XC2700 User's Manual, Volume 1 (of 2): System Units

U s e r ’ s M a n u a l , V 2 . 1, Au g . 2 0 0 8
XC2700 Derivatives
1 6 / 3 2 - B i t S i n g l e -C h i p M i c r o c o n t r o l l e r w i t h
32-Bit Performance
V o l u m e 1 ( o f 2 ) : S y s t e m U n i ts
M i c r o c o n t r o l l e rs
Edition 2008-08
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2008 Infineon Technologies AG
All Rights Reserved.
Legal Disclaimer
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and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights
of any third party.
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be endangered.
U s e r ’ s M a n u a l , V 2 . 1, Au g . 2 0 0 8
XC2700 Derivatives
1 6 / 3 2 - B i t S i n g l e -C h i p M i c r o c o n t r o l l e r w i t h
32-Bit Performance
V o l u m e 1 ( o f 2 ) : S y s t e m U n i ts
M i c r o c o n t r o l l e rs
XC2700 Derivatives
System Units (Vol. 1 of 2)
XC2700
Revision History: V2.1, 2008-08
Previous Version(s):
V2.0, 2007-12
V1.0, 2007-06 (XC2000)
V0.1, 2007-03, Draft version
Page
Subjects (major changes since last revision)
1-5
Derivative synopsis table replaced by reference to Data Sheets
3-49ff
Recommendations for Flash usage added
6-1ff
Various descriptions refined and corrected (throughout the chapter)
6-77ff
Description of EVR registers corrected
6-112ff
Software Boot Support added
6-155ff
Description of register ISSR corrected
6-161ff
Description of Double Watchdog Timer Error corrected
6-182
Memory Content Protection added (was in memory chapter before)
8-2
Description of pin TRef updated
9-1ff
Minor updates in description of EBC
10-2ff
Status information added
10-29
Bootstrap loader information improved
11-1ff
Minor updates in debug chapter
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User’s Manual
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Summary Of Chapters
Summary Of Chapters
This User’s Manual consists of two Volumes, “System Units” and “Peripheral Units”. For
a quick overview this table of chapters summarizes both volumes, so you immediately
can find the reference to the desired section in the corresponding document ([1] or [2]).
Summary Of Chapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-1 [1]
Table Of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-2 [1]
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 [1]
2
Architectural Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 [1]
3
Memory Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 [1]
4
Central Processing Unit (CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 [1]
5
Interrupt and Trap Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 [1]
6
System Control Unit (SCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 [1]
7
Parallel Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 [1]
8
Dedicated Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 [1]
9
The External Bus Controller EBC . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 [1]
10
Startup Configuration and Bootstrap Loading . . . . . . . . . . . . . . . 10-1 [1]
11
Debug System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1 [1]
12
Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1 [1]
13
Device Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1 [1]
14
The General Purpose Timer Units . . . . . . . . . . . . . . . . . . . . . . . . . 14-1 [2]
15
Real Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1 [2]
16
Analog to Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1 [2]
17
Capture/Compare Unit 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-1 [2]
18
Capture/Compare Unit 6 (CCU6) . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1 [2]
19
Universal Serial Interface Channel . . . . . . . . . . . . . . . . . . . . . . . . . 19-1 [2]
20
Controller Area Network (MultiCAN) Controller . . . . . . . . . . . . . . 20-1 [2]
Keyword Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-1 [2]
Register Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-7 [2]
User’s Manual
L-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
Table Of Contents
This User’s Manual consists of two Volumes, “System Units” and “Peripheral Units”. For
your convenience this table of contents (and also the keyword and register index) lists
both volumes, so you can immediately find the reference to the desired section in the
corresponding document ([1] or [2]).
Summary Of Chapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-1 [1]
Table Of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-2 [1]
1
1.1
1.2
1.3
1.4
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 [1]
Members of the 16-bit Microcontroller Family . . . . . . . . . . . . . . . . . . . 1-3 [1]
Summary of Basic Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 [1]
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9 [1]
Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10 [1]
2
2.1
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.2
2.3
2.4
2.5
2.6
Architectural Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 [1]
Basic CPU Concepts and Optimizations . . . . . . . . . . . . . . . . . . . . . . . 2-2 [1]
High Instruction Bandwidth/Fast Execution . . . . . . . . . . . . . . . . . . . 2-4 [1]
Powerful Execution Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 [1]
High Performance Branch-, Call-, and Loop-Processing . . . . . . . . . 2-6 [1]
Consistent and Optimized Instruction Formats . . . . . . . . . . . . . . . . 2-7 [1]
Programmable Multiple Priority Interrupt System . . . . . . . . . . . . . . 2-8 [1]
Interfaces to System Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 [1]
On-Chip System Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 [1]
On-Chip Peripheral Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 [1]
Clock Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 [1]
Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 [1]
On-Chip Debug Support (OCDS) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34 [1]
3
3.1
3.2
3.3
3.4
3.4.1
3.4.2
3.5
3.6
3.7
3.8
3.9
3.9.1
Memory Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 [1]
Address Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 [1]
Special Function Register Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5 [1]
Data Memory Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9 [1]
Program Memory Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11 [1]
Program/Data SRAM (PSRAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 [1]
Non-Volatile Program Memory (Flash) . . . . . . . . . . . . . . . . . . . . . 3-13 [1]
System Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14 [1]
IO Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15 [1]
External Memory Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16 [1]
Crossing Memory Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17 [1]
Embedded Flash Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18 [1]
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18 [1]
User’s Manual
L-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
3.9.2
3.9.3
3.9.4
3.9.5
3.9.6
3.9.7
3.9.8
3.9.9
3.9.10
3.10
3.10.1
3.10.2
3.10.3
3.11
Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Details of Command Sequences . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protection Handling Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protection Handling Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EEPROM Emulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommendations for Optimized Flash Usage . . . . . . . . . . . . . . .
On-Chip Program Memory Control . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Register Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Error Reporting Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Retention Memories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
4.1
4.2
4.2.1
4.2.2
4.2.3
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.4
4.5
4.5.1
4.5.2
4.6
4.7
4.7.1
4.7.2
4.7.3
4.7.4
4.7.5
4.8
4.8.1
4.8.2
4.8.3
4.9
4.9.1
Central Processing Unit (CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 [1]
Components of the CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 [1]
Instruction Fetch and Program Flow Control . . . . . . . . . . . . . . . . . . . . 4-5 [1]
Branch Detection and Branch Prediction Rules . . . . . . . . . . . . . . . . 4-7 [1]
Correctly Predicted Instruction Flow . . . . . . . . . . . . . . . . . . . . . . . . 4-7 [1]
Incorrectly Predicted Instruction Flow . . . . . . . . . . . . . . . . . . . . . . . 4-9 [1]
Instruction Processing Pipeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 [1]
Pipeline Conflicts Using General Purpose Registers . . . . . . . . . . . 4-13 [1]
Pipeline Conflicts Using Indirect Addressing Modes . . . . . . . . . . . 4-15 [1]
Pipeline Conflicts Due to Memory Bandwidth . . . . . . . . . . . . . . . . 4-17 [1]
Pipeline Conflicts Caused by CPU-SFR Updates . . . . . . . . . . . . . 4-20 [1]
CPU Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26 [1]
Use of General Purpose Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29 [1]
GPR Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31 [1]
Context Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33 [1]
Code Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37 [1]
Data Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39 [1]
Short Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39 [1]
Long Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41 [1]
Indirect Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44 [1]
DSP Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46 [1]
The System Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-52 [1]
Standard Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56 [1]
16-bit Adder/Subtracter, Barrel Shifter, and 16-bit Logic Unit . . . . 4-60 [1]
Bit Manipulation Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-60 [1]
Multiply and Divide Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-62 [1]
DSP Data Processing (MAC Unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-64 [1]
MAC Unit Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-65 [1]
User’s Manual
L-3
3-20 [1]
3-22 [1]
3-25 [1]
3-35 [1]
3-38 [1]
3-45 [1]
3-47 [1]
3-49 [1]
3-49 [1]
3-51 [1]
3-51 [1]
3-53 [1]
3-64 [1]
3-65 [1]
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
4.9.2
4.9.3
4.9.4
4.9.5
4.9.6
4.9.7
4.9.8
4.9.9
4.9.10
4.9.11
4.10
Representation of Numbers and Rounding . . . . . . . . . . . . . . . . . .
The 16-bit by 16-bit Signed/Unsigned Multiplier and Scaler . . . . .
Concatenation Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
One-bit Scaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The 40-bit Adder/Subtracter . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Data Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Accumulator Shifter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The 40-bit Signed Accumulator Register . . . . . . . . . . . . . . . . . . . .
The MAC Unit Status Word MSW . . . . . . . . . . . . . . . . . . . . . . . . .
The Repeat Counter MRW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Constant Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
5.1
5.2
5.3
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.4.5
5.5
5.6
5.7
5.8
5.9
5.10
5.11
Interrupt and Trap Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 [1]
Interrupt System Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 [1]
Interrupt Arbitration and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 [1]
Interrupt Vector Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 [1]
Operation of the Peripheral Event Controller Channels . . . . . . . . . . 5-20 [1]
The PECC Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 [1]
The PEC Source and Destination Pointers . . . . . . . . . . . . . . . . . . 5-24 [1]
PEC Transfer Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 [1]
Channel Link Mode for Data Chaining . . . . . . . . . . . . . . . . . . . . . . 5-28 [1]
PEC Interrupt Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 [1]
Prioritization of Interrupt and PEC Service Requests . . . . . . . . . . . . 5-31 [1]
Context Switching and Saving Status . . . . . . . . . . . . . . . . . . . . . . . . 5-33 [1]
Interrupt Node Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-36 [1]
External Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37 [1]
OCDS Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39 [1]
Service Request Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-40 [1]
Trap Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-42 [1]
6
6.1
6.1.1
6.1.2
6.1.3
6.1.4
6.1.5
6.1.6
6.1.7
6.2
6.2.1
6.2.2
6.3
6.3.1
System Control Unit (SCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 [1]
Clock Generation Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 [1]
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 [1]
Trimmed Current Controlled Wake-up Clock (OSC_WU) . . . . . . . . 6-4 [1]
High Precision Oscillator Circuit (OSC_HP) . . . . . . . . . . . . . . . . . . 6-4 [1]
Phase-Locked Loop (PLL) Module . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 [1]
Clock Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15 [1]
External Clock Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20 [1]
CGU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23 [1]
Wake-up Timer (WUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44 [1]
Wake-up Timer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44 [1]
WUT Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-46 [1]
Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-49 [1]
Reset Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-49 [1]
User’s Manual
L-4
4-65 [1]
4-66 [1]
4-66 [1]
4-66 [1]
4-66 [1]
4-67 [1]
4-67 [1]
4-68 [1]
4-70 [1]
4-72 [1]
4-74 [1]
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
6.3.2
6.3.3
6.3.4
6.3.5
6.3.6
6.3.7
6.4
6.4.1
6.4.2
6.4.3
6.5
6.5.1
6.5.2
6.5.3
6.5.4
6.6
6.6.1
6.6.2
6.7
6.7.1
6.8
6.8.1
6.8.2
6.8.3
6.8.4
6.8.5
6.8.6
6.8.7
6.8.8
6.9
6.9.1
6.9.2
6.9.3
6.10
6.10.1
6.11
6.11.1
6.11.2
6.11.3
6.11.4
6.12
6.12.1
6.12.2
General Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50 [1]
Debug Reset Assertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53 [1]
Coupling of Reset Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53 [1]
Reset Request Trigger Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54 [1]
Module Reset Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-56 [1]
Reset Controller Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58 [1]
External Service Request (ESR) Pins . . . . . . . . . . . . . . . . . . . . . . . . 6-68 [1]
General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-68 [1]
ESR Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-72 [1]
ESR Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-76 [1]
Power Supply and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-77 [1]
Supply Watchdog (SWD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-79 [1]
Monitoring the Voltage Level of a Core Domain . . . . . . . . . . . . . . 6-85 [1]
Controlling the Voltage Level of a Core Domain . . . . . . . . . . . . . . 6-92 [1]
Handling the Power System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-102 [1]
Global State Controller (GSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-103 [1]
GSC Control Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-103 [1]
GSC Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-107 [1]
Software Boot Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-112 [1]
Start-up Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-112 [1]
External Request Unit (ERU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113 [1]
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113 [1]
ERU Pin Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-115 [1]
External Request Select Unit (ERSx) . . . . . . . . . . . . . . . . . . . . . 6-119 [1]
Event Trigger Logic (ETLx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-120 [1]
Connecting Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-122 [1]
Output Gating Unit (OGUy) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-123 [1]
ERU Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-127 [1]
ERU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-129 [1]
SCU Interrupt Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-136 [1]
Interrupt Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-136 [1]
SCU Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-137 [1]
Interrupt Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-138 [1]
Temperature Compensation Unit . . . . . . . . . . . . . . . . . . . . . . . . . . 6-157 [1]
Temperature Compensation Registers . . . . . . . . . . . . . . . . . . . . 6-159 [1]
Watchdog Timer (WDT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-161 [1]
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-161 [1]
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-161 [1]
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-162 [1]
WDT Kernel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-166 [1]
SCU Trap Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-170 [1]
Trap Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-170 [1]
SCU Trap Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-171 [1]
User’s Manual
L-5
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
6.12.3
6.13
6.13.1
6.14
6.14.1
6.14.2
6.15
6.15.1
6.15.2
6.15.3
6.16
6.17
6.17.1
SCU Trap Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Memory Content Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parity Error Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Register Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Register Access Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Register Protection Registers . . . . . . . . . . . . . . . . . . . . . . . . . . .
Miscellaneous System Registers . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Marker Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCU Register Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clock Generation Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
7.1
7.1.1
7.1.2
7.1.3
7.2
7.2.1
7.2.2
7.2.3
7.2.4
7.2.5
7.2.6
7.3
7.3.1
7.3.2
7.3.3
7.3.4
7.3.5
7.3.6
7.3.7
7.3.8
7.3.9
7.3.10
7.3.11
7.3.12
7.3.13
7.4
Parallel Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 [1]
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 [1]
Basic Port Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 [1]
Input Stage Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 [1]
Output Driver Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 [1]
Port Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 [1]
Pad Driver Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 [1]
Port Output Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9 [1]
Port Output Modification Register . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 [1]
Port Input Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12 [1]
Port Input/Output Control Registers . . . . . . . . . . . . . . . . . . . . . . . . 7-13 [1]
Port Digital Input Disable Register . . . . . . . . . . . . . . . . . . . . . . . . . 7-16 [1]
Port Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17 [1]
Port 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18 [1]
Port 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19 [1]
Port 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 [1]
Port 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22 [1]
Port 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23 [1]
Port 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24 [1]
Port 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-25 [1]
Port 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-26 [1]
Port 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27 [1]
Port 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28 [1]
Port 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-29 [1]
Port 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-31 [1]
Port 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-32 [1]
Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-33 [1]
8
Dedicated Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 [1]
User’s Manual
L-6
6-172 [1]
6-182 [1]
6-182 [1]
6-191 [1]
6-191 [1]
6-194 [1]
6-196 [1]
6-196 [1]
6-197 [1]
6-202 [1]
6-203 [1]
6-209 [1]
6-209 [1]
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
9
9.1
9.2
9.2.1
9.2.2
9.2.3
9.3
9.3.1
9.3.2
9.3.3
9.3.4
9.3.5
9.3.6
9.3.7
9.3.8
9.3.9
9.4
The External Bus Controller EBC . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 [1]
External Bus Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 [1]
Timing Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4 [1]
Basic Bus Cycle Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4 [1]
Bus Cycle Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7 [1]
Bus Cycle Examples: Fastest Access Cycles . . . . . . . . . . . . . . . . . 9-9 [1]
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11 [1]
Configuration Register Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11 [1]
The EBC Mode Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-14 [1]
The EBC Mode Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16 [1]
The Timing Configuration Registers TCONCSx . . . . . . . . . . . . . . 9-17 [1]
The Function Configuration Registers FCONCSx . . . . . . . . . . . . . 9-20 [1]
The Address Window Selection Registers ADDRSELx . . . . . . . . . 9-23 [1]
Ready Controlled Bus Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-26 [1]
External Bus Arbitration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-28 [1]
Shutdown Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-32 [1]
LXBus Access Control and Signal Generation . . . . . . . . . . . . . . . . . 9-33 [1]
10
10.1
10.2
10.2.1
10.2.2
10.2.3
10.2.4
10.3
10.3.1
10.3.2
10.3.3
10.4
10.5
10.5.1
10.6
10.6.1
10.6.2
10.6.3
10.6.4
10.6.5
Startup Configuration and Bootstrap Loading . . . . . . . . . . . . . . . 10-1 [1]
Start-Up Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 [1]
Device Status after Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2 [1]
Registers modified by the Start-Up Procedure . . . . . . . . . . . . . . . 10-2 [1]
System Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4 [1]
Watchdog Timer handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4 [1]
Start-up Error state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5 [1]
Special Start-up Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-6 [1]
Supplementary Start-up Information from/to the User . . . . . . . . . . 10-6 [1]
Support for Power-saving Modes . . . . . . . . . . . . . . . . . . . . . . . . . 10-8 [1]
Preparing to activate Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8 [1]
Internal Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11 [1]
External Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11 [1]
Specific Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13 [1]
Bootstrap Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-14 [1]
General Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-14 [1]
Bootstrap Loaders using UART Protocol . . . . . . . . . . . . . . . . . . . 10-16 [1]
Synchronous Serial Channel Bootstrap Loader . . . . . . . . . . . . . . 10-23 [1]
CAN Bootstrap Loader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-26 [1]
Summary of Bootstrap Loader Modes . . . . . . . . . . . . . . . . . . . . . 10-29 [1]
11
11.1
11.1.1
11.2
11.2.1
Debug System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Debug Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Routing of Debug Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OCDS Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Debug Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
User’s Manual
L-7
11-1 [1]
11-2 [1]
11-3 [1]
11-5 [1]
11-6 [1]
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
11.2.2
11.3
11.3.1
11.4
Debug Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8 [1]
Cerberus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-9 [1]
Functional Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-9 [1]
Boundary-Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11 [1]
12
Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1 [1]
13
Device Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1 [1]
14
14.1
14.1.1
14.1.2
14.1.3
14.1.4
14.1.5
14.1.6
14.1.7
14.2
14.2.1
14.2.2
14.2.3
14.2.4
14.2.5
14.2.6
14.2.7
14.2.8
14.3
14.4
The General Purpose Timer Units . . . . . . . . . . . . . . . . . . . . . . . . . 14-1 [2]
Timer Block GPT1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-2 [2]
GPT1 Core Timer T3 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4 [2]
GPT1 Core Timer T3 Operating Modes . . . . . . . . . . . . . . . . . . . . . 14-8 [2]
GPT1 Auxiliary Timers T2/T4 Control . . . . . . . . . . . . . . . . . . . . . 14-15 [2]
GPT1 Auxiliary Timers T2/T4 Operating Modes . . . . . . . . . . . . . 14-18 [2]
GPT1 Clock Signal Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-27 [2]
GPT1 Timer Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-30 [2]
Interrupt Control for GPT1 Timers . . . . . . . . . . . . . . . . . . . . . . . . 14-31 [2]
Timer Block GPT2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-32 [2]
GPT2 Core Timer T6 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-34 [2]
GPT2 Core Timer T6 Operating Modes . . . . . . . . . . . . . . . . . . . . 14-38 [2]
GPT2 Auxiliary Timer T5 Control . . . . . . . . . . . . . . . . . . . . . . . . 14-41 [2]
GPT2 Auxiliary Timer T5 Operating Modes . . . . . . . . . . . . . . . . . 14-44 [2]
GPT2 Register CAPREL Operating Modes . . . . . . . . . . . . . . . . . 14-48 [2]
GPT2 Clock Signal Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-54 [2]
GPT2 Timer Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-57 [2]
Interrupt Control for GPT2 Timers and CAPREL . . . . . . . . . . . . . 14-58 [2]
Miscellaneous Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-59 [2]
Interfaces of the GPT Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-62 [2]
15
15.1
15.2
15.3
15.4
15.5
15.6
15.7
15.8
Real Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1 [2]
Defining the RTC Time Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2 [2]
RTC Run Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5 [2]
RTC Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-7 [2]
48-bit Timer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-11 [2]
System Clock Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-11 [2]
Cyclic Interrupt Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-12 [2]
RTC Interrupt Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-13 [2]
Miscellaneous Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-15 [2]
16
16.1
16.1.1
16.1.2
16.1.3
Analog to Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADC Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feature Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
User’s Manual
L-8
16-1 [2]
16-1 [2]
16-2 [2]
16-3 [2]
16-4 [2]
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
16.1.4
16.1.5
16.1.6
16.1.7
16.1.8
16.1.9
16.2
16.2.1
16.2.2
16.2.3
16.2.4
16.2.5
16.2.6
16.2.7
16.2.8
16.2.9
16.2.10
16.2.11
16.2.12
16.2.13
16.2.14
16.2.15
16.2.16
16.2.17
16.2.18
16.3
16.3.1
16.3.2
16.3.3
16.3.4
ADC Kernel Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-5 [2]
Conversion Request Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-7 [2]
Conversion Result Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-9 [2]
Interrupt Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-10 [2]
Electrical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-11 [2]
Transfer Characteristics and Error Definitions . . . . . . . . . . . . . . . 16-14 [2]
Operating the ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-15 [2]
Register Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-16 [2]
Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-19 [2]
Module Activation and Power Saving Modes . . . . . . . . . . . . . . . 16-21 [2]
Clocking Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-22 [2]
General ADC Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-23 [2]
Request Source Arbiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-32 [2]
Arbiter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-36 [2]
Scan Request Source Handling . . . . . . . . . . . . . . . . . . . . . . . . . . 16-38 [2]
Scan Request Source Registers . . . . . . . . . . . . . . . . . . . . . . . . . 16-42 [2]
Sequential Request Source Handling . . . . . . . . . . . . . . . . . . . . . 16-46 [2]
Sequential Source Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-51 [2]
Channel-Related Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-62 [2]
Channel-Related Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-67 [2]
Conversion Result Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-77 [2]
Conversion Result-Related Registers . . . . . . . . . . . . . . . . . . . . . 16-85 [2]
External Multiplexer Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-95 [2]
Synchronized Conversions for Parallel Sampling . . . . . . . . . . . . 16-97 [2]
Additional Feature Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-100 [2]
Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-103 [2]
Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-103 [2]
Interrupt Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-103 [2]
Analog Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-104 [2]
Digital Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-107 [2]
17
17.1
17.2
17.3
17.3.1
17.4
17.5
17.5.1
17.5.2
17.5.3
17.5.4
17.5.5
Capture/Compare Unit 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-1 [2]
The CAPCOM2 Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-4 [2]
CAPCOM2 Timer Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-10 [2]
Capture/Compare Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-11 [2]
Capture/Compare Registers for the CAPCOM2 (CC31 … CC16) 17-11 [2]
Capture Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-14 [2]
Compare Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-15 [2]
Compare Mode 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-16 [2]
Compare Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-16 [2]
Compare Mode 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-19 [2]
Compare Mode 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-19 [2]
Double-Register Compare Mode . . . . . . . . . . . . . . . . . . . . . . . . 17-24 [2]
User’s Manual
L-9
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
17.6
17.7
17.8
17.9
17.10
17.10.1
17.11
Compare Output Signal Generation . . . . . . . . . . . . . . . . . . . . . . . .
Single Event Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Staggered and Non-Staggered Operation . . . . . . . . . . . . . . . . . . . .
CAPCOM2 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Input Signal Requirements . . . . . . . . . . . . . . . . . . . . . . . .
Miscellaneous Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interfaces of the CAPCOM Units . . . . . . . . . . . . . . . . . . . . . . . . . . .
18
18.1
18.1.1
18.1.2
18.1.3
18.2
18.2.1
18.2.2
18.2.3
18.2.4
18.2.5
18.2.6
18.2.7
18.2.8
18.2.9
18.3
18.3.1
18.3.2
18.3.3
18.3.4
18.3.5
18.3.6
18.4
18.5
18.6
18.6.1
18.6.2
18.6.3
18.6.4
18.7
18.7.1
18.7.2
18.7.3
18.7.4
18.8
Capture/Compare Unit 6 (CCU6) . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1 [2]
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1 [2]
Feature Set Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-2 [2]
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-3 [2]
Register Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-4 [2]
Operating Timer T12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-7 [2]
T12 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-8 [2]
T12 Counting Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-10 [2]
T12 Compare Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-14 [2]
Compare Mode Output Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-21 [2]
T12 Capture Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-26 [2]
T12 Shadow Register Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . 18-30 [2]
Timer T12 Operating Mode Selection . . . . . . . . . . . . . . . . . . . . . 18-31 [2]
T12 related Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-32 [2]
Capture/Compare Control Registers . . . . . . . . . . . . . . . . . . . . . . 18-37 [2]
Operating Timer T13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-49 [2]
T13 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-49 [2]
T13 Counting Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-52 [2]
T13 Compare Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-57 [2]
Compare Mode Output Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-59 [2]
T13 Shadow Register Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . 18-60 [2]
T13 related Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-62 [2]
Trap Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-65 [2]
Multi-Channel Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-67 [2]
Hall Sensor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-69 [2]
Hall Pattern Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-70 [2]
Hall Pattern Compare Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-72 [2]
Hall Mode Flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-73 [2]
Hall Mode for Brushless DC-Motor Control . . . . . . . . . . . . . . . . . 18-75 [2]
Modulation Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-77 [2]
Modulation Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-77 [2]
Trap Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-79 [2]
Passive State Level Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-82 [2]
Multi-Channel Mode Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 18-83 [2]
Interrupt Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-88 [2]
User’s Manual
L-10
17-27 [2]
17-29 [2]
17-31 [2]
17-36 [2]
17-38 [2]
17-39 [2]
17-42 [2]
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
18.8.1
18.8.2
18.9
18.9.1
18.9.2
18.9.3
18.10
18.10.1
18.10.2
18.10.3
18.10.4
Interrupt Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-88 [2]
Interrupt Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-90 [2]
General Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-102 [2]
Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-102 [2]
Input Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-105 [2]
General Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-106 [2]
Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-113 [2]
Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-113 [2]
Interrupt Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-114 [2]
Synchronous Start Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-115 [2]
Digital Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-116 [2]
19
19.1
19.1.1
19.1.2
19.1.3
19.1.4
19.1.5
19.1.6
19.1.7
19.2
19.2.1
19.2.2
19.2.3
19.2.4
19.2.5
19.2.6
19.2.7
19.2.8
19.2.9
19.2.10
19.2.11
19.2.12
19.2.13
19.2.14
19.3
19.3.1
19.3.2
19.3.3
19.3.4
19.3.5
19.4
Universal Serial Interface Channel . . . . . . . . . . . . . . . . . . . . . . . . . 19-1 [2]
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-1 [2]
Feature Set Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-2 [2]
Channel Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-5 [2]
Input Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-6 [2]
Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-7 [2]
Baud Rate Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-8 [2]
Channel Events and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-9 [2]
Data Shifting and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-9 [2]
Operating the USIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-13 [2]
Register Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-13 [2]
Operating the USIC Communication Channel . . . . . . . . . . . . . . . 19-18 [2]
Channel Control and Configuration Registers . . . . . . . . . . . . . . . 19-26 [2]
Protocol Related Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-34 [2]
Operating the Input Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-37 [2]
Input Stage Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-39 [2]
Operating the Baud Rate Generator . . . . . . . . . . . . . . . . . . . . . . 19-42 [2]
Baud Rate Generator Registers . . . . . . . . . . . . . . . . . . . . . . . . . 19-47 [2]
Operating the Transmit Data Path . . . . . . . . . . . . . . . . . . . . . . . . 19-52 [2]
Operating the Receive Data Path . . . . . . . . . . . . . . . . . . . . . . . . 19-56 [2]
Transfer Control and Status Registers . . . . . . . . . . . . . . . . . . . . 19-58 [2]
Data Buffer Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-70 [2]
Operating the FIFO Data Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . 19-80 [2]
FIFO Buffer and Bypass Registers . . . . . . . . . . . . . . . . . . . . . . . 19-90 [2]
Asynchronous Serial Channel (ASC = UART) . . . . . . . . . . . . . . . . 19-111 [2]
Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-111 [2]
Frame Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-112 [2]
Operating the ASC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-115 [2]
ASC Protocol Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-123 [2]
Hardware LIN Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-129 [2]
Synchronous Serial Channel (SSC) . . . . . . . . . . . . . . . . . . . . . . . 19-131 [2]
User’s Manual
L-11
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Table Of Contents
19.4.1
19.4.2
19.4.3
19.4.4
19.4.5
19.4.6
19.5
19.5.1
19.5.2
19.5.3
19.5.4
19.5.5
19.6
19.6.1
19.6.2
19.6.3
19.6.4
19.6.5
19.7
19.7.1
19.7.2
19.7.3
19.7.4
19.7.5
19.7.6
Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating the SSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating the SSC in Master Mode . . . . . . . . . . . . . . . . . . . . . .
Operating the SSC in Slave Mode . . . . . . . . . . . . . . . . . . . . . . .
SSC Protocol Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SSC Timing Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inter-IC Bus Protocol (IIC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating the IIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symbol Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Flow Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IIC Protocol Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IIS Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating the IIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating the IIS in Master Mode . . . . . . . . . . . . . . . . . . . . . . .
Operating the IIS in Slave Mode . . . . . . . . . . . . . . . . . . . . . . . .
IIS Protocol Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
USIC Implementation in XC2700 . . . . . . . . . . . . . . . . . . . . . . . . . .
Implementation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Channel Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Identification Registers . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input/Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
20.1
20.1.1
20.1.2
20.2
20.2.1
20.2.2
20.2.3
20.2.4
20.2.5
20.2.6
20.2.7
20.2.8
20.2.9
20.3
20.3.1
20.3.2
Controller Area Network (MultiCAN) Controller . . . . . . . . . . . . . . 20-1 [2]
MultiCAN Short Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1 [2]
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1 [2]
CAN Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-2 [2]
CAN Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-3 [2]
Conventions and Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-3 [2]
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-3 [2]
CAN Node Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-9 [2]
Message Object List Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-13 [2]
CAN Node Analysis Features . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-18 [2]
Message Acceptance Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-21 [2]
Message Postprocessing Interface . . . . . . . . . . . . . . . . . . . . . . . 20-24 [2]
Message Object Data Handling . . . . . . . . . . . . . . . . . . . . . . . . . . 20-28 [2]
Message Object Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-35 [2]
MultiCAN Kernel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-44 [2]
Register Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-44 [2]
Global MultiCAN Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-49 [2]
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19-131 [2]
19-139 [2]
19-142 [2]
19-149 [2]
19-151 [2]
19-157 [2]
19-160 [2]
19-160 [2]
19-164 [2]
19-170 [2]
19-173 [2]
19-178 [2]
19-184 [2]
19-184 [2]
19-188 [2]
19-193 [2]
19-197 [2]
19-198 [2]
19-204 [2]
19-204 [2]
19-205 [2]
19-205 [2]
19-206 [2]
19-208 [2]
19-210 [2]
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Table Of Contents
20.3.3
20.3.4
20.4
20.4.1
20.4.2
20.4.3
20.4.4
20.5
20.5.1
20.5.2
20.5.3
20.5.4
20.5.5
20.5.6
20.5.7
CAN Node Specific Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-62 [2]
Message Object Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-79 [2]
General Control and Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-102 [2]
Clock Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-102 [2]
Port Input Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-103 [2]
Suspend Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-104 [2]
Interrupt Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-105 [2]
MultiCAN Module Implementation . . . . . . . . . . . . . . . . . . . . . . . . . 20-106 [2]
Interfaces of the CAN Module . . . . . . . . . . . . . . . . . . . . . . . . . . 20-106 [2]
Module Clock Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-107 [2]
Mode Control Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-116 [2]
Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-117 [2]
Mode Control Register Description . . . . . . . . . . . . . . . . . . . . . . 20-119 [2]
Connection of External Signals . . . . . . . . . . . . . . . . . . . . . . . . . 20-122 [2]
MultiCAN Module Register Address Map . . . . . . . . . . . . . . . . . 20-125 [2]
Keyword Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-1 [2]
Register Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-7 [2]
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Introduction
1
Introduction
The rapidly growing area of embedded control applications is representing one of the
most time-critical operating environments for today’s microcontrollers. Complex control
algorithms have to be processed based on a large number of digital as well as analog
input signals, and the appropriate output signals must be generated within a defined
maximum response time. Embedded control applications also are often sensitive to
board space, power consumption, and overall system cost.
Embedded control applications therefore require microcontrollers, which:
• offer a high level of system integration
• eliminate the need for additional peripheral devices and the associated software
overhead
• provide system security and fail-safe mechanisms
• provide effective means to control (and reduce) the device’s power consumption
The increasing complexity of embedded control applications requires microcontrollers
for new high-end embedded control systems to possess a significant CPU performance
and peripheral functionality. To achieve this high performance goal, Infineon has decided
to develop its families of 16/32-bit CMOS microcontrollers without the constraints of
backward compatibility wih previous architectures.
Nonetheless the architectures of these microcontroller families pursue successful
hardware and software concepts, which have been established in Infineon’s popular
8-bit controller families, while delivering 32-bit performance.
This established functionality, which has been the basis for system solutions in a wide
range of application areas, is amended with flexible peripheral modules and effective
power control features. The sum of this provides the prerequisites for powerful, yet
efficient systems-on-chip.
Solutions for PowerTrain Systems
The XC2700 derivatives address the increasing requirements for value, performance,
and features in PowerTrain applications. The combination of 32-bit features with the well
established C166SV2 core supports competitive engine- and transmission-applications:
• The scaleable XC2700 product portfolio fits perfectly to your requirements
• Compatibility provides easy adaptation to changing requirements in performance and
functionality
• 32-bit (system) performance and features ensure long term usability
• Flexible peripherals such as USIC, MultiCAN, ADC maximize re-use across your
developments
• Enhanced value through single voltage supply and embedded voltage regulator
Soon to come variants enlarging the portfolio, and Infineon’s high quality standards
make the XC2700 Controllers an ideal choice for performing and upgradable systems.
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Introduction
About this Manual
This manual describes the functionality of a number of microcontroller types of the
Infineon XC2000 Family, the XC2700 derivatives.
These microcontrollers provide identical functionality to a large extent, but each device
type has specific unique features as indicated here.
The descriptions in this manual cover a superset of the provided features.
The “Summary of Basic Features” on Page 1-5 lists the derivatives covered by this
manual for a quick summary and comparison.
This manual is valid for these derivatives and describes all variations of the different
available temperature ranges and packages.
For simplicity, these various device types are referred to by the collective term XC2700
throughout this manual. The complete Pro Electron conforming designations are listed
in the respective Data Sheets.
Some sections of this manual do not refer to all of the XC2700 derivatives which are
currently available or planned (such as devices with different types of on-chip memory
or peripherals). These sections contain respective notes wherever possible.
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1.1
Members of the 16-bit Microcontroller Family
The microcontrollers in the Infineon 16-bit family have been designed to meet the high
performance requirements of real-time embedded control applications. The architecture
of this family has been optimized for high instruction throughput and minimized response
time to external stimuli (interrupts). Intelligent peripheral subsystems have been
integrated to reduce the need for CPU intervention to a minimum extent. This also
minimizes the need for communication via the external bus interface. The high flexibility
of this architecture allows to serve the diverse and varying needs of different application
areas such as automotive, industrial control, or data communications.
The core of the 16-bit family has been developed with a modular family concept in mind.
All family members execute an efficient control-optimized instruction set (additional
instructions for members of the second generation). This allows easy and quick
implementation of new family members with different internal memory sizes and
technologies, different sets of on-chip peripherals, and/or different numbers of IO pins.
The XBUS/LXBus concept (internal representation of the external bus interface)
provides a straightforward path for building application-specific derivatives by integrating
application-specific peripheral modules with the standard on-chip peripherals.
As programs for embedded control applications become larger, high level languages are
favored by programmers, because high level language programs are easier to write, to
debug and to maintain. The C166 Family supports this starting with its 2nd generation.
The 80C166-type microcontrollers were the first generation of the 16-bit controller
family. These devices established the C166 architecture.
The C165-type and C167-type devices are members of the second generation of this
family. This second generation is even more powerful due to additional instructions for
HLL support, an increased address space, increased internal RAM, and highly efficient
management of various resources on the external bus.
Enhanced derivatives of this second generation provide more features such as
additional internal high-speed RAM, an integrated CAN-Module, an on-chip PLL, etc.
The design of more efficient systems may require the integration of application-specific
peripherals to boost system performance while minimizing the part count. These efforts
are supported by the XBUS, defined for the Infineon 16-bit microcontrollers (second
generation). The XBUS is an internal representation of the external bus interface which
opens and simplifies the integration of peripherals by standardizing the required
interface. One representative taking advantage of this technology is the integrated CAN
module.
The C165-type devices are reduced functionality versions of the C167 because they do
not have the A/D converter, the CAPCOM units, and the PWM module. This results in a
smaller package, reduced power consumption, and design savings.
The C164-type devices, the C167CS derivatives, and some of the C161-type devices
are further enhanced by a flexible power management and form the third generation of
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Introduction
the 16-bit controller family. This power management mechanism provides an effective
means to control the power that is consumed in a certain state of the controller and thus
minimizes the overall power consumption for a given application.
The XC16x derivatives represent the fourth generation of the 16-bit controller family.
The XC166 Family dramatically increases the performance of 16-bit microcontrollers by
several major improvements and additions. The MAC-unit adds DSP-functionality to
handle digital filter algorithms and greatly reduces the execution time of multiplications
and divisions. The 5-stage pipeline, single-cycle execution of most instructions, and
PEC-transfers within the complete addressing range increase system performance.
Debugging the target system is supported by integrated functions for On-Chip Debug
Support (OCDS).
The present XC2000 Family of microcontrollers builds the fifth generation of 16-bit
microcontrollers which provides 32-bit performance and takes users and applications a
considerable step towards industry’s target of systems on chip. Integrated memories and
peripherals allow compact systems, the integrated core power supply and control
reduces system requirements to one single voltage supply, the powerful combination of
CPU and MAC-unit is unleashed by optimized compilers. This leaves no performance
gap towards 32-bit systems.
A variety of different versions is provided which offer various kinds of on-chip program
memory1):
•
•
•
•
Mask-programmable ROM
Flash memory
OTP memory
ROMless without non-volatile memory.
Also there are devices with specific functional units.
The devices may be offered in different packages, temperature ranges and speed
classes.
Additional standard and application-specific derivatives are planned and are in
development.
Note: Not all derivatives will be offered in all temperature ranges, speed classes,
packages, or program memory variations.
Information about specific versions and derivatives will be made available with the
devices themselves. Contact your Infineon representative for up-to-date material or refer
to http://www.infineon.com/microcontrollers.
Note: As the architecture and the basic features, such as the CPU core and built-in
peripherals, are identical for most of the currently offered versions of the XC2700,
descriptions within this manual that refer to the “XC2700” also apply to the other
variations, unless otherwise noted.
1)
Not all derivatives are offered with all kinds of on-chip memory.
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1.2
Summary of Basic Features
The XC2700 devices are enhanced members of the Infineon XC2000 Family of full
featured single-chip CMOS microcontrollers.
This manual covers several device types are covered in this manual. The various
derivates are referred to as XC2200 throughout this manual.
Note: Please refer to the corresponding Data Sheets for a description of the features of
a specific device type.
The XC2700 combines the extended functionality and performance of the
C166SV2 Core with powerful on-chip peripheral subsystems and on-chip memory units
and provides several means for power reduction.
The following key features contribute to the high performance of the XC2700:
Intelligent On-Chip Peripheral Subsystems
• Two synchronizable A/D Converters with programmable resolution (10-bit or 8-bit)
and conversion time (down to approx. 1 µs), up to 24 analog input channels, auto scan
modes, channel injection, data reduction features
• One Capture/Compare Unit with 2 independent time bases,
very flexible PWM unit/event recording unit with different operating modes,
includes two 16-bit timers/counters, maximum resolution fSYS
• Four Capture/Compare Units for flexible PWM Signal Generation (CCU6)
(3/6 Capture/Compare Channels and 1 Compare Channel)
• Two Multifunctional General Purpose Timer Units:
– GPT1: three 16-bit timers/counters, maximum resolution fSYS/4
– GPT2: two 16-bit timers/counters, maximum resolution fSYS/2
• Six Serial Channels with baud rate generator, receive/transmit FIFOs, programmable
data length and shift direction, usable as UART, SPI-like, IIC, IIS, and LIN interface
• Controller Area Network (MultiCAN) Module, Rev. 2.0B active,
two nodes operating independently or exchanging data via a gateway function, FullCAN/Basic-CAN
• Real Time Clock with alarm interrupt
• Watchdog Timer with programmable time intervals
• Bootstrap Loader for flexible system initialization
• Protection management for system configuration and control registers
Integrated On-Chip Memories
•
•
•
•
2 Kbytes Dual-Port RAM (DPRAM) for variables, register banks, and stacks
16 Kbytes on-chip high-speed Data SRAM (DSRAM) for variables and stacks
32 Kbytes on-chip high-speed Program/Data SRAM (PSRAM) for code and data
768 Kbytes on-chip Flash Program Memory for instruction code or constant data
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Note: The system stack can be located in any memory area within the complete
addressing range.
High Performance 16-bit CPU with Five-Stage Pipeline and MAC Unit
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Single clock cycle instruction execution
1 cycle minimum instruction cycle time (most instructions)
1 cycle multiplication (16-bit × 16-bit)
4 + 17 cycles division (32-bit / 16-bit), 4 cycles delay, 17 cycles background execution
1 cycle multiply and accumulate instruction (MAC) execution
Automatic saturation or rounding included
Multiple high bandwidth internal data buses
Register-based design with multiple, variable register banks
Two additional fast register banks
Fast context switching support
16 Mbytes of linear address space for code and data (von Neumann architecture)
System stack cache support with automatic stack overflow/underflow detection
High performance branch, call, and loop processing
Zero-cycle jump execution
Control Oriented Instruction Set with High Efficiency
• Bit, byte, and word data types
• Flexible and efficient addressing modes for high code density
• Enhanced boolean bit manipulation with direct addressability of 6 Kbits for peripheral
control and user-defined flags
• Hardware traps to identify exception conditions during runtime
• HLL support for semaphore operations and efficient data access
Power Management Features
•
•
•
•
•
Two IO power domains fulfill system requirements from 3 V to 5 V
Gated clock concept for improved power consumption and EMC
Programmable system slowdown via clock generation unit
Flexible management of peripherals, can be individually disabled
Programmable frequency output
16-Priority-Level Interrupt System
•
•
•
•
•
96 interrupt nodes with separate interrupt vectors on 15 priority levels (8 group levels)
7 cycles minimum interrupt latency in case of internal program execution
Fast external interrupts
Programmable external interrupt source selection
Programmable vector table (start location and step-width)
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8-Channel Peripheral Event Controller (PEC)
• Interrupt driven single cycle data transfer
• Programmable PEC interrupt request level, (15 down to 8)
• Transfer count option
(standard CPU interrupt after programmable number of PEC transfers)
• Separate interrupt level for PEC termination interrupts selectable
• Overhead from saving and restoring system state for interrupt requests eliminated
• Full 24-bit addresses for source and destination pointers, supporting transfers within
the total address space
On-Chip Debug Support
•
•
•
•
•
•
•
•
On-chip debug controller and related interface to JTAG controller
JTAG interface and break interface
Hardware, software and external pin breakpoints
Up to 4 instruction pointer breakpoints
Debug event control, e.g. with monitor call or CPU halt or trigger of data transfer
Dedicated DEBUG instructions with control via JTAG interface
Access to any internal register or memory location via JTAG interface
Single step support and watchpoints with MOV-injection
Input/Output Lines With Individual Bit Addressability
•
•
•
•
Tri-stated in input mode
Push/pull or open drain output mode
Programmable port driver control
Two I/O power domains with a supply voltage range from 3.0 V to 5.5 V
(core-logic and oscillator input voltage is 1.5 V)
Various Temperature Ranges
• -40 to +85 °C
• -40 to +125 °C1)
Infineon CMOS Process
• Low power CMOS technology enables power saving modes with flexible power
management.
Green Plastic Low-Profile Quad Flat Pack (LQFP) Packages
• PG-LQFP-144, 20 × 20 mm body, 0.5 mm (19.7 mil) lead spacing,
surface mount technology
1)
Not all derivatives are offered in all temperature ranges.
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Introduction
• PG-LQFP-100, 14 × 14 mm body, 0.5 mm (19.7 mil) lead spacing,
surface mount technology
Complete Development Support
For the development tool support of its microcontrollers, Infineon follows a clear third
party concept. Currently around 120 tool suppliers world-wide, ranging from local niche
manufacturers to multinational companies with broad product portfolios, offer powerful
development tools for the Infineon C500, C800, XC800, C166, XC166, XC2000, XE166,
and TriCore microcontroller families, guaranteeing a remarkable variety of priceperformance classes as well as early availability of high quality key tools such as
compilers, assemblers, simulators, debuggers or in-circuit emulators.
Infineon incorporates its strategic tool partners very early into the product development
process, making sure embedded system developers get reliable, well-tuned tool
solutions, which help them unleash the power of Infineon microcontrollers in the most
effective way and with the shortest possible learning curve.
The tool environment for the Infineon 16-bit microcontrollers includes the following tools:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Compilers (C/C++)
Macro-assemblers, linkers, locators, library managers, format-converters
Architectural simulators
HLL debuggers
Real-time operating systems
VHDL chip models
In-circuit emulators (based on bondout or standard chips)
Plug-in emulators
Emulation and clip-over adapters, production sockets
Logic analyzer disassemblers
Starter kits
Evaluation boards with monitor programs
Industrial boards (also for CAN, FUZZY, PROFIBUS, FORTH applications)
Low level driver software (CAN, PROFIBUS, LIN)
Chip configuration code generation tool (DAvE)
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1.3
Abbreviations
The following acronyms and terms are used within this document:
ADC
Analog Digital Converter
ALE
Address Latch Enable
ALU
Arithmetic and Logic Unit
ASC
Asynchronous/synchronous Serial Channel
CAN
Controller Area Network (License Bosch)
CAPCOM
CAPture and COMpare unit
CISC
Complex Instruction Set Computing
CMOS
Complementary Metal Oxide Silicon
CPU
Central Processing Unit
DMU
Data Management Unit
EBC
External Bus Controller
ESFR
Extended Special Function Register
EVVR
Embedded Validated Voltage Regulator
Flash
Non-volatile memory that may be electrically erased
GPR
General Purpose Register
GPT
General Purpose Timer unit
HLL
High Level Language
IIC
Inter Integrated Circuit (Bus)
IIS
Inter Integrated Circuit Sound (Bus)
IO
Input/Output
JTAG
Joint Test Access Group
LIN
Local Interconnect Network
LPR
Low Power Reference
LQFP
Low Profile Quad Flat Pack
LXBus
Internal representation of the external bus
MAC
Multiply/Accumulate (unit)
OCDS
On-Chip Debug Support
OTP
One-Time Programmable memory
PEC
Peripheral Event Controller
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PLA
Programmable Logic Array
PLL
Phase Locked Loop
PMU
Program Management Unit
PVC
Power Validation Circuit
PWM
Pulse Width Modulation
RAM
Random Access Memory
RISC
Reduced Instruction Set Computing
ROM
Read Only Memory
RTC
Real Time Clock
SFR
Special Function Register
SSC
Synchronous Serial Channel
SWD
Supply Watchdog
UART
Universal Asynchronous Receiver/Transmitter
USIC
Universal Serial Interface Channel
1.4
Naming Conventions
The diverse bitfields used for control functions and status indication and the registers
housing them are equipped with unique names wherever applicable. Thereby these
control structures can be referred to by their names rather than by their location. This
makes the descriptions by far more comprehensible.
To describe regular structures (such as ports) indices are used instead of a plethora of
similar bit names, so bit 3 of port 5 is referred to as P5.3.
Where it helps to clarify the relation between several named structures, the next higher
level is added to the respective name to make it unambiguous.
The term ADC0_GLOBCTR clearly identifies register GLOBCTR as part of module
ADC0, the term SYSCON0.CLKSEL clearly identifies bitfield CLKSEL as part of register
SYSCON0.
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Architectural Overview
2
Architectural Overview
The architecture of the XC2700 core combines the advantages of both RISC and CISC
processors in a very well-balanced way. This computing and controlling power is
completed by the DSP-functionality of the MAC-unit. The XC2700 integrates this
powerful CPU core with a set of powerful peripheral units into one chip and connects
them very efficiently. On-chip memory blocks with dedicated buses and control units
store code and data. This combination of features results in a high performance
microcontroller, which is the right choice not only for today’s applications, but also for
future engineering challenges. One of the buses used concurrently on the XC2700 is the
LXBus, an internal representation of the external bus interface. This bus provides a
standardized method for integrating additional application-specific peripherals into
derivatives of the standard XC2700.
PSRAM
32 Kbytes
DPRAM
2 Kbytes
DSRAM
16 Kbytes
OCDS
Debug Support
CPU
C166SV2 - Core
Program Flash 2
256 Kbytes
WDT
System Functions
Clock, Reset, Power Control
Interrupt & PEC
RTC
LXBus
XTAL
EBC
LXBus Control
External Bus
Control
DMU
Program Flash 1
256 Kbytes
PMU
IMB
Program Flash 0
256 Kbytes
ADC1
8-/10Bit,
8/5
Chan.
ADC0
8-/10Bit,
16/11
Chan.
GPT
T2
T3
T4
... CCU60
CC2
CCU63
T7
T12
T12
T8
T13
T13
Peri pheral
Data B us
Interrupt Bus
USIC2 USIC1 USIC0 Multi
2 Ch., 2 Ch., 2 Ch., CAN
64 x
64 x
64 x
Buffer Buffer Buffer
RS232, RS232, RS232,
2
LIN,
LIN,
LIN,
chan.
SPI,
SPI,
SPI,
IIC, IIS IIC, IIS IIC, IIS
T5
T6
BRGen
P15
8/5
Port 5
16/11
P11
6
P10
16
P9
P8
8
P7 P6
7
5
P4
4/3
8/4
P3
8
P2
13
P1
P0
8
8
MC_XC 27XX_BLOCKDIAGRAM
Figure 2-1
XC2700 Functional Block Diagram
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Architectural Overview
2.1
Basic CPU Concepts and Optimizations
The main core of the CPU consists of a set of optimized functional units including the
instruction fetch/processing pipelines, a 16-bit Arithmetic and Logic Unit (ALU), a 40-bit
Multiply and Accumulate Unit (MAC), an Address and Data Unit (ADU), an Instruction
Fetch Unit (IFU), a Register File (RF), and dedicated Special Function Registers (SFRs).
Single clock cycle execution of instructions results in superior CPU performance, while
maintaining C166 code compatibility. Impressive DSP performance, concurrent access
to different kinds of memories and peripherals boost the overall system performance.
PSRAM
Flash/ROM
PMU
CPU
Prefetch
Unit
Branch
Unit
CSP
IP
VECSEG
CPUCON1
CPUCON2
Return
Stack
FIFO
IDX0
IDX1
QX0
QX1
QR0
QR1
+/-
+/-
Multiply
Unit
MRW
+/-
MCW
MSW
MAH
MAL
2-Stage
Prefetch
Pipeline
TFR
Injection/
Exception
Handler
5-Stage
Pipeline
IFU
DPP0
DPP1
DPP2
DPP3
DPRAM
IPIP
SPSEG
SP
STKOV
STKUN
ADU
Division Unit
Bit-Mask-Gen.
Multiply Unit
Barrel-Shifter
MDC
R15
R15
R14
R15
R14
R14
R15
R14
GPRs
GPRs
GPRs
GPRs
R1
R1
R0
R0R1
R0
R1
R0
RF
PSW
+/-
MDH
MDL
ZEROS
ONES
MAC
CP
Buffer
ALU
WB
DSRAM
EBC
Peripherals
DMU
mca04917_x.vsd
Figure 2-2
CPU Block Diagram
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Architectural Overview
Summary of CPU Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Opcode fully upward compatible with C166 Family
2-stage instruction fetch pipeline with FIFO for instruction pre-fetching
5-stage instruction execution pipeline
Pipeline forwarding controls data dependencies in hardware
Multiple high bandwidth buses for data and instructions
Linear address space for code and data (von Neumann architecture)
Nearly all instructions executed in one CPU clock cycle
Fast multiplication (16-bit × 16-bit) in one CPU clock cycle
Fast background execution of division (32-bit/16-bit) in 21 CPU clock cycles
Built-in advanced MAC (Multiply Accumulate) Unit:
– Single cycle MAC instruction with zero cycle latency including a 16 × 16 multiplier
– 40-bit barrel shifter and 40-bit accumulator to handle overflows
– Automatic saturation to 32 bits or rounding included with the MAC instruction
– Fractional numbers supported directly
– One Finite Impulse Response Filter (FIR) tap per cycle with no circular buffer
management
Enhanced boolean bit manipulation facilities
High performance branch-, call-, and loop-processing
Zero cycle jump execution
Register-based design with multiple variable register banks (byte or word operands)
Two additional fast register banks
Variable stack with automatic stack overflow/underflow detection
“Fast interrupt” and “Fast context switch” features
The high performance and flexibility of the CPU is achieved by a number of optimized
functional blocks (see Figure 2-2). Optimizations of the functional blocks are described
in detail in the following sections.
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2.1.1
High Instruction Bandwidth/Fast Execution
Based on the hardware provisions, most of the XC2700’s instructions can be executed
in just one clock cycle (1/fSYS). This includes arithmetic instructions, logic instructions,
and move instructions with most addressing modes.
Special instructions such as JMPS take more than one machine cycle. Divide
instructions are mainly executed in the background, so other instructions can be
executed in parallel. Due to the prediction mechanism (see Section 4.2), correctly
predicted branch instructions require only one cycle or can even be overlaid with another
instruction (zero-cycle jump).
The instruction cycle time is dramatically reduced through the use of instruction
pipelining. This technique allows the core CPU to process portions of multiple sequential
instruction stages in parallel. Up to seven stages can operate in parallel:
The two-stage instruction fetch pipeline fetches and preprocesses instructions from
the respective program memory:
PREFETCH: Instructions are prefetched from the PMU in the predicted order. The
instructions are preprocessed in the branch detection unit to detect branches. The
prediction logic determines if branches are assumed to be taken or not.
FETCH: The instruction pointer for the next instruction to be fetched is calculated
according to the branch prediction rules. The branch folding unit preprocesses detected
branches and combines them with the preceding instructions to enable zero-cycle
branch execution. Prefetched instructions are stored in the instruction FIFO, while stored
instructions are moved from the instruction FIFO to the instruction processing pipeline.
The five-stage instruction processing pipeline executes the respective instructions:
DECODE: The previously fetched instruction is decoded and the GPR used for indirect
addressing is read from the register file, if required.
ADDRESS: All operand addresses are calculated. For instructions implicitly accessing
the stack the stack pointer (SP) is decremented or incremented.
MEMORY: All required operands are fetched.
EXECUTE: The specified operation (ALU or MAC) is performed on the previously
fetched operands. The condition flags are updated. Explicit write operations to CPUSFRs are executed. GPRs used for indirect addressing are incremented or
decremented, if required.
WRITE BACK: The result operands are written to the specified locations. Operands
located in the DPRAM are stored via the write-back buffer.
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2.1.2
Powerful Execution Units
The 16-bit Arithmetic and Logic Unit (ALU) performs all standard (word) arithmetic
and logical operations. Additionally, for byte operations, signals are provided from bits 6
and 7 of the ALU result to set the condition flags correctly. Multiple precision arithmetic
is provided through a ‘CARRY-IN’ signal to the ALU from previously calculated portions
of the desired operation.
Most internal execution blocks have been optimized to perform operations on either 8-bit
or 16-bit quantities. Instructions have been provided as well to allow byte packing in
memory while providing sign extension of bytes for word wide arithmetic operations. The
internal bus structure also allows transfers of bytes or words to or from peripherals based
on the peripheral requirements.
A set of consistent flags is updated automatically in the PSW after each arithmetic,
logical, shift, or movement operation. These flags allow branching on specific conditions.
Support for both signed and unsigned arithmetic is provided through user-specifiable
branch tests. These flags are also preserved automatically by the CPU upon entry into
an interrupt or trap routine.
A 16-bit barrel shifter provides multiple bit shifts in a single cycle. Rotates and arithmetic
shifts are also supported.
The Multiply and Accumulate Unit (MAC) performs extended arithmetic operations
such as 32-bit addition, 32-bit subtraction, and single-cycle 16-bit × 16-bit multiplication.
The combined MAC operations (multiplication with cumulative addition/subtraction)
represent the major part of the DSP performance of the CPU.
The Address Data Unit (ADU) contains two independent arithmetic units to generate,
calculate, and update addresses for data accesses. The ADU performs the following
major tasks:
• The Standard Address Unit supports linear arithmetic for the short, long, and indirect
addressing modes. It also supports data paging and stack handling.
• The DSP Address Generation Unit contains an additional set of address pointers and
offset registers which are used in conjunction with the CoXXX instructions only.
The CPU provides a lot of powerful addressing modes for word, byte, and bit data
accesses (short, long, indirect). The different addressing modes use different formats
and have different scopes.
Dedicated bit processing instructions provide efficient control and testing of peripherals
while enhancing data manipulation. These instructions provide direct access to two
operands in the bit-addressable space without requiring them to be moved into
temporary flags. Logical instructions allow the user to compare and modify a control bit
for a peripheral in one instruction. Multiple bit shift instructions (single cycle execution)
avoid long instruction streams of single bit shift operations. Bitfield instructions allow the
modification of multiple bits from one operand in a single instruction.
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2.1.3
High Performance Branch-, Call-, and Loop-Processing
Pipelined execution delivers maximum performance with a stream of subsequent
instructions. Any disruption requires the pipeline to be refilled and the new instruction to
step through the pipeline stages. Due to the high percentage of branching in controller
applications, branch instructions have been optimized to require pipeline refilling only in
special cases. This is realized by detecting and preprocessing branch instructions in the
prefetch stage and by predicting the respective branch target address.
Prefetching then continues from the predicted target address. If the prediction was
correct subsequent instructions can be fed to the execution pipeline without a gap, even
if a branch is executed, i.e. the code execution is not linear. Branch target prediction (see
also Section 4.2.1) uses the following rules:
• Unconditional branches: Branch prediction is trivial in this case, as the branches will
always be taken and the target address is defined. This applies to implicitly
unconditional branches such as JMPS, CALLR, or RET as well as to branches with
condition code “unconditional” such as JMPI cc_UC.
• Fixed prediction: Branch instructions which are often used to realize loops are
assumed to be taken if they branch backward to a previous location (the begin of the
loop). This applies to conditional branches such as JMPR cc_XX or JNB.
• Variable prediction: In this case the respective prediction (taken or not taken) is
coded into the instruction and can, therefore, be selected for each individual branch
instruction. Thus, the software designer can optimize the instruction flow to the
specific code to be executed1). This applies to the branch instructions JMPA and
CALLA.
• Conditional indirect branches: These branches are always assumed to be not
taken. This applies to branch instructions JMPI cc_XX, [Rw] and CALLI cc_XX, [Rw].
The system state information is saved automatically on the internal system stack, thus
avoiding the use of instructions to preserve state upon entry and exit of interrupt or trap
routines. Call instructions push the value of the IP on the system stack, and require the
same execution time as branch instructions. Additionally, instructions have been
provided to support indirect branch and call instructions. This feature supports
implementation of multiple CASE statement branching in assembler macros and high
level languages.
1)
The programming tools accept either dedicated mnemonics for each prediction leaving the choice up to
programmer, or they accept generic mnemonics and apply their own prediction rules.
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2.1.4
Consistent and Optimized Instruction Formats
To obtain optimum performance in a pipelined design, an instruction set has been
designed which incorporates concepts from Reduced Instruction Set Computing (RISC).
These concepts primarily allow fast decoding of the instructions and operands while
reducing pipeline holds. These concepts, however, do not preclude the use of complex
instructions required by microcontroller users. The instruction set was designed to meet
the following goals:
• Provide powerful instructions for frequently-performed operations which traditionally
have required sequences of instructions. Avoid transfer into and out of temporary
registers such as accumulators and carry bits. Perform tasks in parallel such as saving
state upon entry into interrupt routines or subroutines.
• Avoid complex encoding schemes by placing operands in consistent fields for each
instruction and avoid complex addressing modes which are not frequently used.
Consequently, the instruction decode time decreases and the development of
compilers and assemblers is simplified.
• Provide most frequently used instructions with one-word instruction formats. All other
instructions use two-word formats. This allows all instructions to be placed on word
boundaries: this alleviates the need for complex alignment hardware. It also has the
benefit of increasing the range for relative branching instructions.
The high performance of the CPU-hardware can be utilized efficiently by a programmer
by means of the highly functional XC2700 instruction set which includes the following
instruction classes:
•
•
•
•
•
•
•
•
•
•
•
•
•
Arithmetic Instructions
DSP Instructions
Logical Instructions
Boolean Bit Manipulation Instructions
Compare and Loop Control Instructions
Shift and Rotate Instructions
Prioritize Instruction
Data Movement Instructions
System Stack Instructions
Jump and Call Instructions
Return Instructions
System Control Instructions
Miscellaneous Instructions
Possible operand types are bits, bytes, words, and doublewords. Specific instructions
support the conversion (extension) of bytes to words. Various direct, indirect, and
immediate addressing modes are provided to specify the required operands.
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2.1.5
Programmable Multiple Priority Interrupt System
The XC2700 provides 96 separate interrupt nodes that may be assigned to 16 priority
levels with 8 group priorities on each level. Most interrupt sources are connected to a
dedicated interrupt node. In some cases, multi-source interrupt nodes are incorporated
for efficient use of system resources. These nodes can be activated by several source
requests and are controlled via interrupt subnode control registers.
The following enhancements within the XC2700 allow processing of a large number of
interrupt sources:
• Peripheral Event Controller (PEC): This processor is used to off-load many interrupt
requests from the CPU. It avoids the overhead of entering and exiting interrupt or trap
routines by performing single-cycle interrupt-driven byte or word data transfers
between any two locations with an optional increment of the PEC source pointer, the
destination pointer, or both. Only one cycle is ‘stolen’ from the current CPU activity to
perform a PEC service.
• Multiple Priority Interrupt Controller: This controller allows all interrupts to be assigned
any specified priority. Interrupts may also be grouped, which enables the user to
prevent similar priority tasks from interrupting each other. For each of the interrupt
nodes, there is a separate control register which contains an interrupt request flag, an
interrupt enable flag, and an interrupt priority bitfield. After being accepted by the CPU,
an interrupt service can be interrupted only by a higher prioritized service request. For
standard interrupt processing, each of the interrupt nodes has a dedicated vector
location.
• Multiple Register Banks: Two local register banks for immediate context switching add
to a relocatable global register bank. The user can specify several register banks
located anywhere in the internal DPRAM and made of up to sixteen general purpose
registers. A single instruction switches from one register bank to another (switching
banks flushes the pipeline, changing the global bank requires a validation sequence).
The XC2700 is capable of reacting very quickly to non-deterministic events because its
interrupt response time is within a very narrow range of typically 7 clock cycles (in the
case of internal program execution). Its fast external interrupt inputs are sampled every
clock cycle and allow even very short external signals to be recognized.
The XC2700 also provides an excellent mechanism to identify and process exceptions
or error conditions that arise during run-time, so called ‘Hardware Traps’. A hardware
trap causes an immediate non-maskable system reaction which is similar to a standard
interrupt service (branching to a dedicated vector table location). The occurrence of a
hardware trap is additionally signified by an individual bit in the trap flag register (TFR).
Unless another, higher prioritized, trap service is in progress, a hardware trap will
interrupt any current program execution. In turn, a hardware trap service can normally
not be interrupted by a standard or PEC interrupt.
Software interrupts are supported by means of the ‘TRAP’ instruction in combination with
an individual trap (interrupt) number.
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2.1.6
Interfaces to System Resources
The CPU of the XC2700 interfaces to the system resources via several bus systems
which contribute to the overall performance by transferring data concurrently. This
avoids stalling the CPU because instructions or operands need to be transferred.
The Dual Port RAM (DPRAM) is directly coupled to the CPU because it houses the
global register banks. Transfers from/to these locations affect the performance and are,
therefore, carefully optimized.
The Program Management Unit (PMU) controls accesses to the on-chip program
memory blocks such as the ROM/Flash module and the Program/Data RAM (PSRAM)
and also fetches instructions from external memory.
The 64-bit interface between the PMU and the CPU delivers the instruction words, which
are requested by the CPU. The PMU decides whether the requested instruction word
has to be fetched from on-chip memory or from external memory.
The Data Management Unit (DMU) controls accesses to the on-chip Data RAM
(DSRAM), to the on-chip peripherals connected to the peripheral bus, and to resources
on the external bus. External accesses (including accesses to peripherals connected to
the on-chip LXBus) are executed by the External Bus Controller (EBC).
The 16-bit interface between the DMU and the CPU handles all data transfers
(operands). Data accesses by the CPU are distributed to the appropriate buses
according to the defined address map.
PMU and DMU are directly coupled to perform cross-over transfers with high speed.
Crossover transfers are executed in both directions:
• PMU via DMU: Code fetches from external locations are redirected via the DMU to
EBC. Thus, the XC2700 can execute code from external resources. No code can be
fetched from the Data RAM (DSRAM).
• DMU via PMU: Data accesses can also be executed to on-chip resources controlled
by the PMU. This includes the following types of transfers:
– Read a constant from the on-chip program ROM/Flash
– Read data from the on-chip PSRAM
– Write data to the on-chip PSRAM (required prior to executing out of it)
– Program/Erase the on-chip Flash memory
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2.2
On-Chip System Resources
The XC2700 controllers provide a number of powerful system resources designed
around the CPU. The combination of CPU and these resources results in the high
performance of the members of this controller family.
Peripheral Event Controller (PEC) and Interrupt Control
The Peripheral Event Controller enables response to an interrupt request with a single
data transfer (word or byte) which consumes only one instruction cycle and does not
require saving and restoring the machine status. Each interrupt source is prioritized for
every machine cycle in the interrupt control block. If PEC service is selected, a PEC
transfer is started. If CPU interrupt service is requested, the current CPU priority level
stored in the PSW register is tested to determine whether a higher priority interrupt is
currently being serviced. When an interrupt is acknowledged, the current state of the
machine is saved on the internal system stack and the CPU branches to the system
specific vector for the peripheral.
The PEC contains a set of SFRs which store the count value and control bits for eight
data transfer channels. In addition, the PEC uses a dedicated area of RAM which
contains the source and destination addresses. The PEC is controlled in a manner
similar to any other peripheral: through SFRs containing the desired configuration of
each channel.
An individual PEC transfer counter is implicitly decremented for each PEC service
except in the continuous transfer mode. When this counter reaches zero, a standard
interrupt is performed to the vector location related to the corresponding source. PEC
services are very well suited, for example, to moving register contents to/from a memory
table. The XC2700 has eight PEC channels, each of which offers such fast interruptdriven data transfer capabilities.
Memory Areas
The memory space of the XC2700 is configured in a Von Neumann architecture. This
means that code memory, data memory, registers, and IO ports are organized within the
same linear address space which covers up to 16 Mbytes. The entire memory space can
be accessed bytewise or wordwise. Particular portions of the on-chip memory have been
made directly bit addressable as well.
Note: The actual memory sizes depend on the selected device type. This overview
describes the maximum block sizes.
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768 Kbytes of on-chip Flash memory store code or constant data. The on-chip Flash
memory consists of 3 Flash modules, each built up from 4-Kbyte sectors. Each sector
can be separately write protected1), erased and programmed (in blocks of 128 bytes).
The complete Flash area can be read-protected. A user-defined password sequence
temporarily unlocks protected areas. The Flash modules combine 128-bit read accesses
with protected and efficient writing algorithms for programming and erasing. Dynamic
error correction provides extremely high read data security for all read accesses.
Accesses to different Flash modules can be executed in parallel.
Note: Program execution from on-chip program memory is the fastest of all possible
alternatives and results in maximum performance. The size of the on-chip
program memory depends on the chosen derivative. On-chip program memory
also includes the PSRAM.
32 Kbytes of on-chip Program SRAM (PSRAM) are provided to store user code or
data. The PSRAM is accessed via the PMU and is, therefore, optimized for code fetches.
A section of the PSRAM with programmable size can be write-protected.
16 Kbytes of on-chip Data SRAM (DSRAM) are provided as a storage for general user
data. The DSRAM is accessed via a separate interface and is, therefore, optimized for
data accesses.
2 Kbytes of on-chip Dual-Port RAM (DPRAM) are provided as a storage for user
defined variables, for the system stack, and in particular for general purpose register
banks. A register bank can consist of up to 16 wordwide (R0 to R15) and/or bytewide
(RL0, RH0, …, RL7, RH7) so-called General Purpose Registers (GPRs).
The upper 256 bytes of the DPRAM are directly bitaddressable. When used by a GPR,
any location in the DPRAM is bitaddressable.
The CPU has an actual register context of up to 16 wordwide and/or bytewide global
GPRs at its disposal, which are physically located within the on-chip RAM area. A
Context Pointer (CP) register determines the base address of the active global register
bank to be accessed by the CPU at a time. The number of register banks is restricted
only by the available internal RAM space. For easy parameter passing, a register bank
may overlap other register banks.
A system stack of up to 32 Kwords is provided as storage for temporary data. The system
stack can be located anywhere within the complete addressing range and it is accessed
by the CPU via the Stack Pointer (SP) register and the Stack Pointer Segment (SPSEG)
register. Two separate SFRs, STKOV and STKUN, are implicitly compared against the
stack pointer value upon each stack access for the detection of a stack overflow or
underflow. This mechanism also supports the control of a bigger virtual stack. Maximum
performance for stack operations is achieved by allocating the system stack to internal
data RAM areas (DPRAM, DSRAM).
1)
To save control bits, sectors are clustered for protection purposes, they remain separate for programming/
erasing.
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Hardware detection of the selected memory space is placed at the internal memory
decoders and allows the user to specify any address directly or indirectly and obtain the
desired data without using temporary registers or special instructions.
For Special Function Registers three areas of the address space are reserved: The
standard Special Function Register area (SFR) uses 512 bytes, while the Extended
Special Function Register area (ESFR) uses the other 512 bytes. A range of 4 Kbytes is
provided for the internal IO area (XSFR). SFRs are wordwide registers which are used
for controlling and monitoring functions of the different on-chip units. Unused SFR
addresses are reserved for future members of the XC2000 Family with enhanced
functionality. Therefore, they should either not be accessed, or written with zeros, to
ensure upward compatibility.
In order to meet the needs of designs where more memory is required than is provided
on chip, up to 12 Mbytes (approximately, see Table 2-1) of external RAM and/or ROM
can be connected to the microcontroller. The External Bus Interface also provides
access to external peripherals.
Table 2-1
XC2700 Memory Map
Address Area
Start Loc.
End Loc.
Area Size1)
Notes
IMB register space
FF’FF00H
FF’FFFFH
256 Bytes
–
Reserved (Access trap) F0’0000H
FF’FEFFH
<1 Mbyte
Minus IMB reg.
Reserved for EPSRAM E9’0000H
EF’FFFFH
448 Kbytes
Mirrors EPSRAM
Emulated PSRAM
E8’0000H
E8’FFFFH
64 Kbytes
Flash timing
Reserved for PSRAM
E1’0000H
E7’FFFFH
448 Kbytes
Mirrors PSRAM
Program SRAM
E0’0000H
E0’FFFFH
64 Kbytes
Maximum speed
Reserved for pr. mem.
CC’0000H
DF’FFFFH
<1.25 Mbytes –
Program Flash 2
C8’0000H
CB’FFFFH
256 Kbytes
Program Flash 1
C4’0000H
C7’FFFFH
256 Kbytes
–
–
Program Flash 0
C0’0000H
C3’FFFFH
256 Kbytes
2)
External memory area
40’0000H
BF’FFFFH
8 Mbytes
–
Available Ext. IO area3) 20’5800H
3F’FFFFH
< 2 Mbytes
Minus USIC/CAN
USIC registers
20’4000H
20’57FFH
6 Kbytes
Accessed via EBC
MultiCAN registers
20’0000H
20’3FFFH
16 Kbytes
Accessed via EBC
External memory area
01’0000H
1F’FFFFH
< 2 Mbytes
Minus segment 0
SFR area
00’FE00H
00’FFFFH
0.5 Kbyte
–
Dual-Port RAM
00’F600H
00’FDFFH
2 Kbytes
–
Reserved for DPRAM
00’F200H
00’F5FFH
1 Kbyte
–
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Table 2-1
XC2700 Memory Map (cont’d)
Address Area
Start Loc.
End Loc.
Area Size1)
Notes
ESFR area
00’F000H
00’F1FFH
0.5 Kbyte
–
XSFR area
00’E000H
00’EFFFH
4 Kbytes
–
Data SRAM
00’A000H
00’DFFFH
16 Kbytes
–
Reserved for DSRAM
00’8000H
00’9FFFH
8 Kbytes
–
External memory area
00’0000H
00’7FFFH
32 Kbytes
–
1)
The areas marked with “<” are slightly smaller than indicated, see column “Notes”.
2)
The uppermost 4-Kbyte sector of the first Flash segment is reserved for internal use (C0’F000H to C0’FFFFH).
3)
Several pipeline optimizations are not active within the external IO area. This is necessary to control external
peripherals properly.
Note: For an overview of the available memory sections for the different derivatives,
please refer to “Summary of Basic Features” on Page 1-5.
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External Bus Interface
To meet the needs of designs where more memory is required than is provided on chip,
up to 12 Mbytes of external RAM/ROM/Flash or peripherals can be connected to the
XC2700 microcontroller via its external bus interface.
All of the external memory accesses are performed by a particular on-chip External Bus
Controller (EBC). It can be programmed either to Single Chip Mode when no external
memory is required, or to an external bus mode with the following possible selections1):
• Address Bus Width with a range of 0 … 24-bit
• Data Bus Width 8-bit or 16-bit
• Bus Operation Multiplexed or Demultiplexed
In the demultiplexed bus modes, addresses are output on Port 0 and Port 1 and data is
input/output on Port 10 and Port 2. In the multiplexed bus modes both addresses and
data use Port 10 and Port 2 for input/output. The high order address (segment) lines use
Port 2. The number of active segment address lines is selectable, restricting the external
address space to 8 Mbytes … 64 Kbytes. This is required when interface lines are
assigned to Port 2.
For up to five address areas the bus mode (multiplexed/demultiplexed), the data bus
width (8-bit/16-bit) and even the length of a bus cycle (waitstates, signal delays) can be
selected independently. This allows access to a variety of memory and peripheral
components directly and with maximum efficiency.
Access to very slow memories or modules with varying access times is supported via a
particular ‘Ready’ function. The active level of the control input signal is selectable.
A HOLD/HLDA protocol is available for bus arbitration and allows the sharing of external
resources with other bus masters.
The external bus timing is related to the rising edge of the reference clock output
CLKOUT. The external bus protocol is compatible with that of the standard C166 Family.
For applications which require less than 64 Kbytes of address space, a non-segmented
memory model can be selected, where all locations can be addressed by 16 bits. Thus,
the upper Port 2 is not needed as an output for the upper address bits (Axx … A16), as
is the case when using the segmented memory model.
The EBC also controls accesses to resources connected to the on-chip LXBus. The
LXBus is an internal representation of the external bus and allows accessing integrated
peripherals and modules in the same way as external components.
The MultiCAN module and the USIC modules are connected to and accessed via the
LXBus.
1)
Bus modes are switched dynamically if several address windows with different mode settings are used.
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2.3
On-Chip Peripheral Blocks
The XC2000 Family clearly separates peripherals from the core. This structure permits
the maximum number of operations to be performed in parallel and allows peripherals to
be added or deleted from family members without modifications to the core. Each
functional block processes data independently and communicates information over
common buses. Peripherals are controlled by data written to the respective Special
Function Registers (SFRs). These SFRs are located within either the standard SFR area
(00’FE00H … 00’FFFFH), the extended ESFR area (00’F000H … 00’F1FFH), or within
the internal IO area (00’E000H … 00’EFFFH).
These built-in peripherals either allow the CPU to interface with the external world or
provide functions on-chip that otherwise would need to be added externally in the
respective system.
The XC2700 generic peripherals are:
•
•
•
•
•
•
•
General Purpose Timer Unit (GPT1, GPT2)
Watchdog Timer
Capture/Compare Unit (CAPCOM2)
Four Capture/Compare Units CCU6 (CCU60, CCU61, CCU62, CCU63)
Two 10-bit Analog/Digital Converters (ADC0, ADC1)
Real Time Clock (RTC)
Thirteen/Nine Parallel Ports with a total of 118/75 I/O lines
Because the LXBus is the internal representation of the external bus, it does not support
bit-addressing. Accesses are executed by the EBC as if it were external accesses. The
LXBus connects on-chip peripherals to the CPU:
• MultiCAN Module with 2 CAN nodes and gateway functionality
• Two Universal Serial Interface Channel Modules (USIC)
Each peripheral also contains a set of Special Function Registers (SFRs) which control
the functionality of the peripheral and temporarily store intermediate data results. Each
peripheral has an associated set of status flags. Individually selected clock signals are
generated for each peripheral from binary multiples of the master clock.
Note: For an overview of the available peripherals for the different derivatives, please
refer to “Summary of Basic Features” on Page 1-5.
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Peripheral Interfaces
The on-chip peripherals generally have two different types of interfaces: an interface to
the CPU and an interface to external hardware. Communication between the CPU and
peripherals is performed through Special Function Registers (SFRs) and interrupts. The
SFRs serve as control/status and data registers for the peripherals. Interrupt requests
are generated by the peripherals based on specific events which occur during their
operation, such as operation complete, error, etc.
To interface with external hardware, specific pins of the parallel ports are used, when an
input or output function has been selected for a peripheral. During this time, the port pins
are controlled either by the peripheral (when used as outputs) or by the external
hardware which controls the peripheral (when used as inputs). This is called the
‘alternate (input or output) function’ of a port pin, in contrast to its function as a general
purpose I/O pin.
Peripheral Timing
Internal operation of the CPU and peripherals is based on the system clock (fSYS). The
clock generation unit uses external (e.g. a crystal) or internal clock sources to generate
the system clock signal. Peripherals can be disconnected from the clock signal either
temporarily to save energy or permanently if they are not used in a specific application.
Peripheral SFRs may be accessed by the CPU once per state. When an SFR is written
to by software in the same state where it is also to be modified by the peripheral, the
software write operation has priority. Further details on peripheral timing are included in
the specific sections describing each peripheral.
Programming Hints
• Access to SFRs: All SFRs reside in data page 3 of the memory space. The following
addressing mechanisms allow access to the SFRs:
– Indirect or direct addressing with 16-bit (mem) addresses must guarantee that the
used data page pointer (DPP0 … DPP3) selects data page 3.
– Accesses via the Peripheral Event Controller (PEC) use the SRCPx and DSTPx
pointers instead of the data page pointers.
– Short 8-bit (reg) addresses to the standard SFR area do not use the data page
pointers but directly access the registers within this 512-byte area.
– Short 8-bit (reg) addresses to the extended ESFR area require switching to the
512-byte Extended SFR area. This is done via the EXTension instructions EXTR,
EXTP(R), EXTS(R).
• Byte Write Operations to wordwide SFRs via indirect or direct 16-bit (mem)
addressing or byte transfers via the PEC force zeros in the non-addressed byte. Byte
write operations via short 8-bit (reg) addressing can access only the low byte of an
SFR and force zeros in the high byte. It is therefore recommended, to use the bitfield
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instructions (BFLDL and BFLDH) to write to any number of bits in either byte of an
SFR without disturbing the non-addressed byte and the unselected bits.
• Write Operations to Write-Only Bits/Registers usually modify bits within other
registers. In some cases this modification is controlled by state machines. Therefore,
the effect of the write operation may not be visible, when the modified register is read
immediately after the write access that triggers the modification.
• Reserved Bits: Some of the bits which are contained in the XC2700’s SFRs are
marked as ‘Reserved’. User software should never write ‘1’s to reserved bits. These
bits are currently not implemented and may be used in future products to invoke new
functions. In that case, the active state for those new functions will be ‘1’, and the
inactive state will be ‘0’. Therefore writing only ‘0’s to reserved locations allows
portability of the current software to future devices. After read accesses, reserved bits
should be ignored or masked out.
Capture/Compare Unit (CAPCOM2)
The CAPCOM units support generation and control of timing sequences on up to
16 channels with a maximum resolution of 1 system clock cycle (8 cycles in staggered
mode). The CAPCOM unit is typically used to handle high speed I/O tasks such as pulse
and waveform generation, pulse width modulation (PMW), Digital to Analog (D/A)
conversion, software timing, or time recording relative to external events.
Two 16-bit timers (T7/T8) with reload registers provide two independent time bases for
each capture/compare register.
The input clock for the timers is programmable to several prescaled values of the internal
system clock, or may be derived from an overflow/underflow of timer T6 in module GPT2.
This provides a wide range of variation for the timer period and resolution and allows
precise adjustments to the application specific requirements. In addition, external count
inputs for CAPCOM timer T7 allow event scheduling for the capture/compare registers
relative to external events.
The capture/compare register array contains 16 dual purpose capture/compare
registers, each of which may be individually allocated to either CAPCOM timer T7 or T8
and programmed for capture or compare function.
All registers of each module have each one port pin associated with it which serves as
an input pin for triggering the capture function, or as an output pin to indicate the
occurrence of a compare event.
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Table 2-2
Compare Modes (CAPCOM2)
Compare Modes
Function
Mode 0
Interrupt-only compare mode;
several compare interrupts per timer period are possible
Mode 1
Pin toggles on each compare match;
several compare events per timer period are possible
Mode 2
Interrupt-only compare mode;
only one compare interrupt per timer period is generated
Mode 3
Pin set ‘1’ on match; pin reset ‘0’ on compare timer overflow;
only one compare event per timer period is generated
Double Register
Mode
Two registers operate on one pin;
pin toggles on each compare match;
several compare events per timer period are possible
Single Event Mode
Generates single edges or pulses;
can be used with any compare mode
When a capture/compare register has been selected for capture mode, the current
contents of the allocated timer will be latched (‘captured’) into the capture/compare
register in response to an external event at the port pin which is associated with this
register. In addition, a specific interrupt request for this capture/compare register is
generated. Either a positive, a negative, or both a positive and a negative external signal
transition at the pin can be selected as the triggering event.
The contents of all registers which have been selected for one of the five compare modes
are continuously compared with the contents of the allocated timers.
When a match occurs between the timer value and the value in a capture/compare
register, specific actions will be taken based on the selected compare mode.
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Capture/Compare Units CCU6
The CCU6 units support generation and control of timing sequences on up to three 16bit capture/compare channels plus one independent 16-bit compare channel.
In compare mode, the CCU6 units provide two output signals per channel which have
inverted polarity and non-overlapping pulse transitions (deadtime control). The compare
channel can generate a single PWM output signal and is further used to modulate the
capture/compare output signals.
In capture mode the contents of compare timer T12 is stored in the capture registers
upon a signal transition at pins CCx.
The output signals can be generated in edge-aligned or center-aligned PWM mode.
They are generated continuously or in single-shot mode.
Compare timers T12 and T13 are free running timers which are clocked by the prescaled
system clock.
For motor control applications (brushless DC-drives) both subunits may generate
versatile multichannel PWM signals which are basically either controlled by compare
timer T12 or by a typical hall sensor pattern at the interrupt inputs (block commutation).
The latter mode provides noise filtering for the hall inputs and supports automatic
rotational speed measurement.
The trap function offers a fast emergency stop without CPU activity. Triggered by an
external signal (CTRAP) the outputs are switched to selectable logic levels which can be
adapted to the connected power stages.
Note: The number of available CCU6 units and channels depends on the selected
device type.
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General Purpose Timer Unit (GPT1, GPT2)
The GPT12E unit represents a very flexible multifunctional timer/counter structure which
may be used for many different time related tasks such as event timing and counting,
pulse width and duty cycle measurements, pulse generation, or pulse multiplication.
The GPT12E unit incorporates five 16-bit timers which are organized in two separate
blocks, GPT1 and GPT2. Each timer in each block may operate independently in a
number of different modes, or may be concatenated with another timer of the same
block.
Each of the three timers T2, T3, T4 of block GPT1 can be configured individually for one
of four basic modes of operation, which are Timer, Gated Timer, Counter, and
Incremental Interface Mode. In Timer Mode, the input clock for a timer is derived from
the system clock, divided by a programmable prescaler, while Counter Mode allows a
timer to be clocked in reference to external events.
Pulse width or duty cycle measurement is supported in Gated Timer Mode, where the
operation of a timer is controlled by the ‘gate’ level on an external input pin. For these
purposes, each timer has one associated port pin (TxIN) which serves as gate or clock
input. The maximum resolution of the timers in block GPT1 is 4 system clock cycles.
The count direction (up/down) for each timer is programmable by software or may
additionally be altered dynamically by an external signal on a port pin (TxEUD) to
facilitate e.g. position tracking.
In Incremental Interface Mode the GPT1 timers (T2, T3, T4) can be directly connected
to the incremental position sensor signals A and B via their respective inputs TxIN and
TxEUD. Direction and count signals are internally derived from these two input signals,
so the contents of the respective timer Tx corresponds to the sensor position. The third
position sensor signal TOP0 can be connected to an interrupt input.
Timer T3 has an output toggle latch (T3OTL) which changes its state on each timer overflow/underflow. The state of this latch may be output on pin T3OUT e.g. for time out
monitoring of external hardware components. It may also be used internally to clock
timers T2 and T4 for measuring long time periods with high resolution.
In addition to their basic operating modes, timers T2 and T4 may be configured as reload
or capture registers for timer T3. When used as capture or reload registers, timers T2
and T4 are stopped. The contents of timer T3 is captured into T2 or T4 in response to a
signal at their associated input pins (TxIN). Timer T3 is reloaded with the contents of T2
or T4 triggered either by an external signal or by a selectable state transition of its toggle
latch T3OTL. When both T2 and T4 are configured to alternately reload T3 on opposite
state transitions of T3OTL with the low and high times of a PWM signal, this signal can
be constantly generated without software intervention.
With its maximum resolution of 2 system clock cycles, the GPT2 block provides precise
event control and time measurement. It includes two timers (T5, T6) and a capture/
reload register (CAPREL). Both timers can be clocked with an input clock which is
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derived from the CPU clock via a programmable prescaler or with external signals. The
count direction (up/down) for each timer is programmable by software or may
additionally be altered dynamically by an external signal on a port pin (TxEUD).
Concatenation of the timers is supported via the output toggle latch (T6OTL) of timer T6,
which changes its state on each timer overflow/underflow.
The state of this latch may be used to clock timer T5, and/or it may be output on pin
T6OUT. The overflows/underflows of timer T6 can additionally be used to clock the
CAPCOM1/2 timers, and to cause a reload from the CAPREL register.
The CAPREL register may capture the contents of timer T5 based on an external signal
transition on the corresponding port pin (CAPIN), and timer T5 may optionally be cleared
after the capture procedure. This allows the XC2700 to measure absolute time
differences or to perform pulse multiplication without software overhead.
The capture trigger (timer T5 to CAPREL) may also be generated upon transitions of
GPT1 timer T3’s inputs T3IN and/or T3EUD. This is especially advantageous when T3
operates in Incremental Interface Mode.
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Real Time Clock (RTC)
The Real Time Clock (RTC) module of the XC2700 is directly clocked wih a separate
clock signal. Several internal and external clock sources can be selected via register
RTCCLKCON. It is, therefore, independent from the selected clock generation mode of
the XC2700.
The RTC basically consists of a chain of divider blocks:
• Selectable 32:1 and 8:1 dividers (on - off)
• The reloadable 16-bit timer T14
• The 32-bit RTC timer block (accessible via registers RTCH and RTCL), made of:
– a reloadable 10-bit timer
– a reloadable 6-bit timer
– a reloadable 6-bit timer
– a reloadable 10-bit timer
All timers count up. Each timer can generate an interrupt request. All requests are
combined to a common node request.
Note: The registers associated with the RTC are not affected by an application reset in
order to maintain the contents even when intermediate resets are executed.
The RTC module can be used for different purposes:
• System clock to determine the current time and date
• Cyclic time based interrupt, to provide a system time tick independent of CPU
frequency and other resources
• 48-bit timer for long term measurements
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Analog/Digital Converters (ADC0, ADC1)
For analog signal measurement, two 10-bit A/D converters (ADC0, ADC1) with 16 (or 8)
multiplexed input channels including a sample and hold circuit have been integrated onchip. They use the method of successive approximation. The sample time (for loading
the capacitors) and the conversion time are programmable and can thus be adjusted to
the external circuitry. The A/D converters can also operate in 8-bit conversion mode,
where the conversion time is further reduced.
Several independent conversion result registers, selectable interrupt requests, and
highly flexible conversion sequences provide a high degree of programmability to fulfill
the requirements of the respective application. Both modules can be synchronized to
allow parallel sampling of two input channels.
For applications that require more analog input channels, external analog multiplexers
can be controlled automatically.
For applications that require less analog input channels, the remaining channel inputs
can be used as digital input port pins.
The A/D converters of the XC2700 support two types of request sources which can be
triggered by several internal and external events.
• Parallel requests are activated at the same time and then executed in a predefined
sequence.
• Queued requests are executed in a user-defined sequence.
In addition, the conversion of a specific channel can be inserted into a running sequence
without disturbing this sequence. All requests are arbitrated according to the priority level
that has been assigned to them.
Data reduction features, such as limit checking or result accumulation, reduce the
number of required CPU accesses and so allow the precise evaluation of analog inputs
(high conversion rate) even at low CPU speed.
The Peripheral Event Controller (PEC) may be used to control the A/D converters or to
automatically store conversion results into a table in memory for later evaluation, without
requiring the overhead of entering and exiting interrupt routines for each data transfer.
Therefore, each A/D converter contains 8 result registers which can be concatenated to
build a result FIFO. Wait-for-read mode can be enabled for each result register to
prevent loss of conversion data.
In order to decouple analog inputs from digital noise and to avoid input trigger noise
those pins used for analog input can be disconnected from the digital input stages under
software control. This can be selected for each pin separately via registers P5_DIDIS
and P15_DIDIS (Port x Digital Input Disable).
The Auto-Power-Down feature of the A/D converters minimizes the power consumption
when no conversion is in progress.
Note: The number of available analog channels depends on the selected device type.
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Universal Serial Interface Channel Modules (USIC)
Each USIC channel can be individually configured to match the application needs, e.g.
the protocol can be selected or changed during run time without the need for a reset. The
following protocols are supported:
• UART (ASC, asynchronous serial channel)
- module capability: receiver/transmitter with max. baud rate fsys/4
- application target baud rate range: 1.2 kBaud to 3.5 MBaud
- number of data bits per data frame 1 to 63
- MSB or LSB first
• LIN Support by HW (low-cost network, baud rate up to 20 kBaud)
- data transfers based on ASC protocol
- baud rate detection possible by built-in capture event of baud rate generator
- checksum generation under SW control for higher flexibility
• SSC/SPI (synchronous serial channel with or without slave select lines)
- module capability: slave mode with max. baud rate fsys
- module capability: master mode with max. baud rate fsys /2
- application target baud rate range: 2 kBaud to 10 MBaud
- number of data bits per data frame 1 to 63, more with explicit stop condition
- MSB or LSB first
• IIC (Inter-IC Bus)
- application baud rate 100 kBaud to 400 kBaud
- 7-bit and 10-bit addressing supported
- full master and slave device capability
• IIS (infotainment audio bus)
- module capability: receiver with max. baud rate fSYS
- module capability: transmitter with max. baud rate fSYS /2
- application target baud rate range: up to 26 MBaud
In addition to the flexible choice of the communication protocol, the USIC structure has
been designed to reduce the system load (CPU load) allowing efficient data handling.
The following aspects have been considered:
• Data buffer capability
The standard buffer capability includes a double word buffer for receive data and a
single word buffer for transmit data. This allows longer CPU reaction times (e.g.
interrupt latency).
• Additional FIFO buffer capability
In addition to the standard buffer capability, the received data and the data to be
transmitted can be buffered in a FIFO buffer structure. The size of the receive and the
transmit FIFO buffer can be programmed independently. Depending on the
application needs, a total buffer capability of 64 data words can be assigned to the
receive and transmit FIFO buffers of a USIC module (the two channels of the USIC
module share the 64 data word buffer).
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•
•
•
•
•
•
•
•
In addition to the FIFO buffer, a bypass mechanism allows the introduction of highpriority data without flushing the FIFO buffer.
Transmit control information
For each data word to be transmitted, a 5-bit transmit control information has been
added to automatically control some transmission parameters, such as word length,
frame length, or the slave select control for the SPI protocol. The transmit control
information is generated automatically by analyzing the address where the user SW
has written the data word to be transmitted (32 input locations = 2^5 = 5 bit transmit
control information).
This feature allows individual handling of each data word, e.g. the transmit control
information associated to the data words stored in a transmit FIFO can automatically
modify the slave select outputs to select different communication targets (slave
devices) without CPU load. Alternatively, it can be used to control the frame length.
Flexible frame length control
The number of bits to be transferred within a data frame is independent of the data
word length and can be handled in two different ways. The first option allows
automatic generation of frames up to 63 bits with a known length. The second option
supports longer frames (even unlimited length) or frames with a dynamically controlled
length.
Interrupt capability
The events of each USIC channel can be individually routed to one of 4 service
request outputs, depending on the application needs. Furthermore, specific start and
end of frame indications are supported in addition to protocol-specific events.
Flexible interface routing
Each USIC channel offers the choice between several possible input and output pins
connections for the communications signals. This allows a flexible assignment of
USIC signals to pins that can be changed without resetting the device.
Input conditioning
Each input signal is handled by a programmable input conditioning stage with
programmable filtering and synchronization capability.
Baud rate generation
Each USIC channel contains an own baud rate generator. The baud rate generation
can be based either on the internal module clock or on an external frequency input.
This structure allows data transfers with a frequency that can not be generated
internally, e.g. to synchronize several communication partners.
Transfer trigger capability
In master mode, data transfers can be triggered events generated outside the USIC
module, e.g. at an input pin or a timer unit (transmit data validation). This feature
allows time base related data transmission.
Debugger support
The USIC offers specific addresses to read out received data without interaction with
the FIFO buffer mechanism. This feature allows debugger accesses without the risk
of a corrupted receive data sequence.
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To reach a desired baud rate, two criteria have to be respected, the module capability
and the application environment. The module capability is defined with respect to the
module’s input clock frequency fsys, being the base for the module operation. Although
the module’s capability being much higher (depending on the module clock and the
number of module clock cycles needed to represent a data bit), the reachable baud rate
is generally limited by the application environment. In most cases, the application
environment limits the maximum reachable baud rate due to driver delays, signal
propagation times, or due to EMI reasons.
Note: Depending on the selected additional functions (such as digital filters, input
synchronization stages, sample point adjustment, data structure, etc.), the
maximum reachable baud rate can be limited. Please also take care about
additional delays, such as (internal or external) propagation delays and driver
delays (e.g. for collision detection in ASC mode, for IIC, etc.).
SRx
Baud Rate Generator
User Interface
Data
Buffer
Data
Shift
Unit
To Interrupt
Registers
f SYS
PPP
Input
Stages
(ASC,
SSC. ..)
Channel 0
f SYS
Baud Rate Generator
Data
Buffer
Data
Shift
Unit
PPP
Pins
UxC0
UxC1
Signal Distribution
Interrupt Generation
Input
Stages
(ASC,
SSC. ..)
Channel 1
Optional : FIFO Data Buffer shared
between UxC 0 and UxC1
USIC
Module x
USIC_Module
Figure 2-3
USIC Channel Structure
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The USIC module contains two independent communication channels, with structure
shown in Figure 2-3.
The data shift unit and the data buffering of each channel support full-duplex data
transfers. The protocol-specific actions are handled by protocol pre-processors (PPP).
In order to simplify data handling, an additional FIFO data buffer is optionally available
for each USIC module to store transmit and receive data for each channel. This FIFO
data buffer is not necessarily available in all devices (please refer to USIC
implementation chapter for details).
Due to the independent channel control and baud rate generation, the communication
protocol, baud rate and the data format can be independently programmed for each
communication channel.
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MultiCAN Module
The MultiCAN module contains two independently operating CAN nodes with Full-CAN
functionality which are able to exchange Data and Remote Frames via a gateway
function. Transmission and reception of CAN frames is handled in accordance with CAN
specification V2.0 B (active). Each CAN node can receive and transmit standard frames
with 11-bit identifiers as well as extended frames with 29-bit identifiers.
Note: The number of available CAN nodes depends on the selected device type.
All CAN nodes share a common set of 128 message objects. Each message object can
be individually allocated to one of the CAN nodes. Besides serving as a storage
container for incoming and outgoing frames, message objects can be combined to build
gateways between the CAN nodes or to setup a FIFO buffer.
The message objects are organized in double-chained linked lists, where each CAN
node has its own list of message objects. A CAN node stores frames only into message
objects that are allocated to its own message object list, and it transmits only messages
belonging to this message object list. A powerful, command-driven list controller
performs all message object list operations.
MultiCAN Module Kernel
Clock
Control
CAN
Node 1
fCAN
Message
Object
Buffer
Address
Decoder
Linked
List
Control
Port
Control
CAN
Node 0
Interrupt
Control
TXDC1
RXDC2
TXDC0
RXDC0
CAN Control
mc_multican_block2.vsd
Figure 2-4
Block Diagram of the MultiCAN Module
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MultiCAN Features
• CAN functionality conforms to CAN specification V2.0 B active for each CAN node
(compliant to ISO 11898)
• Up to Five independent CAN nodes
• Up to 128 independent message objects (shared by the CAN nodes)
• Dedicated control registers for each CAN node
• Data transfer rate up to 1 Mbit/s, individually programmable for each node
• Flexible and powerful message transfer control and error handling capabilities
• Full-CAN functionality for message objects:
– Can be assigned to one of the CAN nodes
– Configurable as transmit or receive objects, or as message buffer FIFO
– Handle 11-bit or 29-bit identifiers with programmable acceptance mask for filtering
– Remote Monitoring Mode, and frame counter for monitoring
• Automatic Gateway Mode support
• 16 individually programmable interrupt nodes
• Analyzer mode for CAN bus monitoring
Watchdog Timer
The Watchdog Timer represents one of the fail-safe mechanisms which have been
implemented to prevent the controller from malfunctioning for longer periods of time.
The Watchdog Timer is always enabled after a reset of the chip, and can be disabled
and enabled at any time by executing instructions DISWDT and ENWDT. Thus, the
chip’s start-up procedure is always monitored. The software has to be designed to restart
the Watchdog Timer before it overflows. If, due to hardware or software related failures,
the software fails to do so, the Watchdog Timer overflows and generates a reset request.
The Watchdog Timer is a 16-bit timer, clocked with the system clock divided by 16,384
or 256. The high byte of the Watchdog Timer register can be set to a prespecified reload
value (stored in WDTREL) to allow further variation of the monitored time interval. Each
time it is serviced by the application software, the high byte of the Watchdog Timer is
reloaded and the low byte is cleared.
Thus, time intervals between 3.9 µs and 16.3 s can be monitored (@ 66 MHz).
The default Watchdog Timer interval after reset is 6.5 ms (@ 10 MHz).
User’s Manual
ArchitectureX27, V1.1
2-29
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Architectural Overview
Parallel Ports
The XC2700 derivatives are available in two different packages:
• In LQFP-144, they provide up to 118 I/O lines which are organized into 11 input/output
ports and 2 input ports.
• In LQFP-100, they provide up to 75 I/O lines which are organized into 7 input/output
ports and 2 input ports.
All port lines are bit-addressable, and all input/output lines can be individually (bit-wise)
configured via port control registers. This configuration selects the direction (input/
output), push/pull or open-drain operation, activation of pull devices, and edge
characteristics (shape) and driver characteristics (output current) of the port drivers. The
I/O ports are true bidirectional ports which are switched to high impedance state when
configured as inputs. During the internal reset, all port pins are configured as inputs
without pull devices active.
All port lines have programmable alternate input or output functions associated with
them. These alternate fucntions can be assigned to various port pins to support the
optimal utilization for a given application. For this reason, certain functions appear
several times in Table 2-3.
All port lines that are not used for these alternate functions may be used as general
purpose IO lines.
Table 2-3
Summary of the XC2700’s Parallel Ports
Port
Width
1441)
Width
1001)
Alternate Functions
Port 0
8
8
Address lines,
Serial interface lines of USIC1, CAN0, and CAN1,
Input/Output lines for CCU61
Port 1
8
8
Address lines,
Serial interface lines of USIC1 and USIC2,
Input/Output lines for CCU62,
OCDS control, interrupts
Port 2
13
13
Address and/or data lines, bus control,
Serial interface lines of USIC0, CAN0, and CAN1,
Input/Output lines for CCU60, CCU63, and CAPCOM2,
Timer control signals,
JTAG, interrupts, system clock output
Port 3
8
---
Bus arbitration signals,
Serial interface lines of USIC0, USIC2, CAN3, and CAN4
User’s Manual
ArchitectureX27, V1.1
2-30
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Architectural Overview
Table 2-3
Summary of the XC2700’s Parallel Ports (cont’d)
Port
Width
1441)
Width
1001)
Alternate Functions
Port 4
8
4
Chip select signals,
Serial interface lines of CAN2,
Input/Output lines for CAPCOM2,
Timer control signals
Port 5
16
11
Analog input channels to ADC0,
Input/Output lines for CCU6x,
Timer control signals,
JTAG, OCDS control, interrupts
Port 62)
4
3
ADC control lines,
Serial interface lines of USIC1,
Timer control signals,
OCDS control
Port 7
5
5
ADC control lines,
Serial interface lines of USIC0 and CAN4,
Input/Output lines for CCU62,
Timer control signals,
JTAG, OCDS control,system clock output
Port 8
7
---
Input/Output lines for CCU60,
JTAG, OCDS control
Port 9
8
---
Serial interface lines of USIC2,
Input/Output lines for CCU60 and CCU63,
OCDS control
Port 10
16
16
Address and/or data lines, bus control,
Serial interface lines of USIC0, USIC1, CAN2, CAN3, and
CAN4,
Input/Output lines for CCU60,
JTAG, OCDS control
Port 11
6
---
Input/Output lines for CCU63
Port 15
8
5
Analog input channels to ADC1,
Timer control signals
1)
These columns describe the availability of port pins in the different packages.
2)
The drivers of these pins are supplied by VDDPA.
User’s Manual
ArchitectureX27, V1.1
2-31
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Architectural Overview
2.4
Clock Generation
The Clock Generation Unit uses a programmable on-chip PLL with multiple prescalers
to generate the clock signals for the XC2700 with high flexibility. The system clock fSYS
is the reference clock signal, which can be output to the external system. The system
clock fSYS can be derived from several internal and external clock sources.
The on-chip high-precision oscillator (OSC_HP) can drive an external crystal or accepts
an external clock signal. The oscillator clock frequency can be multiplied by the on-chip
PLL (by a programmable factor) or can be divided by a programmable prescaler factor.
An internal clock source can provide a clock signal without requiring an external crystal.
The Oscillator Watchdog (OWD) supervises the input clock and enables an emergency
clock if the input clock appears as not reliable.
User’s Manual
ArchitectureX27, V1.1
2-32
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Architectural Overview
2.5
Power Management
The XC2700 can operate within a wide supply voltage range from 3 V to 5 V. The internal
core supply voltage is generated via on-chip Embedded Voltage Regulators and is
supervised by on-chip Power Validation Circuits.
Two IO power domains help to reduce heat dissipation by supplying the major part of the
device with a low voltage (3 V), while still connecting analog 5 V sensor signals to the
ADCs (5 V).
The XC2700 provides several means to control the power it consumes either at a given
time or averaged over a certain timespan. Three mechanisms can be used (partly in
parallel):
• Supply Voltage Management allows to switch off the supply voltage. This drastically
reduces the power consumed because of leakage current, in particular at high
temperature. A power-on reset restarts the system.
• Clock Generation Management controls the distribution and the frequency of
internal and external clock signals. While the clock signals for currently inactive parts
of logic are disabled automatically, the user can reduce the XC2700’s CPU clock
frequency which drastically reduces the consumed power.
External circuitry can be controlled via the programmable frequency output EXTCLK.
• Peripheral Management permits temporary disabling of peripheral modules. Each
peripheral can separately be disabled/enabled.
Note: When selecting the supply voltage and the clock source and generation method,
the required parameters must be carefully written to the respective bitfields, to
avoid unintended intermediate states. Recommended sequences are provided
which ensure the intended operation of power supply system and clock system.
User’s Manual
ArchitectureX27, V1.1
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Architectural Overview
2.6
On-Chip Debug Support (OCDS)
The On-Chip Debug Support system provides a broad range of debug and emulation
features built into the XC2700. The user software running on the XC2700 can thus be
debugged within the target system environment.
The OCDS is controlled by an external debugging device via the debug interface,
consisting of the IEEE-1149-conforming JTAG port and a break interface. The debugger
controls the OCDS via a set of dedicated registers accessible via the JTAG interface.
Additionally, the OCDS system can be controlled by the CPU, e.g. by a monitor program.
An injection interface allows the execution of OCDS-generated instructions by the CPU.
Multiple breakpoints can be triggered by on-chip hardware, by software, or by an
external trigger input. Single stepping is supported as well as the injection of arbitrary
instructions and read/write access to the complete internal address space. A breakpoint
trigger can be answered with a CPU-halt, a monitor call, a data transfer, or/and the
activation of an external signal.
The data transferred at a watchpoint (see above) can be obtained via the JTAG interface
or via the external bus interface for increased performance.
The debug interface uses a set of 4 to 6 interface signals (4 JTAG lines, 1 or 2 optional
break lines) to communicate with external circuitry.
User’s Manual
ArchitectureX27, V1.1
2-34
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
3
Memory Organization
The memory space of the XC2700 is configured in a “Von Neumann” architecture. This
means that code and data are accessed within the same linear address space. All of the
physically separated memory areas, including internal ROM and Flash, internal RAM,
the internal Special Function Register Areas (SFRs and ESFRs), the internal IO area,
and external memory are mapped into one common address space.
239...224
On-Chip
Program Memory
Areas
223...208
207...192
191...176
175...160
~12 Mbytes
External Addressing Capability
159...144
143...128
External
Memory
Area
FF’FFFF
H
E0’0000
H
C0’0000H
A0’0000
H
80’0000
127...112
111...96
95...80
79...64
60’0000H
40’0000
63...48
External
IO
Area
47...32
External
Memory
Area
20’0000
31...16
15...0
H
16 Mbytes
Total Addressing Capability
255...240
H
H
00’0000H
Total Address Space
16 Mbytes, Segments 255...0
mc_xc16x_mmap.vsd
Figure 3-1
Address Space Overview
User’s Manual
MemoryX2K, V1.3
3-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
The XC2700 provides a total addressable memory space of 16 Mbytes. This address
space is arranged as 256 segments of 64 Kbytes each, and each segment is again
subdivided into four data pages of 16 Kbytes each (see Figure 3-1).
Bytes are stored at even or odd byte addresses. Words are stored in ascending memory
locations with the low byte at an even byte address being followed by the high byte at
the next odd byte address (“little endian”). Double words (code only) are stored in
ascending memory locations as two subsequent words. Single bits are always stored in
the specified bit position at a word address. Bit position 0 is the least significant bit of the
byte at an even byte address, and bit position 15 is the most significant bit of the byte at
the next odd byte address. Bit addressing is supported for a part of the Special Function
Registers, a part of the internal RAM and for the General Purpose Registers.
xxxx’xxxAH
xxxx’xxx9H
7
6
… Bits ...
0
xxxx’xxx8H
Byte
xxxx’xxx7H
Byte
xxxx’xxx6H
Word (High Byte)
xxxx’xxx5H
Word (Low Byte)
xxxx’xxx4H
Double Word (High Byte)
xxxx’xxx3H
Double Word (Third Byte)
xxxx’xxx2H
Double Word (Second Byte)
xxxx’xxx1H
Double Word (Low Byte)
xxxx’xxx0H
xxxx’xxxFH
imb_endianess.vsd:byte_orga
Figure 3-2
Storage of Words, Bytes and Bits in a Byte Organized Memory
Note: Byte units forming a single word or a double word must always be stored within
the same physical (internal, external, ROM, RAM) and organizational (page,
segment) memory area.
User’s Manual
MemoryX2K, V1.3
3-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
3.1
Address Mapping
All the various memory areas and peripheral registers (see Table 3-1) are mapped into
one contiguous address space. All sections can be accessed in the same way. The
memory map of the XC2700 contains some reserved areas, so future derivatives can be
enhanced in an upward-compatible fashion.
Note: Table 3-1 shows the maximum available memory areas. The actual available
memory areas depend on the selected device type.
Table 3-1
XC2700 Memory Map 1)
Area Size2)
Address Area
Start Loc. End Loc.
IMB register space
FF’FF00H FF’FFFFH 256 Bytes
Reserved (access trap)
F0’0000H
FF’FEFFH < 1 MByte
Minus IMB registers
Reserved for EPSRAM
E9’0000H
EF’FFFFH 448 KBytes
Mirrors EPSRAM
Emulated PSRAM
E8’0000H
E8’FFFFH 64 KBytes
With Flash timing
Reserved for PSRAM
E1’0000H
E7’FFFFH 448 KBytes
Mirrors PSRAM
PSRAM
E0’0000H
E0’FFFFH 64 KBytes
Program SRAM
Reserved for Flash
CC’0000H DF’FFFFH <1.25 MBytes
Flash 2
C8’0000H
CB’FFFFH 256 KBytes
Flash 1
C4’0000H
C7’FFFFH 256 KBytes
Flash 0
C0’0000H
C3’FFFFH 252 KBytes3)
External memory area
40’0000H
BF’FFFFH 8 MBytes
External IO area4)
20’5800H
3F’FFFFH < 2 MBytes
Minus CAN/USIC
USIC registers
20’4000H
20’57FFH
6 KBytes
Accessed via EBC
MultiCAN registers
20’0000H
20’3FFFH
16 KBytes
Accessed via EBC
External memory area
01’0000H
1F’FFFFH < 2 MBytes
SFR area
00’FE00H
00’FFFFH 0.5 KBytes
Dualport RAM (DPRAM) 00’F600H
00’FDFFH 2 KBytes
Reserved for DPRAM
00’F200H
00’F5FFH
1 KBytes
ESFR area
00’F000H
00’F1FFH
0.5 KBytes
XSFR area
00’E000H
00’EFFFH 4 KBytes
Data SRAM (DSRAM)
00’A000H
00’DFFFH 16 KBytes
Reserved for DSRAM
00’8000H
00’9FFFH
8 KBytes
External memory area
00’0000H
00’7FFFH
32 KBytes
User’s Manual
MemoryX2K, V1.3
3-3
Notes
Minus res. seg.
Minus segment 0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
1)
Accesses to the shaded areas are reserved. In devices with external bus interface these accesses generate
external bus accesses.
2)
The areas marked with “<” are slightly smaller than indicated, see column “Notes”.
3)
The uppermost 4-Kbyte sector of the first Flash segment is reserved for internal use (C0’F000H to C0’FFFFH).
4)
Several pipeline optimizations are not active within the external IO area. This is necessary to control external
peripherals properly.
User’s Manual
MemoryX2K, V1.3
3-4
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
3.2
Special Function Register Areas
The Special Function Registers (SFRs) controlling the system and peripheral functions
of the XC2700 can be accessed via four dedicated address areas:
•
•
•
•
512-byte SFR area (located above the internal RAM: 00’FFFFH … 00’FE00H).
512-byte ESFR area (located below the internal RAM: 00’F1FFH … 00’F000H).
4-Kbyte XSFR area (located below the ESFR area: 00’EFFFH … 00’E000H).
256-byte IMB SFR area (located in: FF’FF00H … FF’FFFFH)1).
SFR Area
This arrangement provides upward compatibility with the derivatives of the C166 and
XC166 families.
SFRs
00'FE00 H
00'FC00 H
DPRAM
00'FA00 H
00'F800 H
ESFRs
EBC
Interrupt/PEC
XSFR Area
CC6
Ports
Reserved
Reserved
Reserved
ADC
00'F400 H
00'F200 H
00'F000 H
00'EE00 H
00'EC00 H
Upper Half of Data Page 3
Reserved for
DPRAM
8 KBytes
ESFR Area
00'F600 H
00'EA00 H
00'E800 H
00'E600 H
00'E400 H
00'E200 H
00'E000 H
x c 2000_regareas. v s d
Figure 3-3
Special Function Register Mapping
Note: The upper 256 bytes of SFR area, ESFR area, and internal RAM are bitaddressable (see hashed blocks in Figure 3-3).
1)
Attention: the IMB SFR area is not recognized by the CPU as special IO area (see Section 3.6).
User’s Manual
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Special Function Registers
The functions of the CPU, the bus interface, the IO ports, and the on-chip peripherals of
the XC2700 are controlled via a number of Special Function Registers (SFRs).
All Special Function Registers can be addressed via indirect and long 16-bit addressing
modes. The (word) SFRs and their respective low bytes in the SFR/ESFR areas can be
addressed using an 8-bit offset together with an implicit base address. However, this
does not work for the respective high bytes!
Note: Writing to any byte of an SFR causes the not addressed complementary byte to
be cleared.
The upper half of the SFR-area (00’FFFFH … 00’FF00H) and the ESFR-area (00’F1FFH
… 00’F100H) is bit-addressable, so the respective control/status bits can be modified
directly or checked using bit addressing.
When accessing registers in the ESFR area using 8-bit addresses or direct bit
addressing, an Extend Register (EXTR) instruction is required beforehand to switch the
short addressing mechanism from the standard SFR area to the Extended SFR area.
This is not required for 16-bit and indirect addresses. The GPRs R15 … R0 are
duplicated, i.e. they are accessible within both register blocks via short 2-, 4-, or 8-bit
addresses without switching.
ESFR_SWITCH_EXAMPLE:
EXTR #4
;Switch to ESFR area for next 4 instr.
MOV
STMREL, #data16
;STMREL uses 8-bit reg addressing
BFLDL STMCON, #mask, #data8 ;Bit addressing for bitfields
BSET WUCR.CLRTRG
;Bit addressing for single bits
MOV
T8REL, R1
;T8REL uses 16-bit mem address,
;R1 is duplicated into the ESFR space
;(EXTR is not required for this access)
;---- ;--------------;The scope of the EXTR #4 instruction …
;… ends here!
MOV
T8REL, R1
;T8REL uses 16-bit mem address,
;R1 is accessed via the SFR space
In order to minimize the use of the EXTR instructions the ESFR area mostly holds
registers which are mainly required for initialization and mode selection. Registers that
need to be accessed frequently are allocated to the standard SFR area, wherever
possible.
Note: The tools are equipped to monitor accesses to the ESFR area and will
automatically insert EXTR instructions, or issue a warning in case of missing or
excessive EXTR instructions.
Accesses to registers in the XSFR area use 16-bit addresses and require no specific
addressing modes or precautions.
User’s Manual
MemoryX2K, V1.3
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
General Purpose Registers
The General Purpose Registers (GPRs) use a block of 16 consecutive words either
within the global register bank or within one of the two local register banks. The bit-field
BANK in register PSW selects the currently active register bank. The global register bank
is mirrored to a section in the DPRAM, the Context Pointer (CP) register determines the
base address of the currently active global register bank section. This register bank may
consist of up to 16 Word-GPRs (R0, R1, … R15) and/or of up to 16 byte-GPRs
(RL0,RH0, … RL7, RH7). The sixteen byte-GPRs are mapped onto the first eight Word
GPRs (see Table 3-2).
In contrast to the system stack, a register bank grows from lower towards higher address
locations and occupies a maximum space of 32 bytes. The GPRs are accessed via short
2-, 4-, or 8-bit addressing modes using the Context Pointer (CP) register as base
address for the global bank (independent of the current DPP register contents).
Additionally, each bit in the currently active register bank can be accessed individually.
Table 3-2
Mapping of General Purpose Registers to DPRAM Addresses
DPRAM Address High Byte Registers Low Byte Registers Word Registers
<CP> + 1EH
–
–
R15
<CP> + 1CH
–
–
R14
<CP> + 1AH
–
–
R13
<CP> + 18H
–
–
R12
<CP> + 16H
–
–
R11
<CP> + 14H
–
–
R10
<CP> + 12H
–
–
R9
<CP> + 10H
–
–
R8
<CP> + 0EH
RH7
RL7
R7
<CP> + 0CH
RH6
RL6
R6
<CP> + 0AH
RH5
RL5
R5
<CP> + 08H
RH4
RL4
R4
<CP> + 06H
RH3
RL3
R3
<CP> + 04H
RH2
RL2
R2
<CP> + 02H
RH1
RL1
R1
<CP> + 00H
RH0
RL0
R0
The XC2700 supports fast register bank (context) switching. Multiple global register
banks can physically exist within the DPRAM at the same time. Only the global register
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
bank selected by the Context Pointer register (CP) is active at a given time, however.
Selecting a new active global register bank is simply done by updating the CP register.
A particular Switch Context (SCXT) instruction performs register bank switching by
automatically saving the previous context and loading the new context. The number of
implemented register banks (arbitrary sizes) is limited only by the size of the available
DPRAM.
Note: The local GPR banks are not memory mapped and the GPRs cannot be accessed
using a long or indirect memory address.
PEC Source and Destination Pointers
The source and destination address pointers for data transfers on the PEC channels are
located in the XSFR area.
Each channel uses a pair of pointers stored in two subsequent word locations with the
source pointer (SRCPx) on the lower and the destination pointer (DSTPx) on the higher
word address (x = 7 … 0). An additional segment register stores the associated source
and destination segments, so PEC transfers can move data from/to any location within
the complete addressing range.
Whenever a PEC data transfer is performed, the pair of source and destination pointers
(selected by the specified PEC channel number) accesses the locations referred to by
these pointers independently of the current DPP register contents.
If a PEC channel is not used, the corresponding pointer locations can be used for other
purposes.
Note: Writing to any byte of the PEC pointers causes the not addressed complementary
byte to be cleared.
User’s Manual
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Memory Organization
3.3
Data Memory Areas
The XC2700 provides two on-chip RAM areas exclusively for data storage:
•
•
The Dual Port RAM (DPRAM) can be used for global register banks (GPRs), system
stack, storage of variables and other data, in particular for MAC operands.
The Data SRAM (DSRAM) can be used for system stack (recommended), storage
of variables and other data.
Note: Data can also be stored in the PSRAM (see Section 3.10). However, both data
memory areas provide the fastest access.
Depending on the device additional on-chip memory areas may exist with the special
purpose to retain data while the system power domain is switched off. The XC2700
contains:
•
The Marker Memory (MKMEM).
Dual-Port RAM (DPRAM)
The XC2700 provides 2 Kbytes of DPRAM (00’F600H … 00’FDFFH). Any word or byte
data in the DPRAM can be accessed via indirect or long 16-bit addressing modes, if the
selected DPP register points to data page 3. Any word data access is made on an even
byte address. The highest possible word data storage location in the DPRAM is
00’FDFEH.
For PEC data transfers, the DPRAM can be accessed independent of the contents of the
DPP registers via the PEC source and destination pointers.
The upper 256 bytes of the DPRAM (00’FD00H through 00’FDFFH) are provided for
single bit storage, and thus they are bit addressable.
Note: Code cannot be executed out of the DPRAM.
An area of 3 Kbytes is dedicated to DPRAM (00’F200H … 00’FDFFH). The locations
without implemented DPRAM are reserved.
Data SRAM (DSRAM)
The XC2700 provides 16 Kbytes of DSRAM (00’A000H … 00’DFFFH). Any word or byte
data in the DSRAM can be accessed via indirect or long 16-bit addressing modes, if the
selected DPP register points to data page 3 (for the range 00’C000H … 00’DFFFH) or to
data page 2 (for the range 00’A000H … 00’BFFFH). Any word data access is made on
an even byte address. The highest possible word data storage location in the DSRAM is
00’DFFEH.
For PEC data transfers, the DSRAM can be accessed independent of the contents of the
DPP registers via the PEC source and destination pointers.
Note: Code cannot be executed out of the DSRAM.
User’s Manual
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
An area of 24 Kbytes is dedicated to DSRAM (00’8000H … 00’DFFFH). The locations
without implemented DSRAM are reserved.
Marker Memory (MKMEM)
The MKMEM provides 4 bytes of memory supplied by the wake-up power domain. Its
purpose is the same as the SBRAM.
The MKEM consists of 2 16-bit SFRs that are accessible as all other SFRs. Details are
described in Section 3.11.
Note: Code cannot be executed out of the MKMEM.
User’s Manual
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
3.4
Program Memory Areas
The XC2700 provides two on-chip program memory areas for code/data storage:
•
•
The Program Flash/ROM stores code and constant data. Flash memory is (re-)
programmed by the application software or flash loaders, ROM is mask-programmed
in the factory.
The Program SRAM (PSRAM) stores temporary code sequences and other data.
For example higher level boot loader software can be written to the PSRAM and then
be executed to program the on-chip Flash memory.
IMB Reg.
FF'FFFF H
FF'FF00 H
FF'FFFF H
FF'FF00 H
Reserved
Reserved
F0'0000H
Reserved
PSRAM
Reserved
PSRAM
F0'0000H
E8'0000H
PSRAM (64 KB)
Flash Access
Timing
E9'0000H
E8'0000 H
E0'0000 H
E1'0000 H
Reserved
Flash Area
PSRAM (64 KB)
SRAM Timing
E0'0000 H
D0'0000 H
Flash 2 (256 KB)
C4'0000H
Flash 1 (256 KB)
Flash 0 (252 KB)
Flash 0 (192 KB)
C0'0000 H
Reserved (4 KB)
Flash 0 (60 KB)
C1'0000H
C0'F000H
No software access
to this Flash range.
C0'0000H
imb_memory_map.vsd
Figure 3-4
On-Chip Program Memory Mapping
User’s Manual
MemoryX2K, V1.3
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3.4.1
Program/Data SRAM (PSRAM)
The XC2700 provides 64 Kbytes of PSRAM (E0’0000H … E0’FFFFH). The PSRAM
provides fast code execution without initial delays. Therefore, it supports non-sequential
code execution, for example via the interrupt vector table.
Any word or byte data in the PSRAM can be accessed via indirect or long 16-bit
addressing modes, if the selected DPP register points to one of its data pages 896 – 899.
Any word data access is made on an even byte address. The highest possible word data
storage location in the PSRAM is E0’FFFEH.
For PEC data transfers, the PSRAM can be accessed independent of the contents of the
DPP registers via the PEC source and destination pointers.
Any data can be stored in the PSRAM. Because the PSRAM is optimized for code
fetches, however, data accesses to the data memories provide higher performance.
Note: The PSRAM is not bit-addressable.
Note: The upper 256 Bytes of the PSRAM may be altered during the initialization phase
after a reset. This area, therefore, should not store data to be preserved beyond a
reset.
Also, during bootstrap loader operation, the serially received data is stored in the
PSRAM starting at location E0’0000H.
An area of 512 Kbytes is dedicated to PSRAM (E0’0000H … F7’FFFFH). The locations
without implemented PSRAM are reserved.
Flash Emulation
During code development the PSRAM will often be used for storing code or data that the
production chip will later contain in the flash memory. In order to ensure similar execution
time the PSRAM supports a second access path in the range E8’0000H … EF’FFFFH
with timing parameters that correspond to Flash timing. The number of wait-cycles is
determined by the flash access timing configuration (see IMB_IMBCTRL.WSFLASH).
Writes are always performed without wait-cycles.
This flash access timing imitation is nearly cycle accurate because the same read logic
as for reading the flash memory is used1). Discrepancies might occur if the software uses
the PSRAM for flash emulation and directly as PSRAM. During emulation access
conflicts can cause a slightly different timing as in the product chip where these conflicts
do not occur.
Another source of timing differences can be access conflicts at the flash modules in the
product chip. Data reads and instruction fetches that target different flash modules can
1)
The dual use of the flash read logic might cause unexpected behavior: while the IMB Core is busy with
updating the protection configuration (after startup or after changing the security pages) read accesses to the
flash emulation range of the PSRAM are blocked because Flash data reads would be blocked also.
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be executed concurrently whereas if they target the same flash module they are
executed sequentially with the data access as first. In the flash emulation this type of
conflict can not occur. The data and the instruction access will both incur the defined
number of wait-cycles (as if they would target different flash modules) and if they collide
at the PSRAM interface the instruction fetch will see an additional wait-cycle.
Data Integrity
The PSRAM contains its own error control. Details are described in the SCU chapter.
Write Protection
As the PSRAM is often used to store timing critical code or constant data it is supplied
with a write protection. After storing critical data in the PSRAM the register field
IMB_IMBCTRH.PSPROT can be used to split the PSRAM into a read-only and a
writable part. Write accesses to the read-only part are blocked and a trap can be
activated.
3.4.2
Non-Volatile Program Memory (Flash)
The XC2700 provides up to 764 Kbytes of program Flash (C0’0000H … CB’FFFFH).
Code and data fetches are always 64-bit aligned, using byte select lines for word and
byte data.
Any word or byte data in the program memory can be accessed via indirect or long 16bit addressing modes, if the selected DPP register points to one of the respective data
pages. Any word data access is made on an even byte address. The highest possible
word data storage location in the program memory is CB’FFFEH.
For PEC data transfers, the program memory can be accessed independent of the
contents of the DPP registers via the PEC source and destination pointers.
Note: The program memory is not bit-addressable.
An area of 2 Mbytes is dedicated to program memory (C0’0000H … DF’FFFFH). The
locations without implemented program memory are reserved.
A more detailed description can be found in “Embedded Flash Memory” on
Page 3-18.
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3.5
System Stack
The system stack may be defined anywhere within the XC2700’s memory areas
(including external memory).
For all system stack operations the respective stack memory is accessed via a 24-bit
stack pointer. The Stack Pointer (SP) register provides the lower 16 bits of the stack
pointer (stack pointer offset), the Stack Pointer Segment (SPSEG) register adds the
upper 8 bits of the stack pointer (stack segment). The system stack grows downward
from higher towards lower locations as it is filled. Only word accesses are supported to
the system stack.
Register SP is decremented before data is pushed on the system stack, and
incremented after data has been pulled from the system stack. Only word accesses are
supported to the system stack.
By using register SP for stack operations, the size of the system stack is limited to
64 KBytes. The stack must be located in the segment defined by register SPSEG.
The stack pointer points to the latest system stack entry, rather than to the next available
system stack address.
A stack overflow (STKOV) register and a stack underflow (STKUN) register are provided
to control the lower and upper limits of the selected stack area. These two stack
boundary registers can be used both for protection against data corruption.
For best performance it is recommended to locate the stack to the DPRAM or to the
DSRAM. Using the DPRAM may conflict with register banks or MAC operands.
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3.6
IO Areas
The following areas of the XC2700’s address space are marked as IO area:
•
•
The external IO area is provided for external peripherals (or memories) and also
comprises the on-chip LXBus-peripherals, such as the CAN or USIC modules. It is
located from 20’0000H to 3F’FFFFH (2 Mbytes).
The internal IO area provides access to the internal peripherals and is split into three
blocks:
– The SFR area, located from 00’FE00H to 00’FFFFH (512 bytes).
– The ESFR area, located from 00’F000H to 00’F1FFH (512 bytes).
– The XSFR area, located from 00’E000H to 00’EFFFH (4 Kbytes).
Note: The external IO area supports real byte accesses. The internal IO area does not
support real byte transfers, the complementary byte is cleared when writing to a
byte location.
The IO areas have special properties, because peripheral modules must be controlled
in a different way than memories:
•
•
•
Accesses are not buffered and cached, the write back buffers and caches are not
used to store IO read and write accesses.
Speculative reads are not executed, but delayed until all speculations are solved (e.g.
pre-fetching after conditional branches).
Data forwarding is disabled, an IO read access is delayed until all IO writes pending
in the pipeline are executed, because peripherals can change their internal state after
a write access.
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3.7
External Memory Space
The XC2700 is capable of using an address space of up to 16 Mbytes. Only parts of this
address space are occupied by internal memory areas or are reserved. A total area of
approximately 12 Mbytes references external memory locations. This external memory
is accessed via the XC2700’s external bus interface.
Selectable memory bank sizes are supported: The maximum size of a bank in the
external memory space depends on the number of activated address bits. It can vary
from 64 Kbytes (with A15 … A0 activated) to 12 Mbytes (with A23 … A0 activated). The
logical size of a memory bank and its location in the address space is defined by
programming the respective address window. It can vary from 4 Kbytes to 12 Mbytes.
•
•
•
•
Non-segmented mode:
– 64 Kbytes with A15 … A0 on PORT0 or PORT1.
1-bit segmented mode:
– 128 Kbytes with A16 on Port 4
– and A15 … A0 on PORT0 or PORT1.
2-bit … 7-bit segmented mode:
– with Ax … A16 on Port 4
– and A15 … A0 on PORT0 or PORT1.
8-bit segmented mode:
– 12 Mbytes with A23 … A16 on Port 4
– and A15 … A0 on PORT0 or PORT1.
Each bank can be directly addressed via the address bus, while the programmable chip
select signals can be used to select various memory banks.
The XC2700 also supports four different bus types:
•
•
•
•
Multiplexed 16-bit Bus with address and data on PORT0 (default after Reset).
Multiplexed 8-bit Bus with address and data on PORT0/P0L.
Demultiplexed 16-bit Bus with address on PORT1 and data on PORT0.
Demultiplexed 8-bit Bus with address on PORT1 and data on P0L.
Memory model and bus mode are preselected during reset by pin EA and PORT0 pins.
For further details about the external bus configuration and control please refer to
Chapter XX (The External Bus Controller).
External word and byte data can only be accessed via indirect or long 16-bit addressing
modes using one of the four DPP registers. There is no short addressing mode for
external operands. Any word data access is made to an even byte address.
For PEC data transfers the external memory can be accessed independent of the
contents of the DPP registers via the PEC source and destination pointers.
Note: The external memory is not bit addressable.
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3.8
Crossing Memory Boundaries
The address space of the XC2700 is implicitly divided into equally sized blocks of
different granularity and into logical memory areas. Crossing the boundaries between
these blocks (code or data) or areas requires special attention to ensure that the
controller executes the desired operations.
Memory Areas are partitions of the address space assigned to different kinds of
memory (if provided at all). These memory areas are the SFR areas, the on-chip
program or data RAM areas, the on-chip ROM/Flash (if available), the on-chip LXBusperipherals (if integrated), and the external memory.
Accessing subsequent data locations which belong to different memory areas is no
problem. However, when executing code, the different memory areas must be switched
explicitly via branch instructions. Sequential boundary crossing is not supported and
leads to erroneous results.
Note: Changing from the external memory area to the on-chip RAM area takes place
within segment 0.
Segments are contiguous blocks of 64 Kbytes each. They are referenced via the Code
Segment Pointer CSP for code fetches and via an explicit segment number for data
accesses overriding the standard DPP scheme.
During code fetching, segments are not changed automatically, but rather must be
switched explicitly. The instructions JMPS, CALLS and RETS will do this.
In larger sequential programs, make sure that the highest used code location of a
segment contains an unconditional branch instruction to the respective following
segment to prevent the pre-fetcher from trying to leave the current segment.
Data Pages are contiguous blocks of 16 Kbytes each. They are referenced via the data
page pointers DPP3 … DPP0 and via an explicit data page number for data accesses
overriding the standard DPP scheme. Each DPP register can select one of the possible
1024 data pages. The DPP register which is used for the current access is selected via
the two upper bits of the 16-bit data address. Therefore, subsequent 16-bit data
addresses which cross the 16-Kbytes data page boundaries will use different data page
pointers, while the physical locations need not be subsequent within memory.
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3.9
Embedded Flash Memory
This chapter describes the embedded flash memory of the XC2700:
•
•
•
•
•
•
•
Section 3.9.1 defines the flash specific nomenclature and the structure of the flash
memory.
Section 3.9.2 describes the operating modes.
Section 3.9.3 contains all operations.
Section 3.9.4 gives the details of operating sequences.
The three sections Section 3.9.5, Section 3.9.6 and Section 3.9.7 look more into
depth of maintaining data integrity and protection issues.
Section 3.9.8 discusses Flash EEPROM emulation.
Section 3.9.9 describes interrupt generation by the flash memory.
The Chapter 3.10 describes how the flash memory is embedded into the memory
architecture of the XC2700 and lists all SFRs that affect its behavior.
3.9.1
Definitions
This section defines the nomenclature and some abbreviations as a base for the rest of
the document. The used flash memory is a non-volatile memory (“NVM”) based on a
floating gate one-transistor cell. It is called “non-volatile” because the memory content is
kept when the memory power supply is shut off.
Logical and Physical States
Flash memory content can not be changed directly as in SRAMs. Changing data is a
complicated process with a typically much longer duration than reading.
•
•
Erasing: The erased state of a cell is logical 0. Forcing an flash cell to this state is
called “erasing”. Erasing is possible with a minimum granularity of one page (see
below). A device is delivered with completely erased flash memory.
Programming: The programmed state of a cell is logical 1. Changing an erased cell
to this state is called “programming”. A page must only be programmed once and has
to be erased before it can be programmed again.
The above listed processes have certain limitations:
•
•
Retention: This is the time during which the data of a flash cell can be read reliably.
The retention time is a statistical figure that depends on the operating conditions of
the flash array (temperature profile) and the accesses to the flash array. With an
increasing number of program/erase cycles (see endurance) the retention is lowered.
Drain and gate disturbs decrease data retention as well.
Endurance: As described above the data retention is reduced with an increasing
number of program/erase cycles. A flash cell incurs one cycle whenever its page or
sector is erased. This number is called “endurance”. As said for the retention it is a
statistical figure that depends on operating conditions and the use of the flash cells
and not to forget on the required quality level.
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•
Drain Disturb: Because of using a so called “one-transistor” flash cell each program
access disturbs all pages of the same sector slightly. Over long these “drain disturbs”
make 0 and 1 values indistinguishable and thus provoke read errors. This effect is
again interrelated with the retention. A cell that incurred a high number of drain
disturbs will have a lower retention. The physical sectors of the flash array are
isolated from each other. So pages of a different sector do not incur a drain disturb.
This effect must be therefor considered when the page erase feature is used.
The durations of programming and erasing as well as the limits for endurance, retention
and drain disturbs are documented in the data sheet.
Attention: No means exist in the device that prevent the application from violating
these limitation.
Array Structure
The flash memory is hierarchically structured:
•
•
•
•
•
Block: A block consists of 128 user data bits (i.e. 16 bytes) and 9 ECC bits. One read
access delivers one block.
Page: A page consists of 8 blocks (i.e. 128 bytes). Programming changes always
complete pages.
Sector: A sector consists of 32 pages (i.e. 4096 bytes). The pages of one sector are
affected by drain disturb as described above. The pages of different sectors are
isolated from each other.
Array: Each array has in the XC2700 64 sectors1). Usually when referring to an
“array” this contains as well all accompanying logic as assembly buffer, high voltage
logic and the digital logic that allows to operate them in parallel.
Memory: The complete flash memory of the XC2700 consists of 3 flash arrays.
This structure is visualized in Figure 3-5.
1)
In the Flash0 one sector is reserved for device internal purposes. It is not accessible by software.
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256 KB
Array
Sect or
Num ber
63
Page
Num ber
Sector
Block
Num ber
31
Page
7
2
2
2
1
1
1
Sector
0
0
Page
Sect or
[ 5: 0]
Page
[4: 0]
Block
[2: 0]
Block
137 Bits
Combined flash memory byte address
Array
[ 1: 0]
0
Byte
[ 3: 0]
[.. ][. . . . . .][. . . . .][. . .][. . . .]
9 Bits ECC
128 Bits Data
flash_array_userview_diagram.vsd
Figure 3-5
3.9.2
Flash Structure
Operating Modes
The IMB and the flash memory and each flash module have certain modes of operation.
Some modes define clocking and power supply and the operating state of the analog
logic as oscillators and voltage pumps. Overall system modes (e.g. startup mode)
influence the behavior or the flash memory as well.
Other modes define the functional behavior. These will be discussed here.
3.9.2.1
Standard Read Mode
After reset and after performing a clean startup the flash memory with all its modules is
in “standard read mode”. In this mode it behaves as an on-chip ROM. This mode is
entered:
•
•
•
After reset when the complete start-up has been performed.
After completion of a longer lasting command like “erase” or “program” which is
acknowledged by clearing the “busy” flag.
Immediately after each other command execution.
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•
In case of detecting an execution error like attempting to write to a write protected
range, sending a wrong password, after all sequence errors.
For the long lasting commands the read mode stays active until the last command of the
sequence is received and the operation is started.
3.9.2.2
Command Mode
After receiving the last command of a command sequence the addressed flash module
(not the whole flash memory!) is placed into command mode. For most commands this
will not be noticed by the user as the command executes immediately and afterwards the
flash module is placed again into read mode. For the long lasting commands the flash
module stays in command mode for several milliseconds. This is reported by setting the
corresponding “busy” flag. The data of a busy flash module cannot be read. New
command sequences are not accepted (even if they target different flash modules) and
cause a sequence error until the running operation has finished.
Read accesses to busy flash modules stall the CPU until the read mode is entered again.
A stalled CPU responds only to the reset. As no interrupts can be handled this state must
be avoided. Nevertheless this feature can be used to execute code from a flash module
that erases or programs data in the same flash module.
The IMB Core is limited to control only one running operation. Consequently when one
flash module is in command mode no other commands to either modules are accepted
but the other modules stay readable.
3.9.2.3
Page Mode
The page mode is entered with the “Enter Page Mode” command. Please find its
description below. A flash module that is in page mode can still be read (so it is
concurrently in “read mode”). At a time only one flash module can be in page mode.
When the flash memory is in page mode — i.e. one of the flash modules is in page mode
— some command sequences are not allowed. These are all erase sequences and the
“change read margin” sequence. These are ignored and a sequence error is reported.
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3.9.3
Operations
The flash memory supports the following operations:
•
•
•
Instruction fetch.
Data read.
Command sequences to change data and control the protection.
3.9.3.1
Instruction Fetch from Flash Memory
Instructions are fetched by the PMU in groups of aligned 64 bits. These code requests
are forwarded to the flash memory. It needs a varying number of cycles (depending on
the system clock frequency) to perform the read access. The number of cycles must be
known to the IMB Core because the flash does not signal data availability. The number
of wait-cycles is therefore stored in the IMB_IMBCTRL register.
One read access to the flash memory delivers 128 data bits and a 9-bit ECC value. The
ECC value is used to detect and possibly correct errors. The addressed 64-bit part of the
128-bit chunk is sent to the PMU. The complete 128 data bits and the 9 ECC bits are
stored in the IMB Core with their address. If a succeeding fetch request matches this
address the data is delivered from the buffer without performing a read access in the
flash memory. The delivery from the buffer happens after one cycle. The flash read waitcycles are not waited.
The stored data are a kind of instruction cache. In order to support self-modifying code
(e.g. boot loaders) this cache is invalidated when the corresponding address is written
(i.e. erased or programmed).
In addition to this fetch buffer the IMB Core has an additional performance increasing
feature — the Linear Code Pre-Fetch. When this feature is enabled with
IMB_IMBCTRL.DLCPF = 0 the IMB Core fetches autonomously the following
instructions while the CPU executes from its own buffers or the fetch buffer. As this
feature is fetching only the linear successors (it does not analyze the code stream) it is
most effective for code with longer linear sequences. For code with a high density of
jumps and calls it can even cause a reduction of performance and should be switched
off.
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3.9.3.2
Data Reads from Flash Memory
Data reads are issued by the DMU. Data is always requested in 16-bit words. The flash
memory delivers for every read request 128 bits plus ECC as described in “Instruction
Fetch from Flash Memory” on Page 3-22.
The IMB Core has to get all 128 bits to evaluate the ECC data. The requested 16 bits will
be delivered to the DMU. All data and ECC bits are kept in the data register and their
address is kept in the address register. For all following data reads the address is
compared with the address register and in case of a match the data is delivered after one
cycle from the data register. Every data read that is not delivered from this cache
invalidates the cache content. When the requested data arrives the cache contains again
valid data.
This small data cache is invalidated when a write (i.e. erase or program) access to this
address happens.
For data reads the IMB Core does not perform any autonomous pre-fetching.
3.9.3.3
Data Writes to Flash Memory
Flash memory content can not be changed by directly writing data to this memory.
Command sequences are used to execute all other operations in the flash except
reading. Command sequences consist of data writes with certain data to the flash
memory address range. All data moves targeting this range are interpreted as command
sequences. If they do not match a defined one or if the IMB Core is busy with executing
a sequence (i.e. it is in “command mode”) a sequence error is reported.
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3.9.3.4
Command Sequences
As described before changing data in the flash memory is performed with command
sequences.
Table 3-3
Command Sequence Overview
Command Sequence
Description
Details on
Page
Reset to Read
Reset Flash into read mode and clear
error flags.
Page 3-26
Clear Status
Clear error and status flags.
Page 3-26
Change Read Margin
Change read margins.
Page 3-26
Enter Page Mode
Prepare page for programming.
Page 3-27
Enter Security Page Mode
Prepare security page for programming.
Page 3-28
Load Page Word
Load page with data.
Page 3-28
Program Page
Start page programming process.
Page 3-29
Erase Sector
Start sector erase process.
Page 3-30
Erase Page
Start page erase process.
Page 3-31
Erase Security Page
Start security page erase process.
Page 3-32
Disable Read Protection
Disable temporarily read protection with
password.
Page 3-32
Disable Write Protection
Disable temporarily write protection with
password.
Page 3-33
Re-Enable Read/Write
Protection
Re-enable protection.
Page 3-34
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3.9.4
Details of Command Sequences
The description defines the command sequence with pseudo assembler code. It is
“pseudo” because all addresses are direct addresses which is generally not possible in
real assembler code.
The commands are called by a sequence of one to six data moves into the flash memory
range. The data moves must be of the “word” type, i.e. not byte move instructions. The
following sections describe each command. The following abbreviations for addresses
and data will be used:
•
•
•
•
•
•
•
•
PA: “Page Address”. This is the base address of the destination page. For example
the very first page has the address C0’0000H. The page 13 of the second array has
the PA = C0’0000H + 1·256·1024 (for the array) + 0·4·1024 (for the sector) + 13·128
(for the page) = C4’0680H.
SECPA: “Security Page Address”. This is the virtual address of a security page. It is
“virtual” because SECPA is just used as argument of the command sequence to
identify the security page but the physical storage of the security page is hidden.
Two security pages are defined:
SecP0: address C0’0000H.
SecP1: address C0’0080H.
WD: “Write Data”. This is a 16-bit data word that is written into the assembly buffer.
SA: “Sector Address”. This is the physical sector number as defined in Figure 3-6
based on the address of the flash module. Two examples as clarification:
1. Physical sector number 16 of the first array that is based on C0’0000H is addressed
with SA = C0’0000H + 16·4·1024 = C1’0000H.
2. The second 256 KB array has the base address C4’0000H (as shown in
Table 3-1). So its physical sector number 3 has the SA = C4’0000H + 3·4·1024 =
C4’3000H.
PWD: “Password”. This is a 64-bit password. It is transferred in 4 16-bit data words
PWD0 = PWD[15:0], PWD1 = PWD[31:16], PWD2 = PWD[47:32] and PWD3 =
PWD[63:48].
Address XX followed by two hexadecimal digits, for example “XXAAH”. If the
command targets a certain flash module the XX must be translated to its base
address. So “XXAAH” means C0’00AAH for all commands addressing flash 0,
C4’00AAH for flash 1 and C8’00AAH for flash 2. If a command (e.g. “Clear Status”)
addresses the complete flash memory the base address of flash module 0 must be
used.
Data XX followed by two hexadecimal digits, e.g. XXA5H. This is a “don’t care” data
word where only the low byte must match a certain pattern. So in this example all data
words like 12A5H or 79A5H can be used.
MR: “Margin”. This 8-bit number defines the read margin. MR can take the values 00H
(normal read), 01H (hard read 0), 02H (alternate hard read 0), 05H (hard read 1), 06H
(alternate hard read 1). All other values of MR are reserved.
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Reset to Read
Arguments: –
Definition:
MOV XXAAH, XXF0H
Timing: One cycle command that does not set any “BUSY” flags. But note that an
immediately following write access to the IMB Core is stalled for a few clock cycles during
which the IMB Core is busy with aborting a previous command.
Description: The internal command state machine is reset to initial state and returns to
read mode. An already started programming or erase operation is not affected and will
be continued (the “Reset to Read” command — i.e. all commands — will anyhow not be
accepted while the IMB Core is busy).
The “Reset to Read” command is a single cycle command. It can be used during a
command sequence to reset the command interpreter and return the IMB Core into its
initial state. It clears also all error flags in the Flash Status Register IMB_FSR and an
active page mode is aborted. Because all commands are rejected with a SQER while the
IMB Core is busy “Reset to Read” can not be used to abort an active command mode.
This command clears: PROER, PAGE, SQER, OPER, ISBER, IDBER, DSBER,
DDBER.
Clear Status
Arguments: –
Definition:
MOV XXAAH, XXF5H
Timing: 1-cycle command that does not set any busy flags.
Description: The flags OPER, SQER, PROER, ISBER, IDBER, DSBER, DDBER in
Flash status register are cleared. Additionally, the process status bits (PROG, ERASE,
POWER, MAR) are cleared.
Change Read Margin
Arguments: MR
Definition:
MOV XXAAH, XXB0H
MOV XX54H, XXMRH
Timing: 2-cycle command that sets “BUSY” for around 30 micro seconds.
Description: This command sequence changes the read margin of one flash module.
The address XX of the second move identifies the targeted flash module. The flash
module needs some time to change its read voltage. During this time BUSY is set and
this flash module cannot be accessed. The other flash modules stay readable.
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The argument “MR” defines the read margin:
•
•
•
•
•
•
00H: normal read margin.
01H: hard read 0 margin.
02H: alternate hard read 0 margin.
05H: hard read 1 margin.
06H: alternate hard read 1 margin.
Other values: reserved.
For understanding the read margins please refer to “Margin Reads” on Page 3-36.
This command must not be issued when the flash memory is in page mode. In this case
it is ignored and a sequence error is reported.
Note: As noted in “Margin Control” on Page 3-61 the command sequences “Program
Page”, “Erase Sector”, “Erase Page” and “Erase Security Page” reset the read
margin back to 00H, i.e. to the normal read margin. The same happens in case of
a flash wake-up.
Enter Page Mode
Arguments: PA
Definition:
MOV XXAAH, XX50H
MOV PA, XXAAH
Timing: 2-cycle command that sets “BUSY” for around 100 clock cycles.
Description: The page mode is entered to prepare a page programming operation on
page address PA. (Write data are accepted only with the “Load Page Word” command.)
With this command, the IMB Core initializes the write pointer of its block assembly
register to zero so that it points to the first word. The page mode is indicated in the status
register IMB_FSR with the PAGE bit, separately for each flash module. The page mode
and the read mode are allowed in parallel at the same time and in the same flash module
so the flash module stays readable. When the addressed page PA is read the content of
the flash memory is delivered. The page mode can be aborted and the related PAGE bit
in IMB_FSR be cleared with the “Reset to Read” command. A new “Enter Page Mode”
command during page mode aborts the actual page mode, which is indicated with the
error flag SQER, and restarts a new page operation. So as mentioned above only one
of the flash modules can be in page mode at a time. If one of the erase commands or the
“Change Read Margin” command are received while in page mode it is ignored and a
sequence error is reported.
If write protection is installed for the sector to be programmed, the “Enter Page Mode”
command is only accepted when write protection has before been disabled using the
unlock command sequence “Disable Write Protection” with four passwords. If global
write protection is installed with read protection, also the command “Disable Read
Protection” can be used if no sector specific protection is installed. If write protection is
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not disabled when the “Enter Page Mode” command is received, the command is not
executed, and the protection error flag PROER is set in the IMB_FSR.
Enter Security Page Mode
Arguments: SECPA
Definition:
MOV XXAAH, XX55H
MOV SECPA, XXAAH
Timing: 2-cycle command that sets “BUSY” for around 100 clock cycles.
Description: This command is identical to the “Enter Page Mode” command (see
above), with the following exceptions: The addressed page (SECPA) belongs to the
security pages of the flash memory and not to the user flash range. This command can
only be executed after disabling of read protection and of sector write protection. Only if
protection is not installed (e.g. for the very first installation of keywords), read/write
protection need not be disabled. This command is not accepted and a protection error is
reported if any protection is installed and active.
The use of this command to install passwords and to disable them again is described in
“Protection Handling Details” on Page 3-38.
Load Page Word
Arguments: WD
Definition:
MOV XXF2H, WD
Timing: 1-cycle command that does not set any “BUSY” flags. But note that an
immediately following write access to the IMB Core or read from the flash memory is
stalled for a few clock cycles if it arrives while the IMB Core is busy with copying its block
assembly register content into the flash module assembly buffer. During this stall time
the CPU can not perform any action! So either the user software can accept this stall time
(which must be taken into account for the worst-case interrupt latency) or the software
must avoid the blocking accesses.
Description: Load the IMB Core block assembly register with a 16-bit word and
increment the write pointer. The 128 byte assembly buffer (i.e. a complete page) is filled
by a sequence of 64 “Load Page Word” commands. The word address is not determined
by the command but the “Enter Page Mode” command sets a write word pointer to zero
which is incremented after each “Load Page Word” command.
This (sequential) data write access to the block assembly register belongs to and is only
accepted in Page Mode. The command address of this single cycle command is always
the same (F2H). These low order address bits also identify the “Load Page Word”
command and the sequential write data to be loaded into the block assembly register.
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The high order bits XX should address the target page. The IMB Core takes always the
page address that was used by the last “Enter Page Mode” command.
When the 128-bit block assembly register of the IMB Core is filled completely after 8
“Load Page Word” commands the IMB Core calculates the 9 ECC bits and transfers the
block into the assembly buffer of the flash module. After that it sets the write pointer of
the block assembly register back to zero. The following 8 “Load Page Word” commands
fill again the block. After all 8 blocks are filled the “Program Page” command can be
used to trigger the program process that transfers the assembly buffer content into the
flash array.
While the IMB Core transfers the completed block assembly register to the flash module
it can not accept new data for a few cycles. A “Load Page Word” command arriving
during this time is stalled by the IMB Core.
If “Program Page” is called before all blocks of the assembly buffer have received new
data then the remaining bits are cleared.
If more than 8 times 8 commands are used the additional data is lost. The overflow
condition is indicated by the sequence error flag, but the execution of a following
“Program Page” command is not suppressed (the page mode is not aborted).
When a “Load Page Word” command is received and the flash is not in page mode, a
sequence error is reported in IMB_FSR with SQER flag. In case of a new “Enter Page
Mode” command or a “Reset to Read” command during page mode, or in case of an
Application Reset, the write data in the assembly buffer is lost. The current page mode
is aborted and in case of a new “Enter Page Mode” command entered again for the new
address.
Program Page
Arguments: –
Definition:
MOV XXAAH, XXA0H
MOV XX5AH, XXAAH
Timing: 2-cycle command that sets “BUSY” for the whole programming duration.
Description: The assembly buffer of the flash module is programmed into the flash array.
If the last block of data was not filled completely this command finalizes its ECC
calculation and copies its data into the assembly buffer before it starts the program
process. The selection of the flash module and the page to be programmed depends on
the page address used by the last “Enter Page Mode” command. The user software
should always address the targeted page.
The programming process is autonomously performed by the selected flash module. The
CPU is not occupied and can continue with its application.
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The “Program Page” command is only accepted if the addressed flash module is in
Page Mode (otherwise, a sequence error is reported instead of execution). With the
“Program Page” command, the page mode is terminated, indicated by resetting the
related PAGE flag and the command mode is entered and the PROG flag in the status
register IMB_FSR is activated and the BUSY flag for the addressed module is set in
IMB_FSR. While BUSY is set the IMB Core does not accept any further commands.
When the program process has finished BUSY is cleared but PROG stays set. It
indicates which operation has finished and will be cleared by a System Reset or by
“Clear Status”.
Read accesses to the busy flash module are not possible. Reading a busy flash module
stalls until the flash module becomes ready again.
If write protection is installed for the sector to be programmed, the “Program Page”
command is not accepted because the Flash is not in Page Mode (see description of the
“Enter Page Mode” command).
If the page to be programmed is a security page (accepted only in security page mode),
the new protection configuration (including keywords or protection confirmation code) is
valid directly after execution of this command.
While the IMB Core reads the new protection configuration all DMU accesses to any
flash module are stalled.
Erase Sector
Arguments: SA
Definition:
MOV XXAAH, XX80H
MOV XX54H, XXAAH
MOV SA, XX33H
Timing: 3-cycle command that sets BUSY for the whole erasing duration.
Description: The addressed physical sector in the flash array is erased. Following data
reads deliver all-zero data with correct ECC.
The erasing process is autonomously performed by the selected flash module. The CPU
is not occupied and can continue with its application.
The sector to be erased is addressed by SA (sector address) in the last command cycle.
With the last cycle of the “Erase Sector” command, the command mode is entered,
indicated by activation of the ERASE flag and after start of erase operation also by the
related busy flag in the status register IMB_FSR. The BUSY flag is cleared after finishing
the operation but ERASE stays set. It can be cleared by a System Reset or the “Clear
Status” command.
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Read accesses to the busy flash module are not possible. Read accesses to the not busy
flash module are especially supported. Reading a busy flash module stalls until the flash
module becomes ready again.
If write protection is installed for the sector to be erased, the Erase Sector command is
only accepted when write protection has before been disabled using the unlock
command sequence “Disable Write Protection”. If global write protection is installed
with read protection, also the command “Disable Read Protection” can be used if no
sector specific protection is installed. If write protection is not disabled when the “Erase
Sector” command is received, the command is not executed, and the protection error
flag PROER is set in the IMB_FSR.
This command must not be issued when the flash memory is in page mode. In this case
it is ignored and a sequence error is reported.
Erase Page
Arguments: PA
Definition:
MOV XXAAH, XX80H
MOV XX54H, XXAAH
MOV PA, XX03H
Timing: 3-cycle command that sets BUSY for the whole erasing duration.
Description: The addressed page is erased. Following data reads deliver all-zero data
with correct ECC.
With the last cycle of the “Erase Page” command, the command mode is entered,
indicated by activation of the ERASE flag and after start of erase operation also by the
related BUSY flag in the status register IMB_FSR. BUSY is cleared automatically after
finishing the operation but ERASE stays set. It is cleared by a System Reset or the
“Clear Status” command.
Read accesses to the busy flash array are not possible. Read accesses to the not busy
flash modules are especially supported. Reading a busy flash module stalls until the
flash module becomes ready again.
If the page to be erased belongs to a sector which is write protected, the command is
only executed when write protection has before been disabled (see “Erase Sector”
command).
In case of using the page erase care must be taken not to exceed the drain disturb limit
of the other pages of the same sector.
This command must not be issued when the flash memory is in page mode. In this case
it is ignored and a sequence error is reported.
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Erase Security Page
Arguments: SECPA
Definition:
MOV XXAAH, XX80H
MOV XX54H, XXA5H
MOV SECPA, XX53H
Timing: 3-cycle command that sets BUSY for the whole erasing duration.
Description: The addressed security page is erased.
This command is identical to the “Erase Page” command with the following exceptions:
The addressed page (SecP0 or SecP1) belongs not to the user visible flash memory
range. This command can only be executed after disabling of read protection and of
sector write protection.
See “Protection Handling Examples” on Page 3-45 for a detailed description of reprogramming security pages.
The structure of the two security pages (SecP0 and SecP1) is described in “Layout of
the Security Pages” on Page 3-43.
After erasing a security page the new protection configuration (including keywords or
protection confirmation code) is valid directly after execution of this command.
While the IMB Core reads the protection configuration all DMU accesses to any flash
module are stalled.
This command must not be issued when the flash memory is in page mode. In this case
it is ignored and a sequence error is reported.
Disable Read Protection
Arguments: PWD
Definition:
MOV
MOV
MOV
MOV
MOV
MOV
XX3CH,
XX54H,
XXAAH,
XX54H,
XXAAH,
XX5AH,
XXXXH
PWD0
PWD1
PWD2
PWD3
XX55H
Timing: 6-cycle command that does not set any busy flag.
Description: Disable temporarily Flash read protection and — if activated — global write
protection of the whole flash memory. The RPA bit in IMB_IMBCTR is reset.
This is a protected command sequence, using four user defined passwords to release
this command or to check the programmed keywords. For every password one
command cycle is required. If the second or fourth password represents the code of the
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“Reset to Read” command, it is interpreted as password and the reset is not executed.
The 16-bit passwords are internally compared with the keywords out of the “Security
Page 0”. If one or more passwords are not identical to their related keywords, the
protected sectors remain in the locked state and a protection error (PROER) is indicated
in the Flash status register. In this case, a new “Disable Read Protection” command or
a “Disable Write Protection” command is only accepted after the next Application
Reset.
Note: During execution of the “Disable Read” (or Write) Protection command a
password compare error is only indicated after all four passwords have been
compared with the related keywords.
Note: This command sequence is also used to check the correctness of keywords
before the protection is confirmed in the Security Page 1. A wrong keyword is
indicated by the IMB_FSR flag PROER.
After correct execution of this command, the whole flash memory is unlocked and the
read protection disable bit RPRODIS is set in the Flash Status Register (IMB_FSR).
Erase and program operations on all sectors are then possible, if the flash memory was
also globally write protected (WPA=1), and if they are not separately write protected. The
read protection (including global write protection, if so selected) remains disabled until
the command “Re-Enable Read/Write Protection” is executed, or until the next
Application Reset (including HW and SW reset).
Disable Write Protection
Arguments: PWD
Definition:
MOV
MOV
MOV
MOV
MOV
MOV
XX3CH,
XX54H,
XXAAH,
XX54H,
XXAAH,
XX5AH,
XXXXH
PWD0
PWD1
PWD2
PWD3
XX05H
Timing: 6-cycle command that does not set any busy flag.
Description: Disable temporarily the global flash write protection or/and the sector write
protection of all protected sectors. The WPA bit in IMB_IMBCTR is reset.
This is a protected command sequence, using four user defined passwords to release
this command (as described above for the “Disable Read Protection” command).
After correct execution of this command, all write-protected sectors are unlocked, which
is indicated in the Flash Status Register (IMB_FSR) with the WPRODIS bit. Erase and
program operations on all sectors are now possible, until
•
The command “Re-Enable Read/Write Protection” is executed, or
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•
The next Application Reset (including HW and SW reset) is received.
Re-Enable Read/Write Protection
Arguments: –
Definition:
MOV XX5EH, XXXXH
Timing: 1-cycle command that does not set any busy flags.
Description: Flash read and write protection is resumed.
This single-cycle command clears RPRODIS and WPRODIS. The IMB Core is triggered
to restore the protection states RPA and WPA from the content of the security page 0 as
defined in Table 3-4 ““Flash State” Determining RPA and WPA” on Page 3-40. So
in effect this command resumes all kinds of temporarily disabled protection installations.
This command is released immediately after execution.
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3.9.5
Data Integrity
This section describes means for detecting and preventing the inadvertent modification
of data in the flash memory.
3.9.5.1
Error Correcting Codes (ECC)
With very low probability a flash cell can become disturbed or lose its data value faster
than specified. In order to reach the defined overall device reliability each 128-bit block
of flash data is accompanied with a 9-bit ECC value. This redundancy supplies SECDED capability, meaning “single error correction and double error detection”. All single
bit errors are corrected (and the incident is detected), all double bit errors are detected
and even most triple bit errors are detected but some of these escape as valid data or
corrected data.
A detected error is reported in the register IMB_FSR_PROT. Software can select which
type of error should trigger a trap by the means of register IMB_INTCTR. In the system
control further means exist to modify the handling of errors. The enabled trap requests
by the flash module are handled there as “Flash Access Trap”. In case of a double-bit
error the read data is always replaced with a dummy data word.
3.9.5.2
Aborted Program/Erase Detection
Where the ECC should protect from intrinsic failures of the flash memory that affect
usually only single bits; an interruption of a running program or erase process might
cause massive data corruption:
•
•
The erase process programs first all cells to 1 before it erases them. So depending
on the time when it is interrupted the data might be in a different state. This can be
the old data, all-one, a random value, a weak all-zero or finally all-zero.
The program process programs all bits concurrently from 0 to 1. If it is interrupted not
all set bits might read as 1 or contain a weak 1.
The register IMB_FSR_OP contains the bits ERASE and PROG. These bits stay set until
the next “Clear Status” command or System Reset. So if an erase or program process
is interrupted by an Application Reset one of these bits is still set which allows to detect
the interruption. It lies in the responsibility of the software to send the “Clear Status”
command after a finalized program/erase process to enable this evaluation.
Another possible measure against aborted program/erase processes is to prevent resets
by configuring the SCU appropriately.
If a program or erase process was aborted by a Power-On Reset (e.g. due to a power
failure) there do not exist reliable means to detect this by reading the affected flash
range. Even with margin reads an early or late aborted process might go unnoticed
although it might in the long-term affect reliability.
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Therefore the application must ensure that flash processes can perform uninterrupted
and under the defined operating conditions, e.g. by early brown-out warning that
prevents the software from starting flash processes.
After a flash process aborted the affected address range must be erased and reprogrammed.
3.9.5.3
Margin Reads
Margin reads can be used to verify that flash data is readable with a certain margin. This
is typically used as additional check directly after end-of-line programming. As explained
above this is not a reliable method for detecting interrupted program or erase processes
but the probability of detecting such cases can be increased.
Reading with “hard read 0 margin” returns weak 0s as 1s and reading with “hard read 1
margin” returns weak 1s as 0s. Changing the read margin is done with the command
sequence “Change Read Margin” and is reported by the status register “IMB_MAR”.
3.9.5.4
Protection Overview
The flash memory supports read and write protection for the whole memory and
separate write protection for each logical sector. The logical sector structure is depicted
in Figure 3-6.
256 KB Array
Phys.
Sector
Number
Logical
Sector
Address
63
63
Logical
Sector
Number
9 = 64 KB
48
8 = 64 KB
Logical
Grouping
32
7 = 64 KB
16
12
15
Phys. Sector 15
Reserved in
Flash 0
0
8
4
0
6 = 12 KB/16 KB
5 = 16 KB
4 = 16 KB
0 - 3 = 4 * 4 KB
flash_array_logsectors_diagram.vsd
Figure 3-6
Logical Sectors
If read protection is installed and active, any flash read access is disabled in case of start
after reset from external memory or from internal RAM. Debug access is as well disabled
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and thus the execution of injected OCDS instructions. In case of start after reset in
internal flash, all flash access operations are controlled by the flash-internal user code
and are therefore allowed, as long as not especially disabled by the user, e.g. before
enabling the debug interface.
Per default, the read protection includes a full (global) flash memory write protection
covering all flash modules. This is necessary to eliminate the possibility to program a
dump routine into the Flash, which reads the whole Flash and writes it out via the
external bus or a serial interface. Program and erase accesses to the flash during active
read protection are only possible, if write protection is separately disabled. Flash write
and read protection can be temporarily disabled, if the user authorizes himself with
correct passwords.
The device also features a sector specific write protection. Software locking of flash
memory sectors is provided to protect code and data. This feature disables both program
and erase operations for all protected sectors. With write protection it is supported to
protect the flash memory or parts of it from unauthorized programming or erase
accesses and to provide virus-proof protection for all sectors.
Read and write protection is installed by specific security configuration words which are
programmed by the user directly into two “Security Pages” (SecP0/1). After any reset,
the security configuration is checked by the command state machine (IMB Core) and
installations are stored (and indicated) in related registers. If any protection is enabled
also the security pages are especially protected.
For authorization of short-term disabling of read protection or/and of write protection a
password checking feature is provided. Only with correct 64-bit password a temporary
unprotected state is taken and the protected command sequences are enabled. If not
finished by the command “Re-Enable Read/Write Protection”, the unprotected state is
terminated with the next reset. Password checking is based on four 16-bit keywords
(together 64 bits) which are programmed by the user directly into the “Security Page 0”
(SecP0).
Special support is provided to protect also the protection installation itself against any
stressing or beaming aggressors. The codes of configuration bits are selected, so that
in case of any violation in the flash array, on the read path or in registers the protected
state is taken per default. In registers and security pages, protection control bits are
coded always with two bits, having both codes, “00B” and “11B” as indication of illegal
and therefore protected state.
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3.9.6
Protection Handling Details
As shortly described in “Protection Overview” on Page 3-36 the flash memory can be
in different protection states. The protection handling can be separated into different
layers that interact which each other (see Figure 3-7).
•
•
•
The lowest layer consists of the physical content of the security pages SecP0 and
SecP1. This information is used to initialize the protection system during startup.
The next layer consists of registers that report the state of the physical layer
(IMB_PROCONx) and the protection state (IMB_FSR). The protection state can be
temporarily changed with command sequences which is reflected in the IMB_FSR.
The highest layer is represented by 4 fields of the IMB_IMBCTR register. These fields
define the protection rights of the customer software (are read or write accesses
currently allowed or not).
The IMB Core controls the protection state of all connected flash modules centrally. In
this position it can supervise all accesses that are issued by the CPU.
Boot Mode
Upper Layer
IMB_CTRL
DDF
DCF
IMB_CTRH
RPA
WPA
Write to
DDF/DCF
Middle Layer
IMB_PROCONx
IMB_FSR
IMB_FSR
Disable/ ReEnable
Protection
PROCONs
WPRODIS
RPRO
RPRODIS
PROIN
PROINER
Physical Layer
Security Page 0
Passwords
Security Page 1
Lock Code
RPRO
PROCONs
Erase/
Program
Sec. Page
copied
influences
influences indirectly
flash_protection.vsd
Figure 3-7
Protection Layers
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3.9.6.1
The Lower Layer “Physical State”
After reset the protection state of the device is restored from the following information:
•
•
The security page 1 contains a “lock code”. This consists of two words of data (32
bits). If it has the value AA55AA55H then security page 0 determines the protection
state. Otherwise (i.e. the lock code was not found) the device is in the “non-protected
state”. The content of the security page 0 is still copied into the registers as described
in “The Middle Layer “Flash State”” on Page 3-39 but their values are ignored in
the non-protected state.
The security page 0 contains the RPRO double bit, the write protection bits SnU and
4 passwords. If the field RPRO contains a valid 01B or 10B entry the page is valid and
the device is in the “protection installed state”. The page content determines the
security settings after startup. If SecP0 contains an invalid RPRO entry the device is
in the “errored protection” state.
To summarize: the content of the security pages determines if the device is in the “nonprotected state”, “protection installed state” or “errored protection state”. These states
are reflected in the register settings of the next layer.
The device is usually delivered in the “non-protected state”.
The exact layout of the security pages is described in “Layout of the Security Pages”
on Page 3-43.
3.9.6.2
The Middle Layer “Flash State”
The middle layer consists of the registers IMB_PROCONx and IMB_FSRx and
commands that manipulate them and the content of the security pages.
During startup the physical state is examined by the IMB Core and it is reflected in the
following bit settings:
•
•
•
“non-protected state”: IMB_FSR.PROIN = 0, IMB_FSR.PROINER = 0.
“protection installed state”: IMB_FSR.PROIN = 1, IMB_FSR.PROINER = 0.
“errored protection state”: IMB_FSR.PROIN = 0, IMB_FSR.PROINER = 1.
The fourth possible setting PROIN=1 and PROINER=1 is invalid and can not occur.
The IMB_PROCONx registers are initialized during startup with the content of the
security page 0. The bits DSBER and DDBER indicate if an ECC error occurred. The
customer software has thus the possibility to detect disturbed security pages and it can
refresh their content.
Commands
Other bits of the IMB_FSR: RPRODIS, WPRODIS, PROER can be manipulated with
command sequences and define together with the other bits the protection effective for
the next layer. All three bits are 0 after system startup.
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The command “Disable Read Protection” sets RPRODIS to 1 if the correct passwords
that are stored in SecP0 are supplied. If incorrect passwords are entered the bit PROER
is set and RPRODIS stays unchanged. As protection against “brute force attacks” that
search the correct password the password detection is locked. So after supplying the
first incorrect password all following passwords even the correct ones are rejected with
PROER. This state is only left by an Application Reset or by erasing SecP0.
The disabled protection can be enabled again by the Application Reset or by the
command “Re-Enable Read/Write Protection” which clears RPRODIS again.
The bit PROER can be reset by an Application Reset or by the commands “Reset to
Read” and “Clear Status”.
The command “Disable Write Protection” sets WPRODIS to 1 if the correct passwords
are supplied. It behaves analog to RPRODIS as described above.
The command “Re-Enable Read/Write Protection” clears RPRODIS and WPRODIS.
The commands “Enter Page Mode”, “Enter Security Page Mode”, “Erase Page”,
“Erase Security Page” and “Erase Sector” set PROER if the write access to the
addressed range is not allowed. If a write access is allowed or not is determined by the
next level.
Table 3-4 summarizes how the “Flash State” of protection determines the RPA and WPA
fields of IMB_IMBCTR. For the double bits a short notation is used here and in the
following sections: 1 means active, 0 means inactive, ‘#’ means invalid and ‘–’ means do
not care including invalid states. The symbol ‘|’ means logic or.
Table 3-4
“Flash State” Determining RPA and WPA
IMB_
FSR.
PROI
N
IMB_
FSR.
PROI
NER
IMB_
FSR.
RPR
O
IMB_
FSR.
RPR
ODIS
IMB_
FSR.
WPR
ODIS
Resulting Security Level in RPA and WPA
0
0
–
–
–
Non-protected state:
RPA = 0, WPA = 0.
1
0
Protection installed state (possibly disabled,
see below):
0
–
0
RPA = 0, WPA = 1.
0
0
1
RPA = 0, WPA = 0.
1|#
0
0
RPA = 1, WPA = 1.
–
1
1
RPA = 0, WPA = 0 (all disabled).
1|#
0
1
RPA = 1, WPA = 0.
1|#
1
0
RPA = 0, WPA = 1.
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Table 3-4
“Flash State” Determining RPA and WPA (cont’d)
IMB_
FSR.
PROI
N
IMB_
FSR.
PROI
NER
0
1
3.9.6.3
IMB_
FSR.
RPR
O
IMB_
FSR.
RPR
ODIS
IMB_
FSR.
WPR
ODIS
Resulting Security Level in RPA and WPA
Errored protection state (see below):
–
0
0
RPA = 1, WPA = 1.
–
0
1
RPA = 1, WPA = 0.
–
1
0
RPA = 0, WPA = 1.
–
1
1
RPA = 0, WPA = 0.
The Upper Layer “Protection State”
This layer consists mainly of the 4 fields DCF, DDF, WPA and RPA of the IMB_IMBCTR
register. These determine the effective protection state together with registers of the
lower layers. Some of the above mentioned command sequences directly influence
these fields as well. In order to increase the resistance against beaming or power supply
manipulation all 4 fields are coded with 2 bits. Generally “01” means active, “10” inactive
and the two other states “00” and “11” are invalid and are recognized as “attacked” state.
Effective Security Level
The effective security level based on these 4 double-bits is summarized in Table 3-5 and
Table 3-6. For the double bits the same short notation is used as before: 1 means active,
0 means inactive, ‘#’ means invalid and ‘–’ means do not care including invalid states.
Table 3-5
Effective Read Security
RPA
DCF
DDF
Security Level
0
–
–
No read protection.
1|#
0
0
No read protection.
–
1|#
Data reads prohibited.
1|#
–
Code fetches prohibited.
Table 3-6
Effective Write Security
WPA
RPA
Security Level
0
–
No write protection
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Table 3-6
Effective Write Security (cont’d)
WPA
RPA
Security Level
1|#
1|#
Global write protection.
1|#
0
Sector specific write protection depending on
IMB_PROCONx.
To summarize:
•
•
Read protection is always globally affecting the whole flash memory range. Code
fetches and data reads can be separately controlled.
Write protection can be global when the read protection is effective or it can be
specific for each logical sector.
The lower and the middle security layers determine how the 4 effective IMB_IMBCTR
fields are preset, changed and how software can access them. This is discussed in the
following paragraphs.
Initialization of the Effective Security Level
After Application Reset protection is activated so that RPA, WPA, DDF and DCF are set.
During startup the IMB Core determines the stored security level as described in “The
Lower Layer “Physical State”” on Page 3-39 and sets IMB_FSR.PROIN and
IMB_FSR.PROINER and IMB_PROCONx as described in “The Middle Layer “Flash
State”” on Page 3-39. The IMB Core further initializes the IMB_IMBCTR fields RPA and
WPA according to the rules of Table 3-4.
The bits DDF and DCF of the IMB_IMBCTR are not initialized by the IMB Core. During
system startup they are initialized depending on the startup condition. If code fetching
starts in the flash memory then they are set to the inactive state. In all other cases they
are activated to prevent read access to the flash memory without proving password
knowledge.
Changing the Effective Security Level
During run-time the effective security level can be changed. This can be done by directly
writing to the IMB_IMBCTR register or indirectly by changing the bits of the middle layer
by commands as “Disable Write Protection” or even double indirectly by changing the
content of the security pages which changes bits in the middle layer and influences the
effective security level.
Writing directly to IMB_IMBCTR:
•
DCF and DDF can be deactivated only if RPA is inactive. They can always be
activated.
Indirectly by using a command sequence:
•
A successful “Disable Read Protection” sets RPRODIS and clears RPA.
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•
•
A successful “Disable Write Protection” sets WPRODIS and clears WPA.
“Re-Enable Read/Write Protection” clears RPRODIS and WPRODIS and sets RPA
and WPA according to Table 3-4 depending on PROIN, PROINER and RPRO.
Double indirect by changing security pages. After executing a command sequence that
changed the content of a security page the IMB Core immediately reads back the pages
and determines all resulting security data as described for system startup in
“Initialization of the Effective Security Level” on Page 3-42. The examples in
“Protection Handling Examples” on Page 3-45 will show how this can be used for
installing and removing protection or changing passwords.
3.9.6.4
Reaction on Protection Violation
If software tries to violate the protection rules the following happens:
•
•
•
Reading data when read protection is effective: The bit IMB_FSR.PROER is set and
the Flash access trap can be triggered via the SCU if IMB_INTCTR.DPROTRP is 0.
Default data is delivered.
Fetching code when read protection is effective: the trap code “TRAP 15D” is
delivered instead.
Programming or erasing memory ranges when they are write protected: PROER is
set.
3.9.6.5
Layout of the Security Pages
The previous sections just mentioned the content of the security pages. This section
depicts their exact layout. Figure 3-8 depicts symbolically the layout of the security
pages 0 and 1.
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Security Page 0
Block 1…7 unused
unused
unused
unused
FF'0010 H
FF'0008 H
4 PassWords
FF'0000 H
unused
P2
P1
P0
FF'0090 H
unused
unused
unused
unused
unused
unused
RPRO
PW3
PW2
PW1
PW0
Block 0
3 PROCON
Words
Block 1
unused
unused
unused
unused
FF'0080 H
CH
CL
Block 0
FF'0020 H
FF'00FF H
Block 2…7 unused
FF'007F H
Security Page 1
Lock Code
(2 Words)
flash_security_page_layout.vsd
Figure 3-8
Layout of Security Pages
Generally the 16-bit words are stored as always in the XC2700 in little endian format.
•
•
•
•
The PWx words contain the passwords.
The double bit RPRO is stored as in the related ISFR IMB_FSR_PROT in the bits 15
and 14. The other bits of this word are unused and should be kept all-zero.
The PROCON data is stored as defined in the IMB_PROCONx (x=0-2) ISFR.
The lock code consists of the two words CL and CH. Both contain “AA55H” to form
the correct lock code.
All bytes of the used blocks of the security pages (block 0 and 1 of SecP0 and block 0 of
SecP1) are to be considered as “reserved” and must be kept erased, i.e. with all-zero
content. The unused blocks of the security pages (blocks 2 to 7 of SecP0 and blocks 1
to 7 of SecP1) shall be programmed with all-one data.
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3.9.7
Protection Handling Examples
Some examples on how to work with the protection system.
Delivery State
The device is delivered in the “non-protected state”.
Security page 1 is erased (so it does not contain the “lock code” AA55AA55H).
Security page 0 is erased and so “invalid” but because SecP1 is erased this data is
anyhow not evaluated. Only its content is copied into corresponding the registers.
During startup the bits DDF and DCF are set depending on the start mode but as RPA
and WPA are inactive all accesses to the flash memory are allowed.
The data sectors of the flash memory are delivered in the erased state as well. All sectors
can be programmed. After uploading the software the customer can install write and read
protection.
First Time Password Installation
In order to install a password generally the lock code in SecP1 has to be erased. In this
case the code is not present.
After that SecP0 must be erased with “Erase Security Page” in order to be able to
change RPRO. Erasing SecP0 clears RPRO to “00B” which is an invalid state. After
finishing the erase command the IMB Core restores the IMB_FSR and IMB_IMBCTR
fields from the flash data.
Because no lock code is present in SecP1 the invalid state of RPRO has no effect on the
user visible protection. Still all parts of the flash memory can be written.
The second step is to program the information of SecP0 with the required security
information. Again the IMB Core reads immediately back the stored data and initializes
the security system. As SecP1 still does not contain the lock code the device stays in the
“non-protected” mode.
The security pages cannot be read directly by customer software. The data programmed
into SecP0 can therefore only be verified indirectly. The data of the RPRO and SnU fields
can be checked by reading the IMB_PROCON and IMB_FSR registers. The passwords
can be verified with the command “Disable Read Protection”. If the password does not
match the bit PROER is set. But because of the erased SecP1 the flash memory stays
writable. So after erasing SecP0 the correct password can be programmed again.
After the SecP0 was verified successfully SecP1 gets programmed with the lock code
AA55AA55H which enables the security settings of SecP0.
Because the password validation left RPRODIS set the command “Re-Enable Read/
Write Protection” must be used to finally activate the new protection.
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Changing Passwords or Security Settings
Changing the passwords is a delicate operation. The interrelation of the two security
pages must be kept in mind.
Usually in the protected state the SecP1 contains the lock code. First write protection
must be disabled with the correct passwords. Then the lock code in SecP1 is erased. If
this operation was successful PROIN will be cleared by the IMB Core. Now SecP0 can
be safely erased.
From this point on the security pages are in the factory delivery state and the new
passwords and security settings can be installed as described above.
Attention: The number of times a security page may be changed is noted in the
data sheet.
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3.9.8
EEPROM Emulation
The flash memory of the XC2700 is used for three purposes:
1. Storage of program code. Updates happen usually very seldom. The main criteria to
be fulfilled is a retention of the life-time of the product.
2. Storage of constant data: this data is stored together with program code. So this data
is very seldom updated. Endurance is of no issue here but retention identical to the
code memory is required.
3. Data updated during run-time: this might be data with a very high frequency of
updates like a mileage counter or access keys for key-less entry. Other data might
be changed only in case of failures and other data might only be transferred from
RAM to non-volatile memory before the system is powered down.
Especially for the third type of data the non-volatile memory needs EEPROM like
characteristics:
•
•
•
Fine program/erase granularity which is in EEPROMs typically 1 byte.
Higher endurance than the intrinsic endurance of flash cells.
Short program and erase duration per byte. Especially for storing data in an
emergency (e.g. power failure) short latencies might be required.
A basic requirement for changing data during run-time is that code execution can still
resume, especially interrupt requests must still be serviced. This requirement is fulfilled
in the XC2700 because all three flash modules work independently. If one is busy with
program or erase then code can still be executed from the other two.
The other requirements are more difficult to fulfill because the XC2700 does not have an
EEPROM available but only the flash memory with the already frequently mentioned
limitations: big program/erase granularity, moderately long program/erase duration,
limited cell endurance with reduced retention at high number of program/erase cycles,
pages not isolated but affected by drain disturbs.
In order to alleviate these effects on run-time storage of data software is used to emulate
EEPROM. There is quite a number of algorithms for efficiently using flash memory as
EEPROM. The following section describes one (the most simple) of these algorithms.
It should be noted that the XC2700 does not offer the customer any hardware means for
EEPROM emulation. All of the following must be realized by software.
3.9.8.1
The Traditional EEPROM Emulation
The key point is to solve the limited endurance by storing data in N different physical
places. In XC2700 the algorithm could use N sequential pages or groups of pages. If
data is currently stored in the page “x” then the next program happens to the page “(x+1)
mod N”.
After boot up the last correct page group must be found. This could be done by either
evaluating a counter (from 0 to 2*N-1) or the old entries are invalidated by erasing the
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page after programming the new one. Additionally a CRC check could be performed over
the group.
As all involved pages are re-used cyclically the endurance from customer perspective is
increased by the factor N. N must be chosen high enough to fulfill endurance and
retention requirements. Disturbs in the group of N pages are no issue because they incur
at most N-1 disturbs before they get written with new data. Care must be taken however
if one sector accommodates different groups of pages with different update behavior. In
this case the updates of one group of pages could exceed the disturb limits of the other
group. So generally one sector should be used only by one such EEPROM cyclic buffer.
The algorithm keeps the old data until the new data is verified so power failure during
programming can only destroy the last update but the older data is still available. There
are still some issues with power failure that need special treatment:
•
•
Power is cut during programming: the following boot-up might find an apparently
correctly programmed page. However the cells might be not fully programmed and
thus have a much lower retention or the read data is unstable (e.g. changing
operating conditions cause read errors).
If the power is cut early the page can appear as erased although some cells are partly
programmed. When programming different data to this apparently erased page read
errors might occur.
Power is cut during erase: the same as above can happen. Data may appear as
erased but the retention is lowered. A power failure during a page-erase can inhibit
readability of all data in its physical sector. Therefore an algorithm is advantageous
that performs erases only in sectors that don’t contain anymore current data.
The algorithm can be improved to be more robust against such cases, e.g. program
always two pages, mark the end of an erase process by programming a page. But
generally aborting flash processes is a forbidden “operating condition”.
The main deficiency of the described algorithm is that the software designer is required
to plan the use of the flash memory thoroughly. The user has to choose the correct value
of N. Then all data has to be allocated to pages. Data sharing one page should have a
similar or better identical update pattern (otherwise unchanged data is unnecessarily
written). If one set of data does not fill a complete sector the available pages must be
possibly left unused because they might incur too many drain disturbs.
There are other algorithms that try to alleviate these efforts by monitoring the flash usage
and adapt automatically the assignment of data to flash cells.
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3.9.9
Interrupt Generation
Long lasting processes (these are mainly: program page, erase page, erase sector and
margin changes) set the IMB_FSR.BUSY flag of one flash module when accepting the
request and reset this flag after finishing the process. Software is required to poll the
busy flag in order to determine the end of the operation. In order to release the software
from this burden an interrupt can be generated. If the interrupt is enabled by
IMB_INTCTRL.IEN then all transitions from 1 to 0 of one of the 3 IMB_FSR.BUSY flags
send an interrupt request.
The “Enter Page Mode” command sets BUSY only for around 100 clock cycles. It is
usually not advisable to enable the interrupt for this command.
The register IMB_INTCTR contains fields for the interrupt status “ISR”, an enable for the
interrupt request “IEN” and fields for clearing the status flag “ICLR” or setting if “ISET”. It
should be noted that the interrupt request is only sent when ISR becomes 1 and IEN was
already 1. No interrupt is sent when IEN becomes 1 when ISR was already 1 or both are
set to 1 at the same time.
3.9.10
Recommendations for Optimized Flash Usage
This section describes best practices for using the flash in certain application scenarios,
e.g. how to use effectively ECC and margin reads. For a description of the hardware
features consult “Data Integrity” on Page 3-35.
3.9.10.1 Programming Code and Constant Data
Code and constant data are programmed only few times during life-time of a device, e.g.
end-of-line in ECU production or when service updates are performed. As the readability
of this data is decisive for the product quality customers might want to implement the
elaborate “best practice” advice.
Basic Advice
Always ensure correct operating conditions and prevent power failures during flash
operation.
As basic protection against handling errors all data should be verified after programming.
Single-bit ECC errors should be ignored. The appearance of small numbers of single-bit
errors is a consequence of known physical effects.
Best Practice
This approach offers best possible quality but risks that programming steps need to
repeated even unnecessarily (“false negatives”):
•
Use “Erase Sector” to erase complete sectors.
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•
•
•
•
•
Program the sector with data. A common protection against software crashes is to fill
the unused part of the sector with trap codes.
Change the read level to hard margin 0.
Verify the programmed data, note comparison errors and double-bit ECC errors and
count single-bit ECC errors. Take care to evaluate the ECC error flags only once per
128-bit data block and clear them afterwards.
Repeat this check with hard margin 1.
After programming all sectors:
– Erase and re-program all sectors with comparison or double-bit ECC errors.
– If a flash module contained more than a certain number (e.g. 10) of single-bit ECC
errors it is recommended to erase and re-program the affected sectors (i.e. those
containing at least one single-bit error).
– Attention: a high number of single-bit errors indicates usually a violation of
operating conditions.
The threshold of allowed single-bit errors could be increased for in-service updates in
order to reduce the risk of false negatives.
3.9.10.2 EEPROM Emulation
For EEPROM emulation the goal is usually not readability over device life-time but
highest possible robustness (against violated operating conditions, power failures, even
failing flash pages e.g. due to over-cycling). The risk of false negatives should be
minimized.
A good robustness is achieved with the following approach:
•
•
•
Verify data after programming with the normal read level. Single-bit ECC errors
should be ignored.
In case of comparison error or double-bit ECC error the data should be programmed
again to the next flash range (e.g. next page or sector).
The number of re-programming trials should be limited (e.g. to 3) to protect against
violated operating conditions.
Obviously this jumping over failed pages can be only used optimally when the algorithm
does not expect data on fixed addresses.
Failing pages can prevent “Erase Sector” from erasing any data in the affected sector.
The “Erase Page” command however could still erase all other pages. These other
pages stay readable and programmable.
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3.10
On-Chip Program Memory Control
The internal memory block “IMB” contains all memories of the so called “on-chip program
memory area” in the address range from C0’0000H to FF’FFFFH. Included are the
program SRAM, the embedded flash memories and central control logic called “IMB
Core”.
In the XC2700 device the IMB contains the following memories:
•
•
764 KB flash memory in three independent modules.
64 KB program SRAM (see Section 3.4.1).
The IMB connects these memories to the CPU data bus and the instruction fetch bus.
Each memory can contain instruction code, data or a mixture of both. The IMB manages
accesses to the memories and supports flash programming and erase.
3.10.1
Overview
The Figure 3-9 shows how the IMB and its memories are integrated into the device
architecture. Only the main data streams are included. The data buses are usually
accompanied by address and control signals and check-sum data like parity or ECC.
IMB
C166SV2
DMU
(Data access)
CPU
PMU
(Instr fetch)
Data
IMB
Core
16
PSRAM
64
(Program
SRA M)
Instructions
Flash Memory
64
Flash Module 0
128
Flash Module 1
128
Flash Module 2
128
imb_block_diagram.vsd
Figure 3-9
IMB Block Diagram
The CPU has two independent busses. The instruction fetch bus is controlled by the
program management unit “PMU” of the CPU. It fetches instructions in aligned groups of
64 bits. The instruction fetch unit of the CPU predicts the outcome of jumps and fetches
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instructions on the predicted branch in advance. In case of a misprediction this interface
can abort outstanding requests and continues fetching on the correct branch. As the
CPU can consume up to one 32-bit instruction per clock cycle the performance of this
interface determines the CPU performance.
The data bus is controlled by the data management unit “DMU” of the CPU. It reads data
in words of 16 bits. Write accesses address as well 16-bit words but additional byte
enables allow changing single bytes.
Because of the CPU’s “von Neumann” architecture data and instructions (and “special
function registers” to complete the list) share a common address range. When
instructions are used as data (e.g. when copying code from an IO interface to the
PSRAM) they are accessed via the data bus. The pipelined behavior of the CPU can
cause that code fetches and data accesses are requested simultaneously. The IMB
takes care that accesses can perform concurrently if they address different memories or
flash modules.
Additional connections of the IMB to central system control units exist. These are not
shown in the block diagram.
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3.10.2
Register Interface
The “IMB Registers” on Page 3-53 describes the special function registers of the IMB.
In “System Control Registers” on Page 3-HIDDEN the special function registers that
influence the IMB but are not allocated to the IMB address range are described.
3.10.2.1 IMB Registers
The section describes all IMB special function registers.
Table 3-7
Registers Overview
Register Short
Name
Register Long Name
Offset
Address
Page Number
IMB_IMBCTRL
IMB Control Low
FF FF00H
Page 3-53
IMB_IMBCTRH
IMB Control High
FF FF02H
Page 3-55
IMB_INTCTR
Interrupt Control
FF FF04H
Page 3-56
IMB_FSR_BUSY
Flash State Busy
FF FF06H
Page 3-58
IMB_FSR_OP
Flash State Operations
FF FF08H
Page 3-58
IMB_FSR_PROT
Flash State Protection
FF FF0AH
Page 3-60
IMB_MAR
Margin
FF FF0CH
Page 3-62
IMB_PROCON0
Protection Configuration 0
FF FF10H
Page 3-63
IMB_PROCON1
Protection Configuration 1
FF FF12H
Page 3-63
IMB_PROCON2
Protection Configuration 2
FF FF14H
Page 3-63
IMB Control
Global IMB control.
Both IMB_IMBCTRL and IMB_IMBCTRH are reset by an Application Reset.
The write access to both registers is controlled by the register security mechanism as
defined in the SCU chapter “Register Control” on Page 6-191. Please note that the
register write-protection is not activated automatically again after an access to
IMB_IMBCTR because this happens only for SCU internal registers.
IMB_IMBCTRL
IMB Control Low
15
14
13
12
ISFR (FF FF00H)
Reset value: 558CH
11
10
9
8
7
6
5
4
3
2
1
0
DDF
DCF
-
-
-
-
-
-
-
-
DLC
PF
WSFLASH
rw
rw
-
-
-
-
-
-
-
-
rw
rw
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Field
Bits
Typ Description
WSFLASH
[2:0]
rw
Wait States for Flash Access
Number of wait cycles after which the IMB expects
read data from the flash memory.
This field determines as well the read timing of the
PSRAM in the flash emulation address range. See
“Flash Emulation” on Page 3-12.
Note: WSFLASH must not be 0. This value is
forbidden!
DLCPF
3
rw
Disable Linear Code Pre-Fetch
0:
“High Speed Mode”: When the next read
request will be delivered from the buffer and so
the flash memory would be idle, the IMB Core
autonomously increments the last address
and reads the next 128-bit block from the flash
memory.
1:
“Low Power Mode”: This feature is disabled.
Usually for code with power minimization
requirements or for code with short linear code
sections this feature should be disabled (DLCPF =
1). Enabling this feature is only advantageous for
code section with longer linear sequences. With
lower values of WSFLASH the performance gain of
DLCPF=0 is reduced. In case of low WSFLASH
settings DLCPF=1 might even lead to better
performance than with linear code pre-fetch.
DCF
[13:12] rw
Disable Code Fetch from Flash Memory
“01”: Short notation DCF = 1. If RPA = 1 instructions
cannot be fetched from flash memory. If RPA
= 0 this field has no effect.
“10”: Short notation DCF = 0. Instructions can be
fetched independent of RPA.
“00” | “11”: Illegal state. Has the same effect as “01”.
This state can only be left by an Application
Reset.
During startup or test mode or when RPA = 0
software can change this field to any value.
Otherwise code fetch can only be disabled but not
enabled anymore until the next Application Reset.
User’s Manual
MemoryX2K, V1.3
3-54
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Field
Bits
Typ Description
DDF
[15:14] rw
Disable Data Read from Flash Memory
“01”: Short notation DDF = 1. If RPA = 1 data cannot
be read from flash memory. If RPA = 0 this
field has no effect.
“10”: Short notation DDF = 0. Data can be read
independent of RPA.
“00” | “11”: Illegal state. Has the same effect as “01”.
This state can only be left by an Application
Reset.
During startup or test mode or when RPA = 0
software can change this field to any value.
Otherwise data reads can only be disabled but not
enabled anymore until the next Application Reset.
IMB control high word. The WPA and RPA fields are described in “Protection Handling
Details” on Page 3-38.
IMB_IMBCTRH
IMB Control High
15
14
13
ISFR (FF FF02H)
12
11
10
9
8
7
6
5
4
PSPROT
–
–
–
–
RPA
WPA
rw
–
–
–
–
rh
rh
Field
Bits
Typ Description
WPA
[1:0]
rh
User’s Manual
MemoryX2K, V1.3
Reset value: 0005H
3
2
1
0
Write Protection Activated
“01”: Short notation WPA = 1. The write protection
of the flash memory is activated.
“10”: Short notation WPA = 0. The write protection
is not activated.
“00” | “11”: Illegal state. Same effect as “01”. The
illegal state can only be left by an Application
Reset.
This field is only changed by the IMB Core. Software
writes are ignored.
3-55
V2.1, 2008-08
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System Units (Vol. 1 of 2)
Memory Organization
Field
Bits
Typ Description
RPA
[3:2]
rh
Read Protection Activated
“01”: Short notation RPA = 1. The read protection of
the flash memory is activated.
“10”: Short notation RPA = 0. The read protection is
not activated.
“00” | “11”: Illegal state. Same effect as “01”. The
illegal state can only be left by an Application
Reset.
This field is only changed by the IMB Core. Software
writes are ignored.
PSPROT
[15:8]
rw
PSRAM Write Protection
This 8-bit field determines the address up to which
the PSRAM is write protected.
The start address of the writable range is E0’0000H
+ 1000H*PSPROT. The end address is determined
by the implemented memory. The equivalent range
in the PSRAM area with flash access timing is
protected as well. Here the writable range starts at
E8’0000H + 1000H*PSPROT and ends at E8’FFFFH
for XC2700.
So with PSPROT=00H the complete PSRAM is
writable. In case of XC2700 with PSPROT=10H or
bigger the complete implemented PSRAM is writeprotected.
Interrupt Control
Interrupt control and status.
Reset by Application Reset.
IMB_INTCTR
Interrupt Control
ISFR (FF FF04H)
15
14
13
12
11
ISR
PSE
R
–
–
–
rh
rh
–
–
–
User’s Manual
MemoryX2K, V1.3
10
9
8
PSE
RCL ISET ICLR
R
w
w
w
3-56
Reset value: 0000H
7
6
5
4
–
–
–
–
–
–
–
–
3
2
1
0
DPR
DDD DIDT
OTR
IEN
TRP RP
P
rw
rw
rw
rw
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Field
Bits
Typ Description
IEN
0
rw
Interrupt Enable
If set, the interrupt signal of the IMB gets activated
when ISR is set.
DIDTRP
1
rw
Disable Instruction Fetch Double Bit Error Trap
If set, a double bit ECC error does not cause the
replacement of the fetched data by a trap instruction.
DDDTRP
2
rw
Disable Data Read Double Bit Error Trap
If set, a double bit ECC error during data read does
not trigger the Flash access hardware trap.
DPROTRP
3
rw
Disable Protection Trap
If set, a read request from read protected flash
memory does not trigger the Flash access hardware
trap.
ICLR
8
w
Interrupt Clear
When written with 1 the ISR is cleared. Reading this
bit delivers always 0. Writing a 0 is ignored.
ISET
9
w
Interrupt Set
When written with 1 the ISR is set and if IEN is set
the interrupt signal is activated. Reading this bit
delivers always 0. Writing a 0 is ignored. When
writing ISET and ICLR to 1 concurrently ISET takes
priority so ISR is set.
PSERCLR
10
w
Clear PSRAM Error Flag
When written with 1 the PSER is cleared. Reading
this bit delivers always 0. Writing a 0 is ignored.
PSER
14
rh
PSRAM Error Flag
This flag is set when write requests to the write
protected or not implemented PSRAM range are
detected. This flag can be cleared by writing 1 to
PSERCLR.
ISR
15
rh
Interrupt Service Request
If set, it indicates that at least one IMB_FSR.BUSY
bit changed from 1 to 0. If IEN was set an interrupt
request is sent to the interrupt controller. After
servicing the interrupt the software handler clears
this flag by writing a 1 to ICLR.
User’s Manual
MemoryX2K, V1.3
3-57
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Flash State
Flash state. Split into 3 registers IMB_FSR_BUSY, IMB_FSR_OP, and
IMB_FSR_PROT. The protection relevant fields or IMB_FSR_PROT are described in
“Protection Handling Details” on Page 3-38.
The registers are reset by the Application Reset with the exception of “ERASE”, “PROG”,
and “OPER”. These three fields are only reset by a System Reset.
IMB_FSR_BUSY
Flash State Busy
ISFR (FF FF06H)
15
14
13
12
11
–
–
–
–
–
–
–
–
–
–
10
9
8
Reset value: 0000H
7
6
5
4
3
2
1
PAGE
–
–
–
–
–
BUSY
rh
–
–
–
–
–
rh
0
Field
Bits
Typ Description
BUSY
[2:0]
rh
Busy
A flash module is busy with a task. Each bit position
corresponds to one of the 3 flash modules. The task
is indicated by the bits MAR, POWER, ERASE or
PROG of IMB_FSR_OP. BUSY is automatically
cleared when the task has finished. The
corresponding task indication is not cleared in order
to allow an interrupt handler to determine the
finished task.
PAGE
[10:8]
rh
Page Mode Indication
Set as long the corresponding flash module is in
page mode. Page mode is entered by the “Enter
Page Mode” commands and finished by a “Program
Page” command. The page mode can be also left by
a “Reset to Read” command. Also an Application
Reset clears this bit.
IMB_FSR_OP
Flash State Operations
ISFR (FF FF08H)
15
14
13
12
11
10
9
8
7
6
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
User’s Manual
MemoryX2K, V1.3
3-58
Reset value: 0000H
5
4
3
2
1
0
OPE SQE
POW ERA PRO
MAR
R
R
ER SE
G
rh
rh
rh
rh
rh
rh
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Field
Bits
Typ Description
PROG
0
rh
Program Task Indication
This bit is set when a program task is started. The
affected flash module is indicated by a BUSY bit.
The PROG bit is not automatically reset but must be
cleared by a “Clear Status” command. This bit is not
cleared by an Application Reset but only by a
System Reset.
ERASE
1
rh
Erase Task Indication
This bit is set when an erase task is started. The
affected flash module is indicated by a BUSY bit.
The ERASE bit is not automatically reset but must be
cleared by a “Clear Status” command. This bit is not
cleared by an Application Reset but only by a
System Reset.
POWER
2
rh
Power Change Indication
This bit indicates that a flash module is in its startup
phase or in a shutdown phase. The BUSY bits
indicate which flash module is busy. This bit is not
automatically reset but must be cleared by a “Clear
Status” command.
MAR
3
rh
Margin Change Indication
If a read margin modification is requested this bit is
set together with the corresponding BUSY bit. The
BUSY bit is cleared when the margin change is
effective and the flash module can be read again.
The MAR bit must be cleared by a “Clear Status”
command.
SQER
4
rh
Sequence Error
This bit is set by a errored command sequence or a
command that is not accepted. It is cleared by “Clear
Status” and “Reset to Read”.
User’s Manual
MemoryX2K, V1.3
3-59
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Field
Bits
Typ Description
OPER
5
rh
IMB_FSR_PROT
Flash State Protection
15
14
13
12
RPRO
–
–
rh
–
–
11
Operation Error
The IMB Core maintains internal bits that are set
when starting a program or erase process. They are
cleared when this process finishes. These bits are
not reset by an Application Reset but only by a
System Reset. If one of these bits is set after
Application Reset the IMB Core sets OPER. So this
signals that a running erase or program process was
interrupted by an Application Reset.
The OPER is cleared by “Reset to Read”, “Clear
Status” or a System Reset.
ISFR (FF FF0AH)
10
9
8
DDB DSB IDBE ISBE
ER ER
R
R
rh
rh
rh
rh
Reset value: x000H
7
6
5
–
–
–
–
–
–
4
3
2
1
0
PRO WPR RPR PROI PROI
ER ODIS ODIS NER N
rh
rh
rh
rh
rh
Field
Bits
Typ Description
PROIN
0
rh
Flash Protection Installed
Modified by the IMB Core. Cleared by Application
Reset.
PROINER
1
rh
Flash Protection Installation Error
Modified by the IMB Core. Cleared by Application
Reset.
RPRODIS
2
rh
Read Protection Disabled
The read protection was temporarily disabled with
the “Disable Read Protection” command. Modified
by the IMB Core. Cleared by Application Reset.
WPRODIS
3
rh
Write Protection Disabled
The write protection was temporarily disabled with
the “Disable Write Protection” command. Modified
by the IMB Core. Cleared by Application Reset.
User’s Manual
MemoryX2K, V1.3
3-60
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Field
Bits
Typ Description
PROER
4
rh
Protection Error
Set by a violation of the installed protection. Reset by
the “Clear Status” and “Reset to Read” commands
or an Application Reset.
ISBER
8
rh
Instruction Fetch Single Bit Error
Set if during instruction fetch a single-bit ECC error
was detected (and corrected). Reset by “Clear
Status” or “Reset to Read” commands or an
Application Reset.
IDBER
9
rh
Instruction Fetch Double Bit Error
Set if during instruction fetch a double-bit ECC error
was detected (and not corrected). Reset by “Clear
Status” or “Reset to Read” commands or an
Application Reset.
DSBER
10
rh
Data Read Single Bit Error
Same as ISBER for data reads.
DDBER
11
rh
Data Read Double Bit Error
Same as IDBER for data reads.
RPRO
[15:14] rh
Read Protection Configuration
This field is copied by the IMB Core from the
corresponding field in the security page 0. After
Application Reset read protection is activated.
Margin Control
Read margin control. Each field corresponds to one flash module. A hard read 0 detects
not completely erased cells. These are read as “1”. A hard read 1 detects not completely
programmed cells. These are read as “0”. Read margin changes are caused by the
command sequence “Change Read Margin”. The resulting read margin is reflected in
this status register.
The command sequences “Program Page”, “Erase Sector”, “Erase Page” and “Erase
Security Page” resets the read margin back to “normal”. The same happens in case of
a flash wake-up.
Reset by Application Reset.
User’s Manual
MemoryX2K, V1.3
3-61
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
IMB_MAR
Margin Control
ISFR (FF FF0CH)
8
7
6
Reset value: 0000H
15
14
13
12
11
10
9
5
4
3
2
1
–
–
–
–
–
–
–
HREAD2
HREAD1
HREAD0
–
–
–
–
–
–
–
rh
rh
rh
Field
Bits
Typ Description
HREAD0
[2:0]
rh
Hard Read 0
Active read margin of flash module 0.
“000”:Normal read.
“001”:Hard read 0.
“010”: Alternate hard read 0 (usually harder than
001).
“101”:Hard read 1.
“110”: Alternate hard read 1 (usually harder than
101).
other codes:Reserved.
HREAD1
[5:3]
rh
Hard Read 1
Same for flash module 1.
HREAD2
[8:6]
rh
Hard Read 2
Same for flash module 2.
0
Protection Configuration
Protection configuration register of each implemented flash module. In XC2700
PROCON0, PROCON1 and PROCON2 are implemented. PROCON0 is described
below. PROCON1 (at address FF’FF12H) and PROCON2 (at address FF’FF14H) have
the same functionality for the other two flash modules. The logical sector numbering is
depicted in Figure 3-6.
Each bit of the PROCONs is related to a logical sector. If it is cleared the write access to
the corresponding logical sector (this means to the range of physical sectors) is locked
under the conditions that are documented in “Protection Handling Details” on
Page 3-38. The PROCON registers are exclusively modified by the IMB Core.
Reset by Application Reset.
User’s Manual
MemoryX2K, V1.3
3-62
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
IMB_PROCONx (x=0-2)
Protection Configuration.
ISFR (FF FF10H+2*x)
15
14
13
12
11
10
–
–
–
–
–
–
–
–
–
–
–
–
9
8
7
5
4
3
2
1
0
S9U S8U S7U S6U S5U S4U S3U S2U S1U S0U
rh
rh
rh
Field
Bits
Typ Description
SsU (s=0-9)
s
rh
User’s Manual
MemoryX2K, V1.3
6
Reset value: 0000H
rh
rh
rh
rh
rh
rh
rh
Sector 0 to 9 Unlock
s:
Logical sector s of flash module 0 is writeprotected.
3-63
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
3.10.3
Error Reporting Summary
The Table 3-8 summarizes the types of detected errors and the possible reactions.
Table 3-8
IMB Error Reporting
Error
Reaction
Data read from PSRAM with parity error.
If PECON.PEENPS:
HW trap (see Section 6.13).
Instruction fetch from PSRAM with parity
error.
If PECON.PEENPS:
HW trap (see Section 6.13).
Data read from flash memory with single bit Silently corrected. Bit IMB_FSR.DSBER
error.
set.
Data read from flash memory with double
bit error.
Bit IMB_FSR.DDBER set.
If IMB_INTCTR.DDDTRP = 0:
Flash access trap1) and default data is
delivered.
Instruction fetch from flash memory with
single bit error.
Silently corrected. Bit IMB_FSR.ISBER
set.
Instruction fetch from flash memory with
double bit error.
Bit IMB_FSR.IDBER set.
If IMB_INTCTR.DIDTRP = 0:
“TRAP 15D” delivered instead of corrupted
data.
Data read from protected flash memory.
IMB_FSR.PROER set.
If IMB_INTCTR.DPROTRP = 0:
Flash access trap1) and default data is
delivered.
Instruction fetch from protected flash
memory.
“TRAP 15D” delivered.
Program/erase request of write protected
flash range.
Only bit PROER in IMB_FSR set.
Data read or instruction fetch from busy
flash memory.
Read access stalled until end of busy
state.
Instruction fetch from ISFR addresses.
Default data (“TRAP 15D”) delivered.
Data read from not implemented ISFRs.
Default data delivered.
Data writes to not implemented ISFRs.
Silently ignored.
Data read from not implemented address
range.
Unpredictable. Mirrored data from other
memories might be returned or default
values.
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MemoryX2K, V1.3
3-64
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
Table 3-8
IMB Error Reporting (cont’d)
Error
Reaction
Instruction fetch from not implemented
address range.
Unpredictable. Mirrored data from other
memories might be returned or default
values.
Data written to not implemented PSRAM or Bit IMB_INTCTR.PSER set.
Flash access trap1) and no data is
write protected PSRAM address range
(both determined by
changed in the PSRAM.
IMB_IMBCTR.PSPROT).
Program or erase command targeting not
implemented flash memory.
Unpredictable. Access is ignored2) or
mirrored into implemented flash
memory3).
Data read from powered-down flash
modules.
Considered as access to not-implemented
memory range. Default data or data from
implemented flash modules will be
returned.
Instruction fetch from powered-down flash
modules.
Considered as access to not-implemented
memory range. Default data (“TRAP 15D”)
will be returned or data from implemented
flash modules.
Program or erase command targeting
powered-down flash modules.
Silently ignored2).
Shutdown or power-down request received The command interpreter is reset and a
while the command sequence interpreter is “Reset to Read” command sequence is
executed.
waiting for the last words of a command
sequence.
1)
More information about the Flash Access Trap can be found in chapter “SCU”.
2)
Attention: when an access (i.e. MOV) is ignored, the command sequence interpreter will still wait for this
outstanding MOV. So the next command sequence might cause a SQER because it delivers an unexpected
MOV.
3)
The flash protection can not be by-passed by accessing the reserved memory ranges.
3.11
Data Retention Memories
This section describes the usage of the special purpose data memories Stand-By RAM
(SBRAM) and Marker Memory (MKMEM). Depending on the device not all of them are
available. The XC2700 contains:
•
MKMEM.
User’s Manual
MemoryX2K, V1.3
3-65
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4
Central Processing Unit (CPU)
Basic tasks of the Central Processing Unit (CPU) are to fetch and decode instructions,
to supply operands for the Arithmetic and Logic unit (ALU) and the Multiply and
Accumulate unit (MAC), to perform operations on these operands in the ALU and MAC,
and to store the previously calculated results. As the CPU is the main engine of the
XC2700 microcontroller, it is also affected by certain actions of the peripheral
subsystem.
Because a five-stage processing pipeline (plus 2-stage fetch pipeline) is implemented in
the XC2700, up to five instructions can be processed in parallel. Most instructions of the
XC2700 are executed in one single clock cycle due to this parallelism.
This chapter describes how the pipeline works for sequential and branch instructions in
general, and the hardware provisions which have been made to speed up execution of
jump instructions in particular. General instruction timing is described, including standard
timing, as well as exceptions.
While internal memory accesses are normally performed by the CPU itself, external
peripheral or memory accesses are performed by a particular on-chip External Bus
Controller (EBC) which is invoked automatically by the CPU whenever a code or data
address refers to the external address space.
Whenever possible, the CPU continues operating while an external memory access is in
progress. If external data are required but are not yet available, or if a new external
memory access is requested by the CPU before a previous access has been completed,
the CPU will be held by the EBC until the request can be satisfied. The EBC is described
in a separate chapter.
The on-chip peripheral units of the XC2700 work nearly independently of the CPU with
a separate clock generator. Data and control information are interchanged between the
CPU and these peripherals via Special Function Registers (SFRs).
Whenever peripherals need a non-deterministic CPU action, an on-chip Interrupt
Controller compares all pending peripheral service requests against each other and
prioritizes one of them. If the priority of the current CPU operation is lower than the
priority of the selected peripheral request, an interrupt will occur.
There are two basic types of interrupt processing:
•
•
Standard interrupt processing forces the CPU to save the current program status
and return address on the stack before branching to the interrupt vector jump table.
PEC interrupt processing steals only one machine cycle from the current CPU
activity to perform a single data transfer via the on-chip Peripheral Event Controller
(PEC).
System errors detected during program execution (hardware traps) and external nonmaskable interrupts are also processed as standard interrupts with a very high priority.
User’s Manual
CPUSV2_X, V2.2
4-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
In contrast to other on-chip peripherals, there is a closer conjunction between the
watchdog timer and the CPU. If enabled, the watchdog timer expects to be serviced by
the CPU within a programmable period of time, otherwise it will reset the chip. Thus, the
watchdog timer is able to prevent the CPU from going astray when executing erroneous
code. After reset, the watchdog timer starts counting automatically but, it can be disabled
via software, if desired.
In addition to its active operation state, the CPU can enter idle mode by executing the
IDLE instruction. In idle mode the CPU stops program execution but still reacts to
interrupt or PEC requests. Transition to the active state can be forced by an interrupt
request or a reset.
A set of Special Function Registers is dedicated to the CPU core (CSFRs):
•
•
•
•
•
•
•
•
•
•
CPU Status Indication and Control: PSW, CPUCON1, CPUCON2
Code Access Control: IP, CSP
Data Paging Control: DPP0, DPP1, DPP2, DPP3
Global GPRs Access Control: CP
System Stack Access Control: SP, SPSEG, STKUN, STKOV
Multiply and Divide Support: MDL, MDH, MDC
Indirect Addressing Offset: QR0, QR1, QX0, QX1
MAC Address Pointers: IDX0, IDX1
MAC Status Indication and Control: MCW, MSW, MAH, MAL, MRW
ALU Constants Support: ZEROS, ONES
The CPU also uses CSFRs to access the General Purpose Registers (GPRs). Since all
CSFRs can be controlled by any instruction capable of addressing the SFR/CSFR
memory space, there is no need for special system control instructions.
However, to ensure proper processor operation, certain restrictions on the user access
to some CSFRs must be imposed. For example, the instruction pointer (CSP, IP) cannot
be accessed directly at all. These registers can only be changed indirectly via branch
instructions. Registers PSW, SP, and MDC can be modified not only explicitly by the
programmer, but also implicitly by the CPU during normal instruction processing.
Note: Note that any explicit write request (via software) to an CSFR supersedes a
simultaneous modification by hardware of the same register.
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4-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
All CSFRs may be accessed wordwise, or bytewise (some of them even bitwise).
Reading bytes from word CSFRs is a non-critical operation. Any write operation to a
single byte of a CSFR clears the non-addressed complementary byte within the specified
CSFR.
Attention: Reserved CSFR bits must not be modified explicitly, and will always
supply a read value of 0. If a byte/word access is preferred by the
programmer or is the only possible access the reserved CSFR bits
must be written with 0 to provide compatibility with future versions.
User’s Manual
CPUSV2_X, V2.2
4-3
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.1
Components of the CPU
The high performance of the CPU results from the cooperation of several units which are
optimized for their respective tasks (see Figure 4-1). Prefetch Unit and Branch Unit
feed the pipeline minimizing CPU stalls due to instruction reads. The Address Unit
supports sophisticated addressing modes avoiding additional instructions needed
otherwise. Arithmetic and Logic Unit and Multiply and Accumulate Unit handle
differently sized data and execute complex operations. Three memory interfaces and
Write Buffer minimize CPU stalls due to data transfers.
PSRAM
Flash/ROM
PMU
CPU
Prefetch
Unit
CSP
IP
VECSEG
CPUCON1
CPUCON2
Branch
Unit
Return
Stack
FIFO
IDX0
IDX1
QX0
QX1
QR0
QR1
+/-
+/-
Multiply
Unit
MRW
+/-
MCW
MSW
MAH
MAL
2-Stage
Prefetch
Pipeline
TFR
Injection/
Exception
Handler
5-Stage
Pipeline
IFU
DPP0
DPP1
DPP2
DPP3
DPRAM
IPIP
SPSEG
SP
STKOV
STKUN
ADU
Division Unit
Bit-Mask-Gen.
Multiply Unit
Barrel-Shifter
MDC
R15
R15
R14
R15
R14
R14
R15
R14
GPRs
GPRs
GPRs
GPRs
R1
R1
R0
R0R1
R0
R1
R0
RF
PSW
+/-
MDH
MDL
ZEROS
ONES
MAC
CP
Buffer
ALU
WB
DSRAM
EBC
Peripherals
DMU
mca04917_x.vsd
Figure 4-1
CPU Block Diagram
User’s Manual
CPUSV2_X, V2.2
4-4
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Central Processing Unit (CPU)
In general the instructions move through 7 pipeline stages, where each stage processes
its individual task (see Section 4.3 for a summary):
•
•
the 2-stage fetch pipeline prefetches instructions from program memory and stores
them into an instruction FIFO
the 5-stage processing pipeline executes each instruction stored in the instruction
FIFO
Because passing through one pipeline stage takes at least one clock cycle, any isolated
instruction takes at least five clock cycles to be completed. Pipelining, however, allows
parallel (i.e. simultaneous) processing of up to five instructions (with branches up to six
instructions). Therefore, most of the instructions appear to be processed during one
clock cycle as soon as the pipeline has been filled once after reset.
The pipelining increases the average instruction throughput considered over a certain
period of time.
4.2
Instruction Fetch and Program Flow Control
The Instruction Fetch Unit (IFU) prefetches and preprocesses instructions to provide a
continuous instruction flow. The IFU can fetch simultaneously at least two instructions
via a 64-bit wide bus from the Program Management Unit (PMU). The prefetched
instructions are stored in an instruction FIFO.
Preprocessing of branch instructions enables the instruction flow to be predicted. While
the CPU is in the process of executing an instruction fetched from the FIFO, the
prefetcher of the IFU starts to fetch a new instruction at a predicted target address from
the PMU. The latency time of this access is hidden by the execution of the instructions
which have already been buffered in the FIFO. Even for a non-sequential instruction
execution, the IFU can generally provide a continuous instruction flow. The IFU contains
two pipeline stages: the Prefetch Stage and the Fetch Stage.
During the prefetch stage, the Branch Detection and Prediction Logic analyzes up to
three prefetched instructions stored in the first Instruction Buffer (can hold up to six
instructions). If a branch is detected, then the IFU starts to fetch the next instructions
from the PMU according to the prediction rules. After having been analyzed, up to three
instructions are stored in the second Instruction Buffer (can hold up to three instructions)
which is the input register of the Fetch Stage.
In the case of an incorrectly predicted instruction flow, the instruction fetch pipeline is
bypassed to reduce the number of dead cycles.
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24-bit
Address
64-bit
Data
IFU Control
IFU Pipeline
Instruction Buffer (up to 6 Instr.)
CSP
+/-
IP
Branch Detection and Prediction Logic
Prefetch
Stage
Return Stack
CPUCON1
CPUCON2
Control Registers
Instruction
FIFO
Injection and Exception
Handler
VECSEG
TFR
Bypass Fetch to Decode
Branch Folding
Unit
Bypass Prefetch to Decode
Instruction Buffer (up to 3 Instr.)
Fetch
Stage
Instruction Buffer (up to 1 Instr.)
Decode
Stage
MCA05501
Figure 4-2
IFU Block Diagram
On the Fetch Stage, the prefetched instructions are stored in the instruction FIFO. The
Branch Folding Unit (BFU) allows processing of branch instructions in parallel with
preceding instructions. To achieve this the BFU preprocesses and reformats the branch
instruction. First, the BFU defines (calculates) the absolute target address. This address
— after being combined with branch condition and branch attribute bits — is stored in
the same FIFO step as the preceding instruction. The target address is also used to
prefetch the next instructions.
For the Processing Pipeline, both instructions are fetched from the FIFO again and are
executed in parallel. If the instruction flow was predicted incorrectly (or FIFO is empty),
the two stages of the IFU can be bypassed.
Note: Pipeline behavior in case of a incorrectly predicted instruction flow is described in
the following sections.
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4.2.1
Branch Detection and Branch Prediction Rules
The Branch Detection Unit preprocesses instructions and classifies detected branches.
Depending on the branch class, the Branch Prediction Unit predicts the program flow
using the following rules:
Table 4-1
Branch Classes and Prediction Rules
Branch Instruction Classes
Instructions
Prediction Rule (Assumption)
Inter-segment branch
instructions
JMPS seg, caddr
CALLS seg, caddr
The branch is always taken
Branch instructions with
user programmable branch
prediction
JMPA- xcc, caddr
JMPA+ xcc, caddr
CALLA- xcc, caddr
CALLA+ xcc, caddr
User-specified1) via bit 8 (‘a’) of
the instruction long word:
…+: branch ‘taken’ (a = 0)
…-: branch ‘not taken’ (a = 1)
Indirect branch instructions
JMPI cc, [Rw]
CALLI cc, [Rw]
Unconditional: branch ‘taken’
Conditional: ‘not taken’
Relative branch instructions
with condition code
JMPR cc, rel
Unconditional or backward:
branch ‘taken’
Conditional forward: ‘not taken’
Relative branch instructions
without condition code
CALLR rel
The branch is always taken
Branch instructions with bitcondition
JB(C) bitaddr, rel
JNB(S) bitaddr, rel
Backward: branch ‘taken’
Forward: ‘not taken’
Return instructions
RET, RETP
RETS, RETI
The branch is always taken
1) This bit can be also set/cleared automatically by the Assembler for generic JMPA and CALLA instructions
depending on the jump condition (condition is cc_Z: ‘not taken’, otherwise: ‘taken’).
4.2.2
Correctly Predicted Instruction Flow
Table 4-2 shows the continuous execution of instructions, assuming a 0-waitstate
program memory. In this example, most of the instructions are executed in one CPU
cycle while instruction In+6 takes two CPU cycles (general example for multicycle
instructions). The diagram shows the sequential instruction flow through the different
pipeline stages. Figure 4-3 shows the corresponding program memory section.
The instructions for the processing pipeline are fetched from the Instruction FIFO while
the IFU prefetches the next instructions to fill the FIFO. As long as the instruction flow is
correctly predicted by the IFU, both processes are independent.
In this example with a fast Internal Program Memory, the Prefetcher is able to fetch more
instructions than the processing pipeline can execute. In Tn+4, the FIFO and prefetch
buffer are filled and no further instructions can be prefetched. The PMU address stays
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stable (Tn+4) until a whole 64-bit double word can be buffered (Tn+7) in the 96-bit prefetch
buffer again.
Table 4-2
Correctly Predicted Instruction Flow (Sequential Execution)
Tn
Tn+1
Tn+2
Tn+3
Tn+4
Tn+5
Tn+6
Tn+7
Tn+8
Ia+16
Ia+24
Ia+32
Ia+40
Ia+40
Ia+40
Ia+40
Ia+48
Ia+48
PMU Data 64bit Id+1
Id+2
Id+3
Id+4
Id+5
Id+5
Id+5
Id+5
Id+7
PREFETCH
96-bit Buffer
In+6
…
In+9
In+9
…
In+11
In+12
In+13
In+14
In+15
In+15
…
In+19
In+15
…
In+19
In+16
…
In+19
In+17
…
In+19
In+18
…
In+21
FETCH
Instruction
Buffer
In+5
In+6
In+7
In+8
In+9
In+10
In+11
In+12
In+13
In+14
–
In+15
In+16
In+17
FIFO contents
In+3
…
In+5
In+4
…
In+8
In+5
…
In+11
In+6
…
In+13
In+7
…
In+14
In+7
…
In+14
In+8
…
In+15
In+9
…
In+16
In+10
…
In+17
Fetch from FIFO In+4
In+5
In+6
In+7
In+7
In+8
In+9
In+10
In+11
DECODE
In+3
In+4
In+5
In+6
In+6
In+7
In+8
In+9
In+10
ADDRESS
In+2
In+3
In+4
In+5
In+6
In+6
In+7
In+8
In+9
MEMORY
In+1
In+2
In+3
In+4
In+5
In+6
In+6
In+7
In+8
EXECUTE
In
In+1
In+2
In+3
In+4
In+5
In+6
In+6
In+7
WRITE BACK
–
In
In+1
In+2
In+3
In+4
In+5
In+6
In+6
PMU Address
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In+21
In+21
In+20
In+20
In+19
In+18
In+17
In+16
In+16
In+15
In+15
In+14
In+14
In+13
In+12
In+12
In+11
In+11
In+10
In+10
In+9
In+8
In+7
In+6
Ia+40
Ia+32
Ia+24
Ia+16
Ia+8
Ia
MCA04918
Figure 4-3
4.2.3
Program Memory Section for Correctly Predicted Flow
Incorrectly Predicted Instruction Flow
If the CPU detects that the IFU made an incorrect prediction of the instruction flow, then
the pipeline stages and the Instruction FIFO containing the wrong prefetched instructions
are canceled. The entire instruction fetch is restarted at the correct point of the program.
Table 4-3 shows the restarted execution of instructions, assuming a 0-waitstate program
memory. Figure 4-4 shows the corresponding program memory section.
During the cycle Tn, the CPU detects an incorrectly prediction case which leads to a
canceling of the pipeline. The new address is transferred to the PMU in Tn+1 which
delivers the first data in the next cycle Tn+2. But, the target instruction crosses the 64-bit
memory boundary and a second fetch in Tn+3 is required to get the entire 32-bit
instruction. In Tn+4, the Prefetch Buffer contains two 32-bit instructions while the first
instruction Im is directly forwarded to the Decode stage.
The prefetcher is now restarted and prefetches further instructions. In Tn+5, the
instruction Im+1 is forwarded from the Fetch Instruction Buffer directly to the Decode
stage as well. The Fetch row shows all instructions in the Fetch Instruction Buffer and
the instructions fetched from the Instruction FIFO. The instruction Im+3 is the first
instruction fetched from the FIFO during Tn+6. During the same cycle, instruction Im+2 was
still forwarded from the Fetch Instruction Buffer to the Decode stage.
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Table 4-3
Incorrectly Predicted Instruction Flow (Restarted Execution)
Tn
Tn+1
Tn+2
Tn+3
Tn+4
Tn+5
Tn+6
Tn+7
Tn+8
I…
Ia
Ia+8
Ia+16
Ia+24
I…
I…
I…
I…
PMU Data 64bit I…
–
Id
Id+1
Id+2
Id+3
I…
I…
I…
PREFETCH
96-bit Buffer
I…
–
–
–
Im
Im+1
Im+2
Im+3
Im+4
Im+5
I…
I…
FETCH
Instruction
Buffer
Inext+2
–
–
–
–
Im+1
Im+2
Im+3
Im+4
Im+5
I…
Fetch from FIFO –
–
–
–
–
–
Im+3
Im+4
Im+5
DECODE
Inext+1
–
–
–
Im
Im+1
Im+2
Im+3
Im+4
ADDRESS
Inext
–
–
–
–
Im
Im+1
Im+2
Im+3
MEMORY
Ibranch
–
–
–
–
–
Im
Im+1
Im+2
EXECUTE
In
Ibranch
–
–
–
–
–
Im
Im+1
WRITE BACK
–
In
Ibranch
–
–
–
–
–
Im
PMU Address
I...
I...
Im+5
Im+5
Im+4
Im+4
Im+3
Im+3
Im+2
Im+2
Im+1
Im+1
Im
Im
I...
I...
Ia+24
Ia+16
Ia+8
Ia
MCA04919
64-bit wide Program Memory with four 16 bit packages
Figure 4-4
Program Memory Section for Incorrectly Predicted Flow
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4.3
Instruction Processing Pipeline
The XC2700 uses five pipeline stages to execute an instruction. All instructions pass
through each of the five stages of the instruction processing pipeline. The pipeline stages
are listed here together with the 2 stages of the fetch pipeline:
1st -> PREFETCH: This stage prefetches instructions from the PMU in the predicted
order. The instructions are preprocessed in the branch detection unit to detect branches.
The prediction logic decides if the branches are assumed to be taken or not.
2nd -> FETCH: The instruction pointer of the next instruction to be fetched is calculated
according to the branch prediction rules. For zero-cycle branch execution, the Branch
Folding Unit preprocesses and combines detected branches with the preceding
instructions. Prefetched instructions are stored in the instruction FIFO. At the same time,
instructions are transported out of the instruction FIFO to be executed in the instruction
processing pipeline.
3rd -> DECODE: The instructions are decoded and, if required, the register file is
accessed to read the GPR used in indirect addressing modes.
4th -> ADDRESS: All the operand addresses are calculated. Register SP is
decremented or incremented for all instructions which implicitly access the system stack.
5th -> MEMORY: All the required operands are fetched.
6th -> EXECUTE: An ALU or MAC-Unit operation is performed on the previously fetched
operands. The condition flags are updated. All explicit write operations to CPU-SFRs
and all auto-increment/auto-decrement operations of GPRs used as indirect address
pointers are performed.
7th -> WRITE BACK: All external operands and the remaining operands within the
internal DPRAM space are written back. Operands located in the internal SRAM are
buffered in the Write Back Buffer.
Specific so-called injected instructions are generated internally to provide the time
needed to process instructions requiring more than one CPU cycle for processing. They
are automatically injected into the decode stage of the pipeline, then they pass through
the remaining stages like every standard instruction. Program interrupt, PEC transfer,
and OCE operations are also performed by means of injected instructions. Although
these internally injected instructions will not be noticed in reality, they help to explain the
operation of the pipeline.
The performance of the CPU (pipeline) is decreased by bandwidth limitations (same
resource is accessed by different stages) and data dependencies between instructions.
The XC2700’s CPU has dedicated hardware to detect and to resolve different kinds of
dependencies. Some of those dependencies are described in the following section.
Because up to five different instructions are processed simultaneously, additional
hardware has been dedicated to deal with dependencies which may exist between
instructions in different pipeline stages. This extra hardware supports ‘forwarding’ of the
operand read and write values and resolves most of the possible conflicts — such as
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multiple usage of buses — in a time optimized way without performance loss. This
makes the pipeline unnoticeable for the user in most cases. However, there are some
rare cases in which the pipeline requires attention by the programmer. In these cases,
the delays caused by the pipeline conflicts can be used for other instructions to optimize
performance.
Note: The XC2700 has a fully interlocked pipeline, which means that these conflicts do
not cause any malfunction. Instruction re-ordering is only required for performance
reasons.
The following examples describe the pipeline behavior in special cases and give
principle rules to improve the performance by re-ordering the execution of instructions.
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4.3.1
Pipeline Conflicts Using General Purpose Registers
The GPRs are the working registers of the CPU and there are a lot of possible
dependencies between instructions using GPRs. A high-speed five-port register file
prevents bandwidth conflicts. Dedicated hardware is implemented to detect and resolve
the data dependencies. Special forwarding busses are used to forward GPR values from
one pipeline stage to another. In most cases, this allows the execution of instructions
without any delay despite of data dependencies.
Conflict_GPRs_Resolved:
In
ADD R0,R1
;Compute new value for R0
In+1 ADD R3,R0
;Use R0 again
In+2 ADD R6,R0
;Use R0 again
In+3 ADD R6,R1
;Use R6 again
In+4 ...
Table 4-4
Resolved Pipeline Dependencies Using GPRs
Tn+2
Tn+31)
Tn+42)
Stage
Tn
Tn+1
DECODE
In = ADD
R0, R1
In+1 = ADD In+2 = ADD In+3 = ADD In+4
R3, R0
R6, R0
R6, R1
Tn+53)
In+5
ADDRESS In-1
In = ADD
R0, R1
In+1 = ADD In+2 = ADD In+3 = ADD In+4
R3, R0
R6, R0
R6, R1
MEMORY
In-2
In-1
In = ADD
R0, R1
In+1 = ADD In+2 = ADD In+3 = ADD
R3, R0
R6, R0
R6, R1
EXECUTE
In-3
In-2
In-1
In = ADD
R0, R1
In+1 = ADD In+2 = ADD
R3, R0
R6, R0
WR.BACK In-4
In-3
In-2
In-1
In = ADD
R0, R1
In+1 = ADD
R3, R0
1) R0 forwarded from EXECUTE to MEMORY.
2) R0 forwarded from WRITE BACK to MEMORY.
3) R6 forwarded from EXECUTE to MEMORY.
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However, if a GPR is used for indirect addressing the address pointer (i.e. the GPR) will
be required already in the DECODE stage. In this case the instruction is stalled in the
address stage until the operation in the ALU is executed and the result is forwarded to
the address stage.
Conflict_GPRs_Pointer_Stall:
In
ADD R0,R1
;Compute new value for R0
In+1 MOV R3,[R0]
;Use R0 as address pointer
In+2 ADD R6,R0
In+3 ADD R6,R1
In+4 ...
Table 4-5
Pipeline Dependencies Using GPRs as Pointers (Stall)
Tn+21)
Stage
Tn
Tn+1
DECODE
In = ADD
R0, R1
In+1 = MOV In+2
R3, [R0]
Tn+32)
Tn+4
Tn+5
In+2
In+2
In+3
ADDRESS In-1
In = ADD
R0, R1
In+1 = MOV In+1 = MOV In+1 = MOV In+2
R3, [R0]
R3, [R0]
R3, [R0]
MEMORY
In-2
In-1
In = ADD
R0, R1
–
–
In+1 = MOV
R3, [R0]
EXECUTE
In-3
In-2
In-1
In = ADD
R0, R1
–
–
WR.BACK In-4
In-3
In-2
In-1
In = ADD
R0, R1
–
1) New value of R0 not yet available.
2) R0 forwarded from EXECUTE to ADDRESS (next cycle).
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To avoid these stalls, one multicycle instruction or two single cycle instructions may be
inserted. These instructions must not update the GPR used for indirect addressing.
Conflict_GPRs_Pointer_NoStall:
In
ADD R0,R1
;Compute new value for R0
;R0 is not updated, just read
In+1 ADD R6,R0
In+2 ADD R6,R1
In+3 MOV R3,[R0]
;Use R0 as address pointer
In+4 ...
Table 4-6
Pipeline Dependencies Using GPRs as Pointers (No Stall)
Tn+2
Tn+31)
Stage
Tn
Tn+1
Tn+4
DECODE
In = ADD
R0, R1
In+1 = ADD In+2 = ADD In+3 = MOV In+4
R6, R0
R6, R1
R3, [R0]
Tn+5
In+5
ADDRESS In-1
In = ADD
R0, R1
In+1 = ADD In+2 = ADD In+3 = MOV In+4
R6, R0
R6, R1
R3, [R0]
MEMORY
In-2
In-1
In = ADD
R0, R1
In+1 = ADD In+2 = ADD In+3 = MOV
R6, R0
R6, R1
R3, [R0]
EXECUTE
In-3
In-2
In-1
In = ADD
R0, R1
In+1 = ADD In+2 = ADD
R6, R0
R6, R1
WR.BACK In-4
In-3
In-2
In-1
In = ADD
R0, R1
In+1 = ADD
R6, R0
1) R0 forwarded from EXECUTE to ADDRESS (next cycle).
4.3.2
Pipeline Conflicts Using Indirect Addressing Modes
In the case of read accesses using indirect addressing modes, the Address Generation
Unit uses a speculative addressing mechanism. The read data path to one of the
different memory areas (DPRAM, DSRAM, etc.) is selected according to a history table
before the address is decoded. This history table has one entry for each of the GPRs.
The entries store the information of the last accessed memory area using the
corresponding GPR. In the case of an incorrect prediction of the memory area, the read
access must be restarted.
It is recommended that the GPRs used for indirect addressing always point to the same
memory area. If an updated GPR points to a different memory area, the next read
operation will access the wrong memory area. The read access must be repeated, which
leads to pipeline stalls.
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Conflict_GPRs_Pointer_WrongHistory:
In
ADD R3,[R0]
;R0 points to DPRAM (e.g.)
In+1 MOV R0,R4
...
Ii
MOV DPPX, ...
;change DPPx
...
Im
ADD R6,[R0]
;R0 now points to SRAM (e.g.)
Im+1 MOV R6,R1
Im+2 ...
Table 4-7
Pipeline Dependencies with Pointers (Valid Speculation)
Stage
Tn
Tn+1
Tn+2
DECODE
In = ADD
R3, [R0]
In+1 = MOV In+2
R0, R4
Tn+3
Tn+4
Tn+5
In+3
In+4
In+5
In+3
In+4
In+3
ADDRESS In-1
In = ADD
R3, [R0]
In+1 = MOV In+2
R0, R4
MEMORY
In-2
In-1
In = ADD
R3, [R0]
In+1 = MOV In+2
R0, R4
EXECUTE
In-3
In-2
In-1
In = ADD
R3, [R0]
In+1 = MOV In+2
R0, R4
WR.BACK In-4
In-3
In-2
In-1
In = ADD
R3, [R0]
Table 4-8
In+1 = MOV
R0, R4
Pipeline Dependencies with Pointers (Invalid Speculation)
Tm+21)
Stage
Tm
DECODE
Im = ADD Im+1 = MOV Im+1 = MOV Im+2
R6, [R0] R6, R1
R6, R1
Tm+1
Tm+3
Tm+4
Tm+5
Im+3
Im+4
Im+3
ADDRESS Im-1
Im = ADD
R6, [R0]
Im = ADD
R6, [R0]
Im+1 = MOV Im+2
R6, R1
MEMORY
Im-2
Im-1
–
Im = ADD
R6, [R0]
Im+1 = MOV Im+2
R6, R1
EXECUTE
Im-3
Im-2
Im-1
–
Im = ADD
R6, [R0]
Im+1 = MOV
R6, R1
WR.BACK Im-4
Im-3
Im-2
Im-1
–
Im = ADD
R6, [R0]
1) Access to location [R0] must be repeated due to wrong history (target area was changed).
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4.3.3
Pipeline Conflicts Due to Memory Bandwidth
Memory bandwidth conflicts can occur if instructions in the pipeline access the same
memory area at the same time. Special access mechanisms are implemented to
minimize conflicts. The DPRAM of the CPU has two independent read/write ports; this
allows parallel read and write operation without delays. Write accesses to the DSRAM
can be buffered in a Write Back Buffer until read accesses are finished.
All instructions except the CoXXX instructions can read only one memory operand per
cycle. A conflict between the read and one write access cannot occur because the
DPRAM has two independent read/write ports. Only other pipeline stall conditions can
generate a DPRAM bandwidth conflict. The DPRAM is a synchronous pipelined
memory. The read access starts with the valid addresses on the address stage. The data
are delivered in the Memory stage. If a memory read access is stalled in the Memory
stage and the following instruction on the Address stage tries to start a memory read, the
new read access must be delayed as well. But, this conflict is hidden by an already
existing stall of the pipeline.
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Central Processing Unit (CPU)
The CoXXX instructions are the only instructions able to read two memory operands per
cycle. A conflict between the two read and one pending write access can occur if all three
operands are located in the DPRAM area. This is especially important for performance
in the case of executing a filter routine. One of the operands should be located in the
DSRAM to guarantee a single-cycle execution of the CoXXX instructions.
Conflict_DPRAM_Bandwidth:
In
ADD op1,R1
In+1 ADD R6,R0
In+2 CoMAC [IDX0],[R0]
In+3 MOV R3,[R0]
In+4 ...
Table 4-9
Pipeline Dependencies in Case of Memory Conflicts (DPRAM)
Tn+2
Tn+3
Tn+41)
Stage
Tn
Tn+1
DECODE
In = ADD
op1, R1
In+1 = ADD In+2 =
In+3 = MOV In+4
R6, R0
CoMAC … R3, [R0]
Tn+5
In+4
ADDRESS In-1
In = ADD
op1, R1
In+1 = ADD In+2 =
In+3 = MOV In+3 = MOV
R6, R0
CoMAC … R3, [R0]
R3, [R0]
MEMORY
In-2
In-1
In = ADD
op1, R1
In+1 = ADD In+2 =
In+2 =
R6, R0
CoMAC … CoMAC …
EXECUTE
In-3
In-2
In-1
In = ADD
op1, R1
In+1 = ADD –
R6, R0
WR.BACK In-4
In-3
In-2
In-1
In = ADD
op1, R1
In+1 = ADD
R6, R0
1) COMAC instruction stalls due to memory bandwidth conflict.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
The DSRAM is a single-port memory with one read/write port. To reduce the number of
bandwidth conflict cases, a Write Back Buffer is implemented. It has three data entries.
Only if the buffer is filled and a read access and a write access occur at the same time,
must the read access be stalled while one of the buffer entries is written back.
Conflict_DSRAM_Bandwidth:
In
ADD op1,R1
In+1 ADD R6,R0
In+2 ADD R6,op2
In+3 MOV R3,R2
In+4 ...
Table 4-10
Pipeline Dependencies in Case of Memory Conflicts (DSRAM)
Tn+41)
Stage
Tn
Tn+1
DECODE
In = ADD
op1, R1
In+1 = ADD In+2 = ADD In+3 = MOV In+4
R6, R0
R6, op2
R3, R2
Tn+2
Tn+3
Tn+5
In+4
ADDRESS In-1
In = ADD
op1, R1
In+1 = ADD In+2 = ADD In+3 = MOV In+3 = MOV
R6, R0
R6, op2
R3, R2
R3, R2
MEMORY
In-2
In-1
In = ADD
op1, R1
In+1 = ADD In+2 = ADD In+2 = ADD
R6, R0
R6, op2
R6, op2
EXECUTE
In-3
In-2
In-1
In = ADD
op1, R1
In+1 = ADD –
R6, R0
WR.BACK In-4
In-3
In-2
In-1
In = ADD
op1, R1
In+1 = ADD
R6, R0
WB.Buffer full
full
full
full
full
full
1) ADD R6, op2 instruction stalls due to memory bandwidth conflict.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.3.4
Pipeline Conflicts Caused by CPU-SFR Updates
CPU-SFRs control the CPU functionality and behavior. Changes and updates of CSFRs
influence the instruction flow in the pipeline. Therefore, special care is required to ensure
that instructions in the pipeline always work with the correct CSFR values. CSFRs are
updated late on the EXECUTE stage of the pipeline. Meanwhile, without conflict
detection, the instructions in the DECODE, ADDRESS, and MEMORY stages would still
work without updated register values. The CPU detects conflict cases and stalls the
pipeline to guarantee a correct execution. For performance reasons, the CPU
differentiates between different classes of CPU-SFRs. The flow of instructions through
the pipeline can be improved by following the given rules used for instruction re-ordering.
There are three classes of CPU-SFRs:
•
•
•
CSFRs not generating pipeline conflicts (ONES, ZEROS, MCW)
CSFR result registers updated late in the EXECUTE stage, causing one stall cycle
CSFRs affecting the whole CPU or the pipeline, causing canceling
CSFR Result Registers
The CSFR result registers MDH, MDL, MSW, MAH, MAL, and MRW of the ALU and
MAC-Unit are updated late in the EXECUTE stage of the pipeline. If an instruction
(except CoSTORE) accesses explicitly these registers in the memory stage, the value
cannot be forwarded. The instruction must be stalled for one cycle on the MEMORY
stage.
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Central Processing Unit (CPU)
Conflict_CSFR_Update_Stall:
In
MUL R0,R1
In+1 MOV R6,MDL
In+2 ADD R6,R1
In+3 MOV R3,[R0]
In+4 ...
Table 4-11
Pipeline Dependencies with Result CSFRs (Stall)
Tn+2
Tn+31)
Stage
Tn
Tn+1
Tn+4
Tn+5
DECODE
In = MUL
R0, R1
In+1 = MOV In+2 = ADD In+3 = MOV In+3 = MOV In+4
R6, MDL
R6, R1
R3, [R0]
R3, [R0]
ADDRESS In-1
In = MUL
R0, R1
In+1 = MOV In+2 = ADD In+2 = ADD In+3 = MOV
R6, MDL
R6, R1
R6, R1
R3, [R0]
MEMORY
In-2
In-1
In = MUL
R0, R1
In+1 = MOV In+1 = MOV In+2 = ADD
R6, MDL
R6, MDL
R6, R1
EXECUTE In-3
In-2
In-1
In = MUL
R0, R1
–
In+1 = MOV
R6, MDL
WR.BACK In-4
In-3
In-2
In-1
In = MUL
R0, R1
–
1) Cannot read MDL here.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
By reordering instructions, the bubble in the pipeline can be filled with an instruction not
using this resource.
Conflict_CSFR_Update_Resolved:
In
MUL R0,R1
In+1 MOV R3,[R0]
In+2 MOV R6,MDL
In+3 ADD R6,R1
In+4 ...
Table 4-12
Pipeline Dependencies with Result CSFRs (No Stall)
Tn+2
Tn+3
Tn+41)
Stage
Tn
Tn+1
DECODE
In = MUL
R0, R1
In+1 = MOV In+2 = MOV In+3 = ADD In+4
R3, [R0]
R6, MDL
R6, R1
Tn+5
In+5
ADDRESS In-1
In = MUL
R0, R1
In+1 = MOV In+2 = MOV In+3 = ADD In+4
R3, [R0]
R6, MDL
R6, R1
MEMORY
In-2
In-1
In = MUL
R0, R1
In+1 = MOV In+2 = MOV In+3 = ADD
R3, [R0]
R6, MDL
R6, R1
EXECUTE In-3
In-2
In-1
In = MUL
R0, R1
In+1 = MOV In+2 = MOV
R3, [R0]
R6, MDL
WR.BACK In-4
In-3
In-2
In-1
In = MUL
R0, R1
In+1 = MOV
R3, [R0]
1) MDL can be read now, no stall cycle necessary.
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Central Processing Unit (CPU)
CSFRs Affecting the Whole CPU
Some CSFRs affect the whole CPU or the pipeline before the Memory stage. The CPUSFRs CPUCON1, CP, SP, STKUN, STKOV, VECSEG, TFR, and PSW affect the overall
CPU function, while the CPU-SFRs IDX0, IDX1, QX1, QX0, DPP0, DPP1, DPP2, and
DPP3 only affect the DECODE, ADDRESS, and MEMORY stage when they are
modified explicitly. In this case the pipeline behavior depends on the instruction and
addressing mode used to modify the CSFR.
In the case of modification of these CSFRs by “POP CSFR” or by instructions using the
reg,#data16 addressing mode, a special mechanism is implemented to improve
performance during the initialization.
For further explanation, the instruction which modifies the CSFR can be called
“instruction_modify_CSFR”. This special case is detected in the DECODE stage when
the instruction_modify_CSFR enters the processing pipeline. Further on, instructions
described in the following list are held in the DECODE stage (all other instructions are
not held):
•
•
•
•
Instructions using long addressing mode (mem)
Instructions using indirect addressing modes ([Rw], [Rw+]…), except JMPI and CALLI
ENWDT, DISWDT, EINIT
All CoXXX instructions
If the CPUCON1, CP, SP, STKUN, STKOV, VECSEG, TFR, or the PSW are modified
and the instruction_modify_CSFR reaches the EXECUTE stage, the pipeline is
canceled. The modification affects the entire pipeline and the instruction prefetch. A
clean cancel and restart mechanism is required to guarantee a correct instruction flow.
In case of modification of IDX0, IDX1, QX1, QX0, DPP0, DPP1, DPP2, or DPP3 only the
DECODE, ADDRESS, and MEMORY stages are affected and the pipeline needs not to
be canceled. The modification does not affect the instructions in the ADDRESS,
MEMORY stage because they are not using this resource. Other kinds of instructions are
held in the DECODE stage until the CSFR is modified.
The following example shows a case in which the pipeline is stalled. The instruction
“MOV R6, R1” after the “MOV IDX1, #12” instruction which modifies the CSFR will be
held in DECODE Stage until the IDX1 register is updated. The next example shows an
optimized initialization routine.
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Central Processing Unit (CPU)
Conflict_Canceling:
In
MOV IDX1,#12
In+1 MOV R6,mem
In+2 ADD R6,R1
In+3 MOV R3,[R0]
Table 4-13
Pipeline Dependencies with Control CSFRs (Canceling)
Stage
Tn
Tn+1
Tn+2
Tn+3
Tn+4
Tn+5
DECODE
In = MOV
IDX1, #12
In+1 = MOV In+1 = MOV In+1 = MOV In+1 = MOV In+2 = ADD
R6, mem R6, mem R6, mem R6, mem R6, R1
ADDRESS In-1
In = MOV
IDX1, #12
–
–
–
In+1 = MOV
R6, mem
MEMORY
In-2
In-1
In = MOV
IDX1, #12
–
–
–
EXECUTE In-3
In-2
In-1
In = MOV
IDX1, #12
–
–
WR.BACK In-4
In-3
In-2
In-1
In = MOV
IDX1, #12
–
Conflict_Canceling_Optimized:
In
MOV IDX1,#12
In+1 MOV MAH,#23
In+2 MOV MAL,#25
In+3 MOV R3,#08
In+4 ...
Table 4-14
Pipeline Dependencies with Control CSFRs (Optimized)
Stage
Tn
Tn+1
DECODE
In = MOV
IDX1, #12
In+1 = MOV In+2 = MOV In+3 = MOV In+4
MAH, #23 MAL, #25 R3, #08
Tn+2
Tn+3
Tn+4
Tn+5
In+5
ADDRESS In-1
In = MOV
IDX1, #12
In+1 = MOV In+2 = MOV In+3 = MOV In+4
MAH, #23 MAL, #25 R3, #08
MEMORY
In-2
In-1
In = MOV
IDX1, #12
In+1 = MOV In+2 = MOV In+3 = MOV
MAH, #23 MAL, #25 R3, #08
EXECUTE In-3
In-2
In-1
In = MOV
IDX1, #12
In+1 = MOV In+2 = MOV
MAH, #23 MAL, #25
WR.BACK In-4
In-3
In-2
In-1
In = MOV
IDX1, #12
User’s Manual
CPUSV2_X, V2.2
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In+1 = MOV
MAH, #23
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XC2700 Derivatives
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Central Processing Unit (CPU)
For all the other instructions that modify this kind of CSFR, a simple stall and cancel
mechanism guarantees the correct instruction flow.
A possible explicit write-operation to this kind of CSFRs is detected on the MEMORY
stage of the pipeline. The following instructions on the ADDRESS and DECODE Stage
are stalled. If the instruction reaches the EXECUTE stage, the entire pipeline and the
Instruction FIFO of the IFU are canceled. The instruction flow is completely re-started.
Conflict_Canceling_Completely:
In
MOV PSW,R4
In+1 MOV R6,R1
In+2 ADD R6,R1
In+3 MOV R3,[R0]
In+4 ...
Table 4-15
Pipeline Dependencies with Control CSFRs (Cancel All)
Stage
Tn+1
DECODE
In+1 = MOV In+2 = ADD In+2 = ADD –
R6, R1
R6, R1
R6, R1
Tn+2
Tn+3
Tn+4
Tn+5
Tn+6
–
In+1 = MOV
R6, R1
ADDRESS In = MOV
PSW, R4
In+1 = MOV In+1 = MOV –
R6, R1
R6, R1
–
–
MEMORY
In = MOV
PSW, R4
–
–
–
–
EXECUTE In-2
In-1
In = MOV
PSW, R4
–
–
–
WR.BACK In-3
In-2
In-1
In = MOV
PSW, R4
–
–
In-1
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Central Processing Unit (CPU)
4.4
CPU Configuration Registers
The CPU configuration registers select a number of general features and behaviors of
the XC2700’s CPU core. In general, these registers must not be modified by application
software (exceptions will be documented, e.g. in an errata sheet).
Note: The CPU configuration registers are protected by the register security mechanism
after the EINIT instruction has been executed.
CPUCON1
CPU Control Register 1
SFR (FE18H/0CH)
Reset Value: 0007H
15
14
13
12
11
10
9
8
7
6
5
-
-
-
-
-
-
-
-
-
VECSC
-
-
-
-
-
-
-
-
-
rw
4
3
2
1
WDT SGT INTS
BP
CTL DIS CXT
rw
rw
rw
rw
0
ZCJ
Field
Bits
Type
Description
VECSC
[6:5]
rw
Scaling Factor of Vector Table
00
Space between two vectors is 2 words1)
01
Space between two vectors is 4 words
10
Space between two vectors is 8 words
11
Space between two vectors is 16 words
WDTCTL
4
rw
Configuration of Watchdog Timer
0
DISWDT executable only until End Of Init2)
1
DISWDT/ENWDT always executable
(enhanced WDT mode)
SGTDIS
3
rw
Segmentation Disable/Enable Control
0
Segmentation enabled
1
Segmentation disabled
INTSCXT
2
rw
Enable Interruptibility of Switch Context
0
Switch context is not interruptible
1
Switch context is interruptible
BP
1
rw
Enable Branch Prediction Unit
0
Branch prediction disabled
1
Branch prediction enabled
ZCJ
0
rw
Enable Zero Cycle Jump Function
0
Zero cycle jump function disabled
1
Zero cycle jump function enabled
rw
1) The default value (2 words) is compatible with the vector distance defined in the C166 Family architecture.
2) The DISWDT (executed after EINIT) and ENWDT instructions are internally converted in a NOP instruction.
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Central Processing Unit (CPU)
CPUCON2
CPU Control Register 2
15
14
13
12
SFR (FE1AH/0DH)
11
10
FIFODEPTH
FIFOFED
rw
rw
8
7
6
5
4
3
BYP BYP EIO STE
OV RET
LFIC
PF
F IAEN N
RUN ST
rw
rw
rw
rw
rw
rw
rw
2
-
1
0
DAID SL
rw
rw
Field
Bits
FIFODEPTH
[15:12] rw
FIFO Depth Configuration
0000 No FIFO (entries)
0001 One FIFO entry
…
…
1000 Eight FIFO entries
1001 reserved
…
…
1111 reserved
FIFOFED
[11:10] rw
FIFO Fed Configuration
00
FIFO disabled
01
FIFO filled with up to one instruction per cycle
10
FIFO filled with up to two instructions per cycle
11
FIFO filled with up to three instruction per cycle
BYPPF
9
rw
Prefetch Bypass Control
0
Bypass path from prefetch to decode disabled
1
Bypass path from prefetch to decode available
BYPF
8
rw
Fetch Bypass Control
0
Bypass path from fetch to decode disabled
1
Bypass path from fetch to decode available
EIOIAEN
7
rw
Early IO Injection Acknowledge Enable
0
Injection acknowledge by destructive read not
guaranteed
1
Injection acknowledge by destructive read
guaranteed
STEN
6
rw
Stall Instruction Enable (for debug purposes)
0
Stall Instruction disabled
1
Stall Instruction enabled (see example below)
LFIC
5
rw
Linear Follower Instruction Cache
0
Linear Follower Instruction Cache disabled
1
Linear Follower Instruction Cache enabled
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Type
9
Reset Value: 8FBBH
Description
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Central Processing Unit (CPU)
Field
Bits
Type
Description
OVRUN
4
rw
Pipeline Control
0
Overrun of pipeline bubbles not allowed
1
Overrun of pipeline bubbles allowed
RETST
3
rw
Enable Return Stack
0
Return Stack is disabled
1
Return Stack is enabled
DAID
1
rw
Disable Atomic Injection Deny
0
Injection-requests are denied during Atomic
1
Injection-requests are not denied during
Atomic
SL
0
rw
Enables Short Loop Mode
0
Short loop mode disabled
1
Short loop mode enabled
Example for dedicated stall debug instructions:
STALLAM da,ha,dm,hm
STALLEW de,he,dw,hw
;Opcode: 44 dahadmhm
;Opcode: 45 dehedwhw
;Stalls the corresponding pipeline
;stage after “d” cycles for “h” cycles
;(“d” and “h” are 6-bit values)
Note: In general, these registers must not be modified by application software
(exceptions will be documented, e.g. in an errata sheet).
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Central Processing Unit (CPU)
4.5
Use of General Purpose Registers
The CPU uses several banks of sixteen dedicated registers R0, R1, R2, … R15, called
General Purpose Registers (GPRs), which can be accessed in one CPU cycle. The
GPRs are the working registers of the arithmetic and logic units and many also serve as
address pointers for indirect addressing modes.
The register banks are accessed via the 5-port register file providing the high access
speed required for the CPU’s performance. The register file is split into three
independent physical register banks. There are two types of register banks:
•
•
Two local register banks which are a part of the register file
A global register bank which is memory-mapped and cached in the register file
Core-RAM
Registerfile
Global
Local
AGU Write Port
ALU Write Port
Memory
mapped
GPR Bank
R15
R0
CP
R15
R15
R15
R14
R14
R13
R13
R12
R12
R11
R11
R10
R10
R9
R9
R8
R8
R7
R7
R6
R6
R5
R5
R4
R4
R3
R3
R2
R2
R1
R1
R0
R0
AGU Read Port
ALU Read Port 1
ALU Read Port 2
MCD04873
Figure 4-5
Register File
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Central Processing Unit (CPU)
Bitfield BANK in register PSW selects which of the three physical register banks is
activated. The selected bank can be changed explicitly by any instruction which writes
to the PSW, or implicitly by a RETI instruction, an interrupt or hardware trap. In case of
an interrupt, the selection of the register bank is configured via registers BNKSELx in the
Interrupt Controller ITC. Hardware traps always use the global register bank.
The local register banks are built of dedicated physical registers, while the global register
bank represents a cache. The banks of the memory-mapped GPRs (global bank) are
located in the internal DPRAM. One bank uses a block of 16 consecutive words. A
Context Pointer (CP) register determines the base address of the current selected bank.
To provide the required access speed, the GPRs located in the DPRAM are cached in
the 5-port register file (only one memory-mapped GPR bank can be cached at the time).
If the global register bank is activated, the cache will be validated before further
instructions are executed. After validation, all further accesses to the GPRs are
redirected to the global register bank.
Internal DPRAM
R15
(CP) + 30
R14
(CP) + 28
Register File
R13
R12
R11
15
0
16-Bit Context Pointer
R10
R15
R9
R8
R7
R0
R6
R5
R4
Global
R3
local
R2
R1
(CP) + 2
R0
(CP)
MCA04921
Figure 4-6
Register Bank Selection via Register CP
User’s Manual
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Central Processing Unit (CPU)
4.5.1
GPR Addressing Modes
Because the GPRs are the working registers and are accessed frequently, there are
three possible ways to access a register bank:
•
•
•
Short GPR Address (mnemonic: Rw or Rb)
Short Register Address (mnemonic: reg or bitoff)
Long Memory Address (mnemonic: mem), for the global bank only
Short GPR Addresses specify the register offset within the current register bank
(selected via bitfield BANK). Short 4-bit GPR addresses can access all sixteen registers,
short 2-bit addresses (used by some instructions) can access the lower four registers.
Depending on whether a relative word (Rw) or byte (Rb) GPR address is specified, the
short GPR address is either multiplied by two (Rw) or not (Rb) before it is used to
physically access the register bank. Thus, both byte and word GPR accesses are
possible in this way.
Note: GPRs used as indirect address pointers are always accessed wordwise.
For the local register banks the resulting offset is used directly, for the global register
bank the resulting offset is logically added to the contents of register CP which points to
the memory location of the base of the current global register bank (see Figure 4-7).
Short 8-Bit Register Addresses within a range from F0H to FFH interpret the four least
significant bits as short 4-bit GPR addresses, while the four most significant bits are
ignored. The respective physical GPR address is calculated in the same way as for short
4-bit GPR addresses. For single bit GPR accesses, the GPR’s word address is
calculated in the same way. The accessed bit position within the word is specified by a
separate additional 4-bit value.
11
12-Bit Context Pointer
1 0
Specified by reg or bitoff
1 1 1 1
For byte
GPR
accesses
4-Bit GPR
Address
*1
*2
For word GPR
accesses
Internal
DRAM
Must be
within
the internal
DPRAM area
+
GPRs
MCA04922
Figure 4-7
Implicit CP Use by Logical Short GPR Addressing Modes
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Central Processing Unit (CPU)
24-Bit Memory Addresses can be directly used to access GPRs located in the DPRAM
(not applicable for local register banks). In case of a memory read access, a hit detection
logic checks if the accessed memory location is cached in the global register bank. In
case of a cache hit, an additional global register bank read access is initiated. The data
that is read from cache will be used and the data that is read from memory will be
discarded. This leads to a delay of one CPU cycle (MOV R4, mem
[CP ≤ mem ≤ CP + 31]). In case of a memory write access, the hit detection logic
determines a cache hit in advance. Nevertheless, the address conversion needs one
additional CPU cycle. The value is directly written into the global register bank without
further delay (MOV mem, R4).
Note: The 24-bit GPR addressing mode is not recommended because it requires an
extra cycle for the read and write access.
Table 4-16
Addressing Modes to Access GPRs
Word Registers1)
Short Address2)
Byte Registers
Name
Mem. Addr.3)
Name
Mem. Addr.3)
8-Bit
4-Bit
2-Bit
R0
(CP) + 0
RL0
(CP) + 0
F0H
0H
0H
R1
(CP) + 2
RH0
(CP) + 1
F1H
1H
1H
R2
(CP) + 4
RL1
(CP) + 2
F2H
2H
2H
R3
(CP) + 6
RH1
(CP) + 3
F3H
3H
3H
R4
(CP) + 8
RL2
(CP) + 4
F4H
4H
---
R5
(CP) + 10
RH2
(CP) + 5
F5H
5H
---
R6
(CP) + 12
RL3
(CP) + 6
F6H
6H
---
R7
(CP) + 14
RH3
(CP) + 7
F7H
7H
---
R8
(CP) + 16
RL4
(CP) + 8
F8H
8H
---
R9
(CP) + 18
RH4
(CP) + 9
F9H
9H
---
R10
(CP) + 20
RL5
(CP) + 10
FAH
AH
---
R11
(CP) + 22
RH5
(CP) + 11
FBH
BH
---
R12
(CP) + 24
RL6
(CP) + 12
FCH
CH
---
R13
(CP) + 26
RH6
(CP) + 13
FDH
DH
---
R14
(CP) + 28
RL7
(CP) + 14
FEH
EH
---
R15
(CP) + 30
RH7
(CP) + 15
FFH
FH
---
1) The first 8 GPRs (R7 … R0) may also be accessed bytewise. Writing to a GPR byte does not affect the other
byte of the respective GPR.
2) Short addressing modes are usable for all register banks.
3) Long addressing mode only usable for the memory mapped global GPR bank.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.5.2
Context Switching
When a task scheduler of an operating system activates a new task or an interrupt
service routine is called or terminated, the working context (i.e. the registers) of the left
task must be saved and the working context of the new task must be restored. The CPU
context can be changed in two ways:
•
•
Switching the selected register bank
Switching the context of the global register
Switching the Selected Physical Register Bank
By updating bitfield BANK in register PSW the active register bank is switched
immediately. It is possible to switch between the current memory-mapped GPR bank
cached in the global register bank (BANK = 00B), local register bank 1 (BANK = 10B),
and local register bank 2 (BANK = 11B).
In case of an interrupt service, the bank switch can be automatically executed by
updating bitfield BANK from registers BNKSELx in the interrupt controller. By executing
a RETI instruction, bitfield BANK will automatically be restored and the context will
switched to the original register bank.
The switch between the three physical register banks of the register file can also be
executed by writing to bitfield BANK. Because of pipeline dependencies an explicit
change of register PSW must cancel the pipeline.
Global Bank
Local Bank
Global Bank
Execution Task A
Execution Task B
ExecutionTask A
Interrupt of
Task B
recognized
Execution of
RETI
MCA04877
Figure 4-8
Context Switch by Changing the Physical Register Bank
After a switch to a local register bank, the new bank is immediately available. After
switching to the global register bank, the cached memory-mapped GPRs must be valid
before any further instructions can be executed. If the global register bank is not valid at
this time (in case if the context switch process has been interrupted), the cache
validation process is repeated automatically.
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Central Processing Unit (CPU)
Switching the Context of the Global Register Bank
The contents of the global register bank are switched by changing the base address of
the memory-mapped GPR bank. The base address is given by the contents of the
Context Pointer (CP).
After the CP has been updated, a state machine starts to store the old contents of the
global register bank and to load the new one. The store and load algorithm is executed
in nineteen CPU cycles: the execution of the cache validation process takes sixteen
cycles plus three cycles to stall an instruction execution to avoid pipeline conflicts upon
the completion of the validation process. The context switch process has two phases:
•
•
Store phase: The contents of the global register bank1) is stored back into the
DPRAM by executing eight injected STORE instructions. After the last STORE
instruction the contents of the global register bank are invalidated.
Load phase: The global register bank is loaded with the new context by executing
eight injected LOAD instructions. After the last LOAD instruction the contents of the
global register bank are validated.
The code execution is stopped until the global register bank is valid again. A hardware
interrupt can occur during the validation process. The way the validation process is
completed depends on the type of register bank selected for this interrupt:
•
•
If the interrupt also uses a global register bank the validation process is finished
before executing the service routine (see Figure 4-9).
If the interrupt uses a local register bank the validation process is interrupted and the
service routine is executed immediately (see Figure 4-10). After switching back to
the global register bank, the validation process is finished:
– If the interrupt occurred during the store phase, the entire validation process is
restarted from the very beginning.
– If the interrupt occurred during the load phase, only the load phase is repeated.
If a local-bank interrupt routine (Task B in Figure 4-11) is again interrupted by a globalbank interrupt (Task C), the suspended validation process must be finished before code
of Task C can be executed. This means that the validation process of Task A does not
affect the interrupt latency of Task B but the latency of Task C.
Note: If Task C would immediately interrupt Task A, the register bank validation process
of Task A would be finished first. The worst case interrupt latency is identical in
both cases (see Figure 4-9 and Figure 4-11).
1) During the store phase of the context switch the complete register bank is written to the DPRAM even if the
application only uses a part of this register bank. A register bank must not be located above FDE0H, otherwise
the store phase will overwrite SFRs (beginning at FE00H).
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Central Processing Unit (CPU)
Global Bank
Execution
Task A
Execution
Task B
Interrupt of
Task B
recognized
Execution of
SCXT CP
Register Bank
Validation
Process
Started
Finished
Figure 4-9
Global Bank
Global Bank
Execution
Task B
Execution of
SCXT CP
Execution
Task B
Execution
Task A
Execution of
POP CP
Register Bank
Validation
Process
Started
Finished
Execution of
RETI
Register Bank
Validation
Process
Started
Finished
MCA04874
Validation Process Interrupted by Global-Bank Interrupt
Global Bank
Global Bank
Local Bank
Execution
Task A
Execution
Task A
Execution Task B
Execution of
SCXT CP
Interrupt of
Task B
recognized
Execution of
RETI
Register Bank
Validation
Process
Started
Stopped
Register Bank
Validation
Process
Restarted Finished
MCA04875
Figure 4-10 Validation Process Interrupted by Local-Bank Interrupt
Local Bank
Global Bank
Execution
Task A
Global Bank
Execution
Task B
Interrupt of
Task C
recognized
Execution of
SCXT CP
Interrupt of
Task B
recognized
Local Bank
Global Bank
Execution
Task B
Execution
Task A
Execution
Task C
Register Bank
Validation
Process
Restarted Finished
Register Bank
Validation
Process
Started
Stopped
Execution of
RETI
Execution of
RETI
MCA04876
Figure 4-11 Validation Process Interrupted by Local- and Global-Bank Intr.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.5.2.1
The Context Pointer (CP)
This non-bit-addressable register selects the current global register bank context. It can
be updated via any instruction capable of modifying SFRs.
CP
Context Pointer
SFR (FE10H/08H)
11
10
9
8
7
6
Reset Value: FC00H
15
14
13
12
5
4
3
2
1
0
1
1
1
1
cp
0
r
r
r
r
rw
r
Field
Bits
Type
Description
cp
[11:1]
rw
Modifiable Portion of Register CP
Specifies the (word) base address of the current
global (memory-mapped) register bank.
When writing a value to register CP with bits CP[11:9]
= 000B, bits CP[11:10] are set to 11B by hardware.
Note: It is the user’s responsibility to ensure that the physical GPR address specified via
CP register plus short GPR address is always an internal DPRAM location. If this
condition is not met, unexpected results may occur. Do not set CP below the
internal DPRAM start address. Do not set CP above FDE0H, otherwise the store
phase will overwrite SFRs (beginning at FE00H).
The XC2700 switches the complete memory-mapped GPR bank with a single
instruction. After switching, the service routine executes within its own separate context.
The instruction “SCXT CP, #New_Bank” pushes the value of the current context pointer
(CP) into the system stack and loads CP with the immediate value “New_Bank”, which
selects a new register bank. The service routine may now use its “own registers”. This
memory register bank is preserved when the service routine terminates, i.e. its contents
are available on the next call.
Before returning from the service routine (RETI), the previous CP is simply popped from
the system stack which returns the registers to the original bank.
Note: Due to the internal instruction pipeline, a write operation to the CP register stalls
the instruction flow until the register file context switch is really executed. The
instruction immediately following the instruction that updates CP register can use
the new value of the changed CP.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.6
Code Addressing
The XC2700 provides a total addressable memory space of 16 Mbytes. This address
space is arranged as 256 segments of 64 Kbytes each. A dedicated 24-bit code address
pointer is used to access the memories for instruction fetches. This pointer has two parts:
an 8-bit code segment pointer CSP and a 16-bit offset pointer called Instruction Pointer
(IP). The concatenation of the CSP and IP results directly in a correct 24-bit physical
memory address.
Memory organized
in segments
15
87
CSP
0
15
IP
0
255
FF'0000H
254
FE'0000H
1
01'0000H
0
00'0000H
23
16 15
Segment
0
Offset
MCA04920
Figure 4-12 Addressing via the Code Segment and Instruction Pointer
tbd RAS
The Code Segment Pointer CSP selects the code segment being used at run-time to
access instructions. The lower 8 bits of register CSP select one of up 256 segments of
64 Kbytes each, while the higher 8 bits are reserved for future use. The reset value is
specified by the contents of the VECSEG register (Section 5.3).
Note: Register CSP can only be read but cannot be written by data operations.
In segmented memory mode (default after reset), register CSP is modified either
directly by JMPS and CALLS instructions, or indirectly via the stack by RETS and RETI
instructions.
In non-segmented memory mode (selected by setting bit SGTDIS in register
CPUCON1), CSP is fixed to the segment of the instruction that disabled segmentation.
Modification by inter-segment CALLs or RETurns is no longer possible.
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Central Processing Unit (CPU)
For processing an accepted interrupt or a TRAP, register CSP is automatically loaded
with the segment of the vector table (defined in register VECSEG).
Note: For the correct execution of interrupt tasks in non-segmented memory mode, the
contents of VECSEG must select the same segment as the current value of CSP,
i.e. the vector table must be located in the segment pointed to by the CSP.
CSP
Code Segment Pointer
SFR (FE08H/04H)
7
6
Reset Value: xxxxH
15
14
13
12
11
10
9
8
5
4
3
-
-
-
-
-
-
-
-
SEGNR
-
-
-
-
-
-
-
-
rh
2
1
0
Field
Bits
Type
Description
SEGNR
[7:0]
rh
Specifies the code segment from which the current
instruction is to be fetched.
Note: After a reset, register CSP is automatically loaded from register VECSEG.
The Instruction Pointer IP determines the 16-bit intra-segment address of the currently
fetched instruction within the code segment selected by the CSP register. Register IP is
not mapped into the XC2700’s address space; thus, it is not directly accessible by the
programmer. However, the IP can be modified indirectly via the stack by means of a
return instruction. IP is implicitly updated by the CPU for branch instructions and after
instruction fetch operations.
IP
Instruction Pointer
15
14
13
12
- - - (- - - -/- -)
11
10
9
8
7
Reset Value: 0000H
6
5
4
3
2
1
0
ip
0
(r)(w)h
r
Field
Bits
Type
Description
ip
[15:1]
h
Specifies the intra segment offset from which the
current instruction is to be fetched. IP refers to the
current segment <SEGNR>.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.7
Data Addressing
The Address Data Unit (ADU) contains two independent arithmetic units to generate,
calculate, and update addresses for data accesses, the Standard Address Generation
Unit (SAGU) and the DSP Address Generation Unit (DAGU). The ADU performs the
following major tasks:
•
•
•
•
Standard Address Generation (SAGU)
DSP Address Generation (DAGU)
Data Paging (SAGU)
Stack Handling (SAGU)
The SAGU supports linear arithmetic for the indirect addressing modes and also
generates the address in case of all other short and long addressing modes.
The DAGU contains an additional set of address pointers and offset registers which are
used in conjunction with the CoXXX instructions only.
The CPU provides a lot of powerful addressing modes (short, long, indirect) for word,
byte, and bit data accesses. The different addressing modes use different formats and
have different scopes.
4.7.1
Short Addressing Modes
Short addressing modes allow access to the GPR, SFR or bit-addressable memory
space. All of these addressing modes use an offset (8/4/2 bits) together with an implicit
base address to specify a 24-bit physical address:
Table 4-17
Short Addressing Modes
Mnemo- Base
nic
Address1)
Offset
Short Address Scope of Access
Range
Rw
(CP)
2 × Rw
0 … 15
GPRs (word)
Rb
(CP)
1 × Rb
0 … 15
GPRs (byte)
reg
00’FE00H
00’F000H
(CP)
(CP)
2 × reg
2 × reg
2 × (reg ∧ 0FH)
1 × (reg ∧ 0FH)
00H … EFH
00H … EFH
F0H … FFH
F0H … FFH
SFRs (word, low byte)
ESFRs (word, low byte)
GPRs (word)
GPRs (bytes)
bitoff
00’FD00H
00’FF00H
00’F100H
(CP)
2 × bitoff
2 × (bitoff ∧ 7FH)
2 × (bitoff ∧ 7FH)
2 × (bitoff ∧ 0FH)
00H … 7FH
80H … EFH
80H … EFH
F0H … FFH
RAM Bit word offset
SFR Bit word offset
ESFR Bit word offset
GPR Bit word offset
bitaddr
Bit word
see bitoff
Immediate bit
position
0 … 15
Any single bit
1) Accesses to general purpose registers (GPRs) may also access local register banks, instead of using CP.
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Physical Address = Base Address + ∆ × Short Address
Note: ∆ is 1 for byte GPRs, ∆ is 2 for word GPRs.
Rw, Rb: Specifies direct access to any GPR in the currently active context (global
register bank or local register bank). Both ‘Rw’ and ‘Rb’ require four bits in the instruction
format. The base address of the global register bank is determined by the contents of
register CP. ‘Rw’ specifies a 4-bit word GPR address, ‘Rb’ specifies a 4-bit byte GPR
address within a local register bank or relative to (CP).
reg: Specifies direct access to any (E)SFR or GPR in the currently active context (global
or local register bank). The ‘reg’ value requires eight bits in the instruction format. Short
‘reg’ addresses in the range from 00H to EFH always specify (E)SFRs. In that case, the
factor ‘∆’ equates 2 and the base address is 00’FE00H for the standard SFR area or
00’F000H for the extended ESFR area. The ‘reg’ accesses to the ESFR area require a
preceding EXT*R instruction to switch the base address. Depending on the opcode,
either the total word (for word operations) or the low byte (for byte operations) of an SFR
can be addressed via ‘reg’. Note that the high byte of an SFR cannot be accessed via
the ‘reg’ addressing mode. Short ‘reg’ addresses in the range from F0H to FFH always
specify GPRs. In that case, only the lower four bits of ‘reg’ are significant for physical
address generation and, therefore, it is identical to the address generation described for
the ‘Rb’ and ‘Rw’ addressing modes.
bitoff: Specifies direct access to any word in the bit addressable memory space. The
‘bitoff’ value requires eight bits in the instruction format. The specified ‘bitoff’ range
selects different base addresses to generate physical addresses (see Table 4-17). The
‘bitoff’ accesses to the ESFR area require a preceding EXT*R instruction to switch the
base address.
bitaddr: Any bit address is specified by a word address within the bit addressable
memory space (see ‘bitoff’) and a bit position (‘bitpos’) within that word. Therefore,
‘bitaddr’ requires twelve bits in the instruction format.
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Central Processing Unit (CPU)
4.7.2
Long Addressing Modes
Long addressing modes specify 24-bit addresses and, therefore, can access any word
or byte data within the entire address space. Long addresses can be specified in
different ways to generate the full 24-bit address:
•
•
•
Use one of the four Data Page Pointers (DPP registers): The used 16-bit pointer
selects a DPP with bits 15 … 14, bits 13 … 0 specify the 14-bit data page offset (see
Figure 4-13).
Select the used data page directly: The data page is selected by a preceeding
EXTP(R) instruction, bits 13 … 0 of the used 16-bit pointer specify the 14-bit data
page offset.
Select the used segment directly: The segment is selected by a preceeding
EXTS(R) instruction, the used 16-bit pointer specifies the 16-bit segment offset.
Note: Word accesses on odd byte addresses are not executed. A hardware trap will be
triggered.
16-Bit Data Address
Memory
15 14
0
255
FF'0000H
254
FE'0000H
Selects DPP
9
DPP
0
DPP3 - 11
DPP2 - 10
DPP1 - 01
X
DPP0 - 00
23
1
15 14
0
01'0000H
0
Page
Page Offset
Segment
Segment Offset
00'0000H
MCA04924
Figure 4-13 Data Page Pointer Addressing
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.7.2.1
Data Page Pointers DPP0, DPP1, DPP2, DPP3
These four non-bit-addressable registers select up to four different data pages to be
active simultaneously at run-time. The lower 10 bits of each DPP register select one of
the 1024 possible 16-Kbyte data pages; the upper 6 bits are reserved for future use.
DPP0
Data Page Pointer 0
DPP1
Data Page Pointer 1
DPP2
Data Page Pointer 2
DPP3
Data Page Pointer 3
SFR (FE00H/00H)
Reset Value: 0000H
SFR (FE02H/01H)
Reset Value: 0001H
SFR (FE04H/02H)
Reset Value: 0002H
SFR (FE06H/03H)
Reset Value: 0003H
15
14
13
12
11
10
9
8
7
6
5
4
-
-
-
-
-
-
DPPxPN
-
-
-
-
-
-
rw
3
2
1
Field
Bits
Type
Description
DPPxPN
[9:0]
rw
Data Page Number of DPPx
Specifies the data page selected via DPPx.
0
The DPP registers allow access to the entire memory space in pages of 16 Kbytes each.
The DPP registers are implicitly used whenever data accesses to any memory location
are made via indirect or direct long 16-bit addressing modes (except for override
accesses via EXTended instructions and PEC data transfers). After reset, the Data Page
Pointers are initialized in such a way that all indirect or direct long 16-bit addresses result
in identical 18-bit addresses. This allows access to data pages 3 … 0 within segment 0
as shown in Figure 4-13. If the user does not want to use data paging, no further action
is required.
Data paging is performed by concatenating the lower 14 bits of an indirect or direct long
16-bit address with the contents of the DPP register selected by the upper two bits of the
16-bit address. The contents of the selected DPP register specify one of the 1024
possible data pages. This data page base address together with the 14-bit page offset
forms the physical 24-bit address (even if segmentation is disabled).
The selected number of segment address bits (via bitfield SALSEL) of the respective
DPP register is output on the respective segment address pins for all external data
accesses.
A DPP register can be updated via any instruction capable of modifying an SFR.
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Central Processing Unit (CPU)
Note: Due to the internal instruction pipeline, a write operation to the DPPx registers
could stall the instruction flow until the DPP is actually updated. The instruction
that immediately follows the instruction which updates the DPP register can use
the new value of the changed DPPx.
15 14 13
EXTP(R):
0
16-Bit Long Address
#pag
14-Bit Page Offset
24-Bit Physical Address
0
15
EXTS(R):
16-Bit Long Address
#seg
16-Bit Segment Offset
24-Bit Physical Address
MCA04925
Figure 4-14 Overriding the DPP Mechanism
Note: The overriding page or segment may be specified as a constant (#pag, #seg) or
via a word GPR (Rw).
Table 4-18
Long Addressing Modes
Mnemonic
Base Address1)
Offset
Scope of Access
mem
(DPPx)
mem ∧ 3FFFH
Any Word or Byte
mem
pag
mem ∧ 3FFFH
Any Word or Byte
mem
seg
mem
Any Word or Byte
1) Represents either a 10-bit data page number to be concatenated with a 14-bit offset, or an 8-bit segment
number to be concatenated with a 16-bit offset.
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Central Processing Unit (CPU)
4.7.3
Indirect Addressing Modes
Indirect addressing modes can be considered as a combination of short and long
addressing modes. This means that the “long” 16-bit pointer is provided indirectly by the
contents of a word GPR which itself is specified directly by a short 4-bit address
(‘Rw’ = 0 … 15).
There are indirect addressing modes, which add a constant value to the GPR contents
before the long 16-bit address is calculated. Other indirect addressing modes can
decrement or increment the indirect address pointers (GPR contents) by 2 or 1 (referring
to words or bytes) or by the contents of the offset registers QR0 or QR1.
Table 4-19
Generating Physical Addresses from Indirect Pointers
Step Executed Action
Calculation
Notes
1
Calculate the address of the GPR Address =
indirect pointer (word GPR) 2 × Short Addr.
from its short address
[+ (CP)]
see Table 4-17
2
Pre-decrement indirect
pointer (‘-Rw’) depending
on datatype (∆ = 1 or 2 for
byte or word operations)
(GPR Address) = Optional step, executed only if
(GPR Address)
required by addressing mode
-∆
3
Adjust the pointer by a
constant value
(‘Rw + const16’)
Pointer =
(GPR Address)
+ Constant
4
Calculate the physical 24-bit Physical Addr. = Uses DPPs or page/segment
address using the resulting Page/Segment + override mechanisms,
pointer
Pointer offset
see Table 4-18
5
Post-in/decrement indirect (GPR Address) = Optional step, executed only if
pointer (‘Rw±’) depending
(GPR Address)
required by addressing mode
on datatype (∆ = 1 or 2 for ± ∆
byte or word operations), or
depending on offset
registers (∆ = QRx)1)
Optional step, executed only if
required by addressing mode
1) Post-decrement and QRx-based modification is provided only for CoXXX instructions.
Note: Some instructions only use the lowest four word GPRs (R3 … R0) as indirect
address pointers, which are specified via short 2-bit addresses in that case.
The following indirect addressing modes are provided:
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Table 4-20
Indirect Addressing Modes
Mnemonic
Particularities
[Rw]
Most instructions accept any GPR (R15 … R0) as indirect address
pointer. Some instructions accept only the lower four GPRs (R3 … R0).
[Rw+]
The specified indirect address pointer is automatically post-incremented
by 2 or 1 (for word or byte data operations) after the access.
[-Rw]
The specified indirect address pointer is automatically pre-decremented
by 2 or 1 (for word or byte data operations) before the access.
[Rw +
#data16]
The specified 16-bit constant is added to the indirect address pointer,
before the long address is calculated.
[Rw-]
The specified indirect address pointer is automatically postdecremented by 2 (word data operations) after the access.
[Rw + QRx]
The specified indirect address pointer is automatically post-incremented
by QRx (word data operations) after the access.
[Rw - QRx]
The specified indirect address pointer is automatically postdecremented by QRX (word data operations) after the access.
4.7.3.1
Offset Registers QR0 and QR1
The non-bit-addressable offset registers QR0 and QR1 are used with CoXXX
instructions. For possible instruction flow stalls refer to Section 4.3.4.
QR0
Offset Register
QR1
Offset Register
15
14
13
12
11
10
ESFR (F004H/02H)
Reset Value: 0000H
ESFR (F006H/03H)
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
QR
0
rw
r
Field
Bits
Type
Description
QR
[15:1]
rw
Modifiable Portion of Register QRx
Specifies the 16-bit word offset address for indirect
addressing modes (LSB always zero).
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Central Processing Unit (CPU)
4.7.4
DSP Addressing Modes
In addition to the Standard Address Generation Unit (SAGU), the DSP Address
Generation Unit (DAGU) provides an additional set of pointer registers (IDX0, IDX1) and
offset registers (QX0, QX1). The additional set of pointer registers IDX0 and IDX1 allows
the execution of DSP specific CoXXX instructions in one CPU cycle. An independent
arithmetic unit allows the update of these dedicated pointer registers in parallel with the
GPR-pointer modification of the SAGU. The DAGU only supports indirect addressing
modes that use the special pointer registers IDX0 and IDX1.
The address pointers can be used for arithmetic operations as well as for the special
CoMOV instruction. The generation of the 24-bit memory address is different:
•
For CoMOV instructions, the IDX pointers are concatenated with the DPPs or the
selected page/segment address, as described for long addressing modes (see
Figure 4-13 for a summary).
For arithmetic CoXXX instructions, the IDX pointers are automatically extended to
a 24-bit memory address pointing to the internal DPRAM area, as shown in
Figure 4-15.
•
IDX0
Address Pointer
IDX1
Address Pointer
15
14
13
12
11
10
SFR (FF08H/84H)
Reset Value: 0000H
SFR (FF0AH/85H)
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
idx
0
rw
r
Field
Bits
Type
Description
idx
[15:1]
rw
Modifiable Portion of Register IDXx
Specifies the 16-bit word address pointer
Note: During the initialization of the IDX registers, instruction flow stalls are possible. For
the proper operation, refer to Section 4.3.4.
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Central Processing Unit (CPU)
There are indirect addressing modes which allow parallel data move operations before
the long 16-bit address is calculated (see Figure 4-16 for an example). Other indirect
addressing modes allow decrementing or incrementing the indirect address pointers
(IDXx contents) by 2 or by the contents of the offset registers QX0 and QX1 (used in
conjunction with the IDX pointers).
QX0
Offset Register
QX1
Offset Register
15
14
13
12
11
10
ESFR (F000H/00H)
Reset Value: 0000H
ESFR (F002H/01H)
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
qx
0
rw
r
Field
Bits
Type
Description
qx
[15:1]
rw
Modifiable Portion of Register QXx
Specifies the 16-bit word offset for indirect
addressing modes
Note: During the initialization of the QX registers, instruction flow stalls are possible. For
the proper operation, refer to Section 4.3.4.
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Central Processing Unit (CPU)
15
Memory
16-Bit IDX Pointer
12 11
0
12 11
0
2
02'0000H
1
01'0000H
DPRAM in Data Page 3
0
23
00'0000H
15
000000001111
MCA04926
Figure 4-15 Arithmetic MAC Operations and Addressing via the IDX Pointers
Table 4-21
Generating Physical Addresses from Indirect Pointers (IDXx)
Step Executed Action
Calculation
Notes
1
Determine the used IDXx
pointer
---
–
2
Calculate an intermediate
Interm. Addr. =
long address for the parallel (IDXx Address)
data move operation and
±∆
in/decrement indirect
pointer (‘IDXx±’) by 2
(∆ = 2), or depending on
offset registers (∆ = QXx)
Optional step, executed only if
required by instruction
CoXXXM and addressing
mode
3
Calculate long 16-bit
address
–
4
Calculate the physical 24-bit Physical Addr. = Uses DPPs or page/segment
address using the resulting Page/Segment + override mechanisms, see
pointer
Pointer offset
Table 4-18 and Figure 4-15
5
Post-in/decrement indirect
pointer (‘IDXx±’) by 2
(∆ = 2), or depending on
offset registers (∆ = QXx)
User’s Manual
CPUSV2_X, V2.2
Long Address =
(IDXx Pointer)
(IDXx Pointer) =
(IDXx Pointer)
±∆
4-48
Optional step, executed only if
required by addressing mode
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Central Processing Unit (CPU)
The following indirect addressing modes are provided:
Table 4-22
DSP Addressing Modes
Mnemonic
Particularities
[IDXx]
Most CoXXX instructions accept IDXx (IDX0, IDX1) as an indirect
address pointer.
[IDXx+]
The specified indirect address pointer is automatically post-incremented
by 2 after the access.
with parallel
data move
In case of a CoXXXM instruction, the address stored in the specified
indirect address pointer is automatically pre-decremented by 2 for the
parallel move operation. The pointer itself is not pre-decremented.
Then, the specified indirect address pointer is automatically postincremented by 2 after the access.
[IDXx-]
The specified indirect address pointer is automatically postdecremented by 2 after the access.
with parallel
data move
In case of a CoXXXM instruction, the address stored in the specified
indirect address pointer is automatically pre-incremented by 2 for the
parallel move operation. The pointer itself is not pre-incremented. Then,
the specified indirect address pointer is automatically post-decremented
by 2 after the access.
[IDXx + QXx]
The specified indirect address pointer is automatically post-incremented
by QXx after the access.
with parallel
data move
In case of a CoXXXM instruction, the address stored in the specified
indirect address pointer is automatically pre-decremented by QXx for
the parallel move operation. The pointer itself is not pre-decremented.
Then, the specified indirect address pointer is automatically postincremented by QXx after the access.
[IDXx - QXx]
The specified indirect address pointer is automatically postdecremented by QXx after the access.
with parallel
data move
In case of a CoXXXM instruction, the address stored in the specified
indirect address pointer is automatically pre-incremented by QXx for the
parallel move operation. The pointer itself is not pre-incremented. Then,
the specified indirect address pointer is automatically post-decremented
by QXx after the access.
Note: An example for parallel data move operations can be found in Figure 4-16.
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Central Processing Unit (CPU)
The CoREG Addressing Mode
The CoSTORE instruction utilizes the special CoREG addressing mode for immediate
storage of the MAC-Unit register after a MAC operation. The address of the MAC-Unit
register is coded in the CoSTORE instruction format as described in Table 4-23:
Table 4-23
Coding of the CoREG Addressing Mode
Mnemonic
Register
Coding of wwww:w bits [31:27]
MSW
MAC-Unit Status Word
00000
MAH
MAC-Unit Accumulator High Word
00001
MAS
Limited MAC-Unit Accumulator High 00010
Word
MAL
MAC-Unit Accumulator Low Word
00100
MCW
MAC-Unit Control Word
00101
MRW
MAC-Unit Repeat Word
00110
The example in Figure 4-16 shows the complex operation of CoXXXM instructions with
a parallel move operation based on the descriptions about addressing modes given in
Section 4.7.3 (Indirect Addressing Modes) and Section 4.7.4 (DSP Addressing
Modes).
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CoXXXMxx [IDX0+], [R2+]
Address Operations
1) Calculate Pointer Addresses
IDXx = IDX0
R2 Address = CP + 2 × 2
(Global Register Bank)
2) Intermediate Address of Write Pointer
for the Parallel Move Operation
Intermediate Address = (IDX0) - 2
3) Calculate Long 16-Bit Address
Long Address 1 = (IDX0)
Long Address 2 = (R2)
4) Calculate 24-Bit Physical Address
Physical Address 1 = Page 3 + Page Offset
Physical Address 2 = (DPPi) + Page Offset
5) Post Modify Address Pointer
(IDX0)new = (IDX0) + 2
(R2)new = (R2) + 2
Data Operations
1) Read Operands
op1 = (Physical Address 1)
op2 = (Physical Address 2)
1) Write Operand op1
(Intermediate Address) = op1
(IDX0)new (Updated Pointer)
op1
Parallel
Move
(R2)new (Updated Pointer)
op2
(IDX0) (Read Pointer)
(R2) (Read Pointer)
Intermediate Address
(Write Pointer for Parallel Move)
MCA04928
Figure 4-16 Arithmetic MAC Operations with Parallel Move
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4.7.5
The System Stack
The XC2700 supports a system stack of up to 64 Kbytes. The stack can be located
internally in one of the on-chip memories or externally. The 16-bit Stack Pointer register
(SP) addresses the stack within a 64-Kbyte segment selected by the Stack Pointer
Segment register (SPSG). A virtual stack (usually bigger than 64 Kbytes) can be
implemented by software. This mechanism is supported by the Stack Overflow register
STKOV and the Stack Underflow register STKUN (see descriptions below).
4.7.5.1
The Stack Pointer Registers SP and SPSEG
Register SPSEG (not bitaddressable) selects the segment being used at run-time to
access the system stack. The lower eight bits of register SPSEG select one of up
256 segments of 64 Kbytes each, while the higher 8 bits are reserved for future use.
The Stack Pointer SP (not bitaddressable) points to the top of the system stack (TOS).
SP is pre-decremented whenever data is pushed onto the stack, and it is postincremented whenever data is popped from the stack. Therefore, the system stack
grows from higher towards lower memory locations.
System stack addresses are generated by directly extending the 16-bit contents of
register SP by the contents of register SPSG, as shown in Figure 4-17.
The system stack cannot cross a 64-Kbyte segment boundary.
Stack Pointer
Segment
SPSEG
15
7 SPSEGNR 0
15
SP
0
255
FF'0000H
254
FE'0000H
1
01'0000H
0
00'0000H
23
16 15
0
MCA04929
Figure 4-17 Addressing via the Stack Pointer
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Central Processing Unit (CPU)
SP
Stack Pointer Register
15
14
13
12
SFR (FE12H/09H)
11
10
9
8
7
6
Reset Value: FC00H
5
4
3
1
0
sp
0
rwh
r
Field
Bits
Type
Description
sp
[15:1]
rwh
Modifiable Portion of Register SP
Specifies the top of the system stack.
SPSEG
Stack Pointer Segment
2
SFR (FF0CH/86H)
7
6
Reset Value: 0000H
15
14
13
12
11
10
9
8
5
4
3
-
-
-
-
-
-
-
-
SPSEGNR
-
-
-
-
-
-
-
-
rw
2
1
Field
Bits
Type
Description
SPSEGNR
[7:0]
rw
Stack Pointer Segment Number
Specifies the segment where the stack is located.
0
Note: SPSEG and SP can be updated via any instruction capable of modifying a 16-bit
SFR. Due to the internal instruction pipeline, a write operation to SPSG or SP
stalls the instruction flow until the register is really updated. The instruction
immediately following the instruction updating SPSG or SP can use the new value.
Extreme care should be taken when changing the contents of the stack pointer
registers. Improper changes may result in erroneous system behavior.
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4.7.5.2
The Stack Overflow/Underflow Pointers STKOV/STKUN
These limit registers (not bit-addressable) supervise the stack pointer. A trap is
generated when the stack pointer reaches its upper or lower limit. The Stack Pointer
Segment Register SPSG is not taken into account for the stack pointer comparison. The
system stack cannot cross a 64-Kbyte segment.
STKOV is compared with SP before each implicit write operation which decrements the
contents of SP (instructions CALLA, CALLI, CALLR, CALLS, PCALL, TRAP, SCXT, or
PUSH). If the contents of SP are equal to the contents of STKOV a stack overflow trap
is triggered.
STKUN is compared with SP before each implicit read operation which increments the
contents of SP (instructions RET, RETS, RETP, RETI, or POP). If the contents of SP are
equal to the contents of STKUN a stack underflow trap is triggered.
The Stack Overflow/Underflow Traps may be used in two different ways:
•
•
Fatal error indication treats the stack overflow as a system error and executes the
associated trap service routine.
In case of a stack overflow trap, data in the bottom of the stack may have been
overwritten by the status information stacked upon servicing the trap itself.
Virtual stack control allows the system stack to be used as a ‘Stack Cache’ for a
bigger external user stack: flush cache in case of an overflow, refill cache in case of
an underflow.
Scope of Stack Limit Control
The stack limit control implemented by the register pair STKOV and STKUN detects
cases in which the Stack Pointer (SP) crosses the defined stack area as a result of an
implicit change.
If the stack pointer was explicitly changed as a result of move or arithmetic instruction,
SP is not compared to the contents of STKOV and STKUN. In this case, a stack violation
will not be detected if the modified stack pointer is on or outside the defined limits, i.e.
below (STKOV) or above (STKUN). Stack overflow/underflow is detected only in case of
implicit SP modification.
SP may be operated outside the permitted SP range without triggering a trap. However,
if SP reaches the limit of the permitted SP range from outside the range as a result of an
implicit change (PUSH or POP, for example), the respective trap will be triggered.
Note: STKOV and STKUN can be updated via any instruction capable of modifying an
SFR. If a stack overflow or underflow event occurs in an ATOMIC/EXT sequence,
the stack operations that are part of the sequence are completed. The trap is
issued after the completion of the entire ATOMIC/EXT sequence.
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STKOV
Stack Overflow Reg.
15
14
13
12
SFR (FE14H/0AH)
11
10
9
8
7
6
Reset Value: FA00H
5
4
3
2
1
stkov
0
0
rw
Field
Bits
Type
Description
stkov
[15:1]
rw
Modifiable Portion of Register STKOV
Specifies the segment offset address of the lower
limit of the system stack.
STKUN
Stack Underflow Reg.
15
14
13
12
SFR (FE16H/0BH)
11
10
9
8
7
6
Reset Value: FC00H
5
4
3
2
1
stkun
0
rw
r
Field
Bits
Type
Description
stkun
[15:1]
rw
Modifiable Portion of Register STKUN
Specifies the segment offset address of the upper
limit of the system stack.
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4.8
Standard Data Processing
All standard arithmetic, shift-, and logical operations are performed in the 16-bit ALU. In
addition to the standard functions, the ALU of the XC2700 includes a bit-manipulation
unit and a multiply and divide unit. Most internal execution blocks have been optimized
to perform operations on either 8-bit or 16-bit numbers. After the pipeline has been filled,
most instructions are completed in one CPU cycle. The status flags are automatically
updated in register PSW after each ALU operation and reflect the current state of the
microcontroller. These flags allow branching upon specific conditions. Support of both
signed and unsigned arithmetic is provided by the user selectable branch test. The
status flags are also preserved automatically by the CPU upon entry into an interrupt or
trap routine. Another group of bits represents the current CPU interrupt status. Two
separate bits (USR0 and USR1) are provided as general purpose flags.
PSW
Processor Status Word
15
14
13
12
SFR
11
10
ILVL
IEN
HLD
EN
BANK
rwh
rw
rw
rwh
Type
9
8
7
Reset Value: 0000H
6
5
USR USR MUL
1
0
IP
rwh
rwh
r
4
3
2
1
0
E
Z
V
C
N
rwh
rwh
rwh
rwh
rwh
Field
Bits
Description
ILVL
[15:12] rwh
CPU Priority Level
0H Lowest Priority
…
…
FH Highest Priority
IEN
11
rw
Global Interrupt/PEC Enable Bit
0
Interrupt/PEC requests are disabled
1
Interrupt/PEC requests are enabled
HLDEN
10
rw
Hold Enable
0
External bus arbitration disabled
1
External bus arbitration enabled
Note: The selected arbitration mode is activated
when HLDEN is set for the first time.
BANK
User’s Manual
CPUSV2_X, V2.2
[9:8]
rwh
Reserved for Register File Bank Selection
00
Global register bank
01
Reserved
10
Local register bank 1
11
Local register bank 2
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Field
Bits
Type
Description
USR1
7
rwh
General Purpose Flag
May be used by application
USR0
6
rwh
General Purpose Flag
May be used by application
MULIP
5
r
Multiplication/Division in Progress
Note: Always set to 0 (MUL/DIV not interruptible),
for compatibility with existing software.
E
4
rwh
End of Table Flag
0
Source operand is neither 8000H nor 80H
1
Source operand is 8000H or 80H
Z
3
rwh
Zero Flag
0
ALU result is not zero
1
ALU result is zero
V
2
rwh
Overflow Flag
0
No Overflow produced
1
Overflow produced
C
1
rwh
Carry Flag
0
No carry/borrow bit produced
1
Carry/borrow bit produced
N
0
rwh
Negative Result
0
ALU result is not negative
1
ALU result is negative
ALU/MAC Status (N, C, V, Z, E, USR0, USR1)
The condition flags (N, C, V, Z, E) within the PSW indicate the ALU status after the most
recently performed ALU operation. They are set by most of the instructions according to
specific rules which depend on the ALU or data movement operation performed by an
instruction.
After execution of an instruction which explicitly updates the PSW register, the condition
flags cannot be interpreted as described below because any explicit write to the PSW
register supersedes the condition flag values which are implicitly generated by the CPU.
Explicitly reading the PSW register supplies a read value which represents the state of
the PSW register after execution of the immediately preceding instruction.
Note: After reset, all of the ALU status bits are cleared.
N-Flag: For most of the ALU operations, the N-flag is set to 1, if the most significant bit
of the result contains a 1; otherwise, it is cleared. In the case of integer operations, the
N-flag can be interpreted as the sign bit of the result (negative: N = 1, positive: N = 0).
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Central Processing Unit (CPU)
Negative numbers are always represented as the 2’s complement of the corresponding
positive number. The range of signed numbers extends from -8000H to +7FFFH for the
word data type, or from -80H to +7FH for the byte data type. For Boolean bit operations
with only one operand, the N-flag represents the previous state of the specified bit. For
Boolean bit operations with two operands, the N-flag represents the logical XORing of
the two specified bits.
C-Flag: After an addition, the C-flag indicates that a carry from the most significant bit of
the specified word or byte data type has been generated. After a subtraction or a
comparison, the C-flag indicates a borrow which represents the logical negation of a
carry for the addition.
This means that the C-flag is set to 1, if no carry from the most significant bit of the
specified word or byte data type has been generated during a subtraction, which is
performed internally by the ALU as a 2’s complement addition, and, the C-flag is cleared
when this complement addition caused a carry.
The C-flag is always cleared for logical, multiply and divide ALU operations, because
these operations cannot cause a carry.
For shift and rotate operations, the C-flag represents the value of the bit shifted out last.
If a shift count of zero is specified, the C-flag will be cleared. The C-flag is also cleared
for a prioritize ALU operation, because a 1 is never shifted out of the MSB during the
normalization of an operand.
For Boolean bit operations with only one operand, the C-flag is always cleared. For
Boolean bit operations with two operands, the C-flag represents the logical ANDing of
the two specified bits.
V-Flag: For addition, subtraction, and 2’s complementation, the V-flag is always set to 1
if the result exceeds the range of 16-bit signed numbers for word operations (-8000H to
+7FFFH), or 8-bit signed numbers for byte operations (-80H to +7FH). Otherwise, the
V-flag is cleared. Note that the result of an integer addition, integer subtraction, or 2’s
complement is not valid if the V-flag indicates an arithmetic overflow.
For multiplication and division, the V-flag is set to 1 if the result cannot be represented
in a word data type; otherwise, it is cleared. Note that a division by zero will always cause
an overflow. In contrast to the result of a division, the result of a multiplication is valid
whether or not the V-flag is set to 1.
Because logical ALU operations cannot produce an invalid result, the V-flag is cleared
by these operations.
The V-flag is also used as a ‘Sticky Bit’ for rotate right and shift right operations. With
only using the C-flag, a rounding error caused by a shift right operation can be estimated
up to a quantity of one half of the LSB of the result. In conjunction with the V-flag, the
C-flag allows evaluation of the rounding error with a finer resolution (see Table 4-24).
For Boolean bit operations with only one operand, the V-flag is always cleared. For
Boolean bit operations with two operands, the V-flag represents the logical ORing of the
two specified bits.
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Table 4-24
Shift Right Rounding Error Evaluation
C-Flag
V-Flag
Rounding Error Quantity
0
0
1
1
0
1
0
1
No rounding error
0 < Rounding error < 1/2 LSB
Rounding error = 1/2 LSB
Rounding error > 1/2 LSB
Z-Flag: The Z-flag is normally set to 1 if the result of an ALU operation equals zero,
otherwise it is cleared.
For the addition and subtraction with carry, the Z-flag is only set to 1, if the Z-flag already
contains a 1 and the result of the current ALU operation also equals zero. This
mechanism is provided to support multiple precision calculations.
For Boolean bit operations with only one operand, the Z-flag represents the logical
negation of the previous state of the specified bit. For Boolean bit operations with two
operands, the Z-flag represents the logical NORing of the two specified bits. For the
prioritize ALU operation, the Z-flag indicates whether the second operand was zero.
E-Flag: End of table flag. The E-flag can be altered by instructions which perform ALU
or data movement operations. The E-flag is cleared by those instructions which cannot
be reasonably used for table search operations. In all other cases, the E-flag value
depends on the value of the source operand to signify whether the end of a search table
is reached or not. If the value of the source operand of an instruction equals the lowest
negative number which is representable by the data format of the corresponding
instruction (8000H for the word data type, or 80H for the byte data type), the E-flag is set
to 1; otherwise, it is cleared.
General Control Functions (USR0, USR1, BANK, HLDEN)
A few bits in register PSW are dedicated to general control functions. Thus, they are
saved and restored automatically upon task switches and interrupts.
USR0/USR1-Flags: These bits can be set automatically during the execution of
repeated MAC instructions. These bits can also be used as general flags by an
application.
BANK: Bitfield BANK selects the currently active register bank (local or global). Bitfield
BANK is updated implicitly by hardware upon entering an interrupt service routine, and
by a RETI instruction. It can be also modified explicitly via software by any instruction
which can write to PSW.
HLDEN: Setting this bit for the first time activates the selected bus arbitration mode (see
Section 9.3.8). Bus arbitration can be disabled by temporarily clearing bit HLDEN. In this
case the bus is locked, while the bus arbitration mode remains selected.
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Central Processing Unit (CPU)
CPU Interrupt Status (IEN, ILVL)
IEN: The Interrupt Enable bit allows interrupts to be globally enabled (IEN = 1) or
disabled (IEN = 0).
ILVL: The four-bit Interrupt Level field (ILVL) specifies the priority of the current CPU
activity. The interrupt level is updated by hardware on entry into an interrupt service
routine, but it can also be modified via software to prevent other interrupts from being
acknowledged. If an interrupt level 15 has been assigned to the CPU, it has the highest
possible priority; thus, the current CPU operation cannot be interrupted except by
hardware traps or external non-maskable interrupts. For details refer to Chapter 5.
After reset, all interrupts are globally disabled, and the lowest priority (ILVL = 0) is
assigned to the initial CPU activity.
4.8.1
16-bit Adder/Subtracter, Barrel Shifter, and 16-bit Logic Unit
All standard arithmetic and logical operations are performed by the 16-bit ALU. In case
of byte operations, signals from bits 6 and 7 of the ALU result are used to control the
condition flags. Multiple precision arithmetic is supported by a “CARRY-IN” signal to the
ALU from previously calculated portions of the desired operation.
A 16-bit barrel shifter provides multiple bit shifts in a single cycle. Rotations and
arithmetic shifts are also supported.
4.8.2
Bit Manipulation Unit
The XC2700 offers a large number of instructions for bit processing. These instructions
either manipulate software flags within the internal RAM, control on-chip peripherals via
control bits in their respective SFRs, or control IO functions via port pins.
Unlike other microcontrollers, the XC2700 features instructions that provide direct
access to two operands in the bit addressable space without requiring them to be moved
to temporary locations. Multiple bit shift instructions have been included to avoid long
instruction streams of single bit shift operations. These instructions require a single CPU
cycle.
The instructions BSET, BCLR, BAND, BOR, BXOR, BMOV, BMOVN explicitly set or
clear specific bits. The bitfield instructions BFLDL and BFLDH allow manipulation of up
to 8 bits of a specific byte at one time. The instructions JBC and JNBS implicitly clear or
set the specified bit when the jump is taken. The instructions JB and JNB (also
conditional jump instructions that refer to flags) evaluate the specified bit to determine if
the jump is to be taken.
Note: Bit operations on undefined bit locations will always read a bit value of ‘0’, while
the write access will not affect the respective bit location.
All instructions that manipulate single bits or bit groups internally use a read-modify-write
sequence that accesses the whole word containing the specified bit(s).
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
This method has several consequences:
•
•
The read-modify-write approach may be critical with hardware-affected bits. In these
cases, the hardware may change specific bits while the read-modify-write operation
is in progress; thus, the writeback would overwrite the new bit value generated by the
hardware. The solution is provided by either the implemented hardware protection
(see below) or through special programming (see Section 4.3).
Bits can be modified only within the internal address areas (internal RAM and SFRs).
External locations cannot be used with bit instructions.
The upper 256 bytes of SFR area, ESFR area, and internal DPRAM are bit-addressable;
so, the register bits located within those respective sections can be manipulated directly
using bit instructions. The other SFRs must be accessed byte/word wise.
Note: All GPRs are bit-addressable independently from the allocation of the register
bank via the Context Pointer (CP). Even GPRs which are allocated to non-bitaddressable RAM locations provide this feature.
Protected bits are not changed during the read-modify-write sequence, such as when
hardware sets an interrupt request flag between the read and the write of the readmodify-write sequence. The hardware protection logic guarantees that only the intended
bit(s) is/are affected by the write-back operation.
Note: If a conflict occurs between a bit manipulation generated by hardware and an
intended software access, the software access has priority and determines the
final value of the respective bit.
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.8.3
Multiply and Divide Unit
The XC2700’s multiply and divide unit has two separated parts. One is the fast 16 ×
16-bit multiplier that executes a multiplication in one CPU cycle. The other one is a
division sub-unit which performs the division algorithm in 18 … 21 CPU cycles
(depending on the data and division types). The divide instruction requires four CPU
cycles to be executed. For performance reasons, the rest of the division algorithm runs
in the background during the following seventeen CPU cycles, while further instructions
are executed in parallel. Interrupt tasks can also be started and executed immediately
without any delay. If an instruction (from the original instruction stream or from the
interrupt task) tries to use the unit while a division is still running, the execution of this
new instruction is stalled until the previous division is finished.
To avoid these stalls, the multiply and division unit should not be used during the first
fourteen CPU cycles of the interrupt tasks. For example, this requires up to fourteen onecycle instructions to be executed between the interrupt entry and the first instruction
which uses the multiply and divide unit again (worst case).
Multiplications and divisions implicitly use the 32-bit multiply/divide register MD
(represented by the concatenation of the two non-bit-addressable data registers MDH
and MDL) and the associated control register MDC. This bit-addressable 16-bit register
is implicitly used by the CPU when it performs a division or multiplication in the ALU.
After a multiplication, MD represents the 32-bit result. For long divisions, MD must be
loaded with the 32-bit dividend before the division is started. After any division, register
MDH represents the 16-bit remainder, register MDL represents the 16-bit quotient.
MDH
Multiply/Divide High Reg.
15
14
13
12
11
SFR (FE0CH/06H)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
mdh
rwh
Field
Bits
Type
Description
mdh
[15:0]
rwh
High Part of MD
The high order sixteen bits of the 32-bit multiply and
divide register MD.
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
MDL
Multiply/Divide Low Reg.
15
14
13
12
11
SFR (FE0EH/07H)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
mdl
rwh
Field
Bits
Type
Description
mdl
[15:0]
rwh
Low Part of MD
The low order sixteen bits of the 32-bit multiply and
divide register MD.
Whenever MDH or MDL is updated via software, the Multiply/Divide Register In Use flag
(MDRIU) in the Multiply/Divide Control register (MDC) is set to ‘1’. The MDRIU flag is
cleared, whenever register MDL is read via software.
MDC
Multiply/Divide Control Reg.
SFR (FF0EH/87H)
Reset Value: 0000H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
-
-
-
-
MDR
IU
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
r(w)h
-
-
-
-
Field
Bits
Type
Description
MDRIU
4
rwh
Multiply/Divide Register In Use
0
Cleared when MDL is read via software.
1
Set when MDL or MDH is written via software,
or when a multiply or divide instruction is
executed.
Note: The MDRIU flag indicates the usage of register MD (MDL and MDH). In this case
MD must be saved prior to a new multiplication or division operation.
User’s Manual
CPUSV2_X, V2.2
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.9
DSP Data Processing (MAC Unit)
The new CoXXX arithmetic instructions are performed in the MAC unit. The MAC unit
provides single-instruction-cycle, non-pipelined, 32-bit additions; 32-bit subtraction; right
and left shifts; 16-bit by 16-bit multiplication; and multiplication with cumulative
subtraction/addition. The MAC unit includes the following major components, shown in
Figure 4-18:
•
•
•
•
•
•
•
•
16-bit by 16-bit signed/unsigned multiplier with signed result1)
Concatenation Unit
Scaler (one-bit left shifter) for fractional computing
40-bit Adder/Subtracter
40-bit Signed Accumulator
Data Limiter
Accumulator Shifter
Repeat Counter
16-Bit Input Operands
16
16
16
Repeat Counter
MCW Register
16
Signed/
Unsigned
Multiplier
Concatenation
Unit
32
32
32
Signed
Ext.
40-Bit Adder/Subtracter
Round + Saturation
ACCU-Shifter
40
40-Bit Signed
Accumulator
MSW Register
40
40
40
Limiter
MCA04930
Figure 4-18 Functional MAC Unit Block Diagram
1) The same hardware-multiplier is used in the ALU.
User’s Manual
CPUSV2_X, V2.2
4-64
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.9.1
MAC Unit Control
The working register of the MAC unit is a dedicated 40-bit accumulator register. A set of
consistent flags is automatically updated in status register MSW after each MAC
operation. These flags allow branching on specific conditions. Unlike the PSW flags,
these flags are not preserved automatically by the CPU upon entry into an interrupt or
trap routine. All dedicated MAC registers must be saved on the stack if the MAC unit is
shared between different tasks and interrupts. General properties of the MAC unit are
selected via the MAC control word MCW.
MCW
MAC Control Word
SFR (FFDCH/EEH)
Reset Value: 0000H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-
-
-
-
-
MP
MS
-
-
-
-
-
-
-
-
-
-
-
-
-
-
rw
rw
-
-
-
-
-
-
-
-
-
Field
Bits
Type
Description
MP
10
rw
One-Bit Scaler Control
0
Multiplier product shift disabled
1
Multiplier product shift enabled for signed
multiplications
MS
9
rw
Saturation Control
0
Saturation disabled
1
Saturation to 32-bit value enabled
4.9.2
Representation of Numbers and Rounding
The XC2700 supports the 2’s complement representation of binary numbers. In this
format, the sign bit is the MSB of the binary word. This is set to zero for positive numbers
and set to one for negative numbers. Unsigned numbers are supported only by
multiply/multiply-accumulate instructions which specify whether each operand is signed
or unsigned.
In 2’s complement fractional format, the N-bit operand is represented using the 1.[N-1]
format (1 signed bit, N-1 fractional bits). Such a format can represent numbers between
-1 and +1 - 2-[N-1]. This format is supported when bit MP of register MCW is set.
The XC2700 implements 2’s complement rounding. With this rounding type, one is
added to the bit to the right of the rounding point (bit 15 of MAL), before truncation (MAL
is cleared).
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.9.3
The 16-bit by 16-bit Signed/Unsigned Multiplier and Scaler
The multiplier executes 16-bit by 16-bit parallel signed/unsigned fractional and integer
multiplication in one CPU-cycle. The multiplier allows the multiplication of unsigned and
signed operands. The result is always presented in a signed fractional or integer format.
The result of the multiplication feeds a one-bit scaler to allow compensation for the extra
sign bit gained in multiplying two 16-bit 2’s complement numbers.
4.9.4
Concatenation Unit
The concatenation unit enables the MAC unit to perform 32-bit arithmetic operations in
one CPU cycle. The concatenation unit concatenates two 16-bit operands to a 32-bit
operand before the 32-bit arithmetic operation is executed in the 40-bit adder/subtracter.
The second required operand is always the current accumulator contents. The
concatenation unit is also used to pre-load the accumulator with a 32-bit value.
4.9.5
One-bit Scaler
The one-bit scaler can shift the result of the concatenation unit or the output of the
multiplier one bit to the left. The scaler is controlled by the executed instruction for the
concatenation or by control bit MP in register MCW.
If bit MP is set the product is shifted one bit to the left to compensate for the extra sign
bit gained in multiplying two 16-bit 2’s-complement numbers. The enabled automatic
shift is performed only if both input operands are signed.
4.9.6
The 40-bit Adder/Subtracter
The 40-bit Adder/Subtracter allows intermediate overflows in a series of
multiply/accumulate operations. The Adder/Subtracter has two input ports. The 40-bit
port is the feedback of the accumulator output through the ACCU-Shifter to the
Adder/Subtracter. The 32-bit port is the input port for the operand coming from the onebit Scaler. The 32-bit operands are signed and extended to 40 bits before the
addition/subtraction is performed.
The output of the Adder/Subtracter goes to the accumulator. It is also possible to round
the result and to saturate it on a 32-bit value automatically after every accumulation. The
round operation is performed by adding 00’0000’8000H to the result. Automatic
saturation is enabled by setting the saturation control bit MS in register MCW.
When the accumulator is in the overflow saturation mode and an overflow occurs, the
accumulator is loaded with either the most positive or the most negative value
representable in a 32-bit value, depending on the direction of the overflow as well as on
the arithmetic used. The value of the accumulator upon saturation is either
00’7FFF’FFFFH (positive) or FF’8000’0000H (negative).
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.9.7
The Data Limiter
Saturation arithmetic is also provided to selectively limit overflow when reading the
accumulator by means of a CoSTORE <destination>., MAS instruction. Limiting is
performed on the MAC-Unit accumulator. If the contents of the accumulator can be
represented in the destination operand size without overflow, then the data limiter is
disabled and the operand is not modified. If the contents of the accumulator cannot be
represented without overflow in the destination operand size, the limiter will substitute a
“limited” data as explained in Table 4-25:
Table 4-25
Limiter Output
ME-flag
MN-flag
Output of Limiter
0
x
unchanged
1
0
7FFFH
1
1
8000H
Note: In this particular case, both the accumulator and the status register are not
affected. MAS is readable by means of a CoSTORE instruction only.
4.9.8
The Accumulator Shifter
The accumulator shifter is a parallel shifter with a 40-bit input and a 40-bit output. The
source accumulator shifting operations are:
•
•
•
No shift (Unmodified)
Up to 16-bit Arithmetic Left Shift
Up to 16-bit Arithmetic Right Shift
Notice that bits ME, MSV, and MSL in register MSW are affected by left shifts; therefore,
if the saturation mechanism is enabled (MS) the behavior is similar to the one of the
Adder/Subtracter.
Note: Certain precautions are required in case of left shift with saturation enabled.
Generally, if MAE contains significant bits, then the 32-bit value in the accumulator
is to be saturated. However, it is possible that left shift may move some significant
bits out of the accumulator. The 40-bit result will be misinterpreted and will be
either not saturated or saturated incorrectly. There is a chance that the result of
left shift may produce a result which can saturate an original positive number to
the minimum negative value, or vice versa.
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.9.9
The 40-bit Signed Accumulator Register
The 40-bit accumulator consists of three concatenated registers MAE, MAH, and MAL.
MAE is 8 bits wide, MAH and MAL are 16 bits wide. MAE is the Most Significant Byte of
the 40-bit accumulator. This byte performs a guarding function. MAE is accessed as the
lower byte of register MSW.
When MAH is written, the value in the accumulator is automatically adjusted to signed
extended 40-bit format. That means MAL is cleared and MAE will be automatically
loaded with zeros for a positive number (the most significant bit of MAH is 0), and with
ones for a negative number (the most significant bit of MAH is 1), representing the
extended 40-bit negative number in 2’s complement notation. One may see that the
extended 40-bit value is equal to the 32-bit value without extension. In other words, after
this extension, MAE does not contain significant bits. Generally, this condition is present
when the highest 9 bits of the 40-bit signed result are the same.
During the accumulator operations, an overflow may happen and the result may not fit
into 32 bits and MAE will change. The extension flag “E” in register MSW is set when the
signed result in the accumulator has exceeded the 32-bit boundary. This condition is
present when the highest 9 bits of the 40-bit signed result are not the same, i.e. MAE
contains significant bits.
Most CoXXX operations specify the 40-bit accumulator register as a source and/or a
destination operand.
MAL
Accumulator Low Word
15
14
13
12
11
SFR (FE5CH/2EH)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
MAL
rwh
Field
Bits
Type
Description
MAL
[15:0]
rwh
Low Part of Accumulator
The 40-bit accumulator is completed by the
accumulator high word (MAH) and bitfield MAE
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
MAH
Accumulator High Word
15
14
13
12
11
SFR (FE5EH/2FH)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
MAH
rwh
Field
Bits
Type
Description
MAH
[15:0]
rwh
High Part of Accumulator
The 40-bit accumulator is completed by the
accumulator low word (MAL) and bitfield MAE
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.9.10
The MAC Unit Status Word MSW
The upper byte of register MSW (bit-addressable) shows the current status of the MAC
Unit. The lower byte of register MSW represents the 8-bit MAC accumulator extension,
building the 40-bit accumulator together with registers MAH and MAL.
MSW
MAC Status Word
15
14
13
12
SFR (FFDEH/EFH)
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
-
MV MSL ME MSV MC
MZ
MN
MAE
-
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
2
1
0
Field
Bits
Type
Description
MV
14
rwh
Overflow Flag
0
No Overflow produced
1
Overflow produced
MSL
13
rwh
Sticky Limit Flag
0
Result was not saturated
1
Result was saturated
ME
12
rwh
MAC Extension Flag
0
MAE does not contain significant bits
1
MAE contains significant bits
MSV
11
rwh
Sticky Overflow Flag
0
No Overflow occurred
1
Overflow occurred
MC
10
rwh
Carry Flag
0
No carry/borrow produced
1
Carry/borrow produced
MZ
9
rwh
Zero Flag
0
MAC result is not zero
1
MAC result is zero
MN
8
rwh
Negative Result
0
MAC result is positive
1
MAC result is negative
MAE
[7:0]
rwh
MAC Accumulator Extension
The most significant bits of the 40-bit accumulator,
completing registers MAH and MAL
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System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
MAC Unit Status (MV, MN, MZ, MC, MSV, ME, MSL)
These condition flags indicate the MAC status resulting from the most recently
performed MAC operation. These flags are controlled by the majority of MAC instructions
according to specific rules. Those rules depend on the instruction managing the MAC or
data movement operation.
After execution of an instruction which explicitly updates register MSW, the condition
flags may no longer represent an actual MAC status. An explicit write operation to
register MSW supersedes the condition flag values implicitly generated by the MAC unit.
An explicit read access returns the value of register MSW after execution of the
immediately preceding instruction. Register MSW can be accessed via any instruction
capable of accessing an SFR.
Note: After reset, all MAC status bits are cleared.
MN-Flag: For the majority of the MAC operations, the MN-flag is set to 1 if the most
significant bit of the result contains a 1; otherwise, it is cleared. In the case of integer
operations, the MN-flag can be interpreted as the sign bit of the result (negative: MN = 1,
positive: MN = 0). Negative numbers are always represented as the 2’s complement of
the corresponding positive number. The range of signed numbers extends from
80’0000’0000H to 7F’FFFF’FFFFH.
MZ-Flag: The MZ-flag is normally set to 1 if the result of a MAC operation equals zero;
otherwise, it is cleared.
MC-Flag: After a MAC addition, the MC-flag indicates that a “Carry” from the most
significant bit of the accumulator extension MAE has been generated. After a MAC
subtraction or a MAC comparison, the MC-flag indicates a “Borrow” representing the
logical negation of a “Carry” for the addition. This means that the MC-flag is set to 1 if no
“Carry” from the most significant bit of the accumulator has been generated during a
subtraction. Subtraction is performed by the MAC Unit as a 2’s complement addition and
the MC-flag is cleared when this complement addition caused a “Carry”.
For left-shift MAC operations, the MC-flag represents the value of the bit shifted out last.
Right-shift MAC operations always clear the MC-flag. The arithmetic right-shift MAC
operation can set the MC-flag if the enabled round operation generates a “Carry” from
the most significant bit of the accumulator extension MAE.
MSV-Flag: The addition, subtraction, 2’s complement, and round operations always set
the MSV-flag to 1 if the MAC result exceeds the maximum range of 40-bit signed
numbers. If the MSV-flag indicates an arithmetic overflow, the MAC result of an
operation is not valid.
The MSV-flag is a ‘Sticky Bit’. Once set, other MAC operations cannot affect the status
of the MSV-flag. Only a direct write operation can clear the MSV-flag.
ME-Flag: The ME-flag is set if the accumulator extension MAE contains significant bits,
that means if the nine highest accumulator bits are not all equal.
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Central Processing Unit (CPU)
MSL-Flag: The MSL-flag is set if an automatic saturation of the accumulator has
happened. The automatic saturation is enabled if bit MS in register MCW is set. The
MSL-Flag can be also set by instructions which limit the contents of the accumulator. If
the accumulator has been limited, the MSL-Flag is set.
The MSL-Flag is a ‘Sticky Bit’. Once set, it cannot be affected by the other MAC
operations. Only a direct write operation can clear the MSL-flag.
MV-Flag: The addition, subtraction, and accumulation operations set the MV-flag to 1 if
the result exceeds the maximum range of signed numbers (80’0000’0000H to
7F’FFFF’FFFFH); otherwise, the MV-flag is cleared. Note that if the MV-flag indicates an
arithmetic overflow, the result of the integer addition, integer subtraction, or
accumulation is not valid.
4.9.11
The Repeat Counter MRW
The Repeat Counter MRW controls the number of repetitions a loop must be executed.
The register must be pre-loaded before it can be used with -USRx CoXXX operations.
MAC operations are able to decrement this counter. When a -USRx CoXXX instruction
is executed, MRW is checked for zero before being decremented. If MRW equals zero,
bit USRx is set and MRW is not further decremented. Register MRW can be accessed
via any instruction capable of accessing a SFR.
MRW
MAC Repeat Word
15
14
13
12
SFR (FFDAH/EDH)
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
REPEAT_COUNT
rwh
Field
Bits
Type
Description
REPEAT_
COUNT
[15:0]
rwh
16-bit loop counter
All CoXXX instructions have a 3-bit wide repeat control field ‘rrr’ (bit positions [31:29]) in
the operand field to control the MRW repeat counter. Table 4-26 lists the possible
encodings.
User’s Manual
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
Table 4-26
Encoding of MAC Repeat Word Control
Code in ‘rrr’
Effect on Repeat Counter
000B
regular CoXXX instruction
001B
RESERVED
010B
‘-USR0 CoXXX’ instruction,
decrements repeat counter and sets bit USR0 if MRW is zero
011B
‘-USR1 CoXXX’ instruction,
decrements repeat counter and sets bit USR1 if MRW is zero
1XXB
RESERVED
Note: Bit USR0 has been a general purpose flag also in previous architectures. To
prevent collisions due to using this flag by programmer or compiler, use
‘-USR0 C0XXX’ instructions very carefully.
The following example shows a loop which is executed 20 times. Every time the
CoMACM instruction is executed, the MRW counter is decremented.
MOV
loop01:
-USR1
MRW, #19
;Pre-load loop counter
CoMACM [IDX0+], [R0+]
;Calculate and decrement MSW
ADD
R2,#0002H
JMPA
cc_nusr1, loop01 ;Repeat loop until USR1 is set
Note: Because correctly predicted JMPA is executed in 0-cycle, it offers the functionality
of a repeat instruction.
User’s Manual
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Central Processing Unit (CPU)
4.10
Constant Registers
All bits of these bit-addressable registers are fixed to 0 or 1 by hardware. These registers
can be read only. Register ZEROS/ONES can be used as a register-addressable
constant of all zeros or all ones, for example for bit manipulation or mask generation. The
constant registers can be accessed via any instruction capable of addressing an SFR.
ZEROS
Zeros Register
SFR (FF1CH/8EH)
Reset Value: 0000H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
Field
Bits
Type Description
0
[15:0]
r
Constant Zero Bit
ONES
Ones Register
SFR (FF1EH/8FH)
Reset Value: FFFFH
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
Field
Bits
Type Description
1
[15:0]
r
User’s Manual
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Constant One Bit
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
5
Interrupt and Trap Functions
The architecture of the XC2700 supports several mechanisms for fast and flexible
response to service requests from various internal or external sources. Different kinds of
exceptions are handled in a similar way:
•
•
•
Interrupts generated by the Interrupt Controller (ITC)
DMA transfers issued by the Peripheral Event Controller (PEC)
Traps caused by the TRAP instruction or issued by faults or specific system states
Normal Interrupt Processing
The CPU temporarily suspends current program execution and branches to an interrupt
service routine to service an interrupt requesting device. The current program status (IP,
PSW, also CSP in segmentation mode) is saved on the internal system stack. A
prioritization scheme with 16 priority levels allows the user to specify the order in which
multiple interrupt requests are to be handled.
Interrupt Processing via the Peripheral Event Controller (PEC)
A faster alternative to normal software controlled interrupt processing is servicing an
interrupt requesting device with the XC2700’s integrated Peripheral Event Controller
(PEC). Triggered by an interrupt request, the PEC performs a single word or byte data
transfer between any two locations through one of eight programmable PEC Service
Channels. During a PEC transfer, normal program execution of the CPU is halted. No
internal program status information needs to be saved. The same prioritization scheme
is used for PEC service as for normal interrupt processing.
Trap Functions
Trap functions are activated in response to special conditions that occur during the
execution of instructions. A trap can also be caused externally via the External Service
Request pins, ESRx. Several hardware trap functions are provided to handle erroneous
conditions and exceptions arising during instruction execution. Hardware traps always
have highest priority and cause immediate system reaction. The software trap function
is invoked by the TRAP instruction that generates a software interrupt for a specified
interrupt vector. For all types of traps, the current program status is saved on the system
stack.
External Interrupt Processing
Although the XC2700 does not provide dedicated interrupt pins, it allows connection of
external interrupt sources and provides several mechanisms to react to external events
including standard inputs, non-maskable interrupts, and fast external interrupts. Except
for the non-maskable interrupt and the reset input, these interrupt functions are alternate
port functions.
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ICU_X2K, V2.2
5-1
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XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
5.1
Interrupt System Structure
The XC2700 provides 96 separate interrupt nodes assignable to 16 priority levels, with
8 sub-levels (group priority) on each level. In order to support modular and consistent
software design techniques, most sources of an interrupt or PEC request are supplied
with a separate interrupt control register and an interrupt vector. The control register
contains the interrupt request flag, the interrupt enable bit, and the interrupt priority of the
associated source. Each source request is then activated by one specific event,
determined by the selected operating mode of the respective device. For efficient
resource usage, multi-source interrupt nodes are also incorporated. These nodes can be
activated by several source requests, such as by different kinds of errors in the serial
interfaces. However, specific status flags which identify the type of error are
implemented in the serial channels’ control registers. Additional sharing of interrupt
nodes is supported via interrupt subnode control registers.
The XC2700 provides a vectored interrupt system. In this system specific vector
locations in the memory space are reserved for the reset, trap, and interrupt service
functions. Whenever a request occurs, the CPU branches to the location that is
associated with the respective interrupt source. This allows direct identification of the
source which caused the request. The Class B hardware traps all share the same
interrupt vector. The status flags in the Trap Flag Register (TFR) can then be used to
determine which exception caused the trap. For the special software TRAP instruction,
the vector address is specified by the operand field of the instruction, which is a seven
bit trap number.
The reserved vector locations build a jump table in the low end of a segment (selected
by register VECSEG) in the XC2700’s address space. The jump table consists of the
appropriate jump instructions which transfer control to the interrupt or trap service
routines and which may be located anywhere within the address space. The entries of
the jump table are located at the lowest addresses in the selected code segment. Each
entry occupies 2, 4, 8, or 16 words (selected by bitfield VECSC in register CPUCON1),
providing room for at least one doubleword instruction. The respective vector location
results from multiplying the trap number by the selected step width (2(VECSC+2)).
All pending interrupt requests are arbitrated. The arbitration winner is indicated to the
CPU together with its priority level and action request. The CPU triggers the
corresponding action based on the required functionality (normal interrupt, PEC, jump
table cache, etc.) of the arbitration winner.
An action request will be accepted by the CPU if the requesting source has a higher
priority than the current CPU priority level and interrupts are globally enabled. If the
requesting source has a lower (or equal) interrupt level priority than the current CPU
task, it remains pending.
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Interrupt and Trap Functions
Interrupt and Peripheral Event Controller
PEC Pointer
Interrupt
Request
Lines
SRCP0
DSTP0
PECSEG0
SRCP1
DSTP1
PECSEG1
SRCP7
DSTP7
PECSEG7
irq0
irq1
C166S V2
CPU
PEC Request
irq2
irq3
Arbitration
irq n-3
irq n-1
irq n-2 1)
Arbitr.
Winner
EOP
INT 2)
Peripheral
Event
Controller
(PEC)
Request
Control
Request
Control
Interrupt
Handler
Interrupt
Request
Arbitration
Control
PEC
Control
Interrupt
Handler Control
(Interrupt Control
Registers)
(PEC Control
Registers)
Fast Bank
Switching
Interrupt
Request
Injection
Control
(CPU Action
Request)
OCE Injection
Request & Control
Injection
Interface
OCE/OCDS
BNKSEL0
irq0IC
PECC0
irq1IC
PECC1
irq126IC
PECC7
EOPIC
PECISNC
BNKSEL3
Interrupt Jump
Table Cache
FINT0CSP
FINT0ADDR
FINT1CSP
FINT1ADDR
1)
2)
Number of interrupt nodes n (up to 128)
End of PEC Interrupt (EOPINT) is connected to Interrupt request line irq n-1.
Therefore, only n-1 interrupt lines (irq n-2 ... 0) are available for peripheral request handling.
Figure 5-1
User’s Manual
ICU_X2K, V2.2
MCB04915
Block Diagram of the Interrupt and PEC Controller
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Interrupt and Trap Functions
5.2
Interrupt Arbitration and Control
The XC2700’s interrupt arbitration system handles interrupt requests from up to
80 sources. Interrupt requests may be triggered either by the on-chip peripherals or by
external inputs.
Interrupt processing is controlled globally by register PSW through a general interrupt
enable bit (IEN) and the CPU priority field (ILVL). Additionally, the different interrupt
sources are controlled individually by their specific interrupt control registers (… IC).
Thus, the acceptance of requests by the CPU is determined by both the individual
interrupt control registers and by the PSW. PEC services are controlled by the respective
PECCx register and by the source and destination pointers which specify the task of the
respective PEC service channel.
An interrupt request sets the associated interrupt request flag xxIR. If the requesting
interrupt node is enabled by the associated interrupt enable bit xxIE arbitration starts with
the next clock cycle, or after completion of an arbitration cycle that is already in progress.
All interrupt requests pending at the beginning of a new arbitration cycle are considered,
independently from when they were actually requested.
Figure 5-2 shows the three-stage interrupt prioritization scheme:
Hardware
Traps
OCDS
break
request
OCDS
or
OCE
Interrupt
Request
Lines
Request
Lines
Arbitration
xxxx
(ILVL)+
x.xx
(XGLVL)
PEC/
Interrupt
Handler
xxxxx
(OCDS
service
request
priority
level)
0xxxx
(ILVL
extended
with
0 in MSB)
CPU
CPU
Action
Control
xxxxx
(request
priority
level)
0xxxx
(PSW.ILVL
extended
with 0
in MSB)
CPU
Arbitration
PSW
Stage 1:
Compared 4-Bit ILVL+
2/3-Bit XGLVL
priority levels of
interrupt sources
(64/128 priority levels)
Stage 2:
4-Bit IRQ/PEC priority level
comparated with
5-Bit OCDS priority level
Stage 3:
5-Bit request priority level
comparated with
4-Bit PSW priority level
MCD04913
Figure 5-2
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Interrupt Arbitration
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Interrupt and Trap Functions
The interrupt prioritization is done in three stages:
•
•
•
Select one of the active interrupt requests
Compare the priority levels of the selected interrupt request and an eventual OCDS
service request
Compare the priority level of the resulting request with the actual CPU priority level
The First Arbitration Stage
compares the priority levels of the active interrupt request lines. The interrupt priority
level of each requestor is defined by bitfield ILVL in the respective xxIC register. The
extended group priority level XGLVL (combined from bitfields GPX and GLVL) defines
up to eight sub-priorities within one interrupt level. The group priority level distinguishes
interrupt requests assigned to the same priority level, so one winner can be determined.
Note: All interrupt request sources that are enabled and programmed to the same
interrupt priority level (ILVL) must have different group priority levels. Otherwise,
an incorrect interrupt vector will be generated.
The Second Arbitration Stage
compares the priority of the first stage winner with the priority of OCDS service requests.
OCDS service requests bypass the first stage of arbitration and go directly to the CPU
Action Control Unit. The CPU Action Control Unit compares the winner’s 4-bit priority
level (disregarding the group level) with the 5-bit OCDS service request priority. The 4-bit
ILVL of the interrupt request is extended to a 5-bit value with MSB = 0. This means that
any OCDS request with MSB = 1 will always win the second stage arbitration. However,
if there is a conflict between an OCDS request and an interrupt request, the interrupt
request wins.
The Third Arbitration Stage
compares the priority level of the second stage winner with the priority of the current CPU
task. An action request will be accepted by the CPU only if the priority level of the request
is higher than the current CPU priority level (bitfield ILVL in register PSW) and if interrupt
and PEC requests are globally enabled by the global interrupt enable flag IEN in register
PSW. To compare with the 5-bit priority level of the second stage winner, the 4-bit CPU
priority level is extended to a 5-bit value with MSB = 0. This means that any request with
MSB = 1 will always interrupt the current CPU task. If the requestor has a priority level
lower than or equal to the current CPU task, the request remains pending.
Note: Priority level 0000B is the default level of the CPU. Therefore, a request on
interrupt priority level 0000B will be arbitrated, but the CPU will never accept an
action request on this level. However, every individually enabled interrupt request
(including all denied interrupt requests and priority level 0000B requests) triggers
a CPU wake-up from idle state independent of the global interrupt enable bit IEN.
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System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Both the OCDS break requests and the hardware traps bypass the arbitration scheme
and go directly to the core (see also Figure 5-2).
The arbitration process starts with an enabled interrupt request and stays active as long
as an interrupt request is pending. If no interrupt request is pending the arbitration is
stopped to save power.
Interrupt Control Registers
The control functions for each interrupt node are grouped in a dedicated interrupt control
register (xxIC, where “xx” stands for a mnemonic for the respective node). All interrupt
control registers are organized identically. The lower 9 bits of an interrupt control register
contain the complete interrupt control and status information of the associated source
required during one round of prioritization (arbitration cycle); the upper 7 bits are
reserved for future use. All interrupt control registers are bit-addressable and all bits can
be read or written via software. Therefore, each interrupt source can be programmed or
modified with just one instruction.
xxIC
Interrupt Control Register
(E)SFR (yyyyH/zzH)
15
14
13
12
11
10
9
-
-
-
-
-
-
-
-
-
-
-
-
-
-
8
7
6
Reset Value: - 000H
5
GPX xxIR xxIE
rw
rwh
rw
4
3
2
1
0
ILVL
GLVL
rw
rw
Field
Bits
Type
Description
GPX
8
rw
Group Priority Extension
Completes bitfield GLVL to the 3-bit group level
xxIR1)
7
rwh
Interrupt Request Flag
0
No request pending
1
This source has raised an interrupt request
xxIE
6
rw
Interrupt Enable Control Bit
(individually enables/disables a specific source)
0
Interrupt request is disabled
1
Interrupt request is enabled
ILVL
[5:2]
rw
Interrupt Priority Level
FH Highest priority level
…
…
0H Lowest priority level
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Interrupt and Trap Functions
Field
Bits
Type
Description
GLVL
[1:0]
rw
Group Priority Level
(Is completed by bit GPX to the 3-bit group level)
3H Highest priority level
…
…
0H Lowest priority level
1) Bit xxIR supports bit-protection.
When accessing interrupt control registers through instructions which operate on word
data types, their upper 7 bits (15 … 9) will return zeros when read, and will discard
written data. It is recommended to always write zeros to these bit positions. The layout
of the interrupt control registers shown below applies to each xxIC register, where “xx”
represents the mnemonic for the respective source.
The Interrupt Request Flag is set by hardware whenever a service request from its
respective source occurs. It is cleared automatically upon entry into the interrupt service
routine or upon a PEC service. In the case of PEC service, the Interrupt Request flag
remains set if the COUNT field in register PECCx of the selected PEC channel
decrements to zero and bit EOPINT is cleared. This allows a normal CPU interrupt to
respond to a completed PEC block transfer on the same priority level.
Note: Modifying the Interrupt Request flag via software causes the same effects as if it
had been set or cleared by hardware.
The Interrupt Enable Control Bit determines whether the respective interrupt node
takes part in the arbitration process (enabled) or not (disabled). The associated request
flag will be set upon a source request in any case. The occurrence of an interrupt request
can so be polled via xxIR even while the node is disabled.
Note: In this case the interrupt request flag xxIR is not cleared automatically but must be
cleared via software.
Interrupt Priority Level and Group Level
The four bits of bitfield ILVL specify the priority level of a service request for the
arbitration of simultaneous requests. The priority increases with the numerical value of
ILVL: so, 0000B is the lowest and 1111B is the highest priority level.
When more than one interrupt request on a specific level becomes active at the same
time, the values in the respective bitfields GPX and GLVL are used for second level
arbitration to select one request to be serviced. Again, the group priority increases with
the numerical value of the concatenation of bitfields GPX and GLVL, so 000B is the
lowest and 111B is the highest group priority.
Note: All interrupt request sources enabled and programmed to the same priority level
must always be programmed to different group priorities. Otherwise, an incorrect
interrupt vector will be generated.
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System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Upon entry into the interrupt service routine, the priority level of the source that won the
arbitration and whose priority level is higher than the current CPU level, is copied into
bitfield ILVL of register PSW after pushing the old PSW contents onto the stack.
The interrupt system of the XC2700 allows nesting of up to 15 interrupt service routines
of different priority levels (level 0 cannot be arbitrated).
Interrupt requests programmed to priority levels 15 … 8 (i.e., ILVL = 1XXXB) can be
serviced by the PEC if the associated PEC channel is properly assigned and enabled
(please refer to Section 5.4). Interrupt requests programmed to priority levels 7 through
1 will always be serviced by normal interrupt processing.
Note: Priority level 0000B is the default level of the CPU. Therefore, a request on level 0
will never be serviced because it can never interrupt the CPU. However, an
individually enabled interrupt request (independent of bit IEN) on level 0000B will
reactivate the CPU.
General Interrupt Control Functions in Register PSW
The acceptance of an interrupt request depends on the current CPU priority level (bitfield
ILVL in register PSW) and the global interrupt enable control bit IEN in register PSW (see
Section 4.8).
CPU Priority ILVL defines the current level for the operation of the CPU. This bitfield
reflects the priority level of the routine currently executed. Upon entry into an interrupt
service routine, this bitfield is updated with the priority level of the request being serviced.
The PSW is saved on the system stack before the request is serviced. The CPU level
determines the minimum interrupt priority level which will be serviced. Any request on
the same or a lower level will not be acknowledged. The current CPU priority level may
be adjusted via software to control which interrupt request sources will be
acknowledged. PEC transfers do not really interrupt the CPU, but rather “steal” a single
cycle, so PEC services do not influence the ILVL field in the PSW.
Hardware traps switch the CPU level to maximum priority (i.e. 15) so no interrupt or PEC
requests will be acknowledged while an exception trap service routine is executed.
Note: The TRAP instruction does not change the CPU level, so software invoked trap
service routines may be interrupted by higher requests.
Interrupt Enable bit IEN globally enables or disables PEC operation and the
acceptance of interrupts by the CPU. When IEN is cleared, no new interrupt requests are
accepted by the CPU (see also Section 4.3.4). When IEN is set to 1, all interrupt
sources, which have been individually enabled by the interrupt enable bits in their
associated control registers, are globally enabled. Traps are non-maskable and are,
therefore, not affected by the IEN bit.
Note: To generate requests, interrupt sources must be also enabled by the interrupt
enable bits in their associated control register.
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System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Register Bank Select bitfield BANK defines the currently used register bank for the
CPU operation. When the CPU enters an interrupt service routine, this bitfield is updated
to select the register bank associated with the serviced request:
•
•
•
•
Requests on priority levels 15 … 12 use the register bank pre-selected via the
respective bitfield GPRSELx in the corresponding BNKSEL register
Requests on priority levels 11 … 1 always use the global register bank,
i.e. BANK = 00B
Hardware traps always use the global register bank, i.e. BANK = 00B
The TRAP instruction does not change the current register bank
Temporary Control of Interrupts
Interrupt requests may be temporarily disabled and enabled during the execution of the
software. This may be required to exclude specific interrupt sources based on the current
status of the application. In particular, this is necessary to achieve a deterministic
execution of time-critical code sequences.
Interrupt requests in the XC2700 can be disabled and enabled on three different levels:
•
•
•
Control all interrupt requests globally
Control configurable groups of interrupt requests
Control single interrupt requests
Global interrupt control is achieved with a single instruction:
BCLR IEN
;Clear IEN flag (causes pipeline restart)
Groups of interrupts (classes) are defined and controlled by software as described in
Section 5.5.
Specific interrupt control is achieved by controlling the enable bits in the associated
interrupt control registers.
BCLR T2IE
;Clear enable flag to disable intr.node
Due to pipeline effects, however, an interrupt request may be executed after the
corresponding node was disabled, if the request coincides with clearing the enable flag.
If the application must avoid this, the following sequence can be used, ensuring that no
interrupt requests from this source will be serviced after disabling the interrupt node:
BCLR IEN
BCLR T2IE
JNB T2IE, Next
Next:
BSET IEN
User’s Manual
ICU_X2K, V2.2
;Globally disable interrupts
;Disable Timer 2 interrupt node
;Any instruction reading T2IC can be used
;(assures that T2IC is written by BCLR
;before being read by JNB or other instr.)
;Globally enable interrupts again
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Interrupt and Trap Functions
Please note that the sequence above blindly controls the global enable flag. If the global
setting must not be changed, the code sequence can be enhanced, as shown below:
JNB IEN, GlobalIntOff
BCLR IEN
;Globally disable interrupts
BCLR T2IE
;Disable Timer 2 interrupt node
JNB T2IE, Next
;Any instruction reading T2IC can be used
Next:
;(assures that T2IC is written by BCLR
;before being read by JNB or other instr.)
BSET IEN
;Globally enable interrupts again
JMPR cc_uc, Continue
GlobalIntOff:
;Interrupts are globally disabled anyway
BCLR T2IE
;Disable Timer 2 interrupt node
JNB T2IE, Continue ;Reading T2IC can be omitted if the next
Continue:
;few instructions do not set IEN
...
The same function can easily be implemented as a C macro:
#define Disable_One_Interrupt(IE_bit) \\
{if(IEN) {IEN=0; IE_bit=0; while (IE_bit); IEN=1;} else
{IE_bit=0; while IE_bit);}}
Usage Example:
Disable_One_Interrupt(T2IE) ; // T2 interrupt enable flag
ATOMIC or EXTend sequences preserve the status of the interrupt arbitration when they
begin. An accepted request is processed after the ATOMIC/EXTend sequence.
Therefore, the following code sequence may not produce the desired result:
AvoidThis:
ATOMIC #3
BCLR T2IE
NOP
NOP
User’s Manual
ICU_X2K, V2.2
;Disable Timer 2 interrupt node
;Timer 2 request may be processed
;after this instruction!!!
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Interrupt and Trap Functions
5.3
Interrupt Vector Table
The XC2700 provides a vectored interrupt system. This system reserves a set of specific
memory locations, which are accessed automatically upon the respective trigger event.
Entries for the following events are provided:
•
•
•
Reset (hardware, software, watchdog)
Traps (hardware-generated by fault conditions or via TRAP instruction)
Interrupt service requests
Whenever a request is accepted, the CPU branches to the location associated with the
respective trigger source. This vector position directly identifies the source causing the
request, with two exceptions:
•
•
Class B hardware traps all share the same interrupt vector. The status flags in the
Trap Flag Register (TFR) are used to determine which exception caused the trap. For
details, see Section 5.11.
An interrupt node may be shared by several interrupt requests, e.g. within a module.
Additional flags identify the requesting source, so the software can handle each
request individually. For details, see Section 5.7.
The reserved vector locations build a vector table located in the address space of the
XC2700. The vector table usually contains the appropriate jump instructions that transfer
control to the interrupt or trap service routines. These routines may be located anywhere
within the address space. The location and organization of the vector table is
programmable.
The Vector Segment register VECSEG defines the segment of the Vector Table (can be
located in all segments, except for reserved areas).
Bitfield VECSC in register CPUCON1 defines the space between two adjacent vectors
(can be 2, 4, 8, or 16 words). For a summary of register CPUCON1, please refer to
Section 4.4.
Each vector location has an offset address to the segment base address of the vector
table (given by VECSEG). The offset can be easily calculated by multiplying the vector
number with the vector space programmed in bitfield VECSC.
Table 0-2 lists all sources capable of requesting interrupt or PEC service in the XC2700,
the associated interrupt vector locations, the associated vector numbers, and the
associated interrupt control registers.
Note: All interrupt nodes which are currently not used by their associated modules or are
not connected to a module in the actual derivative may be used to generate
software controlled interrupt requests by setting the respective IR flag.
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Interrupt and Trap Functions
VECSEG
Vector Segment Pointer
SFR (FF12H/89H)
7
6
Reset Value: Table 5-1
15
14
13
12
11
10
9
8
5
4
3
-
-
-
-
-
-
-
-
vecseg
-
-
-
-
-
-
-
-
rwh
Field
Bits
Type
Description
vecseg
[7:0]
rwh
Segment number of the Vector Table
2
1
0
The reset value of register VECSEG, that means the initial location of the vector table,
depends on the reset configuration. Table 5-1 lists the possible locations. This is
required because the vector table also provides the reset vector.
Table 5-1
Reset Values for Register VECSEG
Initial Value
Reset Configuration
0000H
Standard start from external memory
00C0H
Standard start from Internal Program Memory
00E0H
Execute bootstrap loader code
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Interrupt and Trap Functions
Table 5-2
XC2700 Interrupt Nodes
Source of Interrupt or PEC
Service Request
Control
Register
Vector
Location1)
Trap
Number
CAPCOM Register 16, or
ERU Request 0
CC2_CC16IC
xx’0040H
10H / 16D
CAPCOM Register 17, or
ERU Request 1
CC2_CC17IC
xx’0044H
11H / 17D
CAPCOM Register 18, or
ERU Request 2
CC2_CC18IC
xx’0048H
12H / 18D
CAPCOM Register 19, or
ERU Request 3
CC2_CC19IC
xx’004CH
13H / 19D
CAPCOM Register 20, or
USIC0 Request 6
CC2_CC20IC
xx’0050H
14H / 20D
CAPCOM Register 21, or
USIC0 Request 7
CC2_CC21IC
xx’0054H
15H / 21D
CAPCOM Register 22, or
USIC1 Request 6
CC2_CC22IC
xx’0058H
16H / 22D
CAPCOM Register 23, or
USIC1 Request 7
CC2_CC23IC
xx’005CH
17H / 23D
CAPCOM Register 24, or
ERU Request 0
CC2_CC24IC
xx’0060H
18H / 24D
CAPCOM Register 25, or
ERU Request 1
CC2_CC25IC
xx’0064H
19H / 25D
CAPCOM Register 26, or
ERU Request 2
CC2_CC26IC
xx’0068H
1AH / 26D
CAPCOM Register 27, or
ERU Request 3
CC2_CC27IC
xx’006CH
1BH / 27D
CAPCOM Register 28, or
USIC2 Request 6
CC2_CC28IC
xx’0070H
1CH / 28D
CAPCOM Register 29, or
USIC2 Request 7
CC2_CC29IC
xx’0074H
1DH / 29D
CAPCOM Register 30
CC2_CC30IC
xx’0078H
1EH / 30D
CAPCOM Register 31
CC2_CC31IC
xx’007CH
1FH / 31D
GPT1 Timer 2
GPT12E_T2IC
xx’0080H
20H / 32D
GPT1 Timer 3
GPT12E_T3IC
xx’0084H
21H / 33D
GPT1 Timer 4
GPT12E_T4IC
xx’0088H
22H / 34D
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Interrupt and Trap Functions
Table 5-2
XC2700 Interrupt Nodes (cont’d)
Source of Interrupt or PEC
Service Request
Control
Register
Vector
Location1)
Trap
Number
GPT2 Timer 5
GPT12E_T5IC
xx’008CH
23H / 35D
GPT2 Timer 6
GPT12E_T6IC
xx’0090H
24H / 36D
GPT2 CAPREL Register
GPT12E_CRIC
xx’0094H
25H / 37D
CAPCOM Timer 7
CC2_T7IC
xx’0098H
26H / 38D
CAPCOM Timer 8
CC2_T8IC
xx’009CH
27H / 39D
A/D Converter Request 0
ADC_0IC
xx’00A0H
28H / 40D
A/D Converter Request 1
ADC_1IC
xx’00A4H
29H / 41D
A/D Converter Request 2
ADC_2IC
xx’00A8H
2AH / 42D
A/D Converter Request 3
ADC_3IC
xx’00ACH
2BH / 43D
A/D Converter Request 4
ADC_4IC
xx’00B0H
2CH / 44D
A/D Converter Request 5
ADC_5IC
xx’00B4H
2DH / 45D
A/D Converter Request 6
ADC_6IC
xx’00B8H
2EH / 46D
A/D Converter Request 7
ADC_7IC
xx’00BCH
2FH / 47D
CCU60 Request 0
CCU60_0IC
xx’00C0H
30H / 48D
CCU60 Request 1
CCU60_1IC
xx’00C4H
31H / 49D
CCU60 Request 2
CCU60_2IC
xx’00C8H
32H / 50D
CCU60 Request 3
CCU60_3IC
xx’00CCH
33H / 51D
CCU61 Request 0
CCU61_0IC
xx’00D0H
34H / 52D
CCU61 Request 1
CCU61_1IC
xx’00D4H
35H / 53D
CCU61 Request 2
CCU61_2IC
xx’00D8H
36H / 54D
CCU61 Request 3
CCU61_3IC
xx’00DCH
37H / 55D
CCU62 Request 0
CCU62_0IC
xx’00E0H
38H / 56D
CCU62 Request 1
CCU62_1IC
xx’00E4H
39H / 57D
CCU62 Request 2
CCU62_2IC
xx’00E8H
3AH / 58D
CCU62 Request 3
CCU62_3IC
xx’00ECH
3BH / 59D
CCU63 Request 0
CCU63_0IC
xx’00F0H
3CH / 60D
CCU63 Request 1
CCU63_1IC
xx’00F4H
3DH / 61D
CCU63 Request 2
CCU63_2IC
xx’00F8H
3EH / 62D
CCU63 Request 3
CCU63_3IC
xx’00FCH
3FH / 63D
CAN Request 0
CAN_0IC
xx’0100H
40H / 64D
User’s Manual
ICU_X2K, V2.2
5-14
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Table 5-2
XC2700 Interrupt Nodes (cont’d)
Source of Interrupt or PEC
Service Request
Control
Register
Vector
Location1)
Trap
Number
CAN Request 1
CAN_1IC
xx’0104H
41H / 65D
CAN Request 2
CAN_2IC
xx’0108H
42H / 66D
CAN Request 3
CAN_3IC
xx’010CH
43H / 67D
CAN Request 4
CAN_4IC
xx’0110H
44H / 68D
CAN Request 5
CAN_5IC
xx’0114H
45H / 69D
CAN Request 6
CAN_6IC
xx’0118H
46H / 70D
CAN Request 7
CAN_7IC
xx’011CH
47H / 71D
CAN Request 8
CAN_8IC
xx’0120H
48H / 72D
CAN Request 9
CAN_9IC
xx’0124H
49H / 73D
CAN Request 10
CAN_10IC
xx’0128H
4AH / 74D
CAN Request 11
CAN_11IC
xx’012CH
4BH / 75D
CAN Request 12
CAN_12IC
xx’0130H
4CH / 76D
CAN Request 13
CAN_13IC
xx’0134H
4DH / 77D
CAN Request 14
CAN_14IC
xx’0138H
4EH / 78D
CAN Request 15
CAN_15IC
xx’013CH
4FH / 79D
USIC0 Request 0
U0C0_0IC
xx’0140H
50H / 80D
USIC0 Request 1
U0C0_1IC
xx’0144H
51H / 81D
USIC0 Request 2
U0C0_2IC
xx’0148H
52H / 82D
USIC0 Request 3
U0C1_0IC
xx’014CH
53H / 83D
USIC0 Request 4
U0C1_1IC
xx’0150H
54H / 84D
USIC0 Request 5
U0C1_2IC
xx’0154H
55H / 85D
USIC1 Request 0
U1C0_0IC
xx’0158H
56H / 86D
USIC1 Request 1
U1C0_1IC
xx’015CH
57H / 87D
USIC1 Request 2
U1C0_2IC
xx’0160H
58H / 88D
USIC1 Request 3
U1C1_0IC
xx’0164H
59H / 89D
USIC1 Request 4
U1C1_1IC
xx’0168H
5AH / 90D
USIC1 Request 5
U1C1_2IC
xx’016CH
5BH / 91D
USIC2 Request 0
U2C0_0IC
xx’0170H
5CH / 92D
USIC2 Request 1
U2C0_1IC
xx’0174H
5DH / 93D
USIC2 Request 2
U2C0_2IC
xx’0178H
5EH / 94D
User’s Manual
ICU_X2K, V2.2
5-15
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Table 5-2
XC2700 Interrupt Nodes (cont’d)
Source of Interrupt or PEC
Service Request
Control
Register
Vector
Location1)
Trap
Number
USIC2 Request 3
U2C1_0IC
xx’017CH
5FH / 95D
USIC2 Request 4
U2C1_1IC
xx’0180H
60H / 96D
USIC2 Request 5
U2C1_2IC
xx’0184H
61H / 97D
Unassigned node
–
xx’0188H
62H / 98D
Unassigned node
–
xx’018CH
63H / 99D
Unassigned node
–
xx’0190H
64H / 100D
Unassigned node
–
xx’0194H
65H / 101D
Unassigned node
–
xx’0198H
66H / 102D
Unassigned node
–
xx’019CH
67H / 103D
Unassigned node
–
xx’01A0H
68H / 104D
Unassigned node
–
xx’01A4H
69H / 105D
Unassigned node
–
xx’01A8H
6AH / 106D
SCU Request 1
SCU_1IC
xx’01ACH
6BH / 107D
SCU Request 0
SCU_0IC
xx’01B0H
6CH / 108D
Program Flash Modules
PFM_IC
xx’01B4H
6DH / 109D
RTC
RTC_IC
xx’01B8H
6EH / 110D
End of PEC Subchannel
EOPIC
xx’01BCH
6FH / 111D
1) Register VECSEG defines the segment where the vector table is located to.
Bitfield VECSC in register CPUCON1 defines the distance between two adjacent vectors. This table
represents the default setting, with a distance of 4 (two words) between two vectors.
User’s Manual
ICU_X2K, V2.2
5-16
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Table 5-3 lists the vector locations for hardware traps and the corresponding status flags
in register TFR. It also lists the priorities of trap service for those cases in which more
than one trap condition might be detected within the same instruction. After any reset
(hardware reset, software reset instruction SRST, or reset by watchdog timer overflow)
program execution starts at the reset vector at location xx’0000H. Reset conditions have
priority over every other system activity and, therefore, have the highest priority (trap
priority III).
Software traps may be initiated to any defined vector location. A service routine entered
via a software TRAP instruction is always executed on the current CPU priority level
which is indicated in bitfield ILVL in register PSW. This means that routines entered via
the software TRAP instruction can be interrupted by all hardware traps or higher level
interrupt requests.
Table 5-3
Hardware Trap Summary
Exception Condition
Trap
Flag
Trap
Vector
Vector
Trap
Trap
1)
Location
Number Priority
Reset Functions
–
RESET
xx’0000H
00H
III
Class A Hardware Traps:
• System Request 0
• Stack Overflow
• Stack Underflow
• Software Break
SR0
STKOF
STKUF
SOFTBRK
SR0TRAP
STOTRAP
STUTRAP
SBRKTRAP
xx’0008H
xx’0010H
xx’0018H
xx’0020H
02H
04H
06H
08H
II
II
II
II
SR1
UNDOPC
ACER
PRTFLT
BTRAP
BTRAP
BTRAP
BTRAP
xx’0028H
xx’0028H
xx’0028H
xx’0028H
0AH
0AH
0AH
0AH
I
I
I
I
ILLOPA
BTRAP
xx’0028H
0AH
I
Reserved
–
–
[2CH - 3CH] [0BH 0FH]
–
Software Traps:
• TRAP Instruction
–
–
Any
Any
[xx’0000H - [00H xx’01FCH] 7FH]
in steps of
4H
Current
CPU
Priority
Class B Hardware Traps:
• System Request 1
• Undefined Opcode
• Memory Access Error
• Protected Instruction
Fault
• Illegal Word Operand
Access
1) Register VECSEG defines the segment where the vector table is located to.
Bitfield VECSC in register CPUCON1 defines the distance between two adjacent vectors. This table
represents the default setting, with a distance of 4 (two words) between two vectors.
User’s Manual
ICU_X2K, V2.2
5-17
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Interrupt Jump Table Cache
Servicing an interrupt request via the vector table usually incurs two subsequent
branches: an implicit branch to the vector location and an explicit branch to the actual
service routine. The interrupt servicing time can be reduced by the Interrupt Jump Table
Cache (ITC, also called “fast interrupt”). This feature eliminates the second explicit
branch by directly providing the CPU with the service routine’s location.
The ITC provides two 24-bit pointers, so the CPU can directly branch to the respective
service routines. These fast interrupts can be selected for two interrupt sources on
priority levels 15 … 12.
The two pointers are each stored in a pair of interrupt jump table cache registers
(FINTxADDR, FINTxCSP), which store a pointer’s segment and offset along with the
priority level it shall be assigned to (select the same priority that is programmed for the
respective interrupt node).
FINT0ADDR
Fast Interrupt Address Reg. 0
FINT1ADDR
Fast Interrupt Address Reg. 1
15
14
13
12
11
10
XSFR (EC02H/--)
Reset Value: 0000H
XSFR (EC06H/--)
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
ADDR
0
rw
r
Field
Bits
Type
Description
ADDR
[15:1]
rw
Address of Interrupt Service Routine
Specifies address bits 15 … 1 of the 24-bit pointer to
the interrupt service routine. This word offset is
concatenated with FINTxCSP.SEG.
FINT0CSP
Fast Interrupt Control Reg. 0
FINT1CSP
Fast Interrupt Control Reg. 1
10
Reset Value: 0000H
XSFR (EC04H/--)
Reset Value: 0000H
15
14
13
12
EN
-
-
GPX
ILVL
GLVL
SEG
rw
-
-
rw
rw
rw
rw
User’s Manual
ICU_X2K, V2.2
11
XSFR (EC00H/--)
9
8
7
5-18
6
5
4
3
2
1
0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Field
Bits
Type
Description
EN
15
rw
Fast Interrupt Enable
0
The interrupt jump table cache is not used
1
The interrupt jump table cache is enabled,
the vector table entry for the specified request
is bypassed, the cache pointer is used
GPX
12
rw
Group Priority Extension
Used together with bitfield GLVL
ILVL
[11:10] rw
Interrupt Priority Level
This selects the interrupt priority (15 … 12) of the
request this pointer shall be assigned to
00
Interrupt priority level 12 (1100B)
01
Interrupt priority level 13 (1101B)
10
Interrupt priority level 14 (1110B)
11
Interrupt priority level 15 (1111B)
GLVL
[9:8]
rw
Group Priority Level
Together with bit GPX this selects the group priority
of the request this pointer shall be assigned to
SEG
[7:0]
rw
Segment Number of Interrupt Service Routine
Specifies address bits 23 … 16 of the 24-bit pointer
to the interrupt service routine, is concatenated with
FINTxADDR.
User’s Manual
ICU_X2K, V2.2
5-19
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
5.4
Operation of the Peripheral Event Controller Channels
The XC2700’s Peripheral Event Controller (PEC) provides 8 PEC service channels
which move a single byte or word between any two locations. A PEC transfer can be
triggered by an interrupt service request and is the fastest possible interrupt response.
In many cases a PEC transfer is sufficient to service the respective peripheral request
(for example, serial channels, etc.).
PEC transfers do not change the current context, but rather “steal” cycles from the CPU,
so the current program status and context needs not to be saved and restored as with
standard interrupts.
The PEC channels are controlled by a dedicated set of registers which are assigned to
dedicated PEC resources:
•
•
•
•
A 24-bit source pointer for each channel
A 24-bit destination pointer for each channel
A Channel Counter/Control register (PECCx) for each channel, selecting the
operating mode for the respective channel
Two interrupt control registers to control the operation of block transfers
5.4.1
The PECC Registers
The PECC registers control the action performed by the respective PEC channel.
Transfer Size (bit BWT) controls whether a byte or a word is moved during a PEC
service cycle. This selection controls the transferred data size and the increment step for
the pointer(s) to be modified.
Pointer Modification (bitfield INC) controls, which of the PEC pointers is incremented
after the PEC transfer. If the pointers are not modified (INC = 00B), the respective
channel will always move data from the same source to the same destination.
Transfer Control (bitfield COUNT) controls if the respective PEC channel remains
active after the transfer or not. Bitfield COUNT also generally enables a PEC channel
(COUNT > 00H).
The PECC registers also select the assignment of PEC channels to interrupt priority
levels (bitfield PLEV) and the interrupt behavior after PEC transfer completion (bit
EOPINT).
Note: All interrupt request sources that are enabled and programmed for PEC service
should use different channels. Otherwise, only one transfer will be performed for
all simultaneous requests. When COUNT is decremented to 00H, and the CPU is
to be interrupted, an incorrect interrupt vector will be generated.
PEC transfers are executed only if their priority level is higher than the CPU level.
User’s Manual
ICU_X2K, V2.2
5-20
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
PECCx (x=0-7)
PEC Channel Control Reg. x
13
12
11
SFR(FEC0H+2*x)
10
9
8
7
6
Reset Value: 0000H
15
14
5
4
3
-
EOP
INT
PLEV
CL
INC
BWT
COUNT
-
rw
rw
rw
rw
rw
rwh
2
1
0
Field
Bits
Type
Description
EOPINT
14
rw
End of PEC Interrupt Selection
End of PEC interrupt on the same (PEC) level
0B
1B
End of PEC interrupt via separate node EOPIC
PLEV
[13:12] rw
PEC Level Selection
This bitfield controls the PEC channel assignment to
an arbitration priority level (see section below)
CL
11
rw
Channel Link Control
0B
PEC channels work independently
1B
Pairs of PEC channels are linked together1)
INC
[10:9]
rw
Increment Control (Pointer Modification)2)
00B Pointers are not modified
01B Increment DSTPx by 1 or 2 (BWT = 1 or 0)
10B Increment SRCPx by 1 or 2 (BWT = 1 or 0)
11B Increment both DSTPx and SRCPx by 1 or 2
BWT
8
rw
Byte/Word Transfer Selection
Transfer a word
0B
1B
Transfer a byte
COUNT
[7:0]
rwh
PEC Transfer Count
Counts PEC transfers and influences the channel’s
action (see Section 5.4.3)
1) For a functional description see “Channel Link Mode for Data Chaining”.
2) Pointers are incremented/decremented only within the current segment.
Table 5-4
PEC Control Register Addresses
Register
Address
PECC0
Register
Address
FEC0H / 60H SFR
PECC4
FEC8H / 64H SFR
PECC1
FEC2H / 61H SFR
PECC5
FECAH / 65H SFR
PECC2
FEC4H / 62H SFR
PECC6
FECCH / 66H SFR
PECC3
FEC6H / 63H SFR
PECC7
FECEH / 67H SFR
User’s Manual
ICU_X2K, V2.2
Reg. Space
5-21
Reg. Space
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
The PEC channel number is derived from the respective ILVL (LSB) and GLVL, where
the priority band (ILVL) is selected by the channel’s bitfield PLEV (see Table 5-5). So,
programming a source to priority level 15 (ILVL = 1111B) selects the PEC channel group
7 … 4 with PLEV = 00B; programming a source to priority level 14 (ILVL = 1110B) selects
the PEC channel group 3 … 0 with PLEV = 00B; programming a source to priority level
10 (ILVL = 1010B) selects the PEC channel group 3 … 0 with PLEV = 10B. The actual
PEC channel number is then determined by the group priority (levels 3 … 0, i.e.
GPX = 0).
Simultaneous requests for PEC channels are prioritized according to the PEC channel
number, where channel 0 has lowest and channel 7 has highest priority.
Note: All sources requesting PEC service must be programmed to different PEC
channels. Otherwise, an incorrect PEC channel may be activated.
Table 5-5
PEC Channel Assignment
Selected
PEC Channel
Group
Level
7
3
6
2
5
1
4
0
3
3
2
2
1
1
0
0
Used Interrupt Priorities Depending on Bitfield PLEV
PLEV = 00B
PLEV = 01B
PLEV = 10B
PLEV = 11B
15
13
11
9
14
12
10
8
Table 5-6 shows in a few examples which action is executed with a given programming
of an interrupt control register and a PEC channel.
User’s Manual
ICU_X2K, V2.2
5-22
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Table 5-6
Interrupt Priority Examples
Priority Level
Type of Service
Interr. Group COUNT = 00H,
Level Level PLEV = XXB
COUNT ≠ 00H,
PLEV = 00B
COUNT ≠ 00H,
PLEV = 01B
1111 111
CPU interrupt,
level 15, group prio 7
CPU interrupt,
level 15, group prio 7
CPU interrupt,
level 15, group prio 7
1111 011
CPU interrupt,
level 15, group prio 3
PEC service,
channel 7
CPU interrupt,
level 15, group prio 3
1111 010
CPU interrupt,
level 15, group prio 2
PEC service,
channel 6
CPU interrupt,
level 15, group prio 2
1110 010
CPU interrupt,
level 14, group prio 2
PEC service,
channel 2
CPU interrupt,
level 14, group prio 2
1101 110
CPU interrupt,
level 13, group prio 6
CPU interrupt,
level 13, group prio 6
CPU interrupt,
level 13, group prio 6
1101 010
CPU interrupt,
level 13, group prio 2
CPU interrupt,
level 13, group prio 2
PEC service,
channel 6
0001 011
CPU interrupt,
level 1, group prio 3
CPU interrupt,
level 1, group prio 3
CPU interrupt,
level 1, group prio 3
0001 000
CPU interrupt,
level 1, group prio 0
CPU interrupt,
level 1, group prio 0
CPU interrupt,
level 1, group prio 0
0000 XXX
No service!
No service!
No service!
Note: PEC service is only achieved when bit GPX = 0 and COUNT ≠ 0.
Requests on levels 7 … 1 cannot initiate PEC transfers. They are always serviced
by an interrupt service routine: no PECC register is associated and no COUNT
field is checked.
User’s Manual
ICU_X2K, V2.2
5-23
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
5.4.2
The PEC Source and Destination Pointers
The PEC channels’ source and destination pointers specify the locations between which
the data is to be moved. Both 24-bit pointers are built by concatenating the 16-bit offset
register (SRCPx or DSTPx) with the respective 8-bit segment bitfield (SRCSEGx or
DSTSEGx, combined in register PECSEGx).
PECSEGx
SRCSEGx
15
DSTSEGx
8 7
SRCPx
0
DSTPx
SRCPx
15
DSTPx
0
15
Source Pointer
23
16 15
Segment Address
Destination Pointer
0
Segment Offset
0
23
16 15
Segment Address
0
Segment Offset
Data Transfer
MCD04916
x = 7 … 0, depending on PEC channel number
Figure 5-3
PEC Data Pointers
When a PEC pointer is automatically incremented after a transfer, only the offset part is
incremented (SRCPx and/or DSTPx), while the respective segment part is not modified
by hardware. Thus, a pointer may be incremented within the current segment, but may
not cross the segment boundary. When a PEC pointer reaches the maximum offset
(FFFEH for word transfers, FFFFH for byte transfers), it is not incremented further, but
keeps its maximum offset value. This protects memory in adjacent segments from being
overwritten unintentionally.
No explicit error event is generated by the system in case of a pointer saturation;
therefore, it is the user’s responsibility to prevent this condition.
Note: PEC data transfers do not use the data page pointers DPP3 … DPP0.
Unused PEC pointers may be used for general data storage.
User’s Manual
ICU_X2K, V2.2
5-24
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
SRCPx (x=0-7)
PEC Source Pointer x
15
14
13
12
XSFR(EC40H+4*x)
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
SRCPx
rwh
Field
Bits
Type
Description
SRCPx
[15:0]
rwh
Source Pointer Offset of Channel x
Source address bits 15 … 0
DSTPx (x=0-7)
PEC Destination Pointer x
15
14
13
12
11
XSFR(EC42H+4*x)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
DSTPx
rwh
Field
Bits
Type
Description
DSTPx
[15:0]
rwh
Destination Pointer Offset of Channel x
Destination address bits 15 … 0
PECSEGx (x=0-7)
PEC Segment Pointer x
15
14
13
12
XSFR(EC80H+2*x)
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
SRCSEGx
DSTSEGx
rw
rw
2
1
Field
Bits
Type
Description
SRCSEGx
[15:8]
rw
Source Pointer Segment of Channel x
Source address bits 23 … 16
DSTSEGx
[7:0]
rw
Destination Pointer Segment of Channel x
Destination address bits 23 … 16
User’s Manual
ICU_X2K, V2.2
5-25
0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
Table 5-7
PEC Data Pointer Register Addresses
Channel #
0
1
2
3
4
5
6
7
PECSEGx
EC80H
EC82H
EC84H
EC86H
EC88H
EC8AH EC8CH EC8EH
SRCPx
EC40H
EC44H
EC48H
EC4CH EC50H
EC54H
EC58H
DSTPx
EC42H
EC46H
EC4AH EC4EH EC52H
EC56H
EC5AH EC5EH
EC5CH
Note: If word data transfer is selected for a specific PEC channel (BWT = 0), the
respective source and destination pointers must both contain a valid word address
which points to an even byte boundary. Otherwise, the Illegal Word Access trap
will be invoked when this channel is used.
5.4.3
PEC Transfer Control
The PEC Transfer Count Field COUNT controls the behavior of the respective PEC
channel. The contents of bitfield COUNT select the action to be taken at the time the
request is activated. COUNT may allow a specified number of PEC transfers, unlimited
transfers, or no PEC service at all. Table 5-8 summarizes, how the COUNT field, the
interrupt requests flag IR, and the PEC channel action depend on the previous contents
of COUNT.
Table 5-8
Influence of Bitfield COUNT
Previous
COUNT
Modified
COUNT
IR after
Service
Action of PEC Channel and Comments
FFH
FFH
0
Move a Byte/Word
Continuous transfer mode, i.e. COUNT is not
modified
FEH … 02H
FDH … 01H
0
Move a Byte/Word and decrement COUNT
01H
00H
1
EOPINT = 0 (channel-specific interrupt)
Move a Byte/Word and leave request flag set,
which triggers another request
0
EOPINT = 1 (separate end-of-PEC interrupt)
Move a Byte/Word and clear request flag, set
the respective PEC subnode request flag CxIR
instead1)
–
No PEC action!
Activate interrupt service routine rather than
PEC channel
00H
00H
1) Setting a subnode request flag also sets flag EOPIR if the subnode request is enabled (CxIE = 1).
User’s Manual
ICU_X2K, V2.2
5-26
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
The PEC transfer counter allows service of a specified number of requests by the
respective PEC channel, and then (when COUNT reaches 00H) activation of an interrupt
service routine, either associated with the PEC channel’s priority level or with the general
end-of-PEC interrupt. After each PEC transfer, the COUNT field is decremented (except
for COUNT = FFH) and the request flag is cleared to indicate that the request has been
serviced.
When COUNT contains the value 00H, the respective PEC channel remains idle and the
associated interrupt service routine is activated instead. This allows servicing requests
on all priority levels by standard interrupt service routines.
Continuous transfers are selected by the value FFH in bitfield COUNT. In this case,
COUNT is not modified and the respective PEC channel services any request until it is
disabled again.
When COUNT is decremented from 01H to 00H after a transfer, a standard interrupt is
requested which can then handle the end of the PEC block transfer (channel-specific
interrupt or common end-of-PEC interrupt, see Table 5-8).
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5.4.4
Channel Link Mode for Data Chaining
In channel link mode, every two PEC channels build a pair (channels 0+1, 2+3, 4+5,
6+7), where the two channels of a pair are activated in turn. Requests for the even
channel trigger the currently active PEC channel (or the end-of-block interrupt), while
requests for the odd channel only trigger its associated interrupt node. When the transfer
count of one channel expires, control is switched to the other channel, and back. This
mode supports data chaining where independent blocks of data can be transferred to the
same destination (or vice versa), e.g. to build communication frames from several
blocks, such as preamble, data, etc.
Channel link mode for a pair of channels is enabled if at least one of the channel link
control bits (bit CL in register PECCx) of the respective pair is set. A linked channel pair
is controlled by the priority-settings (level, group) for its even channel. After enabling
channel link mode the even channel is active.
Channel linking is executed if the active channel’s link control bit CL is 1 at the time its
transfer count decrements from 1 to 0 (count > 0 before) and the transfer count of the
other channel is non-zero. In this case the active channel issues an EOP interrupt
request and the respective other channel of the pair is automatically selected.
Note: Channel linking always begins with the even channel.
Channel linking is terminated if the active channel’s link control bit CL is 0 at the time
its transfer count decrements from 1 to 0, or if the transfer count of the respective linked
channel is zero. In this case an interrupt is triggered as selected by bit EOPINT (channelspecific or general EOP interrupt).
A data-chaining sequence using PEC channel linking is programmed by setting bit CL
together with a transfer count value (> 0). This is repeated, triggered by the channel link
interrupts, for the complete sequence. For the last transfer, the interrupt routine should
clear the respective bit CL, so, at the end of the complete transfer, either a standard or
an END of PEC interrupt can be selected by bit EOPINT of the last channel.
Note: To enable linking, initially both channels must receive a non-zero transfer count.
For the rest of the sequence only the channel with the expired transfer count
needs to be reconfigured.
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5.4.5
PEC Interrupt Control
When the selected number of PEC transfers has been executed, the respective PEC
channel is disabled and a standard interrupt service routine is activated instead. Each
PEC channel can either activate the associated channel-specific interrupt node, or
activate its associated PEC subnode request flag in register PECISNC, which then
activates the common node request flag in register EOPIC (see Figure 5-4).
PECISNC
PEC Intr. Sub-Node Ctrl. Reg.
15
14
13
12
11
10
SFR (FFD8H/ECH)
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
C7IR C7IE C6IR C6IE C5IR C5IE C4IR C4IE C3IR C3IE C2IR C2IE C1IR C1IE C0IR C0IE
rwh
rw
rwh
rw
rwh
rw
rwh
rw
rwh
rw
rwh
rw
rwh
rw
rwh
rw
Field
Bits
Type
Description
CxIR
(x = 0-7)
2*x+1
rwh
Interrupt Request Flag of PEC Channel x
0B
No request from PEC channel x pending
1B
PEC channel x has raised an end-of-PEC
interrupt request
Note: These request flags must be cleared by SW.
CxIE
(x = 0-7)
2*x
rw
Interrupt Enable Control Bit of PEC Channel x
(individually enables/disables a specific source)
0B
End-of-PEC request of channel x disabled
1B
End-of-PEC request of channel x enabled1)
1) It is recommended to clear an interrupt request flag (CxIR) before setting the respective enable flag (CxIE).
Otherwise, former requests still pending cannot trigger a new interrupt request.
EOPIC
End-of-PEC Intr. Ctrl. Reg.
ESFR (F19EH/CFH)
15
14
13
12
11
10
9
8
7
-
-
-
-
-
-
-
GPX
-
-
-
-
-
-
-
rw
6
EOP EOP
IR
IE
rwh
rw
Reset Value: 0000H
5
4
3
2
1
0
ILVL
GLVL
rw
rw
Note: Please refer to the general Interrupt Control Register description for an
explanation of the control fields.
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PECISNC
C7IR C7IE C6IR C6IE C5IR C5IE C4IR C4IE C3IR C3IE C2IR C2IE C1IR C1IE C0IR C0IE
&
&
&
&
&
1
&
&
0
&
15
Interrupt Request
Pulse Generator
EOPIC
0
0
15
0
0
0
0
0
GPX
EOP EOP
IR
IE
87
ILVL
GLVL
0
MCD04914
Figure 5-4
End of PEC Interrupt Sub Node
Note: The interrupt service routine must service and clear all currently active requests
before terminating. Requests occurring later will set EOPIR again and the service
routine will be re-entered.
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5.5
Prioritization of Interrupt and PEC Service Requests
Interrupt and PEC service requests from all sources can be enabled so they are
arbitrated and serviced (if they win), or they may be disabled, so their requests are
disregarded and not serviced.
Enabling and disabling interrupt requests may be done via three mechanisms:
•
•
•
Control Bits
Priority Level
ATOMIC and EXTended Instructions
Control Bits allow switching of each individual source “ON” or “OFF” so that it may
generate a request or not. The control bits (xxIE) are located in the respective interrupt
control registers. All interrupt requests may be enabled or disabled generally via bit IEN
in register PSW. This control bit is the “main switch” which selects if requests from any
source are accepted or not.
For a specific request to be arbitrated, the respective source’s enable bit and the global
enable bit must both be set.
The Priority Level automatically selects a certain group of interrupt requests to be
acknowledged and ignores all other requests. The priority level of the source that won
the arbitration is compared against the CPU’s current level and the source is serviced
only if its level is higher than the current CPU level. Changing the CPU level to a specific
value via software blocks all requests on the same or a lower level. An interrupt source
assigned to level 0 will be disabled and will never be serviced.
The ATOMIC and EXTend instructions automatically disable all interrupt requests for
the duration of the following 1 … 4 instructions. This is useful for semaphore handling,
for example, and does not require to re-enable the interrupt system after the inseparable
instruction sequence.
Interrupt Class Management
An interrupt class covers a set of interrupt sources with the same importance, i.e. the
same priority from the system’s viewpoint. Interrupts of the same class must not interrupt
each other. The XC2700 supports this function with two features:
•
•
Classes with up to eight members can be established by using the same interrupt
priority (ILVL) and assigning a dedicated group level to each member. This
functionality is built-in and handled automatically by the interrupt controller.
Classes with more than eight members can be established by using a number of
adjacent interrupt priorities (ILVL) and the respective group levels (eight per ILVL).
Each interrupt service routine within this class sets the CPU level to the highest
interrupt priority within the class. All requests from the same or any lower level are
blocked now, i.e. no request of this class will be accepted.
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The example shown below establishes 3 interrupt classes which cover 2 or 3 interrupt
priorities, depending on the number of members in a class. A level 6 interrupt disables
all other sources in class 2 by changing the current CPU level to 8, which is the highest
priority (ILVL) in class 2. Class 1 requests or PEC requests are still serviced, in this case.
In this way, the interrupt sources (excluding PEC requests) are assigned to 3 classes of
priority rather than to 7 different levels, as the hardware support would do.
Table 5-9
ILVL
(Priority)
Software Controlled Interrupt Classes (Example)
Group Level
7
15
Interpretation
6 5 4 3 2 1 0
PEC service on up to 8 channels
14
13
12
11
X X X X X X X X Interrupt Class 1
9 sources on 2 levels
X
10
9
8
7
X X X X X X X X Interrupt Class 2
X X X X X X X X 17 sources on 3 levels
6
X
5
X X X X X X X X Interrupt Class 3
9 sources on 2 levels
X
4
3
2
1
0
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5.6
Context Switching and Saving Status
Before an interrupt request that has been arbitrated is actually serviced, the status of the
current task is automatically saved on the system stack. The CPU status (PSW) is saved
together with the location at which execution of the interrupted task is to be resumed after
returning from the service routine. This return location is specified through the Instruction
Pointer (IP) and, in the case of a segmented memory model, the Code Segment Pointer
(CSP). Bit SGTDIS in register CPUCON1 controls how the return location is stored.
The system stack receives the PSW first, followed by the IP (unsegmented), or followed
by CSP and then IP (segmented mode). This optimizes the usage of the system stack if
segmentation is disabled.
The CPU priority field (ILVL in PSW) is updated with the priority of the interrupt request
to be serviced, so the CPU now executes on the new level.
The register bank select field (BANK in PSW) is changed to select the register bank
associated with the interrupt request. The association between interrupt requests and
register banks are partly pre-defined and can partly be programmed.
The interrupt request flag of the source being serviced is cleared. IP and CSP are loaded
with the vector associated with the requesting source, and the first instruction of the
service routine is fetched from the vector location which is expected to branch to the
actual service routine (except when the interrupt jump table cache is used). All other
CPU resources, such as data page pointers and the context pointer, are not affected.
When the interrupt service routine is exited (RETI is executed), the status information is
popped from the system stack in the reverse order, taking into account the value of bit
SGTDIS.
High
Addresses
Status of
Interrupted
Task
SP
---
SP
--
PSW
PSW
IP
CSP
--
IP
SP
Low
Addresses
a) System Stack before
Interrupt Entry
b) System Stack after
Interrupt Entry
(Unsegmented)
b) System Stack after
Interrupt Entry
(Segmented)
MCD02226
Figure 5-5
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Context Switching
An interrupt service routine usually saves all the registers it uses on the stack and
restores them before returning. The more registers a routine uses, the more time is spent
saving and restoring. The XC2700 allows switching the complete bank of CPU registers
(GPRs) either automatically or with a single instruction, so the service routine executes
within its own separate context (see also Section 4.5.2).
There are two ways to switch the context in the XC2700 core:
Switching Context of the Global Register Bank changes the complete global register
bank of CPU registers (GPRs) by changing the Context Pointer with a single instruction,
so the service routine executes within its own separate context. The instruction “SCXT
CP, #New_Bank” pushes the contents of the context pointer (CP) on the system stack
and loads CP with the immediate value “New_Bank”; this in turn, selects a new register
bank. The service routine may now use its “own registers”. This register bank is
preserved when the service routine terminates, i.e. its contents are available on the next
call. Before returning (RETI), the previous CP is simply POPped from the system stack,
which returns the registers to the original global bank.
Resources used by the interrupting program, such as the DPPs, must eventually be
saved and restored.
Note: There are certain timing restrictions during context switching that are associated
with pipeline behavior.
Switching Context by changing the selected register bank automatically updates
bitfield BANK to select one of the two local register banks or the current global register
bank, so the service routine may now use its “own registers” directly. This local register
bank is preserved when the service routine is terminated; thus, its contents are available
on the next call.
When switching to the global register bank, the service routine usually must also switch
the context of the global register bank to get a private set of GPRs, because the global
bank is likely to be used by several tasks.
For interrupt priority levels 15 … 12 the target register bank can be pre-selected and
then be switched automatically. The register bank selection registers BNKSELx provide
a 2-bit field for each possible arbitration priority level. The respective bitfield is then
copied to bitfield BANK in register PSW to select the register bank, as soon as the
respective interrupt request is accepted.
Table 5-10 identifies the arbitration priority level assignment to the respective bitfields
within the four register bank selection registers.
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BNKSEL0
Register Bank Selection Reg. 0
BNKSEL1
Register Bank Selection Reg. 1
BNKSEL2
Register Bank Selection Reg. 2
BNKSEL3
Register Bank Selection Reg. 3
15
14
13
12
11
10
XSFR(EC20H)
Reset Value: 0000H
XSFR(EC22H)
Reset Value: 0000H
XSFR(EC24H)
Reset Value: 0000H
XSFR(EC26H)
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
GPRSEL7 GPRSEL6 GPRSEL5 GPRSEL4 GPRSEL3 GPRSEL2 GPRSEL1 GPRSEL0
rw
rw
rw
rw
Field
Bits
GPRSEL0,
GPRSEL1,
GPRSEL2,
GPRSEL3,
GPRSEL4,
GPRSEL5,
GPRSEL6,
GPRSEL7
[1:0],
rw
[3:2],
[5:4],
[7:6],
[9:8],
[11:10],
[13:12],
[15:14]
Table 5-10
rw
rw
rw
rw
Type Description
Register Bank Selection
00B Global register bank
01B Reserved
10B Local register bank 1
11B Local register bank 2
Assignment of Register Bank Control Fields
Bank Select Control Register
Interrupt Node Priority
Notes
Register Name
Bitfields
Intr. Level
Group Levels
BNKSEL0
(EC20H/--)
GPRSEL0 … 3
12
0…3
13
0…3
14
0…3
15
0…3
12
4…7
13
4…7
14
4…7
15
4…7
BNKSEL1
(EC22H/--)
BNKSEL2
(EC24H/--)
BNKSEL3
(EC26H/--)
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GPRSEL4 … 7
GPRSEL0 … 3
GPRSEL4 … 7
GPRSEL0 … 3
GPRSEL4 … 7
GPRSEL0 … 3
GPRSEL4 … 7
5-35
Lower
group
levels
Upper
group
levels
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5.7
Interrupt Node Sharing
Interrupt nodes may be shared among several module requests if either the requests are
generated mutually exclusively or the requests are generated at a low rate. If more than
one source is enabled in this case, the interrupt handler will first need to determine the
requesting source. However, this overhead is not critical for low rate requests.
This node sharing is either controlled via interrupt sub-node control registers (ISNC)
which provide separate request flags and enable bits for each supported request source,
or via register ISSR, where each bit selects one of two interrupt sources. The interrupt
level used for arbitration is determined by the node control register (… IC).
The specific request flags within ISNC registers must be reset by software, contrary to
the node request bits which are cleared automatically.
Table 5-11
Sub-Node Control Bit Allocation
Interrupt Node
Interrupt Sources
Control
EOPIC
PEC channels 7 … 0
PECISNC
RTC_IC
RTC: overflow of T14, CNT0 … CNT3
RTC_ISNC
CC2_CC16IC
CAPCOM2 request, ERU request 0
ISSR
CC2_CC17IC
CAPCOM2 request, ERU request 1
ISSR
CC2_CC18IC
CAPCOM2 request, ERU request 2
ISSR
CC2_CC19IC
CAPCOM2 request, ERU request 3
ISSR
CC2_CC20IC
CAPCOM2 request, USIC0 request 6
ISSR
CC2_CC21IC
CAPCOM2 request, USIC0 request 7
ISSR
CC2_CC22IC
CAPCOM2 request, USIC1 request 6
ISSR
CC2_CC23IC
CAPCOM2 request, USIC1 request 7
ISSR
CC2_CC24IC
CAPCOM2 request, ERU request 0
ISSR
CC2_CC25IC
CAPCOM2 request, ERU request 1
ISSR
CC2_CC26IC
CAPCOM2 request, ERU request 2
ISSR
CC2_CC27IC
CAPCOM2 request, ERU request 3
ISSR
CC2_CC28IC
CAPCOM2 request, USIC2 request 6
ISSR
CC2_CC29IC
CAPCOM2 request, USIC2 request 7
ISSR
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5.8
External Interrupts
Although the XC2700 has no dedicated INTR input pins, it supports many possibilities to
react to external asynchronous events. It does this by using a number of IO lines for
interrupt input. The interrupt function may be either combined with the pin’s main function
or used instead of it if the main pin function is not required.
The External Request Unit provides flexible trigger signals with selectable qualifiers,
which can directly control peripherals (ADC, MultiCAN) or generate additional
interrupt/PEC requests from external input signals.
Table 5-12
Pins Usable as External Interrupt Inputs
Port Pin
Original Function
Control Register
P4.7-0/CC31-24IO
CAPCOM Register 31-24 Capture Input
1)
CC31-CC24
P2.10-3/CC23-16IO
CAPCOM Register 23-16 Capture Input
P4.2/T2IN
Auxiliary timer T2 input pin
T2CON
P4.6/T4IN
Auxiliary timer T4 input pin
T4CON
P2.10/CAPIN
GPT2 capture input pin1)
T5CON
CC23-CC16
1) Pin P2.10 overlays two possible input functions.
For each of these pins, either a positive, a negative, or both a positive and a negative
external transition can be selected to cause an interrupt or PEC service request. The
edge selection is performed in the control register of the peripheral device associated
with the respective port pin (separate control for ERU inputs). The peripheral must be
programmed to a specific operating mode to allow generation of an interrupt by the
external signal. The priority of the interrupt request is determined by the interrupt control
register of the respective peripheral interrupt source, and the interrupt vector of this
source will be used to service the external interrupt request.
Note: In order to use any of the listed pins as an external interrupt input, it must be
switched to input mode via its port control register.
When port pins CCxIO are to be used as external interrupt input pins, bitfield CCMODx
in the control register of the corresponding capture/compare register CCx must select
capture mode. When CCMODx is programmed to 001B, the interrupt request flag CCxIR
in register CCxIC will be set on a positive external transition at pin CCxIO. When
CCMODx is programmed to 010B, a negative external transition will set the interrupt
request flag. When CCMODx = 011B, both a positive and a negative transition will set
the request flag. In all three cases, the contents of the allocated CAPCOM timer will be
latched into capture register CCx, independent of whether or not the timer is running.
When the interrupt enable bit CCxIE is set, a PEC request or an interrupt request for
vector CCxINT will be generated.
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Pins T2IN or T4IN can be used as external interrupt input pins when the associated
auxiliary timer T2 or T4 in block GPT1 is configured for capture mode. This mode is
selected by programming the mode control fields T2M or T4M in control registers
T2CON or T4CON to 101B. The active edge of the external input signal is determined by
bitfields T2I or T4I. When these fields are programmed to X01B, interrupt request flags
T2IR or T4IR in registers T2IC or T4IC will be set on a positive external transition at pins
T2IN or T4IN, respectively. When T2I or T4I is programmed to X10B, then a negative
external transition will set the corresponding request flag. When T2I or T4I is
programmed to X11B, both a positive and a negative transition will set the request flag.
In all three cases, the contents of the core timer T3 will be captured into the auxiliary
timer registers T2 or T4 based on the transition at pins T2IN or T4IN. When the interrupt
enable bits T2IE or T4IE are set, a PEC request or an interrupt request for vector T2INT
or T4INT will be generated.
Pin CAPIN differs slightly from the timer input pins as it can be used as external interrupt
input pin without affecting peripheral functions. When the capture mode enable bit T5SC
in register T5CON is cleared to ‘0’, signal transitions on pin CAPIN will only set the
interrupt request flag CRIR in register CRIC, and the capture function of register
CAPREL is not activated.
So register CAPREL can still be used as reload register for GPT2 timer T5, while pin
CAPIN serves as external interrupt input. Bitfield CI in register T5CON selects the
effective transition of the external interrupt input signal. When CI is programmed to 01B,
a positive external transition will set the interrupt request flag. CI = 10B selects a negative
transition to set the interrupt request flag, and with CI = 11B, both a positive and a
negative transition will set the request flag. When the interrupt enable bit CRIE is set, an
interrupt request for vector CRINT or a PEC request will be generated.
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5.9
OCDS Requests
The OCDS module issues high-priority break requests or standard service requests. The
break requests are routed directly to the CPU (like the hardware trap requests) and are
prioritized there. Therefore, break requests ignore the standard interrupt arbitration and
receive highest priority.
The standard OCDS service requests are routed to the CPU Action Control Unit together
with the arbitrated interrupt/PEC requests. The service request with the higher priority is
sent to the CPU to be serviced. If both the interrupt/PEC request and the OCDS request
have the same priority level, the interrupt/PEC request wins.
This approach ensures precise break control, while affecting the system behavior as little
as possible.
The CPU Action Control Unit also routes back request acknowledges and denials from
the core to the corresponding requestor.
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5.10
Service Request Latency
The numerous service requests of the XC2700 (requests for interrupt or PEC service)
are generated asynchronously with respect to the execution of the instruction flow.
Therefore, these requests are arbitrated and are inserted into the current instruction
stream. This decouples the service request handling from the currently executed
instruction stream, but also leads to a certain latency.
The request latency is the time from activating a request signal at the interrupt controller
(ITC) until the corresponding instruction reaches the pipeline’s execution stage.
Table 5-13 lists the consecutive steps required for this process.
Table 5-13
Steps Contributing to Service Request Latency
Description of Step
Interrupt Response
PEC Response
Request arbitration in 3 stages,
leads to acceptance by the CPU
(see Section 5.2)
3 cycles
3 cycles
Injection of an internal instruction into
the pipeline’s instruction stream
4 cycles
4 cycles
The first instruction fetched from the
interrupt vector table reaches the
pipeline’s execution stage
4 cycles / 01)
---
Resulting minimum request latency
11/7 cycles
7 cycles
1) Can be saved by using the interrupt jump table cache (see Section 5.3).
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Sources for Additional Delays
Because the service requests are inserted into the current instruction stream, the
properties of this instruction stream can influence the request latency.
Table 5-14
Additional Delays Caused by System Logic
Reason for Delay
Interrupt Response
PEC Response
Interrupt controller busy,
max. 7 cycles
because the previous interrupt request
is still in process
max. 7 cycles
Pipeline is stalled,
2 × TACCmax1)
because instructions preceding the
injected instruction in the pipeline need
to write/read data to/from a peripheral
or memory
2 × TACCmax
Pipeline cancelled,
because instructions preceding the
injected instruction in the pipeline
update core SFRs
4 cycles
4 cycles
Memory access for stack writes (if not
to DPRAM or DSRAM)
2/3 × TACC2)
---
Memory access for vector table read
(except for intr. jump table cache)
2 × TACC
---
1) This is the longest possible access time within the XC2700 system.
2) Depending on segmentation off/on.
The actual response to an interrupt request may be delayed further depending on
programming techniques used by the application. The following factors can contribute:
•
•
Actual interrupt service routine is only reached via a JUMP from the interrupt vector
table.
Time-critical instructions can be placed directly into the interrupt vector table,
followed by a branch to the remaining part of the interrupt service routine. The space
between two adjacent vectors can be selected via bitfield VECSC in register
CPUCON1.
Context switching is executed before the intended action takes place (see
Section 5.6)
Time-critical instructions can be programmed “non-destructive” and can be executed
before switching context for the remaining part of the interrupt service routine.
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5.11
Trap Functions
Traps interrupt current execution in a manner similar to standard interrupts. However,
trap functions offer the possibility to bypass the interrupt system’s prioritization process
for cases in which immediate system reaction is required. Trap functions are not
maskable and always have priority over interrupt requests on any priority level.
The XC2700 provides two different kinds of trapping mechanisms: Hardware Traps are
triggered by events that occur during program execution (such as illegal access or
undefined opcode); Software Traps are initiated via an instruction within the current
execution flow.
Software Traps
The TRAP instruction causes a software call to an interrupt service routine. The vector
number specified in the operand field of the trap instruction determines which vector
location in the vector table will be branched to.
Executing a TRAP instruction causes an effect similar to the occurrence of an interrupt
at the same vector. PSW, CSP (in segmentation mode), and IP are pushed on the
internal system stack and a jump is taken to the specified vector location. When a trap
is executed, the CSP for the trap service routine is loaded from register VECSEG. No
Interrupt Request flags are affected by the TRAP instruction. The interrupt service
routine called by a TRAP instruction must be terminated with a RETI (return from
interrupt) instruction to ensure correct operation.
Note: The CPU priority level and the selected register bank in register PSW are not
modified by the TRAP instruction, so the service routine is executed on the same
priority level from which it was invoked. Therefore, the service routine entered by
the TRAP instruction uses the original register bank and can be interrupted by
other traps or higher priority interrupts, other than when triggered by a hardware
event.
Hardware Traps
Hardware traps are issued by faults or specific system states which occur during runtime
of a program (not identified at assembly time). A hardware trap may also be triggered
intentionally, for example: to emulate additional instructions by generating an Illegal
Opcode trap. The XC2700 distinguishes nine different hardware trap functions. When a
hardware trap condition has been detected, the CPU branches to the trap vector location
for the respective trap condition. The instruction which caused the trap is completed
before the trap handling routine is entered.
Hardware traps are non-maskable and always have priority over every other CPU
activity. If several hardware trap conditions are detected within the same instruction
cycle, the highest priority trap is serviced (see Table 5-3).
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Interrupt and Trap Functions
PSW, CSP (in segmentation mode), and IP are pushed on the internal system stack and
the CPU level in register PSW is set to the highest possible priority level (level 15),
disabling all interrupts. The global register bank is selected. Execution branches to the
respective trap vector in the vector table. A trap service routine must be terminated with
the RETI instruction.
The nine hardware trap functions of the XC2700 are divided into two classes:
Class A traps are:
•
•
•
•
System Request 0 (SR0)
Stack Overflow
Stack Underflow trap
Software Break
These traps share the same trap priority, but have individual vector addresses.
Class B traps are:
•
•
•
•
•
System Request 1 (SR1)
Undefined Opcode
Memory Access Error
Protection Fault
Illegal Word Operand Access
The Class B traps share the same trap priority and the same vector address.
The bit-addressable Trap Flag Register (TFR) allows a trap service routine to identify the
kind of trap which caused the exception. Each trap function is indicated by a separate
request flag. When a hardware trap occurs, the corresponding request flag in register
TFR is set to ‘1’.
The reset functions may be regarded as a type of trap. Reset functions have the highest
system priority (trap priority III).
Class A traps have the second highest priority (trap priority II), on the 3rd rank are
Class B traps, so a Class A trap can interrupt a Class B trap. If more than one Class A
trap occur at a time, they are prioritized internally, with the SR0 trap at the highest and
the software break trap at the lowest priority.
In the case where e.g. an Undefined Opcode trap (Class B) occurs simultaneously with
an SR0 trap (Class A), both the SR0 and the UNDOPC flag is set, the IP of the instruction
with the undefined opcode is pushed onto the system stack, but the SR0 trap is
executed. After return from the SR0 service routine, the IP is popped from the stack and
immediately pushed again because of the pending UNDOPC trap.
Note: The trap service routine must clear the respective trap flag; otherwise, a new trap
will be requested after exiting the service routine. Setting a trap request flag by
software causes the same effects as if it had been set by hardware.
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Interrupt and Trap Functions
TFR
Trap Flag Register
15
14
12
11
Reset Value: 0000H
10
9
8
7
6
5
STK STK
SR0
OF UF
-
-
-
UND
OPC
-
-
rwh
-
-
-
rwh
-
-
rwh
13
SFR (FFACH/D6H)
SOF
T SR1
BRK
rwh rwh rwh
4
3
1
0
AC PRT ILL
ER FLT OPA
-
-
rwh
-
-
rwh
2
rwh
Field
Bits
Type
Description
SR0
15
rwh
System Request 0 Flag
No trigger detected
0B
1B
The selected condition has been detected
STKOF
14
rwh
Stack Overflow Flag
0B
No stack overflow event detected
The current stack pointer value falls below the
1B
contents of register STKOV
STKUF
13
rwh
Stack Underflow Flag
0B
No stack underflow event detected
1B
The current stack pointer value exceeds the
contents of register STKUN
SOFTBRK
12
rwh
Software Break
0B
No software break event detected
1B
Software break event detected
SR1
11
rwh
System Request 1 Flag
0B
No trigger detected
1B
The selected condition has been detected
UNDOPC
7
rwh
Undefined Opcode
0B
No undefined opcode event detected
1B
The currently decoded instruction has no valid
XC2700 opcode
ACER
4
rwh
Memory Access Error
0B
No access error event detected
1B
Illegal or erroneous access detected
PRTFLT
3
rwh
Protection Fault
0B
No protection fault event detected
1B
A protected instruction with an illegal format
has been detected
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Field
Bits
Type
Description
ILLOPA
2
rwh
Illegal Word Operand Access
No illegal word operand access event detected
0B
1B
A word operand access (read or write) to an
odd address has been attempted
Class A Traps
Class A traps are generated by the high priority system request SR0 or by special CPU
events such as the software break, a stack overflow, or an underflow event. Class A
traps are not used to indicate hardware failures. After a Class A event, a dedicated
service routine is called to react on the events. Each Class A trap has its own vector
location in the vector table. Class A traps cannot interrupt atomic/extend sequences and
I/O accesses in progress, because after finishing the service routine, the instruction flow
must be further correctly executed. For example, an interrupted extend sequence cannot
be restarted. All Class A traps are generated in the pipeline during the execution of
instructions, except for SR0, which is an asynchronous external event. Class A trap
events can be generated only during the memory stage of execution, so traps cannot be
generated by two different instructions in the pipeline in the same CPU cycle. The
execution of instructions which caused a Class A trap event is always completed. In the
case of an atomic/extend sequence or I/O read access in progress, the complete
sequence is executed. Upon completion of the instruction or sequence, the pipeline is
canceled and the IP of the instruction following the last one executed is pushed on the
stack. Therefore, in the case of a Class A trap, the stack always contains the IP of the
first not-executed instruction in the instruction flow.
Note: The Branch Folding Unit allows the execution of a branch instruction in parallel
with the preceding instruction. The pre-processed branch instruction is combined
with the preceding instruction. The branch is executed together with the instruction
which caused the Class A trap. The IP of the first following not-executed
instruction in the instruction flow is then pushed on the stack.
If more than one Class A trap occur at the same time, they are prioritized internally. The
SR0 trap has the highest priority and the software break has the lowest.
Note: In the case of two different Class A traps occurring simultaneously, both trap flags
are set. The IP of the instruction following the last one executed is pushed on the
stack. The trap with the higher priority is executed. After return from the service
routine, the IP is popped from the stack and immediately pushed again because
of the other pending Class A trap (unless the trap related to the second trap flag
in TFR has been cleared by the first trap service routine).
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Class B Traps
Class B traps are generated by unrecoverable hardware failures. In the case of a
hardware failure, the CPU must immediately start a failure service routine. Class B traps
can interrupt an atomic/extend sequence and an I/O read access. After finishing the
Class B service routine, a restoration of the interrupted instruction flow is not possible.
All Class B traps have the same priority (trap priority I). When several Class B traps
become active at the same time, the corresponding flags in the TFR register are set and
the trap service routine is entered. Because all Class B traps have the same vector, the
priority of service of simultaneously occurring Class B traps is determined by software in
the trap service routine.
The access error (ACER) and system request 1 (SR1) are asynchronous external (to the
CPU) events, while all other Class B traps are generated in the pipeline during the
execution of instructions. Class B trap events can be generated only during the memory
stage of execution, so traps cannot be generated by two different instructions in the
pipeline in the same CPU cycle. Instructions which caused a Class B trap event are
always executed, then the pipeline is canceled and the IP of the instruction following the
one which caused the trap is pushed on the stack. Therefore, the stack always contains
the IP of the first following not-executed instruction in the instruction flow.
Note: The Branch Folding Unit allows the execution of a branch instruction in parallel
with the preceding instruction. The pre-processed branch instruction is combined
with the preceding instruction. The branch is executed together with the instruction
causing the Class B trap. The IP of the first following not-executed instruction in
the instruction flow is pushed on the stack.
A Class A trap occurring during the execution of a Class B trap service routine will be
serviced immediately. During the execution of a Class A trap service routine, however,
any Class B trap occurring will not be serviced until the Class A trap service routine is
exited with a RETI instruction. In this case, the occurrence of the Class B trap condition
is stored in the TFR register, but the IP value of the instruction which caused this trap is
lost.
Note: If a Class A trap occurs simultaneously with a Class B trap, both trap flags are set.
The IP of the instruction following the one which caused the trap is pushed into the
stack, and the Class A trap is executed. If this occurs during execution of an
atomic/extend sequence or I/O read access in progress, then the presence of the
Class B trap breaks the protection of atomic/extend operations and the Class A
trap will be executed immediately without waiting for the sequence completion.
After return from the service routine, the IP is popped from the system stack and
immediately pushed again because of the other pending Class B trap. In this
situation, the restoration of the interrupted instruction flow is not possible.
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System Request 0 Trap (A)
Whenever a high-to-low transition on the respective CPU-input is detected (i.e. the
defined condition has become true), the SR0 flag in register TFR is set and the CPU will
enter the SR0 trap routine.
Stack Overflow Trap (A)
Whenever the stack pointer is implicitly decremented and the stack pointer is equal to
the value in the stack overflow register STKOV, the STKOF flag in register TFR is set
and the CPU will enter the stack overflow trap routine.
For recovery from stack overflow, it must be ensured that there is enough excess space
on the stack to save the current system state twice (PSW, IP, in segmented mode also
CSP). Otherwise, a system reset should be generated.
Stack Underflow Trap (A)
Whenever the stack pointer is implicitly incremented and the stack pointer is equal to the
value in the stack underflow register STKUN, the STKUF flag is set in register TFR and
the CPU will enter the stack underflow trap routine.
Software Break Trap (A)
When the instruction currently being executed by the CPU is a SBRK instruction, the
SOFTBRK flag is set in register TFR and the CPU enters the software break debug
routine. The flag generation of the software break instruction can be disabled by the Onchip Emulation Module. In this case, the instruction only breaks the instruction flow and
signals this event to the debugger, the flag is not set and the trap will not be executed.
System Request 1 Trap (B)
Whenever a high-to-low transition on the respective CPU-input is detected (i.e. the
defined condition has become true), the SR1 flag in register TFR is set and the CPU will
enter the SR1 trap routine.
Undefined Opcode Trap (B)
When the instruction currently decoded by the CPU does not contain a valid XC2700
opcode, the UNDOPC flag is set in register TFR and the CPU enters the undefined
opcode trap routine. The instruction that causes the undefined opcode trap is executed
as a NOP.
This can be used to emulate unimplemented instructions. The trap service routine can
examine the faulting instruction to decode operands for unimplemented opcodes based
on the stacked IP. In order to resume processing, the stacked IP value must be
incremented by the size of the undefined instruction, which is determined by the user,
before a RETI instruction is executed.
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Interrupt and Trap Functions
Memory Access Error (B)
When a memory access error is detected, the ACER flag is set in register TFR and the
CPU enters the access error trap routine. The access error is reported in the following
cases:
•
•
•
•
•
access to Flash memory while it is disabled
access to Flash memory from outside while read-protection is active
double bit error detected when reading Flash memory
access to reserved locations (see memory map in Table 3-1)
parity error during an access to RAM
In case of an access error, additionally the soft-trap code 1E9BH is issued.
Protection Fault Trap (B)
Whenever one of the special protected instructions is executed where the opcode of that
instruction is not repeated twice in the second word of the instruction and the byte
following the opcode is not the complement of the opcode, the PRTFLT flag in register
TFR is set and the CPU enters the protection fault trap routine. The protected
instructions include DISWDT, EINIT, IDLE, PWRDN, SRST, ENWDT and SRVWDT.
The instruction that causes the protection fault trap is executed like a NOP.
Illegal Word Operand Access Trap (B)
Whenever a word operand read or write access is attempted to an odd byte address, the
ILLOPA flag in register TFR is set and the CPU enters the illegal word operand access
trap routine.
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System Control Unit (SCU)
6
System Control Unit (SCU)
The System Control Unit (SCU) of the XC2700 handles all system control tasks besides
the debug related tasks which are controlled by the OCDS/Cerberus. All functions
described in this chapter are tightly coupled, thus, they are conveniently handled by one
unit, the SCU.
The SCU contains the following functional sub-blocks:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Clock Generation (see Chapter 6.1)
Wake-up Timer (see Chapter 6.2)
Reset Operation (see Chapter 6.3)
External Service Requests (see Chapter 6.4)
Power Supply and Control (see Chapter 6.5)
Global State Control (see Chapter 6.6)
Software Boot Support (see Chapter 6.7)
External Request Unit (see Chapter 6.8)
Interrupt Generation (see Chapter 6.9)
Temperature Compensation (see Chapter 6.10)
Watchdog Timer (see Chapter 6.11)
Trap Generation (see Chapter 6.12)
Memory Content Protection (see Chapter 6.13)
Register Access Control (see Chapter 6.14)
Miscellaneous System Registers (see Chapter 6.15)
SCU Registers and Address map (see Chapter 6.16)
Important Information: Register Programming
The System Control Unit contains special function registers, which can not be
programmed in an arbitrary order in particular due to the usage of an internal voltage
regulator. In order to prevent critical system conditions because of an improper setup
and to provide means for easy and quick configuration and control of sensitve features
such as power supply and clock generation, recommendations and examples for the
programming sequence of the registers will be given in the Programmer’s Guide.
In particular the registers listed below have to be updated with care:
•
•
•
Clock Generation Unit: WUOSCCON, HPOSCCON, PLLOSCCON, PLLCONx
Power Supply: EVR1CON0, EVR1SET15VHP,
EVRMCON0,EVRMSET15VHP,
PVC1CON0, PVCMCON0,
SWDCON0
System: SYSCON0
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System Control Unit (SCU)
6.1
Clock Generation Unit
The Clock Generation Unit (CGU) allows a very flexible clock generation for the XC2700.
During user program execution the frequency can be programmed for an optimal ratio
between performance and power consumption in the actual application state.
6.1.1
Overview
The CGU can convert a low-frequency external clock to a high-speed system clock or
can create a high-speed system clock without external input.
The CGU consists of a Clock Generator and a Clock Control Unit (CCU).
XTAL1
fOSC
XTAL2
fSYS
fPLL
Clock Generator
fWU
CLKIN1
CLKIN2
CCU
fCLKIN1
fRTC
fCLKIN2
fEXT
RTC
EXTCLK
CC60
Clock Generation Unit (CGU)
CGU_Block_Diagram_MR.vsd
Figure 6-1
Clock Generation Unit Block Diagram
The input connections of the CGU are described in Chapter 6.17.1.
The following clock signals are generated:
•
•
•
•
System clock fSYS
RTC count clock fRTC (
Wake-Up Timer (WUT) clock fWUT
External clock fEXT
Chapter 6.1.5 and Chapter 6.1.6 describe which clock signals is generated out of which
selectable clocks.
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Register Overview
The CGU is controlled by a number of registers shown in the following figure.
Oscillator Control
PLL Control
System Control
Output Control
WUOSCCON
PLLSTAT
SYSCON0
RTCCLKCON
HPOSCCON
STATCLR1
STATCLR 0
EXTCON
PLLOSCCON
PLLCON 0
PLLCON 1
PLLCON 2
PLLCON 3
WUOSCCON
HPOSCCON
PLLOSCCON
PLLSTAT
STATCLR 1
PLLCON 0
PLLCON 1
PLLCON 2
Wake-up OSC Control Register
High Precision OSC Control Register
PLL OSC Configuration Register
PLL Status Register
PLL Status Clear 1 Register
PLL Configuration 0 Register
PLL Configuration 1 Register
PLL Configuration 2 Register
PLLCON 3 PLL Configuration 3 Register
SYSCON 0 System Control 0 Register
STATCLR 0 Status Clear 0 Register
RTCCLKCON
EXTCON
Figure 6-2
RTC Clock Control Register
External Clock Control Register
CGU_Register _Overview .vsd
Clock Generation Unit Register Overview
The following sections describe the different parts of the CGU.
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6.1.2
Trimmed Current Controlled Wake-up Clock (OSC_WU)
The trimmed current controlled wake-up clock source provides a clock to control internal
operations independent of the standard clock supplies and requires no external
components. Its output frequency fWU is configured via bit field WUOSCCON.FREQSEL
and has a typical range from 130 kHz to 500 kHz.
6.1.3
High Precision Oscillator Circuit (OSC_HP)
The high precision oscillator circuit can drive an external crystal or accepts an external
clock source. It consists of an inverting amplifier with XTAL1 as input, and XTAL2 as
output.
Figure 6-4 and Figure 6-3 show the recommended external circuitries for both
operating modes, External Crystal Mode and External Input Clock Mode.
6.1.3.1
External Input Clock Mode
An external clock signal is supplied directly not using an external crystal and bypassing
the amplifier of the oscillator. The maximum allowed input frequency depends on the
characteristics of pin XTAL1.
When using an external clock signal it must be connected to XTAL1. XTAL2 is left open
(unconnected).
Note: Voltages on XTAL1 must comply to the voltage defined in the data sheet.
XTAL1
External
Clock Signal
XTAL2
OSC_HP
fOSC
leave unconnected
VSS
CGU_OSC _HP_ExtIn.vsd
Figure 6-3
6.1.3.2
XC2700 External Clock Input Mode for the High-Precision Oscillator
External Crystal Mode
An external oscillator load circuitry must be used, connected to both pins, XTAL1 and
XTAL2. It consists normally of the two load capacitances C1 and C2. For some crystals
a series damping resistor might be necessary. The exact values and related operating
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range depend on the crystal and have to be determined and optimized together with the
crystal vendor using the negative resistance method.
Fundamental Mode
Crystal
XTAL1
OSC_HP
XTAL2
C1
fOSC
C2
VSS
CGU_OSC _HP_Crystal.vsd
Figure 6-4
6.1.4
XC2700 External Crystal Mode Circuitry for the High-Precision
Oscillator
Phase-Locked Loop (PLL) Module
The PLL can convert a low-frequency external clock signal to a high-speed system clock
for maximum performance. The PLL also has fail-safe logic that detects degenerate
external clock behavior such as abnormal frequency deviations or a total loss of the
external clock. It can execute emergency actions if it loses its lock on the external clock.
This module is a phase locked loop for integer frequency synthesis. It allows the use of
input and output frequencies of a wide range by varying the different divider factors.
6.1.4.1
Features
Here is a brief overview of the functions that are offered by the PLL.
•
•
•
•
•
•
•
•
VCO lock detection
4-bit input divider P: (divide by PDIV+1)
6-bit feedback divider N: (multiply by NDIV+1)
10-bit output divider K2: (divide K2DIV+1)
10-bit VCO bypass divider K1: (divide by either by K1DIV+1)
Oscillator run detection and Watchdog
Different operating modes
– Prescaler Mode
– Unlocked Mode
– Normal Mode
Different power saving modes
– Power Down
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•
•
•
– Sleep Mode (VCO Power Down)
Glitchless programming of output divider K2 and VCO bypass divider K1
Glitchless switching between Normal Mode and Prescaler Mode
Trimmed current controlled clock source
6.1.4.2
PLL Functional Description
The PLL consists of a Voltage Controlled Oscillator (VCO) with a feedback path. A
divider in the feedback path (N-Divider) divides the VCO frequency. The resulting
frequency is then compared with the divided external frequency (P-Divider). The phase
detection logic determines the difference between the two clocks and accordingly
controls the frequency of the VCO (fVCO). A PLL lock detection unit monitors and signals
this condition. The phase detection logic continues to monitor the two clocks and adjusts
the VCO clock if required. The PLL output clock fPLL is derived from the VCO clock using
the K2-Divider or from the oscillator clockusing the K1-Divider.
The following figure shows the PLL block structure.
PLLCON 1.
OSCSEL
0
fIN
1
PLLSTAT .
FINDIS
K1Divider
M
U
X
fINT
fR
fP
PDivider
fREF
Clock
Lock
Source Detect.
VCO
Core
fVCO
fK1
1
K20
Divider fK2
M
U
X
fPLL
NfDIV Divider
Osc.
WDG
PLL Block
HPOSCCON. HPOSCCON. PLLCON1. PLLSTAT .
OSCWDTRST PLLV
RESLD VCOLOCK
Figure 6-5
PLLCON0.
VCOBY
PLL _Block _Diagram.vsd
PLL Block Diagram
Clock Source Control
The reference frequency fR can be selected to be either taken from the trimmed current
controlled clock source fINT or from an external clock source fIN.
PLL Modes
The PLL clock fPLL is generated from fR in one of the following software selectable
modes:
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•
•
•
Normal Mode
Prescaler Mode
Unlocked Mode
In Normal Mode the reference frequency fR is divided by a factor P, multiplied by a factor
N and then divided by a factor K2. The output frequency is given by
(6.1)
N
f PLL = P-------- ⋅ fR
⋅ K2
In Prescaler Mode the reference frequency fR is divided by a factor K1. The output
frequency is given by
(6.2)
fR
f PLL = --K1
In Unlocked Mode the base output frequency of the Voltage Controlled Oscillator (VCO)
fVCObase is divided by a factor K2. The output frequency is given by
(6.3)
f VCObase
f PLL = --------------K2
PLL Power Saving Modes
PLL Power Down Mode The PLL offers a Power Down Mode to save power if the PLL
is not needed at all. While the PLL is in Power Down Mode no PLL output frequency is
generated.
PLL Sleep Mode The PLL offers a Sleep Mode (also called VCO Power Down Mode) to
save power within the PLL. While the PLL is in Sleep Mode only the Prescaler Mode can
be used.
6.1.4.3
Configuration and Operation of the PLL Modes
The following section describes the configuration and the operation of the different PLL
modes. Further information can be found in the Programmer’s Guide.
Configuration and Operation of the Unlocked Mode
In Unlocked Mode, the PLL is running at its VCO base frequency and fPLL is derived from
fVCO by the K2-Divider.
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PLLSTAT .
FINDIS = 1
PLLCON0.
VCOBY
1
´0´
Lock
Detect.
fREF
fDIV
VCO
Core
fVCO
0
K2f
Divider K2
M
U
X
fPLL
NDivider
PLL Block
PLL_Unlocked_Mode. vsd
Figure 6-6
PLL Unlocked Mode Diagram
The Unlocked Mode is selected by the following settings:
•
•
STATCLR1.SETFINDIS = 1
PLLCON0.VCOBY = 0
The Unlocked Mode is entered when all following conditions are true:
•
•
PLLSTAT.FINDIS = 1
PLLSTAT.VCOBYST = 1
Operation in Unlocked Mode does not require an input clock fIN. The Unlocked Mode is
automatically entered on a PLL VCO Loss-of-Lock event if bit PLLCON1.EMFINDISEN
is cleared. This mechanism allows a fail-safe operation of the PLL as in emergency
cases still a clock is available.
The frequency of the Unlocked Mode fVCObase is listed in the Data Sheet.
Note: Changing the system operation frequency by changing the value of the K2-Divider
or the VCO range has a direct influence on the power consumption of the device.
Therefore, this has to be done carefully.
Configuration and Operation of the Normal Mode
In Normal Mode, the PLL is running at frequency fPLL, where fR is divided by a factor P,
multiplied by a factor N and then divided by a factor K2.
User’s Manual
SCU, V1.13
6-8
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
PLLCON 1.
OSCSEL
fIN
0
1
M
U
X
fINT
fR
PLLSTAT .
FINDIS
fP
PDivider
Clock
Lock
Source Detect.
Osc.
WDG
HPOSCCON. HPOSCCON. PLLCON1.
OSCWDTRST PLLV
RESLD
Figure 6-7
fREF
fDIV
PLLCON0.
VCOBY
1
VCO
Core
fVCO
K20
Divider f
K2
M
U
X
fPLL
NDivider
PLL Block
PLLSTAT .
VCOLOCK
PLL _Normal_Mode.vsd
PLL Normal Mode Diagram
The Normal Mode is selected by the following settings:
•
•
PLLCON0.VCOBY = 0
STATCLR1.CLRFINDIS = 1
The Normal Mode is entered when all following conditions are true:
•
•
•
•
PLLSTAT.FINDIS = 0
PLLSTAT.VCOBYST = 1
PLLSTAT.VCOLOCK = 1
HPOSCCON.PLLV = 1
Operation in Normal Mode requires a clock frequency of fR. When fIN is selected as
source for fR it is recommended to check and monitor if an input frequency fR is available
at all by checking HPOSCCON.PLLV.
The system operation frequency in Normal Mode is controlled by the values of the three
dividers: P, N, and K2. A modification of the two dividers P and N has a direct influence
on the VCO frequency and leads to a loss of the VCO Lock status. A modification of the
K2-divider has no impact on the VCO Lock status but changes the PLL output frequency.
Note: Changing the system operation frequency by changing the value of the K2-Divider
has a direct influence on the power consumption of the device. Therefore, this has
to be done carefully.
To modify or enter the Normal Mode frequency, follow the sequence described below:
Configure and enter Prescaler Mode. For more details see the Prescaler Mode.
Disable the trap generation for the VCO Lost-of-Lock.
User’s Manual
SCU, V1.13
6-9
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
While the Prescaler Mode is used the Normal Mode can be configured and checked for
a positive VCO Lock status. The first target frequency of the Normal Mode should be
selected in a way that it matches or is only slightly higher as the one used in the
Prescaler Mode. This avoids big changes in the system operation frequency and,
therefore, the power consumption when switching later from Prescaler Mode to Normal
Mode. The P and N dividers should be selected in the following way:
•
•
Selecting P and N in a way that fVCO is in the lower area of its allowed values leads
to a slightly reduced power consumption but to a slightly increased jitter
Selecting P and N in a way that fVCO is in the upper area of its allowed values leads
to a slightly increased power consumption but to a slightly reduced jitter
After the P, and N dividers are updated for the first configuration, the indication of the
VCO Lock status (PLLSTAT.VCOLOCK = 1) should be awaited.
Note: It is recommended to reset the VCO Lock detection (PLLCON1.RESLD = 1) after
the new values of the dividers have been configured to get a defined VCO lock
check time.
When this happens the switch from Prescaler Mode to Normal Mode can be done.
Normal Mode is requested by clearing PLLCON0.VCOBY. The Normal Mode is entered
when the status bit PLLSTAT.VCOBYST is set.
Now the Normal Mode is entered. The trap status flag for the VCO Lock trap should be
cleared and then enabled again.
The intended PLL output target frequency can be configured by changing only the K2Divider. Depending on the selected divider value of the K2-Divider, the duty cycle of the
clock is selected. This can have an impact on the operation with an external
communication interface. In order to avoid too big frequency changes it might be
neccessary to change the K2-Divider in multiple steps. When the value of the K2-Diver
was changed the next update of this value should not be done before bit
PLLSTAT.K2RDY is set.
Note: The Programmers’s Guide describes a smooth frequency stepping to achieve an
appropriate load regulation of the internal voltage regulator.
PLL VCO Lock Detection
The PLL has a lock detection that supervises the VCO part of the PLL in order to detect
instable VCO circuit behavior. The lock detector marks the VCO circuit and therefore the
output fVCO of the VCO as instable if the two inputs fREF and fDIV differ too much. Changes
in one or both input frequencies below a level are not marked by a loss of lock because
the VCO can handle such small changes without any problem for the system.
PLL VCO Loss-of-Lock Event
The PLL may become unlocked, caused by a break of the crystal or the external clock
line. In such a case, a trap is generated if the according trap is enabled. Additionally, the
clock fR is disconnected from the PLL VCO to avoid unstable operation due to noise or
User’s Manual
SCU, V1.13
6-10
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
sporadic clock pulses coming from the oscillator circuit. Without a clock input fR, the PLL
gradually slows down to its VCO base frequency and remains there. The automatic
disconnection of the VCO from its input clock fR in case of a VCO Loss-of-Lock event
can be enabled by setting bit PLLCON1.EMFINDISEN. If this bit is cleared the clock fR
remains connected to the VCO.
Configuration and Operation of the Prescaler Mode
In Prescaler Mode, the PLL is running at frequency fPLL, where fR is divided by the K1Divider.
PLLCON 1.
OSCSEL
fIN
0
1
PLLCON0.
VCOBY
K1Divider
M
U
X
fINT
fR
1
0
M
U
X
fPLL
Clock
Source
Osc.
WDG
PLL Block
HPOSCCON. HPOSCCON.
OSCWDTRST PLLV
Figure 6-8
fK1
PLL _Prescaler _Mode.vsd
PLL Prescaler Mode Diagram
The Prescaler Mode is selected by the following setting:
•
PLLCON0.VCOBY = 1
The Prescaler Mode is entered when all following conditions are true:
•
•
PLLSTAT.VCOBYST = 0
HPOSCCON.PLLV = 1
Operation in Prescaler Mode requires an input clock frequency fR. If fIN is selected as
clock source for fR it is recommended to check and monitor if an input frequency fOSC is
available at all by checking HPOSCCON.PLLV. There are no requirements regarding the
frequency of fR.
The system operation frequency in Prescaler Mode is controlled by the value of the K1Divider. When the value of PLLCON1.K1DIV was changed the next update of this value
should not be done before bit PLLSTAT.K1RDY is set.
User’s Manual
SCU, V1.13
6-11
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Note: Changing the system operation frequency by changing the value of the K1-Divider
has a direct influence on the power consumption of the device. Therefore, this has
to be done carefully.
The duty cycle of the clock signal depends on the selected value of the K1-Divider. This
can have an impact for the operation with an external communication interface.
The Prescaler Mode is requested from the Unlocked or Normal Mode by setting bit
PLLCON0.VCOBY. The Prescaler Mode is entered when the status bit
PLLSTAT.VCOBYST is cleared.
Before the Prescaler Mode is requested the K1-Divider should be configured with a value
generating a PLL output frequency fPLL that matches the one generated by the Unlocked
or Normal Mode as much as possible. In this way the frequency change resulting out of
the mode change is reduced to a minimum.
The Prescaler Mode is requested to be left by clearing bit PLLCON0.VCOBY. The
Prescaler Mode is left when the status bit PLLSTAT.VCOBYST is set.
Configuration and Operation of the PLL Power Down Mode
The Power Down Mode is entered by setting bit PLLCON0.PLLPWD. While the PLL is
in Power Down Mode no PLL output frequency is generated.
Configuration and Operation of the PLL Sleep Mode
The Sleep Mode (also called VCO Power Down Mode) is entered by setting bit
PLLCON0.VCOPWD. While the PLL is in Sleep Mode only the Prescaler Mode is
operable. Selecting the Sleep Mode does not automatically switch to the Prescaler
Mode. Therefore, before the Sleep Mode is entered the Prescaler Mode must be active.
6.1.4.4
Trimmed Current Controlled Clock
The trimmed current controlled clock source can provide a clock fINT for the PLL. This is
configured via bit PLLCON1.OSCSEL.
Note: The clock fINT is also required for the operation of the oscillator watchdog.
6.1.4.5
Oscillator Watchdog
The oscillator watchdog continuously monitors the input clock fIN. If the input frequency
becomes too low or if the input clock fails, this oscillator fail condition is indicated by
HPOSCCON.PLLV = 0 and an interrupt request is generated.
By setting bit HPOSCCON.OSCWDTRST the detection can be restarted without a reset
of the complete PLL, e.g. in case of a VCO loss-of-lock condition.
User’s Manual
SCU, V1.13
6-12
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Note: The oscillator watchdog requires the trimmed currenct controlled clock fINT as a
reference. Therefore, it can only be used (HPOSCCON.PLLV is valid) while the
clock source is active.
User’s Manual
SCU, V1.13
6-13
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.4.6
Switching PLL Parameters
The following restriction applies when changing PLL parameters inside the PLLCON0 to
PLLCON3 registers:
•
•
•
•
•
The VCO bypass switch may be used at any time, however, it has to be ensured that
the maximum operating frequency of the device (see data sheet) will not be
exceeded.
Prescaler Mode should be selected.
After switching to Prescaler Mode, NDIV and PDIV can be adjusted.
Before deselecting the Prescaler Mode, the RESLD bit has to be set and then the
VCOLOCK flag has to be checked. Only when the VCOLOCK flag is set again, the
Prescaler Mode may be deselected.
Before changing VCOSEL, the Prescaler Mode must be selected.
Note: PDIV and NDIV can also be switched in Normal Mode. When changing NDIV, it
must be regarded that the VCO clock fVCO may exceed the target frequency until
the PLL becomes locked. After changing PDIV or NDIV, it must be waited for the
PLL lock condition. This procedure is typically used for increasing the VCO clock
step-by-step.
User’s Manual
SCU, V1.13
6-14
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.5
Clock Control Unit
The Clock Control Unit (CCU) selects the current clock sources for the clock signals
used in the XC2700. It generates the following clocks:
•
•
•
System clock fSYS
RTC count clock fRTC
Output clock fEXT
The following clock signals can be selected:
•
•
•
•
•
PLL clock fPLL
The oscillator clock (OSC_HP) fOSC
Wake-up clock fWU
Input CLKIN1 as Direct Clock Input fCLKIN1
Input CLKIN2 as Direct Clock Input fCLKIN2
6.1.5.1
Clock Generation
Different clock sources can be selected for the generated clock signals.
Note: The selected clock sources are affected by the start-up procedure. See chapter
Device Status after Start-up for the register values set by the different start-up
procedures.
System Clock Generation
The system clock fSYS can be selected from the following clock sources in the CCU:
•
•
•
•
Wake-up clock fWU
The oscillator clock (OSC_HP) fOSC
PLL clock fPLL
Input CLKIN1 as Direct Clock Input fCLKIN1
User’s Manual
SCU, V1.13
6-15
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
SYSCON 0.
CLKSEL
fWU
00
fOSC
01
fPLL
10
fCLKIN1
11
M
U
X
OSCWDT
Emergency
Event
Master
Clock
Multiplexer
(MCM)
10
System
Clock
Selection
SYSCON 0.EMCLKSELEN
PLLCON 1.EMCLKEN
HPOSCCON.EMCLKEN
0
1
00
01
VCOLCK
Emergency
Event
M
U
X
Emergency
Clock
M
U
X
fSYS
to EXTCLK selection
11
SYSCON 0.
EMCLKSEL
Figure 6-9
User’s Manual
SCU, V1.13
CCU_SYSCLK _EXT .vsd
Clock Control Unit, System Clock Generation
6-16
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
RTC Clock Generation
For the RTC module it is possible to select the operation in synchronous or
asynchronous mode in the module itself. The asynchronous clock for the RTC can be
selected out of following clock sources in the CCU:
•
•
•
•
PLL clock fPLL
The oscillator clock (OSC_HP) fOSC
Input CLKIN2 as Direct Clock Input fCLKIN2
Wake-up clock fWU
RTCCLKCON.
RTCCLKSEL
fPLL
00
fOSC
01
fWU
10
fCLKIN2
11
RTCCLKCON.
RTCCM
M
U
X
fRTC
0
1
M
U
X
to RTC block
fSYS
CCU
CCU_RTCCLK_EXT.vsd
Figure 6-10 Clock Control Unit, RTC Clock Generation
User’s Manual
SCU, V1.13
6-17
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.5.2
Selecting and Changing the Operating Frequency
When selecting the clock source and the clock generation method, the required
parameters must be carefully written to the respective bit fields, to avoid unintended
intermediate states.
Many applications change the frequency of the system clock fSYS during operation to
optimize performance and power consumption of the system. Modifying the operating
frequency changes the consumed switching current, which influences the power supply.
Therefore, while the core voltage is generated by the on-chip Embedded Voltage
Regulators (EVRs), the operating frequency may only be changed according to the rules
given in the data sheet.
Note: To avoid the indicated problems, specific sequences are recommened that ensure
the intended operation of the clock system interacting with the power system.
Please refer to the document “Programmer’s Guide”.
6.1.5.3
System Clock Emergency Handling
The generation of the system clock fSYS can be affected, if either the PLL is no more
locked to its input signal fIN, or if the input clock fIN is no more active. Both events can be
detected and are indicated to the application software. The clock system takes
appropriate actions where necessary, so the device and the application is never left
without an alternate clock signal.
Oscillator Watchdog Event
If the clock frequency of the external source drops below a limit value the oscillator
watchdog (OSCWDT) (see Chapter 6.1.4.5) then the clock source for the system clock
fSYS is switched to an alternate clock source, if enabled (HPOSCCON.EMCLKEN = 1).
In this case following information is available:
•
•
•
•
The oscillator watchdog trap flag (TRAPSTAT.OSCWDTT) is set and a trap request
to the CPU is activated, if enabled (TRAPDIS.OSCWDTT = 0).
Bit HPOSCCON.PLLV = 0, while the clock fIN is missing
Bit SYSCON0.EMSOSC is set, if SYSCON0.EMCLKSELEN is set
The source of the system clock fSYS is switched to alternate clock source selected by
SYSCON0.EMCLKSEL, if enabled (SYSCON0.EMCLKSELEN = 1). This is indicated
by bit SYSCON0.SELSTAT = 1.
PLL VCO Loss-of-Lock Event
If the PLL output frequency is no longer locked to its input frequency fIN, the PLL switches
from PLL Normal mode to the Unlocked mode, if enabled (PLLCON1.EMFINDISEN = 1).
In this case following information is available:
•
The PLL VCO loss of lock trap flag (TRAPSTAT.VCOLCKT) is set and a trap request
to the CPU is activated, if enabled (TRAPDIS.VCOLCKT = 0).
User’s Manual
SCU, V1.13
6-18
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
•
•
•
Bit PLLSTAT.VCOLOCK = 0, while the PLL is not locked
Bit SYSCON0.EMSVCO is set, if SYSCON0.EMCLKSELEN is set
The PLL VCO clock input is disconnected (PLLSTAT.FINDIS = 1) and the PLL clock
slows down to its VCO base frequency.
System Behavior
Emergency routines can be executed with the alternate clock (emergency clock or VCO
base frequency). The application can then enter a safe status and stop operation, or it
can switch to an emergency operating mode, where a reduced performance and/or
feature set is provided.
The Programmer’s Guide describes both, how to enable these features, and how to react
properly on each of the two events.
User’s Manual
SCU, V1.13
6-19
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.6
External Clock Output
An external clock output can be provided via pin EXTCLK to clock an external system or
to observe one of the selectable device clocks. This external clock is enabled by setting
bit EXTCON.EN and by selecting the clock signal as alternate output function at pin
EXTCLK. Following clocks can be selected by EXTCON.SEL for external clock fEXT:
•
•
•
•
•
•
System clock fSYS
Programmable clock output fOUT
Direct Clock from oscillator OSC_HP fOSC
PLL clock fPLL
Wake-up clock fWU
RTC clock fRTC
Note: Changing bit field EXTCON.SEL can lead to spikes at pin EXTCLK.
EXTCON .SEL
0000
fSYS
Reload fOUT
Counter
0001
fPLL
0010
fOSC
0011
fWU
0100
fCLKIN1
0101
Reserved
0110
Reserved
0111
EXTCON.EN
'0'
M
U
X
0
1
M
U
X
EXTCLK
fEXT
1000
fRTC
'0'
1001
...
1111
CCU_EXTCLK.vsd
Figure 6-11 EXTCLK Generation
6.1.6.1
Programmable Frequency Output
The programmable frequency output fOUT can be selected as clock output (EXTCLK).
This clock can be controlled via software, and so can be adapted to the requirements of
the connected external circuitry. The programmability also extends the power
management to a system level, as also circuitry (peripherals, etc.) outside the XC2700
can be run at a scalable frequency or can temporarily be left without a clock.
Clock fOUT is generated via a reload counter, so the output frequency can be selected in
small steps.
User’s Manual
SCU, V1.13
6-20
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
EXTCON.FORV
EXTCON.
FOEN
Ctrl.
Reload
1
fSYS
Counter
0
FOTL
M
U
X
fOUT
EXTCON.FOSS
EXTCON.FOTL
Reload Counter
CCU_EXTCLK_Counter.vsd
Figure 6-12 Programmable Frequency Output Generation
fOUT always provides complete output periods (provided fSYS is available):
• When fOUT is started (EXTCON.FOEN is set) counter FOCNT is loaded from
•
EXTCON.FORV
When OUT is stopped (EXTCON.FOEN is cleared) counter FOCNT is stopped when
fOUT has reached (or is) ’0’.
Register EXTCON provides control over the output generation (frequency, waveform,
activation) as well as all status information (EXTCON.FOTL).
User’s Manual
SCU, V1.13
6-21
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
f SYS
1)
f OUT
(FORV = 0)
2)
1)
f OUT
(FORV = 2)
2)
1)
f OUT
(FORV = 5)
2)
FOEN
1
1) FOSS = 1, Output of Counter
2) FOSS = 0, Output of Toggle Latch
FOEN
The counter starts here
0
The counter stops here
mc_xc16x_foutwaves.vsd
Figure 6-13 Output Waveforms Examples
Note: The output (for EXTCON.FOSS= 1) is high for the duration of one fSYS cycle for all
reload values EXTCON.FORV > 0. For EXTCON.FORV = 0 the output frequency
corresponds to fSYS.
When a reference clock is required (e.g. for the bus interface), fSYS must be
selected directly.
User’s Manual
SCU, V1.13
6-22
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7
CGU Registers
6.1.7.1
Wake-up Clock Register
This register controls the settings of OSC_WU.
WUOSCCON
Wake-up OSC Control Register ESFR (F1AEH/D7H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
0
DIS
0
FREQSEL
r
rw
rw
rw
Field
Bits
Type
Description
FREQSEL
[1:0]
rw
Frequency Selection
00B fWU is approximately 500 kHz
01B fWU is approximately 300 kHz
10B fWU is approximately 200 kHz
11B fWU is approximately 130 kHz
Note: This value must not be changed while fWU is
used as clock source for any logic.
0
[3:2]
rw
Reserved
Must be written with reset value 00B.
DIS
4
rw
Clock Disable
0B
The oscillator is switched on and the clock is
enabled
1B
The oscillator is swiched off and the clock is
disabled
0
[15:5]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
6-23
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7.2
High Precision Oscillator Register
This register controls the setting of OSC_HP.
HPOSCCON
High Precision OSC Control Register
ESFR (F1B4H/DAH)
15
14
13
0
r
12
11
10
9
8
7
EM
OSC OSC
EM
FIN
SH
2
2
CLK
DIS
BY
L0
L1
EN
EN
rh
rh
rw
rw
rw
6
Reset Value: 053CH
5
4
X1D
X1D GAINSEL
EN
rw
rh
r
3
2
MODE
rw
1
0
OSC
PLL
WDT
V
RST
w
rh
Field
Bits
Type
Description
PLLV
0
rh
Oscillator for PLL Valid Status Bit
This bit indicates whether the frequency output of
OSC_HP is usable.
This is checked by the Oscillator Watchdog of the
PLL.
0B
The OSC_HP frequency is not usable. The
frequency is below the limit.
1B
The OSC_HP frequency is usable. The
frequency is not below the limit.
For more information see Chapter 6.1.4.5.
OSCWDTRST 1
w
Oscillator Watchdog Reset
No action
0B
1B
The Oscillator Watchdog of the PLL is reset
and restarted
MODE
rw
Oscillator Mode
00B The oscillator is active (crystal or ext. input)
01B Reserved, do not use
10B Reserved, do not use
11B OSC_HP is disabled and in power-saving
mode
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SCU, V1.13
[3:2]
6-24
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
GAINSEL
[5:4]
r
Oscillator Gain Selection
00B Reserved
01B Reserved
10B Reserved
11B The gain control is configured for frequencies
from 4 MHz to 25 MHz
Note: Used for testing only.
X1D
6
rh
XTAL1 Data Value
This bit reflects the inverted level of pin XTAL1.
This bit is sampled with fSYS while X1DEN is set.
Note: Voltages on XTAL1 must comply to the voltage
defined in the data sheet.
X1DEN
7
rw
XTAL1 Data Enable
0B
Bit X1D is not updated
1B
Bit X1D can be updated
SHBY
8
rw
Shaper Bypass
The shaper forms a proper signal from the input
signal. This bit must be 0 for proper operation.
The shaper is not bypassed
0B
1B
The shaper is bypassed
EMCLKEN
9
rw
OSCWDT Emergency System Clock Source
Select Enable
This bit requests the master clock multiplexer (MCM)
to switch to an alternate clock (selected by bit field
SYSCON0.EMCLKSEL) in an OSCWDT emergency
case.
MCM remains controlled by
0B
SYSCON0.CLKSEL
1B
MCM is controlled by SYSCON0.EMCLKSEL
EMFINDISEN
10
rw
Emergency Input Clock Disconnect Enable
This bit defines if bit PLLSTAT.FINDIS is set in an
OSCWDT emergency case.
0B
No action
1B
PLLSTAT.FINDIS is set in an emergency case
Note: Please refer to the Programmer’s Guide for a
description of the proper handling.
User’s Manual
SCU, V1.13
6-25
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
OSC2L1
11
rh
OSC_HP Not Usable Frequency Event
This sticky bit indicates if bit PLLV has been cleared
since OSC2L1 has last been cleared (by writing 1 to
bit STATCLR1.OSC2L1CLR).
0B
No change of PLLV detected
1B
Bit PLLV has been cleared at least once
OSC2L0
12
rh
OSC_HP Usable Frequency Event
This sticky bit indicates if bit PLLV has been set since
OSC2L0 has last been cleared (by writing 1 to bit
STATCLR1.OSC2L0CLR).
0B
No change of PLLV detected
1B
PLLV has been set at least once
0
[15:13] r
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-26
V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7.3
PLL Control Register
This register controls the trimmed current controlled clock source.
PLLOSCCON
PLL OSC Control Register
ESFR (F1B6H/DBH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
0
OSCTRIM
OSC
PD
r
rw
rw
Field
Bits
Type
Description
OSCPD
0
rw
Clock Source Power Saving Mode
0B
Trimmed current controlled clock source is
active
1B
Trimmed current controlled clock source is off
OSCTRIM
[9:1]
rw
Clock Source Trim Configuration
This value is used to adjust the frequency range of
the current controlled clock source.
Do not change this value when writing to this register.
0
[15:10] r
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-27
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7.4
PLL Registers
These registers control the settings of the PLL.
PLLSTAT
PLL Status Register
15
14
13
0
r
12
ESFR (F0BCH/5EH)
11
10
9
8
7
6
Reset Value: 0000H
5
REG
VCO VCO FIN K2 K1
N
P
STA
L1
L0 DIS RDY RDY RDY RDY
T
rh
rh
rh
rh
rh
rh
rh
rh
4
0
r
3
2
1
0
VCO OSC PWD VCO
LOC SEL STA BY
ST
T
ST
K
rh
rh
rh
rh
Field
Bits
Type
Description
VCOBYST
0
rh
VCO Bypass Status
0B
The PLL clock is derived from divider K1
(Prescaler Mode)
1B
The PLL clock is derived from divider K2
(Normal / Unlocked Mode)
Note: Coding of PLLCON0.VCOBY and VCOBYST
are different.
PWDSTAT
1
rh
PLL Power-saving Mode Status
0B
The PLL is operable
The digital part of the PLL is disabled
1B
OSCSELST
2
rh
Oscillator Input Selection Status
0B
External input clock source for the PLL (fIN)
1B
Internal input clock source for the PLL
VCOLOCK
3
rh
PLL VCO Lock Status
0B
The frequency difference of fREF and fDIV is
greater than allowed. The PLL cannot lock.
1B
The PLL clock fPLL is locked to fREF and is
stable.
Note: In case of a loss of lock, the VCO frequency
fVCO approaches to the upper/lower boundary
of the selected VCO band if the reference
frequency is higher/lower than possible for
locking.
User’s Manual
SCU, V1.13
6-28
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
PRDY
5
rh
P-Divider Ready Status
0B
Bit field PLLCON1.PDIV has been changed,
new K1 divider value not yet used.
1B
The P-Divider operates with the value defined
in bit field PLLCON1.PDIV.
NRDY
6
rh
N-Divider Ready Status
0B
Bit field PLLCON0.NDIV has been changed,
new K1 divider value not yet used.
1B
The P-Divider operates with the value defined
in bit field PLLCON0.NDIV.
K1RDY
7
rh
K1-Divider Ready Status
Bit field PLLCON2.K1DIV has been changed,
0B
new K1 divider value not yet used.
1B
The K1-Divider operates with the value defined
in bit field PLLCON2.K1DIV.
K2RDY
8
rh
K2-Divider Ready Status
0B
Bit field PLLCON3.K2DIV has been changed,
new K2 divider value not yet used.
1B
The K2-Divider operates with the value defined
in bit field PLLCON3.K2DIV.
FINDIS
9
rh
Input Clock Disconnect Select Status
0B
The VCO is connected to the reference clock
1B
The VCO is disconnected from the reference
clock
Note: Software can control this bit by writing 1 to bits
SETFINDIS or CLRFINDIS in register
STATCLR1.
VCOL0
User’s Manual
SCU, V1.13
10
rh
VCO Lock Detection Lost Status
This sticky bit indicates if bit VCOLOCK has been
cleared since VCOL0 has last been cleared (by
writing 1 to bit STATCLR1.VCOL0CLR).
0B
No falling edge detected
1B
PLLV has been cleared at least once
(VCO lock was lost)
6-29
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
VCOL1
11
rh
VCO Lock Detection Reached Status
This sticky bit indicates if bit VCOLOCK has been set
since VCOL1 has last been cleared (by writing 1 to bit
STATCLR1.VCOL1CLR).
0B
No rising edge detected
1B
VCO lock was reached
REGSTAT
12
rh
PLL Power Regulator Status
The PLL is powered by a separate internal regulator.
0B
The PLL is not powered (off)
The PLL is powered (operation possible)
1B
Note: Software can control this bit by writing 1 to bits
REGENSET or REGENCLR in register
PLLCON0.
0
User’s Manual
SCU, V1.13
r
4,
[15:13]
Reserved
Read as 0; should be written with 0.
6-30
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
STATCLR1
PLL Status Clear 1 Register
15
14
13
12
11
10
ESFR (F0E2H/71H)
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
CLR SET OSC OSC VCO VCO
FIN FIN 2L0 2L1 L1
L0
DIS DIS CLR CLR CLR CLR
w
w
w
w
w
w
0
r
Field
Bits
Type
Description
VCOL0CLR
0
w
VCOL0 Clear Trigger
No action
0B
1B
Bit PLLSTAT.VCOL0 is cleared
VCOL1CLR
1
w
VCOL1 Clear Trigger
0B
No action
Bit PLLSTAT.VCOL1 is cleared
1B
OSC2L1CLR
2
w
OSC2L1 Clear Trigger
0B
No action
1B
Bits HPOSCCON.OSC2L1 is cleared
OSC2L0CLR
3
w
OSC2L0 Clear Trigger
0B
No action
1B
Bit HPOSCCON.OSC2L0 is cleared
SETFINDIS
4
w
Set Status Bit PLLSTAT.FINDIS
0B
No action
1B
Bit PLLSTAT.FINDIS is set. The VCO input
clock is disconnected.
CLRFINDIS
5
w
Clear Status Bit PLLSTAT.FINDIS
0B
No action
1B
Bit PLLSTAT.FINDIS is cleared. The VCO
input clock is connected.
0
[15:6]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
0
6-31
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
PLLCON0
PLL Configuration 0 Register
15
14
13
12
11
10
ESFR (F1B8H/DCH)
9
8
7
6
N
ACK
0
NDIV
0
rw
r
rw
r
Reset Value: 1302H
5
4
3
2
1
0
REG REG
VCO VCO
EN EN VCOSEL
PWD BY
SET CLR
w
w
rw
rw
rw
Field
Bits
Type
Description
VCOBY
0
rw
VCO Bypass
Select divider K2 for PLL clock
0B
(Normal / Unlocked Mode)
1B
Select divider K1 for PLL clock
(Prescaler Mode, i.e. VCO is bypassed)
Bit PLLSTAT.VCOBYST shows the actually selected
divider.
Note: Coding of VCOBY and PLLSTAT.VCOBYST
are different.
VCOPWD
1
rw
VCO Power Saving Mode
0B
Normal behavior
The VCO is put into a power saving mode and
1B
can no longer be used. Only the Prescaler
Mode is active if previously selected.
VCOSEL
[3:2]
rw
VCO Range Select
The values for the different settings are listed in the
data sheet.
REGENCLR
4
w
Power Regulator Enable Clear
0B
No action
1B
Switch off the PLL’s power regulator.
The PLL is not powered (no operation
possible).
REGENSET
5
w
Power Regulator Enable Set
0B
No action
1B
Switch on the PLL’s power regulator.
The PLL is powered (operation possible).
User’s Manual
SCU, V1.13
6-32
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
NDIV
[13:8]
rw
N-Divider Value
The value the N-Divider operates is NDIV+1.
Only values between N = 8 and N = 28 are allowed
for VCOSEL = 00B.
Only values between N = 16 and N = 40 are allowed
for VCOSEL = 01B.
Outside of this range no stable operation is
guaranteed.
NACK
15
rw
N-Divider Ready Acknowledge
Setting this bit provides the acknowledge signal to
NRDY.
0
6, 7
14
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
6-33
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
PLLCON1
PLL Configuration 1 Register ESFR (F1BAH/DDH)
15
14
13
12
11
10
9
8
7
P
ACK
0
PDIV
0
rw
r
rw
r
6
Reset Value: 000AH
5
EM
EM
FIN
CLK
DIS
EN
EN
rw
rw
4
0
r
3
2
1
0
A
RES OSC PLL
OSC
LD SEL PWD
SEL
rw
w
rw
rw
Field
Bits
Type
Description
PLLPWD
0
rw
PLL Power Saving Mode
0B
Normal behavior
1B
Complete PLL block is put into a power saving
mode and no longer operates
OSCSEL
1
rw
Oscillator Input Selection
0B
Select external clock as input for PLL
1B
Select trimmed current controlled clock as
input for PLL
RESLD
2
w
Restart VCO Lock Detection
Setting this bit will reset bit PLLSTAT.VCOLOCK and
restart the VCO lock detection.
AOSCSEL
3
rw
Asynchronous Oscillator Input Selection
This bit overrules the setting of bit OSCSEL.
0B
Configuration is controlled via bit OSCSEL
Select asynchronously trimmed current
1B
controlled clock as input for PLL
EMCLKEN
5
rw
VCOLCK Emergency System Clock Source
Select Enable
This bit requests the master clock multiplexer (MCM)
to switch to an alternate clock (selected by bit field
SYSCON0.EMCLKSEL) in a VCOLCK emergency
case.
0B
MCM remains controlled by
SYSCON0.CLKSEL
1B
MCM is controlled by SYSCON0.EMCLKSEL
User’s Manual
SCU, V1.13
6-34
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
EMFINDISEN
6
rw
Emergency Input Clock Disconnect Enable
This bit defines if bit PLLSTAT.FINDIS is set in a
VCOLCK emergency case.
0B
No action
1B
PLLSTAT.FINDIS is set in a VCOLCK
emergency case
Note: Please refer to the Programmer’s Guide for a
description of the proper handling.
PDIV
[11:8]
rw
P-Divider Value
The value the P-Divider operates is PDIV+1.
PACK
15
rw
P-Divider Ready Acknowledge
Setting this bit provides the acknowledge to PRDY.
0
4, 7,
r
[14:12]
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-35
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
PLLCON2
PLL Configuration 2 Register ESFR (F1BCH/DEH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0001H
5
4
3
2
1
0
K1
ACK
0
K1DIV
rw
r
rw
Field
Bits
Type
Description
K1DIV
[9:0]
rw
K1-Divider Value
The value the K1-Divider operates is K1DIV+1.
K1ACK
15
rw
K1-Divider Ready Acknowledge1)
Setting this bit provides the acknowledge to K1RDY.
0
[14:10] r
1)
Reserved
Read as 0; should be written with 0.
Please refer to the Programmer’s Guide for a description of the proper handling.
User’s Manual
SCU, V1.13
6-36
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
PLLCON3
PLL Configuration 3 Register
15
14
13
12
11
10
ESFR (F1BEH/DFH)
9
8
7
6
Reset Value: 00CBH
5
4
3
2
1
0
K2
ACK
0
K2DIV
rw
r
rw
Field
Bits
Type
Description
K2DIV
[9:0]
rw
K2-Divider Value
The value the K2-Divider operates is K2DIV+1.
K2ACK
15
rw
K2-Divider Ready Acknowledge1)
Setting this bit provides the acknowledge to K2RDY.
0
[14:10] r
1)
Reserved
Read as 0; should be written with 0.
Please refer to the Programmer’s Guide for a description of the proper handling.
User’s Manual
SCU, V1.13
6-37
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7.5
System Clock Control Registers
These registers control the system level clock behavior.
SYSCON0
System Control 0 Register
15
14
SEL
STA
T
0
rh
r
13
12
11
SFR (FF4AH/A5H)
10
EMS EMS
VCO OSC
rh
9
8
7
EM
CLK
SEL
EN
rw
0
rh
6
r
Reset Value: 0000H
5
4
3
2
1
0
0
EM
CLKSEL
0
CLKSEL
r
rw
r
rw
Field
Bits
Type
Description
CLKSEL
[1:0]
rw
Clock Select
This bit field defines the clock source that is used as
system clock for normal operation.
00B The Wake-up clock fWU is used
01B The oscillator clock (OSC_HP) fOSC is used
10B The PLL clock fPLL is used
11B CLKIN1 as direct input clock fCLKIN1 is used
EMCLKSEL
[4:3]
rw
Emergency Clock Select
This bit field defines the clock source that is used as
system clock in case of an OSCWDT or VCOLCK
emergency event.
00B The Wake-up clock fWU is used
01B The oscillator clock (OSC_HP) fOSC is used
10B The PLL clock fPLL is used
11B CLKIN1 as direct input clock fCLKIN1 is used
EMCLKSELEN 6
rw
Emergency Clock Select Enable
Controls switching the system clock to an alternate
source in case of an OSCWDT or VCOLCK event.
The switching is disabled
0B
1B
The switching is enabled
EMSOSC
rh
OSCWDT Emergency Event Source Status
0B
No OSCWDT emergency event occurred since
EMSOSC has been cleared last
1B
An OSCWDT emergency event has occurred
12
Note: This bit is only set if EMCLKSELEN is set.
User’s Manual
SCU, V1.13
6-38
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
EMSVCO
13
rh
VCOLCK Emergency Event Source Status
0B
No VCOLCK emergency event occurred since
EMSVCO has been cleared last
1B
A VCOLCK emergency event has occurred
Note: This bit is only set if EMCLKSELEN is set.
SELSTAT
15
0
2, 5,
r
[11:7],
14
User’s Manual
SCU, V1.13
rh
Clock Select Status
0B
The standard configuration from bit field
CLKSEL is used currently
1B
The configuration from bit field EMCLKSEL is
used currently
Reserved
Read as 0; should be written with 0.
6-39
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
STATCLR0
Status Clear 0 Register
15
14
0
13
12
ESFR (F0E0H/70H)
11
10
9
8
7
EMC EMC
VCO OSC
r
w
Reset Value: 0000H
6
5
4
3
2
1
0
w
r
Field
Bits
Type
Description
EMCOSC
12
w
EMSOSC Clear Trigger
0B
No action
1B
Bit SYSCON0.EMSOSC is cleared
EMCVCO
13
w
EMSVCO Clear Trigger
0B
No action
1B
Bit SYSCON0.EMSVCO is cleared
0
[11:0], r
[15:14]
User’s Manual
SCU, V1.13
0
Reserved
Read as 0; should be written with 0.
6-40
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7.6
RTC Clock Control Register
Note: Only change register RTCCLKCON while the RTC is off.
RTCCLKCON
RTC Clock Control Register
15
14
13
12
11
10
SFR (FF4EH/A7H)
9
8
7
6
Reset Value: 0006H
5
4
3
2
1
0
0
RTC
CM
RTC
CLKSEL
r
rw
rw
Field
Bits
Type
Description
RTCCLKSEL
[1:0]
rw
RTC Clock Select
This bit field defines the count clock source for the
RTC.
00B The PLL clock fPLL is used
01B The oscillator clock (OSC_HP) fOSC is used
10B The Wake-up clock signal fWU is used
11B CLKIN2 as direct input clock fCLKIN2 is used
RTCCM
2
rw
RTC Clocking Mode
0B
Asynchronous Mode:
The RTC internally operates with fRTC.
No register access is possible.
1B
Synchronous Mode:
The RTC internally operates with fSYS clock.
Registers can be read and written.
0
[15:3]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
6-41
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.1.7.7
External Clock Control Register
This register control the setting of external clock for pin 2.8 and 7.1.
EXTCON
External Clock Control Register SFR (FF5EH/AFH)
15
14
FO
EN
FO
SS
rw
rw
13
12
11
10
9
8
Reset Value: 0000H
7
6
5
4
3
2
1
0
FORV
0
FO
TL
0
SEL
EN
rw
r
rh
r
rw
rw
Field
Bits
Type
Description
EN
0
rw
External Clock Enable
0B
No external clock signal is provided. The signal
is tied to zero.
1B
The configured external clock signal is
provided as alternate output signal
SEL
[4:1]
rw
External Clock Select
Selects the clock signal to be routed to the EXTCLK
pin:
0000BSystem clock fSYS
0001BProgrammable clock signal fOUT
0010BPLL output clock fPLL
0011BOscillator clock fOSC
0100BWake-up clock fWU
0101BDirect Input clock fCLKIN1
1000BRTC count clock fRTC
All other combination are reserved, do not use.
FOTL
6
rh
Frequency Output Toggle Latch
Toggled upon each underflow of FOCNT.
FORV
[13:8]
rw
Frequency Output Reload Value
Copied to FOCNT upon each underflow of FOCNT.
FOSS
14
rw
Frequency Output Signal Select
0B
Output of the toggle latch
1B
Output of the reload counter: duty cycle
depends on FORV
User’s Manual
SCU, V1.13
6-42
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
FOEN
15
rw
Frequency Output Enable
0B
Frequency output generation stops when fOUT
is/becomes low.
1B
FOCNT is running, fOUT is gated to pin.
First reload after 0 - 1 transition.
0
5, 7
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
6-43
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.2
Wake-up Timer (WUT)
The Wake-up Timer provides an additional resource to trigger system functions after a
specific period of time.
The master clock fSYS is prescaled and drives a simple counter. All functions are
controlled by register WUCR.
WUCR.
TTSTAT
OSC_WU
fWU
Trim
Interrupt
Trigger
Sync.
fSYS
64:1
WIC
Wake-up
Interrupt
Trigger
WUCR.
WUTRG
CGU
reset
run
Wake-up
Trigger
Run
Control
WUCR.
AONCON
To
CCU60
WUCR.
ASPCON
WUCR.
RUNCON
Wake-Up Timer
WUT_MR_noSB .vsd
Figure 6-14 Wake-up Timer Logic
6.2.1
Wake-up Timer Operation
The Wake-up Timer start and stop is controlled by the Run Control logic. The timer can
be started in the following way:
•
bit WUCR.RUN is set
When the timer is started the prescaler is reset and the counter WIC starts to count
down.
The wake-up interval counter (WIC) is clocked with fSYS/64, and counts down until it
reaches zero. It then generates a wake-up trigger and sets bit WUCR.WUTRG.
The timer is stopped in the following ways:
•
•
bit WUCR.RUN is cleared
bit WUCR.ASP is set AND a wake-up trigger is generated
If the counter WIC is not stopped by its zero trigger it continues counting down from
FFFFH.
User’s Manual
SCU, V1.13
6-44
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Determination of Wake-up Period
The actual frequency of the trimmed current controlled wake-up clock (OSC_WU) can
be measured prior to entering power-save mode in order to adjust the number of clock
cycles to be counted (value written to WIC), and such, to define the time until wake-up.
The period of OSC_WU can be measured by evaluating its (synchronized) clock output,
which can generate an interrupt request or which can be monitored via bit
WUCR.TTSTAT.
As using an interrupt together with software contain some uncertainty there is a second
way to determine the wake-up period. The wake-up triggers generated by the WUT are
forwarded to the CCU60 and can there be evaluated compared to the accurate system
clock.
User’s Manual
SCU, V1.13
6-45
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.2.2
WUT Registers
6.2.2.1
Register WICR
Via this register the status and configuration of the WIC counter is done.
WICR
Wake-up Interval Count Register
ESFR (F0B0H/58H)
15
14
13
12
11
10
9
8
7
6
Reset Value: FFFFH
5
4
3
2
1
0
WIC
rwh
Field
Bits
Type
Description
WIC
[15:0]
rwh
Wake-up Interval Counter
This free-running 16-bit counter counts down and
issues a trigger when its count reaches zero.
User’s Manual
SCU, V1.13
6-46
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.2.2.2
Register WUCR
This register the status and control bits for the WUT.
WUCR
Wake-up Control Register
15
14
13
12
WU TTS
TRG TAT
rh
11
0
rh
ESFR (F1B0H/D8H)
10
9
8
ASP AON RUN
r
rh
rh
rh
Reset Value: 0000H
7
6
5
4
3
2
1
CLR
TRG
0
ASP
CON
AON
CON
RUN
CON
w
r
w
w
w
Field
Bits
Type
Description
RUNCON
[1:0]
w
Control Field for RUN
00B No action
01B Set bit RUN
10B Clear bit RUN
11B Reserved, do not use this combination
AONCON
[3:2]
w
Control Field for AON
00B No action
01B Reserved, do not use this combination
10B Clear bit AON
11B Reserved, do not use this combination
ASPCON
[5:4]
w
Control Field for ASP
00B No action
01B Set bit ASP
10B Clear bit ASP
11B Reserved, do not use this combination
CLRTRG
7
w
Clear Bit WUTRG
0B
No action
1B
Clear bit WUTRG
RUN
8
rh
Run Indicator
0B
Wake-up counter is stopped
Wake-up counter is counting down
1B
0
Note: Clearing this bit via a write action to bit field
RUNCON stops the WUT after four cycles of
fWUT.
User’s Manual
SCU, V1.13
6-47
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
AON
9
rh
Auto-Start Indicator
0B
Wake-up counter is started by software only
1B
Reserved, do not use this combination
Note: This bit is cleared by writing 01B to bit field
AONCON.
ASP
10
rh
Auto-Stop Indicator
Wake-up counter runs continuously
0B
1B
Wake-up counter stops after generating a
trigger when reaching zero
TTSTAT
14
rh
Trim Trigger Status
0B
No trim trigger event is active. No trim interrupt
trigger is generated.
1B
A trim trigger event is active. A trim interrupt
trigger is generated.
Note: This bit is not valid if fSYS = fWU is configured by
SYSCON0.CLKSEL
WUTRG
15
rh
0
6,
r
[13:11]
WUT Trigger Indicator
0B
No trigger event has occurred since WUTRG
has been cleared last. No interrupt trigger is
generated.
A wake-up trigger event has occurred. A wake1B
up interrupt trigger is generated.
Reserved
Read as 0; should be written with 0.
Note: The bits in the upper byte of register WUCR indicate the current status of the
wake-up counter logic. They are not influenced by a write access, but are
controlled by their associated control fields (lower byte) or by hardware.
The control bit(field)s in the lower byte of register WUCR determine the state of
the status bits (upper byte) of the wake-up counter logic. Setting bits by software
triggers the associated action, writing 0 has no effect.
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6.3
Reset Operation
All resets are generated by the Reset Control Block. It handles the control of the reset
triggers as well as the length of a reset and the reset timing. A reset leads the system,
or a part of the system depending on the reset, to a initialization into a defined state.
6.3.1
Reset Architecture
The XC2700 contains a very sophisticated reset architecture to offer the greatest amount
of flexibility for the support of different applications. The reset architecture supports the
different power domains.
Different reset types for the complete system are supported.
6.3.1.1
Device Reset Hierarchy
The device reset hierarchy is divided according to the power domains (see Chapter 6.5)
into following linked levels:
Level 1: I/O domain (power domain DMP_B)
Level 2: System power domain DMP_M
Level 3: System power domain DMP_1
If a power domain (level) is deactivated all resets of the deactivated level and all resets
of all lower power domains are asserted.
6.3.1.2
Reset Types
The following summary shows the different reset types.
Power Reset
•
•
Power-on Reset
This reset leads to a defined state of the complete system. This reset should only be
requested on a real power-on event and not by any non power related event.
Power Reset for DMP_M and DMP_1 power domains
This reset regains data consistency upon a power fail in the DMP_M or DMP_1
power domains.
Functional / User Reset
•
•
Debug Reset
This reset leads to a defined state of the complete debug system.
Internal Application Reset
This reset leads to a defined state of the complete application system with the
following parts: all peripherals (except the RTC), the CPU and partially the SCU and
the flash memory.
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•
Application Reset
This reset leads to a defined state of the complete application system with the
following parts: all peripherals (except the Ports and the RTC), the CPU and partially
the SCU and the flash memory.
After a reset has been executed, the Reset Status registers RSTSTATx indicate the
latest reset that has occured.
To identify the type and the trigger of the latest reset registers RSTSTATx and may be
SWDCON1evaluated according to the following table. The latest reset that has occured
is always the reset of the highest type. If two reset triggers of the same type are
indicated, this means that the two triggers have been active at the same time. If two or
more reset triggers of a different type are reported, always the reset of the highest type
is the latest one.
Table 6-1
Identification of a reset
Type of Reset
(in hierarchical order, highest on
top)
Identification
Power-on Reset
SWDCON1.PON = 1B
RSTSTAT1.STM = 11B
RSTSTAT1.ST1 = 11B
Further action: clear PON bit to be able to identify
a Power Reset for DMP_M and DMP_1 power
domains.
Power Reset for DMP_M and
DMP_1 power domains
SWDCON1.PON = 0B (unchanged after clearing)
RSTSTAT1.STM = 11B
RSTSTAT1.ST1 = 11B
Internal Application Reset
RSTSTAT1.ST1 = 00B
RSTSTATx.y = 10B
Application Reset
RSTSTAT1.ST1 = 00B
RSTSTATx.y = 11B
6.3.2
General Reset Operation
A reset is generated if an enabled reset request trigger is asserted. Most reset request
triggers can be configured for the reset type it should initiate. No action (disabled) is one
possible configuration and can be selected for a reset request trigger by setting the
respective bit field in a Reset Configuration Register to 00B. The debug reset can only
be requested by dedicated reset request triggers and can not be selected via a Reset
Configuration Register. For more information see also registers RSTCON0 and
RSTCON1.
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The duration of a reset is defined by two independent counters. One counter for the
System and Application Reset types and one separate counter for the debug reset. A
separate counter for the debug reset was implemented to allow a non-intrusive
adaptation of the reset length to the debugger needs without modification of the
application setting.
6.3.2.1
Reset Counters (RSTCNTA and RSTCNTD)
RSTCNTA is the reset counter that controls the reset length for all application relevant
resets (Internal Application Reset, and Application Reset). RSTCNTD is the reset
counter that controls the reset length for the debug reset.
The reset counters control the length of the internal resets. This can be used to configure
the duration of a reset output via the ESRx pins, so this matches with the reset input
requirements of external blocks connected to these signals.
A reset counter RSTCNT is an 8-bit counter counting down from the reload value defined
by RSTCNTCON.RELx (x = A or D). The counter is started by the reset control block as
soon as a reset request trigger condition becomes active (for more information see
Table 6-2 and Table 6-3). Whether the counter has to be started or not depends on the
reset request trigger and whether the counter is already active or not. In case of that the
counter is inactive, not counting down, it is always started. While the counter is already
active it depends on the reset type of the new reset request trigger that was asserted
anew if the counter is restarted or not. This behavior is summarized in Table 6-2 and
Table 6-3.
Table 6-2
Restart of RSTCNTA
Reset Active
New Reset Trigger
Power-On
Debug Reset
Internal
Application
Reset
Application
Reset
Internal Application
Reset
Restart with
default delay
No Change
No Change
No Change
Application Reset
Restart with
default delay
No Change
Restart with
defined delay
No Change
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Table 6-3
Restart of RSTCNTD
Reset Active
New Reset Trigger
Power-On
Debug Reset
Restart with
default delay
Debug Reset
No Change
Internal
Application
Reset
No Change
Application
Reset
No Change
The reset counters RSTCNTx ensure a configurable minimum duration of a generated
reset. If a reset request trigger remains asserted after the respective counter has
counted down, the counter is not started again, instead the reset control block keeps the
reset asserted until the reset request trigger is deasserted.
6.3.2.2
De-assertion of a Reset
The reset of a dedicated type is de-asserted when all of the following conditions are
fulfilled:
•
•
The reset counter has been expired (reached zero).
No reset request trigger that is configured to generate a reset of the dedicated type
(or higher) is currently asserted.
Example1
Reset request trigger A is asserted and leads to an Application Reset. If the reset request
trigger is de-asserted before RSTCNTA reached zero the Application Reset is deasserted when RSTCNTA reaches zero. If the reset request trigger is de-asserted after
RSTCNTA reached zero the Application Reset is de-asserted when the reset request
trigger is de-asserted.
Example2
Reset request trigger A is asserted and leads to an Application Reset. Reset request
trigger A is de-asserted before RSTCNTA reached zero. Reset request trigger B is
asserted after reset request trigger A but before RSTCNTA reaches zero. Reset request
trigger B is also configured to result in a Application Reset. If the reset request trigger B
is de-asserted before RSTCNTA reached zero the Application Reset is de-asserted
when RSTCNTA reaches zero. If the reset request trigger B is de-asserted after
RSTCNTA reached zero the Application Reset is de-asserted when the reset request
trigger B is de-asserted.
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6.3.3
Debug Reset Assertion
Unlike the other reset types a Debug Reset can only be asserted if the following two
conditions are valid:
•
•
A reset request trigger is asserted that request a debug reset
An Application Reset is already active in the system
6.3.4
Coupling of Reset Types
The different reset types are coupled for a better usage:
•
•
The assertion of a Power-on Reset automatically asserts also the following reset
types:
– Debug Reset
– Internal Application Reset
– Application Reset
The assertion of an Internal Application Reset automatically asserts also the
following reset type:
– Application Reset
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6.3.5
Reset Request Trigger Sources
The following overview summarizes the different reset request trigger sources within the
system.
Power-On Reset Pin PORST
A Power-on Reset is requests asynchronously, by driving the PORST pin low.
Supply Watchdog (SWD)
If the power supply for I/O domain is below the value required for proper functionality, a
non-synchronized reset request trigger is generated if the SWD reset generation is
enabled. This ensures a reproducible behavior in the case of power-fail. This can also
be used to restart the system without the usage of the PORST pin. As long as the I/O
power domain does not get the required voltage level the system is held in the reset.
Core Power Validation (PVC_M and PVC_1)
If the core power supply is below the value required for proper functionality of the main
power domain (PVC_M), a reset request trigger can be forwarded to the system. The
generation of a Power-on Reset is configured by bit PVCMCON0.L1RSTEN = 1B. If the
bit PVCMCON0.L1RSTEN = 1B a request trigger is asserted for PVC_M1 upon a level
check match. If the bit PVCMCON0.L2RSTEN = 1B a request trigger is asserted for
PVC_M2 upon a level check match.
If the core power supply is below the value required for proper functionality of the
application power domain (PVC_1), a reset request trigger can be forwarded to the
system. The generation of a Power-on Reset (Application Power Domain only) is
configured by bit PVC1CON0.L1RSTEN = 1B. If bit PVC1CON0.L1RSTEN = 1B a
request trigger is asserted for PVC_11 upon a level check match. If the bit
PVC1CON0.L2RSTEN = 1B a request trigger is asserted for PVC_12 upon a level check
match.
For more information about the Power Validation Circuit see Chapter 6.5.2.
ESRx
An ESRx reset request trigger leads to a configurable reset. The type of reset can be
configured via RSTCON1.ESRx.
The pins ESRx can serve as an external reset input as well as a reset output (open drain)
for Internal Application and Application Resets. Furthermore, several GPIO pad triggers,
that can be enabled additionally via register ESREXCONx (x = 1, 2), interfere with the
ESR pin function. GPIO and ESRx pin triggers can be enabled/disabled individually and
are combined for the reset trigger generation.
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If pin ESRx is enabled as reset output and the input level is low while the output stage is
disabled (indicating that it is still driven low externally), the reset circuitry holds the chip
in reset until a high level is detected on ESRx. Minimum value for RSTCNTCON.RELA
must be the reset value.
Note: The reset output is only driven low for the duration the reset counter RSTCNTA is
active. During a possible reset extension the reset output is no longer driven.
Software
A software reset request trigger leads to a configurable reset. The type of reset can be
configured via RSTCON0.SW.
Watchdog Timer
A WDT reset request trigger leads to a configurable reset. The type of reset can be
configured via RSTCON1.WDT. A WDT reset is requested on a WDT overflow event.
For more information see Chapter 6.11.
CPU
A CPU reset request trigger leads to a configurable reset. The type of reset can be
configured via RSTCON0.CPU. A CPU reset is requested when instruction SRST is
executed.
Memory Parity
A MP reset request trigger leads to a configurable reset. The type of reset can be
configured via RSTCON1.MP. For more information see Chapter 6.13.1.
OCDS Block
The OCDS block has several options to request different reset types:
1. A Debug Reset either via the OCDS reset function or via bit CBS_OJCONF.RSTCL1
AND CBS_OJCONF.RSTCL3
2. An Internal Application Reset via bit CBS_OJCONF.RSTCL2
3. An Application Reset via bit CBS_OJCONF.RSTCL3
6.3.5.1
Reset Sources Overview
The connection of the reset sources and the activated reset types are shown in
Table 6-4.
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Table 6-4
Effects of Reset Types for Reset Activation
Reset Request Trigger
Application
Reset
Internal
Application
Reset
Debug Reset
PORST
Activated
Activated
Activated
SWD
Activated
Activated
Activated
PVC_M1
Activated
Activated
Activated
PVC_M2
Activated
Activated
Activated
PVC_11
Activated
Activated
Activated
PVC_12
Activated
Activated
Activated
ESR0
Configurable
Configurable
Not Activated
ESR1
Configurable
Configurable
Not Activated
ESR2
Configurable
Configurable
Not Activated
WDT
Configurable
Configurable
Not Activated
SW
Configurable
Configurable
Not Activated
CPU
Configurable
Configurable
Not Activated
MP
Configurable
Configurable
Not Activated
OCDS Reset
Not Activated
Not Activated
Activated1)
CBS_OJCONF.RSTCL1
Not Activated
Not Activated
Activated1)
CBS_OJCONF.RSTCL2
Activated
Activated
Not Activated
CBS_OJCONF.RSTCL3
Activated
Not Activated
Not Activated
1)
Only if an Application Reset is active or is requested in parallel.
6.3.6
Module Reset Behavior
Table 6-5 lists how the various functions of the XC2700 are affected through a reset
depending on the reset type. A “X” means that this block has at least some register/bits
that are affected by this reset type.
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Table 6-5
Effect of Reset on Device Functions
Module / Function
Application
Reset
Internal
Application
Reset
Debug Reset
CPU Core
X
X
X
Peripherals
(except SCU
and RTC)
X
X
X
SCU
X
Not affected
Not affected
RTC
Not affected
Not affected
X
On-chip
DPRAM
1)
Static RAMs
Not affected,
reliable
Not affected,
reliable
Not affected,
reliable
PSRAM
Not affected,
reliable
Not affected,
reliable
Not affected,
reliable
DSRAM
Not affected,
reliable
Not affected,
reliable
Not affected,
reliable
Flash
Memory
X
X
2)
2)
Not affected,
reliable
JTAG
Interface
Not affected
Not affected
Not affected
OCDS
Not affected
Not affected
X
Oscillator,
PLL
Not affected
Not affected
Not affected
Port Pins
Not affected
X
Not affected
Pins ESRx
Not affected
X
Not affected
1)
Reliable here means that also the redundancy is not affected by the reset.
2)
Parts of the flash memory block are only reset by a Power-on Reset. For more detail see the flash chapter.
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6.3.7
Reset Controller Registers
6.3.7.1
Status Registers
After a reset has been executed, the Reset Status registers provide information on the
type of the last reset.
RSTSTAT0
Reset Status 0 Register
15
14
13
12
ESFR (F0B2H/59H)
11
10
9
8
7
Reset Value: 0000H
6
5
SW
CPU
0
rh
rh
r
3
2
1
0
Field
Bits
CPU
[13:12] rh
CPU Reset Type Status
00B The CPU reset trigger was not relevant for the
last reset
01B Reserved
10B The CPU reset trigger was relevant for the last
reset. Internal Application and Application
Resets were generated.
11B The CPU reset trigger was relevant for the last
reset. Application Reset was generated.
SW
[15:14] rh
Software Reset Type Status
00B The Software reset trigger was not relevant for
the last reset
01B Reserved
10B The Software reset trigger was relevant for the
last reset. Internal Application and Application
Resets were generated.
11B The Software reset trigger was relevant for the
last reset. Application Reset was generated.
0
[11:0]
Reserved
Read as 0; should be written with 0.
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Type
4
r
Description
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RSTSTAT1
Reset Status 1 Register
15
14
13
12
ESFR (F0B4H/5AH)
11
10
9
8
7
6
Reset Value: F000H
5
4
3
2
1
0
ST1
STM
0
MP
WDT
ESR2
ESR1
ESR0
rh
rh
r
rh
rh
rh
rh
rh
Field
Bits
Type
Description
ESR0
[1:0]
rh
ESR0 Reset Status
00B The ESR0 reset trigger was not relevant for the
last reset
01B Reserved
10B The ESR0 reset trigger was relevant for the
last reset. Internal Application, and Application
Resets were generated.
11B The ESR0 reset trigger was relevant for the
last reset. Application Reset was generated.
ESR1
[3:2]
rh
ESR1 Reset Status
00B The ESR1 reset trigger was not relevant for the
last reset
01B Reserved
10B The ESR1 reset trigger was relevant for the
last reset. Internal Application, and Application
Resets were generated.
11B The ESR1 reset trigger was relevant for the
last reset. Application Reset was generated.
ESR2
[5:4]
rh
ESR2 Reset Status
00B The ESR2 reset trigger was not relevant for the
last reset
01B Reserved
10B The ESR2 reset trigger was relevant for the
last reset. Internal Application, and Application
Resets were generated.
11B The ESR2 reset trigger was relevant for the
last reset. Application Reset was generated.
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Field
Bits
Type
Description
WDT
[7:6]
rh
WDT Reset Status
00B The WDT reset trigger was not relevant for the
last reset
01B Reserved
10B The WDT reset trigger was relevant for the last
reset. Internal Application, and Application
Resets were generated.
11B The WDT reset trigger was relevant for the last
reset. Application Reset was generated.
MP
[9:8]
rh
MP Reset Status
00B The MP reset trigger was not relevant for the
last reset
01B Reserved
10B The MP reset trigger was relevant for the last
reset. Internal Application, and Application
Resets were generated.
11B The MP reset trigger was relevant for the last
reset. Application Reset was generated.
STM
[13:12] rh
Power-on for DMP_M Reset Status
00B The power-on reset for DMP_M reset trigger
was not relevant for the last reset
01B The power-on reset for DMP_M reset trigger
was not relevant for the last reset
10B The power-on reset for DMP_M reset trigger
was not relevant for the last reset
11B The power-on reset for DMP_M reset trigger
was relevant for the last reset
ST1
[15:14] rh
Power-on for DMP_1 Reset Status
00B The power-on reset for DMP_1 reset trigger
was not relevant for the last reset
01B The power-on reset for DMP_1 reset trigger
was not relevant for the last reset
10B The power-on reset for DMP_1 reset trigger
was not relevant for the last reset
11B The power-on reset for DMP_1 reset trigger
was relevant for the last reset
0
[11:10] r
Reserved
Read as 0; should be written with 0.
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RSTSTAT2
Reset Status 2 Register
15
14
13
12
ESFR (F0B6H/5BH)
11
10
0
9
8
7
6
Reset Value: 0000H
5
4
OJCONF3 OJCONF2 OJCONF1
r
rh
rh
rh
3
2
1
0
0
DB
r
rh
Field
Bits
Type
Description
DB
[1:0]
rh
Debug Reset Status
00B The DB reset trigger was not relevant for the
last reset
01B The DB reset trigger was not relevant for the
last reset
10B The DB reset trigger was not relevant for the
last reset
11B The DB reset trigger was relevant for the last
reset
OJCONF1
[5:4]
rh
OJCONF1 Reset Status
00B The OJCONF1 reset trigger was not relevant
for the last reset
01B The OJCONF1 reset trigger was not relevant
for the last reset
10B The OJCONF1 reset trigger was not relevant
for the last reset
11B The OJCONF1 reset trigger was relevant for
the last reset. Debug Reset was generated.
OJCONF2
[7:6]
rh
OJCONF2 Reset Status
00B The OJCONF2 reset trigger was not relevant
for the last reset
01B The OJCONF2 reset trigger was not relevant
for the last reset
10B The OJCONF2 reset trigger was relevant for
the last reset. Internal Application, and
Application Resets were generated.
11B The OJCONF2 reset trigger was not relevant
for the last reset
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Field
Bits
Type
Description
OJCONF3
[9:8]
rw
OJCONF3 Reset Status
00B The OJCONF3 reset trigger was not relevant
for the last reset
01B The OJCONF3 reset trigger was not relevant
for the last reset
10B The OJCONF3 reset trigger was not relevant
for the last reset
11B The OJCONF3 reset trigger was relevant for
the last reset. Application Reset was
generated.
0
[3:2],
r
[15:10]
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Reserved
Read as 0; should be written with 0.
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6.3.7.2
Configuration Registers
These registers allow the behavioral configuration for the various reset trigger sources.
RSTCON0
Reset Configuration 0 Register ESFR (F0B8H/5CH)
15
14
13
12
11
10
9
8
7
Reset Value: 0000H
6
5
SW
CPU
0
rw
rw
rw
3
2
1
0
Field
Bits
CPU
[13:12] rw
CPU Reset Type Selection
This bit field defines which reset types are generated
by a CPU reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
SW
[15:14] rw
Software Reset Type Selection
This bit field defines which reset types are generated
by a software reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
0
[11:0]
Reserved
Must be written with reset value 0.
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Type
4
rw
Description
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RSTCON1
Reset Configuration 1 Register ESFR (F0BAH/5DH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0002H
5
4
3
2
1
0
0
MP
WDT
ESR2
ESR1
ESR0
rw
rw
rw
rw
rw
rw
Field
Bits
Type
Description
ESR0
[1:0]
rw
ESR0 Reset Type Selection
This bit field defines which reset types are generated
by a ESR0 reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
ESR1
[3:2]
rw
ESR1 Reset Type Selection
This bit field defines which reset types are generated
by a ESR1 reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
ESR2
[5:4]
rw
ESR2 Reset Type Selection
This bit field defines which reset types are generated
by a ESR2 reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
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Field
Bits
Type
Description
WDT
[7:6]
rw
WDT Reset Type Selection
This bit field defines which reset types are generated
by a WDT reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
MP
[9:8]
rw
MP Reset Type Selection
This bit field defines which reset types are generated
by a MP reset request trigger.
00B No reset is generated
01B Reserved, do not use this combination
10B Internal Application, and Application Resets
are generated
11B Application Reset is generated
0
[15:10] rw
User’s Manual
SCU, V1.13
Reserved
Should be written with 0.
6-65
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
RSTCNTCON
Reset Counter Control RegisterESFR (F1B2H/D9H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0A0AH
5
4
3
RELD
RELA
rw
rw
2
1
0
Field
Bits
Type
Description
RELA
[7:0]
rw
Application Reset Counter Reload Value
This bit field defines the reload value of RSTCNTA.
This value is always used when counter RSTCNTA is
started.
This counter value is used for Internal Application,
and Application Resets.
In case of an ESRx reset the counter value must be
not less than the reset value.
RELD
[15:8]
rw
Debug Reset Counter Reload Value
This bit field defines the reload value of RSTCNTD.
This value is always used when counter RSTCNTD
is started.
This counter value is used for the Debug Reset.
In case of an ESRx reset the counter value must be
not less than the reset value.
User’s Manual
SCU, V1.13
6-66
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Software Reset Control Register
This register controls the software reset operation.
SWRSTCON
Software Reset Control RegisterESFR (F0AEH/57H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
SWCFG
0
rw
r
3
2
1
0
SW SW
RST BOO
REQ T
w
rw
Field
Bits
Type
Description
SWBOOT
0
rw
Software Boot Configuration Selection
0B
Bit field STSTAT.HWCFG is not updated with
the content of SWCFG upon an Application
Reset
1B
Bit field STSTAT.HWCFG is updated with the
content of SWCFG upon an Application Reset
SWRSTREQ
1
w
Software Reset Request
0B
No software reset is requested
1B
A software reset request trigger is generated
SWCFG
[15:8]
rw
Software Boot Configuration
A valid software boot configuration (also different
from the external applied hardware configuration)
can be specified with these bits.
The configuration encoding is equal to the HWCFG
encoding in register STSTAT.
0
[7:2]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.4
External Service Request (ESR) Pins
The ESR pins serve as multi-functional pins for an amount of different options:
•
•
•
•
•
Act as reset trigger input
Act as reset output
Act as trap input
Act as trigger input for the GSC
Independent pad configuration
6.4.1
General Operation
Each ESR pin is equipped with an edge detection that allows the selection of the edges
used as triggers. One, both, or no edge can be selected via bit field ESRCFGx.SEDCON
if a clock is active. Additionally, there is a digital (3-stage median) filter (DF) to suppress
spikes. The signal at ESRx pin has to be held at the active signal level for at least 2
system clock cycles (fSYS) in order to generate a trigger. The digital filter can be disabled
by clearing bit ESRCFGx.DFEN.
Each ESRx pin can be individually configured.
If an ESR trigger is generated please note that triggers for all purposes (reset, trap,
GSC, and non SCU module functions) are generated. If some of the actions resulting out
of such a trigger should not occur this has to be disabled by each feature for its own.
The pins that should be used as trigger input for an ESR operation have to be configured
as input pin.
User’s Manual
SCU, V1.13
6-68
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
DMPMIT.
ESRxT
Edge
Detection
ESRCFGx.
SEDCON
ESRx Input
Selection
Trap
GSC
Digital
Filter
to System
ESRCFGx.
DFEN
ESRx Control
Reset
Control
ESRx
ESR _control _noSB .vsd
Figure 6-15 ESRx Control
Up to three ESR pins (ESR0/ESR1/ESR2) are available. The availability of pins ESR1
and ESR2 is device and package dependent and is described in the data sheet.
User’s Manual
SCU, V1.13
6-69
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.4.1.1
ESR as Reset Input
The pins ESRx can serve as an external reset input as well as a reset output (open drain)
for Internal Application and Application Resets. Additionally several GPIO pad triggers
that can be enabled additionally via register ESREXCONx interfere with the ESR pin
function. GPIO and ESR pin triggers can be enabled/disabled individually and are
combined for the reset trigger generation. For more information about the reset system
see Chapter 6.3.
Note: The reset output is only asserted for the duration the reset counter RSTCNTA is
active. During a possible reset extension the reset output is not longer asserted.
6.4.1.2
ESR as Reset Output
If pin ESRx is enabled as reset output and the input level is low while the output stage is
disabled (indicating that it is still driven low externally), the reset circuitry holds the chip
in reset until a high level is detected on ESRx. The internal output stage drives a low level
during reset only while RSTCNTA is active. It deactivates the output stage when the time
defined by RSTCNTCON.RELA has passed. For more information about the reset
system see Chapter 6.3.
6.4.1.3
ESR as Trap Trigger
The ESR can request traps. The control mechanism if and which trap is requested is
located in the trap control logic. For more information see Chapter 6.12.
6.4.1.4
ESR as Trigger Input for the GSC
The ESR can be used to request a change in the Control Mode. For more information
see Chapter 6.6.
User’s Manual
SCU, V1.13
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.4.1.5
Pad Configuration for ESR Pads
The configuration is selected via bit field ESRCFGx.PC.
The pad functionality control can be configured independently for each pin, comprising:
•
•
•
A selection of the driver type (open-drain or push-pull)
An enable function for the output driver (input and/or output capability)
An enable function for the pull-up/down resistance
The following table defines the coding of the bit fields PC in registers ESRCFG0,
ESRCFG1, and ESRCFG2.
Note: The coding is the same as for the port register bit fields Pn_IOCRx.PC.
Table 6-6
PC Coding
PCx[3:0]
Selected Pull-up/Pull-down /
Selected Output Function
I/O
0000B
No pull device activated
0001B
Pull-down device activated
0010B
Pull-up device activated
Input is not inverted,
the input stage is
active in power-down
mode
0011B
No pull device activated
0100B
No pull device activated
0101B
Pull-down device activated
0110B
Pull-up device activated
0111B
No pull device activated
1000B
Output of ESRCFGx.OUT
1001B
Output of ESRCFGx.OUT
1010B
Output drives a 0 for an Internal
Application Reset, a 1 otherwise.
1011B
Output drives a 0 for an
Application Reset, a 1 otherwise.
1100B
Output of ESRCFGx.OUT
1101B
Output of ESRCFGx.OUT
1110B
Output drives a 0 for an Internal
Application Reset
1111B
Output drives a 0 for an
Application Reset
User’s Manual
SCU, V1.13
Output
Characteristics
Input is inverted,
the input stage is
active in power-down
mode
6-71
Output,
Push-pull
the input stage is not
inverted and active in
power-down mode
Open-drain,
a pull-up device
is activated
while the output
is not driving a 0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.4.2
ESR Control Registers
6.4.2.1
Configuration Registers
ESR External Control Register
ESREXCON1
ESR1 External Control Register SFR (FF32H/99H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0001H
5
4
3
2
1
ESR
1
EN
rw
0
rw
Field
Bits
Type
Description
ESR1EN
0
rw
ESR1 Pin Enable
This bit enables/disables the ESR1 pin for the
activation of all ESR1 related actions.
0B
The input from pin ESR1 is disabled
1B
The input from pin ESR1 is enabled
0
[15:1]
rw
Reserved
Must be written with reset value 0.
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SCU, V1.13
6-72
0
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System Control Unit (SCU)
ESREXCON2
ESR2 External Control Register SFR (FF34H/9AH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0001H
5
4
3
2
1
ESR
2
EN
rw
0
rw
Field
Bits
Type
Description
ESR2EN
0
rw
ESR2 Pin Enable
This bit enables/disables the ESR2 pin for the
activation of all ESR2 related actions.
0B
The input from pin ESR2 is disabled
1B
The input from pin ESR2 is enabled
0
[15:1]
rw
Reserved
Must be written with reset value 0.
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SCU, V1.13
6-73
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System Control Unit (SCU)
ESR Configuration Register
The ESR configuration registers contains bits required for the behavioral control of the
ESR pins.
ESRCFG0
ESR0 Configuration Register
ESRCFG1
ESR1 Configuration Register
ESRCFG2
ESR2 Configuration Register
15
14
13
12
11
10
ESFR (F100H/80H)
Reset Value: 000EH
ESFR (F102H/81H)
Reset Value: 0002H
ESFR (F104H/82H)
Reset Value: 0002H
9
8
7
6
5
4
3
2
1
0
0
SEDCON
IN
OUT
DF
EN
PC
r
rw
rw
rh
rh
rw
rw
0
Field
Bits
Type
Description
PC
[3:0]
rw
Pin Control of ESRx
This bit field controls the behavior of the associated
ESRx pin.
The coding is described in Table 6-6.
DFEN
4
rw
Digital Filter Enable
This bit defines if the 3-stage median filter of the
ESRx is used or bypassed.
0B
The filter is bypassed
1B
The filter is used
OUT
5
rh
Data Output
This bit can be used as output value for the
associated ESRx pin.
0B
If selected, the output level is 0
1B
If selected, the output level is 1
This bit is controlled via bit field ESRDAT.MOUTx.
IN
6
rh
Data Input
This bit monitors the input value at the associated
ESRx pin.
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SCU, V1.13
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V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
SEDCON
[8:7]
rw
Synchronous Edge Detection Control
This bit field defines the edges that lead to an ESRx
trigger of the synchronous path.
00B No trigger is generated
01B A trigger is generated upon a raising edge
10B A trigger is generated upon a falling edge
11B A trigger is generated upon a raising AND
falling edge
0
[10:9]
rw
Reserved
Must be written with reset value 00B.
0
[15:11] r
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-75
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.4.3
ESR Data Register
6.4.3.1
ESRDAT
The ESR data register contains bits required if ESRx are used as data ports.
ESRDAT
ESR Data Register
15
14
13
12
ESFR (F106H/83H)
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
0
MOUT2
MOUT1
MOUT0
r
w
w
w
Field
Bits
Type
Description
MOUT0
[1:0]
w
Modification of ESRCFG0.OUT
Writing to this bit field can modify the content of bit
ESRCFG0.OUT for ESR0. It always reads 0.
00B Bit ESRCFG0.OUT is unchanged
01B Bit ESRCFG0.OUT is set
10B Bit ESRCFG0.OUT is cleared
11B Reserved, do not use this combination
MOUT1
[3:2]
w
Modification of ESRCFG1.OUT
Writing to this bit field can modify the content of bit
ESRCFG1.OUT for ESR1. It always reads 0.
00B Bit ESRCFG1.OUT is unchanged
01B Bit ESRCFG1.OUT is set
10B Bit ESRCFG1.OUT is cleared
11B Reserved, do not use this combination
MOUT2
[5:4]
w
Modification of ESRCFG2.OUT
Writing to this bit field can modify the content of bit
ESRCFG2.OUT for ESR2. It always reads 0.
00B Bit ESRCFG2.OUT is unchanged
01B Bit ESRCFG2.OUT is set
10B Bit ESRCFG2.OUT is cleared
11B Reserved, do not use this combination
0
[15:6]
w
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
6-76
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XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5
Power Supply and Control
The XC2700 can run from a single external power supply. The core supply voltages can
be generated by on-chip Embedded Voltage Regulators (EVRs).
Power Domains
The I/O part is divided in two parts DMP_A and DMP_B. DMP_A contains all ADC
related I/Os and DMP_B the remaining system and communication I/Os.
The major part of the on-chip logic is located in an independent core power domain
(DMP_1). A second power domain (DMP_M), marked grey in the figure below, controls
important device infrastructure plus a Standby RAM (SBRAM).
ESR
CPU
WDT
PEC/
INT
PSRAM
IMB
Clock Temp.
Control Comp.
PLL
DPRAM
PMU
OSC_
HP
DSRAM
GSC
MPU
OSC_ Reset Power
WU Control Control
Program
Flash
DMU
SCU
ERU
LXBus
Stand-By RAM
EBC
LXBus Control
External Bus
Control
OCDS
Debug Support
Peripheral
Data Bus
ADC
x
GPT
CC
x
LXBus
CCU
6x
RTC
USIC
x
Multi
CAN
Ports
BLOCKDIAGRAM_MR
Figure 6-16 XC2700 Power Domain Structure
Power Supply and Control Functions
The power supply and control is divided into following parts:
•
•
monitoring of the supply voltage
controlling and adjusting the supply voltage
User’s Manual
SCU, V1.13
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XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
The supply voltage of pad IO domain for system and communication I/Os (power domain
DMP_B) is monitored by a Supply WatchDog (SWD, see Chapter 6.5.1).
The core voltage for each of the two core supply domains is supervised by a separate
Power Validation Circuit (PVC) that provides two monitoring levels. Each monitoring
level can request an interrupt (e.g. power-fail warning) or a reset depending on the
voltage level. A PVC is used to detect under voltage due to an external short (see
Chapter 6.5.2).
By controlling the regulator, the core power can be switched off to save the leakage
current (see Chapter 6.5.3).
Table 6-7
XC2700 Power Domains Supply and Control
Power Domain
Supply
Source
Pad IO domain
(DMP_B)
External supply VDDPB: 3.0 … 5.5 typ
See data sheet
SWD
ADC IO domain
(DMP_A)
External supply VDDPA: 3.0 … 5.5 typ
See data sheet
-
Core domain
(DMP_M and DMP_1)
EVR_M
EVR_1
PVC_1,
PVC_M
User’s Manual
SCU, V1.13
Supply Voltage
[V]
VDDIM, VDDI1: 1.5 typ
See data sheet
6-78
Supply
Checked by
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System Units (Vol. 1 of 2)
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6.5.1
Supply Watchdog (SWD)
The supply voltage of the pad I/O domain for systems and communication I/Os (DMP_B)
is monitored to validate the overall power supply. The external supply voltage is
monitored for following purposes:
•
•
•
•
POR
Detecting the ramp-up of the external supply voltage, so the device can be started
without requiring an external power-on reset (PORST).
Brown-out
Detecting the ramp-down of the external supply voltage, so the device can be brought
into a save state without requiring an external power-on reset (PORST).
Monitoring the external power supply allows the usage of a low-cost regulator without
additional status signals (standard 3-pin device).
Guarantee that the supply voltage for the EVRs is sufficient to generate a valid core
voltage under every operating condition
Feature list
The following list is a summary of the SWD functions.
•
•
•
•
Trigger a power-on reset whenever the supply falls and as long as the supply remains
below VVAL
Two completely independent threshold levels and comparators
16 selectable threshold levels
Power Saving Mode (only VVAL detection active)
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Operating the SWD
VOP
VLEV2
VLEV1
VVAL
VSS
0V
start-up
reset
L2OK
L1OK
Power-Off
Power-On Operation
Operation
Operation
Fail
Warning
Power-Off
Figure 6-17 SWD Power Validation Example
The lower fix threshold VVAL defines the absolute minimum operation voltage for the IO
domain. If VVAL has not been reached the device is held in reset. When VDDPB raises
above VVAL, bit SWDCON1.PON is set.
Note: The physical value for VVAL can found in the XC2700 data sheet.
The SWD provides two adjustable threshold levels (LEV1 and LEV2) that can be
individually programmed, via SWDCON0.LEV1V and SWDCON0.LEV2V, and deliver a
compare value each. The two compare results can be monitored via bits
SWDCON0.L1OK and SWDCON0.L2OK. A reset or interrupt request can be generated
while the voltage level is below or equal/above the configured level of a threshold. If an
User’s Manual
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XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
action and which action is triggered by each threshold can be configured via bit field
SWDCON0.LxACON and bit fieldSWDCON0.LxALEV (x = 1,2).
The SWD control (programming of the threshold levels) is done by software only.
With these features, an external supply watchdog, e.g. integrated in some external VR,
can be replaced. It detects the minimum specified supply voltage level and can be
configured to monitor other voltage levels.
Note: If the PORST pin is used it has the same functionality as the SWD.
Power-Saving Mode of the SWD
The two configurable thresholds can be disabled if not needed. This is called the SWD
Power Saving Mode. The minimum operating voltage detection (POR/Brown-out
detection) can not be disabled and it is always active. The SWD Power Saving Mode is
entered by setting bit SWDCON1.POWENSET and exit by setting bit
SWDCON1.POWENCLR. If the SWD Power Saving Mode is active is indicated by bit
SWDCON1.POWEN.
Note: The reset request and interrupt request action should be switched off before
entering power-save mode.
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SCU, V1.13
6-81
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XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5.1.1
SWD Control Registers
The following registers are the software interface for the SWD.
SWDCON0
SWD Control 0 Register
15
L2
A
LEV
rw
14
11
ESFR (F080H/40H)
13
12
10
9
L2ACON
L2
OK
LEV2V
rw
rh
rw
8
7
L1
A
LEV
rw
Reset Value: 0941H
6
5
4
3
2
1
L1ACON
L1
OK
LEV1V
rw
rh
rw
0
Field
Bits
Type
Description
LEV1V
[3:0]
rw
Level Threshold 1 Voltage
This bit field defines the voltage level that is used as
threshold 1 check level.
The values of the level thresholds are listed in the
data sheet.
L1OK
4
rh
Level Threshold 1 Check Result
0B
The supply voltage is below the Level
Threshold 1 voltage LEV1V
1B
The supply voltage is equal or above the Level
Threshold 1 voltage LEV1V
L1ACON
[6:5]
rw
Level Threshold 1 Action Control
This bit field defines which actions are requested if
the supply voltage comparison matches the action
level L1ALEV. Following actions can be requested:
00B No action is requested
01B An interrupt is requested
10B A reset is requested
11B A reset and an interrupt are requested
L1ALEV
7
rw
Level Threshold 1 Action Level
When the supply voltage is below the Level
0B
Threshold 1 voltage LEV1V the actions
configured by bit field L1ACON are requested
1B
When the supply voltage is equal or above the
Level Threshold 1 voltage LEV1V the actions
configured by bit field L1ACON are requested
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
LEV2V
[11:8]
rw
Level Threshold 2 Voltage
This bit field defines the voltage level that is used as
check level threshold 2.
The values of the level thresholds are listed in the
data sheet.
L2OK
12
rh
Level Threshold 2 Check Result
0B
The supply voltage is below the Level
Threshold 2 voltage LEV2V
1B
The supply voltage is equal or above the Level
Threshold 2 voltage LEV2V
L2ACON
[14:13] rw
Level Threshold 2 Action Control
This bit field defines which actions are requested if
the supply voltage comparison matches the action
level L2ALEV. Following actions can be requested:
00B No action is requested
01B An interrupt is requested
10B A reset is requested
11B A reset and an interrupt are requested
L2ALEV
15
Level Threshold 2 Action Level
0B
When the supply voltage is below the Level
Threshold 2 voltage LEV2V the actions
configured by bit field L2ACON are requested
1B
When the supply voltage is equal or above the
Level Threshold 2 voltage LEV2V the actions
configured by bit field L2ACON are requested
User’s Manual
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rw
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System Control Unit (SCU)
SWDCON1
SWD Control 1 Register
15
14
13
12
11
ESFR (F082H/41H)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
POW POW
CLR
POW
PON
EN EN
PON
EN
SET CLR
w
rh
rh
w
w
0
r
Field
Bits
Type
Description
POWENCLR
0
w
SWD Power Saving Mode Enable Clear
No action
0B
1B
Bit POWEN is cleared
POWENSET
1
w
SWD Power Saving Mode Enable Set
0B
No action
Bit POWEN is set
1B
POWEN
2
rh
SWD Power Saving Mode Enable
0B
All SWD functions are enabled
1B
The SWD Power Saving Mode is enabled.
Comparators are disabled.
PON
3
rh
Power-On Status Flag
No power-on event occurred
0B
1B
A power-on event occurred (VDDP became
greater than VVAL).
CLRPON
4
w
Clear Power-On Status Flag
0B
No action
1B
Bit PON is cleared
0
[15:5]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
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0
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System Control Unit (SCU)
6.5.2
Monitoring the Voltage Level of a Core Domain
A Power Validation Circuit (PVC) monitors the internal core supply voltage of a core
domain. It can be configured to monitor two programmable independent voltage levels.
The voltage of the core domain is monitored by PVC_1 and PVC_M.
Feature list
The following list summarizes the features of a PVC.
•
•
•
•
Two independent comparators
Threshold levels selectable
Shut-off, which disables the complete module
Configurable action level
A PVC provides two adjustable threshold levels (LEV1 and LEV2) that can be
individually programmed via PVCxCON0.LEV1V and PVCxCON0.LEV2V (x = M or
1)PVC1CON0.LEV1V and PVC1CON0.LEV2V. The current supply level of a domain is
compared with the threshold values. The two compare results can be monitored via bits
PVCxCON0.LEV1OK and PVCxCON0.LEV2OK (x = M or 1) PVC1CON0.LEV1OK and
PVC1CON0.LEV2OK
A reset or interrupt request can be generated in case the core domain voltage level is
below or equal / above the configured threshold level. An interrupt is requested if bit
PVCxCON0.L1INTEN and / or PVCxCON0.L2INTEN (x = M or 1) PVC1CON0.L1INTEN
and / or PVC1CON0.L2INTEN is set. A reset is requested if bit PVCxCON0.L1RSTEN
and / or PVCxCON0.L2RSTEN (x = M or 1) PVC1CON0.L1RSTEN and / or
PVC1CON0.L2RSTEN is set.
Note: For a single threshold both interrupt and reset request generation should not be
enabled at the same time.
User’s Manual
SCU, V1.13
6-85
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5.2.1
PVC Status and Control Registers
These registers are the software interface for PVC_1 and PVC_M.
PVC1CON0
PVC_1 Control Step 0 Register
ESFR (F014H/0AH)
15
L2
AS
EN
rw
14
13
12
11
10
L2
L2
L2 LEV
RST INT
A
2
EN EN LEV OK
rw
rw
rw
rh
9
LEV2V
rw
8
7
L1
AS
EN
rw
6
Reset Value: 0504H
5
4
3
L1
L1
L1 LEV
RST INT
A
1
EN EN LEV OK
rw rrw
rw
rh
2
1
0
LEV1V
rw
Field
Bits
Type
Description
LEV1V
[2:0]
rw
Level Threshold 1 Voltage
This bit field defines the Level Threshold 1 that is
compared with the DMP_1 core voltage.
The values for the different configurations are listed
in the data sheet.
LEV1OK
3
rh
Level Threshold 1 Check Result
0B
The core supply voltage of the DMP_1 is below
Level Threshold 1 voltage LEV1V
1B
The core supply voltage of the DMP_1 is equal
or above the Level Threshold 1 voltage LEV1V
L1ALEV
4
rw
Level Threshold 1 Action Level
0B
When the core supply voltage is below Level
Threshold 1 voltage LEV1V the action
configured by bits L1INTEN, L1RSTEN, and
L1ASEN are requested
1B
When the core supply voltage is equal or
above Level Threshold 1 voltage LEV1V the
actions configured by bits L1INTEN,
L1RSTEN, and L1ASEN are requested
L1INTEN
5
rw
Level Threshold 1 Interrupt Request Enable
This bit defines if an interrupt request trigger is
requested if the comparison check was successful.
When a check is successful is defined via bit
L1ALEV.
0B
No interrupt is requested
1B
An interrupt is requested
User’s Manual
SCU, V1.13
6-86
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
L1RSTEN
6
rw
Level Threshold 1 Reset Request Enable
This bit defines if a reset request trigger is requested
if the comparison check was successful. When a
check is successful is defined via bit L1ALEV.
0B
No reset is requested
1B
An reset is requested
L1ASEN
7
rw
Level Threshold 1 Asynchronous Action Enable
This bit defines if asynchronous action can be
performed if the comparison check was successful.
When a check is successful is defined via bit
L1ALEV.
0B
No asynchronous actions are performed
1B
Asynchronous actions can be performed
LEV2V
[10:8]
rw
Level Threshold 2 Voltage
This bit field defines the level of threshold 2 that is
compared with the DMP_1 core voltage..
The values for the different configurations are listed
in the data sheet.
LEV2OK
11
rh
Level Threshold 2 Check Result
0B
The core supply voltage of the DMP_1 is below
the Level Threshold 2 LEV2V
1B
The core supply voltage of the DMP_1 is equal
or above the Level Threshold 2 LEV2V
L2ALEV
12
rw
Level Threshold 2 Action Level
0B
When the core supply voltage is below the
Level Threshold 2 voltage LEV2V the action
configured by bits L2INTEN, L2RSTEN, and
L2ASEN are requested
When the core supply voltage is equal or
1B
above the Level Threshold 2 voltage LEV2V
the action configured by bits L2INTEN,
L2RSTEN, and L2ASEN are requested
L2INTEN
13
rw
Level Threshold 2 Interrupt Request Enable
This bit defines if an interrupt request trigger is
requested if the comparison check was successful.
When a check is successful is defined via bit
L2ALEV.
0B
No interrupt is requested
1B
An interrupt is requested
User’s Manual
SCU, V1.13
6-87
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
L2RSTEN
14
rw
Level Threshold 2 Reset Request Enable
This bit defines if a reset request trigger is requested
if the comparison check was successful. When a
check is successful is defined via bit L2ALEV.
0B
No reset is requested
1B
An reset is requested
L2ASEN
15
rw
Level Threshold 2 Asynchronous Action Enable
This bit defines if asynchronous action can be
performed if the comparison check was successful.
When a check is successful is defined via bit
L2ALEV.
0B
No asynchronous actions are performed
1B
Asynchronous actions can be performed
User’s Manual
SCU, V1.13
6-88
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
PVCMCON0
PVC_M Control Step 0 Register
MEM (F1E4H/--)
15
L2
AS
EN
rw
14
13
12
11
10
L2
L2
L2 LEV
RST INT
A
2
EN EN LEV OK
rw
rw
rw
rh
9
LEV2V
rw
8
7
L1
AS
EN
rw
6
Reset Value: 0544H
5
4
3
L1
L1
L1 LEV
RST INT
A
1
EN EN LEV OK
rw
rw
rw
rh
2
1
0
LEV1V
rw
Field
Bits
Type
Description
LEV1V
[2:0]
rw
Level Threshold 1 Voltage
This bit field defines the Level Threshold 1 that is
compared with the DMP_M core supply voltage.
The values for the different configurations are listed
in the data sheet.
LEV1OK
3
rh
Level Threshold 1 Check Result
0B
The core supply voltage of the DMP_M is
below Level Threshold 1 voltage LEV1V
1B
The core supply voltage of the DMP_M is equal
or above the Level Threshold 1 voltage LEV1V
L1ALEV
4
rw
Level Threshold 1 Action Level
0B
When the core supply voltage is below Level
Threshold 1 voltage LEV1V the action
configured by bits L1INTEN, L1RSTEN, and
L1ASEN are requested
1B
When the core supply voltage is equal or
above Level Threshold 1 voltage LEV1V the
actions configured by bits L1INTEN,
L1RSTEN, and L1ASEN are requested
L1INTEN
5
rw
Level Threshold 1 Interrupt Request Enable
This bit defines if an interrupt request trigger is
requested if the comparison check was successful.
When a check is successful is defined via bit
L1ALEV.
0B
No interrupt is requested
1B
An interrupt is requested
User’s Manual
SCU, V1.13
6-89
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
L1RSTEN
6
rw
Level Threshold 1 Reset Request Enable
This bit defines if a reset request trigger is requested
if the comparison check was successful. When a
check is successful is defined via bit L1ALEV.
0B
No reset is requested
1B
An reset is requested
L1ASEN
7
rw
Level Threshold 1 Asynchronous Action Enable
This bit defines if asynchronous action can be
performed if the comparison check was successful.
When a check is successful is defined via bit
L1ALEV.
0B
No asynchronous actions are performed
1B
Asynchronous actions can be performed
LEV2V
[10:8]
rw
Level Threshold 2 Voltage
This bit field defines the Level Threshold 2 that is
compared with the DMP_M core supply voltage.
The values for the different configurations are listed
in the data sheet.
LEV2OK
11
rh
Level Threshold 2 Check Result
0B
The core supply voltage of the DMP_M is
below Level Threshold 2 voltage LEV2V
1B
The core supply voltage of the DMP_M is equal
or above the Level Threshold 2 voltage LEV2V
L2ALEV
12
rw
Level Threshold 2 Action Level
0B
When the core supply voltage is below the
Level Threshold 2 voltage LEV2V the action
configured by bits L2INTEN, L2RSTEN, and
L2ASEN are requested
When the core supply voltage is equal or
1B
above the Level Threshold 2 voltage LEV2V
the action configured by bits L2INTEN,
L2RSTEN, and L2ASEN are requested
L2INTEN
13
rw
Level Threshold 2 Interrupt Request Enable
This bit defines if an interrupt request trigger is
requested if the comparison check was successful.
When a check is successful is defined via bit
L2ALEV.
0B
No interrupt is requested
1B
An interrupt is requested
User’s Manual
SCU, V1.13
6-90
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
L2RSTEN
14
rw
Level Threshold 2 Reset Request Enable
This bit defines if a reset request trigger is requested
if the comparison check was successful. When a
check is successful is defined via bit L2ALEV.
0B
No reset is requested
1B
An reset is requested
L2ASEN
15
rw
Level Threshold 2 Asynchronous Action Enable
This bit defines if asynchronous action can be
performed if the comparison check was successful.
When a check is successful is defined via bit
L2ALEV.
0B
No asynchronous actions are performed
1B
Asynchronous actions can be performed
User’s Manual
SCU, V1.13
6-91
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5.3
Controlling the Voltage Level of a Core Domain
The core powercan be controlled within certain limits. The voltage level is controlled by
two Embedded Voltage Regulators (EVR).
The power domain is controlled by both EVR_M and EVR_1.
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5.3.1
Embedded Voltage Regulator
The main part of the device logic operates at a typical voltage level of 1.5 V. This supply
voltage is generated by the Embedded Power Regulators (EVRs) out of the pad voltage.
External buffer caps are required for stable regulation.
Feature list:
•
•
•
•
Multiple core voltage levels including zero
Core voltage generation based on a High Precision Bandgap
External supply possible via capacitor-pin while EVR is switched-off
Core current limit
The EVR configurations to select the desired voltage and reference pair are combined
within EVR settings EVRxSETyyV (x = M or 1 and yy = 15). Each setting contains a bit
field (VRSEL) to select the voltage level and reference and a bit field to fine-tune the
voltage level (VLEV). One out of the possible settings is used to control each of the
EVRs, but only in the allowed combinations for the two EVRs. The EVRsusea High
Precision Bandgap (HP) as reference
The BG voltage of each setting can be adjusted to compensate application and
environmental influences by the bit field EVRxSETyyV.VLEV. VLEV is set by default or
trimmed by each device during production test to reach the default setting targets.
High Precision Bandgap (HP)
The HP bandgap of the system is used for following purposes:
•
•
Provide a very stable reference for the two EVRs
Provide an accurate reference for the flash memory. For more information see the
flash memory description.
The HP bandgap can be enabled / disabled via the bit EVRMCON1.HPEN.
User’s Manual
SCU, V1.13
6-93
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
EVR Status and Control Registers
EVR1CON0
EVR_1 Control 0 Register
ESFR (F088H/44H)
7
6
Reset Value: DF20H
15
14
13
12
11
10
9
8
5
4
3
2
1
EVR
DIS
-
0
CC
DIS
CCLEV
-
RES
1
0
RES0
0
rh
-
rw
rh
rw
-
rw
rw
rw
r
0
Field
Bits
Type
Description
RES0
[5:3]
rw
Reserved
Do not change this value when writing to this register.
0
[7:6]
rw
Reserved
Must be written with reset value 00B.
RES1
8
rw
Reserved
Must be written with reset value 1B.
CCLEV
[11:10] rw
Current Control Level
The values for the different configurations are listed
in the data sheet.
CCDIS
12
rh
Current Control Disable
0B
The current control is enabled
1B
The current control is disabled
This bit is updated by bit EVR1SETy.CCDIS.
0
13
rw
Reserved
Must be written with reset value 0.
EVRDIS
15
rh
EVR_1 Disable
0B
The EVR_1 is enabled
1B
The EVR_1 is disabled
This bit is updated by bit EVR1SETy.EVRDIS.
0
[2:0]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
6-94
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
EVR1SET15VHP
EVR_1 Setting for 1.5 V HP Register
ESFR (F09EH/4FH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 001BH
5
4
3
2
EVR
DIS
0
CC
DIS
0
RES
0
VRSEL
VLEV
rw
rw
rw
rw
rw
rw
rw
rw
1
0
Field
Bits
Type
Description
VLEV
[5:0]
rw
Voltage Level Adjust
This bit field adjusts the BG voltage and is trimmed
by each device during production test to reach the
default setting targets.
Do not change this value when writing to this register.
VRSEL
[7:6]
rw
Voltage Reference Selection
00B 15VHP - Full Voltage with high precision
bandgap selected
01B Reserved, do not use this combination
10B Reserved, do not use this combination
11B Reserved, do not use this combination
Note: The reset value should always be written to
this bit field.
RES
9
rw
Reserved
Must be written with 1B.
CCDIS
12
rw
Current Control Disable
0B
The current control is enabled
1B
The current control is disabled
This bit updates bit EVR1CON0.CCDIS.
Note: Before switching off the current control the
CCLEV setting in EVR1CON0 has to be set to
00B.
EVRDIS
User’s Manual
SCU, V1.13
15
rw
EVR_1 Disable
0B
The EVR_1 is enabled
1B
The EVR_1 is disabled
This bit updates bit EVR1CON0.EVRDIS.
6-95
V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
0
8,
rw
[11:10],
[14:13]
User’s Manual
SCU, V1.13
Type
Description
Reserved
Must be written with reset value 0.
6-96
V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
EVRMCON0
EVR_M Control 0 Register
15
14
13
ESFR (F084H/42H)
12
11
10
9
8
7
6
Reset Value: 0D20H
5
4
3
2
1
EVR
DIS
0
CC
DIS
CCLEV
-
RES
1
0
RES0
0
rh
r
rh
rw
-
rw
rw
rw
r
0
Field
Bits
Type
Description
RES0
[5:3]
rw
Reserved
Do not change this value when writing to this register.
0
[7:6]
rw
Reserved
Must be written with reset value 00B.
RES1
8
rw
Reserved
Must be written with 1.
CCLEV
[11:10] rw
Current Control Level
The values for the different configurations are listed
in the data sheet.
CCDIS
12
rh
Current Control Disable
The current control is enabled
0B
1B
The current control is disabled
This bit is updated by bit EVRMSETy.CCDIS.
EVRDIS
15
rh
EVR_M Disable
0B
The EVR_M is enabled
1B
The EVR_M is disabled
This bit is updated by bit EVRMSETy.EVRDIS.
0
[2:0], 8 r
[14:13]
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-97
V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
EVRMCON1
EVR_M Control 1 Register
15
14
13
12
11
ESFR (F086H/43H)
10
9
8
7
6
Reset Value: 0101H
5
4
3
0
HP
EN
HPADJUST
r
rw
rw
2
1
0
Field
Bits
Type
Description
HPADJUST
[7:0]
rw
HP Bandgap Adjustment
This bit field is a device specific trimmvalue for the
HP bandgap.
Do not change this value when writing to this register.
HPEN
8
rw
HP Bandgap Enable
0B
The HP bandgap is disabled
1B
The HP bandgap is enabled
0
[15:9]
r
Reserved
Read as 0; should be written with 0.
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SCU, V1.13
6-98
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
EVRMSET15VHP
EVR_M Setting for 1.5 V HP Register
ESFR (F096H/4BH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 001BH
5
4
3
2
EVR
DIS
0
CC
DIS
0
RES
0
0
VRSEL
VLEV
rw
rw
rw
rw
rw
rw
rw
rw
1
0
Field
Bits
Type
Description
VLEV
[5:0]
rw
Voltage Level Adjust
This bit field adjusts the BG voltage and is trimmed
by each device during production test to reach the
default setting targets.
Do not change this value when writing to this register.
VRSEL
[7:6]
rw
Voltage Reference Selection
00B 15VHP - Full Voltage with high precision
bandgap selected
01B Reserved, do not use this combination
10B Reserved, do not use this combination
11B Reserved, do not use this combination
Note: The reset value should always be written to
this bit field.
RES0
9
rw
Reserved
Must always be written with 1B.
CCDIS
12
rw
Current Control Disable
0B
The current control is enabled
1B
The current control is disabled
This bit updates bit EVRMCON0.CCDIS.
Note: Before switching off the current control the
CCLEV setting in EVRMCON0 has to be set to
00B.
EVRDIS
User’s Manual
SCU, V1.13
15
rw
EVR_M Disable
0B
The EVR_M is enabled
1B
The EVR_M is disabled
This bit updates bit EVR1CON0.EVRDIS.
6-99
V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
0
8,
rw
[11:10],
[14:13]
User’s Manual
SCU, V1.13
Type
Description
Reserved
Must be written with reset value 0.
6-100
V2.1, 2008-08
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5.3.2
Sources for Core Supply Voltage
The on-chip EVRs can generate the XC2700’s core supply voltage from the (externally
supplied) IO voltage.
Core Supply via On-chip EVRs
Generating the core supply voltage via the integrated EVRs is the preferred operating
mode, because it saves an additional external voltage regulator. The integrated EVRs
are fed from supply voltage VDDPB.
Proper operation of the EVRs requires external buffer capacitances. Please refer to the
respective Data Sheet for the recommended values. The current is delivered by the
integrated pass devices.
Microcontroller
Ext.
Voltage
Reg.
VDDPB
Onchip
EVR
VDDI
CEVR
V SS
MC_XC2X_POWER _EVR
Figure 6-18 Selecting the EVR for Core Supply
Generating the core supply voltage with on-chip resources provides full control of power
reduction modes, so the application can control and minimize the energy consumption
of the XC2700 using built-in mechanisms without requiring additional external circuitry.
User’s Manual
SCU, V1.13
6-101
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.5.4
Handling the Power System
Using the power system correctly is the key to power saving. Depending on the
application different operating states can be defined in order to save maximal power. The
XC2700 supports following power saving mechanisms:
•
•
•
•
Reduction of the system performance
– the power consumption depends directly on the frequency of the system
– the system performance is controlled with the clock operation mechanism
Stopping single unused peripheral
– a peripheral not needed for an application can be disabled
– the module operation is controlled via register MOD_KSCCFG
Stopping multiple unused peripherals
– peripherals not needed for an application can be disabled
– system peripheral operation is controlled via the Global State Controller (GSC)
Stopping single unused analog parts
– an analog part not needed for an application can be stopped
– the operation is controlled via register either located in the SCU (PLL, clocks,
PVCs, SWD, Temperature Compensation) or the ADC
User’s Manual
SCU, V1.13
6-102
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.6
Global State Controller (GSC)
Mode Control for the system peripherals provides besides power saving modes and the
clock management an additional opportunity for configuring the system to the application
needs.
Mode Control is described in detail in this chapter and is implemented by the Global
State Controller (GSC). The GSC enables the user to configure one operating mode in
a fast and easy way, reacting fast and explicit to needs of an application.
Feature Overview
The following issues are handled by the GSC:
•
•
•
Control of peripheral clock operation
Suspend control for debugging
Arbitration between the different request sources
According to the requests coming from the OCDS, the SWD pre-warning detection or
other blocks, the GSC does an internal prioritization. The result is forwarded as
command request broadcast to all peripherals. The GSC internal prioritization scheme
for the implemented request sources is shown in Table 6-8.
6.6.1
GSC Control Flow
The sequence begins when at least one request source asserts its trigger in order to
request a mode change in the SoC. If several requests are pending there is an arbitration
mechanism that treats this issue. Request triggers are not stored by the GSC, therefore
a trigger source has to assert its trigger until the trigger is no longer valid or needed.
A request trigger is kept asserted as long as either the request is still pending or the
resulting command of the request was entered and acknowledged by the system. The
communication of the GSC and the peripherals is based on commands. Three different
commands are defined resulting in three modes:
•
•
•
Wake-up command: requests Normal Mode
Clock-off command: requests Stop Mode
Debug command: requests Suspend Mode
The specific behavior in these three modes is defined for each peripheral in its module
register mod_KSCCFG.
6.6.1.1
Request Source Arbitration
The highest priority for the arbitration is zero (see Table 6-8).
Each system clock cycle a new arbitration round is started. The winner of an arbitration
round requests the next command towards the SoC. Please note that winning an
arbitration does not lead automatically to a new command raised. Only if currently no
command is broadcast in the SoC a new command can be generated and broadcast. If
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
the winner of the arbitration round is the same request trigger as in the previous round
or if no winner was detected no new command request is generated.
Table 6-8
Connection of the Request Sources
Request Source
Priority
OCDS exit
4
ESR0
5
ESR1
6
ESR2
7
WUT
8
ITC
9
GPT12E
10
SW1
11
SW2
12
OCDS entry
14
6.6.1.2
Generation of a New Command
When a new request trigger was detected and arbitrated a new command request is
generated if currently no command request is broadcast that is not received by all slaves.
Table 6-9
Request Source and Command Request Coupling
Request Source
Command Description
OCDS exit
Wake-up; Normal Mode
ESR0
Wake-up; Normal Mode
ESR1
Wake-up; Normal Mode
ESR2
Clock-off; Stop Mode
WUT
Wake-up; Normal Mode
ITC
Wake-up; Normal Mode
GPT12E
Wake-up; Normal Mode
SW1
Wake-up; Normal Mode
SW2
Clock-off; Stop Mode
OCDS entry
Debug; Suspend Mode
User’s Manual
SCU, V1.13
6-104
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.6.1.3
Usage of Commands
The complete control mechanism for the different operation modes of the various slaves
is divided into two parts:
•
•
A central control and configuration part; the Global State Controller (GSC)
One local control part in each slave; the Kernel State Controller (KSC)
Via the GSC either different hardware sources (e.g. the WUT or the OCDS) or the
software can request the system to enter a specific mode. The parts that are affected by
the mode can be pre-defined locally for each part via the KSC. For each command a
specific reaction can be pre-configured in each KSC for each individual part.
Note: When a GSC mode request has been successfully entered, the GSC arbiter is
open for any new request. In case a request occurs to enter the current mode, this
request is pipelined and remains pending.
It is recommended to request a command by a software trigger. In particular the
clock-off command should be triggered by SW2. The usage of commands
requested by hardware has to be done carefully. Only hardware resources
requesting Normal Mode should be selected. If the software has detected a wakeup then pending mode change requests can be removed by clearing the bits of the
selected sources in GSCEN and then enabling the bits in GSCEN again.
6.6.1.4
Terminating a Request Trigger
A request trigger is no longer taken into account for the arbitration after the de-assertion
of the request trigger, if it is not enabled or when its respective enable bit is cleared.
6.6.1.5
Suspend Control Flow
The suspend feature is controlled by the OCDS block. The GSC operates only as control
and communication interface towards the system. The suspend feature is composed out
of two requirements:
The mode that has to be entered when the Suspend Mode is requested.
The mode that has to be entered when the Suspend Mode is left.
The request to enter Suspend Mode is forwarded from the OCDS. When the Suspend
Mode is requested the system is expected to be stopped as soon as possible in an idle
state where no internal process is pending and in a way that this system state does not
lead to any damage internally or externally and can also be left without any damage.
Therefore all peripherals in the system are requested to enter a mode where the clock
can be stopped. This is done by sending a debug command.
Leaving the Suspend Mode should serve the goal that debugging is a non-intrusive
operation. Therefore leaving the Suspend Mode can not lead to only one dedicated
system mode, instead it leads to the system mode the system left when it was requested
to exit the Suspend Mode. The system mode is stored when a Suspend Mode request
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is detected by the GSC and is used as target system mode when a leave Suspend Mode
trigger is detected by the GSC.
6.6.1.6
Error Feedback for a Mode Transition
In case at least one peripheral reports an error the error flag in register GSCSTAT is set.
If no error is currently detected upon a new assertion of a system mode by the GSC the
error flag is cleared. To inform the system of this erroneous state an interrupt can be
generated.
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6.6.2
GSC Registers
6.6.2.1
GSC Control and Status Registers
The following register control and configure the behavior of the GSC.
GSCSWREQ
GSC Software Request Register
SFR (FF14H/8AH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
SWT SWT
RG2 RG1
0
r
rwh
rwh
Field
Bits
Type
Description
SWTRG1
0
rwh
Software Trigger 1 (SW1)
0B
No SW1 request trigger is generated
1B
A SW1 request trigger is generated
This bit is automatically cleared if the SW1 request
trigger wins the arbitration and was broadcast to the
system.
SWTRG2
1
rwh
Software Trigger 2 (SW2)
0B
No SW2 request trigger is generated
A SW2 request trigger is generated
1B
This bit is automatically cleared if the SW2 request
trigger wins the arbitration and was broadcast to the
system.
0
[15:2]
r
Reserved
Read as 0; should be written with 0.
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GSCEN
GSC Enable Register
15
0
r
14
13
12
SFR (FF16H/8BH)
11
10
9
8
7
6
Reset Value: 7FFFH
5
4
OCD
ESR ESR ESR OCD
RES SW2 SW1 GPT ITC WUT
SEN
2
1
0 SEX
1
EN EN EN EN EN
EN
EN EN EN EN
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
3
2
1
0
RES0
rw
Field
Bits
Type
Description
RES0
[3:0]
rw
Reserved
Must be written with 0000B.
OCDSEXEN
4
rw
OCDS Exit Request Trigger Enable
0B
OCDS exit request trigger is not taken into
account (disabled)
1B
OCDS exit request trigger is taken into account
(enabled)
ESR0EN
5
rw
ESR0 Request Trigger Enable
0B
ESR0 request trigger is not taken into account
(disabled)
1B
ESR0 request trigger is taken into account
(enabled)
ESR1EN
6
rw
ESR1 Request Trigger Enable
0B
ESR1 request trigger is not taken into account
(disabled)
1B
ESR1 request trigger is taken into account
(enabled)
ESR2EN
7
rw
ESR2 Request Trigger Enable
0B
ESR2 request trigger is not taken into account
(disabled)
1B
ESR2 request trigger is taken into account
(enabled)
WUTEN
8
rw
WUT Request Trigger Enable
0B
WUT request trigger is not taken into account
(disabled)
1B
WUT request trigger is taken into account
(enabled)
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Field
Bits
Type
Description
ITCEN
9
rw
ITC Request Trigger Enable
0B
ITC request trigger is not taken into account
(disabled)
1B
ITC request trigger is taken into account
(enabled)
GPTEN
10
rw
GTP12E Request Trigger Enable
0B
GPT12E request trigger is not taken into
account (disabled)
1B
GPT12E request trigger is taken into account
(enabled)
SW1EN
11
rw
Software 1 Request Trigger Enable
SW1 request trigger is not taken into account
0B
(disabled)
1B
SW1 request trigger is taken into account
(enabled)
SW2EN
12
rw
Software 2 Request Trigger Enable
0B
SW2 request trigger is not taken into account
(disabled)
1B
SW2 request trigger is taken into account
(enabled)
RES1
13
rw
Reserved
Read as 1 after reset; returns the value that is written.
OCDSENEN
14
rw
OCDS Entry Request Trigger Enable
0B
OCDS entry request trigger is not taken into
account (disabled)
1B
OCDS entry request trigger is taken into
account (enabled)
OCDS entry is the request source belonging to the
according connector interface.
0
15
r
Reserved
Read as 0; should be written with 0.
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GSCSTAT
GSC Status Register
15
14
13
12
SFR (FF18H/8CH)
11
0
SOURCE
r
rh
10
9
8
7
PEN ERR
rh
rh
6
Reset Value: 3C00H
5
4
3
2
1
0
0
NEXT
0
CURRENT
r
rh
r
rh
Field
Bits
Type
Description
CURRENT
[1:0]
rh
Currently used Command
This bit field states the currently used system mode.
NEXT
[5:4]
rh
Next to use Command
This bit field states the next to be used system mode.
ERR
8
rh
Error Status Flag
This bit flags if with the last command that was
broadcast was acknowledge with at least one error.
This bit is automatically cleared when a new
command is broadcast.
PEN
9
rh
Command Pending Flag
This flag states if currently a command is pending or
not. A command is pending after the broadcast as
long as no all blocks acknowledge that they finished
the operation requested by the command.
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Field
Bits
SOURCE
[13:10] rh
Requesting Source Status
This bit field monitors the source that triggered the
last request.
0000B Reserved
0001B Reserved
0010B Reserved
0011B Reserved
0100B OCDS exit
0101B ESR0
0110B ESR1
0111B ESR2
1000B WUT
1001B ITC
1010B GPT12E
1011B SW1
1100B SW2
1101B Reserved, do not use this combination
1110B OCDS entry
1111B Reserved, do not use this combination
0
[3:2],
r
[7:6],
[15:14]
Reserved
Read as 0; should be written with 0.
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Description
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6.7
Software Boot Support
In order to determine the correct starting point of operation for the software a minimum
of hardware support is required. As much as possible is done via software. Some
decisions have to be done in hardware because they must be known before any software
is operational.
6.7.1
Start-up Registers
6.7.1.1
Start-up Status Register
Register STSTAT contains the information required by the boot software to identify the
different start-up settings that can be selected.
STSTAT
Start-up Status Register
15
14
13
12
11
MEM (F1E0H/--)
10
9
8
7
6
Reset Value: 8000H
5
4
3
1
0
HWCFG
r
r
rh
2
1
0
Field
Bits
Type
Description
HWCFG
[7:0]
rh
Hardware Configuration Setting
This bit field contains the value that is used by the
boot software.
This bit field is updated in case of an Application
Reset with the content by register
SWRSTCON.SWCFG if bit SWRSTCON.SWBOOT
is set.
0
[14:8]
r
Reserved
Read as 0; should be written with 0.
1
15
r
Reserved
Read as 1; should be written with 1.
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6.8
External Request Unit (ERU)
The External Request Unit (ERU) is a versatile event and pattern detection unit. Its major
task is the generation of interrupts based on selectable trigger events at different
inputs, e.g. to generate external interrupt requests if an edge occurs at an input pin.
The detected events can also be used by other modules to trigger or to gate modulespecific actions, such as conversions of the ADC module.
6.8.1
Introduction
The ERU of the XC2700 can be split in three main functional parts:
•
•
•
4 independent Input Channels x for input selection and conditioning of trigger or
gating functions
Event distribution: A Connecting Matrix defines the events of the Input Channel x
that lead to a reaction of an Output Channel y.
4 independent Output Channels y for combination of events, definition of their
effects and distribution to the system (interrupt generation, ADC conversion triggers)
External Request Unit
from pins or
modules
ERU_0A[3:0]
ERU_0B[3:0]
4
4
External
Request Select
Units
ERS0
Event Trigger
Logic Units
Output
Gating Units
ETL0
OGU 0
Output Channel 0
4
4
ERS1
Connecting Matrix
ERU_1B[3:0]
ETL1
Input Channel 1
ERU_2A[3:0]
ERU_2B[3:0]
4
4
ERS2
ETL2
ERU_3B[3:0]
ERU_PDOUT1
ERU_GOUT1
ERU_IOUT1
ERU_TOUT1
OGU 1
Output Channel 1
ERU_PDOUT2
ERU_GOUT2
ERU_IOUT2
OGU 2
ERU_TOUT2
Output Channel 2
Input Channel 2
ERU_3A[3:0]
ERU_PDOUT0
ERU_GOUT0
ERU_IOUT0
ERU_TOUT0
Input Channel 0
ERU_1A[3:0]
to interrupt
controller,
ADC
4
4
ERS3
ERU_PDOUT3
ERU_GOUT3
ERU_IOUT3
ERU_TOUT3
OGU 3
ETL3
Input Channel 3
Output Channel 3
Peripheral Triggers
ERU_Block _Overview .vsd
Figure 6-19 External Request Unit Overview
These tasks are handled by the following building blocks:
•
An External Request Select Unit (ERSx) per Input Channel allows the selection of
one out of two or a logical combination of two input signals (ERU_xA, ERU_xB) to a
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•
•
•
common trigger. For each of these two signals, an input vector of 4 possible inputs is
available (e.g. the actual input ERU_xA can be selected from one of the ERU inputs
ERU_xA[3:0], similar for ERU_xB).
An Event Trigger Logic (ETLx) per Input Channel allows the definition of the
transition (edge selection, or by software) that lead to a trigger event and can also
store this status. Here, the input levels of the selected signals are translated into
events (event detected = event flag becomes set, independent of the polarity of the
original input signals).
The Connecting Matrix distributes the events and status flags generated by the
Input Channels to the Output Channels. Additionally, some Peripheral Trigger signals
from other modules (e.g. CC2) are made available and can be combined with the
triggers generated by the Input Channels of the ERU.
An Output Gating Unit (OGUy) per Output Channel that combines the available
trigger events and status information from the Input Channels. An event of one Input
Channel can lead to reactions of several Output Channels, or also events of several
Input Channels can be combined to a reaction of one Output Channel (pattern
detection).
Different types of reactions are possible, e.g. interrupt generation (based on signals
ERU_IOUTy), triggering of ADC conversions (based on signals ERU_TOUTy), or
gating of ADC conversions (based on signals ERU_GOUTy).
The ERU is controlled by a number of registers, shown in Figure 6-20, and described in
Section 6.8.8.
Input Selection
Input & Trigger
Control
Output Control
EXISEL
EXICON0
EXOCON0
EXICON1
EXOCON1
EXICON2
EXOCON2
EXICON3
EXOCON3
EXISEL:
EXICON0..3:
EXOCON0..3:
Input Selection Register
Input and Trigger Control Registers
Output Control Registers
ERU_Register_Overview.vsd
Figure 6-20 ERU Registers Overview
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6.8.2
ERU Pin Connections
Figure 6-21 shows the ERU input connections, either directly with pins or via
communication modules, such as USIC or MultiCAN. These communication modules
provide their input signals (e.g. CAN receive input, or USIC data, clock, or control inputs)
that have been selected in these modules. With this structure, the number of possible
input pins is significantly increased, because not only the selection capability of the ERU
is used, but also the selection capability of the communication modules.
ERS0
ERS1
P2.1
ERU_0A0
P2.2
ERU_1A0
ESR1
ERU_0A1
ESR2
ERU_1A1
U0C0_DX0INS,
selected data input
ERU_0A2
U1C0_DX0INS,
selected data input
ERU_1A2
U0C0_DX2INS,
selected control input
ERU_0A3
U1C0_DX2INS,
selected control input
ERU_1A3
P1.1
P1.0
ERU_0B0
P5.13
ERU_0B1
MultiCAN_CAN4INS,
selected receive input CAN4
ERU_1B1
U0C1_DX0INS,
selected data input
ERU_0B2
U1C1_DX0INS,
selected data input
ERU_1B2
U0C1_DX2INS,
selected control input
ERU_0B3
U1C1_DX2INS,
selected control input
ERU_1B3
ERU_1B0
ERS2
P1.2
ERS3
P1.3
ERU_2A0
ERU_3A0
MultiCAN_CAN1INS,
selected receive input CAN1
MultiCAN_CAN3INS,
selected receive input CAN3
ERU_2A1
U2C0_DX0INS,
selected data input
ERU_2A2
reserved
ERU_3A2
U2C0_DX2INS,
selected control input
ERU_2A3
reserved
ERU_3A3
U2C0_DX1INS,
selected clock input
ERU_2B0
U1C0_DX1INS,
selected clock input
ERU_3B0
MultiCAN_CAN2INS,
selected receive input CAN2
ERU_2B1
MultiCAN_CAN0INS,
selected receive input CAN0
ERU_3B1
U2C1_DX0INS,
selected data input
ERU_2B2
reserved
ERU_3B2
U2C1_DX2INS,
selected control input
ERU_2B3
reserved
ERU_3B3
ERU_3A1
ERU_Inputs_Overview.vsd
Figure 6-21 ERU Inputs Overview
The inputs to the ERU can be selected from a large number of input signals. While some
of the inputs come directly from a pin, other inputs use signals from various peripheral
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modules, such as the USIC (signals named with prefix UxCy to indicate which the
communication channel) and the MultiCAN modules. These signals are input signals
from the pin that has been selected as input for a USIC or MultiCAN function. The
selection of the input is made within the respective USIC or MultiCAN module.
Usually, such signals would be selected for an ERU function when the input function to
the USIC or MultiCAN module is not used otherwise, or the module is not used at all.
However, it is also possible to select a input which is actually needed in a USIC or
MultiCAN module, and to use it also in the ERU to provide for certain trigger functions,
eventually combined with other signals (e.g. to generate an interrupt trigger in case a
start of frame is detected at a selected communication).
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The following table describes the ERU input connections for the ERSx stages. The
selection is defined by the bit fields in register EXISEL.
Note: All functional inputs of the ERU are synchronized to fSYS before they can affect the
internal logic. The resulting delay of 2/fSYS and an uncertainty of 1/fSYS have to be
taken into account for precise timing calculation.
An edge of an input can only be correctly detected if both, the high phase and the
low phase of the input are each longer than 1/fSYS.
Table 6-10
ERSx Connections in XC2700
Input
from/to
Module
I/O to
ERSx
Can be used to/as
ERU_0A0
P2.1
I
ERS0 input A
ERU_0A1
ESR1
I
ERU_0A2
U0C0_DX0INS
I
ERU_0A3
U0C0_DX2INS
I
ERU_0B0
P1.0
I
ERU_0B1
P5.13
I
ERU_0B2
U0C1_DX0INS
I
ERU_0B3
U0C1_DX2INS
I
ERU_1A0
P2.2
I
ERU_1A1
ESR2
I
ERU_1A2
U1C0_DX0INS
I
ERU_1A3
U1C0_DX2INS
I
ERU_1B0
P1.1
I
ERU_1B1
MultiCAN_CAN4INS
I
ERU_1B2
U1C1_DX0INS
I
ERU_1B3
U1C1_DX2INS
I
ERU_2A0
P1.2
I
ERU_2A1
MultiCAN_CAN3INS
I
ERU_2A2
U2C0_DX0INS
I
ERU_2A3
U2C0_DX2INS
I
ERS0 Inputs
ERS0 input B
ERS1 Inputs
ERS1 input A
ERS1 input B
ERS2 Inputs
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Table 6-10
ERSx Connections in XC2700 (cont’d)
Input
from/to
Module
I/O to
ERSx
Can be used to/as
ERU_2B0
U2C0_DX1INS
I
ERS2 input B
ERU_2B1
MultiCAN_CAN2INS
I
ERU_2B2
U2C1_DX0INS
I
ERU_2B3
U2C1_DX2INS
I
ERU_3A0
P1.3
I
ERU_3A1
MultiCAN_CAN1INS
I
ERU_3A2
0
I
ERU_3A3
0
I
ERU_3B0
U1C0_DX1INS
I
ERU_3B1
MultiCAN_CAN0INS
I
ERU_3B2
0
I
ERU_3B3
0
I
ERS3 Inputs
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ERS3 input B
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6.8.3
External Request Select Unit (ERSx)
For each Input Channel x (x = 0-3), an ERSx unit handles the input selection for the
associated ETLx unit. Each ERSx performs a logical combination of two signals (Ax, Bx)
to provide one combined output ERSxO to the associated ETLx. Input Ax can be
selected from 4 options of the input vector ERU_xA[3:0] and can be optionally inverted.
A similar structure exists for input Bx (selection from ERU_xB[3:0]).
In addition to the direct choice of either input Ax or Bx or their inverted values, the
possible logical combinations for two selected inputs are a logical AND or a logical OR.
ERU_xA0
ERU_xA1
ERU_xA2
ERU_xA3
EXISEL.
EXSxA
EXICONx.
NA
Select
Input
Ax
Select
Polarity
Ax
EXICONx.
SS
Ax
Bx
1
Ax OR Bx
ERU_xB0
ERU_xB1
ERU_xB2
Select
Input
Bx
Select
Polarity
Bx
EXISEL.
EXSxB
EXICONx.
NB
&
Ax AND Bx
Select
Source
for
ERSxO
ERSxO
ETLx
ERU_xB3
External Request
Select Unit x (ERSx)
ERU_ERS.vsd
Figure 6-22 External Request Select Unit Overview
The ERS units are controlled via register EXISEL (one register for all four ERSx units)
and registers EXICONx (one register for each ERSx and associated ETLx unit, e.g.
EXICON0 for Input Channel 0).
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6.8.4
Event Trigger Logic (ETLx)
For each Input Channel x (x = 0-3), an event trigger logic ETLx derives a trigger event
and a status from the input ERUxO delivered by the associated ERSx unit. Each ETLx
is based on an edge detection block, where the detection of a rising or a falling edge can
be individually enabled. Both edges lead to a trigger event if both enable bits are set (e.g.
to handle a toggling input).
Each of the four ETLx units has an associated EXICONx register, that controls all options
of an ETLx (the register also holds control bits for the associated ERSx unit, e.g.
EXICON0 to control ESR0 and ETL0).
EXICONx.
FE
EXICONx.
LD
Modify
Status
Flag
ERSx
ERSxO
Detect
Event
(edge)
Event Trigger
Logic x (ETLx)
set
clear
Status Flag
FL
edge event
Enable
Trigger
Pulse
EXICONx.FL
to all OGUy
TRx0 to
OGU0
trigger pulse
Select
Trigger
Output
TRx1 to
OGU1
TRx2 to
OGU2
TRx3 to
OGU3
EXICONx.
RE
EXICONx.
PE
EXICONx.
OCS
ERU_ETL.vsd
Figure 6-23 Event Trigger Logic Overview
When the selected event (edge) is detected, the status flag EXICONx.FL becomes set.
This flag can also be modified by software (set or clear). Two different operating modes
are supported by this status flag.
It can be used as “sticky” flag, that is set by hardware when the desired event has been
detected and has to be cleared by software. In this operating mode, it indicates that the
event has taken place, but without indicating the actual status of the input.
In the second operating mode, it is cleared automatically if the “opposite” event is
detected. For example, if only the falling edge detection is enabled to set the status flag,
it is cleared when the rising edge is detected. In this mode, it can be used for pattern
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detection where the actual status of the input is important (enabling both edge detections
is not useful in this mode).
The output of the status flag is connected to all following Output Gating Units (OGUy) in
parallel (see Figure 6-24) to provide pattern detection capability of all OGUy units
based on different or the same status flags.
In addition to the modification of the status flag, a trigger pulse output TRxy of ETLx can
be enabled (by bit EXICONx.PE) and selected to trigger actions in one of the OGUy
units. The target OGUy for the trigger is selected by bit field EXICON.OCS.
The trigger becomes active when the selected edge event is detected, independently
from the status flag EXICONx.FL.
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System Control Unit (SCU)
6.8.5
Connecting Matrix
The connecting matrix distributes the trigger signals (TRxy) and status signals
(EXICONx.FL) from the different ETLx units between the OGUy units. In addition, it
receives peripheral trigger signals that can be OR-combined with the ETLx trigger
signals in the OGUy units. Figure 6-24 provides a complete overview of the connections
between the ETLx and the OGUy units.
EXICON0.FL
TR00
ETL0
TR01
TR02
TR10
TR11
TR12
TR13
ERU_IOUT0
ERU_GOUT0
TR20
TR21
TR22
Peripheral
Triggers
Pattern
Detection
Inputs
ERU_PDOUT1
OGU1
ERU_IOUT1
Trigger
Inputs
TRx1
EXICON2.FL
ERU_GOUT1
ERU_TOUT1
Peripheral
Triggers
Pattern
Detection
Inputs
ERU_PDOUT2
OGU2
ERU_IOUT2
ERU_GOUT2
ERU_TOUT2
TR23
EXICON3.FL
TR30
ETL3
OGU0
Trigger
Inputs
TRx0
EXICON1.FL
ETL2
ERU_PDOUT0
ERU_TOUT0
TR03
ETL1
Pattern
Detection
Inputs
TR31
TR32
Trigger
Inputs
TRx2
Peripheral
Triggers
Pattern
Detection
Inputs
ERU_PDOUT3
OGU3
ERU_IOUT3
Trigger
Inputs
TRx3
TR33
ERU_GOUT3
ERU_TOUT3
Peripheral
Triggers
ERU_ETL_OGU_Overview.vsd
Figure 6-24 Connecting Matrix between ETLx and OGUy
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System Control Unit (SCU)
6.8.6
Output Gating Unit (OGUy)
Each OGUy (y = 0-3) unit combines the available trigger events and status flags from
the Input Channels and distributes the results to the system. Figure 6-25 illustrates the
logic blocks within an OGUy unit. All functions of an OGUy unit are controlled by its
associated EXOCONy register, e.g. EXOCON0 for OGU0. The function of an OGUy unit
can be split into two parts:
•
•
Trigger combination (see Section 6.8.6.1):
All trigger signals TRxy from the Input Channels that are enabled and directed to
OGUy, a selected peripheral-related trigger event, and a pattern change event (if
enabled) are logically OR-combined.
Pattern detection (see Section 6.8.6.2):
The status flags EXICONx.FL of the Input Channels can be enabled to take part in
the pattern detection. A pattern match is detected while all enabled status flags are
set.
Status Flags
EXICON0.FL
EXOCONy.
IPEN0
EXOCONy.
GEEN
EXICON1.FL
EXOCONy.
IPEN1
EXICON2.FL
ERU_PDOUTy
Detect
Pattern
EXOCONy.
PDR
EXOCONy.
IPEN2
Select
Gating
Scheme
EXICON3.FL
Triggers
from Input
Channels
EXOCONy.
IPEN3
TR0y
ERU_GOUTy
Combine
OGU
Triggers
(OR)
TR1y
TR2y
TR3y
EXOCONy.
GP
Interrupt
Gating
(AND)
ERU_IOUTy
ERU_TOUTy
ERU_OGUy1
Peripheral
Triggers
ERU_OGUy2
ERU_OGUy3
Select
Periph.
Triggers
EXOCONy.
ISS
Output Gating
Unit y (OGUy)
ERU_OGU.vsd
Figure 6-25 Output Gating Unit for Output Channel y
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Each OGUy unit generates 4 output signals that are distributed to the system (not all of
them are necessarily used, please refer to Section 6.8.7):
•
•
•
•
ERU_PDOUTy to directly output the pattern match information for gating purposes
in other modules (pattern match = 1).
ERU_GOUTy to output the pattern match or pattern miss information (inverted
pattern match), or a permanent 0 or 1 under software control for gating purposes in
other modules.
ERU_TOUTy as combination of a peripheral trigger, a pattern detection result
change event, or the ETLx trigger outputs TRxy to trigger actions in other modules.
ERU_IOUTy as gated trigger output (ERU_GOUTy logical AND-combined with
ERU_TOUTy) to trigger interrupts (e.g. the interrupt generation can be gated to allow
interrupt activation during a certain time window).
6.8.6.1
Trigger Combination
The trigger combination logically OR-combines different trigger inputs to form a common
trigger ERU_TOUTy. Possible trigger inputs are:
•
•
•
In each ETLx unit of the Input Channels, the trigger output TRxy can be enabled and
the trigger event can be directed to one of the OGUy units.
One out of three peripheral trigger signals per OGUy can be selected as additional
trigger source. These peripheral triggers are generated by on-chip peripheral
modules, such as capture/compare or timer units. The selection is done by bit field
EXOCONy.ISS.
In the case that at least one pattern detection input is enabled (EXOCONy.IPENx)
and a change of the pattern detection result from pattern match to pattern miss (or
vice-versa) is detected, a trigger event is generated to indicate a pattern detection
result event (if enabled by ECOCONy.GEEN).
The trigger combination offers the possibility to program different trigger criteria for
several input signals (independently for each Input Channel) or peripheral signals, and
to combine their effects to a single output, e.g. to generate an interrupt or to start an ADC
conversion. This combination capability allows the generation of an interrupt per OGU
that can be triggered by several inputs (multitude of request sources -> one reaction).
The following table describes the peripheral trigger connections for the OGUy stages.
The selection is defined by the bit fields ISS in registers EXOCON0 (for OGU0),
EXOCON1 (for OGU1), EXOCON2 (for OGU2), or EXOCON3 (for OGU3).
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Table 6-11
OGUy Peripheral Trigger Connections in XC2700
Input
from/to
Module
I/O to
OGUy
Can be used to/as
ERU_OGU01 CCU60_MCM_ST
I
Peripheral triggers for OGU0
ERU_OGU02 CCU60_T13_PM
I
ERU_OGU03 CC2_28
I
OGU0 Inputs
OGU1 Inputs
ERU_OGU11 CCU61_MCM_ST
I
ERU_OGU12 CCU61_T13_PM
I
ERU_OGU13 CC2_29
I
Peripheral triggers for OGU1
OGU2 Inputs
ERU_OGU21 CCU62_MCM_ST
I
ERU_OGU22 CCU62_T13_PM
I
ERU_OGU23 CC2_30
I
Peripheral triggers for OGU2
OGU3 Inputs
ERU_OGU31 CCU63_MCM_ST
I
ERU_OGU32 CCU63_T13_PM
I
ERU_OGU33 CC2_31
I
6.8.6.2
Peripheral triggers for OGU3
Pattern Detection
The pattern detection logic allows the combination of the status flags of all ETLx units.
Each status flag can be individually included or excluded from the pattern detection for
each OGUy, via control bits EXOCONy.IPENx. The pattern detection block outputs the
following pattern detection results:
•
•
Pattern match (EXOCONy.PDR = 1 and ERU_PDOUTy = 1):
A pattern match is indicated while all status flags FL that are included in the pattern
detection are 1.
Pattern miss (EXOCONy.PDR = 0 and ERU_PDOUTy = 0):
A pattern miss is indicated while at least one of the status flags FL that are included
in the pattern detection is 0.
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In addition, the pattern detection can deliver a trigger event if the pattern detection result
changes from match to miss or vice-versa (if enabled by EXOCONy.GEEN = 1). The
pattern result change event is logically OR-combined with the other enabled trigger
events to support interrupt generation or to trigger other module functions (e.g. in the
ADC). The event is indicated when the pattern detection result changes and
EXOCONy.PDR becomes updated.
The interrupt generation in the OGUy is based on the trigger ERU_TOUTy that can be
gated (masked) with the pattern detection result ERU_PDOUTy. This allows an
automatic and reproducible generation of interrupts during a certain time window, where
the request event is elaborated by the trigger combination block and the time window
information (gating) is given by the pattern detection. For example, interrupts can be
issued on a regular time base (peripheral trigger input from capture/compare unit is
selected) while a combination of input signals occurs (pattern detection based on ETLx
status bits).
A programmable gating scheme introduces flexibility to adapt to application
requirements and allows the generation of interrupt requests ERU_IOUTy under
different conditions:
•
•
•
•
Pattern match (EXOCONy.GP = 10B):
An interrupt request is issued when a trigger event occurs while the pattern detection
shows a pattern match.
Pattern miss (EXOCONy.GP = 11B):
An interrupt request is issued when the trigger event occurs while the pattern
detection shows a pattern miss.
Independent of pattern detection (EXOCONy.GP = 01B):
In this mode, each occurring trigger event leads to an interrupt request. The pattern
detection output can be used independently from the trigger combination for gating
purposes of other peripherals (independent use of ERU_TOUTy and ERU_PDOUTy
with interrupt requests on trigger events).
No interrupts (EXOCONy.GP = 00B, default setting)
In this mode, an occurring trigger event does not lead to an interrupt request. The
pattern detection output can be used independently from the trigger combination for
gating purposes of other peripherals (independent use of ERU_TOUTy and
ERU_PDOUTy without interrupt requests on trigger events).
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6.8.7
ERU Output Connections
This section describes the connections of the ERU output signals for gating or triggering
other module functions, as well as the connections to the interrupt control registers.
Table 6-12
ERU Output Connections in XC2700
Output
from/to
Module
I/O to
OGUy
Can be used to/as
ERU_PDOUT0
not connected
O
Pattern detection output
ERU_GOUT0
ADC0 (REQGT0A)
ADC0 (REQGT1A)
ADC0 (REQGT2A)
ADC1 (REQGT0A)
ADC1 (REQGT1A)
ADC1 (REQGT2A)
O
Gated pattern detection output
ERU_TOUT0
not connected
O
Trigger output
ERU_IOUT0
ITC (CC2_CC16IC)
O
Interrupt output
ERU_PDOUT1
not connected
O
Pattern detection output
ERU_GOUT1
ADC0 (REQGT0B)
ADC0 (REQGT1B)
ADC0 (REQGT2B)
ADC1 (REQGT0B)
ADC1 (REQGT1B)
ADC1 (REQGT2B)
O
Gated pattern detection output
ERU_TOUT1
ADC0 (REQTR0A)
ADC0 (REQTR1A)
ADC0 (REQTR2A)
ADC1 (REQTR0A)
ADC1 (REQTR1A)
ADC1 (REQTR2A)
O
Trigger output
ERU_IOUT1
ITC (CC2_CC17IC)
O
Interrupt output
ERU_PDOUT2
not connected
O
Pattern detection output
ERU_GOUT2
not connected
O
Gated pattern detection output
OGU0 Outputs
OGU1 Outputs
OGU2 Outputs
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Table 6-12
ERU Output Connections in XC2700 (cont’d)
Output
from/to
Module
I/O to
OGUy
Can be used to/as
ERU_TOUT2
not connected
O
Trigger output
ERU_IOUT2
ITC (CC2_CC18IC)
O
Interrupt output
ERU_PDOUT3
not connected
O
Pattern detection output
ERU_GOUT3
not connected
O
Gated pattern detection output
ERU_TOUT3
not connected
O
Trigger output
ERU_IOUT3
ITC (CC2_CC19IC)
O
Interrupt output
OGU3 Outputs
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6.8.8
ERU Registers
6.8.8.1
External Input Selection Register EXISEL
This register selects the A and B inputs for all four ERS units. The possible input signals
are given in Table 6-10.
EXISEL
External Input Select Register ESFR (F1A0H/D0H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
EXS3B
EXS3A
EXS2B
EXS2A
EXS1B
EXS1A
EXS0B
EXS0A
rw
rw
rw
rw
rw
rw
rw
rw
Field
Bits
Type Description
EXS0A [1:0]
rw
External Source Select for A0 (ERS0)
This bit field defines which input is selected for A0.
00B Input ERU_0A0 is selected
01B Input ERU_0A1 is selected
10B Input ERU_0A2 is selected
11B Input ERU_0A3 is selected
EXS0B [3:2]
rw
External Source Select for B0 (ERS0)
This bit field defines which input is selected for B0.
00B Input ERU_0B0 is selected
01B Input ERU_0B1 is selected
10B Input ERU_0B2 is selected
11B Input ERU_0B3 is selected
EXS1A [5:4]
rw
External Source Select for A1 (ERS1)
This bit field defines which input is selected for A1.
00B Input ERU_1A0 is selected
01B Input ERU_1A1 is selected
10B Input ERU_1A2 is selected
11B Input ERU_1A3 is selected
EXS1B [7:6]
rw
External Source Select for B1 (ERS1)
This bit field defines which input is selected for B1.
00B Input ERU_1B0 is selected
01B Input ERU_1B1 is selected
10B Input ERU_1B2 is selected
11B Input ERU_1B3 is selected
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Field
Bits
EXS2A [9:8]
Type Description
rw
External Source Select for A2 (ERS2)
This bit field defines which input is selected for A2.
00B Input ERU_2A0 is selected
01B Input ERU_2A1 is selected
10B Input ERU_2A2 is selected
11B Input ERU_2A3 is selected
EXS2B [11:10] rw
External Source Select for B2 (ERS2)
This bit field defines which input is selected for B2.
00B Input ERU_2B0 is selected
01B Input ERU_2B1 is selected
10B Input ERU_2B2 is selected
11B Input ERU_2B3 is selected
EXS3A [13:12] rw
External Source Select for A3 (ERS3)
This bit field defines which input is selected for A3.
00B Input ERU_3A0 is selected
01B Input ERU_3A1 is selected
10B Input ERU_3A2 is selected
11B Input ERU_3A3 is selected
EXS3B [15:14] rw
External Source Select for B3 (ERS3)
This bit field defines which input is selected for B3.
00B Input ERU_3B0 is selected
01B Input ERU_3B1 is selected
10B Input ERU_3B2 is selected
11B Input ERU_3B3 is selected
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6.8.8.2
External Input Control Registers EXICONx
These registers control the inputs of the ERSx unit and the trigger functions of the ETLx
units (x = 0..3).
EXICON0
External Input Control 0 Register
ESFR (F030H/18H)
EXICON1
External Input Control 1 Register
ESFR (F032H/19H)
EXICON2
External Input Control 2 Register
ESFR (F034H/1AH)
EXICON3
External Input Control 3 Register
ESFR (F036H/1CH)
15
14
13
12
11
10
9
8
7
0
NB
NA
SS
FL
r
rw
rw
rw
rwh
6
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
5
4
3
2
1
0
OCS
FE
RE
LD
PE
rw
rw
rw
rw
rw
Field
Bits
Type
Description
PE
0
rw
Output Trigger Pulse Enable for ETLx
This bit enables the generation of an output trigger
pulse at TRxy when the selected edge is detected
(set condition for the status flag FL).
0B
The trigger pulse generation is disabled
1B
The trigger pulse generation is enabled
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Field
Bits
Type
Description
LD
1
rw
Rebuild Level Detection for Status Flag for ETLx
This bit selects if the status flag FL is used as “sticky”
bit or if it rebuilds the result of a level detection.
0B
The status flag FL is not cleared by hardware
and is used as “sticky” bit. Once set, it is not
influenced by any edge until it becomes
cleared by software.
1B
The status flag FL rebuilds a level detection of
the desired event. It becomes automatically set
with a rising edge if RE = 1 or with a falling
edge if FE = 1. It becomes automatically
cleared with a rising edge if RE = 0 or with a
falling edge if FE = 0.
RE
2
rw
Rising Edge Detection Enable ETLx
This bit enables/disables the rising edge event as
edge event as set condition for the status flag FL or
as possible trigger pulse for TRxy.
A rising edge is not considered as edge event
0B
1B
A rising edge is considered as edge event
FE
3
rw
Falling Edge Detection Enable ETLx
This bit enables/disables the falling edge event as
edge event as set condition for the status flag FL or
as possible trigger pulse for TRxy.
0B
A falling edge is not considered as edge event
1B
A falling edge is considered as edge event
OCS
[6:4]
rw
Output Channel Select for ETLx Output Trigger
Pulse
This bit field defines which Output Channel OGUy is
targeted by an enabled trigger pulse TRxy.
000B Trigger pulses are sent to OGU0
001B Trigger pulses are sent to OGU1
010B Trigger pulses are sent to OGU2
011B Trigger pulses are sent to OGU3
1XXB Reserved, do not use this combination
FL
7
rwh
Status Flag for ETLx
This bit represents the status flag that becomes set
or cleared by the edge detection.
0B
The enabled edge event has not been
detected
1B
The enabled edge event has been detected
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Field
Bits
Type
Description
SS
[9:8]
rw
Input Source Select for ERSx
This bit field defines which logical combination is
taken into account as ESRxO.
00B Input A without additional combination
01B Input B without additional combination
10B Input A OR input B
11B Input A AND input B
NA
10
rw
Input A Negation Select for ERSx
This bit selects the polarity for the input A.
Input A is used directly
0B
1B
Input A is inverted
NB
11
rw
Input B Negation Select for ERSx
This bit selects the polarity for the input B.
0B
Input B is used directly
1B
Input B is inverted
0
[15:12] r
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
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6.8.8.3
Output Control Registers EXOCONy
These registers control the outputs of the Output Gating Unit y (y = 0..3).
EXOCON0
External Output Trigger Control 0 Register
SFR (FE30H/18H)
EXOCON1
External Output Trigger Control 1 Register
SFR (FE32H/19H)
EXOCON2
External Output Trigger Control 2 Register
SFR (FE34H/1AH)
EXOCON3
External Output Trigger Control 3 Register
SFR (FE36H/1BH)
15
14
13
12
11
IPEN IPEN IPEN IPEN
3
2
1
0
rw
rw
rw
rw
10
9
8
7
6
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
5
4
3
2
1
0
0
GP
PDR
GE
EN
ISS
r
rw
rh
rw
rw
Field
Bits
Type
Description
ISS
[1:0]
rw
Internal Trigger Source Selection
This bit field defines which input is selected as
peripheral trigger input for OGUy. The possible input
signals are given in Table 6-11.
00B The peripheral trigger function is disabled
01B Input ERU_OGUy1 is selected
10B Input ERU_OGUy2 is selected
11B Input ERU_OGUy3 is selected
GEEN
2
rw
Gating Event Enable
Bit GEEN enables the generation of a trigger event
when the result of the pattern detection changes from
match to miss or vice-versa.
0B
The event detection is disabled
1B
The event detection is enabled
PDR
3
rh
Pattern Detection Result Flag
This bit represents the pattern detection result.
0B
A pattern miss is detected
1B
A pattern match is detected
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Field
Bits
Type
Description
GP
[5:4]
rw
Gating Selection for Pattern Detection Result
This bit field defines the gating scheme for the interrupt
generation (relation between the OGU output
ERU_PDOUTy and ERU_GOUTy).
00B ERU_GOUTy is always disabled and
ERU_IOUTy can not be activated
01B ERU_GOUTy is always enabled and ERU_IOUTy
becomes activated with each activation of
ERU_TOUTy
10B ERU_GOUTy is equal to ERU_PDOUTy and
ERU_IOUTy becomes activated with an activation
of ERU_TOUTy while the desired pattern is
detected (pattern match PDR = 1)
11B ERU_GOUTy is inverted to ERU_PDOUTy and
ERU_IOUTy becomes activated with an activation
of ERU_TOUTy while the desired pattern is not
detected (pattern miss PDR = 0)
IPENx
(x = 0-3)
12+x
rw
Pattern Detection Enable for ETLx
Bit IPENx defines whether the trigger event status flag
EXICONx.FL of ETLx takes part in the pattern detection
of OGUy.
Flag EXICONx.FL is excluded from the pattern
0B
detection
1B
Flag EXICONx.FL is included in the pattern
detection
0
[11:6]
r
Reserved
Read as 0; should be written with 0.
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6.9
SCU Interrupt Generation
The interrupt structure of the SCU is shown in Figure 6-26.
INTCLR.x
Interrupt
Event
DMPMIT.x
clear
INTSTAT.x
INTSET.x
INTNPy.x
1
1
request
&
1
set
SCU
int 0
SCU
int 1
to ITC node 6CH ,
ISS block
to ITC node 6B H ,
ISS block
Reserved
disable
Reserved
INTDIS.x
other interrupt sources
to the same ITC node
SCU Interrupt Structure
SCU_Int _Struct _MR. vsd
Figure 6-26 SCU Interrupt Structure
If enabled by the corresponding bit in register INTDIS, an interrupt is triggered either by
the incoming interrupt request line, or by a software set of the respective bit in register
INTSET. The trigger sets the respective flag in register INTSTAT and is gated to one of
the interrupt nodes, selected by the node pointer registers INTNP0 or INTNP1.
The interrupt flag can be cleared by software by writing to the corresponding bit in
register INTCLR.
If more than one interrupt source is connected to the same interrupt node pointer (in
register INTNPx), the requests are combined to one common line.
Interrupt Node Assignment
The interrupt sources of the SCU module can be mapped to the dedicated interrupt node
6CH or 6BH by programming the interrupt node pointer registers INTNP0 and INTNP1.
The default assignment of the interrupt sources to the nodes and their corresponding
control registers are shown in Table 6-13.
6.9.1
Interrupt Support
Some of the interrupt requests are first fed through a sticky flag register in the DMP_M
domain. These flags are set with a trigger and if set trigger the interrupt generation in the
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DMP_1.. Please note that the disable control of register INTDIS also influences the
sticky bit in register DMPMIT (see Section 6.9.3.7).
Which of the interrupt requests have a sticky flag in register DMPMIT is listed in
Table 6-13.
Note: When servicing an SCU interrupt request, make sure that all related request flags
are cleared after the identified request has been handled. To clear an interrupt
request that is stored in register DMPMIT, first clear the request source of the
source (e.g. WUTRG), clear the request within DMP_M via DMPMITCLR, and
then clear the request within DMP_1 via INTCLR.
6.9.2
SCU Interrupt Sources
The SCU receives the interrupt request lines listed in Table 6-13.
Table 6-13
SCU Interrupt Overview
Source of Interrupt
Short Name Sticky Flag Default Interrupt Node
in DMPMIT Assignment in INTNPx
SWD OK 1 Interrupt
SWDI1
yes
6CH
SWD OK 2 Interrupt
SWDI2
yes
6BH
PVC_M OK 1 Interrupt
PVCMI1
yes
6CH
PVC_M OK 2 Interrupt
PVCMI2
yes
6BH
PVC_1 OK 1 Interrupt
PVC1I1
yes
6CH
PVC_1 OK 2 Interrupt
PVC1I2
yes
6BH
Wake-up Timer Interrupt
WUTI
yes
6BH
Wake-up Trim Interrupt
WUI
yes
6CH
Watchdog Timer Interrupt
WDTI
---
6BH
GSC Interrupt
GSCI
yes
6CH
User’s Manual
SCU, V1.13
6-137
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3
Interrupt Control Registers
6.9.3.1
Register INTSTAT
This register contains the status flags for all interrupt request trigger sources of the SCU.
For setting and clearing of these status bits by software see registers INTSET and
INTCLR, respectively.
INTSTAT
Interrupt Status Register
15
14
13
12
11
SFR (FF00H/80H)
10
9
8
7
6
GSC WDT WU WUT
I
I
I
I
0
rh
rh
rh
rh
rh
Reset Value: 0000H
5
4
3
2
1
0
PVC PVC PVC PVC
SWD SWD
1
1
M
M
I2
I1
I2
I1
I2
I1
rh
rh
rh
rh
rh
rh
Field
Bits
Type
Description
SWDI1
0
rh
SWD Interrupt Request Flag 1
This bit is set if bit DMPMIT.SWDI1 is set.
0B
No SWDI1 interrupt trigger has occured since
this bit was cleared the last time
1B
A SWDI1 interrupt trigger has occured since
this bit was cleared the last time
SWDI2
1
rh
SWD Interrupt Request Flag 2
This bit is set if bit DMPMIT.SWDI2 is set.
0B
No SWDI2 interrupt trigger has occured since
this bit was cleared the last time
1B
A SWDI2 interrupt trigger has occured since
this bit was cleared the last time
PVCMI1
2
rh
PVC_M Interrupt Request Flag 1
This bit is set if bit DMPMIT.PVCMI1 is set.
0B
No PVCMI1 interrupt trigger has occured since
this bit was cleared the last time
1B
A PVCMI1 interrupt trigger has occured since
this bit was cleared the last time
User’s Manual
SCU, V1.13
6-138
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
PVCMI2
3
rh
PVC_M Interrupt Request Flag 2
This bit is set if bit DMPMIT.PVCMI2 is set.
0B
No PVCMI2 interrupt trigger has occured since
this bit was cleared the last time
A PVCMI2 interrupt trigger has occured since
1B
this bit was cleared the last time
PVC1I1
4
rh
PVC_1 Interrupt Request Flag 1
This bit is set if bit DMPMIT.PVC1I1 is set.
0B
No PVC1I1 interrupt trigger has occured since
this bit was cleared the last time
A PVCI1 interrupt trigger has occured since
1B
this bit was cleared the last time
PVC1I2
5
rh
PVC_1 Interrupt Request Flag 2
This bit is set if bit DMPMIT.PVC1I2 is set.
0B
No PVC1I2 interrupt trigger has occured since
this bit was cleared the last time
1B
A PVC1I2 interrupt trigger has occured since
this bit was cleared the last time
WUTI
6
rh
Wake-up Timer Trim Interrupt Request Flag
This bit is set if the WUT trim trigger event occur and
bit is INTDIS.WUTI = 0.
0B
No WUT interrupt trigger has occured since
this bit was cleared the last time
1B
A WUT interrupt trigger has occured since this
bit was cleared the last time
WUI
7
rh
Wake-up Timer Interrupt Request Flag
This bit is set if the WU trigger event occur and bit is
INTDIS.WUI = 0.
No WU interrupt trigger has occured since this
0B
bit was cleared the last time
1B
A WU interrupt trigger has occured since this
bit was cleared the last time
WDTI
8
rh
Watchdog Timer Interrupt Request Flag
This bit is set if the WDT Prewarning Mode is entered
and bit is INTDIS.WDTI = 0.
0B
No WDT interrupt trigger has occured since
this bit was cleared the last time
1B
A WDT interrupt trigger has occured since this
bit was cleared the last time
User’s Manual
SCU, V1.13
6-139
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
GSCI
9
rh
GSC Interrupt Request Flag
This bit is set if the GSC error bit is set and bit is
INTDIS.GSCI = 0.
0B
No GSC interrupt trigger has occured since
this bit was cleared the last time
1B
A GSC interrupt trigger has occured since this
bit was cleared the last time
0
[15:10] rh
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-140
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3.2
Register INTCLR
This register contains the software clear option for all status flags of all interrupt request
trigger sources of the SCU.
INTCLR
Interrupt Clear Register
15
14
13
12
SFR (FE82H/41H)
11
10
9
8
7
6
GSC WDT WU WUT
I
I
I
I
0
w
w
w
w
w
Reset Value: 0000H
5
4
3
2
1
PVC PVC PVC PVC
SWD SWD
1
1
M
M
I2
I1
I2
I1
I2
I1
w
w
w
w
w
w
Field
Bits
Type
Description
SWDI1
0
w
Clear SWD Interrupt Request Flag 1
0B
No action
1B
Bit INTSTAT.SWDI1 is cleared
SWDI2
1
w
Clear SWD Interrupt Request Flag 2
No action
0B
1B
Bit INTSTAT.SWDI2 is cleared
PVCMI1
2
w
Clear PVC_M Interrupt Request Flag 1
0B
No action
1B
Bit INTSTAT.PVCMI1 is cleared
PVCMI2
3
w
Clear PVC_M Interrupt Request Flag 2
0B
No action
1B
Bit INTSTAT.PVCMI2 is cleared
PVC1I1
4
w
Clear PVC_1 Interrupt Request Flag 1
0B
No action
1B
Bit INTSTAT.PVC1I1 is cleared
PVC1I2
5
w
Clear PVC_1 Interrupt Request Flag 2
0B
No action
1B
Bit INTSTAT.PVC1I2 is cleared
WUTI
6
w
Clear Wake-up Trim Interrupt Request Flag
0B
No action
1B
Bit INTSTAT.WUTI is cleared
WUI
7
w
Clear Wake-up Interrupt Request Flag
0B
No action
1B
Bit INTSTAT.WUI is cleared
User’s Manual
SCU, V1.13
6-141
0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
WDTI
8
w
Clear Watchdog Timer Interrupt Request Flag
0B
No action
1B
Bit INTSTAT.WDTI is cleared
GSCI
9
w
Clear GSC Interrupt Request Flag
No action
0B
Bit INTSTAT.GSCI is cleared
1B
0
[15:10] w
User’s Manual
SCU, V1.13
Reserved
Must be written with 0.
6-142
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3.3
Register INTSET
This register contains the software set option for all status flags of all interrupt request
trigger sources of the SCU.
INTSET
Interrupt Set Register
15
14
13
12
SFR (FE80H/40H)
11
10
9
8
7
6
GSC WDT WU WUT
I
I
I
I
0
w
w
w
w
w
Reset Value: 0000H
5
4
3
2
1
PVC PVC PVC PVC
SWD SWD
1
1
M
M
I2
I1
I2
I1
I2
I1
w
w
w
w
w
w
Field
Bits
Type
Description
SWDI1
0
w
Set SWD Interrupt Request Flag 1
0B
No action
1B
Bit INTSTAT.SWDI1 is set
SWDI2
1
w
Set SWD Interrupt Request Flag 2
No action
0B
1B
Bit INTSTAT.SWDI2 is set
PVCMI1
2
w
Set PVC_M Interrupt Request Flag 1
0B
No action
1B
Bit INTSTAT.PVCMI1 is set
PVCMI2
3
w
Set PVC_M Interrupt Request Flag 2
0B
No action
1B
Bit INTSTAT.PVCMI2 is set
PVC1I1
4
w
Set PVC_1 Interrupt Request Flag 1
0B
No action
1B
Bit INTSTAT.PVC1I1 is set
PVC1I2
5
w
Set PVC_1 Interrupt Request Flag 2
0B
No action
1B
Bit INTSTAT.PVC1I2 is set
WUTI
6
w
Set Wake-up Trim Interrupt Request Flag
0B
No action
1B
Bit INTSTAT.WUTI is set
WUI
7
w
Set Wake-up Interrupt Request Flag
0B
No action
1B
Bit INTSTAT.WUI is set
User’s Manual
SCU, V1.13
6-143
0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
WDTI
8
w
Set Watchdog Timer Interrupt Request Flag
0B
No action
1B
Bit INTSTAT.WDTI is set
GSCI
9
w
Set GSC Interrupt Request Flag
No action
0B
Bit INTSTAT.GSCI is set
1B
0
[15:10] w
User’s Manual
SCU, V1.13
Reserved
Must be written with 0.
6-144
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3.4
Register INTDIS
This register contains the software disable control for all interrupt request trigger sources
of the SCU.
INTDIS
Interrupt Disable Register
15
14
13
12
11
SFR (FE84H/42H)
10
9
8
7
6
GSC WDT WU WUT
I
I
I
I
0
rw
rw
rw
rw
rw
Reset Value: 0000H
5
4
3
Bits
Type Description
SWDI1
0
rw
Disable SWD Interrupt Request 1
0B
SWDI1 interrupt request enabled
1B
SWDI1 interrupt request disabled
SWDI2
1
rw
Disable SWD Interrupt Request 2
SWDI2 interrupt request enabled
0B
1B
SWDI2 interrupt request disabled
PVCMI1
2
rw
Disable PVC_M Interrupt Request 1
0B
PVCMI1 interrupt request enabled
1B
PVCMI1 interrupt request disabled
PVCMI2
3
rw
Disable PVC_M Interrupt Request 2
0B
PVCMI2 interrupt request enabled
1B
PVCMI2 interrupt request disabled
PVC1I1
4
rw
Disable PVC_1 Interrupt Request 1
0B
PVC1I1 interrupt request enabled
1B
PVC1I1 interrupt request disabled
PVC1I2
5
rw
Disable PVC_1 Interrupt Request 2
0B
PVC1I2 interrupt request enabled
1B
PVC1I2 interrupt request disabled
WUTI
6
rw
Disable Wake-up Trim Interrupt Request
0B
WUT interrupt request enabled
1B
WUT interrupt request disabled
WUI
7
rw
Disable Wake-up Interrupt Request
0B
WU interrupt request enabled
1B
WU interrupt request disabled
6-145
1
0
PVC PVC PVC PVC
SWD SWD
1
1
M
M
I2
I1
I2
I1
I2
I1
rw
rw
rw
rw
rw
rw
Field
User’s Manual
SCU, V1.13
2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
WDTI
8
rw
Disable Watchdog Timer Interrupt Request
0B
WDT interrupt request enabled
1B
WDT interrupt request disabled
GSCI
9
rw
Disable GSC Interrupt Request
GSC interrupt request enabled
0B
GSC interrupt request disabled
1B
0
[15:10] rw
User’s Manual
SCU, V1.13
Reserved
Should be written with 0.
6-146
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3.5
Registers INTNP0 and INPNP1
These registers contain the control for the interrupt node pointers of all interrupt request
trigger sources of the SCU.
INTNP0
Interrupt Node Pointer 0 Register
SFR (FE86H/43H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 4444H
5
4
3
2
1
0
WU
WUT
PVC12
PVC11
PVCM2
PVCM1
SWD2
SWD1
rw
rw
rw
rw
rw
rw
rw
rw
Field
Bits
Type Description
SWD1
[1:0]
rw
Interrupt Node Pointer for SWD 1 Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.SWDI1 (if enabled by bit
INTDIS.SWDI1).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
SWD2
[3:2]
rw
Interrupt Node Pointer for SWD 2 Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.SWDI2 (if enabled by bit
INTDIS.SWDI2).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
PVCM1 [5:4]
rw
Interrupt Node Pointer for PVC_M 1 Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.PCVMI1 (if enabled by bit
INTDIS.PVCMI1).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
User’s Manual
SCU, V1.13
6-147
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
PVCM2 [7:6]
rw
Interrupt Node Pointer for PVC_M 2 Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.PCVMI2 (if enabled by bit
INTDIS.PVCMI2).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
PVC11 [9:8]
rw
Interrupt Node Pointer for PVC_1 1 Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.PCV1I1 (if enabled by bit
INTDIS.PVC1I1).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
PVC12 [11:10] rw
Interrupt Node Pointer for PVC_1 2 Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.PCV1I2 (if enabled by bit
INTDIS.PVC1I2).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
WUT
[13:12] rw
Interrupt Node Pointer for WU Trim Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.WUTI (if enabled by bit
INTDIS.WUTI).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
WU
[15:14] rw
Interrupt Node Pointer for WU Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.WUI (if enabled by bit
INTDIS.WUI).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
User’s Manual
SCU, V1.13
6-148
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
INTNP1
Interrupt Node Pointer 1 Register
SFR (FE88H/44H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0001H
5
4
3
2
1
0
-
GSC
WDT
-
rw
rw
6.9.3.6
Field
Bits
Type Description
WDT
[1:0]
rw
Interrupt Node Pointer for WDT Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.WDTI (if enabled by bit
INTDIS.WDTI).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
GSC
[3:2]
rw
Interrupt Node Pointer for GSC Interrupts
This bit field defines the interrupt node, which is requested due
to the set condition for bit INTSTAT.GSCI (if enabled by bit
INTDIS.GSCI).
00B Interrupt node 6CH is selected
01B Interrupt node 6BH is selected
10B Reserved, do not use this combination
11B Reserved, do not use this combination
User’s Manual
SCU, V1.13
6-149
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3.7
Register DMPMIT
This register contains additional sticky interrupt and trap flags within the DMP_M power
domain.
DMPMIT
DMP_M Interrupt and Trap Trigger Register
SFR (FE96H/4BH)
15
14
RA
T
0
rh
r
13
12
11
ESR ESR ESR
2
1
0
T
T
T
rh
rh
rh
10
9
8
0
GSC
r
rh
7
6
WU WUT
I
I
rh
rh
Reset Value: 0000H
5
4
3
2
1
0
PVC PVC PVC PVC
SWD SWD
1
1
M
M
I2
I1
I2
I1
I2
I1
rh
rh
rh
rh
rh
rh
Field
Bits
Type Description
SWDI1
0
rh
SWD Interrupt Request Flag 1
This bit is set if bit SWDCON0.L1OK is cleared and
SWDCON0.L1ACON = 01B and INTDIS.SWDI1 = 0.
0B
No SWDI1 interrupt was requested since this bit was
cleared the last time
1B
A SWDI1 interrupt was requested since this bit was
cleared the last time
SWDI2
1
rh
SWD Interrupt Request Flag 2
This bit is set if bit SWDCON0.L2OK is cleared and
SWDCON0.L2ACON = 01B and INTDIS.SWDI2 = 0.
0B
No SWDI2 interrupt was requested since this bit was
cleared the last time
1B
A SWDI2 interrupt was requested since this bit was
cleared the last time
PVCMI1 2
rh
PVC_M Interrupt Request Flag 1
This bit is set if bit PVCMCON0.LEV1OK is cleared and
PVCMCON0.L1INTEN = 1B and INTDIS.PVCMI1 = 0.
0B
No PVCMI1 interrupt was requested since this bit was
cleared the last time
1B
A PVCMI1 interrupt was requested since this bit was
cleared the last time
User’s Manual
SCU, V1.13
6-150
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
PVCMI2 3
rh
PVC_M Interrupt Request Flag 2
This bit is set if bit PVCMCON0.LEV2OK is cleared and
PVCMCON0.L2INTEN = 1B and INTDIS.PVCMI2 = 0.
No PVCMI2 interrupt was requested since this bit was
0B
cleared the last time
1B
A PVCMI2 interrupt was requested since this bit was
cleared the last time
PVC1I1
4
rh
PVC_1 Interrupt Request Flag 1
This bit is set if bit PVC1CON0.LEV1OK is cleared and
PVC1CON0.L1INTEN = 1B and INTDIS.PVC1I1 = 0.
0B
No PVC1I1 interrupt was requested since this bit was
cleared the last time
1B
A PVC1I1 interrupt was requested since this bit was
cleared the last time
PVC1I2
5
rh
PVC_1 Interrupt Request Flag 2
This bit is set if bit PVC1CON0.LEV2OK is cleared and
PVC1CON0.L2INTEN = 1B and INTDIS.PVC1I2 = 0.
No PVC1I2 interrupt was requested since this bit was
0B
cleared the last time
1B
A PVC1I2 interrupt was requested since this bit was
cleared the last time
WUTI
6
rh
Wake-up Trim Interrupt Request Flag
This bit is set if a wake-up trim trigger occurs and
INTDIS.WUTI = 0.
0B
No WUT interrupt was requested since this bit was
cleared the last time
1B
A WUT interrupt was requested since this bit was
cleared the last time
WUI
7
rh
Wake-up Interrupt Request Flag
This bit is set if a wake-up trigger occurs and INTDIS.WUI = 0.
0B
No WU interrupt was requested since this bit was
cleared the last time
1B
A WU interrupt was requested since this bit was cleared
the last time
User’s Manual
SCU, V1.13
6-151
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
GSC
8
rh
GSC Interrupt Request Flag
This bit is set if a GSC trigger occurs and INTDIS.GSCI = 0.
0B
No GSC interrupt was requested since this bit was
cleared the last time
A GSC interrupt was requested since this bit was
1B
cleared the last time
ESR0T
11
rh
ESR0 Trap Request Flag
This bit is set if pin ESR0 is asserted.
0B
No ESR0 trap was requested since this bit was cleared
the last time
An ESR0 trap was requested since this bit was cleared
1B
the last time
ESR1T
12
rh
ESR1 Trap Request Flag
This bit is set if pin ESR1 is asserted.
0B
No ESR1 trap was requested since this bit was cleared
the last time
1B
An ESR1 trap was requested since this bit was cleared
the last time
ESR2T
13
rh
ESR2 Trap Request Flag
This bit is set if pin ESR2 is asserted.
0B
No ESR2 trap was requested since this bit was cleared
the last time
1B
An ESR2 trap was requested since this bit was cleared
the last time
RAT
15
rh
Register Access Trap Request Flag
This bit is set a protected register is written by an nonauthorized access.
0B
No RA trap was requested since this bit was cleared the
last time
1B
A RA trap was requested since this bit was cleared the
last time
0
[10:9], r
14
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
6-152
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.9.3.8
Register DMPMITCLR
This register contains the software clear option for all sticky status flags of all interrupt
and trap request trigger sources of the DMP_M power domain.
DMPMITCLR
DMP_M Interrupt and Trap Clear Register
SFR (FE98H/4CH)
15
14
RA
T
0
w
r
13
12
11
ESR ESR ESR
2
1
0
T
T
T
w
w
w
10
9
8
0
GSC
r
w
7
6
WU WUT
I
I
w
w
Reset Value: 0000H
5
4
3
2
1
0
PVC PVC PVC PVC
SWD SWD
1
1
M
M
I2
I1
I2
I1
I2
I1
w
w
w
w
w
w
6.9.3.9
Field
Bits
Type Description
SWDI1
0
w
Clear SWD1 Interrupt Request Flag 1
0B
No action
1B
Bit DMPMIT.SWDI1 is cleared
SWDI2
1
w
Clear SWD Interrupt Request Flag 2
0B
No action
1B
Bit DMPMIT.SWDI2 is cleared
PVCMI1
2
w
Clear PVC_M Interrupt Request Flag 1
0B
No action
Bit DMPMIT.PVCMI1 is cleared
1B
PVCMI2
3
w
Clear PVC_M Interrupt Request Flag 2
0B
No action
1B
Bit DMPMIT.PVCMI2 is cleared
PVC1I1
4
w
Clear PVC_1 Interrupt Request Flag 1
0B
No action
1B
Bit DMPMIT.PVC1I1 is cleared
PVC1I2
5
w
Clear PVC_1 Interrupt Request Flag 2
0B
No action
1B
Bit DMPMIT.PVC1I2 is cleared
WUTI
6
w
Clear Wake-up Trim Interrupt Request Flag
0B
No action
1B
Bit DMPMIT.WUTI is cleared
WUI
7
w
Clear Wake-up Interrupt Request Flag
0B
No action
1B
Bit DMPMIT.WUI is cleared
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Field
Bits
Type Description
GSC
8
w
Clear GSC Interrupt Request Flag
0B
No action
1B
Bit DMPMIT.GSCI is cleared
ESR0T
11
w
Clear ESR0 Trap Request Flag
0B
No action
Bit DMPMIT.ESR0T is cleared
1B
ESR1T
12
w
Clear ESR1 Trap Request Flag
0B
No action
1B
Bit DMPMIT.ESR1T is cleared
ESR2T
13
w
Clear ESR2 Trap Request Flag
0B
No action
1B
Bit DMPMIT.ESR2T is cleared
RAT
15
w
Clear Register Access Trap Request Flag
0B
No action
1B
Bit DMPMIT.RAT is cleared
0
[10:9], r
14
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Reserved
Read as 0; should be written with 0.
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6.9.3.10 Alternate Interrupt Source Assignment
In order to map the interrupt request sources in the complete system to the available
interrupt nodes, interrupt nodes are shared between selected modules.
ISSR
Interrupt Source Select Register
SFR (FF2EH/97H)
Reset Value: 0000H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ISS
15
ISS
14
ISS
13
ISS
12
ISS
11
ISS
10
ISS
9
ISS
8
ISS
7
ISS
6
ISS
5
ISS
4
ISS
3
ISS
2
ISS
1
ISS
0
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Field
Bits Type Description
ISS0
0
rw
Interrupt Source Select for CC2_CC16IC
0B
CC2 channel 16 interrupt is selected
1B
External interrupt request ERU_IOUT0 is selected
ISS1
1
rw
Interrupt Source Select for CC2_CC17IC
0B
CC2 channel 17 interrupt is selected
External interrupt request ERU_IOUT1 is selected
1B
ISS2
2
rw
Interrupt Source Select for CC2_CC18IC
0B
CC2 channel 18 interrupt is selected
1B
External interrupt request ERU_IOUT2 is selected
ISS3
3
rw
Interrupt Source Select for CC2_CC19IC
0B
CC2 channel 19 interrupt is selected
1B
External interrupt request ERU_IOUT3 is selected
ISS4
4
rw
Interrupt Source Select for CC2_CC20IC
0B
CC2 channel 20 interrupt is selected
1B
USIC0 channel 0 SR3 is selected
ISS5
5
rw
Interrupt Source Select for CC2_CC21IC
0B
CC2 channel 21 interrupt is selected
1B
USIC0 channel 1 SR3 is selected
ISS6
6
rw
Interrupt Source Select for CC2_CC22IC
0B
CC2 channel 22 interrupt is selected
1 B USIC1 channel 0 SR3 is selected
ISS7
7
rw
Interrupt Source Select for CC2_CC23IC
0B
CC2 channel 23 interrupt is selected
1B
USIC1 channel 1 SR3 is selected
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Field
Bits Type Description
ISS8
8
rw
Interrupt Source Select for CC2_CC24IC
0B
CC2 channel 24 interrupt is selected
1B
External interrupt request ERU_IOUT0 is selected
ISS9
9
rw
Interrupt Source Select for CC2_CC25IC
CC2 channel 25 interrupt is selected
0B
External interrupt request ERU_IOUT1 is selected
1B
ISS10
10
rw
Interrupt Source Select for CC2_CC26IC
0B
CC2 channel 26 interrupt is selected
1B
External interrupt request ERU_IOUT2 is selected
ISS11
11
rw
Interrupt Source Select for CC2_CC27IC
0B
CC2 channel 27 interrupt is selected
1B
External interrupt request ERU_IOUT3 is selected
ISS12
12
rw
Interrupt Source Select for CC2_CC28IC
0B
CC2 channel 28 interrupt is selected
1B
USIC2 channel 0 SR3 is selected
ISS13
13
rw
Interrupt Source Select for CC2_CC29IC
0B
CC2 channel 29 interrupt is selected
1B
USIC2 channel 1 SR3 is selected
ISS14
14
rw
Interrupt Source Select for CC2_CC30IC
0B
CC2 channel 30 interrupt is selected
SCU Interrupt 2 is selected
1B
ISS15
15
rw
Interrupt Source Select for CC2_CC31IC
0B
CC2 channel 31 interrupt is selected
1B
SCU Interrupt 3 is selected
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6.10
Temperature Compensation Unit
The temperature compensation for the port drivers provides driver output characteristics
which are stable (within a certain band of parameter variation) over the specified
temperature range.
The temperature compensation oscillator (sensor) provides a reference clock from a
free-running temperature-dependent oscillator. An enable trigger is used to define
counting cycles where the reference clock pulses are accumulated to build the sensor
value TCLR.THCOUNT. The enable trigger is derived from the system clock by a
prescaler and a programmable divider (see Figure 6-27). The value for the
programmable divider must be written by the user according to the selected system
frequency.
After the count cycle, the resulting count value, i.e. the number of reference clock cycles,
is copied to bit field TCLR.THCOUNT. Thus, TCLR.THCOUNT is updated after every
count cycle while the temperature compensation is enabled.
Software can compare the temperature-related count value (TCLR.THCOUNT) to
several thresholds (temperature levels) in order to determine the control values
TCCR.TCC.
fREF
OSC_TC
fSYS
Figure 6-27
32:1
N:1
Prescaler
Programmable Divider
N = (TCDIV+1)
fEnable
Temperature Compensation Clock Generation
The clock divider is programmed via bit field TCCR.TCDIV. The value that should be
used for bit field TCCR.TCDIV can be calculated using the following formula
documented in the data sheet.
Generally, temperature compensation is a user-controlled feature. The Temperature
Compensation Control Register TCCR provides access to the actual compensation
value (generated by the sensor) and allows software control of the pads. During
operation the device (i.e. the pads) can be controlled by the value of the on-chip sensor,
or by externally provided compensation values. Register TCCR also provides the
programmable divider value.
Note: The relation between the counter value and the temperature can differ between
two devices and need to be evaluated for each device individually.
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Note: The temperature compensation circuit does not generate temperature
compensation values continously. The idea is, that the SW frequently updates the
pad control with the value currently found in the tempcomp register (e.g. by an
interrupt generated by a timer). Since temparature is a continous function it is not
relevant, whether the temperature value read is new or the value of a previous
meaurement.
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6.10.1
Temperature Compensation Registers
6.10.1.1 TCCR
This register contains the control options.
TCCR
Temperature Compensation Control Register
ESFR (F1ACH/D6H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0003H
5
4
3
2
1
0
0
TCE
TCDIV
TCC
r
rw
rw
rw
Field
Bits
Type
Description
TCC
[1:0]
rw
Temperature Compensation Control
The value which controls the temperature
compensation inputs of the pads.
00B Maximum reduction = min. driver strength,
i.e. very low temperature
11B No reduction = max. driver strength,
i.e. very high temperature
TCDIV
[6:2]
rw
Temperature Compensation Clock Divider
This value adjusts the temperature compensation
logic to the selected operating frequency.
TCE
7
rw
Temperature Compensation Enable
0B
No action
1B
Enable counting to generate new temperature
values.
Clearing this bit also stops the temperature
compensation oscillator.
0
[15:8]
r
Reserved
Read as 0; should be written with 0.
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TCLR
Temperature Comp. Level Register
ESFR (F0ACH/56H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
0
THCOUNT
r
rh
2
1
0
Field
Bits
Type
Description
THCOUNT
[7:0]
rh
Threshold Counter
Returns the result of the most recent count cycle of
the temperature sensor, to be compared with the
thresholds.
0
[15:8]
r
Reserved
Read as 0; should be written with 0.
Note: The threshold counter will not overflow but rather stop at count 255.
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6.11
Watchdog Timer (WDT)
The following part describes the Watchdog Timer (WDT) and its functionality.
6.11.1
Introduction
The Watchdog Timer (WDT) is a secure mechanism to overcome life- and dead-locks.
An enabled WDT generates a reset for the system if not serviced in a configured time
frame.
Features
The following list is a summary of the WDT functions:
•
•
•
•
•
16-bit Watchdog Timer
Selectable operating frequency: fIN / 256 or fIN / 16384
Timer overflow error detection
Individual disable for timer functionality
Double Reset Detection
Figure 6-28 provides an overview on the registers of the Watchdog Timer.
W DT Control &
Status Register
W DT Reload
Register
W DT Timer
Register
WDTCS
WDTREL
WDTTIM
WDTCS WDT Control and Status Register
WDTREL WDT Reload Register
WDTTIM WDT Timer Register
WDT_Reg_Overview.vsd
Figure 6-28 Watchdog Timer Register Overview
6.11.2
Overview
The Watchdog Timer (WDT) provides a highly reliable and secure way to detect and
recover from software or hardware failure. The WDT helps to abort an accidental
malfunction of the XC2700 in a user-specified time period. When enabled, the WDT will
cause the XC2700 system to be reset if the WDT is not serviced within a userprogrammable time period. The CPU must service the WDT within this time interval to
prevent the WDT from causing a WDT reset request trigger. Hence, regular service of
the WDT confirms that the system is functioning properly.
A further feature of the Watchdog Timer is its reset prewarning operation. Instead of
immediately resetting the device on the detection of an error, a prewarning output is
given to the system via an interrupt request. This makes it possible to bring the system
into a defined and predictable status, before the reset is finally issued.
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6.11.3
Functional Description
The following part describes all functions of the WDT.
6.11.3.1 Timer Operation
The timer is enabled when instruction ENWDT (Enable Watchdog Timer) is executed
correctly.
The WDT uses the input clock fIN which is equal to the system clock fsys. A clock divider
in front of the WDT timer provides two output frequencies, fIN / 256 and fIN / 16384. The
selection of the counting rate is done via bit WDTCS.IR.
WDT Periods
The general formula to calculate a Watchdog period is:
period =
⎛ 2 16 – startvalue⎞ ⋅ 256 ⋅ 2 ( 1 – IR ) ⋅ 6
⎝
⎠
----------------------------------------------------------------------------------------------------------------------------------IN
(6.4)
f
The parameter <startvalue> represents either the user-programmable reload value
WDTREL.RELV (default value FFFCH) for the calculation of the period in Normal Mode
or the fixed value FFFFH for the calculation of the period in Prewarning Mode.
WDT Timer Reload
The counter is reloaded and the prescaler is cleared when one of the following conditions
occurs:
•
•
•
•
•
A successful access to register WDTREL
The WDT is serviced via instruction SRVWDT
A WDT overflow condition (Prewarning Mode is entered).
The different reload value for the counter in Prewarning Mode is FFFFH.
The Disable Mode is entered (when instruction DISWDT is executed)
Upon any reset
6.11.3.2 Timer Modes
The Watchdog Timer provides following modes:
•
•
•
Normal Mode
Disable Mode
Prewarning Mode
Figure 6-29 provides a state diagram of the different Timer Modes and the transition
possibilities. Please refer to the description of the conditions for changing from one mode
to the other.
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Internal Application
Reset
Application
Reset
Normal
Mode
Timer
overflow /
DISWDT
WDT interrupt trigger
Reload WDT with FFFFH
ENWDT
Pre-Warning
Mode
Disable
Mode
Overflow and
STMEM0.WDTCSOE = 0 and
(Internal Application Reset
or Application Reset configured) /
Overflow and
STMEM0.WDTCSOE = 1 and
(Internal Application Reset
or Application Reset configured) /
WDT Reset Trigger
STMEM0.WDTCSOE = 1
Permanent WDT Reset Trigger
Permanent
Reset
WDT Stopped
WDT_modes _MR.vsd
Figure 6-29 State Diagram of the Timer Modes
Normal Mode
Normal Mode is the default mode after an Application Resetor or an Internal Application
Reset. Normal Mode can be entered from Disable Mode only when instruction ENWDT
is executed.
The timer is loaded with RELV when the Normal Mode is entered, and it starts counting
upwards. After reset the timer is loaded with FFFCH (default value of RELV).
It has to be serviced before the counter overflows. Servicing is performed by the CPU
via instructions SRVWDT and/or ENWDT.
If the WDT is not serviced before the timer overflows, a system malfunction is assumed,
and following operations are done:
•
•
An WDT interrupt trigger is issued
Prewarning Mode is entered
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•
Timer is reloaded with FFFFH
Disable Mode
Disable Mode is provided for applications that do not require the Watchdog Timer
function. Disable Mode is entered when instruction DISWDT is executed, either before
End-of-Init, if CPUCON1.WDTCTL = 0, or at any time, if CPUCON1.WDTCTL = 1.
The timer is reloaded with the value of WDTREL.RELV when Disable Mode is entered.
A transition from Disable Mode to Normal Mode is performed when instruction ENWDT
is executed while CPUCON1.WDTCTL = 1.
Prewarning Mode
Prewarning Mode is entered always when a Watchdog error is detected. This is an
overflow in Normal Mode. Instead of immediately requesting a reset of the device, the
WDT enables the system to enter a secure state by issuing the prewarning output before
the reset occurs. Receiving the prewarning, the CPU and the system are requested to
finish all pending transaction requests and to not generate new ones. The prewarning is
signalled via an interrupt. The CPU can recognize the WDT prewarning interrupt via
register INTSTAT. After finishing all pending transactions, the CPU should execute the
IDLE instruction to stop all further processing before the coming reset.
In Prewarning Mode, the WDT starts counting from FFFFH upwards, and then requests
a WDT reset on the overflow of the WDT from FFFFH to 0000H. A reset request of the
type as configured in RSTCON1.WDT can not be avoided. No reset will be requested If
RSTCON1.WDT is cleared. The WDT does not react anymore to accesses to its
registers and to the ENWDT or DISWDT instruction, nor will it change its state until it is
reset.
A further feature of the WDT detects double errors and sets the whole system into a
permanent WDT reset. This feature prevents the XC2700 from executing random wrong
code for longer than the occurence of the overflow, and prevents the XC2700 from being
repeatedly reset by the WDT.
Double WDT Reset
If the Watchdog induced reset (Application or Internal Application Reset) occurs twice
back-to-back, a severe system malfunction is assumed and the XC2700 is held in a reset
of the type as configured in RSTCON1.WDT (or just not) until a Power-on Reset occurs.
This prevents the device from being periodically reset if, for instance, connection to the
external memory has been lost such that even system initialization could not be
performed.
Note: Triggering a PORST upon a WDT reset will never result in a double WDT overflow.
If the WDT is configured by RSTCON1.WDT to request an Application Reset or an
Internal Application Reset the second reset request will be permanently asserted
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resulting (without any change in the reset configuration) in a permanent reset of the type
configured by RSTCON1.WDT.
The information about the first WDT reset request is stored in bit STMEM0.WDTCSOE
(see Section 10.3.1). The bit is set when a WDT overflow had occured in Prewarning
Mode and a reset was generated. If the bit STMEM0.WDTCSOE is already set then a
double WDT reset event has occurred and a permanent reset request is generated.
The bit is cleared by any Power-on Reset or when bit STMEM0.WDTCSOE is cleared.
A correct service of the WDT does not clear this bit nor do any access to the WDT related
registers or commands. Therefore, if correct WDT-servicing has been done after the first
WDT reset and a next WDT reset must not immediately lead to a double error state,
application software has to clear STMEM0.WDTCSOE, too.
Note: After the double WDT reset request trigger is generated the counter is stopped
after the overflow.
Port Configuration during WDT Reset
The behavior of the ESRx ports can be defined with respect to the reset type by bit field
ESRCFGx.PC. For the coding of PC see Table 6-6. The allows to signal the occurence
of a reset.
The configuration of the GPIOS ports depends on the reset type. In case of an
Application Reset the pad configuration is unchanged1), in case of an Internal Application
Reset the ports are configured for input.
6.11.3.3 Suspend Mode Support
In an enabled and active debug session, the Watchdog functionality can lead to
unintended resets. Therefore, to avoid these resets, the OCDS can control whether the
WDT is enabled or disabled (default after reset). This is done via bit CBS_IOSR.DB.
Table 6-14
OCDS Behavior of WDT
WDTCS.DS
CBS_DBGSR.DBGEN
CBS_IOSR.DB
WDT Action
1
X
X
Stopped
0
0
X
Running
0
1
0
Stopped
0
1
1
Running
1)
Ports P2.[2:0] and P10.[12:0] are set to input during the execution of the Application
Reset.
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6.11.4
WDT Kernel Registers
6.11.4.1 WDT Reload Register
This register defines the WDT reload value.
WDTREL
WDT Reload Register
15
14
13
12
ESFR (F0C8H/64H)
11
10
9
8
7
6
Reset Value: FFFCH
5
4
3
2
1
0
RELV
rw
Field
Bits
Type
Description
RELV
[15:0]
rw
Reload Value for the Watchdog Timer
This bit field defines the reload value for the WDT.
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6.11.4.2 WDT Control and Status Register
The Control and Status Register can only be accessed in Secured Mode.
WDTCS
WDT Control and Status Register
ESFR (F0C6H/63H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
0
IR
0
PR
DS
OE
r
rw
r
rh
rh
rh
Field
Bits
Type
Description
OE
0
rh
Overflow Error Status Flag
0B
No WDT overflow error
1B
A WDT overflow error has occurred.
This bit is set by hardware when the Watchdog Timer
overflows from FFFFH to 0000H.
This bit is only cleared through:
• any Power-on Reset
• an executed SRVWDT or ENWDT instruction
Note: It is not possible to clear this bit in Prewarning
Mode with the SRVWDT or ENWDT
instruction.
DS
1
rh
Timer Enable/Disable Status Flag
Timer is enabled (default after reset)
0B
1B
Timer is disabled
This bit is cleared when instruction ENWDT was
executed and CPUCON1.WDTCTL = 1.
This bit is set when instruction DISWDT was
executed before EINIT or CPUCON1.WDTCTL = 1.
Note: ENWDT and DISWDT instruction will be
reflected in this bit but in Prewarning Mode the
WDT mode is not changed.
PR
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rh
Prewarning Mode Flag
0B
Normal Mode (default after reset)
Prewarning Mode
1B
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Field
Bits
Type
Description
IR
8
rw
Input Frequency Request Bit
0B
Request to set input frequency to fIN / 16384
1B
Request to set input frequency to fIN / 256
An update of this bit is taken into account after the
next successful execution of instruction SRVWDT or
ENWDT, on a write to register WDTREL, and always
when the WDT is in Disable Mode.
0
[7:3],
[15:9]
r
Reserved
Read as 0; should be written with 0;
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6.11.4.3 WDT Timer Register
WDTTIM
WDT Timer Register
15
14
13
12
ESFR (F0CAH/65H)
11
10
9
8
7
6
Reset Value: FFFCH
5
4
3
2
1
0
TIM
rh
Field
Bits
Type
Description
TIM
[15:0]
rh
Timer Value
Reflects the current contents of the Watchdog Timer.
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6.12
SCU Trap Generation
The basic trap structure of the SCU is shown in Figure 6-30.
TRAPCLR.x
Trap
Event
DMPMIT.x
clear
TRAPSTAT.x
TRAPSET.x
1
1
request
TRAPNPn.y
&
set
1
1
disable
SCU
TRQ0
SCU
TRQ1
SCU
TRQ2
to TFR.ACER
to TFR.SR1
to TFR.SR0
Reserved
TRAPDIS.x
other trap sources to the
same trap
SCU Trap Structure
SCU_Trap_Struct .vsd
Figure 6-30 SCU Trap Structure
If enabled by the corresponding bit in register TRAPDIS, a trap is triggered either by a
pulse on the incoming trap line, or by a software set of the respective bit in register
TRAPSET. The trigger sets the respective flag in register TRAPSTAT and is gated to
one of the trap nodes, selected by the node pointer register TRAPNP.
The trap flag in register TRAPSTAT can be cleared by software by writing to the
corresponding bit in register TRAPCLR.
If more than one trap source is connected to the same trap (via register TRAPNP), the
requests are combined to one common line.
Trap Node Assignment
The trap sources of the system can be mapped to three trap nodes by programming the
trap node pointer register TRAPNP. The default assignment of the trap sources to the
nodes and their corresponding control register is listed in Table 6-15.
6.12.1
Trap Support
Some of the trap requests are first fed through a sticky flag register in the DMP_M
domain. These flags are set with a trigger and if set trigger the trap generation in the
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DMP_1. . Please note that the disable control of register TRAPDIS also influences the
sticky bit in register DMPMIT (see Section 6.9.3.7).
Which of the trap requests have a sticky flag in register DMPMIT is listed in Table 6-15.
Note: When servicing an SCU trap request, make sure that all related request flags are
cleared after the identified request has been handled. To clear a trap request that
is stored in register DMPMIT, first clear the request source of the source, clear the
request within DMP_M via DMPMITCLR, and then clear the request within DMP_1
via TRAPCLR.
6.12.2
SCU Trap Sources
The SCU receives the trap lines listed in Table 6-15.
Table 6-15
SCU Trap Request Overview
Source of Trap
Short Name
Sticky Flag
in DMPMIT
Default Trap Flag
Assignment in
Register TFR
Flash Access Trap
FAT
---
TFR.ACER (SCU_TRQ0)
ESR0 Trap
ESR0T
yes
TFR.SR1 (SCU_TRQ1)
ESR1 Trap
ESR1T
yes
TFR.SR1 (SCU_TRQ1)
ESR2 Trap
ESR2T
yes
TFR.SR1 (SCU_TRQ1)
PLL Trap
OSCWDTT
---
TFR.SR1 (SCU_TRQ1)
Register Access Trap
RAT
yes
TFR.ACER (SCU_TRQ0)
Parity Error Trap
PET
---
TFR.ACER (SCU_TRQ0)
VCO Lock Trap
VCOLCKT
---
TFR.SR0 (SCU_TRQ2)
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System Control Unit (SCU)
6.12.3
SCU Trap Control Registers
6.12.3.1 Register TRAPSTAT
This register contains the status flags for all trap request trigger sources of the SCU.
For setting and clearing of these status bits by software see registers TRAPSET and
TRAPCLR, respectively.
TRAPSTAT
Trap Status Register
15
14
13
12
SFR (FF02H/81H)
11
10
9
8
7
6
VCO
PE
LCK
T
T
rh
rh
0
r
Reset Value: 0000H
5
4
3
2
1
OSC ESR ESR ESR
RA
WDT 2
1
0
T
T
T
T
T
rh
rh
rh
rh
rh
0
FA
T
rh
Field
Bits
Type Description
FAT
0
rh
Flash Access Trap Request Flag
TRAPSTAT.FAT is set when a flash access violation
occurs and TRAPDIS.FAT = 0.
No FA trap trigger has occured since this bit was
0B
cleared the last time
1B
A FA trap trigger has occured since this bit was
cleared the last time
ESR0T
1
rh
ESR0 Trap Request Flag
TRAPSTAT.ESR0T is set when bit DMPMIT.ESR0T is
set and TRAPDIS.ESR0T = 0.
0B
No ESR0 trap trigger has occured since this bit
was cleared the last time
1B
An ESR0 trap trigger has occured since this bit
was cleared the last time
ESR1T
2
rh
ESR1 Trap Request Flag
TRAPSTAT.ESR1T is set when bit DMPMIT.ESR1T is
set and TRAPDIS.ESR1T = 0.
0B
No ESR1 trap trigger has occured since this bit
was cleared the last time
1B
An ESR1 trap trigger has occured since this bit
was cleared the last time
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SCU, V1.13
6-172
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
ESR2T
3
rh
ESR2 Trap Request Flag
TRAPSTAT.ESR2T is set when bit DMPMIT.ESR0T is
set and TRAPDIS.ESR2T = 0.
0B
No ESR2 trap trigger has occured since this bit
was cleared the last time
1B
An ESR2 trap trigger has occured since this bit
was cleared the last time
OSCWDTT
4
rh
OSCWDT Trap Request Flag
TRAPSTAT.OSCWDTT is set when an OSCWDT
emergency event occurs and
TRAPDIS.OSCWDTT = 0.
0B
No OSCWDT trap trigger has occured since this
bit was cleared the last time
1B
An OSCWDT trap trigger has occured since this
bit was cleared the last time
RAT
5
rh
Register Access Trap Request Flag
TRAPSTAT.RAT is set when bit DMPMIT.RAT is set
and TRAPDIS.RAT = 0.
0B
No RA trap trigger has occured since this bit was
cleared the last time
1B
A RA trap trigger has occured since this bit was
cleared the last time
PET
6
rh
Parity Error Trap Request Flag
TRAPSTAT.PET is set when a memory parity error
occurs and TRAPDIS.PET = 0.
0B
No PE trap trigger has occured since this bit was
cleared the last time
1B
A PE trap trigger has occured since this bit was
cleared the last time
VCOLCKT
7
rh
VCOLCK Trap Request Flag
TRAPSTAT.VCOLCKT is set when a VCOLCK
emergency event occurs and
TRAPDIS.VCOLCKT = 0.
0B
No VCOLCK trap trigger has occured since this
bit was cleared the last time
1B
A VCOLCK trap trigger has occured since this
bit was cleared the last time
0
[15:8]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.12.3.2 Register TRAPCLR
This register contains the software clear control for the trap status flags in register
TRAPSTAT. Clearing a bit in this register has no effect, reading a bit always returns zero.
TRAPCLR
Trap Clear Register
15
14
13
SFR (FE8EH/47H)
12
11
10
9
8
7
6
VCO
PE
LCK
T
T
w
w
0
r
Reset Value: 0000H
5
4
3
2
1
OSC ESR ESR ESR
RA
WDT 2
1
0
T
T
T
T
T
w
w
w
w
w
Field
Bits
Type Description
FAT
0
w
Clear Flash Access Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.FAT is cleared
ESR0T
1
w
Clear ESR0 Trap Request Flag
No action
0B
1B
Flag TRAPSTAT.ESR0T is cleared
ESR1T
2
w
Clear ESR1 Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.ESR1T is cleared
ESR2T
3
w
Clear ESR2 Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.ESR2T is cleared
OSCWDTT
4
w
Clear OSCWDT Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.OSCWDTT is cleared
RAT
5
w
Clear Register Access Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.RAT is cleared
PET
6
w
Clear Parity Error Access Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.PET is cleared
VCOLCKT
7
w
Clear VCOLCK Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.VCOLCKT is cleared
User’s Manual
SCU, V1.13
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0
FA
T
w
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
0
[15:8]
r
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0
6-175
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System Control Unit (SCU)
6.12.3.3 Register TRAPSET
This register contains the software set control for the trap status flags in register
TRAPSTAT. Clearing a bit in this register has no effect, reading a bit always returns zero.
TRAPSET
Trap Set Register
15
14
13
SFR (FE8CH/46H)
12
11
10
9
8
7
6
VCO
PE
LCK
T
T
w
w
0
r
Reset Value: 0000H
5
4
3
2
1
OSC ESR ESR ESR
RA
WDT 2
1
0
T
T
T
T
T
w
w
w
w
w
Field
Bits
Type Description
FAT
0
w
Set Flash Access Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.FAT is set
ESR0T
1
w
Set ESR0 Trap Request Flag
No action
0B
1B
Flag TRAPSTAT.ESR0T is set
ESR1T
2
w
Set ESR1 Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.ESR1T is set
ESR2T
3
w
Set ESR2 Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.ESR2T is set
OSCWDTT
4
w
Set OSCWDT Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.OSCWDTT is set
RAT
5
w
Set Register Access Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.RAT is set
PET
6
w
Set Parity Error Access Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.PET is set
VCOLCKT
7
w
Set VCOLCK Trap Request Flag
0B
No action
1B
Flag TRAPSTAT.VCOLCKT is set
User’s Manual
SCU, V1.13
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0
FA
T
w
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
0
[15:8]
r
User’s Manual
SCU, V1.13
Reserved
Read as 0; should be written with 0.
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System Control Unit (SCU)
6.12.3.4 Register TRAPDIS
This register contains the software disable control for all trap request trigger sources.
Note that the bits ESRxT and RAT in this register also disable the setting of the
respective flags in register DMPMIT (see Section 6.9.1).
TRAPDIS
Trap Disable Register
15
14
13
12
SFR (FE90H/48H)
11
10
9
8
7
6
VCO
PE
LCK
T
T
rw
rw
0
r
Reset Value: 009EH
5
4
3
2
1
OSC ESR ESR ESR
RA
WDT 2
1
0
T
T
T
T
T
rw
rw
rw
rw
rw
Field
Bits
Type
Description
FAT
0
rw
Disable Flash Access Trap Request
0B
FA trap request enabled
1B
FA trap request disabled
ESR0T
1
rw
Disable ESR0 Trap Request
0B
ESR0 trap request enabled
1B
ESR0 trap request disabled
ESR1T
2
rw
Disable ESR1 Trap Request
0B
ESR1 trap request enabled
ESR1 trap request disabled
1B
ESR2T
3
rw
Disable ESR2 Trap Request
0B
ESR2 trap request enabled
1B
ESR2 trap request disabled
OSCWDTT
4
rw
Disable OSCWDT Trap Request
0B
OSCWDT trap request enabled
1B
OSCWDT trap request disabled
RAT
5
rw
Disable Register Access Trap Request
0B
RA trap request enabled
1B
RA trap request disabled
PET
6
rw
Disable Parity Error Trap Request
0B
PE trap request enabled
1B
PE trap request disabled
VCOLCKT
7
rw
Disable VCOLCK Trap Request
0B
VCOLCK trap request enabled
1B
VCOLCK trap request disabled
User’s Manual
SCU, V1.13
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0
FA
T
rw
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
0
[15:8]
r
Reserved
Read as 0; should be written with 0.
User’s Manual
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.12.3.5 Register TRAPNP
This register contains the control for the trap node pointers of all SCU trap request trigger
sources.
TRAPNP
Trap Node Pointer Register
15
14
13
12
11
10
SFR (FE92H/49H)
9
8
7
6
Reset Value: 8254H
5
4
3
2
1
0
VCOLCK
PE
RA
OSCWDT
ESR2
ESR1
ESR0
FA
rw
rw
rw
rw
rw
rw
rw
rw
Field
Bits
Type Description
FA
[1:0]
rw
Trap Node Pointer for Flash Access Traps
TRAPNP.FA selects the trap request output for an
enabled FAT trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
ESR0
[3:2]
rw
Trap Node Pointer for ESR0 Traps
TRAPNP.ESR0 selects the trap request output for an
enabled ESR0 trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
ESR1
[5:4]
rw
Trap Node Pointer for ESR1 Traps
TRAPNP.ESR1 selects the trap request output for an
enabled ESR1 trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type Description
ESR2
[7:6]
rw
Trap Node Pointer for ESR2 Traps
TRAPNP.ESR2 selects the trap request output for an
enabled ESR2 trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
OSCWDT
[9:8]
rw
Trap Node Pointer for OSCWDT Traps
TRAPNP.OSCWDT selects the trap request output for
an enabled OSCWDT trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
RA
[11:10] rw
Trap Node Pointer for Register Access Traps
TRAPNP.RA selects the trap request output for an
enabled RAT trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
PE
[13:12] rw
Trap Node Pointer for Parity Error Traps
TRAPNP.PE selects the trap request output for an
enabled PET trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
VCOLCK
[15:14] rw
Trap Node Pointer for VCOLCK Traps
TRAPNP.VCOLCK selects the trap request output for
an enabled VCOLCK trap request.
00B Select request output SCU_TRQ0 (TFR.ACER)
01B Select request output SCU_TRQ1 (TFR.SR1)
10B Select request output SCU_TRQ2 (TFR.SR0)
11B Reserved, do not use this combination
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.13
Memory Content Protection
For supervising the content of the on-chip memories (Flash memory is not considered
here) Parity Checking is provided.
6.13.1
Parity Error Handling
The on-chip RAM modules check parity information during read accesses and in case of
an error a signal can be generated if enabled. These signals are combined and trigger a
trap. If a parity error is detected during the trap handler routine a reset request trigger is
generated. Register PECON controls the behavior of parity errors.
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
U0RAM
Parity
error
&
MCRAM
Parity
error
&
SBRAM
Parity
error
&
PSRAM
Parity
error
&
Parity
DSRAM
error
&
Parity
error
&
DPRAM
&
&
&
&
p_trap
>1
pf_trap
&
&
&
&
PECON.PEENDP
Parity
error
PECON.PEENDS
U1RAM
PECON.PEENPS
&
PECON.PEENSB
Parity
error
PECON.PEENMC
U2RAM
PECON.PEENU0
PECON.PEENU1
PECON.PEENU2
PMTSR.
PESEN
p_rst_req
&
&
PECON.PEFDP
PECON.PEFDS
PECON.PEFPS
PECON.PEFSB
PECON.PEFMC
PECON.PEFU0
PECON.PEFU1
PECON.PEFU2
parity_error_MR
Figure 6-31 Parity Error Control Logic
A parity error, detected while the respective trap flag TFR.ACER is set, generates a reset
request. The second error trap cannot be detected and handled by the CPU.
Note: The parity trap trigger should activate the Access Error trap (ACER).
The parity reset request trigger (p_rst_req) is generated when a parity error trap is
request AND flag TFR.ACER is set.
User’s Manual
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.13.1.1 Parity Software Testing Support
To support testing algorithms for the parity error trap routines a memory parity test logic
is implemented for the C166SV2 subsystem memories (PSRAM, DSRAM, and DPRAM)
and SBRAM.
The logic is controlled by registers PMTSR and PMTPR. Via bit field PMTPR.PWR a
parity value can be writing to any address of every memory. The parity control software
test update has to be enabled with bit PMTSR.MTEx for each memory individually.
Otherwise a write to the parity control has no effect. With each read access to a memory
the parity from the memory parity control is stored in register PMTPR.PRD.
The width and therefore the valid bits in register PMTPR is listed in Table 6-16.
Table 6-16
Memory Widths
Memory
Number of Parity Bits
Valid Bits in PWR/PRD
Dual Port (DP) Memory
2
PWR[1:0]/PRD[9:8]
Data SRAM (DS) Memory
2
PWR[1:0]/PRD[9:8]
Program SRAM (PS) Memory
8
PWR[7:0]/PRD[15:8]
Standby RAM (SB) Memory
2
PWR[1:0]/PRD[9:8]
Test software should be located in external memory and should be written in a way that
no pre-fetching is performed.
User’s Manual
SCU, V1.13
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
6.13.1.2 Parity Error Registers
Register PECON
The following register controls the functional parity check mechanism.
PECON
Parity Error Control Register
15
14
13
12
11
10
ESFR (F0C4H/41H)
9
8
PEF PEF PEF PEF PEF PEF PEF PEF
SB MC U2 U1 U0 PS DS DP
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
Reset Value: 0000H
7
6
5
4
3
2
1
0
PE
EN
SB
rw
PE
EN
MC
rw
PE
EN
U2
rw
PE
EN
U1
rw
PE
EN
U0
rw
PE
EN
PS
rw
PE
EN
DS
rw
PE
EN
DP
rw
Field
Bits
Type
Description
PEENDP
0
rw
Parity Error Trap Enable for Dual Port Memory
0B
No Parity trap is requested for dual port
memory parity errors
1B
A Parity trap is requested for dual port memory
parity errors
PEENDS
1
rw
Parity Error Trap Enable for Data SRAM
0B
No Parity trap is requested for data SRAM
parity errors
1B
A Parity trap is requested for data SRAM parity
errors
PEENPS
2
rw
Parity Error Trap Enable for Program SRAM
0B
No Parity trap is requested for program SRAM
parity errors
1B
A Parity trap is requested for program SRAM
parity errors
PEENU0
3
rw
Parity Error Trap Enable for USIC0 Memory
0B
No Parity trap is requested for USIC0 memory
parity errors
1B
A Parity trap is requested for USIC0 memory
parity errors
PEENU1
4
rw
Parity Error Trap Enable for USIC1 Memory
0B
No Parity trap is requested for USIC1 memory
parity errors
1B
A Parity trap is requested for USIC1 memory
parity errors
User’s Manual
SCU, V1.13
6-185
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XC2700 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
PEENU2
5
rw
Parity Error Trap Enable for USIC2 Memory
0B
No Parity trap is requested for USIC2 memory
parity errors
1B
A Parity trap is requested for USIC2 memory
parity errors
PEENMC
7
rw
Parity Error Trap Enable for MultiCAN Memory
0B
No Parity trap is requested for MultiCAN
memory parity errors
1B
A Parity trap is requested for MultiCAN
memory parity errors
PEENSB
8
rw
Parity Error Trap Enable for Standby Memory
No Parity trap is requested for Standby
0B
memory parity errors
1B
A Parity trap is requested for Standby memory
parity errors
PEFDP
8
rwh
Parity Error Flag for Dual Port Memory
0B
No Parity errors have been detected for dual
port memory
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for dual port memory
The bit is only set by the enabled parity error from the
dual port memory. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
PEFDS
9
rwh
Parity Error Flag for Data SRAM
0B
No Parity errors have been detected for data
SRAM
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for data SRAM
The bit is only set by the enabled parity error from the
data SRAM. This bit can only be cleared via software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
User’s Manual
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
PEFPS
10
rwh
Parity Error Flag for Program SRAM
0B
No Parity errors have been detected for
program SRAM
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for program SRAM
The bit is only set by the enabled parity error from the
program SRAM. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
PEFU0
11
rwh
Parity Error Flag for USIC0 Memory
0B
No Parity errors have been detected for USIC0
memory
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for USIC0 memory
The bit is only set by the enabled parity error from the
USIC0 memory. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
PEFU1
12
rwh
Parity Error Flag for USIC1 Memory
0B
No Parity errors have been detected for USIC1
memory
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for USIC1 memory
The bit is only set by the enabled parity error from the
USIC1 memory. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
PEFU2
13
rwh
Parity Error Flag for USIC2 Memory
0B
No Parity errors have been detected for USIC2
memory
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for USIC2 memory
The bit is only set by the enabled parity error from the
USIC2 memory. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
User’s Manual
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
Field
Bits
Type
Description
PEFMC
14
rwh
Parity Error Flag for MultiCAN Memory
0B
No Parity errors have been detected for
MultiCAN memory
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for MultiCAN
memory
The bit is only set by the enabled parity error from the
MutliCAN memory. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
PEFSB
15
rwh
Parity Error Flag for Standby Memory
0B
No Parity errors have been detected for
Standby memory
1B
A Parity error is indicated and can trigger a trap
request trigger, if enabled for Standby memory
The bit is only set by the enabled parity error from the
Standby memory. This bit can only be cleared via
software.
Writing a zero to this bit does not change the content.
Writing a one to this bit does clear the bit.
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System Control Unit (SCU)
PMTPR
Parity Memory Test Pattern RegisterESFR (F0E4H/72H)
15
14
13
12
11
10
9
8
7
6
5
Reset Value: 0000H
4
3
PRD
PWR
rh
rw
2
1
0
Field
Bits
Type
Description
PRD
[15:8]
rh
Parity Read Values for Memory Test
For each byte of a memory module the parity bits
generated during the most recent read access are
indicated here.
PWR
[7:0]
rw
Parity Write Values for Memory Test
For each byte of a memory module the parity bits
corresponding to the next write access are stored
here.
User’s Manual
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System Units (Vol. 1 of 2)
System Control Unit (SCU)
PMTSR
Parity Memory Test Select RegisterESFR (F0E6H/73H)
15
14
13
12
11
10
9
8
0
PES
EN
r
rw
7
MT
EN
SB
rw
6
Reset Value: 0000H
5
4
3
0
rw
2
1
0
MT
EN
PS
rw
MT
EN
DS
rw
MT
EN
DP
rw
Field
Bits
Type
Description
MTENDP
0
rw
Memory Test Enable Control for Dual Port
Memory
Controls the test multiplexer for the dual port
memory.
Standard operation
0B
1B
Test parity bits used (from PMTPR)
MTENDS
1
rw
Memory Test Enable Control for Data SRAM
Controls the test multiplexer for the data SRAM.
0B
Standard operation
1B
Test parity bits used (from PMTPR)
MTENPS
2
rw
Memory Test Enable Control for Program SRAM
Controls the test multiplexer for the program SRAM.
0B
Standard operation
1B
Test parity bits used (from PMTPR)
MTENSB
7
rw
Memory Test Enable Control for Standby Memory
Controls the test multiplexer for the Standby memory.
0B
Standard operation
1B
Test parity bits used (from PMTPR)
PESEN
8
rw
Parity Error Sensitivity Enable
0B
Parity errors have no effect
1B
Parity errors are indicated and can trigger a
trap, if enabled
0
[6:3]
rw
Reserved
Must be written with reset value 0.
0
[15:9]
r
Reserved
Read as 0; should be written with 0.
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System Control Unit (SCU)
6.14
Register Control
This block handles the register accesses of the SCU and the register access control for
all system register that use one of the following protection modes:
•
•
•
Unprotected Mode
Write Protection Mode
Secured Mode
6.14.1
Register Access Control
There are some dedicated registers that control critical system functions and modes.
These registers are protected by a special register security mechanism so these vital
system functions cannot be changed inadvertently after the executing of the EINIT
instruction. However, as these registers control central system behavior they need to be
accessed during operation. The system control software gets this access via a special
security state machine.
If an access violation is detected a trap trigger request is generated.
This security mechanism controls the following security levels wich can be configured via
register SLC:
•
•
•
Unprotected Mode
No protection is active. Registers can be written at any time. This mode is entered
after the Application Reset.
Write Protected Mode
Protected registers are locked against any write access. Write accesses have no
effect on these registers. This mode is entered automatically after the EINIT
instruction is executed.
Secured Mode
Protected registers can be written using a special command. Registers that are
protected by this mode are marked in Table 6-19 as Sec protected.
Access in Secured Mode can be achieved by preceding the intended write access
with writing “command 4” to register SLC. After writing “command 4” to register SLC
the register protection mechanism remains disabled until the next write to a register
on the PD+Bus (SFR, ESFR, XSFR area), i.e. accesses to registers (e.g. CSFR)
outside this area do not enable the protection again automatically. Therefore, the lock
mechanism after writing “command 4” works differently depending on the register
address. Normally one single write access to a protected register is enabled. After
this write access the protected registers are locked again automatically. Thereafter,
“command 4” has to be written again in order to enable the next write to a protected
register. The lock mechanism is not enabled again after a write access to a CSFR
register or to a LXBus peripheral register (XLOC area, e.g. USIC, CAN, IMB).
Note: In Secured Mode the re-enabling of register protection with respect to the write
address after “command 4” can lead to an unexpected, not obvious behaviour of
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System Control Unit (SCU)
an application:
In case the succeeding write to a protected register is delayed due to an interrupt
and the ISR itself uses the “command 4” mechanism. After writing “command 4”
inside the ISR the protection is expectedly re-installed instead of released and the
following write will lead to an ACER trap within the ISR. An ATOMIC instruction,
which couples the unlock with the write to the protected register could be used.
In case the succeeding write is to a register which does not re-enable the
protection mechanism again then the write itself will succeed, but in a following
“command 4” sequence the write to SLC register re-locks the protection again and
the write to a protected register fails.
All registers that are equipped with this protection mechanism have additional to normal
access parameters (e.g. read only, bit type r or rh) the access limitations defined by the
selected security level. Independently of the security level all protected registers can also
be read.
6.14.1.1 Controlling the Security Level
The two registers Security Level Command register (SLC) and Security Level Status
register (SLS) control the security level. The SLC register accepts the commands to
control the state machine modifying the security level, while the SLS register shows the
actual password, the actual security level, and the state of the state machine.
Any SCU
register
write access
State 4
Command 2
or any other SCU
register write access
Command 1
or any other SCU
register write access
State 1
Command 1
State 3
Command 2
Command 4
and low
protected
mode
Command 0
State 0
Reset
Command 3
or any other SCU
register write access
State 2
MCA05336
Figure 6-32 State Machine for Security Level Controlling
The following mechanism is used to control the actual security level:
•
Changing the security level
can be done by executing the following command sequence:
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System Control Unit (SCU)
“command 0 - command 1 - command 2 - command 3”.
This sequence establishes a new security level and/or a new password.
Table 6-17
Commands for Security Level Control
Command
Definition
Command 0
AAAAH
Command 1
5554H
Command 2
96H +1) <inverse password>
Command 3
000B + <new level> + 000B + <new password>
Command 4
8EH + <inverse password>
1)
Note
Secured Mode only
’+’ denotes a bit field concatenation
Note: It is recommended to lock all command sequences with an atomic sequence.
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System Control Unit (SCU)
6.14.2
Register Protection Registers
Register SLC
This register is the interface for the protection commands.
SLC
Security Level Command RegisterESFR (F0C0H/60H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
COMMAND
rw
Field
Bits
Type
Description
COMMAND
[15:0]
rw
Security Level Control Command
The commands to control the security level must be
written to this register (see table)
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Register SLS
This register monitors the status of the register protection.
SLS
Security Level Status Register ESFR (F0C2H/61H)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
STATE
SL
0
PASSWORD
rh
rh
r
rh
2
1
0
Field
Bits
Type
Description
PASSWORD
[7:0]
rh
Current Security Control Password
Default after reset = 00H
SL
[12:11] rh
Security Level 1)
00B Unprotected Mode (default)
01B Secured Mode
10B Reserved, Do not use this combination
11B Write Protected Mode
STATE
[15:13] rh
Current State of Switching State Machine
000B Awaiting command 0 or command 4 (default)
001B Awaiting command 1
010B Awaiting command 2
011B Awaiting new security level and password
100B Next access granted in Secured Mode
101B Reserved, do not use this combination
11XB Reserved, do not use this combination
0
[10:8]
Reserved
Read as 0; should be written with 0;
1)
r
While the security level is “unprotected” after reset, it changes to “write protected” after the execution of
instruction EINIT.
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6.15
Miscellaneous System Registers
This chapter acts as container for various register that are not connected to one specific
application topic.
6.15.1
System Registers
6.15.1.1 System Control Register
The following register serve several different system tasks.
SYSCON1
System Control 1 Register
15
14
13
12
11
SFR (FF4CH/A6H)
10
9
8
7
6
Reset Value: 0003H
5
4
3
2
1
GLC OCD
CST SEN
0
r
rw
rw
0
1
r
Field
Bits
Type
Description
1
[1:0]
r
Reserved
Should be written with reset value 11B.
Will be changed in future versions.
OCDSEN
2
rw
OCDS/Cerberus Enable
0B
OCDS and Cerberus are still in reset state
1B
ODCS and Cerberus are operable
GLCCST
3
rw
Global CAPCOM Start
This bit starts all CAPCOM units synchronously if
enabled.
0B
CAPCOM timer start is controlled locally in
each unit
1B
All CAPCOM timers are started synchronously
This bit needs to be cleared via software before
setting starts a new CAPCOM start.
0
[15:4]
r
Reserved
Read as 0; should be written with 0.
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6.15.2
Identification Block
For identification of the most important silicon parameters a set of identification registers
is defined that provide information on the chip manufacturer, the chip type and its
properties.
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6.15.2.1 Identification Registers
Register IDMANUF
This register contains information about the manufacturer.
IDMANUF
Manufacturer Identification Register
ESFR (F07EH/3FH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 1820H
5
4
3
2
1
MANUF
DEPT
r
r
0
Field
Bits
Type
Description
DEPT
[4:0]
r
Department
Indicates the department within Infineon.
00HAIM MC
MANUF
[15:5]
r
Manufacturer
This is the JEDEC normalized manufacturer code.
0C1HInfineon Technologies AG
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System Control Unit (SCU)
Register IDCHIP
This register contains information about the device.
IDCHIP
Chip Identification Register
15
14
13
12
11
10
ESFR (F07CH/3EH)
9
8
7
6
Reset Value: XXXXH
5
4
3
CHIPID
Revision
r
r
2
1
0
Field
Bits
Type
Description
Revision
[7:0]
r
Device Revision Code
Identifies the device step.
Please refer to the data sheet for the device specific
value.
CHIPID
[15:8]
r
Device Identification
Identifies the device name.
Please refer to the data sheet for the device specific
value.
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Register IDMEM
This register contains information about the program memory.
IDMEM
Program Memory Identification Register
ESFR (F07AH/3DH)
15
14
13
12
11
10
9
8
7
Reset Value: 3XXXH
6
5
TYPE
SIZE
r
rw
4
3
2
1
0
Field
Bits
Type
Description
SIZE
[11:0]
rw
Size of on-chip Program Memory
The size of the implemented program memory in
terms of 4 K blocks, i.e. memory size =
<SIZE>*4 Kbyte.
Please refer to the data sheet for the device specific
value.
TYPE
[15:12] r
User’s Manual
SCU, V1.13
Type of on-chip Program Memory
Identifies the memory type on this silicon.
Please refer to the data sheet for the device specific
value.
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Register IDPROG
This register contains information about the flash programming voltage.
IDPROG
Programming Voltage Id. Register
ESFR (F078H/3CH)
15
14
13
12
11
10
9
8
7
6
Reset Value: 1313H
5
4
3
PROGVPP
PROGVDD
r
r
2
1
0
Field
Bits
Type
Description
PROGVDD
[7:0]
r
Programming VDD Voltage
The voltage of the standard power supply required to
program or erase (if applicable) the on-chip program
memory.
Please refer to the data sheet for the device specific
value.
PROGVPP
[15:8]
r
Programming VPP Voltage
The voltage of the special programming power
supply (if existent) required to program or erase (if
applicable) the on-chip program memory.
Please refer to the data sheet for the device specific
value.
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6.15.3
Marker Memory
6.15.3.1 Marker Memory Registers
The marker memory consists of following SFRs located in the DMP_M for free usage of
the user software.
MKMEM0
Marker Memory 0 Register
MKMEM1
Marker Memory 1 Register
15
14
13
12
11
10
SFR (FED0H/68H)
Reset Value: 0000H
SFR (FED2H/69H)
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
MARKER
rw
Field
Bits
Type
Description
MARKER
[15:0]
rw
Marker Content
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6.16
SCU Register Addresses
The SCU registers are within the (E)SFR space of the XC2700. Therefore, their specified
addresses equal an offset from zero.
Table 6-18
Registers Address Space
Module
Base Address
End Address
SCU
00 0000H
00 FFFEH
Note
SCU Register Overview
Table 6-19
Register Overview of SCU
Protection1) Reset 2)
Short Name
Register Long Name
Offset
Addr.
WUOSCCON
Wake-up OSC Control
Register
F1AEH Sec
Power-on
Reset
HPOSCCON
High Precision Oscillator
Configuration Register
F1B4H
Sec
Power-on
Reset
PLLOSCCON
PLL Control Register
F1B6H
Sec
Power-on
Reset
PLLSTAT
PLL Status Register
F0BCH -
STATCLR1
PLL Status Clear 1
Register
F0E2H
Sec
Power-on
Reset
PLLCON0
PLL Configuration 0
Register
F1B8H
Sec
Power-on
Reset
PLLCON1
PLL Configuration 1
Register
F1BAH Sec
Power-on
Reset
PLLCON2
PLL Configuration 2
Register
F1BCH Sec
Power-on
Reset
PLLCON3
PLL Configuration 3
Register
F1BEH Sec
Power-on
Reset
SYSCON0
System Configuration 0
Register
FF4AH
Sec
Power-on
Reset
STATCLR0
Status Clear 0 Register
F0E0H
Sec
Power-on
Reset
RTCCLKCON
RTC Clock Control
Register
FF4EH
Sec
Power-on
Reset
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Power-on
Reset
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Table 6-19
Register Overview of SCU
Short Name
Register Long Name
Offset
Addr.
Protection1) Reset 2)
EXTCON
External Clock Control
Register
FF5EH
Sec
Power-on
Reset
WICR
Wake-up Interval Count
Register
F0B0H
Sec
Power-on
Reset
WUCR
Wake-up Control Register
F1B0H
Sec
Power-on
Reset
RSTSTAT0
Reset Status 0 Register
F0B2H
-
Power-on
Reset
RSTSTAT1
Reset Status 1 Register
F0B4H
-
Power-on
Reset
RSTSTAT2
Reset Status 2 Register
F0B6H
-
Power-on
Reset
RSTCON0
Reset Configuration 0
Register
F0B8H
Sec
Power-on
Reset
RSTCON1
Reset Configuration 1
Register
F0BAH Sec
Power-on
Reset
RSTCNTCON
Reset Counter
Configuration Register
F1B2H
Sec
Power-on
Reset
SWRSTCON
SW Reset Control Register F0AEH Sec
Power-on
Reset
ESREXCON1
ESR 1 External Control
Register
FF32H
Sec
Power-on
Reset
ESREXCON2
ESR 2 External Control
Register
FF34H
Sec
Power-on
Reset
ESRCFG0
ESR 0 Configuration
Register
F100H
Sec
Power-on
Reset
ESRCFG1
ESR 1 Configuration
Register
F102H
Sec
Power-on
Reset
ESRCFG2
ESR 2 Configuration
Register
F104H
Sec
Power-on
Reset
ESRDAT
ESR Data Register
F106H
-
Power-on
Reset
SWDCON0
SWD Control 0 Register
F080H
Sec
Power-on
Reset
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System Control Unit (SCU)
Table 6-19
Register Overview of SCU
Short Name
Register Long Name
Offset
Addr.
Protection1) Reset 2)
SWDCON1
SWD Control 1 Register
F082H
Sec
Power-on
Reset
PVC1CON0
PVC_1 Control for Step 0
Register
F014H
Sec
Power-on
Reset
PVCMCON0
PVC_M Control for Step 0
Register
F1E4H
Sec
Power-on
Reset
EVR1CON0
EVR_1 Control 0 Register
F088H
Sec
Power-on
Reset
EVR1SET15VHP
EVR_1 Setting for 1.5V HP F09EH
Register
Sec
Power-on
Reset
EVRMCON0
EVR_M Control 0 Register F084H
Sec
Power-on
Reset
EVRMCON1
EVR_M Control 1 Register F086H
Sec
Power-on
Reset
EVRMSET15VHP
EVR_M Setting for 1.5V HP F096H
Register
Sec
Power-on
Reset
GSCSWREQ
GSC SW Request Register FF14H
Sec
Application
Reset
GSCEN
GSC Enable Register
FF16H
Sec
Application
Reset
GSCSTAT
GSC Status Register
FF18H
-
Application
Reset
STSTAT
Start-up Status Register
F1E0H
-
Application
Reset
EXISEL
External Interrupt Input
Select Register
F1A0H
Sec
Application
Reset
EXICON0
External Interrupt Input
Trigger Control 0 Register
F030H
Sec
Application
Reset
EXICON1
External Interrupt Input
Trigger Control 1 Register
F032H
Sec
Application
Reset
EXICON2
External Interrupt Input
Trigger Control 2 Register
F034H
Sec
Application
Reset
EXICON3
External Interrupt Input
Trigger Control 3 Register
F036H
Sec
Application
Reset
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System Control Unit (SCU)
Table 6-19
Register Overview of SCU
Short Name
Register Long Name
Offset
Addr.
Protection1) Reset 2)
EXOCON0
External Output Trigger
Control 0 Register
FE30H
Sec
Application
Reset
EXOCON1
External Output Trigger
Control 1 Register
FE32H
Sec
Application
Reset
EXOCON2
External Output Trigger
Control 2 Register
FE34H
Sec
Application
Reset
EXOCON3
External Output Trigger
Control 3 Register
FE36H
Sec
Application
Reset
INTSTAT
Interrupt Status Register
FF00H
-
Application
Reset
INTCLR
Interrupt Clear Register
FE82H
Sec
Application
Reset
INTSET
Interrupt Set Register
FE80H
Sec
Application
Reset
INTDIS
Interrupt Disable Register
FE84H
Sec
Application
Reset
INTNP0
Interrupt Node Pointer 0
Register
FE86H
Sec
Application
Reset
INTNP1
Interrupt Node Pointer 1
Register
FE88H
Sec
Application
Reset
DMPMIT
DMP_M Interrupt and Trap FE96H
Trigger Register
-
Power-on
Reset
DMPMITCLR
DMP_M Interrupt and Trap FE98H
Clear Register
Sec
Power-on
Reset
ISSR
Interrupt Source Select
Register
FF2EH
Sec
Application
Reset
TCCR
Temperature
Compensation Control
Register
F1ACH Sec
Application
Reset
TCLR
Temperature
Compensation Level
Register
F0ACH Sec
Application
Reset
WDTREL
WDT Reload Register
F0C8H
Application
Reset
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Table 6-19
Register Overview of SCU
Short Name
Register Long Name
Offset
Addr.
Protection1) Reset 2)
WDTCS
WDT Control and Status
Register
F0C6H
Sec
Application
Reset
WDTTIM
WDT Timer Register
F0CAH Sec
Application
Reset
TRAPSTAT
Trap Status Register
FF02H
TRAPCLR
Trap Clear Register
FE8EH Sec
Power-on
Reset
TRAPSET
Trap Set Register
FE8CH Sec
Power-on
Reset
TRAPDIS
Trap Disable Register
FE90H
Sec
Power-on
Reset
TRAPNP
Trap Node Pointer Register FE92H
Sec
Power-on
Reset
PECON
Parity Error Control
Register
F0C4H
Sec
Application
Reset
PMTPR
Parity Memory Test Pattern F0E4H
Register
Sec
Application
Reset
PMTSR
Parity Memory Test Select
Register
F0E6H
Sec
Application
Reset
SLC
Security Level Command
Register
F0C0H
-
Application
Reset
SLS
Security Level Status
Register
F0C2H
-
Application
Reset
SYSCON1
System Control 1 Register
FF4CH Sec
IDMANUF
Manufacturer Identification F07EH
Register
-
Power-on
Reset
IDCHIP
Chip Identification Register F07CH
-
Power-on
Reset
IDMEM
Program Memory
Identification Register
F07AH
-
Power-on
Reset
IDPROG
Programming Voltage
Identification Register
F078H
-
Power-on
Reset
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-
Power-on
Reset
Application
Reset
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Table 6-19
Register Overview of SCU
Offset
Addr.
Protection1) Reset 2)
Short Name
Register Long Name
MKMEM0
Marker Memory 0 Register FED0H Sec
Power-on
Reset
MKMEM1
Marker Memory 1 Register FED2H Sec
Power-on
Reset
1)
Register write protection mechanism: “Sec” = register security mechanism, “-” = always accessible (no
protection), otherwise no access is possible.
2)
Reset types are defined in Chapter 6.3.1.2.
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6.17
Implementation
This section shows the connections of the module to the system.
6.17.1
Clock Generation Unit
The following table shows the input connection of the Clock Genation Unit.
Table 6-20
CGU Input Connection
Input
Connected to
XTAL 1
XTAL 1
XTAL 2
XTAL 2
CLKIN1
Port 2.9
CLKIN2
Port 4.4
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Parallel Ports
7
Parallel Ports
The XC2700 provides a set of General Purpose Input/Output (GPIO) ports that can be
controlled by software and by the on-chip peripheral units:
Table 7-1
Ports of the XC2700
Group
Width
I/O
Connected Modules
P0
8
I/O
EBC (A7...A0), CCU6, USIC, CAN
P1
8
I/O
EBC (A15...A8), CCU6
P2
13
I/O
EBC (READY, BHE, A23...A16, AD15...AD13, D15...D13),
CAN, CCU2, GPT12E, USIC, JTAG
P3
8
I/O
EBC arbitration (BREQ, HLDA, HOLD), CAN, USIC
P4
8
I/O
EBC (CS4...CS0), CCU2, CAN, GPT12E
P5
16
I
Analog Inputs, CCU6, JTAG, GPT12E, CAN
P6
4
I/O
ADC, GPT12E
P7
5
I/O
P7.0 J-LINK, CAN, GPT12E, SCU, JTAG, CCU6, ADC
P8
7
I/O
CCU6, JTAG
P9
8
I/O
CCU6, JTAG, CAN
P10
16
I/O
EBC(ALE, RD, WR, AD12...AD0, D12...D0), CCU6, USIC,
JTAG, CAN
P11
6
I/O
CCU6
P15
8
I
Analog Inputs, GPT12E, CCU6
Note: The availability of ports and port pins depends on the selected device type.
This chapter describes the maximum set of ports.
User’s Manual
Parallel Ports, V1.6D6
7-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.1
General Description
This chapter describes the architecture of the digital control circuit for a single port pin.
7.1.1
Basic Port Operation
There are three types of digital control circuits: with/without hardware override for digital
GPIOs, and for one for analog inputs. Each port pin contains one of them.
POCON.PPS
PWS
A
N
D
SCU_PERCFG.PGRx
Pn_OUT
Pn_IN
control
4
2
2
2
OD, DIR
ALTSEL0,1
Pn_OMR
pull
devices
1
1
FF
ALTIN
Alternate Data signals or other control
lines from Peripherals or SCU
control
4
ENABQ
Access to port registers
by PD Bus
Pn_IOCR
O
R
X
O
R
0
1
Input
stage
INV
ALT1
1
ALT2
1
ALT3
1
DQ1
ENDQ1
TC[1:0]
PD[2:0]
output
stage
pad
pin
1
1
2
3
Standard_port_structure_4.vsd
Figure 7-1
Structure of the Ports without Hardware Override Functionality
Note: INV signal is derived from Pn_IOCR.PC[3:2].
User’s Manual
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Parallel Ports
POCON.PPS
PWS
A
N
D
O
R
SCU_PERCFG.PGRx
HW_DIR
Alternate Data signals or other
control lines from Peripherals
3
Pn_IN
1
1
FF
ALTIN
X
O
R
control
4
2 2
2
ALTSEL0,1
Pn_OMR
Pn_OUT
control
pull
devices
OD, DIR
4
ENABQ
Access to port registers
by PD Bus
Pn_IOCR
0
1
2
input
stage
HW_EN
msb
INV*
ALT1
1
ALT2
1
ALT3
1
HW_OUT
DQ1
ENDQ1
TC[1:0]
PD[2:0]
output
stage
pad
pin
1
1
1
2
3
Standard_EBCport_structure_5.vsd
Figure 7-2
Structure of the Ports with Hardware Override Functionality
Note: If HW_EN is activated, INV* signal is always zero.
Note: When HW_EN is disabled, the respective ports go to Power Save Mode as all
other ports. When HW_EN is active, then the user should set the
POCON.PPSx=0.
User’s Manual
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7-3
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System Units (Vol. 1 of 2)
Access to port registers
by PD Bus
Parallel Ports
ENABQ
Pn_DIDIS
Pn_IN
Input
stage
Analog Input
pad
pin
Analog_port_digital_structure_2.vsd
Figure 7-3
Structure of Port 5 and Port 15
Note: There is always a standard digital input connected in parallel to each analog input.
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Parallel Ports
7.1.2
Input Stage Control
An input stage consists of a Schmitt trigger, which can be enabled or disabled via
software, and an input multiplexer that by default selects the output of the input
Schmitt trigger.
A disabled input driver drives high logical level. During and after reset, all input stages
are enabled by default.
7.1.3
Output Driver Control
An output stage consists of an output driver, output multiplexer, and register bit fields for
their control.
7.1.3.1
Active Mode Behavior
Each output driver can be configured in a push-pull or an open-drain mode, or it can be
deactivated (three-stated). An output multiplexer in front of the output driver selects the
signal source, choosing either the appropriate bit of the Pn_OUT register, or one of
maximum three lines coming from a peripheral unit, see Figure 7-1. The selection is
done via the Pn_IOCR register. Software can set or clear the bit Pn_OUT.Px, which
drives the port pin in case it is selected by the output multiplexer.
An output driver with hardware override can select an additional output signal coming
from a peripheral. While the hardware override is activated, this signal has higher priority
than all other output signals and can not be deselected by the port. In this case, the
peripheral controls the direction of the pin.
7.1.3.2
Power Saving Mode Behavior
In Power Saving Mode (core and IO supply voltages available), the behavior of a pin
depends on the setting of the POCONx.PPSx bit. Basically, groups of four pins within a
port can be configured to react to Power Save Mode Request or to ignore it. In case a
pin group is configured to react to a Power Save Mode Request, each pin within a group
reacts according to its own configuration according to the Table 7-4.
7.1.3.3
Reset Behavior
During reset, all output stages of GPIO pins go to tri-state mode without any pull-up or
pull-down device.
7.1.3.4
Power-fail Behavior
When the core supply fails while the pad supply remains stable, the output stages go into
tri-state mode.
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Parallel Ports
7.2
Port Register Description
7.2.1
Pad Driver Control
The pad structure used in this device offers the possibility to select the output driver
strength and the slew rate. These selections are independent from the output port
functionality, such as open-drain, push/pull or input only.
In order to minimize EMI problems, the driver strength can be adapted to the application
requirements by bit fields PDMx. The selection is done in groups of four pins.
The Port Output Control registers POCON provide the corresponding control bits. A
4-bit control field configures the driver strength and the edge shape. Word ports
consume four control nibbles each, byte ports consume two control nibbles each, where
each control nibble controls 4 pins of the respective port.
Note: P2_POCON register in the XC2700 contains an exception regarding the additional
strong output driver connected in parallel to the standard output driver of the P2.8
pin. See port 2 section.
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Parallel Ports
Px_POCON (x=0-4)
Port x Output Control Register XSFR (E8A0H+2*x)
Px_POCON (x=6-11)
Port x Output Control Register XSFR (E8A0H+2*x)
15
14
13
12
11
10
9
8
7
Reset Value: 0000H
Reset Value: 0000H
6
5
4
3
2
1
PPS
3
PDM3
PPS
2
PDM2
PPS
1
PDM1
PPS
0
PDM0
rw
rwr
rw
rw
rw
rw
rw
rw
0
Field
Bit
Type Description
PDM0,
PDM1,
PDM2,
PDM3
[2:0],
[6:4],
[10:8],
[14:12]
rw
Port Driver Mode x
Code Driver strength 1)
000 Strong driver
001 Strong driver
010 Strong driver
011 Weak driver
100 Medium driver
101 Medium driver
110 Medium driver
111 Weak driver
PPS0,
PPS1,
PPS2,
PPS3
3,
7,
11,
15
rw
Pin Power Save
0
Pin behaves like in the Active Mode. Power
Save Management is ignored.
1
Behavior in the Power Save Mode described in
the Table 7-4.
Edge Shape2)
Sharp edge mode
Medium edge mode
Soft edge mode
1)
Defines the current the respective driver can deliver to the external circuitry.
2)
Defines the switching characteristics to the respective new output level. This also influences the peak currents
through the driver when producing an edge, i.e. when changing the output level.
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Parallel Ports
Mapping of the POCON Registers to Pins and Ports
The table below lists the defined POCON registers and the allocation of control bit fields
and port pins.
Table 7-2
Port Output Control Register Allocation
Controlled Pins (by Px_POCON.[y:z])1)
Control
Register
[15:12]
[11:8]
[7:4]
[3:0]
P0_POCON
---
---
P0.[7:4]
P0.[3:0]
8
P1_POCON
---
---
P1.[7:4]
P1.[3:0]
8
P2_POCON
CLOCKOUT P2.[11:8] +
driver2) at
P2.12
P2.8
P2.[7:4]
P2.[3:0]
13
P3_POCON
---
---
P3.[7:4]
P3.[3:0]
8
P4_POCON
---
---
P4.[7:4]
P4.[3:0]
8
P6_POCON
---
---
---
P6.[3:0]
4
P7_POCON
---
---
P7.4
P7.[3:0]
5
P8_POCON
---
---
P8.[6:4]
P8.[3:0]
7
P9_POCON
---
---
P9.[7:4]
P9.[3:0]
8
P10_POCON P10.[15:12]
P10.[11:8]
P10.[7:4]
P10.[3:0]
16
P11_POCON ---
---
P11.[5:4]
P11.[3:0]
6
Port Width
1)
x denotes the port number, while [y:z] represents the bit field range.
2)
The high-speed clock driver at P2.8 is enabled instead of the standard driver, while P2_POCON.PDM3 = xx1B.
The standard driver for P2.8 is added to the next lower pin group and is controlled via P2_POCON.PDM2. Bit
P2_POCON.PPS3 has no function. See also Section 7.3.3.
Note: When assigning functional signals to port pins, please consider the fact that the
driver strength is selected for pin groups. Assign functions with similar
requirements to pins within the same POCON control group.
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7.2.2
Port Output Register
The port output register defines the values of the output pins if the pin is used as GPIO
output.
Pn_OUT (n=0-4)
Port n Output Register
Pn_OUT (n=6-11)
Port n Output Register
15
14
6
5
4
3
2
1
0
P15 P14 P13 P12 P11 P10
P9
P8
P7
P6
P5
P4
P3
P2
P1
P0
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
10
Reset Value: 0000H
7
rwh
11
SFR (FFA2H+2*n)
8
rwh
12
Reset Value: 0000H
9
rwh
13
SFR (FFA2H+2*n)
rwh
Field
Bits
Type
Description
Px
(x = 0-15)
x
rwh
Port Output Bit x
This bit defines the level at the output pin of port Pn,
pin x if the output is selected as GPIO output.
0
The output level of Pn.x is 0.
1
The output level of Pn.x is 1.
User’s Manual
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Parallel Ports
7.2.3
Port Output Modification Register
The port output modification register contains the bits to individually set, clear, or toggle
the value of the port n output register.
P2_OMRH
Port 2 Output Modification Register HighXSFR (E9CAH)
P10_OMRH
Port 10 Output Modification Register HighXSFR (E9EAH)
Reset Value: XXXXH
Reset Value: XXXXH
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PC
15
PC
14
PC
13
PC
12
PC
11
PC
10
PC
9
PC
8
PS
15
PS
14
PS
13
PS
12
PS
11
PS
10
PS
9
PS
8
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
Field
Bits
Type Description
PSx
(x = 8-15)
x-8
w
Port Set Bit x
Setting this bit sets or toggles the corresponding bit in
the port output register Pn_OUT (see Table 7-3).
On a read access, this bit returns X.
PCx
(x = 8-15)
x
w
Port Clear Bit x
Setting this bit clears or toggles the corresponding bit
in the port output register Pn_OUT. (see Table 7-3).
On a read access, this bit returns X.
Pn_OMRL (n=0-4)
Port n Output Modification Register LowXSFR (E9C0H+4*n) Reset Value: XXXXH
Pn_OMRL (n=6-11)
Port n Output Modification Register LowXSFR (E9C0H+4*n) Reset Value: XXXXH
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PC
7
PC
6
PC
5
PC
4
PC
3
PC
2
PC
1
PC
0
PS
7
PS
6
PS
5
PS
4
PS
3
PS
2
PS
1
PS
0
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
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System Units (Vol. 1 of 2)
Parallel Ports
Field
Bits
Type Description
PSx
(x = 0-7)
x
w
Port Set Bit x
Setting this bit sets or toggles the corresponding bit in
the port output register Pn_OUT (see Table 7-3).
On a read access, this bit returns X.
PCx
(x = 0-7)
x+8
w
Port Clear Bit x
Setting this bit clears or toggles the corresponding bit
in the port output register Pn_OUT. (see Table 7-3).
On a read access, this bit returns X.
Function of the PCx and PSx bit fields
Table 7-3
Function of the Bits PCx and PSx
PCx
PSx
Function
0 or no write access
0 or no write access
Bit Pn_OUT.Px is not changed.
0 or no write access
1
Bit Pn_OUT.Px is set.
1
0 or no write access
Bit Pn_OUT.Px is cleared.
1
1
Bit Pn_OUT.Px is toggled.
Note: If a bit position is not written (one out of two bytes not targeted by a byte write), the
corresponding value is considered as 0. Toggling a bit requires one 16-bit write.
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Parallel Ports
7.2.4
Port Input Register
The port input register contains the values currently read at the input pins, also if a port
line is assigned as output.
Pn_IN (n=0-11)
Port n Input Register
P15_IN
Port 15 Input Register
15
14
13
12
11
10
P15 P14 P13 P12 P11 P10
rh
1)
rh
rh
rh
rh
rh
SFR (FF80H+2*n)
Reset Value: 0000H1)
SFR (FF9EH)
Reset Value: 0000H1)
9
8
7
6
5
4
3
2
1
0
P9
P8
P7
P6
P5
P4
P3
P2
P1
P0
rh
rh
rh
rh
rh
rh
rh
rh
rh
rh
Px bits for non implemented I/O lines are always read as 0.
Field
Bits
Type Description
Px
(x = 0-15)
x
rh
User’s Manual
Parallel Ports, V1.6D6
Port Input Bit x
This bit indicates the level at the input pin of port Pn,
pin x.
0
The input level of Pn.x is 0.
1
The input level of Pn.x is 1.
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7.2.5
Port Input/Output Control Registers
The port input/output control registers contain the bit fields to select the digital output and
input driver characteristics, such as pull-up/down devices, port direction (input/output),
open-drain and alternate output selections. The coding of the options is shown in
Table 7-4.
Depending on the port functionality not all of the input/output control registers may be
implemented. The structure with one control bit field for each port pin located in different
register offers the possibility to configure port pin functionality of a single pin without
accessing some other PCx in the same register by word-oriented writes.
P0_IOCRx (x=00-07)
Port 0 Input/Output Control Register x XSFR (E800H+2*x)
P1_IOCRx (x=00-07)
Port 1 Input/Output Control Register x XSFR (E820H+2*x)
P2_IOCRx (x=00-12)
Port 2 Input/Output Control Register x XSFR (E840H+2*x)
P3_IOCRx (x=00-07)
Port 3 Input/Output Control Register x XSFR (E860H+2*x)
P4_IOCRx (x=00-07)
Port 4 Input/Output Control Register x XSFR (E880H+2*x)
P6_IOCRx (x=00-03)
Port 6 Input/Output Control Register x XSFR (E8C0H+2*x)
P7_IOCRx (x=00-04)
Port 7 Input/Output Control Register x XSFR (E8E0H+2*x)
P8_IOCRx (x=00-06)
Port 8 Input/Output Control Register x XSFR (E900H+2*x)
P9_IOCRx (x=00-07)
Port 9 Input/Output Control Register x XSFR (E920H+2*x)
P10_IOCRx (x=00-15)
Port 10 Input/Output Control Register x XSFR (E940H+2*x)
P11_IOCRx (x=00-05)
Port 11 Input/Output Control Register x XSFR (E960H+2*x)
15
14
13
12
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Parallel Ports, V1.6D6
11
10
9
8
7
6
5
4
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
Reset Value: 0000H
3
2
1
0
PC
0
r
rw
r
7-13
0
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Parallel Ports
Field
Bits
Type Description
PC
[7:4]
rw
Port Input/Output Control Bit
see Table 7-4
0
[3:0],
[15:8]
r
reserved
Coding of the PC bit field
The coding of the GPIO port behavior is done by the bit fields in the port control registers
Pn_IOCRx. There’s a control bit field PC for each port pin. The bit fields PC are located
in separate control registers in order to allow modifying a port pin (without influencing the
others) with simple move operations.
Note: When the pin direction is switched to output and the mode is test mode, the output
characteristic must be push-pull only.
Table 7-4
PC Coding
PC[3:0]
I/O
Selected Pull-up/down /
Selected Output Function
Behavior in Power Saving
Mode1)
0000B
Direct
Input
No pull device connected
Input value = Pn_OUT.x; no pull
0001B
Pull-down device connected Input value = 0; pull-down
0010B
Pull-up device connected
Input value = 1; pull-up
0011B
No pull device connected.
Bit Pn_OUT.x reflects the
current input value
Input value = Pn_OUT.x; no pull
Pn_OUT.x contains the input value
before entering in power save
mode = freeze of input value
0100B
0101B
Inverted No pull device connected
Input value = Pn_OUT; no pull
Input
Pull-down device connected Input value = 1; pull-down
0110B
Pull-up device connected
Input value = 0; pull-up
0111B
No pull device connected
Bit Pn_OUT.x reflects the
current input value
Input value = Pn_OUT; no pull
Pn_OUT.x contains the input value
before entering in power save
mode = freeze of input value2)
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Parallel Ports
Table 7-4
PC Coding
PC[3:0]
I/O
Selected Pull-up/down /
Selected Output Function
Behavior in Power Saving
Mode1)
1000B
Output
(Direct
input)
Pushpull
General purpose Output
Output driver off.
Input Schmitt trigger off.
Pn_OUT delivered to the internal
logic; no pull
1001B
1010B
1011B
1100B
1101B
1110B
1111B
Output
(Direct
input)
Opendrain
Output function ALT1
Output function ALT2
Output function ALT3
General purpose Output
Output function ALT1
Output function ALT2
Output function ALT3
1)
In power saving mode, the input Schmitt trigger is always switched off. A defined input value is driven to the
internal circuitry instead of the level detected at the input pin.
2)
If the IOCR setting is “inverted input”, then an inverted signal Pn_OUT is driven internally. The Pn_OUT
register itself always contains the real, non-inverted input value of the pin. See Figure 7-1 and Figure 7-2.
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7.2.6
Port Digital Input Disable Register
Ports 5 and 15 have, additionally to the analog input functionality, digital input
functionality too. In order to save switching of the internal Schmitt triggers of the digital
inputs, they can be disabled by means of Px_DIDIS Register. P5_DIDIS is a 16-bit
register, and P15_DIDIS is an 8-bit register.
P5_DIDIS
Port 5 Digital Input Disable RegisterSFR (FE8AH)
P15_DIDIS
Port 15 Digital Input Disable RegisterSFR (FE9EH)
15
14
13
12
11
10
P15 P14 P13 P12 P11 P10
rw
rw
rw
rw
rw
rw
Reset Value: 0000H
Reset Value: 0000H
9
8
7
6
5
4
3
2
1
0
P9
P8
P7
P6
P5
P4
P3
P2
P1
P0
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Field
Bit
Type
Description
Py
(y = 0-15)
y
rw
Port 5 Bit y Digital Input Control
0
Digital input stage (schmitt trigger) is
enabled.
1
Digital input stage (schmitt trigger) is
disabled, necessary if pin is used as
analog input.
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7.3
Port Description
The bit positions in the port registers always start right-aligned. For example, a port
comprising only 8 pins only uses the bit positions [7:0] of the corresponding register. The
remaining bit positions are filled with 0 (r).
The pad driver mode registers may be different for each port. As a result, they are
described independently for each port in the corresponding chapter.
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7.3.1
Port 0
Port 0 is an 8-bit GPIO port. The registers of Port 0 are shown in Figure 7-4.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P0_IOCR00
:
P0_IOCR07
P0_OMRL
Data
Registers
P0_OUT
P0_IN
P0_POCON
Port0_Regs.vsd
Figure 7-4
Port 0 Register Overview
Table 7-5
Port 0 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P0_OUT
Port 0 Output Register
FFA2H
0000H
P0_IN
Port 0 Input Register
FF80H
0000H
P0_OMRL
Port 0 Output Modification Register Low
E9C0H
XXXXH
P0_POCON
Port 0 Output Control Register
E8A0H
0000H
P0_IOCR00
Port 0 Input/Output Control Register 0
E800H
0000H
P0_IOCR01
Port 0 Input/Output Control Register 1
E802H
0000H
P0_IOCR02
Port 0 Input/Output Control Register 2
E804H
0000H
P0_IOCR03
Port 0 Input/Output Control Register 3
E806H
0000H
P0_IOCR04
Port 0 Input/Output Control Register 4
E808H
0000H
P0_IOCR05
Port 0 Input/Output Control Register 5
E80AH
0000H
P0_IOCR06
Port 0 Input/Output Control Register 6
E80CH
0000H
P0_IOCR07
Port 0 Input/Output Control Register 7
E80EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-18
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.2
Port 1
Port 1 is an 8-bit GPIO port. Theregisters of Port 1 are shown in Figure 7-5.
Control
Registers
Modification
Registers
P1_IOCR00
:
P1_IOCR07
P1_OMRL
Data
Registers
P1_OUT
P1_IN
P1_POCON
Port1_Regs.vsd
Figure 7-5
Port 1 Register Overview
For this port, all pins can be read as GPIO, from the Port Input Register.
Table 7-6
Port 1 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P1_OUT
Port 1 Output Register
FFA4H
0000H
P1_IN
Port 1 Input Register
FF82H
0000H
P1_OMRL
Port 1 Output Modification Register Low
E9C4H
XXXXH
P1_POCON
Port 1 Output Control Register
E8A2H
0000H
P1_IOCR00
Port 1 Input/Output Control Register 0
E820H
0000H
P1_IOCR01
Port 1 Input/Output Control Register 1
E822H
0000H
P1_IOCR02
Port 1 Input/Output Control Register 2
E824H
0000H
P1_IOCR03
Port 1 Input/Output Control Register 3
E826H
0000H
P1_IOCR04
Port 1 Input/Output Control Register 4
E828H
0000H
P1_IOCR05
Port 1 Input/Output Control Register 5
E82AH
0000H
P1_IOCR06
Port 1 Input/Output Control Register 6
E82CH
0000H
P1_IOCR07
Port 1 Input/Output Control Register 7
E82EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-19
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.3
Port 2
Port 2 is an 13-bit GPIO port. The registers of Port 2 are shown in Figure 7-6.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P2_IOCR00
:
P2_IOCR12
Data
Registers
P2_OMRL
P2_OUT
P2_OMRH
P2_IN
P2_POCON
Port2_Regs.vsd
Figure 7-6
Port 2 Register Overview
Table 7-7
Port 2 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P2_OUT
Port 2 Output Register
FFA6H
0000H
P2_IN
Port 2 Input Register
FF84H
0000H
P2_OMRL
Port 2 Output Modification Register Low
E9C8H
XXXXH
P2_OMRH
Port 2 Output Modification Register High
E9CAH
XXXXH
P2_POCON
Port 2 Output Control Register
E8A4H
0000H
P2_IOCR00
Port 2 Input/Output Control Register 0
E840H
0000H
P2_IOCR01
Port 2 Input/Output Control Register 1
E842H
0000H
P2_IOCR02
Port 2 Input/Output Control Register 2
E844H
0000H
P2_IOCR03
Port 2 Input/Output Control Register 3
E846H
0000H
P2_IOCR04
Port 2 Input/Output Control Register 4
E848H
0000H
P2_IOCR05
Port 2 Input/Output Control Register 5
E84AH
0000H
P2_IOCR06
Port 2 Input/Output Control Register 6
E84CH
0000H
P2_IOCR07
Port 2 Input/Output Control Register 7
E84EH
0000H
P2_IOCR08
Port 2 Input/Output Control Register 8
E850H
0000H
P2_IOCR09
Port 2 Input/Output Control Register 9
E852H
0000H
User’s Manual
Parallel Ports, V1.6D6
7-20
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-7
Port 2 Registers (cont’d)
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P2_IOCR10
Port 2 Input/Output Control Register 10
E854H
0000H
P2_IOCR11
Port 2 Input/Output Control Register 11
E856H
0000H
P2_IOCR12
Port 2 Input/Output Control Register 12
E858H
0000H
The CLKOUT Pad P2.8
In order to drive high frequency clock signals, a strong driver is connected parallel to the
normal output driver of pad P2.8. This clock driver only operates in strong driver sharp
edge mode. It is enabled instead of the standard driver, while bitfield P2_POCON.PDM3
= xx1B. Bit P2_POCON.PPS3 has no function.
The standard driver of pin P2.8 is controlled by bits P2_POCON.PDM2 and PPS2, along
with pins P2.7 … P2.4. The standard driver is the default selection.
Register P2_IOCR08 controls the driver that is currently active.
User’s Manual
Parallel Ports, V1.6D6
7-21
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.4
Port 3
Port 3 is an 8-bit GPIO port. The registers of Port 3 are shown in Figure 7-7.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P3_IOCR00
:
P3_IOCR07
P3_OMRL
Data
Registers
P3_OUT
P3_IN
P3_POCON
Port3_Regs.vsd
Figure 7-7
Port 3 Register Overview
Table 7-8
Port 3 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P3_OUT
Port 3 Output Register
FFA8H
0000H
P3_IN
Port 3 Input Register
FF86H
0000H
P3_OMRL
Port 3 Output Modification Register Low
E9CCH
XXXXH
P3_POCON
Port 3 Output Control Register
E8A6H
0000H
P3_IOCR00
Port 3 Input/Output Control Register 0
E860H
0000H
P3_IOCR01
Port 3 Input/Output Control Register 1
E862H
0000H
P3_IOCR02
Port 3 Input/Output Control Register 2
E864H
0000H
P3_IOCR03
Port 3 Input/Output Control Register 3
E866H
0000H
P3_IOCR04
Port 3 Input/Output Control Register 4
E868H
0000H
P3_IOCR05
Port 3 Input/Output Control Register 5
E86AH
0000H
P3_IOCR06
Port 3 Input/Output Control Register 6
E86CH
0000H
P3_IOCR07
Port 3 Input/Output Control Register 7
E86EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-22
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.5
Port 4
Port 4 is an 8-bit GPIO port. The registers of Port 4 are shown in Figure 7-8.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P4_IOCR00
:
P4_IOCR07
P4_OMRL
Data
Registers
P4_OUT
P4_IN
P4_POCON
Port4_Regs.vsd
Figure 7-8
Port 4 Register Overview
Table 7-9
Port 4 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P4_OUT
Port 4 Output Register
FFAAH
0000H
P4_IN
Port 4 Input Register
FF88H
0000H
P4_OMRL
Port 4 Output Modification Register Low
E9D0H
XXXXH
P4_POCON
Port 4 Output Control Register
E8A8H
0000H
P4_IOCR00
Port 4 Input/Output Control Register 0
E880H
0000H
P4_IOCR01
Port 4 Input/Output Control Register 1
E882H
0000H
P4_IOCR02
Port 4 Input/Output Control Register 2
E884H
0000H
P4_IOCR03
Port 4 Input/Output Control Register 3
E886H
0000H
P4_IOCR04
Port 4 Input/Output Control Register 4
E888H
0000H
P4_IOCR05
Port 4 Input/Output Control Register 5
E88AH
0000H
P4_IOCR06
Port 4 Input/Output Control Register 6
E88CH
0000H
P4_IOCR07
Port 4 Input/Output Control Register 7
E88EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-23
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.6
Port 5
Port 5 is an 16-bit analog or digital input port.
To use the Port 5 as an analog input, the Schmitt trigger in the input stage must be
disabled. This is achieved by setting the corresponding bit in the register P5_DIDIS.
Data
Registers
Control
Registers
P5_DIDIS
P5_IN
Port5_Regs.vsd
Figure 7-9
Port 5 Register Overview
Table 7-10
Port 5 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P5_IN
Port 5 Input Register
FF8AH
0000H
P5_DIDIS
Port 5 Digital Input Disable Register
FE8AH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-24
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.7
Port 6
Port 6 is an 4-bit GPIO port. The registers of Port 6 are shown in Figure 7-10.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P6_IOCR00
:
P6_IOCR03
P6_OMRL
Data
Registers
P6_OUT
P6_IN
P6_POCON
Port6_Regs.vsd
Figure 7-10 Port 6 Register Overview
Table 7-11
Port 6 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P6_OUT
Port 6 Output Register
FFAEH
0000H
P6_IN
Port 6 Input Register
FF8CH
0000H
P6_OMRL
Port 6 Output Modification Register Low
E9D8H
XXXXH
P6_POCON
Port 6 Output Control Register
E8ACH
0000H
P6_IOCR00
Port 6 Input/Output Control Register 0
E8C0H
0000H
P6_IOCR01
Port 6 Input/Output Control Register 1
E8C2H
0000H
P6_IOCR02
Port 6 Input/Output Control Register 2
E8C4H
0000H
P6_IOCR03
Port 6 Input/Output Control Register 4
E8C6H
0000H
User’s Manual
Parallel Ports, V1.6D6
7-25
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.8
Port 7
Port 7 is a 5-bit GPIO port. The port registers of Port 7 are shown in Figure 7-11.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P7_IOCR00
:
P7_IOCR04
P7_OMRL
Data
Registers
P7_OUT
P7_IN
P7_POCON
Port7_Regs.vsd
Figure 7-11 Port 7 Register Overview
Table 7-12
Port 7 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P7_OUT
Port 7 Output Register
FFB0H
0000H
P7_IN
Port 7 Input Register
FF8EH
0000H
P7_OMRL
Port 7 Output Modification Register Low
E9DCH
XXXXH
P7_POCON
Port 7 Output Control Register
E8AEH
0000H
P7_IOCR00
Port 7 Input/Output Control Register 0
E8E0H
0000H
P7_IOCR01
Port 7 Input/Output Control Register 1
E8E2H
0000H
P7_IOCR02
Port 7 Input/Output Control Register 2
E8E4H
0000H
P7_IOCR03
Port 7 Input/Output Control Register 3
E8E6H
0000H
P7_IOCR04
Port 7 Input/Output Control Register 4
E8E8H
0000H
User’s Manual
Parallel Ports, V1.6D6
7-26
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.9
Port 8
Port 8 is an 7-bit GPIO port. The registers of Port 8 are shown in Figure 7-12.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P8_IOCR00
:
P8_IOCR06
P8_OMRL
Data
Registers
P8_OUT
P8_IN
P8_POCON
Port8_Regs.vsd
Figure 7-12 Port 8 Register Overview
Table 7-13
Port 8 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P8_OUT
Port 8 Output Register
FFB2H
0000H
P8_IN
Port 8 Input Register
FF90H
0000H
P8_OMRL
Port 8 Output Modification Register Low
E9E0H
XXXXH
P8_POCON
Port 8 Output Control Register
E8B0H
0000H
P8_IOCR00
Port 8 Input/Output Control Register 0
E900H
0000H
P8_IOCR01
Port 8 Input/Output Control Register 1
E902H
0000H
P8_IOCR02
Port 8 Input/Output Control Register 2
E904H
0000H
P8_IOCR03
Port 8 Input/Output Control Register 3
E906H
0000H
P8_IOCR04
Port 8 Input/Output Control Register 4
E908H
0000H
P8_IOCR05
Port 8 Input/Output Control Register 5
E90AH
0000H
P8_IOCR06
Port 8 Input/Output Control Register 6
E90CH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-27
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.10
Port 9
Port 9 is an 8-bit GPIO port. The port registers of Port 9 are shown in Figure 7-13.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P9_IOCR00
:
P9_IOCR07
P9_OMRL
Data
Registers
P9_OUT
P9_IN
P9_POCON
Port9_Regs.vsd
Figure 7-13 Port 9 Register Overview
Table 7-14
Port 9 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P9_OUT
Port 9 Output Register
FFB4H
0000H
P9_IN
Port 9 Input Register
FF92H
0000H
P9_OMRL
Port 9 Output Modification Register Low
E9E4H
XXXXH
P9_POCON
Port 9 Output Control Register
E8B2H
0000H
P9_IOCR00
Port 9 Input/Output Control Register 0
E920H
0000H
P9_IOCR01
Port 9 Input/Output Control Register 1
E922H
0000H
P9_IOCR02
Port 9 Input/Output Control Register 2
E924H
0000H
P9_IOCR03
Port 9 Input/Output Control Register 3
E926H
0000H
P9_IOCR04
Port 9 Input/Output Control Register 4
E928H
0000H
P9_IOCR05
Port 9 Input/Output Control Register 5
E92AH
0000H
P9_IOCR06
Port 9 Input/Output Control Register 6
E92CH
0000H
P9_IOCR07
Port 9 Input/Output Control Register 7
E92EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-28
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.11
Port 10
Port 10 is a 16-bit GPIO port. The registers of Port 10 are shown in Figure 7-14.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
Data
Registers
P10_IOCR00
:
P10_IOCR15
P10_OMRL
P10_OUT
P10_OMRH
P10_IN
P10_POCON
Port10_Regs.vsd
Figure 7-14 Port 10 Register Overview
Table 7-15
Port 10 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P10_OUT
Port 10 Output Register
FFB6H
0000H
P10_IN
Port 10 Input Register
FF94H
0000H
P10_OMRL
Port 10 Output Modification Register Low
E9E8H
XXXXH
P10_OMRH
Port 10 Output Modification Register High
E9EAH
XXXXH
P10_POCON Port 10 Output Control Register
E8B4H
0000H
P10_IOCR00 Port 10 Input/Output Control Register 0
E940H
0000H
P10_IOCR01 Port 10 Input/Output Control Register 1
E942H
0000H
P10_IOCR02 Port 10 Input/Output Control Register 2
E944H
0000H
P10_IOCR03 Port 10 Input/Output Control Register 3
E946H
0000H
P10_IOCR04 Port 10 Input/Output Control Register 4
E948H
0000H
P10_IOCR05 Port 10 Input/Output Control Register 5
E94AH
0000H
P10_IOCR06 Port 10 Input/Output Control Register 6
E94CH
0000H
P10_IOCR07 Port 10 Input/Output Control Register 7
E94EH
0000H
P10_IOCR08 Port 10 Input/Output Control Register 8
E950H
0000H
P10_IOCR09 Port 10 Input/Output Control Register 9
E952H
0000H
User’s Manual
Parallel Ports, V1.6D6
7-29
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-15
Register
Short Name
Port 10 Registers (cont’d)
Register Long Name
Address
Offset
Reset
Value
P10_IOCR10 Port 10 Input/Output Control Register 10
E954H
0000H
P10_IOCR11 Port 10 Input/Output Control Register 11
E956H
0000H
P10_IOCR12 Port 10 Input/Output Control Register 12
E958H
0000H
P10_IOCR13 Port 10 Input/Output Control Register 13
E95AH
0000H
P10_IOCR14 Port 10 Input/Output Control Register 14
E95CH
0000H
P10_IOCR15 Port 10 Input/Output Control Register 15
E95EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-30
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.12
Port 11
Port 11 is an 6-bit GPIO port. The registers of Port 11 are shown in Figure 7-15.
For this port, all pins can be read as GPIO, from the Port Input Register.
Control
Registers
Modification
Registers
P11_IOCR00
:
P11_IOCR05
P11_OMRL
Data
Registers
P11_OUT
P11_IN
P11_POCON
Port11_Regs.vsd
Figure 7-15 Port 11 Register Overview
Table 7-16
Port 11 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P11_OUT
Port 11 Output Register
FFB8H
0000H
P11_IN
Port 11 Input Register
FF96H
0000H
P11_OMRL
Port 11 Output Modification Register Low
E9ECH
XXXXH
P11_POCON Port 11 Output Control Register
E8B6H
0000H
P11_IOCR00 Port 11 Input/Output Control Register 0
E960H
0000H
P11_IOCR01 Port 11 Input/Output Control Register 1
E962H
0000H
P11_IOCR02 Port 11 Input/Output Control Register 2
E964H
0000H
P11_IOCR03 Port 11 Input/Output Control Register 3
E966H
0000H
P11_IOCR04 Port 11 Input/Output Control Register 4
E968H
0000H
P11_IOCR05 Port 11 Input/Output Control Register 5
E96AH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-31
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.3.13
Port 15
Port 15 is an 8-bit analog or digital input port. To use the Port 15 as an analog input, the
Schmitt trigger in the input stage must be disabled. This is achieved by setting the
corresponding bit in the register P15_DIDIS.
Data
Registers
Control
Registers
P15_DIDIS
P15_IN
Port15_Regs.vsd
Figure 7-16 Port 15 Register Overview
Table 7-17
Port 15 Registers
Register
Short Name
Register Long Name
Address
Offset
Reset
Value
P15_IN
Port 15 Input Register
FF9EH
0000H
P15_DIDIS
Port 15 Digital Input Disable Register
FE9EH
0000H
User’s Manual
Parallel Ports, V1.6D6
7-32
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
7.4
Pin Description
Each port pin of the XC2700 can serve several functions of different modules. Also, most
functions are available on several port pins. This enables an application so select the
optimal connections for its specific circumstances.
A pin can output its own port output signal or one of up to three signals coming from the
peripherals. Its input signal is available in its own input register and at several
peripherals.
Note: Output signals are selected at the respective port pin, input signals are selected
at the respective peripheral.
Optionally a pin can be fully controlled by a peripheral, in case the peripheral is enabled
(for example, EBC).
Table 7-18 summarizes the various function of each pin of the XC2700.
Notes to Pin Definitions
1. Ctrl.: The output signal for a port pin is selected via bitfield PC in the associated
register Px_IOCRy. Output O0 is selected by setting the respective bitfield PC to
1x00B, output O1 is selected by 1x01B, etc.
Output signal OH is controlled by hardware.
2. Type: Indicates the employed pad type (St=standard pad, Sp=special pad,
DP=double pad, In=input pad, PS=power supply) and its power supply domain (A, B,
M, 1).
Table 7-18
Pin Definitions and Functions
Pin
Symbol
Ctrl.
Type Function
3
TESTM
I
In/B
4
P7.2
O0 / I St/B
5
Testmode Enable
Enables factory test modes, must be held HIGH for
normal operation (connect to VDDPB).
An internal pullup device will hold this pin high
when nothing is driving it.
Bit 2 of Port 7, General Purpose Input/Output
CCU62_CCP I
OS0A
St/B
CCU62 Position Input 0
TDI_C
I
St/B
JTAG Test Data Input
P8.4
O0 / I St/B
Bit 4 of Port 8, General Purpose Input/Output
CCU60_COU O1
T61
St/B
CCU60 Channel 1 Output
TMS_D
St/B
JTAG Test Mode Selection Input
User’s Manual
Parallel Ports, V1.6D6
I
7-33
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
Type Function
6
TRST
I
In/B
7
P8.3
O0 / I St/B
8
9
10
11
Test-System Reset Input
For normal system operation, pin TRST should be
held low. A high level at this pin at the rising edge
of PORST activates the XC2700’s debug system.
In this case, pin TRST must be driven low once to
reset the debug system.
An internal pulldown device will hold this pin low
when nothing is driving it.
Bit 3 of Port 8, General Purpose Input/Output
CCU60_COU O1
T60
St/B
CCU60 Channel 0 Output
TDI_D
I
St/B
JTAG Test Data Input
P7.0
O0 / I St/B
Bit 0 of Port 7, General Purpose Input/Output
T3OUT
O1
St/B
GPT1 Timer T3 Toggle Latch Output
T6OUT
O2
St/B
GPT2 Timer T6 Toggle Latch Output
TDO
OH
St/B
JTAG Test Data Output
ESR2_1
I
St/B
ESR2 Trigger Input 1
P7.3
O0 / I St/B
Bit 3 of Port 7, General Purpose Input/Output
U0C1_DOUT O2
St/B
USIC0 Channel 1 Shift Data Output
U0C0_DOUT O3
St/B
USIC0 Channel 0 Shift Data Output
CCU62_CCP I
OS1A
St/B
CCU62 Position Input 1
TMS_C
I
St/B
JTAG Test Mode Selection Input
U0C1_DX0F
I
St/B
USIC0 Channel 1 Shift Data Input
P8.2
O0 / I St/B
Bit 2 of Port 8, General Purpose Input/Output
CCU60_CC6
2
O1 / I St/B
CCU60 Channel 2 Input/Output
P7.1
O0 / I St/B
Bit 1 of Port 7, General Purpose Input/Output
EXTCLK
O1
St/B
Programmable Clock Signal Output
CCU62_CTR
APA
I
St/B
CCU62 Emergency Trap Input
BRKIN_C
I
St/B
OCDS Break Signal Input
User’s Manual
Parallel Ports, V1.6D6
7-34
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
12
P7.4
O0 / I St/B
13
14
16
17
18
Type Function
Bit 4 of Port 7, General Purpose Input/Output
U0C1_DOUT O2
St/B
USIC0 Channel 1 Shift Data Output
U0C1_SCLK
St/B
USIC0 Channel 1 Shift Clock Output
CCU62_CCP I
OS2A
St/B
CCU62 Position Input 2
TCK_C
I
St/B
JTAG Clock Input
U0C0_DX0D
I
St/B
USIC0 Channel 0 Shift Data Input
U0C1_DX1E
I
St/B
USIC0 Channel 1 Shift Clock Input
P8.1
O0 / I St/B
Bit 1 of Port 8, General Purpose Input/Output
CCU60_CC6
1
O1 / I St/B
CCU60 Channel 1 Input/Output
P8.0
O0 / I St/B
Bit 0 of Port 8, General Purpose Input/Output
CCU60_CC6
0
O1 / I St/B
CCU60 Channel 0 Input/Output
P6.0
O0 / I St/A
Bit 0 of Port 6, General Purpose Input/Output
EMUX0
O1
St/A
External Analog MUX Control Output 0 (ADC0)
BRKOUT
O3
St/A
OCDS Break Signal Output
ADCx_REQG I
TyC
St/A
External Request Gate Input for ADC0/1
U1C1_DX0E
I
St/A
USIC1 Channel 1 Shift Data Input
P6.1
O0 / I St/A
Bit 1 of Port 6, General Purpose Input/Output
EMUX1
O1
St/A
External Analog MUX Control Output 1 (ADC0)
T3OUT
O2
St/A
GPT1 Timer T3 Toggle Latch Output
U1C1_DOUT O3
St/A
USIC1 Channel 1 Shift Data Output
ADCx_REQT I
RyC
St/A
External Request Trigger Input for ADC0/1
O3
P6.2
O0 / I St/A
Bit 2 of Port 6, General Purpose Input/Output
EMUX2
O1
St/A
External Analog MUX Control Output 2 (ADC0)
T6OUT
O2
St/A
GPT2 Timer T6 Toggle Latch Output
U1C1_SCLK
O3
St/A
USIC1 Channel 1 Shift Clock Output
U1C1_DX1C
I
St/A
USIC1 Channel 1 Shift Clock Input
User’s Manual
Parallel Ports, V1.6D6
7-35
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
19
P6.3
O0 / I St/A
Bit 3 of Port 6, General Purpose Input/Output
T3OUT
O2
St/A
GPT1 Timer T3 Toggle Latch Output
U1C1_SELO
0
O3
St/A
USIC1 Channel 1 Select/Control 0 Output
U1C1_DX2D
I
St/A
USIC1 Channel 1 Shift Control Input
ADCx_REQT I
RyD
St/A
External Request Trigger Input for ADC0/1
P15.0
I
In/A
Bit 0 of Port 15, General Purpose Input
ADC1_CH0
I
In/A
Analog Input Channel 0 for ADC1
P15.1
I
In/A
Bit 1 of Port 15, General Purpose Input
ADC1_CH1
I
In/A
Analog Input Channel 1 for ADC1
P15.2
I
In/A
Bit 2 of Port 15, General Purpose Input
ADC1_CH2
I
In/A
Analog Input Channel 2 for ADC1
T5IN
I
In/A
GPT2 Timer T5 Count/Gate Input
P15.3
I
In/A
Bit 3 of Port 15, General Purpose Input
ADC1_CH3
I
In/A
Analog Input Channel 3 for ADC1
T5EUD
I
In/A
GPT2 Timer T5 External Up/Down Control Input
P15.4
I
In/A
Bit 4 of Port 15, General Purpose Input
ADC1_CH4
I
In/A
Analog Input Channel 4 for ADC1
T6IN
I
In/A
GPT2 Timer T6 Count/Gate Input
P15.5
I
In/A
Bit 5 of Port 15, General Purpose Input
ADC1_CH5
I
In/A
Analog Input Channel 5 for ADC1
T6EUD
I
In/A
GPT2 Timer T6 External Up/Down Control Input
P15.6
I
In/A
Bit 6 of Port 15, General Purpose Input
ADC1_CH6
I
In/A
Analog Input Channel 6 for ADC1
P15.7
I
In/A
Bit 7 of Port 15, General Purpose Input
ADC1_CH7
I
In/A
Analog Input Channel 7 for ADC1
VAREF1
VAREF0
VAGND
-
PS/A Reference Voltage for A/D Converter ADC1
-
PS/A Reference Voltage for A/D Converter ADC0
-
PS/A Reference Ground for A/D Converters ADC0/1
21
22
23
24
25
26
27
28
29
30
31
User’s Manual
Parallel Ports, V1.6D6
Type Function
7-36
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
Type Function
32
P5.0
I
In/A
Bit 0 of Port 5, General Purpose Input
ADC0_CH0
I
In/A
Analog Input Channel 0 for ADC0
P5.1
I
In/A
Bit 1 of Port 5, General Purpose Input
ADC0_CH1
I
In/A
Analog Input Channel 1 for ADC0
P5.2
I
In/A
Bit 2 of Port 5, General Purpose Input
ADC0_CH2
I
In/A
Analog Input Channel 2 for ADC0
TDI_A
I
In/A
JTAG Test Data Input
P5.3
I
In/A
Bit 3 of Port 5, General Purpose Input
ADC0_CH3
I
In/A
Analog Input Channel 3 for ADC0
T3IN
I
In/A
GPT1 Timer T3 Count/Gate Input
P5.4
I
In/A
Bit 4 of Port 5, General Purpose Input
ADC0_CH4
I
In/A
Analog Input Channel 4 for ADC0
CCU63_T12
HRB
I
In/A
External Run Control Input for T12 of CCU63
T3EUD
I
In/A
GPT1 Timer T3 External Up/Down Control Input
TMS_A
I
In/A
JTAG Test Mode Selection Input
P5.5
I
In/A
Bit 5 of Port 5, General Purpose Input
ADC0_CH5
I
In/A
Analog Input Channel 5 for ADC0
CCU60_T12
HRB
I
In/A
External Run Control Input for T12 of CCU60
P5.6
I
In/A
Bit 6 of Port 5, General Purpose Input
ADC0_CH6
I
In/A
Analog Input Channel 6 for ADC0
P5.7
I
In/A
Bit 7 of Port 5, General Purpose Input
ADC0_CH7
I
In/A
Analog Input Channel 7 for ADC0
P5.8
I
In/A
Bit 8 of Port 5, General Purpose Input
ADC0_CH8
I
In/A
Analog Input Channel 8 for ADC0
CCU6x_T12H I
RC
In/A
External Run Control Input for T12 of CCU60/1/
2/3
CCU6x_T13H I
RC
In/A
External Run Control Input for T13 of CCU60/1/
2/3
33
34
35
39
40
41
42
43
User’s Manual
Parallel Ports, V1.6D6
7-37
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
Type Function
44
P5.9
I
In/A
Bit 9 of Port 5, General Purpose Input
ADC0_CH9
I
In/A
Analog Input Channel 9 for ADC0
CC2_T7IN
I
In/A
CAPCOM2 Timer T7 Count Input
P5.10
I
In/A
Bit 10 of Port 5, General Purpose Input
ADC0_CH10
I
In/A
Analog Input Channel 10 for ADC0
BRKIN_A
I
In/A
OCDS Break Signal Input
P5.11
I
In/A
Bit 11 of Port 5, General Purpose Input
ADC0_CH11
I
In/A
Analog Input Channel 11 for ADC0
P5.12
I
In/A
Bit 12 of Port 5, General Purpose Input
ADC0_CH12
I
In/A
Analog Input Channel 12 for ADC0
P5.13
I
In/A
Bit 13 of Port 5, General Purpose Input
ADC0_CH13
I
In/A
Analog Input Channel 13 for ADC0
EX0BINB
I
In/A
External Interrupt Trigger Input
P5.14
I
In/A
Bit 14 of Port 5, General Purpose Input
ADC0_CH14
I
In/A
Analog Input Channel 14 for ADC0
P5.15
I
In/A
Bit 15 of Port 5, General Purpose Input
ADC0_CH15
I
In/A
Analog Input Channel 15 for ADC0
P2.12
O0 / I St/B
Bit 12 of Port 2, General Purpose Input/Output
U0C0_SELO
4
O1
St/B
USIC0 Channel 0 Select/Control 4 Output
U0C1_SELO
3
O2
St/B
USIC0 Channel 1 Select/Control 3 Output
READY
I
St/B
External Bus Interface READY Input
P2.11
O0 / I St/B
Bit 11 of Port 2, General Purpose Input/Output
U0C0_SELO
2
O1
St/B
USIC0 Channel 0 Select/Control 2 Output
U0C1_SELO
2
O2
St/B
USIC0 Channel 1 Select/Control 2 Output
BHE/WRH
OH
St/B
External Bus Interf. High-Byte Control Output
Can operate either as Byte High Enable (BHE) or
as Write strobe for High Byte (WRH).
P11.5
O0 / I St/B
Bit 5 of Port 11, General Purpose Input/Output
45
46
47
48
49
50
51
52
53
User’s Manual
Parallel Ports, V1.6D6
7-38
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
55
P2.0
O0 / I St/B
Bit 0 of Port 2, General Purpose Input/Output
CCU63_CC6
0
O2 / I St/B
CCU63 Channel 0 Input/Output
AD13
OH / I St/B
External Bus Interface Address/Data Line 13
RxDC0C
I
CAN Node 0 Receive Data Input
P2.1
O0 / I St/B
Bit 1 of Port 2, General Purpose Input/Output
TxDC0
O1
CAN Node 0 Transmit Data Output
CCU63_CC6
1
O2 / I St/B
CCU63 Channel 1 Input/Output
AD14
OH / I St/B
External Bus Interface Address/Data Line 14
ESR1_5
I
St/B
ESR1 Trigger Input 5
EX0AINA
I
St/B
External Interrupt Trigger Input
57
P11.4
O0 / I St/B
Bit 4 of Port 11, General Purpose Input/Output
58
P2.2
O0 / I St/B
Bit 2 of Port 2, General Purpose Input/Output
TxDC1
O1
CAN Node 1 Transmit Data Output
CCU63_CC6
2
O2 / I St/B
CCU63 Channel 2 Input/Output
AD15
OH / I St/B
External Bus Interface Address/Data Line 15
ESR2_5
I
St/B
ESR2 Trigger Input 5
EX1AINA
I
St/B
External Interrupt Trigger Input
59
P11.3
O0 / I St/B
Bit 3 of Port 11, General Purpose Input/Output
60
P4.0
O0 / I St/B
Bit 0 of Port 4, General Purpose Input/Output
CC2_24
O3 / I St/B
CAPCOM2 CC24IO Capture Inp./ Compare Out.
CS0
OH
External Bus Interface Chip Select 0 Output
56
User’s Manual
Parallel Ports, V1.6D6
Type Function
St/B
St/B
St/B
St/B
7-39
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
Type Function
61
P2.3
O0 / I St/B
Bit 3 of Port 2, General Purpose Input/Output
U0C0_DOUT O1
St/B
USIC0 Channel 0 Shift Data Output
CCU63_COU O2
T63
St/B
CCU63 Channel 3 Output
CC2_16
O3 / I St/B
CAPCOM2 CC16IO Capture Inp./ Compare Out.
A16
OH
St/B
External Bus Interface Address Line 16
ESR2_0
I
St/B
ESR2 Trigger Input 0
U0C0_DX0E
I
St/B
USIC0 Channel 0 Shift Data Input
U0C1_DX0D
I
St/B
USIC0 Channel 1 Shift Data Input
Note: Not available in step AA.
62
RxDC0A
I
P11.2
O0 / I St/B
CCU63_CCP I
OS2A
63
64
St/B
St/B
CAN Node 0 Receive Data Input
Bit 2 of Port 11, General Purpose Input/Output
CCU63 Position Input 2
P4.1
O0 / I St/B
Bit 1 of Port 4, General Purpose Input/Output
CC2_25
O3 / I St/B
CAPCOM2 CC25IO Capture Inp./ Compare Out.
CS1
OH
External Bus Interface Chip Select 1 Output
P2.4
O0 / I St/B
U0C1_DOUT O1
St/B
St/B
Bit 4 of Port 2, General Purpose Input/Output
USIC0 Channel 1 Shift Data Output
Note: Not available in step AA.
65
TxDC0
O2
CC2_17
O3 / I St/B
CAPCOM2 CC17IO Capture Inp./ Compare Out.
A17
OH
St/B
External Bus Interface Address Line 17
ESR1_0
I
St/B
ESR1 Trigger Input 0
U0C0_DX0F
I
St/B
USIC0 Channel 0 Shift Data Input
RxDC1A
I
St/B
CAN Node 1 Receive Data Input
P11.1
O0 / I St/B
CCU63_CCP I
OS1A
User’s Manual
Parallel Ports, V1.6D6
St/B
St/B
CAN Node 0 Transmit Data Output
Bit 1 of Port 11, General Purpose Input/Output
CCU63 Position Input 1
7-40
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
66
P11.0
O0 / I St/B
CCU63_CCP I
OS0A
67
68
69
70
71
Type Function
St/B
Bit 0 of Port 11, General Purpose Input/Output
CCU63 Position Input 0
P2.5
O0 / I St/B
Bit 5 of Port 2, General Purpose Input/Output
U0C0_SCLK
OUT
O1
St/B
USIC0 Channel 0 Shift Clock Output
TxDC0
O2
St/B
CAN Node 0 Transmit Data Output
CC2_18
O3 / I St/B
CAPCOM2 CC18IO Capture Inp./ Compare Out.
A18
OH
St/B
External Bus Interface Address Line 18
U0C0_DX1D
I
St/B
USIC0 Channel 0 Shift Clock Input
P4.2
O0 / I St/B
Bit 2 of Port 4, General Purpose Input/Output
CC2_26
O3 / I St/B
CAPCOM2 CC26IO Capture Inp./ Compare Out.
CS2
OH
St/B
External Bus Interface Chip Select 2 Output
T2IN
I
St/B
GPT1 Timer T2 Count/Gate Input
P2.6
O0 / I St/B
Bit 6 of Port 2, General Purpose Input/Output
U0C0_SELO
0
O1
St/B
USIC0 Channel 0 Select/Control 0 Output
U0C1_SELO
1
O2
St/B
USIC0 Channel 1 Select/Control 1 Output
CC2_19
O3 / I St/B
CAPCOM2 CC19IO Capture Inp./ Compare Out.
A19
OH
St/B
External Bus Interface Address Line 19
U0C0_DX2D
I
St/B
USIC0 Channel 0 Shift Control Input
RxDC0D
I
St/B
CAN Node 0 Receive Data Input
P4.4
O0 / I St/B
Bit 4 of Port 4, General Purpose Input/Output
CC2_28
O3 / I St/B
CAPCOM2 CC28IO Capture Inp./ Compare Out.
CS4
OH
St/B
External Bus Interface Chip Select 4 Output
DRTC
I
St/B
RTC Count Clock Signal Input
P4.3
O0 / I St/B
Bit 3 of Port 4, General Purpose Input/Output
CC2_27
O3 / I St/B
CAPCOM2 CC27IO Capture Inp./ Compare Out.
CS3
OH
St/B
External Bus Interface Chip Select 3 Output
T2EUD
I
St/B
GPT1 Timer T2 External Up/Down Control Input
User’s Manual
Parallel Ports, V1.6D6
7-41
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
75
P0.0
O0 / I St/B
U1C0_DOUT O1
76
77
78
79
Type Function
St/B
Bit 0 of Port 0, General Purpose Input/Output
USIC1 Channel 0 Shift Data Output
CCU61_CC6
0
O3 / I St/B
CCU61 Channel 0 Input/Output
A0
OH
St/B
External Bus Interface Address Line 0
U1C0_DX0A
I
St/B
USIC1 Channel 0 Shift Data Input
P4.5
O0 / I St/B
Bit 5 of Port 4, General Purpose Input/Output
CC2_29
O3 / I St/B
CAPCOM2 CC29IO Capture Inp./Compare Out.
P4.6
O0 / I St/B
Bit 6 of Port 4, General Purpose Input/Output
CC2_30
O3 / I St/B
CAPCOM2 CC30IO Capture Inp./ Compare Out.
T4IN
I
GPT1 Timer T4 Count/Gate Input
P2.7
O0 / I St/B
Bit 7 of Port 2, General Purpose Input/Output
U0C1_SELO
0
O1
St/B
USIC0 Channel 1 Select/Control 0 Output
U0C0_SELO
1
O2
St/B
USIC0 Channel 0 Select/Control 1 Output
CC2_20
O3 / I St/B
CAPCOM2 CC20IO Capture Inp./ Compare Out.
A20
OH
St/B
External Bus Interface Address Line 20
U0C1_DX2C
I
St/B
USIC0 Channel 1 Shift Control Input
RxDC1C
I
St/B
CAN Node 1 Receive Data Input
P0.1
O0 / I St/B
St/B
Bit 1 of Port 0, General Purpose Input/Output
U1C0_DOUT O1
St/B
USIC1 Channel 0 Shift Data Output
TxDC0
O2
St/B
CAN Node 0 Transmit Data Output
CCU61_CC6
1
O3 / I St/B
CCU61 Channel 1 Input/Output
A1
OH
St/B
External Bus Interface Address Line 1
U1C0_DX0B
I
St/B
USIC1 Channel 0 Shift Data Input
U1C0_DX1A
I
St/B
USIC1 Channel 0 Shift Clock Input
User’s Manual
Parallel Ports, V1.6D6
7-42
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
80
P2.8
O0 / I DP/B Bit 8 of Port 2, General Purpose Input/Output
U0C1_SCLK
OUT
O1
DP/B USIC0 Channel 1 Shift Clock Output
EXTCLK
O2
DP/B Programmable Clock Signal Output
CC2_21
O3 / I DP/B CAPCOM2 CC21IO Capture Inp./ Compare Out.
A21
OH
DP/B External Bus Interface Address Line 21
U0C1_DX1D
I
DP/B USIC0 Channel 1 Shift Clock Input
P4.7
O0 / I St/B
Bit 7 of Port 4, General Purpose Input/Output
CC2_31
O3 / I St/B
CAPCOM2 CC31IO Capture Inp./ Compare Out.
T4EUD
I
GPT1 Timer T4 External Up/Down Control Input
P2.9
O0 / I St/B
81
82
83
Type Function
1)
St/B
Bit 9 of Port 2, General Purpose Input/Output
U0C1_DOUT O1
St/B
USIC0 Channel 1 Shift Data Output
TxDC1
O2
St/B
CAN Node 1 Transmit Data Output
CC2_22
O3 / I St/B
CAPCOM2 CC22IO Capture Inp./ Compare Out.
A22
OH
St/B
External Bus Interface Address Line 22
DIRIN
I
St/B
Clock Signal Input
TCK_A
I
St/B
JTAG Clock Input
P0.2
O0 / I St/B
Bit 2 of Port 0, General Purpose Input/Output
U1C0_SCLK
OUT
O1
St/B
USIC1 Channel 0 Shift Clock Output
TxDC0
O2
St/B
CAN Node 0 Transmit Data Output
CCU61_CC6
2
O3 / I St/B
CCU61 Channel 2 Input/Output
A2
OH
St/B
External Bus Interface Address Line 2
U1C0_DX1B
I
St/B
USIC1 Channel 0 Shift Clock Input
User’s Manual
Parallel Ports, V1.6D6
7-43
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
84
P10.0
O0 / I St/B
U0C1_DOUT O1
85
86
St/B
Bit 0 of Port 10, General Purpose Input/Output
USIC0 Channel 1 Shift Data Output
CCU60_CC6
0
O2 / I St/B
CCU60 Channel 0 Input/Output
AD0
OH / I St/B
External Bus Interface Address/Data Line 0
ESR1_2
I
St/B
ESR1 Trigger Input 2
U0C0_DX0A
I
St/B
USIC0 Channel 0 Shift Data Input
U0C1_DX0A
I
St/B
USIC0 Channel 1 Shift Data Input
P3.0
O0 / I St/B
Bit 0 of Port 3, General Purpose Input/Output
U2C0_DOUT O1
St/B
USIC2 Channel 0 Shift Data Output
BREQ
OH
St/B
External Bus Request Output
ESR1_1
I
St/B
ESR1 Trigger Input 1
U2C0_DX0A
I
St/B
USIC2 Channel 0 Shift Data Input
U2C0_DX1A
I
St/B
USIC2 Channel 0 Shift Clock Input
P10.1
O0 / I St/B
U0C0_DOUT O1
87
Type Function
St/B
Bit 1 of Port 10, General Purpose Input/Output
USIC0 Channel 0 Shift Data Output
CCU60_CC6
1
O2 / I St/B
CCU60 Channel 1 Input/Output
AD1
OH / I St/B
External Bus Interface Address/Data Line 1
U0C0_DX0B
I
St/B
USIC0 Channel 0 Shift Data Input
U0C0_DX1A
I
St/B
USIC0 Channel 0 Shift Clock Input
P0.3
O0 / I St/B
Bit 3 of Port 0, General Purpose Input/Output
U1C0_SELO
0
O1
St/B
USIC1 Channel 0 Select/Control 0 Output
U1C1_SELO
1
O2
St/B
USIC1 Channel 1 Select/Control 1 Output
CCU61_COU O3
T60
St/B
CCU61 Channel 0 Output
A3
OH
St/B
External Bus Interface Address Line 3
U1C0_DX2A
I
St/B
USIC1 Channel 0 Shift Control Input
RxDC0B
I
St/B
CAN Node 0 Receive Data Input
User’s Manual
Parallel Ports, V1.6D6
7-44
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
88
P3.1
O0 / I St/B
U2C0_DOUT O1
Type Function
St/B
Bit 1 of Port 3, General Purpose Input/Output
USIC2 Channel 0 Shift Data Output
HLDA
OH / I St/B
External Bus Hold Acknowledge Output/Input
Output in master mode, input in slave mode.
U2C0_DX0B
I
USIC2 Channel 0 Shift Data Input
P10.2
O0 / I St/B
Bit 2 of Port 10, General Purpose Input/Output
U0C0_SCLK
OUT
O1
USIC0 Channel 0 Shift Clock Output
CCU60_CC6
2
O2 / I St/B
CCU60 Channel 2 Input/Output
AD2
OH / I St/B
External Bus Interface Address/Data Line 2
U0C0_DX1B
I
USIC0 Channel 0 Shift Clock Input
P0.4
O0 / I St/B
Bit 4 of Port 0, General Purpose Input/Output
U1C1_SELO
0
O1
St/B
USIC1 Channel 1 Select/Control 0 Output
U1C0_SELO
1
O2
St/B
USIC1 Channel 0 Select/Control 1 Output
CCU61_COU O3
T61
St/B
CCU61 Channel 1 Output
A4
OH
St/B
External Bus Interface Address Line 4
U1C1_DX2A
I
St/B
USIC1 Channel 1 Shift Control Input
RxDC1B
I
St/B
CAN Node 1 Receive Data Input
92
TRef
IO
Sp/1
Control Pin for Core Voltage Generation
Connect TRef to VDDPB to use the on-chip EVRs.
Connect TRef to VDDI1 for external core voltage
supply (on-chip EVRs off).
93
P3.2
O0 / I St/B
Bit 2 of Port 3, General Purpose Input/Output
U2C0_SCLK
OUT
O1
St/B
USIC2 Channel 0 Shift Clock Output
U2C0_DX1B
I
St/B
USIC2 Channel 0 Shift Clock Input
HOLD
I
St/B
External Bus Master Hold Request Input
89
90
User’s Manual
Parallel Ports, V1.6D6
St/B
St/B
St/B
7-45
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
94
P2.10
O0 / I St/B
95
97
Bit 10 of Port 2, General Purpose Input/Output
U0C1_DOUT O1
St/B
USIC0 Channel 1 Shift Data Output
U0C0_SELO
3
O2
St/B
USIC0 Channel 0 Select/Control 3 Output
CC2_23
O3 / I St/B
CAPCOM2 CC23IO Capture Inp./ Compare Out.
A23
OH
St/B
External Bus Interface Address Line 23
U0C1_DX0E
I
St/B
USIC0 Channel 1 Shift Data Input
CAPIN
I
St/B
GPT2 Register CAPREL Capture Input
P10.3
O0 / I St/B
CCU60_COU O2
T60
96
Type Function
St/B
Bit 3 of Port 10, General Purpose Input/Output
CCU60 Channel 0 Output
AD3
OH / I St/B
External Bus Interface Address/Data Line 3
U0C0_DX2A
I
St/B
USIC0 Channel 0 Shift Control Input
U0C1_DX2A
I
St/B
USIC0 Channel 1 Shift Control Input
P0.5
O0 / I St/B
Bit 5 of Port 0, General Purpose Input/Output
U1C1_SCLK
OUT
O1
St/B
USIC1 Channel 1 Shift Clock Output
U1C0_SELO
2
O2
St/B
USIC1 Channel 0 Select/Control 2 Output
CCU61_COU O3
T62
St/B
CCU61 Channel 2 Output
A5
OH
St/B
External Bus Interface Address Line 5
U1C1_DX1A
I
St/B
USIC1 Channel 1 Shift Clock Input
U1C0_DX1C
I
St/B
USIC1 Channel 0 Shift Clock Input
P3.3
O0 / I St/B
Bit 3 of Port 3, General Purpose Input/Output
U2C0_SELO
0
O1
St/B
USIC2 Channel 0 Select/Control 0 Output
U2C1_SELO
1
O2
St/B
USIC2 Channel 1 Select/Control 1 Output
U2C0_DX2A
I
St/B
USIC2 Channel 0 Shift Control Input
User’s Manual
Parallel Ports, V1.6D6
7-46
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
98
P10.4
O0 / I St/B
Bit 4 of Port 10, General Purpose Input/Output
U0C0_SELO
3
O1
St/B
USIC0 Channel 0 Select/Control 3 Output
CCU60_COU O2
T61
St/B
CCU60 Channel 1 Output
99
100
101
Type Function
AD4
OH / I St/B
External Bus Interface Address/Data Line 4
U0C0_DX2B
I
St/B
USIC0 Channel 0 Shift Control Input
U0C1_DX2B
I
St/B
USIC0 Channel 1 Shift Control Input
P3.4
O0 / I St/B
Bit 4 of Port 3, General Purpose Input/Output
U2C1_SELO
0
O1
St/B
USIC2 Channel 1 Select/Control 0 Output
U2C0_SELO
1
O2
St/B
USIC2 Channel 0 Select/Control 1 Output
U0C0_SELO
4
O3
St/B
USIC0 Channel 0 Select/Control 4 Output
U2C1_DX2A
I
St/B
USIC2 Channel 1 Shift Control Input
P10.5
O0 / I St/B
Bit 5 of Port 10, General Purpose Input/Output
U0C1_SCLK
OUT
O1
St/B
USIC0 Channel 1 Shift Clock Output
CCU60_COU O2
T62
St/B
CCU60 Channel 2 Output
AD5
OH / I St/B
External Bus Interface Address/Data Line 5
U0C1_DX1B
I
USIC0 Channel 1 Shift Clock Input
P3.5
O0 / I St/B
Bit 5 of Port 3, General Purpose Input/Output
U2C1_SCLK
OUT
O1
St/B
USIC2 Channel 1 Shift Clock Output
U2C0_SELO
2
O2
St/B
USIC2 Channel 0 Select/Control 2 Output
U0C0_SELO
5
O3
St/B
USIC0 Channel 0 Select/Control 5 Output
U2C1_DX1A
I
St/B
USIC2 Channel 1 Shift Clock Input
User’s Manual
Parallel Ports, V1.6D6
St/B
7-47
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
102
P0.6
O0 / I St/B
103
104
Type Function
Bit 6 of Port 0, General Purpose Input/Output
U1C1_DOUT O1
St/B
USIC1 Channel 1 Shift Data Output
TxDC1
O2
St/B
CAN Node 1 Transmit Data Output
CCU61_COU O3
T63
St/B
CCU61 Channel 3 Output
A6
OH
St/B
External Bus Interface Address Line 6
U1C1_DX0A
I
St/B
USIC1 Channel 1 Shift Data Input
CCU61_CTR
APA
I
St/B
CCU61 Emergency Trap Input
U1C1_DX1B
I
St/B
USIC1 Channel 1 Shift Clock Input
P10.6
O0 / I St/B
Bit 6 of Port 10, General Purpose Input/Output
U0C0_DOUT O1
St/B
USIC0 Channel 0 Shift Data Output
U1C0_SELO
0
O3
St/B
USIC1 Channel 0 Select/Control 0 Output
AD6
OH / I St/B
External Bus Interface Address/Data Line 6
U0C0_DX0C
I
St/B
USIC0 Channel 0 Shift Data Input
U1C0_DX2D
I
St/B
USIC1 Channel 0 Shift Control Input
CCU60_CTR
APA
I
St/B
CCU60 Emergency Trap Input
P3.6
O0 / I St/B
Bit 6 of Port 3, General Purpose Input/Output
U2C1_DOUT O1
St/B
USIC2 Channel 1 Shift Data Output
U0C0_SELO
6
O3
St/B
USIC0 Channel 0 Select/Control 6 Output
U2C1_DX0A
I
St/B
USIC2 Channel 1 Shift Data Input
U2C1_DX1B
I
St/B
USIC2 Channel 1 Shift Clock Input
User’s Manual
Parallel Ports, V1.6D6
7-48
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
105
P10.7
O0 / I St/B
106
107
111
Type Function
Bit 7 of Port 10, General Purpose Input/Output
U0C1_DOUT O1
St/B
USIC0 Channel 1 Shift Data Output
CCU60_COU O2
T63
St/B
CCU60 Channel 3 Output
AD7
OH / I St/B
External Bus Interface Address/Data Line 7
U0C1_DX0B
I
St/B
USIC0 Channel 1 Shift Data Input
CCU60_CCP I
OS0A
St/B
CCU60 Position Input 0
P0.7
O0 / I St/B
Bit 7 of Port 0, General Purpose Input/Output
U1C1_DOUT O1
St/B
USIC1 Channel 1 Shift Data Output
U1C0_SELO
3
O2
St/B
USIC1 Channel 0 Select/Control 3 Output
A7
OH
St/B
External Bus Interface Address Line 7
U1C1_DX0B
I
St/B
USIC1 Channel 1 Shift Data Input
CCU61_CTR
APB
I
St/B
CCU61 Emergency Trap Input
P3.7
O0 / I St/B
Bit 7 of Port 3, General Purpose Input/Output
U2C1_DOUT O1
St/B
USIC2 Channel 1 Shift Data Output
U2C0_SELO
3
O2
St/B
USIC2 Channel 0 Select/Control 3 Output
U0C0_SELO
7
O3
St/B
USIC0 Channel 0 Select/Control 7 Output
U2C1_DX0B
I
St/B
USIC2 Channel 1 Shift Data Input
P1.0
O0 / I St/B
Bit 0 of Port 1, General Purpose Input/Output
U1C0_MCLK
OUT
O1
St/B
USIC1 Channel 0 Master Clock Output
U1C0_SELO
4
O2
St/B
USIC1 Channel 0 Select/Control 4 Output
A8
OH
St/B
External Bus Interface Address Line 8
ESR1_3
I
St/B
ESR1 Trigger Input 3
EX0BINA
I
St/B
External Interrupt Trigger Input
CCU62_CTR
APB
I
St/B
CCU62 Emergency Trap Input
User’s Manual
Parallel Ports, V1.6D6
7-49
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
112
P9.0
O0 / I St/B
Bit 0 of Port 9, General Purpose Input/Output
CCU63_CC6
0
O1 / I St/B
CCU63 Channel 0 Input/Output
P10.8
O0 / I St/B
Bit 8 of Port 10, General Purpose Input/Output
U0C0_MCLK
OUT
O1
St/B
USIC0 Channel 0 Master Clock Output
U0C1_SELO
0
O2
St/B
USIC0 Channel 1 Select/Control 0 Output
AD8
OH / I St/B
113
114
115
Type Function
External Bus Interface Address/Data Line 8
CCU60_CCP I
OS1A
St/B
CCU60 Position Input 1
U0C0_DX1C
I
St/B
USIC0 Channel 0 Shift Clock Input
BRKIN_B
I
St/B
OCDS Break Signal Input
P9.1
O0 / I St/B
Bit 1 of Port 9, General Purpose Input/Output
CCU63_CC6
1
O1 / I St/B
CCU63 Channel 1 Input/Output
P10.9
O0 / I St/B
Bit 9 of Port 10, General Purpose Input/Output
U0C0_SELO
4
O1
St/B
USIC0 Channel 0 Select/Control 4 Output
U0C1_MCLK
OUT
O2
St/B
USIC0 Channel 1 Master Clock Output
AD9
OH / I St/B
External Bus Interface Address/Data Line 9
CCU60_CCP I
OS2A
St/B
CCU60 Position Input 2
TCK_B
St/B
JTAG Clock Input
User’s Manual
Parallel Ports, V1.6D6
I
7-50
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
116
P1.1
O0 / I St/B
117
118
119
Type Function
Bit 1 of Port 1, General Purpose Input/Output
CCU62_COU O1
T62
St/B
CCU62 Channel 2 Output
U1C0_SELO
5
O2
St/B
USIC1 Channel 0 Select/Control 5 Output
U2C1_DOUT O3
St/B
USIC2 Channel 1 Shift Data Output
A9
OH
St/B
External Bus Interface Address Line 9
ESR2_3
I
St/B
ESR2 Trigger Input 3
EX1BINA
I
St/B
External Interrupt Trigger Input
U2C1_DX0C
I
St/B
USIC2 Channel 1 Shift Data Input
P10.10
O0 / I St/B
Bit 10 of Port 10, General Purpose Input/Output
U0C0_SELO
0
O1
St/B
USIC0 Channel 0 Select/Control 0 Output
CCU60_COU O2
T63
St/B
CCU60 Channel 3 Output
AD10
OH / I St/B
External Bus Interface Address/Data Line 10
U0C0_DX2C
I
St/B
USIC0 Channel 0 Shift Control Input
TDI_B
I
St/B
JTAG Test Data Input
U0C1_DX1A
I
St/B
USIC0 Channel 1 Shift Clock Input
P10.11
O0 / I St/B
Bit 11 of Port 10, General Purpose Input/Output
U1C0_SCLK
OUT
O1
St/B
USIC1 Channel 0 Shift Clock Output
BRKOUT
O2
St/B
OCDS Break Signal Output
AD11
OH / I St/B
External Bus Interface Address/Data Line 11
U1C0_DX1D
I
St/B
USIC1 Channel 0 Shift Clock Input
TMS_B
I
St/B
JTAG Test Mode Selection Input
P9.2
O0 / I St/B
Bit 2 of Port 9, General Purpose Input/Output
CCU63_CC6
2
O1 / I St/B
CCU63 Channel 2 Input/Output
User’s Manual
Parallel Ports, V1.6D6
7-51
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
120
P1.2
O0 / I St/B
Bit 2 of Port 1, General Purpose Input/Output
CCU62_CC6
2
O1 / I St/B
CCU62 Channel 2 Input/Output
U1C0_SELO
6
O2
St/B
USIC1 Channel 0 Select/Control 6 Output
U2C1_SCLK
OUT
O3
St/B
USIC2 Channel 1 Shift Clock Output
A10
OH
St/B
External Bus Interface Address Line 10
ESR1_4
I
St/B
ESR1 Trigger Input 4
CCU61_T12
HRB
I
St/B
External Run Control Input for T12 of CCU61
EX2AINA
I
St/B
External Interrupt Trigger Input
U2C1_DX0D
I
St/B
USIC2 Channel 1 Shift Data Input
U2C1_DX1C
I
St/B
USIC2 Channel 1 Shift Clock Input
P10.12
O0 / I St/B
121
122
123
Type Function
Bit 12 of Port 10, General Purpose Input/Output
U1C0_DOUT O1
St/B
USIC1 Channel 0 Shift Data Output
TDO
O3
St/B
JTAG Test Data Output
AD12
OH / I St/B
External Bus Interface Address/Data Line 12
U1C0_DX0C
I
St/B
USIC1 Channel 0 Shift Data Input
U1C0_DX1E
I
St/B
USIC1 Channel 0 Shift Clock Input
P9.3
O0 / I St/B
Bit 3 of Port 9, General Purpose Input/Output
CCU63_COU O1
T60
St/B
CCU63 Channel 0 Output
BRKOUT
O2
St/B
OCDS Break Signal Output
P10.13
O0 / I St/B
Bit 13 of Port 10, General Purpose Input/Output
U1C0_DOUT O1
St/B
USIC1 Channel 0 Shift Data Output
U1C0_SELO
3
O3
St/B
USIC1 Channel 0 Select/Control 3 Output
WR/WRL
OH
St/B
External Bus Interface Write Strobe Output
Active for each external write access, when WR,
active for ext. writes to the low byte, when WRL.
U1C0_DX0D
I
St/B
USIC1 Channel 0 Shift Data Input
User’s Manual
Parallel Ports, V1.6D6
7-52
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
124
P1.3
O0 / I St/B
125
126
128
Type Function
Bit 3 of Port 1, General Purpose Input/Output
CCU62_COU O1
T63
St/B
CCU62 Channel 3 Output
U1C0_SELO
7
O2
St/B
USIC1 Channel 0 Select/Control 7 Output
U2C0_SELO
4
O3
St/B
USIC2 Channel 0 Select/Control 4 Output
A11
OH
St/B
External Bus Interface Address Line 11
ESR2_4
I
St/B
ESR2 Trigger Input 4
CCU62_T12
HRB
I
St/B
External Run Control Input for T12 of CCU62
EX3AINA
I
St/B
External Interrupt Trigger Input
P9.4
O0 / I St/B
Bit 4 of Port 9, General Purpose Input/Output
CCU63_COU O1
T61
St/B
CCU63 Channel 1 Output
U2C0_DOUT O2
St/B
USIC2 Channel 0 Shift Data Output
P9.5
O0 / I St/B
Bit 5 of Port 9, General Purpose Input/Output
CCU63_COU O1
T62
St/B
CCU63 Channel 2 Output
U2C0_DOUT O2
St/B
USIC2 Channel 0 Shift Data Output
U2C0_DX0E
I
St/B
USIC2 Channel 0 Shift Data Input
CCU60_CCP I
OS2B
St/B
CCU60 Position Input 2
P10.14
O0 / I St/B
Bit 14 of Port 10, General Purpose Input/Output
U1C0_SELO
1
O1
St/B
USIC1 Channel 0 Select/Control 1 Output
U0C1_DOUT O2
St/B
USIC0 Channel 1 Shift Data Output
RD
OH
St/B
External Bus Interface Read Strobe Output
ESR2_2
I
St/B
ESR2 Trigger Input 2
U0C1_DX0C
I
St/B
USIC0 Channel 1 Shift Data Input
User’s Manual
Parallel Ports, V1.6D6
7-53
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
129
P1.4
O0 / I St/B
130
131
132
Type Function
Bit 4 of Port 1, General Purpose Input/Output
CCU62_COU O1
T61
St/B
CCU62 Channel 1 Output
U1C1_SELO
4
O2
St/B
USIC1 Channel 1 Select/Control 4 Output
U2C0_SELO
5
O3
St/B
USIC2 Channel 0 Select/Control 5 Output
A12
OH
St/B
External Bus Interface Address Line 12
U2C0_DX2B
I
St/B
USIC2 Channel 0 Shift Control Input
P10.15
O0 / I St/B
Bit 15 of Port 10, General Purpose Input/Output
U1C0_SELO
2
O1
St/B
USIC1 Channel 0 Select/Control 2 Output
U0C1_DOUT O2
St/B
USIC0 Channel 1 Shift Data Output
U1C0_DOUT O3
St/B
USIC1 Channel 0 Shift Data Output
ALE
OH
St/B
External Bus Interf. Addr. Latch Enable Output
U0C1_DX1C
I
St/B
USIC0 Channel 1 Shift Clock Input
P1.5
O0 / I St/B
Bit 5 of Port 1, General Purpose Input/Output
CCU62_COU O1
T60
St/B
CCU62 Channel 0 Output
U1C1_SELO
3
O2
St/B
USIC1 Channel 1 Select/Control 3 Output
BRKOUT
O3
St/B
OCDS Break Signal Output
A13
OH
St/B
External Bus Interface Address Line 13
U2C0_DX0C
I
St/B
USIC2 Channel 0 Shift Data Input
P9.6
O0 / I St/B
Bit 6 of Port 9, General Purpose Input/Output
CCU63_COU O1
T63
St/B
CCU63 Channel 3 Output
CCU63_COU O2
T62
St/B
CCU63 Channel 2 Output
CCU63
_CTRAPA
I
St/B
CCU63 Emergency Trap Input
CCU60_CCP I
OS1B
St/B
CCU60 Position Input 1
User’s Manual
Parallel Ports, V1.6D6
7-54
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
133
P1.6
O0 / I St/B
Bit 6 of Port 1, General Purpose Input/Output
CCU62_CC6
1
O1 / I St/B
CCU62 Channel 1 Input/Output
U1C1_SELO
2
O2
St/B
USIC1 Channel 1 Select/Control 2 Output
U2C0_DOUT O3
St/B
USIC2 Channel 0 Shift Data Output
A14
OH
St/B
External Bus Interface Address Line 14
U2C0_DX0D
I
St/B
USIC2 Channel 0 Shift Data Input
P9.7
O0 / I St/B
Bit 7 of Port 9, General Purpose Input/Output
CCU63_CTR
APB
I
St/B
CCU63 Emergency Trap Input
U2C0_DX1D
I
St/B
USIC2 Channel 0 Shift Clock Input
CCU60_CCP I
OS0B
St/B
CCU60 Position Input 0
134
135
Type Function
P1.7
O0 / I St/B
Bit 7 of Port 1, General Purpose Input/Output
CCU62_CC6
0
O1 / I St/B
CCU62 Channel 0 Input/Output
U1C1_MCLK
OUT
O2
St/B
USIC1 Channel 1 Master Clock Output
U2C0_SCLK
OUT
O3
St/B
USIC2 Channel 0 Shift Clock Output
A15
OH
St/B
External Bus Interface Address Line 15
U2C0_DX1C
I
St/B
USIC2 Channel 0 Shift Clock Input
136
XTAL2
O
Sp/1
Crystal Oscillator Amplifier Output
137
XTAL1
I
Sp/1
Crystal Oscillator Amplifier Input
To clock the device from an external source, drive
XTAL1, while leaving XTAL2 unconnected.
Voltages on XTAL1 must comply to the core
supply voltage VDDI1.
User’s Manual
Parallel Ports, V1.6D6
7-55
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
Type Function
138
PORST
I
In/B
139
ESR1
O0 / I St/B
External Service Request 1
U1C0_DX0F
I
St/B
USIC1 Channel 0 Shift Data Input
U1C0_DX2C
I
St/B
USIC1 Channel 0 Shift Control Input
U1C1_DX0C
I
St/B
USIC1 Channel 1 Shift Data Input
U1C1_DX2B
I
St/B
USIC1 Channel 1 Shift Control Input
U2C1_DX2C
I
St/B
USIC2 Channel 1 Shift Control Input
EX0AINB
I
St/B
External Interrupt Trigger Input
ESR2
O0 / I St/B
External Service Request 2
U1C1_DX0D
I
St/B
USIC1 Channel 1 Shift Data Input
U1C1_DX2C
I
St/B
USIC1 Channel 1 Shift Control Input
U2C1_DX0E
I
St/B
USIC1 Channel 1 Shift Data Input
U2C1_DX2B
I
St/B
USIC2 Channel 1 Shift Control Input
EX1AINB
I
St/B
External Interrupt Trigger Input
ESR0
O0 / I St/B
140
141
Power On Reset Input
A low level at this pin resets the XC2700
completely. A spike filter suppresses input pulses
<10 ns. Input pulses >100 ns safely pass the filter.
The minimum duration for a safe recognition
should be 120 ns.
An internal pullup device will hold this pin high
when nothing is driving it.
External Service Request 0
Note: After power-up, ESR0 operates as opendrain bidirectional reset with a weak pull-up.
142
U1C0_DX0E
I
St/B
USIC1 Channel 0 Shift Data Input
U1C0_DX2B
I
St/B
USIC1 Channel 0 Shift Control Input
P8.6
O0 / I St/B
Bit 6 of Port 8, General Purpose Input/Output
CCU60_COU O1
T63
St/B
CCU60 Channel 3 Output
CCU60_CTR
APB
I
St/B
CCU60 Emergency Trap Input
BRKIN_D
I
St/B
OCDS Break Signal Input
User’s Manual
Parallel Ports, V1.6D6
7-56
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
Table 7-18
Pin Definitions and Functions (cont’d)
Pin
Symbol
Ctrl.
Type Function
143
P8.5
O0 / I St/B
Bit 5 of Port 8, General Purpose Input/Output
CCU60_COU O1
T62
St/B
CCU60 Channel 2 Output
TCK_D
I
St/B
JTAG Clock Input
15
VDDIM
-
PS/M Digital Core Supply Voltage for Domain M
Decouple with a ceramic capacitor, see Data
Sheet for details.
54,
91,
127
VDDI1
-
PS/1 Digital Core Supply Voltage for Domain 1
Decouple with a ceramic capacitor, see Data
Sheet for details.
All VDDI1 pins must be connected to each other.
20
VDDPA
-
PS/A Digital Pad Supply Voltage for Domain A
Connect decoupling capacitors to adjacent VDDP/
VSS pin pairs as close as possible to the pins.
Note: The A/D_Converters and ports P5, P6, and
P15 are fed from supply voltage VDDPA.
VDDPB
2,
36,
38,
72,
74,
108,
110,
144
1,
37,
73,
109
1)
VSS
-
PS/B Digital Pad Supply Voltage for Domain B
Connect decoupling capacitors to adjacent VDDP/
VSS pin pairs as close as possible to the pins.
Note: The on-chip voltage regulators and all ports
except P5, P6, and P15 are fed from supply
voltage VDDPB.
-
PS/-- Digital Ground
All VSS pins must be connected to the ground-line
or ground-plane.
To generate the reference clock output for bus timing measurement, fSYS must be selected as source for
EXTCLK and P2.8 must be selected as output pin. Also the high-speed clock pad must be enabled. This
configuration is referred to as reference clock output signal CLKOUT.
User’s Manual
Parallel Ports, V1.6D6
7-57
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Dedicated Pins
8
Dedicated Pins
Most of the input/output or control signals of the functional the XC2700 are realized as
alternate functions of pins of the parallel ports. There is, however, a number of signals
that use separate pins, including the oscillator, special control signals and, of course, the
power supply.
Table 8-1 summarizes the dedicated pins of the XC2700.
Table 8-1
XC2700 Dedicated Pins
Pin(s)
Function
PORST
Power-On Reset Input
ESR0
External Service Request Input 0
ESR1
External Service Request Input 1
ESR2
External Service Request Input 2
XTAL1, XTAL2
Oscillator Input/Output (main oscillator)
TESTM
Test Mode Enable
TRST
Test-System Reset Input
TRef
Control Pin for Core Voltage Generation
VAREFx, VAGND
VDDIM
VDDI1
VDDPA
VDDPB
VSS
Power Supply for the Analog/Digital Converter(s)
Digital Core Supply for Domain M (1 pin)
Digital Core Supply for Domain 1 (3 pins)
Digital Pad Supply for Domain A (1 pin)
Digital Pad Supply for Domain B (8 pins)
Digital Ground (4 pins)
The Power-On Reset Input PORST allows to put the XC2700 into the well defined reset
condition either at power-up or external events like a hardware failure or manual reset.
The External Service Request Inputs ESR0, ESR1, and ESR2 can be used for several
system-related functions:
• trigger interrupt or trap (Class A or Class B) requests via an external signal (e.g. a
power-fail signal)
• generate wake-up request signals
• generate hardware reset requests (ESR0 is bidirectional by default, ESR1 and ESR2
can optionally output a reset signal)
• data/control input for CCU6x, MultiCAN, and USIC (ESR1 or ESR2)
• software-controlled input/output signal
User’s Manual
DediPins_X7, V2.0
8-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Dedicated Pins
The Oscillator Input XTAL1 and Output XTAL2 connect the internal Main Oscillator
to the external crystal. The oscillator provides an inverter and a feedback element. The
standard external oscillator circuitry comprises the crystal, two low end capacitors and
series resistor to limit the current through the crystal. The main oscillator is intended for
the generation of a high-precision operating clock signal for the XC2700.
An external clock signal may be fed to the input XTAL1, leaving XTAL2 open. The current
logic state of input XTAL1 can be read via a status flag, so XTAL1 can be used as digital
input if neither the oscillator interface nor the clock input is required.
Note: Pin XTAL1 belongs to the core power domain DMP_M. All input signals, therefore,
must be within the core voltage range.
The Test Mode Input TESTM puts the XC2700 into a test mode, which is used during
the production tests of the device. In test mode, the XC2700 behaves different from
normal operation. Therefore, pin TESTM must be held HIGH (connect to VDDPB) for
normal operation in an application system.
The Test Reset Input TRST puts the XC2700’s debug system into reset state. During
normal operation this input should be held low. For debugging purposes the on-chip
debugging system can be enabled by driving pin TRST high at the rising edge of PORST.
The Control Pin for Core Voltage Generation TRef was used to control the generation
method for the core supply voltage VDDI in step AA. For that step, pin TRef must be
connected to VDDPB (use the on-chip EVRs).
This connection is no more required from step AB on. For the current step, pin TRef is
logically not connected.
Future derivatives will feature an additional general purpose IO pin at this position.
The Analog Reference Voltage Supply pins VAREFx and VAGND provide separate
reference voltage for the on-chip Analog/Digital-Converter(s). This reduces the noise
that is coupled to the analog input signals from the digital logic sections and so improves
the stability of the conversion results, when VAREF and VAGND are properly discoupled
from VDD and VSS. Also, because conversion results are generated in relation to the
reference voltages, ratiometric conversions are easily achieved.
Note: Channel 0 of each module can be used as an alternate reference voltage input.
The Core Supply pins VDDIM/VDDI1 serve two purposes: While the on-chip EVVRs
provide the power for the core logic of the XC2700 these pins connect the EVVRs to their
external buffer capacitors. For external supply, the core voltage is applied to these pins.
The respective VDDI/VSS pairs should be decoupled as close to the pins as possible. Use
ceramic capacitors and observe their values recommended in the respective Data
Sheet.
User’s Manual
DediPins_X7, V2.0
8-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Dedicated Pins
The Power Supply pins VDDPA/VDDPB provide the power supply for all the analog and
digital logic of the XC2700. Each power domain (DMP_A and DMP_B) can be supplied
with an arbitrary voltage within the specified supply voltage range (please refer to the
corresponding Data Sheets). These pins supply the output drivers as well as the on-chip
EVVRs (VDDPB), except for external core voltage supply. The respective VDDP/VSS pairs
should be decoupled as close to the pins as possible.
The Ground Reference pins VSS provide the ground reference voltage for the power
supplies as well as the reference voltage for the input signals.
Note: All VDDx pins and all VSS pins must be connected to the power supplies and
ground, respectively.
User’s Manual
DediPins_X7, V2.0
8-3
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9
The External Bus Controller EBC
All external memory accesses are performed by a particular on-chip External Bus
Controller (EBC). It can be programmed either to Single Chip Mode when no external
memory is required at all, or dynamically (depending on the selected address range,
belonging to a chip-select signal) to one of four different external memory access modes,
which are as follows:
•
•
•
•
1 … 24-bit Addresses, 16-bit Data, Demultiplexed
1 … 24-bit Addresses, 16-bit Data, Multiplexed
1 … 24-bit Addresses, 8-bit Data, Multiplexed
1 … 24-bit Addresses, 8-bit Data, Demultiplexed
Note: The following description refers to the general EBC feature set. In the 100-pin
package, some features are not available, see Table 9-1. In the 64-pin package,
no external bus interface is available.
In the multiplexed bus modes, the intra-segment address outputs (A15 … A0) and data
input/outputs are overlaid on 16 port pins. The higher segment address outputs
(A23 … A16) are mapped to separate port pins. In the demultiplexed bus modes,
address outputs and data input/outputs are not overlaid but mapped to the port pins
separately. For applications which do not use all address lines for external devices, the
external address space can be restricted by enabling only the required address lines. Up
to 5 external CS signals can be generated in order to save external glue logic. Memories
or peripherals with variable access time are supported via a particular ‘Ready’ function.
A HOLD/HLDA protocol is available for bus arbitration.
The XC2700 External Bus Controller (EBC) allows access to external
peripherals/memories and to internal LXBus modules. The LXBus is an internal
representation of the ExtBus and it controls accesses to integrated peripherals and
modules in the same way as accesses to external components.
The function of the EBC is controlled via a set of configuration registers. The basic and
general behaviour is programmed via the mode-selection registers EBCMOD0 and
EBCMOD1.
Similar to the supported external bus chip-select channels, LXBus modules are selected
by a specific chip select signal (both access types are handled as ‘external’ accesses by
the EBC).
The Function CONtrol register for CSx (FCONCSx) register specifies the external
bus/LXBus cycles in terms of address (multiplexed/demultiplexed), data (16-bit/8-bit),
READY control, and chip-select enable. The timing of the bus access is controlled by the
Timing CONfiguration registers for CSx (TCONCSx), which specify the timing of the bus
cycle with the lengths of the different access phases. All these parameters are used for
accesses within a specific address area that is defined via the corresponding ADDRess
SELect register ADDRSELx.
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EBC_X8, V1.0d1
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V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
The five register sets (FCONCSx/TCONCSx/ADDRSELx, x = 7, 4, 3, 2, 1) define five
independent “address windows”, whereas all external accesses outside these windows
are controlled via registers FCONCS0 and TCONCS0. Chip Select signals CS0 … CS4
and their associated programmable address windows belong to access to resources on
the external bus. Chip Select signal CS7 and its associated fixed address window is
used for access to the internal MultiCAN and USIC modules on the LXBus.
The external bus timing is related to the reference CLocK OUTput (CLKOUT1)). All bus
signals are generated in relation to the rising edge of this clock. The external bus protocol
is compatible with those of the C166 Family and the XC166 Family.
These improvements are configured via an enhanced register set (see above) in
comparison to C166 Family. The C16x registers SYSCON and BUSCONx are no longer
used. But because the configuration of the external bus controller is done during the
application initialization, only some initialization code has to be adapted for using the
new EBC module instead of the C16x external bus controller.
1) The term CLKOUT refers to the reference clock output signal which is generated by selecting fSYS as source
signal for the clock output signal EXTCLK on pin P2.8 and by enabling the high-speed clock driver on this pin.
User’s Manual
EBC_X8, V1.0d1
9-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.1
External Bus Signals
The External Bus uses the following I/O signals1):
Table 9-1
Signal
EBC Bus Signals
I/O
Port
Pins
Description
Signals available both in the 100-pin and 144-pin package
ALE
O
P10
Address Latch Enable; active high
RD
O
ReaD strobe: activated for every read access (active low)
WR, WRL
O
WRite/WRite Low byte strobe (active low)
WR-mode: activated for every write access.
WRL-mode: activated for low byte write accesses on a 16-bit
bus and for every data write access on an 8-bit bus.
BHE, WRH O
P2
Byte High Enable/WRite High byte strobe (active low)
BHE-mode: activated for every data access to the upper
byte of the 16-bit bus (handled as additional address bit)
WRH-mode: activated for high byte write accesses on a
16-bit bus.
READY/
READY
P2
READY; used for dynamic wait state insertion;
programmable active high or low
AD[12..0]
I/O
AD[15..13]
P10
P2
Address/Data bus; in multiplexed mode this bus is used for
both address and data, in demultiplexed mode it is data bus
only
A[7..0]
A[15..8]
A[23..16]
O
P0
P1
P2
Address bus
CS[3..0]
O
P4
Chip Select; active low;
CS7-used for internal LXBus access to MultiCAN and USICs
I
Signals available additionally in the 144-pin package
BREQ
O
P3
HLDA
I/O
HoLD Accepted output (by the master); active low
HoLD Accepted input (at the slave); active low
HOLD
I
HOLD request; active low
CS4
O
P6
Bus REQuest; active low
Chip Select; active low;
CS7-used for internal LXBus access to MultiCAN and USICs
1) In the 64-pin package the External Bus is not available.
User’s Manual
EBC_X8, V1.0d1
9-3
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
Table 9-2
Write Configurations (see Chapter 9.3.2)
Written Byte
General Write Configuration
Low
High
WR
BHE
–
–
inactive
don’t care 0/1
write
–
active
inactive
–
write
active
write
write
active
9.2
Separated Byte Low/High Writes
ADDR[0] WRL
WRH
ADDR[0]
inactive
inactive
0/1
0
active
inactive
0/1
active
1
inactive
active
0/1
active
0
active
active
0/1
Timing Principles
The external bus timing is subdivided into six different timing phases (A-F).
9.2.1
Basic Bus Cycle Protocols
The phases A-F define the flow of all control signals needed for any access sequence to
external devices. At the beginning of a phase, the output signals may change within a
given output delay time. After the output delay time, the values of the control output
signals are stable within this phase. The output delay times are specified in the AC
characteristics (see Data Sheet). Each phase can occupy a programmable number of
clock cycles. The number of clock cycles is programmed in the TCONCSx register
selected via the related address range and CSx.
Access n
Phases
A
Address
BCDEF
Address n
FCONCSx
FCON of n
Access n + 1
A
BCDEF
Address n + 1
Access n + 2
A
BCDEF
Address n + 2
FCON of n + 1
Access n + 3
A
BCDEF
A
Address n + 3
FCON of n + 2
FCON of n + 3
MCA05373
Figure 9-1
Phases of a Sequence of Several Accesses
Phase A is used for tristating databus drivers from the previous cycle (tristate wait states
after CS switch). Phase A cycles are not inserted at every access cycle but only when
changing the CS. If an access using one CS (CSx) was finished and the next access with
a different CS (CSy) is started then Phase A cycle(s) are performed according to the
control bits as set in the first CS (CSx).
The A Phase cycles are inserted while the addresses and ALE of the next cycle are
already applied.
The following diagrams show the 6 timing phases for read and write accesses on the
demultiplexed bus and the multiplexed bus.
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EBC_X8, V1.0d1
9-4
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.2.1.1
Demultiplexed Bus
During demultiplexed access, the address and data signals exists on the bus in parallel.
Phases
A
B
C
D
E
F
ALE
Valid
ADDR, CS
RD
Valid
Read DATA
Programmable
Clocks
0-3 1-2
0-3
0-1
1 - 32
0-3
MCT05374
Figure 9-2
Demultiplexed Bus Read
Phases
A
B
C
D
E
F
ALE
Valid
ADDR, CS
WR
Valid
Write DATA
Programmable
Clocks
0-3 1-2
0-3
0-1
1 - 32
0-3
MCT05375
Figure 9-3
•
•
•
•
•
•
Demultiplexed Bus Write
A phase: Addresses valid, ALE high, no command. CS switch tristate wait states
B phase: Addresses valid, ALE high, no command. ALE length
C phase: Addresses valid, ALE low, no command. R/W delay
D phase: Write data valid, ALE low, no command. Data valid for write cycles
E phase: Command (read or write) active. Access time
F phase: Command inactive, address hold. Read data tristate time, write data hold
time
User’s Manual
EBC_X8, V1.0d1
9-5
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.2.1.2
Multiplexed Bus
During time multiplexed access, the address and data signals share the same external
lines.
Phases
A
B
C
D
E
F
ALE
Valid
ADDR, CS
RD
Address Valid
RD DATA
Programmable
Clocks
0-3 1-2
0-3
Data In
0-1
1 - 32
0-3
MCT05376
Figure 9-4
Multiplexed Bus Read
Phases
A
B
C
D
E
F
ALE
Valid
ADDR, CS
WR
WR DATA
Programmable
Clocks
Address Valid
0-3 1-2
0-3
Data Out
0-1
1 - 32
Next Address
0-3
MCT05377
Figure 9-5
•
•
•
•
•
•
Multiplexed Bus Write
A phase: addresses valid, ALE high, no command. CS switch tristate wait states
B phase: addresses valid, ALE high, no command. ALE length
C phase: addresses valid, ALE low, no command. Address hold, R/W delay
D phase: address tristate for read cycles, data valid for write cycles, ALE low, no
command
E phase: command (read or write) active. Access time
F phase: command inactive, address hold. Read data tristate time, write data hold
time
User’s Manual
EBC_X8, V1.0d1
9-6
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.2.2
Bus Cycle Phases
This chapter provides a detail description of each phase of an external memory bus
access cycle.
9.2.2.1
A Phase - CS Change Phase
The A phase can take 0-3 clocks. It is used for tristating databus drivers from the
previous cycle (tristate wait states after chip select switch).
A phase cycles are not inserted at every access cycle, but only when changing the CS.
If an access using one CS (CSx) ends and the next access with a different CS (CSy) is
started, then A phase cycles are performed according to the bits set in the first CS
(CSx). This feature is used to optimize wait states with devices having a long turn-off
delay at their databus drivers, such as EPROMs and flash memories.
The A phase cycles are inserted while the addresses and ALE of the next cycle are
already applied.
If there are some idle cycles between two accesses, these clocks are taken into account
and the A phase is shortened accordingly. For example, if there are three tristate cycles
programmed and two idle cycles occur, then the A phase takes only one clock.
9.2.2.2
B Phase - Address Setup/ALE Phase
The B phase can take 1-2 clocks. It is used for addressing devices before giving a
command, and defines the length of time that ALE is active. In multiplexed bus mode,
the address is applied for latching.
9.2.2.3
C Phase - Delay Phase
The C phase is similar to the A an B phases but ALE is already low. It can take 0-3 clocks.
In multiplexed bus mode, the address is held in order to be latched safely. Phase C
cycles can be used to delay the command signals (RW delay).
9.2.2.4
D Phase - Write Data Setup/MUX Tristate Phase
The D phase can take 0-1 clocks. It is used to tristate the address on the multiplexed bus
when a read cycle is performed. For all write cycles, it is used to ensure that the data are
valid on the bus before the command is applied.
9.2.2.5
E Phase - RD/WR Command Phase
The E phase is the command or access phase, and takes 1-32 clocks. Read data are
fetched, write data are put onto the bus, and the command signals are active. Read data
are registered with the terminating clock of this phase.
The READY function lengthens this phase, too. READY-controlled access cycles may
have an unlimited cycle time.
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EBC_X8, V1.0d1
9-7
V2.1, 2008-08
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System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.2.2.6
F Phase - Address/Write Data Hold Phase
The F phase is at the end of an access. It can take 0-3 clocks.
Addresses and write data are held while the command is inactive. The number of wait
states inserted during the F phase is independently programmable for read and write
accesses. The F phase is used to program tristate wait states on the bidirectional data
bus in order to avoid bus conflicts for read accesses and to assure data hold times for
write accesses. The F phase is configured individually for read and write accesses.
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EBC_X8, V1.0d1
9-8
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.2.3
Bus Cycle Examples: Fastest Access Cycles
The fastest possible bus cycle in a system depends also on the pad timing. Therefore,
the number of required cycles for a bus access depends on the current system
frequency. The minimum bus cycles shown below cannot be achieved at very high
system frequencies.
b
e
CLK
ALE
ADDR, CS
Valid
RD
DATA In
Valid
MCT05378
Figure 9-6
Fastest Read Cycle Demultiplexed Bus
b
e
CLK
ALE
ADDR, CS
Valid
WR
DATA Out
Valid
MCT05379
Figure 9-7
Fastest Write Cycle Demultiplexed Bus
User’s Manual
EBC_X8, V1.0d1
9-9
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
b
e
d
f
CLK
ALE
ADDR, CS
Valid
RD
Muxed
Address Out /
Data In
Addr. Valid
Data Valid
MCT05380
Figure 9-8
Fastest Read Cycle Multiplexed Bus
b
e
CLK
ALE
ADDR, CS
Valid
RD
Muxed
Address Out /
Data Out
Addr.
Valid
Valid
MCT05381
Figure 9-9
Fastest Write Cycle Multiplexed Bus
User’s Manual
EBC_X8, V1.0d1
9-10
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3
Functional Description
The following section describes the EBC registers and their settings.
9.3.1
Configuration Register Overview
There are 3 groups of EBC registers:
•
•
•
EBC mode registers influencing the global functions.
Chip-select-related registers controlling the functionality linked to one CS.
MultiCAN and USIC related registers are used to control the access to the internal
LXBus.
CS0 is the default chip-select signal that is active whenever no other chip-select or
internal address space is addressed. Therefore, CS0 has no ADDRSEL register.
Note: All EBC registers are write-protected by the EINIT protection mechanism. Thus,
after execution of the EINIT instruction, these registers are not writable anymore.
A 128-byte address space is occupied/reserved by the EBC. Figure 9-10 shows the
mapping in this address space, Table 9-3 lists all implemented configuration registers
with address and reset value.
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V2.1, 2008-08
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System Units (Vol. 1 of 2)
The External Bus Controller EBC
00EE8E
ADDRSEL7
00EE4E
FCONCS7
00EE4A
TCONCS7
00EE48
ADDRSEL4
00EE36
FCONCS4
00EE32
CS7 Channel Control
CS4 Channel Control
TCONCS4
00EE30
ADDRSEL3
00EE2E
FCONCS3
00EE2A
TCONCS3
00EE28
ADDRSEL2
00EE26
FCONCS2
00EE22
TCONCS2
ADDRSEL1
00EE20
00EE1E
FCONCS1
TCONCS1
00EE1A
00EE18
FCONCS0
TCONCS0
00EE12
00EE10
EBCMO D1
00EE02
CS3 Channel Control
CS2 Channel Control
CS1 Channel Control
CS0 Channel Control
G eneral EBC Control
EBCMO D0
00EE00
MCA05382_XC
Figure 9-10 Mapping of EBC Registers into the XSFR Space
Note: CS5 and CS6 register sets are not available (reserved for future LXBus
peripherals).
User’s Manual
EBC_X8, V1.0d1
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V2.1, 2008-08
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System Units (Vol. 1 of 2)
The External Bus Controller EBC
Table 9-3
EBC Memory Table (ordered by physical address)
Name
Physical Description
Address
Reset
Value1)
EBCMOD0
EE00H
EBC Mode Register 0
5000H
EBCMOD1
EE02H
EBC Mode Register 1
003FH
TCONCS0
EE10H
CS0 Timing Configuration Register
7C3DH
FCONCS0
EE12H
CS0 Function Configuration Register
0011H
TCONCS1
EE18H
CS1 Timing Configuration Register
0000H
FCONCS1
EE1AH
CS1 Function Configuration Register
0000H
ADDRSEL1
EE1EH
CS1 Address Size and Range Register
0000H
TCONCS2
EE20H
CS2 Timing Configuration Register
0000H
FCONCS2
EE22H
CS2 Function Configuration Register
0000H
ADDRSEL2
EE26H
CS2 Address Size and Range Register
0000H
TCONCS3
EE28H
CS3 Timing Configuration Register
0000H
FCONCS3
EE2AH
CS3 Function Configuration Register
0000H
ADDRSEL3
EE2EH
CS3 Address Size and Range Register
0000H
TCONCS4
EE30H
CS4 Timing Configuration Register
0000H
FCONCS4
EE32H
CS4 Function Configuration Register
0000H
ADDRSEL4
EE36H
CS4 Address Size and Range Register
0000H
TCONCS7
EE48H
CS7 Timing Configuration Register
0000H
FCONCS7
EE4AH
CS7 Function Configuration Register
0027H
ADDRSEL7
EE4EH
CS7 Address Size and Range Register
2003H
reserved
EE50H
EEFFH
reserved - do not use
–
1) NOTE: Reserved (and not listed) addresses are always read as FFFFH. However, for enabling future
enhancements without any compatibility problems, these addresses should neither be written nor be used as
read value by the software.
User’s Manual
EBC_X8, V1.0d1
9-13
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.2
The EBC Mode Register 0
EBCMODe Register 0
EBCMOD0
EBC Mode Register 0
15
14
13
12
XSFR (EE00H/--)
11
10
9
8
7
RDY RDY ALE BYT WR EBC SLA ARB
POL DIS DIS DIS CFG DIS VE EN
rw
rw
rw
rw
rw
rw
rw
rw
Reset Value: 5000H
6
5
4
3
2
1
CSPEN
SAPEN
rw
rw
Field
Bits
Type
Description
RDYPOL
15
rw
READY Pin Polarity1)
0B
READY is active low
1B
READY is active high
RDYDIS
14
rw
READY Pin Disable1)
0B
READY enabled
1B
READY disabled
ALEDIS
13
rw
ALE Pin Disable
0B
ALE enabled
1B
ALE disabled
BYTDIS
12
rw
BHE Pin Disable
0B
BHE enabled
1B
BHE disabled
WRCFG2)
11
rw
Configuration for Pins WR/WRL, BHE/WRH
0B
WR and BHE
1B
WRL and WRH
EBCDIS
10
rw
EBC Pins Disable
0B
EBC is using the pins for external bus
1B
EBC pins disabled
SLAVE
9
rw
SLAVE Mode Enable
0B
Bus arbiter acts in master mode
1B
Bus arbiter acts in slave mode
ARBEN
8
rw
BUS Arbitration Pins Enable
0B
HOLD, HLDA and BREQ pins are disabled
1B
Pins act as HOLD, HLDA, and BREQ
User’s Manual
EBC_X8, V1.0d1
9-14
0
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
Field
Bits
Type
Description
CSPEN
[7:4]
rw
CSx Pins Enable (only external CSx)
0000BAll external Chip Select pins disabled.
0001BCS0 pin enabled
0010BCS1 and CS0 pin enabled
…
…
0101BFive CSx pins enabled: CS4 - CS0
Else not supported (reserved)
SAPEN
[3:0]
rw
Segment Address Pins Enable
0000B All segment address pins disabled
0001B One: A[16] enabled
…
…
1000B Eight: A[23:16] enabled
Else not supported (reserved)
1) Not available in the 100-pin package.
2)
A change of the bit content is not valid before the next external bus access cycle.
Notes
1. Disabled pins are used for general purpose IO or for alternate functions (see port and
pin descriptions).
2. Bit field CSPEN controls the number of available CSx pins. The related address
windows and bus functions are enabled with the specific ENCSx bits in the
FCONCSx registers (see Page 9-21). There, an additional chip select (CS7) is
defined for internal access to the LXBus peripherals MultiCAN and USIC.
3. The external bus arbitration pins have a separate ARBitration ENable bit (ARBEN)
that has to be set in order to use the pins for arbitration and not for General Purpose
IO (GPIO). If ARBEN is cleared, the arbitration inputs HLDA and HOLD are fixed
internally to an inactive high state. Additionally, the master/slave setting of the arbiter
is done with a separate bit (SLAVE).
4. The reset value depends on the selected startup configuration.
User’s Manual
EBC_X8, V1.0d1
9-15
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.3
The EBC Mode Register 1
EBC MODe register 1 controls the general use of port pins for external bus.
EBCMOD1
EBC Mode Register 1
XSFR (EE02H/--)
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
7
6
Reset Value: 003FH
5
4
WRP DHP ALP A0P
DIS DIS DIS DIS
rw
rw
rw
rw
3
2
1
0
APDIS
rw
Field
Bits
Type
Description
WRPDIS
7
rw
WR/WRL Pin Disable
0B
WR/WRL pin enabled
1B
WR/WRL pin disabled
DHPDIS
6
rw
Data High Port Pins Disable
0B
Address/Data bus pins 15-8 enabled
1B
Address/Data bus pins 15-8 disabled
ALPDIS
5
rw
Address Low Pins Disable
0B
Address bus pins 7-0 generally enabled
(depending on APDIS/A0PDIS)
1B
Address bus pins 7-0 disabled
A0PDIS
4
rw
Address Bit 0 Pin Disable
0B
Address bus pin 0 enabled
1B
Address bus pin 0 disabled
APDIS
[3:0]
rw
Address Port Pins Disable
0000B Address bus pins 15-1 enabled
0001B Pin A15 disabled, A14-A1 enabled
0010B Pins A15-A14 disabled, A13-A1 enabled
0011B Pins A15-A13 disabled, A12-A1 enabled
…
…
1110B Pins A15-A2 disabled, A1 enabled
1111B Address bus pins 15-1 disabled
Notes
1. Disabled bus pins may be used for general purpose IO or for alternate functions (see
port and pin descriptions).
2. After reset, the address and data bus pins are enabled, but in Idle state.
User’s Manual
EBC_X8, V1.0d1
9-16
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.4
The Timing Configuration Registers TCONCSx
The timing control registers are used to program the described cycle timing for the
different access phases (see Section 9.2.2). The timing control registers may be
reprogrammed during code fetches from the affected address window. The new settings
are first valid for the next access.
TCONCS0
Timing Cfg. Reg. for CS0
15
14
13
12
11
XSFR (EE10H/--)
10
9
8
7
6
Reset Value: 7C3DH
5
4
3
2
1
0
-
WRPHF
RDPHF
PHE
PHD
PHC
PHB
PHA
-
rw
rw
rw
rw
rw
rw
rw
Field
Bits
WRPHF
[14:13] rw
Write Phase F
00B 0 clock cycles
…
…
11B 3 clock cycles (default)
RDPHF
[12:11] rw
Read Phase F
00B 0 clock cycles (default)
…
…
11B 3 clock cycles
PHE
[10:6]
rw
Phase E
00000B1 clock cycle
…
… (default: 9 clock cycles)
11111B32 clock cycles
PHD
5
rw
Phase D
0B
0 clock cycles (default)
1B
1 clock cycle
PHC
[4:3]
rw
Phase C
00B 0 clock cycles (default)
…
…
11B 3 clock cycles
PHB
2
rw
Phase B
0B
1 clock cycle (default)
2 clock cycles
1B
User’s Manual
EBC_X8, V1.0d1
Type
Description
9-17
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
Field
Bits
Type
Description
PHA
[1:0]
rw
Phase A
00B 0 clock cycles
…
…
11B 3 clock cycles (default)
TCONCSx (x = 1-4)
Timing Cfg. Reg. for CSx
15
14
13
12
11
XSFR (EE10H + x*8/--)
10
9
8
7
Reset Value: 0000H
6
5
4
3
2
1
0
-
WRPHF
RDPHF
PHE
PHD
PHC
PHB
PHA
-
rw
rw
rw
rw
rw
rw
rw
Field
Bits
WRPHF
[14:13] rw
Write Phase F
00B 0 clock cycles
…
…
11B 3 clock cycles
RDPHF
[12:11] rw
Read Phase F
00B 0 clock cycles
…
…
11B 3 clock cycles
PHE
[10:6]
rw
Phase E
00000B1 clock cycle
…
…
11111B32 clock cycles
PHD
5
rw
Phase D
0B
0 clock cycles
1B
1 clock cycle
PHC
[4:3]
rw
Phase C
00B 0 clock cycles
…
…
11B 3 clock cycles
PHB
2
rw
Phase B
0B
1 clock cycle
1B
2 clock cycles
User’s Manual
EBC_X8, V1.0d1
Type
Description
9-18
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
Field
Bits
Type
Description
PHA
[1:0]
rw
Phase A
00B 0 clock cycles
…
…
11B 3 clock cycles
Note: The register TCONCS4 controls the chip select CS4, that is available only in the
144-pin package.
TCONCS7
Timing Cfg. Reg. for CS7
15
14
13
12
11
XSFR (EE48H/--)
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
-
WRPHF
RDPHF
PHE
PHD
PHC
PHB
PHA
-
r
r
r
r
r
r
r
Field
Bits
Type
Description
WRPHF
[14:13] r
Write Phase F
00B 0 clock cycles
RDPHF
[12:11] r
Read Phase F
00B 0 clock cycles
PHE
[10:6]
r
Phase E
00000B1 clock cycle
PHD
5
r
Phase D
0B
0 clock cycles
PHC
[4:3]
r
Phase C
00B 0 clock cycles
PHB
2
r
Phase B
0B
1 clock cycle
PHA
[1:0]
r
Phase A
00B 0 clock cycles
Note: CS7 is used and defined for internal access to the LXBus peripherals MultiCAN
and USIC.
User’s Manual
EBC_X8, V1.0d1
9-19
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.5
The Function Configuration Registers FCONCSx
The Function Control registers are used to control the bus and READY functionality for
a selected address window. It can be distinguished between 8 and 16-bit bus and
multiplexed and demultiplexed accesses. Furthermore it can be defined whether the
address window (and its chip select signal CSx) is generally enabled or not.
FCONCS0
Function Cfg. Reg. for CS0
XSFR (EE12H/--)
15
14
13
12
11
10
9
8
7
6
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Reset Value: 0011H
5
4
3
-
BTYP
-
-
rw
-
2
1
0
RDY RDY EN
MOD EN CS
rw
rw
rw
Field
Bits
Type
Description
BTYP
[5:4]
rw
Bus Type Selection
00B 8 bit Demultiplexed
01B 08 bit Multiplexed
10B 16 bit Demultiplexed
11B 16 bit Multiplexed
RDYMOD
2
rw
Ready Mode
0B
Asynchronous READY
1B
Synchronous READY
RDYEN
1
rw
Ready Enable
0B
Access time is controlled by bit field PHEx
1B
Access time is controlled by bit field PHEx and
READY signal
ENCS1)
0
rw
Enable Chip Select
0B
Disable
1B
Enable
1) Disabling a chip select not only effects the chip select output signal, it also deactivates the respective address
window of the disabled chip select. A disabled address window is also ignored by an address window
arbitration (see Chapter 9.3.6.3).
User’s Manual
EBC_X8, V1.0d1
9-20
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
FCONCSx (x = 1-4)
Function Cfg. Reg. for CSx
XSFR (EE12H + x*8/--)
15
14
13
12
11
10
9
8
7
6
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Reset Value: 0000H
5
4
3
-
BTYP
-
-
rw
-
2
1
0
RDY RDY EN
MOD EN CS
rw
rw
rw
Field
Bits
Type
Description
BTYP
[5:4]
rw
Bus Type Selection
00B 8 bit Demultiplexed
01B 8 bit Multiplexed
10B 16 bit Demultiplexed
11B 16 bit Multiplexed
RDYMOD
2
rw
Ready Mode
0B
Asynchronous READY
Synchronous READY
1B
RDYEN
1
rw
Ready Enable
0B
Access time is controlled by bit field PHEx
1B
Access time is controlled by bit field PHEx and
READY signal
ENCS1)
0
rw
Enable Chip Select
0B
Disable
1B
Enable
1) Disabling a chip select not only effects the chip select output signal, it also deactivates the respective address
window of the disabled chip select. A disabled address window is also ignored by an address window
arbitration (see Chapter 9.3.6.3).
Notes
1. The register FCONCS4 controls the chip select CS4, that is available only in the 144pin package.
2. The specific ENCSx bits in the FCONCSx registers enable the related address
windows and bus functions and the corresponding chip select signal CSx. But it
depends on the definition of bit field CSPEN in register EBCMOD0 how many CSx
pins are available and used for the external system. If an address window is enabled
but no external pin is available for the CSx, the external bus cycle is executed without
chip select signal.
User’s Manual
EBC_X8, V1.0d1
9-21
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
FCONCS7
Function Cfg. Reg. for CS7
XSFR (EE4AH/--)
15
14
13
12
11
10
9
8
7
6
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Reset Value: 0027H
5
4
3
-
BTYP
-
-
r
-
2
1
0
RDY RDY EN
MOD EN CS
r
r
r
Field
Bits
Type
Description
BTYP
[5:4]
r
Bus Type Selection
10B 16 bit Demultiplexed
RDYMOD
2
r
Ready Mode
1B
Synchronous READY
RDYEN
1
r
Ready Enable
1B
Access time is controlled by bit field PHEx and
READY signal
ENCS
0
r
Enable Chip Select
1B
Enable
Notes
1. With ENCS7 the chip select CS7 and its related register set is enabled and defined
for internal access to the LXBus peripherals MultiCAN and USIC.
User’s Manual
EBC_X8, V1.0d1
9-22
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.6
The Address Window Selection Registers ADDRSELx
Each chip select signal is associated with an ADDRSEL register.
9.3.6.1
Registers ADDRSELx
ADDRSELx (x = 1-4)
Address Range/Size for CSx XSFR (EE16H + x*8/--)
15
14
13
12
11
10
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
RGSAD
RGSZ
rw
rw
Field
Bits
Type
Description
RGSAD
[15:4]
rw
Address Range Start Address Selection
RGSZ
[3:0]
rw
Address Range Size Selection (see Table 9-4)
0
Note: There is no register ADDRSEL0, as register set FCONCS0/TCONCS0 controls all
external accesses outside the address windows built by the enabled (by ENCS bit
in FCONCSx) address selects ADDRSELx. The register ADDRSEL4 controls the
chip select CS4, that is available only in the 144-pin package.
ADDRSEL7
Address Range/Size for CS7
15
14
13
12
11
XSFR (EE4EH/--)
10
9
8
7
6
Reset Value: 2003H
5
4
3
2
1
RGSAD
RGSZ
r
r
Field
Bits
Type
Description
RGSAD
[15:4]
r
Address Range Start Address 20’0000H
RGSZ
[3:0]
r
Address Range Size 32 Kbytes (see Table 9-4)
9.3.6.2
0
Definition of Address Areas
The enabled register sets FCONCSx/TCONCSx/ADDRSELx (x = 1 … 4, 7) define
separate address areas within the address space of the XC2700. Within each of these
address areas the conditions of external accesses and LXBus accesses (x = 7) can be
User’s Manual
EBC_X8, V1.0d1
9-23
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
controlled separately, whereby the different address areas (windows) are defined by the
ADDRSELx registers. Each ADDRSELx register cuts out an address window, where the
corresponding parameters of the registers FCONCSx and TCONCSx are used to control
external accesses. The range start address of such a window defines the most
significant address bits of the selected window which are consequently not needed to
address the memory/module in this window (Table 9-4). The size of the window chosen
by ADDRSELx.RGSZ defines the relevant bits of ADDRSELx.RGSAD (marked with ‘R’)
which are used to select with the most significant bits of the request address the
corresponding window. The other bits of the request address are used to address the
memory locations inside this window. The lower bits of ADDRSELx.RGSAD (marked ‘x’)
are disregarded.
The address area from 00’8000H to 00’FFFFH (32 Kbytes) is reserved for CPU internal
registers and data RAM, the area from BF’0000H to BF’7FFFH (32 Kbytes) for internal
startup memory and the area from C0’0000H to FF’FFFFH (4 Mbytes) is used by the
internal program memory. Therefore, these address areas cannot be used by external
resources connected to the external bus.
Table 9-4
Address Range and Size for ADDRSELx
ADDRSELx
Address Window
Range
Size
RGSZ
Relevant (R) Bits
of RGSAD
Selected
Address
Range
Range Start Address A[23:0]
Selected with R-bits of RGSAD
3…0
15 … 4
Size
A23 … A0
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
11xx
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRx
RRxx
Rxxx
xxxx
4 Kbytes
8 Kbytes
16 Kbytes
32 Kbytes
64 Kbytes
128 Kbytes
256 Kbytes
512 Kbytes
1 Mbytes
2 Mbytes
4 Mbytes
8 Mbytes
reserved1)
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRRR
RRR0
RR00
R000
----
RRRR
RRRR
RRRR
RRRR
RRRR
RRRx
RRxx
Rxxx
xxxx
xxxx
xxxx
xxxx
xxxx
RRRR
RRRx
RRxx
Rxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
RRRR
RRRR
RRRR
RRRR
RRRR
RRR0
RR00
R000
0000
0000
0000
0000
----
RRRR
RRR0
RR00
R000
0000
0000
0000
0000
0000
0000
0000
0000
----
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
----
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
----
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
----
1) The complete address space of 12 Mbytes can be selected by the default chip select CS0.
Note: The range start address can only be on boundaries specified by the selected
range size according to Table 9-4.
User’s Manual
EBC_X8, V1.0d1
9-24
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.6.3
Address Window Arbitration
For each external access the EBC compares the current address with all address select
registers (programmable ADDRSELx and hard wired address select registers for startup
memory) of enabled windows. This comparison is done in four levels:
Priority 1:
Registers ADDRSELx [x = 2, 4] are evaluated first. A window match with one of these
registers directs the access to the respective external area using the corresponding set
of control registers FCONCSx/TCONCSx and ignoring registers ADDRSELy. An
overlapping of windows of this group will lead to an undefined behaviour.
Priority 2:
A match with registers ADDRSELy [y = 1, 3, 7] directs the access to the respective
external area using the corresponding set of control registers FCONCSy/TCONCSy. An
overlapping of windows of this group will lead to an undefined behaviour. Overlaps with
priority 2 ADDRSELx are only allowed for the (x, y) pairs (2, 1) and (4, 3).
Priority 3:
If there is no match with any address select register (neither the hardware ones nor the
programmable ADDRSEL) the access to the external bus uses the general set of control
registers FCONCS0/TCONCS0 if enabled.
User’s Manual
EBC_X8, V1.0d1
9-25
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.7
Ready Controlled Bus Cycles
In cases, where the response (access) time of a peripheral is not constant, or where the
programmable wait states are not enough, the EBC provides external bus cycles that are
terminated via a READY input signal.
A READY controlled bus cycle requires one synchronization cycle to terminate.
Programmed phase F cycles include this synchronization cycle. Therefore, setting
TCONCSx phase F to 0 clock cycles will have the same effect as setting it to 1 clock
cycle.
9.3.7.1
General
If READY is enabled, the EBC counts a programmable number of clock cycles (1 … 32)
during phase E and then monitors the internal READY line (see Figure 9-11) to
determine the actual end of the current bus cycle. The external device drives READY
active in order to indicate that data has been latched (write cycle) or is available (read
cycle).
The READY pin is generally enabled by setting the bit RDYDIS in EBCMOD0 to ‘0’ in
order to switch the corresponding port pin. Also the polarity of the READY is defined
inside the EBCMOD0 register on the RDYPOL bit.
For a specific address window the READY function is enabled via the RDYEN bit in the
FCONCSx register. With FCONCSx.RDYMOD the READY is handled either in
synchronous or in asynchronous mode (see also Figure 9-11).
When the READY function is enabled for a specific address window, each bus cycle
within this window must be terminated with an active READY signal. Otherwise the
controller hangs until the next reset. This is also the case for an enabled RDYEN but a
disabled READY port pin.
MUX
READY Ext
Async.
0
1
Sync.
1
EBCMOD0.RDYPOL
MUX
0
1
READY Int
FCONCSx.RDYMODx
MCA05383
Figure 9-11 External to Internal READY Conversion
User’s Manual
EBC_X8, V1.0d1
9-26
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.7.2
The Synchronous/Asynchronous READY
The synchronous READY provides faster bus cycles, but requires setup and hold times
to be met. The CLKOUT signal should be enabled and may be used by the peripheral
logic to control the READY timing in this case.
The asynchronous READY is less restrictive, but requires one additional wait state
caused by the internal synchronization. As the asynchronous READY is sampled earlier
programmed wait states may be necessary to provide proper bus cycles.
A READY signal (especially asynchronous READY) that has been activated by an
external device may be deactivated in response to the trailing (rising) edge of the
respective command (RD or WR).
Bus Cycle with active READY
Bus Cycle extended via READY
3 programmed phase E
wait states(TCONCSx.PHE=2)
3 programmed phase E
wait states(TCONCSx.PHE=2)
ALE
RD/WR
sync. READY
async. READY
sampling of READY input
not interesting READY cycles
Figure 9-12 READY Controlled Bus Cycles
9.3.7.3
Combining the READY Function with Predefined Wait States
Typically an external wait state or READY control logic takes a while to generate the
READY signal when a cycle was started. After a predefined number of clock cycles the
EBC will start checking its READY line to determine the end of the bus cycle.
When using the READY function with so-called ‘normally-ready’ peripherals, it may lead
to erroneous bus cycles, if the READY line is sampled too early. These peripherals pull
their READY output active, while they are idle. When they are accessed, they drive
READY inactive until the bus cycle is complete, then drive it active again. If, however,
the peripheral drives READY inactive a little late, after the first sample point of the
XC2700, the controller samples an active READY and terminates the current bus cycle
too early. By inserting predefined wait states the first READY sample point can be shifted
to a time, where the peripheral has safely controlled the READY line.
User’s Manual
EBC_X8, V1.0d1
9-27
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
The External Bus Controller EBC
9.3.8
External Bus Arbitration
The XC2700 supports multi master systems on the external bus by its external bus
arbitration. This bus arbitration allows an external master to request the external bus.
The XC2700 will release the external bus and will float the data, address bus, and control
lines.
Note: In this case, the pins are controlled by their respective IOCR registers (lower 3
bits). It is recommended to activate a pull-up or pull-down device by preconfiguring the IOCR registers. The default setting leaves the pins floating. In
particular it is strongly recommended to configure pull-ups at least for the control
lines RD, WR, and BREQ, and a pull-down for ALE. External pull resistors serve
the same purpose, of course.
9.3.8.1
Initialization of Arbitration
During reset all arbitration pins are tristate. After reset the XC2700 EBC always starts in
‘init mode’ where the external bus is available but no arbitration is enabled. All arbitration
pins are ignored in this state. Other XC2700 EBCs connected to the external bus, also
assume to have the bus, so potential bus conflicts are not resolved. For a multi master
system the arbitration should be initialized first before starting any bus access. The EBC
can either be chosen as arbitration master or as arbitration slave by programming bit
SLAVE in register EBCMOD0. The selected mode and the arbitration gets active by the
first setting of bit HLDEN in (CPU) register PSW. Afterwards a change of the
slave/master mode is not possible without resetting the device. Of course, for arbitration
the dedicated pins have to be activated by setting bit EBCMOD0.ARBEN.
9.3.8.2
Arbitration Master Scheme
If the XC2700 EBC is configured as arbitration master, it is default owner of the external
bus, controls the arbitration protocol and drives the bus also during idle phases with no
bus requests. To perform the arbitration handshake, a HOLD input allows the request of
the external bus from the arbitration master. When the arbitration master hands over the
bus to the requester, this is signaled by driving the hold acknowledge pin HLDA low,
which remains at this level until the arbitration slave frees the bus by releasing its request
on the HOLD input. If the arbitration master is not the owner of the bus it releases the
external bus interface.
Note: Pull devices provide a safe inactive state of the external bus during the bus owner
transition. Make sure to enable these pull devices on the respective port pins
before using the bus arbitration (see also note above).
In this state the arbitration slave can take over the bus.
If the arbitration master requires the bus again, it can request the bus via the bus request
signal BREQ. As soon as the arbitration master regains the bus it releases the BREQ
signal and drives HLDA to high.
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The External Bus Controller EBC
Not fixed number of cycles (0 … n)
HOLD
HLDA
Earliest Change
BREQ
CSx, WRH
Pull Up
WR/WRL, RD
Not Active Driven
ADD, DATA
High Impedance
BHE
MCT05385
Figure 9-13 Releasing the Bus by the Arbitration Master
Note: Figure 9-13 shows the first possibility for BREQ to get active. The XC2700 will
complete the currently running bus cycle before granting the external bus as
indicated by the broken lines.
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The External Bus Controller EBC
HOLD
HLDA
No BREQ Request
BREQ
Latest Possible Change
CSx, WRH
WR/WRL, RD
ADD, BHE
Pull Up
Not Active Driven
High Impedance
MCT05386
Figure 9-14 Regaining the Bus by the Arbitration Master
Note: The falling BREQ edge shows the last chance for BREQ to trigger the indicated
regain-sequence. Even if BREQ is activated earlier the regain-sequence is
initiated by HOLD going high. Please note that HOLD may also be deactivated
without the XC2700 requesting the bus.
9.3.8.3
Arbitration Slave Scheme
If the EBC is configured as arbitration slave it is by default not owner of the external bus
and has to request the bus first. As long as it has not finished all its queued requests and
the arbitration master is not requesting the bus the arbitration slave stays owner of the
bus. For the description of the signal handling of the handshake see Chapter 9.3.8.2.
For the arbitration slave the hold acknowledge pin HLDA is configured as input.
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The External Bus Controller EBC
9.3.8.4
Bus Lock Function
If an application in a multi master system requires a sequence of undisturbed bus access
it has the possibility (independently of being arbitration slave or master) to lock1) the bus
by setting the PSW bit HLDEN to ‘0’. In this case the locked EBC will not answer to HOLD
requests from other external bus master until HLDEN is set to ‘1’ again. Of course a
locked bus master not owning the bus can request the external bus. If a master and a
slave are requesting the external bus at the same time for several accesses, they toggle
the ownership after each access cycle if the bus is not locked.
9.3.8.5
Direct Master Slave Connection
If one XC2700 is configured as master and the other as slave and both are working on
the same external bus as bus master, they can be connected directly together for bus
arbitration as shown in Figure 9-15. As both EBCs assume after reset to own the
external bus, the ‘slave’ CPU has to be released from reset and initialized first, before
starting the ‘master’ CPU. The other way is to start both systems at the same time but
then both EBC must be configured from internal memory and the PSW.HLDEN bits set
before the first external bus request.
EBC in
Master Mode
EBC in
Slave Mode
HOLD
HOLD
HLDA
HLDA
BREQ
BREQ
MCA05387
Figure 9-15 Connecting two XC2700 Using Master/Slave Arbitration
When multiple (more than two) bus masters (XC2700 or other masters) shall share the
same external resources an additional external bus arbiter logic is required that
determines the currently active bus master and that controls the necessary signal
sequences.
1) It is not allowed to lock the bus by resetting the EBCMOD0.ARBEN bit, as this can lead to bus conflicts.
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The External Bus Controller EBC
9.3.9
Shutdown Control
In case of a shutdown request from the SCU the EBC ensures that all the different
functions of the EBC are in a non-active state before the whole chip is switched to a
power save mode. A running bus cycle is finished, still requested bus cycles are
executed. Depending on the master/slave configuration of EBC, the external bus arbiter
is controlled for regaining the bus (master) before performing the requested cycles, or
the external bus must be released after complete execution of still requested bus cycles
(see Table 9-5). Only when this shutdown sequence is terminated, the shutdown
acknowledge is generated from EBC (and from other modules, as described for SCU)
and the chip can enter the requested mode.
Table 9-5 gives an overview of the shutdown control in EBC depending on the EBC
configuration.
Table 9-5
EBC Shutdown Control
Arbitration
Mode
Master Mode
Slave Mode
Bus Control With Control of Without
the Bus
Control of the
Bus
With Control of Without
the Bus
Control of the
Bus
–
Finish all
pending
requests.
Send shutdown
acknowledge
after leaving the
bus.
Finish all
pending cycle
requests.
Send shutdown
acknowledge
with the control
of the bus.
User’s Manual
EBC_X8, V1.0d1
Ask for the bus.
Finish all
pending cycle
requests.
Send shutdown
acknowledge
with the control
of the bus.
9-32
Ask for the bus if
needed and
finish all
requests.
Send shutdown
acknowledge
after leaving the
bus.
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9.4
LXBus Access Control and Signal Generation
Access control to the LXBus1) is required for the on-chip peripherals MultiCAN and USIC.
For these accesses, CS7 and its fixed control registers ADDRSEL7, TCONCS7, and
FCONCS7 are used. The address range (from 20’0000H to 20’7FFFH), defined by the
ADDRSEL7 value of 2003H, is located in the ’External IO Area’. Only for the External IO
Area (within the total external address range) it is guaranteed that a read access is
executed after a preceding write access.
The value of the bus function control register FCONCS7 is selected according to the
requirements of the MultiCAN and USIC: 16-bit demultiplexed bus, access time
controlled with synchronous READY. This function control is represented by the
FCONCS7 value of 0027H.
The minimum LXBus cycle timing (as controlled with register TCONCS7) will be
lengthened with waitstate(s) controlled by the MultiCAN/USIC itself with the READY
function. This timing control is defined by the TCONCS7 value of 0000H.
Accesses to the LXBus do not generate valid external bus cycles on an enabled external
bus interface:
•
•
•
the configured chip select signals are driven high
the external control signal pins (RD, WR, ALE) are driven inactive and then switched
to input
the other bus pins are switched to input, the address lines may reflect the LXBus
address for a short period
Note: In this case, the pins are controlled by their respective IOCR registers (lower 3
bits). It is recommended to activate a pull-up or pull-down device by preconfiguring the IOCR registers. The default setting leaves the pins floating. In
particular it is strongly recommended to configure pull-ups at least for the control
lines RD and WR, and a pull-down for ALE. External pull resistors serve the same
purpose, of course.
1) The LXBus is an internal (local) extension of the external bus. It is controlled by the EBC identically to the
external bus, using the select and cycle control functions as described for the external bus.
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Startup Configuration and Bootstrap Loading
10
Startup Configuration and Bootstrap Loading
After start-up, the XC2700 executes code out of an on-chip or off-chip program memory.
The initial code source can be selected via hardware configuration (i.e. defined levels on
specific pins):
•
•
•
Internal Start Mode: executes code out of the on-chip program Flash.
External Start Mode: executes code out of an off-chip memory connected to the
External Bus Interface.
Bootstrap Loading Modes: execute code out of the on-chip program SRAM
(PSRAM). This code is downloaded beforehand via a selectable serial interface.
10.1
Start-Up Mode Selection
After any start-up the currently valid start-up configuration is indicated in bitfield HWCFG
of register SCU_STSTAT. Table 10-1 summarizes the defined start up modes.
A start-up configuration can be selected in two ways:
1. Via an externally applied hardware configuration upon a Power-on or Internal
Application reset
The hardware configuration is applied to Port 10 pins (P10.[3:0]).
The hardware that activates a startup configuration during reset may be simple pull
resistors for systems that use this feature upon every reset. You may want to use a
switchable solution (via jumpers or an external signal) for systems that only
temporarily use a hardware configuration.
2. By executing the following software sequence (using SCU_SWRSTCON and
SCU_RSTCON1 registers):
a) Write respective configuration value (refer to Table 10-1) to bitfield
SCU_SWRSTCON.SWCFG;
b) Assign desired type of reset to the software request trigger by writing into
SCU_RSTCON1.SW bitfield (by default SCU_RSTCON1.SW=00B meaning no
reset generated by software request trigger)
c) Set Software Boot Configuration bit: SCU_SWRSTCON.SWBOOT = 1;
d) Trigger a software reset by activating Software Reset Request:
SCU_SWRSTCON.SWRSTREQ = 1.
There is a differentiation of XC2700 behavior in case of Application reset which must be
noted:
•
•
an Application reset triggered by hardware request (for example WDT, ESRx) does
not cause evaluation of the P10 pins - the same start-up configuration is used as after
the previous reset;
an
Application
reset
triggered
by
software
(with
setting
SCU_SWRSTCON.SWRSTREQ=1) can have different consequences:
– if Software Boot Configuration is selected (SCU_SWRSTCON.SWBOOT=1) - the
start-up configuration is updated from SCU_SWRSTCON.SWCFG bitfield;
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– otherwise - the same start-up configuration is used as after the previous reset.
Table 10-1
XC2700 Start-Up Mode Configuration
Start-Up Mode
STSTAT.HWCFG
Value 1)
Configuration Pins
P10.[3:0] 2)
Internal Start from Flash
0000’0011B
x
x
1
1
Standard UART Bootloader mode
0000’0110B
x
1
1
0
Enhanced UART Bootloader mode
0000’0010B
x
0
1
0
CAN Bootloader mode
0000’0101B
x
1
0
1
SSC Bootloader mode
0000’1001B
1
0
0
1
External Start
0000’0000B
0
0
0
0
1) Bitfield HWCFG can be loaded from Port 10 or from bitfield SWCFG in register SWRSTCON.
2) x means that the level on the corresponding pin is irrelevant.
10.2
Device Status after Start-Up
The main parameters of XC2700-status at the point of time when the first user instruction
is executed are summarized below.
10.2.1
Registers modified by the Start-Up Procedure
Table 10-2 shows the XC2700 registers which are initialized during the start-up
procedure with values different from their reset-content (defined into respective registerdescriptions).
There are two groups of registers regarding the way they are affected by start-up
procedure:
1. registers initialized after any start-up;
2. registers initialized after start-up triggered by a power-on in DMP_1 power domain.
Note: Power-on in DMP_M domain means power-on also in DMP_1.
The registers in Table 10-2 are grouped in accordance to the above differentiation.
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Table 10-2
XC2700 Registers installed by the Start-Up Procedure
Register
Value
Comments
1. After any start-up:
TRAPDIS
009FH
All SCU-controlled traps disabled except PET and RAT
RSTCON1
UU:
Application Reset request generated by WDT
11uu:UH
WDTCS
UUU:
uuu0H
Overflow Error Status is reset ; the original flag is saved in
STMEM0.WDTCSOE (refer to Page 10-4)
TRAPDIS
009FH
All SCU-controlled traps disabled except PET and RAT
PMTSR
0100H
Parity Error Sensitivity Enabled
2. After power-on in DMP_1:
PLLCON0
0F00H
PLL in Normal Mode, N-divider = 16
PLLCON1
000AH
Internal clock as input for PLL
PLLCON2
0000H
K1-divider = 1
PLLCON3
8007H
K2-divider = 8
SYSCON0
0002H
The PLL output (fPLL) used as system clock
WUOSCCON
0000H
Wake up Oscillator enabled with fWU approx. 500kHz
HPOSCCON
U:u0uu: PLLSTAT.FINDIS bit will not be set
UUH
in an OSCWDT emergency case
PLLOSCCON
XXXXH
Device-specific value (chip-to-chip trimming)
EVRMCON0
0110H
EVR_M Control 0 register
EVR1CON0
0D10H
EVR_1 Control 0 register
EVRMCON1
0101H
EVR_M Control 1 register
EVRMSET15VHP 001BH
EVR_1 Setting for 1.5V HP register
EVR1SET15VHP
001BH
EVR_1 Setting for 1.5V HP register
PVCMCON0
2544H
PVC_M Control for Step 0 register
PVC1CON0
2544H
PVC_1 Control for Step 0 register
SWDCON0
0941H
SWD Control 0 register
EVRMSET10V
005BH
EVR_M Setting for 1.0V register
EVRMSET15VLP
00DDH
EVR_M Setting for 1.5V LP register
EVR1SET10V
005BH
EVR_1 Setting for 1.0V register
EVR1SET15VLP
00DDH
EVR_1 Setting for 1.5V LP register
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Two additional points regarding register-content after start-up must be taken into
account:
•
•
The register-modifications shown in Table 10-2 happen independently on the startup mode currently selected, which means also in Internal Start mode.
Next to these, in other modes - External Start and Bootstrap Loading
(Chapter 10.5, Chapter 10.6) - more registers are additionally modified during startup, as described into respective Specific Settings chapters for any of the modes.
The values seen in some bits after start-up can be affected not only by the reset
procedure itself but also by other events during and even before the last start-up - for
example an Emergency Event can change the clock-system status.
Therefore occasional exceptions are possible from the above values (as well as from
the default register content after reset), mainly for some clock control/status flags. For
more information on such special cases and their handling - refer to XC2000
Programmer’s Guide.
10.2.2
System Frequency
The system clock which is active when the first user instruction is executed, depends on
the currently selected start-up mode and the last start-up trigger:
•
•
•
after power-on in all modes except CAN Bootstrap Loader (Chapter 10.6.4) - 10MHz
(nominal value) from the XC2700 internal oscillator (doubled frequency);
after power-on in CAN Bootstrap Loader mode (Chapter 10.6.4) - the frequency of
an external crystal connected to XTAL-pins, 4MHz minimum;
after any functional (not power-on) reset - the clock system configuration is not
changed by device start-up, respectively the system frequency remains as before the
reset.
10.2.3
Watchdog Timer handling
The Watchdog Timer (WDT) in XC2700 is always enabled by the start-up procedure and
configured to generate Application Reset.
Therefore, the user software must:
•
•
if WDT-usage is foreseen by the code - service it for a first time within approx. 65500
system clock cycles after start-up;
otherwise - disable it within the same time frame as above but before to execute End
of Init (EINIT).
Watchdog Timer Double Error
“Watchdog Timer Double Error” in XC2700 means the following sequence of events:
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1. WDT overflow happens - WDT rolls from FFFFH to 0000H and enters
Mode;
2. device starts-up anew - could be due to WDT-reset (unavoidable once
Mode is entered) or another reset request triggered before Prewarning
expired;
3. a following WDT-reset causes the next - after the start-up according to
restart.
Prewarning
Prewarning
Mode been
2. - device
In other words, in this scenario WDT overflow happens two times one after another with
one device restart in between.
Such a situation is considered as indicating major and systematic malfunction and the
device enters Start-up Error state (refer to Chapter 10.2.4).
This (WDT Double Error) feature is supported in XC2700 by WDTCSOE bit in STMEM0
register (refer to Page 10-7) which bit is copied by the start-up procedure from
SCU_WDTCS.OE (refer to WDT Control and Status Register, Section 6.11.4.2),
SCU_WDTCS.OE is reset immediately afterwards. Next, upon any device restart the
following conditions are checked by the start-up procedure:
•
•
Is STMEM0.WDTCSOE bit set? AND
Is the start-up caused by a WDT-reset?
If both the above conditions are true - a Watchdog Timer Double Error is recognized and
Start-up Error state is immediately entered by the device.
Therefore, if entering power-save mode upon WDT Double Error is not desired for some
reasons, the user software must care to reset STMEM0.WDTCSOE bit. Different
possibilities for handling exist:
•
•
reset the bit always at the beginning of application code or inside the WDT
Prewarning Mode handler routine (if any) - in such a case WDT Double Error will be
never recognized;
reset the bit together with servicing the WDT - in such a case WDT Double Error will
be recognized only if WDT has not been serviced at all after the previous overflow
and device restart.
Note: If after the first WDT overflow/device restart a second reset is triggered by another
source but not WDT, the STMEM0.WDTCSOE bit will be automatically reset by
the start-up procedure.
10.2.4
Start-up Error state
To prevent possible negative consequences for the device and/or the system, upon
unrecoverable error during startup XC2700 is put onto a stable, passive and neutral to
the external world state - power-save mode with DMP_1 shut down and DMP_M
powered with 1V.
This state can be exited with power-on reset only.
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10.3
Special Start-up Features
XC2700 supports some special features, which allow the user software to influence the
device start-up, providing additional functionality next to the above (in Chapter 10.1)
described.
10.3.1
Supplementary Start-up Information from/to the User
The special start-up features require/provide additional information from/to the
application software, using a dedicated register inside the System Control Unit STMEM0.
STMEM0 Register
The SCU_STMEM0 register is located in DMP_M power-supply domain and is Securityprotected.
The following start-up information can be exchanged with application software using this
register:
1. the user software can influence the next device start-up by writing into STMEM0
bits[15,13:11];
The supported feature (SRAM initialization) is described in Chapter 10.3.3.
2. the emergency-status flags indicated in SCU_SYSCON0 bits[15:12] upon device
start-up can be read by user software from SCU_STMEM0 bits[3:0];
The background here is that the start-up procedure itself could cause (for example
due to clock-system reconfiguration) a change in some of these flags.
3. the handling of Watchdog Timer Double Error is supported by SCU_STMEM0
bit[4] - refer to Page 10-4;
4. the handling of “Flash not operable” scenario (refer to Chapter 10.3.2) is supported
by SCU_STMEM0 bit[14] - refer to Chapter 10.3.2.
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Startup Configuration and Bootstrap Loading
STMEM0
Start-up Memory 0 Register
15
14
13
12
ESFR (F0A0H/50H)
11
10 9
USSET FNOP RINDP RINDS RINPS
rw
rw
rw
rw
rw
8
7
6
5
Reset Value: 0000H
4
3
2
1
0
0
WDT SEL EMS EMS EMS
CSOE STAT PWR VCO OSC
r
rw
Field
Bits
Typ Description
EMSOSC
0
rw
OSCWDT Emergency Event Source Status 1)
EMSVCO
1
rw
VCOLCK Emergency Event Source Status 1)
EMSPWR
2
rw
PVC1 Emergency Event Source Status 1)
SELSTAT
3
rw
Clock Select Status 1)
WDTCSOE 4
rw
Watchdog Timer Overflow Error status flag 2)
0
[10:5]
r
Reserved, do not change these bits
RINPS
11
rw
Initialization of the PSRAM:
0
not requested
1
will be performed upon start-up
RINDS
12
rw
Initialization of the DSRAM:
0
not requested
1
will be performed upon start-up
RINDP
13
rw
Initialization of the DPRAM:
0
not requested
1
will be performed upon start-up
FNOP
14
r
Flash operability:
0
Flash operable
1
Flash not operable (no functional resets allowed)
USSET
15
rw
RAM Initialization upon start-up:
0
not requested
1
requested in STMEM0 [13:11]
1) Bits copied from SYSCON0 register upon startup.
2) Bit copied from WDTCS.OE upon startup.
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10.3.2
Support for Power-saving Modes
XC2700 allows several power-saving modes - for information about these modes and
how they can be controlled by user software refer to XC2000 Programmer’s Guide.
One rule regarding power-system handling in XC2700 is: if a power-state is entered with
DMP_1 supply below the minimum value at which the Flash is operable, this state must
be exited only by power-on (wake-up from power-save mode) but not by a functional
reset.
STMEM0.FNOP bit is defined to support application-compliance with this rule as follows:
•
•
if FNOP is set upon device restart; AND
this restart is caused by a functional (not power-on) reset
the start-up procedure terminates and device enters Start-up Error state.
Therefore the user software controlling the power-states must:
1. before to enter a power-state in which Flash is not operable - set STMEM0.FNOP;
2. after exiting this power-state (Flash not operable) by power-on in DMP_1 - reset
STMEM0.FNOP.
Note: After power-on in DMP_M the FNOP bit as the complete STMEM0 register will be
anyway reset.
10.3.3
Preparing to activate Parity
XC2700 supports parity as memory content protection mechanism, which can request
trap or reset upon a single-bit data error (refer to Memory Content Protection,
Section 6.13).
The user software must activate parity trap/reset generation for any one of PSRAM,
DSRAM and DPRAM only after every location from the respective memory is written at
least once after the last power reset. In other words, parity must be activated for a
memory only after this memory has been initialized.
Note: The RAMs in USIC and MultiCAN modules implement special access mechanism,
which assures a memory location will be read only after it has been written before,
therefore for these memories no initialization is necessary.
The parity can be activated by user software using the sequence shown at Figure 10-1:
•
if
STMEM0[15]=0
after
power-on
in
DMP_1
(indicated
by
SCU_RSTSTAT1.ST1=11B) - RAM initialization is needed and not been requested:
– optionally - if the application will run with system clock faster than 10MHz (system
frequency after power-on) - the clock reconfiguration can be done still here to use
increased speed for a faster RAM initialization;
– install request for RAMs initialization by setting STMEM0[15:11]=10111B;
It is also possible to set selectively only some of the bits[13:11] corresponding to
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•
•
•
the memories in which the parity will be activated (refer to STMEM0-description
and Figure 10-1).
– trigger application reset to cause a new device start-up
During this new device start-up the RAMs are initialized as requested in
STMEM0[13:11].
if STMEM0[15]=1 after startup - meaning RAMs have been just initialized:
– RAM-initialization request is cleared - STMEM0[15:11]=00000B;
– parity is configured/enabled as required by the application
if STMEM0[15]=0 after functional reset (not power-on) - RAM initialization is not
needed and the request is not active:
– parity is configured as required by the application - this is needed because enable
bits in SCU_PECON register are reset upon any start-up;
continue with further system initialization (if any) and starting the application.
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Startup Configuration and Bootstrap Loading
Power-On
or Functional reset
Device Startup
Parity will be used ?
Yes
Parity Preparation
SCU_STMEM0[15] = 0 ?
Yes RAM Initialization
has not been requested
SCU_RSTSTAT1.ST1 = 11 B ?
No
Functional
Reset
No
Power-on –
RAM Initialization
is needed
Set-up the system clock as needed
for the application ( optionally here )
RAM Initialization
has been performed
Clear RAM Initialization Request:
---------------------------------------------------------SCU_STMEM 0:= SCU_STMEM0 & 07FF H
Yes
No
Request RAM Initialization during Start-up:
---------------------------------------------------------SCU_STMEM0 := 10CD P000 0000 0000B
where bit=1 is to initialize respectively:
C – DPRAM; D – DSRAM; P - PSRAM
Trigger an Application (Software) Reset:
---------------------------------------------------------SCU_RSTCON0 := 0300H
Execute SRST instruction
Enable parity as needed
Application-specific system initialization...
EINIT
( Register protection activated )
Application Software
P11_MR-RAM_Init_Request-v2.vsd
Figure 10-1 Software sequence to prepare Parity usage
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Startup Configuration and Bootstrap Loading
10.4
Internal Start
When internal start mode is configured, the XC2700 immediately begins executing code
out of the on-chip Flash memory (first instruction from location C0’0000H).
No additional configuration options are required, when selecting internal startup mode.
Note: Because internal start mode is expected to be the configuration used in most
cases, this mode can be selected by pulling high just 2 pins.
10.5
External Start
When external start mode is configured, the XC2700 begins executing code out of an
off-chip memory (first instruction from location 00’0000H), connected to the XC2700’s
external bus interface.
The External Bus Controller is adjusted to the employed external memory by evaluating
additional configuration pins.
Seven pins of P10 are used to select the EBC mode (P10.[10:8]), the address width
(P10.[12:11]), and the number of chip select lines (P10.[14:13]). The following tables
summarize the available options.
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Table 10-3
EBC Configuration: EBC Mode
EBC Startup Mode
Cfg. Pins
P10[10:8]
Pins Used by the EBC
8-Bit Data, Multiplexed
0
0
0
P2.0 … P2.2, P10.0 … P10.15
8-Bit Data, Demultiplexed
0
0
1
P0.0 … P0.7, P1.0 … P1.7, P2.0 … P2.2,
P10.0 … P10.7, P10.13, P10.14
16-Bit Data, MUX, BHE mode 0
1
0
P2.0 … P2.2, P2.11, P10.0 … P10.15
16-Bit Data, MUX, WRH mode 0
1
1
P2.0 … P2.2, P2.11, P10.0 … P10.15
16-Bit Data, DeMUX,
BHE mode, A0
1
0
0
P0.0 … P0.7, P1.0 … P1.7, P2.0 … P2.2,
P2.11, P10.0 … P10.14
16-Bit Data, DeMUX,
WRH mode, A0
1
0
1
P0.0 … P0.7, P1.0 … P1.7, P2.0 … P2.2,
P2.11, P10.0 … P10.14
16-Bit Data, DeMUX,
BHE mode, A1
1
1
0
P2.0 … P2.2,
P10.0 … P10.15
16-Bit Data, DeMUX,
WRH mode, A1
1
1
1
P0.0 … P0.7, P1.0 … P1.7, P2.0 … P2.2,
P10.0 … P10.7, P10.13, P10.14
Table 10-4
EBC Configuration: Address Width
Available Address Lines
Cfg. Pins Additional Address Pins
P10[12:11]
A15 … A0
0
0
None
A17 … A0
0
1
P2.3, P2.4
A19 … A0
1
0
P2.3 … P2.6
A23 … A0
1
1
P2.3 … P2.10
Table 10-5
EBC Configuration: Chip Select Lines
Available Chip Select Lines Cfg. Pins Used Pins
P10[14:13]
CS0 … CS4
0
0
P4.0 … P4.4
CS0
0
1
P4.0
CS0 … CS1
1
0
P4.0, P4.1
None
1
1
None
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Startup Configuration and Bootstrap Loading
10.5.1
Specific Settings
When the XC2700 has entered External Start mode, the configuration is automatically
set: according to Table 10-6 and Table 10-7.
Note, that the startup procedure does not configure any address window within
ADDRSELx registers. Therefore, even if some CS signal is configured (refer to
Table 10-5 and Table 10-6), the startup procedure only makes the proper settings to
assure the adequate pin-functionality in regard to the selected EBC mode. The user
software must take care:
•
•
to configure the address window (in ADDRSELx register) for the CSx pin(s) which
will be used;
to enable those pins by setting FCONCSx.ENCS.
Table 10-6
External start mode-Specific State in EBC Registers
Configuration
at P10[10:8]
EBCMOD0
[15:8]
EBCMOD1
FCONCSx 1) Comment (EBC Mode)
000B
30H
001FH
0011H
8-Bit Multiplexed
001B
70H
0020H
0001H
8-Bit Demultiplexed
010B
40H
0000H
0031H
16-Bit MUX, BHE
011B
48H
0000H
0031H
16-Bit MUX, WRH
100B
60H
0000H
0021H
16-Bit DeMUX, BHE, A0
101B
61H
0000H
0021H
16-Bit DeMUX, WRH, A0
110B
60H
0010H
0021H
16-Bit DeMUX, BHE, A1
111B
61H
0010H
0021H
16-Bit DeMUX, WRH, A1
1) Which FCONCSx registers are affected is dependant on the configuration at P10[14:13] as follows:
11B or 01B - FCONCS0 is affected
10B - FCONCS0 and FCONCS1 are affected
00B - FCONCS0..FCONCS4 are affected
The other (unaffected) FCONCS registers retain their default values - refer to Section 9.3.5.
Table 10-7
External start mode-Specific State in EBCMOD0[7:0]
Configuration
at P10[14:13]
Configuration at P10[12:11]
00B (0 Segm.)
01B (2 Segm.)
10B (4 Segm.)
11B (8 Segm.)
00B (5 CS)
50H
52H
54H
58H
01B (1 CS)
10H
12H
14H
18H
10B (2 CS)
20H
22H
24H
28H
11B (0 CS)
00H
02H
04H
08H
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Startup Configuration and Bootstrap Loading
10.6
Bootstrap Loading
Bootstrap Loading is the technique of transferring code to the XC2700 via a certain
interface (usually serial) before the regular code execution out of non-volatile program
memory commences. Instead, the XC2700 executes the previously received code.
This boot-code may be complete (e.g. temporary software for testing or calibration),
amend existing code in non-volatile program memory (e.g. with product-specific data or
routines), or load additional code (e.g. using higher or more secure protocols). A possible
application for bootstrap loading is the programming of virgin Flash memory at the end
of a production line, with no external memory or internal Flash required for the
initialization code.
The BSL mechanism may be used for standard system startup as well as only for special
occasions like system maintenance (firmware update) or end-of-line programming or
testing.
The XC2700 supports bootstrap loading using several protocols/modes:
•
•
•
•
Standard UART protocol, loading 32 bytes (see Section 10.6.2.1)
UART protocol, Enhanced bootstrap loader transferring arbitrary number of bytes
(see Section 10.6.2.2)
Synchronous serial protocol (see Section 10.6.3)
CAN protocol (see Section 10.6.4)
For a summary of these modes, see also Table 10-14
10.6.1
General Functionality
Even though each bootstrap loader has its particular functionality, the general handling
is the same for all of them.
Entering a Bootstrap Loader
Bootstrap loaders are enabled by selecting a specific start-up configuration (see
Section 10.1).
The required configuration patterns are described in Table 10-14 for the bootstrap
loaders, and are summarized in Table 10-1.
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Loading the Startup Code
After establishing communication, the BSL enters a loop to receive the respective
number of bytes. These bytes are stored sequentially into the on-chip PSRAM, starting
at location E0’0000H. To execute the loaded code the BSL then points register VECSEG
to location E0’0000H, i.e. the first loaded instruction, and then jumps to this instruction.
The loaded code may be the final application code or another, more sophisticated,
loader routine that adds a transmission protocol to enhance the integrity of the loaded
code or data. It may also contain a code sequence to change the system configuration
and enable the bus interface to store the received data into external memory.
This process may go through several iterations or may directly execute the final
application.
Note: Data fetches from a protected Flash will not be executed.
Exiting Bootstrap Loader Mode
The watchdog timer and the debug system are disabled as long as the Bootstrap loader
is active. Watchdog timer and debug system are released automatically when the BSL
terminates after having received the last byte from the host.
If 2nd level loaders are used, the loader routine should deactivate the watchdog timer via
instruction DISWDT to allow for an extended download period.
The XC2700 will start executing out of user memory as externally configured after a nonBSL reset .
Interface to the Host
The bootstrap loader communicates with the external host over a predefined set of
interface pins. These interface pins are automatically enabled and controlled by the
bootstrap loader. The host must connect to these predefined interface pins.
Table 10-14 indicates the interface pins that are used in each bootstrap loader mode.
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10.6.2
Bootstrap Loaders using UART Protocol
XC2700 users have different possibilities to download code/data in which the
communication is based on UART (Universal Asynchronous Receiver and Transmitter)
protocol.
10.6.2.1 Standard UART Bootstrap Loader
The standard UART bootstrap loader transfers program code/data via channel 0 of
USIC0 (U0C0) into the PSRAM. The U0C0 receiver is only enabled after the
identification byte has been transmitted. A half duplex connection to the host is,
therefore, sufficient to feed the BSL.
Data is transferred from the external host to the XC2700 using asynchronous eight-bit
data frames without parity (1 start bit, 1 stop bit). The number of data bytes to be received
in standard UART boot mode is fixed to 32 bytes, which allows up to 16 two-byte
instructions.
Reset
CONFIG.
PINS
RxD
TxD
CSP:IP
Internal BSL-Routine
32 bytes
User Software
mc_bsl_x2k.vsd
Figure 10-2 Bootstrap Loader Sequence
The XC2700 scans the RxD line to receive a zero byte after entering UART BSL mode
and the respective initialization. The zero byte is considered as containing one start bit,
eight 0 data bits and one stop bit. From the duration of this zero byte it calculates the
corresponding baudrate factor with respect to the current CPU clock, initializes the serial
interface U0C0 accordingly and switches pin TxD to output. Using this baudrate, an
identification byte (D5H) is returned to the host that provides the loaded data.
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Once the identification byte is transmitted, the BSL enters a loop to receive 32 bytes via
U0C0. These bytes are stored sequentially into locations E0’0000H through E0’001FH of
the internal PSRAM and then executed.
Note: For loading more code, two possibilities exist:
- via a 2nd-level loader - see below
- using the Enhanced UART Bootstrap Loader - refer to Section 10.6.2.2
Second Level Bootloader
Most probably the initially loaded routine will load additional code or data, as an average
application is likely to require substantially more instructions than could fit into 32 bytes.
This second receive loop may directly use the pre-initialized interface U0C0 to receive
data and store it to arbitrary user-defined locations.
The example code below shows how to fit such a 2nd-level loader into the available 32
bytes. This is possible due to the pre-initialized serial channel and the pre-set registers
(see Table 10-8).
;Example for Secondary UART Bootstrap Loader Routine
;--------------------------------------------------------------TargetStart LIT ’0E00020H’
;Definition of target area:
TargetEnd
LIT ’0E001FFH’
;480 bytes in this example
StartOfCode LIT ’0E00100H’
;Continue executing here...
;...after download
Level2Loader:
DISWDT
;No WDT for further download
MOV
DPP0,#(PAG TargetStart)
MOV
R10, #(DPP0:TargetStart);Set pointer to target area
Level2MainLoop:
MOV
[R1],R3
;Clear RIF for new byte
Level2RecLoop:
MOV
R4, [R0]
;Access PSR
JNB
R4.14,Level2RecLoop
;Wait for RIF
MOVB [R10],[R2]
;Copy new byte to target
CMPI1 R10, #POF (TargetEnd);All bytes received??
JMPR cc_NE,Level2MainLoop ;Repeat for complete area
Level2Terminate:
JMPS
SEG StartOfCode, SOF StartOfCode
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Startup Configuration and Bootstrap Loading
Specific Settings
The following configuration is automatically set when the XC2700 has entered Standard
UART BSL mode:
Table 10-8
Standard UART BSL-Specific State
Item
Value
Comments
U0C0_CCR
0002H
ASC mode selected for USIC0 Channel 0
U0C0_PCRL
0401H
1 stop bit, three RxD-samples at point 4
U0C0_SCTRL
0002H
Passive data level = 1
U0C0_SCTRH
0707H
8 data bits
U0C0_FDRL
43FFH
Normal divider mode 1:1 selected
U0C0_BRGH
0XXXH
Measured PDIV value (zero-byte) in bits[9:0]
U0C0_BRGL
1C00H
Normal mode, FDIV, 8 clocks/bit
U0C0_DX0CR
0003H
Data input selection
DPP1
0081H
Points to USIC0 base address 1)
R0
4044H
Pointer to U0C0_PSR 1)
R1
4048H
Pointer to U0C0_PSCR 1)
R2
405CH
Pointer to U0C0_RBUF 1)
R3
4000H
Mask to clear RIF 1)
Devices in 144/100-pin package:
P7_IOCR03
00B0H
P7.3 is push/pull output (TxD)
P7_IOCR04
0020H
P7.4 is input with pull-up (RxD)
Devices in 64-pin package:
P2_IOCR03
00B0H
P2.3 is push/pull output (TxD)
P2_IOCR04
0020H
P2.4 is input with pull-up (RxD)
1) This register setting is provided for a 2nd-level loader routine (see at Page 10-17).
The identification byte identifies the device to be booted. The following codes are
defined:
55H: 8xC166.
A5H: Previous versions of the C167 (obsolete).
B5H: Previous versions of the C165.
C5H: C167 derivatives.
D5H: All devices equipped with identification registers (including the XC2700).
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Note: The identification byte D5H does not directly identify a specific derivative. This
information can, in this case, be obtained from the identification registers.
10.6.2.2 Enhanced UART Bootstrap Loader
The enhanced UART bootstrap loader transfers program code/data via Channel 0 of
USIC0 Module (U0C0) into PSRAM.
Data is transferred from the external host to the XC2700 using asynchronous eight-bit
data frames without parity (1 start bit, 1 stop bit). The length of the code/data is not fixed
as in the Standard UART Bootstrap Loader but can be arbitrary up to the PSRAM total
size minus 256 bytes. Also the code execution can start from arbitrary PSRAM address,
as well as the initial baudrate can be changed - e.g. increased for faster transfer of long
code/data blocks.
The initial steps of this bootloader are the same as of the Standard UART Bootstrap
Loader. XC2700 first scans the RxD line to receive a zero byte, i.e. one start bit, eight 0
data bits and one stop bit. From the duration of this zero byte it calculates the
corresponding baudrate factor with respect to the current CPU clock, initializes the serial
interface U0C0 accordingly and switches pin TxD to output. Using this baudrate, an
identification byte (DAH) is returned to the host.
The next steps in this mode are to process the so-called Bootloader Header as follows:
1. XC2700 sends the current PDIV divider from U0C0_BRGH register - the 10-bit value
is sent in 2 bytes
Note: In this bootloader, the multi-byte values are sent in high-to-low order.
2. XC2700 receives and sends back to the host a Header_Code (1B)
3. XC2700 receives and sends back to the host number of bytes to be transferred
Code_Length (3B)
- the allowed range for this number is between 1 and the PSRAM size for the device
minus 256 bytes
4. XC2700 receives and sends back to the host the start address STADD for codeexecution (3B)
- the segment address (highest STADD byte) must equal E0H for XC2700
5. XC2700 receives and sends back to the host a value for PDIV divider (2B, bits[9:0]
effective only)
- if the new value is different from the current - the new one is written into
U0C0_BRGH register and a zero confirmation byte is sent back to the host with
baudrate already changed
6. XC2700 receives and sends back to the host a Trailer_Code (1B)
a) if both the Header_Code and Trailer_Code are equal to the XC2700 identification
byte (DAH) - the Bootloader sends to the Host a zero byte and continues further;
b) if the above condition is not true - the Bootloader sends an identification byte (DAH)
to the host and restarts Header processing again from point 1.
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Once the Header is successfully processed according to the above steps, the Bootstrap
loader receives Code_Length bytes and stores them sequentially starting from the
beginning of PSRAM at address E0’0000H.
The Bootstrap loader starts code-execution after the last byte is received and stored.
The execution is started from address STADD as received within the header.
Specific Settings
The following configuration is automatically set when the XC2700 has entered Enhanced
UART BSL mode:
Table 10-9
Enhanced UART BSL-Specific State
Item
Value
Comments
U0C0_CCR
0002H
ASC mode selected for USIC0 Channel 0
U0C0_PCRL
0401H
1 stop bit, three RxD-samples at point 4
U0C0_SCTRL
0002H
Passive data level = 1
U0C0_SCTRH
0707H
8 data bits
U0C0_FDRL
43FFH
Normal divider mode 1:1 selected
U0C0_BRGH
0XXXH
PDIV-value as sent by the host inside header
U0C0_BRGL
1C00H
Normal mode, FDIV, 8 clocks/bit
U0C0_DX0CR
0003H
Data input selection
Devices in 144/100-pin package:
P7_IOCR03
00B0H
P7.3 is push/pull output (TxD)
P7_IOCR04
0020H
P7.4 is input with pull-up (RxD)
Devices in 64-pin package:
P2_IOCR03
00B0H
P2.3 is push/pull output (TxD)
P2_IOCR04
0020H
P2.4 is input with pull-up (RxD)
The identification byte identifies the device to be booted. XC2700 is the first
microcontroller family supporting Enhanced UART BSL mode, the code defined for it is
DAH.
Note: The identification byte does not directly identify a specific derivative. This
information can, in this case, be obtained from the identification registers.
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10.6.2.3 Choosing the Baudrate for the BSL
The calculation of the serial baudrate for U0C0 from the length of the first zero byte that
is received, allows the operation of the bootstrap loader of the XC2700 with a wide range
of baudrates. However, the upper and lower limits have to be kept, in order to ensure
proper data transfer.
The XC2700 uses bitfield PDIV to measure the length of the initial zero byte. The
quantization uncertainty of this measurement implies the deviation from the real
baudrate.
For a correct data transfer from the host to the XC2700 the maximum deviation between
the internal initialized baudrate for U0C0 and the real baudrate of the host should be
below 2.5%. The deviation (FB, in percent) between host baudrate and XC2700 baudrate
can be calculated via Equation (10.1):
B Contr – B Host
F B = ------------------------------------ × 100%
B Contr
F B ≤ 2.5%
(10.1)
Note: Function (FB) does not consider the tolerances of oscillators and other devices
supporting the serial communication.
This baudrate deviation is a nonlinear function depending on the system clock and the
baudrate of the host. The maxima of the function (FB) increase with the host baudrate
due to the smaller baudrate prescaler factors and the implied higher quantization error
(see Figure 10-3).
Ι
FB
2.5%
B Low
B High
B Host
ΙΙ
MCA02260
Figure 10-3 Baudrate Deviation between Host and XC2700
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The minimum baudrate (BLow in Figure 10-3) is determined by the maximum count
capacity of bitfield PDIV, when measuring the zero byte, i.e. it depends on the system
clock. The minimum baudrate is obtained by using the maximum PDIV count 210 in the
baudrate formula. Baudrates below BLow would cause PDIV to overflow. In this case
U0C0 cannot be initialized properly and the communication with the external host is likely
to fail.
The maximum baudrate (BHigh in Figure 10-3) is the highest baudrate where the
deviation still does not exceed the limit, i.e. all baudrates between BLow and BHigh are
below the deviation limit. BHigh marks the baudrate up to which communication with the
external host will work properly without additional tests or investigations.
Higher baudrates, however, may be used as long as the actual deviation does not
exceed the indicated limit. A certain baudrate (marked I) in Figure 10-3) may e.g. violate
the deviation limit, while an even higher baudrate (marked II) in Figure 10-3) stays very
well below it. Any baudrate can be used for the bootstrap loader provided that the
following three prerequisites are fulfilled:
•
•
•
the baudrate is within the specified operating range for U0C0
the external host is able to use this baudrate
the computed deviation error is below the limit.
Note: When the bootstrap loader mode is entered after a power reset, the bootstrap
loader will begin to operate with fSYS = fIOSC × 2 (approximately 10 MHz) which will
limit the maximum baudrate for U0C0.
Higher levels of the bootstrapping sequence can then switch the clock generation
mode in order to achieve higher baudrates for the download.
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10.6.3
Synchronous Serial Channel Bootstrap Loader
The Synchronous Serial Channel (SSC) bootstrap loader transfers program code/data
from an external serial EEPROM via channel 0 of USIC0 (U0C0) into the PSRAM. The
XC2700 is the master, so no additional elements (except for the EEPROM) are required.
The SSC bootstrap loading is a convenient way for initial and basic (go/fail) testing
during software development - it allows many various code-versions to be easy started
on the target system by re-programming a serial EEPROM.
During SSC bootstrap loading data is transferred from the external EEPROM to the
XC2700 using synchronous eight-bit data frames with MSB first. The number of data
bytes to be received in SSC boot mode is user-selectable. The serial clock rate is set to
fSYS/10, which results in 1 MHz after a power reset.
Once SSC BSL mode is entered and the respective initialization done, the XC2700 first
reads the header from the first addresses (00...0) of the target EEPROM.
This header consists of two items:
•
•
The memory identification byte: D5H
The data size field: 1 byte or 2 bytes, depending on the EEPROM’s addressing mode
(8-bit or 16-bit, see Section 10.6.3.1)
If both items are valid the BSL enters a loop to read the number of bytes defined by the
data size field (maximum is FFH or FF00H, depending on the EEPROM) via U0C0.
These bytes are stored sequentially into PSRAM starting at location E0’0000H and are
then executed. Therefore, the size of the PSRAM in the respective derivative determines
the real maximum block size to be downloaded.
An invalid header (identification byte ≠ D5H, data size field = 0 or greater than
65280/FF00H) is indicated by toggling the CS line low 3 times. This helps debugging
during the system setup phase.
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10.6.3.1 Supported EEPROM Types
The XC2700’s SSC bootstrap loader assumes an SPI-compatible EEPROM (25xxx
series). It supports devices with 8-bit addressing as well as with 16-bit addressing. The
connected EEPROM type is determined by examining the received header bytes, as
indicated in Table 10-10.
Table 10-10 Determining the EEPROM Type
SSC Frame Meaning of
Number
Transmitted Data
Received Data from
8-bit Addr. Device
Received Data from
16-bit Addr. Device
1
03H: Read command
XXH (default level)
XXH (default level)
2
00H: Address byte
(high for 16-bit addr.)
XXH (default level)
XXH (default level)
3
00H: Address byte low
D5H: Identification byte XXH (default level)
4
00H: Dummy byte
Size n in bytes
D5H: Identification byte
5
00H: Dummy byte
Data byte 1
Size n in bytes, MSB
6
00H: Dummy byte
Data byte 2
Size n in bytes, LSB
7
00H: Dummy byte
Data byte 3
Data byte 1
…
00H: Dummy byte
Data byte 4 … n
n=1..FFH
Data byte 2 … n
n=1..FF00H
Note: The value of the returned default bytes (indicated as XXH) depends on the
employed EEPROM type.
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Startup Configuration and Bootstrap Loading
10.6.3.2 Specific Settings
When the XC2700 has entered the SSC BSL mode, the following configuration is
automatically set:
Table 10-11 SSC BSL-Specific State
Item
Value
Comments
U0C0_CCR
0001H
SSC mode selected for USIC0 Channel 0
U0C0_PCRL
0011H
SSC master mode, frequency from fPPP
U0C0_PCRH
8000H
MCLK generation is enabled
U0C0_SCTRL
0103H
MSB first, passive data level=1
U0C0_SCTRH
073FH
8 data bits, infinite frame
U0C0_DX0CR
0015H
Data input selection
U0C0_FDRL
43FFH
Normal divider mode 1:1 selected
U0C0_BRGL
0000H
Normal mode, FDIV - default value after reset
U0C0_BRGH
8004H
Passive levels MCLK/SCLK=0, PDIV=4
P2_IOCR03
00D0H
P2.3 is open-drain output (MTSR)
P2_IOCR04
0020H
P2.4 is input with pull-up (MRST)
P2_IOCR05
00D0H
P2.5 is open-drain output (SCLK)
P2_IOCR06
00C0H
P2.6 is open-drain output (SLS)
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Startup Configuration and Bootstrap Loading
10.6.4
CAN Bootstrap Loader
The CAN bootstrap loader transfers program code/data via node 0 of the MultiCAN
module into the PSRAM. Data is transferred from the external host to the XC2700 using
eight-byte data frames. The number of data frames to be received is programmable and
determined by the 16-bit data message count value DMSGC.
The communication between XC2700 and external host is based on the following three
CAN standard frames:
•
•
•
Initialization frame - sent by the external host to the XC2700
Acknowledge frame - sent by the XC2700 to the external host
Data frame(s) - sent by the external host to the XC2700
The initialization frame is used in the XC2700 for baud rate detection. After a successful
baud rate detection is reported to the external host by sending the acknowledge frame,
data is transmitted using data frames. Table 10-12 shows the parameters and settings
for the three utilized CAN standard frames.
Note: The CAN bootstrap loader requires a point-to-point connection with the host, i.e.
the XC2700 must be the only CAN node connected to the network. A crystal with
at least 4 MHz is required for CAN bootstrap loader operation.
Initialization Phase
The first BSL task is to determine the CAN baud rate at which the external host is
communicating. Therefore the external host must send initialization frames continuously
to the XC2700. The first two data bytes of the initialization frame must include a 2-byte
baud rate detection pattern (5555H), an 11-bit (sent in 2 bytes) identifier ACKID1) for the
acknowledge frame, a 16-bit data message count value DMSGC, and an 11-bit (2-byte)
identifier DMSGID1) to be used by the data frame(s).
The CAN baud rate is determined by analyzing the received baud rate detection pattern
(5555H) and the baud rate registers of the MultiCAN module are set accordingly. The
XC2700 is now ready to receive CAN frames with the baud rate of the external host.
Acknowledge Phase
In the acknowledge phase, the bootstrap loader waits until it receives the next correctly
recognized initialization frame from the external host, and acknowledges this frame by
generating a dominant bit in its ACK slot. Afterwards, the bootstrap loader transmits an
acknowledge frame back to the external host, indicating that it is now ready to receive
data frames. The acknowledge frame uses the message identifier ACKID that has been
received with the initialization frame.
1) The CAN bootstrap loader copies the two identifier bytes received in the initialization frame directly to register
MOAR. Therefore, the respective fields in the initialization frame must contain the intended identifier padded
with two dummy bits at the lower end and extended with bitfields IDE (=0B) and PRI (=01B) at the upper end.
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Startup Configuration and Bootstrap Loading
To summarize: the external host must send initialization frames (the content as above
defined) continuously until an acknowledge frame is received back from the XC2700
having the same message identifier as sent by the host in data bytes 2/3 from the
initialization frame, then the Data Transmission Phase begins.
Data Transmission Phase
In the data transmission phase, data frames are sent by the external host and received
by the XC2700. The data frames use the 11-bit data message identifier DMSGID that
has been sent with the initialization frame. Eight data bytes are transmitted with each
data frame. The first data byte is stored in PSRAM at E0’0000H. Consecutive data bytes
are stored at incrementing addresses.
Both communication partners evaluate the data message count DMSGC until the
requested number of CAN data frames has been transmitted. After the reception of the
last CAN data frame, the bootstrap loader finishes and executes the loaded code.
Timing Parameters
There are no general restrictions for CAN timings of the external host. During the
initialization phase the external host transmits initialization frames. If no acknowledge
frame is sent back within a certain time as defined in the external host (e.g. after a
dedicated number of initialization frame transmissions), the external host can decide that
the XC2700 is not able to establish the CAN boot communication link.
Table 10-12 CAN Bootstrap Loader Frames
Frame Type
Parameter
Description
Initialization
Frame
Identifier
11-bit, don’t care
DLC = 8
Data length code, 8 bytes within CAN frame
Data bytes 0/1
Baud rate detection pattern (5555H)
Data bytes 2/3
Acknowledge message identifier ACKID
(complete register contents)
Data bytes 4/5
Data message count DMSGC, 16-bit
Data bytes 6/7
Data message identifier DMSGID
(complete register contents)
Acknowledge Identifier
Frame
Acknowledge message identifier ACKID as received
by data bytes [3:2] of the initialization frame
DLC = 4
Data length code, 4 bytes within CAN frame
Data bytes 0/1
Contents of bit-timing register
Data bytes 2/3
Copy of acknowledge identifier from initialization frame
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System Units (Vol. 1 of 2)
Startup Configuration and Bootstrap Loading
Table 10-12 CAN Bootstrap Loader Frames (cont’d)
Frame Type
Parameter
Description
Data frame
Identifier
Data message identifier DMSGID as sent by data
bytes [7:6] of the initialization frame
DLC = 8
Data length code, 8 bytes within CAN frame
Data bytes
0 to 7
Data bytes, assigned to increasing destination
(PSRAM) addresses
10.6.4.1 Specific Settings
When the XC2700 has entered the CAN BSL mode, the following configuration is
automatically set:
Table 10-13 CAN BSL-Specific State
Item
Value
Comments
P2_IOCR05
00A0H
P2.5 is push/pull output (TxD)
P2_IOCR06
0020H
P2.6 is input with pull-up (RxD)
SCU_HPOSCCON
0030H
OSC_HP enabled, External Crystal/Clock mode
SCU_SYSCON0
0001H
OSC_HP selected as system clock
CAN_MOCTR0L
0008H
Message Object 0 Control, low
CAN_MOCTR0H
00A0H
Message Object 0 Control, high
CAN_MOCTR1L
0000H
Message Object 1 Control, low
CAN_MOCTR1H
0F28H
Message Object 1 Control, high
CAN_MOFCR1H
0400H
Message Object Function Control, high
CAN_MOAMR0H
1FFFH
Message Object 0 - Acceptance Mask bit set
CAN_NPCR0
0003H
Data input selection
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System Units (Vol. 1 of 2)
Startup Configuration and Bootstrap Loading
10.6.5
Summary of Bootstrap Loader Modes
This table summarizes the external hardware provisions that are required to activate a
bootstrap loader in a system.
Table 10-14 Configuration Data for Bootstrap Loader Modes
Bootstrap Configuration
on P10.[3:0] 1)
Loader
Mode
Receive Line Transmit
from Host
Line to Host
Standard
UART
RxD = P7.4
TxD = P7.3
32 bytes
(100/144-pin) (100/144-pin)
x110B
RxD = P2.4
(64-pin)
Enhanced x010B
UART
Transferred Supported
Data
Host
Speed
TxD = P2.3
(64-pin)
RxD = P7.4
TxD = P7.3
l bytes 2)
(100/144-pin) (100/144-pin)
RxD = P2.4
(64-pin)
2.4 - 19.2
kbaud
TxD = P2.3
(64-pin)
Sync.
Serial
1001B
MRST = P2.4 MTSR = P2.3 m bytes 3)
SCLK = P2.5
SLS = P2.6
MultiCAN
x101B
RxDC0 =
P2.6
2.4-19.2
kbaud at
start, then
changeable
by Header
--(controlled
by XC2700)
TxDC0 = P2.5 8 × n bytes 4) 125 - 500
kBaud
1) x means that the level on the corresponding pin is irrelevant.
2) l = Code_Length sent by the host, the values allowed are 1...(PSRAM_size-256).
3) m = data size read from EEPROM, the values allowed are 1...(PSRAM_size-256).
4) n = DMSGC, Data Message Count sent by the host with Initialization frame, the values allowed are 1...
(PSRAM_size-256)/8.
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Debug System
11
Debug System
The XC2700 includes an On-Chip Debug Support (OCDS) system, which provides
convenient debugging, controlled directly by an external tool via debug interface pins.
On-Chip Debug Support (OCDS)
The OCDS system supports a broad range of debug features including breakpoints and
tracing memory locations. Typical application of the OCDS is to debug the user software
running on the XC2700 in a real time system environment.
The OCDS system is controlled by an external tool via the JTAG Debug Interface and
an optional break interface with one or two pins (Figure 11-1). The break interface
supports very low latency triggers between XC2700 and tool and/or system environment
if needed. The memory mapped OCDS registers are accessible via the JTAG interface
using Cerberus. In addition there is a limited set of special Cerberus debug IO
instructions. As an alternative the OCDS can be controlled by a debug monitor program,
which communicates with the tool over a user interface like CAN. The OCDS system
interacts with the core through an injection interface to allow execution of Cerberusgenerated instructions, and through a break port.
OCDS System
break_in
Trace Interface
Break Interface
OCDS
Module
break_out
CPU
Debugger
JTAG Interface
Debug
Interface
JTAG
Module
Controller
Cerberus
(IO Module)
Injection Interface
CPU Status
Other
Resources
MCA05388
Figure 11-1 OCDS Overall Structure
The OCDS system consists of the three components Debug Interface, OCDS Module
and Cerberus.
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Debug System
OCDS System Features
•
•
•
•
•
•
•
•
Hardware, software and external pin breakpoints
Reaction on break with CPU-Halt, monitor call, data transfer and external signal
Read/write access to the whole address space
Single stepping
Debug Interface pins for JTAG interface and break interface
Injection of arbitrary instructions
Fast memory tracing through transfer to external bus
Analysis and status registers
11.1
Debug Interface
The Debug Interface is a channel to access OCDS resources. Through it data can be
transferred to/from all on- and off-chip (if any) memories and memory mapped control
registers.
Features and Functions
•
•
•
•
•
Independent interface for OCDS
JTAG port based on the IEEE 1149.1-2001 JTAG standard
Break interface for external trigger input and signaling of internal triggers
Generic memory access functionality
Independent data transfer channel for e.g. programming of flash memory
The Debug Interface is represented by:
• Standard JTAG Interface with 4 pins
• Two optional trigger pins - OCDS Break-Interface
Note: The JTAG clock frequency must be below the current CPU frequency.
JTAG Interface
The JTAG interface is a standardized and dedicated port usually used for boundary scan
and for chip internal tests. Because both of these applications are not enabled during
normal operation of the device in a system, the JTAG port is an ideal interface for
debugging tasks.
This interface holds the JTAG IEEE.1149.1-2001 standard signals:
•
•
•
•
•
TDI - Serial data input
TDO - Serial data output
TCK - JTAG clock
TMS - State machine control signal
TRST - Reset/Module enable
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Debug System
OCDS Break-Interface
Two additional signals are used to implement a direct asynchronous-break channel
between the Debugger and XC2700 OCDS Module:
• BRKIN (BReaK IN request) allows the Debugger asynchronously to interrupt the CPU
and force it to a predefined status/action.
• BRKOUT (BReaK OUT signal) can be activated by OCDS to notify the external world
that some predefined debug event has happened.
11.1.1
Routing of Debug Signals
The signals used to connect an external debugger via the JTAG interface and the break
interface usually conflict with the requirements of the application, which needs as many
IO pins as possible. In the XC2700, these signals are only provided as alternate
functions (no dedicated pins). To minimize the impact caused by the debug interface
pins, these signals can be mapped to several pins. Thus, each application can select the
variant with the least impact. This is controlled via the Debug Pin Routing Register
DBGPRR. Pin BRKOUT can be assigned to pins P6.0, P10.11, P1.5, or P9.3 as a
standard alternate output signal via the respective IOC register.
11.1.1.1 Register DBGPRR
This register controls the pin mapping of the JTAG pins.
DBGPRR
Debug Pin Routing Register
15
14
13
12
11
10
ESFR (F06EH/37H)
9
8
7
6
Reset Value: 0000H
5
4
3
2
1
0
TRS
TL
0
DPR
BRKIN
DPR
TCK
DPR
TMS
DPR
TDI
DPR
TDO
rh
r
rw
rw
rw
rw
rw
Field
Bits
Type
Description
DPRTDO
[1:0]
rw
Debug Pin Routing for TDO
00
P7.0
01
P10.12
10
Reserved, do not use
11
Reserved, do not use
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System Units (Vol. 1 of 2)
Debug System
Field
Bits
Type
Description
DPRTDI
[3:2]
rw
Debug Pin Routing for TDI
00
P5.2
01
P10.10
10
P7.2
11
P8.3
DPRTMS
[5:4]
rw
Debug Pin Routing for TMS
00
P5.4
01
P10.11
10
P7.3
11
P8.4
DPRTCK
[7:6]
rw
Debug Pin Routing for TCK
00
P2.9
01
P10.9
10
P7.4
11
P8.5
DPRBRKIN
[9:8]
rw
Debug Pin Routing for BRKIN
00
P5.10
01
P10.8
10
P7.1
11
P8.6
TRSTL
15
rh
TRST Pin Start-up Value
This bit indicates if the Debug Mode can be entered
or not.
0
A debugger can not be connected
1
A debugger can be connected
0
[14:10] r
Reserved
read as 0; should be written with 0.
Note: Make sure that the selected pins are available to the debug system at all times. In
particular, do not enable power save behavior (see register POCON) for these
pins.
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System Units (Vol. 1 of 2)
Debug System
11.2
OCDS Module
The application of the OCDS Module is to debug the user software running on the CPU
in the customer’s system. This is done with an external debugger that controls the OCDS
Module via the independent Debug Interface.
Features
•
•
•
•
•
•
•
Hardware, software and external pin breakpoints
Up to 4 instruction pointer breakpoints
Masked comparisons for hardware breakpoints
The OCDS can also be configured by a monitor
Support of multi CPU/master system
Single stepping with monitor or CPU halt
PC is visible in halt mode (IO_READ_IP instruction injection via Cerberus)
Basic Concept
The on chip debug concept is split up into two parts. The first part covers the generation
of debug events and the second part defines what actions are taken when a debug event
is generated.
• Debug events:
– Hardware Breakpoints
– Decoding of a SBRK Instruction
– Break Pin Input activated
• Debug event actions:
– Halt Mode of the CPU
– Call a Monitor
– Trigger Transfer
– Activate External Pin Output
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System Units (Vol. 1 of 2)
Debug System
Debug Event Sources
Hardware
Triggers
Debug Actions
HALT the CPU
Programmable
Combination
Debug
Event
Processing
CALL a Monitor
SBRK Instruction
Transfer Triggered
Break_In Pin Activated
Break_Out Pin Activated
MCB05389
Figure 11-2 OCDS Concept: Block Diagram
11.2.1
Debug Events
The Debug Events can come from a few different sources.
Hardware Breakpoints
The Hardware Breakpoint is a debug-event, raised when a single or a combination of
multiple trigger-signals are matching with the programmed conditions.
The following hardware trigger sources can be used:
Table 11-1
Hardware Triggers
Trigger Source
Size
Task Identifier
16 bits
Instruction Pointer
24 bits
Data address of reads (two busses monitored)
2 × 24 bits
Data address of writes
24 bits
Data value (reads or writes)
16 bits
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Debug System
SBRK Instruction
This is a mechanism through which the software can explicitly generate a debug event.
It can be used for instance by a debugger to temporarily patch code held in RAM in order
to implement Software Breakpoints.
A special SBRK (Software BReaK) instruction is defined with opcode 0x8C00. When this
instruction has been decoded and it reaches the Execute stage, the whole pipeline is
canceled including the SBRK itself. Hence in fact the SBRK instruction is never
“executed” by itself.
The further behavior is dependent on how OCDS has been programmed:
• if the OCDS is enabled and the software breakpoints are also enabled, then the CPU
goes into Halt Mode
• if the OCDS is disabled or the software breakpoints are disabled, then the Software
Break Trap (SBRKTRAP) is executed-Class A Trap, number 08H
Break Pin Input
An external debug break pin (BRKIN) is provided to allow the debugger to
asynchronously interrupt the processor.
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Debug System
11.2.2
Debug Actions
When the OCDS is enabled and a debug event is generated, one of the following actions
is taken:
Trigger Transfer
One of the actions that can be specified to occur on a debug event being raised is to
trigger the Cerberus:
• to execute a Data Transfer - this can be used in critical routines where the system
cannot be interrupted to transfer a memory location
• to inject an instruction to the Core - using this mechanism, an arbitrary instruction can
be injected into the XC2700 pipeline
Halt Mode
Upon this Action the OCDS Module sends a Break-Request to the Core.
The Core accepts this request, if the OCDS Break Level is higher than current CPU
priority level. In case a Break-Request is accepted, the system suspends execution with
halting the instruction flow.
The Halt Mode can be still interrupted by higher priority user interrupts. It then relies on
the external debugger system to interrogate the target purely through reading and
updating via the debug interface.
Call a Monitor
One of the possible actions to be taken when a debug event is raised is to call a Monitor
Program.
This short entry to a Monitor allows a flexible debug environment to be defined which is
capable of satisfying many of the requirements for efficient debugging of a real time
system. In the common case the Monitor has the highest priority and can not be
interrupted from any other requesting source.
It is also possible to have an Interruptible Monitor Program. In such a case safety critical
code can be still served while the Monitor (Debugger) is active, which gives a maximum
flexibility to the user.
Activate External Pin
This action activates the external pin BRKOUT of the OCDS Break-Interface. It can be
used in critical routines where the system cannot be interrupted to signal to the external
world that a particular event has happened. The feature could also be useful to
synchronize the internal and external debug hardware.
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Debug System
11.3
Cerberus
Cerberus is the module which provides and controls all the operations necessary to
interact between the external debugger (via the Debug Interface), the OCDS Module
and the internal system of XC2700.
Features
• JTAG interface is used as control and data channel
• Generic memory read/write functionality (RW mode) with access to the whole address
space
• Reading and writing of general-purpose registers (GPRs)
• Injection of arbitrary instructions
• External host controls all transactions
• All transactions are available at normal run time and in halt mode
• Priority of transactions can be configured
• Full support for communication between the monitor and an external host (debugger)
• Optional error protection
• Tracing memory locations through transferring values to the external bus
• Analysis Register for internal bus locking situations
The target application of Cerberus is to use the JTAG interface as an independent port
for On Chip Debug Support. The external debugger can access the OCDS registers and
arbitrary memory locations with the injection mechanism.
11.3.1
Functional Overview
Cerberus is operated by an external debugger across the JTAG Interface. The
Debugger supplies Cerberus IO Instructions and performs bidirectional data-transfers.
The Cerberus distinguishes between two main modes of operation:
Read/Write Mode of Operation
Read/Write (RW) Mode is the most typical way to operate Cerberus. This mode is used
to read and write memory locations or to inject instructions. The injection interface to the
core is actively used in this mode.
In this mode an external Debugger (host), using JTAG Interface, can:
• read and write memory locations from the target system (data-transfer);
• inject arbitrary instructions to be executed by the Core.
All Cerberus IO Instructions can be used in RW mode. The dedicated IO_READ_IP
instruction is provided in RW mode to read the IP of the CPU while in Break.
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Debug System
The access to any memory location is performed with injected instructions, as PEC
transfer. The following Cerberus IO Instructions can be used in their generic meaning:
• IO_READ_WORD, IO_WRITE_WORD
• IO_READ_BLOCK, IO_WRITE_BLOCK
• IO_WRITE_BYTE
Within these instructions, the host writes/reads data to/from a dedicated
register/memory, while the Cerberus itself takes care of the rest: to perform a PEC
transfer by injection of the appropriate instructions to the Core.
Communication Mode of Operation
In this mode the external host (debugger) communicates with a program (Monitor)
running on the CPU. The data-transfers are made via a PDBus+ register. The external
host is master of all transactions, requesting the monitor to write or read a value.
The difference to Read/Write Mode of Operation is that the read or write request now
is not actively executed by the Cerberus, but it sets request bits in a CPU accessible
register to signal the Monitor, that the host wants to send (IO_WRITE_WORD) or receive
(IO_READ_WORD) a value. The Monitor has to poll this status register and perform
respectively the proper actions
Communication Mode is the default mode after reset. Only the IO_WRITE_WORD and
IO_READ_WORD Instructions are effectively used in Communication Mode.
The Host and the Monitor exchange data directly with the dedicated data-register. For a
synchronization of Host (Debugger) and Monitor accesses, there are associated control
bits in a Cerberus status register.
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Debug System
11.4
Boundary-Scan
The XC2700 eases board-level analysis in the application system by providing
Boundary-Scan according to the IEEE standard 1149.1. It supports testing of the
interconnections between several devices mounted on a PCB.
Boundary-Scan is accomplished via the JTAG module, using standard JTAG
instructions (IEEE1149.1).
Note: For Boundary-Scan to operate properly, the JTAG interface must use the default
pins. The reset value of register DBGPRR ensures this.
Initialization of Boundary-Scan
The following sequence is defined to activate Boundary-Scan mode:
•
•
•
•
Set PORST = 1; TRST = 1; TESTM = 1
Negative Pulse on PORST
Wait for Power Domain to startup.
Negative pulse on TRST to reset the JTAG controller.
Now the test access port for Boundary-Scan is enabled. The Boundary-Scan test can be
used for board test with instructions like PRELOAD and EXTEST.
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Instruction Set Summary
12
Instruction Set Summary
This chapter briefly summarizes the XC2700’s instructions ordered by instruction
classes. This provides a basic understanding of the XC2700’s instruction set, the power
and versatility of the instructions and their general usage.
A detailed description of each single instruction, including its operand data type,
condition flag settings, addressing modes, length (number of bytes) and object code
format is provided in the “Instruction Set Manual” for the XC2000 Family. This manual
also provides tables ordering the instructions according to various criteria, to allow quick
references.
Summary of Instruction Classes
Grouping the various instruction into classes aids in identifying similar instructions (e.g.
SHR, ROR) and variations of certain instructions (e.g. ADD, ADDB). This provides an
easy access to the possibilities and the power of the instructions of the XC2700.
Note: The used mnemonics refer to the detailed description.
Table 12-1
Arithmetic Instructions
Addition of two words or bytes:
ADD
ADDB
Addition with Carry of two words or bytes:
ADDC
ADDCB
Subtraction of two words or bytes:
SUB
SUBB
Subtraction with Carry of two words or bytes:
SUBC
SUBCB
16 × 16 bit signed or unsigned multiplication:
MUL
MULU
16/16 bit signed or unsigned division:
DIV
DIVU
32/16 bit signed or unsigned division:
DIVL
DIVLU
1’s complement of a word or byte:
CPL
CPLB
2’s complement (negation) of a word or byte:
NEG
NEGB
Bitwise ANDing of two words or bytes:
AND
ANDB
Bitwise ORing of two words or bytes:
OR
ORB
Bitwise XORing of two words or bytes:
XOR
XORB
Table 12-2
Logical Instructions
User’s Manual
InstrSummary_X, V2.0
12-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Instruction Set Summary
Table 12-3
Compare and Loop Control Instructions
Comparison of two words or bytes:
CMP
CMPB
Comparison of two words with post-increment by
either 1 or 2:
CMPI1
CMPI2
Comparison of two words with post-decrement by
either 1 or 2:
CMPD1
CMPD2
Manipulation of a maskable bit field in either the high
or the low byte of a word:
BFLDH
BFLDL
Setting a single bit (to ‘1’):
BSET
–
Clearing a single bit (to ‘0’):
BCLR
–
Movement of a single bit:
BMOV
–
Movement of a negated bit:
BMOVN
–
ANDing of two bits:
BAND
–
ORing of two bits:
BOR
–
XORing of two bits:
BXOR
–
Comparison of two bits:
BCMP
–
Shifting right of a word:
SHR
–
Shifting left of a word:
SHL
–
Rotating right of a word:
ROR
–
Rotating left of a word:
ROL
–
Arithmetic shifting right of a word (sign bit shifting):
ASHR
–
Table 12-4
Table 12-5
Table 12-6
Boolean Bit Manipulation Instructions
Shift and Rotate Instructions
Prioritize Instruction
Determination of the number of shift cycles required to PRIOR
normalize a word operand (floating point support):
User’s Manual
InstrSummary_X, V2.0
12-2
–
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Instruction Set Summary
Table 12-7
Data Movement Instructions
Standard data movement of a word or byte:
MOV
MOVB
Data movement of a byte to a word location with either MOVBS
sign or zero byte extension:
MOVBZ
Note: The data movement instructions can be used with a big number of different
addressing modes including indirect addressing and automatic pointer in-/
decrementing.
Table 12-8
System Stack Instructions
Pushing of a word onto the system stack:
PUSH
–
Popping of a word from the system stack:
POP
–
Saving of a word on the system stack, and then
updating the old word with a new value (provided for
register bank switching):
SCXT
–
Table 12-9
Jump Instructions
Conditional jumping to an either absolutely, indirectly, JMPA
or relatively addressed target instruction within the
current code segment:
JMPI
JMPR
Unconditional jumping to an absolutely addressed
target instruction within any code segment:
–
–
Conditional jumping to a relatively addressed target
JB
instruction within the current code segment depending
on the state of a selectable bit:
JNB
–
Conditional jumping to a relatively addressed target
JBC
instruction within the current code segment depending
on the state of a selectable bit with a post-inversion of
the tested bit in case of jump taken (semaphore
support):
JNBS
–
User’s Manual
InstrSummary_X, V2.0
12-3
JMPS
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Instruction Set Summary
Table 12-10 Call Instructions
Conditional calling of an either absolutely or indirectly CALLA
addressed subroutine within the current code
segment:
CALLI
Unconditional calling of a relatively addressed
subroutine within the current code segment:
CALLR
–
Unconditional calling of an absolutely addressed
subroutine within any code segment:
CALLS
–
Unconditional calling of an absolutely addressed
subroutine within the current code segment plus an
additional pushing of a selectable register onto the
system stack:
PCALL
–
Unconditional branching to the interrupt or trap vector TRAP
jump table in code segment <VECSEG>:
–
Table 12-11 Return Instructions
Returning from a subroutine within the current code
segment:
RET
–
Returning from a subroutine within any code segment: RETS
–
Returning from a subroutine within the current code
segment plus an additional popping of a selectable
register from the system stack:
RETP
–
Returning from an interrupt service routine:
RETI
–
User’s Manual
InstrSummary_X, V2.0
12-4
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Instruction Set Summary
Table 12-12 System Control Instructions
Resetting the XC2700 via software:
SRST
–
Entering the Idle mode:
IDLE
–
No function, do not use1):
PWRDN
–
Servicing the Watchdog Timer:
SRVWDT
–
Disabling the Watchdog Timer:
DISWDT
–
Enabling the Watchdog Timer (can only be executed
in WDT enhanced mode):
ENWDT
–
Signifying the end of the initialization routine (switches EINIT
the register security mechanism to “protected” and
disables the effect of any later execution of a DISWDT
instruction in WDT compatibility mode):
1)
–
Instruction PWRDN is used to enter Power Down mode in previous 16-bit architectures. In the XC2700
devices, however, PWRDN has no effect and is executed like a NOP instruction.
Table 12-13 Miscellaneous
Null operation which requires 2 Bytes of storage and
the minimum time for execution:
NOP
–
Definition of an unseparable instruction sequence:
ATOMIC
–
Switch ‘reg’, ‘bitoff’ and ‘bitaddr’ addressing modes to EXTR
the Extended SFR space:
–
Override the DPP addressing scheme using a specific EXTP
data page instead of the DPPs, and optionally switch
to ESFR space:
EXTPR
Override the DPP addressing scheme using a specific EXTS
segment instead of the DPPs, and optionally switch to
ESFR space:
EXTSR
Note: The ATOMIC and EXT* instructions provide support for uninterruptable code
sequences e.g. for semaphore operations. They also support data addressing
beyond the limits of the current DPPs (except ATOMIC), which is advantageous
for bigger memory models in high level languages.
User’s Manual
InstrSummary_X, V2.0
12-5
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Instruction Set Summary
Table 12-14 MAC-Unit Instructions
Multiply (and Accumulate):
CoMUL
CoMAC
Add/Subtract:
CoADD
CoSUB
Shift right/Shift left:
CoSHR
CoSHL
Arithmetic Shift right:
CoASHR
–
Load Accumulator:
CoLOAD
–
Store MAC register:
CoSTORE
–
Compare values:
CoCMP
–
Minimum/Maximum:
CoMIN
CoMAX
Absolute value:
CoABS
–
Rounding:
CoRND
–
Move data:
CoMOV
–
Negate accumulator:
CoNEG
–
Null operation:
CoNOP
–
Protected Instructions
Some instructions of the XC2700 which are critical for the functionality of the controller
are implemented as so-called Protected Instructions. These protected instructions use
the maximum instruction format of 32 bits for decoding, while the regular instructions
only use a part of it (e.g. the lower 8 bits) with the other bits providing additional
information like involved registers. Decoding all 32 bits of a protected doubleword
instruction increases the security in cases of data distortion during instruction fetching.
Critical operations like a software reset are therefore only executed if the complete
instruction is decoded without an error. This enhances the safety and reliability of a
microcontroller system.
User’s Manual
InstrSummary_X, V2.0
12-6
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Device Specification
13
Device Specification
The device specification describes the electrical parameters of the device. It lists DC
characteristics like input, output or supply voltages or currents, and AC characteristics
like timing characteristics and requirements.
Other than the architecture, the instruction set, or the basic functions of the XC2700 core
and its peripherals, these DC and AC characteristics are subject to changes due to
device improvements or specific derivatives of the standard device.
Therefore, these characteristics are not contained in this manual, but rather provided in
a separate Data Sheet, which can be updated more frequently.
Please refer to the current version of the Data Sheet of the respective device for all
electrical parameters.
Note: In any case the specific characteristics of a device should be verified, before a new
design is started. This ensures that the used information is up to date.
The XC2700 derivatives are shipped in several packages. Figure 13-1 and Figure 13-2
show the basic pin diagrams of the XC2700. They show the location of the different
supply and IO pins. A detailed description of all the pins and their selectable functions
can be found in the corresponding Data Sheet.
Note: Not all alternate functions shown in Figure 13-1 are supported by all derivatives.
Please refer to the corresponding descriptions in the data sheets.
User’s Manual
DeviceSpecX2K, V1.0
13-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
1 44
1 43
1 42
1 41
1 40
1 39
1 38
1 37
1 36
1 35
1 34
1 33
1 32
1 31
1 30
1 29
1 28
1 27
1 26
1 25
1 24
1 23
1 22
1 21
1 20
1 19
1 18
1 17
1 16
1 15
1 14
1 13
1 12
1 11
1 10
1 09
V DDPB
P8.5
P8.6
ESR0
ESR2
ES R1
POR ST
XTAL 1
XTAL2
P1.7
P9.7
P1.6
P9.6
P1.5
P10.15
P1.4
P10.14
V DDI1
P9.5
P9.4
P1.3
P10.13
P9.3
P10.12
P1.2
P9.2
P10.11
P10.10
P1.1
P10.9
P9.1
P10.8
P9.0
P1.0
V DDPB
V SS
Device Specification
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
LQFP-144
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
VDDPB
P3.7
P0.7
P10.7
P3.6
P10.6
P0.6
P3.5
P10.5
P3.4
P10.4
P3.3
P0.5
P10.3
P2.10
P3.2
TRef
VDDI1
P0.4
P10.2
P3.1
P0.3
P10.1
P3.0
P10.0
P0.2
P2.9
P4.7
P2.8
P0.1
P2.7
P4.6
P4.5
P0.0
VDDPB
VSS
V SS
V DDPB
P5.4
P5.5
P5.6
P5.7
P5.8
P5.9
P5.10
P5.11
P5.12
P5.13
P5.14
P5.15
P2.12
P2.11
P11.5
V DDI1
P2.0
P2.1
P11.4
P2.2
P11.3
P4.0
P2.3
P11.2
P4.1
P2.4
P11.1
P11.0
P2.5
P4.2
P2.6
P4.4
P4.3
V DDPB
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
VSS
VDDPB
TESTM
P7.2
P8.4
TRST
P8.3
P7.0
P7.3
P8.2
P7.1
P7.4
P8.1
P8.0
VDDIM
P6.0
P6.1
P6.2
P6.3
VDDPA
P15.0
P15.1
P15.2
P15.3
P15.4
P15.5
P15.6
P15.7
VAREF1
VAREF0
VAGND
P5.0
P5.1
P5.2
P5.3
VDDPB
MC_XX_PIN144
Figure 13-1 Pin Configuration PG-LQFP-144 Package (top view)
User’s Manual
DeviceSpecX2K, V1.0
13-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
VDDPB
ESR0
ESR1
PORST
XTAL1
XTAL2
P1.7
P1.6
P1.5
P10.15
P1.4
P10.14
VDDI1
P1.3
P10.13
P10.12
P1.2
P10.11
P10.10
P1.1
P10.9
P10.8
P1.0
VDDPB
VS S
Device Specification
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
LQFP-100
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
VDDPB
P0.7
P10.7
P10.6
P0.6
P10.5
P10.4
P0.5
P10.3
P2.10
TRef
VDDI1
P0.4
P10.2
P0.3
P10.1
P10.0
P0.2
P2.9
P2.8
P0.1
P2.7
P0.0
VDDPB
VSS
VSS
VDDPB
P5.4
P5.5
P5.8
P5.9
P5.10
P5.11
P5.13
P5.15
P2.12
P2.11
VDDI1
P2.0
P2.1
P2.2
P4.0
P2.3
P4.1
P2.4
P2.5
P4.2
P2.6
P4.3
VDDPB
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
VSS
VDDPB
TESTM
P7.2
TRST
P7.0
P7.3
P7.1
P7.4
VDDIM
P6.0
P6.1
P6.2
VDDPA
P15.0
P15.2
P15.4
P15.5
P15.6
VAREF
VAGND
P5.0
P5.2
P5.3
VDDPB
MC_XX_PIN100
Figure 13-2 Pin Configuration PG-LQFP-100 Package (top view)
User’s Manual
DeviceSpecX2K, V1.0
13-3
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Keyword Index
Keyword Index
This section lists a number of keywords which refer to specific details of the XC2700 in
terms of its architecture, its functional units or functions. This helps to quickly find the
answer to specific questions about the XC2700.
This User’s Manual consists of two Volumes, “System Units” and “Peripheral Units”. For
your convenience this keyword index refers to both volumes, so you can immediately
find the reference to the desired section in the corresponding document ([1] or [2]).
Note: Registers are listed in a separate index: Register Index.
A
MultiCAN
Analysis mode 20-18 [2]
Bit timing 20-9 [2]
Block diagram 20-6 [2]
Error handling 20-11 [2]
Gateway mode 20-41 [2]
Interrupts 20-12 [2]
Message acceptance filtering
20-21 [2]
Message object FIFO 20-36 [2]
Message object lists 20-13 [2]
Node control 20-9 [2]
Overview 20-4 [2]
Registers
LISTiH 20-57 [2]
LISTiL 20-58 [2]
MCR 20-55 [2]
MITR 20-56 [2]
MOAMRnH 20-95 [2]
MOAMRnL 20-95 [2]
MOARnH 20-97 [2]
MOARnL 20-98 [2]
MOCTRnH 20-79 [2], 20-82 [2]
MOCTRnL 20-80 [2], 20-82 [2]
MODATAnHH 20-101 [2]
MODATAnHL 20-101 [2]
MODATAnLH 20-100 [2]
MODATAnLL 20-100 [2]
MOFCRnH 20-89 [2]
MOFCRnL 20-91 [2]
MOFGPRnH 20-93 [2]
Acronyms 1-9 [1]
Addressing Modes
CoREG Addressing Mode 4-50 [1]
DSP Addressing Modes 4-46 [1]
Indirect Addressing Modes 4-44 [1]
Long Addressing Modes 4-41 [1]
Short Addressing Modes 4-39 [1]
ALU 4-57 [1]
B
BANKSEL0 Register 5-35 [1]
BANKSEL1 Register 5-35 [1]
Baudrate
Bootstrap Loader 10-21 [1]
Bit
Handling 4-60 [1]
Manipulation Instructions 12-2 [1]
protected 4-61 [1]
reserved 2-17 [1]
Block Diagram ITC / PEC 5-3 [1]
Bootstrap Loader 10-14 [1]
C
CAN
Block diagram 20-1 [2]
Clock control 20-102 [2]
Features 20-2 [2]
Functional description 20-3 [2]
Interrupt structure 20-105 [2]
Module implementation 20-106 [2]
User’s Manual
L-1
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Keyword Index
MOFGPRnL 20-93 [2]
MOIPRnH 20-87 [2]
MOIPRnL 20-87 [2]
MSIDk 20-60 [2]
MSIMASKH 20-61 [2]
MSIMASKL 20-61 [2]
MSPNDkH 20-59 [2]
MSPNDkL 20-59 [2]
NBTRxH 20-72 [2]
NBTRxL 20-72 [2]
NCRx 20-62 [2]
NECNTxH 20-73 [2]
NECNTxL 20-74 [2]
NFCRxH 20-75 [2]
NFCRxL 20-76 [2]
NIPRx 20-70 [2]
NPCRx 20-71 [2]
NSRx 20-66 [2]
PANCTRH 20-50 [2]
PANCTRL 20-50 [2]
CAPCOM12
Capture Mode 17-14 [2]
Counter Mode 17-9 [2]
CAPCOM2 2-17 [1]
Capture Mode
GPT1 14-26 [2]
GPT2 (CAPREL) 14-48 [2]
Capture/Compare Registers 17-11 [2]
CCU6 2-19 [1]
Clock
generation 2-32 [1]
output signal 6-20 [1]
Clock System
Main oscillator 6-4 [1]
Oscillator run detection 6-12 [1]
Clock system
Clock source 6-6 [1]
PLL, see “PLL”
Concatenation of Timers 14-22 [2],
14-47 [2]
Context
Pointer Updating 4-34 [1]
Switch 4-33 [1]
User’s Manual
Switching 5-34 [1]
Count direction 14-6 [2], 14-36 [2]
Counter 14-20 [2], 14-45 [2]
Counter Mode (GPT1) 14-10 [2], 14-40 [2]
CPU 2-2 [1], 4-1 [1]
D
Data Management Unit (Introduction)
2-9 [1]
Data Page 4-42 [1]
Development Support 1-8 [1]
Direction
count 14-6 [2], 14-36 [2]
Disable
Interrupt 5-31 [1]
Division 4-62 [1]
Double-Register Compare 17-24 [2]
DPP 4-42 [1]
E
EBC
Bus Signals 9-3 [1]
Enable
Interrupt 5-31 [1]
End of PEC Interrupt Sub Node 5-30 [1]
ESR 6-68 [1]
ESRx 5-1 [1]
External
Bus 2-14 [1]
Interrupts 5-37 [1]
F
Flags 4-56 [1]–4-59 [1]
Flash
Recommdations
EEPROM Emulation 3-50 [1]
Programming Code and Constant
Data 3-49 [1]
Recommendations 3-49 [1]
Fractional divider
Block diagram 20-108 [2]
Operating modes 20-110 [2]
Suspend mode 20-111 [2]
L-2
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Keyword Index
Frequency
output signal 6-20 [1]
G
Gated timer mode (GPT1) 14-9 [2]
Gated timer mode (GPT2) 14-39 [2]
GPT 2-20 [1]
GPT1 14-2 [2]
GPT2 14-32 [2]
H
Hardware
Traps 5-42 [1]
I
Incremental Interface Mode (GPT1)
14-11 [2]
Instruction 12-1 [1]
Bit Manipulation 12-2 [1]
Pipeline 4-11 [1]
protected 12-6 [1]
Interface
External Bus 9-1 [1]
Interrupt
Arbitration 5-4 [1]
Enable/Disable 5-31 [1]
External 5-37 [1]
Jump Table Cache 5-18 [1]
Latency 5-40 [1]
Node Sharing 5-36 [1]
Priority 5-7 [1]
Processing 5-1 [1]
RTC 15-13 [2]
System 2-8 [1], 5-2 [1]
L
Latency
Interrupt, PEC 5-40 [1]
LXBus 2-14 [1]
M
Memory 2-10 [1]
Multiplication 4-62 [1]
User’s Manual
O
OCDS
Requests 5-39 [1]
P
PEC 2-10 [1], 5-20 [1]
Latency 5-40 [1]
Transfer Count 5-21 [1]
Peripheral
Event Controller --> PEC 5-20 [1]
Summary 2-15 [1]
Pins 8-1 [1]
Pipeline 4-11 [1]
PLL 6-5 [1]
Functionality 6-6 [1]
Switching parameters 6-14 [1]
Port 2-30 [1]
Temperature compensation 6-157 [1]
Ports
Configuring a Pin 7-14 [1]
Output register Pn_OUT 7-9 [1]
Pad driver control 7-6 [1]
Structure
Analog 7-4 [1]
Hardware Override 7-3 [1]
Standard 7-2 [1]
Program Management Unit (Introduction)
2-9 [1]
Protected
Bits 4-61 [1]
instruction 12-6 [1]
R
Real Time Clock (->RTC) 2-22 [1], 15-1 [2]
Register
BANKSEL0 5-35 [1]
BANKSEL1 5-35 [1]
SRCPx 5-25 [1]
Reserved bits 2-17 [1]
Reset 6-49 [1]
Module behavior 6-56 [1]
RTC 2-22 [1], 15-1 [2]
L-3
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Keyword Index
Protocol interrupts 19-120 [2]
Protocol registers 19-123 [2]
Pulse shaping 19-118 [2]
Receive buffer 19-122 [2]
Signals 19-111 [2]
Sync-break detection 19-122 [2]
Baud rate 19-8 [2]
Channel structure 19-5 [2]
Data buffer 19-10 [2]
Data shifting and handling 19-9 [2]
Data transfer interrupts 19-22 [2]
External frequency 19-42 [2]
Feature set 19-2 [2]
FIFO buffer 19-11 [2]
FIFO data buffer 19-80 [2]
Fractional divider 19-42 [2]
General interrupts 19-20 [2]
IIC mode 19-160 [2]
Baud rate 19-165 [2]
Byte stretching 19-165 [2]
Data bit symbol 19-172 [2]
Data flow handling 19-173 [2]
Frame format 19-163 [2]
Master arbitration 19-165 [2]
Master transmission 19-177 [2]
Mode control 19-166 [2]
Protocol interrupts 19-167 [2]
Protocol registers 19-178 [2]
Receiver address acknowledge
19-168 [2]
Receiver handling 19-168 [2]
Receiver status 19-169 [2]
Signals 19-161 [2]
Start symbol 19-171 [2]
Stop symbol 19-172 [2]
Symbol timing 19-170 [2]
Transmission chain 19-165 [2]
Transmit data 19-173 [2]
IIS mode 19-184 [2]
Baud rate 19-193 [2]
Connection of Audio devices
19-187 [2]
Data interrupts 19-191 [2]
Registers
T14 15-8 [2]
T14REL 15-8 [2]
S
Segmentation 4-37 [1]
Sharing
Interrupt Nodes 5-36 [1]
Software
Traps 5-42 [1]
SR0 5-47 [1]
SR1 5-47 [1]
SRCPx Register 5-25 [1]
Stack 4-52 [1]
T
Temperature compensation 6-157 [1]
Timer 14-2 [2], 14-32 [2]
Auxiliary Timer 14-15 [2], 14-41 [2]
Concatenation 14-22 [2], 14-47 [2]
Core Timer 14-4 [2], 14-34 [2]
Counter Mode (GPT1) 14-10 [2],
14-40 [2]
Gated Mode (GPT1) 14-9 [2]
Gated Mode (GPT2) 14-39 [2]
Incremental Interface Mode (GPT1)
14-11 [2]
Mode (GPT1) 14-8 [2]
Mode (GPT2) 14-38 [2]
Tools 1-8 [1]
Traps 5-42 [1]
U
USIC
ASC mode 19-111 [2]
Automatic shaping 19-119 [2]
Baud rate 19-117 [2]
Bit timing 19-116 [2]
Collision detection 19-117 [2]
Data transfer interrupts 19-121 [2]
EOF control 19-119 [2]
Frame format 19-112 [2]
Noise detection 19-117 [2]
User’s Manual
L-4
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Keyword Index
FMRH 19-69 [2]
FMRL 19-68 [2]
INPRH 19-33 [2]
INPRL 19-32 [2]
Input stage register 19-39 [2]
INx 19-106 [2]
KSCFG 19-30 [2]
OUTDRH 19-108 [2]
OUTDRL 19-108 [2]
OUTRH 19-107 [2]
OUTRL 19-107 [2]
Overview 19-14 [2]
PCRH 19-34 [2], 19-126 [2],
19-153 [2], 19-178 [2], 19-200 [2]
PCRL 19-34 [2], 19-123 [2],
19-151 [2], 19-178 [2], 19-198 [2]
Protocol registers 19-34 [2]
PSCR 19-36 [2]
PSR 19-35 [2], 19-127 [2],
19-155 [2], 19-181 [2], 19-201 [2]
RBCTRH 19-103 [2]
RBCTRL 19-102 [2]
RBUF 19-77 [2]
RBUF0 19-71 [2]
RBUF01SRH 19-74 [2]
RBUF01SRL 19-71 [2]
RBUF1 19-74 [2]
RBUFD 19-78 [2]
RBUFSR 19-79 [2]
SCTRH 19-60 [2]
SCTRL 19-58 [2]
TBCTRH 19-100 [2]
TBCTRL 19-99 [2]
TBUFx 19-70 [2]
TCSRH 19-66 [2]
TCSRL 19-61 [2]
Transfer control/status registers
19-58 [2]
TRBPTRH 19-110 [2]
TRBPTRL 19-109 [2]
TRBSCR 19-97 [2]
TRBSRH 19-96 [2]
TRBSRL 19-93 [2]
Frame and word length 19-188 [2]
Mode control 19-188 [2]
Protocol interrupts 19-196 [2],
19-197 [2]
Protocol overview 19-186 [2]
Protocol registers 19-198 [2]
Receive data 19-192 [2]
Signals 19-184 [2]
Slave mode operation 19-197 [2]
Transfer delay 19-186 [2],
19-189 [2]
Transmit data 19-191 [2]
WA generation 19-194 [2],
19-195 [2]
Implementation
Address map 19-205 [2]
Channels 19-205 [2]
I/O connections 19-210 [2]
I/O lines of USIC0 19-211 [2]
I/O lines of USIC1 19-214 [2]
I/O lines of USIC2 19-217 [2]
Interrupt registers 19-208 [2]
Overview 19-204 [2]
Input stages 19-6 [2], 19-37 [2]
Kernel registers
Baud rate registers 19-47 [2]
BRGH 19-51 [2]
BRGL 19-49 [2]
BYP 19-90 [2]
BYPCRH 19-92 [2]
BYPCRL 19-90 [2]
CCFG 19-29 [2]
CCR 19-26 [2]
Channel control and configuration
registers 19-26 [2]
Data buffer registers 19-70 [2]
DX0CR 19-39 [2]
DX1CR 19-39 [2]
DX2CR 19-39 [2]
FDRH 19-48 [2]
FDRL 19-47 [2]
FIFO buffer and bypass registers
19-90 [2]
User’s Manual
L-5
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Keyword Index
Mode control 19-19 [2]
Module registers
USIC0_IDH 19-207 [2]
USIC0_IDL 19-206 [2]
USIC1_IDH 19-207 [2]
USIC1_IDL 19-206 [2]
USIC2_IDH 19-207 [2]
USIC2_IDL 19-206 [2]
Output signals 19-7 [2]
Protocol control and status 19-18 [2]
Protocol interrupts 19-25 [2]
Protocol related counter 19-43 [2]
Receive buffering 19-56 [2]
Registers overview 19-14 [2]
SSC mode 19-131 [2]
Automatic Shadow mechanism
19-139 [2]
Baud rate 19-142 [2]
Data frame control 19-140 [2]
EOF control 19-147 [2], 19-150 [2]
Master mode 19-142 [2]
Protocol interrupts 19-146 [2],
19-149 [2]
Protocol registers 19-151 [2]
Receive buffer 19-141 [2]
Signals 19-131 [2]
Slave mode 19-149 [2]
Slave select delay 19-145 [2]
Slave select generation 19-143 [2]
Time quanta counter 19-45 [2]
Transmit buffering 19-52 [2]
W
Watchdog 2-29 [1]
Watchdog Timer 6-161 [1]
Kernel Registers 6-166 [1]
Modes of operation
Disable Mode 6-164 [1]
Normal Mode 6-163 [1]
Prewarning Mode 6-164 [1]
Period calculation 6-162 [1]
User’s Manual
L-6
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Register Index
Register Index
This section lists the registers of the XC2700. This helps to quickly find the reference to
the description of the respective register.
This User’s Manual consists of two Volumes, “System Units” and “Peripheral Units”. For
your convenience this register index refers to both volumes, so you can immediately find
the reference to the desired section in the corresponding document ([1] or [2]).
Note: Keywords are listed in a separate index: Keyword Index.
A
ADC0_KSCFG 16-23 [2]
ADCx_ALR0 16-76 [2]
ADCx_ASENR 16-36 [2]
ADCx_CHCTRx 16-67 [2]
ADCx_CHINCR 16-72 [2]
ADCx_CHINFR 16-71 [2]
ADCx_CHINPRx 16-73 [2]
ADCx_CRCRx 16-42 [2]
ADCx_CRMRx 16-44 [2]
ADCx_CRPRx 16-43 [2]
ADCx_EMCTR 16-100 [2]
ADCx_EMENR 16-101 [2]
ADCx_EVINCR 16-92 [2]
ADCx_EVINFR 16-91 [2]
ADCx_EVINPRx 16-93 [2]
ADCx_GLOBCTR 16-25 [2]
ADCx_GLOBSTR 16-27 [2]
ADCx_INPRx 16-69 [2]
ADCx_LCBRx 16-70 [2]
ADCx_PISEL 16-30 [2]
ADCx_Q0Rx 16-56 [2]
ADCx_QBURx 16-58 [2]
ADCx_QINRx 16-60 [2]
ADCx_QMRx 16-51 [2]
ADCx_QSRx 16-54 [2]
ADCx_RCRx 16-89 [2]
ADCx_RESRAVx 16-86 [2]
ADCx_RESRAx 16-86 [2]
ADCx_RESRVx 16-85 [2]
ADCx_RESRx 16-85 [2]
ADCx_RSPRx 16-37 [2]
User’s Manual
ADCx_RSSR 16-87 [2]
ADCx_SYNCTR 16-102 [2]
ADCx_VFR 16-88 [2]
ADDRSELx 9-23 [1]
C
CAN_LISTiH 20-57 [2]
CAN_LISTiL 20-58 [2]
CAN_MCR 20-55 [2]
CAN_MITR 20-56 [2]
CAN_MOAMRnH 20-95 [2]
CAN_MOAMRnL 20-95 [2]
CAN_MOARnH 20-97 [2]
CAN_MOARnL 20-98 [2]
CAN_MOCTRnH 20-79 [2]
CAN_MOCTRnL 20-80 [2]
CAN_MODATAnHH 20-101 [2]
CAN_MODATAnHL 20-101 [2]
CAN_MODATAnLH 20-100 [2]
CAN_MODATAnLL 20-100 [2]
CAN_MOFCRnH 20-89 [2]
CAN_MOFCRnL 20-91 [2]
CAN_MOFGPRnH 20-93 [2]
CAN_MOFGPRnL 20-93 [2]
CAN_MOIPRnH 20-87 [2]
CAN_MOIPRnL 20-87 [2]
CAN_MOSTATnH 20-82 [2]
CAN_MOSTATnL 20-82 [2]
CAN_MSIDk 20-60 [2]
CAN_MSIMASKH 20-61 [2]
CAN_MSIMASKL 20-61 [2]
CAN_MSPNDkH 20-59 [2]
L-7
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Register Index
CAN_MSPNDkL 20-59 [2]
CAN_NBTRxH 20-72 [2]
CAN_NBTRxL 20-72 [2]
CAN_NCRx 20-62 [2]
CAN_NECNTxH 20-73 [2]
CAN_NECNTxL 20-74 [2]
CAN_NFCRxH 20-75 [2]
CAN_NFCRxL 20-76 [2]
CAN_NIPRx 20-70 [2]
CAN_NPCRx 20-71 [2]
CAN_NSRx 20-66 [2]
CAN_PANCTRH 20-50 [2]
CAN_PANCTRL 20-50 [2]
CAPREL 14-57 [2]
CC2_CCyIC 17-36 [2]
CC2_DRM 17-25 [2]
CC2_IOC 17-31 [2]
CC2_KSCCFG 17-39 [2]
CC2_M4/5/6/7 17-11 [2]
CC2_OUT 17-27 [2]
CC2_SEE 17-29 [2]
CC2_SEM 17-29 [2]
CC2_T78CON 17-5 [2]
CC2_T7IC 17-10 [2]
CC2_T8IC 17-10 [2]
CCU6x_CC63R 18-64 [2]
CCU6x_CC63SR 18-64 [2]
CCU6x_CC6xR 18-33 [2]
CCU6x_CC6xSR 18-34 [2]
CCU6x_CMPMODIF 18-39 [2]
CCU6x_CMPSTAT 18-37 [2]
CCU6x_IEN 18-97 [2]
CCU6x_INP 18-100 [2]
CCU6x_IS 18-90 [2]
CCU6x_ISR 18-95 [2]
CCU6x_ISS 18-93 [2]
CCU6x_KSCFG 18-110 [2]
CCU6x_KSCSR 18-112 [2]
CCU6x_MCMCTR 18-83 [2]
CCU6x_MCMOUT 18-86 [2]
CCU6x_MCMOUTS 18-85 [2]
CCU6x_MODCTR 18-77 [2]
CCU6x_PISELH 18-108 [2]
User’s Manual
CCU6x_PISELL 18-106 [2]
CCU6x_PSLR 18-82 [2]
CCU6x_T12 18-32 [2]
CCU6x_T12DTC 18-35 [2]
CCU6x_T12MSEL 18-40 [2]
CCU6x_T12PR 18-32 [2]
CCU6x_T13 18-62 [2]
CCU6x_T13PR 18-63 [2]
CCU6x_TCTR0 18-41 [2]
CCU6x_TCTR2 18-44 [2]
CCU6x_TCTR4 18-47 [2]
CCU6x_TRPCTR 18-79 [2]
CP 4-36 [1]
CPUCON1 4-26 [1]
CPUCON2 4-27 [1]
CRIC 14-58 [2]
CSP 4-38 [1]
D
DPP0/1/2/3 4-42 [1]
DSTPx 5-25 [1]
E
EBCMOD0 9-14 [1]
EBCMOD1 9-16 [1]
EOPIC 5-29 [1]
F
FCONCS0 9-20 [1]
FCONCS1/2/3/4/7 9-21 [1]
FINT0/1ADDR 5-18 [1]
FINT0/1CSP 5-18 [1]
FSR_BUSY 3-58 [1]
FSR_OP 3-58 [1]
FSR_PROT 3-60 [1]
G
GPT12E_CAPREL 14-57 [2]
GPT12E_CRIC 14-58 [2]
GPT12E_KSCCFG 14-59 [2]
GPT12E_T2,-T3,-T4 14-30 [2]
GPT12E_T2/3/4IC 14-31 [2]
GPT12E_T2CON 14-15 [2]
L-8
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Register Index
GPT12E_T3CON 14-4 [2]
GPT12E_T4CON 14-15 [2]
GPT12E_T5,-T6 14-57 [2]
GPT12E_T5/6IC 14-58 [2]
GPT12E_T5CON 14-41 [2]
GPT12E_T6CON 14-34 [2]
Ports
Pn_IN 7-12 [1]
Pn_IOCRx 7-13 [1]
Pn_OMR 7-10 [1]
PROCONx 3-63 [1]
PSW 4-56 [1]
I
Q
IDX0/1 4-46 [1]
IMBCTRH 3-55 [1]
IMBCTRL 3-53 [1]
INTCTR 3-56 [1]
IP 4-38 [1]
QR0/1 4-45 [1]
QX0/1 4-47 [1]
M
MAH 4-69 [1]
MAL 4-68 [1]
MAR 3-62 [1]
MCW 4-65 [1]
MDC 4-63 [1]
MDH 4-62 [1]
MDL 4-63 [1]
MRW 4-72 [1]
MSW 4-70 [1]
O
ONES 4-74 [1]
P
PECCx 5-21 [1]
PECISNC 5-29 [1]
PECSEGx 5-25 [1]
Pn_DIDIS
P15 7-16 [1]
P5 7-16 [1]
Pn_IN 7-12 [1]
Pn_IOCRx 7-13 [1]
Pn_OMRH
P10 7-10 [1]
P2 7-10 [1]
Pn_OMRL 7-10 [1]
Pn_OUT 7-9 [1]
Pn_POCON 7-7 [1]
User’s Manual
R
RELH/L 15-10 [2]
RTC_CON 15-6 [2]
RTC_IC 15-14 [2]
RTC_ISNC 15-14 [2]
RTC_KSCCFG 15-15 [2]
RTC_RELH/L 15-10 [2]
RTC_RTCH/L 15-9 [2]
RTC_T14 15-8 [2]
RTC_T14REL 15-8 [2]
RTCH/L 15-9 [2]
S
SCU
Registers
ESREXCON1 6-72 [1]
ESREXCON2 6-73 [1]
WICR 6-46 [1]
SP 4-53 [1]
SPSEG 4-53 [1]
SRCPx 5-25 [1]
STKOV 4-55 [1]
STKUN 4-55 [1]
T
T14 15-8 [2]
T14REL 15-8 [2]
T2, T3, T4 14-30 [2]
T2/3/4IC 14-31 [2]
T2CON 14-15 [2]
T3CON 14-4 [2]
T4CON 14-15 [2]
L-9
V2.1, 2008-08
XC2700 Derivatives
System Units (Vol. 1 of 2)
Register Index
T5, T6 14-57 [2]
T5/6IC 14-58 [2]
T5CON 14-41 [2]
T6CON 14-34 [2]
T7IC 17-10 [2]
T8IC 17-10 [2]
TCONCS0 9-17 [1]
TCONCS1/2/3/4 9-18 [1], 9-19 [1]
TFR 5-44 [1]
U
USIC0_IDH 19-207 [2]
USIC0_IDL 19-206 [2]
USIC1_IDH 19-207 [2]
USIC1_IDL 19-206 [2]
USIC2_IDH 19-207 [2]
USIC2_IDL 19-206 [2]
UxCy_BRGH 19-51 [2]
UxCy_BRGL 19-49 [2]
UxCy_BYP 19-90 [2]
UxCy_BYPCRH 19-92 [2]
UxCy_BYPCRL 19-90 [2]
UxCy_CCFG 19-29 [2]
UxCy_CCR 19-26 [2]
UxCy_DX0CR 19-39 [2]
UxCy_DX1CR 19-39 [2]
UxCy_DX2CR 19-39 [2]
UxCy_FDRH 19-48 [2]
UxCy_FDRL 19-47 [2]
UxCy_FMRH 19-69 [2]
UxCy_FMRL 19-68 [2]
UxCy_INPRH 19-33 [2]
UxCy_INPRL 19-32 [2]
UxCy_INx 19-106 [2]
UxCy_KSCFG 19-30 [2]
UxCy_OUTDRH 19-108 [2]
UxCy_OUTDRL 19-108 [2]
UxCy_OUTRH 19-107 [2]
UxCy_OUTRL 19-107 [2]
UxCy_PCRH 19-34 [2], 19-126 [2],
19-153 [2], 19-178 [2], 19-200 [2]
UxCy_PCRL 19-34 [2], 19-123 [2],
19-151 [2], 19-178 [2], 19-198 [2]
User’s Manual
UxCy_PSCR 19-36 [2]
UxCy_PSR 19-35 [2], 19-127 [2],
19-155 [2], 19-181 [2], 19-201 [2]
UxCy_RBCTRH 19-103 [2]
UxCy_RBCTRL 19-102 [2]
UxCy_RBUF 19-77 [2]
UxCy_RBUF0 19-71 [2]
UxCy_RBUF01SRH 19-74 [2]
UxCy_RBUF01SRL 19-71 [2]
UxCy_RBUF1 19-74 [2]
UxCy_RBUFD 19-78 [2]
UxCy_RBUFSR 19-79 [2]
UxCy_SCTRH 19-60 [2]
UxCy_SCTRL 19-58 [2]
UxCy_TBCTRH 19-100 [2]
UxCy_TBCTRL 19-99 [2]
UxCy_TBUFx 19-70 [2]
UxCy_TCSRH 19-66 [2]
UxCy_TCSRL 19-61 [2]
UxCy_TRBPTRH 19-110 [2]
UxCy_TRBPTRL 19-109 [2]
UxCy_TRBSCR 19-97 [2]
UxCy_TRBSRH 19-96 [2]
UxCy_TRBSRL 19-93 [2]
V
VECSEG 5-12 [1]
X
xxIC (gen.) 5-6 [1]
Z
ZEROS 4-74 [1]
L-10
V2.1, 2008-08
w w w . i n f i n e o n . c o m
B158-H9136-G1-X-7600
Published by Infineon Technologies AG