371
RTSD
RTSD
Return From Subroutine With Delay Slot (AGU)
Operation
Assembler Syntax
If (RAS valid), then RAS → PC;
else (SP – 8) → PC;
RTSD
RTSD
always SP – 8 → SP
Description
RTSD
Returns from a subroutine after executing the execution set in the delay slot. If the RAS is valid, the PC is
restored from the RAS. Otherwise, the PC is popped from the active stack in memory as a 32-bit long
word. The implicit pop is done before the execution set in the delay slot is executed. The stack pointer
always decrements by 8, RAS becomes invalid, and program execution continues at the address specified
in the PC.
Note:
Because RTSD uses the RAS mechanism, returning from an exception using RTSD is illegal. The
result is undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used.
Status and Conditions Changed by Instruction
None.
Example
rtsd
Instruction
Comment
Initially ESP = $2000
SUB
jsr SUB
Jump to subroutine at SUB.
- - -
Skip over these instructions.
MOVE.w #$20,d1
Execute the subroutine here. PC and SR pushed onto the
stack at $2000 and $2004.
- - rtsd move.w #$47,d9 Execute the $47 to d9 and increment d9 to $48, the instruction in the delay slot. Return from the subroutine. PC and
inc d9
SR popped from the stack.
A-372
SC140 DSP Core Reference Manual
RTSD
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
RTSD
1
3/5/6
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
0
0
0
0
Note 1: RTSD uses 3 cycles if the RAS is valid. RTSD uses 5 cycles if the RAS is not valid and the shadow SP
is valid.RTSD uses 6 cycles if neither the RAS nor the shadow SP are valid. To get the correct cycle count
for this instruction, subtract the execution time taken by the execution set in the delay slot. The cycle count
for this instruction cannot be less than 1 cycle (2 cycles if shadow SP is not valid).
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A-373
RTSTK
RTSTK
Restore PC from Stack (AGU)
Operation
Assembler Syntax
(SP – 8) → PC
SP – 8 → SP
RTSTK
RTSTK
Description
RTSTK
Forces a return from a subroutine or exception by restoring the program counter (PC) from the active stack
in memory. The restore to the PC is not from the RAS register, even if RAS is valid. The implicit pop is
done before the execution set in the delay slot is executed. The stack pointer decrements by 8 and RAS
becomes invalid. This instruction can be used to bypass RAS (for example, when the return address is
changed directly on the stack). RTSTK does one 32-bit long-word memory access.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[3]
NMID
Cleared .
A-374
SC140 DSP Core Reference Manual
RTSTK
Example
rtstk
Instruction
Comment
- - -
SUB
jsr SUB
Jump to subroutine at SUB. Push the PC and SR onto the
stack.
- - -
Skip over these instructions.
MOVE.w #$16,d4
Execute the subroutine here.
- - -
lbl
move.w #lbl,(SP-8)
Change the original value in the stack for PC to lbl.
rtstk
Restore the new value lbl to PC.
move.l #$16,d5
This instruction skipped.
move.l #$16,d6
Continue executing here.
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
RTSTK
1
5/6
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
0
1
0
1
Note 1: RTSTK uses 5 cycles if the shadow SP is valid. RTSTK uses 6 cycles if the shadow SP is not valid.
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A-375
RTSTKD
RTSTKD
RTSTKD
Restore PC from Stack
Using a Delay Slot (AGU)
Operation
Assembler Syntax
(SP – 8) → PC
SP – 8 → SP
RTSTKD
Description
RTSTKD
Forces a return from a subroutine or exception by restoring the program counter (PC) from the active stack
in memory after executing the execution set in the delay slot. The restore to the PC is not from the RAS
register, even if RAS is valid. The implicit pop is done before the execution set in the delay slot is
executed.The stack pointer decrements by 8 and RAS becomes invalid. This instruction can be used to
bypass RAS (for example, when the return address is changed directly on the stack). RTSTK does one
32-bit long-word memory access.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[3]
NMID
Cleared .
A-376
SC140 DSP Core Reference Manual
RTSTKD
Example
rtstkd
Instruction
Comment
- - -
SUB
jsr SUB
Jump to subroutine at SUB. Push the PC and SR onto the
stack.
- - -
Skip over these instructions.
MOVE.w #$16,d4
Execute the subroutine here.
- - move.w #lbl,(SP-8)
Change the original value in the stack for PC to lbl.
rtstk move.l #$35,d1Restore the new value lbl to PC. Load $35 into d1. Increinc d1
ment d1 to $36, the delay slot instruction.
lbl
move.l #$16,d5
This instruction skipped.
move.l #$16,d6
Continue executing here.
Instruction Formats and Opcodes
Instruction
Words
Cycles1
Type
Opcode
15
RTSTKD
1
5/6
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
0
1
0
0
Note 1: RTSTKD uses 5 cycles if shadow SP is valid. RTSTKD uses 6 cycles if the shadow SP is not valid. To
get the correct cycle count for this instruction, subtract the execution time used by the execution set in the
delay slot. The cycle count for this instruction cannot be less than 2 cycles.
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A-377
SAT.F
S
SAT.F
Saturate Fractional Data Register
(DALU)
SAT.F
Operation
Assembler Syntax
If Da > $007FFFFFFF then $007FFF0000 → Dn
SAT.F Da,Dn
If Da < $FF80000000 then $FF80000000 → Dn
Else Da & $FFFFFF0000 → Dn
Description
SAT.F Da,Dn
If the values of the extension bits [39:32] and bit 31 of the source register are all zeros or all ones (no
overflow), the source register is transferred to the destination register, and the LP is cleared. If the source
register indicates an overflow, the saturated value (positive or negative depending on bit 39) is transferred
to the HP of the destination register, sign-extended, and the LP is cleared. The saturated positive value is
$007FFF0000; the saturated negative value is $FF80000000. This operation is independent of the SM bit in
SR. It is intended for use after an instruction that is not affected by the saturation mode and before a
MOVES instruction.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if saturation occurs.
Example
sat.f d2,d3
Register/Memory Address
L2:D2
L3:D3
EMR
A-378
Before
After
$1:$00 846D 0000
$0:$00 7FFF 0000
$0000 0004
SC140 DSP Core Reference Manual
SAT.F
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
SAT.F Da,Dn
Note:
1
1
0
8
*
1
1
0
1
7
0
F F F
1
0
1
1
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
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A-379
SAT.L
SAT.L
SAT.L
Saturate 32-Bit Data Register
(DALU)
Operation
Assembler Syntax
If Dn > $007FFFFFFF then $007FFFFFF → Dn
SAT.L Dn
If Dn < $FF80000000 then $FF80000000 → Dn
Else Dn → Dn
Description
SAT.L Dn
If the values of the extension bits [39:32] and bit 31 of the source register are all zeros or all ones (no
overflow), Dn is left alone. If the source register indicates an overflow, the saturated value (positive or
negative depending on bit 39) is transferred to the destination register and sign-extended. The saturated
positive value is $007FFFFFFF; the saturated negative value is $FF80000000. This operation is
independent of the SM bit in SR. It is intended for use after an instruction that is not affected by the
saturation mode and before a MOVES instruction.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
EMR[2]
DOVF
Set if saturation occurs.
Example
sat.l d6
Register/Memory Address
Before
L6:D6
After
$1:$00 828B 5E9E
$0:$00 7FFF FFFF
EMR
$0000 0004
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
SAT.L Dn
Note:
A-380
1
1
1
0
8
*
1
0
0
1
7
F F F
0
1
1
0
0
1
0
1
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
SAT.L
Instruction Fields
Dn
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-381
SBC
SBC
Subtract With Borrow (DALU)
Operation
Assembler Syntax
Db – Dc – C → Dd
SBC Dc,Dd
SBC
Description
SBC Dc,Dd
Subtracts the first data register (Dc) from the second (Dd), then subtracts the borrow (C bit) and stores the
result in the second data register (Dd). The source operands are a data register pair. The destination register
is the second register of the pair.
This instruction can be used in multiple-precision subtraction as illustrated in the example, which is a
64-bit subtraction.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[0]
C
Subtracted as a borrow from the LSB.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the Ln bit
calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits.
Ln
L
Calculates and updates the Ln bit in the destination register.
SR[0]
C
Calculates and updates the carry bit in the status register.
Note: The carry bit is set correctly for multiple-precision arithmetic using long word operands if the extension of the destination
data register is the sign-extension of bit 31.
Example
sub d0,d1,d1
sbc d2,d3
Register/Memory Address
D0
L1:D1
Before
After
$00 0000 0008
$0:$00 0000 0005
$0:$FF FFFF FFFD
SR
$00E4 0000
$00E4 0001
D2
$00 0000 0003
L3:D3
A-382
$0:$00 0000 0005
$0:$00 0000 0001
SC140 DSP Core Reference Manual
SBC
Register/Memory Address
Before
After
SR
$00E4 0001
$00E4 0000
EMR
$0000 0000
The two instructions shown can be used for a 64-bit subtraction, with the sub d0,d1,d1 performing the
lower 32 bits, and the resultant borrow used for the LSB calculation of the upper 32 bits calculated by sbc
d2,d3.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
SBC Dc,Dd
Note:
1
1
0
*
1
0
1
1
e
8
7
e
0
0
1
1
1
1
0
1
1
** indicates serial grouping encoding.
Instruction Fields
Dc,Dd
ee
Data Register Pairs
00
Note:
D0,D1
01
D2,D3
10
D4,D5
11
D6,D7
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-383
SBR
SBR
Subtract And Round (DALU)
Operation
Assembler Syntax
Rnd(Dn – Da) → Dn
SBR Da,Dn
SBR
Description
SBR Da,Dn
Subtracts the first data register (Da) of a pair from the second (Dn), then rounds the result and stores the
result in the second data register (Dn). Rounding adjusts the LSB of the high part of the destination register
according to the value of the low part of the register, and then zeros the low part. The two modes of the
round function, Rnd(), are described on page A-359.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[3]
RM
Rounding mode
SR[5:4]
S[1:0]
Scaling bits determine which bits in the result are used in the Ln bit
calculation and which bits are used in rounding.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Example
sbr d3,d0
Register/Memory Address
Before
After
SR
$00E0 0000
D3
$00 1539 0030
L0:D0
EMR
A-384
$0:$00 2AE7 0080
$0:$00 15AE 0000
$0000 0000
SC140 DSP Core Reference Manual
SBR
0010 1010 1110 0111 0000 0000 1000$2AE7 0080
– 0001 0101 0011 0000 0000 0000 0011$1539 0030
0001 0101 1010 1110 0000 0000 0101$15AE 0050
rounded
$15AE 0000
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
SBR Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
F F F
0
1
0
0
1
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
001
Note:
Dn
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-385
SKIPLS
SKIPLS
Skip Loop If LC Less Than or
Equal to Zero (AGU)
Operation
If LCn ≤ 0,
SKIPLS
Assembler Syntax
then PC + displacement → PC
0 → LFn
SKIPLS label
Description
SKIPLS label
Branches to an address that is the current PC plus the displacement and disables the active loop if its loop
counter (LCn) is less than or equal to zero. The displacement is calculated by the assembler and linker.
SKIPLS is typically placed before a loop to bypass it if the loop count at run time does not indicate any
iterations. Some programming rules apply to the use of this instruction. If no loops are enabled, this
instruction is undefined.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Determines which loop is active.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[30:27]
LF[3:0]
Clear the active loop flag if the active loop counter is less than or equal
to one.
Example
skipls _label
Register/Memory Address
SR
_label (displacement)
PC
A-386
Before
After
$10E0 0000
$00E0 0000
$0010
$0000 000E
$0000 001E
SC140 DSP Core Reference Manual
SKIPLS
Instruction Formats and Opcodes
Instruction
Words
Cycles
Type
Opcode
15
SKIPLS label
2
1/41
4
8
0
0
0
0
7
1 A A A 0
0
0
0
1
1
0
0 A A A A A A A A A A A A a
0
0
1
1
Note 1: If LC>1, the instruction takes 1 cycle. If LC<=0 and the branch is taken, the instruction takes 4 cycles.
Instruction Fields
displacement
aAAAAAAAAAAAAAAA0
SC140 DSP Core Reference Manual
16-bit signed PC relative displacement.
The encoding is the displacement with bit
0 stripped and replaced by the sign bit.
A-387
STOP
STOP
Stop Instruction Processing (AGU)
Operation
Assembler Syntax
Enter the stop processing state.
STOP
STOP
Description
STOP
Halts instruction execution and enters the STOP processing state. This state is intended for the lowest
power consumption mode. The core informs the system about the intention to enter the STOP processing
state, and it is up to the system to shut down the clocks.
All activity in the processor is halted until one of the following actions occurs:
•
The wake_from_stop signal is asserted. In many chip configurations, this core interface signal is
connected to one of the external interrupt request pins.
•
A low level is applied to the RESET_B signal.
•
A low level is applied to the EE0 debug signal.
•
A JTAG debug request command is made.
Any of these actions causes the core to exit the STOP processing state, as follows:
If STOP is exited by assertion of the RESET signal, the processor enters the reset processing state.
If STOP is exited in parallel with an external interrupt request, the processor services the highest priority
pending interrupt. If no interrupt is pending, or if no interrupt is enabled, the processor resumes execution
at the instruction following the STOP instruction that caused entry into the stop state.
If STOP is exited by a low level on the EE0 signal or a JTAG debug request command, the processor enters
the debug state immediately.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines execution working mode.
Status and Conditions Changed by Instruction
None
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
STOP
A-388
1
8
4
1
0
0
1
1
1
1
8
7
1
0
0
1
1
1
1
0
0
1
SC140 DSP Core Reference Manual
SUB
SUB
SUB
Subtract (DALU)
Operation
Assembler Syntax
Dn – #u5 → Dn
SUB #u5,Dn {0 ≤ u5 < 32}
Db – Da → Dn
SUB Da,Db,Dn
Description
SUB #u5,Dn
Subtracts an immediate unsigned 5-bit value from a data register (Dn) and stores the result in the
destination data register (Dn).
SUB Da,Db,Dn
Subtracts one source data register (Da) from a second data register (Db) and stores the result in a
destination data register (Dn).
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates the borrow and updates the carry bit in the status
register.
EMR[2]
DOVF
Set if the result cannot be represented in 40 bits, or if the result
saturates to 32 bits in arithmetic saturation mode.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Example 1
sub d1,d0,d2
Register/Memory Address
Before
After
D0
$00 0000 0005
D1
$00 0000 0008
SR
$00E4 0000
SC140 DSP Core Reference Manual
$00E4 0001
A-389
SUB
Register/Memory Address
Before
After
L2:D2
$0:$FF FFFF FFFD
EMR
$0000 0000
Example 2
sub d0,d1,d2
Register/Memory Address
Before
After
D0
$FF D000 0000
D1
$00 2000 0000
SR
$00E4 0020
$00E4 0021
L2:D2
$1:$00 5000 0000
EMR
$0000 0000
Scaling up is set in SR[5], so L2 bit is set from overflow from bit 30.
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
SUB #u5,Dn
1
1
1
SUB Da,Db,Dn
1
1
1
0
8
*
1
1
1
0
F F F
*
1
0
1
1
F F F
15
0
8
15
SUB Db,Da,Dn
1
1
1
0
8
*
1
0
1
1
15
SUB Da,Da,Dn
Note:
A-390
1
1
1
0
7
*
1
0
0
0
1
1
i
i
i
i
0
0
J
J
J
J
7
J
0
0
1
J
J
J
J
7
F F F
i
0
7
F F F
8
0
J
0
1
1
0
0
1
j
j
** indicates serial grouping encoding.
SC140 DSP Core Reference Manual
SUB
Instruction Fields
Da,Db
JJJJJ
Data Register Pairs
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
00111
Notes:
Da,Da
Data Register Pairs
Note:
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
This instruction can specify D8-D15 as operands by using a prefix.
FFF
Single Source/Destination Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
#u5
This instruction can specify D8-D15 as operands by using a prefix.
The order of source operands specifies the opcode for subtract operations.
The JJJJJ encoding does not include the pairs: D1,D1; D3,D3; D5,D5; and D7,D7. These
are covered in the jj encoding.
jj
00
Dn
1.
2.
3.
This instruction can specify D8-D15 as operands by using a prefix.
iiiii
SC140 DSP Core Reference Manual
5-bit unsigned immediate data
A-391
SUB2
SUB2
Subtract Two 16-Bit Values (DALU)
Operation
Assembler Syntax
Dn.H – Da.H → Dn.H
Dn.L – Da.L → Dn.L
SUB2 Da,Dn
SUB2
Description
SUB2 Da,Dn
Performs a 32-bit subtraction of source register Da from Dn with borrow disabled between bits 15 and 16
so that the high and low words of each register are subtracted separately. The result is stored back in Dn.
The extension byte of the result is undefined.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Example 1
sub2 d0,d1
Register/Memory Address
Before
D0
L1:D1
After
$00 0003 2A14
$0:$FF FFFE 2A18
$0:$FF FFFB 0004
Example 2
sub2 d0,d1
Register/Memory Address
D0
L1:D1
A-392
Before
After
$00 7000 8000
$0:$FF 8000 7000
$0:$FF 1000 F000
SC140 DSP Core Reference Manual
SUB2
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
SUB2 Da,Dn
1
2
1
8
1
0
1
0
0
7
0
F F F
1
0
0
1
J
J
J
Instruction Fields
Dn
FFF
000
001
Note:
Da
Single Source/Destination Data Register
D0
010
D2
100
D4
110
D6
D1
011
D3
101
D5
111
D7
This instruction can specify D8-D15 as operands by using a prefix.
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
SC140 DSP Core Reference Manual
A-393
SUBA
SUBA
SUBA
Subtract (AGU)
Operation
Assembler Syntax
Rx – #u5 → Rx
SUBA #u5,Rx {0 ≤ u5 < 64}
Rx – rx → Rx
SUBA rx,Rx
Description
This instruction subtracts an immediate or an AGU register from another AGU register. For R0-R7
destinations, this instruction is affected by the modifier mode selected in MCTL.
SUBA #u5,Rx
Subtracts an immediate unsigned 5-bit integer from an AGU register (Rx) and stores the result in the same
register. If the stack pointer is the destination operand, then the immediate value must be a multiple of eight
since the resulting 3 LSBs are forced to zero.
SUBA rx,Rx
Subtracts one AGU register (rx) from another (Rx) and stores the result in the destination AGU register
(Rx). If the stack pointer is the destination operand, then the value in rx must be a multiple of eight since
the resulting 3 LSBs are forced to zero.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer is used when the stack pointer is an
operand. Otherwise, the instruction is not affected by SR.
MCTL[31:0]
AM3–AM0
Address modification bits when updating R0–R7. Otherwise, the
instruction is not affected by MCTL.
Status and Conditions Changed by Instruction
None.
Example
suba r1,r0
Register/Memory Address
Before
After
MCTL
$0000 0000
R1
$0000 0001
R0
$0000 0010
A-394
$0000 000F
SC140 DSP Core Reference Manual
SUBA
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
SUBA #u5,Rx
1
1
2
SUBA rx,Rx
1
1
2
1
8
0
1
1
0 R R R R 0
1
1
0 R R R R 0
15
1
7
8
1
1
i
i
i
i
0
1
1
r
r
r
7
i
0
r
Instruction Fields
rx
rrrr
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
PC
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
Rx
This instruction can specify R8-R15 as operands by using a high register prefix.
RRRR
AGU Source/Destination Register
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
N3
0111
SP
1011
R3
1111
R7
0011
Note:
#u5
AGU Source Register
This instruction can specify R8-R15 as operands by using a high register prefix.
iiiii
SC140 DSP Core Reference Manual
5-bit unsigned immediate data
A-395
SUBL
SUBL
Shift Left and Subtract (DALU)
Operation
Assembler Syntax
(2 * Dn) – Da → Dn
SUBL Da,Dn
SUBL
Description
SUBL Da,Dn
Subtracts the source register (Da) from two times the destination register (Dn) and stores the result in the
destination register. Dn is arithmetically shifted left one bit prior to the subtraction operation.
Status and Conditions that Affect Instruction
Register Address
Bit Name
Description
SR[2]
SM
If set, selects 32-bit arithmetic saturation mode.
SR[5:4]
S[1:0]
Scaling mode bits determine which bits in the result are used in the
Ln bit calculation.
Status and Conditions Changed by Instruction
Register Address
Bit Name
Description
SR[0]
C
Calculates the borrow and updates the carry bit in the status
register.
EMR[2]
DOVF
Set if the MS bit of the result cannot be represented in 40 bits, or
saturates to 32 bits in arithmetic saturation mode, or the MS bit of
the result changed due to the instruction’s left shift operation.
Ln
L
If not in arithmetic saturation mode (SR [SM] = 0), calculates and
updates the Ln bit in the destination register. If in arithmetic
saturation mode (SR [SM] = 1), clears the Ln bit in the destination
register.
Example 1
subl d0,d1
Register/Memory Address
Before
After
SR
$00E0 0000
D0
$00 0000 0003
L1:D1
EMR
A-396
$0:$00 0000 0004
$00E0 0000
$0:$00 0000 0005
$0000 0000
SC140 DSP Core Reference Manual
SUBL
Example 2
subl d0,d1
Register/Memory Address
Before
D0
After
$00 0000 000A
L1:D1
$0:$00 0000 0004
$0:$FF FFFF FFFE
$00E4 0000
$00E4 0001
SR
Instruction Formats and Opcodes
Instruction
Words Cycles Type
Opcode
15
1
SUBL Da,Dn
Note:
1
1
0
8
*
1
1
0
0
7
0
F F F
1
0
1
1
J
J
J
** indicates serial grouping encoding.
Instruction Fields
Da
JJJ
Single Source Data Register
000
D0
010
D2
100
D4
110
D6
001
D1
011
D3
101
D5
111
D7
Note:
Dn
This instruction can specify D8-D15 as operands by using a prefix.