MCF5407 ColdFire®
Integrated Microprocessor
User’s Manual
MCF5407UM/D
Rev. 0.1, 11/2001
ColdFire is a registered trademark and DigitalDNA is a trademark of Motorola, Inc.
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Overview
Part I: MCF5407 Processor Core
1
Part I
ColdFire Core
2
Hardware Multiply/Accumulate (MAC) Unit
3
Local Memory
4
Debug Support
5
Part II: System Integration Module (SIM)
Part II
SIM Overview
6
Phase-Locked Loop (PLL)
7
I2C
Module
8
Interrupt Controller
9
Chip-Select Module
10
Synchronous/Asynchronous DRAM Controller Module
11
Part III: Peripheral Module
Part III
DMA Controller Module
12
Timer Module
13
UART Modules
14
Parallel Port (General-Purpose I/O)
15
Part IV: Hardware Interface
Part IV
Mechanical Data
16
Signal Descriptions
17
Bus Operation
18
IEEE 1149.1 Test Access Port (JTAG)
19
Electrical Specifications
20
Appendix A: Migration
A
Appendix B: Memory Map
B
Glossary of Terms and Abbreviations
GLO
Index
IND
IND
B
GLO
IND
1
Part I
Overview
Part I: MCF5407 Processor Core
2
ColdFire Core
3
Hardware Multiply/Accumulate (MAC) Unit
4
Local Memory
5
Debug Support
Part II
Part II: System Integration Module (SIM)
6
SIM Overview
7
Phase-Locked Loop (PLL)
8
I2C Module
9
Interrupt Controller
10
Chip-Select Module
11
Synchronous/Asynchronous DRAM Controller Module
Part III
Part III: Peripheral Module
12
DMA Controller Module
13
Timer Module
14
UART Modules
15
Parallel Port (General-Purpose I/O)
Part IV
Part IV: Hardware Interface
16
Mechanical Data
17
Signal Descriptions
18
Bus Operation
19
IEEE 1149.1 Test Access Port (JTAG)
20
Electrical Specifications
A
Appendix A: Migration
B
Appendix B: Memory Map
GLO
Glossary of Terms and Abbreviations
IND
Index
CONTENTS
Paragraph
Number
Title
Page
Number
Chapter 1
Overview
1.1
1.2
1.2.1
1.3
1.3.1
1.3.1.1
1.3.1.2
1.3.1.3
1.3.1.4
1.3.2
1.3.2.1
1.3.2.2
1.3.3
1.3.4
1.3.5
1.3.6
1.3.7
1.3.8
1.3.8.1
1.3.8.2
1.3.8.3
1.3.8.4
1.3.8.5
1.3.9
1.3.10
1.4
1.4.1
1.4.2
Features ............................................................................................................... 1-1
MCF5407 Features.............................................................................................. 1-4
Process ............................................................................................................ 1-7
ColdFire Module Description ............................................................................. 1-7
ColdFire Core ................................................................................................. 1-7
Instruction Fetch Pipeline (IFP).................................................................. 1-7
Operand Execution Pipeline (OEP) ............................................................ 1-8
MAC Module.............................................................................................. 1-8
Integer Divide Module................................................................................ 1-8
Harvard Architecture ...................................................................................... 1-8
16-Kbyte Instruction Cache/8-Kbyte Data Cache ...................................... 1-9
Internal 2-Kbyte SRAMs ............................................................................ 1-9
DRAM Controller ........................................................................................... 1-9
DMA Controller.............................................................................................. 1-9
UART Modules............................................................................................. 1-10
Timer Module ............................................................................................... 1-11
I2C Module ................................................................................................... 1-11
System Interface ........................................................................................... 1-11
External Bus Interface .............................................................................. 1-11
Chip Selects .............................................................................................. 1-11
16-Bit Parallel Port Interface .................................................................... 1-12
Interrupt Controller ................................................................................... 1-12
JTAG......................................................................................................... 1-12
System Debug Interface................................................................................ 1-12
PLL Module.................................................................................................. 1-13
Programming Model, Addressing Modes, and Instruction Set......................... 1-13
Programming Model ..................................................................................... 1-15
User Registers ............................................................................................... 1-15
Contents
v
CONTENTS
Paragraph
Number
1.4.3
1.4.4
Title
Page
Number
Supervisor Registers ..................................................................................... 1-16
Instruction Set ............................................................................................... 1-16
Part I
MCF5407 Processor Core
Chapter 2
ColdFire Core
2.1
2.1.1
2.1.2
2.1.2.1
2.1.2.1.1
2.1.2.2
2.1.2.2.1
2.1.2.2.2
2.1.2.2.3
2.1.2.3
2.1.3
2.2
2.2.1
2.2.1.1
2.2.1.2
2.2.1.3
2.2.1.4
2.2.1.5
2.2.1.6
2.2.2
2.2.2.1
2.2.2.2
2.2.2.3
2.2.2.4
2.2.2.5
2.2.2.6
2.3
2.4
2.4.1
2.4.2
2.5
2.6
2.6.1
vi
Features and Enhancements................................................................................ 2-1
Clock-Multiplied Microprocessor Core.......................................................... 2-2
Enhanced Pipelines ......................................................................................... 2-2
Instruction Fetch Pipeline (IFP).................................................................. 2-4
Branch Acceleration ............................................................................... 2-4
Operand Execution Pipeline (OEP) ............................................................ 2-4
Illegal Opcode Handling......................................................................... 2-5
Hardware Multiply/Accumulate (MAC) Unit ........................................ 2-5
Hardware Divide Unit............................................................................. 2-6
Harvard Memory Architecture ................................................................... 2-6
Debug Module Enhancements ........................................................................ 2-6
Programming Model ........................................................................................... 2-7
User Programming Model .............................................................................. 2-8
Data Registers (D0–D7) ............................................................................. 2-8
Address Registers (A0–A6) ........................................................................ 2-9
Stack Pointer (A7, SP) ................................................................................ 2-9
Program Counter (PC) ................................................................................ 2-9
Condition Code Register (CCR) ................................................................. 2-9
MAC Programming Model....................................................................... 2-10
Supervisor Programming Model................................................................... 2-10
Status Register (SR).................................................................................. 2-11
Vector Base Register (VBR) .................................................................... 2-12
Cache Control Register (CACR) .............................................................. 2-12
Access Control Registers (ACR0–ACR3)................................................ 2-12
RAM Base Address Registers (RAMBAR0 and RAMBAR1) ................ 2-12
Module Base Address Register (MBAR) ................................................. 2-12
Integer Data Formats......................................................................................... 2-13
Organization of Data in Registers..................................................................... 2-13
Organization of Integer Data Formats in Registers ...................................... 2-13
Organization of Integer Data Formats in Memory ....................................... 2-14
Addressing Mode Summary ............................................................................. 2-15
Instruction Set Summary................................................................................... 2-15
Additions to the Instruction Set Architecture ............................................... 2-18
MCF5407 User’s Manual
CONTENTS
Paragraph
Number
2.6.2
2.7
2.7.1
2.7.2
2.7.3
2.7.4
2.7.5
2.8
2.8.1
2.8.2
2.9
Title
Page
Number
Instruction Set Summary ..............................................................................
Execution Timings ............................................................................................
MOVE Instruction Execution Timing ..........................................................
Execution Timings—One-Operand Instructions ..........................................
Execution Timings—Two-Operand Instructions..........................................
Miscellaneous Instruction Execution Times.................................................
Branch Instruction Execution Times ............................................................
Exception Processing Overview .......................................................................
Exception Stack Frame Definition................................................................
Processor Exceptions ....................................................................................
ColdFire Instruction Set Architecture Enhancements.......................................
2-19
2-23
2-25
2-26
2-27
2-29
2-30
2-31
2-32
2-34
2-36
Chapter 3
Hardware Multiply/Accumulate (MAC) Unit
3.1
3.1.0.1
3.1.0.2
3.1.0.3
3.1.0.4
3.2
Overview.............................................................................................................
MAC Programming Model.........................................................................
General Operation.......................................................................................
MAC Instruction Set Summary ..................................................................
Data Representation....................................................................................
MAC Instruction Execution Timings..................................................................
3-1
3-2
3-3
3-4
3-4
3-5
Chapter 4
Local Memory
4.1
4.2
4.3
4.4
4.4.1
4.5
4.5.1
4.6
4.7
4.8
4.8.1
4.8.2
4.9
4.9.1
4.9.1.1
4.9.1.2
4.9.1.3
Interactions between Local Memory Modules ................................................... 4-1
SRAM Overview ................................................................................................ 4-1
SRAM Operation ................................................................................................ 4-2
SRAM Programming Model............................................................................... 4-3
SRAM Base Address Registers (RAMBAR0/RAMBAR1)........................... 4-3
SRAM Initialization............................................................................................ 4-4
SRAM Initialization Code .............................................................................. 4-5
Power Management ............................................................................................ 4-6
Cache Overview.................................................................................................. 4-6
Cache Organization............................................................................................. 4-8
Cache Line States: Invalid, Valid-Unmodified, and Valid-Modified............. 4-8
The Cache at Start-Up..................................................................................... 4-9
Cache Operation................................................................................................ 4-11
Caching Modes ............................................................................................. 4-13
Cacheable Accesses .................................................................................. 4-14
Write-Through Mode (Data Cache Only)................................................. 4-14
Copyback Mode (Data Cache Only)......................................................... 4-14
Contents
vii
CONTENTS
Paragraph
Number
4.9.2
4.9.3
4.9.3.1
4.9.3.2
4.9.3.3
4.9.3.4
4.9.4
4.9.5
4.9.5.1
4.9.5.2
4.9.5.2.1
4.9.5.2.2
4.9.6
4.10
4.10.1
4.10.2
4.11
4.12
4.12.1
4.12.2
4.13
Title
Page
Number
Cache-Inhibited Accesses .............................................................................
Cache Protocol..............................................................................................
Read Miss .................................................................................................
Write Miss (Data Cache Only) .................................................................
Read Hit ....................................................................................................
Write Hit (Data Cache Only) ....................................................................
Cache Coherency (Data Cache Only)...........................................................
Memory Accesses for Cache Maintenance...................................................
Cache Filling.............................................................................................
Cache Pushes ............................................................................................
Push and Store Buffers .........................................................................
Push and Store Buffer Bus Operation...................................................
Cache Locking ..............................................................................................
Cache Registers.................................................................................................
Cache Control Register (CACR) ..................................................................
Access Control Registers (ACR0–ACR3)....................................................
Cache Management...........................................................................................
Cache Operation Summary ...............................................................................
Instruction Cache State Transitions ..............................................................
Data Cache State Transitions........................................................................
Cache Initialization Code..................................................................................
4-14
4-15
4-16
4-16
4-16
4-17
4-17
4-17
4-17
4-18
4-18
4-18
4-19
4-21
4-21
4-23
4-24
4-27
4-27
4-28
4-32
Chapter 5
Debug Support
5.1
5.2
5.2.1
5.3
5.3.1
5.3.2
5.3.3
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.4.5
5.4.6
5.4.7
5.4.8
viii
Overview............................................................................................................. 5-1
Signal Descriptions ............................................................................................. 5-2
Processor Status/Debug Data (PSTDDATA[7:0]) ......................................... 5-3
Real-Time Trace Support.................................................................................... 5-4
Begin Execution of Taken Branch (PST = 0x5) ............................................. 5-6
Processor Stopped or Breakpoint State Change (PST = 0xE) ........................ 5-7
Processor Halted (PST = 0xF) ........................................................................ 5-7
Programming Model ........................................................................................... 5-8
Address Attribute Trigger Registers (AATR, AATR1)................................ 5-10
Address Breakpoint Registers (ABLR/ABLR1, ABHR/ABHR1) ............. 5-12
BDM Address Attribute Register (BAAR)................................................... 5-12
Configuration/Status Register (CSR)............................................................ 5-13
Data Breakpoint/Mask Registers (DBR/DBR1, DBMR/DBMR1) ............ 5-15
Program Counter Breakpoint/Mask Registers
(PBR, PBR1, PBR2, PBR3, PBMR) ........................................................ 5-16
Trigger Definition Register (TDR) ............................................................... 5-18
Extended Trigger Definition Register (XTDR) ............................................ 5-19
MCF5407 User’s Manual
CONTENTS
Paragraph
Number
5.4.9
5.5
5.5.1
5.5.2
5.5.2.1
5.5.2.2
5.5.3
5.5.3.1
5.5.3.1.1
5.5.3.2
5.5.3.3
5.5.3.3.1
5.5.3.3.2
5.5.3.3.3
5.5.3.3.4
5.5.3.3.5
5.5.3.3.6
5.5.3.3.7
5.5.3.3.8
5.5.3.3.9
5.5.3.3.10
5.5.3.3.11
5.5.3.3.12
5.5.3.3.13
5.6
5.6.1
5.6.1.1
5.6.2
5.7
5.8
5.8.1
5.8.2
Title
Page
Number
Resulting Set of Possible Trigger Combinations..........................................
Background Debug Mode (BDM) ....................................................................
CPU Halt.......................................................................................................
BDM Serial Interface....................................................................................
Receive Packet Format .............................................................................
Transmit Packet Format............................................................................
BDM Command Set......................................................................................
ColdFire BDM Command Format............................................................
Extension Words as Required...............................................................
Command Sequence Diagrams.................................................................
Command Set Descriptions ......................................................................
Read A/D Register (RAREG/RDREG) .....................................................
Write A/D Register (WAREG/WDREG)...................................................
Read Memory Location (READ)............................................................
Write Memory Location (WRITE) .........................................................
Dump Memory Block (DUMP) ..............................................................
Fill Memory Block (FILL) .....................................................................
Resume Execution (GO)........................................................................
No Operation (NOP) ..............................................................................
Synchronize PC to the PSTDDATA Lines (SYNC_PC) ........................
Read Control Register (RCREG) ............................................................
Write Control Register (WCREG) ..........................................................
Read Debug Module Register (RDMREG) .............................................
Write Debug Module Register (WDMREG) ...........................................
Real-Time Debug Support ................................................................................
Theory of Operation......................................................................................
Emulator Mode .........................................................................................
Concurrent BDM and Processor Operation ..................................................
Motorola-Recommended BDM Pinout.............................................................
Debug C Definition of PSTDDATA Outputs...................................................
User Instruction Set ......................................................................................
Supervisor Instruction Set.............................................................................
5-21
5-22
5-22
5-24
5-25
5-26
5-26
5-27
5-28
5-28
5-30
5-30
5-31
5-32
5-33
5-35
5-37
5-39
5-40
5-41
5-42
5-43
5-44
5-45
5-45
5-46
5-48
5-48
5-49
5-49
5-50
5-53
Part II
System Integration Module (SIM)
Chapter 6
SIM Overview
6.1
6.2
6.2.1
Features ............................................................................................................... 6-1
Programming Model ........................................................................................... 6-3
SIM Register Memory Map............................................................................ 6-3
Contents
ix
CONTENTS
Paragraph
Number
6.2.2
6.2.3
6.2.4
6.2.5
6.2.6
6.2.7
6.2.8
6.2.9
6.2.10
6.2.10.1
6.2.10.1.1
6.2.10.1.2
Title
Page
Number
Module Base Address Register (MBAR) ....................................................... 6-4
Reset Status Register (RSR) ........................................................................... 6-5
Software Watchdog Timer.............................................................................. 6-6
System Protection Control Register (SYPCR) ............................................... 6-8
Software Watchdog Interrupt Vector Register (SWIVR)............................... 6-9
Software Watchdog Service Register (SWSR)............................................... 6-9
PLL Clock Control for CPU STOP Instruction ............................................ 6-10
Pin Assignment Register (PAR) ................................................................... 6-10
Bus Arbitration Control ................................................................................ 6-11
Default Bus Master Park Register (MPARK) .......................................... 6-11
Arbitration for Internally Generated Transfers (MPARK[PARK])...... 6-12
Arbitration between Internal and External Masters
for Accessing Internal Resources ......................................................... 6-14
Chapter 7
Phase-Locked Loop (PLL)
7.1
7.1.1
7.2
7.2.1
7.2.2
7.2.3
7.2.4
7.3
7.4
7.4.1
7.4.2
7.5
Overview.............................................................................................................
PLL:PCLK Ratios...........................................................................................
PLL Operation ....................................................................................................
Reset/Initialization ..........................................................................................
Normal Mode..................................................................................................
Reduced-Power Mode.....................................................................................
PLL Control Register (PLLCR)......................................................................
PLL Port List.......................................................................................................
Timing Relationships ..........................................................................................
PCLK, PSTCLK, and BCLKO .......................................................................
RSTI Timing ...................................................................................................
PLL Power Supply Filter Circuit ........................................................................
7-1
7-2
7-2
7-2
7-2
7-3
7-3
7-4
7-4
7-4
7-5
7-6
Chapter 8
I2C Module
8.1
8.2
8.3
8.4
8.4.1
8.4.2
8.4.3
8.4.4
8.5
x
Overview.............................................................................................................
Interface Features................................................................................................
I2C System Configuration...................................................................................
I2C Protocol ........................................................................................................
Arbitration Procedure .....................................................................................
Clock Synchronization....................................................................................
Handshaking ...................................................................................................
Clock Stretching .............................................................................................
Programming Model ...........................................................................................
MCF5407 User’s Manual
8-1
8-1
8-3
8-3
8-4
8-5
8-5
8-5
8-6
CONTENTS
Paragraph
Number
8.5.1
8.5.2
8.5.3
8.5.4
8.5.5
8.6
8.6.1
8.6.2
8.6.3
8.6.4
8.6.5
8.6.6
8.6.7
Title
Page
Number
I2C Address Register (IADR) ......................................................................... 8-6
I2C Frequency Divider Register (IFDR)......................................................... 8-6
I2C Control Register (I2CR) ........................................................................... 8-7
I2C Status Register (I2SR).............................................................................. 8-8
I2C Data I/O Register (I2DR) ......................................................................... 8-9
I2C Programming Examples ............................................................................. 8-10
Initialization Sequence.................................................................................. 8-10
Generation of START................................................................................... 8-10
Post-Transfer Software Response................................................................. 8-11
Generation of STOP...................................................................................... 8-12
Generation of Repeated START................................................................... 8-12
Slave Mode ................................................................................................... 8-13
Arbitration Lost............................................................................................. 8-13
Chapter 9
Interrupt Controller
9.1
9.2
9.2.1
9.2.2
9.2.3
9.2.4
Overview.............................................................................................................
Interrupt Controller Registers .............................................................................
Interrupt Control Registers (ICR0–ICR9) ......................................................
Autovector Register (AVR) ............................................................................
Interrupt Pending and Mask Registers (IPR and IMR)...................................
Interrupt Port Assignment Register (IRQPAR) ..............................................
9-1
9-2
9-3
9-5
9-6
9-7
Chapter 10
Chip-Select Module
10.1
10.2
10.3
10.3.1
10.3.1.1
10.3.1.2
10.4
10.4.1
10.4.1.1
10.4.1.2
10.4.1.3
10.4.1.4
Overview...........................................................................................................
Chip-Select Module Signals .............................................................................
Chip-Select Operation.......................................................................................
General Chip-Select Operation.....................................................................
8-, 16-, and 32-Bit Port Sizing..................................................................
Global Chip-Select Operation...................................................................
Chip-Select Registers........................................................................................
Chip-Select Module Registers ......................................................................
Chip-Select Address Registers (CSAR0–CSAR7) ...................................
Chip-Select Mask Registers (CSMR0–CSMR7)......................................
Chip-Select Control Registers (CSCR0–CSCR7) ....................................
Code Example...........................................................................................
10-1
10-1
10-2
10-3
10-4
10-4
10-5
10-6
10-6
10-7
10-8
10-9
Chapter 11
Synchronous/Asynchronous DRAM Controller Module
Contents
xi
CONTENTS
Paragraph
Number
11.1
11.1.1
11.1.2
11.2
11.2.1
11.3
11.3.1
11.3.2
11.3.2.1
11.3.2.2
11.3.2.3
11.3.3
11.3.3.1
11.3.3.2
11.3.3.3
11.3.3.4
11.3.3.5
11.4
11.4.1
11.4.2
11.4.3
11.4.3.1
11.4.3.2
11.4.3.3
11.4.4
11.4.4.1
11.4.4.2
11.4.4.3
11.4.4.4
11.4.4.5
11.4.4.6
11.4.5
11.4.5.1
11.5
11.5.1
11.5.2
11.5.3
11.5.4
11.5.5
11.5.6
xii
Title
Page
Number
Overview........................................................................................................... 11-1
Definitions .................................................................................................... 11-2
Block Diagram and Major Components ....................................................... 11-2
DRAM Controller Operation ............................................................................ 11-3
DRAM Controller Registers ......................................................................... 11-3
Asynchronous Operation .................................................................................. 11-4
DRAM Controller Signals in Asynchronous Mode...................................... 11-4
Asynchronous Register Set........................................................................... 11-4
DRAM Control Register (DCR) in Asynchronous Mode ........................ 11-4
DRAM Address and Control Registers (DACR0/DACR1) ..................... 11-5
DRAM Controller Mask Registers (DMR0/DMR1) ................................ 11-7
General Asynchronous Operation Guidelines .............................................. 11-8
Non-Page-Mode Operation..................................................................... 11-11
Burst Page-Mode Operation ................................................................... 11-12
Continuous Page Mode........................................................................... 11-13
Extended Data Out (EDO) Operation..................................................... 11-15
Refresh Operation ................................................................................... 11-16
Synchronous Operation................................................................................... 11-16
DRAM Controller Signals in Synchronous Mode...................................... 11-17
Using Edge Select (EDGESEL) ................................................................. 11-18
Synchronous Register Set ........................................................................... 11-19
DRAM Control Register (DCR) in Synchronous Mode......................... 11-19
DRAM Address and Control Registers (DACR0/DACR1)
in Synchronous Mode ......................................................................... 11-20
DRAM Controller Mask Registers (DMR0/DMR1) .............................. 11-22
General Synchronous Operation Guidelines............................................... 11-23
Address Multiplexing ............................................................................. 11-23
Interfacing Example................................................................................ 11-27
Burst Page Mode..................................................................................... 11-27
Continuous Page Mode........................................................................... 11-29
Auto-Refresh Operation.......................................................................... 11-31
Self-Refresh Operation ........................................................................... 11-32
Initialization Sequence................................................................................ 11-32
Mode Register Settings........................................................................... 11-33
SDRAM Example ........................................................................................... 11-34
SDRAM Interface Configuration................................................................ 11-34
DCR Initialization....................................................................................... 11-35
DACR Initialization.................................................................................... 11-35
DMR Initialization...................................................................................... 11-37
Mode Register Initialization ....................................................................... 11-38
Initialization Code....................................................................................... 11-39
MCF5407 User’s Manual
CONTENTS
Paragraph
Number
Title
Page
Number
Part III
Peripheral Module
Chapter 12
DMA Controller Module
12.1
12.1.1
12.2
12.3
12.4
12.4.1
12.4.2
12.4.3
12.4.4
12.4.5
12.4.6
12.5
12.5.1
12.5.2
12.5.2.1
12.5.2.2
12.5.3
12.5.3.1
12.5.3.2
12.5.4
12.5.4.1
12.5.4.2
12.5.4.3
12.5.5
Overview........................................................................................................... 12-1
DMA Module Features ................................................................................. 12-2
DMA Signal Description .................................................................................. 12-2
DMA Transfer Overview.................................................................................. 12-4
DMA Controller Module Programming Model................................................ 12-5
Source Address Registers (SAR0–SAR3) .................................................... 12-7
Destination Address Registers (DAR0–DAR3) ........................................... 12-7
Byte Count Registers (BCR0–BCR3)........................................................... 12-7
DMA Control Registers (DCR0–DCR3)...................................................... 12-8
DMA Status Registers (DSR0–DSR3) ....................................................... 12-10
DMA Interrupt Vector Registers (DIVR0–DIVR3) ................................... 12-11
DMA Controller Module Functional Description........................................... 12-11
Transfer Requests (Cycle-Steal and Continuous Modes) ........................... 12-12
Data Transfer Modes .................................................................................. 12-12
Dual-Address Transfers .......................................................................... 12-12
Single-Address Transfers........................................................................ 12-13
Channel Initialization and Startup .............................................................. 12-13
Channel Prioritization ............................................................................. 12-13
Programming the DMA Controller Module ........................................... 12-13
Data Transfer .............................................................................................. 12-14
External Request and Acknowledge Operation ...................................... 12-14
Auto-Alignment ...................................................................................... 12-17
Bandwidth Control.................................................................................. 12-18
Termination................................................................................................. 12-18
Chapter 13
Timer Module
13.1
13.1.1
13.2
13.3
13.3.1
13.3.2
13.3.3
13.3.4
Overview...........................................................................................................
Key Features .................................................................................................
General-Purpose Timer Units ...........................................................................
General-Purpose Timer Programming Model ..................................................
Timer Mode Registers (TMR0/TMR1) ........................................................
Timer Reference Registers (TRR0/TRR1) ...................................................
Timer Capture Registers (TCR0/TCR1).......................................................
Timer Counters (TCN0/TCN1) ....................................................................
Contents
13-1
13-2
13-2
13-2
13-3
13-4
13-4
13-5
xiii
CONTENTS
Paragraph
Number
13.3.5
13.4
13.5
Title
Page
Number
Timer Event Registers (TER0/TER1)........................................................... 13-5
Code Example................................................................................................... 13-6
Calculating Time-Out Values ........................................................................... 13-7
Chapter 14
UART Modules
14.1
14.2
14.3
14.3.1
14.3.2
14.3.3
14.3.4
14.3.5
14.3.6
14.3.7
14.3.8
14.3.9
14.3.10
14.3.11
14.3.12
14.3.13
14.3.14
14.3.15
14.3.16
14.3.17
14.3.18
14.3.19
14.4
14.5
14.5.1
14.5.1.1
14.5.1.2
14.5.1.2.1
14.5.1.2.2
14.5.2
14.5.2.1
14.5.2.2
14.5.2.2.1
14.5.2.3
14.5.2.4
xiv
Overview........................................................................................................... 14-1
Serial Module Overview ................................................................................... 14-2
Register Descriptions ........................................................................................ 14-3
UART Mode Registers 1 (UMR1n).............................................................. 14-5
UART Mode Register 2 (UMR2n) ............................................................... 14-7
Rx FIFO Threshold Register (RXLVL)........................................................ 14-8
Modem Control Register (MODCTL).......................................................... 14-9
Tx FIFO Threshold Register (TXLVL) ...................................................... 14-10
UART Status Registers (USRn) ................................................................. 14-10
UART Clock-Select Registers (UCSRn).................................................... 14-12
Receive Samples Available Register (RSMP)............................................ 14-12
Transmit Space Available Register (TSPC) ............................................... 14-13
UART Command Registers (UCRn) .......................................................... 14-13
UART Receiver Buffers (URBn) ............................................................... 14-15
UART Transmitter Buffers (UTBn) ........................................................... 14-16
UART Input Port Change Registers (UIPCRn).......................................... 14-17
UART Auxiliary Control Register (UACRn)............................................. 14-17
UART Interrupt Status/Mask Registers (UISRn/UIMRn).......................... 14-18
UART Divider Upper/Lower Registers (UDUn/UDLn) ............................ 14-19
UART Interrupt Vector Register (UIVRn)................................................. 14-20
UART Input Port Register (UIPn) .............................................................. 14-20
UART Output Port Data Registers (UOP1n/UOP0n)................................. 14-21
UART Module Signal Definitions .................................................................. 14-21
Operation......................................................................................................... 14-23
Transmitter/Receiver Clock Source............................................................ 14-23
Programmable Divider............................................................................ 14-24
Calculating Baud Rates........................................................................... 14-24
CLKIN Baud Rates............................................................................. 14-24
External Clock .................................................................................... 14-25
Transmitter and Receiver Operating Modes............................................... 14-25
Transmitting in UART Mode ................................................................. 14-26
Transmitter in Modem Mode (UART1) ................................................. 14-27
AC ‘97 Low-Power Mode .................................................................. 14-29
Receiver .................................................................................................. 14-29
UART1 in UART Mode ......................................................................... 14-31
MCF5407 User’s Manual
CONTENTS
Paragraph
Number
14.5.2.4.1
14.5.2.5
14.5.2.6
14.5.3
14.5.3.1
14.5.3.2
14.5.3.3
14.5.4
14.5.5
14.5.5.1
14.5.5.2
14.5.5.3
14.5.6
14.5.6.1
Title
Page
Number
Receiver in Modem Mode (UART1)..................................................
FIFO Stack in UART0............................................................................
FIFOs in UART1 ....................................................................................
Looping Modes ...........................................................................................
Automatic Echo Mode ............................................................................
Local Loop-Back Mode ..........................................................................
Remote Loop-Back Mode.......................................................................
Multidrop Mode..........................................................................................
Bus Operation .............................................................................................
Read Cycles ............................................................................................
Write Cycles ...........................................................................................
Interrupt Acknowledge Cycles ...............................................................
Programming ..............................................................................................
UART Module Initialization Sequence ..................................................
14-31
14-32
14-33
14-34
14-34
14-34
14-35
14-35
14-37
14-37
14-37
14-37
14-37
14-38
Chapter 15
Parallel Port (General-Purpose I/O)
15.1
15.1.1
15.1.2
15.1.3
15.1.4
Parallel Port Operation......................................................................................
Pin Assignment Register (PAR) ...................................................................
Port A Data Direction Register (PADDR)....................................................
Port A Data Register (PADAT) ....................................................................
Code Example...............................................................................................
15-1
15-1
15-2
15-2
15-4
Part IV
Hardware Interface
Chapter 16
Mechanical Data
16.1
16.2
16.3
16.4
Package .............................................................................................................
Pinout ................................................................................................................
Mechanical Diagram.........................................................................................
Case Drawing....................................................................................................
16-1
16-1
16-8
16-9
Chapter 17
Signal Descriptions
17.1
17.2
17.2.1
Overview........................................................................................................... 17-1
MCF5407 Bus Signals ...................................................................................... 17-7
Address Bus .................................................................................................. 17-7
Contents
xv
CONTENTS
Paragraph
Number
17.2.1.1
17.2.1.2
17.2.2
17.2.3
17.2.4
17.2.5
17.2.6
17.2.7
17.2.8
17.2.9
17.2.10
17.3
17.3.1
17.4
17.4.1
17.4.2
17.4.3
17.5
17.5.1
17.5.2
17.5.3
17.5.4
17.5.5
17.5.5.1
17.5.5.2
17.5.5.3
17.5.5.4
17.5.6
17.5.6.1
17.6
17.6.1
17.6.2
17.6.3
17.7
17.7.1
17.7.2
17.7.3
17.7.4
17.7.5
17.7.6
17.7.7
17.8
17.8.1
xvi
Title
Page
Number
Address Bus (A[23:0]).............................................................................. 17-7
Address Bus (A[31:24]/PP[15:8]) ............................................................ 17-7
Data Bus (D[31:0]) ....................................................................................... 17-8
Read/Write (R/W)......................................................................................... 17-8
Size (SIZ[1:0]) .............................................................................................. 17-8
Transfer Start (TS) ........................................................................................ 17-9
Address Strobe (AS) ..................................................................................... 17-9
Transfer Acknowledge (TA) ......................................................................... 17-9
Transfer In Progress (TIP/PP7)................................................................... 17-10
Transfer Type (TT[1:0]/PP[1:0]) ................................................................ 17-10
Transfer Modifier (TM[2:0]/PP[4:2]/DACK[1:0])..................................... 17-10
Interrupt Control Signals................................................................................. 17-12
Interrupt Request (IRQ1/IRQ2, IRQ3/IRQ6, IRQ5/IRQ4, and IRQ7)....... 17-12
Bus Arbitration Signals................................................................................... 17-12
Bus Request (BR) ....................................................................................... 17-12
Bus Grant (BG).......................................................................................... 17-12
Bus Driven (BD)......................................................................................... 17-13
Clock and Reset Signals.................................................................................. 17-13
Reset In (RSTI)........................................................................................... 17-13
Clock Input (CLKIN).................................................................................. 17-13
Bus Clock Output (BCLKO) ...................................................................... 17-13
Reset Out (RSTO)....................................................................................... 17-13
Data/Configuration Pins (D[7:0]) ............................................................... 17-14
D[7:5,3]—Boot Chip-Select (CS0) Configuration ................................. 17-14
D7—Auto Acknowledge Configuration (AA_CONFIG) ...................... 17-14
D[6:5]—Port Size Configuration (PS_CONFIG[1:0]) ........................... 17-14
D3—Byte-Enable Configuration (BE_CONFIG) .................................. 17-15
D4—Address Configuration (ADDR_CONFIG) ....................................... 17-15
D[2:0]—Divide Control (DIVIDE[2:0]) ................................................ 17-15
Chip-Select Module Signals ........................................................................... 17-15
Chip-Select (CS[7:0]) ................................................................................. 17-15
Byte Enables/Byte Write Enables (BE[3:0]/BWE[3:0]) ............................ 17-16
Output Enable (OE) .................................................................................... 17-16
DRAM Controller Signals .............................................................................. 17-16
Row Address Strobes (RAS[1:0])............................................................... 17-16
Column Address Strobes (CAS[3:0]) ......................................................... 17-16
DRAM Write (DRAMW)........................................................................... 17-16
Synchronous DRAM Column Address Strobe (SCAS) ............................. 17-17
Synchronous DRAM Row Address Strobe (SRAS)................................... 17-17
Synchronous DRAM Clock Enable (SCKE) .............................................. 17-17
Synchronous Edge Select (EDGESEL) ...................................................... 17-17
DMA Controller Module Signals.................................................................... 17-17
DMA Request (DREQ[1:0]/PP[6:5]).......................................................... 17-17
MCF5407 User’s Manual
CONTENTS
Paragraph
Number
17.8.2
17.9
17.9.1
17.9.2
17.9.3
17.9.4
17.10
17.10.1
17.10.2
17.11
17.12
17.12.1
17.12.2
17.13
17.13.1
17.13.2
17.13.3
17.13.4
17.14
17.14.1
17.14.2
17.14.3
17.14.4
17.14.5
Title
Page
Number
Transfer Modifier/DMA Acknowledge (TM[2:0]/DACK[1:0]) ................
Serial Module Signals .....................................................................................
Transmitter Serial Data Output (TxD)........................................................
Receiver Serial Data Input (RxD)...............................................................
Clear to Send (CTS)....................................................................................
Request to Send (RTS) ...............................................................................
Timer Module Signals.....................................................................................
Timer Inputs (TIN[1:0])..............................................................................
Timer Outputs (TOUT1, TOUT0) ..............................................................
Parallel I/O Port (PP[15:0]) ............................................................................
I2C Module Signals.........................................................................................
I2C Serial Clock (SCL) ...............................................................................
I2C Serial Data (SDA) ................................................................................
Debug and Test Signals ..................................................................................
Test Mode (MTMOD[3:0]) ........................................................................
High Impedance (HIZ)................................................................................
Processor Clock Output (PSTCLK)............................................................
Processor Status Debug Data (PSTDDATA[7:0])......................................
Debug Module/JTAG Signals.........................................................................
Test Reset/Development Serial Clock (TRST/DSCLK) ............................
Test Mode Select/Breakpoint (TMS/BKPT) ..............................................
Test Data Input/Development Serial Input (TDI/DSI) ...............................
Test Data Output/Development Serial Output (TDO/DSO).......................
Test Clock (TCK) .......................................................................................
17-18
17-18
17-18
17-19
17-19
17-19
17-19
17-19
17-19
17-19
17-20
17-20
17-20
17-20
17-20
17-20
17-20
17-21
17-21
17-21
17-21
17-22
17-22
17-22
Chapter 18
Bus Operation
18.1
18.2
18.3
18.4
18.4.1
18.4.2
18.4.3
18.4.4
18.4.5
18.4.6
18.4.7
18.4.7.1
18.4.7.2
18.4.7.3
Features ............................................................................................................. 18-1
Bus and Control Signals.................................................................................... 18-1
Bus Characteristics............................................................................................ 18-2
Data Transfer Operation ................................................................................... 18-2
Bus Cycle Execution..................................................................................... 18-4
Data Transfer Cycle States ........................................................................... 18-5
Read Cycle.................................................................................................... 18-7
Write Cycle ................................................................................................... 18-8
Fast-Termination Cycles............................................................................... 18-9
Back-to-Back Bus Cycles ........................................................................... 18-10
Burst Cycles................................................................................................ 18-11
Line Transfers ......................................................................................... 18-12
Line Read Bus Cycles............................................................................. 18-12
Line Write Bus Cycles............................................................................ 18-14
Contents
xvii
CONTENTS
Paragraph
Number
18.4.7.4
18.5
18.6
18.7
18.7.1
18.7.2
18.8
18.8.1
18.9
18.9.1
18.9.2
18.10
18.10.1
18.10.2
Title
Page
Number
Transfers Using Mixed Port Sizes ..........................................................
Misaligned Operands ......................................................................................
Bus Errors .......................................................................................................
Interrupt Exceptions........................................................................................
Level 7 Interrupts........................................................................................
Interrupt-Acknowledge Cycle.....................................................................
Bus Arbitration................................................................................................
Bus Arbitration Signals...............................................................................
General Operation of External Master Transfers............................................
Two-Device Bus Arbitration Protocol (Two-Wire Mode) .........................
Multiple External Bus Device Arbitration Protocol (Three-Wire Mode)...
Reset Operation...............................................................................................
Master Reset ...............................................................................................
Software Watchdog Reset...........................................................................
18-15
18-16
18-17
18-17
18-18
18-19
18-20
18-21
18-21
18-25
18-29
18-33
18-34
18-35
Chapter 19
IEEE 1149.1 Test Access Port (JTAG)
19.1
19.2
19.3
19.4
19.4.1
19.4.2
19.4.3
19.4.4
19.5
19.6
19.7
Overview........................................................................................................... 19-1
JTAG Signal Descriptions ............................................................................... 19-2
TAP Controller.................................................................................................. 19-3
JTAG Register Descriptions ............................................................................. 19-4
JTAG Instruction Shift Register .................................................................. 19-5
IDCODE Register ......................................................................................... 19-6
JTAG Boundary-Scan Register .................................................................... 19-7
JTAG Bypass Register................................................................................ 19-10
Restrictions ..................................................................................................... 19-10
Disabling IEEE Standard 1149.1 Operation ................................................... 19-10
Obtaining the IEEE Standard 1149.1.............................................................. 19-11
Chapter 20
Electrical Specifications
20.1
20.1.1
20.2
20.3
20.4
20.5
20.6
20.7
20.8
xviii
General Parameters ........................................................................................... 20-1
Supply Voltage Sequencing and Separation Cautions.................................. 20-3
Clock Timing Specifications............................................................................. 20-4
Input/Output AC Timing Specifications........................................................... 20-6
Reset Timing Specifications ........................................................................... 20-15
Debug AC Timing Specifications................................................................... 20-16
Timer Module AC Timing Specifications ...................................................... 20-17
I2C Input/Output Timing Specifications......................................................... 20-18
UART Module AC Timing Specifications ..................................................... 20-19
MCF5407 User’s Manual
CONTENTS
Paragraph
Number
20.9
20.10
20.11
Title
Page
Number
Parallel Port (General-Purpose I/O) Timing Specifications ........................... 20-22
DMA Timing Specifications........................................................................... 20-23
IEEE 1149.1 (JTAG) AC Timing Specifications ........................................... 20-24
Appendix A
Migrating from the ColdFire MCF5307 to the MCF5407
A.1
A.2
A.3
A.4
A.5
A.6
A.6.1
A.6.2
A.7
A.8
A.8.1
A.8.2
A.8.2.1
A.8.3
A.8.3.1
A.8.3.2
A.8.3.3
A.8.3.4
A.8.3.5
A.8.4
A.8.5
A.8.6
A.9
A.10
A.11
Overview............................................................................................................ A-1
Instruction Set Additions ................................................................................... A-2
Enhanced Memories........................................................................................... A-3
On-Chip DMA Modifications............................................................................ A-4
UART Enhancements ........................................................................................ A-5
Timing Differences ............................................................................................ A-6
Phase-Locked Loop (PLL)............................................................................. A-6
Timing Relationships..................................................................................... A-7
Reset Initialization Modifications...................................................................... A-8
Revision C Debug ............................................................................................ A-10
Debug Interrupts and Interrupt Requests
in Emulator Mode .................................................................................... A-10
On-Chip Breakpoint Registers..................................................................... A-12
Write Debug Module Register (wdmreg) ................................................ A-12
Debug Programming Model ........................................................................ A-14
Address Breakpoint 1 Registers (ABLR1, ABHR1) ............................... A-14
Address Attribute Breakpoint Register 1 (AATR1) ................................ A-14
Program Counter Breakpoint Registers 1–3 (PBR1–PBR3) ................... A-14
Data Breakpoint Register 1 (DBR1, DBMR1) ........................................ A-15
Extended Trigger Definition Register (XTDR) ....................................... A-15
Debug Interrupt Exception Vectors ............................................................. A-15
Processor Status and Debug Data Output Signals ....................................... A-16
Debug C Summary....................................................................................... A-17
Voltage Input Changes..................................................................................... A-17
PLL Power Supply Filter Circuit ..................................................................... A-18
Pin-Assignment Compatibility......................................................................... A-18
Appendix B
List of Memory Maps
Contents
xix
CONTENTS
Paragraph
Number
xx
Title
MCF5407 User’s Manual
Page
Number
ILLUSTRATIONS
Figure
Number
1-1
1-2
1-3
1-4
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-1
3-1
3-2
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
5-1
5-2
5-3
5-4
5-5
5-6
Title
Page
Number
MCF5407 Block Diagram............................................................................................. 1-2
UART Module Block Diagram................................................................................... 1-10
PLL Module ................................................................................................................ 1-13
ColdFire MCF5407 Programming Model .................................................................. 1-15
ColdFire Enhanced Pipeline ......................................................................................... 2-3
ColdFire Multiply-Accumulate Functionality Diagram ............................................... 2-5
ColdFire Programming Model...................................................................................... 2-8
Condition Code Register (CCR) ................................................................................... 2-9
Status Register (SR).................................................................................................... 2-11
Vector Base Register (VBR)....................................................................................... 2-12
Organization of Integer Data Formats in Data Registers............................................ 2-13
Organization of Integer Data Formats in Address Registers ...................................... 2-14
Memory Operand Addressing..................................................................................... 2-14
Exception Stack Frame Form...................................................................................... 2-33
ColdFire MAC Multiplication and Accumulation........................................................ 3-2
MAC Programming Model ........................................................................................... 3-2
SRAM Base Address Registers (RAMBARn) ............................................................. 4-3
Data Cache Organization .............................................................................................. 4-7
Data Cache Organization and Line Format .................................................................. 4-8
Data Cache—A: at Reset, B: after Invalidation, C and D: Loading Pattern............... 4-10
Data Caching Operation.............................................................................................. 4-11
Write-Miss in Copyback Mode................................................................................... 4-16
Data Cache Locking.................................................................................................... 4-20
Cache Control Register (CACR) ................................................................................ 4-21
Access Control Register Format (ACRn) ................................................................... 4-24
An Format (Data Cache)............................................................................................. 4-25
An Format (Instruction Cache) ................................................................................... 4-25
Instruction Cache Line State Diagram........................................................................ 4-27
Data Cache Line State Diagram—Copyback Mode ................................................... 4-28
Data Cache Line State Diagram—Write-Through Mode ........................................... 4-29
Processor/Debug Module Interface............................................................................... 5-1
PSTCLK Timing........................................................................................................... 5-3
PSTDDATA: Single-Cycle Instruction Timing............................................................ 5-3
Example JMP Instruction Output on PSTDDATA....................................................... 5-6
Debug Programming Model ......................................................................................... 5-9
Address Attribute Trigger Registers (AATR, AATR1).............................................. 5-11
Illustrations
xxi
ILLUSTRATIONS
Figure
Page
Title
Number
Number
5-7
Address Breakpoint Registers (ABLR, ABHR, ABLR1, ABHR1)............................ 5-12
5-8
BDM Address Attribute Register (BAAR)................................................................. 5-13
5-9
Configuration/Status Register (CSR).......................................................................... 5-13
5-10
Data Breakpoint/Mask Registers (DBR/DBR1 and DBMR/DBMR1)....................... 5-16
5-11
Program Counter Breakpoint Registers (PBR, PBR1, PBR2, PBR3) ........................ 5-17
5-12
Program Counter Breakpoint Mask Register (PBMR) ............................................... 5-17
5-13
Trigger Definition Register (TDR) ............................................................................. 5-18
5-14
Extended Trigger Definition Register (XTDR) .......................................................... 5-20
5-15
BDM Serial Interface Timing ..................................................................................... 5-24
5-16
Receive BDM Packet.................................................................................................. 5-25
5-17
Transmit BDM Packet ................................................................................................ 5-26
5-18
BDM Command Format ............................................................................................. 5-27
5-19
Command Sequence Diagram..................................................................................... 5-29
RAREG/RDREG Command Sequence............................................................................ 5-30
5-21
RAREG/RDREG Command Format ............................................................................... 5-30
5-20
WAREG/WDREG Command Sequence .......................................................................... 5-31
5-23
WAREG/WDREG Command Format.............................................................................. 5-31
5-22
READ Command Sequence.......................................................................................... 5-32
5-25
5-24
read Command/Result Formats................................................................................... 5-32
WRITE Command Format ............................................................................................ 5-33
5-26
WRITE Command Sequence ........................................................................................ 5-34
5-27
DUMP Command/Result Formats ................................................................................ 5-35
5-28
DUMP Command Sequence ......................................................................................... 5-36
5-29
FILL Command Format................................................................................................ 5-37
5-30
FILL Command Sequence............................................................................................ 5-38
5-31
GO Command Sequence.............................................................................................. 5-39
5-33
GO Command Format.................................................................................................. 5-39
5-32
NOP Command Sequence ............................................................................................ 5-40
5-35
NOP Command Format................................................................................................ 5-40
5-34
SYNC_PC Command Sequence .................................................................................... 5-41
5-37
SYNC_PC Command Format........................................................................................ 5-41
5-36
RCREG Command Sequence........................................................................................ 5-42
5-39
RCREG Command/Result Formats............................................................................... 5-42
5-38
WCREG Command Sequence ....................................................................................... 5-43
5-41
WCREG Command/Result Formats.............................................................................. 5-43
5-40
RDMREG Command Sequence..................................................................................... 5-44
5-43
RDMREG bdm Command/Result Formats.................................................................... 5-44
5-42
WDMREG Command Sequence .................................................................................... 5-45
5-45
WDMREG BDM Command Format.............................................................................. 5-45
5-44
5-46
Recommended BDM Connector................................................................................. 5-49
6-1
SIM Block Diagram...................................................................................................... 6-1
6-2
Module Base Address Register (MBAR) ..................................................................... 6-4
6-3
Reset Status Register (RSR) ......................................................................................... 6-5
xxii
MCF5407 User’s Manual
ILLUSTRATIONS
Figure
Number
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
7-1
7-2
7-3
7-4
7-5
8-1
8-2
8-3
8-4
8-5
8-6
8-7
8-8
8-9
8-10
9-1
9-2
9-3
9-4
9-5
10-1
10-2
10-3
10-4
11-1
11-2
11-3
11-4
11-5
11-6
11-7
11-8
11-9
Title
Page
Number
MCF5407 Embedded System Recovery from Unterminated Access........................... 6-7
System Protection Control Register (SYPCR) ............................................................ 6-8
Software Watchdog Interrupt Vector Register (SWIVR)............................................ 6-9
Software Watchdog Service Register (SWSR)............................................................ 6-9
Pin Assignment Register (PAR) ................................................................................. 6-10
Default Bus Master Register (MPARK) ..................................................................... 6-11
Round Robin Arbitration (PARK = 00)...................................................................... 6-12
Park on Master Core Priority (PARK = 01) ............................................................... 6-13
Park on DMA Module Priority (PARK = 10)............................................................. 6-13
Park on Current Master Priority (PARK = 01) ........................................................... 6-14
PLL Module Block Diagram ........................................................................................ 7-1
PLL Control Register (PLLCR).................................................................................... 7-3
CLKIN, PCLK, PSTCLK, and BCLKO Timing .......................................................... 7-5
Reset and Initialization Timing..................................................................................... 7-6
PLL Power Supply Filter Circuit ................................................................................. 7-6
I2C Module Block Diagram .......................................................................................... 8-2
I2C Standard Communication Protocol ........................................................................ 8-3
Repeated START .......................................................................................................... 8-4
Synchronized Clock SCL.............................................................................................. 8-5
I2C Address Register (IADR) ....................................................................................... 8-6
I2C Frequency Divider Register (IFDR)....................................................................... 8-7
I2C Control Register (I2CR) ......................................................................................... 8-8
I2CR Status Register (I2SR) ......................................................................................... 8-9
I2C Data I/O Register (I2DR) ..................................................................................... 8-10
Flow-Chart of Typical I2C Interrupt Routine............................................................. 8-14
Interrupt Controller Block Diagram.............................................................................. 9-1
Interrupt Control Registers (ICR0–ICR9) .................................................................... 9-3
Autovector Register (AVR) .......................................................................................... 9-5
Interrupt Pending Register (IPR) and Interrupt Mask Register (IMR) ......................... 9-7
Interrupt Port Assignment Register (IRQPAR) ............................................................ 9-7
Connections for External Memory Port Sizes ............................................................ 10-4
Chip Select Address Registers (CSAR0–CSAR7) ..................................................... 10-6
Chip Select Mask Registers (CSMRn) ....................................................................... 10-7
Chip-Select Control Registers (CSCR0–CSCR7) ...................................................... 10-8
Asynchronous/Synchronous DRAM Controller Block Diagram ............................... 11-2
DRAM Control Register (DCR) (Asynchronous Mode) ............................................ 11-5
DRAM Address and Control Registers (DACR0/DACR1)........................................ 11-6
DRAM Controller Mask Registers (DMR0 and DMR1)............................................ 11-7
Basic Non-Page-Mode Operation RCD = 0, RNCN = 1 (4-4-4-4) .......................... 11-11
Basic Non-Page-Mode Operation RCD = 1, RNCN = 0 (5-5-5-5) .......................... 11-12
Burst Page-Mode Read Operation (4-3-3-3)............................................................. 11-13
Burst Page-Mode Write Operation (4-3-3-3)............................................................ 11-13
Continuous Page-Mode Operation............................................................................ 11-14
Illustrations
xxiii
ILLUSTRATIONS
Figure
Page
Title
Number
Number
11-10 Write Hit in Continuous Page Mode......................................................................... 11-15
11-11 EDO Read Operation (3-2-2-2) ................................................................................ 11-15
11-12 DRAM Access Delayed by Refresh ......................................................................... 11-16
11-13 MCF5407 SDRAM Interface.................................................................................... 11-18
11-14 Using EDGESEL to Change Signal Timing............................................................. 11-19
11-15 DRAM Control Register (DCR) (Synchronous Mode) ............................................ 11-19
11-16 DACR0 and DACR1 Registers (Synchronous Mode).............................................. 11-20
11-17 DRAM Controller Mask Registers (DMR0 and DMR1).......................................... 11-22
11-18 Burst Read SDRAM Access ..................................................................................... 11-28
11-19 Burst Write SDRAM Access .................................................................................... 11-29
11-20 Synchronous, Continuous Page-Mode Access—Consecutive Reads....................... 11-30
11-21 Synchronous, Continuous Page-Mode Access—Read after Write........................... 11-31
11-22 Auto-Refresh Operation............................................................................................ 11-32
11-23 Self-Refresh Operation ............................................................................................. 11-32
11-24 Mode Register Set (mrs) Command ......................................................................... 11-34
11-25 Initialization Values for DCR ................................................................................... 11-35
11-26 SDRAM Configuration............................................................................................. 11-36
11-27 DACR Register Configuration.................................................................................. 11-36
11-28 DMR0 Register ......................................................................................................... 11-37
11-29 Mode Register Mapping to MCF5407 A[31:0] ........................................................ 11-38
12-1
DMA Signal Diagram ................................................................................................. 12-1
12-2
MCF5307/MCF5407 TM[2:0] Pin Remapping .......................................................... 12-4
12-3
Dual-Address Transfer................................................................................................ 12-4
12-4
Single-Address Transfers............................................................................................ 12-5
12-6
Destination Address Registers (DARn) ...................................................................... 12-7
12-5
Source Address Registers (SARn) .............................................................................. 12-7
12-7
Byte Count Registers (BCRn)..................................................................................... 12-8
12-8
DMA Control Registers (DCRn) ............................................................................... 12-8
12-9
DMA Status Registers (DSRn) ................................................................................ 12-10
12-10 DMA Interrupt Vector Registers (DIVRn) ............................................................... 12-11
12-11 DREQ Timing Constraints, Dual-Address DMA Transfer....................................... 12-15
12-12 Dual-Address, Peripheral-to-SDRAM, Lower-Priority DMA Transfer ................... 12-16
12-13 Single-Address DMA Transfer ................................................................................. 12-17
13-1
Timer Block Diagram ................................................................................................. 13-1
13-2
Timer Mode Registers (TMR0/TMR1) ...................................................................... 13-3
13-3
Timer Reference Registers (TRR0/TRR1) ................................................................. 13-4
13-4
Timer Capture Register (TCR0/TCR1) ...................................................................... 13-5
13-5
Timer Counters (TCN0/TCN1)................................................................................... 13-5
13-6
Timer Event Registers (TER0/TER1)......................................................................... 13-5
14-1
Simplified Block Diagram .......................................................................................... 14-1
14-2
UART Mode Registers 1 (UMR1n)............................................................................ 14-6
14-3
UART Mode Register 2 (UMR2n) ............................................................................. 14-7
14-4
Rx FIFO Threshold Register (RXLVL)...................................................................... 14-8
xxiv
MCF5407 User’s Manual
ILLUSTRATIONS
Figure
Number
14-5
14-6
14-7
14-8
14-9
14-10
14-11
14-12
14-13
14-14
14-15
14-16
14-17
14-18
14-19
14-20
14-21
14-22
14-24
14-23
14-25
14-26
14-27
14-28
14-29
14-30
14-31
14-32
14-33
14-34
14-35
14-36
14-37
14-38
14-39
15-1
15-2
15-3
16-1
16-2
16-3
17-1
17-2
Title
Page
Number
Modem Control Register (MODCTL) ........................................................................ 14-9
Tx FIFO Threshold Register (TXLVL) .................................................................... 14-10
UART Status Register (USRn) ................................................................................. 14-10
UART Clock-Select Register (UCSRn).................................................................... 14-12
Receive Samples Available Register (RSMP).......................................................... 14-13
Tx Space Available Register (TSPC) ....................................................................... 14-13
UART Command Register (UCRn).......................................................................... 14-14
UART Receiver Buffer for UART0 (URB0)............................................................ 14-16
UART Receiver Buffer for UART1 (URB1)............................................................ 14-16
UART Transmitter Buffer for UART0 (UTB0) ....................................................... 14-16
UART Transmitter Buffer for UART1 (UTB1) ....................................................... 14-17
UART Input Port Change Register (UIPCRn).......................................................... 14-17
UART Auxiliary Control Register (UACRn) ........................................................... 14-18
UART Interrupt Status/Mask Registers (UISRn/UIMRn)........................................ 14-18
UART Divider Upper Register (UDUn)................................................................... 14-19
UART Divider Lower Register (UDLn)................................................................... 14-19
UART Interrupt Vector Register (UIVRn) ............................................................... 14-20
UART Input Port Register (UIPn) ............................................................................ 14-20
UART Block Diagram Showing External and Internal Interface Signals ................ 14-21
UART Output Port Data 1 Register (UOP1/UOP0) ................................................. 14-21
UART/RS-232 Interface ........................................................................................... 14-23
UART1/CODEC Interface........................................................................................ 14-23
UART1/AC ’97 Interface ......................................................................................... 14-23
Clocking Source Diagram......................................................................................... 14-24
Transmitter and Receiver Functional Diagram......................................................... 14-25
Transmitter Timing Diagram .................................................................................... 14-27
16-Bit CODEC Interface Timing (lsb First) ............................................................. 14-27
8-Bit CODEC Interface Timing (msb First) ............................................................. 14-28
AC ‘97 Interface Timing........................................................................................... 14-28
Receiver Timing........................................................................................................ 14-30
Automatic Echo ........................................................................................................ 14-34
Local Loop-Back ...................................................................................................... 14-34
Remote Loop-Back ................................................................................................... 14-35
Multidrop Mode Timing Diagram ............................................................................ 14-36
UART Mode Programming Flowchart ..................................................................... 14-39
Parallel Port Pin Assignment Register (PAR) ............................................................ 15-1
Port A Data Direction Register (PADDR).................................................................. 15-2
Port A Data Register (PADAT) .................................................................................. 15-3
Mechanical Diagram................................................................................................... 16-9
MCF5407 Case Drawing (General View) ................................................................ 16-10
Case Drawing (Details)............................................................................................. 16-11
MCF5407 Block Diagram with Signal Interfaces ...................................................... 17-2
MCF5307 to MCF5407 TM[2:0] Pin Remapping .................................................... 17-18
Illustrations
xxv
ILLUSTRATIONS
Figure
Page
Title
Number
Number
18-1
Signal Relationship to CLKIN for Non-DRAM Access............................................. 18-2
18-2
Connections for External Memory Port Sizes ............................................................ 18-4
18-3
Chip-Select Module Output Timing Diagram ............................................................ 18-4
18-4
Data Transfer State Transition Diagram ..................................................................... 18-6
18-5
Read Cycle Flowchart................................................................................................. 18-7
18-6
Basic Read Bus Cycle................................................................................................. 18-8
18-7
Write Cycle Flowchart................................................................................................ 18-9
18-8
Basic Write Bus Cycle ................................................................................................ 18-9
18-9
Read Cycle with Fast Termination ........................................................................... 18-10
18-10 Write Cycle with Fast Termination........................................................................... 18-10
18-11 Back-to-Back Bus Cycles ......................................................................................... 18-11
18-12 Line Read Burst (2-1-1-1), External Termination .................................................... 18-12
18-13 Line Read Burst (2-1-1-1), Internal Termination ..................................................... 18-13
18-14 Line Read Burst (3-2-2-2), External Termination .................................................... 18-13
18-15 Line Read Burst-Inhibited, Fast, External Termination............................................ 18-14
18-16 Line Write Burst (2-1-1-1), Internal/External Termination...................................... 18-14
18-17 Line Write Burst (3-2-2-2) with One Wait State, Internal Termination ................... 18-15
18-18 Line Write Burst-Inhibited, Internal Termination .................................................... 18-15
18-19 Longword Read from an 8-Bit Port, External Termination...................................... 18-16
18-20 Longword Read from an 8-Bit Port, Internal Termination ....................................... 18-16
18-21 Example of a Misaligned Longword Transfer (32-Bit Port) .................................... 18-17
18-22 Example of a Misaligned Word Transfer (32-Bit Port) ............................................ 18-17
18-23 Interrupt-Acknowledge Cycle Flowchart ................................................................. 18-20
18-24 Basic No-Wait-State External Master Access .......................................................... 18-22
18-25 External Master Burst Line Access to 32-Bit Port.................................................... 18-24
18-26 MCF5407 Two-Wire Mode Bus Arbitration Interface............................................. 18-25
18-27 Two-Wire Bus Arbitration with Bus Request Asserted............................................ 18-26
18-28 Two-Wire Implicit and Explicit Bus Mastership...................................................... 18-27
18-29 MCF5407 Two-Wire Bus Arbitration Protocol State Diagram................................ 18-28
18-30 Three-Wire Implicit and Explicit Bus Mastership.................................................... 18-30
18-31 Three-Wire Bus Arbitration...................................................................................... 18-31
18-32 Three-Wire Bus Arbitration Protocol State Diagram ............................................... 18-32
18-33 Master Reset Timing................................................................................................. 18-34
18-34 Software Watchdog Reset Timing ............................................................................ 18-35
19-1
JTAG Test Logic Block Diagram ............................................................................... 19-2
19-2
JTAG TAP Controller State Machine......................................................................... 19-4
19-3
IDCODE Register ....................................................................................................... 19-6
19-4
Disabling JTAG in JTAG Mode ............................................................................... 19-11
19-5
Disabling JTAG in Debug Mode .............................................................................. 19-11
20-1
Supply Voltage Sequencing and Separation Cautions................................................ 20-3
20-2
Example Circuit to Control Supply Sequencing......................................................... 20-4
20-3
CLKIN-to-Core Clock Frequency Ranges.................................................................. 20-4
20-4
Clock Timing .............................................................................................................. 20-5
xxvi
MCF5407 User’s Manual
ILLUSTRATIONS
Figure
Number
20-5
20-6
20-7
20-8
20-9
20-10
20-11
20-12
20-13
20-14
20-15
20-16
20-17
20-18
20-19
20-20
20-21
20-22
20-23
20-24
A-1
A-2
A-3
A-4
A-5
A-6
A-7
Title
Page
Number
PSTCLK Timing......................................................................................................... 20-6
AC Timings—Normal Read and Write Bus Cycles ................................................... 20-8
SDRAM Read Cycle with EDGESEL Tied to Buffered CLKIN ............................... 20-9
SDRAM Write Cycle with EDGESEL Tied to Buffered CLKIN ............................ 20-10
SDRAM Read Cycle with EDGESEL Tied High..................................................... 20-11
SDRAM Write Cycle with EDGESEL Tied High.................................................... 20-12
SDRAM Read Cycle with EDGESEL Tied Low ..................................................... 20-13
SDRAM Write Cycle with EDGESEL Tied Low .................................................... 20-14
AC Output Timing—High Impedance...................................................................... 20-14
Reset Timing............................................................................................................. 20-15
Real-Time Trace AC Timing .................................................................................... 20-16
BDM Serial Port AC Timing .................................................................................... 20-16
Timer Module AC Timing ........................................................................................ 20-17
I2C Input/Output Timings ......................................................................................... 20-19
UART0 and UART1 Module AC Timing—UART Mode ....................................... 20-20
UART1 in 8- and 16-bit CODEC Mode ................................................................... 20-21
UART1 in AC ‘97 Mode .......................................................................................... 20-21
General-Purpose I/O Timing..................................................................................... 20-22
DMA Timing ............................................................................................................ 20-23
IEEE 1149.1 (JTAG) AC Timing ............................................................................. 20-25
MCF5307 to MCF5407 TM[2:0] Pin Remapping ....................................................... A-5
Simplified Block Diagram ........................................................................................... A-6
PLL Module................................................................................................................. A-7
Exception Stack Frame Form .................................................................................... A-11
Write Debug Module Register Command (WDMREG)............................................... A-12
WDMREG Command Sequence................................................................................... A-13
PLL Power Supply Filter Circuit............................................................................... A-18
Illustrations
xxvii
ILLUSTRATIONS
Figure
Number
xxviii
Title
MCF5407 User’s Manual
Page
Number
9/1/00
TABLES
Table
Number
1-1
1-2
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
3-1
3-2
3-3
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
Title
Page
Number
User-Level Registers................................................................................................... 1-15
Supervisor-Level Registers......................................................................................... 1-16
CCR Field Descriptions ............................................................................................. 2-10
MOVEC Register Map ............................................................................................... 2-11
Status Field Descriptions ............................................................................................ 2-11
Integer Data Formats................................................................................................... 2-13
ColdFire Effective Addressing Modes........................................................................ 2-15
Notational Conventions .............................................................................................. 2-16
ColdFire ISA_B Extension Summary......................................................................... 2-19
User-Level Instruction Set Summary.......................................................................... 2-19
Supervisor-Level Instruction Set Summary................................................................ 2-23
Misaligned Operand References ................................................................................. 2-24
Move Byte and Word Execution Times...................................................................... 2-25
Move Long Execution Times...................................................................................... 2-25
Miscellaneous Move Execution Times....................................................................... 2-26
One-Operand Instruction Execution Times ................................................................ 2-27
Two-Operand Instruction Execution Times................................................................ 2-27
Miscellaneous Instruction Execution Times............................................................... 2-29
Branch Instruction Execution Times .......................................................................... 2-30
Bcc Instruction Execution Times................................................................................ 2-30
Exception Vector Assignments................................................................................... 2-32
Format Field Encoding ............................................................................................... 2-33
Fault Status Encodings................................................................................................ 2-33
MCF5407 Exceptions ................................................................................................. 2-34
MAC Instruction Summary........................................................................................... 3-4
Two-Operand MAC Instruction Execution Times ....................................................... 3-5
MAC Move Instruction Execution Times..................................................................... 3-6
RAMBARn Field Description ...................................................................................... 4-3
Examples of Typical RAMBAR Settings ..................................................................... 4-6
Valid and Modified Bit Settings ................................................................................... 4-8
CACR Field Descriptions ........................................................................................... 4-21
ACRn Field Descriptions............................................................................................ 4-24
Instruction Cache Line State Transitions.................................................................... 4-27
Data Cache Line State Transitions.............................................................................. 4-29
Data Cache Line State Transitions (Current State Invalid) ........................................ 4-30
Data Cache Line State Transitions (Current State Valid)........................................... 4-31
Tables
xxix
TABLES
Table
Number
4-10
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
5-21
5-22
5-23
5-24
5-25
5-26
5-27
5-28
6-1
6-2
6-3
6-4
6-5
6-6
7-1
7-2
7-3
7-4
8-1
8-2
8-3
8-4
xxx
Title
Page
Number
Data Cache Line State Transitions (Current State Modified)..................................... 4-31
Debug Module Signals.................................................................................................. 5-2
PSTDDATA: Sequential Execution of Single-Cycle Instructions .............................. 5-3
PSTDDATA: Data Operand Captured.......................................................................... 5-4
Processor Status Encoding............................................................................................ 5-5
0xE Status Posting ........................................................................................................ 5-7
BDM/Breakpoint Registers........................................................................................... 5-9
AATR and AATR1 Field Descriptions....................................................................... 5-11
ABLR and ABLR1 Field Description......................................................................... 5-12
ABHR and ABHR1 Field Description........................................................................ 5-12
BAAR Field Descriptions ........................................................................................... 5-13
CSR Field Descriptions............................................................................................... 5-14
DBRn Field Descriptions............................................................................................ 5-16
DBMRn Field Descriptions ........................................................................................ 5-16
Access Size and Operand Data Location .................................................................... 5-16
PBR, PBR1, PBR2, PBR3 Field Descriptions............................................................ 5-17
PBMR Field Descriptions ........................................................................................... 5-17
TDR Field Descriptions .............................................................................................. 5-19
XTDR Field Descriptions ........................................................................................... 5-20
Receive BDM Packet Field Description ..................................................................... 5-25
Transmit BDM Packet Field Description ................................................................... 5-26
BDM Command Summary ......................................................................................... 5-26
BDM Field Descriptions ............................................................................................. 5-27
Control Register Map.................................................................................................. 5-42
Definition of DRc Encoding—Read........................................................................... 5-44
PSTDDATA Nibble/CSR[BSTAT] Breakpoint Response......................................... 5-46
Exception Vector Assignments................................................................................... 5-47
PSTDDATA Specification for User-Mode Instructions............................................. 5-50
PSTDDATA Specification for Supervisor-Mode Instructions ................................... 5-54
SIM Registers .............................................................................................................. 6-3
MBAR Field Descriptions ............................................................................................ 6-5
RSR Field Descriptions................................................................................................. 6-6
SYPCR Field Descriptions ........................................................................................... 6-8
PLLIPL Settings.......................................................................................................... 6-10
MPARK Field Descriptions........................................................................................ 6-11
Divide Ratio Encodings ............................................................................................... 7-2
PLLCR Field Descriptions............................................................................................ 7-3
PLL Module Input SIgnals............................................................................................ 7-4
PLL Module Output Signals ......................................................................................... 7-4
I2C Interface Memory Map........................................................................................... 8-6
I2C Address Register Field Descriptions ...................................................................... 8-6
IFDR Field Descriptions ............................................................................................... 8-7
I2CR Field Descriptions................................................................................................ 8-8
MCF5407 User’s Manual
TABLES
Table
Number
8-5
9-1
9-2
9-3
9-4
9-5
9-6
9-7
9-8
10-1
10-2
10-3
10-4
10-5
10-6
10-7
10-8
10-9
10-10
11-1
11-2
11-3
11-4
11-5
11-6
11-7
11-8
11-9
11-10
11-11
11-12
11-13
11-14
11-15
11-16
11-17
11-18
11-19
11-20
11-21
11-22
11-23
11-24
Title
Page
Number
I2SR Field Descriptions................................................................................................ 8-9
Interrupt Controller Registers ....................................................................................... 9-2
Interrupt Control Registers ........................................................................................... 9-2
ICRn Field Descriptions ............................................................................................... 9-3
Interrupt Priority Scheme.............................................................................................. 9-4
AVR Field Descriptions................................................................................................ 9-6
Autovector Register Bit Assignments........................................................................... 9-6
IPR and IMR Field Descriptions................................................................................... 9-7
IRQPAR Field Descriptions ......................................................................................... 9-8
Chip-Select Module Signals ....................................................................................... 10-1
Byte Enables/Byte Write Enable Signal Settings ....................................................... 10-2
Accesses by Matches in CSCRs and DACRs ............................................................. 10-3
D7/AA, Automatic Acknowledge of Boot CS0.......................................................... 10-4
D[6:5]/PS[1:0], Port Size of Boot CS0 ....................................................................... 10-5
D3/BE_CONFIG0, BE[3:0] Boot Configuration ....................................................... 10-5
Chip-Select Registers.................................................................................................. 10-5
CSARn Field Description ........................................................................................... 10-7
CSMRn Field Descriptions ......................................................................................... 10-7
CSCRn Field Descriptions.......................................................................................... 10-8
DRAM Controller Registers ....................................................................................... 11-3
SDRAM Signal Summary .......................................................................................... 11-4
DCR Field Descriptions (Asynchronous Mode)......................................................... 11-5
DACR0/DACR1 Field Description ............................................................................ 11-6
DMR0/DMR1 Field Descriptions............................................................................... 11-7
Generic Address Multiplexing Scheme ...................................................................... 11-8
DRAM Addressing for Byte-Wide Memories.......................................................... 11-10
DRAM Addressing for 16-Bit Wide Memories........................................................ 11-10
DRAM Addressing for 32-Bit Wide Memories........................................................ 11-11
SDRAM Commands ................................................................................................. 11-17
Synchronous DRAM Signal Connections ................................................................ 11-17
DCR Field Descriptions (Synchronous Mode) ......................................................... 11-19
DACR0/DACR1 Field Descriptions (Synchronous Mode)...................................... 11-21
DMR0/DMR1 Field Descriptions............................................................................. 11-23
MCF5407 to SDRAM Interface (8-Bit Port, 9-Column Address Lines).................. 11-24
MCF5407 to SDRAM Interface (8-Bit Port,10-Column Address Lines)................. 11-24
MCF5407 to SDRAM Interface (8-Bit Port,11-Column Address Lines)................. 11-24
MCF5407 to SDRAM Interface (8-Bit Port,12-Column Address Lines)................. 11-24
MCF5407 to SDRAM Interface (8-Bit Port,13-Column Address Lines)................. 11-25
MCF5407 to SDRAM Interface (16-Bit Port, 8-Column Address Lines)................ 11-25
MCF5407 to SDRAM Interface (16-Bit Port, 9-Column Address Lines)................ 11-25
MCF5407 to SDRAM Interface (16-Bit Port, 10-Column Address Lines).............. 11-25
MCF5407 to SDRAM Interface (16-Bit Port, 11-Column Address Lines).............. 11-25
MCF5407 to SDRAM Interface (16-Bit Port, 12-Column Address Lines).............. 11-26
Tables
xxxi
TABLES
Table
Number
11-25
11-26
11-27
11-28
11-29
11-30
11-31
11-32
11-33
11-34
11-35
11-36
11-37
12-1
12-2
12-3
12-4
12-5
13-1
13-2
13-3
13-4
14-1
14-2
14-3
14-4
14-5
14-6
14-7
14-8
14-9
14-10
14-11
14-12
14-13
14-14
14-15
14-16
14-17
14-18
14-19
15-1
15-2
xxxii
Title
Page
Number
MCF5407 to SDRAM Interface (16-Bit Port, 13-Column-Address Lines) ............. 11-26
MCF5407 to SDRAM Interface (32-Bit Port, 8-Column Address Lines)................ 11-26
MCF5407 to SDRAM Interface (32-Bit Port, 9-Column Address Lines)................ 11-26
MCF5407 to SDRAM Interface (32-Bit Port, 10-Column Address Lines).............. 11-26
MCF5407 to SDRAM Interface (32-Bit Port, 11-Column Address Lines).............. 11-27
MCF5407 to SDRAM Interface (32-Bit Port, 12-Column Address Lines).............. 11-27
SDRAM Hardware Connections............................................................................... 11-27
SDRAM Example Specifications ............................................................................. 11-34
SDRAM Hardware Connections............................................................................... 11-35
DCR Initialization Values......................................................................................... 11-35
DACR Initialization Values...................................................................................... 11-36
DMR0 Initialization Values...................................................................................... 11-37
Mode Register Initialization ..................................................................................... 11-38
DMA Signals .............................................................................................................. 12-2
MCF5407 Signal Configurations for PP[4:2]/TM[2:0]/DACK[1:0] .......................... 12-3
Memory Map for DMA Controller Module Registers................................................ 12-6
DCRn Field Descriptions............................................................................................ 12-8
DSRn Field Descriptions .......................................................................................... 12-10
General-Purpose Timer Module Memory Map .......................................................... 13-3
TMRn Field Descriptions ........................................................................................... 13-4
TERn Field Descriptions............................................................................................. 13-6
Time-Out Values (in Seconds)—TRR[REF] = 0xFFFF(162-MHz Processor Clock) 13-7
UART Module Programming Model.......................................................................... 14-4
UMR1n Field Descriptions ......................................................................................... 14-6
UMR2n Field Descriptions ......................................................................................... 14-7
RXLVL Field Descriptions......................................................................................... 14-8
Modem Control Register (MODCTL) Field Descriptions.......................................... 14-9
TXLVL Field Descriptions ....................................................................................... 14-10
USRn Field Descriptions .......................................................................................... 14-11
UCSRn Field Descriptions........................................................................................ 14-12
RSMP Field Descriptions ......................................................................................... 14-13
TSPC Field Descriptions........................................................................................... 14-13
UCRn Field Descriptions.......................................................................................... 14-14
UIPCRn Field Descriptions ...................................................................................... 14-17
UACRn Field Descriptions ....................................................................................... 14-18
UISRn/UIMRn Field Descriptions ........................................................................... 14-19
UIVRn Field Descriptions ........................................................................................ 14-20
UIPn Field Descriptions............................................................................................ 14-20
UOP1/UOP0 Field Descriptions ............................................................................... 14-21
UART Module Signals ............................................................................................. 14-22
UART Module Initialization Sequence .................................................................... 14-38
Parallel Port Pin Descriptions ..................................................................................... 15-2
PADDR Field Description .......................................................................................... 15-2
MCF5407 User’s Manual
TABLES
Table
Number
15-3
16-1
16-2
16-3
16-4
16-5
17-1
17-2
17-3
17-4
17-5
17-6
17-7
17-8
17-9
17-10
17-11
17-12
17-13
17-14
17-15
18-1
18-2
18-3
18-4
18-5
18-6
18-7
18-8
18-9
18-10
18-11
18-12
19-1
19-2
19-3
19-4
20-1
20-2
20-3
20-4
20-5
20-6
Title
Page
Number
Relationship between PADAT Register and Parallel Port Pin (PP) ........................... 15-3
Pins 1–52 (Left, Top-to-Bottom) ................................................................................ 16-1
Pins 53–104 (Bottom, Left-to-Right).......................................................................... 16-3
Pins 105–156 (Right, Bottom-to-Top)........................................................................ 16-5
Pins 157–208 (Top, Right-to-Left) ............................................................................. 16-6
Dimensions ............................................................................................................... 16-11
MCF5407 Signal Index............................................................................................... 17-3
MCF5407 Alphabetical Signal Index ......................................................................... 17-5
Data Pin Configuration ............................................................................................... 17-8
Bus Cycle Size Encoding............................................................................................ 17-9
Bus Cycle Transfer Type Encoding.......................................................................... 17-10
TM[2:0] Encodings for TT = 00 (Normal Access)................................................... 17-10
TM2 Encoding for DMA as Master (TT = 01) ......................................................... 17-11
TM[1:0] Encoding for DMA as Master (TT = 01) ................................................... 17-11
TM[2:0] Encodings for TT = 10 (Emulator Access) ................................................ 17-11
TM[2:0] Encodings for TT = 11 (Interrupt Level) ................................................... 17-12
Data Pin Configuration ............................................................................................. 17-14
D7 Selection of CS0 Automatic Acknowledge ........................................................ 17-14
D6 and D5 Selection of CS0 Port Size ..................................................................... 17-14
D3/BE_CONFIG, BE[3:0] Boot Configuration ....................................................... 17-15
D4/ADDR_CONFIG, Address Pin Assignment....................................................... 17-15
ColdFire Bus Signal Summary ................................................................................... 18-1
Bus Cycle Size Encoding............................................................................................ 18-3
Accesses by Matches in CSCRs and DACRs ............................................................. 18-5
Bus Cycle States ......................................................................................................... 18-6
Allowable Line Access Patterns ............................................................................... 18-12
MCF5407 Arbitration Protocol States ...................................................................... 18-20
ColdFire Bus Arbitration Signal Summary............................................................... 18-21
Cycles for Basic No-Wait-State External Master Access......................................... 18-23
Cycles for External Master Burst Line Access to 32-Bit Port .................................. 18-24
MCF5407 Two-Wire Bus Arbitration Protocol Transition Conditions.................... 18-28
Three-Wire Bus Arbitration Protocol Transition Conditions ................................... 18-32
Data Pin Configuration ............................................................................................. 18-35
JTAG Pin Descriptions ............................................................................................... 19-3
JTAG Instructions....................................................................................................... 19-5
IDCODE Bit Assignments.......................................................................................... 19-6
Boundary-Scan Bit Definitions................................................................................... 19-7
Absolute Maximum Ratings ....................................................................................... 20-1
Operating Temperatures.............................................................................................. 20-1
DC Electrical Specifications ....................................................................................... 20-2
Divide Ratio Encodings .............................................................................................. 20-4
Clock Timing Specification ........................................................................................ 20-5
Input AC Timing Specification................................................................................... 20-6
Tables
xxxiii
TABLES
Table
Number
20-7
20-8
20-9
20-10
20-11
20-12
20-13
20-14
20-15
20-16
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-11
A-12
A-13
B-1
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
B-10
xxxiv
Title
Page
Number
Output AC Timing Specification ................................................................................ 20-6
Reset Timing Specification....................................................................................... 20-15
Debug AC Timing Specification .............................................................................. 20-16
Timer Module AC Timing Specification.................................................................. 20-17
I2C Input Timing Specifications between SCL and SDA......................................... 20-18
I2C Output Timing Specifications between SCL and SDA ...................................... 20-18
UART Module AC Timing Specifications ............................................................... 20-19
General-Purpose I/O Port AC Timing Specifications............................................... 20-22
DMA AC Timing Specifications .............................................................................. 20-23
IEEE 1149.1 (JTAG) AC Timing Specifications ..................................................... 20-24
Differences between MCF5307 and MCF5407........................................................... A-1
MOVEC CPU Space Register Map ............................................................................. A-4
TM[2:1] Encoding for MCF5307 Internal DMA as Master (TT = 01) ....................... A-4
TM0 Encoding for MCF5307 Internal DMA as Master (TT = 01) ............................. A-5
Divide Ratio Encodings ............................................................................................... A-7
D[7:0] Multiplexing ..................................................................................................... A-8
D7/AA, Automatic Acknowledge of Boot CS0........................................................... A-9
D[6:5]/PS[1:0], Port Size of Boot CS0 ........................................................................ A-9
D4/ADDR_CONFIG, Address Pin Assignment.......................................................... A-9
D3/BE_CONFIG, BE[3:0] Boot Configuration .......................................................... A-9
Definition of DRc Encoding—Write ......................................................................... A-13
Debug C Exception Vector Assignments .................................................................. A-16
Version 4 Debug C Processor Status Encodings ....................................................... A-17
SIM Registers................................................................................................................B-1
Interrupt Controller Registers .......................................................................................B-1
Chip-Select Registers....................................................................................................B-2
DRAM Controller Registers .........................................................................................B-3
General-Purpose Timer Registers .................................................................................B-4
UART0 Control Registers.............................................................................................B-4
UART1 Control Registers.............................................................................................B-6
Parallel Port Memory Map............................................................................................B-7
I2C Interface Memory Map...........................................................................................B-8
DMA Controller Registers............................................................................................B-8
MCF5407 User’s Manual
About This Book
The primary objective of this user’s manual is to define the functionality of the MCF5407
processors for use by software and hardware developers.
The information in this book is subject to change without notice, as described in the
disclaimers on the title page of this book. As with any technical documentation, it is the
readers’ responsibility to be sure they are using the most recent version of the
documentation.
To locate any published errata or updates for this document, refer to the world-wide web at
http://www.motorola.com/coldfire.
Audience
This manual is intended for system software and hardware developers and applications
programmers who want to develop products for the MCF5407. It is assumed that the reader
understands operating systems, microprocessor system design, basic principles of software
and hardware, and basic details of the ColdFire architecture.
Organization
Following is a summary and a brief description of the major sections of this manual:
•
Chapter 1, “Overview,” includes general descriptions of the modules and features
incorporated in the MCF5407, focussing in particular on new features defined by the
Version 4 (V4) programming model, such as the Harvard memory architecture
implementation, new instructions, and new registers.
•
Part I is intended for system designers who need to understand the operation of the
MCF5407 ColdFire core and its multiply/accumulate (MAC) execution unit. It
describes the programming and exception models, Harvard memory
implementation, and debug module.
— Chapter 2, “ColdFire Core,” provides an overview of the microprocessor core of
the MCF5407. The chapter begins with a description of enhancements from the
V3 ColdFire core, and then fully describes the V4 programming model as it is
implemented on the MCF5407. It also includes a full description of exception
handling, data formats, an instruction set summary, and a table of instruction
timings.
About This Book
xxxv
Organization
— Chapter 3, “Hardware Multiply/Accumulate (MAC) Unit,” describes the
MCF5407 multiply/accumulate unit, which executes integer multiply,
multiply-accumulate, and miscellaneous register instructions. The MAC is
integrated into the operand execution pipeline (OEP).
•
— Chapter 4, “Local Memory.” This chapter describes the MCF5407
implementation of the ColdFire V4 local memory specification. It consists of the
two following major sections.
– Section 4.2, “SRAM Overview,” describes the MCF5407 on-chip static RAM
(SRAM) implementation. It covers general operations, configuration, and
initialization. It also provides information and examples showing how to
minimize power consumption when using the SRAM.
– Section 4.7, “Cache Overview,” describes the MCF5407 cache
implementation, including organization, configuration, and coherency. It
describes cache operations and how the cache interacts with other memory
structures.
— Chapter 5, “Debug Support,” describes the Revision C enhanced hardware debug
support in the MCF5407. This revision of the ColdFire debug architecture
encompasses earlier revisions.
Part II, “System Integration Module (SIM),” describes the system integration
module, which provides overall control of the bus and serves as the interface
between the ColdFire core processor complex and internal peripheral devices. It
includes a general description of the SIM and individual chapters that describe
components of the SIM, such as the phase-lock loop (PLL) timing source, interrupt
controller for peripherals, configuration and operation of chip selects, and the
SDRAM controller.
— Chapter 6, “SIM Overview,” describes the SIM programming model, bus
arbitration, and system-protection functions for the MCF5407.
— Chapter 7, “Phase-Locked Loop (PLL),” describes configuration and operation
of the PLL module. It describes in detail the registers and signals that support the
PLL implementation.
— Chapter 8, “I2C Module,” describes the MCF5407 I2C module, including I2C
protocol, clock synchronization, and the registers in the I2C programing model.
It also provides extensive programming examples.
— Chapter 9, “Interrupt Controller,” describes operation of the interrupt controller
portion of the SIM. Includes descriptions of the registers in the interrupt
controller memory map and the interrupt priority scheme.
— Chapter 10, “Chip-Select Module,” describes the MCF5407 chip-select
implementation, including the operation and programming model, which
includes the chip-select address, mask, and control registers.
— Chapter 11, “Synchronous/Asynchronous DRAM Controller Module,”
describes configuration and operation of the synchronous/asynchronous DRAM
xxxvi
MCF5407 User’s Manual
Organization
controller component of the SIM. It begins with a general description and brief
glossary, and includes a description of signals involved in DRAM operations.
The remainder of the chapter is divided between descriptions of asynchronous
and synchronous operations.
•
•
Part III, “Peripheral Module,” describes the operation and configuration of the
MCF5407 DMA, timer, UART, and parallel port modules, and describes how they
interface with the system integration unit, described in Part II.
— Chapter 12, “DMA Controller Module,” provides an overview of the DMA
controller module and describes in detail its signals and registers. The latter
sections of this chapter describe operations, features, and supported data transfer
modes in detail, showing timing diagrams for various operations.
— Chapter 13, “Timer Module,” describes configuration and operation of the two
general-purpose timer modules, timer 0 and timer 1. It includes programming
examples.
— Chapter 14, “UART Modules,” describes the use of the universal
asynchronous/synchronous receiver/transmitters (UARTs) implemented on the
MCF5407 and includes programming examples. Particular attention is given to
the UART1 implementation of a synchronous interface that provides a controller
for an 8- or 16-bit CODEC interface and an audio CODEC ‘97 (AC ’97) digital
interface.
— Chapter 15, “Parallel Port (General-Purpose I/O),” describes the operation and
programming model of the parallel port pin assignment, direction-control, and
data registers. It includes a code example for setting up the parallel port.
Part IV, “Hardware Interface,” provides a pinout and both electrical and functional
descriptions of the MCF5407 signals. It also describes how these signals interact to
support the variety of bus operations shown in timing diagrams.
— Chapter 16, “Mechanical Data,” provides a functional pin listing and package
diagram for the MCF5407.
— Chapter 17, “Signal Descriptions,” provides an alphabetical listing of MCF5407
signals. This chapter describes the MCF5407 signals. In particular, it shows
which are inputs or outputs, how they are multiplexed, which signals require
pull-up resistors, and the state of each signal at reset.
— Chapter 18, “Bus Operation,” describes data transfers, error conditions, bus
arbitration, and reset operations. It describes transfers initiated by the MCF5407
and by an external bus master, and includes detailed timing diagrams showing
the interaction of signals in supported bus operations. Note that Chapter 11,
“Synchronous/Asynchronous DRAM Controller Module,” describes DRAM
cycles.
— Chapter 19, “IEEE 1149.1 Test Access Port (JTAG),” describes configuration
and operation of the MCF5407 JTAG test implementation. It describes the use of
JTAG instructions and how to disable JTAG functionality.
About This Book
xxxvii
Suggested Reading
— Chapter 20, “Electrical Specifications,” describes AC and DC electrical
specifications and thermal characteristics for the MCF5407. Because additional
speeds may have become available since the publication of this book, consult
Motorola’s ColdFire web page, http://www.motorola.com/coldfire, to confirm
that this is the latest information.
This manual includes the following two appendixes:
•
Appendix A, “Migrating from the ColdFire MCF5307 to the MCF5407,” highlights
the differences between the MCF5307B and MCF5407. Users of the MCF5307 and
MCF5307A should use this document in conjunction with the MCF5307 User's
Manual Mask Set Addendum. For additional information, see the MCF5407
Integrated ColdFire Microprocessor Product Brief.
•
Appendix B, “List of Memory Maps,” lists the entire address-map for MCF5407
memory-mapped registers.
This manual also includes a glossary and an index.
Suggested Reading
This section lists additional reading that provides background for the information in this
manual as well as general information about the ColdFire architecture.
General Information
The following documentation provides useful information about the ColdFire architecture
and computer architecture in general:
ColdFire Documentation
The ColdFire documentation is available from the sources listed on the back cover of this
manual. Document order numbers are included in parentheses for ease in ordering.
•
ColdFire Programmers Reference Manual, R1.0 (MCF5200PRM/AD)
•
User’s manuals—These books provide details about individual ColdFire
implementations and are intended to be used in conjunction with The ColdFire
Programmers Reference Manual. These include the following:
— ColdFire MCF5102 User’s Manual (MCF5102UM/AD)
— ColdFire MCF5202 User’s Manual (MCF5202UM/AD)
•
xxxviii
— ColdFire MCF5204 User’s Manual (MCF5204UM/AD)
— ColdFire MCF5206 User’s Manual (MCF5206EUM/AD)
— ColdFire MCF5206E User’s Manual (MCF5206EUM/AD)
— ColdFire MCF5307 User’s Manual (MCF5307UM/AD)
ColdFire Programmers Reference Manual, R1.0 (MCF5200PRM/AD)
MCF5407 User’s Manual
Conventions
•
Using Microprocessors and Microcomputers: The Motorola Family, William C.
Wray, Ross Bannatyne, Joseph D. Greenfield
Additional literature on ColdFire implementations is being released as new processors
become available. For a current list of ColdFire documentation, refer to the World Wide
Web at http://www.motorola.com/ColdFire/.
Conventions
This document uses the following notational conventions:
MNEMONICS
In text, instruction mnemonics are shown in uppercase.
mnemonics
In code and tables, instruction mnemonics are shown in lowercase.
italics
0x0
Italics indicate variable command parameters.
Book titles in text are set in italics.
Prefix to denote hexadecimal number
0b0
Prefix to denote binary number
REG[FIELD]
Abbreviations for registers are shown in uppercase. Specific bits,
fields, or ranges appear in brackets. For example, RAMBAR[BA]
identifies the base address field in the RAM base address register.
nibble
A 4-bit data unit
byte
An 8-bit data unit
word
A 16-bit data unit
longword
A 32-bit data unit
x
In some contexts, such as signal encodings, x indicates a don’t care.
n
Used to express an undefined numerical value
¬
NOT logical operator
&
AND logical operator
|
OR logical operator
Acronyms and Abbreviations
Table i lists acronyms and abbreviations used in this document.
Table i. Acronyms and Abbreviated Terms
Term
Meaning
ADC
Analog-to-digital conversion
ALU
Arithmetic logic unit
AVEC
Autovector
About This Book
xxxix
Acronyms and Abbreviations
Table i. Acronyms and Abbreviated Terms (Continued)
Term
xl
Meaning
BDM
Background debug mode
BIST
Built-in self test
BSDL
Boundary-scan description language
CODEC
Code/decode
DAC
Digital-to-analog conversion
DMA
Direct memory access
DSP
Digital signal processing
EA
Effective address
EDO
Extended data output (DRAM)
FIFO
First-in, first-out
GPIO
General-purpose I/O
I2C
Inter-integrated circuit
IEEE
Institute for Electrical and Electronics Engineers
IFP
Instruction fetch pipeline
IPL
Interrupt priority level
JEDEC
Joint Electron Device Engineering Council
JTAG
Joint Test Action Group
LIFO
Last-in, first-out
LRU
Least recently used
LSB
Least-significant byte
lsb
Least-significant bit
MAC
Multiple accumulate unit
MBAR
Memory base address register
MSB
Most-significant byte
msb
Most-significant bit
Mux
Multiplex
NOP
No operation
OEP
Operand execution pipeline
PC
Program counter
PCLK
Processor clock
PLL
Phase-locked loop
PLRU
Pseudo least recently used
MCF5407 User’s Manual
Terminology and Notational Conventions
Table i. Acronyms and Abbreviated Terms (Continued)
Term
Meaning
POR
Power-on reset
PQFP
Plastic quad flat pack
RISC
Reduced instruction set computing
Rx
Receive
SIM
System integration module
SOF
Start of frame
TAP
Test access port
TTL
Transistor-to-transistor logic
Tx
Transmit
UART
Universal asynchronous/synchronous receiver transmitter
Terminology and Notational Conventions
Table ii shows notational conventions used throughout this document.
Table ii Notational Conventions
Instruction
Operand Syntax
Opcode Wildcard
cc
Logical condition (example: NE for not equal)
Register Specifications
An
Ay,Ax
Any address register n (example: A3 is address register 3)
Source and destination address registers, respectively
Dn
Any data register n (example: D5 is data register 5)
Dy,Dx
Source and destination data registers, respectively
Rc
Any control register (example VBR is the vector base register)
Rm
MAC registers (ACC, MAC, MASK)
Rn
Any address or data register
Rw
Destination register w (used for MAC instructions only)
Ry,Rx
Xi
Any source and destination registers, respectively
index register i (can be an address or data register: Ai, Di)
About This Book
xli
Terminology and Notational Conventions
Table ii Notational Conventions (Continued)
Instruction
Operand Syntax
Register Names
ACC
MAC accumulator register
CCR
Condition code register (lower byte of SR)
MACSR
MAC status register
MASK
MAC mask register
PC
Program counter
SR
Status register
Port Name
PSTDDATA
Processor status/debug data port
Miscellaneous Operands
#<data>
<ea>
<ea>y,<ea>x
<label>
<list>
<shift>
<size>
Immediate data following the 16-bit operation word of the instruction
Effective address
Source and destination effective addresses, respectively
Assembly language program label
List of registers for MOVEM instruction (example: D3–D0)
Shift operation: shift left (<<), shift right (>>)
Operand data size: byte (B), word (W), longword (L)
bc
Both instruction and data caches
dc
Data cache
ic
Instruction cache
# <vector>
<>
<xxx>
Identifies the 4-bit vector number for trap instructions
identifies an indirect data address referencing memory
identifies an absolute address referencing memory
dn
Signal displacement value, n bits wide (example: d16 is a 16-bit displacement)
SF
Scale factor (x1, x2, x4 for indexed addressing mode, <<1n>> for MAC operations)
Operations
xlii
+
Arithmetic addition or postincrement indicator
–
Arithmetic subtraction or predecrement indicator
x
Arithmetic multiplication
MCF5407 User’s Manual
Terminology and Notational Conventions
Table ii Notational Conventions (Continued)
Instruction
Operand Syntax
/
Arithmetic division
~
Invert; operand is logically complemented
&
Logical AND
|
Logical OR
^
Logical exclusive OR
<<
Shift left (example: D0 << 3 is shift D0 left 3 bits)
>>
Shift right (example: D0 >> 3 is shift D0 right 3 bits)
→
Source operand is moved to destination operand
←→
Two operands are exchanged
sign-extended
All bits of the upper portion are made equal to the high-order bit of the lower portion
If <condition>
then
<operations>
else
<operations>
Test the condition. If true, the operations after ‘then’ are performed. If the condition is false and the
optional ‘else’ clause is present, the operations after ‘else’ are performed. If the condition is false
and else is omitted, the instruction performs no operation. Refer to the Bcc instruction description
as an example.
Subfields and Qualifiers
{}
Optional operation
()
Identifies an indirect address
dn
Displacement value, n-bits wide (example: d16 is a 16-bit displacement)
Address
Calculated effective address (pointer)
Bit
Bit selection (example: Bit 3 of D0)
lsb
Least significant bit (example: lsb of D0)
LSB
Least significant byte
LSW
Least significant word
msb
Most significant bit
MSB
Most significant byte
MSW
Most significant word
Condition Code Register Bit Names
C
Carry
N
Negative
V
Overflow
X
Extend
Z
Zero
About This Book
xliii
Terminology and Notational Conventions
xliv
MCF5407 User’s Manual
Chapter 1
Overview
This chapter is an overview of the MCF5407 ColdFire® processor. It includes general
descriptions of the modules and features incorporated in the MCF5407, focusing in
particular on new features defined by the Version 4 (V4) programming model, such as the
Harvard memory architecture implementation, new instructions, and new registers.
1.1 Features
The MCF5407 integrated microprocessor combines a V4 ColdFire processor core with the
following components, as shown in Figure 1-1:
•
•
•
•
•
•
•
•
•
Harvard architecture memory system with 16-Kbyte instruction cache and 8-Kbyte
data cache
Two, 2-Kbyte on-chip SRAMs
Integer/fractional multiply-accumulate (MAC) unit
Divide unit
System debug interface
DRAM controller for synchronous and asynchronous DRAM
Four-channel DMA controller
Two general-purpose timers
Two UARTs, one that supports synchronous operations
•
•
•
I2C™ interface
Parallel I/O interface
System integration module (SIM)
Designed for embedded control applications, the MCF5407 delivers 233 Dhrystone MIPS
at 162 MHz while minimizing system costs.
Chapter 1. Overview
1-1
Features
V4 COLDFIRE PROCESSOR COMPLEX
Instruction Unit
8-Entry
Branch
Cache
..
.
Instruction Fetch
Pipeline (IFP)
IAG
IC1
IC2
IED
Branch Logic
JTAG
LIFO Return
Stack
Ten-Instruction
FIFO Buffer
128-Entry
Prediction
Table
Operand Execution
Pipeline (OEP)
CCR
DS
AG
OC1
OC2
EX MAC
DA
DIV
Debug
Module
GeneralPurpose Registers
A0–A7 D0–D7
31
0
31
0
Local Memory
÷2
SRAM Controller
PSTCLK
RAMBAR0 RAMBAR1
2-Kbyte
SRAM0
CLKIN
(to on-chip
peripherals)
CLKIN
PLL
Xn
RSTI
Local Memory
Instruction Bus
2-Kbyte
SRAM1
Local Memory
Data Bus
Harvard Cache Controller
CACR
PCLK
RSTO
ACR2
ACR3
ACR0
ACR1
16-Kbyte
Instruction
Cache
8-Kbyte
Data
Cache
31
0
4-Entry
Store
Buffer
DMA
SYSTEM INTEGRATION MODULE (SIM)
PLL Control
PLL
System Control
RSR
SWIVR
Base Address
Bus Master Park
Parallel Port
MBAR
MPARK
PLL
Software
Watchdog
SYPCR SWSR
DRAM Controller
Chip-Select Module
DRAM Control
DCR
External
Bus Interface
Interrupt Controller
I2C Module
IRQPAR
Two UARTs
10 ICRs
8
8
8
CSARs CSCRs CSMRs
IPR
Addr/Cntrl Mask
DACR0/1
IMR
DMR0/1
AVR
8
DRAM Controller
Outputs
CS[7:0]
32-Bit Address Bus
32-Bit Data Bus
Control Signals
4
IRQ[1,3,5,7]
Figure 1-1. MCF5407 Block Diagram
1-2
Four
Channels
MCF5407 User’s Manual
Two
GeneralPurpose
Timers
Features
Features common to many embedded applications, such as DMAs, various DRAM
controller interfaces, and on-chip memories, are integrated using advanced process
technologies.
The MCF5407 extends the legacy of Motorola’s 68K family by providing a compatible path
for 68K and ColdFire customers in which development tools and customer code can be
leveraged. In fact, customers moving from 68K to ColdFire can use code translation and
emulation tools that facilitate modifying 68K assembly code to the ColdFire architecture.
The package, pinout, and integration mix of the MCF5407 create an especially simple
upgrade for current MCF5307 designs with over triple the system performance.
Based on the concept of variable-length RISC technology, the ColdFire family combines
the architectural simplicity of conventional 32-bit RISC with a memory-saving,
variable-length instruction set. In defining the ColdFire architecture for embedded
processing applications, a 68K-code compatible core combines performance advantages of
a RISC architecture with the optimum code density of a streamlined, variable-length
M68000 instruction set.
By using a variable-length instruction set architecture, embedded system designers using
ColdFire RISC processors enjoy significant advantages over conventional fixed-length
RISC architectures. The denser binary code for ColdFire processors consumes less memory
than many fixed-length instruction set RISC processors available. This improved code
density means more efficient system memory use for a given application and allows use of
slower, less costly memory to help achieve a target performance level.
The MCF5407 is the first standard product to implement the Version 4 ColdFire
microprocessor core. The V4 microarchitecture implements a number of advanced
techniques, including a Harvard memory architecture, branch cache acceleration logic, and
limited superscalar support (dual-instruction issue), which contribute to the 233 Dhrystone
MIPS performance level. Increasing the internal speed of the core also allows higher
performance while providing the system designer with an easy-to-use lower speed system
interface. The processor complex frequency is an integer multiple, 3 to 6 times, of the
external bus frequency. The core clock can be stopped to support a low-power mode.
Serial communication channels are provided by an I2C interface module and two
programmable full-duplex UARTs, one of which provides synchronous communications
for soft-modem applications. Four channels of DMA allow for fast data transfer using a
programmable burst mode independent of processor execution. The two 16-bit
general-purpose multimode timers provide separate input and output signals. For system
protection, the processor includes a programmable 16-bit software watchdog timer. In
addition, common system functions such as chip selects, interrupt control, bus arbitration,
and an IEEE 1149.1 JTAG module are included.A sophisticated debug interface supports
background-debug mode plus real-time trace and debug with an expanded set of on-chip
breakpoint registers. This interface is present in all ColdFire standard products and allows
common emulator support across the entire family of microprocessors.
Chapter 1. Overview
1-3
MCF5407 Features
1.2 MCF5407 Features
The following list summarizes MCF5407 features:
•
•
•
•
1-4
ColdFire processor core
— Variable-length RISC, clock-multiplied Version 4 microprocessor core
— Implementation of Revision B of the ColdFire instruction set architecture (ISA),
which leverages the 68K programming model
— Two independent decoupled pipelines: four-stage instruction fetch pipeline (IFP)
and five-stage operand execution pipeline (OEP)
— Ten-instruction FIFO buffer provides decoupling between the pipelines
— Limited superscalar design achieves performance levels close to dual-issue
performance
— Programmable two-level branch acceleration mechanism with an 8-entry branch
cache plus a 128-entry prediction table for increased performance
— 32-bit internal address bus supporting 4 Gbytes of linear address space
— 32-bit data bus
— 16 user-accessible, 32-bit-wide, general-purpose registers
— Supervisor/user modes for system protection
— Vector base register to relocate exception-vector table
— Optimized for high-level language constructs
Multiply and accumulate unit (MAC)
— High-speed, complex arithmetic processing for DSP applications
— Tightly coupled to the OEP
— Three-stage execute pipeline with one clock issue rate for 16 x 16 operations
— 16 x 16 and 32 x 32 multiplies support, all with 32-bit accumulate
— Signed or unsigned integer support, plus signed fractional operands
Hardware integer divide unit
— Unsigned and signed integer divide support
— Tightly coupled to the OEP
— 32/16 and 32/32 operation support producing quotient and/or remainder results
16-Kbyte instruction cache, 8-Kbyte data cache
— Four-way set-associative organization
— Operates at higher processor core frequency
— Provides pipelined, single-cycle access to critical code and data
— Data cache supports write-through and copyback modes
— Four-entry, 32-bit store buffer to improve performance of operand writes
MCF5407 User’s Manual
MCF5407 Features
•
•
•
•
•
Two, 2-Kbyte SRAMs
— Programmable location anywhere within 4-Gbyte linear address space
— Higher core-frequency operation
— Pipelined, single-cycle access to critical code or data
— Each block mappable to either the instruction or data operand bus
DMA controller
— Four fully programmable channels: two support external requests and external
acknowledges
— Dual-address and single-address transfer support with 8-, 16-, and 32-bit data
capability
— Source/destination address pointers that can increment or remain constant
— 24-bit transfer counter per channel
— Operand packing and unpacking supported
— Auto-alignment transfers supported for efficient block movement
— Bursting and cycle steal support
— Two-bus-clock internal access
— Automatic DMA transfers from on-chip UARTs using internal interrupts
DRAM controller
— Synchronous DRAM (SDRAM), extended-data-out (EDO) DRAM, and fast
page mode support
— Up to 512 Mbytes of DRAM
— Programmable timer provides CAS-before-RAS refresh for asynchronous
DRAMs
— Support for two separate memory blocks
Two UARTs
— One UART offers synchronous mode with expanded buffers for soft modem
support
— Full-duplex operation
— Programmable clock
— Modem control signals available (CTS, RTS)
— Processor-interrupt capability
Dual 16-bit general-purpose multiple-mode timers
— 8-bit prescaler
— Timer input and output pins
— Processor-interrupt capability
— Up to 18.5-nS resolution at 54 MHz
Chapter 1. Overview
1-5
MCF5407 Features
•
•
•
•
•
•
•
1-6
I2C module
— Interchip bus interface for EEPROMs, LCD controllers, A/D converters, and
keypads
— Fully compatible with industry-standard I2C bus
— Master or slave modes support multiple masters
— Automatic interrupt generation with programmable level
System interface module (SIM)
— Chip selects provide direct interface to 8-, 16-, and 32-bit SRAM, ROM,
FLASH, and memory-mapped I/O devices
— Eight fully programmable chip selects, each with a base address register
— Programmable wait states and port sizes per chip select
— User-programmable processor clock/input clock frequency ratio
— Programmable interrupt controller
— Low interrupt latency
— Four external interrupt request inputs
— Programmable autovector generator
— Software watchdog timer
16-bit general-purpose I/O interface
IEEE 1149.1 test (JTAG) module
System debug support
— Real-time trace for determining dynamic execution path while in emulator mode
— Background debug mode (BDM) for debug features while halted
— Real-time debug support, including 13 user-visible hardware breakpoint
registers supporting 8 separate breakpoints
— Supports servicing of critical, real-time interrupt requests while the BDM is in
emulator mode
— Supports comprehensive emulator functions through trace and breakpoint logic
On-chip PLL
— Accepts various clock input (CLKIN) frequencies between 25 and 54 MHz
— Supports core frequencies between 100 and 162 MHz
— Supports low-power mode
Product offerings
— 233 Dhrystone MIPS at 162 MHz
— Implemented in 0.22 µ, quad-layer-metal process technology with 1.8-V
operation (3.3-V compliant I/O pads)
— 208-pin plastic QFP package
— 0°–70° C operating temperature
MCF5407 User’s Manual
ColdFire Module Description
1.2.1 Process
The MCF5407 is manufactured in a 0.22-µ CMOS process with quad-layer-metal routing
technology. This process combines the high performance and low power needed for
embedded system applications. Inputs are 3.3-V tolerant; outputs are CMOS or open-drain
CMOS with outputs operating from VDD + 0.5 V to GND - 0.5 V, with guaranteed
TTL-level specifications.
1.3 ColdFire Module Description
The following sections provide overviews of the various modules incorporated in the
MCF5407.
1.3.1 ColdFire Core
The Version 4 ColdFire core consists of two independent and decoupled pipelines to
maximize performance—the instruction fetch pipeline (IFP) and the operand execution
pipeline (OEP).
1.3.1.1 Instruction Fetch Pipeline (IFP)
The four-stage instruction fetch pipeline (IFP) is designed to prefetch instructions for the
operand execution pipeline (OEP). Because the fetch and execution pipelines are decoupled
by a ten-instruction FIFO buffer, the fetch mechanism can prefetch instructions in advance
of their use by the OEP, thereby minimizing the time stalled waiting for instructions. To
maximize the performance of conditional branch instructions, the Version 4 IFP
implements a sophisticated two-level acceleration mechanism.
The first level is an 8-entry, direct-mapped branch cache with a 2-bit prediction state
(strongly/weakly, taken/not-taken) for each entry. The branch cache implements instruction
folding techniques. These allow conditional branch instructions that are predicted correctly
as taken to execute in zero cycles.
For those conditional branches with no information in the branch cache, a second-level,
direct-mapped prediction table containing 128 entries is accessed. Again, each entry uses
the same 2-bit prediction state definition as the branch cache. This branch prediction state
is then used to predict the direction of prefetched conditional branch instructions.
Other change-of-flow instructions, including unconditional branches, jumps, and
subroutine calls, use a similar mechanism where the IFP calculates the target address. The
performance of subroutine return instructions is improved through the use of a four-entry,
LIFO return stack.
In all cases, these mechanisms allow the IFP to redirect the fetch stream down the path
predicted to be taken well in advance of the actual instruction execution. The result is
significantly improved performance.
Chapter 1. Overview
1-7
ColdFire Module Description
1.3.1.2 Operand Execution Pipeline (OEP)
The prefetched instruction stream is gated from the FIFO buffer into the five-stage OEP.
The OEP consists of two, traditional two-stage RISC compute engines with a register file
access feeding an arithmetic/logic unit (ALU). The compute engine located at the top of the
OEP is typically used for operand memory address calculations (the address ALU), while
the compute engine located at the bottom of the pipeline is used for instruction execution
(the execution ALU). The resulting structure provides 3.9 Gbytes/S data operand
bandwidth at 162 MHz to the two compute engines and supports single-cycle execution
speeds for most instructions, including all load, store, and most embedded-load operations.
In response to users and developers’ comments, the V4 design supports execution of the
ColdFire Revision B instruction set, which adds a small number of new instructions to
improve performance and code density.
The OEP also implements two advanced performance features. It dynamically determines
the appropriate location of instruction execution (either in the address ALU or the execution
ALU) based on the pipeline state. The address compute engine, in conjunction with register
renaming resources, can be used to execute a number of heavily-used opcodes and forward
the results to subsequent instructions without any pipeline stalls. Additionally, the OEP
implements instruction folding techniques involving MOVE instructions so that two
instructions can be issued in a single machine cycle. The resulting microarchitecture
approaches the performance of a full superscalar implementation, but at a much lower
silicon cost.
1.3.1.3 MAC Module
The MAC unit provides signal processing capabilities for the MCF5407 in a variety of
applications including digital audio and servo control. Integrated as an execution unit in the
processor’s OEP, the MAC unit implements a three-stage arithmetic pipeline optimized for
16 x 16 multiplies. Both 16- and 32-bit input operands are supported by this design in
addition to a full set of extensions for signed and unsigned integers, plus signed, fixed-point
fractional input operands.
1.3.1.4 Integer Divide Module
Integrated into the OEP, the divide module performs operations using signed and unsigned
integers. The module supports word and longword divides producing quotients and/or
remainders.
1.3.2 Harvard Architecture
A Harvard memory architecture implements separate instruction and data buses to the
processor-local memories, removing conflicts between instruction fetches and operand
accesses.
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MCF5407 User’s Manual
ColdFire Module Description
1.3.2.1 16-Kbyte Instruction Cache/8-Kbyte Data Cache
The MCF5407 Harvard architecture includes a 16-Kbyte instruction cache and an 8-Kbyte
data cache. These four-way, set-associative caches provide pipelined, single-cycle access
on cached instructions and operands.
As with all ColdFire caches, the cache controllers implement a non-lockup, streaming
design. The use of processor-local memories decouples performance from external
memory speeds and increases available bandwidth for external devices or the on-chip
4-channel DMA.
Both caches implement line-fill buffers to optimize 16-byte line burst accesses.
Additionally, the data cache supports copyback, write-through, or cache-inhibited modes.
A 4-entry, 32-bit buffer is used for cache line push operations and can be configured for
deferred write buffering in write-through or cache-inhibited modes.
The INTOUCH instruction can be used to prefetch instructions that, when used with the
cache locking feature, cannot be displaced from the instruction cache by instruction cache
misses. This function may be desirable in systems where deterministic real-time
performance is critical.
1.3.2.2 Internal 2-Kbyte SRAMs
Two 2-Kbyte on-chip SRAM modules are also connected to the Harvard memory
architecture and provide pipelined, single-cycle access to memory regions mapped to these
devices. Each memory can be independently mapped to any 0-modulo-2K location in the
4-Gbyte address space and can be configured either for instruction or data accesses.
Time-critical functions can be mapped onto the instruction memory bus, while the system
stack or heavily-referenced data operands can be mapped onto the data bus.
1.3.3 DRAM Controller
The MCF5407 DRAM controller provides a direct interface for up to two blocks of DRAM.
The controller supports 8-, 16-, or 32-bit memory widths and can easily interface to PC-100
DIMMs. A unique addressing scheme allows for increases in system memory size without
rerouting address lines and rewiring boards. The controller operates in normal mode or in
page mode and supports SDRAMs and EDO DRAMs.
1.3.4 DMA Controller
The MCF5407 provides four fully programmable DMA channels for quick data transfer.
Dual- and single-address modes support bursting and cycle steal. Data transfers are 32 bits
long with packing and unpacking supported along with an auto-alignment option for
efficient block transfers. Automatic block transfers from on-chip serial UARTs are also
supported through the DMA channels.
Chapter 1. Overview
1-9
ColdFire Module Description
1.3.5 UART Modules
The MCF5407 contains two UARTs, which function independently. One UART has been
enhanced to provide synchronous operation and a CODEC interface for soft modem
support. Either UART can be clocked by the system bus clock, eliminating the need for an
external crystal. Each UART module interfaces directly to the CPU, as shown in Figure 1-2.
UART
Internal Channel
Control Logic
CTS
Serial
Communications
Channel
RTS
RxD
TxD
System Integration
Module (SIM)
Interrupt
Controller
Interrupt Control
Logic
Programmable
Clock
Generation
CLKIN
or
External clock (TIN)
Figure 1-2. UART Module Block Diagram
Each UART module consists of the following major functional areas:
•
•
•
•
Serial communication channel
16-bit divider for clock generation
Internal channel control logic
Interrupt control logic
UART1 is enhanced to provide a CODEC interface for soft modem support. UART1 can be
programmed to function like UART0 or in one of following modem modes:
•
•
•
An 8-bit CODEC interface
A 16-bit CODEC interface
An audio CODEC ’97 (AC97) digital interface controller
Each UART contains an programmable clock-rate generator. Data formats can be 5, 6, 7,
or 8 bits with even, odd, or no parity, and up to 2 stop bits in 1/16 increments. The UARTs
include the following transmit and receive FIFO buffers:
•
•
UART0 has a 4-byte FIFO receive buffer and a 2-byte FIFO transmit buffer.
In UART1, the Tx and Rx FIFOs can hold the following:
— 32 1-byte samples when programmed as a UART or as an 8-bit CODEC interface
— 16 2-byte samples when programmed as a 16-bit CODEC interface
— 16 20-bit samples when programmed as a Digital AC ’97 Controller
The UART modules also provide several error-detection and maskable-interrupt
capabilities. Modem support includes request-to-send (RTS) and clear-to-send (CTS) lines.
CLKIN provides the time base through a programmable prescaler. The UART time scale
can also be sourced from a timer input. Full-duplex, auto-echo loopback, local loopback,
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MCF5407 User’s Manual
ColdFire Module Description
and remote loopback modes allow testing of UART connections. The programmable
UARTs can interrupt the CPU on various normal or error-condition events.
1.3.6 Timer Module
The timer module includes two general-purpose timers, each of which contains a
free-running 16-bit timer for use in any of three modes. One mode captures the timer value
with an external event. Another mode triggers an external signal or interrupts the CPU when
the timer reaches a set value, while a third mode counts external events.
The timer unit has an 8-bit prescaler that allows programming of the clock input frequency,
which is derived from the system bus cycle or an external clock input pin (TIN). The
programmable timer-output pin generates either an active-low pulse or toggles the output.
1.3.7 I2C Module
The I2C interface is a two-wire, bidirectional serial bus used for quick data exchanges
between devices. The I2C minimizes the interconnection between devices in the end system
and is best suited for applications that need occasional bursts of rapid communication over
short distances among several devices. The I2C can operate in master, slave, or
multiple-master modes.
1.3.8 System Interface
The MCF5407 processor provides a direct interface to 8-, 16-, and 32-bit FLASH, SRAM,
ROM, and peripheral devices through the use of fully programmable chip selects and write
enables. Support for burst ROMs is also included. Through the on-chip PLL, users can
input a slower clock (25 to 54 MHz) that is internally multiplied to create the faster
processor clock (100 to 162 MHz).
1.3.8.1 External Bus Interface
The bus interface controller transfers information between the ColdFire core or DMA and
memory, peripherals, or other devices on the external bus. The external bus interface
provides up to 32 bits of address bus space, a 32-bit data bus, and all associated control
signals. This interface implements an extended synchronous protocol that supports bursting
operations.
Simple two-wire request/acknowledge bus arbitration between the MCF5407 processor
and another bus master, such as an external DMA device, is glueless with arbitration logic
internal to the MCF5407 processor. Multiple-master arbitration is also available with some
simple external arbitration logic.
1.3.8.2 Chip Selects
Eight fully programmable chip select outputs support the use of external memory and
peripheral circuits with user-defined wait-state insertion. These signals interface to 8-, 16-,
Chapter 1. Overview
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ColdFire Module Description
or 32-bit ports. The base address, access permissions, and internal bus transfer terminations
are programmable with configuration registers for each chip select. CS0 also provides
global chip select functionality of boot ROM upon reset for initializing the MCF5407.
1.3.8.3 16-Bit Parallel Port Interface
A 16-bit general-purpose programmable parallel port serves as either an input or an output
on a pin-by-pin basis.
1.3.8.4 Interrupt Controller
The interrupt controller provides user-programmable control of ten internal peripheral
interrupts and implements four external fixed interrupt-request pins. Each internal interrupt
can be programmed to any one of seven interrupt levels and four priority levels within each
of these levels. Additionally, the external interrupt request pins can be mapped to levels 1,
3, 5, and 7 or levels 2, 4, 6, and 7. Autovector capability is available for both internal and
external interrupts.
1.3.8.5 JTAG
To help with system diagnostics and manufacturing testing, the MCF5407 processor
includes dedicated user-accessible test logic that complies with the IEEE 1149.1a standard
for boundary-scan testability, often referred to as the Joint Test Action Group, or JTAG. For
more information, refer to the IEEE 1149.1a standard.
1.3.9 System Debug Interface
The ColdFire processor core debug interface is provided to support system debugging in
conjunction with low-cost debug and emulator development tools. Through a standard
debug interface, users can access real-time trace and debug information. This allows the
processor and system to be debugged at full speed without the need for costly in-circuit
emulators. The debug unit in the MCF5407 is a compatible upgrade to the MCF52xx and
MCF53xx debug modules with added breakpoint registers and support for I/O interrupt
request servicing while in emulator mode.
The on-chip breakpoint resources include a total of 13 programmable registers—two sets
of address registers (each with two 32-bit registers), two sets of data registers (each with a
32-bit data register plus a 32-bit data mask register), one 32-bit PC register plus a 32-bit PC
mask register and three additional 32-bit PC registers. These registers can be accessed
through the dedicated debug serial communication channel or from the processor’s
supervisor mode programming model. The breakpoint registers can be configured to
generate triggers by combining the address, data, and PC conditions in a variety of single
or dual-level definitions. The trigger event can be programmed to generate a processor halt
or initiate a debug interrupt exception.
The MCF5407’s new interrupt servicing options during emulator mode allow real-time
critical interrupt service routines to be serviced while processing a debug interrupt event,
thereby ensuring that the system continues to operate even during debugging.
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MCF5407 User’s Manual
Programming Model, Addressing Modes, and Instruction Set
To support program trace, the Version 4 debug module has combined the processor status
and debug data outputs into a single 8-bit bus (PSTDDATA[7:0]). This bus and the
PSTCLK output provide execution status, captured operand data, and branch target
addresses defining processor activity at one-half the CPU’s clock rate.
1.3.10 PLL Module
The MCF5407 PLL module is shown in Figure 1-3.
CLKIN (to on-chip peripherals)
BCLKO
PCLK (to core)
CLKIN
DIVIDE[2:0]
RSTI
Debug Module
÷2
PLL
RSTO
PSTCLK (= PCLK/2)
Figure 1-3. PLL Module
The PLL module’s three modes of operation are described as follows.
•
•
•
Reset mode—When RSTI is asserted, the PLL enters reset mode. At reset, the PLL
asserts RSTO from the MCF5407. The core:bus frequency ratio and other MCF5407
configuration information are sampled during reset.
Normal mode—In normal mode, the input frequency programmed at reset is
clock-multiplied to provide the processor clock (PCLK).
Reduced-power mode—In reduced-power mode, the PCLK is disabled by executing
a sequence that includes programming a control bit in the system configuration
register (SCR) and then executing the STOP instruction. Register contents are
retained in reduced-power mode, so the system can be reenabled quickly when an
unmasked interrupt or reset is detected.
1.4 Programming Model, Addressing Modes, and
Instruction Set
The ColdFire programming model has two privilege levels—supervisor and user. The S bit
in the status register (SR) indicates the privilege level. The processor identifies a logical
address that differentiates between supervisor and user modes by accessing either the
supervisor or user address space.
Chapter 1. Overview
1-13
Programming Model, Addressing Modes, and Instruction Set
•
•
1-14
User mode—When the processor is in user mode (SR[S] = 0), only a subset of
registers can be accessed, and privileged instructions cannot be executed. Typically,
most application processing occurs in user mode. User mode is usually entered by
executing a return from exception instruction (RTE, assuming the value of SR[S]
saved on the stack is 0) or a MOVE, SR instruction (assuming SR[S] is 0).
Supervisor mode—This mode protects system resources from uncontrolled access
by users. In supervisor mode, complete access is provided to all registers and the
entire ColdFire instruction set. Typically, system programmers use the supervisor
programming model to implement operating system functions and provide I/O
control. The supervisor programming model provides access to the same registers as
the user model, plus additional registers for configuring on-chip system resources,
as described in Section 1.4.3, “Supervisor Registers.”
Exceptions (including interrupts) are handled in supervisor mode.
MCF5407 User’s Manual
Programming Model, Addressing Modes, and Instruction Set
1.4.1 Programming Model
Figure 1-4 shows the MCF5407 programming model.
31
0
Data registers
A0
A1
A2
A3
A4
A5
A6
A7
PC
CCR
Address registers
MACSR
ACC
MASK
MAC status register
MAC accumulator
MAC mask register
SR
VBR
CACR
ACR0
ACR1
ACR2
ACR3
RAMBAR0
RAMBAR1
MBAR
Status register
Vector base register
Cache control register
Access control register 0 (data)
Access control register 1 (data)
Access control register 2 (instruction)
Access control register 3 (instruction)
RAM 0 base address register
RAM 1 base address register
Module base address register
0
User Registers
31
D0
D1
D2
D3
D4
D5
D6
D7
31
Stack pointer
Program counter
Condition code register
0
15
19
Supervisor Registers
31
(CCR)
Must be zeros
Figure 1-4. ColdFire MCF5407 Programming Model
1.4.2 User Registers
The user programming model is shown in Figure 1-4 and summarized in Table 1-1.
Table 1-1. User-Level Registers
Register
Description
Data registers
(D0–D7)
These 32-bit registers are for bit, byte, word, and longword operands. They can also be used as
index registers.
Address registers
(A0–A7)
These 32-bit registers serve as software stack pointers, index registers, or base address
registers. The base address registers can be used for word and longword operations. A7
functions as a hardware stack pointer during stacking for subroutine calls and exception handling.
Chapter 1. Overview
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Programming Model, Addressing Modes, and Instruction Set
Table 1-1. User-Level Registers (Continued)
Register
Description
Program counter
(PC)
Contains the address of the instruction currently being executed by the MCF5407 processor
Condition code
register (CCR)
The CCR is the lower byte of the SR. It contains indicator flags that reflect the result of a previous
operation and are used for conditional instruction execution.
MAC status
register (MACSR)
Defines the operating configuration of the MAC unit and contains indicator flags from the results
of MAC instructions.
Accumulator
(ACC)
General-purpose register used to accumulate the results of MAC operations
Mask register
(MASK)
General-purpose register provides an optional address mask for MAC instructions that fetch
operands from memory. It is useful in the implementation of circular queues in operand memory.
1.4.3 Supervisor Registers
Table 1-2 summarizes the MCF5407 supervisor-level registers.
Table 1-2. Supervisor-Level Registers
Register
Description
Status register (SR)
The upper byte of the SR provides interrupt information in addition to a variety of mode indicators
signaling the operating state of the ColdFire processor. The lower byte of the SR is the CCR, as
shown in Figure 1-4.
Vector base register
(VBR)
Defines the upper 12 bits of the base address of the exception vector table used during exception
processing. The low-order 20 bits are forced to zero, locating the vector table on 0-modulo-1
Mbyte address.
Cache configuration
register (CACR)
Defines the operating modes of the Version 4 cache memories. Control fields configuring the
instruction, data, and branch cache are provided by this register, along with the default attributes
for the 4-Gbyte address space.
Access control
registers (ACR0/1,
ACR2/3)
Define address ranges and attributes associated with various memory regions within the 4-Gbyte
address space. Each ACR defines the location of a given memory region and assigns attributes
such as write-protection and cache mode (copyback, write-through, cacheability). ACR0 and
ACR1 support data memory; ACR2 and ACR3 support instruction memory. Additionally, CACR
fields assign default attributes to the instruction and data memory spaces.
RAM base address
registers (RAMBAR0,
RAMBAR1)
Provide the logical base address for the two 2-Kbyte SRAM modules and define attributes and
access types allowed for the corresponding SRAM.
Module base address
register (MBAR)
Defines the logical base address for the memory-mapped space containing the control registers
for the on-chip peripherals.
1.4.4 Instruction Set
The Version 4 ColdFire core implements Revision B of the instruction set, which adds
opcodes to enhance support for byte- and word-sized operands and position-independent
code. The ColdFire instruction set supports high-level languages and is optimized for those
instructions most commonly generated by compilers in embedded applications. Table 2-8
provides an alphabetized listing of the ColdFire instruction set opcodes, supported
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MCF5407 User’s Manual
Programming Model, Addressing Modes, and Instruction Set
operation sizes, and assembler syntax. For two-operand instructions, the first operand is
generally the source operand and the second is the destination.
Because the ColdFire architecture provides an upgrade path for 68K customers, its
instruction set supports most of the common 68K opcodes. A majority of the instructions
are binary compatible or optimized 68K opcodes. This feature, when coupled with the code
conversion tools from third-party developers, generally minimizes software porting issues
for customers with 68K applications.
The following list summarizes new and enhanced instructions of Revision B ISA:
•
•
New instructions:
— INTOUCH loads blocks of instructions to be locked in the instruction cache.
— MOV3Q.L moves 3-bit immediate data to destination location.
— MVS.{B,W} sign-extends the source operand and moves it to destination
register.
— MVZ.{B,W} zero-fills the source operand and moves it to destination register.
— SATS.L updates bit 31 of destination register depending on CCR overflow bit.
— TAS.B tests and set byte operand being addressed.
Enhancements to existing Revision A instructions:
— Longword support for branch instructions (Bcc, BRA, BSR)
— Byte and word support for compare instructions (CMP, CMPI)
— Byte and longword support for MOVE.x where the source is of type #<data> and
the destination is of type d16(Ax); that is, move.b #<data>, d16(Ax)
Chapter 1. Overview
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Programming Model, Addressing Modes, and Instruction Set
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MCF5407 User’s Manual
Part I
MCF5407 Processor Core
Intended Audience
Part I is intended for system designers who need a general understanding of the
functionality supported by the MCF5407. It also describes the operation of the MCF5407
ColdFire core and its multiply/accumulate (MAC) execution unit. It describes the
programming and exception models, Harvard memory implementation, and debug module.
Contents
•
•
•
Chapter 2, “ColdFire Core,” provides an overview of the microprocessor core of the
MCF5407. The chapter begins with a description of enhancements from the V3
ColdFire core, and then fully describes the V4 programming model as it is
implemented on the MCF5407. It also includes a full description of exception
handling, data formats, an instruction set summary, and a table of instruction
timings.
Chapter 3, “Hardware Multiply/Accumulate (MAC) Unit,” describes the MCF5407
multiply/accumulate unit, which executes integer multiply, multiply-accumulate,
and miscellaneous register instructions. The MAC is integrated into the operand
execution pipeline (OEP).
Chapter 4, “Local Memory.” This chapter describes the MCF5407 implementation
of the ColdFire V4 local memory specification. It consists of the two following
major sections.
— Section 4.2, “SRAM Overview,” describes the MCF5407 on-chip static RAM
(SRAM) implementation. It covers general operations, configuration, and
initialization. It also provides information and examples showing how to
minimize power consumption when using the SRAM.
— Section 4.7, “Cache Overview,” describes the MCF5407 cache implementation,
including organization, configuration, and coherency. It describes cache
operations and how the cache interacts with other memory structures.
Part I. MCF5407 Processor Core
I-xix
•
Chapter 5, “Debug Support,” describes the Revision C enhanced hardware debug
support in the MCF5407. This revision of the ColdFire debug architecture
encompasses earlier revisions.
Suggested Reading
The following literature may be helpful with respect to the topics in Part I:
•
•
ColdFire Programmers Reference Manual, R1.0 (MCF5200PRM/AD)
Using Microprocessors and Microcomputers: The Motorola Family, William C.
Wray, Ross Bannatyne, Joseph D. Greenfield
Acronyms and Abbreviations
Table I-i contains acronyms and abbreviations are used in Part I.
Table I-i. Acronyms and Abbreviated Terms
Term
Meaning
ADC
Analog-to-digital conversion
ALU
Arithmetic logic unit
BDM
Background debug mode
BIST
Built-in self test
BSDL
Boundary-scan description language
CODEC
Code/decode
DAC
Digital-to-analog conversion
DMA
Direct memory access
DSP
Digital signal processing
EA
Effective address
EDO
Extended data output (DRAM)
FIFO
First-in, first-out
GPIO
General-purpose I/O
I2C
Inter-integrated circuit
IEEE
Institute for Electrical and Electronics Engineers
IFP
Instruction fetch pipeline
IPL
Interrupt priority level
JEDEC
Joint Electron Device Engineering Council
JTAG
Joint Test Action Group
LIFO
Last-in, first-out
I-xx
MCF5407 User’s Manual
Table I-i. Acronyms and Abbreviated Terms (Continued)
Term
Meaning
LRU
Least recently used
LSB
Least-significant byte
lsb
Least-significant bit
MAC
Multiple accumulate unit
MBAR
Memory base address register
MSB
Most-significant byte
msb
Most-significant bit
Mux
Multiplex
NOP
No operation
OEP
Operand execution pipeline
PC
Program counter
PCLK
Processor clock
PLL
Phase-locked loop
PLRU
Pseudo least recently used
POR
Power-on reset
PQFP
Plastic quad flat pack
RISC
Reduced instruction set computing
Rx
Receive
SIM
System integration module
SOF
Start of frame
TAP
Test access port
TTL
Transistor-to-transistor logic
Tx
Transmit
UART
Universal asynchronous/synchronous receiver transmitter
Part I. MCF5407 Processor Core
I-xxi
I-xxii
MCF5407 User’s Manual
Chapter 2
ColdFire Core
This chapter provides an overview of the microprocessor core of the MCF5407. The
chapter begins with a description of enhancements from the Version 3 (V3) ColdFire core,
and then fully describes the V4 programming model as it is implemented on the MCF5407.
It also includes a full description of exception handling, data formats, an instruction set
summary, and a table of instruction timings.
2.1 Features and Enhancements
The MCF5407 is the first standard product to contain a Version 4 ColdFire microprocessor
core. To create this next-generation, high-performance core, many advanced
microarchitectural techniques were implemented. Most notable are a Harvard memory
architecture, branch cache acceleration logic, and limited superscalar dual-instruction issue
capabilities, which together provide 233 (Dhrystone 2.1) MIPS performance at 162 MHz.
The MCF5407 core design emphasizes performance and backward compatibility, and
represents the next step on the ColdFire performance roadmap.
The following list summarizes MCF5407 features:
•
•
•
•
•
•
•
•
•
•
Variable-length RISC, clock-multiplied Version 4 microprocessor core
Revision B of the ColdFire instruction set architecture provides new instructions to
improve performance and code density
Two independent, decoupled pipelines—four-stage instruction fetch pipeline (IFP)
and five-stage operand execution pipeline (OEP) for increased performance of
conditional branch instructions
Ten-instruction FIFO buffer provides decoupling between the pipelines
Limited superscalar design approaches dual-issue performance
Sophisticated two-level branch acceleration mechanism with a branch cache plus a
prediction table for increased performance of conditional Bcc instructions
32-bit internal address bus supporting 4 Gbytes of linear address space
32-bit data bus
16 user-accessible, 32-bit-wide, general-purpose registers
Supervisor/user modes for system protection
Chapter 2. ColdFire Core
2-1
Features and Enhancements
•
•
Vector base register to relocate exception-vector table
Optimized for high-level language constructs
2.1.1 Clock-Multiplied Microprocessor Core
The MCF5407 incorporates a clock-multiplying phase-locked loop (PLL). Increasing the
internal speed of the core also allows higher performance while providing the system
designer with an easy-to-use lower speed system interface.
The frequency of the processor complex is an integer multiple of the external bus speed.
Chapter 20, “Electrical Specifications,” lists the supported clock ratios.
The processor, instruction and data caches, integrated SRAMs, and misalignment module
operate at the higher speed clock (PCLK); other system integrated modules operate at the
speed of the input clock (CLKIN). When combined with the enhanced pipeline structure of
the Version 4 ColdFire core, the processor and its local memories provide a high level of
performance for today’s demanding embedded applications.
PCLK can be disabled to minimize dissipation when a low-power mode is entered. This is
described in Section 7.2.3, “Reduced-Power Mode.”
2.1.2 Enhanced Pipelines
The IFP prefetches instructions. The OEP decodes instructions, fetches required operands,
then executes the specified function. The two independent, decoupled pipeline structures
maximize performance while minimizing core size. Pipeline stages are shown in Figure 2-1
and are summarized as follows:
•
•
2-2
Four-stage IFP (plus optional instruction buffer stage)
— Instruction address generation (IAG) calculates the next prefetch address.
— Instruction fetch cycle 1 (IC1) initiates prefetch on the processor’s local
instruction bus.
— Instruction fetch cycle 2 (IC2) completes prefetch on the processor’s instruction
local bus.
— Instruction early decode (IED) generates time-critical decode signals needed for
the OEP.
— Instruction buffer (IB) optional stage uses FIFO queue to minimize effects of
fetch latency.
Five-stage OEP with two optional processor bus write cycles.
— Decode stage (DS/secDS) decodes and selects for two sequential instructions.
— Operand address generation (OAG) generates the address for the data operand.
— Operand fetch cycle 1 and 2 (OC1 and OC2) fetch data operands.
— Execute (EX) performs prescribed operations on previously fetched data
operands.
MCF5407 User’s Manual
Features and Enhancements
— Write data available (DA) makes data available for operand write operations
only.
— Store data (ST) updates memory element for operand write operations only.
Instruction Fetch
Pipeline
IAG
Branch
Cache
Instruction
Memory
IC1
IC2
Branch
Accel. IED
IB
Internal
Bus
Operand Execution
Pipeline
DS
secDS
OAG
Data
(Operand)
Memory
OC1
OC2
Misalignment
Module
EX
DA
Debug
DSCLK DSI
DSO
DDATA
PSTDDATA PSTCLK
Figure 2-1. ColdFire Enhanced Pipeline
Chapter 2. ColdFire Core
2-3
Features and Enhancements
2.1.2.1 Instruction Fetch Pipeline (IFP)
Because the fetch and execution pipelines are decoupled by a ten-instruction FIFO buffer,
the IFP can prefetch instructions before the OEP needs them, minimizing stalls.
2.1.2.1.1 Branch Acceleration
To maximize the performance of conditional branch instructions, the IFP implements a
sophisticated two-level acceleration mechanism. The first level is an 8-entry, direct-mapped
branch cache with 2 bits for indicating four prediction states (strongly/weakly
taken/not-taken) for each entry. The branch cache also provides the association between
instruction addresses and the corresponding target address. In the event of a branch cache
hit, if the branch is predicted as taken, the branch cache sources the target address from the
IC1 stage back into the IAG to redirect the prefetch stream to the new location.
The branch cache implements instruction folding, so conditional branch instructions
correctly predicted as taken can execute in zero cycles. For conditional branches with no
information in the branch cache, a second-level, direct-mapped prediction table is accessed.
Each of its 128 entries uses the same 2-bit prediction mechanism as the branch cache.
If a branch is predicted as taken, branch acceleration logic in the IED stage generates the
target address. Other change-of-flow instructions, including unconditional branches,
jumps, and subroutine calls, use a similar mechanism where the IFP calculates the target
address. The performance of subroutine return instruction (RTS) is improved through the
use of a four-entry, LIFO hardware return stack. In all cases, these mechanisms allow the
IFP to redirect the fetch stream down the predicted path well ahead of instruction execution.
2.1.2.2 Operand Execution Pipeline (OEP)
The two instruction registers in the decode stage (DS) of the OEP are loaded from the FIFO
instruction buffer or are bypassed directly from the instruction early decode (IED). The
OEP consists of two, traditional two-stage RISC compute engines with a dual-ported
register file access feeding an arithmetic logic unit (ALU).
The compute engine at the top of the OEP (the address ALU) is used typically for operand
address calculations; the execution ALU at the bottom is used for instruction execution. The
resulting structure provides 4 Gbytes/S operand bandwidth (at 162 MHz) to the two
compute engines and supports single-cycle execution speeds for most instructions,
including all load and store operations and most embedded-load operations. The V4 OEP
supports the ColdFire Revision B instruction set, which adds a few new instructions to
improve performance and code density.
The OEP also implements the following advanced performance features:
•
•
2-4
Stalls are minimized by dynamically basing the choice between the address ALU or
execution ALU for instruction execution on the pipeline state.
The address ALU and register renaming resources together can execute heavily used
opcodes and forward results to subsequent instructions with no pipeline stalls.
MCF5407 User’s Manual
Features and Enhancements
•
Instruction folding involving MOVE instructions allows two instructions to be
issued in one cycle. The resulting microarchitecture approaches full superscalar
performance at a much lower silicon cost.
2.1.2.2.1 Illegal Opcode Handling
To aid in conversion from M68000 code, every 16-bit operation word is decoded to ensure
that each instruction is valid. If the processor attempts execution of an illegal or
unsupported instruction, an illegal instruction exception (vector 4) is taken.
2.1.2.2.2 Hardware Multiply/Accumulate (MAC) Unit
The MAC is an optional unit in Version 4 that provides hardware support for a limited set
of digital signal processing (DSP) operations used in embedded code, while supporting the
integer multiply instructions in the ColdFire microprocessor family. The MAC features a
three-stage execution pipeline, optimized for 16 x 16 multiplies. It is tightly coupled to the
OEP, which can issue a 16 x 16 multiply with a 32-bit accumulation plus fetch a 32-bit
operand in a single cycle. A 32 x 32 multiply with a 32-bit accumulation requires three
cycles before the next instruction can be issued.
Figure 2-2 shows basic functionality of the MAC. A full set of instructions are provided for
signed and unsigned integers plus signed, fixed-point fractional input operands.
Operand Y
Operand X
X
Shift 0,1,-1
+/-
Accumulator
Figure 2-2. ColdFire Multiply-Accumulate Functionality Diagram
The MAC provides functionality in the following three related areas, which are described
in detail in Chapter 3, “Hardware Multiply/Accumulate (MAC) Unit.”
•
•
•
Signed and unsigned integer multiplies
Multiply-accumulate operations with signed and unsigned fractional operands
Miscellaneous register operations
Chapter 2. ColdFire Core
2-5
Features and Enhancements
2.1.2.2.3 Hardware Divide Unit
The hardware divide unit performs the following integer division operations:
•
•
•
32-bit operand/16-bit operand producing a 16-bit quotient and a 16-bit remainder
32-bit operand/32-bit operand producing a 32-bit quotient
32-bit operand/32-bit operand producing a 32-bit remainder
2.1.2.3 Harvard Memory Architecture
A Harvard memory architecture supports the increased bandwidth requirements of the V4
processor pipelines by providing separate configuration, access control, and protection
resources for data (operand) and instruction memory. The MCF5407 has separate
instruction and data buses to processor-local memories, eliminating conflicts between
instruction fetches and operand accesses.
2.1.3 Debug Module Enhancements
The ColdFire processor core debug interface supports system integration in conjunction
with low-cost development tools. Real-time trace and debug information can be accessed
through a standard interface, which allows the processor and system to be debugged at full
speed without costly in-circuit emulators. The MCF5407 debug unit is a compatible
upgrade to MCF52xx and MCF53xx debug modules with added breakpoint registers and
support for I/O interrupt request servicing while in emulator mode.
On-chip breakpoint resources include the following:
•
Configuration/status register (CSR)
•
Background debug mode (BDM) address attributes register (BAAR)
•
Bus attributes and mask registers (AATR and AATR1)
•
Breakpoint registers. These can be used to define triggers combining address, data,
and PC conditions in single- or dual-level definitions. They include the following:
•
— Four PC breakpoint registers (PBR, PBR1, PBR2, and PBR3)
— PC breakpoint mask register (PBMR)
— Two pairs of data operand address breakpoint registers (ABHR/ABLR and
ABLR1/ABHR1)
— Data breakpoint registers (DBR and DBR1)
— Data breakpoint mask registers (DBMR and DBMR1)
Trigger event registers. These can be programmed to generate a processor halt or
initiate a debug interrupt exception. They include the following:
— Trigger definition register (TDR)
— Extended trigger definition register (XTDR)
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MCF5407 User’s Manual
Programming Model
These registers can be accessed through the dedicated debug serial communication channel,
or from the processor’s supervisor programming model, using the WDEBUG instruction.
The MCF5407’s new interrupt servicing options during emulator mode allow real-time
critical interrupt service routines to be serviced while processing a debug interrupt event,
thereby ensuring that the system continues to operate even during debugging.
To support program trace, the Version 4 debug module combines the processor status and
debug data outputs into a single 8-bit bus, PSTDDATA[7:0]. This bus along with the
PSTCLK output provide execution status, captured operand data, and branch target
addresses defining processor activity at one-half the CPU’s clock rate.
The enhancements of the Revision C debug specification are fully backward-compatible
with the A and B revisions. For more information, see Chapter 5, “Debug Support.”
2.2 Programming Model
The MCF5407 programming model consists of three instruction and register groups—user,
MAC (also user-mode), and supervisor, shown in Figure 2-2. User mode programs are
restricted to user and MAC instructions and programming models. Supervisor-mode
system software can reference all user-mode and MAC instructions and registers and
additional supervisor instructions and control registers. The user or supervisor
programming model is selected based on SR[S]. The following sections describe the
registers in the user, MAC, and supervisor programming models.
Chapter 2. ColdFire Core
2-7
Programming Model
31
0
Data registers
A0
A1
A2
A3
A4
A5
A6
A7
PC
CCR
Address registers
MACSR
ACC
MASK
MAC status register
MAC accumulator
MAC mask register
SR
VBR
CACR
ACR0
ACR1
ACR2
ACR3
RAMBAR0
RAMBAR1
MBAR
Status register
Vector base register
Cache control register
Access control register 0 (data)
Access control register 1 (data)
Access control register 2 (instruction)
Access control register 3 (instruction)
RAM 0 base address register
RAM 1 base address register
Module base address register
0
User Registers
31
D0
D1
D2
D3
D4
D5
D6
D7
31
Stack pointer
Program counter
Condition code register
0
15
Supervisor Registers
31
19
(CCR)
Must be zeros
Figure 2-3. ColdFire Programming Model
2.2.1 User Programming Model
As Figure 2-3 shows, the user programming model consists of the following registers:
•
•
•
16 general-purpose 32-bit registers, D0–D7 and A0–A7
32-bit program counter
8-bit condition code register
2.2.1.1 Data Registers (D0–D7)
Registers D0–D7 are used as data registers for bit, byte (8-bit), word (16-bit), and longword
(32-bit) operations. They may also be used as index registers.
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MCF5407 User’s Manual
Programming Model
2.2.1.2 Address Registers (A0–A6)
The address registers (A0–A6) can be used as software stack pointers, index registers, or
base address registers and may be used for word and longword operations.
2.2.1.3 Stack Pointer (A7, SP)
The processor core supports a single hardware stack pointer (A7) used during stacking for
subroutine calls, returns, and exception handling. The stack pointer is implicitly referenced
by certain operations and can be explicitly referenced by any instruction specifying an
address register. The initial value of A7 is loaded from the reset exception vector, address
0x0000. The same register is used for user and supervisor modes, and may be used for word
and longword operations.
A subroutine call saves the program counter (PC) on the stack and the return restores the
PC from the stack. The PC and the status register (SR) are saved on the stack during
exception and interrupt processing. The return from exception instruction restores SR and
PC values from the stack.
2.2.1.4 Program Counter (PC)
The PC holds the address of the executing instruction. For sequential instructions, the
processor automatically increments PC. When program flow changes, the PC is updated
with the target instruction. For some instructions, the PC specifies the base address for
PC-relative operand addressing modes.
2.2.1.5 Condition Code Register (CCR)
The CCR, Figure 2-4, occupies SR[7–0], as shown in Figure 2-3. CCR[4–0] are indicator
flags based on results generated by arithmetic operations.
7
Field
4
3
2
1
0
—
6
5
X
N
Z
V
C
R
R/W
R/W
R/W
R/W
Reset
R/W
Undefined
R/W
Figure 2-4. Condition Code Register (CCR)
Table 2-1 describes the CCR fields.
Chapter 2. ColdFire Core
2-9
Programming Model
Table 2-1. CCR Field Descriptions
Bits
Name
Description
7–5
—
Reserved, should be cleared.
4
X
Extend condition code bit. Assigned the value of the carry bit for arithmetic operations; otherwise not
affected or set to a specified result. Also used as an input operand for multiple-precision arithmetic.
3
N
Negative condition code bit. Set if the msb of the result is set; otherwise cleared.
2
Z
Zero condition code bit. Set if the result equals zero; otherwise cleared.
1
V
Overflow condition code bit. Set if an arithmetic overflow occurs, implying that the result cannot be
represented in the operand size; otherwise cleared.
0
C
Carry condition code bit. Set if a carry-out of the data operand msb occurs for an addition or if a
borrow occurs in a subtraction; otherwise cleared.
2.2.1.6 MAC Programming Model
Figure 2-3 shows the registers in the MAC portion of the user programming model. These
registers are described as follows:
•
•
•
Accumulator (ACC)—This 32-bit, read/write, general-purpose register is used to
accumulate the results of MAC operations.
Mask register (MASK)—This 16-bit general-purpose register provides an optional
address mask for MAC instructions that fetch operands from memory. It is useful in
the implementation of circular queues in operand memory.
MAC status register (MACSR)—This 8-bit register defines configuration of the
MAC unit and contains indicator flags affected by MAC instructions. Unless noted
otherwise, MACSR indicator flag settings are based on the final result, that is, the
result of the final operation involving the product and accumulator.
2.2.2 Supervisor Programming Model
The MCF5407 supervisor programming model is shown in Figure 2-3. Typically, system
programmers use the supervisor programming model to implement operating system
functions and provide memory and I/O control. The supervisor programming model
provides access to the user registers and additional supervisor registers, which include the
upper byte of the status register (SR), the vector base register (VBR), and registers for
configuring attributes of the address space connected to the Version 4 processor core. Most
supervisor-level registers are accessed by using the MOVEC instruction with the control
register definitions in Table 2-2.
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MCF5407 User’s Manual
Programming Model
Table 2-2. MOVEC Register Map
Rc[11–0]
Register Definition
0x002
Cache control register (CACR)
0x004
Access control register 0 (ACR0)
0x005
Access control register 1 (ACR1)
0x006
Access control register 2 (ACR2)
0x007
Access control register 3 (ACR3)
0x801
Vector base register (VBR)
0xC04
RAM base address register 0 (RAMBAR0)
0xC05
RAM base address register 1 (RAMBAR1)
0xC0F
Module base address register (MBAR)
2.2.2.1 Status Register (SR)
The SR stores the processor status, the interrupt priority mask, and other control bits.
Supervisor software can read or write the entire SR; user software can read or write only
SR[7–0], described in Section 2.2.1.5, “Condition Code Register (CCR).” The control bits
indicate processor states—trace mode (T), supervisor or user mode (S), and master or
interrupt state (M). SR is set to 0x27xx after reset.
15
14
13
12
11
10
9
8
7
6
System byte
5
4
3
2
1
0
Condition code register (CCR)
Field
T
—
S
M
—
I
—
X
N
Z
V
C
Reset
0
0
1
0
0
111
000
—
—
—
—
—
R
R/W
R/W
R
R/W
R
R/W
R/W
R/W
R/W
R/W
R/W R/W
Figure 2-5. Status Register (SR)
Table 2-3 describes SR fields.
Table 2-3. Status Field Descriptions
Bits
Name
Description
15
T
Trace enable. When T is set, the processor performs a trace exception after every instruction.
13
S
Supervisor/user state. Indicates whether the processor is in supervisor or user mode
0 User mode
1 Supervisor mode
12
M
Master/interrupt state. Cleared by an interrupt exception. It can be set by software during execution
of the RTE or move to SR instructions so the OS can emulate an interrupt stack pointer.
10–8
I
Interrupt priority mask. Defines the current interrupt priority. Interrupt requests are inhibited for all
priority levels less than or equal to the current priority, except the edge-sensitive level-7 request,
which cannot be masked.
7–0
CCR
Condition code register. See Table 2-1.
Chapter 2. ColdFire Core
2-11
Programming Model
2.2.2.2 Vector Base Register (VBR)
The VBR holds the base address of the exception vector table in memory. The displacement
of an exception vector is added to the value in this register to access the vector table.
VBR[19–0] are not implemented and are assumed to be zero, forcing the vector table to be
aligned on a 0-modulo-1-Mbyte boundary.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
Field
Reset
Exception vector table base address
9
8
7
6
5
4
3
2
1
0
—
0000_0000_0000_0000_0000_0000_0000_0000
R/W Written from a BDM serial command or from the CPU using the MOVEC instruction. VBR can be read from
the debug module only. The upper 12 bits are returned, the low-order 20 bits are undefined.
Rc[11–0]
0x801
Figure 2-6. Vector Base Register (VBR)
2.2.2.3 Cache Control Register (CACR)
The CACR controls operation of both the instruction and data cache memory. It includes
bits for enabling, freezing, and invalidating cache contents. It also includes bits for defining
the default cache mode and write-protect fields. See Section 4.10.1, “Cache Control
Register (CACR).”
2.2.2.4 Access Control Registers (ACR0–ACR3)
The access control registers (ACR0–ACR3) define attributes for four user-defined memory
regions. ACR0 and ACR1 control data memory space and ACR2 and ACR3 control
instruction memory space. Attributes include definition of cache mode, write protect and
buffer write enables. See Section 4.10.2, “Access Control Registers (ACR0–ACR3).”
2.2.2.5 RAM Base Address Registers (RAMBAR0 and RAMBAR1)
The RAMBAR registers determine the base address location of the internal SRAM
modules and indicate the types of references mapped to each. Each RAMBAR includes a
base address, write-protect bit, address space mask bits, and an enable. The RAM base
address must be aligned on a 0-module-2-Kbyte boundary. See Section 4.4.1, “SRAM Base
Address Registers (RAMBAR0/RAMBAR1).”
2.2.2.6 Module Base Address Register (MBAR)
The module base address register (MBAR) defines the logical base address for the
memory-mapped space containing the control registers for the on-chip peripherals. See
Section 6.2.2, “Module Base Address Register (MBAR).”
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MCF5407 User’s Manual
Integer Data Formats
2.3 Integer Data Formats
Table 2-4 lists the integer operand data formats. Integer operands can reside in registers,
memory, or instructions. The operand size for each instruction is either explicitly encoded
in the instruction or implicitly defined by the instruction operation.
Table 2-4. Integer Data Formats
Operand Data Format
Size
Bit
1 bit
Byte integer
8 bits
Word integer
16 bits
Longword integer
32 bits
2.4 Organization of Data in Registers
The following sections describe data organization within the data, address, and control
registers.
2.4.1 Organization of Integer Data Formats in Registers
Figure 2-7 shows the integer format for data registers. Each integer data register is 32 bits
wide. Byte and word operands occupy the lower 8- and 16-bit portions of integer data
registers, respectively. Longword operands occupy the entire 32 bits of integer data
registers. A data register that is either a source or destination operand only uses or changes
the appropriate lower 8 or 16 bits in byte or word operations, respectively. The remaining
high-order portion does not change. The least significant bit (lsb) of all integer sizes is zero,
the most-significant bit (msb) of a longword integer is 31, the msb of a word integer is 15,
and the msb of a byte integer is 7.
31
30
1
msb
31
7
Not used
31
msb
Bit (0 ≤ bit number ≤ 31)
0
msb Low order byte
lsb
Lower order word
lsb
15
Not used
Byte (8 bits)
0
31
msb
0
lsb
Word (16 bits)
0
Longword
lsb
Longword (32 bits)
Figure 2-7. Organization of Integer Data Formats in Data Registers
The instruction set encodings do not allow the use of address registers for byte-sized
operands. When an address register is a source operand, either the low-order word or the
entire longword operand is used, depending on the operation size. Word-length source
Chapter 2. ColdFire Core
2-13
Organization of Data in Registers
operands are sign-extended to 32 bits and then used in the operation with anaddress register
destination. When an address register is a destination, the entire register is affected,
regardless of the operation size. Figure 2-8 shows integer formats for address registers.
31
16
15
0
Sign-Extended
16-Bit Address Operand
31
0
Full 32-Bit Address Operand
Figure 2-8. Organization of Integer Data Formats in Address Registers
The size of control registers varies according to function. Some have undefined bits
reserved for future definition by Motorola. Those particular bits read as zeros and must be
written as zeros for future compatibility.
All operations to the SR and CCR are word-size operations. For all CCR operations, the
upper byte is read as all zeros and is ignored when written, regardless of privilege mode.
2.4.2 Organization of Integer Data Formats in Memory
All ColdFire processors use a big-endian addressing scheme. The byte-addressable
organization of memory allows lower addresses to correspond to higher order bytes. The
address N of a longword data item corresponds to the address of the high-order word. The
lower order word is located at address N + 2. The address N of a word data item corresponds
to the address of the high-order byte. The lower order byte is located at address N + 1. This
organization is shown in Figure 2-9.
31
23
15
7
0
Longword 0x0000_0000
Word 0x0000_0000
Byte 0x0000_0000
Word 0x0000_0002
Byte 0x0000_0001
Byte 0x0000_0002
Byte 0x0000_0003
Longword 0x0000_0004
Word 0x0000_0004
Byte 0x0000_0004
Word 0x0000_0006
Byte 0x0000_0005
Byte 0x0000_0006
Byte 0x0000_0007
.
.
.
Longword 0xFFFF_FFFC
Word 0xFFFF_FFFC
Byte 0xFFFF_FFFC
Word 0xFFFF_FFFE
Byte 0xFFFF_FFFD
Byte 0xFFFF_FFFE
Byte 0xFFFF_FFFF
Figure 2-9. Memory Operand Addressing
2-14
MCF5407 User’s Manual
Addressing Mode Summary
2.5 Addressing Mode Summary
Addressing modes are categorized by how they are used. Data addressing modes refer to
data operands. Memory addressing modes refer to memory operands. Alterable addressing
modes refer to alterable (writable) data operands. Control addressing modes refer to
memory operands without an associated size.
These categories sometimes combine to form more restrictive categories. Two combined
classifications are alterable memory (both alterable and memory) and data alterable (both
alterable and data). Twelve of the most commonly used effective addressing modes from
the M68000 Family are available on ColdFire microprocessors. Table 2-5 summarizes
these modes and their categories.
Table 2-5. ColdFire Effective Addressing Modes
Addressing Modes
Mode
Field
Reg.
Field
Dn
An
000
001
(An)
(An)+
–(An)
(d16, An)
Syntax
Category
Data
Memory
Control
Alterable
reg. no.
reg. no.
X
—
—
—
—
—
X
X
010
011
100
101
reg. no.
reg. no.
reg. no.
reg. no.
X
X
X
X
X
X
X
X
X
—
—
X
X
X
X
X
(d8, An,
Xi*SF)
110
reg. no.
X
X
X
X
Program counter indirect
with displacement
(d16, PC)
111
010
X
X
X
—
Program counter indirect
with scaled index
8-bit displacement
(d8, PC,
Xi*SF)
111
011
X
X
X
—
Absolute data addressing
Short
Long
(xxx).W
(xxx).L
111
111
000
001
X
X
X
X
X
X
—
—
Immediate
#<xxx>
111
100
X
X
—
—
Register direct
Data
Address
Register indirect
Address
Address with
Postincrement
Address with
Predecrement
Address with
Displacement
Address register indirect with
scaled index
8-bit displacement
2.6 Instruction Set Summary
The ColdFire instruction set is a simplified version of the M68000 instruction set. The
removed instructions include BCD, bit field, logical rotate, decrement and branch, and
integer multiply with a 64-bit result. Nine new MAC instructions have been added.
Table 2-6 lists notational conventions used throughout this manual.
Chapter 2. ColdFire Core
2-15
Instruction Set Summary
Table 2-6. Notational Conventions
Instruction
Operand Syntax
Opcode Wildcard
cc
Logical condition (example: NE for not equal)
Register Specifications
An
Ay,Ax
Any address register n (example: A3 is address register 3)
Source and destination address registers, respectively
Dn
Any data register n (example: D5 is data register 5)
Dy,Dx
Source and destination data registers, respectively
Rc
Any control register (example VBR is the vector base register)
Rm
MAC registers (ACC, MAC, MASK)
Rn
Any address or data register
Rw
Destination register w (used for MAC instructions only)
Ry,Rx
Xi
Any source and destination registers, respectively
index register i (can be an address or data register: Ai, Di)
Register Names
ACC
MAC accumulator register
CCR
Condition code register (lower byte of SR)
MACSR
MAC status register
MASK
MAC mask register
PC
Program counter
SR
Status register
Port Name
PSTDDATA
Processor status/debug data port
Miscellaneous Operands
#<data>
<ea>
<ea>y,<ea>x
<label>
<list>
Source and destination effective addresses, respectively
Assembly language program label
List of registers for MOVEM instruction (example: D3–D0)
<shift>
Shift operation: shift left (<<), shift right (>>)
<size>
Operand data size: byte (B), word (W), longword (L)
bc
Both instruction and data caches
dc
Data cache
ic
Instruction cache
# <vector>
<>
2-16
Immediate data following the 16-bit operation word of the instruction
Effective address
Identifies the 4-bit vector number for trap instructions
identifies an indirect data address referencing memory
MCF5407 User’s Manual
Instruction Set Summary
Table 2-6. Notational Conventions (Continued)
Instruction
<xxx>
Operand Syntax
identifies an absolute address referencing memory
dn
Signal displacement value, n bits wide (example: d16 is a 16-bit displacement)
SF
Scale factor (x1, x2, x4 for indexed addressing mode, <<1n>> for MAC operations)
Operations
+
Arithmetic addition or postincrement indicator
–
Arithmetic subtraction or predecrement indicator
x
Arithmetic multiplication
/
Arithmetic division
~
Invert; operand is logically complemented
&
Logical AND
|
Logical OR
^
Logical exclusive OR
<<
Shift left (example: D0 << 3 is shift D0 left 3 bits)
>>
Shift right (example: D0 >> 3 is shift D0 right 3 bits)
→
Source operand is moved to destination operand
←→
Two operands are exchanged
sign-extended
All bits of the upper portion are made equal to the high-order bit of the lower portion
If <condition>
then
<operations>
else
<operations>
Test the condition. If the condition is true, the operations in the then clause are performed. If the
condition is false and the optional else clause is present, the operations in the else clause are
performed. If the condition is false and the else clause is omitted, the instruction performs no
operation. Refer to the Bcc instruction description as an example.
Subfields and Qualifiers
{}
Optional operation
()
Identifies an indirect address
dn
Displacement value, n-bits wide (example: d16 is a 16-bit displacement)
Address
Calculated effective address (pointer)
Bit
Bit selection (example: Bit 3 of D0)
lsb
Least significant bit (example: lsb of D0)
LSB
Least significant byte
LSW
Least significant word
msb
Most significant bit
MSB
Most significant byte
MSW
Most significant word
Chapter 2. ColdFire Core
2-17
Instruction Set Summary
Table 2-6. Notational Conventions (Continued)
Instruction
Operand Syntax
Condition Code Register Bit Names
C
Carry
N
Negative
V
Overflow
X
Extend
Z
Zero
2.6.1 Additions to the Instruction Set Architecture
The original ColdFire instruction set architecture (ISA) was derived from the M68000
Family opcodes based on extensive analysis of embedded application code. After the initial
ColdFire compilers were created, developers identified ISA additions that would enhance
both code density and overall performance. Additionally, as users implemented
ColdFire-based designs into a wide range of embedded systems, they identified frequently
used instruction sequences that could be improved by the creation of new instructions. This
observation was especially prevalent in development environments that made use of
substantial amounts of assembly language code.
The original ISA definition minimized the support for instructions referencing byte and
word operands. Full support for the MOVE.B and MOVEC.W instructions was provided,
but clr (clear) and tst (test) are the only other opcodes supporting these data types. Based
on input from compiler writers and system users, a set of instruction enhancements was
proposed that address the two following areas:
•
•
Enhanced support for byte and word-sized operands through new move operations
Enhanced support for position-independent code
The following list summarizes new and enhanced instructions of Revision_B ISA:
•
2-18
New instructions:
— INTOUCH loads blocks of instructions to be locked in the instruction cache
— MOV3Q.L moves 3-bit immediate data to the destination location
— MVS.{B,W} sign-extends the source operand and moves it to the destination
register
— MVZ.{B,W} zero-fills the source operand and moves it to the destination
register
— SATS.L updates the destination register depending on CCR[V] and bit 31 of the
register
— TAS.B performs an indivisible read-modify-write cycle to test and set the
addressed memory byte.
MCF5407 User’s Manual
Instruction Set Summary
•
Enhancements to existing Revision_A instructions:
— Longword support for branch instructions (Bcc, BRA, BSR)
— Byte and word support for compare instructions (CMP, CMPI)
— Word support for the compare address register instruction (CMPA)
— Byte and longword support for MOVE.x ,where the source is immediate data and
the destination is specified by d16(Ax); that is, MOVE.{B,W} #<data>, d16(Ax)
Table 2-7 shows the syntax for the new and enhanced instructions, which are fully
described in Section 2.9, “ColdFire Instruction Set Architecture Enhancements.”
Table 2-7. ColdFire ISA_B Extension Summary
Mnemonic1
Instruction
Destination
68K
Branch Always
bra.l
<label>
Yes
Branch Conditionally
bcc.l
<label>
Yes
Branch to Subroutine
bsr.l
<label>
Yes
Compare
Compare Address
Compare Immediate
Source
cmp.{b,w,l}
<ea>y
Dx
Yes
cmpa.w
<ea>y
Ax
Yes
cmpi.{b,w}
#<data>
Dx
Yes
Instruction Fetch Touch
intouch
<Ay>
Move 3-Bit Data Quick
mov3q.l
#<data>
<ea>x
Move Data Source to Destination
move.{b,w}
#<data>
d16(Ax)
Move with Sign Extend
mvs.{b,w}
<ea>y
Dx
Move with Zero-Fill
mvz.{b,w}
<ea>y
Dx
Signed Saturate
sats.l
Dx
Test and Set an Operand
tas.b
<ea>x
1
Yes
Yes
Operand sizes in this column reflect only newly supported operand sizes for existing instructions
(Bcc, BRA, BSR, CMP, CMPA, CMPI, and MOVE)
Some proposed opcodes were formerly present in the M68000 family, while other opcodes
are new functions.
2.6.2 Instruction Set Summary
Table 2-8 lists implemented user-level instructions by opcode.
Table 2-8. User-Level Instruction Set Summary
Instruction
Operand Syntax
Operand Size
Operation
ADD
Dy,<ea>x
<ea>y,Dx
.L
.L
Source + destination → destination
ADDA
<ea>y,Ax
.L
Source + destination → destination
Chapter 2. ColdFire Core
2-19
Instruction Set Summary
Table 2-8. User-Level Instruction Set Summary (Continued)
Instruction
Operand Syntax
Operand Size
Operation
ADDI
#<data>,Dx
.L
Immediate data + destination → destination
ADDQ
#<data>,<ea>x
.L
Immediate data + destination → destination
ADDX
Dy,Dx
.L
Source + destination + X → destination
AND
Dy,<ea>x
<ea>y,Dx
.L
.L
Source & destination → destination
ANDI
#<data>,Dx
.L
Immediate data & destination → destination
ASL
Dy,Dx
#<data>,Dx
.L
.L
X/C ← (Dx << Dy) ← 0
X/C ← (Dx << #<data>) ← 0
ASR
Dy,Dx
#<data>,Dx
.L
.L
MSB → (Dx >> Dy) → X/C
MSB → (Dx >> #<data>) → X/C
Bcc
<label>
.B,.W,.L
If condition true, then PC + 2 + dn → PC
BCHG
Dy,<ea>x
#<data>,<ea-1>x
.B,.L
.B,.L
~(<bit number> of destination) → Z,
Bit of destination
BCLR
Dy,<ea>x
#<data>,<ea-1>x
.B,.L
.B,.L
~(<bit number> of destination) → Z;
0 → bit of destination
BRA
<label>
.B,.W,.L
PC + 2 + dn → PC
BSET
Dy,<ea>x
#<data>,<ea-1>x
.B,.L
.B,.L
~(<bit number> of destination) → Z;
1→ bit of destination
BSR
<label>
.B,.W,.L
SP – 4 → SP; next sequential PC→ (SP); PC + 2 + dn → PC
BTST
Dy,<ea>x
#<data>,<ea-1>x
.B,.L
.B,.L
~(<bit number> of destination) → Z
CLR
<ea>y,Dx
.B,.W,.L
0 → destination
CMP
<ea>y,Ax
.B,.W,.L
Destination – source
CMPA
<ea>y,Dx
.W,.L
Destination – source
CMPI
<ea>y,Dx
.B,.W,.L
Destination – immediate data
DIVS
<ea-1>y,Dx
<ea>y,Dx
.W
.L
Dx /<ea>y → Dx {16-bit remainder; 16-bit quotient}
Dx /<ea>y → Dx {32-bit quotient}
Signed operation
DIVU
<ea-1>y,Dx
Dy,<ea>x
.W
.L
Dx /<ea>y → Dx {16-bit remainder; 16-bit quotient}
Dx /<ea>y → Dx {32-bit quotient}
Unsigned operation
EOR
Dy,<ea>x
.L
Source ^ destination → destination
EORI
#<data>,Dx
.L
Immediate data ^ destination → destination
EXT
#<data>,Dx
.B →.W
.W →.L
Sign-extended destination → destination
EXTB
Dx
.B →.L
Sign-extended destination → destination
HALT1
None
Unsized
Enter halted state
JMP
<ea-3>y
Unsized
Address of <ea> → PC
JSR
<ea-3>y
Unsized
SP – 4 → SP; next sequential PC → (SP); <ea> → PC
LEA
<ea-3>y,Ax
.L
<ea> → Ax
2-20
MCF5407 User’s Manual
Instruction Set Summary
Table 2-8. User-Level Instruction Set Summary (Continued)
Instruction
Operand Syntax
Operand Size
Operation
LINK
Ax,#<d16>
.W
SP – 4 → SP; Ax → (SP); SP → Ax; SP + d16 → SP
LSL
Dy,Dx
#<data>,Dx
.L
.L
X/C ← (Dx << Dy) ← 0
X/C ← (Dx << #<data>) ← 0
LSR
Dy,Dx
#<data>,Dx
.L
.L
0 → (Dx >> Dy) → X/C
0 → (Dx >> #<data>) → X/C
MAC
Ry,RxSF
.L + (.W × .W) → .L
.L + (.L × .L) → .L
ACC + (Ry × Rx){<< 1 | >> 1} → ACC
ACC + (Ry × Rx){<< 1 | >> 1} → ACC; (<ea>y{&MASK}) →
Rw
MACL
Ry,RxSF,<ea-1>y,Rw
.L + (.W × .W) → .L, .L
.L + (.L × .L) → .L, .L
ACC + (Ry × Rx){<< 1 | >> 1} → ACC
ACC + (Ry × Rx){<< 1 | >> 1} → ACC; (<ea-1>y{&MASK})
→ Rw
MOV3Q
#<data>,<ea>x
.L
3-bit immediate→destination
MOVE
<ea>y,<ea>x
.B,.W,.L
<ea>y → <ea>x
MOVE from
MAC
MASK,Rx
ACC,Rx
MACSR,Rx
.L
Rm → Rx
MACSR,CCR
.L
MACSR → CCR
Ry,ACC
Ry,MACSR
Ry,MASK
.L
Ry → Rm
#<data>,ACC
#<data>,MACSR
#<data>,MASK
.L
#<data> → Rm
MOVE from
CCR
CCR,Dx
.W
CCR → Dx
MOVE to
CCR
Dy,CCR
#<data>,CCR
.B
Dy → CCR
#<data> → CCR
MOVEA
<ea>y,Ax
.W,.L → .L
Source → destination
MOVEM
#<list>,<ea-2>x
<ea-2>y,#<list>
.L
.L
Listed registers → destination
Source → listed registers
MOVE to
MAC
MOVEQ
#<data>,Dx
.B → .L
Sign-extended immediate data → destination
MSAC
Ry,RxSF
.L - (.W × .W) → .L
.L - (.L × .L) → .L
ACC – (Ry × Rx){<< 1 | >> 1} → ACC
MSACL
Ry,RxSF,<ea-1>y,Rw
.L - (.W × .W) → .L, .L
.L - (.L × .L) → .L, .L
ACC – (Ry × Rx){<< 1 | >> 1} → ACC;
(<ea-1>y{&MASK}) → Rw
MULS
<ea>y,Dx
.W X .W → .L
.L X .L → .L
Source × destination → destination
Signed operation
MULU
<ea>y,Dx
.W X .W → .L
.L X .L → .L
Source × destination → destination
Unsigned operation
MVS
<ea>y,Dx
.B,.W
Sign-extended source → destination
MVZ
<ea-1>y,Dx
.B,.W
Zero-filled source → destination
NEG
Dx
.L
0 – destination → destination
NEGX
Dx
.L
0 – destination – X → destination
Chapter 2. ColdFire Core
2-21
Instruction Set Summary
Table 2-8. User-Level Instruction Set Summary (Continued)
Instruction
Operand Syntax
Operand Size
Operation
NOP
none
Unsized
Synchronize pipelines; PC + 2 → PC
NOT
Dx
.L
~ Destination → destination
OR
<ea>y,Dx
Dy,<ea>x
.L
Source | destination → destination
ORI
#<data>,Dx
.L
Immediate data | destination → destination
PEA
<ea-3>y
.L
SP – 4 → SP; Address of <ea> → (SP)
PULSE
none
Unsized
Set PST= 0x4
REMS
<ea-1>,Dx
.L
Dx/<ea>y → Dw {32-bit remainder}
Signed operation
REMU
<ea-1>,Dx
.L
Dx/<ea>y → Dw {32-bit remainder}
Unsigned operation
RTS
none
Unsized
(SP) → PC; SP + 4 → SP
SATS
Dx
.L
If CCR.V=1,
then if Dx[31] =0
then 0x80000000 → Dx
else 0x7FFFFFFF→ Dx
else Dx is unchanged
Scc
Dx
.B
If condition true, then 1s destination;
Else 0s → destination
SUB
<ea>y,Dx
Dy,<ea>x
.L
.L
Destination – source → destination
SUBA
<ea>y,Ax
.L
Destination – source → destination
SUBI
#<data>,Dx
.L
Destination – immediate data → destination
SUBQ
#<data>,<ea>x
.L
Destination – immediate data → destination
SUBX
Dy,Dx
.L
Destination – source – X → destination
SWAP
Dx
.W
MSW of Dx ←→ LSW of Dx
TAS
<ea>x
.B
Set CCR; 1→ Bit 7 of <ea>x
TRAP
#<vector>
Unsized
SP – 4 → SP;PC → (SP);
SP – 2 → SP;SR → (SP);
SP – 2 → SP; format → (SP);
Vector address → PC
TRAPF
None
#<data>
Unsized
.W
.L
PC + 2 → PC
PC + 4 → PC
PC + 6 → PC
TST
<ea>y
.B,.W,.L
Set condition codes
UNLK
Ax
Unsized
Ax →SP; (SP) → Ax; SP + 4 → SP
WDDATA
<ea>y
.B,.W,.L
<ea>y →DDATA port
1
By default the HALT instruction is a supervisor-level instruction; however, it can be configured to allow user-mode
execution by setting CSR[UHE].
Table 2-9 describes supervisor-level instructions.
2-22
MCF5407 User’s Manual
Execution Timings
Table 2-9. Supervisor-Level Instruction Set Summary
Instruction
CPUSHL
Operand Syntax
Operand Size
(An)
Unsized
Operation
Invalidate instruction cache line
Push and invalidate data cache line
Push data cache line and invalidate (I,D)-cache lines
HALT1
none
Unsized
Enter halted state
INTOUCH
(Ay)
Unsized
Touch instruction space at address Ay
MOVE from SR
SR, Dx
.W
SR → Dx
MOVE to SR
Dy,SR
.W
Source → SR
#<data>,SR
MOVEC
Ry,Rc
.L
Ry → Rc
Rc
Register Definition
0x002
0x004
0x005
0x006
0x007
0x801
0xC04
0xC05
Cache control register (CACR)
Access control register 0 (ACR0)
Access control register 1 (ACR1)
Access control register 2 (ACR2)
Access control register 3 (ACR3)
Vector base register (VBR)
RAM base address register 0 (RAMBAR0)
RAM base address register 1 (RAMBAR1)
RTE
None
Unsized
(SP+2) → SR; SP+4 → SP; (SP) → PC; SP + formatfield SP
STOP
#<data>
.W
Immediate data → SR; enter stopped state
WDEBUG
<ea-2>y
.L
<ea-2>y → debug module
1
The HALT instruction can be configured to allow user-mode execution by setting CSR[UHE].
2.7 Execution Timings
The timing data presented in this section assumes the following:
•
•
•
Execution times are shown for individual instructions without assumptions
regarding the OEP’s ability to dispatch multiple instructions at a time. For sequences
where instruction pairs are issued, the execution time of the two instructions is
defined by the execution time of the first instruction; that is, the second instruction
effectively executes in zero cycles.
The OEP is loaded with the opword and all required extension words at the
beginning of each instruction execution. This implies that the OEP spends no time
waiting for the IFP to supply opwords and/or extension words.
The OEP experiences no sequence-related pipeline stalls. For the MCF5407, the
most common example of such a stall occurs when a register is modified in the EX
compute engine and a subsequent instruction generating an address uses the
previously modified register. The second instruction stalls in the OEP until the
register is updated by the previous instruction. For example:
muls.l
move.l
#<data>,d0
(a0,d0.l*4),d1
Chapter 2. ColdFire Core
2-23
Execution Timings
In this sequence, the second instruction is held for three cycles stalling for the
multiply instruction to update d0. If consecutive instructions update a register and
use that register as a base of index value with a scale factor of 1 (Xi.l*1) in an address
calculation, a two-cycle pipeline stall occurs. Using the destination register as an
index register with any other scale factor (Xi.l*2, Xi.l*4) causes a three-cycle stall.
Some instructions are optimized to ensure against causing such stalls on subsequent
instructions. The destination register on the following instructions is always
available for subsequent instructions:
lea
move.l
mov.w
moveq
clr.l
mov3q.l
<op>
<op>
<op>
<op>
•
•
<ea>y,Ax
#<data>,Rx
#<data>,Ax
#<data>,Dx
Dx
#<data>,Rx
(Ay)+,Rx
-(Ay),Rx
Ry,(Ax)+
Ry,-(Ax)
Note that the address register results from postincrement and predecrement modes
are available to subsequent instructions without stalls.
The OEP can complete all memory accesses without memory causing any stall
conditions. Thus, timing details in this section assume an infinite zero-wait state
memory attached to the core.
Operand data accesses are assumed to be aligned on the same byte boundary as the
operand size:
— 16-bit operands aligned on 0-modulo-2 addresses
— 32-bit operands aligned on 0-modulo-4 addresses
Operands not meeting these guidelines are misaligned. Table 2-10 shows how the
core decomposes a misaligned operand reference into a series of aligned accesses.
Table 2-10. Misaligned Operand References
Additional C(R/W) 1
A[1:0]
1
Size
Bus Operations
Read
Write
x1
Word
Byte, Byte
2(1/0)
1(0/1)
x1
Long
Byte, Word, Byte
3(2/0)
2(0/2)
10
Long
Word, Word
2(1/0)
1(0/1)
Each timing entry is presented as C(R/W), described as follows:
C is the number of processor clock cycles, including all applicable operand fetches and writes, as well as all
internal core cycles required to complete the instruction execution.
R/W is the number of operand reads (r) and writes (w) required by the instruction. An operation performing a
read-modify write function is denoted as (1/1).
2-24
MCF5407 User’s Manual
Execution Timings
2.7.1 MOVE Instruction Execution Timing
Execution timing for the MOVE.{B,W,L} instructions are shown in the next tables.
Table 2-13 shows the timing for the other generic move operations.
NOTE:
For all tables in this section, the execution time of any
instruction using the PC-relative effective addressing modes is
equivalent to the time using comparable An-relative mode.
ET with {<ea> = (d16,PC)}
ET with {<ea> = (d8,PC,Xi*SF)}
equals ET with {<ea> = (d16,An)}
equals ET with {<ea> = (d8,An,Xi*SF)}
The nomenclature “(xxx).wl” refers to both forms of absolute
addressing, (xxx).w and (xxx).l.
Table 2-11 lists execution times for MOVE.{B,W} instructions.
Table 2-11. Move Byte and Word Execution Times
Destination
Source
Rx
(Ax)
(Ax)+
-(Ax)
(d16,Ax)
(d8,Ax,Xi*SF)
(xxx).wl
Dy
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
Ay
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
(Ay)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
(Ay)+
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
-(Ay)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
(d16,Ay)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
(d8,Ay,Xi*SF)
2(1/0)
3(1/1)
3(1/1)
3(1/1)
—
—
—
(xxx).w
1(1/0)
2(1/1)
2(1/1)
2(1/1)
—
—
—
(xxx).l
1(1/0)
2(1/1)
2(1/1)
2(1/1)
—
—
—
(d16,PC)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
(d8,PC,Xi*SF)
2(1/0)
3(1/1)
3(1/1)
3(1/1)
—
—
—
#<xxx>
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
—
—
Table 2-12 lists timings for MOVE.L.
Table 2-12. Move Long Execution Times
Destination
Source
Rx
(Ax)
(Ax)+
-(Ax)
(d16,Ax)
(d8,Ax,Xi*SF)
(xxx).wl
Dy
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
Ay
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
(Ay)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
(Ay)+
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
Chapter 2. ColdFire Core
2-25
Execution Timings
Table 2-12. Move Long Execution Times (Continued)
Destination
Source
Rx
(Ax)
(Ax)+
-(Ax)
(d16,Ax)
(d8,Ax,Xi*SF)
(xxx).wl
-(Ay)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
(d16,Ay)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
(d8,Ay,Xi*SF)
2(1/0)
3(1/1)
3(1/1)
3(1/1)
—
—
—
(xxx).w
1(1/0)
2(1/1)
2(1/1)
2(1/1)
—
—
—
—
(xxx).l
1(1/0)
2(1/1)
2(1/1)
2(1/1)
—
—
(d16,PC)
1(1/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
(d8,PC,Xi*SF)
2(1/0)
3(1/1)
3(1/1)
3(1/1)
—
—
—
#<xxx>
1(0/0)
1(0/1)
1(0/1)
1(0/1)
—
—
—
Table 2-13 gives execution times for MOVE.L instructions accessing program-visible
registers of the MAC unit, along with other MOVE.L timings. Execution times for moving
contents of the ACC or MACSR into a destination location represent the best-case scenario
when the store instruction is executed and no load, MAC, or MSAC instructions are in the
MAC execution pipeline. In general, these store operations require only one cycle for
execution, but if they are preceded immediately by a load, MAC, or MSAC instruction, the
MAC pipeline depth is exposed and execution time is 3 cycles.
Table 2-13. Miscellaneous Move Execution Times
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
move.l
<ea>,ACC
1(0/0)
—
—
—
—
—
—
1(0/0)
move.l
<ea>,MACSR
6(0/0)
—
—
—
—
—
—
6(0/0)
move.l
<ea>,MASK
5(0/0)
—
—
—
—
—
—
5(0/0)
move.l
ACC,Rx
1(0/0)
—
—
—
—
—
—
—
move.l
MACSR,CCR
1(0/0)
—
—
—
—
—
—
—
move.l
MACSR,Rx
1(0/0)
—
—
—
—
—
—
—
move.l
MASK,Rx
1(0/0)
—
—
—
—
—
—
—
moveq
#imm,Dx
—
—
—
—
—
—
—
1(0/0)
mov3q
#imm,<ea>
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
—
mvs
<ea>,Dx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
mvz
<ea>,Dx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
2.7.2 Execution Timings—One-Operand Instructions
Table 2-14 shows standard timings for single-operand instructions.
2-26
MCF5407 User’s Manual
Execution Timings
Table 2-14. One-Operand Instruction Execution Times
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#xxx
clr.b
<ea>
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
—
clr.w
<ea>
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
—
clr.l
<ea>
1(0/0)
1(0/1)
1(0/1)
1(0/1)
1(0/1)
2(0/1)
1(0/1)
—
ext.w
Dx
1(0/0)
—
—
—
—
—
—
—
ext.l
Dx
1(0/0)
—
—
—
—
—
—
—
extb.l
Dx
1(0/0)
—
—
—
—
—
—
—
neg.l
Dx
1(0/0)
—
—
—
—
—
—
—
negx.l
Dx
1(0/0)
—
—
—
—
—
—
—
—
not.l
Dx
1(0/0)
—
—
—
—
—
—
sats.l
Dx
1(0/0)
—
—
—
—
—
—
—
scc
Dx
1(0/0)
—
—
—
—
—
—
—
swap
Dx
1(0/0)
—
—
—
—
—
—
—
tas
<ea>
1(1/1)
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
tst.b
<ea>
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
tst.w
<ea>
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
tst.l
<ea>
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
2.7.3 Execution Timings—Two-Operand Instructions
Table 2-15 shows standard timings for two-operand instructions.
Table 2-15. Two-Operand Instruction Execution Times
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
1(0/0)
add.l
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
add.l
Dy,<ea>
—
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
addi.l
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
addq.l
#imm,<ea>
1(0/0)
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
addx.l
Dy,Dx
1(0/0)
—
—
—
—
—
—
—
and.l
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
and.l
Dy,<ea>
—
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
andi.l
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
asl.l
<ea>,Dx
1(0/0)
—
—
—
—
—
—
1(0/0)
asr.l
<ea>,Dx
1(0/0)
—
—
—
—
—
—
1(0/0)
bchg
Dy,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
—
Chapter 2. ColdFire Core
2-27
Execution Timings
Table 2-15. Two-Operand Instruction Execution Times (Continued)
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
bchg
#imm,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
—
bclr
Dy,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
—
bclr
#imm,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
—
bset
Dy,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
—
bset
#imm,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
—
btst
Dy,<ea>
2(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
3(1/1)
2(1/1)
—
btst
#imm,<ea>
1(0/0)
2(1/1)
2(1/1)
2(1/1)
2(1/1)
—
—
1(0/0)
cmp.b
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
cmp.w
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
1(0/0)
cmp.l
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
cmpi.b
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
cmpi.w
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
cmpi.l
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
divs.w
<ea>,Dx
20(0/0)
20(1/0)
20(1/0)
20(1/0)
20(1/0)
21(1/0)
20(1/0)
20(0/0)
divu.w
<ea>,Dx
20(0/0)
20(1/0)
20(1/0)
20(1/0)
20(1/0)
21(1/0)
20(1/0)
20(0/0)
divs.l
<ea>,Dx
35(0/0)
35(1/0)
35(1/0)
35(1/0)
35(1/0)
—
—
—
divu.l
<ea>,Dx
35(0/0)
35(1/0)
35(1/0)
35(1/0)
35(1/0)
—
—
—
eor.l
Dy,<ea>
1(0/0)
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
eori.l
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
lea
<ea>,Ax
—
1(0/0)
—
—
1(0/0)
2(0/0)
1(0/0)
—
lsl.l
<ea>,Dx
1(0/0)
—
—
—
—
—
—
1(0/0)
lsr.l
<ea>,Dx
1(0/0)
—
—
—
—
—
—
1(0/0)
mac.w
Ry,Rx
1(0/0)
—
—
—
—
—
—
—
mac.l
Ry,Rx
3(0/0)
—
—
—
—
—
—
—
msac.w
Ry,Rx
1(0/0)
—
—
—
—
—
—
—
msac.l
Ry,Rx
3(0/0)
—
—
—
—
—
—
—
mac.w
Ry,Rx,ea,Rw
—
1(1/0)
1(1/0)
1(1/0)
1(1/0)
—
—
—
mac.l
Ry,Rx,ea,Rw
—
3(1/0)
3(1/0)
3(1/0)
3(1/0)
—
—
—
msac.w
Ry,Rx,ea,Rw
—
1(1/0)
1(1/0)
1(1/0)
1(1/0)
—
—
—
msac.l
Ry,Rx,ea,Rw
—
3(1/0)
3(1/0)
3(1/0)
3(1/0)
—
—
—
muls.w
<ea>,Dx
3(0/0)
3(1/0)
3(1/0)
3(1/0)
3(1/0)
4(1/0)
3(1/0)
3(0/0)
mulu.w
<ea>,Dx
3(0/0)
3(1/0)
3(1/0)
3(1/0)
3(1/0)
4(1/0)
3(1/0)
3(0/0)
muls.l
<ea>,Dx
5(0/0)
5(1/0)
5(1/0)
5(1/0)
5(1/0)
—
—
—
mulu.l
<ea>,Dx
5(0/0)
5(1/0)
5(1/0)
5(1/0)
5(1/0)
—
—
—
or.l
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
2-28
MCF5407 User’s Manual
Execution Timings
Table 2-15. Two-Operand Instruction Execution Times (Continued)
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
or.l
Dy,<ea>
—
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
or.l
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
rems.l
<ea>,Dx
35(0/0)
35(1/0)
35(1/0)
35(1/0)
35(1/0)
—
—
—
remu.l
<ea>,Dx
35(0/0)
35(1/0)
35(1/0)
35(1/0)
35(1/0)
—
—
—
sub.l
<ea>,Rx
1(0/0)
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
1(0/0)
sub.l
Dy,<ea>
—
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
subi.l
#imm,Dx
1(0/0)
—
—
—
—
—
—
—
subq.l
#imm,<ea>
1(0/0)
1(1/1)
1(1/1)
1(1/1)
1(1/1)
2(1/1)
1(1/1)
—
subx.l
Dy,Dx
1(0/0)
—
—
—
—
—
—
—
2.7.4 Miscellaneous Instruction Execution Times
Table 2-16 lists timings for miscellaneous instructions.
Table 2-16. Miscellaneous Instruction Execution Times
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
—
—
—
—
—
—
—
cpushl
(Ax)
—
9(0/1)
intouch
(Ay)
—
19(1/0)
link.w
Ay,#imm
2(0/1)
—
—
—
—
—
—
move.w
CCR,Dx
1(0/0)
—
—
—
—
—
—
—
move.w
<ea>,CCR
1(0/0)
—
—
—
—
—
—
1(0/0)
move.w
SR,Dx
1(0/0)
—
—
—
—
—
—
—
move.w
<ea>,SR
4(0/0)
—
—
—
—
—
—
4(0/0)
movec
Ry,Rc
20(0/1)
—
—
—
—
—
—
—
1
<ea>,&list
—
n(n/0)
—
—
n(n/0)
—
—
—
movem.l 1
&list,<ea>
—
n(0/n)
—
—
n(0/n)
—
—
—
6(0/0)
—
—
—
—
—
—
—
—
1(0/1)
—
—
1(0/1)
2(0/1)
1(0/1)
—
1(0/0)
—
—
—
—
—
—
—
movem.l
nop
pea
<ea>
pulse
stop
#imm
—
—
—
—
—
—
—
6(0/0)2
trap
#imm
—
—
—
—
—
—
—
18(1/2)
trapf
1(0/0)
—
—
—
—
—
—
—
trapf.w
1(0/0)
—
—
—
—
—
—
—
trapf.l
1(0/0)
—
—
—
—
—
—
—
Chapter 2. ColdFire Core
2-29
Execution Timings
Table 2-16. Miscellaneous Instruction Execution Times (Continued)
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
unlk
Ax
1(1/0)
—
—
—
—
—
—
—
wddata.
{b,w,l}
<ea>
—
1(1/0)
1(1/0)
1(1/0)
1(1/0)
2(1/0)
1(1/0)
—
wdebug.l
<ea>
—
15(2/0)
—
—
15(2/0)
—
—
—
1
n is the number of registers moved by the MOVEM opcode
2 The execution time for STOP is the time required until the processor begins sampling continuously for interrupts.
2.7.5 Branch Instruction Execution Times
Table 2-17 shows general branch instruction timing.
Table 2-17. Branch Instruction Execution Times
Effective Address
Opcode
<ea>
bra
bsr
jmp
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
—
—
—
—
1(0/1)1
—
—
—
—
—
—
6(0/0)
1(0/0)1
—
—
—
—
—
—
1(0/1)1
—
5(0/0)
—
—
5(0/0)
—
5(0/1)
—
—
5(0/1)
6(0/1)
1(0/1)1
rte
—
—
15(2/0)
—
—
—
—
—
rts
—
—
2(1/0)2
9(1/0)3
8(1/0)4
—
—
—
—
—
jsr
<ea>
1
Assumes branch acceleration.
If predicted correctly by the hardware return stack.
3 If mispredicted by the hardware return stack.
4 If not predicted by the hardware return stack.
2
Table 2-18 shows timing for Bcc instructions.
Table 2-18. Bcc Instruction Execution Times
Opcode
Branch Cache Correctly
Predicts Taken
Prediction Table Correctly
Predicts Taken
Predicted
Correctly as
Not Taken
Predicted Incorrectly
bcc
0(0/0)
1(0/0)
1(0/0)
8(0/0)
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MCF5407 User’s Manual
Exception Processing Overview
2.8 Exception Processing Overview
Exception processing for ColdFire processors is streamlined for performance. Differences
from previous M68000 Family processors include the following:
•
•
•
•
A simplified exception vector table
Reduced relocation capabilities using the vector base register
A single exception stack frame format
Use of a single, self-aligning system stack pointer
ColdFire processors use an instruction restart exception model but require more software
support to recover from certain access errors. See Table 2-19 for details.
Exception processing can be defined as the time from the detection of the fault condition
until the fetch of the first handler instruction has been initiated. It is comprised of the
following four major steps:
1. The processor makes an internal copy of the SR and then enters supervisor mode by
setting SR[S] and disabling trace mode by clearing SR[T]. The occurrence of an
interrupt exception also forces SR[M] to be cleared and the interrupt priority mask
to be set to the level of the current interrupt request.
2. The processor determines the exception vector number. For all faults except
interrupts, the processor performs this calculation based on the exception type. For
interrupts, the processor performs an interrupt-acknowledge (IACK) bus cycle to
obtain the vector number from a peripheral device. The IACK cycle is mapped to a
special acknowledge address space with the interrupt level encoded in the address.
3. The processor saves the current context by creating an exception stack frame on the
system stack. ColdFire processors support a single stack pointer in the A7 address
register; therefore, there is no notion of separate supervisor and user stack pointers.
As a result, the exception stack frame is created at a 0-modulo-4 address on the top
of the current system stack. Additionally, the processor uses a simplified
fixed-length stack frame for all exceptions. The exception type determines whether
the program counter in the exception stack frame defines the address of the faulting
instruction (fault) or of the next instruction to be executed (next).
4. The processor acquires the address of the first instruction of the exception handler.
The exception vector table is aligned on a 1-Mbyte boundary. This instruction
address is obtained by fetching a value from the table at the address defined in the
vector base register. The index into the exception table is calculated as
4 x vector_number. When the index value is generated, the vector table contents
determine the address of the first instruction of the desired handler. After the fetch
of the first opcode of the handler is initiated, exception processing terminates and
normal instruction processing continues in the handler.
ColdFire processors support a 1024-byte vector table aligned on any 1-Mbyte address
boundary; see Table 2-19. The table contains 256 exception vectors where the first 64 are
Chapter 2. ColdFire Core
2-31
Exception Processing Overview
defined by Motorola; the remaining 192 are user-defined interrupt vectors.
Table 2-19. Exception Vector Assignments
Vector Numbers
Vector Offset (Hex)
Stacked Program Counter 1
0
000
—
Initial stack pointer
1
004
—
Initial program counter
2
008
Fault
Access error
3
00C
Fault
Address error
4
010
Fault
Illegal instruction
5
014
Fault
Divide by zero
6–7
018–01C
—
8
020
Fault
Privilege violation
9
024
Next
Trace
1
Assignment
Reserved
10
028
Fault
Unimplemented line-a opcode
11
02C
Fault
Unimplemented line-f opcode
12
030
Next
Non-PC breakpoint debug interrupt
13
034
Next
PC breakpoint debug interrupt
14
038
Fault
Format error
15
03C
Next
Uninitialized interrupt
16–23
040–05C
—
Reserved
24
060
Next
Spurious interrupt
25–31
064–07C
Next
Level 1–7 autovectored interrupts
32–47
080–0BC
Next
Trap #0–15 instructions
48–60
0C0–0F0
—
61
0F4
Fault
62–63
0F8–0FC
—
64–255
100–3FC
Next
Reserved
Unsupported instruction
Reserved
User-defined interrupts
The term ‘fault’ refers to the PC of the instruction that caused the exception. The term ‘next’ refers to the PC
of the instruction that immediately follows the instruction that caused the fault.
ColdFire processors inhibit sampling for interrupts during the first instruction of all
exception handlers. This allows any handler to effectively disable interrupts, if necessary,
by raising the interrupt mask level contained in the status register.
2.8.1 Exception Stack Frame Definition
The exception stack frame is shown in Figure 2-1. The first longword of the exception stack
frame contains the 16-bit format/vector word (F/V) and the 16-bit status register. The
second longword contains the 32-bit program counter address.
2-32
MCF5407 User’s Manual
Exception Processing Overview
31
A7→
28
Format
27
26
25
FS[3–2]
+ 0x04
18
Vector[7–0]
17
16
15
0
FS[1–0]
Status Register
Program Counter [31–0]
Figure 2-1. Exception Stack Frame Form
The 16-bit format/vector word contains three unique fields:
•
Format field—This 4-bit field at the top of the system stack is always written with a
value of {4,5,6,7} by the processor indicating a 2-longword frame format. See
Table 2-20. This field records any longword misalignment of the stack pointer that
may have existed when the exception occurred.
Table 2-20. Format Field Encoding
•
Original A7 at Time of
Exception, Bits 1–0
A7 at First Instruction of
Handler
Format Field Bits
31–28
00
Original A[7–8]
0100
01
Original A[7–9]
0101
10
Original A[7–10]
0110
11
Original A[7–11]
0111
Fault status field—The 4-bit field, FS[3–0], at the top of the system stack is defined
for access and address errors along with interrupted debug service routines. See
Table 2-21.
Table 2-21. Fault Status Encodings
FS[3–0]
0000
Not an access or address error nor an interrupted debug service routine
0001
Reserved
0010
Interrupt during a debug service routine
0011
Reserved
0100
Error on instruction fetch
0101–011x
Reserved
1000
Error on operand write
1001
Attempted write to write-protected space
101x
Reserved
1100
Error on operand read
1101–111x
•
Definition
Reserved
Vector number—This 8-bit field, vector[7–0], defines the exception type. It is
calculated by the processor for internal faults and is supplied by the peripheral for
interrupts. See Table 2-19.
Chapter 2. ColdFire Core
2-33
Exception Processing Overview
2.8.2 Processor Exceptions
Table 2-22 describes MCF5407 exceptions.
Table 2-22. MCF5407 Exceptions
Exception
Description
Access Error
Access errors are reported only in conjunction with an attempted store to write-protected memory.
Thus, access errors associated with instruction fetch or operand read accesses are not possible.
The Version 4 processor, unlike the Version 2 and 3 processors, updates the condition code register
if a write-protect error occurs during a CLR or MOV3Q operation to memory.
Address
Error
Caused by an attempted execution transferring control to an odd instruction address (that is, if bit 0 of
the target address is set), an attempted use of a word-sized index register (Xi.w) or a scale factor of
8 on an indexed effective addressing mode, or attempted execution of an instruction with a full-format
indexed addressing mode.
If an address error occurs on a JSR instruction, the Version 4 processor first pushes the return
address onto the stack and then calculates the target address. On Version 2 and 3 processors, these
functions are reversed.
If an address error occurs on an RTS instruction, the Version 4 processor preserves the original
return PC and writes the exception stack frame above this value. On Version 2 and 3 processors, the
faulting return PC is overwritten by the address error stack frame.
Illegal
Instruction
On Version 2 ColdFire implementations, only some illegal opcodes were decoded and generated an
illegal instruction exception. Version 3 and Version 4 processors decode the full 16-bit opcode and
generate this exception if execution of an unsupported instruction is attempted. Additionally,
attempting to execute an illegal line A or line F opcode generates unique exception types: vectors 10
and 11, respectively.
ColdFire processors do not provide illegal instruction detection on extension words of any instruction,
including MOVEC. Attempting to execute an instruction with an illegal extension word causes
undefined results.
Divide by
Zero
Attempted division by zero causes an exception (vector 5, offset = 0x014) except when the PC points
to the faulting instruction (DIVU, DIVS, REMU, REMS).
Privilege
Violation
Caused by attempted execution of a supervisor mode instruction while in user mode. The ColdFire
Programmer’s Reference Manual lists supervisor- and user-mode instructions.
Trace
Exception
ColdFire processors provide instruction-by-instruction tracing. While the processor is in trace mode
(SR[T] = 1), instruction completion signals a trace exception. This allows a debugger to monitor
program execution.
The only exception to this definition is the STOP instruction. If the processor is in trace mode, the
instruction before the STOP executes and then generates a trace exception. In the exception stack
frame, the PC points to the STOP opcode. When the trace handler is exited, the STOP instruction is
executed, loading the SR with the immediate operand from the instruction. The processor then
generates a trace exception. The PC in the exception stack frame points to the instruction after
STOP, and the SR reflects the just-loaded value.
If the processor is not in trace mode and executes a STOP instruction where the immediate operand
sets the trace bit in the SR, hardware loads the SR and generates a trace exception. The PC in the
exception stack frame points to the instruction after STOP, and the SR reflects the just-loaded value.
Because ColdFire processors do not support hardware stacking of multiple exceptions, it is the
responsibility of the operating system to check for trace mode after processing other exception types.
As an example, consider a TRAP instruction executing in trace mode. The processor initiates the
TRAP exception and passes control to the corresponding handler. If the system requires that a trace
exception be processed, the TRAP exception handler must check for this condition (SR[15] in the
exception stack frame asserted) and pass control to the trace handler before returning from the
original exception.
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MCF5407 User’s Manual
Exception Processing Overview
Table 2-22. MCF5407 Exceptions (Continued)
Exception
Description
Debug
Interrupt
Caused by a hardware breakpoint register trigger. Rather than generating an IACK cycle, the
processor internally calculates the vector number (12 or 13, depending on the type of breakpoint
trigger). Additionally, the M bit and the interrupt priority mask fields of the SR are unaffected by the
interrupt. See Section 2.2.2.1, “Status Register (SR).”
The debug interrupt exception vector is expanded from Version 3 such that PC breakpoints are
distinguishable from other triggers. The two unique entries occur when a PC breakpoint generates
the 0x034 vector. In case of a two-level trigger, the last breakpoint event determines the vector.
The changes are described in more detail in Chapter 5, “Debug Support.”
RTE and
Format Error
Exceptions
When an RTE instruction executes, the processor first examines the 4-bit format field to validate the
frame type. For a ColdFire processor, any attempted execution of an RTE where the format is not
equal to {4,5,6,7} generates a format error. The exception stack frame for the format error is created
without disturbing the original exception frame and the stacked PC points to RTE.The selection of the
format value provides limited debug support for porting code from M68000 applications. On M68000
Family processors, the SR was at the top of the stack. Bit 30 of the longword addressed by the
system stack pointer is typically zero; so, attempting an RTE using this old format generates a format
error on a ColdFire processor.
If the format field defines a valid type, the processor does the following:
1 Reloads the SR operand.
2 Fetches the second longword operand.
3 Adjusts the stack pointer by adding the format value to the auto-incremented address after the first
longword fetch.
4 Transfers control to the instruction address defined by the second longword operand in the stack
frame.
TRAP
Executing TRAP always forces an exception and is useful for implementing system calls. The trap
instruction may be used to change from user to supervisor mode.
Interrupt
Exception
Interrupt exception processing, with interrupt recognition and vector fetching, includes uninitialized
and spurious interrupts as well as those where the requesting device supplies the 8-bit interrupt
vector. Autovectoring may optionally be configured through the system interface module (SIM). See
Section 9.2.2, “Autovector Register (AVR).”
Reset
Exception
Asserting the reset input signal (RSTI) causes a reset exception. Reset has the highest exception
priority; it provides for system initialization and recovery from catastrophic failure. When assertion of
RSTI is recognized, current processing is aborted and cannot be recovered. The reset exception
places the processor in supervisor mode by setting SR[S] and disables tracing by clearing SR[T].
This exception also clears SR[M] and sets the processor’s interrupt priority mask in the SR to the
highest level (level 7). Next, the VBR is initialized to 0x0000_0000. Configuration registers controlling
the operation of all processor-local memories are invalidated, disabling the memories.
Note: Other implementation-specific supervisor registers are also affected. Refer to each of the
modules in this manual for details on these registers.
After RSTI is negated, the processor waits 16 cycles before beginning the actual reset exception
process. During this time, certain events are sampled, including the assertion of the debug
breakpoint signal. If the processor is not halted, it initiates the reset exception by performing two
longword read bus cycles. The longword at address 0 is loaded into the stack pointer and the
longword at address 4 is loaded into the PC. After the initial instruction is fetched from memory,
program execution begins at the address in the PC. If an access error or address error occurs before
the first instruction executes, the processor enters the fault-on-fault halted state.
Unsupported
Instruction
Exception
If the MCF5407 attempts to execute a valid instruction but the required optional hardware module is
not present in the OEP, a non-supported instruction exception is generated (vector 0x61). Control is
then passed to an exception handler that can then process the opcode as required by the system.
If a ColdFire processor encounters any type of fault during the exception processing of
another fault, the processor immediately halts execution with the catastrophic fault-on-fault
condition. A reset is required to force the processor to exit this halted state.
Chapter 2. ColdFire Core
2-35
ColdFire Instruction Set Architecture Enhancements
2.9 ColdFire Instruction Set Architecture
Enhancements
This section describes the new opcodes implemented as part of the Revision B
enhancements to the basic ColdFire ISA. In some cases, the opcodes represent minor
enhancements to existing ColdFire functions, while in other cases, the functionality is new
and not covered in the existing ISA.
2-36
MCF5407 User’s Manual
ColdFire Instruction Set Architecture Enhancements
Bcc
Bcc
Branch Conditionally
If Condition True
Then PC + dn → PC
Operation:
Assembler Syntax: Bcc <label>
Attributes:
Size = byte, word, long
Description: If the condition is true, execution continues at (PC) + displacement. PC holds
the address of the instruction word for the Bcc instruction, plus two. The displacement is a
two’s-complement integer that represents the relative distance in bytes from the current PC
to the destination PC. If the 8-bit displacement field is 0, a 16-bit displacement (the word
after the instruction) is used. If the 8-bit displacement field is 0xFF, the 32-bit displacement
(longword after the instruction) is used. Condition code specifies one of the following tests:
Code
Condition
Code
Condition
Code
Condition
Code
Condition
CC(HI)
Carry clear
GT
Greater than
LT
Less than
VC
Overflow clear
CS(LO)
Carry set
HI
High
MI
Minus
VS
Overflow set
EQ
Equal
LE
Less or equal
NE
Not equal
GE
Greater or equal
LS
Low or same
PL
Plus
Condition Codes:
Instruction
Format:
Not affected
15
14
13
12
0
1
1
0
11
10
9
8
7
Condition
6
5
4
3
2
1
0
8-bit displacement
16-bit displacement if 8-bit displacement = 0x00
32-bit displacement if 8-bit displacement = 0xFF
Instruction Fields:
• Condition field—Binary code for one of the conditions listed in the table.
• 8-bit displacement field—Two’s complement integer specifying the number of bytes
between the branch and the next instruction to be executed if the condition is met.
• 16-bit displacement field—Used when the 8-bit displacement contains 0x00.
• 32-bit displacement field—Used when the 8-bit displacement contains 0xFF.
NOTE:
A branch to the next immediate instruction uses 16-bit
displacement because the 8-bit displacement field is 0x00.
Bcc
V2, V3 Core
V4 Core
Opcode present
Yes
Yes
Operand sizes supported
.b, .w
.b, .w, .l
Chapter 2. ColdFire Core
2-37
ColdFire Instruction Set Architecture Enhancements
BRA
BRA
Branch Always
Operation:
PC + dn → PC
Assembler Syntax: BRA <label>
Attributes:
Size = byte, word, long
Description: Program execution continues at location (PC) + displacement. The PC
contains the address of the instruction word of the BRA instruction, plus two. The
displacement is a two’s complement integer that represents the relative distance in bytes
from the current PC to the destination PC. If the 8-bit displacement field in the instruction
word is 0, a 16-bit displacement (the word immediately following the instruction) is used.
If the 8-bit displacement field in the instruction word is all ones (0xFF), the 32-bit
displacement (longword immediately following the instruction) is used.
Condition codes:
Instruction
Format:
Not affected
15
14
13
12
11
10
9
8
0
1
1
0
0
0
0
0
7
6
5
4
3
2
1
0
8-bit displacement
16-bit displacement if 8-bit displacement = 0x00
32-bit displacement if 8-bit displacement = 0xFF
Instruction Fields:
• 8-bit displacement field—Two’s complement integer specifying the number of bytes
between the branch instruction and the next instruction to be executed.
• 16-bit displacement field—Used for displacement when the 8-bit displacement
contains 0x00.
• 32-bit displacement field—Used for displacement when the 8-bit displacement
contains 0xFF.
NOTE:
A branch to the next immediate instruction automatically uses
the 16-bit displacement format because the 8-bit displacement
field contains 0x00 (zero offset).
BRA
2-38
V2, V3 Core
V4 Core
Opcode present
Yes
Yes
Operand sizes supported
.b, .w
.b, .w, .l
MCF5407 User’s Manual
ColdFire Instruction Set Architecture Enhancements
BSR
BSR
Branch to Subroutine
Operation:
SP – 4 → SP; PC → (SP); PC + dn → PC
Assembler Syntax: BSR <label>
Attributes:
Size = byte, word, long
Description: Pushes the word address of the instruction immediately following the BSR
instruction onto the system stack. The PC contains the address of the instruction word, plus
two. Program execution then continues at location (PC) + displacement. The displacement
is a two’s complement integer that represents the relative distance in bytes from the current
PC to the destination PC. If the 8-bit displacement field in the instruction word is 0, a 16-bit
displacement (the word immediately following the instruction) is used. If the 8-bit
displacement field in the instruction word is all ones (0xFF), the 32-bit displacement
(longword immediately following the instruction) is used.
Condition Codes:
Instruction
Format:
Not affected
15
14
13
12
11
10
9
8
0
1
1
0
0
0
0
1
7
6
5
4
3
2
1
0
8-bit displacement
16-bit displacement if 8-bit displacement = 0x00
32-bit displacement if 8-bit displacement = 0xFF
Instruction Fields:
• 8-bit displacement field—Two’s complement integer specifying the number of bytes
between the branch instruction and the next instruction to be executed.
• 16-bit displacement field—Used for displacement when the 8-bit displacement
contains 0x00.
• 32-bit displacement field—Used for displacement when the 8-bit displacement
contains 0xFF.
NOTE:
A branch to the next immediate instruction automatically uses
the 16-bit displacement format because the 8-bit displacement
field contains 0x00 (zero offset).
BSR
V2, V3 Core
V4 Core
Opcode present
Yes
Yes
Operand sizes supported
.b, .w
.b, .w, .l
Chapter 2. ColdFire Core
2-39
ColdFire Instruction Set Architecture Enhancements
CMP
CMP
Compare
Operation:
Destination – Source → cc
Assembler Syntax: CMP <ea>y, Dx
Attributes:
Size = byte, word, long
Description: Subtracts the source operand from the destination operand in the data register
and sets condition codes according to the result; the data register is unchanged. The
operation size may be a byte, word, or longword.
CMPA is used when the destination is an address register; CMPI is used when the source
is immediate data. Most assemblers automatically make this distinction.
Condition Codes:
X
—
N
∗
Z
∗
V
∗
C
∗
X
N
Z
V
C
15
14
13
12
1
0
1
1
Instruction
Format:
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Set if an overflow occurs; cleared otherwise
Set if a borrow occurs; cleared otherwise
11
10
9
8
REGISTER
7
6
5
OPMODE
4
3
2
1
0
EFFECTIVE ADDRESS
MODE
REGISTER
Instruction Fields:
• Register field—specifies the destination register.
• Opmode field:
•
Byte
Word
Long
Operation
000
001
010
Dx - <ea>y
Effective address field specifies the source operand; use addressing modes in the
following table:
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
reg. number:Ay
Dy
000
reg. number:Dy
(d8,Ay,Xi)
110
Ay (word/longword operand only)
001
reg. number:Ay
(xxx).W
111
000
(Ay)
010
reg. number:Ay
(xxx).L
111
001
(Ay) +
011
reg. number:Ay
#<data>
111
100
– (Ay)
100
reg. number:Ay
(d16,PC)
111
010
(d16,Ay)
101
reg. number:Ay
(d8,PC,Xi)
111
011
2-40
CMP
V2, V3 Core
Opcode present
Yes
Yes
Operand sizes supported
.l
.b, .w, .l
MCF5407 User’s Manual
V4 Core
ColdFire Instruction Set Architecture Enhancements
CMPA
CMPA
Compare Address
Operation:
Destination – Source → cc
Assembler Syntax: CMPA <ea>y, Ax
Attributes:
Size = word, long
Description: Operates similarly to CMP, but is used when the destination register is an
address register rather than a data register. The operation size can be word or longword.
Word-length source operands are sign-extended to 32 bits for comparison.
Condition Codes:
X
—
N
∗
Z
∗
V
∗
C
∗
X
N
Z
V
C
15
14
13
12
1
0
1
1
Instruction
Format:
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Set if an overflow occurs; cleared otherwise
Set if a borrow occurs; cleared otherwise
11
10
9
8
REGISTER
7
6
5
4
OPMODE
3
2
1
0
EFFECTIVE ADDRESS
MODE
REGISTER
Instruction Fields:
• Register field—Specifies the destination register.
• Opmode field:
•
Byte
Word
Long
Operation
—
011
111
Ax - <ea>y
Effective address field specifies the source operand; use addressing modes in the
following table:
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
reg. number:Ay
Dy
000
reg. number:Dy
(d8,Ay,Xi)
110
Ay (word/longword operand only)
001
reg. number:Ay
(xxx).W
111
000
(Ay)
010
reg. number:Ay
(xxx).L
111
001
(Ay) +
011
reg. number:Ay
#<data>
111
100
– (Ay)
100
reg. number:Ay
(d16,PC)
111
010
(d16,Ay)
101
reg. number:Ay
(d8,PC,Xi)
111
011
CMPA
V2, V3 Core
Opcode present
Yes
Yes
Operand sizes supported
.l
.w, .l
Chapter 2. ColdFire Core
V4 Core
2-41
ColdFire Instruction Set Architecture Enhancements
CMPI
CMPI
Compare Immediate
Operation:
Destination – Immediate Data → cc
Assembler Syntax: CMPI #<data>, Dx
Attributes:
Size = byte, word, long
Description: Operates similarly to CMP, but is used when the source operand is immediate
data. The size of the operation may be specified as byte, word, or longword. The size of the
immediate data matches the operation size.
Condition Codes:
X
—
N
∗
Instruction
Format:
Z
∗
V
∗
C
∗
X
N
Z
V
C
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Set if an overflow occurs; cleared otherwise
Set if a borrow occurs; cleared otherwise
15
14
13
12
11
10
9
8
0
0
0
0
1
1
0
0
7
6
SIZE
5
4
3
0
0
0
UPPER WORD
LOWER WORD
Instruction Fields:
• Register field—Destination data register.
• Size field:
Byte
Word
Long
Operation
00
01
10
Dx - #<data>
Note that if size = byte, the immediate is contained in bits [7:0]
of the single extension word. If size = word, the immediate is
contained in bits[15:0] of the single extension word. If
size = long, the immediate is contained in the two extension
words.
2-42
CMPI
V2, V3 Core
Opcode present
Yes
Yes
Operand sizes supported
.l
.b, .w, .l
MCF5407 User’s Manual
V4 Core
2
1
0
REGISTER
ColdFire Instruction Set Architecture Enhancements
INTOUCH
INTOUCH
Instruction Fetch Touch
Operation:
If Supervisor State
then Instruction Fetch Touch @ <Ay>
else TRAP
Assembler Syntax
INTOUCH <Ay>
Attributes:
Unsized
Description: Generates an instruction fetch reference at address (Ay). If the referenced
address space is a cacheable region, this instruction can be used to prefetch a 16-byte packet
into the processor’s instruction cache. If the referenced instruction address is a
non-cacheable space, the instruction effectively performs no operation.
The INTOUCH instruction can be used to prefetch, and with the later setting of CACR[11],
lock specific memory lines in the processor’s instruction cache. This function may be
desirable in systems where deterministic real-time performance is critical.
Condition Codes:
Instruction
Format:
Not affected.
15
14
13
12
11
10
9
8
7
6
5
4
3
1
1
1
1
0
1
0
0
0
0
1
0
1
2
1
0
REGISTER
Instruction Fields:
• Register field—Specifies the destination address register number.
INTOUCH
V2, V3 Core
V4 Core
Opcode present
No
Yes
Operand sizes supported
—
—
Chapter 2. ColdFire Core
2-43
ColdFire Instruction Set Architecture Enhancements
MOVE
MOVE
Move Data from Source to Destination
Operation:
Source → Destination
Assembler Syntax: MOVE <ea>y, <ea>x
Attributes:
Size = byte, word, long
Description: Moves the data at the source to the destination location and sets the condition
codes according to the data. The size of the operation may be specified as byte, word, or
longword.
Condition Codes:
X
—
N
∗
Z
∗
Instruction
Format:
V
0
15
14
0
0
C
0
13
X
N
Z
V
C
12
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Always cleared
Always cleared
11
10
SIZE
9
8
7
6
5
4
DESTINATION
REGISTER
3
2
1
0
SOURCE
MODE
MODE
REGISTER
Instruction fields:
• Size field—Specifies the size of the operand to be moved:
01—
11—
10—
•
•
2-44
byte operation
word operation
long operation
Destination effective address field—Specifies destination location; the table below
lists possible data alterable addressing modes. The restrictions on combinations of
source and destination addressing modes are listed in the table at the bottom of the
next page.
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dx
Ax
(Ax)
(Ax) +
– (Ax)
(d16,Ax)
000
—
010
011
100
101
reg. number:Dx
—
reg. number:Ax
reg. number:Ax
reg. number:Ax
reg. number:Ax
(d8,Ax,Xi)
(xxx).W
(xxx).L
#<data>
(d16,PC)
(d8,PC,Xi)
110
111
111
—
—
—
reg. number:Ax
000
001
—
—
—
Source effective address field—Specifies source operand; the table below lists
possible addressing modes. The ColdFire MOVE instruction has restrictions on
combinations of source and destination addressing modes. The table at the end of
this instruction description outlines the restrictions.
MCF5407 User’s Manual
ColdFire Instruction Set Architecture Enhancements
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dy
Ay
(Ay)
(Ay) +
– (Ay)
(d16,Ay)
000
001
010
011
100
101
reg. number:Dy
reg. number:Ay
reg. number:Ay
reg. number:Ay
reg. number:Ay
reg. number:Ay
(d8,Ay,Xi)
(xxx).W
(xxx).L
#<data>
(d16,PC)
(d8,PC,Xi)
110
111
111
111
111
111
reg. number:Ay
000
001
100
010
011
NOTE:
Most assemblers use MOVEA when the destination is an
address register.
Use MOVEQ to move an immediate 8-bit value to a data
register. Use MOV3Q to move a 3-bit immediate value to any
effective destination address.
Not all combinations of source/destination addressing modes
are possible. The table below shows the possible combinations.
Source Addressing Mode
Destination Addressing Mode
Dy, Ay, (Ay), (Ay)+,-(Ay)
All possible
(d16, Ay), (d16, PC)
All possible except (d8, Ax, Xi), (xxx).W, (xxx).L
(d8, Ay, Xi), (d8, PC, Xi), (xxx).W, (xxx).L, #<xxx>
All possible except (d8, Ax, Xi), (xxx).W, (xxx).L
Note: The combination of #<xxx>,d16(Ax) addressing modes can be used only on move byte and move word
opcodes. Refer to the previous tables for valid source and destination addressing modes.
MOVE
V2, V3 Core
V4 Core
Opcode present
Yes
Yes
Operand sizes supported
.b, .w, .l
except
move.x #<data>, d16(Ax)
.b, .w, .l
including
move.{b,w} #<data>, d16(Ax)
Chapter 2. ColdFire Core
2-45
ColdFire Instruction Set Architecture Enhancements
MOVEA
MOVEA
Move Address from Source to Destination
Operation:
Source → Destination
Assembler Syntax: MOVEA <ea>y, Ax
Attributes:
Size = word, long
Description: Moves the address at the source to the destination location and sets the
condition codes according to the data. The size of the operation may be specified as word
or longword.
Condition Codes:
Instruction
Format:
Not affected
15
14
0
0
13
12
11
10
SIZE
9
8
7
6
5
4
DESTINATION
REGISTER
3
2
1
0
SOURCE
MODE
MODE
REGISTER
Instruction fields:
• Size field—specifies the size of the operand to be moved:
11—word operation
10—longword operation
• Destination effective address field—Specifies the destination location; the table
below lists possible addressing modes.
•
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dx
Ax
(Ax)
(Ax) +
– (Ax)
(d16,Ax)
—
001
—
—
—
—
—
reg. number: Ax
—
—
—
—
(d8,Ax,Xi)
(xxx).W
(xxx).L
#<data>
(d16,PC)
(d8,PC,Xi)
—
—
—
—
—
—
—
—
—
—
—
—
Source effective address field—Specifies the source operand; the table below lists
possible modes.
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dy
Ay
(Ay)
(Ay) +
– (Ay)
(d16,Ay)
000
001
010
011
100
101
reg. number:Dy
reg. number:Ay
reg. number:Ay
reg. number:Ay
reg. number:Ay
reg. number:Ay
(d8,Ay,Xi)
(xxx).W
(xxx).L
#<data>
(d16,PC)
(d8,PC,Xi)
110
111
111
111
111
111
reg. number:Ay
000
001
100
010
011
MOVEA
V2, V3 Core
V4 Core
Opcode present
Yes
Yes
Operand sizes supported
2-46
No differences
MCF5407 User’s Manual
ColdFire Instruction Set Architecture Enhancements
MOV3Q
MOV3Q
Move 3-Bit Data Quick
Operation:
Immediate Data → Destination
Assembler Syntax
MOV3Q #<data>,<ea>x
Attributes:
Size = long
Description: Move the immediate data to the operand at the destination location. The data
range is from -1 to 7, excluding 0. The immediate data is zero-filled to a long operand and
all 32 bits are transferred to the destination location.
Condition Codes:
X
—
N
∗
Z
∗
Instruction
Format:
V
0
C
0
X
N
Z
V
C
15
14
13
12
1
0
1
0
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Always cleared
Always cleared
11
10
DATA
9
8
7
6
1
0
1
5
4
3
MODE
2
1
0
REGISTER
Instruction Fields:
• Data field—3 bits of data having a range {-1,1-7} where a data value of 0 represents
-1.
• Effective Address field—Specifies the destination operand; use only data addressing
modes listed in the following table:
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dx
000
reg. number:Dx
(d8,Ax,Xi)
110
reg. number:Ax
Ax
001
reg. number:Ax
(xxx).W
111
000
(Ax)
010
reg. number:Ax
(xxx).L
111
001
(Ax) +
011
reg. number:Ax
#<data>
—
—
– (Ax)
100
reg. number:Ax
(d16,PC)
—
—
(d16,Ax)
101
reg. number:Ax
(d8,PC,Xi)
—
—
MOV3Q
V2, V3 Core
V4 Core
Opcode present
No
Yes
Operand sizes supported
—
.l
Chapter 2. ColdFire Core
2-47
ColdFire Instruction Set Architecture Enhancements
MVS
MVS
Move with Sign Extend
Operation:
(Source with sign extension) → Destination
Assembler Syntax: MVS <ea>y,Dx
Attributes:
Size = byte, word
Description: Sign-extend the source operand and move to the destination register. For the
byte operation, bit 7 of the source is copied to bits 31–8 of the destination. For the word
operation, bit 15 of the source is copied to bits 31-16 of the destination.
Condition Codes:
X
—
N
∗
Z
∗
V
0
C
0
X
N
Z
V
C
15
14
13
12
0
1
1
1
Instruction
Format:
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Always cleared
Always cleared
11
10
9
REGISTER
8
7
6
1
0
SIZ
E
5
4
3
2
1
MODE
REGISTER
Instruction Fields:
• Size field—specifies the size of the operation
0 byte operation
1 word operation
• Register field—specifies a data register as the destination.
• Effective address field—specifies the source operand; use only data addressing
modes from the following table:
Addressing Mode
2-48
Mode
Register
Addressing Mode
Mode
Register
Dy
000
reg. number:Dy
(d8,Ay,Xi)
110
reg. number:Ay
Ay
001
reg. number:Ay
(xxx).W
111
000
(Ay)
010
reg. number:Ay
(xxx).L
111
001
(Ay) +
011
reg. number:Ay
#<data>
111
100
– (Ay)
100
reg. number:Ay
(d16,PC)
111
010
(d16,Ay)
101
reg. number:Ay
(d8,PC,Xi)
111
011
MVS
V2, V3 Core
Opcode present
No
Yes
Operand sizes supported
—
.b, .w
MCF5407 User’s Manual
0
EFFECTIVE ADDRESS
V4 Core
ColdFire Instruction Set Architecture Enhancements
MVZ
MVZ
Move with Zero-Fill
Operation:
(Source with zero fill) → Destination
Assembler Syntax
MVZ <ea>y,Dx
Attributes:
Size = byte, word
Description—Zero-fill the source operand and move to the destination register. For the byte
operation, the source operand is moved to bits 7–0 of the destination and bits 31–8 are filled
with zeros. For the word operation, the source operand is moved to bits 15–0 of the
destination and bits 31–16 are filled with zeros.
Condition Codes:
X
—
N
0
Instruction
Format:
Z
∗
V
0
C
0
X
N
Z
V
C
15
14
13
12
0
1
1
1
Not affected
Always cleared
Set if the result is zero; cleared otherwise
Always cleared
Always cleared
11
10
9
REGISTER
8
7
6
1
1
SIZ
E
5
4
3
2
1
0
EFFECTIVE ADDRESS
MODE
REGISTER
Instruction Fields:
• Size field—Specifies the size of the operation
0 byte operation
1 word operation
• Register field—Specifies a data register as the destination.
• Effective address field—Specifies the source operand; use the following data
addressing modes:
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dy
000
reg. number:Dy
(d8,Ay,Xi)
110
reg. number:Ay
Ay
001
reg. number:Ay
(xxx).W
111
000
(Ay)
010
reg. number:Ay
(xxx).L
111
001
(Ay) +
011
reg. number:Ay
#<data>
111
100
– (Ay)
100
reg. number:Ay
(d16,PC)
111
010
(d16,Ay)
101
reg. number:Ay
(d8,PC,Xi)
111
011
MVZ
V2, V3 Core
Opcode present
No
Yes
Operand sizes supported
—
.b, .w
Chapter 2. ColdFire Core
V4 Core
2-49
ColdFire Instruction Set Architecture Enhancements
SATS
SATS
Signed Saturate
Operation:
If CCR.V == 1,
then if Dx[31] == 0,
then Dx[31:0] = 0x80000000
else Dx[31:0] = 0x7FFFFFFF
else Dx[31:0] is unchanged
Assembler Syntax: SATS Dx
Attributes:
Size = long
Description: Update the destination register only if the overflow bit of the CCR is set. If the
operand is negative, then set the result to greatest positive number, otherwise set the result
to the largest negative value. The condition codes are set according to the result.
Condition Codes:
X
—
N
∗
Instruction
Format:
Z
∗
V
0
C
0
X
N
Z
V
C
Not affected
Set if the result is negative; cleared otherwise
Set if the result is zero; cleared otherwise
Always cleared
Always cleared
15
14
13
12
11
10
9
8
7
6
5
4
3
0
1
0
0
1
1
0
0
1
0
0
0
0
Instruction Fields:
• Register field—Specifies the destination data register.
2-50
SATS
V2, V3 Core
V4 Core
Opcode present
No
Yes
Operand sizes supported
—
.l
MCF5407 User’s Manual
2
1
0
REGISTER
ColdFire Instruction Set Architecture Enhancements
TAS
TAS
Test and Set an Operand
Operation:
Destination Tested → CCR; 1 → bit 7 of Destination
Assembler Syntax: TAS <ea>x
Attributes:
Size = byte
Description: Tests and sets the byte operand addressed by the effective address field. The
instruction tests the current value of the operand and sets the N and Z condition code bits
appropriately. TAS also sets the high-order bit of the operand. The operand uses a
read-modify-write memory cycle that completes the operation without interruption. This
instruction supports use of a flag or semaphore to coordinate several processors.
Condition Codes:
X
—
N
∗
Z
∗
Instruction
Format:
V
0
C
0
X
N
Z
V
C
Not affected
Set if the msb of the operand is currently set; cleared otherwise
Set if the operand was zero; cleared otherwise
Always cleared
Always cleared
15
14
13
12
11
10
9
8
7
6
0
1
0
0
1
0
1
0
1
1
5
4
3
2
1
0
EFFECTIVE ADDRESS
MODE
REGISTER
Instruction Fields:
• Effective address field—specifies the destination location; the possible data alterable
addressing modes are listed in the table below.
Addressing Mode
Mode
Register
Addressing Mode
Mode
Register
Dx
Ax
(Ax)
(Ax) +
– (Ax)
(d16,Ax)
—
—
010
011
100
101
—
—
reg. number:Ax
reg. number:Ax
reg. number:Ax
reg. number:Ax
(d8,Ax,Xi)
(xxx).W
(xxx).L
#<data>
(d16,PC)
(d8,PC,Xi)
110
111
111
—
—
—
reg. number:Ax
000
001
—
—
—
TAS
V2, V3 Core
V4 Core
Opcode present
No
Yes
Operand sizes supported
—
.b
Chapter 2. ColdFire Core
2-51
ColdFire Instruction Set Architecture Enhancements
2-52
MCF5407 User’s Manual
Chapter 3
Hardware Multiply/Accumulate (MAC)
Unit
This chapter describes the MCF5407 multiply/accumulate (MAC) unit, which executes
integer multiply, multiply-accumulate, and miscellaneous register instructions. The MAC
is integrated into the operand execution pipeline (OEP).
3.1 Overview
The MAC unit provides hardware support for a limited set of digital signal processing
(DSP) operations used in embedded code, while supporting the integer multiply
instructions in the ColdFire microprocessor family.
The MAC unit provides signal processing capabilities for the MCF5407 in a variety of
applications including digital audio and servo control. Integrated as an execution unit in the
processor’s OEP, the MAC unit implements a three-stage arithmetic pipeline optimized for
16 x 16 multiplies. Both 16- and 32-bit input operands are supported by this design in
addition to a full set of extensions for signed and unsigned integers plus signed, fixed-point
fractional input operands.
The MAC unit provides functionality in three related areas:
•
•
•
Signed and unsigned integer multiplies
Multiply-accumulate operations supporting signed, unsigned, and signed fractional
operands
Miscellaneous register operations
Each of the three areas of support is addressed in detail in the succeeding sections. Logic
that supports this functionality is contained in a MAC module, as shown in Figure 3-1.
The MAC unit is tightly coupled to the OEP and features a three-stage execution pipeline.
To minimize silicon costs, the ColdFire MAC is optimized for 16 x 16 multiply
instructions. The OEP can issue a 16 x 16 multiply with a 32-bit accumulation and fetch a
32-bit operand in the same cycle. A 32 x 32 multiply with a 32-bit accumulation takes three
cycles before the next instruction can be issued. Figure 3-1 shows the basic functionality of
the ColdFire MAC. A full set of instructions is provided for signed and unsigned integers
plus signed, fixed-point, fractional input operands.
Chapter 3. Hardware Multiply/Accumulate (MAC) Unit
3-1
Overview
Operand Y
Operand X
X
Shift 0,1,-1
+/-
Accumulator
Figure 3-1. ColdFire MAC Multiplication and Accumulation
The MAC unit is an extension of the basic multiplier found on most microprocessors. It can
perform operations native to signal processing algorithms in an acceptable number of
cycles, given the application constraints. For example, small digital filters can tolerate some
variance in the execution time of the algorithm; larger, more complicated algorithms such
as orthogonal transforms may have more demanding speed requirements exceeding the
scope of any processor architecture and requiring a fully developed DSP implementation.
The M68000 architecture was not designed for high-speed signal processing, and a large
DSP engine would be excessive in an embedded environment. In striking a middle ground
between speed, size, and functionality, the ColdFire MAC unit is optimized for a small set
of operations that involve multiplication and cumulative additions. Specifically, the
multiplier array is optimized for single-cycle, 16 x 16 multiplies producing a 32-bit result,
with a possible accumulation cycle following. This is common in a large portion of signal
processing applications. In addition, the ColdFire core architecture has been modified to
allow for an operand fetch in parallel with a multiply, increasing overall performance for
certain DSP operations.
3.1.0.1 MAC Programming Model
Figure 3-2 shows the registers in the MAC portion of the user programming model.
31
0
MACSR
ACC
MASK
MAC status register
MAC accumulator
MAC mask register
Figure 3-2. MAC Programming Model
3-2
MCF5407 User’s Manual
Overview
These registers are described as follows:
•
•
•
Accumulator (ACC)—This 32-bit, read/write, general-purpose register is used to
accumulate the results of MAC operations.
Mask register (MASK)—This 16-bit general-purpose register provides an optional
address mask for MAC instructions that fetch operands from memory. It is useful in
the implementation of circular queues in operand memory.
MAC status register (MACSR)—This 8-bit register defines configuration of the
MAC unit and contains indicator flags affected by MAC instructions. Unless noted
otherwise, the setting of MACSR indicator flags is based on the final result, that is,
the result of the final operation involving the product and accumulator.
3.1.0.2 General Operation
The MAC unit supports the ColdFire integer multiply instructions (MULS and MULU) and
provides additional functionality for multiply-accumulate operations. The added MAC
instructions to the ColdFire ISA provide for the multiplication of two numbers, followed
by the addition or subtraction of this number to or from the value contained in the
accumulator. The product may be optionally shifted left or right one bit before the addition
or subtraction takes place. Hardware support for saturation arithmetic may be enabled to
minimize software overhead when dealing with potential overflow conditions using signed
or unsigned operands.
These MAC operations treat the operands as one of the following formats:
•
•
•
Signed integers
Unsigned integers
Signed, fixed-point, fractional numbers
To maintain compactness, the MAC module is optimized for 16-bit multiplications. Two
16-bit operands produce a 32-bit product. Longword operations are performed by reusing
the 16-bit multiplier array at the expense of a small amount of extra control logic. Again,
the product of two 32-bit operands is a 32-bit result. For longword integer operations, only
the least significant 32 bits of the product are calculated. For fractional operations, the
entire 63-bit product is calculated and then either truncated or rounded to a 32-bit result
using the round-to-nearest (even) method.
Because the multiplier array is implemented in a 3-stage pipeline, MAC instructions can
have an effective issue rate of one clock for word operations, three for longword integer
operations, and four for 32-bit fractional operations. Arithmetic operations use
register-based input operands, and summed values are stored internally in the accumulator.
Thus, an additional MOVE instruction is necessary to store data in a general-purpose
register. MAC instructions can choose the upper or lower word of a register as the input,
which helps filtering operations in which one data register is loaded with input data and
another is loaded with coefficient data. Two 16-bit MAC operations can be performed
without fetching additional operands between instructions by alternating the word choice
during the calculations.
Chapter 3. Hardware Multiply/Accumulate (MAC) Unit
3-3
Overview
The need to move large amounts of data quickly can limit throughput in DSP engines.
However, data can be moved efficiently by using the MOVEM instruction, which
automatically generates line-sized burst references and is ideal for filling registers quickly
with input data, filter coefficients, and output data. Loading an operand from memory into
a register during a MAC operation makes some DSP operations, especially filtering and
convolution, more manageable.
The MACSR has a 4-bit operational mode field and three condition flags. The operational
mode bits control the overflow/saturation mode, whether operands are signed or unsigned,
whether operands are treated as integers or fractions, and how rounding is performed.
Negative, zero and overflow flags are also provided.
The three program-visible MAC registers, a 32-bit accumulator (ACC), the MAC mask
register (MASK), and MACSR, are described in Section 3.1.0.1, “MAC Programming
Model.”
3.1.0.3 MAC Instruction Set Summary
The MAC unit supports the integer multiply operations defined by the baseline ColdFire
architecture, as well as the new multiply-accumulate instructions. Table 3-1 summarizes
the MAC unit instruction set.
Table 3-1. MAC Instruction Summary
Instruction
Mnemonic
Description
Multiply Signed
MULS <ea>y,Dx
Multiplies two signed operands yielding a signed result
Multiply Unsigned
MULU <ea>y,Dx
Multiplies two unsigned operands yielding an unsigned result
Multiply Accumulate
MAC Ry,RxSF
MSAC Ry,RxSF
Multiplies two operands, then adds or subtracts the product
to/from the accumulator
Multiply Accumulate
with Load
MAC Ry,RxSF,Rw
MSAC Ry,RxSF,Rw
Multiplies two operands, then adds or subtracts the product
to/from the accumulator while loading a register with the
memory operand
Load Accumulator
MOV.L {Ry,#imm},ACC
Loads the accumulator with a 32-bit operand
Store Accumulator
MOV.L ACC,Rx
Writes the contents of the accumulator to a register
Load MACSR
MOV.L {Ry,#imm},MACSR Writes a value to the MACSR
Store MACSR
MOV.L MACSR,Rx
Store MACSR to CCR
MOV.L MACSR,CCR
Write the contents of MACSR to the processor’s CCR register
Load MASK
MOV.L {Ry,#imm},MASK
Writes a value to MASK
Store MASK
MOV.L MASK,Rx
Writes the contents of MASK to a register
Write the contents of MACSR to a register
3.1.0.4 Data Representation
The MAC unit supports three basic operand types:
•
3-4
Two’s complement signed integer: In this format, an N-bit operand represents a
number within the range -2(N-1) < operand < 2(N-1) - 1. The binary point is to the right
of the least significant bit.
MCF5407 User’s Manual
MAC Instruction Execution Timings
•
•
Two’s complement unsigned integer: In this format, an N-bit operand represents a
number within the range 0 < operand < 2N - 1. The binary point is to the right of the
least significant bit.
Two’s complement, signed fractional: In an N-bit number, the first bit is the sign bit.
The remaining bits signify the first N-1 bits after the binary point. Given an N-bit
number, aN-1aN-2aN-3... a2a1a0, its value is given by the following formula:
N–2
+
∑2
(i + 1 – N)
⋅ ai
i=0
This format can represent numbers in the range -1 < operand < 1 - 2(N-1).
For words and longwords, the greatest negative number that can be represented is -1,
whose internal representation is 0x8000 and 0x0x8000_0000, respectively. The
most positive word is 0x7FFF or (1 - 2-15); the most positive longword is
0x7FFF_FFFF or (1 - 2-31).
3.2 MAC Instruction Execution Timings
Table 3-2 shows standard timings for two-operand MAC instructions.
Table 3-2. Two-Operand MAC Instruction Execution Times
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
mac.w
Ry,Rx
1(0/0)
—
—
—
—
—
—
—
mac.l
Ry,Rx
3(0/0)
—
—
—
—
—
—
—
msac.w
Ry,Rx
1(0/0)
—
—
—
—
—
—
—
msac.l
Ry,Rx
3(0/0)
—
—
—
—
—
—
—
mac.w
Ry,Rx,ea,Rw
—
1(1/0)
1(1/0)
1(1/0)
1(1/0)
—
—
—
mac.l
Ry,Rx,ea,Rw
—
3(1/0)
3(1/0)
3(1/0)
3(1/0)
—
—
—
msac.w
Ry,Rx,ea,Rw
—
1(1/0)
1(1/0)
1(1/0)
1(1/0)
—
—
—
msac.l
Ry,Rx,ea,Rw
—
3(1/0)
3(1/0)
3(1/0)
3(1/0)
—
—
—
muls.w
<ea>,Dx
3(0/0)
3(1/0)
3(1/0)
3(1/0)
3(1/0)
4(1/0)
3(1/0)
3(0/0)
mulu.w
<ea>,Dx
3(0/0)
3(1/0)
3(1/0)
3(1/0)
3(1/0)
4(1/0)
3(1/0)
3(0/0)
muls.l
<ea>,Dx
5(0/0)
5(1/0)
5(1/0)
5(1/0)
5(1/0)
—
—
—
mulu.l
<ea>,Dx
5(0/0)
5(1/0)
5(1/0)
5(1/0)
5(1/0)
—
—
—
Table 3-3 shows standard timings for MAC move instructions.
Chapter 3. Hardware Multiply/Accumulate (MAC) Unit
3-5
MAC Instruction Execution Timings
Table 3-3. MAC Move Instruction Execution Times
Effective Address
Opcode
<ea>
Rn
(An)
(An)+
-(An)
(d16,An)
(d8,An,Xi*SF)
(xxx).wl
#<xxx>
move.l
<ea>,ACC
1(0/0)
—
—
—
—
—
—
1(0/0)
move.l
<ea>,MACSR
6(0/0)
—
—
—
—
—
—
6(0/0)
move.l
<ea>,MASK
5(0/0)
—
—
—
—
—
—
5(0/0)
move.l
ACC,Rx
1(0/0)
—
—
—
—
—
—
—
move.l
MACSR,CCR
1(0/0)
—
—
—
—
—
—
—
move.l
MACSR,Rx
1(0/0)
—
—
—
—
—
—
—
move.l
MASK,Rx
1(0/0)
—
—
—
—
—
—
—
3-6
MCF5407 User’s Manual
Chapter 4
Local Memory
This chapter describes the MCF5407 implementation of the ColdFire Version 4 local
memory specification. It consists of two major sections.
•
•
Section 4.2, “SRAM Overview,” describes the MCF5407 on-chip static RAM
(SRAM) implementation. It covers general operations, configuration, and
initialization. It also provides information and examples showing how to minimize
power consumption when using the SRAM.
Section 4.7, “Cache Overview,” describes the MCF5407 cache implementation,
including organization, configuration, and coherency. It describes cache operations
and how the cache interfaces with other memory structures.
4.1 Interactions between Local Memory Modules
Depending on configuration information, instruction fetches and data read accesses may be
sent simultaneously to the RAM and cache controllers. This approach is required because
all three controllers are memory-mapped devices and the hit/miss determination is made
concurrently with the read data access. Power dissipation can be minimized by configuring
the RAMBARs to mask unused address spaces whenever possible.
If the access address is mapped into the region defined by the RAM (and this region is not
masked), the RAM provides the data back to the processor, and the cache data is discarded.
Accesses from the RAM module are never cached. The complete definition of the
processor’s local bus priority scheme for read references is as follows:
)
if (RAM “hits”
RAM supplies data to the processor
else if (data cache “hits”)
data cache supplies data to the processor
else system memory reference to access data
For data write references, the memory mapping into the local memories is resolved before
the appropriate destination memory is accessed. Accordingly, only the targeted local
memory is accessed for data write transfers.
4.2 SRAM Overview
The two 2-Kbyte on-chip SRAM modules provide pipelined, single-cycle access to
memory mapped to these modules. Memory can be independently mapped to any
Chapter 4. Local Memory
4-1
SRAM Operation
0-modulo-2K location in the 4-Gbyte address space and configured to respond to either
instruction or data accesses. Time-critical functions can be mapped into instruction
memory and the system stack. Other heavily-referenced data can be mapped into data
memory.
The following summarizes features of the MCF5407 SRAM implementation:
•
•
•
•
•
•
Two 2-Kbyte SRAMs, organized as 512 x 32 bits
Single-cycle throughput. When the pipeline is full, one access can occur per clock
cycle.
Physical location on the processor’s high-speed local bus with a user-programmed
connection to the internal instruction or data bus
Memory location programmable on any 0-modulo-2K address boundary
Byte, word, and longword address capabilities
The RAM base address registers (RAMBAR0 and RAMBAR1) define the logical
base address, attributes, and access types for the two SRAM modules.
4.3 SRAM Operation
Each SRAM module provides a general-purpose memory block that the ColdFire processor
can access with single-cycle throughput. The location of the memory block can be specified
to any word-aligned address in the 4-Gbyte address space by RAMBARn[BA], described
in Section 4.4.1, “SRAM Base Address Registers (RAMBAR0/RAMBAR1).” The memory
is ideal for storing critical code or data structures or for use as the system stack. Because
the SRAM module connects physically to the processor’s high-speed local bus, it can
service processor-initiated accesses or memory-referencing debug module commands.
The Version 4 ColdFire processor core implements a Harvard memory architecture. Each
SRAM module may be logically connected to either the processor’s internal instruction or
data bus. This logical connection is controlled by a configuration bit in the RAM base
address registers (RAMBAR0 and RAMBAR1).
If an instruction fetch is mapped into the region defined by the SRAM, the SRAM sources
the data to the processor and any cache data is discarded. Likewise, if a data access is
mapped into the region defined by the SRAM, the SRAM services the access and the cache
is not affected. Accesses from SRAM modules are never cached, and debug-initiated
references are treated as data accesses.
Note also that the SRAMs cannot be accessed by the on-chip DMAs. The on-chip system
configuration allows concurrent core and DMA execution, where the core can reference
code or data from the internal SRAMs or caches while performing a DMA transfer.
4-2
MCF5407 User’s Manual
SRAM Programming Model
Accesses are attempted in the following order:
1. SRAM
2. Cache (if space is defined as cacheable)
3. External access
4.4 SRAM Programming Model
The SRAM programming model consists of RAMBAR0 and RAMBAR1.
4.4.1 SRAM Base Address Registers (RAMBAR0/RAMBAR1)
The SRAM modules are configured through the RAMBARs, shown in Figure 4-1.
•
•
•
•
Each RAMBAR holds the base address of the SRAM. The MOVEC instruction
provides write-only access to this register from the processor.
Each RAMBAR can be read or written from the debug module in a similar manner.
All undefined RAMBAR bits are reserved. These bits are ignored during writes to
the RAMBAR and return zeros when read from the debug module.
The valid bits, RAMBARn[V], are cleared at reset, disabling the SRAM modules.
All other bits are unaffected.
31
Field
11
BA
10
9
—
Reset
8
WP
7
6
5
4
3
2
1
0
D/I — C/I SC SD UC UD
V
—
R/W
0
W for CPU; R/W for debug
Address
CPU space + 0xC04 (RAMBAR0), CPU space + 0xC05 (RAMBAR1)
Figure 4-1. SRAM Base Address Registers (RAMBARn)
RAMBARn fields are described in detail in Table 4-1.
Table 4-1. RAMBARn Field Description
Bits
Name
Description
31–11 BA
Base address. Defines the SRAM module’s word-aligned base address. Each SRAM module
occupies a 2-Kbyte space defined by the contents of BA. SRAM may reside on any 2-Kbyte
boundary in the 4-Gbyte address space.
10–9
—
Reserved, should be cleared.
8
WP
Write protect. Controls read/write properties of the SRAM.
0 Allows read and write accesses to the SRAM module
1 Allows only read accesses to the SRAM module. Any attempted write reference generates an
access error exception to the ColdFire processor core.
7
D/I
Data/instruction bus. Indicates whether SRAM is connected to the internal data or instruction bus.
0 Data bus
1 Instruction bus
Chapter 4. Local Memory
4-3
SRAM Initialization
Table 4-1. RAMBARn Field Description (Continued)
Bits
Name
Description
6
—
Reserved, should be cleared.
5–1
C/I,
SC,
SD,
UC,
UD
Address space masks (ASn). These fields allow certain types of accesses to be masked, or
inhibited from accessing the SRAM module. These bits are useful for power management as
described in Section 4.6, “Power Management.” In particular, C/I is typically set.
The address space mask bits are follows:
C/I = CPU space/interrupt acknowledge cycle mask. Note that C/I must be set if BA = 0.
SC = Supervisor code address space mask
SD = Supervisor data address space mask
UC = User code address space mask
UD = User data address space mask
For each ASn bit:
0 An access to the SRAM module can occur for this address space
1 Disable this address space from the SRAM module. If a reference using this address space is
made, it is inhibited from accessing the SRAM module and is processed like any other
non-SRAM reference.
0
V
Valid. Enables/disables the SRAM module. V is cleared at reset.
0 RAMBAR contents are not valid.
1 RAMBAR contents are valid.
The mapping of a given access into the RAM uses the following algorithm to determine if
the access hits in the memory:
if (RAMBAR[0] = 1)
if (((access = instructionFetch) & (RAMBAR[7] = 1)) |
((access = dataReference)
& (RAMBAR[7] = 0)))
if (requested address[31:10] = RAMBAR[31:10])
if (requested address[31:n] = RAMBAR[31:n]
if (ASn of the requested type = 0)
Access is mapped to the RAM module
if (access = read)
Read the RAM and return the data
if (access = write)
if (RAMBAR[8] = 0)
Write the data into the RAM
else Signal a write-protect access error
ASn refers to the five address space mask bits: C/I, SC, SD, UC, and UD.
4.5 SRAM Initialization
After a hardware reset, the contents of each SRAM module are undefined. The valid bits,
RAMBARn[V], are cleared, disabling the SRAM modules. If the SRAM requires
initialization with instructions or data, the following steps should be performed:
1. Load RAMBARn with bit 7 = 0, mapping the SRAM module to the desired location.
Clearing RAMBARn[7] logically connects the SRAM module to the processor’s
data bus.
4-4
MCF5407 User’s Manual
SRAM Initialization
2. Read the source data and write it to the SRAM. Various instructions support this
function, including memory-to-memory move instructions and the move multiple
instruction (MOVEM). MOVEM is optimized to generate line-sized burst fetches on
line-aligned addresses, so it generally provides maximum performance.
3. After the data is loaded into the SRAM, it may be appropriate to revise the
RAMBAR attribute bits, including the write-protect and address space mask fields.
If the SRAM contains instructions, RAMBAR[D/I] must be set to logically connect
the memory to the processor’s internal instruction bus.
Remember that the SRAM cannot be accessed by the on-chip DMAs. The on-chip system
configuration allows concurrent core and DMA execution where the core can execute code
out of internal SRAM or cache during DMA access.
The ColdFire processor or an external emulator using the debug module can perform these
initialization functions.
4.5.1 SRAM Initialization Code
The code segment below initializes the SRAM using RAMBAR0. The code sets the base
address of the SRAM at 0x2000_0000 and then initializes the RAM to zeros.
RAMBASE
RAMVALID
move.l
movec.l
EQU
0x20000000
EQU
0x00000035
#RAMBASE+RAMVALID,D0
D0, RAMBAR0
;set this variable to 0x20000000
;load RAMBASE + valid bit into D0
;load RAMBAR0 and enable SRAM
The following loop initializes the entire SRAM to zero:
lea.l
move.l
RAMBASE,A0
#512,D0
;load pointer to SRAM
;load loop counter into D0
(A0)+
#1,D0
SRAM_INIT_LOOP
;clear 4 bytes of SRAM
;decrement loop counter
;exit if done; else continue looping
SRAM_INIT_LOOP:
clr.l
subq.l
bne.b
The following function copies the number of bytesToMove from the source (*src) to the
processor’s local RAM at an offset relative to the SRAM base address defined by
destinationOffset. The bytesToMove must be a multiple of 16. For best performance, source
and destination SRAM addresses should be line-aligned (0-modulo-16).
; copyToCpuRam (*src, destinationOffset, bytesToMove)
RAMBASE
RAMFLAGS
lea.l
movem.l
EQU
EQU
0x20000000
0x00000035
-12(a7),a7
#0x1c,(a7)
;SRAM base address
;RAMBAR valid + mask bits
;allocate temporary space
;store D2/D3/D4 registers
; stack arguments and locations
Chapter 4. Local Memory
4-5
Power Management
;
;
;
;
;
;
;
+0
+4
+8
+12
+16
+20
+24
loop:
saved d2
saved d3
saved d4
returnPc
pointer to source operand
destinationOffset
bytesToMove
move.l
movec.l
RAMBASE+RAMFLAGS,a0
a0,rambar0
;define RAMBAR0 contents
;load it
move.l
16(a7),a0
;load argument defining *src
lea.l
add.l
RAMBASE,a1
20(a7),a1
;memory pointer to RAM base
;include destinationOffset
move.l
asr.l
24(a7),d4
#4,d4
;load byte count
;divide by 16 to convert to loop count
.align
movem.l
movem.l
lea.l
lea.l
subq.l
bne.b
4
(a0),#0xf
#0xf,(a1)
16(a0),a0
16(a1),a1
#1,d4
loop
;force loop on 0-mod-4 address
;read 16 bytes from source
;store into RAM destination
;increment source pointer
;increment destination pointer
;decrement loop counter
;if done, then exit, else continue
movem.l
lea.l
rts
(a7),#0x1c
12(a7),a7
;restore d2/d3/d4 registers
;deallocate temporary space
4.6 Power Management
Because processor memory references may be simultaneously sent to an SRAM module
and cache, power can be minimized by configuring RAMBAR address space masks as
precisely as possible. For example, if an SRAM is mapped to the internal instruction bus
and contains instruction data, setting the ASn mask bits associated with operand references
can decrease power dissipation. Similarly, if the SRAM contains data, setting ASn bits
associated with instruction fetches minimizes power.
Table 4-2 shows typical RAMBAR configurations.
.
Table 4-2. Examples of Typical RAMBAR Settings
Data Contained in SRAM
RAMBAR[5–0]
Code only
0x2B
Data only
0x35
Both code and data
0x21
4.7 Cache Overview
This section describes the MCF5407 cache implementation, including organization,
configuration, and coherency. It describes cache operations and how the cache interacts
with other memory structures.
4-6
MCF5407 User’s Manual
Cache Overview
The MCF5407 implements a special branch instruction cache for accelerating branches,
enabled by a bit in the cache access control register (CACR[BEC]). The branch cache is
described in Section 2.1.2.1.1, “Branch Acceleration.”
The MCF5407 processor’s Harvard memory structure includes an 8-Kbyte data cache and
a 16-Kbyte instruction cache. Both are nonblocking and 4-way set-associative with a
16-byte line. The cache improves system performance by providing single-cycle access to
the instruction and data pipelines. This decouples processor performance from system
memory performance, increasing bus availability for on-chip DMA or external devices.
Figure 4-2 shows the organization and integration of the data cache.
Cache
Control
External
Bus
Control
Control Logic
Control
Data Array
ColdFire
Processor
Core
System
Integration
Module
(SIM)
Directory Array
Data
Address
Address/
Data
Data
Data Path
Address
Address Path
Figure 4-2. Data Cache Organization
Both caches implement line-fill buffers to optimize line-sized burst accesses. The data
cache supports operation of copyback, write-through, or cache-inhibited modes. A
four-entry, 32-bit buffer supports cache line-push operations, and can be configured to defer
write buffering in write-through or cache-inhibited modes. The cache lock feature can be
used to guarantee deterministic response for critical code or data areas.
A nonblocking cache services read hits or write hits from the processor while a fill (caused
by a cache allocation) is in progress. As Figure 4-2 shows, accesses use a single bus
connected to the cache.
All addresses from the processor to the cache are physical addresses. A cache hit occurs
when an address matches a cache entry. For a read, the cache supplies data to the processor.
For a write, which is permitted only to the data cache, the processor updates the cache. If
an access does not match a cache entry (misses the cache) or if a write access must be
written through to memory, the cache performs a bus cycle on the internal bus and
correspondingly on the external bus by way of the system integration module (SIM).
The SRAM module does not implement bus snooping; cache coherency with other possible
bus masters must be maintained in software.
Chapter 4. Local Memory
4-7
Cache Organization
4.8 Cache Organization
A four-way set associative cache is organized as four ways (levels). There are 128 sets in
the 8-Kbyte data cache with each line containing 16 bytes (4 longwords). The 16-Kbyte
instruction cache has 256 sets. Entire cache lines are loaded from memory by burst-mode
accesses that cache 4 longwords of data or instructions. All 4 longwords must be loaded for
the cache line to be valid.
Figure 4-3 shows data cache organization as well as terminology used.
Way 0
Way 1
Way 2
Way 3
•
•
•
•
•
•
Line
•
•
•
•
•
•
Set 0
Set 1
Set 126
Set 127
Cache Line Format
TAG
V
M
Longword 0
Longword 1
Longword 2
Longword 3
Where:
TAG—21-bit address tag
V—Valid bit for line
M—Modified bit for line (data cache only)
Figure 4-3. Data Cache Organization and Line Format
A set is a group of four lines (one from each level, or way), corresponding to the same index
into the cache array.
4.8.1 Cache Line States: Invalid, Valid-Unmodified, and
Valid-Modified
As shown in Table 4-3, a data cache line can be invalid, valid-unmodified (often called
exclusive), or valid-modified. An instruction cache line can be valid or invalid.
Table 4-3. Valid and Modified Bit Settings
V
M
Description
0
x
Invalid. Invalid lines are ignored during lookups.
1
0
Valid, unmodified. Cache line has valid data that matches system memory.
1
1
Valid, modified. Cache line contains most recent data, data at system memory location is stale.
A valid line can be explicitly invalidated by executing a CPUSHL instruction.
4-8
MCF5407 User’s Manual
Cache Organization
4.8.2 The Cache at Start-Up
As Figure 4-4 (A) shows, after power-up, cache contents are undefined; V and M may be
set on some lines even though the cache may not contain the appropriate data for start up.
Because reset and power-up do not invalidate cache lines automatically, the cache should
be cleared explicitly by setting CACR[DCINVA,ICINVA] before the cache is enabled (B).
After the entire cache is flushed, cacheable entries are loaded first in way 0. If way 0 is
occupied, the cacheable entry is loaded into the same set in way 1, as shown in Figure 4-4
(D). This process is described in detail in Section 4.9, “Cache Operation.”
Chapter 4. Local Memory
4-9
Cache Organization
Invalid (V = 0)
Valid, not modified (V = 1, M = 0)
Valid, modified (V = 1, M = 1)
A:Cache population at
start-up
B:Cache after invalidation, C:Cache after loads in
before it is enabled
Way 0
D:First load in Way 1
Way 0 Way 1 Way 2 Way 3
Way 0 Way 1 Way 2 Way 3
Way 0 Way 1 Way 2 Way 3
Way 0 Way 1 Way 2 Way 3
At reset, cache contents
are indeterminate; V and
M may be set. The cache
should be cleared
explicitly by setting
CACR[DCINVA] before
the cache is enabled.
Setting CACR[DCINVA]
invalidates the entire
cache.
Initial cacheable
accesses to memory-fill
positions in way 0.
A line is loaded in
way 1 only if that set is
full in way 0.
Set 0
Set 127
Figure 4-4. Data Cache—A: at Reset, B: after Invalidation, C and D: Loading Pattern
4-10
MCF5407 User’s Manual
Cache Operation
4.9 Cache Operation
Figure 4-5 shows the general flow of a caching operation using the 8-Kbyte data cache as
an example. The discussion in this chapter assumes a data cache. Instruction cache
operations are similar except that there is no support for writing to the cache; therefore such
notions of modified cache lines and write allocation do not apply.
Address
31
11 10
Tag Data/Tag Reference
4 3 0
Way 3
Way 2
Way 1
Way 0
Index
Set
Select
A[10:4]
Set 0
TAG
Set 1
•
•
•
•
•
•
Set 127
TAG
STATUS LW0 LW1 LW2 LW3
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
STATUS LW0 LW1 LW2 LW3
Data
Address
A[31:11]
MUX
3
2
1
Comparator
0
Line Select
Hit 3
Hit 2
Hit 1
Hit 0
Logical OR
Hit
Figure 4-5. Data Caching Operation
The following steps determine if a data cache line is allocated for a given address:
1. The cache set index, A[10:4], selects one cache set.
2. A[31:11] and the cache set index are used as a tag reference or are used to update
the cache line tag field. Note that A[31:11] can specify 21 possible addresses that
can be mapped to one of the four ways.
3. The four tags from the selected cache set are compared with the tag reference. A
cache hit occurs if a tag matches the tag reference and the V bit is set, indicating that
the cache line contains valid data. If a cacheable write access hits in a valid cache
line, the write can occur to the cache line without having to load it from memory.
If the memory space is copyback, the updated cache line is marked modified
(M = 1), because the new data has made the data in memory out of date. If the
memory location is write-through, the write is passed on to system memory and the
M bit is never used. Note that the tag does not have TT or TM bits.
Chapter 4. Local Memory
4-11
Cache Operation
To allocate a cache entry, the cache set index selects one of the cache’s 128 sets. The cache
control logic looks for an invalid cache line to use for the new entry. If none is available,
the cache controller uses a pseudo-round-robin replacement algorithm to choose the line to
be deallocated and replaced. First the cache controller looks for an invalid line, with way 0
the highest priority. If all lines have valid data, a 2-bit replacement counter is used to choose
the way. After a line is allocated, the pointer increments to point to the next way.
Cache lines from ways 0 and 1 can be protected from deallocation by enabling half-cache
locking. If CACR[DHLCK,IHLCK] = 1, the replacement pointer is restricted to way 2 or 3.
As part of deallocation, a valid, unmodified cache line is invalidated. It is consistent with
system memory, so memory does not need to be updated. To deallocate a modified cache
line, data is placed in a push buffer (for an external cache line push) before being
invalidated. After invalidation, the new entry can replace it. The old cache line may be
written after the new line is read.
When a cache line is selected to host a new cache entry, the following three things happen:
1. The new address tag bits A[31:11] are written to the tag.
2. The cache line is updated with the new memory data.
3. The cache line status changes to a valid state (V = 1).
Read cycles that miss in the cache allocate normally as previously described.
Write cycles that miss in the cache do not allocate on a cacheable write-through region, but
do allocate for addresses in a cacheable copyback region.
A copyback byte, word, longword, or line write miss causes the following:
1.
2.
3.
4.
The cache initiates a line fill or flush.
Space is allocated for a new line.
V and M are both set to indicate valid and modified.
Data is written in the allocated space. No write to memory occurs.
Note the following:
•
•
•
•
4-12
Read hits cannot change the status bits and no deallocation or replacement occurs;
the data or instructions are read from the cache.
If the cache hits on a write access, data is written to the appropriate portion of the
accessed cache line. Write hits in cacheable, write-through regions generate an
external write cycle and the cache line is marked valid, but is never marked modified.
Write hits in cacheable copyback regions do not perform an external write cycle; the
cache line is marked valid and modified (V = 1 and M = 1).
Misaligned accesses are broken into at least two cache accesses.
Validity is provided only on a line basis. Unless a whole line is loaded on a cache
miss, the cache controller does not validate data in the cache line.
MCF5407 User’s Manual
Cache Operation
Write accesses designated as cache-inhibited by the CACR or ACR bypass the cache and
perform a corresponding external write.
Normally, cache-inhibited reads bypass the cache and are performed on the external bus.
The exception to this normal operation occurs when all of the following conditions are true
during a cache-inhibited read:
•
•
•
The cache-inhibited fill buffer bit, CACR[DNFB], is set.
The access is an instruction read.
The access is normal (that is, transfer type (TT) equals 0).
In this case, an entire line is fetched and stored in the fill buffer. It remains valid there, and
the cache can service additional read accesses from this buffer until either another fill or a
cache-invalidate-all operation occurs.
Valid cache entries that match during cache-inhibited address accesses are neither pushed
nor invalidated. Such a scenario suggests that the associated cache mode for this address
space was changed. To avoid this, it is generally recommended to use the CPUSHL
instruction to push or invalidate the cache entry or set CACR[DCINVA] to invalidate the
data cache before switching cache modes.
4.9.1 Caching Modes
For every memory reference generated by the processor or debug module, a set of effective
attributes is determined based on the address and the ACRs. Caching modes determine how
the cache handles an access. A data access can be cacheable in either write-through or
copyback mode; it can be cache-inhibited in precise or imprecise modes. For normal
accesses, the ACRn[CM] bit corresponding to the address of the access specifies the
caching modes. If an address does not match an ACR, the default caching mode is defined
by CACR[DDCM,IDCM]. The specific algorithm is as follows:
if (address == ACR0-address including mask)
effective attributes = ACR0 attributes
else if (address == ACR1-address including mask)
effective attributes = ACR1 attributes
else effective attributes = CACR default attributes
Addresses matching an ACR can also be write-protected using ACR[W]. Addresses that do
not match either ACR can be write-protected using CACR[DW].
Reset disables the cache and clears all CACR bits. As shown in Figure 4-4, reset does not
automatically invalidate cache entries; they must be invalidated through software.
The ACRs allow the defaults selected in the CACR to be overridden. In addition, some
instructions (for example, CPUSHL) and processor core operations perform accesses that
have an implicit caching mode associated with them. The following sections discuss the
different caching accesses and their associated cache modes.
Chapter 4. Local Memory
4-13
Cache Operation
4.9.1.1 Cacheable Accesses
If ACRn[CM] or the default field of the CACR indicates write-through or copyback, the
access is cacheable. A read access to a write-through or copyback region is read from the
cache if matching data is found. Otherwise, the data is read from memory and the cache is
updated. When a line is being read from memory for either a write-through or copyback
read miss, the longword within the line that contains the core-requested data is loaded first
and the requested data is given immediately to the processor, without waiting for the three
remaining longwords to reach the cache.
The following sections describe write-through and copyback modes in detail. Note that
some of this information applies to data caches only.
4.9.1.2 Write-Through Mode (Data Cache Only)
Write accesses to regions specified as write-through are always passed on to the external
bus, although the cycle can be buffered, depending on the state of CACR[DESB]. Writes in
write-through mode are handled with a no-write-allocate policy—that is, writes that miss
in the cache are written to the external bus but do not cause the corresponding line in
memory to be loaded into the cache. Write accesses that hit always write through to
memory and update matching cache lines. The cache supplies data to data-read accesses
that hit in the cache; read misses cause a new cache line to be loaded into the cache.
4.9.1.3 Copyback Mode (Data Cache Only)
Copyback regions are typically used for local data structures or stacks to minimize external
bus use and reduce write-access latency. Write accesses to regions specified as copyback
that hit in the cache update the cache line and set the corresponding M bit without an
external bus access.
Be sure to flush the cache using the CPUSHL instruction before invalidating the cache in
copyback mode. Modified cache data is written to memory only if the line is replaced
because of a miss or a CPUSHL instruction pushes the line. If a byte, word, longword, or
line write access misses in the cache, the required cache line is read from memory, thereby
updating the cache. When a miss selects a modified cache line for replacement, the
modified cache data moves to the push buffer. The replacement line is read into the cache
and the push buffer contents are then written to memory.
4.9.2 Cache-Inhibited Accesses
Memory regions can be designated as cache-inhibited, which is useful for memory
containing targets such as I/O devices and shared data structures in multiprocessing
systems. It is also important to not cache the MCF5407 memory mapped registers. If the
corresponding ACRn[CM] or CACR[DDCM] indicates cache-inhibited, precise or
imprecise, the access is cache-inhibited. The caching operation is identical for both
cache-inhibited modes, which differ only regarding recovery from an external bus error.
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MCF5407 User’s Manual
Cache Operation
In determining whether a memory location is cacheable or cache-inhibited, the CPU checks
memory-control registers in the following order:
1.
2.
3.
4.
RAMBARs
ACR0 and ACR2
ACR1 and ACR3
If an access does not hit in the RAMBARs or the ACRs, the default is provided for
all accesses in CACR.
Cache-inhibited write accesses bypass the cache and a corresponding external write is
performed. Cache-inhibited reads bypass the cache and are performed on the external bus,
except when all of the following conditions are true:
•
•
•
The cache-inhibited fill-buffer bit, CACR[DNFB], is set.
The access is an instruction read.
The access is normal (that is, TT = 0).
In this case, a fetched line is stored in the fill buffer and remains valid there; the cache can
service additional read accesses from this buffer until another fill occurs or a
cache-invalidate-all operation occurs.
If ACRn[CM] indicates cache-inhibited mode, precise or imprecise, the controller bypasses
the cache and performs an external transfer. If a line in the cache matches the address and
the mode is cache-inhibited, the cache does not automatically push the line if it is modified,
nor does it invalidate the line if it is valid. Before switching cache mode, execute a
CPUSHL instruction or set CACR[DCINVA,ICINVA] to invalidate the entire cache.
If ACRn[CM] indicates precise mode, the sequence of read and write accesses to the region
is guaranteed to match the instruction sequence. In imprecise mode, the processor core
allows read accesses that hit in the cache to occur before completion of a pending write
from a previous instruction. Writes are not deferred past data-read accesses that miss the
cache (that is, that must be read from the bus).
Precise operation forces data-read accesses for an instruction to occur only once by
preventing the instruction from being interrupted after data is fetched. Otherwise, if the
processor is not in precise mode, an exception aborts the instruction and the data may be
accessed again when the instruction is restarted. These guarantees apply only when
ACRn[CM] indicates precise mode and aligned accesses.
CPU space-register accesses, such as MOVEC, are treated as cache-inhibited and precise.
4.9.3 Cache Protocol
The following sections describe the cache protocol for processor accesses and assumes that
the data is cacheable (that is, write-through or copyback). Note that the discussion of write
operations applies to the data cache only.
Chapter 4. Local Memory
4-15
Cache Operation
4.9.3.1 Read Miss
A processor read that misses in the cache requests the cache controller to generate a bus
transaction. This bus transaction reads the needed line from memory and supplies the
required data to the processor core. The line is placed in the cache in the valid state.
4.9.3.2 Write Miss (Data Cache Only)
The cache controller handles processor writes that miss in the data cache differently for
write-through and copyback regions. Write misses to copyback regions cause the cache line
to be read from system memory, as shown in Figure 4-6.
1. Writing character X to 0x0B generates a write miss. Data cannot be written to an invalid line.
Cache Line
0x0C 0x08
MCF5407
0x04
0x00
V=0
M=0
X
2. The cache line (characters A–P) is updated from system memory, and line is marked valid.
0x0C 0x08 0x04 0x00
V=1
ABCD EFGH IJKL MNOP M = 0
System
Memory
3. After the cache line is filled, the write that initiated the write miss (the character X) completes to 0x0B.
MCF5407
0x0C 0x08 0x04 0x00
V=1
ABCD EXGH IJKL MNOP M = 1
Figure 4-6. Write-Miss in Copyback Mode
The new cache line is then updated with write data and the M bit is set for the line, leaving
it in modified state. Write misses to write-through regions write directly to memory without
loading the corresponding cache line into the cache.
4.9.3.3 Read Hit
On a read hit, the cache provides the data to the processor core and the cache line state
remains unchanged. If the cache mode changes for a specific region of address space, lines
in the cache corresponding to that region that contain modified data are not pushed out to
memory when a read hit occurs within that line. First execute a CPUSHL instruction or set
CACR[DCINVA,ICINVA] before switching the cache mode.
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MCF5407 User’s Manual
Cache Operation
4.9.3.4 Write Hit (Data Cache Only)
The cache controller handles processor writes that hit in the data cache differently for
write-through and copyback regions. For write hits to a write-through region, portions of
cache lines corresponding to the size of the access are updated with the data. The data is
also written to external memory. The cache line state is unchanged. For copyback accesses,
the cache controller updates the cache line and sets the M bit for the line. An external write
is not performed and the cache line state changes to (or remains in) the modified state.
4.9.4 Cache Coherency (Data Cache Only)
The MCF5407 provides limited cache coherency support in multiple-master environments.
Both write-through and copyback memory update techniques are supported to maintain
coherency between the cache and memory.
The cache does not support snooping (that is, cache coherency is not supported while
external or DMA masters are using the bus). Therefore, on-chip DMAs of the MCF5407
cannot access local memory and do not maintain coherency with the data cache.
4.9.5 Memory Accesses for Cache Maintenance
The cache controller performs all maintenance activities that supply data from the cache to
the core, including requests to the SIM for reading new cache lines and writing modified
lines to memory. The following sections describe memory accesses resulting from cache
fill and push operations. Chapter 18, “Bus Operation,” describes required bus cycles in
detail.
4.9.5.1 Cache Filling
When a new cache line is required, a line read is requested from the SIM, which generates
a burst-read transfer by indicating a line access with the size signals, SIZ[1:0].
The responding device supplies 4 consecutive longwords of data. Burst operations can be
inhibited or enabled through the burst read/write enable bits (BSTR/BSTW) in the
chip-select control registers (CSCR0–CSCR7).
SIM line accesses implicitly request burst-mode operations from memory. For more
information regarding external bus burst-mode accesses, see Chapter 18, “Bus Operation.”
The first cycle of a cache-line read loads the longword entry corresponding to the requested
address. Subsequent transfers load the remaining longword entries.
A burst operation is aborted by an a write-protection fault, which is the only possible access
error. Exception processing proceeds immediately. Note that unlike Version 2 and Version 3
access errors, the program counter stored on the exception stack frame points to the faulting
instruction. See Section 2.8.2, “Processor Exceptions.”
Chapter 4. Local Memory
4-17
Cache Operation
4.9.5.2 Cache Pushes
Cache pushes occur for line replacement and as required for the execution of the CPUSHL
instruction. To reduce the requested data’s latency in the new line, the modified line being
replaced is temporarily placed in the push buffer while the new line is fetched from
memory. After the bus transfer for the new line completes, the modified cache line is written
back to memory and the push buffer is invalidated.
4.9.5.2.1 Push and Store Buffers
The 16-byte push buffer reduces latency for requested new data on a cache miss by holding
a displaced modified data cache line while the new data is read from memory.
If a cache miss displaces a modified line, a miss read reference is immediately generated.
While waiting for the response, the current contents of the cache location load into the push
buffer. When the burst-read bus transaction completes, the cache controller can generate the
appropriate line-write bus transaction to write the push buffer contents into memory.
In imprecise mode, the FIFO store buffer can defer pending writes to maximize
performance. The store buffer can support as many as four entries (16 bytes maximum) for
this purpose.
Data writes destined for the store buffer cannot stall the core. The store buffer effectively
provides a measure of decoupling between the pipeline’s ability to generate writes (one per
cycle maximum) and the external bus’s ability to retire those writes. In imprecise mode,
writes stall only if the store buffer is full and a write operation is on the internal bus. The
internal write cycle is held, stalling the data execution pipeline.
If the store buffer is not used (that is, store buffer disabled or cache-inhibited precise mode),
external bus cycles are generated directly for each pipeline write operation. The instruction
is held in the pipeline until external bus transfer termination is received. Therefore, each
write is stalled for 5 cycles, making the minimum write time equal to 6 cycles when the
store buffer is not used. See Section 2.1.2.2, “Operand Execution Pipeline (OEP).”
The data store buffer enable bit, CACR[DESB], controls the enabling of the data store
buffer. This bit can be set and cleared by the MOVEC instruction. DESB is zero at reset and
all writes are performed in order (precise mode). ACRn[CM] or CACR[DDCM] generates
the mode used when DESB is set. Cacheable write-through and cache-inhibited imprecise
modes use the store buffer.
The store buffer can queue data as much as 4 bytes wide per entry. Each entry matches the
corresponding bus cycle it generates; therefore, a misaligned longword write to a
write-through region creates two entries if the address is to an odd-word boundary. It
creates three entries if it is to an odd-byte boundary—one per bus cycle.
4.9.5.2.2 Push and Store Buffer Bus Operation
As soon as the push or store buffer has valid data, the internal bus controller uses the next
available external bus cycle to generate the appropriate write cycles. In the event that
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MCF5407 User’s Manual
Cache Operation
another cache fill is required (for example, cache miss to process) during the continued
instruction execution by the processor pipeline, the pipeline stalls until the push and store
buffers are empty, then generate the required external bus transaction.
Supervisor instructions, the NOP instruction, and exception processing synchronize the
processor core and guarantee the push and store buffers are empty before proceeding. Note
that the NOP instruction should be used only to synchronize the pipeline. The preferred
no-operation function is the TPF instruction.
4.9.6 Cache Locking
Ways 0 and 1 of the data cache can be locked by setting CACR[DHLCK]; likewise, ways
0 and 1 of the instruction cache can be locked by setting CACR[IHLCK]. If a cache is
locked, cache lines in ways 0 and 1 are not subject to being deallocated by normal cache
operations.
As Figure 4-7 (B and C) shows, the algorithm for updating the cache and for identifying
cache lines to be deallocated is otherwise unchanged. If ways 2 and 3 are entirely invalid,
cacheable accesses are first allocated in way 2. Way 3 is not used until the location in way 2
is occupied.
Ways 0 and 1 are still updated on write hits (D in Figure 4-7) and may be pushed or cleared
only explicitly by using specific cache push/invalidate instructions. However, new cache
lines cannot be allocated in ways 0 and 1.
Chapter 4. Local Memory
4-19
Cache Operation
Invalid (V = 0)
Valid, not modified (V = 1, M = 0)
Valid, modified (V = 1, M = 1)
A:Ways 0 and 1 are filled.
Ways 2 and 3 are
invalid.
B:CACR[DHLCK] is set,
locking ways 0 and 1.
C:When a set in Way 2 is
D:Write hits to ways 0
occupied, the set in way 3 and 1 update cache
is used for a cacheable
lines.
access.
Way 0 Way 1 Way 2 Way 3
Way 0 Way 1 Way 2 Way 3
Way 0 Way 1 Way 2 Way 3
Way 0 Way 1 Way 2 Way 3
After CACR[DHLCK] is
set, subsequent cache
accesses go to ways 2
and 3.
While the cache is
locked and after a
position in ways is full,
the set in Way 3 is
updated.
While the cache is
locked, ways 0 and 1 can
be updated by write hits.
In this example, memory
is configured as
copyback, so updated
cache lines are marked
modified.
Set 0
Set 127
After reset, the cache is
invalidated, ways 0 and 1
are then written with data
that should not be
deallocated. Ways 0 and 1
can be filled
systematically by using
the INTOUCH instruction.
Figure 4-7. Data Cache Locking
4-20
MCF5407 User’s Manual
Cache Registers
4.10 Cache Registers
This section describes the MCF5407 implementation of the Version 4 cache registers.
4.10.1 Cache Control Register (CACR)
The CACR in Figure 4-8 contains bits for configuring the cache. It can be written by the
MOVEC register instruction and can be read or written from the debug facility. A hardware
reset clears CACR, which disables the cache; however, reset does not affect the tags, state
information, or data in the cache.
31
30
29
28
27
26
Field DEC DW DESB DDPI DHLCK
25
DDCM
Reset
24
23
DCINVA
20
19
18
BEC BCINVA
—
17
16
—
0000_0000_0000_0000
R/W
Write (R/W by debug module)
15
Field IEC
14
13
12
11
10
— DNFB IDPI IHLCK IDCM
Reset
9
8
—
ICINVA
7
0
—
0000_0000_0000_0000
R/W
Write (R/W by debug module)
Rc
0x002
Figure 4-8. Cache Control Register (CACR)
Table 4-4 describes CACR fields.
Table 4-4. CACR Field Descriptions
Bits
Name
Description
31
DEC
Enable data cache.
0 Cache disabled. The data cache is not operational, but data and tags are preserved.
1 Cache enabled.
30
DW
Data default write-protect. For normal operations that do not hit in the RAMBARs or ACRs, this
field defines write-protection. See Section 4.9.1, “Caching Modes.”
0 Not write protected.
1 Write protected. Write operations cause an access error exception.
29
DESB
Enable data store buffer. Affects the precision of transfers. CACR[DESB] has precedence over
CACR[9–8] and ACRn[9–8]; therefore, the store buffer must be disabled to use imprecise mode.
0 Imprecise-mode, write-through or cache-inhibited writes bypass the store buffer and generate
bus cycles directly. Section 4.9.5.2.1, “Push and Store Buffers,” describes the associated
performance penalty.
1 The four-entry FIFO store buffer is enabled; to maximize performance, this buffer defers
pending imprecise-mode, write-through or cache-inhibited writes.
Precise-mode, cache-inhibited accesses always bypass the store buffer. Precise and imprecise
modes are described in Section 4.9.2, “Cache-Inhibited Accesses.”
28
DDPI
Disable CPUSHL invalidation.
0 Normal operation. A CPUSHL instruction causes the selected line to be pushed if modified and
then invalidated.
1 No clear operation. A CPUSHL instruction causes the selected line to be pushed if modified,
then left valid.
Chapter 4. Local Memory
4-21
Cache Registers
Table 4-4. CACR Field Descriptions (Continued)
Bits
Name
Description
27
DHLCK
Half-data cache lock mode
0 Normal operation. The cache allocates the lowest invalid way. If all ways are valid, the cache
allocates the way pointed at by the counter and then increments this counter modulo-4.
1 Half-cache operation. The cache allocates to the lower invalid way of levels 2 and 3; if both are
valid, the cache allocates to way 2 if the high-order bit of the round-robin counter is zero;
otherwise, it allocates way 3 and increments the round-robin counter modulo-2. This locks the
content of ways 0 and 1. Ways 0 and 1 are still updated on write hits and may be pushed or
cleared by specific cache push/invalidate instructions.
This implementation allows maximum use of available cache memory and provides the flexibility
of setting DHLCK before, during, or after allocations occur.
26–25
DDCM
Default data cache mode. For normal operations that do not hit in the RAMBARs or ACRs, this
field defines the effective cache mode.
00 Cacheable write-through imprecise
01 Cacheable copyback
10 Cache-inhibited precise
11 Cache-inhibited imprecise
Precise and imprecise accesses are described in Section 4.9.2, “Cache-Inhibited Accesses.”
24
23–20
DCINVA
—
19
BEC
18
BCINVA
17–16
—
15
IEC
14
—
13
DNFB
12
IDPI
4-22
Data cache invalidate all. Writing a 1 to this bit initiates entire cache invalidation. Once
invalidation is complete, this bit automatically returns to 0; it is not necessary to clear it explicitly.
Note the caches are not cleared on power-up or normal reset, as shown in Figure 4-4.
0 No invalidation is performed.
1 Initiate invalidation of the entire data cache. The cache controller sequentially clears V and M
bits in all sets. Subsequent data accesses stall until the invalidation is finished, at which point,
this bit is automatically cleared. In copyback mode, the cache should be flushed using a
CPUSHL instruction before setting this bit.
Reserved, should be cleared.
Enable branch cache. The branch cache is described in Section 2.1.2.1.1, “Branch Acceleration.”
0 Branch cache disabled. This may be useful if code is unlikely to be reused.
1 Branch cache enabled.
Branch cache invalidate. Invalidation occurs when this bit is written as a 1. Note that branch
caches are not cleared on power-up or normal reset.
0 No invalidation is performed.
1 Initiate an invalidation of the entire branch cache.
Reserved. These bits must be cleared; otherwise performance may be affected.
Enable instruction cache
0 Instruction cache disabled. All instructions and tags in the cache are preserved.
1 Instruction cache enabled.
Reserved, should be cleared.
Default cache-inhibited fill buffer
0 Fill buffer does not store cache-inhibited instruction accesses (16 or 32 bits).
1 Fill buffer can store cache-inhibited accesses. The buffer is used only for normal (TT = 0)
instruction reads of a cache-inhibited region. Instructions are loaded into the buffer by a burst
access (line fill). They stay in the buffer until they are displaced; subsequent accesses may not
appear on the external bus.
Setting DNFB can cause a coherency problem for self-modifying code. If a cache-inhibited
access uses the buffer while DNFB = 1, instructions remain valid in the buffer until a
cache-invalidate-all instruction, another cache-inhibited burst, or a miss that initiates a fill. A write
to the line in the fill goes to the external bus without updating or invalidating the buffer.
Subsequent reads of that written data are serviced by the fill buffer and receive stale information.
Instruction CPUSHL invalidate disable.
0 Normal operation. A CPUSHL instruction causes the selected line to be invalidated.
1 No clear operation. A CPUSHL instruction causes the selected line to be left valid.
MCF5407 User’s Manual
Cache Registers
Table 4-4. CACR Field Descriptions (Continued)
Bits
Name
Description
11
IHLCK
Instruction cache half-lock.
0 Normal operation. The cache allocates to the lowest invalid way; if all ways are valid, the cache
allocates to the way pointed at by the round-robin counter and then increments this counter
modulo-4.
1 Half cache operation. The cache allocates to the lowest invalid way of ways 2 and 3; if both of
these ways are valid, the cache allocates to way 2 if the high-order bit of the round-robin
counter is zero; otherwise, it allocates way 3 and then increments the round-robin counter
modulo-2. This locks the content of ways 0 and 1. Ways 0 and 1 are still updated on write hits
and may be pushed or cleared by specific cache push/invalidate instructions.
This implementation allows maximum use of the available cache memory and also provides the
flexibility of setting IHLCK before, during, or after the needed allocations occur.
10
IDCM
Instruction default cache mode. For normal operations that do not hit in the RAMBARs or ACRs,
this field defines the effective cache mode.
0 Cacheable
1 Cache-inhibited
9
—
Reserved, should be cleared.
8
ICINVA
Instruction cache invalidate. Invalidation occurs when this bit is written as a 1. Note the caches
are not cleared on power-up or normal reset.
0 No invalidation is performed.
1 Initiate invalidation of instruction cache. The cache controller sequentially clears all V bits.
Subsequent local memory bus accesses stall until invalidation completes, at which point,
ICINVA is cleared automatically without software intervention. For copyback mode, use
CPUSHL before setting ICINVA.
7–0
—
Reserved. These bits must be cleared; otherwise, performance may be affected.
4.10.2 Access Control Registers (ACR0–ACR3)
The ACRs, Figure 4-9, assign control attributes, such as cache mode and write protection,
to specified memory regions. ACR0 and ACR1 control data attributes; ACR2 and ACR3
control instruction attributes. Registers are accessed with the MOVEC instruction with the
Rc encodings in Figure 4-9.
For overlapping data regions, ACR0 takes priority; ACR2 takes priority for overlapping
instruction regions. Data transfers to and from these registers are longword transfers. Bits
12–7, 4, 3, 1, and 0 are always read as zeros.
NOTE:
The SIM MBAR region should be mapped as cache-inhibited
through an ACR.
Chapter 4. Local Memory
4-23
Cache Management
31
Field
24 23
Address Base
Reset
16 15 14 13 12
Address Mask
Uninitialized
R/W
E
S
7
6
—
0
5
CM
4
3
—
2
W1
1
0
—
Uninitialized
Write (R/W by debug module)
Rc
ACR0: 0x004; ACR1: 0x005; ACR2: 0x006; ACR3: 0x007
1 Reserved
in ACR2 and ACR3.
Figure 4-9. Access Control Register Format (ACRn)
Table 4-5 describes ACRn fields.
I
Table 4-5. ACRn Field Descriptions
Bits
Name
Description
31–24
Address
base
Address base. Compared with address bits A[31:24]. Eligible addresses that match are
assigned the access control attributes of this register.
23–16
Address
mask
Address mask. Setting a mask bit causes the corresponding address base bit to be ignored.
The low-order mask bits can be set to define contiguous regions larger than 16 Mbytes. The
mask can define multiple noncontiguous regions of memory.
15
E
Enable. Enables or disables the other ACRn bits.
0 Access control attributes disabled
1 Access control attributes enabled
14–13
S
Supervisor mode. Specifies whether only user or supervisor accesses are allowed in this
address range or if the type of access is a don’t care.
00 Match addresses only in user mode
01 Match addresses only in supervisor mode
1x Execute cache matching on all accesses
12–7
—
Reserved; should be cleared.
6–5
CM
Cache mode. Selects the cache mode and access precision. Precise and imprecise modes are
described in Section 4.9.2, “Cache-Inhibited Accesses.”
00 Cacheable, write-through
01 Cacheable, copyback
10 Cache-inhibited, precise
11 Cache-inhibited, imprecise
4–3
—
Reserved, should be cleared.
2
W
ACR0/ACR1 only. Write protect. Selects the write privilege of the memory region. ACR2[2] and
ACR3[2] are reserved.
0 Read and write accesses permitted
1 Write accesses not permitted
1–0
—
Reserved, should be cleared.
4.11 Cache Management
The cache can be enabled and configured by using a MOVEC instruction to access CACR.
A hardware reset clears CACR, disabling the cache and removing all configuration
information; however, reset does not affect the tags, state information, and data in the cache.
Set CACR[DCINVA,ICINVA] to invalidate the caches before enabling them.
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MCF5407 User’s Manual
Cache Management
The privileged CPUSHL instruction supports cache management by selectively pushing
and invalidating cache lines. The address register used with CPUSHL directly addresses the
cache’s directory array. The CPUSHL instruction flushes a cache line.
The value of CACR[DDPI,IDPI] determines whether CPUSHL invalidates a cache line
after it is pushed. To push the entire cache, implement a software loop to index through all
sets and through each of the four lines within each set (a total of 512 lines for the data cache
and 1024 lines for the instruction cache). The state of CACR[DEC,IEC] does not affect the
operation of CPUSHL or CACR[DCINVA,ICINVA]. Disabling a cache by setting
CACR[IEC] or CACR[DEC] makes the cache nonoperational without affecting tags, state
information, or contents.
The contents of An used with CPUSHL specify cache row and line indexes. This differs
from the MC68040 where a physical address is specified. Figure 4-11 shows the An format
for the data cache.
31
11
10
0
4
3
Set Index
0
Line Index
Figure 4-10. An Format (Data Cache)
Figure 4-11 shows the An format for the instruction cache.
31
12
11
0
4
Set Index
3
0
Line Index
Figure 4-11. An Format (Instruction Cache)
The following code example flushes the entire data cache:
_cache_disable:
nop
move.w
jsr
clr.l
movec
movec
move.l
movec
rts
#0x2700,SR
_cache_flush
d0
d0,ACR0
d0,ACR1
#0x01000000,d0
d0,CACR
;mask off IRQs
;flush the cache completely
;ACR0 off
;ACR1 off
;Invalidate and disable cache
_cache_flush:
nop
moveq.l
moveq.l
move.l
#0,d0
#0,d1
d0,a0
;synchronize—flush store buffer
;initialize way counter
;initialize set counter
;initialize cpushl pointer
setloop:
cpushl
add.l
addq.l
cmpi.l
bne
dc,(a0)
#0x0010,a0
#1,d1
#128,d1
setloop
;push cache line a0
;increment set index by 1
;increment set counter
;are sets for this way done?
#0,d1
;set counter to zero again
moveq.l
Chapter 4. Local Memory
4-25
Cache Management
addq.l
move.l
cmpi.l
bne
rts
#1,d0
d0,a0
#4,d0
setloop
;increment to next way
;set = 0, way = d0
;flushed all the ways?
The following CACR loads assume the instruction cache has been invalidated, the default
instruction cache mode is cacheable, and the default data cache mode is copyback.
dataCacheLoadAndLock:
move.l
movec
#0xa3080800,d0; enable and invalidate data cache ...
d0,cacr ; ... in the CACR
The following code preloads half of the data cache (4 Kbytes). It assumes a contiguous
block of data is to be mapped into the data cache, starting at a 0-modulo-4K address.
move.l
lea
dataCacheLoop:
tst.b
lea
subq.l
bne.b
#256,d0
data_,a0
;256 16-byte lines in 4K space
; load pointer defining data area
(a0)
16(a0),a0
#1,d0
dataCacheLoop
;touch location + load into data cache
;increment address to next line
;decrement loop counter
;if done, then exit, else continue
; A 4K region has been loaded into levels 0 and 1 of the 8K data cache. lock it!
move.l
movec
rts
#0xaa088000,d0
d0,cacr
align
16
;set the data cache lock bit ...
; ... in the CACR
The following CACR loads assume the data cache has been invalidated, the default
instruction cache mode is cacheable and the default operand cache mode is copyback.
Note that this function must be mapped into a cache inhibited or SRAM space or these text
lines will be prefetched into the instruction cache, which may displace some of the 8-Kbyte
space being explicitly fetched.
instructionCacheLoadAndLock:
move.l
movec
#0xa2088100,d0
d0,cacr
;enable and invalidate the instruction
;cache in the CACR
The following code segments preload half of the instruction cache (8 Kbytes). It assumes a
contiguous block of data is to be mapped, starting at a 0-modulo-8K address
move.l #512,d0
lea
code_,a0
instCacheLoop:
;
intouch (a0)
;512 16-byte lines in 8K space
;load pointer defining code area
;touch location + load into instruction cache
; Note in the assembler we use, there is no INTOUCH opcode. The following
; is used to produce the required binary representation
cpushl
4-26
#nc,(a0)
;touch location + load into
MCF5407 User’s Manual
Cache Operation Summary
;instruction cache
lea
16(a0),a0
;increment address to next line
subq.l #1,d0
;decrement loop counter
bne.b
instCacheLoop
;if done, then exit, else continue
; A 8K region was loaded into levels 0 and 1 of the 16-Kbyte instruction cache.
; lock it!
move.l
movec
rts
#0xa2088800,d0
d0,cacr
;set the instruction cache lock bit
;in the CACR
4.12 Cache Operation Summary
This section gives operational details for the cache and presents instruction and data
cache-line state diagrams.
4.12.1 Instruction Cache State Transitions
Because the instruction cache does not support writes, it supports fewer operations than the
data cache. As Figure 4-12 shows, an instruction cache line can be in one of two states, valid
or invalid. Modified state is not supported. Transitions are labeled with a capital letter
indicating the previous state and with a number indicating the specific case listed in
Table 4-6. These numbers correspond to the equivalent operations on data caches,
described in Section 4.12.2, “Data Cache State Transitions.”
II5—ICINVA
II6—CPUSHL & IDPI
II7—CPUSHL & IDPI
IV1—CPU read miss
IV2—CPU read hit
IV7—CPUSHL & IDPI
II1—CPU read miss
Invalid
V=0
Valid
V=1
IV5—ICINVA
IV6—CPUSHL & IDPI
Figure 4-12. Instruction Cache Line State Diagram
Table 4-6 describes the instruction cache state transitions shown in Figure 4-12.
Table 4-6. Instruction Cache Line State Transitions
Current State
Access
Invalid (V = 0)
Valid (V = 1)
Read miss
II1
Read line from memory and update cache; IV1 Read new line from memory and update cache;
supply data to processor; stay in valid state.
supply data to processor;
go to valid state.
Read hit
II2
Not possible
IV2 Supply data to processor;
stay in valid state.
Write miss
II3
Not possible
IV3 Not possible
Write hit
II4
Not possible
IV4 Not possible
Chapter 4. Local Memory
4-27
Cache Operation Summary
Table 4-6. Instruction Cache Line State Transitions (Continued)
Current State
Access
Invalid (V = 0)
Valid (V = 1)
Cache
invalidate
II5
No action;
stay in invalid state.
IV5 No action;
go to invalid state.
Cache
push
II6, No action;
II7 stay in invalid state.
IV6 No action;
go to invalid state.
IV7 No action;
stay in valid state.
4.12.2 Data Cache State Transitions
Using the V and M bits, the data cache supports a line-based protocol allowing individual
cache lines to be invalid, valid, or modified. To maintain memory coherency, the data cache
supports both write-through and copyback modes, specified by the corresponding
ACR[CM], or CACR[DDCM] if no ACR matches.
Read or write misses to copyback regions cause the cache controller to read a cache line
from memory into the cache. If available, tag and data from memory update an invalid line
in the selected set. The line state then changes from invalid to valid by setting the V bit. If
all lines in the row are already valid or modified, the pseudo-round-robin replacement
algorithm selects one of the four lines and replaces the tag and data. Before replacement,
modified lines are temporarily buffered and later copied back to memory after the new line
has been read from memory.
Figure 4-13 shows the three possible data cache line states and possible processor-initiated
transitions for memory configured as copyback. Transitions are labeled with a capital letter
indicating the previous state and a number indicating the specific case listed in Table 4-7.
CI5—DCINVA
CI6—CPUSHL & DDPI
CI7—CPUSHL & DDPI
CV1—CPU read miss
CV2—CPU read hit
CV7—CPUSHL & DDPI
CI1—CPU read miss
Valid
V=1
M=0
CV5—DCINVA
CV6—CPUSHL & DDPI
CI3—CPU
write miss
CD1—CPU
read miss
CD7—CPUSHL
& DDPI
CD5—DCINVA
CV3—CPU write miss
CD6—CPUSHL & DDPI
CV4—CPU write hit
Modified
V=1
M=1
CD2—CPU read hit
CD3—CPU write miss
CD4—CPU write hit
Invalid
V=0
Figure 4-13. Data Cache Line State Diagram—Copyback Mode
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MCF5407 User’s Manual
Cache Operation Summary
Figure 4-14 shows the two possible states for a cache line in write-through mode.
WV1—CPU read miss
WV2—CPU read hit
WV3—CPU write miss
WV4—CPU write hit
WV7—CPUSHL & DDPI
WI3—CPU write miss
WI5—DCINVA
WI6—CPUSHL & DDPI
WI7—CPUSHL & DDPI
WI1—CPU read miss
Invalid
V=0
Valid
V=1
WV5—DCINVA
WV6—CPUSHL & DDPI
Figure 4-14. Data Cache Line State Diagram—Write-Through Mode
Table 4-7 describes data cache line transitions and the accesses that cause them.
Table 4-7. Data Cache Line State Transitions
Current State
Access
Invalid (V = 0)
Valid (V = 1, M = 0)
Modified (V = 1, M = 1)
Read
miss
(C,W)I1 Read line from
memory and update
cache;
supply data to
processor;
go to valid state.
(C,W)V1 Read new line from
memory and update
cache;
supply data to processor;
stay in valid state.
CD1 Push modified line to
buffer;
read new line from memory
and update cache;
supply data to processor;
write push buffer contents
to memory;
go to valid state.
Read hit
(C,W)I2 Not possible.
(C,W)V2 Supply data to processor;
stay in valid state.
CD2 Supply data to processor;
stay in modified state.
Write
miss
(copyback)
CI3
Read line from
memory and update
cache;
write data to cache;
go to modified state.
CV3
Read new line from
memory and update
cache;
write data to cache;
go to modified state.
CD3 Push modified line to
buffer;
read new line from memory
and update cache;
write push buffer contents
to memory;
stay in modified state.
Write
miss
(writethrough)
WI3
Write data to
memory;
stay in invalid state.
WV3
Write data to memory;
stay in valid state.
WD3 Write data to memory;
stay in modified state.
Cache mode changed for
the region corresponding to
this line. To avoid this state,
execute a CPUSHL
instruction or set
CACR[DCINVA,ICINVA]
before switching modes.
Write hit
(copyback)
CI4
Not possible.
CV4
Write data to cache;
go to modified state.
CD4 Write data to cache;
stay in modified state.
Chapter 4. Local Memory
4-29
Cache Operation Summary
Table 4-7. Data Cache Line State Transitions (Continued)
Current State
Access
Invalid (V = 0)
Write hit
(writethrough)
WI4
Not possible.
Valid (V = 1, M = 0)
WV4
Write data to memory and
to cache;
stay in valid state.
Modified (V = 1, M = 1)
WD4 Write data to memory and
to cache;
go to valid state.
Cache mode changed for
the region corresponding to
this line. To avoid this state,
execute a CPUSHL
instruction or set
CACR[DCINVA,ICINVA]
before switching modes.
Cache
(C,W)I5 No action;
invalidate
stay in invalid state.
(C,W)V5 No action;
go to invalid state.
CD5 No action (modified data
lost);
go to invalid state.
Cache
push
(C,W)V6 No action;
go to invalid state.
CD6 Push modified line to
memory;
go to invalid state.
(C,W)V7 No action;
stay in valid state.
CD7 Push modified line to
memory;
go to valid state.
(C,W)I6 No action;
(C,W)I7 stay in invalid state.
The following tables present the same information as Table 4-7, organized by the current
state of the cache line. In Table 4-8 the current state is invalid.
Table 4-8. Data Cache Line State Transitions (Current State Invalid)
Access
Response
Read miss
(C,W)I1 Read line from memory and update cache;
supply data to processor;
go to valid state.
Read hit
(C,W)I2 Not possible
Write miss (copyback)
CI3
Read line from memory and update cache;
write data to cache;
go to modified state.
Write miss (write-through)
WI3
Write data to memory;
stay in invalid state.
Write hit (copyback)
CI4
Not possible
Write hit (write-through)
WI4
Not possible
Cache invalidate
(C,W)I5 No action;
stay in invalid state.
Cache push
(C,W)I6 No action;
stay in invalid state.
Cache push
(C,W)I7 No action;
stay in invalid state.
In Table 4-9 the current state is valid.
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MCF5407 User’s Manual
Cache Operation Summary
Table 4-9. Data Cache Line State Transitions (Current State Valid)
Access
Response
Read miss
(C,W)V1 Read new line from memory and update cache;
supply data to processor; stay in valid state.
Read hit
(C,W)V2 Supply data to processor;
stay in valid state.
Write miss (copyback)
CV3
Read new line from memory and update cache;
write data to cache;
go to modified state.
Write miss (write-through)
WV3
Write data to memory;
stay in valid state.
Write hit (copyback)
CV4
Write data to cache;
go to modified state.
Write hit (write-through)
WV4
Write data to memory and to cache;
stay in valid state.
Cache invalidate
(C,W)V5 No action;
go to invalid state.
Cache push
(C,W)V6 No action;
go to invalid state.
Cache push
(C,W)V7 No action;
stay in valid state.
In Table 4-10 the current state is modified.
Table 4-10. Data Cache Line State Transitions (Current State Modified)
Access
Response
Read miss
CD1 Push modified line to buffer;
read new line from memory and update cache;
supply data to processor;
write push buffer contents to memory;
go to valid state.
Read hit
CD2 Supply data to processor;
stay in modified state.
Write miss
(copyback)
CD3 Push modified line to buffer;
read new line from memory and update cache;
write push buffer contents to memory;
stay in modified state.
Write miss
(write-through)
WD3 Write data to memory;
stay in modified state.
Cache mode changed for the region corresponding to this line. To avoid this state,
execute a CPUSHL instruction or set CACR[DCINVA,ICINVA] before switching modes.
Write hit
(copyback)
CD4 Write data to cache;
stay in modified state.
Write hit
(write-through)
WD4 Write data to memory and to cache;
go to valid state.
Cache mode changed for the region corresponding to this line. To avoid this state,
execute a CPUSHL instruction or set CACR[DCINVA,ICINVA] before switching modes.
Chapter 4. Local Memory
4-31
Cache Initialization Code
Table 4-10. Data Cache Line State Transitions (Current State Modified) (Continued)
Access
Response
Cache invalidate
CD5 No action (modified data lost);
go to invalid state.
Cache push
CD6 Push modified line to memory;
go to invalid state.
Cache push
CD7 Push modified line to memory;
go to valid state.
4.13 Cache Initialization Code
The following example sets up the cache for FLASH or ROM space only.
move.l#0xA30C8100,D0 //enable cache, invalidate it,
//default mode is cache-inhibited imprecise
movecD0, CACR
move.l #0xFF00C000,D0//cache FLASH space, enable,
//ignore FC2, cacheable, writethrough
movecD0,ACR0
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MCF5407 User’s Manual
Chapter 5
Debug Support
This chapter describes the Revision C enhanced hardware debug support in the MCF5407.
This revision of the ColdFire debug architecture encompasses the two earlier revisions.
5.1 Overview
The debug module is shown in Figure 5-1.
High-speed
local bus
ColdFire CPU Core
Debug Module
Control
BKPT
Trace Port
PSTDDATA[7:0]
PSTCLK
Communication Port
DSCLK, DSI, DSO
Figure 5-1. Processor/Debug Module Interface
Debug support is divided into three areas:
•
•
•
Real-time trace support—The ability to determine the dynamic execution path
through an application is fundamental for debugging. The ColdFire solution
implements an 8-bit parallel output bus that reports processor execution status and
data to an external emulator system. See Section 5.3, “Real-Time Trace Support.”
Background debug mode (BDM)—Provides low-level debugging in the ColdFire
processor complex. In BDM, the processor complex is halted and a variety of
commands can be sent to the processor to access memory and registers. The external
emulator uses a three-pin, serial, full-duplex channel. See Section 5.5, “Background
Debug Mode (BDM),” and Section 5.4, “Programming Model.”
Real-time debug support—BDM requires the processor to be halted, which many
real-time embedded applications cannot do. Debug interrupts let real-time systems
execute a unique service routine that can quickly save the contents of key registers
and variables and return the system to normal operation. The emulator can access
saved data because the hardware supports concurrent operation of the processor and
BDM-initiated commands. See Section 5.6, “Real-Time Debug Support.”
Chapter 5. Debug Support
5-1
Signal Descriptions
The Version 2 ColdFire core implemented the original debug architecture, now called
Revision A. Based on feedback from customers and third-party developers, enhancements
have been added to succeeding generations of ColdFire cores. The Version 3 core
implements the Revision B of the debug architecture, providing more flexibility for
configuring the hardware breakpoint trigger registers and removing the restrictions
involving concurrent BDM processing while hardware breakpoint registers are active.
The MCF5407 core implements Revision C of the debug architecture, which more than
doubles the on-chip breakpoint registers and provides an ability to interrupt debug service
routines. For Revision C, the revision level bit, CSR[HRL], is 2. See Section 5.4.4,
“Configuration/Status Register (CSR).”
5.2 Signal Descriptions
Table 5-1 describes debug module signals. All ColdFire debug signals are unidirectional
and related to a rising edge of the processor core’s clock signal. The standard 26-pin debug
connector is shown in Section 5.7, “Motorola-Recommended BDM Pinout.”
Table 5-1. Debug Module Signals
Signal
Description
Development Serial
Clock (DSCLK)
Internally synchronized input that clocks the serial communication port to the debug module.
Maximum frequency is 1/5 the processor CLK speed. At the synchronized rising edge of
DSCLK, the data input on DSI is sampled and DSO changes state. The logic level on DSCLK is
validated if it has the same value on two consecutive rising CLKIN edges.
Development Serial
Input (DSI)
Internally synchronized input that provides data input for the serial communication port to the
debug module.
Development Serial
Output (DSO)
Provides serial output communication for debug module responses. DSO is registered
internally.
Breakpoint (BKPT)
Used to request a manual breakpoint. Assertion of BKPT puts the processor into a halted state
after the current instruction completes. Halt status is reflected on processor status/debug data
signals (PSTDDATA[7:0]) as the value 0xF. If CSR[BKD] is set (disabling normal BKPT
functionality), asserting BKPT generates a debug interrupt exception in the processor.
Processor Status
Clock (PSTCLK)
Half-speed version of the processor clock. Its rising edge appears in the center of the two
processor-cycle window of valid PSTDDATA output. See Figure 5-2. Because debug trace port
signals change on alternate processor cycles and are unrelated to external bus frequency,
PSTCLK helps the development system sample PSTDDATA values.
If real-time trace is not used, setting CSR[PCD] keeps PSTCLK and PSTDDATA outputs from
toggling without disabling triggers. Non-quiescent operation can be reenabled by clearing
CSR[PCD], although the emulator must resynchronize with the PSTDDATA output.
PSTCLK starts clocking only when the first non-zero PST value (0xC, 0xD, or 0xF) occurs
during system reset exception processing. Table 5-4 describes PST values. Chapter 7,
“Phase-Locked Loop (PLL),” describes PSTCLK generation.
Processor
Status/Debug Data
(PSTDDATA[7:0])
These outputs indicate both processor status and captured address and data values and are
discussed more thoroughly in Section 5.2.1, “Processor Status/Debug Data (PSTDDATA[7:0]).
5-2
MCF5407 User’s Manual
Signal Descriptions
Figure 5-2 shows PSTCLK timing.
PSTCLK
PSTDDATA
Figure 5-2. PSTCLK Timing
5.2.1 Processor Status/Debug Data (PSTDDATA[7:0])
Processor status data outputs are used to indicate both processor status and captured address
and data values. They operate at half the processor’s frequency. Given that real-time trace
information appears as a sequence of 4-bit data values, there are no alignment restrictions;
that is, the processor status (PST) values and operands may appear on either nibble of
PSTDDATA[7:0]. The upper nibble (PSTDDATA[7:4]) is the most significant.
CSR controls capturing of data values. Executing the WDDATA instruction captures data
displayed on PSTDDATA. These signals are updated each processor cycle and displayed
two values at a time for two processor clock cycles. Table 5-2 shows the PSTDDATA output
for the processor’s sequential execution of single-cycle instructions (A, B, C, D...). Cycle
counts are shown relative to processor frequency. These outputs indicate the current
processor pipeline status and are not related to the current bus transfer.
Table 5-2. PSTDDATA: Sequential Execution of Single-Cycle Instructions
Cycle
PSTDDATA[7:0]
T
{PST for A, PST for B}
T+1
{PST for A, PST for B}
T+2
{PST for C, PST for D}
T+3
{PST for C, PST for D}
T+4
{PST for E, PST for F}
T+5
{PST for E, PST for F}
The signal timing for the example in Table 5-2 is shown in Figure 5-3.
PCLK
PSTCLK
PSTDDATA
{A, B}
{C, D}
{E, F}
Figure 5-3. PSTDDATA: Single-Cycle Instruction Timing
Chapter 5. Debug Support
5-3
Real-Time Trace Support
Table 5-3 shows the case where a PSTDDATA module captures a memory operand on a
simple load instruction: mov.l <mem>,Rx.
Table 5-3. PSTDDATA: Data Operand Captured
Cycle
T
PSTDDATA[7:0]
{PST for mov.l, PST marker for captured operand) = {0x1, 0xB}
T+1
{0x1, 0xB}
T+2
{Operand[3:0], Operand[7:4]}
T+3
{Operand[3:0], Operand[7:4]}
T+4
{Operand[11:8], Operand[15:12]}
T+5
{Operand[11:8], Operand[15:12]}
T+6
{Operand[19:16], Operand[23:20]}
T+7
{Operand[19:16], Operand[23:20]}
T+8
{Operand[27:24], Operand[31:28]}
T+9
{Operand[27:24], Operand[31:28]}
T+10
(PST for next instruction)
T+11
(PST for next instruction,...)
A PST marker and its data display are transmitted contiguously. Except for this
transmission, the IDLE status (0x0) may appear any time. Again, given the real-time trace
information appears as a sequence of 4-bit values, there are no alignment restrictions. That
is, PST values and operands may appear on either nibble of PSTDDATA.
5.3 Real-Time Trace Support
Real-time trace, which defines the dynamic execution path, is a fundamental debug
function. The ColdFire solution is to include a parallel output port providing encoded
processor status and data to an external development system. This 8-bit port is partitioned
into two consecutive 4-bit nibbles. Each nibble can either transmit information concerning
the processor’s execution status (PST) or debug data (DDATA). The processor status may
not be related to the current bus transfer.
External development systems can use PSTDDATA outputs with an external image of the
program to completely track the dynamic execution path. This tracking is complicated by
any change in flow, especially when branch target address calculation is based on the
contents of a program-visible register (variant addressing). PSTDDATA outputs can be
configured to display the target address of such instructions in sequential nibble increments
across multiple processor clock cycles, as described in Section 5.3.1, “Begin Execution of
Taken Branch (PST = 0x5).” Four 32-bit storage elements form a FIFO buffer connecting
the processor’s high-speed local bus to the external development system through
PSTDDATA[7:0]. The buffer captures branch target addresses and certain data values for
eventual display on the PSTDDATA port, two nibbles at a time starting with the lsb.
5-4
MCF5407 User’s Manual
Real-Time Trace Support
Execution speed is affected only when three storage elements have valid data to be dumped
to the PSTDDATA port. This occurs only when two values are captured simultaneously in
a read-modify-write operation; the core stalls until two FIFO entries are available.
Table 5-4 shows the encoding of these signals.
Table 5-4. Processor Status Encoding
PST[3:0]
Definition
Hex
Binary
0x0
0000
Continue execution. Many instructions execute in one processor cycle. If an instruction requires more
clock cycles, subsequent clock cycles are indicated by driving PSTDDATA outputs with this encoding.
0x1
0001
Begin execution of one instruction. For most instructions, this encoding signals the first clock cycle of
an instruction’s execution. Certain change-of-flow opcodes, plus the PULSE and WDDATA instructions,
generate different encodings.
0x2
0010
Begin execution of two instructions. For superscalar instruction dispatches, this encoding signals the
first clock cycle of the simultaneous instructions’ execution.
0x3
0011
Entry into user-mode. Signaled after execution of the instruction that caused the MCF5407 to enter
user mode.
0x4
0100
Begin execution of PULSE and WDDATA instructions. PULSE defines logic analyzer triggers for debug
and/or performance analysis. WDDATA lets the core write any operand (byte, word, or longword)
directly to the PSTDDATA port, independent of debug module configuration. When WDDATA is
executed, a value of 0x4 is signaled, followed by the appropriate marker, and then the data transfer on
the PSTDDATA port. Transfer length depends on the WDDATA operand size.
0x5
0101
Begin execution of taken branch. For some opcodes, a branch target address may be displayed on
PSTDDATA depending on the CSR settings. CSR also controls the number of address bytes displayed,
indicated by the PST marker value preceding the DDATA nibble that begins the data output. See
Section 5.3.1, “Begin Execution of Taken Branch (PST = 0x5).”
0x6
0110
Begin execution of instruction plus a taken branch. The processor completes execution of a taken
conditional branch instruction and simultaneously starts executing the target instruction. This is
achieved through branch folding.
0x7
0111
Begin execution of return from exception (RTE) instruction.
0x8–
0xB
1000–
1011
Indicates the size of the next consecutive nibbles. The encoding is driven onto the PSTDDATA port one
clock cycle before the data is displayed on PSTDDATA.
0x8 Begin 1-byte transfer on PSTDDATA.
0x9 Begin 2-byte transfer on PSTDDATA.
0xA Begin 3-byte transfer on PSTDDATA.
0xB Begin 4-byte transfer on PSTDDATA.
0xC
1100
Exception processing. Exceptions that enter emulation mode (debug interrupt or optionally trace)
generate a different encoding, 0xD. Because the 0xC encoding defines a multiple-cycle mode,
PSTDDATA outputs are driven with 0xC until exception processing completes.
0xD
1101
Entry into emulator mode. Displayed during emulation mode (debug interrupt or optionally trace).
Because this encoding defines a multiple-cycle mode, PSTDDATA outputs are driven with 0xD until
exception processing completes.
0xE
1110
A breakpoint state change causes this encoding to assert for one cycle only followed by the trigger
status value. If the processor stops waiting for an interrupt, the encoding is asserted for multiple cycles.
See Section 5.3.2, “Processor Stopped or Breakpoint State Change (PST = 0xE).”
0xF
1111
Processor is halted. See Section 5.3.3, “Processor Halted (PST = 0xF).”
Chapter 5. Debug Support
5-5
Real-Time Trace Support
5.3.1 Begin Execution of Taken Branch (PST = 0x5)
PST is 0x5 when a taken branch is executed. For some opcodes, a branch target address may
be displayed on PSTDDATA depending on the CSR settings. CSR also controls the number
of address bytes displayed, which is indicated by the PST marker value immediately
preceding the DDATA nibble that begins the data output.
Bytes are displayed in least-to-most-significant order. The processor captures only those
target addresses associated with taken branches which use a variant addressing mode, that
is, RTE and RTS instructions, JMP and JSR instructions using address register indirect or
indexed addressing modes, and all exception vectors.
The simplest example of a branch instruction using a variant address is the compiled code
for a C language case statement. Typically, the evaluation of this statement uses the variable
of an expression as an index into a table of offsets, where each offset points to a unique case
within the structure. For such change-of-flow operations, the MCF5407 uses the debug pins
to output the following sequence of information on successive processor clock cycles:
1. Use PSTDDATA (0x5) to identify that a taken branch was executed.
2. Optionally signal the target address to be displayed sequentially on the PSTDDATA
pins. Encodings 0x9–0xB identify the number of bytes displayed.
3. The new target address is optionally available on subsequent cycles using the
PSTDDATA port. The number of bytes of the target address displayed on this port
is configurable (2, 3, or 4 bytes).
Another example of a variant branch instruction would be a JMP (A0) instruction.
Figure 5-4 shows when the PSTDDATA outputs that indicate when a JMP (A0) executed,
assuming the CSR was programmed to display the lower 2 bytes of an address.
PCLK
PSTCLK
PSTDDATA
0x59
A0[3–0,7–4]
A0[11–8,15–12]
Figure 5-4. Example JMP Instruction Output on PSTDDATA
PSTDDATA is driven two nibbles at a time with a 0x59; 0x5 indicates a taken branch and
the marker value 0x9 indicates a 2-byte address. Thus, the remaining 4 nibbles display the
lower 2 bytes of address register A0 in least-to-most-significant nibble order. The
PSTDDATA output after the JMP instruction continues with the next instruction.
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MCF5407 User’s Manual
Real-Time Trace Support
5.3.2 Processor Stopped or Breakpoint State Change
(PST = 0xE)
The 0xE encoding is generated either as a one- or multiple-cycle issue as follows:
•
•
When the MCF5407 is stopped by a STOP instruction, this encoding appears in
multiple-cycle format. The ColdFire processor remains stopped until an interrupt
occurs, thus PSTDDATA outputs display 0xE until stopped mode is exited.
When a breakpoint status change is to be output on PSTDDATA, 0xE is displayed
for one cycle, followed immediately with the 4-bit value of the current trigger status,
where the trigger status is left justified rather than in the CSR[BSTAT] description.
Section 5.4.4, “Configuration/Status Register (CSR),” shows that status is right
justified. That is, the displayed trigger status on PSTDDATA after a single 0xE is as
follows:
— 0x0 = no breakpoints enabled
— 0x2 = waiting for level-1 breakpoint
— 0x4 = level-1 breakpoint triggered
— 0xA = waiting for level-2 breakpoint
— 0xC = level-2 breakpoint triggered
Thus, 0xE can indicate multiple events, based on the next value, as Table 5-5 shows.
Table 5-5. 0xE Status Posting
PSTDDATA Stream Includes
Result
{0xE, 0x2}
Breakpoint state changed to waiting for level-1 trigger
{0xE, 0x4}
Breakpoint state changed to level-1 breakpoint triggered
{0xE, 0xA}
Breakpoint state changed to waiting for level-2 trigger
{0xE, 0xC}
Breakpoint state changed to level-2 breakpoint triggered
{0xE, 0xE}
The MCF5407 is in stopped mode.
5.3.3 Processor Halted (PST = 0xF)
PST is 0xF when the processor is halted (see Section 5.5.1, “CPU Halt”). Because this
encoding defines a multiple-cycle mode, the PSTDDATA outputs display 0xF until the
processor is restarted or reset.
HALT can be distinguished from a data output 0xFF by counting 0xFF occurrences on
PSTDDATA. Because data always follows a marker (0x8, 0x9, 0xA, or 0xB), the longest
occurrence in PSTDDATA of 0xFF, in a data output, is four 0xFFs.
Chapter 5. Debug Support
5-7
Programming Model
Two scenarios exist for data—0xFFFF_FFFF
•
•
A B marker occurs on the left nibble of PSTDDATA with the data of 0xFF
following:
PSTDDATA[7:0]
0xBF
0xFF
0xFF
0xFF
0xFX (X indicates that the next PST value is guaranteed to not be 0xF.)
A B marker occurs on the right nibble of PSTDDATA with the data of 0xFF
following:
PSTDDATA[7:0]
0xYB
0xFF
0xFF
0xFF
0xFF
0xXY (X indicates the PST value is guaranteed not to be 0xF, and Y signifies a
PSTDDATA value that doesn’t affect the 0xFF count.)
Thus, a count of either nine or more sequential single 0xF values or five or more sequential
0xFF values signifies the HALT condition.
5.4 Programming Model
In addition to the existing BDM commands that provide access to the processor’s registers
and the memory subsystem, the debug module contains 19 registers to support the required
functionality. These registers are also accessible from the processor’s supervisor
programming model by executing the WDEBUG instruction. Thus, the breakpoint
hardware in the debug module can be accessed by the external development system using
the debug serial interface or by the operating system running on the processor core.
Software is responsible for guaranteeing that accesses to these resources are serialized and
logically consistent. Hardware provides a locking mechanism in the CSR to allow the
external development system to disable any attempted writes by the processor to the
breakpoint registers (setting CSR[IPW]). BDM commands must not be issued if the
MCF5407 is using the WDEBUG instruction to access debug module registers or the
resulting behavior is undefined.
These registers, shown in Figure 5-5, are treated as 32-bit quantities, regardless of the
number of implemented bits.
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MCF5407 User’s Manual
Programming Model
31
15
31
15
31
15
31
7
0
AATR
Address attribute trigger register
ABLR
ABHR
Address low breakpoint register
Address high breakpoint register
AATR1
Address 1 attribute register
0
7
15
0
0
ABLR1 Address low breakpoint 1 register
ABHR1 Address high breakpoint 1 register
31
15
31
15
0
31
15
0
31
7
15
0
BAAR
BDM address attribute register
CSR
Configuration/status register
DBR
DBMR
Data breakpoint register
Data breakpoint mask register
0
DBR1
Data breakpoint 1 register
DBMR1 Data breakpoint mask 1 register
31
15
0
31
15
0
31
15
0
PBR
PBR1
PBR2
PBR3
PBMR
PC breakpoint register
PC breakpoint 1 register
PC breakpoint 2 register
PC breakpoint 3 register
PC breakpoint mask register
TDR
Trigger definition register
XTDR
Extended trigger definition register
Note: Each debug register is accessed as a 32-bit register; shaded fields above are not used (don’t care).
All debug control registers are writable from the external development system or the CPU via the
WDEBUG instruction.
CSR is write-only from the programming model as debug control register 0x00 using the supervisor-mode
WDEBUG instruction. It can be read from and written through the BDM port using the RDMREG and
WDMREG commands.
Figure 5-5. Debug Programming Model
These registers are accessed through the BDM port by new BDM commands, WDMREG and
RDMREG, described in Section 5.5.3.3, “Command Set Descriptions.” These commands
contain a 5-bit field, DRc, that specifies the register, as shown in Table 5-6.
Table 5-6. BDM/Breakpoint Registers
DRc[4–0]
0x00
0x01–0x04
Register Name
Configuration/status register
Abbreviation
Initial State
Page
CSR
0x0020_0000
p. 5-13
—
—
—
0x05
BDM address attribute register
Reserved
BAAR
0x0000_0005
p. 5-12
0x06
Address attribute trigger register
AATR
0x0000_0005
p. 5-10
Chapter 5. Debug Support
5-9
Programming Model
Table 5-6. BDM/Breakpoint Registers (Continued)
DRc[4–0]
Register Name
Abbreviation
Initial State
Page
0x07
Trigger definition register
TDR
0x0000_0000
p. 5-18
0x08
Program counter breakpoint register
PBR
—
p. 5-16
0x09
Program counter breakpoint mask register
PBMR
—
p. 5-16
—
—
—
Address breakpoint high register
ABHR
—
p. 5-12
0x0D
Address breakpoint low register
ABLR
—
p. 5-12
0x0E
Data breakpoint register
DBR
—
p. 5-15
0x0F
Data breakpoint mask register
DBMR
—
p. 5-15
—
—
—
0x0A–0x0B Reserved
0x0C
0x10–0x15
Reserved
0x16
Address attribute trigger register 1
AATR1
0x0000_0005
p. 5-10
0x17
Extended trigger definition register
XTDR
0x0000_0000
p. 5-19
0x18
Program counter breakpoint 1 register
PBR1
0x0000_0000
p. 5-16
0x19
Reserved
—
—
—
0x1A
Program counter breakpoint register 2
PBR2
0x0000_0000
p. 5-16
0x1B
Program counter breakpoint register 3
PBR3
0x0000_0000
p. 5-16
0x1C
Address high breakpoint register 1
ABHR1
—
p. 5-12
0x1D
Address low breakpoint register 1
ABLR1
—
p. 5-12
0x1E
Data breakpoint register 1
DBR1
—
p. 5-15
0x1F
Data breakpoint mask register 1
DBMR1
—
p. 5-15
NOTE:
Debug control registers can be written by the external
development system or the CPU through the WDEBUG
instruction.
CSR is write-only from the programming model as debug
control register 0x00 using the supervisor-mode WDEBUG
instruction. It can be read from and written through the BDM
port using the RDMREG and WDMREG commands.
5.4.1 Address Attribute Trigger Registers (AATR, AATR1)
The address attribute trigger registers (AATR, AATR1) define address attributes and a mask
to be matched in the trigger. The register value is compared with address attribute signals
from the processor’s local high-speed bus, as defined by the setting of the trigger definition
register (TDR) for AATR and the extended trigger definition register (XTDR) for AATR1.
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MCF5407 User’s Manual
Programming Model
15
Field RM
Reset
14
13
SZM
12
11
TTM
10
9
TMM
8
7
6
R
5
SZ
4
3
2
TT
1
0
TM
0000_0000_0000_0101
R/W AATR and AATR1 are accessible in supervisor mode as debug control register 0x06 and 0x16
respectively, and using the WDEBUG instruction and through the BDM port using the WDMREG command.
DRc[4–0]
0x06 (AATR); 0x16 (AATR1)
Figure 5-6. Address Attribute Trigger Registers (AATR, AATR1)
Table 5-7 describes AATR and AATR1 fields.
Table 5-7. AATR and AATR1 Field Descriptions
Bits
Name
Description
15
RM
Read/write mask. Setting RM masks R in address comparisons.
14–13
SZM
Size mask. Setting an SZM bit masks the corresponding SZ bit in address comparisons.
12–11
TTM
Transfer type mask. Setting a TTM bit masks the corresponding TT bit in address comparisons.
10–8
TMM
Transfer modifier mask. Setting a TMM bit masks the corresponding TM bit in address comparisons.
7
R
Read/write. R is compared with the R/W signal of the processor’s local bus.
6–5
SZ
Size. Compared to the processor’s local bus size signals.
00 Longword
01 Byte
10 Word
11 Reserved
4–3
TT
Transfer type. Compared with the local bus transfer type signals.
00 Normal processor access
01 Reserved
10 Emulator mode access
11 Acknowledge/CPU space access
These bits also define the TT encoding for BDM memory commands. In this case, the 01 encoding
indicates an external or DMA access (for backward compatibility). These bits affect the TM bits.
2–0
TM
Transfer modifier. Compared with the local bus transfer modifier signals, which give supplemental
information for each transfer type.
TT = 00 (normal mode):
000 Data and instruction cache line push
001 User data access
010 User code access
011 Instruction cache invalidate
100 Data cache push
101 Supervisor data access
110 Supervisor code access
111 INTOUCH instruction access
TT = 10 (emulator mode):
0xx–100 Reserved
101 Emulator mode data access
110 Emulator mode code access
111 Reserved
TT = 11 (acknowledge/CPU space transfers):
000 CPU space access
001–111 Interrupt acknowledge levels 1–7
These bits also define the TM encoding for BDM memory commands (for backward compatibility).
Chapter 5. Debug Support
5-11
Programming Model
5.4.2 Address Breakpoint Registers (ABLR/ABLR1,
ABHR/ABHR1)
The address breakpoint low and high registers (ABLR, ABLR1, ABHR, and ABHR1),
Figure 5-7, define regions in the processor’s data address space that can be used as part of
the trigger. These register values are compared with the address for each transfer on the
processor’s high-speed local bus. TDR determines if the trigger is in the address in ABLR
or either inside or outside of the range bound by ABLR and ABHR. XTDR determines the
same for ABLR1 and ABHR1.
31
0
Field
Address
Reset
—
R/W ABHR and ABHR1 are accessible in supervisor mode as debug control registers 0x0C and 0x1C, using the
WDEBUG instruction and via the BDM port using the RDMREG and WDMREG commands.
ABLR and ABLR1 are accessible in supervisor mode as debug control register 0x0D and 0x1D, using the
WDEBUG instruction and via the BDM port using the WDMREG command.
DRc[4–0]
0x0D (ABLR); 0x1D (ABLR1); 0x0C (ABHR); 0x1C (ABHR1)
Figure 5-7. Address Breakpoint Registers (ABLR, ABHR, ABLR1, ABHR1)
Table 5-8 describes ABLR and ABLR1 fields.
Table 5-8. ABLR and ABLR1 Field Description
Bits
Name
Description
31–0
Address
Low address. Holds the 32-bit address marking the lower bound of the address breakpoint range.
Breakpoints for specific addresses are programmed into ABLR or ABLR1.
Table 5-9 describes ABHR and ABHR1 fields.
Table 5-9. ABHR and ABHR1 Field Description
Bits
Name
Description
31–0 Address High address. Holds the 32-bit address marking the upper bound of the address breakpoint range.
5.4.3 BDM Address Attribute Register (BAAR)
The BAAR defines the address space for memory-referencing BDM commands. See
Figure 5-8. The reset value of 0x5 sets supervisor data as the default address space.
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MCF5407 User’s Manual
Programming Model
7
Field
6
5
R
4
3
SZ
2
1
TT
Reset
0
TM
0000_0101
R/W BAAR[R,SZ] are loaded directly from the BDM command; BAAR[TT,TM] can be programmed as debug
control register 0x05 from the external development system. For compatibility with Rev. A, BAAR is loaded
each time AATR is written.
DRc[4–0]
0x05
Figure 5-8. BDM Address Attribute Register (BAAR)
Table 5-10 describes BAAR fields.
Table 5-10. BAAR Field Descriptions
Bits
Name
Description
7
R
Read/write
0 Write
1 Read
6–5
SZ
Size
00 Longword
01 Byte
10 Word
11 Reserved
4–3
TT
Transfer type. See the TT definition in Table 5-7.
2–0
TM
Transfer modifier. See the TM definition in Table 5-7.
5.4.4 Configuration/Status Register (CSR)
The configuration/status register (CSR) defines the debug configuration for the processor
and memory subsystem and contains status information from the breakpoint logic.
31
30
29
28
27
26
25
24
23
22
20
19
18
17
16
Field
BSTAT
HRL
—
Reset
0000
0
0
0
0
0010
—
—
—
0
R/W1
R
R
R
R
R
R
—
—
—
R/W
10
9
3
2
1
0
15
14
13
Field MAP TRC EMU
Reset
0
R/W R/W
DRc[4–0]
FOF TRG HALT BKPT
21
12
11
DDC
UHE
8
BTB
BKD PCD IPW
7
6
5
4
—2
NPL
—
SSM
—
0
0
00
0
00
0
0
—
0
—
R/W
R/W
R/W
R/W
R/W
R
R/W
—
R/W
—
0x00
1
CSR is write-only from the programming model. It can be read from and written to through the BDM port. CSR
is accessible in supervisor mode as debug control register 0x00 using the WDEBUG instruction and through
the BDM port using the RDMREG and WDMREG commands.
2 Bit 7 is reserved for Motorola use and must be written as a zero.
Figure 5-9. Configuration/Status Register (CSR)
Chapter 5. Debug Support
5-13
Programming Model
Table 5-11 describes CSR fields.
Table 5-11. CSR Field Descriptions
Bit
31–28
Name
Description
BSTAT Breakpoint status. Provides read-only status information concerning hardware breakpoints. Also
output on PSTDDATA when it is not displaying PST or other processor data. BSTAT is cleared by a
TDR or XTDR write or by a CSR read when either a level-2 breakpoint is triggered or a level-1
breakpoint is triggered and the level-2 breakpoint is disabled.
0000 No breakpoints enabled
0001 Waiting for level-1 breakpoint
0010 Level-1 breakpoint triggered
0101 Waiting for level-2 breakpoint
0110 Level-2 breakpoint triggered
27
FOF
Fault-on-fault. If FOF is set, a catastrophic halt occurred and forced entry into BDM.
26
TRG
Hardware breakpoint trigger. If TRG is set, a hardware breakpoint halted the processor core and
forced entry into BDM. Reset and the debug GO command clear TRG.
25
HALT
Processor halt. If HALT is set, the processor executed a HALT and forced entry into BDM. Reset
and the debug GO command reset HALT.
24
BKPT
Breakpoint assert. If BKPT is set, BKPT was asserted, forcing the processor into BDM. Reset and
the debug GO command clears this bit.
HRL
Hardware revision level. Indicates the level of debug module functionality. An emulator could use
this information to identify the level of functionality supported.
0000 Initial debug functionality (Revision A)
0001 Revision B
0010 Revision C (this is the only valid value for the MCF5407)
19
—
Reserved, should be cleared.
18
BKD
Breakpoint disable. Used to disable the normal BKPT input functionality and to allow the assertion
of BKPT to generate a debug interrupt.
0 Normal operation
1 BKPT is edge-sensitive: a high-to-low edge on BKPT signals a debug interrupt to the processor.
The processor makes this interrupt request pending until the next sample point, when the
exception is initiated. In the ColdFire architecture, the interrupt sample point occurs once per
instruction. There is no support for nesting debug interrupts.
17
PCD
PSTCLK disable. Setting PCD disables generation of PSTCLK and PSTDDATA outputs and forces
them to remain quiescent.
16
IPW
Inhibit processor writes. Setting IPW inhibits processor-initiated writes to the debug module’s
programming model registers. IPW can be modified only by commands from the external
development system.
15
MAP
Force processor references in emulator mode.
0 All emulator-mode references are mapped into supervisor code and data spaces.
1 The processor maps all references while in emulator mode to a special address space, TT = 10,
TM = 101 or 110.
14
TRC
Force emulation mode on trace exception. If TRC = 1, the processor enters emulator mode when a
trace exception occurs.
13
EMU
Force emulation mode. If EMU = 1, the processor begins executing in emulator mode. See
Section 5.6.1.1, “Emulator Mode.”
23–20
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MCF5407 User’s Manual
Programming Model
Table 5-11. CSR Field Descriptions (Continued)
Bit
Name
Description
12–11
DDC
Debug data control. Controls operand data capture for PSTDDATA, which displays the number of
bytes defined by the operand reference size before the actual data; byte displays 8 bits, word
displays 16 bits, and long displays 32 bits (one nibble at a time across multiple clock cycles). See
Table 5-4.
00 No operand data is displayed.
01 Capture all write data.
10 Capture all read data.
11 Capture all read and write data.
10
UHE
User halt enable. Selects the CPU privilege level required to execute the HALT instruction.
0 HALT is a supervisor-only instruction.
1 HALT is a supervisor/user instruction.
9–8
BTB
Branch target bytes. Defines the number of bytes of branch target address PSTDDATA displays.
00 0 bytes
01 Lower 2 bytes of the target address
10 Lower 3 bytes of the target address
11 Entire 4-byte target address
See Section 5.3.1, “Begin Execution of Taken Branch (PST = 0x5).”
7
—
Reserved, should be cleared.
6
NPL
Non-pipelined mode. Determines whether the core operates in pipelined or mode.
0 Pipelined mode
1 Nonpipelined mode. The processor effectively executes one instruction at a time with no overlap.
This adds at least 5 cycles to the execution time of each instruction. Instruction folding is
disabled. Given an average execution latency of 1.6, throughput in non-pipeline mode would be
6.6, approximately 25% or less compared to pipelined performance.
Regardless of the NPL state, a triggered PC breakpoint is always reported before the triggering
instruction executes. In normal pipeline operation, the occurrence of an address and/or data
breakpoint trigger is imprecise. In non-pipeline mode, triggers are always reported before the next
instruction begins execution and trigger reporting can be considered precise.
An address or data breakpoint should always occur before the next instruction begins execution.
Therefore the occurrence of the address/data breakpoints should be guaranteed.
5
—
Reserved, should be cleared.
4
SSM
Single-step mode. Setting SSM puts the processor in single-step mode.
0 Normal mode.
1 Single-step mode. The processor halts after execution of each instruction. While halted, any
BDM command can be executed. On receipt of the GO command, the processor executes the
next instruction and halts again. This process continues until SSM is cleared.
—
Reserved, should be cleared.
3–0
5.4.5 Data Breakpoint/Mask Registers (DBR/DBR1,
DBMR/DBMR1)
The data breakpoint registers (DBR/DBR1), Figure 5-10, specify data patterns used as part
of the trigger into debug mode. Only DBRn bits not masked with a corresponding zero in
DBMRn are compared with the data from the processor’s local bus, as defined in TDR.
Chapter 5. Debug Support
5-15
Programming Model
31
0
Field
Data (DBR/DBR1); Mask (DBMR/DBMR1)
Reset
Uninitialized
R/W DBR and DBR1 are accessible in supervisor mode as debug control register 0x0E and 0x1E, using the
WDEBUG instruction and through the BDM port using the RDMREG and WDMREG commands.
DBMR and DBMR1 are accessible in supervisor mode as debug control register 0x0F and 0x0F1 using the
WDEBUG instruction and via the BDM port using the WDMREG command.
DRc[4–0]
0x0E (DBR), 0x1E (DBR1); 0x0F (DBMR), 0x1F (DBMR1)
Figure 5-10. Data Breakpoint/Mask Registers (DBR/DBR1 and DBMR/DBMR1)
Table 5-12 describes DBRn fields.
Table 5-12. DBRn Field Descriptions
Bits
Name
31–0
Data
Description
Data breakpoint value. Contains the value to be compared with the data value from the processor’s
local bus as a breakpoint trigger.
Table 5-13 describes DBMRn fields.
Table 5-13. DBMRn Field Descriptions
Bits
31–0
Name
Mask
Description
Data breakpoint mask. The 32-bit mask for the data breakpoint trigger. Clearing a DBRn bit allows
the corresponding DBRn bit to be compared to the appropriate bit of the processor’s local data bus.
Setting a DBMRn bit causes that bit to be ignored.
DBRs support both aligned and misaligned references. Table 5-14 shows relationships
between processor address, access size, and location within the 32-bit data bus.
Table 5-14. Access Size and Operand Data Location
A[1:0]
Access Size
Operand Location
00
Byte
D[31:24]
01
Byte
D[23:16]
10
Byte
D[15:8]
11
Byte
D[7:0]
0x
Word
D[31:16]
1x
Word
D[15:0]
xx
Longword
D[31:0]
5.4.6 Program Counter Breakpoint/Mask Registers
(PBR, PBR1, PBR2, PBR3, PBMR)
Each PC breakpoint register (PBR, PBR1, PBR2, PBR3) defines an instruction address for
use as part of the trigger. These registers’ contents are compared with the processor’s
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MCF5407 User’s Manual
Programming Model
program counter register when the appropriate valid bit is set and TDR and/or XTDR are
configured appropriately. PBR bits are masked by clearing corresponding PBMR bits.
Results are compared with the processor’s program counter register, as defined in TDR
and/or XTDR. PBR1–PBR3 are not masked. Figure 5-11 shows the PC breakpoint register.
31
1
0
Field
Program Counter
V1
Reset
—
0
R/W Write. PC breakpoint registers are accessible in supervisor mode using the WDEBUG instruction and
through the BDM port using the RDMREG and WDMREG commands using values shown in Section 5.5.3.3,
“Command Set Descriptions.”
DRc[4–0]
1 PBR
0x08 (PBR); 0x18 (PBR1); 0x1A (PBR2); 0x1B (PBR3)
does not have a valid bit. PBR[0] is read as 0 and should be cleared.
Figure 5-11. Program Counter Breakpoint Registers (PBR, PBR1, PBR2, PBR3)
Table 5-15 describes PBR, PBR1, PBR2, and PBR3 fields.
Table 5-15. PBR, PBR1, PBR2, PBR3 Field Descriptions
Bits
Name
Description
31–1 Address PC breakpoint address. The 31-bit address to be compared with the PC as a breakpoint trigger.
PBR does not have a valid bit.
0
V
Valid. Breakpoint registers are compared with the processor’s program counter register when the
appropriate valid bit is set and TDR and/or XTDR are configured appropriately. This bit is not
implemented on PBR.
PBMR is accessible in supervisor mode as debug control register 0x09 using the WDEBUG
instruction and via the BDM port using the WDMREG command. Figure 5-12 shows PBMR.
31
1
0
Field
Mask
—
Reset
—
—
R/W Write. PBMR is accessible in supervisor mode as debug control register 0x09 using the WDEBUG
instruction and via the BDM port using the wdmreg command.
DRc[4–0]
0x09
Figure 5-12. Program Counter Breakpoint Mask Register (PBMR)
Table 5-16 describes PBMR fields.
Table 5-16. PBMR Field Descriptions
Bits
Name
31–0 Mask
Description
PC breakpoint mask. A zero in a bit position causes the corresponding PBR bit to be compared to
the appropriate PC bit. Set PBMR bits cause PBR bits to be ignored.
Chapter 5. Debug Support
5-17
Programming Model
5.4.7 Trigger Definition Register (TDR)
The TDR, shown in Table 5-13, configures the operation of the hardware breakpoint logic
that corresponds with the ABHR/ABLR/AATR, PBR/PBR1/PBR2/PBR3/PBMR, and
DBR/DBMR registers within the debug module. In conjunction with the XTDR and its
associated debug registers, TDR controls the actions taken under the defined conditions.
Breakpoint logic may be configured as one- or two-level triggers. TDR[31–16] and/or
XTDR[31–16] define second-level triggers and bits 15–0 define first-level triggers.
NOTE:
The debug module has no hardware interlocks, so to prevent
spurious breakpoint triggers while the breakpoint registers are
being loaded, disable TDR and XTDR (by clearing
TDR[29,13] and XTDR[29,13]) before defining triggers.
A write to TDR clears the CSR trigger status bits, CSR[BSTAT].
Section 5.4.9, “Resulting Set of Possible Trigger Combinations,” describes how to handle
multiple breakpoint conditions.
Second-Level Triggers
31
Field
30
TRC
29
EBL
28
27
26
25
24
23
22
EDLW EDWL EDWU EDLL EDLM EDUM EDUU
Reset
21
20
DI
EAI
19
18
17
EAR EAL EPC
16
PCI
0000_0000_0000_0000
R/W Accessible in supervisor mode as debug control register 0x07 using the WDEBUG instruction and through the
BDM port using the WDMREG command.
First-Level Triggers
15
Field
14
—
13
EBL
12
11
10
9
8
7
6
EDLW EDWL EDWU EDLL EDLM EDUM EDUU
Reset
5
4
DI
EAI
3
2
1
EAR EAL EPC
0
PCI
0000_0000_0000_0000
R/W Accessible in supervisor mode as debug control register 0x07 using the WDEBUG instruction and through the
BDM port using the WDMREG command.
DRc[4–0]
0x07
Figure 5-13. Trigger Definition Register (TDR)
Table 5-17 describes TDR fields.
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MCF5407 User’s Manual
Programming Model
Table 5-17. TDR Field Descriptions
Bits
Name
Description
31–30
TRC
Trigger response control. Determines how the processor responds to a completed trigger condition.
The trigger response is always displayed on PSTDDATA.
00 Display on PSTDDATA only
01 Processor halt
10 Debug interrupt
11 Reserved
29/13
EBL
Enable breakpoint. Global enable for the breakpoint trigger. Setting TDR[EBL] or XTDR[EBL]
enables a breakpoint trigger; clearing both disables all breakpoints.
28–22
12–6
EDx
Setting an EDx bit enables the corresponding data breakpoint condition based on the size and
placement on the processor’s local data bus. Clearing all EDx bits disables data breakpoints.
28/12
EDLW
Data longword. Entire processor’s local data bus.
27/11
EDWL
Lower data word.
26/10
EDWU Upper data word.
25/9
EDLL
Lower lower data byte. Low-order byte of the low-order word.
24/8
EDLM
Lower middle data byte. High-order byte of the low-order word.
23/7
EDUM Upper middle data byte. Low-order byte of the high-order word.
22/6
EDUU
Upper upper data byte. High-order byte of the high-order word.
21/5
DI
Data breakpoint invert. Provides a way to invert the logical sense of all the data breakpoint
comparators. This can develop a trigger based on the occurrence of a data value other than the
DBR contents.
20–18/
4–2
EAx
Enable address bits. Setting an EA bit enables the corresponding address breakpoint. Clearing all
three bits disables the breakpoint.
20/4
EAI
Enable address breakpoint inverted. Breakpoint is based outside the range between ABLR
and ABHR.
19/3
EAR
Enable address breakpoint range. The breakpoint is based on the inclusive range defined
by ABLR and ABHR.
EAL
Enable address breakpoint low. The breakpoint is based on the address in the ABLR.
18/2
17/1
EPC
Enable PC breakpoint. If set, this bit enables the PC breakpoint.
16/0
PCI
Breakpoint invert. If set, this bit allows execution outside a given region as defined by
PBR/PBR1/PBR2/PBR3 and PBMR to enable a trigger. If cleared, the PC breakpoint is defined
within the region defined by PBR/PBR1/PBR2/PBR3 and PBMR.
5.4.8 Extended Trigger Definition Register (XTDR)
The XTDR configures the operation of the hardware breakpoint logic that corresponds with
the ABHR1/ABLR1/AATR1 and DBR1/DBMR1 registers within the debug module and,
in conjunction with the TDR and its associated debug registers, controls the actions taken
under the defined conditions. The breakpoint logic may be configured as a one- or two-level
trigger, where TDR[31–16] and/or XTDR[31–16] define the second-level trigger and bits
15–0 define the first-level trigger. The XTDR is accessible in supervisor mode as debug
control register 0x17 using the WDEBUG instruction and via the BDM port using the
WDMREG command.
Chapter 5. Debug Support
5-19
Programming Model
NOTE:
The debug module has no hardware interlocks, so to prevent
spurious breakpoint triggers while the breakpoint registers are
being loaded, disable TDR and XTDR (by clearing
TDR[29,13] and XTDR[29,13]) before defining triggers.
A write to the XTDR clears the trigger status bits, CSR[BSTAT].
Section 5.4.9, “Resulting Set of Possible Trigger Combinations,” describes how to handle
multiple breakpoint conditions.
Second-Level Triggers
31
30
29
EBL
28
27
26
25
24
23
22
EDLW EDWL EDWU EDLL EDLM EDUM EDUU
21
20
19
18
17 16
DI
EAI
EAR
EAL
—
Field
—
Reset
—
000_0000_0000_000
—
R/W
—
Write
—
First-Level Triggers
15
14
13
EBL
12
11
10
9
8
7
6
EDLW EDWL EDWU EDLL EDLM EDUM EDUU
5
4
3
2
DI
EAI
EAR
EAL
1
0
Field
—
Reset
—
000_0000_0000_000
—
R/W
—
Write
—
DRc[4–0]
0x17
Figure 5-14. Extended Trigger Definition Register (XTDR)
Table 5-18 describes XTDR fields.
Table 5-18. XTDR Field Descriptions
Bits
Name
Description
29/13
EBL
Enable breakpoint level. If set, EBL is the global enable for the breakpoint trigger; that is, if
TDR[EBL] or XTDR[EBL] is set, a breakpoint trigger is enabled. Clearing both disables all
breakpoints.
28–22
12–6
EDx
Setting an EDx bit enables the corresponding data breakpoint condition based on the size and
placement on the processor’s local data bus. Clearing all EDx bits disables data breakpoints.
28/12
EDLW
Data longword. Entire processor’s local data bus.
27/11
EDWL
Lower data word.
26/10
EDWU
Upper data word.
25/9
EDLL
Lower lower data byte. Low-order byte of the low-order word.
24/8
EDLM
Lower middle data byte. High-order byte of the low-order word.
23/7
EDUM
Upper middle data byte. Low-order byte of the high-order word.
22/6
EDUU
Upper upper data byte. High-order byte of the high-order word.
5-20
MCF5407 User’s Manual
—
Programming Model
Table 5-18. XTDR Field Descriptions (Continued)
Bits
Name
Description
21/5
DI
Data breakpoint invert. Provides a way to invert the logical sense of all the data breakpoint
comparators. This can develop a trigger based on the occurrence of a data value other than the
DBR1 contents.
20–18/
4–2
EAx
Enable address bits. Setting an EAx bit enables the corresponding address breakpoint. If all three
bits are cleared, this breakpoint is disabled.
20/4
EAI
Enable address breakpoint inverted. Breakpoint is based outside the range between
ABLR1 and ABHR1.
19/3
EAR
Enable address breakpoint range. Breakpoint is based on the range defined between
ABLR1 and ABHR1.
18/2
EAL
Enable address breakpoint low. The breakpoint is based on the address in ABLR1.
17–16,
1–0
—
Reserved, should be cleared.
5.4.9 Resulting Set of Possible Trigger Combinations
The resulting set of possible breakpoint trigger combinations consist of the following
options where || denotes logical OR, && denotes logical AND, and {} denotes an optional
additional trigger term:
One-level triggers of the form:
if
if
if
(PC_breakpoint)
(PC_breakpoint||Address_breakpoint{&& Data_breakpoint})
(PC_breakpoint||Address_breakpoint{&& Data_breakpoint}
||
Address1_breakpoint{&& Data1_breakpoint})
if
if
(Address_breakpoint
{&& Data_breakpoint})
((Address_breakpoint
{&& Data_breakpoint})
||
(Address1_breakpoint{&& Data1_breakpoint}))
if
(Address1_breakpoint
{&& Data1_breakpoint})
Two-level triggers of the form:
if
(PC_breakpoint)
then if
(Address_breakpoint{&& Data_breakpoint})
if
(PC_breakpoint)
then if
(Address_breakpoint{&& Data_breakpoint}
||
Address1_breakpoint{&& Data1_breakpoint})
if
(PC_breakpoint)
then if
(Address1_breakpoint{&& Data1_breakpoint})
if
(Address_breakpoint
{&& Data_breakpoint})
then if
(Address1_breakpoint{&& Data1_breakpoint})
if
(Address1_breakpoint
{&& Data1_breakpoint})
then if
(Address_breakpoint{&& Data_breakpoint})
if
(Address_breakpoint
{&& Data_breakpoint})
then if
(PC_breakpoint)
if
(Address1_breakpoint
{&& Data1_breakpoint})
Chapter 5. Debug Support
5-21
Background Debug Mode (BDM)
then if
(PC_breakpoint)
if
(Address_breakpoint
{&& Data_breakpoint})
then if
(PC_breakpoint
||
Address1_breakpoint{&& Data1_breakpoint})
if
(Address1_breakpoint
{&& Data1_breakpoint})
then if
(PC_breakpoint
||
Address_breakpoint{&& Data_breakpoint})
In this example, PC_breakpoint is the logical summation of the PBR/PBMR, PBR1, PBR2,
and PBR3 breakpoint registers; Address_breakpoint is a function of ABHR, ABLR, and
AATR; Data_breakpoint is a function of DBR and DBMR; Address1_breakpoint is a
function of ABHR1, ABLR1, and AATR1; and Data1_breakpoint is a function of DBR1
and DBMR1. In all cases, the data breakpoints can be included with an address breakpoint
to further qualify a trigger event as an option.
5.5 Background Debug Mode (BDM)
The ColdFire Family implements a low-level system debugger in the microprocessor
hardware. Communication with the development system is handled through a dedicated,
high-speed serial command interface. The ColdFire architecture implements the BDM
controller in a dedicated hardware module. Although some BDM operations, such as CPU
register accesses, require the CPU to be halted, other BDM commands, such as memory
accesses, can be executed while the processor is running.
5.5.1 CPU Halt
Although many BDM operations can occur in parallel with CPU operations, unrestricted
BDM operation requires the CPU to be halted. The sources that can cause the CPU to halt
are listed below in order of priority:
1. A catastrophic fault-on-fault condition automatically halts the processor.
2. A hardware breakpoint can be configured to generate a pending halt condition
similar to the assertion of BKPT. This type of halt is always first made pending in
the processor. Next, the processor samples for pending halt and interrupt conditions
once per instruction. When a pending condition is asserted, the processor halts
execution at the next sample point. See Section 5.6.1, “Theory of Operation.”
3. The execution of a HALT instruction immediately suspends execution. Attempting
to execute HALT in user mode while CSR[UHE] = 0 generates a privilege violation
exception. If CSR[UHE] = 1, HALT can be executed in user mode. After HALT
executes, the processor can be restarted by serial shifting a GO command into the
debug module. Execution continues at the instruction after HALT.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
4. The assertion of the BKPT input is treated as a pseudo-interrupt; that is, the halt
condition is postponed until the processor core samples for halts/interrupts. The
processor samples for these conditions once during the execution of each
instruction. If there is a pending halt condition at the sample time, the processor
suspends execution and enters the halted state.
The assertion of BKPT should be considered in the following two special cases:
•
•
After the system reset signal is negated, the processor waits for 16 clock cycles
before beginning reset exception processing. If the BKPT input is asserted within
eight cycles after RSTI is negated, the processor enters the halt state, signaling halt
status (0xF) on the PSTDDATA outputs. While the processor is in this state, all
resources accessible through the debug module can be referenced. This is the only
chance to force the processor into emulation mode through CSR[EMU].
After system initialization, the processor’s response to the GO command depends on
the set of BDM commands performed while it is halted for a breakpoint.
Specifically, if the PC register was loaded, the GO command causes the processor to
exit halted state and pass control to the instruction address in the PC, bypassing
normal reset exception processing. If the PC was not loaded, the GO command
causes the processor to exit halted state and continue reset exception processing.
The ColdFire architecture also handles a special case of BKPT being asserted while
the processor is stopped by execution of the STOP instruction. For this case, the
processor exits the stopped mode and enters the halted state, at which point, all BDM
commands may be exercised. When restarted, the processor continues by executing
the next sequential instruction, that is, the instruction following the STOP opcode.
CSR[27–24] indicates the halt source, showing the highest priority source for multiple halt
conditions. Debug module Revisions A and B clear CSR[27–24] upon a read of the CSR,
but Revision C (in the MCF5407) does not. The debug GO command clears CSR[26–24].
HALT can be recognized by counting 0xFF occurrences on PSTDDATA. The count is
necessary to determine between a possible data output value of 0xFF and the HALT
condition. Because data always follows a marker (0x8, 0x9, 0xA, or 0xB), PSTDDATA can
display no more than four data 0xFFs. Two such scenarios exist:
•
A B marker occurs on the left nibble of PSTDDATA with the data of 0xFF
following:
PSTDDATA[7:0]
0xBF
0xFF
0xFF
0xFF
0xFX (X indicates that the next PST value is guaranteed to not be 0xF)
Chapter 5. Debug Support
5-23
Background Debug Mode (BDM)
•
A B marker occurs on the right nibble of PSTDDATA with the data of 0xFF
following:
PSTDDATA[7:0]
0xYB
0xFF
0xFF
0xFF
0xFF
0xXY (X indicates that the PST value is guaranteed to not be 0xF; and Y indicates
a PSTDDATA value that doesn’t affect the 0xFF count).
Thus, a count of either nine or more sequential single 0xF values or five or more sequential
0xFF values signifies the HALT condition.
5.5.2 BDM Serial Interface
When the CPU is halted and PSTDDATA reflects the halt status, the development system
can send unrestricted commands to the debug module. The debug module implements a
synchronous protocol using two inputs (DSCLK and DSI) and one output (DSO), where
DSCLK and DSI must meet the required input setup and hold timings and the DSO is
specified as a delay relative to the rising edge of the processor clock. See Table 5-1. The
development system serves as the serial communication channel master and must generate
DSCLK.
The serial channel operates at a frequency from DC to 1/5 of the processor frequency. The
channel uses full-duplex mode, where data is sent and received simultaneously by both
master and slave devices. The transmission consists of 17-bit packets composed of a
status/control bit and a 16-bit data word. As shown in Figure 5-15, all state transitions are
enabled on a rising edge of the processor clock when DSCLK is high; that is, DSI is
sampled and DSO is driven.
C1
C2
C3
C4
CPU CLK
PSTCLK
DSCLK
DSI
BDM State
Machine
DSO
Current
Current State
Past
Next
Next State
Current
Figure 5-15. BDM Serial Interface Timing
5-24
MCF5407 User’s Manual
Background Debug Mode (BDM)
DSCLK and DSI are synchronized inputs. DSCLK acts as a pseudo clock enable and is
sampled on the rising edge of the processor CLK as well as the DSI. DSO is delayed from
the DSCLK-enabled CLK rising edge (registered after a BDM state machine state change).
All events in the debug module’s serial state machine are based on the processor clock
rising edge. DSCLK must also be sampled low (on a positive edge of CLK) between each
bit exchange. The MSB is transferred first. Because DSO changes state based on an
internally-recognized rising edge of DSCLK, DSDO cannot be used to indicate the start of
a serial transfer. The development system must count clock cycles in a given transfer.
C1–C4 are described as follows:
•
•
•
C1—First synchronization cycle for DSI (DSCLK is high).
C2—Second synchronization cycle for DSI (DSCLK is high).
C3—BDM state machine changes state depending upon DSI and whether the entire
input data transfer has been transmitted.
C4—DSO changes to next value.
•
NOTE:
A not-ready response can be ignored except during a
memory-referencing cycle. Otherwise, the debug module can
accept a new serial transfer after 32 processor clock periods.
5.5.2.1 Receive Packet Format
The basic receive packet, Figure 5-16, consists of 16 data bits and 1 status bit.
16
15
S
0
Data Field [15:0]
Figure 5-16. Receive BDM Packet
Table 5-19 describes receive BDM packet fields.
Table 5-19. Receive BDM Packet Field Description
Bits
Name
16
S
15–0 Data
Description
Status. Indicates the status of CPU-generated messages listed below. The not-ready response can
be ignored unless a memory-referencing cycle is in progress. Otherwise, the debug module can
accept a new serial transfer after 32 processor clock periods.
S Data
Message
0 xxxx
Valid data transfer
0 0xFFFF Status OK
1 0x0000
Not ready with response; come again
1 0x0001
Error—Terminated bus cycle; data invalid
1 0xFFFF Illegal command
Data. Contains the message to be sent from the debug module to the development system. The
response message is always a single word, with the data field encoded as shown above.
Chapter 5. Debug Support
5-25
Background Debug Mode (BDM)
5.5.2.2 Transmit Packet Format
The basic transmit packet, Figure 5-17, consists of 16 data bits and 1 control bit.
16
15
0
C
D[15:0]
Figure 5-17. Transmit BDM Packet
Table 5-20 describes transmit BDM packet fields.
Table 5-20. Transmit BDM Packet Field Description
Bits
Name
16
C
15–0 Data
Description
Control. This bit is reserved. Command and data transfers initiated by the development system
should clear C.
Contains the data to be sent from the development system to the debug module.
5.5.3 BDM Command Set
Table 5-21 summarizes the BDM command set. Subsequent paragraphs contain detailed
descriptions of each command. Issuing a BDM command when the processor is accessing
debug module registers using the WDEBUG instruction causes undefined behavior.
Table 5-21. BDM Command Summary
Command
Mnemonic
Read A/D
register
RAREG/
Write A/D
register
WAREG/
Read
memory
location
Description
CPU
State1
Section
Command
(Hex)
Read the selected address or data register and
return the results through the serial interface.
Halted
5.5.3.3.1 0x218 {A/D,
Reg[2:0]}
Write the data operand to the specified address or
data register.
Halted
5.5.3.3.2 0x208 {A/D,
Reg[2:0]}
READ
Read the data at the memory location specified by
the longword address.
Steal
5.5.3.3.3 0x1900—byte
0x1940—word
0x1980—lword
Write
memory
location
WRITE
Write the operand data to the memory location
specified by the longword address.
Steal
5.5.3.3.4 0x1800—byte
0x1840—word
0x1880—lword
Dump
memory
block
DUMP
Used with READ to dump large blocks of memory.
An initial READ is executed to set up the starting
address of the block and to retrieve the first result.
A DUMP command retrieves subsequent operands.
Steal
5.5.3.3.5 0x1D00—byte
0x1D40—word
0x1D80—lword
Fill memory
block
FILL
Used with WRITE to fill large blocks of memory. An
initial WRITE is executed to set up the starting
address of the block and to supply the first operand.
A FILL command writes subsequent operands.
Steal
5.5.3.3.6 0x1C00—byte
0x1C40—word
0x1C80—lword
Resume
execution
GO
The pipeline is flushed and refilled before resuming
instruction execution at the current PC.
Halted
5.5.3.3.7 0x0C00
Perform no operation; may be used as a null
command.
Parallel
5.5.3.3.8 0x0000
RDREG
WDREG
No operation NOP
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MCF5407 User’s Manual
Background Debug Mode (BDM)
Table 5-21. BDM Command Summary (Continued)
CPU
State1
Section
Capture the current PC and display it on the
PSTDDATA output pins.
Parallel
5.5.3.3.9 0x0001
Read control RCREG
register
Read the system control register.
Halted
5.5.3.3.10 0x2980
Write control WCREG
register
Write the operand data to the system control
register.
Halted
5.5.3.3.11 0x2880
Read debug
module
register
RDMREG
Read the debug module register.
Parallel
5.5.3.3.12 0x2D {0x42
DRc[4:0]}
Write debug
module
register
WDMREG
Write the operand data to the debug module
register.
Parallel
5.5.3.3.13 0x2C {0x42
Drc[4:0]}
Command
Output the
current PC
Mnemonic
SYNC_PC
Description
Command
(Hex)
1
General command effect and/or requirements on CPU operation:
- Halted. The CPU must be halted to perform this command.
- Steal. Command generates bus cycles that can be interleaved with bus accesses.
- Parallel. Command is executed in parallel with CPU activity.
2 0x4 is a three-bit field.
Unassigned command opcodes are reserved by Motorola. All unused command formats
within any revision level perform a NOP and return the illegal command response.
5.5.3.1 ColdFire BDM Command Format
All ColdFire Family BDM commands include a 16-bit operation word followed by an
optional set of one or more extension words, as shown in Figure 5-18.
15
10
Operation
9
8
0
R/W
7
6
5
4
3
Op Size
0
0
A/D
2
0
Register
Extension Word(s)
Figure 5-18. BDM Command Format
Table 5-22 describes BDM fields.
Table 5-22. BDM Field Descriptions
Bit
Name
Description
15–10 Operation
Specifies the command. These values are listed in Table 5-21.
9
0
Reserved
8
R/W
Direction of operand transfer.
0 Data is written to the CPU or to memory from the development system.
1 The transfer is from the CPU to the development system.
Chapter 5. Debug Support
5-27
Background Debug Mode (BDM)
Table 5-22. BDM Field Descriptions (Continued)
Bit
7–6
Name
Description
Operand
Size
Operand data size for sized operations. Addresses are expressed as 32-bit absolute values.
Note that a command performing a byte-sized memory read leaves the upper 8 bits of the
response data undefined. Referenced data is returned in the lower 8 bits of the response.
Operand Size Bit Values
00 Byte
8 bits
01 Word
16 bits
10 Longword
32 bits
11 Reserved
—
5–4
00
Reserved
3
A/D
Address/data. Determines whether the register field specifies a data or address register.
0 Indicates a data register.
1 Indicates an address register.
2–0
Register
Contains the register number in commands that operate on processor registers.
5.5.3.1.1 Extension Words as Required
Some commands require extension words for addresses and/or immediate data. Addresses
require two extension words because only absolute long addressing is permitted. Longword
accesses are forcibly longword-aligned and word accesses are forcibly word-aligned.
Immediate data can be 1 or 2 words long. Byte and word data each requires a single
extension word and longword data requires two extension words.
Operands and addresses are transferred most-significant word first. In the following
descriptions of the BDM command set, the optional set of extension words is defined as
address, data, or operand data.
5.5.3.2 Command Sequence Diagrams
The command sequence diagram in Figure 5-19 shows serial bus traffic for commands.
Each bubble represents a 17-bit bus transfer. The top half of each bubble indicates the data
the development system sends to the debug module; the bottom half indicates the debug
module’s response to the previous development system commands. Command and result
transactions overlap to minimize latency.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
COMMANDS TRANSMITTED TO THE DEBUG MODULE
COMMAND CODE TRANSMITTED DURING THIS CYCLE
HIGH-ORDER 16 BITS OF MEMORY ADDRESS
LOW-ORDER 16 BITS OF MEMORY ADDRESS
NONSERIAL-RELATED ACTIVITY
SEQUENCE TAKEN IF
OPERATION HAS NOT
COMPLETED
READ (LONG)
???
MS ADDR
"NOT READY"
LS ADDR
"NOT READY"
XXX
"ILLEGAL"
NEXT CMD
"NOT READY"
READ
MEMORY
LOCATION
XXX
"NOT READY"
XXXXX
XXX
MS RESULT
XXX
BERR
NEXT
COMMAND
CODE
NEXT CMD
LS RESULT
NEXT CMD
"NOT READY"
DATA UNUSED FROM
THIS TRANSFER
SEQUENCE TAKEN IF
ILLEGAL COMMAND
IS RECEIVED BY DEBUG MODULE
RESULTS FROM PREVIOUS COMMAND
SEQUENCE TAKEN IF BUS
ERROR OCCURS ON
MEMORY ACCESS
HIGH- AND LOW-ORDER
16 BITS OF RESULT
RESPONSES FROM THE DEBUG MODULE
Figure 5-19. Command Sequence Diagram
The sequence is as follows:
•
•
In cycle 1, the development system command is issued (READ in this example). The
debug module responds with either the low-order results of the previous command
or a command complete status of the previous command, if no results are required.
In cycle 2, the development system supplies the high-order 16 address bits. The
debug module returns a not-ready response unless the received command is decoded
as unimplemented, which is indicated by the illegal command encoding. If this
occurs, the development system should retransmit the command.
NOTE:
A not-ready response can be ignored except during a
memory-referencing cycle. Otherwise, the debug module can
accept a new serial transfer after 32 processor clock periods.
•
•
In cycle 3, the development system supplies the low-order 16 address bits. The
debug module always returns a not-ready response.
At the completion of cycle 3, the debug module initiates a memory read operation.
Any serial transfers that begin during a memory access return a not-ready response.
Chapter 5. Debug Support
5-29
Background Debug Mode (BDM)
•
Results are returned in the two serial transfer cycles after the memory access
completes. For any command performing a byte-sized memory read operation, the
upper 8 bits of the response data are undefined and the referenced data is returned in
the lower 8 bits. The next command’s opcode is sent to the debug module during the
final transfer. If a memory or register access is terminated with a bus error, the error
status (S = 1, DATA = 0x0001) is returned instead of result data.
5.5.3.3 Command Set Descriptions
The following sections describe the commands summarized in Table 5-21.
NOTE:
The BDM status bit (S) is 0 for normally completed
commands; S = 1 for illegal commands, not-ready responses,
and transfers with bus-errors. Section 5.5.2, “BDM Serial
Interface,” describes the receive packet format.
Motorola reserves unassigned command opcodes for future expansion. Unused command
formats in any revision level perform a NOP and return an illegal command response.
5.5.3.3.1 Read A/D Register (RAREG/RDREG)
Read the selected address or data register and return the 32-bit result. A bus error response
is returned if the CPU core is not halted.
Command/Result Formats:
15
Command
12
11
8
0x2
7
0x1
Result
4
0x8
3
A/D
2
0
Register
D[31:16]
D[15:0]
Figure 5-20. RAREG/RDREG Command Format
Command Sequence:
RAREG/RDREG
???
XXX
MS RESULT
XXX
BERR
NEXT CMD
LS RESULT
NEXT CMD
"NOT READY"
Figure 5-21. RAREG/RDREG Command Sequence
Operand Data:
None
Result Data:
The contents of the selected register are returned as a longword
value, most-significant word first.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.2 Write A/D Register (WAREG/WDREG)
The operand longword data is written to the specified address or data register. A write alters
all 32 register bits. A bus error response is returned if the CPU core is not halted.
Command Format:
15
Command
12
0x2
11
8
7
0x0
Result
4
0x8
3
A/D
2
0
Register
D[31:16]
D[15:0]
Figure 5-22. WAREG/WDREG Command Format
Command Sequence
WDREG/WAREG
???
MS DATA
"NOT READY"
LS DATA
"NOT READY"
XXX
BERR
NEXT CMD
"NOT READY"
NEXT CMD
"CMD COMPLETE"
Figure 5-23. WAREG/WDREG Command Sequence
Operand Data
Longword data is written into the specified address or data register.
The data is supplied most-significant word first.
Result Data
Command complete status is indicated by returning 0xFFFF (with S
cleared) when the register write is complete.
Chapter 5. Debug Support
5-31
Background Debug Mode (BDM)
5.5.3.3.3 Read Memory Location (READ)
Read data at the longword address. Address space is defined by BAAR[TT,TM]. Hardware
forces low-order address bits to zeros for word and longword accesses to ensure that word
addresses are word-aligned and longword addresses are longword-aligned.
Command/Result Formats:
15
12
Byte
11
8
0x1
7
0x9
4
3
0x0
Command
0
0x0
A[31:16]
A[15:0]
Result
Word
X
X
Command
X
X
X
0x1
X
X
X
0x9
D[7:0]
0x4
0x0
0x8
0x0
A[31:16]
A[15:0]
Result
D[15:0]
Longword Command
0x1
0x9
A[31:16]
A[15:0]
Result
D[31:16]
D[15:0]
Figure 5-24. READ Command/Result Formats
Command Sequence:
READ (B/W)
???
MS ADDR
"NOT READY"
LS ADDR
"NOT READY"
READ
MEMORY
LOCATION
XXX
"NOT READY"
XXXCMD
NEXT
RESULT
XXX
BERR
READ (LONG)
???
MS ADDR
"NOT READY"
LS ADDR
"NOT READY"
READ
MEMORY
LOCATION
NEXT CMD
"NOT READY"
XXX
"NOT READY"
XXX
XXX
MS RESULT
NEXT CMD
LS RESULT
XXX
BERR
NEXT CMD
"NOT READY"
Figure 5-25. READ Command Sequence
Operand Data
The only operand is the longword address of the requested location.
Result Data
Word results return 16 bits of data; longword results return 32. Bytes
are returned in the LSB of a word result, the upper byte is undefined.
0x0001 (S = 1) is returned if a bus error occurs.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.4 Write Memory Location (WRITE)
Write data to the memory location specified by the longword address. The address space is
defined by BAAR[TT,TM]. Hardware forces low-order address bits to zeros for word and
longword accesses to ensure that word addresses are word-aligned and longword addresses
are longword-aligned.
Command Formats:
15
12
Byte
11
8
0x1
7
0x8
4
0x0
3
1
0x0
A[31:16]
A[15:0]
X
Word
X
X
0x1
X
X
X
X
X
0x8
D[7:0]
0x4
0x0
0x8
0x0
A[31:16]
A[15:0]
D[15:0]
Longword
0x1
0x8
A[31:16]
A[15:0]
D[31:16]
D[15:0]
Figure 5-26. WRITE Command Format
Chapter 5. Debug Support
5-33
Background Debug Mode (BDM)
Command Sequence:
WRITE (B/W)
???
MS ADDR
"NOT READY"
LS ADDR
"NOT READY"
DATA
"NOT READY"
WRITE
MEMORY
LOCATION
XXX
"NOT READY"
XXX CMD
NEXT
"CMD COMPLETE"
XXX
BERR
NEXT CMD
"NOT READY"
WRITE (LONG)
???
MS ADDR
"NOT READY"
LS ADDR
"NOT READY"
MS DATA
"NOT READY"
LS DATA
"NOT READY"
WRITE
MEMORY
LOCATION
XXX
"NOT READY"
XXX CMD
NEXT
"CMD COMPLETE"
XXX
BERR
NEXT CMD
"NOT READY"
Figure 5-27. WRITE Command Sequence
Operand Data
This two-operand instruction requires a longword absolute address
that specifies a location to which the data operand is to be written.
Byte data is sent as a 16-bit word, justified in the LSB; 16- and 32-bit
operands are sent as 16 and 32 bits, respectively
Result Data
Command complete status is indicated by returning 0xFFFF (with S
cleared) when the register write is complete. A value of 0x0001 (with
S set) is returned if a bus error occurs.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.5 Dump Memory Block (DUMP)
is used with the READ command to access large blocks of memory. An initial READ
is executed to set up the starting address of the block and to retrieve the first result. If an
initial READ is not executed before the first DUMP, an illegal command response is returned.
The DUMP command retrieves subsequent operands. The initial address is incremented by
the operand size (1, 2, or 4) and saved in a temporary register. Subsequent DUMP commands
use this address, perform the memory read, increment it by the current operand size, and
store the updated address in the temporary register.
DUMP
NOTE:
DUMP does not check for a valid address; it is a valid command
only when preceded by NOP, READ, or another DUMP command.
Otherwise, an illegal command response is returned. NOP can
be used for intercommand padding without corrupting the
address pointer.
The size field is examined each time a DUMP command is processed, allowing the operand
size to be dynamically altered.
Command/Result Formats:
15
Byte
Command
Result
Word
Command
12
11
X
X
8
0x1
X
X
0xD
X
0x1
X
4
3
0x0
X
X
0xD
Result
Longword Command
7
0
0x0
D[7:0]
0x4
0x0
0x8
0x0
D[15:0]
0x1
0xD
Result
D[31:16]
D[15:0]
Figure 5-28.
DUMP
Command/Result Formats
Chapter 5. Debug Support
5-35
Background Debug Mode (BDM)
Command Sequence:
READ
MEMORY
LOCATION
DUMP (B/W)
???
XXX
"NOT READY"
NEXT CMD
RESULT
XXX
"ILLEGAL"
NEXT CMD
"NOT READY"
READ
MEMORY
LOCATION
DUMP (LONG)
???
XXX
"ILLEGAL"
XXX
BERR
NEXT CMD
"NOT READY"
XXX
"NOT READY"
NEXT CMD
"NOT READY"
NEXT CMD
MS RESULT
NEXT CMD
LS RESULT
XXX
BERR
NEXT CMD
"NOT READY"
Figure 5-29. DUMP Command Sequence
Operand Data:
None
Result Data:
Requested data is returned as either a word or longword. Byte data is
returned in the least-significant byte of a word result. Word results
return 16 bits of significant data; longword results return 32 bits. A
value of 0x0001 (with S set) is returned if a bus error occurs.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.6 Fill Memory Block (FILL)
A FILL command is used with the WRITE command to access large blocks of memory. An
initial WRITE is executed to set up the starting address of the block and to supply the first
operand. The FILL command writes subsequent operands. The initial address is incremented
by the operand size (1, 2, or 4) and saved in a temporary register after the memory write.
Subsequent FILL commands use this address, perform the write, increment it by the current
operand size, and store the updated address in the temporary register.
If an initial WRITE is not executed preceding the first FILL command, the illegal command
response is returned.
NOTE:
The FILL command does not check for a valid address—FILL is
a valid command only when preceded by another FILL, a NOP,
or a WRITE command. Otherwise, an illegal command response
is returned. The NOP command can be used for intercommand
padding without corrupting the address pointer.
The size field is examined each time a FILL command is processed, allowing the operand
size to be altered dynamically.
Command Formats:
15
12
Byte
X
Word
11
8
0x1
X
7
0xC
X
X
X
0x1
X
4
3
0x0
X
X
0xC
0
0x0
D[7:0]
0x4
0x0
0x8
0x0
D[15:0]
Longword
0x1
0xC
D[31:16]
D[15:0]
Figure 5-30.
FILL
Command Format
Chapter 5. Debug Support
5-37
Background Debug Mode (BDM)
Command Sequence:
FILL
FILL(LONG)
(B/W)
???
MS DATA
"NOT READY"
XXX
"ILLEGAL"
LS DATA
"NOT READY"
WRITE
MEMORY
LOCATION
XXX
"NOT READY"
NEXT CMD
"CMD COMPLETE"
NEXT CMD
"NOT READY"
XXX
BERR
FILL(LONG)
(B/W)
FILL
???
DATA
"NOT READY"
WRITE
MEMORY
LOCATION
XXX
"ILLEGAL"
NEXT CMD
"NOT READY"
NEXT CMD
"NOT READY"
XXX
"NOT READY"
NEXT CMD
"CMD COMPLETE"
XXX
BERR
NEXT CMD
"NOT READY"
Figure 5-31. FILL Command Sequence
Operand Data:
A single operand is data to be written to the memory location. Byte
data is sent as a 16-bit word, justified in the least-significant byte; 16and 32-bit operands are sent as 16 and 32 bits, respectively.
Result Data:
Command complete status (0xFFFF) is returned when the register
write is complete. A value of 0x0001 (with S set) is returned if a bus
error occurs.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.7 Resume Execution (GO)
The pipeline is flushed and refilled before normal instruction execution resumes.
Prefetching begins at the current address in the PC and at the current privilege level. If any
register (such as the PC or SR) is altered by a BDM command while the processor is halted,
the updated value is used when prefetching resumes. If a GO command is issued and the
CPU is not halted, the command is ignored.
15
12
11
8
0x0
0xC
7
4
0x0
3
0
0x0
Figure 5-32. GO Command Format
Command Sequence:
GO
???
NEXT CMD
"CMD COMPLETE"
Figure 5-33. GO Command Sequence
Operand Data:
None
Result Data:
The command-complete response (0xFFFF) is returned during the
next shift operation.
Chapter 5. Debug Support
5-39
Background Debug Mode (BDM)
5.5.3.3.8 No Operation (NOP)
NOP
performs no operation and may be used as a null command where required.
Command Formats:
15
12
11
8
0x0
0x0
7
4
0x0
3
0
0x0
Figure 5-34. NOP Command Format
Command Sequence:
NOP
???
NEXT CMD
"CMD COMPLETE"
Figure 5-35. NOP Command Sequence
Operand Data:
None
Result Data:
The command-complete response, 0xFFFF (with S cleared), is
returned during the next shift operation.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.9 Synchronize PC to the PSTDDATA Lines (SYNC_PC)
The SYNC_PC command captures the current PC and displays it on the PSTDDATA outputs.
After the debug module receives the command, it sends a signal to the ColdFire processor
that the current PC must be displayed. The processor then forces an instruction fetch at the
next PC with the address being captured in the DDATA logic under control of CSR[BTB].
The specific sequence of PSTDDATA values is as follows:
1. Debug signals a SYNC_PC command is pending.
2. CPU completes the current instruction.
3. CPU forces an instruction fetch to the next PC, generates a PST = 0x5 value
indicating a taken branch and signals the capture of DDATA.
4. The instruction address corresponding to the PC is captured.
5. The PST marker (0x9–0xB) is generated and displayed as defined by CSR[BTB]
followed by the captured PC address.
The SYNC_PC command can be used to dynamically access the PC for performance
monitoring. The execution of this command is considerably less obtrusive to the real-time
operation of an application than a HALT-CPU/READ-PC/RESUME command sequence.
Command Formats:
15
12
11
0x0
8
0x0
7
4
0x0
3
0
0x1
Figure 5-36. SYNC_PC Command Format
Command Sequence:
SYNC_PC
NOP
???
NEXT CMD
"CMD COMPLETE"
Figure 5-37. SYNC_PC Command Sequence
Operand Data:
None
Result Data:
Command complete status (0xFFFF) is returned when the register
write is complete.
Chapter 5. Debug Support
5-41
Background Debug Mode (BDM)
5.5.3.3.10 Read Control Register (RCREG)
Read the selected control register and return the 32-bit result. Accesses to the
processor/memory control registers are always 32 bits wide, regardless of register width.
The second and third words of the command form a 32-bit address, which the debug
module uses to generate a special bus cycle to access the specified control register. The
12-bit Rc field is the same as that used by the MOVEC instruction.
Command/Result Formats:
15
Command
12
11
8
7
4
3
0
0x2
0x9
0x8
0x0
0x0
0x0
0x0
0x0
0x0
Rc
Result
D[31:16]
D[15:0]
Figure 5-38. RCREG Command/Result Formats
Rc encoding:
Table 5-23. Control Register Map
Rc
Register Definition
Rc
Register Definition
0x002
Cache control register (CACR)
0x805
MAC mask register (MASK)
0x004
Access control register 0 (ACR0)
0x806
MAC accumulator (ACC)
0x005
Access control register 1 (ACR1)
0x80E
Status register (SR)
0x006
Access control register 2 (ACR2)
0x80F
Program register (PC)
0x007
Access control register 2 (ACR3)
0xC04
RAM base address register (RAMBAR0)
0x801
Vector base register (VBR)
0xC05
RAM base address register (RAMBAR1)
0x804
MAC status register (MACSR)
0xC0F
Memory base address (MBAR)
Command Sequence:
RCREG
???
MS ADDR
EXT
WORD
"NOT READY"
MS ADDR
EXT
WORD
"NOT READY"
READ
CONTROL
MEMORY
REGISTER
LOCATION
XXX
"NOT READY"
XXX
MS RESULT
NEXT CMD
LS RESULT
XXX
BERR
NEXT CMD
"NOT READY"
Figure 5-39. RCREG Command Sequence
Operand Data:
The only operand is the 32-bit Rc control register select field.
Result Data:
Control register contents are returned as a longword,
most-significant word first. The implemented portion of registers
smaller than 32 bits is guaranteed correct; other bits are undefined.
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MCF5407 User’s Manual
Background Debug Mode (BDM)
5.5.3.3.11 Write Control Register (WCREG)
The operand (longword) data is written to the specified control register. The write alters all
32 register bits.
Command/Result Formats:
15
Command
12
11
8
7
4
3
0
0x2
0x8
0x8
0x0
0x0
0x0
0x0
0x0
0x0
Rc
Result
D[31:16]
D[15:0]
Figure 5-40. WCREG Command/Result Formats
Command Sequence:
WCREG
???
MS ADDR
EXT
WORD
"NOT READY"
MS ADDR
EXT
WORD
"NOT READY"
MS DATA
"NOT READY"
LS DATA
"NOT READY"
WRITE
WRITE
CONTROL
MEMORY
REGISTER
LOCATION
XXX
"NOT READY"
XXX CMD
NEXT
"CMD COMPLETE"
XXX
BERR
NEXT CMD
"NOT READY"
Figure 5-41. WCREG Command Sequence
Operand Data:
This instruction requires two longword operands. The first selects the
register to which the operand data is to be written; the second
contains the data.
Result Data:
Successful write operations return 0xFFFF. Bus errors on the write
cycle are indicated by the setting of bit 16 in the status message and
by a data pattern of 0x0001.
Chapter 5. Debug Support
5-43
Background Debug Mode (BDM)
5.5.3.3.12 Read Debug Module Register (RDMREG)
Read the selected debug module register and return the 32-bit result. The only valid register
selection for the RDMREG command is CSR (DRc = 0x00). Note that this read of the CSR
clears the trigger status bits (CSR[BSTAT]) if either a level-2 breakpoint has been triggered
or a level-1 breakpoint has been triggered and no level-2 breakpoint has been enabled.
Command/Result Formats:
15
Command
12
11
8
0x2
7
5
4
0
0x41
0xD
Result
DRc
D[31:16]
D[15:0]
Figure 5-42.
1
RDMREG BDM
Command/Result Formats
Note 0x4 is a 3-bit field
Table 5-24 shows the definition of DRc encoding.
Table 5-24. Definition of DRc Encoding—Read
DRc[4:0]
Debug Register Definition
Mnemonic
Initial State
Page
0x00
Configuration/Status
CSR
0x0
p. 5-13
0x01–0x1F
Reserved
—
—
—
Command Sequence:
RDMREG
???
XXX
MS RESULT
NEXT CMD
LS RESULT
XXX
"ILLEGAL"
NEXT CMD
"NOT READY"
Figure 5-43. RDMREG Command Sequence
Operand Data:
None
Result Data:
The contents of the selected debug register are returned as a
longword value. The data is returned most-significant word first.
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MCF5407 User’s Manual
Real-Time Debug Support
5.5.3.3.13 Write Debug Module Register (WDMREG)
The operand (longword) data is written to the specified debug module register. All 32 bits
of the register are altered by the write. DSCLK must be inactive while the debug module
register writes from the CPU accesses are performed using the WDEBUG instruction.
Command Format:
Figure 5-44. WDMREG BDM Command Format
15
12
11
0x2
8
7
5
4
0x41
0xC
0
DRc
D[31:16]
D[15:0]
1
Note: 0x4 is a three-bit field
Table 5-6 shows the definition of the DRc write encoding.
Command Sequence:
WDMREG
???
MS DATA
"NOT READY"
LS DATA
"NOT READY"
XXX
"ILLEGAL"
NEXT CMD
"NOT READY"
NEXT CMD
"CMD COMPLETE"
Figure 5-45. WDMREG Command Sequence
Operand Data:
Longword data is written into the specified debug register. The data
is supplied most-significant word first.
Result Data:
Command complete status (0xFFFF) is returned when register write
is complete.
5.6 Real-Time Debug Support
The ColdFire Family provides support debugging real-time applications. For these types of
embedded systems, the processor must continue to operate during debug. The foundation
of this area of debug support is that while the processor cannot be halted to allow
debugging, the system can generally tolerate small intrusions into the real-time operation.
The debug module provides three types of breakpoints—PC with mask, operand address
range, and data with mask. These breakpoints can be configured into one- or two-level
triggers with the exact trigger response also programmable. The debug module
programming model can be written from either the external development system using the
debug serial interface or from the processor’s supervisor programming model using the
WDEBUG instruction. Only CSR is readable using the external development system.
Chapter 5. Debug Support
5-45
Real-Time Debug Support
5.6.1 Theory of Operation
Breakpoint hardware can be configured to respond to triggers in several ways. The response
desired is programmed into TDR. As shown in Table 5-25, when a breakpoint is triggered,
an indication (CSR[BSTAT]) is provided on the PSTDDATA output port when it is not
displaying captured processor status, operands, or branch addresses. See Section 5.3.2,
“Processor Stopped or Breakpoint State Change (PST = 0xE).”
Table 5-25. PSTDDATA Nibble/CSR[BSTAT] Breakpoint Response
PSTDDATA Nibble/CSR[BSTAT] 1
1
Breakpoint Status
0000/0000
No breakpoints enabled
0010/0001
Waiting for level-1 breakpoint
0100/0010
Level-1 breakpoint triggered
1010/0101
Waiting for level-2 breakpoint
1100/0110
Level-2 breakpoint triggered
Encodings not shown are reserved for future use.
The breakpoint status is also posted in CSR. Note that CSR[BSTAT] is cleared by a CSR
read when either a level-2 breakpoint is triggered or a level-1 breakpoint is triggered and a
level-2 breakpoint is not enabled. Status is also cleared by writing to either TDR or XTDR.
BDM instructions use the appropriate registers to load and configure breakpoints. As the
system operates, a breakpoint trigger generates the response defined in TDR.
PC breakpoints are treated in a precise manner—exception recognition and processing are
initiated before the excepting instruction is executed. All other breakpoint events are
recognized on the processor’s local bus, but are made pending to the processor and sampled
like other interrupt conditions. As a result, these interrupts are imprecise.
In systems that tolerate the processor being halted, a BDM-entry can be used. With
TDR[TRC] = 01, a breakpoint trigger causes the core to halt (PST = 0xF).
If the processor core cannot be halted, the debug interrupt can be used. With this
configuration, TDR[TRC] = 10, the breakpoint trigger becomes a debug interrupt to the
processor, which is treated higher than the nonmaskable level-7 interrupt request. As with
all interrupts, it is made pending until the processor reaches a sample point, which occurs
once per instruction. Again, the hardware forces the PC breakpoint to occur before the
targeted instruction executes. This is possible because the PC breakpoint is enabled when
interrupt sampling occurs. For address and data breakpoints, reporting is considered
imprecise because several instructions may execute after the triggering address or data is
detected.
As soon as the debug interrupt is recognized, the processor aborts execution and initiates
exception processing. This event is signaled externally by the assertion of a unique PST
value (PST = 0xD) for multiple cycles. The core enters emulator mode when exception
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MCF5407 User’s Manual
Real-Time Debug Support
processing begins. After the standard 8-byte exception stack is created, the processor
fetches a unique exception vector from the vector table. Table 5-26 describes the two
unique entries that distinguish PC breakpoints from other trigger events.
Table 5-26. Exception Vector Assignments
Vector Number
Vector Offset (Hex)
Stacked Program Counter
Assignment
12
0x030
Next
Non-PC-breakpoint debug interrupt
13
0x034
Next
PC-breakpoint debug interrupt
In the case of a two-level trigger, the last breakpoint event determines the exception vector;
however, if the second-level trigger is PC || Address {&& Data} (as shown in the last
condition in the code example in Section 5.4.9, “Resulting Set of Possible Trigger
Combinations”), the vector taken is determined by the first condition that occurs after the
first-level trigger—vector 13 if PC occurs first or vector 12 if Address {&& Data} occurs
first. If both occur simultaneously, the non-PC-breakpoint debug interrupt is taken (vector
number 12).
Execution continues at the instruction address in the vector corresponding to the breakpoint
triggered. The debug interrupt handler can use supervisor instructions to save the necessary
context such as the state of all program-visible registers into a reserved memory area.
During a debug interrupt service routine, all normal interrupt requests are evaluated and
sampled once per instruction. If any exception occurs, the processor responds as follows:
1. It saves a copy of the current value of the emulator mode state bit and then exits
emulator mode by clearing the actual state.
2. Bit 1 of the fault status field (FS1) in the next exception stack frame is set to indicate
the processor was in emulator mode when the interrupt occurred. This corresponds
to bit 17 of the longword at the top of the system stack. See Section 2.8.1,
“Exception Stack Frame Definition.”
3. It passed control to the appropriate exception handler.
4. It executes an RTE instruction when the exception handler finishes. During the
processing of the RTE, FS1 is reloaded from the system stack. If this bit is set, the
processor sets the emulator mode state and resumes execution of the original debug
interrupt service routine. This is signaled externally by the generation of the PST
value that originally identified the debug interrupt exception, that is, PST = 0xD.
Fault status encodings are listed in Table 2-21. Implementation of this debug interrupt
handling fully supports the servicing of a number of normal interrupt requests during a
debug interrupt service routine. The emulator mode state bit is essentially changed to be a
program-visible value, stored into memory during exception stack frame creation, and
loaded from memory by the RTE instruction.
When debug interrupt operations complete, the RTE instruction executes and the processor
exits emulator mode. After the debug interrupt handler completes execution, the external
Chapter 5. Debug Support
5-47
Real-Time Debug Support
development system can use BDM commands to read the reserved memory locations.
The generation of another debug interrupt during the first instruction after the RTE exits
emulator mode is inhibited. This behavior is consistent with the existing logic involving
trace mode where the first instruction executes before another trace exception is generated.
Thus, all hardware breakpoints are disabled until the first instruction after the RTE
completes execution, regardless of the programmed trigger response.
5.6.1.1 Emulator Mode
Emulator mode is used to facilitate non-intrusive emulator functionality. This mode can be
entered in three different ways:
•
•
•
Setting CSR[EMU] forces the processor into emulator mode. EMU is examined
only if RSTI is negated and the processor begins reset exception processing. It can
be set while the processor is halted before reset exception processing begins. See
Section 5.5.1, “CPU Halt.”
A debug interrupt always puts the processor in emulation mode when debug
interrupt exception processing begins.
Setting CSR[TRC] forces the processor into emulation mode when trace exception
processing begins.
While operating in emulation mode, the processor exhibits the following properties:
•
•
Unmasked interrupt requests are serviced. The resulting interrupt exception stack
frame has FS[1] set to indicate the interrupt occurred while in emulator mode.
If CSR[MAP] = 1, all caching of memory and the SRAM module are disabled. All
memory accesses are forced into a specially mapped address space signaled by
TT = 2, TM = 5 or 6. This includes stack frame writes and the vector fetch for the
exception that forced entry into this mode.
The return-from-exception (RTE) instruction exits emulation mode. The processor status
output port provides a unique encoding for emulator mode entry (0xD) and exit (0x7).
5.6.2 Concurrent BDM and Processor Operation
The debug module supports concurrent operation of both the processor and most BDM
commands. BDM commands may be executed while the processor is running, except those
following operations that access processor/memory registers:
•
•
Read/write address and data registers
Read/write control registers
For BDM commands that access memory, the debug module requests the processor’s local
bus. The processor responds by stalling the instruction fetch pipeline and waiting for
current bus activity to complete before freeing the local bus for the debug module to
perform its access. After the debug module bus cycle, the processor reclaims the bus.
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MCF5407 User’s Manual
Motorola-Recommended BDM Pinout
Breakpoint registers must be carefully configured in a development system if the processor
is executing. The debug module contains no hardware interlocks, so TDR and XTDR
should be disabled while breakpoint registers are loaded, after which TDR and XTDR can
be written to define the exact trigger. This prevents spurious breakpoint triggers.
Because there are no hardware interlocks in the debug unit, no BDM operations are allowed
while the CPU is writing the debug’s registers (DSCLK must be inactive).
5.7 Motorola-Recommended BDM Pinout
The ColdFire BDM connector, Figure 5-46, is a 26-pin Berg connector arranged 2 x 13.
Developer reserved 1
1
2
BKPT
GND
3
4
DSCLK
GND
5
6
Developer reserved1
RESET
7
8
DSI
+3.3V2
9
10
DSO
GND
11
12
PSTDDATA7
PSTDDATA6
13
14
PSTDDATA5
PSTDDATA4
15
16
PSTDDATA3
PSTDDATA2
17
18
PSTDDATA1
PSTDDATA0
19
20
GND
Motorola reserved
21
22
Motorola reserved
GND
23
24
PSTCLK
VDD_CPU
25
26
TA
1 Pins reserved for BDM
2 Supplied by target.
developer use.
Figure 5-46. Recommended BDM Connector
5.8 Debug C Definition of PSTDDATA Outputs
This section specifies the ColdFire processor and debug module’s generation of the
PSTDDATA output on an instruction basis. In general, the PSTDDATA output for an
instruction is defined as PSTDDATA = 1, {[89B], operand} where the {...} definition is
optional operand information defined by the setting of the CSR. The [89B] signifies a PST
value that is a marker identifying the presence and size of valid data to follow. A PST value
of 0x8 (1 byte of data), 0x9 (2 bytes), or 0xB (4 bytes) is displayed before the data output.
The CSR allows operands to be displayed based on reference type (read, write, or both). A
PST value {0x8, 0x9, or 0xB} identifies the size and presence of valid data to follow on the
PSTDDATA output {1, 2, or 4 bytes}. Additionally, for certain change-of-flow branch
instructions, CSR[9,8] provides the ability to display {0x2, 0x3, or 0x4} bytes of the target
instruction address. A PST value {0x9, 0xA, or 0xB} provides the marker identifying the
size and presence of a valid target address on the PSTDDATA output.
Chapter 5. Debug Support
5-49
Debug C Definition of PSTDDATA Outputs
5.8.1 User Instruction Set
Table 5-27 shows the PSTDDATA specification for user-mode instructions.
Table 5-27. PSTDDATA Specification for User-Mode Instructions
Instruction
Syntax
PSTDDATA
add.l
<ea>y,Rx
PSTDDATA = 1, {B, source operand}
add.l
Dy,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
addi.l
#imm,Dx
PSTDDATA = 1
addq.l
#imm,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
addx.l
Dy,Dx
PSTDDATA = 1
and.l
<ea>y,Dx
PSTDDATA = 1, {B, source operand}
and.l
Dy,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
andi.l
#imm,Dx
PSTDDATA = 1
asl.l
{Dy,#imm},Dx
PSTDDATA = 1
asr.l
{Dy,#imm},Dx
bcc.{b,w,l}
PSTDDATA = 1
if taken, then PSTDDATA = 5, else PSTDDATA = 1
bchg
Dy,<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
bchg
#imm,<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
bclr
Dy,<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
bclr
#imm,<ea>x
bra.{b,w,l}
PSTDDATA = 1, {8, source}, {8, destination}
PSTDDATA = 5
bset
Dy,<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
bset
#imm,<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
btst
Dy,<ea>x
PSTDDATA = 1, {8, source operand}
btst
#imm,<ea>x
PSTDDATA = 1, {8, source operand}
clr.b
<ea>x
PSTDDATA = 1, {8, destination operand}
clr.w
<ea>x
PSTDDATA = 1, {9, destination operand}
clr.l
<ea>x
PSTDDATA = 1, {B, destination operand}
cmp.b
<ea>y,Rx
PSTDDATA = 1, {8, source operand}
cmp.w
<ea>y,Rx
PSTDDATA = 1, {9, source operand}
cmp.l
<ea>y,Rx
PSTDDATA = 1, {B, source operand}
cmpi.b
#imm,Dx
PSTDDATA = 1
cmpi.w
#imm,Dx
PSTDDATA = 1
cmpi.l
#imm,Dx
PSTDDATA = 1
divs.l
<ea>y,Dx
PSTDDATA = 1, {B, source operand}
divs.w
<ea>y,Dx
PSTDDATA = 1, {9, source operand}
divu.l
<ea>y,Dx
PSTDDATA = 1, {B, source operand}
bsr.{b,w,l}
5-50
PSTDDATA = 5, {B, destination operand}
MCF5407 User’s Manual
Debug C Definition of PSTDDATA Outputs
Table 5-27. PSTDDATA Specification for User-Mode Instructions (Continued)
Instruction
Syntax
PSTDDATA
divu.w
<ea>y,Dx
PSTDDATA = 1, {9, source operand}
eor.l
Dy,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
eori.l
#imm,Dx
PSTDDATA = 1
ext.w
Dx
PSTDDATA = 1
ext.l
Dx
PSTDDATA = 1
extb.l
Dx
PSTDDATA = 1
jmp
<ea>x
PSTDDATA = 5, {[9AB], target address} 1
jsr
<ea>x
PSTDDATA = 5, {[9AB], target address},{B, destination operand} 1
lea
<ea>y,Ax
PSTDDATA = 1
link.w
Ay,#imm
PSTDDATA = 1, {B, destination operand}
lsl.l
{Dy,#imm},Dx
PSTDDATA = 1
lsr.l
{Dy,#imm},Dx
PSTDDATA = 1
mac.l
Ry,Rx
PSTDDATA = 1
mac.l
Ry,Rx,ea,Rw
PSTDDATA = 1, {B, source operand}
mac.w
Ry,Rx
PSTDDATA = 1
mac.w
Ry,Rx,ea,Rw
PSTDDATA = 1, {B, source operand}
mov3q.l
#imm,<ea>x
PSTDDATA = 1, {B, destination operand}
move.b
<ea>y,<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
move.w
<ea>y,<ea>x
PSTDDATA = 1, {9, source}, {9, destination}
move.l
<ea>y,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
move.l
<ea>y,ACC
PSTDDATA = 1
move.l
<ea>y,MACSR
PSTDDATA = 1
move.l
<ea>y,MASK
PSTDDATA = 1
move.l
ACC,Rx
PSTDDATA = 1
move.l
MACSR,CCR
PSTDDATA = 1
move.l
MACSR,Rx
PSTDDATA = 1
move.l
MASK,Rx
PSTDDATA = 1
move.w
CCR,Dx
PSTDDATA = 1
move.w
{Dy,#imm},CCR
PSTDDATA = 1
movem.l
<ea>y,#list
PSTDDATA = 1, {B, source},... 2
movem.l
#list,<ea>x
PSTDDATA = 1, {B, destination},...2
moveq
#imm,Dx
PSTDDATA = 1
msac.l
Ry,Rx
PSTDDATA = 1
msac.l
Ry,Rx,ea,Rw
PSTDDATA = 1, {B, source operand}
msac.w
Ry,Rx
PSTDDATA = 1
msac.w
Ry,Rx,ea,Rw
PSTDDATA = 1, {B, source operand}
Chapter 5. Debug Support
5-51
Debug C Definition of PSTDDATA Outputs
Table 5-27. PSTDDATA Specification for User-Mode Instructions (Continued)
Instruction
Syntax
PSTDDATA
muls.w
<ea>y,Dx
PSTDDATA = 1, {9, source operand}
mulu.w
<ea>y,Dx
PSTDDATA = 1, {9, source operand}
muls.l
<ea>y,Dx
PSTDDATA = 1, {B, source operand}
mulu.l
<ea>y,Dx
PSTDDATA = 1, {B, source operand}
mvs.b
<ea>y,Dx
PSTDDATA = 1, {8, source operand}
mvs.w
<ea>y,Dx
PSTDDATA = 1, {9, source operand}
mvz.b
<ea>y,Dx
PSTDDATA = 1, {8, source operand}
mvz.w
<ea>y,Dx
PSTDDATA = 1, {9, source operand}
neg.l
Dx
PSTDDATA = 1
negx.l
Dx
PSTDDATA = 1
nop
PSTDDATA = 1
not.l
Dx
PSTDDATA = 1
or.l
<ea>y,Dx
PSTDDATA = 1, {B, source operand}
or.l
Dy,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
ori.l
#imm,Dx
PSTDDATA = 1
pea
<ea>y
pulse
PSTDDATA = 1, {B, destination operand}
PSTDDATA = 4
rems.l
<ea>y,Dx:Dw
PSTDDATA = 1, {B, source operand}
remu.l
<ea>y,Dx:Dw
PSTDDATA = 1, {B, source operand}
rts (not predicted)
PSTDDATA=1, {B, source operand},
PSTDDATA=5, {[9AB], target address}
rts (predicted) 3
PSTDDATA=1, {B, source operand}, 5
sats.l
Dx
PSTDDATA = 1
scc
Dx
PSTDDATA = 1
sub.l
<ea>y,Rx
PSTDDATA = 1, {B, source operand}
sub.l
Dy,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
subi.l
#imm,Dx
PSTDDATA = 1
subq.l
#imm,<ea>x
PSTDDATA = 1, {B, source}, {B, destination}
subx.l
Dy,Dx
PSTDDATA = 1
swap
Dx
PSTDDATA = 1
tas
<ea>x
PSTDDATA = 1, {8, source}, {8, destination}
trap
#imm
PSTDDATA = 1 4
tpf
PSTDDATA = 1
tpf.w
PSTDDATA = 1
tpf.l
PSTDDATA = 1
tst.b
5-52
<ea>x
PSTDDATA = 1, {8, source operand}
MCF5407 User’s Manual
Debug C Definition of PSTDDATA Outputs
Table 5-27. PSTDDATA Specification for User-Mode Instructions (Continued)
Instruction
Syntax
PSTDDATA
tst.w
<ea>x
PSTDDATA = 1, {9, source operand}
tst.l
<ea>x
PSTDDATA = 1, {B, source operand}
unlk
Ax
PSTDDATA = 1, {B, destination operand}
wddata.b
<ea>y
PSTDDATA = 4, 8, source operand
wddata.w
<ea>y
PSTDDATA = 4, 9, source operand
wddata.l
<ea>y
PSTDDATA = 4, B, source operand
1
For JMP and JSR instructions, the optional target instruction address is displayed only for those effective
address fields defining variant addressing modes. This includes the following <ea>x values: (An), (d16,An),
(d8,An,Xi), (d8,PC,Xi).
2 For move multiple instructions (MOVEM), the processor automatically generates line-sized transfers if the
address reaches a cache line (0-modulo-16) boundary four or more registers are to be transferred. For these
line-sized transfers, the operand data is never captured nor displayed, regardless of the CSR value.
Automatic line-sized burst transfers maximize performance for these sequential memory accesses.
3 The source operand in predicted RTS is displayed if CSR[12] and/or (CSR[9] or CSR[8]) is set.
4 During normal exception processing, PSTDDATA outputs are driven to 0xC. The exception stack write operands
and the vector read and target address of the exception handler may also be displayed.
Rn represents any {Dn, An} register. In this definition, the ‘y’ suffix generally denotes the
source and ‘x’ denotes the destination operand. For a given instruction, the optional
operand data is displayed only for those effective addresses referencing memory.
Exception Processing
PSTDDATA = C,{B, destination},// stack frame
{B, destination},// stack frame
{B, source},// vector read
PSTDDATA = 5,{[9AB], target}// PC of handler
The PSTDDATA specification for the reset exception is shown below:
Exception Processing
PSTDDATA = C,
PSTDDATA = 5,{[9AB], target}// initial PC
The initial references at address 0 and 4 are never captured nor displayed since these
accesses are treated as instruction fetches.
For all types of exception processing, the PSTDDATA = 0xC value is driven at all times,
unless the PSTDDATA output is needed for one of the optional marker values or for the
taken branch indicator (0x5).
5.8.2 Supervisor Instruction Set
The supervisor instruction set has complete access to the user mode instructions plus the
opcodes shown below. Table 5-28 shows the PSTDDATA specification for these opcodes.
Chapter 5. Debug Support
5-53
Debug C Definition of PSTDDATA Outputs
Table 5-28. PSTDDATA Specification for Supervisor-Mode Instructions
Instruction
Syntax
PSTDDATA
cpushl
PSTDDATA = 1
halt
PSTDDATA = 1,
PSTDDATA = F
intouch
PSTDDATA = 1
move.w
SR,Dx
move.w
{Dy,#imm},SR
PSTDDATA = 1, {3}
movec
Ry,Rc
PSTDDATA = 1
rte
PSTDDATA = 1
PSTDDATA = 7, {B, source operand}, {3},{B, source operand}, {DD},
PSTDDATA = 5, {[9AB], target address}
stop
#imm
PSTDDATA = 1,
PSTDDATA = E
wdebug
<ea>y
PSTDDATA = 1, {B, source, B, source}
The move-to-SR and RTE instructions include an optional PSTDDATA = 0x3 value,
indicating an entry into user mode. Additionally, if the execution of a RTE instruction
returns the processor to emulator mode, a multiple-cycle status of 0xD is signaled.
Similar to the exception processing mode, the stopped state (PSTDDATA = 0xE) and the
halted state (PSTDDATA = 0xF) display this status throughout the entire time the ColdFire
processor is in the given mode.
5-54
MCF5407 User’s Manual
Part II
System Integration Module (SIM)
Intended Audience
Part II is intended for users who need to understand the interface between the ColdFire core
processor complex, described in Part I, and internal peripheral devices, described in
Part III. It includes a general description of the SIM and individual chapters that describe
components of the SIM, such as the phase-lock loop (PLL) timing source, interrupt
controller for both on-chip and external peripherals, configuration and operation of chip
selects, and the SDRAM controller.
Contents
Part II contains the following chapters:
•
•
•
•
•
•
Chapter 6, “SIM Overview,” describes the SIM programming model, bus
arbitration, and system-protection functions for the MCF5407.
Chapter 7, “Phase-Locked Loop (PLL),” describes configuration and operation of
the PLL module. It describes in detail the registers and signals that support the PLL
implementation.
Chapter 8, “I2C Module,” describes the MCF5407 I2C module, including I2C
protocol, clock synchronization, and the registers in the I2C programing model. It
also provides extensive programming examples.
Chapter 9, “Interrupt Controller,” describes operation of the interrupt controller
portion of the SIM. Includes descriptions of the registers in the interrupt controller
memory map and the interrupt priority scheme.
Chapter 10, “Chip-Select Module,” describes the MCF5407 chip-select
implementation, including the operation and programming model, which includes
the chip-select address, mask, and control registers.
Chapter 11, “Synchronous/Asynchronous DRAM Controller Module,” describes
configuration and operation of the synchronous/asynchronous DRAM controller
component of the SIM. It begins with a general description and brief glossary, and
Part II. System Integration Module (SIM)
II-i
includes a description of signals involved in DRAM operations. The remainder of
the chapter is divided between descriptions of asynchronous and synchronous
operations.
Suggested Reading
The following literature may be helpful with respect to the topics in Part II:
The I2C Bus Specification, Version 2.1 (January 2000)
•
Acronyms and Abbreviations
Table II-i contains acronyms and abbreviations are used in Part II.
Table II-i. Acronyms and Abbreviated Terms
Term
Meaning
ADC
Analog-to-digital conversion
BDM
Background debug mode
CODEC
Code/decode
DAC
Digital-to-analog conversion
DMA
Direct memory access
DSP
Digital signal processing
EDO
Extended data output (DRAM)
FIFO
First-in, first-out
GPIO
General-purpose I/O
I2C
Inter-integrated circuit
IEEE
Institute for Electrical and Electronics Engineers
IPL
Interrupt priority level
JEDEC
Joint Electron Device Engineering Council
LIFO
Last-in, first-out
LRU
Least recently used
LSB
Least-significant byte
lsb
Least-significant bit
MBAR
Memory base address register
MSB
Most-significant byte
msb
Most-significant bit
Mux
Multiplex
II-ii
MCF5407 User’s Manual
Table II-i. Acronyms and Abbreviated Terms (Continued)
Term
Meaning
NOP
No operation
PCLK
Processor clock
PLL
Phase-locked loop
POR
Power-on reset
Rx
Receive
SIM
System integration module
SOF
Start of frame
TAP
Test access port
TTL
Transistor-to-transistor logic
Tx
Transmit
UART
Universal asynchronous/synchronous receiver transmitter
Part II. System Integration Module (SIM)
II-iii
II-iv
MCF5407 User’s Manual
Chapter 6
SIM Overview
This chapter provides detailed operation information regarding the system integration
module (SIM). It describes the SIM programming model, bus arbitration, and
system-protection functions for the MCF5407.
6.1 Features
The SIM, shown in Figure 6-1, provides overall control of the bus and serves as the
interface between the ColdFire core processor complex and the internal peripheral devices.
CLKIN (to on-chip peripherals)
V4 COLDFIRE PROCESSOR COMPLEX
CLKIN
PLL
Xn
RSTI
PCLK
RSTO
DMA
SYSTEM INTEGRATION MODULE (SIM)
PLL Control
PLL
System Control
RSR
SWIVR
Base Address
Bus Master Park
Parallel Port
MBAR
MPARK
PAR
Software
Watchdog
SYPCR SWSR
DRAM Controller
Chip Select Module
DRAM Control
DCR
External
Bus Interface
8
8
8
CSARs CSCRs CSMRs
Interrupt Controller
I2C Module
10 ICRs
Two UARTs
IRQPAR
IPR
Addr/Cntrl Mask
DACR0/1
IMR
DMR0/1
AVR
8
DRAM Controller Outputs
Four
Channels
CS[7:0]
32-Bit Data Bus
32-Bit Address Bus
Two
GeneralPurpose
Timers
4
IRQ[1,3,5,7]
Control Signals
Figure 6-1. SIM Block Diagram
Chapter 6. SIM Overview
6-1
Features
The following is a list of the key SIM features:
•
•
•
•
•
•
•
6-2
Module base address register (MBAR)
— Base address location of all internal peripherals and SIM resources
— Address space masking to internal peripherals and SIM resources
Phase-locked loop (PLL) clock control register (PLLCR) for CPU STOP instruction
— Control for turning off clocks to core and interrupt levels that turn clocks back on
Chapter 7, “Phase-Locked Loop (PLL).”
Interrupt controller
— Programmable interrupt level (1–7) for internal peripheral interrupts
— Programmable priority level (0–3) within each interrupt level
— Four external interrupts; one set to interrupt level 7; three others programmable
to two interrupt levels
See Chapter 9, “Interrupt Controller.”
Chip select module
— Eight independent, user-programmable chip-select signals (CS[7:0]) that can
interface with SRAM, PROM, EPROM, EEPROM, Flash, and peripherals
— Address masking for 64-Kbyte to 4-Gbyte memory block sizes
— Programmable wait states and port sizes
— External master access to chip selects
See Chapter 10, “Chip-Select Module.”
System protection and reset status
— Reset status indicating the cause of last reset
— Software watchdog timer with programmable secondary bus monitor
See Section 6.2.4, “Software Watchdog Timer.”
Pin assignment register (PAR) configures the parallel port. See Section 6.2.9, “Pin
Assignment Register (PAR).”
Bus arbitration
— Default bus master park register (MPARK) controls internal and external bus
arbitration and enables display of internal accesses on the external bus for
debugging
— Supports several arbitration algorithms
See Section 6.2.10, “Bus Arbitration Control.”
MCF5407 User’s Manual
Programming Model
6.2 Programming Model
The following sections describe the registers incorporated into the SIM.
6.2.1 SIM Register Memory Map
Table 6-1 shows the memory map for the SIM registers. The internal registers in the SIM
are memory-mapped registers offset from the MBAR address pointer defined in
MBAR[BA]. This supervisor-level register is described in Section 6.2.2, “Module Base
Address Register (MBAR).” Because SIM registers depend on the base address defined in
MBAR[BA], MBAR must be programmed before SIM registers can be accessed.
NOTE:
Although external masters cannot access the MCF5407’s
on-chip memories or MBAR, they can access any of the SIM
memory map and peripheral registers, such as those belonging
to the interrupt controller, chip-select module, UARTs, timers,
DMA, and I2C.
Table 6-1. SIM Registers
MBAR
Offset
0x000
0x004
[31:24]
[23:16]
[15:8]
[7:0]
Reset status register
(RSR) [p. 6-5]
System protection
control register
(SYPCR) [p. 6-8]
Software watchdog
interrupt vector register
(SWIVR) [p. 6-9]
Software watchdog
service register (SWSR)
[p. 6-9]
Interrupt port
assignment register
(IRQPAR) [p. 9-7]
Reserved
Pin assignment register (PAR) [p. 6-10]
0x008
PLL control (PLLCR)
[p. 7-3]
Reserved
0x00C
Default bus master park
register (MPARK)
[p. 6-11]
Reserved
0x010–
0x03C
Reserved
Interrupt Controller Registers [p. 9-2]
0x040
Interrupt pending register (IPR) [p. 9-6]
0x044
Interrupt mask register (IMR) [p. 9-6]
0x048
Reserved
Autovector register
(AVR) [p. 9-5]
Interrupt Control Registers (ICRs) [p. 9-3]
Chapter 6. SIM Overview
6-3
Programming Model
Table 6-1. SIM Registers (Continued)
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x04C
Software watchdog
timer (ICR0) [p. 9-3]
Timer0 (ICR1) [p. 9-3]
Timer1 (ICR2) [p. 9-3]
I2C (ICR3) [p. 9-3]
0x050
UART0 (ICR4) [p. 9-3]
UART1 (ICR5) [p. 9-3]
DMA0 (ICR6) [p. 9-3]
DMA1 (ICR7) [p. 9-3]
0x054
DMA2 (ICR8) [p. 9-3]
DMA3 (ICR9) [p. 9-3]
Reserved
6.2.2 Module Base Address Register (MBAR)
The supervisor-level MBAR, Figure 6-2, specifies the base address and allowable access
types for all internal peripherals. It is written with a MOVEC instruction using the CPU
address 0xC0F. (See the ColdFire Family Programmer’s Reference Manual.) MBAR can
be read or written through the debug module as a read/write register, as described in
Chapter 5, “Debug Support.” Only the debug module can read MBAR.
The valid bit, MBAR[V], is cleared at system reset to prevent incorrect references before
MBAR is written; other MBAR bits are uninitialized at reset. To access internal peripherals,
write MBAR with the appropriate base address (BA) and set MBAR[V] after system reset.
All internal peripheral registers occupy a single relocatable memory block along 4-Kbyte
boundaries. If MBAR[V] is set, MBAR[BA] is compared to the upper 20 bits of the full
32-bit internal address to determine if an internal peripheral is being accessed. MBAR
masks specific address spaces using the address space fields. Attempts to access a masked
address space generate an external bus access.
Addresses hitting overlapping memory spaces take the following priority:
1. MBAR
2. SRAM and caches
3. Chip select
NOTE:
The MBAR region must be mapped to non-cacheable space.
Attribute Mask Bits
31
Field
Reset
R/W
Address
12 11 10 9
BA
—
8
7
6
5
3
2
Undefined
W (supervisor only); R/W through debug module (only the debug module can read MBAR)
CPU + 0x0C0F
Figure 6-2. Module Base Address Register (MBAR)
6-4
4
MCF5407 User’s Manual
1
0
WP — AM C/I SC SD UC UD V
0
Programming Model
Table 6-2 describes MBAR fields.
Table 6-2. MBAR Field Descriptions
Bits
Field
31–12
BA
11–9
—
8
WP
Description
Base address. Defines the base address for a 4-Kbyte address range.
Reserved, should be cleared.
Write protect. Mask bit for write cycles in the MBAR-mapped register address range.
0 Module address range is read/write.
1 Module address range is read only.
7
—
Reserved, should be cleared.
6
AM
Alternate master mask. When AM = 0 and an alternate master (external master or DMA) accesses
MBAR-mapped registers, MBAR[SC,SD,UC,UD] are ignored in address decoding. These fields
mask address space, placing the MBAR-mapped register in a specific address space or spaces.
5
C/I
Mask CPU space and interrupt acknowledge cycles.
0 Activates the corresponding MBAR-mapped register
1 Regular external bus access
4
SC
Setting masks supervisor code space in MBAR address range
3
SD
Setting masks supervisor data space in MBAR address range
2
UC
Setting masks user code space in MBAR address range
1
UD
0
V
Setting masks user data space in MBAR address range
Valid. Determines whether MBAR settings are valid.
0 MBAR contents are invalid.
1 MBAR contents are valid.
The following example shows how to set the MBAR to location 0x1000_0000 using the D0
register. Setting MBAR[V] validates the MBAR location. This example assumes all
accesses are valid:
move.1 #0x10000001,DO
movec DO,MBAR
6.2.3 Reset Status Register (RSR)
The reset status register (RSR), Figure 6-3, contains two status bits, HRST and SWTR.
Reset control logic sets one of the bits depending on whether the last reset was caused by
an external device asserting RSTI (HRST = 1) or by the software watchdog timer
(SWTR = 1). Only one RSR bit can be set at any time. If a reset occurs, reset control logic
sets only the bit that indicates the cause of reset.
7
Field HRST
Reset
R/W
Address
1/0
6
5
—
SWTR
4
—
0
0
1/0
0_0000
Read/Write
MBAR + 0x000
Figure 6-3. Reset Status Register (RSR)
Chapter 6. SIM Overview
6-5
Programming Model
Table 6-3 describes RSR fields.
Table 6-3. RSR Field Descriptions
Bits
Name
7
HRST
6
—
5
SWTR
4–0
—
Description
Hardware or system reset
1 An external device driving RSTI caused the last reset. Assertion of reset by an external
device causes the core processor to take a reset exception. All registers in internal
peripherals and the SIM are reset.
Reserved, should be cleared.
Software watchdog timer reset
1 The last reset was caused by the software watchdog timer. If SYPCR[SWRI] = 1 and the
software watchdog timer times out, a hardware reset occurs.
Reserved, should be cleared.
6.2.4 Software Watchdog Timer
The software watchdog timer prevents system lockup should the software become trapped
in loops with no controlled exit. The software watchdog timer can be enabled or disabled
through SYPCR[SWE]. If enabled, the watchdog timer requires the periodic execution of
a software watchdog servicing sequence. If this periodic servicing action does not occur,
the timer times out, resulting in a watchdog timer IRQ or hardware reset with RSTO driven
low, as programmed by SYPCR[SWRI].
If the timer times out and the software watchdog transfer acknowledge enable bit
(SYPCR[SWTA]) is set, a watchdog timer IRQ is asserted. Note that the software watchdog
timer IACK cycle cannot be autovectored.
If a software watchdog timer IACK cycle has not occurred after another timeout, SWT TA
is asserted in an attempt to terminate the bus cycle and allow the IACK cycle to proceed.
The setting of SYPCR[SWTAVAL] indicates that the watchdog timer TA was asserted.
Figure 6-4 shows termination of a locked bus.
6-6
MCF5407 User’s Manual
Programming Model
Code in the watchdog timer interrupt
handler polls SYPCR[SWTAVAL] to
determine if SWT TA was needed. If so,
execute code to identify bad address.
Code enables software watchdog timer interrupt and
SWTA functionality by writing SYPCR.
Problem:
1. Watchdog timer times out due to unterminated bus
NOTE: The watchdog timer IRQ should
be set to the highest level in the system.
Software
watchdog
timer IRQ
Timeout
2. Watchdog timer interrupt cannot be serviced due to hung bus
cycle. Wait for another timeout before setting SYPCR[SWTA].
3. TA held until another
bus cycle starts
Software
watchdog
timer TA
Timeout
SYPCR[SWTAVAL] 1
1
SWTAVAL is set if watchdog timer TA is asserted.
Watchdog timer
IACK cycle
Figure 6-4. MCF5407 Embedded System Recovery from Unterminated Access
When the watchdog timer times out and SYPCR[SWRI] is programmed for a software
reset, an internal reset is asserted and RSR[SWTR] is set.
To prevent the watchdog timer from interrupting or resetting, the SWSR must be serviced
by performing the following sequence:
1. Write 0x55 to SWSR.
2. Write 0xAA to the SWSR.
Both writes must occur in order before the timeout, but any number of instructions or
SWSR accesses can be executed between the two writes. This order allows interrupts and
exceptions to occur, if necessary, between the two writes.
Caution should be exercised when changing SYPCR values after the software watchdog
timer has been enabled with the setting of SYPCR[SWE], because it is difficult to
determine the state of the watchdog timer while it is running. The countdown value is
constantly compared with the timeout period specified by SYPCR[SWP,SWT]. Therefore,
altering SWP and SWT improperly causes unpredictable processor behavior. The following
steps must be taken to change SWP or SWT:
Chapter 6. SIM Overview
6-7
Programming Model
1.
2.
3.
4.
Disable the software watchdog timer by clearing SYPCR[SWE].
Reset the counter by writing 0x55 and then 0xAA to SWSR.
Update SYPCR[SWT,SWP].
Reenable the watchdog timer by setting SYPCR[SWE]. This can be done in step 3.
6.2.5 System Protection Control Register (SYPCR)
The SYPCR, Figure 6-5, controls the software watchdog timer, timeout periods, and
software watchdog timer transfer acknowledge. The SYPCR can be read at any time, but
can be written only if a software watchdog timer IRQ is not pending. At system reset, the
software watchdog timer is disabled.
Field
7
6
5
SWE
SWRI
SWP
4
3
SWT
Reset
2
1
0
SWTA
SWTAVAL
—
0000_0000
R/W
R/W
Address
MBAR + 0x01
Figure 6-5. System Protection Control Register (SYPCR)
Table 6-4 describes SYPCR fields.
Table 6-4. SYPCR Field Descriptions
Bits
Name
7
SWE
Software watchdog timer enable
0 Software watchdog timer disabled
1 Software watchdog timer enabled
Description
6
SWRI
Software watchdog reset/interrupt select
0 If a timeout occurs, the watchdog timer generates an interrupt to the core processor at the
level programmed into ICR0[IL].
1 The software watchdog timer causes soft reset to be asserted for all modules of the part
except for the PLL (reset mode selects, such as PP_RESET_SEL or chip-select settings,
should not change).
5
SWP
Software watchdog prescaler. This bit interacts with SYPCR[SWT].
0 Software watchdog timer clock not prescaled.
1 Software watchdog timer clock prescaled by 8192.
4–3
SWT
Software watchdog timing delay. SWT and SWP select the timeout period for the watchdog
timer. At system reset, the software watchdog timer is set to the minimum timeout period.
SWP = 0
00 29/system frequency
01 211/system frequency
10 213/system frequency
11 215/system frequency
SWP = 1
00 222/system frequency
01 224/system frequency
10 226/system frequency
11 228/system frequency
Note that if SWP and SWT are modified to select a new software timeout, the software service
sequence must be performed (0x55 followed by 0xAA written to the SWSR) before the new
timeout period takes effect.
6-8
MCF5407 User’s Manual
Programming Model
Table 6-4. SYPCR Field Descriptions (Continued)
Bits
Name
Description
2
SWTA
Software watchdog transfer acknowledge enable
0 SWTA transfer acknowledge disabled
1 SWTA asserts transfer acknowledge enabled. After one timeout period of the unacknowledged
assertion of the software watchdog timer interrupt, the software watchdog transfer
acknowledge asserts, which allows the watchdog timer to terminate a bus cycle and allow the
IACK to occur.
1
SWTAVAL Software watchdog transfer acknowledge valid
0 SWTA transfer acknowledge has not occurred.
1 SWTA transfer acknowledge has occurred. Write a 1 to clear this flag bit.
6.2.6 Software Watchdog Interrupt Vector Register (SWIVR)
The SWIVR, shown in Figure 6-6, contains the 8-bit interrupt vector (SWIV) that the SIM
returns during an interrupt-acknowledge cycle in response to a software watchdog
timer-generated interrupt. SWIVR is set to the uninitialized vector 0x0F at system reset.
7
Field
0
SWIV
Reset
0000_1111
R/W
Supervisor write only
Address
MBAR + 0x002
Figure 6-6. Software Watchdog Interrupt Vector Register (SWIVR)
Note that the software watchdog interrupt cannot be autovectored.
6.2.7 Software Watchdog Service Register (SWSR)
The SWSR, shown in Figure 6-7, is where the software watchdog timer servicing sequence
should be written. To prevent a watchdog timer timeout, the software service sequence must
be performed (0x55 followed by 0xAA written to the SWSR). Both writes must be
performed in order before the timeout, but any number of instructions or accesses to the
SWSR can be executed between the two writes. If the timer has timed out, writing to SWSR
does not cancel the interrupt (that is, IPR[SWT] remains set). The interrupt is cancelled
(and SWT is cleared) automatically when the IACK cycle is run.
7
0
Field
SWSR
Reset
Undetermined
R/W
Address
Supervisor write only
MBAR + 0x003
Figure 6-7. Software Watchdog Service Register (SWSR)
Chapter 6. SIM Overview
6-9
Programming Model
6.2.8 PLL Clock Control for CPU STOP Instruction
The SIM contains the PLL clock control register, which is described in detail in
Section 7.2.4, “PLL Control Register (PLLCR).” PLLCR[ENBSTOP,PLLIPL] are
significant to the operation of the SIM, and are described as follows:
•
•
PLLCR[ENBSTOP] must be set for the ColdFire CPU STOP instruction to be
acknowledged. This bit is cleared at reset and must be set for the MCF5407 to enter
low-power modes. The CPU STOP instruction stops only clocks to the core
processor. All internal modules remain clocked and can generate interrupts to restart
the ColdFire core. For example, the on-chip timer can be used to interrupt the
processor after a given timer countdown.
PLLCR[PLLIPL] determines the minimum level at which an interrupt (decoded as
an interrupt priority level or IPL) must occur to awaken the PLL. The PLL then turns
clocks back on to the core processor and interrupt exception processing takes place.
Table 6-5 describes PLLIPL settings to be compared against the interrupt ranges that
awaken the core processor from a CPU STOP instruction.
Table 6-5. PLLIPL Settings
PLLIPL
Description
000
Any interrupts can wake core
001
Interrupts 2–7
010
Interrupts 3–7
011
Interrupts 4–7
100
Interrupts 5–7
101
Interrupts 6–7
110
Interrupt 7 only
111
No interrupts can wake core
6.2.9 Pin Assignment Register (PAR)
The pin assignment register (PAR), Figure 6-8, allows the selection of pin assignments.
15
14
13
12
11
10
9
8
7
6
Field PAR15 PAR14 PAR13 PAR12 PAR11 PAR10 PAR9 PAR8 PAR7 PAR6
5
4
TIP DREQ0 DREQ1 TM2
A27
A26
A25
PP6
0
PP2
PP7
A24
A28
1
PP5
PP8
PARn = 1 A31
A29
2
PAR2 PAR1 PAR0
PARn = 0 PP15 PP14 PP13 PP12 PP11 PP10 PP9
A30
3
PAR5 PAR4 PAR3
PP4
PP3
PP1 PP0
TM1/ TM0/ TT1
DACK1 DACK0
TT0
Reset Determined by driving D4/ADDR_CONFIG with a 1 or 0 when RSTI negates. The system is configured as PP[15:0] if
D4 is low; otherwise alternate pin functions selected by PAR = 1 are used.
R/W
Address
R/W
Address MBAR + 0x004
Figure 6-8. Pin Assignment Register (PAR)
6-10
MCF5407 User’s Manual
Programming Model
6.2.10 Bus Arbitration Control
This section describes the bus arbitration register and the four arbitration schemes.
6.2.10.1 Default Bus Master Park Register (MPARK)
The MPARK, shown in Figure 6-9, determines the default bus master arbitration between
internal transfers (core and DMA module) and between internal and external transfers to
internal resources. This arbitration is needed because external masters can access internal
registers within the MCF5407 peripherals.
7
Field
6
PARK
5
4
3
2
IARBCTRL EARBCTRL SHOWDATA
Reset
0
—
0000_0000
R/W
R/W
Address
MBAR + 0x0C
Figure 6-9. Default Bus Master Register (MPARK)
Table 6-6 describes MPARK bits.
Table 6-6. MPARK Field Descriptions
Bits
Name
Description
7–6
PARK
5
IARBCTRL
4
EARBCTRL External bus arbitration control. Enables internal register memory space to external bus
arbitration. Internal registers are those accessed at offsets to the MBAR. These include the
SIM, DMA, chip selects, timers, UARTs, I2C, and parallel port registers. These registers do
not include the MBAR; only the core can access the MBAR.
0 Arbitration disabled
1 Arbitration enabled
The use of this field is described in detail in Section 6.2.10.1.2, “Arbitration between Internal
and External Masters for Accessing Internal Resources.”
Park. Indicates the arbitration priority of internal transfers among MCF5407 resources.
00 Round-robin between DMA and ColdFire core
01 Park on master ColdFire core
10 Park on master DMA module
11 Park on current master
Use of this field is described in detail in Section 6.2.10.1.1, “Arbitration for Internally
Generated Transfers (MPARK[PARK]).”
Internal bus arbitration control. Controls external device access to the MCF5407 internal bus.
0 Arbitration disabled (single-master system)
1 Arbitration enabled. IARBCTRL must be set if external masters are using internal
resources like the DRAM controller or chip selects.
Use of this bit depends on whether the system has single or multiple masters, as follows:
• In a single-master system, IARBCTRL should stay cleared, disabling internal arbitration
by external masters. In this scenario, MPARK[PARK] applies only to priority of internal
masters over one another. Note that the internal DMA (master 3) has priority over the
ColdFire core (master 2), if internal DMA bandwidth is at its maximum (BWC = 000).
• In multiple master systems that expect to use internal resources like the DRAM controller
or chip selects, internal arbitration should be enabled. The external master defaults to the
highest priority internal master anytime BG is negated.
Chapter 6. SIM Overview
6-11
Programming Model
Table 6-6. MPARK Field Descriptions (Continued)
Bits
3
2–0
Name
Description
SHOWDATA Enable internal register data bus to be driven on external bus. EARBCTRL must be set for
this function to work. Section 6.2.10.1.2, “Arbitration between Internal and External Masters
for Accessing Internal Resources,” describes the proper use of SHOWDATA.
0 Do not drive internal register data bus values to external bus.
1 Drive internal register data bus values to external bus.
—
Reserved, should be cleared.
6.2.10.1.1 Arbitration for Internally Generated Transfers (MPARK[PARK])
MPARK[PARK] prioritizes internal transfers, which can be initiated by the core and the
on-chip DMA module, which contains all four DMA channels. Priority among the four
DMA channels in the module is determined by the BWC bits in their respective DMA
control registers (see Chapter 12, “DMA Controller Module”).
The four arbitration schemes for internally generated transfers are described as follows:
•
Round-robin scheme (PARK = 00)—Figure 6-10 shows round-robin arbitration
between the core and DMA module. Bus mastership alternates between the core and
DMA module.
Internal Bus Mastership
(Alternates between Core and DMA Module)
DMA MODULE
CORE
5th
3rd
1st
4th
2nd
Channel 0
Channel 1
Channel 2
Channel 3
Figure 6-10. Round Robin Arbitration (PARK = 00)
The DMA module presents only the highest-priority DMA request, and bus
mastership alternates between the core and DMA channel as long as both are
requesting bus mastership. Section 12.5.4.1, “External Request and Acknowledge
Operation,” includes a timing diagram showing a lower-priority DMA transfer.
When the processor is initialized, the core has first priority. If DMA channels 0 and
1 (both set to BWC = 010) assert an internal bus request during a core-generated bus
transfer, DMA channel 0 would gain bus mastership next. However, if the core
requests the bus during this DMA transfer, bus mastership returns to the core rather
than being granted to DMA channel 1.
Note that the internal DMA has higher priority than the core if the internal DMA has
its bandwidth BWC bits set to 000 (maximum bandwidth).
6-12
MCF5407 User’s Manual
Programming Model
•
Park on master core priority (PARK = 01)—The core retains bus mastership as long
as it needs it. After it negates its internal bus request, the core does not have to
rearbitrate for the bus unless the DMA module has requested the bus when it is idle.
The DMA module can be granted bus mastership only when the core is not asserting
its bus request. See Figure 6-11.
Core BR negated
DMA module BR asserted
Core BR negated
DMA module BR negated
DMA Module
Core
Core BR asserted
DMA module BR negated/asserted
Figure 6-11. Park on Master Core Priority (PARK = 01)
•
Park on master DMA priority (PARK = 10)—The DMA module retains bus
mastership as long as it needs it. After it negates its internal bus request, the DMA
module does not have to rearbitrate for the bus unless the core has requested the bus
when it is idle. The core can be granted bus mastership only when the DMA module
is not asserting its bus request. See Figure 6-12.
DMA module BR asserted
Core BR negated/asserted
Core
DMA BR negated
Core BR negated
DMA Module
Core BR asserted
DMA module BR negated
Figure 6-12. Park on DMA Module Priority (PARK = 10)
Chapter 6. SIM Overview
6-13
Programming Model
•
Park on current master priority (PARK = 11)—The current bus master retains
mastership as long as it needs the bus. The other device can become the bus master
only when the bus is idle. For example, if the core is bus master out of reset, it retains
mastership as long as it needs the bus. It loses mastership only when it negates its
bus request signal and the DMA asserts its internal bus request signal. At this point
the DMA module is the bus master, and retains bus mastership as long as it needs
the bus. See Figure 6-13.
DMA module BR asserted
Core BR negated
Core BR negated
DMA module BR negated
Core
Core BR asserted
DMA module BR asserted
DMA module BR negated
Core BR negated
DMA Module
Core BR asserted
DMA module BR negated
DMA module BR asserted
Core BR asserted
Figure 6-13. Park on Current Master Priority (PARK = 01)
6.2.10.1.2 Arbitration between Internal and External Masters for
Accessing Internal Resources
If an external device is programmed to access internal MCF5407 resources
(EARBCTRL = 1), the external device can gain bus mastership only when BG is negated.
This means neither the core nor the DMA controller can access the external bus until the
external device asserts BG. After the external master finishes its bus transfer and asserts
BG, the core has priority on the next available bus cycle regardless of the value of PARK.
Thus if the core asserts its internal bus request on this first bus cycle, it executes a bus cycle
even if PARK indicates the DMA should have priority. Then, after the bus transfer, the
PARK scheme returns to programmed functioning and the DMA is given bus mastership.
NOTE:
In all arbitration modes, if BG is negated, the external master
interface has highest priority. In this case, the ColdFire core has
second-highest priority, until the internal bus grant is asserted.
•
6-14
In a single-master system, the setting of EARBCTRL does not affect arbitration
performance. Typically, BG is tied low and the MCF5407 always owns the external
bus and internal register transfers are already shown on the external bus. In a system
where MCF5407 is the only master, this bit may remain cleared.
If the system needs external visibility of the data bus values during internal register
transfers for system debugging, both EARBCTRL and SHOWDATA must be set.
Note that when an internal register transfer is driven externally, TA becomes an
output, which is asserted (normally an input) to prevent external devices and
MCF5407 User’s Manual
Programming Model
•
memories from responding to internal register transfers that go to the external bus.
The AS signal and all chip-select-related strobe signals are not asserted.
Do not immediately follow a cycle in which SHOWDATA is set with a cycle using
fast termination.
In multiple-master systems, disabling arbitration with EARBCTRL allows
performance improvement because internal register bus transfer cycles do not
interfere with the external bus.
Having internal transfers go external may affect performance in two ways:
— If the internal device does not control the bus immediately, the core stalls until it
wins arbitration of the external bus.
— If the core wins arbitration instantly, it may kick the external master off of the
external bus unnecessarily for a transfer that did not need the external bus. For
debug, where this performance penalty is not a concern, setting EARBCTRL and
SHOWDATA provides external visibility of the internal bus cycles.
Chapter 6. SIM Overview
6-15
Programming Model
6-16
MCF5407 User’s Manual
Chapter 7
Phase-Locked Loop (PLL)
This chapter describes configuration and operation of the phase-locked loop (PLL) module.
It describes in detail the registers and signals that support the PLL implementation.
7.1 Overview
The basic features of the MCF5407 PLL implementation are as follows:
•
•
The MCF5407 PLL is enhanced to support faster processor clock (PCLK)
frequencies than the MCF5307. It also offers a wider range of clock input ratios.
A buffered processor status clock (PSTCLK) is half the PCLK frequency, as
indicated in Figure 7-1. This signal is made available for system development.
The PLL module has the following three modes of operation:
•
•
•
Reset mode—In reset mode, the core/bus frequency ratio and other configuration
information is sampled. At reset, the PLL asserts the reset out signal, RSTO.
Normal mode—During normal operations, the divide ratio is programmed at reset
and is clock-multiplied to provide the processor clock frequency. These frequencies
are described in the electrical specifications.”
Reduced-power mode—In reduced-power mode, the high-speed processor core
clocks are turned off without losing the register contents so that the system can be
reenabled by an unmasked interrupt or reset.
Figure 7-1 shows the frequency relationships of PLL module clock signals.
z
CLKIN (to on-chip peripherals)
BCLKO
PCLK (to core)
CLKIN
DIVIDE[2:0]
RSTI
Debug Module
÷2
PLL
RSTO
PSTCLK (= PCLK/2)
Figure 7-1. PLL Module Block Diagram
Chapter 7. Phase-Locked Loop (PLL)
7-1
PLL Operation
Motorola recommends using CLKIN for the system clock. BCLKO is provided only for
compatibility with slower MCF5307 designs. Regardless of the CLKIN frequency driven
at power-up, CLKIN (and BCLKO) have the same ratio value to the PCLK. Although either
signal can be used as a clock reference, CLKIN leaves more room to meet the bus
specifications than BCLKO, which is generated as a phase-aligned signal to CLKIN.
7.1.1 PLL:PCLK Ratios
The PLL for the MCF5407 is enhanced to support faster processor clock (PCLK)
frequencies. While the MCF5307 supports various PCLK frequencies listed in the electrical
specifications with a clock input (CLKIN) of 1/2 PCLK, the MCF5407 offers a wider range
of clock input ratios and a higher performance processor clock.
Like the MCF5307, the MCF5407 samples clock ratio encodings on the lower data bus bits
at reset to determine the CLKIN-to-PCLK ratio. These bits are DIVIDE[1:0] on the
MCF5307 and are multiplexed with data bits D[1:0]. Because the MCF5407 offers more
divide ratio than the MCF5307, three bits, D[2:0]/DIVIDE[2:0], are provided to offer more
programming options at reset. Also, note that only specific CLKIN ranges are allowed for
each divide ratio on the MCF5407. Table 7-1 shows MCF5407 divide ratio encodings.
Table 7-1. Divide Ratio Encodings
D[2:0]/DIVIDE[2:0]
Multiplier
00x–010
Reserved
011
3
100
4
101
5
110
6
111
Reserved
7.2 PLL Operation
The following sections provide detailed information about the three PLL modes.
7.2.1 Reset/Initialization
The PLL receives RSTI as an input directly from the pin. Additionally, signals are
multiplexed with D[2:0]/DIVIDE[2:0] while RSTI is asserted. These signals are sampled
during reset and registered by the PLL on the negation of RSTI to provide initialization
information. DIVIDE[2:0] are used by the PLL to set the CLKIN/PCLK ratio.
7.2.2 Normal Mode
CLKIN should be used as the system bus clock in 5407 systems. The CLKIN frequency is
7-2
MCF5407 User’s Manual
PLL Operation
multiplied up as determined by the logic level of the multiplexed D[2:0]/DIVIDE[2:0] pins
during reset to create PCLK.
7.2.3 Reduced-Power Mode
The PCLK can be turned off in a predictable manner to conserve system power. To allow
fast restart of the MCF5407 processor core, the PLL continues to operate at the frequency
configured at reset. PCLK is disabled using the CPU STOP instruction and resumes normal
operation on interrupt, as described in Section 7.2.4, “PLL Control Register (PLLCR).”
7.2.4 PLL Control Register (PLLCR)
The PLL control register (PLLCR), Figure 7-2, provides control over the PLL.
7
6
Field ENBSTOP
5
PLLIPL
Reset
4
3
2
DISBCLKO
1
0
—
0000_0000
R/W
R/W
Address
MBAR + 0x08
Figure 7-2. PLL Control Register (PLLCR)
Table 7-2 describes PLLCR bits.
Table 7-2. PLLCR Field Descriptions
Bit
Name
Description
7
ENBSTOP
Enable CPU STOP instruction. Must be set for the ColdFire CPU STOP instruction to be
acknowledged. Cleared at reset and must be subsequently set for the processor to enter
low-power modes. Only clocks to the core are turned off because of the CPU STOP instruction.
Internal modules remain clocked and can generate interrupts to restart the ColdFire core.
0 Disable CPU STOP
1 Enable CPU STOP; STOP instruction turns off clocks to the ColdFire core.
6–4
PLLIPL
PLL interrupt priority level to wake up from CPU STOP. Determines the minimum level an
interrupt (decoded as an interrupt priority level) must be to waken the PLL. The PLL then turns
clocks back on to the core processor and interrupt exception processing occurs.
000 Any interrupts can wake core
001 Interrupts 2–7
010 Interrupts 3–7
011 Interrupts 4–7
100 Interrupts 5–7
101 Interrupts 6–7
110 Interrupt 7 only
111 No interrupts can wake core. Any reset, including a watchdog reset, can wake the core.
No PLL phase lock time is required.
3
2–0
DISBCLKO BCLKO disable. Determines whether BCLKO is driven.
0 BCLKO is driven.
1 BCLKO is three-stated. BCLKO can be reenabled only by a reset.
—
Reserved, should be cleared.
Chapter 7. Phase-Locked Loop (PLL)
7-3
PLL Port List
7.3 PLL Port List
Table 7-3 describes PLL module inputs.
Table 7-3. PLL Module Input SIgnals
SIgnal
Description
CLKIN
Input clock to the PLL. Input frequency must not be changed during operation. Changes are
recognized only at reset.
RSTI
Active-low asynchronous input that, when asserted, indicates PLL is to enter reset mode. As long as
RSTI is asserted, the PLL is held in reset and does not begin to lock.
DIVIDE[2:0] TheMCF5407 samples clock ratio encodings on the lower data bits of the bus to determine the
CLKIN-to-processor clock ratio. D[2:0]/DIVIDE[2:0] support the divide-ratio combinations. Note that
only specific CLKIN ranges are allowed for each divide ratio on the MCF5407. See the electrical
specifications for valid frequencies.
Table 7-4 describes PLL module outputs.
Table 7-4. PLL Module Output Signals
Output
Description
BCLKO
This bus clock output provides a divided version of the processor clock frequency, determined by
DIVIDE[2:0]. BCLKO is provided for MCF5307 compatibility (slower-speed designs).
PSTCLK
Provides a buffered processor status clock. PSTCLK is half the frequency of PCLK. See Section 7.4.1,
“PCLK, PSTCLK, and BCLKO,” and Figure 7-1.
RSTO
This output provides an external reset for peripheral devices.
7.4 Timing Relationships
The MCF5407 CLKIN frequency can be 1/3, 1/4, 1/5, or 1/6 the processor clock. In this
document, bus timings are referenced from CLKIN.
Regardless of the CLKIN frequency driven at power-up, CLKIN and BCLKO have the
same ratio value to the PCLK. Although either signal can be used as a clock reference,
CLKIN leaves more room to meet the bus specifications than BCLKO, which is generated
as a phase-aligned signal to CLKIN.
Although the CLKIN duty cycle remains the same for the MCF5307 and MCF5407,
caution should be used when interfacing signals on the falling edge of CLKIN with only a
4-nS window to work from at high frequencies. Also, note that the MCF5407 CLKIN rise
time is reduced to 2 nS (5 nS in the MCF5307).
If signals are referenced from CLKIN only, setting PLLCR[DISBCLKO] and disabling
BCLKO reduces power consumption. See Section 7.2.4, “PLL Control Register (PLLCR).”
7.4.1 PCLK, PSTCLK, and BCLKO
Figure 7-3 shows the frequency relationships between PCLK, PSTCLK, and the four
7-4
MCF5407 User’s Manual
Timing Relationships
possible versions of CLKIN/BCLKO. This figure does not show the skew between CLKIN
and PCLK, PSTCLK, and BCLKO. PSTCLK is half the frequency of PCLK. Similarly, the
skew between PCLK and BCLKO is unspecified.
PCLK
PSTCLK
CLKIN/BCLKO (/3)
CLKIN/BCLKO (/4)
CLKIN/BCLKO (/5)
CLKIN/BCLKO (/6)
NOTE:
The clock signals are shown with edges aligned to show frequency relationships only.
Actual signal edges have some skew between them.
Figure 7-3. CLKIN, PCLK, PSTCLK, and BCLKO Timing
7.4.2 RSTI Timing
Figure 7-4 shows PLL timing during reset. As shown, RSTI must be asserted for at least 16
CLKIN cycles to give the MCF5407 time to begin its initialization sequence. At this time,
the configuration pins should be asserted (D[2:0] for DIVIDE[2:0]), meeting the minimum
setup and hold times to RSTI given in Chapter 20, “Electrical Specifications.”
On the rising edge of CLKIN before the rising edge of RSTI, the data on D[7:0] is latched
and the PLL begins ramping to its final operating frequency. During this ramp and lock
time, BCLKO and PSTCLK are held low. The PLL locks in about 2 mS or less depending
on the CLKIN frequency, at which time BCLKO begins normal operation in the specified
mode. The PLL requires 50,000 CLKIN cycles to guarantee PLL lock. To allow for reset
of external peripherals requiring a clock source, RSTO remains asserted for a number of
CLKIN cycles, as shown in Figure 7-4. PSTCLK will begin oscillating a minimum of10
clock cycles after RSTO is negated.
Chapter 7. Phase-Locked Loop (PLL)
7-5
PLL Power Supply Filter Circuit
50K CLKIN
Cycle Lock Time
>16 CLKS
>10 CLKS
CLKIN
BCLKO
PSTCLK
RSTI
D[7:0]
D[7:0] latched on rising edge of CLKIN
RSTO
Figure 7-4. Reset and Initialization Timing
7.5 PLL Power Supply Filter Circuit
To ensure PLL stability, the power supply to the PLL power pin should be filtered using a
circuit similar to the one in Figure 7-5. The circuit should be placed as close as possible to
the PLL power pin to ensure maximum noise filtering.
10 Ω
Vdd
PLL power pin
10 µF
0.1 µF
Figure 7-5. PLL Power Supply Filter Circuit
7-6
MCF5407 User’s Manual
Chapter 8
I2C Module
This chapter describes the MCF5407 I2C module, including I2C protocol, clock
synchronization, and the registers in the I2C programing model. It also provides extensive
programming examples.
8.1 Overview
I2C is a two-wire, bidirectional serial bus that provides a simple, efficient method of data
exchange, minimizing the interconnection between devices. This bus is suitable for
applications requiring occasional communications over a short distance between many
devices. The flexible I2C allows additional devices to be connected to the bus for expansion
and system development.
The I2C system is a true multiple-master bus including arbitration and collision detection
that prevents data corruption if multiple devices attempt to control the bus simultaneously.
This feature supports complex applications with multiprocessor control and can be used for
rapid testing and alignment of end products through external connections to an
assembly-line computer.
Note that I2C is defined for 5-V operation and the MCF5407 is a 3.3-V device. Care must
be taken to interface to 5-V peripherals.
8.2 Interface Features
The I2C module has the following key features:
•
•
•
•
•
•
•
•
Compatibility with I2C bus standard
Support for 3.3-V tolerant devices
Multiple-master operation
Software-programmable for one of 64 different serial clock frequencies
Software-selectable acknowledge bit
Interrupt-driven, byte-by-byte data transfer
Arbitration-lost interrupt with automatic mode switching from master to slave
Calling address identification interrupt
Chapter 8. I2C Module
8-1
Interface Features
•
•
•
•
Start and stop signal generation/detection
Repeated START signal generation
Acknowledge bit generation/detection
Bus-busy detection
Figure 8-1 is a block diagram of the I2C module.
Internal Bus
IRQ
Address
Data
Address Decode
Data MUX
I2C Data
I/O Register
(I2DR)
I2C Address
Register
(IADR)
Registers and ColdFire Interface
I2C Frequency
Divider Register
(IFDR)
I2C Control
Register
(I2CR)
I2C Status
Register
(I2SR)
Clock
Control
Start, Stop,
and
Arbitration
Control
Input
Sync
In/Out
Data
Shift
Register
Address
Compare
SCL
SDA
Figure 8-1. I2C Module Block Diagram
Figure 8-1 shows the relationships of the I2C registers, listed below:
• I2C address register (IADR)
8-2
•
I2C frequency divider register (IFDR)
•
I2C control register (I2CR)
•
I2C status register (I2SR)
•
I2C data I/O register (I2DR)
MCF5407 User’s Manual
I2C System Configuration
These registers are described in Section 8.5, “Programming Model.”
8.3 I2C System Configuration
The I2C module uses a serial data line (SDA) and a serial clock line (SCL) for data transfer.
For I2C compliance, all devices connected to these two signals must have open drain or
open collector outputs. (There is no such requirement for inputs.) The logic AND function
is exercised on both lines with external pull-up resistors.
Out of reset, the I2C default is as slave receiver. Thus, when not programmed to be a master
or responding to a slave transmit address, the I2C module should return to the default slave
receiver state. See Section 8.6.1, “Initialization Sequence,” for exceptions.
NOTE:
The I2C module is designed to be compatible with the Philips
I2C bus protocol. For information on system configuration,
protocol, and restrictions, see The I2C Bus Specification,
Version 2.1.
8.4 I2C Protocol
Normally, a standard communication is composed of the following parts:
1. START signal—When no other device is bus master (both SCL and SDA lines are
at logic high), a device can initiate communication by sending a START signal (see
A in Figure 8-2). A START signal is defined as a high-to-low transition of SDA
while SCL is high. This signal denotes the beginning of a data transfer (each data
transfer can be several bytes long) and awakens all slaves.
msb
SCL
SDA
A
1
lsb
2
3
4
5
6
7
8
msb
9
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
START
Signal
Calling Address
B
R/W ACK
Bit
C
D
1
XXX
lsb
2
3
D7 D6 D5
E
4
5
6
7
8
9
D4 D3 D2 D1 D0
Data Byte
No STOP
ACK Signal
Bit
F
Figure 8-2. I2C Standard Communication Protocol
2. Slave address transmission—The master sends the slave address in the first byte
after the START signal (B). After the seven-bit calling address, it sends the R/W bit
(C), which tells the slave data transfer direction.
Chapter 8. I2C Module
8-3
I2C Protocol
Each slave must have a unique address. An I2C master must not transmit an address
that is the same as its slave address; it cannot be master and slave at the same time.
The slave whose address matches that sent by the master pulls SDA low at the ninth
clock (D) to return an acknowledge bit.
3. Data transfer—When successful slave addressing is achieved, the data transfer can
proceed (E) on a byte-by-byte basis in the direction specified by the R/W bit sent by
the calling master.
Data can be changed only while SCL is low and must be held stable while SCL is
high, as Figure 8-2 shows. SCL is pulsed once for each data bit, with the msb being
sent first. The receiving device must acknowledge each byte by pulling SDA low at
the ninth clock; therefore, a data byte transfer takes nine clock pulses.
If it does not acknowledge the master, the slave receiver must leave SDA high. The
master can then generate a STOP signal to abort the data transfer or generate a
START signal (repeated start, shown in Figure 8-3) to start a new calling sequence.
If the master receiver does not acknowledge the slave transmitter after a byte
transmission, it means end-of-data to the slave. The slave releases SDA for the
master to generate a STOP or START signal.
4. STOP signal—The master can terminate communication by generating a STOP
signal to free the bus. A STOP signal is defined as a low-to-high transition of SDA
while SCL is at logical high (F). Note that a master can generate a STOP even if the
slave has made an acknowledgment, at which point the slave must release the bus.
Instead of signalling a STOP, the master can repeat the START signal, followed by a calling
command, (A in Figure 8-3). A repeated START occurs when a START signal is generated
without first generating a STOP signal to end the communication.
msb
SCL
SDA
1
lsb
2
3
4
5
6
7
8
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
START
Signal
Calling Address
lsb
msb
9
1
XX
2
3
4
5
6
7
8
9
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
R/W ACK Repeated
Bit
START
Signal A
New Calling Address
Stop
R/W No
ACK
Bit
STOP
Signal
Figure 8-3. Repeated START
The master uses a repeated START to communicate with another slave or with the same
slave in a different mode (transmit/receive mode) without releasing the bus.
8.4.1 Arbitration Procedure
If multiple devices simultaneously request the bus, the bus clock is determined by a
8-4
MCF5407 User’s Manual
I2C Protocol
synchronization procedure in which the low period equals the longest clock-low period
among the devices and the high period equals the shortest. A data arbitration procedure
determines the relative priority of competing devices. A device loses arbitration if it sends
logic high while another sends logic low; it immediately switches to slave-receive mode
and stops driving SDA. In this case, the transition from master to slave mode does not
generate a STOP condition. Meanwhile, hardware sets I2SR[IAL] to indicate loss of
arbitration.
8.4.2 Clock Synchronization
Because wire-AND logic is used, a high-to-low transition on SCL affects devices
connected to the bus. Devices start counting their low period when the master drives SCL
low. When a device clock goes low, it holds SCL low until the clock high state is reached.
However, the low-to-high change in this device clock may not change the state of SCL if
another device clock is still in its low period. Therefore, the device with the longest low
period holds the synchronized clock SCL low. Devices with shorter low periods enter a high
wait state during this time (See Figure 8-4). When all devices involved have counted off
their low period, the synchronized clock SCL is released and pulled high. There is then no
difference between device clocks and the state of SCL, so all of the devices start counting
their high periods. The first device to complete its high period pulls SCL low again.
Wait
Start counting high period
SCL1
SCL2
SCL
Internal Counter Reset
Figure 8-4. Synchronized Clock SCL
8.4.3 Handshaking
The clock synchronization mechanism can be used as a handshake in data transfers. Slave
devices can hold SCL low after completing one byte transfer (9 bits). In such a case, the
clock mechanism halts the bus clock and forces the master clock into wait states until the
slave releases SCL.
8.4.4 Clock Stretching
Slaves can use the clock synchronization mechanism to slow down the transfer bit rate.
After the master has driven SCL low, the slave can drive SCL low for the required period
and then release it. If the slave SCL low period is longer than the master SCL low period,
Chapter 8. I2C Module
8-5
Programming Model
the resulting SCL bus signal low period is stretched.
8.5 Programming Model
Table 8-1 lists the configuration registers used in the I2C interface.
Table 8-1. I2C Interface Memory Map
MBAR
Offset
[31:24]
[23:16]
[15:8]
0x280
I2C address register (IADR) [p. 8-6]
0x284
I2C
0x288
I2C control register (I2CR) [p. 8-7]
Reserved
0x28C
I2C status register (I2SR) [p. 8-8]
Reserved
0x290
I2C
Reserved
[7:0]
Reserved
frequency divider register (IFDR) [p. 8-6]
Reserved
data I/O register (I2DR) [p. 8-9]
NOTE:
External masters cannot access the MCF5407’s on-chip
memories or MBAR, but can access any I2C module register.
8.5.1 I2C Address Register (IADR)
The IADR holds the address the I2C responds to when addressed as a slave. Note that it is
not the address sent on the bus during the address transfer.
7
6
5
Field
4
3
2
1
ADR
Reset
0000_0000
R/W
Read/Write
Address
0
—
MBAR + 0x280
Figure 8-5.
I2C
Address Register (IADR)
Table 8-2 describes IADR fields.
Table 8-2. I2C Address Register Field Descriptions
Bits
Name
Description
7–1
ADR
Slave address. Contains the specific slave address to be used by the I2C module. Slave mode is
the default I2C mode for an address match on the bus.
0
—
Reserved, should be cleared.
8.5.2 I2C Frequency Divider Register (IFDR)
The IFDR, Figure 8-6, provides a programmable prescaler to configure the clock for
8-6
MCF5407 User’s Manual
Programming Model
bit-rate selection.
7
Field
6
5
4
3
2
—
1
0
IC
Reset
0000_0000
R/W
Read/Write
Address
MBAR + 0x284
Figure 8-6. I2C Frequency Divider Register (IFDR)
Table 8-3 describes IFDR[IC].
Table 8-3. IFDR Field Descriptions
Bits
Name
7–6
—
Reserved, should be cleared.
Description
5–0
IC
I2C clock rate. Prescales the clock for bit-rate selection. Due to potentially slow SCL and SDA rise and
fall times, bus signals are sampled at the prescaler frequency. The serial bit clock frequency is equal to
CLKIN divided by the divider shown below. Note that IC can be changed anywhere in a program.
IC
Divider
IC
Divider
IC
Divider
IC
Divider
0x00
28
0x10
288
0x20
20
0x30
160
0x01
30
0x11
320
0x21
22
0x31
192
0x02
34
0x12
384
0x22
24
0x32
224
0x03
40
0x13
480
0x23
26
0x33
256
0x04
44
0x14
576
0x24
28
0x34
320
0x05
48
0x15
640
0x25
32
0x35
384
0x06
56
0x16
768
0x26
36
0x36
448
0x07
68
0x17
960
0x27
40
0x37
512
0x08
80
0x18
1152
0x28
48
0x38
640
0x09
88
0x19
1280
0x29
56
0x39
768
0x0A
104
0x1A
1536
0x2A
64
0x3A
896
0x0B
128
0x1B
1920
0x2B
72
0x3B
1024
0x0C
144
0x1C
2304
0x2C
80
0x3C
1280
0x0D
160
0x1D
2560
0x2D
96
0x3D
1536
0x0E
192
0x1E
3072
0x2E
112
0x3E
1792
0x0F
240
0x1F
3840
0x2F
128
0x3F
2048
8.5.3 I2C Control Register (I2CR)
The I2CR is used to enable the I2C module and the I2C interrupt. It also contains bits that
govern operation as a slave or a master.
Chapter 8. I2C Module
8-7
Programming Model
Field
7
6
5
4
3
2
IEN
IIEN
MSTA
MTX
TXAK
RSTA
Reset
1
0
—
0000_0000
R/W
Read/Write
Address
MBAR + 0x288
Figure 8-7. I2C Control Register (I2CR)
Table 8-4 describes I2CR fields.
Table 8-4. I2CR Field Descriptions
Bits
Name
Description
7
IEN
I2C enable. Controls the software reset of the entire I2C module. If the module is enabled in the
middle of a byte transfer, slave mode ignores the current bus transfer and starts operating when the
next start condition is detected. Master mode is not aware that the bus is busy; so initiating a start
cycle may corrupt the current bus cycle, ultimately causing either the current master or the I2C
module to lose arbitration, after which bus operation returns to normal.
0 The module is disabled, but registers can still be accessed.
1 The I2C module is enabled. This bit must be set before any other I2CR bits have any effect.
6
IIEN
I2C interrupt enable.
0 I2C module interrupts are disabled, but currently pending interrupt condition are not cleared.
1 I2C module interrupts are enabled. An I2C interrupt occurs if I2SR[IIF] is also set.
5
MSTA
Master/slave mode select bit. If the master loses arbitration, MSTA is cleared without generating a
STOP signal.
0 Slave mode. Changing MSTA from 1 to 0 generates a STOP and selects slave mode.
1 Master mode. Changing MSTA from 0 to 1 signals a START on the bus and selects master mode.
4
MTX
Transmit/receive mode select bit. Selects the direction of master and slave transfers.
0 Receive
1 Transmit. When a slave is addressed, software should set MTX according to I2SR[SRW]. In
master mode, MTX should be set according to the type of transfer required. Therefore, for address
cycles, MTX is always 1.
3
TXAK
Transmit acknowledge enable. Specifies the value driven onto SDA during acknowledge cycles for
both master and slave receivers. Note that writing TXAK applies only when the I2C bus is a receiver.
0 An acknowledge signal is sent to the bus at the ninth clock bit after receiving one byte of data.
1 No acknowledge signal response is sent (that is, acknowledge bit = 1).
2
RSTA
Repeat start. Always read as 0. Attempting a repeat start without bus mastership causes loss of
arbitration.
0 No repeat start
1 Generates a repeated START condition.
1–0
—
Reserved, should be cleared.
8.5.4 I2C Status Register (I2SR)
This I2SR contains bits that indicate transaction direction and status.
8-8
MCF5407 User’s Manual
Programming Model
Field
7
6
5
4
3
2
1
0
ICF
IAAS
IBB
IAL
—
SRW
IIF
RXAK
R/W
R
Reset
R/W
1000_0001
R
R
R/W
Address
MBAR + 0x28C
Figure 8-8. I2CR Status Register (I2SR)
Table 8-5 describes I2SR fields.
Table 8-5. I2SR Field Descriptions
Bits
Name
Description
7
ICF
Data transferring bit. While one byte of data is transferred, ICF is cleared.
0 Transfer in progress
1 Transfer complete. Set by the falling edge of the ninth clock of a byte transfer.
6
IAAS
I2C addressed as a slave bit. The CPU is interrupted if I2CR[IIEN] is set. Next, the CPU must check
SRW and set its TX/RX mode accordingly. Writing to I2CR clears this bit.
0 Not addressed.
1 Addressed as a slave. Set when its own address (IADR) matches the calling address.
5
IBB
I2C bus busy bit. Indicates the status of the bus.
0 Bus is idle. If a STOP signal is detected, IBB is cleared.
1 Bus is busy. When START is detected, IBB is set.
4
IAL
Arbitration lost. Set by hardware in the following circumstances. (IAL must be cleared by software by
writing zero to it.)
• SDA sampled low when the master drives high during an address or data-transmit cycle.
• SDA sampled low when the master drives high during the acknowledge bit of a data-receive
cycle.
• A start cycle is attempted when the bus is busy.
• A repeated start cycle is requested in slave mode.
• A stop condition is detected when the master did not request it.
3
—
Reserved, should be cleared.
2
SRW
Slave read/write. When IAAS is set, SRW indicates the value of the R/W command bit of the calling
address sent from the master. SRW is valid only when a complete transfer has occurred, no other
transfers have been initiated, and the I2C module is a slave and has an address match.
0 Slave receive, master writing to slave.
1 Slave transmit, master reading from slave.
1
IIF
I2C interrupt. Must be cleared by software by writing a zero to it in the interrupt routine.
0 No I2C interrupt pending
1 An interrupt is pending, which causes a processor interrupt request (if IIEN = 1). Set when one of
the following occurs:
• Complete one byte transfer (set at the falling edge of the ninth clock)
• Reception of a calling address that matches its own specific address in slave-receive mode
• Arbitration lost
0
RXAK
Received acknowledge. The value of SDA during the acknowledge bit of a bus cycle.
0 An acknowledge signal was received after the completion of 8-bit data transmission on the bus
1 No acknowledge signal was detected at the ninth clock.
8.5.5 I2C Data I/O Register (I2DR)
In master-receive mode, reading the I2DR, Figure 8-9, allows a read to occur and initiates
Chapter 8. I2C Module
8-9
I2C Programming Examples
next byte data receiving. In slave mode, the same function is available after it is addressed.
7
6
5
4
3
Field
D
Reset
0000_0000
R/W
2
1
0
Read/Write
Address
MBAR + 0x290
Figure 8-9. I2C Data I/O Register (I2DR)
8.6 I2C Programming Examples
The following examples show programming for initialization, signalling START,
post-transfer software response, signalling STOP, and generating a repeated START.
8.6.1 Initialization Sequence
Before the interface can transfer serial data, registers must be initialized, as follows:
1. Set IFDR[IC] to obtain SCL frequency from the system bus clock. See
Section 8.5.2, “I2C Frequency Divider Register (IFDR).”
2. Update the IADR to define its slave address.
3. Set I2CR[IEN] to enable the I2C bus interface system.
4. Modify the I2CR to select master/slave mode, transmit/receive mode, and
interrupt-enable or not.
NOTE:
If IBSR[IBB] when the I2C bus module is enabled, execute the
following code sequence before proceeding with normal
initialization code. This issues a STOP command to the slave
device, placing it in idle state as if it were just power-cycled on.
I2CR = 0x0
I2CR = 0xA
dummy read of I2DR
IBSR = 0x0
I2CR = 0x0
8.6.2 Generation of START
After completion of the initialization procedure, serial data can be transmitted by selecting
the master transmitter mode. On a multiple-master bus system, IBSR[IBB] must be tested
to determine whether the serial bus is free. If the bus is free (IBB = 0), the START signal
and the first byte (the slave address) can be sent. The data written to the data register
comprises the address of the desired slave and the lsb indicates the transfer direction.
8-10
MCF5407 User’s Manual
I2C Programming Examples
The free time between a STOP and the next START condition is built into the hardware that
generates the START cycle. Depending on the relative frequencies of the system clock and
the SCL period, it may be necessary to wait until the I2C is busy after writing the calling
address to the I2DR before proceeding with the following instructions.
The following example signals START and transmits the first byte of data (slave address):
CHFLAG
MOVE.B I2SR,-(A0);Check I2SR[MBB]
BTST.B #5, (A0)+
BNE.S CHFLAG;If I2SR[MBB] = 1, wait until it is clear
TXSTART MOVE.B I2CR,-(A0);Set transmit mode
BSET.B #4,(A0)
MOVE.B (A0)+, I2CR
MOVE.B I2CR, -(A0);Set master mode
BSET.B #5, (A0);Generate START condition
MOVE.B (A0)+, I2CR
MOVE.B CALLING,-(A0);Transmit the calling address, D0=R/W
MOVE.B (A0)+, I2DR
IFREE
MOVE.B I2SR,-(A0);Check I2SR[MBB]
;If it is clear, wait until it is set.
BTST.B #5, (A0)+;
BEQ.S IFREE;
8.6.3 Post-Transfer Software Response
Sending or receiving a byte sets the I2SR[ICF], which indicates one byte communication
is finished. I2SR[IIF] is also set. An interrupt is generated if the interrupt function is
enabled during initialization by setting I2CR[IIEN]. Software must first clear IIF in the
interrupt routine. ICF is cleared either by reading from I2DR in receive mode or by writing
to I2DR in transmit mode.
Software can service the I2C I/O in the main program by monitoring IIF if the interrupt
function is disabled. Polling should monitor IIF rather than ICF because that operation is
different when arbitration is lost.
When an interrupt occurs at the end of the address cycle, the master is always in transmit
mode; that is, the address is sent. If master receive mode is required (I2DR[R/W],
I2CR[MTX] should be toggled.
During slave-mode address cycles (I2SR[IAAS] = 1), I2SR[SRW] is read to determine the
direction of the next transfer. MTX is programmed accordingly. For slave-mode data cycles
(IAAS = 0), SRW is invalid. MTX should be read to determine the current transfer
direction.
The following is an example of a software response by a master transmitter in the interrupt
routine (see Figure 8-10).
I2SR
LEA.L I2SR,-(A7);Load effective address
BCLR.B #1,(A7)+;Clear the IIF flag
MOVE.B I2CR,-(A7);Push the address on stack,
BTST.B #5,(A7)+;check the MSTA flag
BEQ.S SLAVE;Branch if slave mode
MOVE.B I2CR,-(A7);Push the address on stack
BTST.B #4,(A7)+;check the mode flag
Chapter 8. I2C Module
8-11
I2C Programming Examples
BEQ.S RECEIVE;Branch if in receive mode
MOVE.B I2SR,-(A7);Push the address on stack,
BTST.B #0,(A7)+;check ACK from receiver
BNE.B END;If no ACK, end of transmission
TRANSMITMOVE.B DATABUF,-(A7);Stack data byte
MOVE.B (A7)+, I2DR;Transmit next byte of data
8.6.4 Generation of STOP
A data transfer ends when the master signals a STOP, which can occur after all data is sent,
as in the following example.
MASTX
END
MOVE.B I2SR, -(A7);If no ACK, branch to end
BTST.B #0,(A7)+
BNE.B END
MOVE.B TXCNT,D0;Get value from the transmitting counter
BEQ.S END;If no more data, branch to end
MOVE.B DATABUF,-(A7);Transmit next byte of data
MOVE.B (A7)+,I2DR
MOVE.B TXCNT,D0;Decrease the TXCNT
SUBQ.L #1,D0
MOVE.B D0,TXCNT
BRA.S EMASTX;Exit
LEA.L I2CR,-(A7);Generate a STOP condition
BCLR.B #5,(A7)+
EMASTX RTE;Return from interrupt
For a master receiver to terminate a data transfer, it must inform the slave transmitter by not
acknowledging the last data byte. This is done by setting I2CR[TXAK] before reading the
next-to-last byte. Before the last byte is read, a STOP signal must be generated, as in the
following example.
MASR
MOVE.B RXCNT,D0;Decrease RXCNT
SUBQ.L #1,D0
MOVE.B D0,RXCNT
BEQ.S ENMASR;Last byte to be read
MOVE.B RXCNT,D1;Check second-to-last byte to be read
EXTB.L D1
SUBI.L #1,D1;
BNE.S NXMAR;Not last one or second last
LAMAR BSET.B #3,I2CR;Disable ACK
BRA NXMAR
ENMASR
NXMAR
BCLR.B #5,I2CR;Last one, generate STOP signal
MOVE.B I2DR,RXBUF;Read data and store RTE
8.6.5 Generation of Repeated START
After the data transfer, if the master still wants the bus, it can signal another START
followed by another slave address without signalling a STOP, as in the following example.
RESTART MOVE.B
BSET.B
MOVE.B
MOVE.B
MOVE.B
MOVE.B
8-12
I2CR,-(A7);Repeat START (RESTART)
#2, (A7)
(A7)+, I2CR
CALLING,-(A7);Transmit the calling address, D0=R/WCALLING,-(A7);
(A7)+, I2DR
MCF5407 User’s Manual
I2C Programming Examples
8.6.6 Slave Mode
In the slave interrupt service routine, the module addressed as slave bit (IAAS) should be
tested to check if a calling of its own address has just been received. If IAAS is set, software
should set the transmit/receive mode select bit (I2CR[MTX]) according to the I2SR[SRW].
Writing to the I2CR clears the IAAS automatically. The only time IAAS is read as set is
from the interrupt at the end of the address cycle where an address match occurred;
interrupts resulting from subsequent data transfers will have IAAS cleared. A data transfer
can now be initiated by writing information to I2DR for slave transmits, or read from I2DR
in slave-receive mode. A dummy read of I2DR in slave/receive mode releases SCL,
allowing the master to send data.
In the slave transmitter routine, I2SR[RXAK] must be tested before sending the next byte
of data. Setting RXAK means an end-of-data signal from the master receiver, after which
software must switch it from transmitter to receiver mode. Reading I2DR then releases SCL
so that the master can generate a STOP signal.
8.6.7 Arbitration Lost
If several devices try to engage the bus at the same time, one becomes master. Hardware
immediately switches devices that lose arbitration to slave receive mode. Data output to
SDA stops, but SCL is still generated until the end of the byte during which arbitration is
lost. An interrupt occurs at the falling edge of the ninth clock of this transfer with
I2SR[IAL] = 1 and I2CR[MSTA] = 0.
If a device that is not a master tries to transmit or do a START, hardware inhibits the
transmission, clears MSTA without signalling a STOP, generates an interrupt to the CPU,
and sets IAL to indicate a failed attempt to engage the bus. When considering these cases,
the slave service routine should first test IAL and software should clear it if it is set.
Chapter 8. I2C Module
8-13
I2C Programming Examples
Clear
IIF
Y
TX
TX/Rx
?
Master
Mode?
N
Y
RX
Arbitration
Lost?
N
Last Byte
Transmitted
?
N
RXAK= 0
?
Clear IAL
Y
Last
Byte to be
Read ?
N
Y
Y
N
End of
ADDR Cycle
(Master RX)
?
N
Write Next
Byte to I2DR
N
Y
Y
(Read)Y
N Data
Cycle
SRW=1
?
Generate
STOP Signal
Y
Set TX
Mode
Switch to
Rx Mode
Generate
STOP Signal
Tx/Rx
?
N (WRITE)
N
Write Data
to I2DR
Dummy Read
from I2DR
IAAS=1
?
Address Y
Cycle
2nd Last
Byte to be
Read?
Set TXAK =1
Y
IAAS=1
?
Read Data
from I2DR
And Store
TX
ACK from
Receiver
?
N
Read Data
from I2DR
and Store
Tx Next
Byte
Set RX
Mode
Switch to
Rx Mode
Dummy Read
from I2DR
Dummy Read
from I2DR
RTE
Figure 8-10. Flow-Chart of Typical I2C Interrupt Routine
8-14
MCF5407 User’s Manual
RX
Chapter 9
Interrupt Controller
This chapter describes the operation of the interrupt controller portion of the system
integration module (SIM). It includes descriptions of the registers in the interrupt controller
memory map and the interrupt priority scheme.
9.1 Overview
The SIM provides a centralized interrupt controller for all MCF5407 interrupt sources,
which consist of the following:
•
•
•
External interrupts
Software watchdog timer
Timer modules
•
•
•
I2C module
UART modules
DMA module
Figure 9-1 is a block diagram of the interrupt controller.
System Integration Module (SIM)
DMA
Four
Channels
Interrupt Controller
12 ICRs
IRQPAR
Software
Watchdog
I2C Module
IPR
IMR
AVR
4
IRQ[1,3,5,7]
Two UARTs
Two
GeneralPurpose
Timers
Figure 9-1. Interrupt Controller Block Diagram
Chapter 9. Interrupt Controller
9-1
Interrupt Controller Registers
The SIM provides the following registers for managing interrupts:
•
•
•
•
•
Each potential interrupt source is assigned one of the 10 interrupt control registers
(ICR0–ICR9), which are used to prioritize the interrupt sources.
The interrupt mask register (IMR) provides bits for masking individual interrupt
sources.
The interrupt pending register (IPR) provides bits for indicating when an interrupt
request is being made (regardless of whether it is masked in the IMR).
The autovector register (AVEC) controls whether the SIM supplies an autovector or
executes an external interrupt acknowledge cycle for each IRQ.
The interrupt port assignment register (IRQPAR) provides the level assignment of
the primary external interrupt pins—IRQ5, IRQ3, and IRQ1.
9.2 Interrupt Controller Registers
The interrupt controller register portion of the SIM memory map is shown in Table 9-2.
Table 9-1. Interrupt Controller Registers
MBAR
Offset
[31:24]
[23:16]
[15:8]
0x040
Interrupt pending register (IPR) [p. 9-6]
0x044
Interrupt mask register (IMR) [p. 9-6]
0x048
Reserved
[7:0]
Autovector register
(AVR) [p. 9-5]
Interrupt Control Registers (ICRs) [p. 9-3]
0x04C
Software watchdog
timer (ICR0) [p. 9-3]
Timer0 (ICR1) [p. 9-3]
Timer1 (ICR2) [p. 9-3]
I2C (ICR3) [p. 9-3]
0x050
UART0 (ICR4) [p. 9-3]
UART1 (ICR5) [p. 9-3]
DMA0 (ICR6) [p. 9-3]
DMA1 (ICR7) [p. 9-3]
0x054
DMA2 (ICR8) [p. 9-3]
DMA3 (ICR9) [p. 9-3]
Reserved
Each internal interrupt source has its own interrupt control register (ICR0–ICR9), shown in
Table 9-2 and described in Section 9.2.1, “Interrupt Control Registers (ICR0–ICR9).”
Table 9-2. Interrupt Control Registers
9-2
MBAR Offset
Register
Name
0x04C
ICR0
Software watchdog timer
0x04D
ICR1
Timer0
0x04E
ICR2
Timer1
0x04F
ICR3
I2C
0x050
ICR4
UART0
0x051
ICR5
UART1
0x052
ICR6
DMA0
MCF5407 User’s Manual
Interrupt Controller Registers
Table 9-2. Interrupt Control Registers (Continued)
MBAR Offset
Register
Name
0x053
ICR7
DMA1
0x054
ICR8
DMA2
0x055
ICR9
DMA3
Internal interrupts are programmed to a level and priority. Each internal interrupt has a
unique ICR. Each of the 7 interrupt levels has 5 priorities, for a total of 35 possible priority
levels, encompassing internal and external interrupts. The four external interrupt pins offer
seven possible settings at a fixed interrupt level and priority.
The IRQPAR determines these settings for external interrupt request levels. External
interrupts can be programmed to supply an autovector or execute an external interrupt
acknowledge cycle. This is described in Section 9.2.2, “Autovector Register (AVR).”
9.2.1 Interrupt Control Registers (ICR0–ICR9)
The interrupt control registers (ICR0–ICR9) provide bits for defining the interrupt level and
priority for the interrupt source assigned to the ICR, shown in Table 9-2.
7
6
5
Field
AVEC
—
Reset
0
—
R/W
Address
4
3
2
1
0
IL
IP
0_00
00
R/W
MBAR + 0x04C (ICR0); 0x04D (ICR1); 0x04E (ICR2); 0x04F (ICR3); 0x050 (ICR4); 0x051 (ICR5);
0x052 (ICR6); 0x053 (ICR7); 0x054 (ICR8); 0x055 (ICR9)
Figure 9-2. Interrupt Control Registers (ICR0–ICR9)
Table 9-3 describes ICR fields.
Table 9-3. ICRn Field Descriptions
Bits
Field
Description
7
AVEC
Autovector enable. Determines whether the interrupt-acknowledge cycle input (for the internal
interrupt level indicated in IL for each interrupt) requires an autovector response.
0 Interrupting source returns vector during interrupt-acknowledge cycle.
1 SIM generates autovector during interrupt acknowledge cycle.
6–5
—
Reserved, should be cleared.
4–2
IL
Interrupt level. Indicates the interrupt level assigned to each interrupt input. See Table 9-4.
1–0
IP
Interrupt priority. Indicates the interrupt priority for internal modules within the interrupt-level
assignment. See Table 9-4.
00 Lowest
01 Low
10 High
11 Highest
Chapter 9. Interrupt Controller
9-3
Interrupt Controller Registers
NOTE:
Assigning the same interrupt level and priority to multiple
ICRs causes unpredictable system behavior.
Table 9-4 shows possible priority schemes for internal and external sources of the
MCF5407. The internal module interrupt source in this table can be any internal interrupt
source programmed to the given level and priority.
This table shows how external interrupts are prioritized with respect to internal interrupt
sources within the same level. For example, UART0 and UART1 sources are programmed
to IL = 110; in this case, UART0 is given lower priority than UART1, so ICR4[IP] = 01 and
the ICR5[IP] = 10. IRQ3 is programmed to level 6. If all three assert an interrupt request at
the same time, they are serviced in the following order:
1. ICR5[IL] = 110 and ICR5[IP] = 10, so UART1 is serviced first (priority 7 in
Table 9-4).
2. External interrupt IRQ3, set to level 6, is serviced next (priority 8).
3. ICR4[IL] = 110 and ICR5[IP] = 01, so UART0 is serviced last (priority 9).
Table 9-4. Interrupt Priority Scheme
Priority
1
Interrupt
Level
7
2
Interrupt Source
IL
IRQPAR[IRQPAR]
IP
111
11
111
10
Internal module
xxx
xxx
3
xxx
xx
External interrupt pin IRQ7
xxx
4
111
01
Internal module
xxx
5
111
00
6
6
7
110
11
110
10
xxx
Internal module
xxx
xx
External interrupt pin IRQ3 (programmed as IRQ6)
9
110
01
Internal module
10
110
00
12
5
101
11
101
10
xxx
xxx
8
11
9-4
ICR
x1x
xxx
xxx
Internal module
xxx
xxx
13
xxx
xx
External interrupt pin IRQ5
14
101
01
Internal module
15
101
00
0xx
xxx
xxx
MCF5407 User’s Manual
Interrupt Controller Registers
Table 9-4. Interrupt Priority Scheme (Continued)
Priority
ICR
Interrupt
Level
16
Interrupt Source
IL
4
17
IRQPAR[IRQPAR]
IP
100
11
100
10
Internal module
xxx
xxx
18
xxx
xx
External interrupt pin IRQ5 (programmed as IRQ4)
1xx
19
100
01
Internal module
xxx
100
00
011
11
011
10
20
21
3
22
xxx
Internal module
xxx
xxx
23
xxx
xx
External interrupt pin IRQ3
x0x
24
011
01
Internal module
xxx
011
00
010
11
010
10
25
26
2
27
xxx
Internal module
xxx
xxx
28
xxx
xx
External interrupt pin IRQ1 (programmed as IRQ2)
xx1
29
010
01
Internal module
xxx
010
00
001
11
001
10
30
31
1
32
xxx
Internal module
xxx
xxx
33
xxx
xx
External interrupt pin IRQ1
xx0
34
001
01
Internal module
xxx
35
001
00
xxx
9.2.2 Autovector Register (AVR)
The autovector register (AVR), shown in Figure 9-3, enables external interrupt sources to
be autovectored, using the vector offset defined in Table 2-19 in Section 2.8, “Exception
Processing Overview.” Note that the autovector enable for internal interrupt sources applies
for respective ICRs.
7
6
5
Field
4
3
2
AVEC
Reset
1
0
BLK
0000_0000
R/W
R/W
Address
MBAR + 0x04B
Figure 9-3. Autovector Register (AVR)
Table 9-5 describes AVR fields.
Chapter 9. Interrupt Controller
9-5
Interrupt Controller Registers
.
Table 9-5. AVR Field Descriptions
Bit
Name
7–1
AVEC Autovector control. Determines whether the external interrupt at that level is autovectored.
0 Interrupting source returns vector during interrupt-acknowledge cycle.
1 SIM generates autovector during interrupt-acknowledge cycle.
0
BLK
Description
Block address strobe (AS) for external AVEC access. Available for users who use AS as a global
chip select for peripherals and do not want to enable them during an AVEC cycle.
0 Do not block address strobe.
1 Block address strobe from asserting.
Table 9-6 shows the correlation between AVR[AVEC] and the external interrupts. Note that
an AVECn bit is valid only when the corresponding external interrupt request level is
enabled in the IRQPAR.
Table 9-6. Autovector Register Bit Assignments
Autovector Interrupt Source
Autovector Register Bit Location
Vector Offset
External interrupt request 1
AVEC1
0x64
External interrupt request 2
AVEC2
0x68
External interrupt request 3
AVEC3
0x6C
External interrupt request 4
AVEC4
0x70
External interrupt request 5
AVEC5
0x74
External interrupt request 6
AVEC6
0x78
External interrupt request 7
AVEC7
0x7C
9.2.3 Interrupt Pending and Mask Registers (IPR and IMR)
The interrupt pending register (IPR), Figure 9-4, makes visible the interrupt sources that
have an interrupt pending. The interrupt mask register (IMR), also shown in Figure 9-4, is
used to mask the internal and external interrupt sources.
NOTE:
To mask interrupt sources, first set the core’s status register
interrupt mask level to that of the source being masked in the
IMR. Then, the IMR bit can be masked.
An interrupt is masked by setting, and enabled by clearing, the corresponding IMR bit.
When a masked interrupt occurs, the corresponding IPR bit is still set, but no interrupt
request is passed to the core.
9-6
MCF5407 User’s Manual
Interrupt Controller Registers
31
30
29
28
27
26
25
24
Field
—
Reset
—
R/W
23
22
21
20
19
18
17
16
DMA3 DMA2
1
1
Read-only (IPR); R/W (IMR)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Field DMA1 DMA0 UART1 UART0 I2C TIMER2 TIMER1 SWT EINT7 EINT6 EINT5 EINT4 EINT3 EINT2 EINT1
Reset
1111
1111
1111
R/W
Read-only (IPR); R/W (IMR)
Addr
MBAR + 0x040 (IPR); + 0x044 (IMR)
1
1
—
1
—
Figure 9-4. Interrupt Pending Register (IPR) and Interrupt Mask Register (IMR)
Table 9-7 describes IPR and IMR fields.
Table 9-7. IPR and IMR Field Descriptions
Bits
Name
31–18
—
17–1
See
Figure
9-4
Description
Reserved, should be cleared.
Interrupt pending/mask. Each bit corresponds to an interrupt source defined by the ICR. The
corresponding IMR bit determines whether an interrupt condition can generate an interrupt. At
every clock, the IPR samples the signal generated by the interrupting source. The corresponding
IPR bit reflects the state of the interrupt signal even if the corresponding IMR bit is set.
0 The corresponding interrupt source is not masked (IMR) and has no interrupt pending (IPR).
1 The corresponding interrupt source is masked (IMR) and has an interrupt pending (IPR)
9.2.4 Interrupt Port Assignment Register (IRQPAR)
The interrupt port assignment register (IRQPAR), shown in Figure 9-5, provides the level
assignment of the primary external interrupt pins—IRQ5, IRQ3, and IRQ1. The setting of
IRQPAR2–IRQPAR0 determines the interrupt level of these external interrupt pins.
7
Field IRQPAR2
6
5
IRQPAR1
IRQPAR0
Reset
4
3
—
2
1
0
ENBDACK1 ENBDACK0
0000_0000
R/W
R/W
Address
MBAR + 0x06
Figure 9-5. Interrupt Port Assignment Register (IRQPAR)
Table 9-8 describes IRQPAR fields.
Chapter 9. Interrupt Controller
9-7
Interrupt Controller Registers
Table 9-8. IRQPAR Field Descriptions
Bits
Name
Description
7–5
IRQPARn
Configures the IRQ pin assignments and priorities
IRQPARn
External Pin
IRQPARn = 0
IRQPARn = 1
IRQPAR2
IRQ5
Level 5
Level 4
IRQPAR1
IRQ3
Level 3
Level 6
IRQPAR0
IRQ1
Level 1
Level 2
4–2
—
Reserved, should be cleared.
1–0
ENBDACKn
Enable DACK1 and DACK0. Determines the functionality of the respective TMn/DACKn pins.
0 TM1 and TM0 are driven instead of DACK1 and DACK0.
1 If the PAR register is programmed to enable TMn, the DACKn signal for DMA channel n is
driven in place of TMn for DMA transfers.
9-8
MCF5407 User’s Manual
Chapter 10
Chip-Select Module
This chapter describes the MCF5407 chip-select module, including the operation and
programming model of the chip-select registers, which include the chip-select address,
mask, and control registers.
10.1 Overview
The following list summarizes the key chip-select features:
•
•
•
•
Eight independent, user-programmable chip-select signals (CS[7:0]) that can
interface with SRAM, PROM, EPROM, EEPROM, Flash, and peripherals
Address masking for 64-Kbyte to 4-Gbyte memory block sizes
Programmable wait states and port sizes
External master access to chip selects
10.2 Chip-Select Module Signals
Table 10-1 lists signals used by the chip-select module.
Table 10-1. Chip-Select Module Signals
Signal
Description
Chip Selects
(CS[7:0])
Each CSn can be independently programmed for an address location as well as for masking, port
size, read/write burst-capability, wait-state generation, and internal/external termination. Only CS0
is initialized at reset when it acts as a global chip select that allows boot ROM to be at any defined
address space. Port size and termination (internal versus external) and byte enables for CS0 are
configured by the logic levels of D[7:5] when RSTI negates.
Output
Enable (OE)
Interfaces to memory or to peripheral devices and enables a read transfer. It is asserted and
negated on the falling edge of the clock. OE is asserted only when one of the chip selects matches
for the current address decode.
Byte Enables/
Byte Write
Enables
(BE[3:0]/
BWE[3:0])
These multiplexed signals are individually programmed through the byte enable mode bit,
CSCRn[BEM], described in Section 10.4.1.3, “Chip-Select Control Registers (CSCR0–CSCR7).”
These generated signals provide byte data select signals, which are decoded from the transfer
size, A1, and A0 signals in addition to the programmed port size and burstability of the memory
accessed, as Table 10-2 shows.
Table 10-2 shows the interaction of the byte enable/byte-write enables with related signals.
Chapter 10. Chip-Select Module
10-1
Chip-Select Operation
Table 10-2. Byte Enables/Byte Write Enable Signal Settings
BE0/BWE0
BE1/BWE1
BE2/BWE2
BE3/BWE3
D[31:24]
D[23:16]
D[15:8]
D[7:0]
0
1
1
1
1
0
1
1
1
1
0
0
1
1
1
1
1
0
1
1
1
0
0
0
1
1
1
0
1
1
0
1
1
1
0
0
1
1
1
1
1
1
0
1
1
0
0
0
1
1
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
0
0
0
0
1
1
1
0
1
0
1
1
1
1
0
0
1
1
1
1
1
0
1
1
1
0
0
0
0
1
1
1
0
0
0
1
1
Transfer Size
Port Size
A1
A0
Byte
8-bit
0
0
0
16-bit
32-bit
Word
8-bit
16-bit
32-bit
Longword
8-bit
0
0
0
1
1
0
1
1
0
0
0
0
0
1
1
1
0
1
0
1
1
1
1
0
0
1
1
1
1
1
0
1
1
1
0
0
0
0
1
1
1
0
0
0
1
1
32-bit
0
0
0
0
0
0
8-bit
0
0
0
1
1
1
0
1
0
1
1
1
1
0
0
1
1
1
1
1
0
1
1
1
0
0
0
0
1
1
1
0
0
0
1
1
0
0
0
0
0
0
16-bit
Line
0
1
16-bit
32-bit
10.3 Chip-Select Operation
Each chip select has a dedicated set of the following registers for configuration and control.
•
10-2
Chip-select address registers (CSARn) control the base address space of the chip
select. See Section 10.4.1.1, “Chip-Select Address Registers (CSAR0–CSAR7).”
MCF5407 User’s Manual
Chip-Select Operation
•
•
Chip-select mask registers (CSMRn) provide 16-bit address masking and access
control. See Section 10.4.1.2, “Chip-Select Mask Registers (CSMR0–CSMR7).”
Chip-select control registers (CSCRn) provide port size and burst capability
indication, wait-state generation, and automatic acknowledge generation features.
See Section 10.4.1.3, “Chip-Select Control Registers (CSCR0–CSCR7).”
Each CSn can assert during specific CPU space accesses such as interrupt-acknowledge
cycles and each can be accessed by an external master. CS0 is a global chip select after reset
and provides relocatable boot ROM capability.
10.3.1 General Chip-Select Operation
When a bus cycle is initiated, the MCF5407 first compares its address with the base address
and mask configurations programmed for chip selects 0–7 (configured in CSCR0–CSCR7)
and DRAM block 0 and 1 address and control registers (configured in DACR0 and
DACR1). If the driven address matches a programmed chip select or DRAM block, the
appropriate chip select is asserted or the DRAM block is selected using the specifications
programmed in the respective configuration register. Otherwise, the following occurs:
•
If the address and attributes do not match in CSCR or DACR, the MCF5407 runs an
external burst-inhibited bus cycle with a default of external termination on a 32-bit
port.
•
Should an address and attribute match in multiple CSCRs, the matching chip-select
signals are driven; however, the MCF5407 runs an external burst-inhibited bus cycle
with external termination on a 32-bit port.
•
Should an address and attribute match both DACRs or a DACR and a CSCR, the
operation is undefined.
Table 10-3 shows the type of access as a function of match in the CSCRs and DACRs.
Table 10-3. Accesses by Matches in CSCRs and DACRs
Number of CSCR Matches
Number of DACR Matches
Type of Access
0
0
External
1
0
Defined by CSCR
Multiple
0
External, burst-inhibited, 32-bit
0
1
Defined by DACRs
1
1
Undefined
Multiple
1
Undefined
0
Multiple
Undefined
1
Multiple
Undefined
Multiple
Multiple
Undefined
Chapter 10. Chip-Select Module
10-3
Chip-Select Operation
10.3.1.1 8-, 16-, and 32-Bit Port Sizing
Static bus sizing is programmable through the port size bits, CSCR[PS]. See
Section 10.4.1.3, “Chip-Select Control Registers (CSCR0–CSCR7).” Figure 10-1 shows
the correspondence between data byte lanes and the external chip-select memory. Note that
all lanes are driven, although unused lines are undefined.
BE0
BE1
BE2
BE3
D[31:24]
D[23:16]
D[15:8]
D[7:0]
32-bit port
memory
Byte 0
Byte 1
Byte 2
Byte 3
16-bit port
memory
Byte 0
Byte 1
Byte 2
Byte 3
External
data bus
8-bit port
memory
Byte 0
Byte 1
Byte 2
Byte 3
Driven, undefined
Driven, undefined
Figure 10-1. Connections for External Memory Port Sizes
10.3.1.2 Global Chip-Select Operation
CS0, the global (boot) chip select, allows address decoding for boot ROM before system
initialization. Its operation differs from other external chip-select outputs after system reset.
After system reset, CS0 is asserted for every external access. No other chip-select can be
used until the valid bit, CSMR0[V], is set, at which point CS0 functions as configured and
CS[7:1] can be used. At reset, the port size, byte enable, and automatic acknowledge
functions of the global chip-select are determined by the logic levels of the inputs on
D[7:5,3]. Table 10-4 through Table 10-6 list the various reset encodings for the
configuration signals multiplexed with D[7:5,3].
Table 10-4. D7/AA, Automatic Acknowledge of Boot CS0
D7/AA
10-4
Boot CS0 AA Configuration at Reset
0
Disabled
1
Enable with 15 wait states
MCF5407 User’s Manual
Chip-Select Registers
Table 10-5. D[6:5]/PS[1:0], Port Size of Boot CS0
D[6:5]/PS[1:0]
Boot CS0 Port Size at Reset
00
32-bit port
01
8-bit port
1x
16-bit port
Table 10-6. D3/BE_CONFIG0, BE[3:0] Boot Configuration
D3/BE_CONFIG0
Configuration of Byte Enables for Boot CS0
0
BE[3:0] is enabled as byte write enables only.
1
BE[3:0] is enabled as byte enables for reads and writes.
Provided the required address range is in the chip-select address register (CSAR0), CS0 can
be programmed to continue decoding for a range of addresses after the CSMR0[V] is set,
after which the global chip-select can be restored only by a system reset.
10.4 Chip-Select Registers
Table 10-7 is the chip-select register memory map. Reading reserved locations returns
zeros.
Table 10-7. Chip-Select Registers
MBAR
Offset
0x080
0x084
[31:24]
[23:16]
[15:8]
[7:0]
Reserved1
Chip-select address register—bank 0 (CSAR0) [p. 10-6]
Chip-select mask register—bank 0 (CSMR0) [p. 10-7]
0x088
Reserved1
Chip-select control register—bank 0
(CSCR0) [p. 10-8]
0x08C
Chip-select address register—bank 1 (CSAR1) [p. 10-6]
Reserved1
0x090
Chip-select mask register—bank 1 (CSMR1) [p. 10-7]
0x094
Reserved1
Chip-select control register—bank 1
(CSCR1) [p. 10-8]
0x098
Chip-select address register—bank 2 (CSAR2) [p. 10-6]
Reserved1
0x09C
Chip-select mask register—bank 2 (CSMR2) [p. 10-7]
0x0A0
Reserved1
Chip-select control register—bank 2
(CSCR2) [p. 10-8]
0x0A4
Chip-select address register—bank 3 (CSAR3) [p. 10-6]
Reserved1
0x0A8
Chip-select mask register—bank 3 (CSMR3) [p. 10-7]
0x0AC
Reserved1
Chip-select control register—bank 3
(CSCR3) [p. 10-8]
0x0B0
Chip-select address register—bank 4 (CSAR4) [p. 10-6]
Reserved1
0x0B4
Chip-select mask register—bank 4 (CSMR4) [p. 10-7]
Chapter 10. Chip-Select Module
10-5
Chip-Select Registers
Table 10-7. Chip-Select Registers (Continued)
MBAR
Offset
[31:24]
[15:8]
[7:0]
0x0B8
Reserved1
Chip-select control register—bank 4
(CSCR4) [p. 10-8]
0x0BC
Chip-select address register—bank 5 (CSAR5) [p. 10-6]
Reserved1
0x0C0
Chip-select mask register—bank 5 (CSMR5) [p. 10-7]
0x0C4
Reserved
Chip-select control register—bank 5
(CSCR5) [p. 10-8]
0x0C8
Chip-select address register—bank 6 (CSAR6) [p. 10-6]
Reserved1
0x0CC
Chip-select mask register—bank 6 (CSMR6) [p. 10-7]
0x0D0
Reserved1
Chip-select control register—bank 6
(CSCR6) [p. 10-8]
0x0D4
Chip-select address register—bank 7 (CSAR7) [p. 10-6]
Reserved1
0x0D8
Chip-select mask register—bank 7 (CSMR7) [p. 10-7]
Reserved1
0x0DC
1
[23:16]
Chip-select control register—bank 7
(CSCR7) [p. 10-8]
Addresses not assigned to a register and undefined register bits are reserved for expansion. Write accesses to
these reserved address spaces and reserved register bits have no effect.
NOTE:
External masters cannot access MCF5407 on-chip memories or
MBAR, but can access any of the chip-select module registers.
10.4.1 Chip-Select Module Registers
The chip-select module is programmed through the chip select address registers
(CSAR0–CSAR7), chip select mask registers (CSMR0–CSMR7), and the chip select
control registers (CSCR0–CSCR7).
10.4.1.1 Chip-Select Address Registers (CSAR0–CSAR7)
Chip select address registers, Figure 10-2, specify the chip select base addresses.
15
0
Field
BA
Reset
Uninitialized
R/W
R/W
Addr
0x080 (CSAR0); 0x08C (CSAR1); 0x098 (CSAR2); 0x0A4 (CSAR3);
0x0B0 (CSAR4); 0x0BC (CSAR5); 0x0C8 (CSAR6); 0x0D4 (CSAR7)
Figure 10-2. Chip Select Address Registers (CSAR0–CSAR7)
Table 10-8 describes CSAR[BA].
10-6
MCF5407 User’s Manual
Chip-Select Registers
Table 10-8. CSARn Field Description
Bits
Name
Description
15–0
BA
Base address. Defines the base address for memory dedicated to chip select CS[7:0]. BA is compared
to bits 31–16 on the internal address bus to determine if chip-select memory is being accessed.
10.4.1.2 Chip-Select Mask Registers (CSMR0–CSMR7)
The chip select mask registers, Figure 10-3, are used to specify the address mask and
allowable access types for the respective chip selects.
.
31
16 15
Field
9
BAM
—
Reset
8
7
6
5
4
3
2
1
0
WP — AM C/I SC SD UC UD V
Unitialized
R/W
R/W
Addr
0x084 (CSMR0); 0x090 (CSMR1); 0x09C (CSMR2); 0x0A8 (CSMR3);
0x0B4 (CSMR4); 0x0C0 (CSMR5); 0x0CC (CSMR6); 0x0D8 (CSMR7)
0
Figure 10-3. Chip Select Mask Registers (CSMRn)
Table 10-9 describes CSMR fields.
Table 10-9. CSMRn Field Descriptions
Bits
Name
Description
31–16
BAM
Base address mask. Defines the chip select block by masking address bits. Setting a BAM bit
causes the corresponding CSAR bit to be ignored in the decode.
0 Corresponding address bit is used in chip-select decode.
1 Corresponding address bit is a don’t care in chip-select decode.
The block size for CS[7:0] is 2n; n = (number of bits set in respective CSMR[BAM]) + 16.
So, if CSAR0 = 0x0000 and CSMR0[BAM] = 0x0008, CS0 would address two discontinuous
64-Kbyte memory blocks: one from 0x0000–0xFFFF and one from 0x8_0000–0x8_FFFF.
Likewise, for CS0 to access 32 Mbytes of address space starting at location 0x0, CS1 must begin
at the next byte after CS0 for a 16-Mbyte address space. Then CSAR0 = 0x0000,
CSMR0[BAM] = 0x01FF, CSAR1 = 0x0200, and CSMR1[BAM] = 0x00FF.
8
WP
Write protect. Controls write accesses to the address range in the corresponding CSAR.
Attempting to write to the range of addresses for which CSARn[WP] = 1 results in the appropriate
chip select not being selected. No exception occurs.
0 Both read and write accesses are allowed.
1 Only read accesses are allowed.
7
—
Reserved, should be cleared.
6
AM
Alternate master. When AM = 0 during an external master or DMA access, SC, SD, UC, and UD
are don’t cares in the chip-select decode.
Chapter 10. Chip-Select Module
10-7
Chip-Select Registers
Table 10-9. CSMRn Field Descriptions (Continued)
Bits
Name
5–1
C/I,
SC,
SD,
UC,
UD
Description
Address space mask bits. These bits determine whether the specified accesses can occur to the
address space defined by the BAM for this chip select.
C/I
SC
SD
UC
UD
CPU space and interrupt acknowledge cycle mask
Supervisor code address space mask
Supervisor data address space mask
User code address space mask
User data address space mask
0 The address space assigned to this chip select. is available to the specified access type.
1 The address space assigned to this chip select. is not available (masked) to the specified access
type. If this address space is accessed, chip select is not activated and a regular external bus
cycle occurs.
Note that if if AM = 0, SC, SD, UC, and UD are ignored in the chip select decode on external
master or DMA access.
0
V
Valid bit. Indicates whether the corresponding CSAR, CSMR, and CSCR contents are valid.
Programmed chip selects do not assert until V is set (except for CS0, which acts as the global chip
select). Reset clears each CSMRn[V].
0 Chip select invalid
1 Chip select valid
10.4.1.3 Chip-Select Control Registers (CSCR0–CSCR7)
Each chip-select control register, Figure 10-4, controls the auto acknowledge, external
master support, port size, burst capability, and activation of each chip select. Note that to
support the global chip select, CS0, the CSCR0 reset values differ from the other CSCRs.
CS0 allows address decoding for boot ROM before system initialization.
15
14
13
10
9
8
7
6
5
4
3
2
Field
—
WS
—
AA PS1 PS0 BEM BSTR BSTW
Reset: CSCR0
—
11_11
—
D7
Reset: Other CSCRs
D5
D3
—
Unitialized
R/W
Address
D6
0
—
R/W
0x08A (CSCR0); 0x096 (CSCR1); 0x0A2 (CSCR2); 0x0AE (CSCR3);
0x0BA (CSCR4); 0x0C6 (CSCR5); 0x0D2 (CSCR6); 0x0DE (CSCR7)
Figure 10-4. Chip-Select Control Registers (CSCR0–CSCR7)
Table 10-10 describes CSCRn fields.
Table 10-10. CSCRn Field Descriptions
Bits
Name
15–14
—
13–10
WS
9
—
10-8
Description
Reserved, should be cleared.
Wait states. The number of wait states inserted before an internal transfer acknowledge is generated
(WS = 0 inserts zero wait states, WS = 0xF inserts 15 wait states). If AA = 0, TA must be asserted by
the external system regardless of the number of wait states generated. In that case, the external
transfer acknowledge ends the cycle. An external TA supersedes the generation of an internal TA.
Reserved, should be cleared.
MCF5407 User’s Manual
Chip-Select Registers
Table 10-10. CSCRn Field Descriptions
Bits
Name
Description
8
AA
Auto-acknowledge enable. Determines the assertion of the internal transfer acknowledge for
accesses specified by the chip-select address.
0 No internal TA is asserted. Cycle is terminated externally.
1 Internal TA is asserted as specified by WS. Note that if AA = 1 for a corresponding CSn and the
external system asserts an external TA before the wait-state countdown asserts the internal TA, the
cycle is terminated. Burst cycles increment the address bus between each internal termination.
7–6
PS
Port size. Specifies the width of the data associated with each chip select. It determines where data
is driven during write cycles and where data is sampled during read cycles. See Section 10.3.1.1,
“8-, 16-, and 32-Bit Port Sizing.”
00 32-bit port size. Valid data sampled and driven on D[31:0]
01 8-bit port size. Valid data sampled and driven on D[31:24]
1x 16-bit port size. Valid data sampled and driven on D[31:16]
5
BEM
Byte enable mode. Specifies the byte enable operation. Certain SRAMs have byte enables that must
be asserted during reads as well as writes. BEM can be set in the relevant CSCR to provide the
appropriate mode of byte enable in support of these SRAMs.
0 Neither BE nor BWE is asserted for read. BWE is generated for data write only.
1 BE is asserted for read; BWE is asserted for write.
4
BSTR
Burst read enable. Specifies whether burst reads are used for memory associated with each CSn.
0 Data exceeding the specified port size is broken into individual, port-sized non-burst reads. For
example, a longword read from an 8-bit port is broken into four 8-bit reads.
1 Enables data burst reads larger than the specified port size, including longword reads from 8- and
16-bit ports, word reads from 8-bit ports, and line reads from 8-, 16-, and 32-bit ports.
3
BSTW Burst write enable. Specifies whether burst writes are used for memory associated with each CSn.
0 Break data larger than the specified port size into individual port-sized, non-burst writes. For
example, a longword write to an 8-bit port takes four byte writes.
1 Enables burst write of data larger than the specified port size, including longword writes to 8 and
16-bit ports, word writes to 8-bit ports and line writes to 8-, 16-, and 32-bit ports.
2–0
—
Reserved, should be cleared.
10.4.1.4 Code Example
The code below provides an example of how to initialize the chip-selects. Only chip selects
0, 1, 2, and 3 are programmed here; chip selects 4, 5, 6, and 7 are left invalid. MBARx
defines the base of the module address space.
CSAR0 EQU MBARx+0x080
CSMR0 EQU MBARx+0x084
CSCR0 EQU MBARx+0x08A
;Chip select 0 address register
;Chip select 0 mask register
;Chip select 0 control register
CSAR1 EQU MBARx+0x08C
CSMR1 EQU MBARx+0x090
CSCR1 EQU MBARx+0x096
;Chip select 1 address register
;Chip select 1 mask register
;Chip select 1 control register
CSAR2 EQU MBARx+0x098
CSMR2 EQU MBARx+0x09C
CSCR2 EQU MBARx+0x0A2
;Chip select 2 address register
;Chip select 2 mask register
;Chip select 2 control register
CSAR3 EQU MBARx+0x0A4
CSMR3 EQU MBARx+0x0A8
CSCR3 EQU MBARx+0x0AE
;Chip select 3 address register
;Chip select 3 mask register
;Chip select 3 control register
CSAR4 EQU MBARx+0x0B0
CSAR4 EQU MBARx+0x0B4
CSMR4 EQU MBARx+0x0BA
;Chip select 4 address register
;Chip select 4 mask register
;Chip select 4 control register
Chapter 10. Chip-Select Module
10-9
Chip-Select Registers
CSAR5 EQU MBARx+0x0BC
CSMR5 EQU MBARx+0x0C0
CSCR5 EQU MBARx+0x0C6
;Chip select 5 address register
;Chip select 5 mask register
;Chip select 5 control register
CSAR6 EQU MBARx+0x0C8
CSMR6 EQU MBARx+0x0CC
CSCR6 EQU MBARx+0x0D2
;Chip select 6 address register
;Chip select 6 mask register
;Chip select 6 control register
CSAR7 EQU MBARx+0x0D4
CSMR7 EQU MBARx+0x0D8
CSCR7 EQU MBARx+0x0DE
;Chip select 7 address register
;Chip select 7 mask register
;Chip select 7 control register
; All other chip selects should be programmed and made valid before global
; chip select is de-activated by validating CS0
; Program Chip Select 3 Registers
move.w #0x0040,D0
;CSAR3 base address 0x00400000
move.w D0,CSAR3
move.w
move.w
#0x00A0,D0
D0,CSCR3
move.l #0x001F016B,D0
move.l D0,CSMR3
;CSCR3 = no wait states, AA=0, PS=16-bit, BEM=1,
;BSTR=0, BSTW=0
;Address range from 0x00400000 to 0x005FFFFF
;WP,EM,C/I,SD,UD,V=1; SC,UC=0
; Program Chip Select 2 Registers
move.w
move.w
#0x0020,D0
D0,CSAR2
;CSAR2 base address 0x00200000 (to 0x003FFFFF)
move.w
move.w
#0x0538,D0
D0,CSCR2
;CSCR2 = 1 wait state, AA=1, PS=32-bit, BEM=1,
;BSTR=1, BSTW=1
move.l
move.l
#0x001F0001,D0
D0,CSMR2
;Address range from 0x00200000 to 0x003FFFFF
;WP,EM,C/I,SC,SD,UC,UD=0; V=1
; Program Chip Select 1 Registers
move.w
move.w
#0x0000,D0
D0,CSAR1
;CSAR1 base addresses 0x00000000 (to 0x001FFFFF)
;and 0x80000000 (to 0x801FFFFF)
move.w
move.w
#0x09B0,D0
D0,CSCR1
;CSCR1 = 2 wait states, AA=1, PS=16-bit, BEM=1,
;BSTR=1, BSTW=0
move.l
move.l
#0x801F0001,D0
D0,CSMR1
;Address range from 0x00000000 to 0x001FFFFF and
;0x80000000 to 0x801FFFFF
;WP, EM, C/I, SC, SD, UC, UD=0, V=1
; Program Chip Select 0 Registers
move.w
move.w
#0x0080,D0
D0,CSAR0
;CSAR0 base address 0x00800000 (to 0x009FFFFF)
move.w
move.w
#0x0D80,D0
D0,CSCR0
;CSCR0 = three wait states, AA=1, PS=16-bit, BEM=0,
;BSTR=0, BSTW=0
; Program Chip Select 0 Mask Register (validate chip selects)
move.l
move.l
10-10
#0x001F0001,D0
D0,CSMR0
;Address range from 0x00800000 to 0x009FFFFF
;WP,EM,C/I,SC,SD,UC,UD=0; V=1
MCF5407 User’s Manual
Chapter 11
Synchronous/Asynchronous DRAM
Controller Module
This chapter describes configuration and operation of the synchronous/asynchronous
DRAM controller component of the system integration module (SIM). It begins with a
general description and brief glossary, and includes a description of signals involved in
DRAM operations. The remainder of the chapter consists of the two following parts:
•
•
Section 11.3, “Asynchronous Operation,” describes the programming model and
signal timing for the four basic asynchronous modes.
— Non-page mode
— Burst page mode
— Continuous page mode
— Extended data-out mode
Section 11.4, “Synchronous Operation,” describes the programming model and
signal timing, as well as the command set required for synchronous operations. This
section also includes extensive examples the designer can follow to better
understand how to configure the DRAM controller for synchronous operations.
11.1 Overview
The DRAM controller module provides glueless integration of DRAM with the ColdFire
product. The key features of the DRAM controller include the following:
•
•
•
•
•
•
Support for two independent blocks of DRAM
Interface to standard synchronous/asynchronous dynamic random access memory
(ADRAM/SDRAM) components
Programmable SRAS, SCAS, and refresh timing
Support for page mode
Support for 8-, 16-, and 32-bit wide DRAM blocks
Support for synchronous and asynchronous DRAMs, including EDO DRAM,
SDRAM, and fast page mode
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-1
Overview
11.1.1 Definitions
The following terminology is used in this chapter:
•
•
•
A/SDRAM block—Any group of DRAM memories selected by one of the
MCF5407 RAS[1:0] signals. Thus, the MCF5407 can support two independent
memory blocks. The base address of each block is programmed in the DRAM
address and control registers (DACR0 and DACR1).
SDRAM—RAMs that operate like asynchronous DRAMs but with a synchronous
clock, a pipelined, multiple-bank architecture, and faster speed.
SDRAM bank—An internal partition in an SDRAM device. For example, a 64-Mbit
SDRAM component might be configured as four 512K x 32 banks. Banks are
selected through the SDRAM component’s bank select lines.
11.1.2 Block Diagram and Major Components
The basic components of the DRAM controller are shown in Figure 11-1.
DRAM Controller Module
A[31:0]
Address
Multiplexing
Internal
Bus
Page Hit
Logic
Control Logic
and
State Machine
Memory Block 0 Hit Logic
DRAM Address/Control Register 0
(DACR0)
DRAM Control
Register (DCR)
Memory Block 1 Hit Logic
DRAM Address/Control Register 1
(DACR1)
A[31:0]
RAS[1:0]
CAS[3:0]
DRAMW
SCAS
These signals
are used for
SRAS
SDRAM only
SCKE
Refresh Counter
Figure 11-1. Asynchronous/Synchronous DRAM Controller Block Diagram
The DRAM controller’s major components, shown in Figure 11-1, are described as
follows:
•
11-2
DRAM address and control registers (DACR0 and DACR1)—The DRAM
controller consists of two configuration register units, one for each supported
memory block. DACR0 is accessed at MBAR + 0x0108; DACR1 is accessed at
0x010. The register information is passed on to the hit logic.
MCF5407 User’s Manual
DRAM Controller Operation
•
•
•
•
Control logic and state machine—Generates all DRAM signals, taking bus cycle
characteristic data from the block logic, along with hit information to generate
DRAM accesses. Handles refresh requests from the refresh counter.
— DRAM control register (DCR)—Contains data to control refresh operation of
the DRAM controller. Both memory blocks are refreshed concurrently as
controlled by DCR[RC].
— Refresh counter—Determines when refresh should occur, determined by the
value of DCR[RC]. It generates a refresh request to the control block.
Hit logic—Compares address and attribute signals of a current DRAM bus cycle to
both DACRs to determine if a DRAM block is being accessed. Hits are passed to the
control logic along with characteristics of the bus cycle to be generated.
Page hit logic—Determines if the next DRAM access is in the same DRAM page as
the previous one. This information is passed on to the control logic.
Address multiplexing—Multiplexes addresses to allow column and row addresses
to share pins. This allows glueless interface to DRAMs.
11.2 DRAM Controller Operation
The DRAM controller mode is programmed through DCR[SO]. Asynchronous mode
(SO = 0) includes support for page mode and EDO DRAMs. Synchronous mode is
designed to work with industry-standard SDRAMs. These modes act very differently from
one another, especially regarding the use of DRAM registers and pins. Memory blocks
cannot operate in different modes; both are either synchronous or asynchronous.
11.2.1 DRAM Controller Registers
The DRAM controller registers memory map, Table 11-1, is the same regardless of whether
asynchronous or synchronous DRAM is used, although bit configurations may vary.
Table 11-1. DRAM Controller Registers
MBAR
Offset
0x100
[31:24]
[23:16]
[15:8]
DRAM control register (DCR) [p. 11-4]
[7:0]
Reserved
0x104
Reserved
0x108
DRAM address and control register 0 (DACR0) [p. 11-5]
0x10C
DRAM mask register block 0 (DMR0) [p. 11-7]
0x110
DRAM address and control register 1 (DACR1) [p. 11-5]
0x114
DRAM mask register block 1 (DMR1) [p. 11-7]
NOTE:
External masters cannot access MCF5407 on-chip memories or
MBAR, but they can access DRAM controller registers.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-3
Asynchronous Operation
11.3 Asynchronous Operation
The DRAM controller supports asynchronous DRAMs for cost-effective systems. Typical
access times for the DRAM controller interfacing to ADRAM are 4-3-3-3. The DRAM
controller supports the following four asynchronous modes:
•
•
•
•
Non-page mode
Burst page mode
Continuous page mode
Extended data-out mode
In asynchronous mode, RAS and CAS always transition at the falling clock edge. As
summarized previously, operation and timing of each ADRAM block is controlled by
separate registers, but refresh is the same for both. All ADRAM accesses should be
terminated by the DRAM controller. There is no priority encoding between memory
blocks, so programming blocks to overlap with other blocks or with other internal resources
causes undefined behavior.
11.3.1 DRAM Controller Signals in Asynchronous Mode
Table 11-2 summarizes DRAM signals used in asynchronous mode.
Table 11-2. SDRAM Signal Summary
Signal
Description
RAS[1:0]
Row address strobes. Interface to RAS inputs on industry-standard ADRAMs. When SDRAMs are used,
these signals interface to the chip-select lines within an SDRAM’s memory block. Thus, there is one RAS
line for each of the two blocks.
CAS[3:0]
Column address strobes. Interface to CAS inputs on industry-standard DRAMs. These provide CAS for
a given ADRAM block. When SDRAMs are used, CAS[3:0] control the byte enables (DQMx) for standard
SDRAMs. CAS[3:0] strobes data in least-to-most significant byte order (CAS0 is MSB).
DRAMW
DRAM read/write. Asserted when a DRAM write cycle is underway. Negated for read bus cycles.
11.3.2 Asynchronous Register Set
The following register configurations apply when DCR[SO] is 0, indicating the DRAM
controller is interfacing to asynchronous DRAMs.
11.3.2.1 DRAM Control Register (DCR) in Asynchronous Mode
The DCR provides programmable options for the refresh logic as well as the control bit to
determine if the module is operating with synchronous or asynchronous DRAMs. The DCR
is shown in Figure 11-2.
11-4
MCF5407 User’s Manual
Asynchronous Operation
15
Field SO
Reset
14
13
—
NAM
12
11
10
RRA
0
9
8
0
RRP
RC
Uninitialized
R/W
R/W
Address
MBAR + 0x100
Figure 11-2. DRAM Control Register (DCR) (Asynchronous Mode)
Table 11-3 describes DCR fields.
Table 11-3. DCR Field Descriptions (Asynchronous Mode)
Bits
Name
Description
15
SO
Synchronous operation. Selects synchronous or asynchronous mode. A DRAM controller in
synchronous mode can be switched to ADRAM mode only by resetting the MCF5407.
0 Asynchronous DRAMs. Default at reset.
1 Synchronous DRAMs
14
—
Reserved, should be cleared.
13
NAM
No address multiplexing. Some implementations require external multiplexing. For example, when
linear addressing is required, the DRAM should not multiplex addresses on DRAM accesses.
0 The DRAM controller multiplexes the external address bus to provide column addresses.
1 The DRAM controller does not multiplex the external address bus to provide column addresses.
12–11
RRA
Refresh RAS asserted. Determines how long RAS is asserted during a refresh operation.
00 2 clocks
01 3 clocks
10 4 clocks
11 5 clocks
10–9
RRP
Refresh RAS precharge. Controls how many clocks RAS is precharged after a refresh operation
before accesses are allowed to DRAM.
00 1 clock
01 2 clocks
10 3 clocks
11 4 clocks
8–0
RC
Refresh count. Controls refresh frequency. The number of bus clocks between refresh cycles is
(RC + 1) * 16. Refresh can range from 16–8192 bus clocks to accommodate both standard and
low-power DRAMs with bus clock operation from less than 2 MHz to greater than 50 MHz.
The following example calculates RC for an auto-refresh period for 4096 rows to receive 64 mS of
refresh every 15.625 µs for each row (625 bus clocks at 40 MHz).
# of bus clocks = 625 = (RC field + 1) * 16
RC = (625 bus clocks/16) -1 = 38.06, which rounds to 38; therefore, RC = 0x26.
11.3.2.2 DRAM Address and Control Registers (DACR0/DACR1)
DACR0 and DACR1, Figure 11-3, contain the base address compare value and the control
bits for memory blocks 0 and 1. Address and timing are also controlled by these registers.
Memory areas defined for each block should not overlap; operation is undefined for
accesses in overlapping regions.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-5
Asynchronous Operation
31
18 17 16
Field
BA
Reset
—
Unitialized
15
14 13 12 11 10
RE — CAS
RP
9
RNCN
0
8
7
6
RCD — EDO
5
4
PS
3
2
PM
1
0
—
Unitialized
R/W
R/W
Addr
MBAR + 0x10C (DACR0); 0x110 (DACR1)
Figure 11-3. DRAM Address and Control Registers (DACR0/DACR1)
Table 11-4 describes DACRn fields.
Table 11-4. DACR0/DACR1 Field Description
Bits
Name
Description
31–18
BA
Base address. Used with DMR[BAM] to determine the address range in which the associated
DRAM block is located. Each BA bit is compared with the corresponding address of the bus cycle in
progress. If each bit matches, or if bits that do not match are masked in the BAM, the address
selects the associated DRAM block.
17–16
—
Reserved, should be cleared.
15
RE
Refresh enable. Determines whether the DRAM controller generates a refresh to the associated
DRAM block. DRAM contents are not preserved during hard reset or software watchdog reset.
0 Do not refresh associated DRAM block. (Default at reset)
1 Refresh associated DRAM block.
Reserved, should be cleared.
14
—
13–12
CAS
11–10
RP
9
RAS precharge timing. Determines how long RAS is precharged between accesses. Note that RP
is different from DCR[RRP].
00 1 clock cycle
01 2 clock cycles
10 3 clock cycles
11 4 clock cycles
RNCN RAS-negate-to-CAS-negate. Controls whether RAS and CAS negate concurrently or one clock
apart. RNCN is ignored if CAS is asserted for only one clock and both RAS and CAS are negated.
RNCN is used only for non-page-mode accesses and single accesses in page mode.
0 RAS negates concurrently with CAS.
1 RAS negates one clock before CAS.
8
RCD
7
—
6
EDO
11-6
CAS timing. Determines how long CAS is asserted during a DRAM access.
00 1 clock cycle
01 2 clock cycles
10 3 clock cycles
11 4 clock cycles
RAS-to-CAS delay. Determines the number of system clocks between assertions of RAS and CAS.
0 1 clock cycle
1 2 clock cycles
Reserved, should be cleared.
Extended data out. Determines whether the DRAM block operates in a mode to take advantage of
industry-standard EDO DRAMs. Do not use EDO mode with non-EDO DRAM.
0 EDO operation disabled.
1 EDO operation enabled.
MCF5407 User’s Manual
Asynchronous Operation
Table 11-4. DACR0/DACR1 Field Description (Continued)
Bits
Name
Description
5–4
PS
Port size. Determines the port size of the associated DRAM block. For example, if two 16-bit wide
DRAM components form one DRAM block, the port size is 32 bits. Programming PS allows the
DRAM controller to execute dynamic bus sizing for associated accesses.
00 32-bit port
01 8-bit port
1x 16-bit port
3–2
PM
Page mode. Configures page-mode operation for the memory block.
00 No page mode
01 Burst page mode (page mode for bursts only)
10 Reserved
11 Continuous page mode
1–0
—
Reserved, should be cleared.
11.3.2.3 DRAM Controller Mask Registers (DMR0/DMR1)
The DRAM controller mask registers (DMR0 and DMR1), shown in Figure 11-4, include
mask bits for the base address and for address attributes.
31
18 17
Field
BAM
9
—
Reset
8
7
6
5
4
3
2
1
0
WP — C/I AM SC SD UC UD V
Uninitialized
R/W
R/W
Addr
MBAR + 0x10C (DMR0), 0x114 (DMR1)
0
Figure 11-4. DRAM Controller Mask Registers (DMR0 and DMR1)
Table 11-5 describes DMRn fields.
Table 11-5. DMR0/DMR1 Field Descriptions
Bits
Name
Description
31–18
BAM
Base address mask. Masks the associated DACRn[BA]. Lets the DRAM controller connect to various
DRAM sizes. Mask bits need not be contiguous (see Section 11.5, “SDRAM Example.”)
0 The associated address bit is used in decoding the DRAM hit to a memory block.
1 The associated address bit is not used in the DRAM hit decode.
17–9
—
8
WP
7
—
Reserved, should be cleared.
Write protect. Determines whether the associated block of DRAM is write protected.
0 Allow write accesses
1 Ignore write accesses. The DRAM controller ignores write accesses to the memory block and an
address exception occurs. Write accesses to a write-protected DRAM region are compared in the
chip select module for a hit. If no hit occurs, an external bus cycle is generated. If this external bus
cycle is not acknowledged, an access exception occurs.
Reserved, should be cleared.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-7
Asynchronous Operation
Table 11-5. DMR0/DMR1 Field Descriptions (Continued)
Bits
Name
6–1
AMx
Description
Address modifier masks. Determine which accesses can occur in a given DRAM block.
0 Allow access type to hit in DRAM
1 Do not allow access type to hit in DRAM
Bit
0
V
Associated Access Type
Access Definition
C/I
CPU space/interrupt acknowledge
MOVEC instruction or interrupt acknowledge cycle
AM
Alternate master
External or DMA master
SC
Supervisor code
Any supervisor-only instruction access
SD
Supervisor data
Any data fetched during the instruction access
UC
User code
Any user instruction
UD
User data
Any user data
Valid. Cleared at reset to ensure that the DRAM block is not erroneously decoded.
0 Do not decode DRAM accesses.
1 Registers controlling the DRAM block are initialized; DRAM accesses can be decoded.
11.3.3 General Asynchronous Operation Guidelines
The DRAM controller provides control for RAS, CAS, and DRAMW signals, as well as
address multiplexing and bus cycle termination. Whether the mode is synchronous or
asynchronous determines signal control and termination. To reduce complexity,
multiplexing is the same for both modes. Table 11-6 shows the scheme for DRAM
configurations. This scheme works for symmetric configurations (in which the number of
rows equals the number of columns) as well as asymmetric configurations (in which the
number of rows and columns are different).
Table 11-6. Generic Address Multiplexing Scheme
Address Pin
Row Address
Column Address
17
17
0
8-bit port only
16
16
1
8- and 16-bit ports only
15
15
2
14
14
3
13
13
4
12
12
5
11
11
6
10
10
7
11-8
Notes Relating to Port Sizes
9
9
8
17
17
16
32-bit port only
18
18
17
16-bit port only or 32-bit port with only 8 column address lines
19
19
18
16-bit port only when at least 9 column address lines are used
MCF5407 User’s Manual
Asynchronous Operation
Table 11-6. Generic Address Multiplexing Scheme (Continued)
Address Pin
Row Address
Column Address
20
20
19
21
21
20
22
22
21
23
23
22
24
24
23
25
25
24
Notes Relating to Port Sizes
Note the following:
•
•
•
•
•
Each MCF5407 address bit drives both a row address and a column address bit.
As the user upgrades ADRAM, corresponding MCF5407 address bits must be
connected. This multiplexing scheme allows various memory widths to be
connected to the address bus.
Some differences exist for each of the three possible port sizes. Note that only 8-bit
ports use an A0 address from the MCF5407. Because 16- and 32-bit ports issue
either words or longwords when accessed, they do not use the MCF5407 A0 signal.
Likewise, the configuration for 32-bit ports uses neither A0 or A1. This presents a
slight problem because DRAM address signal A0 is issued on physical pin A17 of
the MCF5407 along with the ADRAM address signal A17. Although A0 is not used
for larger ports, A17 is still needed. The MCF5407 DRAM controller provides for
this by changing the column address that appears on physical pin A17 of the
processor whenever an 8-bit port is not selected. This is determined by the
DACRn[PS] settings. For 8-bit ports, MCF5407 physical pin A17 drives logical
address A0 during the CAS cycle. When 16- or 32-bit port sizes are programmed,
the CAS cycle pin A17 drives logical address A16, as indicated in the generic
connection scheme.
If a 32-bit port is used with only eight column address lines, A18 must drive DRAM
address bit A18. Otherwise, in 32-bit port configurations, the MCF5407 physical
address line is not connected with more than eight column address lines.
All ADRAM blocks have a fixed page size of 512 bytes for page-mode operation.
The addresses are connected differently for various width combinations.
Table 11-7, Table 11-8, and Table 11-9 show how 8-, 16-, and 32-bit symmetrical ADRAM
memories are connected to the address bus. The memory sizes show what DRAM size is
accessed if the corresponding bits are connected to the memory. In each case, there is a base
memory size. This limitation exists to allow simple page-mode multiplexing. Notice also
that MCF5407 pin 17 is treated differently in byte-wide operations. In byte-wide
operations, address bits 16 and 17 are driven on MCF5407 physical address pins 16 and 17,
rather than the two bits being driven solely on A17, as they are for 32-wide memories.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-9
Asynchronous Operation
Table 11-7. DRAM Addressing for Byte-Wide Memories
MCF5407 Address Pin
MCF5407 Address Bit
Driven for RAS
MCF5407 Address Bit Driven
when CAS is Asserted
17
17
0
16
16
1
15
15
2
14
14
3
13
13
4
12
12
5
11
11
6
10
10
7
9
9
8
19
19
18
1 Mbyte
21
21
20
4 Mbytes
23
23
22
16 Mbytes
25
25
24
64 Mbytes
Memory Size
Base memory size of
256 Kbytes
Note that in Table 11-8, MCF5407 pin A19 is not connected because DRAM address bit 18
is already provided on MCF5407 pin A18; thus, the next MCF5407 pin used should be A20.
Table 11-8. DRAM Addressing for 16-Bit Wide Memories
MCF5407 Address Pin
MCF5407 Address Bit
Driven for RAS
MCF5407 Address Bit Driven
when CAS is Asserted
16
16
1
15
15
2
14
14
3
13
13
4
12
12
5
11
11
6
10
10
7
9
9
8
18
18
17
512 Kbytes
20
20
19
2 Mbytes
22
22
21
8 Mbytes
24
24
23
32 Mbytes
11-10
MCF5407 User’s Manual
Memory Size
Base memory size of
128 Kbytes
Asynchronous Operation
Table 11-9. DRAM Addressing for 32-Bit Wide Memories
MCF5407 Address
Pin
MCF5407 Address Bit
Driven for RAS
MCF5407 Address Bit Driven
when CAS is Asserted
15
15
2
14
14
3
13
13
4
12
12
5
11
11
6
10
10
7
9
9
8
17
17
16
19
19
18
1 Mbyte
21
21
20
4 Mbytes
23
23
22
16 Mbytes
25
25
24
64 Mbytes
Memory Size
Base Memory Size of
64 Kbytes
256 Kbytes
11.3.3.1 Non-Page-Mode Operation
In non-page mode, the simplest mode, the DRAM controller provides termination and runs
a separate bus cycle for each data transfer. Figure 11-5 shows a non-page-mode access in
which a DRAM read is followed by a write. Addresses for a new bus cycle are driven at the
rising clock edge.
For a DRAM block hit, the associated RAS is driven at the next falling edge. Here
DACRn[RCD] = 0, so the address is multiplexed at the next rising edge to provide the
column address. The required CAS signals are then driven at the next falling edge and
remain asserted for the period programmed in DACRn[CAS]. Here, DACRn[RNCN] = 1,
so it is precharged one clock before CAS is negated. On a read, data is sampled on the last
rising edge of the clock that CAS is valid.
CLKIN
A[31:0]
Row
Column
RAS[1] or [0]
DACRn[RCD] = 0
DACRn[RNCN] = 1
CAS[3:0]
DACRn[CAS] = 01]
DRAMW
D[31:0]
Figure 11-5. Basic Non-Page-Mode Operation RCD = 0, RNCN = 1 (4-4-4-4)
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-11
Asynchronous Operation
Figure 11-6 shows a variation of the basic cycle. In this case, RCD is 1, so there are two
clocks between RAS and CAS. Note that the address is multiplexed on the rising clock
immediately before CAS is asserted. Because RNCN = 0, RAS and CAS are negated
together. The next bus cycle is initiated, but because DACRn[RP] requires RAS to be
precharged for two clocks, RAS is delayed for a clock in the bus cycle. Note that this does
not delay the address signals, only RAS.
CLKIN
A[31:0]
Row
Column
RP = 01
RAS[1] or [0]
RCD = 1
CAS[3:0]
RNCN = 0
CAS = 01
DRAMW
D[31:0]
Figure 11-6. Basic Non-Page-Mode Operation RCD = 1, RNCN = 0 (5-5-5-5)
11.3.3.2 Burst Page-Mode Operation
Burst page-mode operation (DACRn[PM] = 01) optimizes memory accesses in page mode
by allowing a row address to remain registered in the DRAM while accessing data in
different columns. This eliminates the setup and hold times associated with the need to
precharge and assert RAS. Therefore, only the first bus cycle in the page takes the full
access time; subsequent accesses are streamlined. Single accesses look the same as
non-page-mode accesses.
Burst page-mode accesses of any size—byte, word, longword, or line—are assumed to
reside in the same page. In this mode, the DRAM controller generates a burst transfer only
when the operand is larger than the DRAM block port size (such as, a line transfer to a
32-bit port or a longword transfer to an 8-bit port). The primary cycle asserts RAS and
CAS; subsequent cycles assert only CAS. At the end of the access, RAS is precharged. The
DRAM controller increments addresses between cycles.
Figure 11-7 shows a read access in burst page mode. Four accesses take place, which could
be a 32-bit access to an 8-bit port or a line access to a 32-bit port. Other burst page-mode
operations may be from 2 to 16 accesses long, depending on the access and port sizes. In
those cases, timing is similar with more or fewer accesses.
11-12
MCF5407 User’s Manual
Asynchronous Operation
CLKIN
A[31:0]
Row
Column
Column
Column
Column
RAS[1] or [0]
RCD = 0
CAS[3:0]
CAS = 01
DRAMW
D[31:0]
Figure 11-7. Burst Page-Mode Read Operation (4-3-3-3)
Figure 11-8 shows the write operation with the same configuration.
CLKIN
A[31:0]
Row
Column
Column
Column
Column
RAS[1] or [0]
RCD = 0
CAS[3:0]
CAS = 01
DRAMW
D[31:0]
Figure 11-8. Burst Page-Mode Write Operation (4-3-3-3)
11.3.3.3 Continuous Page Mode
Continuous page mode (DACRn[PM] = 11) is a type of page mode that balances
performance, complexity, and size. In typical page-mode implementations, sequential
addresses are checked for multiple hits in a DRAM block. On a hit, RAS remains asserted
and CAS is asserted with the new column address. On a miss, RAS must be precharged
again before the bus cycle begins.
Continuous page mode supports page-mode operation without requiring an address holding
register per memory block and eliminates the delay for a miss-to-precharge RAS for the
upcoming bus cycle. Because the internal MCF5407 address bus is pipelined, addresses for
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-13
Asynchronous Operation
the next bus cycle are often available before the current cycle completes. The two addresses
are compared at the end of the cycle to determine if the next address hits the same page. If
so, RAS remains asserted. If not, or if no access is pending, RAS is precharged before the
next bus cycle is active on the external bus. As a result, a page miss suffers no penalty.
Single accesses not followed by a hit in the page look like non-page-mode accesses.
Figure 11-9 shows a write cycle followed by a read cycle in continuous page mode. The
read hits in the same page as the write so RAS is not negated before the second cycle. Note
that the row address does not appear on the pins for a bus cycle that hits in the page. Column
addresses are immediately multiplexed onto the pins. The third bus cycle is a page miss, so
RAS is precharged before the end of the bus cycle and no extra precharge delay is incurred.
CLKIN
A[31:0]
Row
Column
Column
Page Hit
RAS[1] or [0]
Row
Column
Page Miss
RNCN=1
RCD=0
CAS[3:0]
CAS=01
DRAMW
D[31:0]
Bus Cycle 1
Bus Cycle 2
Bus Cycle 3
Figure 11-9. Continuous Page-Mode Operation
If a write cycle hits in the page, CAS must be delayed by one clock to allow data to become
valid, as shown in Figure 11-10.
11-14
MCF5407 User’s Manual
Asynchronous Operation
CLKIN
A[31:0]
Row
Column
Column
Page Hit
RAS[1] or [0]
Page Miss
RCD = 0
CAS[3:0]
CAS = 01
DRAMW
D[31:0]
Bus Cycle 1
Bus Cycle 2
Figure 11-10. Write Hit in Continuous Page Mode
11.3.3.4 Extended Data Out (EDO) Operation
EDO is a variation of page mode that allows the DRAM to continue driving data out of the
device while CAS is precharging. To support EDO DRAMs, the DRAM controller delays
internal termination of the cycle by one clock so data can continue to be captured as CAS
is being precharged. For data to be driven by the DRAMs, RAS is held after CAS is
negated. EDO operation does not affect write operations. EDO DRAMs can be used in
continuous page or burst page modes. Single accesses not followed by a hit in the page look
like non-page-mode accesses.
Figure 11-11 shows four consecutive EDO accesses. Note that data is sampled after CAS
is negated and that on the last page access, CAS is held until after data is sampled to assure
that the data is driven. This allows RAS to be precharged before the end of the cycle.
CLKIN
A[31:0]
RAS[1] or [0]
RCD = 0
CAS[3:0]
CAS = 00
DRAMW
D[31:0]
Figure 11-11. EDO Read Operation (3-2-2-2)
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-15
Synchronous Operation
11.3.3.5 Refresh Operation
The DRAM controller supports CAS-before-RAS refresh operations that are not
synchronized to bus activity. A special DRAMW pin is provided so refresh can occur
regardless of the state of the processor bus.
When the refresh counter rolls over, it sets an internal flag to indicate that a refresh is
pending. If that happens during a continuous page-mode access, the page is closed (RAS
precharged) when the data transfer completes to allow the refresh to occur. The flag is
cleared when the refresh cycle is run. Both memory blocks are simultaneously refreshed as
determined by the DCR. DRAM accesses are delayed during refresh. Only an active bus
access to a DRAM block can delay refresh.
Figure 11-12 shows a bus cycle delayed by a refresh operation. Notice that DRAMW is
forced high during refresh. The row address is held until the pending DRAM access.
CLKIN
A[31:0]
RAS[1] or [0]
RRA = 01
RRP = 01
CAS[3:0]
DRAMW
Refresh
Access
Figure 11-12. DRAM Access Delayed by Refresh
11.4 Synchronous Operation
By running synchronously with the system clock instead of responding to asynchronous
control signals, SDRAM can (after an initial latency period) be accessed on every clock;
5-1-1-1 is a typical MCF5407 burst rate to SDRAM.
Note that because the MCF5407 cannot have more than one page open at a time, it does not
support interleaving.
SDRAM controllers are more sophisticated than asynchronous DRAM controllers. Not
only must they manage addresses and data, but they must send special commands for such
functions as precharge, read, write, burst, auto-refresh, and various combinations of these
functions. Table 11-10 lists common SDRAM commands.
11-16
MCF5407 User’s Manual
Synchronous Operation
Table 11-10. SDRAM Commands
Command
Definition
ACTV
Activate. Executed before READ or WRITE executes; SDRAM registers and decodes row address.
MRS
Mode register set.
NOP
No-op. Does not affect SDRAM state machine; DRAM controller control signals negated; RAS asserted.
PALL
Precharge all. Precharges all internal banks of an SDRAM component; executed before new page is
opened.
READ
Read access. SDRAM registers column address and decodes that a read access is occurring.
REF
Refresh. Refreshes internal bank rows of an SDRAM component.
SELF
Self refresh. Refreshes internal bank rows of an SDRAM component when it is in low-power mode.
SELFX
Exit self refresh. This command is sent to the DRAM controller when DCR[IS] is cleared.
WRITE
Write access. SDRAM registers column address and decodes that a write access is occurring.
SDRAMs operate differently than asynchronous DRAMs, particularly in the use of data
pipelines and commands to initiate special actions. Commands are issued to memory using
specific encodings on address and control pins. Soon after system reset, a command must
be sent to the SDRAM mode register to configure SDRAM operating parameters. Note that,
after synchronous operation is selected by setting DCR[SO], DRAM controller registers
reflect the synchronous operation and there is no way to return to asynchronous operation
without resetting the processor.
11.4.1 DRAM Controller Signals in Synchronous Mode
Table 11-11 shows the behavior of DRAM signals in synchronous mode.
Table 11-11. Synchronous DRAM Signal Connections
Signal
Description
SRAS
Synchronous row address strobe. Indicates a valid SDRAM row address is present and can be latched
by the SDRAM. SRAS should be connected to the corresponding SDRAM SRAS. Do not confuse SRAS
with the DRAM controller’s RAS[1:0], which should not be interfaced to the SDRAM SRAS signals.
SCAS
Synchronous column address strobe. Indicates a valid column address is present and can be latched by
the SDRAM. SCAS should be connected to the corresponding signal labeled SCAS on the SDRAM. Do
not confuse SCAS with the DRAM controller’s CAS[3:0] signals.
DRAMW
DRAM read/write. Asserted for write operations and negated for read operations.
RAS[1:0]
Row address strobe. Select each memory block of SDRAMs connected to the MCF5407. One RAS
signal selects one SDRAM block and connects to the corresponding CS signals.
SCKE
Synchronous DRAM clock enable. Connected directly to the CKE (clock enable) signal of SDRAMs.
Enables and disables the clock internal to SDRAM. When CKE is low, memory can enter a power-down
mode where operations are suspended or they can enter self-refresh mode. SCKE functionality is
controlled by DCR[COC]. For designs using external multiplexing, setting COC allows SCKE to provide
command-bit functionality.
CAS[3:0]
Column address strobe. For synchronous operation, CAS[3:0] function as byte enables to the SDRAMs.
They connect to the DQM signals (or mask qualifiers) of the SDRAMs.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-17
Synchronous Operation
Table 11-11. Synchronous DRAM Signal Connections (Continued)
Signal
CLKIN
Description
Bus clock output. Connects to the CLK input of SDRAMs.
EDGESEL Synchronous edge select. Provides additional output hold time for signals that interface to external
SDRAMs. EDGESEL supports the three following modes for SDRAM interface signals:
• Tied high. Signals change on the rising edge of CLKIN.
• Tied low. Signals change on the falling edge of CLKIN.
• Tied to buffered CLKIN. Signals change on the rising edge of the buffered clock.
EDGESEL can provide additional output hold time for SDRAM interface signals, however the SDRAM
clock and CLKIN frequencies must be the same. See Section 11.4.2, “Using Edge Select (EDGESEL).”
Figure 11-13 shows a typical signal configuration for synchronous mode.
MCF5407
A[31:0]
D[31:0]
CAS
DRAMW
SCAS
SRAS
SCKE
SDRAM
ADDRESS
DATA
DQM
WE
CAS
RAS
CKE
1
EDGESEL
CLK
CLKIN
1 Trace
CLKIN
length from buffer to CLK must equal length from buffer to EDGESEL.
Figure 11-13. MCF5407 SDRAM Interface
11.4.2 Using Edge Select (EDGESEL)
EDGESEL can ease system-level timings (note that the optional buffer in Figure 11-13 is
for memories that need extra delay). The clock at the input to the SDRAM is monitored and
data is held until the next edge of the bus clock, adding required output hold time to the
address, data, and control signals.
To generate SDRAM interface timing, address, data, and control signals are clocked
through a two-stage shift register. The first stage is clocked on the rising edge of CLKIN;
the second is clocked on the falling edge. This makes the signal available for up to an
additional half bus clock cycle, of which only a small amount is needed for proper timing.
Using the connection shown in Figure 11-13 ensures that data remains held for a longer
time after the rising edge of the SDRAM clock input. This helps to match the MCF5407
output timing with the SDRAM clock.
Figure 11-14 shows the output wave forms for the interface signals changing on the rising
edge (A) and falling edge (B) of CLKIN as determined by whether EDGESEL is tied high
or low. It also shows timing (C) with EDGESEL tied to buffered CLKIN.
11-18
MCF5407 User’s Manual
Synchronous Operation
CLKIN
CLKIN
Address/
Data
VALID
VALID
VALID
Address/
Data
VALID
A: Address and Data Timing with EDGESEL Tied High
VALID
VALID
VALID
B: Address and Data Timing with EDGESEL Tied Low
Buffer Delay
CLKIN
Buffered
CLKIN
Address/
Data
VALID
VALID
VALID
VALID
C: Address and Data Timing with EDGESEL Tied to Buffered Clock
Figure 11-14. Using EDGESEL to Change Signal Timing
11.4.3 Synchronous Register Set
The memory map in Table 11-1 is the same for both synchronous and asynchronous
operation. However, some bits are different, as noted in the following sections.
11.4.3.1 DRAM Control Register (DCR) in Synchronous Mode
The DRAM control register (DCR), Figure 11-15, controls refresh logic.
15
14
Field
SO
—
Reset
0
13
12
NAM COC
11
10
IS
9
8
7
6
RTIM
5
4
3
2
1
0
RC
Uninitialized
R/W
R/W
Addr
MBAR + 0x100
Figure 11-15. DRAM Control Register (DCR) (Synchronous Mode)
Table 11-12 describes DCR fields.
Table 11-12. DCR Field Descriptions (Synchronous Mode)
Bits
Name
Description
15
SO
Synchronous operation. Selects synchronous or asynchronous mode. When in synchronous mode,
the DRAM controller can be switched to ADRAM mode only by resetting the MCF5407.
0 Asynchronous DRAMs. Default at reset.
1 Synchronous DRAMs
14
—
Reserved, should be cleared.
13
NAM
No address multiplexing. Some implementations require external multiplexing. For example, when
linear addressing is required, the DRAM should not multiplex addresses on DRAM accesses.
0 The DRAM controller multiplexes the external address bus to provide column addresses.
1 The DRAM controller does not multiplex the external address bus to provide column addresses.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-19
Synchronous Operation
Table 11-12. DCR Field Descriptions (Synchronous Mode) (Continued)
Bits
Name
Description
12
COC
Command on SDRAM clock enable (SCKE). Implementations that use external multiplexing
(NAM = 1) must support command information to be multiplexed onto the SDRAM address bus.
0 SCKE functions as a clock enable; self-refresh is initiated by the DRAM controller through DCR[IS].
1 SCKE drives command information. Because SCKE is not a clock enable, self-refresh cannot be
used (setting DCR[IS]). Thus, external logic must be used if this functionality is desired. External
multiplexing is also responsible for putting the command information on the proper address bit.
11
IS
Initiate self-refresh command.
0 Take no action or issue a SELFX command to exit self refresh.
1 If DCR[COC] = 0, the DRAM controller sends a SELF command to both SDRAM blocks to put them
in low-power, self-refresh state where they remain until IS is cleared, at which point the controller
sends a SELFX command for the SDRAMs to exit self-refresh. The refresh counter is suspended
while the SDRAMs are in self-refresh; the SDRAM controls the refresh period.
10–9
RTIM
Refresh timing. Determines the timing operation of auto-refresh in the DRAM controller. Specifically,
it determines the number of clocks inserted between a REF command and the next possible ACTV
command. This same timing is used for both memory blocks controlled by the DRAM controller. This
corresponds to tRC in the SDRAM specifications.
00 3 clocks
01 6 clocks
1x 9 clocks
8–0
RC
Refresh count. Controls refresh frequency. The number of bus clocks between refresh cycles is
(RC + 1) * 16. Refresh can range from 16–8192 bus clocks to accommodate both standard and
low-power DRAMs with bus clock operation from less than 2 MHz to greater than 50 MHz.
The following example calculates RC for an auto-refresh period for 4096 rows to receive 64 mS of
refresh every 15.625 µs for each row (625 bus clocks at 40 MHz). This operation is the same as in
asynchronous mode.
# of bus clocks = 625 = (RC field + 1) * 16
RC = (625 bus clocks/16) -1 = 38.06, which rounds to 38; therefore, RC = 0x26.
11.4.3.2 DRAM Address and Control Registers (DACR0/DACR1) in
Synchronous Mode
The DRAM address and control registers (DACR0 and DACR1), shown in Figure 11-16,
contain the base address compare value and the control bits for both memory blocks 0 and
1 of the DRAM controller. Address and timing are also controlled by bits in DACRn.
31
Field
Reset
18
BA
Uninitialized
17
16
—
15
14
13
RE
—
CASL —
0
12
11
10
9
CBM
Uninitialized
R/W
R/W
Addr
MBAR+0x108 (DACR0); 0x110(DACR1)
8
7
6
— IMRS
0
5
4
PS
MCF5407 User’s Manual
2
1 0
IP PM —
Uninitialized
Figure 11-16. DACR0 and DACR1 Registers (Synchronous Mode)
11-20
3
Synchronous Operation
Table 11-13 describes DACRn fields.
Table 11-13. DACR0/DACR1 Field Descriptions (Synchronous Mode)
Bit
Name
31–18
BA
Base address register. With DCMR[BAM], determines the address range in which the associated
DRAM block is located. Each BA bit is compared with the corresponding address of the current bus
cycle. If all unmasked bits match, the address hits in the associated DRAM block. BA functions the
same as in asynchronous operation.
17–16
—
Reserved, should be cleared.
15
RE
Refresh enable. Determines when the DRAM controller generates a refresh cycle to the DRAM
block.
0 Do not refresh associated DRAM block
1 Refresh associated DRAM block
14
—
Reserved, should be cleared.
13–12
Description
CASL CAS latency. Affects the following SDRAM timing specifications. Timing nomenclature varies with
manufacturers. Refer to the SDRAM specification for the appropriate timing nomenclature:
Number of Bus Clocks
Parameter
CASL= 00 CASL = 01 CASL= 10 CASL= 11
11
10–8
7
—
CBM
—
tRCD—SRAS assertion to SCAS assertion
1
2
3
3
tCASL—SCAS assertion to data out
1
2
3
3
tRAS—ACTV command to precharge command
2
4
6
6
tRP—Precharge command to ACTV command
1
2
3
3
tRWL,tRDL—Last data input to precharge
command
1
1
1
1
tEP—Last data out to precharge command)
1
1
1
1
Reserved, should be cleared.
Command and bank MUX [2:0]. Because different SDRAM configurations cause the command and
bank select lines to correspond to different addresses, these resources are programmable. CBM
determines the addresses onto which these functions are multiplexed.
CBM Command Bit
Bank Select Bits
000
17
18 and up
001
18
19 and up
010
19
20 and up
011
20
21 and up
100
21
22 and up
101
22
23 and up
110
23
24 and up
111
24
25 and up
This encoding and the address multiplexing scheme handle common SDRAM organizations. Bank
select bits include a base bit and all address bits above for SDRAMs with multiple bank select bits.
Reserved, should be cleared.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-21
Synchronous Operation
Table 11-13. DACR0/DACR1 Field Descriptions (Synchronous Mode) (Continued)
Bit
Name
Description
IMRS
Initiate mode register set (MRS) command. Setting IMRS generates a MRS command to the
associated SDRAMs. In initialization, IMRS should be set only after all DRAM controller registers are
initialized and PALL and REFRESH commands have been issued. After IMRS is set, the next access to
an SDRAM block programs the SDRAM’s mode register. Thus, the address of the access should be
programmed to place the correct mode information on the SDRAM address pins. Because the
SDRAM does not register this information, it doesn’t matter if the IMRS access is a read or a write or
what, if any, data is put onto the data bus. The DRAM controller clears IMRS after the MRS command
finishes.
0 Take no action
1 Initiate MRS command
5–4
PS
Port size. Indicates the port size of the associated block of SDRAM, which allows for dynamic sizing
of associated SDRAM accesses. PS functions the same in asynchronous operation.
00 32-bit port
01 8-bit port
1x 16-bit port
3
IP
Initiate precharge all (PALL) command. The DRAM controller clears IP after the PALL command is
finished. Accesses via IP should be no wider than the port size programmed in PS.
0 Take no action.
1 A PALL command is sent to the associated SDRAM block. During initialization, this command is
executed after all DRAM controller registers are programmed. After IP is set, the next write to an
appropriate SDRAM address generates the PALL command to the SDRAM block.
2
PM
Page mode. Indicates how the associated SDRAM block supports page-mode operation.
0 Page mode on bursts only. The DRAM controller dynamically bursts the transfer if it falls within a
single page and the transfer size exceeds the port size of the SDRAM block. After the burst, the
page closes and a precharge is issued.
1 Continuous page mode. The page stays open and only SCAS needs to be asserted for sequential
SDRAM accesses that hit in the same page, regardless of whether the access is a burst.
1–0
—
Reserved, should be cleared.
6
11.4.3.3 DRAM Controller Mask Registers (DMR0/DMR1)
The DMRn, Figure 11-17, include mask bits for the base address and for address attributes.
They are the same as in asynchronous operation.
31
Field
18 17
BAM
9
—
Reset
8
7
6
5
4
3
Uninitialized
R/W
R/W
Addr
MBAR + 0x10C (DMR0), 0x114 (DMR1)
Figure 11-17. DRAM Controller Mask Registers (DMR0 and DMR1)
Table 11-14 describes DMRn fields.
11-22
MCF5407 User’s Manual
2
1
0
WP — C/I AM SC SD UC UD V
0
Synchronous Operation
Table 11-14. DMR0/DMR1 Field Descriptions
Bits
Name
Description
31–18
BAM
Base address mask. Masks the associated DACRn[BA]. Lets the DRAM controller connect to various
DRAM sizes. Mask bits need not be contiguous (see Section 11.5, “SDRAM Example.”)
0 The associated address bit is used in decoding the DRAM hit to a memory block.
1 The associated address bit is not used in the DRAM hit decode.
17–9
—
8
WP
7
—
6–1
AMx
Reserved, should be cleared.
Write protect. Determines whether the associated block of DRAM is write protected.
0 Allow write accesses
1 Ignore write accesses. The DRAM controller ignores write accesses to the memory block and an
address exception occurs. Write accesses to a write-protected DRAM region are compared in the
chip select module for a hit. If no hit occurs, an external bus cycle is generated. If this external bus
cycle is not acknowledged, an access exception occurs.
Reserved, should be cleared.
Address modifier masks. Determine which accesses can occur in a given DRAM block.
0 Allow access type to hit in DRAM
1 Do not allow access type to hit in DRAM
Bit
C/I
0
V
Associated Access Type
CPU space/interrupt acknowledge
Access Definition
MOVEC instruction or interrupt acknowledge cycle
AM
Alternate master
External or DMA master
SC
Supervisor code
Any supervisor-only instruction access
SD
Supervisor data
Any data fetched during the instruction access
UC
User code
Any user instruction
UD
User data
Any user data
Valid. Cleared at reset to ensure that the DRAM block is not erroneously decoded.
0 Do not decode DRAM accesses.
1 Registers controlling the DRAM block are initialized; DRAM accesses can be decoded.
11.4.4 General Synchronous Operation Guidelines
To reduce system logic and to support a variety of SDRAM sizes, the DRAM controller
provides SDRAM control signals as well as a multiplexed row address and column address
to the SDRAM.
When SDRAM blocks are accessed, the DRAM controller can operate in either burst or
continuous page mode. The following sections describe the DRAM controller interface to
SDRAM, the supported bus transfers, and initialization.
11.4.4.1 Address Multiplexing
Table 11-6 shows the generic address multiplexing scheme for SDRAM configurations. All
possible address connection configurations can be derived from this table.
The following tables provide a more comprehensive, step-by-step way to determine the
correct address line connections for interfacing the MCF5407 to SDRAM. To use the
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-23
Synchronous Operation
tables, find the one that corresponds to the number of column address lines on the SDRAM
and to the port size as seen by the MCF5407, which is not necessarily the SDRAM port
size. For example, if two 1M x 16-bit SDRAMs together form a 2M x 32-bit memory, the
port size is 32 bits. Most SDRAMs likely have fewer address lines than are shown in the
tables, so follow only the connections shown until all SDRAM address lines are connected.
Table 11-15. MCF5407 to SDRAM Interface (8-Bit Port, 9-Column Address Lines)
MCF5407 A17 A16 A15 A14 A13 A12 A11 A10 A9 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
17
16
15
14
13
12
11
10
9
Column
0
1
2
3
4
5
6
7
8
SDRAM
Pins
18
19
20
21
22
23
24
25
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21 A22
Table 11-16. MCF5407 to SDRAM Interface (8-Bit Port,10-Column Address Lines)
MCF5407 A17 A16 A15 A14 A13 A12 A11 A10 A9 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
17
16
15
14
13
12
11
10
9
19
Column
0
1
2
3
4
5
6
7
8
18
SDRAM
Pins
20
21
22
23
24
25
26
27
28
29
30
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21
Table 11-17. MCF5407 to SDRAM Interface (8-Bit Port,11-Column Address
Lines)
MCF5407 A17 A16 A15 A14 A13 A12 A11 A10 A9 A19 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
17
16
15
14
13
12
11
10
9
19
21
Column
0
1
2
3
4
5
6
7
8
18
20
SDRAM
Pins
22
23
24
25
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20
Table 11-18. MCF5407 to SDRAM Interface (8-Bit Port,12-Column Address Lines)
MCF5407 A17 A16 A15 A14 A13 A12 A11 A10 A9 A19 A21 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
17
16
15
14
13
12
11
10
9
19
21
23
Column
0
1
2
3
4
5
6
7
8
18
20
22
SDRAM
Pins
11-24
31
24
25
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19
MCF5407 User’s Manual
Synchronous Operation
Table 11-19. MCF5407 to SDRAM Interface (8-Bit Port,13-Column Address
Lines)
MCF5407 A17 A16 A15 A14 A13 A12 A11 A10 A9 A19 A21 A23 A25 A26 A27 A28 A29 A30 A31
Pins
Row
Column
SDRAM
Pins
17
16
15
14
13
12
11
10
9
19
21
23
25
0
1
2
3
4
5
6
7
8
18
20
22
24
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18
Table 11-20. MCF5407 to SDRAM Interface (16-Bit Port, 8-Column Address Lines)
MCF5407 A16 A15 A14 A13 A12 A11 A10 A9 A17 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
16
15
14
13
12
11
10
9
Column
1
2
3
4
5
6
7
8
SDRAM
Pins
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21 A22
Table 11-21. MCF5407 to SDRAM Interface (16-Bit Port, 9-Column Address Lines)
MCF5407 A16 A15 A14 A13 A12 A11 A10 A9 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
16
15
14
13
12
11
10
9
18
Column
1
2
3
4
5
6
7
8
17
SDRAM
Pins
19
20
21
22
23
24
25
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21
Table 11-22. MCF5407 to SDRAM Interface (16-Bit Port, 10-Column Address Lines)
MCF5407 A16 A15 A14 A13 A12 A11 A10 A9 A18 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
16
15
14
13
12
11
10
9
18
20
21
22
23
24
25
26
27
28
29
30
31
Column
1
2
3
4
5
6
7
8
17
19
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20
Table 11-23. MCF5407 to SDRAM Interface (16-Bit Port, 11-Column Address Lines)
MCF5407 A16 A15 A14 A13 A12 A11 A10 A9 A18 A20 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
16
15
14
13
12
11
10
9
18
20
22
Column
1
2
3
4
5
6
7
8
17
19
21
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19
23
24
25
26
27
28
29
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
30
31
11-25
Synchronous Operation
Table 11-24. MCF5407 to SDRAM Interface (16-Bit Port, 12-Column Address Lines)
MCF5407
A16 A15 A14 A13 A12 A11 A10
Pins
A9
A18 A20 A22 A24 A25 A26 A27 A28 A29 A30 A31
Row
16
15
14
13
12
11
10
9
18
20
22
24
Column
1
2
3
4
5
6
7
8
17
19
21
23
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
25
26
27
28
29
30
31
A10 A11 A12 A13 A14 A15 A16 A17 A18
Table 11-25. MCF5407 to SDRAM Interface (16-Bit Port, 13-Column-Address Lines)
MCF5407 A16 A15 A14 A13 A12 A11 A10
Pins
Row
16
15
14
13
12
11
A9
10
A18 A20 A22 A24 A26 A27 A28 A29 A30 A31
9
18
20
Column
1
2
3
4
5
6
7
8
17
19
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
22
24
26
21
23
25
27
28
29
30
31
A10 A11 A12 A13 A14 A15 A16 A17
Table 11-26. MCF5407 to SDRAM Interface (32-Bit Port, 8-Column Address Lines)
MCF5407 A15 A14 A13 A12 A11 A10 A9 A17 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
15
14
13
12
11
10
9
17
Column
2
3
4
5
6
7
8
16
SDRAM
Pins
18
19
20
21
22
23
24
25
26
27
28
29
30
31
A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21
Table 11-27. MCF5407 to SDRAM Interface (32-Bit Port, 9-Column Address Lines)
MCF5407 A15 A14 A13 A12 A11 A10 A9 A17 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
15
14
13
12
11
10
9
17
19
Column
2
3
4
5
6
7
8
16
18
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
20
21
22
23
24
25
26
27
28
29
30
31
A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20
Table 11-28. MCF5407 to SDRAM Interface (32-Bit Port, 10-Column Address Lines)
MCF5407 A15 A14 A13 A12 A11 A10 A9 A17 A19 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
15
14
13
12
11
10
9
17
19
21
22
23
24
25
26
27
28
29
30
31
Column
2
3
4
5
6
7
8
16
18
20
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19
11-26
MCF5407 User’s Manual
Synchronous Operation
Table 11-29. MCF5407 to SDRAM Interface (32-Bit Port, 11-Column Address Lines)
MCF5407 A15 A14 A13 A12 A11 A10 A9 A17 A19 A21 A23 A24 A25 A26 A27 A28 A29 A30 A31
Pins
Row
15
14
13
12
11
10
9
17
19
21
23
Column
2
3
4
5
6
7
8
16
18
20
22
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9 A10 A11 A12 A13 A14 A15 A16 A17 A18
24
25
26
27
28
29
30
31
Table 11-30. MCF5407 to SDRAM Interface (32-Bit Port, 12-Column Address Lines)
MCF5407 A15 A14 A13 A12 A11 A10
Pins
A9
A17 A19 A21 A23 A25 A26 A27 A28 A29 A30 A31
Row
15
14
13
12
11
10
9
17
19
21
23
25
Column
2
3
4
5
6
7
8
16
18
20
22
24
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
26
27
28
29
30
31
A10 A11 A12 A13 A14 A15 A16 A17
11.4.4.2 Interfacing Example
The tables in the previous section can be used to configure the interface in the following
example. To interface one 2M x 32-bit x 4 bank SDRAM component (8 columns) to the
MCF5407, the connections would be as shown in Table 11-31.
Table 11-31. SDRAM Hardware Connections
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10 = CMD
BA0
BA1
MCF5407
Pins
A15
A14
A13
A12
A11
A10
A9
A17
A18
A19
A20
A21
A22
11.4.4.3 Burst Page Mode
SDRAM can efficiently provide data when an SDRAM page is opened. As soon as SCAS
is issued, the SDRAM accepts a new address and asserts SCAS every clock for as long as
accesses are in that page. In burst page mode, there are multiple read or write operations for
every ACTV command in the SDRAM if the requested transfer size exceeds the port size of
the associated SDRAM. The primary cycle of the transfer generates the ACTV and READ or
WRITE commands; secondary cycles generate only READ or WRITE commands. As soon as
the transfer completes, the PALL command is generated to prepare for the next access.
Note that in synchronous operation, burst mode and address incrementing during burst
cycles are controlled by the MCF5407 DRAM controller. Thus, instead of the SDRAM
enabling its internal burst incrementing capability, the MCF5407 controls this function.
This means that the burst function that is enabled in the mode register of SDRAMs must be
disabled when interfacing to the MCF5407.
Figure 11-18 shows a burst read operation. In this example, DACR[CASL] = 01, for an
SRAS-to-SCAS delay (tRCD) of 2 CLKIN cycles. Because tRCD is equal to the read CAS
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-27
Synchronous Operation
latency (SCAS assertion to data out), this value is also 2 CLKIN cycles. Notice that NOPs
are executed until the last data is read. A PALL command is executed one cycle after the last
data transfer.
CLKIN
A[31:0]
Row
Column
Column Column
Column
SRAS
tRCD = 2
SCAS
tEP
DRAMW
tCASL = 2
D[31:0]
RAS[0] or [1]
CAS[3:0]
ACTV
NOP
READ
NOP
NOP
PALL
Figure 11-18. Burst Read SDRAM Access
Figure 11-19 shows the burst write operation. In this example, DACR[CASL] = 01, which
creates an SRAS-to-SCAS delay (tRCD) of 2 CLKIN cycles. Note that data is available
upon SCAS assertion and a burst write cycle completes two cycles sooner than a burst read
cycle with the same tRCD. The next bus cycle is initiated sooner, but cannot begin an
SDRAM cycle until the precharge-to-ACTV delay completes.
11-28
MCF5407 User’s Manual
Synchronous Operation
CLKIN
A[31:0]
Row
Column
Column
Column
Column
SRAS
tRP
SCAS
tCASL = 2
tRWL
DRAMW
D[31:0]
RAS[0] or [1]
CAS[3:0]
ACTV
NOP
WRITE
NOP
PALL
Figure 11-19. Burst Write SDRAM Access
Accesses in synchronous burst page mode always cause the following sequence:
1.
2.
3.
4.
5.
6.
command
NOP commands to assure SRAS-to-SCAS delay (if CAS latency is 1, there are no
NOP commands).
Required number of READ or WRITE commands to service the transfer size with the
given port size.
Some transfers need more NOP commands to assure the ACTV-to-precharge delay.
PALL command
Required number of idle clocks inserted to assure precharge-to-ACTV delay.
ACTV
11.4.4.4 Continuous Page Mode
Continuous page mode is identical to burst page mode, except that it allows the processor
core to handle successive bus cycles that hit the same page without having to close the page.
When the current bus cycle finishes, the MCF5407 core internal pipelined bus can predict
whether the upcoming cycle will hit in the same page.
•
If the next bus cycle is not pending or misses in the page, the PALL command is
generated to the SDRAM.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-29
Synchronous Operation
•
If the next bus cycle is pending and hits in the page, the page is left open, and the
next SDRAM access begins with a READ or WRITE command. Because of the nature
of the internal CPU pipeline this condition does not occur often, however, the use of
continuous page mode is recommended because it can provide a slight performance
increase.
Figure 11-20 shows two read accesses in continuous page mode. Note that there is no
precharge between the two accesses. Also notice that the second cycle begins with a read
operation with no ACTV command.
CLKIN
Row
A[31:0]
Column
Column
SRAS
SCAS
tEP
tRCD = 2
DRAMW
tCASL = 2
tCASL = 2
D[31:0]
RAS[0] or [1]
CAS[3:0]
ACTV
NOP
READ
NOP
READ
NOP
NOP
PALL
Figure 11-20. Synchronous, Continuous Page-Mode Access—Consecutive Reads
Figure 11-21 shows a write followed by a read in continuous page mode. Because the bus
cycle is terminated with a WRITE command, the second cycle begins sooner after the write
than after the read. A read requires data to be returned before the bus cycle can terminate.
Note that in continuous page mode, secondary accesses output the column address only.
11-30
MCF5407 User’s Manual
Synchronous Operation
CLKIN
Row
A[31:0]
Column
Column
SRAS
SCAS
tEP
tRCD = 3
DRAMW
tCASL = 3
D[31:0]
RAS[0] or [1]
CAS[3:0]
ACTV
NOP
WRITE
NOP
READ
NOP
NOP
NOP
PALL
Figure 11-21. Synchronous, Continuous Page-Mode Access—Read after Write
11.4.4.5 Auto-Refresh Operation
The DRAM controller is equipped with a refresh counter and control. This logic is
responsible for providing timing and control to refresh the SDRAM. Once the refresh
counter is set, and refresh is enabled, the counter counts to zero. At this time, an internal
refresh request flag is set and the counter begins counting down again. The DRAM
controller completes any active burst operation and then performs a PALL operation. The
DRAM controller then initiates a refresh cycle and clears the refresh request flag. This
refresh cycle includes a delay from any precharge to the auto-refresh command, the
auto-refresh command, and then a delay until any ACTV command is allowed. Any SDRAM
access initiated during the auto-refresh cycle is delayed until the cycle is completed.
Figure 11-22 shows the auto-refresh timing. In this case, there is an SDRAM access when
the refresh request becomes active. The request is delayed by the precharge to ACTV delay
programmed into the active SDRAM bank by the CAS bits. The REF command is then
generated and the delay required by DCR[RTIM] is inserted before the next ACTV
command is generated. In this example, the next bus cycle is initiated, but does not generate
an SDRAM access until TRC is finished. Because both chip selects are active during the REF
command, it is passed to both blocks of external SDRAM.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-31
Synchronous Operation
CLKIN
A[31:0]
SRAS
tRC = 6
tRCD = 2
SCAS
DRAMW
RAS[0] or [1]
PALL
NOP
REF
NOP
ACTV
Figure 11-22. Auto-Refresh Operation
11.4.4.6 Self-Refresh Operation
Self-refresh is a method of allowing the SDRAM to enter into a low-power state, while at
the same time to perform an internal refresh operation and to maintain the integrity of the
data stored in the SDRAM. The DRAM controller supports self-refresh with DCR[IS].
When IS is set, the SELF command is sent to the SDRAM. When IS is cleared, the SELFX
command is sent to the DRAM controller. Figure 11-23 shows the self-refresh operation.
CLKIN
SRAS
tRCD = 2
SCAS
tRC = 6
DRAMW
RAS[0] or [1]
SCKE
(DCR[COC] = 0)
PALL
NOP
SELF
SelfRefresh
Active
SELFX
NOP
First
Possible
ACTV
Figure 11-23. Self-Refresh Operation
11.4.5 Initialization Sequence
Synchronous DRAMs have a prescribed initialization sequence. The DRAM controller
11-32
MCF5407 User’s Manual
Synchronous Operation
supports this sequence with the following procedure:
1. SDRAM control signals are reset to idle state. Wait the prescribed period after reset
before any action is taken on the SDRAMs. This is normally around 100 µs.
2. Initialize the DCR, DACR, and DMR in their operational configuration. Do not yet
enable PALL or REF commands.
3. Issue a PALL command to the SDRAMs by setting DCR[IP] and accessing a
SDRAM location. Wait the time (determined by tRP) before any other execution.
4. Enable refresh (set DACR[RE]) and wait for at least 8 refreshes to occur.
5. Before issuing the MRS command, determine if the DMR mask bits need to be
modified to allow the MRS to execute properly
6. Issue the MRS command by setting DACR[IMRS] and accessing a location in the
SDRAM. Note that mode register settings are driven on the SDRAM address bus, so
care must be taken to change DMR[BAM] if the mode register configuration does
not fall in the address range determined by the address mask bits. After the mode
register is set, DMR mask bits can be restored to their desired configuration.
11.4.5.1 Mode Register Settings
It is possible to configure the operation of SDRAMs, namely their burst operation and CAS
latency, through the SDRAM component’s mode register. CAS latency is a function of the
speed of the SDRAM and the bus clock of the DRAM controller. The DRAM controller
operates at a CAS latency of 1, 2, or 3.
Although the MCF5407 DRAM controller supports bursting operations, it does not use the
bursting features of the SDRAMs. Because the MCF5407 can burst operand sizes of 1, 2,
4, or 16 bytes long, the concept of a fixed burst length in the SDRAMs mode register
becomes problematic. Therefore, the MCF5407 DRAM controller generates the burst
cycles rather than the SDRAM device. Because the MCF5407 generates a new address and
a READ or WRITE command for each transfer within the burst, the SDRAM mode register
should be set either to a burst length of one or to not burst. This allows bursting to be
controlled by the MCF5407 instead.
The SDRAM mode register is written by setting the associated block’s DACR[IMRS].
First, the base address and mask registers must be set to the appropriate configuration to
allow the mode register to be set. Note that improperly set DMR mask bits may prevent
access to the mode register address. Thus, the user should determine the mapping of the
mode register address to the MCF5407 address bits to find out if an access is blocked. If the
DMR setting prohibits mode register access, the DMR should be reconfigured to enable the
access and then set to its necessary configuration after the MRS command executes.
The associated CBM bits should also be initialized. After DACR[IMRS] is set, the next
access to the SDRAM address space generates the MRS command to that SDRAM. The
address of the access should be selected to place the correct mode information on the
SDRAM address pins. The address is not multiplexed for the MRS command. The MRS
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-33
SDRAM Example
access can be a read or write. The important thing is that the address output of that access
needs the correct mode programming information on the correct address bits.
Figure 11-24 shows the MRS command, which occurs in the first clock of the bus cycle.
CLKIN
A[31:0]
SRAS, SCAS
DRAMW
D[31:0]
RAS[1] or [0]
MRS
Figure 11-24. Mode Register Set (MRS) Command
11.5 SDRAM Example
This example interfaces a 2M x 32-bit x 4 bank SDRAM component to a MCF5407
operating at 40 MHz. Table 11-32 lists design specifications for this example.
Table 11-32. SDRAM Example Specifications
Parameter
Speed grade (-8E)
Specification
40 MHz (25-nS period)
10 rows, 8 columns
Two bank-select lines to access four internal banks
ACTV-to-read/write
delay (tRCD)
Period between auto refresh and ACTV command (tRC)
ACTV
command to precharge command (tRAS)
Precharge command to ACTV command (tRP)
20 nS (min.)
70 nS
48 nS (min.)
20 nS (min.)
Last data input to PALL command (tRWL)
1 bus clock (25 nS)
Auto refresh period for 4096 rows (tREF)
64 mS
11.5.1 SDRAM Interface Configuration
To interface this component to the MCF5407 DRAM controller, use the connection table
that corresponds to a 32-bit port size with 8 columns (Table 11-26). Two pins select one of
four banks when the part is functional. Table 11-33 shows the proper hardware hook-up.
11-34
MCF5407 User’s Manual
SDRAM Example
Table 11-33. SDRAM Hardware Connections
MCF5407
Pins
A15
A14
A13
A12
A11
A10
A9
A17
A18
A19
A20
A21
A22
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10 = CMD
BA0
BA1
11.5.2 DCR Initialization
At power-up, the DCR has the following configuration if synchronous operation and
SDRAM address multiplexing is desired.
15
Field SO
Setting
1
14
13
res
X
0
(hex)
12
NAM COC
0
11
IS
0
10
9
8
0
RTIM
0
8
0
RC
0
0
0
0
1
0
0
2
1
1
0
6
Figure 11-25. Initialization Values for DCR
This configuration results in a value of 0x8026 for DCR, as shown in Table 11-34.
Table 11-34. DCR Initialization Values
Bits
Name
Setting
Description
15
SO
1
Indicating synchronous operation
14
—
x
Don’t care (reserved)
13
NAM
0
Indicating SDRAM controller multiplexes address lines internally
12
COC
0
SCKE is used as clock enable instead of command bit because user is not multiplexing
address lines externally and requires external command feed.
11
IS
0
At power-up, allowing power self-refresh state is not appropriate because registers are
being set up.
10–9
RTIM
00
8–0
RC
0x26
Because tRC value is 70 nS, indicating a 3-clock refresh-to-ACTV timing.
Specification indicates auto-refresh period for 4096 rows to be 64 mS or refresh every
15.625 µs for each row, or 625 bus clocks at 40 MHz. Because DCR[RC] is incremented by
1 and multiplied by 16, RC = (625 bus clocks/16) -1 = 38.06 = 0x38
11.5.3 DACR Initialization
As shown in Figure 11-26, in this example the SDRAM is programmed to access only the
second 512-Kbyte block of each 1-Mbyte partition in the SDRAM (each 16 Mbytes). The
starting address of the SDRAM is 0xFF80_0000. Continuous page mode feature is used.
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-35
SDRAM Example
Accessible
Memory
SDRAM Component
Bank 0
Bank 1
512 Kbyte
Bank 2
512 Kbyte
1 Mbyte
Bank 3
512 Kbyte
1 Mbyte
512 Kbyte
1 Mbyte
512 Kbyte
1 Mbyte
512 Kbyte
512 Kbyte
512 Kbyte
Figure 11-26. SDRAM Configuration
The DACRs should be programmed as shown in Figure 11-27.
31
18
Field
Setting
(hex)
Field
Setting
15
14
—
1111_1111_1000_10
xx
0
X
(hex)
15
13
12
11
CASL
—
00
X
0
16
—
15
RE
17
BA
8
10
8
8
7
6
3
2
CBM
—
IMRS
PS
IP
PM
011
X
0
00
0
1
3
5
4
0
1
0
—
xx
4
Figure 11-27. DACR Register Configuration
This configuration results in a value of DACR0 = 0xFF88_0304, as described in
Table 11-35. DACR1 initialization is not needed because there is only one block.
Subsequently, DACR1[RE,IMRS,IP] should be cleared; everything else is a don’t care.
Table 11-35. DACR Initialization Values
Bits
Name
Setting
Description
31–18
BA
Base address. So DACR0[31–16] = 0xFF88, which places the starting address of the
SDRAM accessible memory at 0xFF88_0000.
17–16
—
Reserved. Don’t care.
15
RE
14
—
13–12
11
10–8
CASL
0
00
—
CBM
0, which keeps auto-refresh disabled because registers are being set up at this time.
Reserved. Don’t care.
Indicates a delay of data 1 cycle after CAS is asserted
Reserved. Don’t care.
011
Command bit is pin 20 and bank selects are 21 and up.
7
—
6
IMRS
0
Indicates MRS command has not been initiated.
5–4
PS
00
32-bit port.
3
IP
0
Indicates precharge has not been initiated.
11-36
Reserved. Don’t care.
MCF5407 User’s Manual
SDRAM Example
Table 11-35. DACR Initialization Values
Bits
Name
Setting
2
PM
1
1–0
—
Description
Indicates continuous page mode
Reserved. Don’t care.
11.5.4 DMR Initialization
In this example, again, only the second 512-Kbyte block of each 1-Mbyte space is accessed
in each bank. In addition the SDRAM component is mapped only to readable and writable
supervisor and user data. The DMRs have the following configuration.
31
Field
Setting
17
1
X
BAM
0
0
0
(hex)
0
0
0
0
0
15
9
X
X
X
(hex)
0
1
X
X
0
X
1
1
0
7
—
X
16
—
0
0
Field
Setting
18
X
4
8
7
6
5
4
3
2
1
0
WP
—
C/I
AM
SC
SD
UC
UD
V
0
X
1
1
1
0
1
0
1
0
7
5
Figure 11-28. DMR0 Register
With this configuration, the DMR0 = 0x0074_0075, as described in Table 11-36.
Table 11-36. DMR0 Initialization Values
Bits
Name
31–16
BAM
15–9
—
Setting
Description
With bits 17 and 16 as don’t cares, BAM = 0x0074, which leaves bank select bits and
upper 512K select bits unmasked. Note that bits 22 and 21 are set because they are used
as bank selects; bit 20 is set because it controls the 1-Mbyte boundary address.
Reserved. Don’t care.
8
WP
7
—
0
Allow reads and writes
6
C/I
5
AM
1
Disable alternate master access
4
SC
1
Disable supervisor code accesses
3
SD
0
Enable supervisor data accesses
2
UC
1
Disable user code accesses
1
UD
0
Enable user data accesses
0
V
1
Enable accesses.
Reserved
1
Disable CPU space access
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-37
SDRAM Example
11.5.5 Mode Register Initialization
When DACR[IMRS] is set, a bus cycle initializes the mode register. If the mode register
setting is read on A[10:0] of the SDRAM on the first bus cycle, the bit settings on the
corresponding MCF5407 address pins must be determined while being aware of masking
requirements.
Table 11-37 lists the desired initialization setting:
Table 11-37. Mode Register Initialization
MCF5407 Pins
SDRAM Pins
A20
A10
A19
A18
Mode Register Initialization
Reserved
X
A9
WB
0
A8
Opmode
0
A17
A7
Opmode
0
A9
A6
CASL
0
A10
A5
CASL
0
A11
A4
CASL
1
A12
A3
BT
0
A13
A2
BL
0
A14
A1
BL
0
A15
A0
BL
0
Next, this information is mapped to an address to determine the hexadecimal value.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
X
X
X
X
X
X
X
X
X
X
X
X
0
0
0
X
Field
Setting
(hex)
0
15
14
0
13
12
11
10
0
9
8
7
6
0
5
4
3
2
1
Field
Setting
(hex)
0
V
0
0
0
0
0
1
0
0
X
X
X
8
X
X
X
X
0
X
X
0
Figure 11-29. Mode Register Mapping to MCF5407 A[31:0]
Although A[31:20] corresponds to the address programmed in DACR0, according to how
DACR0 and DMR0 are initialized, bit 19 must be set to hit in the SDRAM. Thus, before
the mode register bit is set, DMR0[19] must be set to enable masking.
11-38
MCF5407 User’s Manual
SDRAM Example
11.5.6 Initialization Code
The following assembly code initializes the SDRAM example.
Power-Up Sequence:
move.w
move.w
move.l
move.l
move.l
move.l
#0x8026, d0
d0, DCR
#0xFF880300, d0
d0, DACR0
#0x00740075, d0
d0, DMR0
//Initialize DCR
//Initialize DACR0
//Initialize DMR0
Precharge Sequence:
move.l
move.l
move.l
move.l
#0xFF880308, d0
d0, DACR0
#0xBEADDEED, d0
d0, 0xFF880000
//Set DACR0[IP]
//Write to memory location to init. precharge
Refresh Sequence:
move.l
move.l
#0xFF888300, d0
d0, DACR0
//Enable refresh bit in DACR0
Mode Register Initialization Sequence:
move.l #0x00600075, d0
move.l d0, DMR0
move.l #0xFF888340, d0
move.l d0, DACR0
move.l #0x00000000, d0
register
move.l d0, 0xFF800800
//Mask bit 19 of address
//Enable DACR0[IMRS]; DACR0[RE] remains set
//Access
SDRAM
address
to
initialize
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
mode
11-39
SDRAM Example
11-40
MCF5407 User’s Manual
Part III
Peripheral Module
Intended Audience
Part III describes the operation and configuration of the MCF5407 DMA, timer, UART, and
parallel port modules, and describes how they interface with the system integration unit,
described in Part II.
Contents
It contains the following chapters:
— Chapter 12, “DMA Controller Module,” provides an overview of the DMA
controller module and describes in detail its signals and registers. The latter
sections of this chapter describe operations, features, and supported data transfer
modes in detail, showing timing diagrams for various operations.
— Chapter 13, “Timer Module,” describes configuration and operation of the two
general-purpose timer modules, timer 0 and timer 1. It includes programming
examples.
— Chapter 14, “UART Modules,” describes the use of the universal
asynchronous/synchronous receiver/transmitters (UARTs) implemented on the
MCF5407 and includes programming examples. Particular attention is given to
the UART1 implementation of a synchronous interface that provides a controller
for an 8- or 16-bit CODEC interface and an audio CODEC ‘97 (AC ’97) digital
interface.
— Chapter 15, “Parallel Port (General-Purpose I/O),” describes the operation and
programming model of the parallel port pin assignment, direction-control, and
data registers. It includes a code example for setting up the parallel port.
Suggested Reading
The following literature may be helpful with respect to the topics in Part III:
Part III. Peripheral Module
III-i
Audio CODEC ‘97 Component Specification
Acronyms and Abbreviations
Table III-i describes acronyms and abbreviations used in Part III.
Table III-i. Acronyms and Abbreviated Terms
Term
Meaning
ADC
Analog-to-digital conversion
BIST
Built-in self test
CODEC
Code/decode
DAC
Digital-to-analog conversion
DMA
Direct memory access
DSP
Digital signal processing
EDO
Extended data output (DRAM)
FIFO
First-in, first-out
GPIO
General-purpose I/O
I2C
Inter-integrated circuit
IEEE
Institute for Electrical and Electronics Engineers
IFP
Instruction fetch pipeline
IPL
Interrupt priority level
JEDEC
Joint Electron Device Engineering Council
JTAG
Joint Test Action Group
LIFO
Last-in, first-out
LRU
Least recently used
LSB
Least-significant byte
lsb
Least-significant bit
MAC
Multiple accumulate unit
MBAR
Memory base address register
MSB
Most-significant byte
msb
Most-significant bit
Mux
Multiplex
NOP
No operation
OEP
Operand execution pipeline
PC
Program counter
III-ii
MCF5407 User’s Manual
Table III-i. Acronyms and Abbreviated Terms (Continued)
Term
Meaning
PCLK
Processor clock
PLL
Phase-locked loop
PLRU
Pseudo least recently used
POR
Power-on reset
PQFP
Plastic quad flat pack
RISC
Reduced instruction set computing
Rx
Receive
SIM
System integration module
SOF
Start of frame
TAP
Test access port
TTL
Transistor-to-transistor logic
Tx
Transmit
UART
Universal asynchronous/synchronous receiver transmitter
Part III. Peripheral Module
III-iii
III-iv
MCF5407 User’s Manual
Chapter 12
DMA Controller Module
This chapter describes the MCF5407 DMA controller module. It provides an overview of
the module and describes in detail its signals and registers. The latter sections of this
chapter describe operations, features, and supported data transfer modes in detail.
12.1 Overview
The direct memory access (DMA) controller module provides an efficient way to move
blocks of data with minimal processor interaction. The DMA module, shown in
Figure 12-1, provides four channels that allow byte, word, or longword operand transfers.
Each channel has a dedicated set of registers that define the source and destination
addresses (SARn and DARn), byte count (BCRn), and control and status (DCRn and
DSRn). Transfers can be dual or single address to off-chip devices or dual address to
on-chip devices, such as UART, SDRAM controller, and parallel port.
Channel 0 Channel 1 Channel 2 Channel 3
Internal
Bus
External
Requests
SAR0
SAR1
SAR2
SAR3
DAR0
DAR1
DAR2
DAR3
BCR0
BCR1
BCR2
BCR3
DCR0
DCR1
DCR2
DCR3
DSR0
DSR1
DSR2
DSR3
Channel
Requests
Interrupts
Channel
Attributes
Channel
Enables
External Bus Address
MUX
MUX
Control
External Bus Size
Current Master Attributes
Arbitration/
Control
Data Path
Read Bus Data
Data Path
Control
Write Bus Data
Interface Bus
Registered
Bus Signals
Figure 12-1. DMA Signal Diagram
Chapter 12. DMA Controller Module
12-1
DMA Signal Description
12.1.1 DMA Module Features
The DMA controller module features are as follows:
•
•
•
•
•
•
•
•
•
•
•
•
Four fully independent, programmable DMA controller channels/bus modules
Auto-alignment feature for source or destination accesses
Dual- and single-address transfers
Two external request pins (DREQ[1:0]) provided for channels 1 and 0
Two external acknowledge pins (DACK[1:0]) provided for channels 1 and 0
Channels 2 and 3 have request signals connected to the interrupt lines of UART0 and
UART1, programmable through the channel select field MODCTL[DSL]. See
Section 14.3.4, “Modem Control Register (MODCTL).”
Channel arbitration on transfer boundaries
Data transfers in 8-, 16-, 32-, or 128-bit blocks using a 16-byte buffer
Continuous-mode and cycle-steal transfers
Independent transfer widths for source and destination
Independent source and destination address registers
Data transfer can occur in as few as two clocks
12.2 DMA Signal Description
Table 12-1 briefly describes the DMA module signals that provide handshake control for
either a source or destination external device.
Table 12-1. DMA Signals
Signal
I/O
Description
DREQ[1:0]/
PP[6:5]
I
External DMA request. DREQ[1:0] can serve as the DMA request inputs or as two parallel port
bits. They are programmable individually through the PAR. A peripheral device asserts these
inputs to request an operand transfer between it and memory.
DREQ signals are asserted to initiate DMA accesses in the respective channels. The system
should drive unused DREQ signals to logic high. Although each channel has an individual
DREQ signal, in the MCF5407 only channels 0 and 1 connect to external DREQ pins. DREQ2
and DREQ3 are programmable for use with UART0 and UART1 through MODCTL[DSL]. See
Section 14.3.4, “Modem Control Register (MODCTL).”
TT[1:0]/
PP[1:0]
O
Transfer type. A DMA access is indicated by the transfer type pins, TT[1:0] = 01. The transfer
modifier, TM[2:0], and DMA acknowledgement, DACK[1:0], configurations shown below are
meaningful only if TT[1:0] = 01, indicating an external master or DMA access.
12-2
MCF5407 User’s Manual
DMA Signal Description
Table 12-1. DMA Signals (Continued)
Signal
I/O
Description
TM[2:0]/
DACK[1:0]
O
Transfer modifier/DMA acknowledge. The MCF5407 TM[2:0] encodings are like the MCF5307,
with functions shifted slightly, as Figure 12-2 shows. Dedicated DMA acknowledgement pins,
DACK[1:0], are added and multiplexed as follows—TM[1:0]/DACK[1:0]/PP[3:2]. TM2 is still
multiplexed only with PP4. Chapter 17, “Signal Descriptions,” describes multiplexing.
Although on the MCF5407, TM[2:0] can be programmed to be DMA acknowledge signals, bit
positions of these encodings differ from the MCF5307. Single-address access indication is now
encoded on TM2 when the PAR is set to enable the transfer modifier signal and an external or
DMA transfer is occurring. This encoding is driven by TM0 on the MCF5307. In addition, DMA
acknowledge signals are multiplexed with TM[1:0] on the MCF5407, as opposed to TM[2:1]
providing DMA transfer information on the MCF5307. The MCF5407 encoding for TM[2:0],
shown below describes when PAR is set to enable these signals and the IRQPAR is
programmed to disable DACK[1:0]. Note that when DACK[1:0] are driven, TM2 is still driven if it
is enabled through the PAR.
To enable DACK[1:0], first enable TM[1:0] and then program the interrupt assignment register
(IRQPAR) to enable bits 0–1. When IRQPAR[ENBDACK1] = 1 and TM1 is enabled, DACK1 for
DMA channel 1 is driven in place of TM1 for DMA transfers. Clearing ENBDACK1 disables this
function and only the TM1 encoding is driven. Likewise, setting ENBDACK0 enables DACK0 to
be driven; clearing ENBDACK0 disables this function and drives the TM0 encoding.
TM2 Encoding
0
Single-address access negated
1
Single-address access
TM[1:0] Encoding
00 DMA acknowledge information not provided
01 DMA transfer, channel 0
10 DMA transfer, channel 1
11 Reserved
The DMA transfer information on TM[1:0] can be provided on every DMA transfer or only on the
last transfer by programming DCR[AT].
DACK[1:0]
I/O
DMA acknowledge. These signals provide an acknowledge of a DMA transfer. They can be
programmed using DCR[AT] to assert on every transfer or only on the final transfer.
Table 12-2 shows MCF5407 pin configurations based on PAR and IRQPAR configurations.
Table 12-2. MCF5407 Signal Configurations for PP[4:2]/TM[2:0]/DACK[1:0]
PAR
Configuration 1
IRQPAR Configuration
PP[4:2]
TM[2:0]
DACK[1:0]
TM[2:0] disabled,
PP[4:2] enabled
ENBDACK[1–0] = 0 or 1
Driven
Not driven
Not driven
TM[2:0] enabled
ENBDACK[1–0] = 0
Not driven
TM[2:0] driven
Not driven
TM[2:0] enabled
ENBDACK[1–0] = 1
Not driven
TM2 driven only
Driven
1
Note that to enable DACK[1:0], PAR must first be programmed to enable TM[1:0].
Designers who used MCF5307 DMA channels should also note that the DMA byte count
registers (BCR) for channels 0–3 exclusively support a 24-bit byte count. A 16-bit byte
count register and MPARK[BCR24BIT] are no longer supported.
As shown in Figure 12-2, when properly connected, TM[2:0] can be used in MCF5407
designs in the same manner as they were on MCF5307 designs or DACK[1:0] can be used
for DMA transfers.
Chapter 12. DMA Controller Module
12-3
DMA Transfer Overview
MCF5307 Function
Pin
Pin
MCF5407 Function
Single/dual cycle access
TM0
TM0
DMA 0 acknowledge
DMA 0 acknowledge configuration
TM1
TM1
DMA 1 acknowledge
DMA 1 acknowledge configuration
TM2
TM2
Single/dual cycle access
Figure 12-2. MCF5307/MCF5407 TM[2:0] Pin Remapping
12.3 DMA Transfer Overview
The DMA module usually transfers data faster than the ColdFire core can under software
control. The term ‘direct memory access’ refers to peripheral device’s ability to access
system memory directly, greatly improving overall system performance. The DMA module
consists of four independent, functionally equivalent channels, so references to DMA in
this chapter apply to any of the channels. It is not possible to implicitly address all four
channels at once. The MCF5407 on-chip peripherals do not support single-address
transfers.
The processor generates DMA requests internally by setting DCR[START]; a device can
generate a DMA request externally by using DREQ pins. The processor can program bus
bandwidth for each channel. The channels support cycle-steal and continuous transfer
modes; see Section 12.5.1, “Transfer Requests (Cycle-Steal and Continuous Modes).”
The DMA controller supports dual- and single-address transfers as follows. In both, the
DMA channel supports 32 address bits and 32 data bits.
•
Dual-address transfers—A dual-address transfer consists of a read followed by a
write and is initiated by an internal request using the START bit or by an external
device using DREQ. Two types of transfer can occur, a read from a source device or
a write to a destination device; see Figure 12-3.
Control and Data
Memory/
Peripheral
DMA
Control and Data
Memory/
Peripheral
Figure 12-3. Dual-Address Transfer
12-4
MCF5407 User’s Manual
DMA Controller Module Programming Model
•
Single-address transfers—An external device can initiate a single-address transfer
by asserting DREQ. The MCF5407 provides address and control signals for
single-address transfers. The external device reads to or writes from the specified
address, as Figure 12-4 shows. External logic is required.
Write:
Control Signals
Memory
DMA
Data
Control Signals
Peripheral
Read:
Control Signals
Memory
DMA
Data
Control Signals
Peripheral
Figure 12-4. Single-Address Transfers
Any operation involving the DMA module follows the same three steps:
1. Channel initialization—Channel registers are loaded with control information,
address pointers, and a byte-transfer count.
2. Data transfer—The DMA accepts requests for operand transfers and provides
addressing and bus control for the transfers.
3. Channel termination—Occurs after the operation is finished, either successfully or
due to an error. The channel indicates the operation status in the channel’s DSR,
described in Section 12.4.5, “DMA Status Registers (DSR0–DSR3).”
12.4 DMA Controller Module Programming Model
This section describes each internal register and its bit assignment. Note that there is no way
to prevent a write to a control register during a DMA transfer. Table 12-3 shows the
mapping of DMA controller registers.
Chapter 12. DMA Controller Module
12-5
DMA Controller Module Programming Model
Table 12-3. Memory Map for DMA Controller Module Registers
DMA
Channel
MBAR
Offset
0
0x300
Source address register 0 (SAR0) [p. 12-7]
0x304
Destination address register 0 (DAR0) [p. 12-7]
0x308
DMA control register 0 (DCR0) [p. 12-8]
1
2
3
[31:24]
[23:16]
[15:8]
0x30C
Reserved
Byte count register 0 (BCR0) [p. 12-7]
0x310
DMA status register 0
(DSR0) [p. 12-10]
Reserved
0x314
DMA interrupt vector
register 0 (DIVR0)
[p. 12-11]
Reserved
0x340
Source address register 1 (SAR1) [p. 12-7]
0x344
Destination address register 1 (DAR1) [p. 12-7]
0x348
DMA control register 1 (DCR1) [p. 12-8]
0x34C
Reserved
Byte count register 1 (BCR1) [p. 12-7]
0x350
DMA status register 1
(DSR1) [p. 12-10]
Reserved
0x354
DMA interrupt vector
register 1 (DIVR1)
[p. 12-11]
Reserved
0x380
Source address register 2 (SAR2) [p. 12-7]
0x384
Destination address register 2 (DAR2) [p. 12-7]
0x388
DMA control register 2 (DCR2) [p. 12-8]
0x38C
Reserved
Byte count register 2 (BCR2) [p. 12-7]
0x390
DMA status register 2
(DSR2) [p. 12-10]
Reserved
0x394
DMA interrupt vector
register 2 (DIVR2)
[p. 12-11]
Reserved
0x3C0
Source address register 3 (SAR3) [p. 12-7]
0x3C4
Destination address register 3 (DAR3) [p. 12-7]
0x3C8
DMA control register 3 (DCR3) [p. 12-8]
0x3CC
Reserved
Byte count register 3 (BCR3) [p. 12-7]
0x3D0
DMA status register 3
(DSR3) [p. 12-10]
Reserved
0x3D4
DMA interrupt vector
register 3 (DIVR3)
[p. 12-11]
Reserved
NOTE:
External masters cannot access MCF5407 on-chip memories or
MBAR, but they can access DMA module registers.
12-6
MCF5407 User’s Manual
[7:0]
DMA Controller Module Programming Model
12.4.1 Source Address Registers (SAR0–SAR3)
SARn, Figure 12-5, contains the address from which the DMA controller requests data. In
single-address mode, SARn provides the address regardless of the direction.
31
0
Field
SAR
Reset
0000_0000_0000_0000_0000_0000_0000_0000
R/W
R/W
Address
MBAR + 0x300, 0x340, 0x380, 0x3C0
Figure 12-5. Source Address Registers (SARn)
NOTE:
SAR/DAR address ranges cannot be programmed to on-chip
SRAM because it cannot be accessed by on-chip DMA.
12.4.2 Destination Address Registers (DAR0–DAR3)
For dual-address transfers only, DARn, Figure 12-6, holds the address to which the DMA
controller sends data.
31
0
Field
DAR
Reset
0000_0000_0000_0000_0000_0000_0000_0000
R/W
Address
R/W
MBAR + 304, 0x344, 0x384, 0x3C4
Figure 12-6. Destination Address Registers (DARn)
NOTE:
On-chip DMAs do not maintain coherency with MCF5407
caches and so must not transfer data to cacheable memory.
12.4.3 Byte Count Registers (BCR0–BCR3)
BCRn, Figure 12-7, holds the number of bytes yet to be transferred for a given block. BCRn
decrements on the successful completion of the address transfer of either a write transfer in
dual-address mode or any transfer in single-address mode. BCRn decrements by 1, 2, 4, or
16 for byte, word, longword, or line accesses, respectively.
Chapter 12. DMA Controller Module
12-7
DMA Controller Module Programming Model
31
24 23
0
Field
—
BCR
Reset
—
0000_0000_0000_0000_0000_0000
R/W
R/W
Address
MBAR + 0x30C, 0x34C, 0x38C, 0x3AC
Figure 12-7. Byte Count Registers (BCRn)
DSR[DONE], shown in Figure 12-9, is set when the block transfer is complete.
When a transfer sequence is initiated and BCRn[BCR] is not divisible by 16, 4, or 2 when
the DMA is configured for line, longword, or word transfers, respectively, DSRn[CE] is set
and no transfer occurs. See Section 12.4.5, “DMA Status Registers (DSR0–DSR3).”
12.4.4 DMA Control Registers (DCR0–DCR3)
DCRn, Figure 12-8, is used for configuring the DMA controller module.
31
30
Field INT EEXT
29
28
CS
AA
27
25
BWC
Reset
24
23
22
SAA S_RW SINC
21
20
SSIZE
19
DINC
18
17
DSIZE
16
START
0000_0000_0000_0000
R/W
R/W
15
Field
AT
Reset
0
14
0
—
N/A
R/W
R/W
Address
MBAR + 0x308, 0x348, 0x388, 0x3A8
Figure 12-8. DMA Control Registers (DCRn)
Table 12-4 describes DCR fields.
Table 12-4. DCRn Field Descriptions
Bits
Name
Description
31
INT
Interrupt on completion of transfer. Determines whether an interrupt is generated by completing a
transfer or by the occurrence of an error condition.
0 No interrupt is generated.
1 Internal interrupt signal is enabled.
30
EEXT
Enable external request. Care should be taken because a collision can occur between the START
bit and DREQ when EEXT = 1.
0 External request is ignored.
1 Enables external request to initiate transfer. Internal request is always enabled. It is initiated by
writing a 1 to the START bit.
12-8
MCF5407 User’s Manual
DMA Controller Module Programming Model
Table 12-4. DCRn Field Descriptions (Continued)
Bits
Name
Description
29
CS
Cycle steal.
0 DMA continuously makes read/write transfers until the BCR decrements to 0.
1 Forces a single read/write transfer per request. The request may be internal by setting the START
bit, or external by asserting DREQ.
28
AA
Auto-align. AA and SIZE determine whether the source or destination is auto-aligned, that is,
transfers are optimized based on the address and size. See Section 12.5.4.2, “Auto-Alignment.”
0 Auto-align disabled
1 If SSIZE indicates a transfer no smaller than DSIZE, source accesses are auto-aligned;
otherwise, destination accesses are auto-aligned. Source alignment takes precedence over
destination alignment. If auto-alignment is enabled, the appropriate address register increments,
regardless of DINC or SINC.
27–25 BWC
Bandwidth control. Indicates the number of bytes in a block transfer. When the byte count reaches
a multiple of the BWC value, the DMA releases the bus.
000
DMA has priority. It does not negate its request until its transfer completes.
001
16384
010
32768
011
65536
100
131072
101
262144
110
524288
111
1048576
24
SAA
Single-address access. Determines whether the DMA channel is in dual- or single-address mode
0 Dual-address mode.
1 Single-address mode. The DMA provides an address from the SAR and directional control, bit
S_RW, to allow two peripherals (one might be memory) to exchange data within a single access.
Data is not stored by the DMA.
23
S_RW
Single-address access read/write value. Valid only if SAA = 1. Specifies the value of the read signal
during single-address accesses. This provides directional control to the bus controller.
0 Forces the read signal to 0.
1 Forces the read signal to 1.
22
SINC
Source increment. Controls whether a source address increments after each successful transfer.
0 No change to SAR after a successful transfer.
1 The SAR increments by 1, 2, 4, or 16, as determined by the transfer size.
21–20 SSIZE
Source size. Determines the data size of the source bus cycle for the DMA control module.
00 Longword
01 Byte
10 Word
11 Line
19
Destination increment. Controls whether a destination address increments after each successful
transfer.
0 No change to the DAR after a successful transfer.
1 The DAR increments by 1, 2, 4, or 16, depending upon the size of the transfer.
DINC
18–17 DSIZE
Destination size. Determines the data size of the destination bus cycle for the DMA controller.
00 Longword
01 Byte
10 Word
11 Line
16
Start transfer.
0 DMA inactive
1 The DMA begins the transfer in accordance to the values in the control registers. START is
cleared automatically after one clock and is always read as logic 0.
START
Chapter 12. DMA Controller Module
12-9
DMA Controller Module Programming Model
Table 12-4. DCRn Field Descriptions (Continued)
Bits
Name
Description
15
AT
DMA acknowledge type. Controls whether acknowledge information is provided for the entire
transfer or only the final transfer.
0 Entire transfer. DMA acknowledge information is displayed anytime the channel is selected as the
result of an external request.
1 Final transfer (when BCR reaches zero). For dual-address transfer, the acknowledge information
is displayed for both the read and write cycles.
14–0
—
Reserved, should be cleared.
12.4.5 DMA Status Registers (DSR0–DSR3)
In response to an event, the DMA controller writes to the appropriate DSRn bit,
Figure 12-9. Only a write to DSRn[DONE] results in action.
7
6
5
4
3
2
1
0
Field
—
CE
BES
BED
—
REQ
BSY
DONE
Reset
—
0
0
0
—
0
0
0
R/W
R/W
Address
MBAR + 0x310, 0x350, 0x390, 0x3D0
Figure 12-9. DMA Status Registers (DSRn)
Table 12-5 describes DSRn fields.
Table 12-5. DSRn Field Descriptions
Bits
Name
Description
7
—
Reserved, should be cleared.
6
CE
Configuration error. Occurs when BCR, SAR, or DAR does not match the requested transfer size,
or if BCR = 0 when the DMA receives a start condition. CE is cleared at hardware reset or by
writing a 1 to DSR[DONE].
0 No configuration error exists.
1 A configuration error has occurred.
5
BES
Bus error on source
0 No bus error occurred.
1 The DMA channel terminated with a bus error either during the read portion of a transfer or
during an access in single-address mode (SAA = 1).
4
BED
Bus error on destination
0 No bus error occurred.
1 The DMA channel terminated with a bus error during the write portion of a transfer.
3
—
Reserved, should be cleared.
2
REQ
Request
0 No request is pending or the channel is currently active. Cleared when the channel is selected.
1 The DMA channel has a transfer remaining and the channel is not selected.
12-10
MCF5407 User’s Manual
DMA Controller Module Functional Description
Table 12-5. DSRn Field Descriptions (Continued)
Bits
Name
Description
1
BSY
Busy
0 DMA channel is inactive. Cleared when the DMA has finished the last transaction.
1 BSY is set the first time the channel is enabled after a transfer is initiated.
0
DONE
Transactions done. Set when all DMA controller transactions complete normally, as determined by
transfer count and error conditions. When BCR reaches zero, DONE is set when the final transfer
completes successfully. DONE can also be used to abort a transfer by resetting the status bits.
When a transfer completes, software must clear DONE before reprogramming the DMA.
0 Writing or reading a 0 has no effect.
1 DMA transfer completed. Writing a 1 to this bit clears all DMA status bits and can be used as an
interrupt handler to clear the DMA interrupt and error bits.
12.4.6 DMA Interrupt Vector Registers (DIVR0–DIVR3)
The contents of a DMA interrupt vector register (DIVRn), Figure 12-10, are driven onto the
internal bus in response to an interrupt acknowledge cycle.
7
0
Field
Interrupt Vector Bits
Reset
0000_1111
R/W
Address
R/W
MBAR + 0x314, 0x354, 0x394, 0x3D4
Figure 12-10. DMA Interrupt Vector Registers (DIVRn)
12.5 DMA Controller Module Functional Description
In the following discussion, the term ‘DMA request’ implies that DCR[START] or
DCR[EEXT] is set, followed by assertion of DREQ. The START bit is cleared when the
channel begins an internal access.
Before initiating a dual-address access, the DMA module verifies that DCR[SSIZE,DSIZE]
are consistent with the source and destination addresses. If the source and destination are
not the same size, the configuration error bit, DSR[CE], is also set. If misalignment is
detected, no transfer occurs, CE is set, and, depending on the DCR configuration, an
interrupt event is issued. Note that if the auto-align bit, DCR[AA], is set, error checking is
performed on appropriate registers.
A read/write transfer reads bytes from the source address and writes them to the destination
address. The number of bytes is the larger of the sizes specified by SSIZE and DSIZE. See
Section 12.4.4, “DMA Control Registers (DCR0–DCR3).”
Source and destination address registers (SAR and DAR) can be programmed in the DCR
to increment at the completion of a successful transfer. BCR decrements when an address
transfer write completes for a single-address access (DCR[SAA] = 0) or when SAA = 1.
Chapter 12. DMA Controller Module
12-11
DMA Controller Module Functional Description
12.5.1 Transfer Requests (Cycle-Steal and Continuous
Modes)
The DMA channel supports internal and external requests. A request is issued by setting
DCR[START] or by asserting DREQ. Setting DCR[EEXT] enables recognition of external
interrupts. Internal interrupts are always recognized. Bus usage is minimized for either
internal or external requests by selecting between cycle-steal and continuous modes.
•
•
Cycle-steal mode (DCR[CS] = 1)—Only one complete transfer from source to
destination occurs for each request. If DCR[EEXT] is set, a request can be either
internal or external. Internal request is selected by setting DCR[START]. An
external request is initiated by asserting DREQ while EEXT is set.
Continuous mode (DCR[CS] = 0)—After an internal or external request, the DMA
continuously transfers data until BCR reaches zero or a multiple of DCR[BWC] or
DSR[DONE] is set. If BCR is a multiple of BWC, the DMA request signal is
negated until the bus cycle terminates to allow the internal arbiter to switch masters.
DCR[BWC] = 000 specifies the maximum transfer rate; other values specify a
transfer rate limit.
The DMA performs the specified number of transfers, then relinquishes bus control.
The DMA negates its internal bus request on the last transfer before the BCR reaches
a multiple of the boundary specified in BWC. On completion, the DMA reasserts its
bus request to regain mastership at the earliest opportunity. The minimum time that
the DMA loses bus control is one bus cycle.
12.5.2 Data Transfer Modes
Each channel supports dual- and single-address transfers, described in the next sections.
12.5.2.1 Dual-Address Transfers
Dual-address transfers consist of a source operand read and a destination operand write.
The DMA controller module begins a dual-address transfer sequence when DCR[SAA] is
cleared during a DMA request. If no error condition exists, DSR[REQ] is set.
•
•
12-12
Dual-address read—The DMA controller drives the SAR value onto the internal
address bus. If DCR[SINC] is set, the SAR increments by the appropriate number
of bytes upon a successful read cycle. When the appropriate number of read cycles
complete (multiple reads if the destination size is wider than the source), the DMA
initiates the write portion of the transfer.
If a termination error occurs, DSR[BES,DONE] are set and DMA transactions stop.
Dual-address write—The DMA controller drives the DAR value onto the address
bus. If DCR[DINC] is set, DAR increments by the appropriate number of bytes at
the completion of a successful write cycle. The BCR decrements by the appropriate
number of bytes. DSR[DONE] is set when BCR reaches zero. If the BCR is greater
MCF5407 User’s Manual
DMA Controller Module Functional Description
than zero, another read/write transfer is initiated. If the BCR is a multiple of
DCR[BWC], the DMA request signal is negated until termination of the bus cycle
to allow the internal arbiter to switch masters.
If a termination error occurs, DSR[BES,DONE] are set and DMA transactions stop.
12.5.2.2 Single-Address Transfers
Single-address transfers consist of one DMA bus cycle, allowing either a read or a write
cycle to occur. The DMA controller begins a single-address transfer sequence when
DCR[SAA] is set during a DMA request. If no error condition exists, DSR[REQ] is set.
When the channel is enabled, DSR[BSY] is set and REQ is cleared. SAR contents are then
driven onto the address bus and the value of DCR[S_RW] is driven on R/W. The BCR
decrements on each successful address access until it is zero, when DSR[DONE] is set.
If a termination error occurs, DSR[BES,DONE] are set and DMA transactions stop.
12.5.3 Channel Initialization and Startup
Before a block transfer starts, channel registers must be initialized with information
describing configuration, request-generation method, and the data block.
12.5.3.1 Channel Prioritization
The four DMA channels are prioritized in ascending order (channel 0 having highest
priority and channel 3 having the lowest) or as determined by DCR[BWC]. If BWC for a
DMA channel is 000, that channel has priority only over the channel immediately
preceding it. For example, if DCR3[BWC] = 000, DMA channel 3 has priority over DMA
channel 2 (assuming DCR2[BWC] ≠ 000) but not over DMA channel 1.
If DCR1[BWC] = DCR2[BWC] = 000, DMA 1 has priority over DMA 0 and DMA 2.
DCR2[BWC] = 000 in this case does not affect prioritization.
Prioritization of simultaneous external requests is either ascending or as determined by
each channel’s BWC bits as described in the previous paragraphs.
12.5.3.2 Programming the DMA Controller Module
Note the following general guidelines for programming the DMA:
•
•
No mechanism exists to prevent writes to control registers during DMA accesses.
If the BWC of sequential channels are equal, channel priority is in ascending order.
The SAR is loaded with the source (read) address. If the transfer is from a peripheral device
to memory, the source address is the location of the peripheral data register. If the transfer
is from memory to either a peripheral device or memory, the source address is the starting
address of the data block. This can be any aligned byte address. In single-address mode, this
data register is used regardless of transfer direction.
Chapter 12. DMA Controller Module
12-13
DMA Controller Module Functional Description
The DAR should contain the destination (write) address. If the transfer is from a peripheral
device to memory, or memory to memory, the DAR is loaded with the starting address of
the data block to be written. If the transfer is from memory to a peripheral device, DAR is
loaded with the address of the peripheral data register. This address can be any aligned byte
address. DAR is not used in single-address mode.
SAR and DAR change after each cycle depending on DCR[SSIZE,DSIZE,SINC,DINC]
and on the starting address. Increment values can be 1, 2, 4, or 16 for byte, word, longword,
or line transfers, respectively. If the address register is programmed to remain unchanged
(no count), the register is not incremented after the data transfer.
BCRn[BCR] must be loaded with the number of byte transfers to occur. It is decremented
by 1, 2, 4, or 16 at the end of each transfer, depending on the transfer size. DSR must be
cleared for channel startup.
As soon as the channel has been initialized, it is started by writing a one to DCR[START]
or asserting DREQ, depending on the status of DCR[EEXT]. Programming the channel for
internal request causes the channel to request the bus and start transferring data
immediately. If the channel is programmed for external request, DREQ must be asserted
before the channel requests the bus.
Changes to DCR are effective immediately while the channel is active. To avoid problems
with changing a DMA channel setup, write a one to DSR[DONE] to stop the DMA channel.
12.5.4 Data Transfer
This section includes timing diagrams that illustrate the interaction of signals in DMA data
transfers. It also describes auto-alignment and bandwidth control.
12.5.4.1 External Request and Acknowledge Operation
Channels 0 and 1 initiate transfers to an external module by means of DREQ[1:0]. The
request for channels 2 and 3 are connected internally to the UART0 and UART1 interrupt
signals, respectively. If DCR[EEXT] = 1 and the channel is idle, the DMA initiates a
transfer when DREQ is asserted.
Figure 12-11 shows the minimum 4-clock cycle delay from when DREQ is sampled
asserted to when a DMA bus cycle begins. This delay may be longer, depending on DMA
priority, bus arbitration, DRAM refresh operations, and other factors.
12-14
MCF5407 User’s Manual
DMA Controller Module Functional Description
0
1
2
3
4
5
6
7
8
9
10
11
CLKIN
DREQ0
TM0/DACK0
TT1
TT0
TS
CS
TA
R/W
A[31:0]
Read
Write
Figure 12-11. DREQ Timing Constraints, Dual-Address DMA Transfer
Although Figure 12-11 does not show TM0/DACK0 signaling a DMA acknowledgement,
this signal can provide an external request acknowledge response, as shown in subsequent
diagrams.
To initiate a request, DREQ need only be asserted long enough to be sampled on one rising
clock edge. However, note the following regarding the negation of DREQ:
•
•
In cycle-steal mode (DCR[CS] = 1), the read/write transaction is limited to a single
transfer. DREQ must be negated appropriately to avoid generating another request.
— For dual-address transfers, DREQ must be negated before TS is asserted for the
write portion, as shown in Figure 12-11, clock cycle 7.
— For single-address transfers, DREQ must be negated before TS is asserted for the
transfer, as shown in Figure 12-13, clock cycle 4.
In burst mode, (DCR[CS] = 0), multiple read/write transfers can occur on the bus as
programmed. DREQ need not be negated until DSR[DONE] is set, indicating the
block transfer is complete. Another transfer cannot be initiated until the DMA
registers are reprogrammed.
Figure 12-12 shows a dual-address, peripheral-to-SDRAM DMA transfer. The DMA is not
parked on the bus, so the diagram shows how the CPU can generate multiple bus cycles
during DMA transfers. It also shows TM0/DACK0 timing. The TT signals indicate whether
the CPU (0) or DMA (1) has bus mastership. TM2 indicates dual-address mode.
If DCR[AT] is 1, TM/DACK is asserted during the final transfer. If DCR[AT] is 0,
TM/DACK asserts during all DMA accesses.
Chapter 12. DMA Controller Module
12-15
DMA Controller Module Functional Description
CLKIN
TS
AS
TIP
A[31:0]
R/W
SIZ[1:0]
D[31:0]
CSx
TA
DRAMW
Precharge
SRAS
SCAS
RAS[1:0]
CAS[3:0]
TT[1:0]
0
1
0
1
0
TM2
TM0/DACK0
DREQ0
CPU
DMA Read
CPU
DMA Write
CPU
Figure 12-12. Dual-Address, Peripheral-to-SDRAM, Lower-Priority DMA Transfer
Figure 12-13 shows a single-address DMA transfer in which the peripheral is reading from
memory. Note that TM2 is high, indicating a single-address transfer. Note that DREQ is
negated in clock 4, before the assertion of TS in clock 6.
12-16
MCF5407 User’s Manual
DMA Controller Module Functional Description
0
1
2
3
4
5
6
7
8
9
10
11
CLKIN
DREQ0
TM0/DACK0
TS
A[31:0], SIZ[1:0]
TIP
R/W
TM2
TT0
TT1
CSx, AS
OE, BE/BWE
TA
D[31:0]
Figure 12-13. Single-Address DMA Transfer
12.5.4.2 Auto-Alignment
Auto-alignment allows block transfers to occur at the optimal size based on the address,
byte count, and programmed size. To use this feature, DCR[AA] must be set. The source is
auto-aligned if SSIZE indicates a transfer size larger than DSIZE. Source alignment takes
precedence over the destination when the source and destination sizes are equal. Otherwise,
the destination is auto-aligned. The address register chosen for alignment increments
regardless of the increment value. Configuration error checking is performed on registers
not chosen for alignment.
If BCR is greater than 16, the address determines transfer size. Bytes, words, or longwords
are transferred until the address is aligned to the programmed size boundary, at which time
accesses begin using the programmed size.
If BCR is less than 16 at the start of a transfer, the number of bytes remaining dictates
transfer size. For example, AA = 1, SAR = 0x0001, BCR = 0x00F0, SSIZE = 00
(longword), and DSIZE = 01 (byte). Because SSIZE > DSIZE, the source is auto-aligned.
Error checking is performed on destination registers. The access sequence is as follows:
1.
2.
3.
4.
Read byte from 0x0001—write 1 byte, increment SAR.
Read word from 0x0002—write 2 bytes, increment SAR.
Read longword from 0x0004—write 4 bytes, increment SAR.
Repeat longwords until SAR = 0x00F0.
Chapter 12. DMA Controller Module
12-17
DMA Controller Module Functional Description
5. Read byte from 0x00F0—write byte, increment SAR.
If DSIZE is another size, data writes are optimized to write the largest size allowed based
on the address, but not exceeding the configured size.
12.5.4.3 Bandwidth Control
Bandwidth control makes it possible to force the DMA off the bus to allow access to
another device. DCR[BWC] provides seven levels of block transfer sizes. If the BCR
decrements to a multiple of the decode of the BWC, the DMA bus request negates until the
bus cycle terminates. If a request is pending, the arbiter may then pass bus mastership to
another device. If auto-alignment is enabled, DCR[AA] = 1, the BCR may skip over the
programmed boundary, in which case, the DMA bus request is not negated.
If BWC = 000, the request signal remains asserted until BCR reaches zero. DMA has
priority over the core. Note that in this scheme, the arbiter can always force the DMA to
relinquish the bus. See Section 6.2.10.1, “Default Bus Master Park Register (MPARK).”
12.5.5 Termination
An unsuccessful transfer can terminate for one of the following reasons:
•
•
12-18
Error conditions—When the MCF5407 encounters a read or write cycle that
terminates with an error condition, DSR[BES] is set for a read and DSR[BED] is set
for a write before the transfer is halted. If the error occurred in a write cycle, data in
the internal holding register is lost.
Interrupts—If DCR[INT] is set, the DMA drives the appropriate internal interrupt
signal. The processor can read DSR to determine whether the transfer terminated
successfully or with an error. DSR[DONE] is then written with a one to clear the
interrupt and the DONE and error bits.
MCF5407 User’s Manual
Chapter 13
Timer Module
This chapter describes the configuration and operation of the two general-purpose timer
modules (timer 0 and timer 1). It includes programming examples.
13.1 Overview
The timer module incorporates two independent, general-purpose 16-bit timers, timer 0 and
timer 1. The output of an 8-bit prescaler clocks each timer. There are two sets of registers,
one for each timer. The timers can operate from CLKIN or from an external clocking source
using one of the TIN signals. If CLKIN is selected, it can be divided by 16 or 1.
Figure 13-1 is a block diagram of one of the two identical ti5mer modules.
GENERAL-PURPOSE TIMER
CLKIN
(÷1 or ÷16)
Timer Mode Register (TMRn)
Prescaler
Mode Bits
Timer
Clock
Generator
TIN
clock
Capture
Detection
15
0
Timer Counter (TCNn)
(contains incrementing value)
15
TOUT
IRQn
Divider
0
Timer Capture Register (TCRn)
(latches TCN value when triggered by TIN)
15
0
Timer Reference Register (TRRn)
(reference value for comparison with TCN)
Timer Event Register (TERn)
(indicates capture or when TCN = TRRn)
Figure 13-1. Timer Block Diagram
Chapter 13. Timer Module
13-1
General-Purpose Timer Units
13.1.1 Key Features
Each general-purpose 16-bit timer unit has the following features:
•
•
•
•
•
•
•
Maximum period of 4.97 seconds at 54 MHz
18.5-nS resolution at 54 MHz
Programmable sources for the clock input, including external clock
Input-capture capability with programmable trigger edge on input pin
Output-compare with programmable mode for the output pin
Free run and restart modes
Maskable interrupts on input capture or reference-compare
13.2 General-Purpose Timer Units
The general-purpose timer units provide the following features:
•
•
•
•
•
•
Each timer can be programmed to count and compare to a reference value stored in
a register or capture the timer value at an edge detected on TIN.
System bus clock can be divided by 16 or 1. This clock is input to the prescaler.
TIN is fed directly into the 8-bit prescaler. The maximum value of TIN is 1/5 of
CLKIN, as described in Chapter 20, “Electrical Specifications.”
The 8-bit prescaler clock divides the clocking source and is user-programmable
from 1 to 256.
Programmed events generate interrupts.
The timer output signal (TOUT) can be configured to toggle or pulse on an event.
13.3 General-Purpose Timer Programming Model
The following features are programmable through the timer registers, shown in Table 13-1:
•
•
13-2
Prescaler—The prescaler clock input is selected from CLKIN (divided by 1 or 16)
or from the corresponding timer input, TIN. TIN is synchronized to CLKIN. The
synchronization delay is between two and three CLKIN clocks. The corresponding
TMRn[ICLK] selects the clock input source. A programmable prescaler divides the
clock input by values from 1 to 256. The prescaler is an input to the 16-bit counter.
Capture mode—Each timer has a 16-bit timer capture register (TCR0 and TCR1)
that latches the counter value when the corresponding input capture edge detector
senses a defined TIN transition. The capture edge bits (TMRn[CE]) select the type
of transition that triggers the capture, sets the timer event register capture event bit,
TERn[CAP], and issues a maskable interrupt.
MCF5407 User’s Manual
General-Purpose Timer Programming Model
•
•
Reference compare—A timer can be configured to count up to a reference value, at
which point TERn[REF] is set. If TMRn[ORI] is one, an interrupt is issued. If the
free run/restart bit TMRn[FRR] is set, a new count starts. If it is clear, the timer
keeps running.
Output mode—When a timer reaches the reference value selected by TMRn[OM],
it can send an output signal on TOUTn. TOUTn can be an active-low pulse or a
toggle of the current output under program control.
NOTE:
Although external devices cannot access MCF5407 on-chip
memories or MBAR, they can access timer module registers.
The timer module registers, shown in Table 13-1, can be modified at any time.
Table 13-1. General-Purpose Timer Module Memory Map
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x140
Timer 0 mode register (TMR0) [p. 13-3]
0x144
Timer 0 reference register (TRR0) [p. 13-4]
Reserved
0x148
Timer 0 capture register (TCR0) [p. 13-4]
Reserved
0x14C
Timer 0 counter (TCN0) [p. 13-5]
Reserved
Reserved
0x150
Reserved
Timer 0 event register
(TER0) [p. 13-5]
Reserved
0x180
Timer 1 mode register (TMR1) [p. 13-3]
0x184
Timer 1 reference register (TRR1) [p. 13-4]
Reserved
0x188
Timer 1 capture register (TCR1) [p. 13-4]
Reserved
0x18C
Reserved
Timer 1 counter (TCN1) [p. 13-5]
Reserved
0x190
Reserved
Timer 1 event register
(TER1) [p. 13-5]
Reserved
13.3.1 Timer Mode Registers (TMR0/TMR1)
Timer mode registers (TMR0/TMR1), Figure 13-2, program the prescaler and various
timer modes.
15
Field
8
6
CE
Reset
5
4
3
OM ORI FRR
2
1
CLK
0
RST
0000_0000_0000_0000
R/W
Address
7
PS
R/W
MBAR + 0x140 (TMR0); + 0x180 (TMR1)
Figure 13-2. Timer Mode Registers (TMR0/TMR1)
Table 13-2 describes TMRn fields.
Chapter 13. Timer Module
13-3
General-Purpose Timer Programming Model
Table 13-2. TMRn Field Descriptions
Bits
Name
Description
15–8
PS
Prescaler value. The prescaler is programmed to divide the clock input (CLKIN/(16 or 1) or clock on
TIN) by values from 1 (PS = 0000_0000) to 256 (PS = 1111_1111).
7–6
CE
Capture edge and enable interrupt
00 Disable interrupt on capture event
01 Capture on rising edge only and enable interrupt on capture event
10 Capture on falling edge only and enable interrupt on capture event
11 Capture on any edge and enable interrupt on capture event
5
OM
Output mode
0 Active-low pulse for one CLKIN cycle (18.5 ns at 54 MHz).
1 Toggle output.
4
ORI
Output reference interrupt enable. If ORI is set when TERn[REF] = 1, an interrupt occurs.
0 Disable interrupt for reference reached (does not affect interrupt on capture function).
1 Enable interrupt upon reaching the reference value.
3
FRR
Free run/restart
0 Free run. Timer count continues to increment after reaching the reference value.
1 Restart. Timer count is reset immediately after reaching the reference value.
2–1
CLK
Input clock source for the timer
00 Stop count
01 System bus clock divided by 1
10 System bus clock divided by 16. Note that this clock source is not synchronized to the timer; thus
successive time-outs may vary slightly.
11 TIN pin (falling edge)
0
RST
Reset timer. Performs a software timer reset similar to an external reset, although other register
values can still be written while RST = 0. A transition of RST from 1 to 0 resets register values. The
timer counter is not clocked unless the timer is enabled.
0 Reset timer (software reset)
1 Enable timer
13.3.2 Timer Reference Registers (TRR0/TRR1)
Each timer reference register (TRR0/TRR1), Figure 13-3, contains the reference value
compared with the respective free-running timer counter (TCN0/TCN1) as part of the
output-compare function. The reference value is not matched until TCNn equals TRRn.
=
15
0
Field
REF
Reset
1111_1111_1111_1111
R/W
Address
R/W
MBAR + 0x144 (TRR0),+ 0x184 (TRR1)
Figure 13-3. Timer Reference Registers (TRR0/TRR1)
13.3.3 Timer Capture Registers (TCR0/TCR1)
Each timer capture register (TCR0/TCR1), Figure 13-4, latches the corresponding TCNn
value during a capture operation when an edge occurs on TIN, as programmed in TMRn.
CLKIN is assumed to be the clock source. TIN cannot simultaneously function as a
13-4
MCF5407 User’s Manual
General-Purpose Timer Programming Model
clocking source and as an input capture pin.
15
0
Field
CAP (16-bit capture counter value)
Reset
0000_0000_0000_0000
R/W
Read only
Address
MBAR + 0x148 (TCR0); + 0x188 (TCR1)
Figure 13-4. Timer Capture Register (TCR0/TCR1)
13.3.4 Timer Counters (TCN0/TCN1)
The current value of the 16-bit, incrementing timer counters (TCN0/TCN1), Figure 13-5,
can be read anytime without affecting counting. Writing to TCNn clears it. The timer
counter decrements on the clock source rising edge (CLKIN ÷ 1, CLKIN ÷ 16, or TIN).
15
0
Field
16-bit timer counter value count
Reset
0000_0000_0000_0000
R/W
R/W (to reset)
Address
MBAR + 0x14C (TCN0); + 0x18C (TCN1)
Figure 13-5. Timer Counters (TCN0/TCN1)
13.3.5 Timer Event Registers (TER0/TER1)
Each timer event register (TER0/TER1), Figure 13-6, reports capture or reference events
events the timer recognizes by setting TERn[CAP] or TERn[REF], which it does regardless
of the corresponding interrupt-enable bit values, TMRn[ORI,CE].
Writing a 1 to either REF or CAP clears it (writing a 0 does not affect bit value); both bits
can be cleared at the same time. REF and CAP must be cleared early in the exception
handler, before the timer negates the IRQn to the interrupt controller.
7
Field
Reset
R/W
Address
2
—
1
0
REF
CAP
0000_0000
R/W (ones clear/zeros have no effect)
MBAR + 0x151 (TER0); + 0x191 (TER1)
Figure 13-6. Timer Event Registers (TER0/TER1)
Chapter 13. Timer Module
13-5
Code Example
Table 13-3 describes TERn fields.
Table 13-3. TERn Field Descriptions
Bits
Name
Description
7–2
—
1
REF
Output reference event. The counter has reached the TRRn value. Setting TMRn[ORI] enables the
interrupt request caused by this event. Writing a one to REF clears the event condition.
0
CAP
Capture event. The counter value has been latched into TCRn. Setting TMRn[CE] enables the
interrupt request caused by this event. Writing a 1 to CAP clears the event condition.
Reserved
13.4 Code Example
The following code provides an example of how to initialize timer 0 and how to use the
timer for counting time-out periods.
MBARx EQU 0x10000 ;Defines the module base address at 0x10000
TMR0 EQU MBARx+0x140;Timer 0 register
TMR1 EQU MBARx+0x180 ;Timer 1 register
TRR0 EQU MBARx+0x144 ;Timer 0 reference register
TRR1 EQU MBARx+0x184 ;Timer 1 reference register
TCR0 EQU MBARx+0x148 ;Timer 0 capture register
TCR1 EQU MBARx+0x188 ;Timer 1 capture register
TCN0 EQU MBARx+0x14C ;Timer 0 counter
TCN1 EQU MBARx+0x18C ;Timer 1 counter
TER0 EQU MBARx+0x151 ;Timer 0 event register
TER1 EQU MBARx+0x191 ;Timer 1 event register
* TMR0 is defined as: *
*[PS]= 0xFF, divide clock by 256
*[CE] = 00disable interrupt
*[OM] = 0 output=active-low pulse
*[ORI] = 0, disable ref.interrupt
*[FRR] = 1, restart mode enabled
*[CLK] = 10, CLKIN/16
*[RST] = 0, timer 0 disabled
move.w #0xFF0C,D0
move.w D0,TMR0
move.w #0x0000,D0;writing to the timer counter with any
move.w DO,TCN0 ;value resets it to zero
move.w #AFAF,DO ;set the timer 0 reference to be
move.w #D0,TRR0 ;defined as 0xAFAF
The simple example below uses 0 to count time-out loops. A time-out occurs when the
reference value, 0xAFAF, is reached.
timer0_ex
clr.l DO
clr.l D1
clt.l D2
move.w #0x0000,D0
move,w D0,TCN0;reset the counter to 0x0000
move.b #0x03,D0 ;writing ones to TER0[REF,CAP]
move.b D0,TER0 ;clears the event flags
13-6
MCF5407 User’s Manual
Calculating Time-Out Values
move.w TMR0,D0;save the contents of TMR0 while setting
bset #0,D0 ;the 0 bit. This enables timer 0 and starts counting
move.w D0, TMR0 ;load the value back into the register, setting TMR0[RST]
T0_LOOP
move.b TER0,D1 ;load TER0 and see if
btst #1,D1 ;TER0[REF] has been set
beq T0_LOOP
addi.l #1,D2;Increment D2
cmp.l #5,D2;Did D2 reach 5? (i.e. timer ref has timed)
beq T0_FINISH;If so, end timer0 example. Otherwise jump back.
move.b #0x02,D0 ;writing one to TER0[REF] clears the event flag
move.b D0,TER0
jmp T0_LOOP
T0_FINISH
HALT;End processing. Example is finished
13.5 Calculating Time-Out Values
The formula below determines time-out periods for various reference values:
Time-out period = (1/clock frequency) x (1 or 16) x (TMRn[PS] + 1) x
(TRRn[REF])
When calculating time-out periods, add 1 to the prescaler to simplify calculating, because
TMRn[PS] = 0x00 yields a prescaler of 1 and TMRn[PS] = 0xFF yields a prescaler of 256.
For example, if a 54-MHz timer clock is divided by 16, TMRn[PS] = 0x7F, and the timer
is referenced at 0xABCD (43,981 decimal), the time-out period is as follows:
Time-out period = (1/54,000,000) x (16) x (127 + 1) x (43,981) = 1.67 S
The time-out values in Table 13-4 represent the time it takes the counter value in TCNn
value to go from 0x0000 to the default reference value, TRRn[REF] = 0xFFFF. Time-out
values shown for CLKIN are divided by 1 and by 16 (TMRn[CLK] is 01 or 10,
respectively).
Any clock source (CLKIN ÷ 1, CLKIN ÷ 16, or TIN) can be prescaled using TMRn[PS].
Table 13-4. Time-Out Values (in Seconds)—TRR[REF] = 0xFFFF
(162-MHz Processor Clock)
CLK = 10 (÷ 1)
CLK = 01 (÷ 16)
TMR[PS]
(Dec)
CLKIN (MHz)
0
CLK = 10 (÷ 1)
CLK = 01 (÷ 16)
TMR[PS]
(Dec)
CLKIN (MHz)
0.019 0.026 0.032 0.001 0.002 0.002
128
2.505 3.340 4.175 0.157 0.209 0.261
1
0.039 0.052 0.065 0.002 0.003 0.004
129
2.524 3.366 4.207 0.158 0.210 0.263
2
0.058 0.078 0.097 0.004 0.005 0.006
130
2.544 3.392 4.240 0.159 0.212 0.265
3
0.078 0.104 0.129 0.005 0.006 0.008
131
2.563 3.418 4.272 0.160 0.214 0.267
4
0.097 0.129 0.162 0.006 0.008 0.010
132
2.583 3.443 4.304 0.161 0.215 0.269
5
0.117 0.155 0.194 0.007 0.010 0.012
133
2.602 3.469 4.337 0.163 0.217 0.271
54
40.5
32.4
54
40.5
32.4
54
Chapter 13. Timer Module
40.5
32.4
54
40.5
32.4
13-7
Calculating Time-Out Values
Table 13-4. Time-Out Values (in Seconds)—TRR[REF] = 0xFFFF
(162-MHz Processor Clock) (Continued)
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLK = 01 (÷ 16)
54
40.5
32.4
54
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLKIN (MHz)
40.5
CLK = 01 (÷ 16)
CLKIN (MHz)
32.4
54
40.5
32.4
54
40.5
32.4
6
0.136 0.181 0.227 0.008 0.011 0.014
134
2.621 3.495 4.369 0.164 0.218 0.273
7
0.155 0.207 0.259 0.010 0.013 0.016
135
2.641 3.521 4.401 0.165 0.220 0.275
8
0.175 0.233 0.291 0.011 0.015 0.018
136
2.660 3.547 4.434 0.166 0.222 0.277
9
0.194 0.259 0.324 0.012 0.016 0.020
137
2.680 3.573 4.466 0.167 0.223 0.279
10
0.214 0.285 0.356 0.013 0.018 0.022
138
2.699 3.599 4.499 0.169 0.225 0.281
11
0.233 0.311 0.388 0.015 0.019 0.024
139
2.719 3.625 4.531 0.170 0.227 0.283
12
0.252 0.337 0.421 0.016 0.021 0.026
140
2.738 3.651 4.563 0.171 0.228 0.285
13
0.272 0.362 0.453 0.017 0.023 0.028
141
2.757 3.676 4.596 0.172 0.230 0.287
14
0.291 0.388 0.485 0.018 0.024 0.030
142
2.777 3.702 4.628 0.174 0.231 0.289
15
0.311 0.414 0.518 0.019 0.026 0.032
143
2.796 3.728 4.660 0.175 0.233 0.291
16
0.330 0.440 0.550 0.021 0.028 0.034
144
2.816 3.754 4.693 0.176 0.235 0.293
17
0.350 0.466 0.583 0.022 0.029 0.036
145
2.835 3.780 4.725 0.177 0.236 0.295
18
0.369 0.492 0.615 0.023 0.031 0.038
146
2.854 3.806 4.757 0.178 0.238 0.297
19
0.388 0.518 0.647 0.024 0.032 0.040
147
2.874 3.832 4.790 0.180 0.239 0.299
20
0.408 0.544 0.680 0.025 0.034 0.042
148
2.893 3.858 4.822 0.181 0.241 0.301
21
0.427 0.570 0.712 0.027 0.036 0.044
149
2.913 3.884 4.855 0.182 0.243 0.303
22
0.447 0.595 0.744 0.028 0.037 0.047
150
2.932 3.910 4.887 0.183 0.244 0.305
23
0.466 0.621 0.777 0.029 0.039 0.049
151
2.952 3.935 4.919 0.184 0.246 0.307
24
0.485 0.647 0.809 0.030 0.040 0.051
152
2.971 3.961 4.952 0.186 0.248 0.309
25
0.505 0.673 0.841 0.032 0.042 0.053
153
2.990 3.987 4.984 0.187 0.249 0.311
26
0.524 0.699 0.874 0.033 0.044 0.055
154
3.010 4.013 5.016 0.188 0.251 0.314
27
0.544 0.725 0.906 0.034 0.045 0.057
155
3.029 4.039 5.049 0.189 0.252 0.316
28
0.563 0.751 0.939 0.035 0.047 0.059
156
3.049 4.065 5.081 0.191 0.254 0.318
29
0.583 0.777 0.971 0.036 0.049 0.061
157
3.068 4.091 5.113 0.192 0.256 0.320
30
0.602 0.803 1.003 0.038 0.050 0.063
158
3.087 4.117 5.146 0.193 0.257 0.322
31
0.621 0.829 1.036 0.039 0.052 0.065
159
3.107 4.143 5.178 0.194 0.259 0.324
32
0.641 0.854 1.068 0.040 0.053 0.067
160
3.126 4.168 5.211 0.195 0.261 0.326
33
0.660 0.880 1.100 0.041 0.055 0.069
161
3.146 4.194 5.243 0.197 0.262 0.328
34
0.680 0.906 1.133 0.042 0.057 0.071
162
3.165 4.220 5.275 0.198 0.264 0.330
35
0.699 0.932 1.165 0.044 0.058 0.073
163
3.185 4.246 5.308 0.199 0.265 0.332
36
0.718 0.958 1.197 0.045 0.060 0.075
164
3.204 4.272 5.340 0.200 0.267 0.334
37
0.738 0.984 1.230 0.046 0.061 0.077
165
3.223 4.298 5.372 0.201 0.269 0.336
38
0.757 1.010 1.262 0.047 0.063 0.079
166
3.243 4.324 5.405 0.203 0.270 0.338
39
0.777 1.036 1.295 0.049 0.065 0.081
167
3.262 4.350 5.437 0.204 0.272 0.340
40
0.796 1.062 1.327 0.050 0.066 0.083
168
3.282 4.376 5.469 0.205 0.273 0.342
41
0.816 1.087 1.359 0.051 0.068 0.085
169
3.301 4.401 5.502 0.206 0.275 0.344
42
0.835 1.113 1.392 0.052 0.070 0.087
170
3.320 4.427 5.534 0.208 0.277 0.346
13-8
MCF5407 User’s Manual
Calculating Time-Out Values
Table 13-4. Time-Out Values (in Seconds)—TRR[REF] = 0xFFFF
(162-MHz Processor Clock) (Continued)
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLK = 01 (÷ 16)
54
40.5
32.4
54
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLKIN (MHz)
40.5
CLK = 01 (÷ 16)
CLKIN (MHz)
32.4
54
40.5
32.4
54
40.5
32.4
43
0.854 1.139 1.424 0.053 0.071 0.089
171
3.340 4.453 5.567 0.209 0.278 0.348
44
0.874 1.165 1.456 0.055 0.073 0.091
172
3.359 4.479 5.599 0.210 0.280 0.350
45
0.893 1.191 1.489 0.056 0.074 0.093
173
3.379 4.505 5.631 0.211 0.282 0.352
46
0.913 1.217 1.521 0.057 0.076 0.095
174
3.398 4.531 5.664 0.212 0.283 0.354
47
0.932 1.243 1.553 0.058 0.078 0.097
175
3.418 4.557 5.696 0.214 0.285 0.356
48
0.951 1.269 1.586 0.059 0.079 0.099
176
3.437 4.583 5.728 0.215 0.286 0.358
49
0.971 1.295 1.618 0.061 0.081 0.101
177
3.456 4.609 5.761 0.216 0.288 0.360
50
0.990 1.320 1.651 0.062 0.083 0.103
178
3.476 4.634 5.793 0.217 0.290 0.362
51
1.010 1.346 1.683 0.063 0.084 0.105
179
3.495 4.660 5.825 0.218 0.291 0.364
52
1.029 1.372 1.715 0.064 0.086 0.107
180
3.515 4.686 5.858 0.220 0.293 0.366
53
1.049 1.398 1.748 0.066 0.087 0.109
181
3.534 4.712 5.890 0.221 0.295 0.368
54
1.068 1.424 1.780 0.067 0.089 0.111
182
3.554 4.738 5.923 0.222 0.296 0.370
55
1.087 1.450 1.812 0.068 0.091 0.113
183
3.573 4.764 5.955 0.223 0.298 0.372
56
1.107 1.476 1.845 0.069 0.092 0.115
184
3.592 4.790 5.987 0.225 0.299 0.374
57
1.126 1.502 1.877 0.070 0.094 0.117
185
3.612 4.816 6.020 0.226 0.301 0.376
58
1.146 1.528 1.909 0.072 0.095 0.119
186
3.631 4.842 6.052 0.227 0.303 0.378
59
1.165 1.553 1.942 0.073 0.097 0.121
187
3.651 4.867 6.084 0.228 0.304 0.380
60
1.185 1.579 1.974 0.074 0.099 0.123
188
3.670 4.893 6.117 0.229 0.306 0.382
61
1.204 1.605 2.007 0.075 0.100 0.125
189
3.689 4.919 6.149 0.231 0.307 0.384
62
1.223 1.631 2.039 0.076 0.102 0.127
190
3.709 4.945 6.181 0.232 0.309 0.386
63
1.243 1.657 2.071 0.078 0.104 0.129
191
3.728 4.971 6.214 0.233 0.311 0.388
64
1.262 1.683 2.104 0.079 0.105 0.131
192
3.748 4.997 6.246 0.234 0.312 0.390
65
1.282 1.709 2.136 0.080 0.107 0.133
193
3.767 5.023 6.279 0.235 0.314 0.392
66
1.301 1.735 2.168 0.081 0.108 0.136
194
3.787 5.049 6.311 0.237 0.316 0.394
67
1.320 1.761 2.201 0.083 0.110 0.138
195
3.806 5.075 6.343 0.238 0.317 0.396
68
1.340 1.786 2.233 0.084 0.112 0.140
196
3.825 5.100 6.376 0.239 0.319 0.398
69
1.359 1.812 2.265 0.085 0.113 0.142
197
3.845 5.126 6.408 0.240 0.320 0.400
70
1.379 1.838 2.298 0.086 0.115 0.144
198
3.864 5.152 6.440 0.242 0.322 0.403
71
1.398 1.864 2.330 0.087 0.117 0.146
199
3.884 5.178 6.473 0.243 0.324 0.405
72
1.418 1.890 2.363 0.089 0.118 0.148
200
3.903 5.204 6.505 0.244 0.325 0.407
73
1.437 1.916 2.395 0.090 0.120 0.150
201
3.922 5.230 6.537 0.245 0.327 0.409
74
1.456 1.942 2.427 0.091 0.121 0.152
202
3.942 5.256 6.570 0.246 0.328 0.411
75
1.476 1.968 2.460 0.092 0.123 0.154
203
3.961 5.282 6.602 0.248 0.330 0.413
76
1.495 1.994 2.492 0.093 0.125 0.156
204
3.981 5.308 6.635 0.249 0.332 0.415
77
1.515 2.019 2.524 0.095 0.126 0.158
205
4.000 5.333 6.667 0.250 0.333 0.417
78
1.534 2.045 2.557 0.096 0.128 0.160
206
4.020 5.359 6.699 0.251 0.335 0.419
79
1.553 2.071 2.589 0.097 0.129 0.162
207
4.039 5.385 6.732 0.252 0.337 0.421
Chapter 13. Timer Module
13-9
Calculating Time-Out Values
Table 13-4. Time-Out Values (in Seconds)—TRR[REF] = 0xFFFF
(162-MHz Processor Clock) (Continued)
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLK = 01 (÷ 16)
54
40.5
32.4
54
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLKIN (MHz)
40.5
CLK = 01 (÷ 16)
CLKIN (MHz)
32.4
54
40.5
32.4
54
40.5
32.4
80
1.573 2.097 2.621 0.098 0.131 0.164
208
4.058 5.411 6.764 0.254 0.338 0.423
81
1.592 2.123 2.654 0.100 0.133 0.166
209
4.078 5.437 6.796 0.255 0.340 0.425
82
1.612 2.149 2.686 0.101 0.134 0.168
210
4.097 5.463 6.829 0.256 0.341 0.427
83
1.631 2.175 2.719 0.102 0.136 0.170
211
4.117 5.489 6.861 0.257 0.343 0.429
84
1.651 2.201 2.751 0.103 0.138 0.172
212
4.136 5.515 6.893 0.259 0.345 0.431
85
1.670 2.227 2.783 0.104 0.139 0.174
213
4.155 5.541 6.926 0.260 0.346 0.433
86
1.689 2.252 2.816 0.106 0.141 0.176
214
4.175 5.567 6.958 0.261 0.348 0.435
87
1.709 2.278 2.848 0.107 0.142 0.178
215
4.194 5.592 6.991 0.262 0.350 0.437
88
1.728 2.304 2.880 0.108 0.144 0.180
216
4.214 5.618 7.023 0.263 0.351 0.439
89
1.748 2.330 2.913 0.109 0.146 0.182
217
4.233 5.644 7.055 0.265 0.353 0.441
90
1.767 2.356 2.945 0.110 0.147 0.184
218
4.253 5.670 7.088 0.266 0.354 0.443
91
1.786 2.382 2.977 0.112 0.149 0.186
219
4.272 5.696 7.120 0.267 0.356 0.445
92
1.806 2.408 3.010 0.113 0.150 0.188
220
4.291 5.722 7.152 0.268 0.358 0.447
93
1.825 2.434 3.042 0.114 0.152 0.190
221
4.311 5.748 7.185 0.269 0.359 0.449
94
1.845 2.460 3.075 0.115 0.154 0.192
222
4.330 5.774 7.217 0.271 0.361 0.451
95
1.864 2.486 3.107 0.117 0.155 0.194
223
4.350 5.800 7.249 0.272 0.362 0.453
96
1.884 2.511 3.139 0.118 0.157 0.196
224
4.369 5.825 7.282 0.273 0.364 0.455
97
1.903 2.537 3.172 0.119 0.159 0.198
225
4.388 5.851 7.314 0.274 0.366 0.457
98
1.922 2.563 3.204 0.120 0.160 0.200
226
4.408 5.877 7.347 0.275 0.367 0.459
99
1.942 2.589 3.236 0.121 0.162 0.202
227
4.427 5.903 7.379 0.277 0.369 0.461
100
1.961 2.615 3.269 0.123 0.163 0.204
228
4.447 5.929 7.411 0.278 0.371 0.463
101
1.981 2.641 3.301 0.124 0.165 0.206
229
4.466 5.955 7.444 0.279 0.372 0.465
102
2.000 2.667 3.333 0.125 0.167 0.208
230
4.486 5.981 7.476 0.280 0.374 0.467
103
2.019 2.693 3.366 0.126 0.168 0.210
231
4.505 6.007 7.508 0.282 0.375 0.469
104
2.039 2.719 3.398 0.127 0.170 0.212
232
4.524 6.033 7.541 0.283 0.377 0.471
105
2.058 2.744 3.431 0.129 0.172 0.214
233
4.544 6.058 7.573 0.284 0.379 0.473
106
2.078 2.770 3.463 0.130 0.173 0.216
234
4.563 6.084 7.605 0.285 0.380 0.475
107
2.097 2.796 3.495 0.131 0.175 0.218
235
4.583 6.110 7.638 0.286 0.382 0.477
108
2.117 2.822 3.528 0.132 0.176 0.220
236
4.602 6.136 7.670 0.288 0.384 0.479
109
2.136 2.848 3.560 0.133 0.178 0.222
237
4.622 6.162 7.703 0.289 0.385 0.481
110
2.155 2.874 3.592 0.135 0.180 0.225
238
4.641 6.188 7.735 0.290 0.387 0.483
111
2.175 2.900 3.625 0.136 0.181 0.227
239
4.660 6.214 7.767 0.291 0.388 0.485
112
2.194 2.926 3.657 0.137 0.183 0.229
240
4.680 6.240 7.800 0.292 0.390 0.487
113
2.214 2.952 3.689 0.138 0.184 0.231
241
4.699 6.266 7.832 0.294 0.392 0.489
114
2.233 2.977 3.722 0.140 0.186 0.233
242
4.719 6.291 7.864 0.295 0.393 0.492
115
2.252 3.003 3.754 0.141 0.188 0.235
243
4.738 6.317 7.897 0.296 0.395 0.494
116
2.272 3.029 3.787 0.142 0.189 0.237
244
4.757 6.343 7.929 0.297 0.396 0.496
13-10
MCF5407 User’s Manual
Calculating Time-Out Values
Table 13-4. Time-Out Values (in Seconds)—TRR[REF] = 0xFFFF
(162-MHz Processor Clock) (Continued)
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLK = 01 (÷ 16)
54
40.5
32.4
54
CLK = 10 (÷ 1)
TMR[PS]
(Dec)
CLKIN (MHz)
40.5
CLK = 01 (÷ 16)
CLKIN (MHz)
32.4
54
40.5
32.4
54
40.5
32.4
117
2.291 3.055 3.819 0.143 0.191 0.239
245
4.777 6.369 7.961 0.299 0.398 0.498
118
2.311 3.081 3.851 0.144 0.193 0.241
246
4.796 6.395 7.994 0.300 0.400 0.500
119
2.330 3.107 3.884 0.146 0.194 0.243
247
4.816 6.421 8.026 0.301 0.401 0.502
120
2.350 3.133 3.916 0.147 0.196 0.245
248
4.835 6.447 8.059 0.302 0.403 0.504
121
2.369 3.159 3.948 0.148 0.197 0.247
249
4.855 6.473 8.091 0.303 0.405 0.506
122
2.388 3.185 3.981 0.149 0.199 0.249
250
4.874 6.499 8.123 0.305 0.406 0.508
123
2.408 3.210 4.013 0.150 0.201 0.251
251
4.893 6.524 8.156 0.306 0.408 0.510
124
2.427 3.236 4.045 0.152 0.202 0.253
252
4.913 6.550 8.188 0.307 0.409 0.512
125
2.447 3.262 4.078 0.153 0.204 0.255
253
4.932 6.576 8.220 0.308 0.411 0.514
126
2.466 3.288 4.110 0.154 0.206 0.257
254
4.952 6.602 8.253 0.309 0.413 0.516
127
2.486 3.314 4.143 0.155 0.207 0.259
255
4.971 6.628 8.285 0.311 0.414 0.518
Chapter 13. Timer Module
13-11
Calculating Time-Out Values
13-12
MCF5407 User’s Manual
Chapter 14
UART Modules
This chapter describes the use of the universal asynchronous/synchronous
receiver/transmitters (UARTs) implemented on the MCF5407 and includes programming
examples. All references to UART refer to one of these modules when in UART mode as
opposed to modem mode. Particular attention is given to the UART1 implementation of a
synchronous interface that provides a controller for an 8- or 16-bit CODEC interface and
an audio CODEC ‘97 (AC ’97) digital interface.
14.1 Overview
The MCF5407 contains two independent UARTs. UART1 on the MCF5407 provides
synchronous operation and a CODEC interface for soft modem support. Each UART can
be clocked by CLKIN, eliminating the need for an external crystal. As Figure 14-1 shows,
each UART module interfaces directly to the CPU and consists of the following:
•
•
•
•
Serial communication channel
Programmable transmitter and receiver clock generation
Internal channel control logic
Interrupt control logic
UART
Internal Channel
Control Logic
CTS
Serial
Communications
Channel
RTS
RxD
TxD
System Integration
Module (SIM)
Interrupt
Controller
Interrupt Control
Logic
Programmable
Clock
Generation
CLKIN
or
External clock (TIN)
Figure 14-1. Simplified Block Diagram
The serial communication channel provides a full-duplex asynchronous/synchronous
receiver and transmitter deriving an operating frequency from CLKIN or an external clock
using the timer pin. The transmitter converts parallel data from the CPU to a serial bit
stream, inserting appropriate start, stop, and parity bits. It outputs the resulting stream on
Chapter 14. UART Modules
14-1
Serial Module Overview
the channel transmitter serial data output (TxD). See Section 14.5.2.1, “Transmitting in
UART Mode.”
The receiver converts serial data from the channel receiver serial data input (RxD) to
parallel format, checks for a start, stop, and parity bits, or break conditions, and transfers
the assembled character onto the bus during read operations. The receiver may be polledor interrupt-driven. See Section 14.5.2.3, “Receiver.”
UART1 can be programmed to function like original UART (identical to UART0) or in one
of the following three modem modes:
•
•
•
An 8-bit CODEC interface
A 16-bit CODEC interface
An audio CODEC ‘97 (AC ’97) digital interface controller
A CODEC (code/decode) chip provides a data conversion interface for high-speed modem
designs meeting a high range of standards, such as ITU-T V.34 and PCM. UART1
interfaces to the CODEC through a serial port consisting of Tx and Rx serial data and serial
bit clock and frame inputs from the CODEC. UART1 transfers digital sample data to and
from the CODEC through the serial port.
AC ’97 defines an architecture for audio-intensive personal computer applications such as
gaming, authoring, and high-resolution music and video playback. An external AC ’97
analog device performs mixing, analog processing, and sample-rate DAC and ADC.
UART1 interfaces to the AC ’97 device through a serial port consisting of Tx and Rx serial
data, a serial bit clock, and a frame sync output generated by UART1 from the serial bit
clock. An MCF5407 general-purpose I/O (GPIO) is used as a reset to the AC ‘97 device.
UART1 transfers digital sample data as well as control/status information to and from the
AC ‘97 device through the serial port.
Unless otherwise specified, descriptions in this chapter refer to UART mode.
14.2 Serial Module Overview
The MCF5407 contains two independent UART modules, whose features are as follows:
•
•
•
•
•
•
14-2
Each can be clocked by CLKIN, eliminating a need for an external crystal
Full-duplex asynchronous/synchronous receiver/transmitter channel
Quadruple-buffered receiver
Double-buffered transmitter
Independently programmable receiver and transmitter clock sources
Programmable data format:
— 5–8 data bits plus parity
— Odd, even, no parity, or force parity
— One, one-and-a-half, or two stop bits
MCF5407 User’s Manual
Register Descriptions
•
•
•
•
•
•
•
•
•
Each channel programmable to normal (full-duplex), automatic echo, local
loop-back, or remote loop-back mode
Automatic wake-up mode for multidrop applications
Four maskable interrupt conditions
UART0 and UART1 have interrupt capability to DMA channels 2 and 3,
respectively, when either the RxRDY or FFULL bit is set in the USR.
Parity, framing, and overrun error detection
False-start bit detection
Line-break detection and generation
Detection of breaks originating in the middle of a character
Start/end break interrupt/status
UART1 has the following additional features:
•
•
•
•
•
Programmable to interface to an 8- or 16-bit CODEC for soft modem support
Programmable to function as a digital AC ’97 controller
Tx and Rx FIFOs can hold the following:
— 32 1-byte samples when programmed as a UART or as an 8-bit CODEC interface
— 16 2-byte samples when programmed as a 16-bit CODEC interface
— 16 20-bit samples when programmed as a digital AC ’97 controller
Both DMA channels associated with the UARTs can be programmed to service
UART1 (one for the Tx channel and one for the Rx channel)
No parity error, framing error, or line break detection in modem mode
14.3 Register Descriptions
This section contains a detailed description of each register and its specific function.
Flowcharts in Section 14.5.6, “Programming,” describe basic UART module programming.
The operation of the UART module is controlled by writing control bytes into the
appropriate registers. Table 14-1 is a memory map for UART module registers.
Chapter 14. UART Modules
14-3
Register Descriptions
Table 14-1. UART Module Programming Model
MBAR Offset
[31:24]
[23:16]
[15:8]
[7:0]
UART0
UART1
0x1C0
0x200
UART mode
registers1—(UMR1n)
[p. 14-5], (UMR2n) [p.
14-7]
Rx FIFO threshold
register—(RXLVL) [p.
14-8] (UART1 only)
Modem control
Tx FIFO threshold
register—(MODCTL)
register—(TXLVL) [p.
[p. 14-9] (UART1 only) 14-10] (UART1 only)
0x1C4
0x204
(Read) UART status
registers—(USRn) [p.
14-10]
—
(Read) Rx samples
available
register—(RSMP) [p.
14-12] (UART1 only)
(Write) UART
clock-select
register1—(UCSRn)
[p. 14-12]
0x1C8
0x1CC
0x208
0x20C
(Read) Tx space
available
register—(TSPC) [p.
14-12] (UART1 only)
(Read) Do not access2 —
(Write) UART
command
registers—(UCRn) [p.
14-13]
—
(UART0/Read) UART
receiver
buffers—(URBn) [p.
14-15]
—
(UART1/Read) UART receiver buffers—(URBn) [p. 14-15]
(UART0/Write) UART
transmitter
buffers—(UTBn) [p.
14-16]
—
(UART1/Write) UART transmitter buffers—(UTBn) [p. 14-16]
0x1D0
0x210
(Read) UART input
port change
registers—(UIPCRn)
[p. 14-17]
—
(Write) UART auxiliary —
control
registers1—(UACRn)
[p. 14-17]
0x1D4
0x214
(Read) UART interrupt —
status
registers—(UISRn) [p.
14-18]
(Write) UART interrupt —
mask
registers—(UIMRn) [p.
14-18]
0x1D8
14-4
0x218
UART divider upper
registers—(UDUn) [p.
14-19]
—
MCF5407 User’s Manual
Register Descriptions
Table 14-1. UART Module Programming Model (Continued)
MBAR Offset
[31:24]
[23:16]
UART0
UART1
0x1DC
0x21C
0x1E0–
0x1EC
0x220– Do not access2
0x22C
—
0x1F0
0x230
UART interrupt vector
register—(UIVRn) [p.
14-20]
—
0x1F4
0x234
(Read) UART input
port registers—(UIPn)
[p. 14-20]
—
UART divider lower
registers—(UDLn) [p.
14-19]
[15:8]
[7:0]
—
(Write) Do not access2 —
0x1F8
0x238
(Read) Do not access2 —
(Write) UART output
port bit set command
registers—(UOP1n3)
[p. 14-21]
0x1FC
0x23C
—
(Read) Do not access2 —
(Write) UART output
port bit reset
command
registers—(UOP0n3)
[p. 14-21]
—
1
UMR1n, UMR2n, and UCSRn should be changed only after the receiver/transmitter is issued a software reset
command. That is, if channel operation is not disabled, undesirable results may occur.
2 This address is for factory testing. Reading this location results in undesired effects and possible incorrect
transmission or reception of characters. Register contents may also be changed.
3 Address-triggered commands
NOTE:
UART registers are accessible only as bytes. Although external
masters cannot access on-chip memories or MBAR, they can
access any UART registers.
14.3.1 UART Mode Registers 1 (UMR1n)
The UART mode registers 1 (UMR1n) control configuration. UMR1n can be read or
written when the mode register pointer points to it, at RESET or after a RESET MODE
REGISTER POINTER command using UCRn[MISC]. After UMR1n is read or written, the
pointer points to UMR2n.
Chapter 14. UART Modules
14-5
Register Descriptions
Field
7
6
5
RxRTS
RxIRQ/FFULL
ERR
Reset
3
PM
2
1
PT
0
B/C
0000_0000
R/W
Address
4
R/W
MBAR + 0x1C0 (UART0), 0x200 (UART1). After UMR1n is read or written, the pointer points to UMR2n.
Figure 14-2. UART Mode Registers 1 (UMR1n)
Table 14-2 describes UMR1n fields.
Table 14-2. UMR1n Field Descriptions
Name
Description
7
Bits
RxRTS
Receiver request-to-send. Allows the RTS output to control the CTS input of the transmitting device
to prevent receiver overrun. If both the receiver and transmitter are incorrectly programmed for RTS
control, RTS control is disabled for both. Transmitter RTS control is configured in UMR2n[TxRTS].
Not used in modem mode.
0 The receiver has no effect on RTS.
1 When a valid start bit is received, RTS is negated if the UART's FIFO is full. RTS is reasserted
when the FIFO has an empty position available.
6
RxIRQ/
FFULL
Receiver interrupt select. This bit is used in UART and modem modes.
0 RxRDY is the source that generates IRQ.
1 FFULL is the source that generates IRQ.
5
ERR
Error mode. Configures the FIFO status bits, USRn[RB,FE,PE]. This bit is not used in modem mode.
0 Character mode. The USRn values reflect the status of the character at the top of the FIFO. ERR
must be 0 for correct A/D flag information when in multidrop mode.
1 Block mode. The USRn values are the logical OR of the status for all characters reaching the top of
the FIFO because the last RESET ERROR STATUS command for the channel was issued. See
Section 14.3.10, “UART Command Registers (UCRn).”
4–3
PM
Parity mode. Selects the parity or multidrop mode for the channel. The parity bit is added to the
transmitted character, and the receiver performs a parity check on incoming data. The value of PM
affects PT, as shown below. PM is not used in modem mode.
2
PT
Parity type. PM and PT together select parity type (PM = 0x) or determine whether a data or address
character is transmitted (PM = 11). PT is not used in modem mode.
PM
1–0
14-6
B/C
Parity Mode
Parity Type (PT= 0)
00
With parity
Even parity
01
Force parity
Low parity
10
No parity
11
Multidrop mode
Parity Type (PT= 1)
Odd parity
High parity
n/a
Data character
Address character
Bits per character. Select the number of data bits per character to be sent. The values shown do not
include start, parity, or stop bits. B/C is not used in modem mode.
00 5 bits
01 6 bits
10 7 bits
11 8 bits
MCF5407 User’s Manual
Register Descriptions
14.3.2 UART Mode Register 2 (UMR2n)
UART mode registers 2 (UMR2n) control UART module configuration. UMR2n can be
read or written when the mode register pointer points to it, which occurs after any access to
UMR1n. UMR2n accesses do not update the pointer.
7
Field
6
CM
5
4
TxRTS
TxCTS
Reset
0
SB
0000_0000
R/W
Address
3
R/W
MBAR + 0x1C0, 0x200. After UMR1n is read or written, the pointer points to UMR2n.
Figure 14-3. UART Mode Register 2 (UMR2n)
Table 14-3 describes UMR2n fields.
Table 14-3. UMR2n Field Descriptions
Bits
Name
7–6
CM
Description
Channel mode. Selects a channel mode. Section 14.5.3, “Looping Modes,” describes individual
modes. CM is used in both UART and modem modes.
00 Normal
01 Automatic echo
10 Local loop-back
11 Remote loop-back
5
TxRTS Transmitter ready-to-send. Controls negation of RTS to automatically terminate a message
transmission. Attempting to program a receiver and transmitter in the same channel for RTS control is
not permitted and disables RTS control for both. TxRTS is not used in modem mode.
0 The transmitter has no effect on RTS.
1 In applications where the transmitter is disabled after transmission completes, setting this bit
automatically clears UOP[RTS] one bit time after any characters in the channel transmitter shift and
holding registers are completely sent, including the programmed number of stop bits.
4
TxCTS Transmitter clear-to-send. If both TxCTS and TxRTS are enabled, TxCTS controls the operation of the
transmitter. TxCTS is not used in modem mode.
0 CTS has no effect on the transmitter.
1 Enables clear-to-send operation. The transmitter checks the state of CTS each time it is ready to
send a character. If CTS is asserted, the character is sent; if it is negated, the channel TxD remains
in the high state and transmission is delayed until CTS is asserted. Changes in CTS as a character is
being sent do not affect its transmission.
Chapter 14. UART Modules
14-7
Register Descriptions
Table 14-3. UMR2n Field Descriptions (Continued)
Bits
Name
Description
3–0
SB
Stop-bit length control. Selects the length of the stop bit appended to the transmitted character.
Stop-bit lengths of 9/16th to 2 bits are programmable for 6–8 bit characters. Lengths of 1 1/16th to 2
bits are programmable for 5-bit characters. In all cases, the receiver checks only for a high condition at
the center of the first stop-bit position, that is, one bit time after the last data bit or after the parity bit, if
parity is enabled. If an external 1x clock is used for the transmitter, clearing bit 3 selects one stop bit
and setting bit 3 selects 2 stop bits for transmission. Not used in modem mode.
SB
5 Bits
6–8 Bits
SB
5 Bits
6–8 Bits
SB
5–8 Bits
SB
5–8 Bits
0000
1.063
0.563
0100
1.313
0.813
1000
1.563
1100
1.813
0001
1.125
0.625
0101
1.375
0.875
1001
1.625
1101
1.875
0010
1.188
0.688
0110
1.438
0.938
1010
1.688
1110
1.938
0011
1.250
0.750
0111
1.500
1.000
1011
1.750
1111
2.000
14.3.3 Rx FIFO Threshold Register (RXLVL)
The Rx FIFO threshold register (RXLVL) supports UART1 only and is used in both UART
and modem modes. The threshold is one less than the value at which the Rx FIFO is
considered to be full for purposes of alerting the CPU that the Rx FIFO needs to be read.
7
5
4
0
Field
—
RXLVL
Reset
000
0_0000
R/W
R/W
Address
MBAR + 0x201
Figure 14-4. Rx FIFO Threshold Register (RXLVL)
Table 14-4 describes RXLVL fields.
Table 14-4. RXLVL Field Descriptions
Bits
Name
7–5
—
4–0
RXLVL
14-8
Description
Reserved, should be cleared.
Rx FIFO full threshold level. Values of 0000–1111 specify 1–32 bytes. The Rx FIFO is full when the
number of bytes in the FIFO equals or exceeds the Rx threshold. Although FIFO thresholds are in
bytes, data is written into and read out of the FIFOs in numbers of samples, as follows:
• 1 sample = 1 byte for 8-bit CODEC and UART modes,
• 1 sample = 2 bytes for 16-bit CODEC and AC ‘97 modes
For choosing threshold values, AC ‘97 samples should be thought of as 2-byte entities.
The Rx threshold is RXLVL + 1, so RXLVL = [(# samples) * (# bytes per sample)] - 1. For example,
for Rx FIFO to indicate full when 13 or more samples have arrived, calculate RXLVL as follows:
• For 8-bit CODEC or UART mode, RXLVL = [(13 samples) * (1 byte per sample)] - 1 = 12 bytes
• For 16-bit CODEC or AC ‘97 modes, RXLVL = [(13 samples) * (2 bytes per sample)] - 1 = 25
bytes
MCF5407 User’s Manual
Register Descriptions
14.3.4 Modem Control Register (MODCTL)
The modem control register (MODCTL), Figure 14-5, controls whether UART1 is in
UART mode or in one of three modem modes.
Field
7
6
ACRB
AWR
5
4
DSL
Reset
3
2
DTS1
SHDIR
1
0
MODE
1000_0000
R/W
R/W
Address
MBAR + 0x202
Figure 14-5. Modem Control Register (MODCTL)
Table 14-5 describes MODCTL fields.
Table 14-5. Modem Control Register (MODCTL) Field Descriptions
Bits
Name
Description
7
ACRB
AC ‘97 cold reset (active low).
0 The genera-purpose I/O used as the AC ‘97 cold reset output pin is active
1 The genera-purpose I/O used as the AC ‘97 cold reset output pin is inactive
6
AWR
AC ‘97 warm reset (active high)
0 Warm reset is inactive, letting UART1’s RTS output to function normally as the AC ‘97 frame
sync.
1 Forces a 1 on UART1’s RTS output, which is used as the AC ‘97 frame sync.
5–4
DSL
Channel select for DMA channels 2 and 3. The sources for the interrupt request lines that drive
DMA DREQ[3:2] are selected by multiplexers in UART1, which are controlled by DSL.
00 DMA DREQ2 is driven by UART0 combined Tx/Rx interrupt
DMA DREQ3 is driven by UART1 combined Tx/Rx interrupt
01 DMA DREQ2 is driven by UART1 Rx interrupt
DMA DREQ3 is driven by UART1 Tx interrupt
10 same as 00
11 DMA DREQ2 is driven by UART1 Rx interrupt
DMA DREQ3 is driven by UART1 combined Tx/Rx interrupt. This combination is a by-product of
implementation and may not be useful.
When UART1 uses both DREQ lines, DREQ3 and DREQ2 are driven by the Tx FIFO empty and Rx
FIFO full conditions, respectively. The Rx FIFO not-empty condition can be used instead of Rx FIFO
full by clearing UMR1n[6]. UART0 and UART1 have separate request lines to the interrupt
controller. Each is sourced from the combined Tx/Rx interrupt from the associated UART.
3
DTS1
Delay of time slot 1. Determines the starting point of the first bit of the first time slot of a new frame.
0 The rising edge of frame sync
1 One bit-clock cycle after the rising edge of frame sync
2
SHDIR
Shift direction. For AC ‘97 this bit must be 0.
0 Samples/time slots are transferred msb first
1 Samples/time slots are transferred lsb first
1–0
MODE
Mode select for UART1.
00 UART mode (default mode after hard reset). Changing from modem mode back to UART mode
by writing 00 to this field has the same effect on UART1 as a hard reset—all registers and
control logic are reset and the Tx and Rx FIFO pointers are reinitialized, effectively emptying the
FIFOs.
01 8-bit CODEC interface mode
10 16-bit CODEC interface mode
11 AC ‘97 mode
Chapter 14. UART Modules
14-9
Register Descriptions
14.3.5 Tx FIFO Threshold Register (TXLVL)
Tx FIFO threshold register (TXLVL) supports only UART1 in both UART and modem
modes. TXLVL holds the Tx FIFO threshold, the value at which the Tx FIFO is considered
to be empty for purposes of alerting the CPU that the Tx FIFO needs more data/samples.
7
5
4
0
Field
—
TXLVL
Reset
—
0_0000
R/W
R/W
Address
MBAR + 0x203
Figure 14-6. Tx FIFO Threshold Register (TXLVL)
Table 14-6 describes TXLVL fields.
Table 14-6. TXLVL Field Descriptions
Bits
Name
7–5
—
4–0
TXLVL
Description
Reserved, should be cleared.
Tx FIFO empty threshold level. 0000–1111 selects values of 0–31 bytes, respectively. The Tx FIFO
is empty when the number of bytes in the FIFO is less than or equal to the Tx threshold value.
Although the FIFO thresholds are in numbers of bytes, data is written into and read out of the
FIFOs in numbers of samples, as follows:
1 sample = 1 byte for 8-bit CODEC and UART modes
1 sample = 2 bytes for 16-bit CODEC and AC ‘97 modes
For choosing threshold values, AC ‘97 samples should be thought of as 2-byte entities.
Choose the Tx threshold register value using the following formula:
TXLVL = (# samples) * (# bytes per sample)
For example, to indicate empty when three or fewer samples remain, calculate TXLVL as follows:
For 8-bit CODEC or UART mode, TXLVL = (3 samples) * (1 byte per sample) = 3 bytes
For 16-bit CODEC or AC ‘97 modes, TXLVL = (3 samples) * (2 bytes per sample) = 6 bytes
14.3.6 UART Status Registers (USRn)
The USRn, Figure 14-7, shows status of the transmitter, the receiver, and the FIFO.
Field
7
6
5
4
3
2
1
0
RB
FE
PE
OE
TxEMP
TxRDY
FFULL
RxRDY
Reset
0000_0000
R/W
Read only
Address
MBAR + 0x1C4 (USR0), 0x204 (USR1)
Figure 14-7. UART Status Register (USRn)
Table 14-7 describes USRn fields.
14-10
MCF5407 User’s Manual
Register Descriptions
Table 14-7. USRn Field Descriptions
Bits
Name
Description
7
RB
Received break. The received break circuit detects breaks that originate in the middle of a received
character. However, a break in the middle of a character must persist until the end of the next
detected character time. RB is not used (and is always 0) in modem mode.
0 No break was received.
1 An all-zero character of the programmed length was received without a stop bit. RB is valid only
when RxRDY = 1. Only a single FIFO position is occupied when a break is received. Further
entries to the FIFO are inhibited until RxD returns to the high state for at least one-half bit time,
which is equal to two successive edges of the UART clock.
6
FE
Framing error. FE is not used (and is always 0) in modem mode.
0 No framing error occurred.
1 No stop bit was detected when the corresponding data character in the FIFO was received. The
stop-bit check occurs in the middle of the first stop-bit position. FE is valid only when RxRDY = 1.
5
PE
Parity error. Valid only if RxRDY = 1. PE is not used (and is always 0) in modem mode.
0 No parity error occurred.
1 If UMR1n[PM] = 0x (with parity or force parity), the corresponding character in the FIFO was
received with incorrect parity. If UMR1n[PM] = 11 (multidrop), PE stores the received A/D bit.
4
OE
Overrun error. Indicates whether an overrun occurs. OE also functions this way for UART1 in
modem mode. (For purposes of overrun, FIFO full means all space in the FIFO is occupied; the Rx
FIFO threshold is irrelevant to overrun.)
0 No overrun occurred.
1 One or more characters in the received data stream have been lost. OE is set upon receipt of a
new character when the FIFO is full and a character is already in the shift register waiting for an
empty FIFO position. When this occurs, the character in the receiver shift register and its break
detect, framing error status, and parity error, if any, are lost. OE is cleared by the RESET ERROR
STATUS command in UCRn.
3
TxEMP Transmitter empty. For UART1, the function of TxEMP depends on which mode is used.
UART mode:
0 The transmitter buffer is not empty. Either a character is being shifted out, or the transmitter is
disabled. The transmitter is enabled/disabled by programming UCRn[TC].
1 The transmitter has underrun (both the transmitter holding register and transmitter shift registers
are empty). This bit is set after transmission of the last stop bit of a character if there are no
characters in the transmitter holding register awaiting transmission.
Modem mode:
0 The transmitter does not have underrun as described above.
1 The transmitter has underrun, which means the number of bytes in the Tx FIFO is zero, the Tx
shift register is empty, and a frame sync occurs. In other words, the time has come to transmit a
new sample but no sample is available in the Tx shift register. Unlike UART mode, TxEMP high
indicates an error condition similar to the overrun condition (OE = 1), and as such it is now
cleared the same way as OE, by a RESET ERROR STATUS command in the UCRn and not by a
RESET TRANSMITTER command in the UCRn.
2
TxRDY
Transmitter ready.
UART0:
0 The CPU loaded the transmitter holding register or the transmitter is disabled.
1 The transmitter holding register is empty and ready for a character. TxRDY is set when a
character is sent to the transmitter shift register and when the transmitter is first enabled. If the
transmitter is disabled, characters loaded into the transmitter holding register are not sent.
UART1 (in UART or modem modes):
0 The transmitter FIFO is not empty, or the transmitter is disabled.
1 The transmitter FIFO is empty, as defined by TXLVL. TxRDY is set when the number of bytes in
the Tx FIFO falls to, or below, the TXLVL value, due to the transfer of a sample (1 or 2 bytes) from
the Tx FIFO to the Tx shift register.
Chapter 14. UART Modules
14-11
Register Descriptions
Table 14-7. USRn Field Descriptions (Continued)
Bits
Name
Description
1
FFULL
FIFO full.
UART0:
0 The FIFO is not full but may hold up to two unread characters.
1 A character was received and is waiting in the receiver buffer FIFO.
UART1 (in UART or modem modes):
1 Rx FIFO is full, as defined by the RXLVL. FFULL is set as soon as the number of bytes in the Rx
FIFO exceeds the RXLVL value, due to the transfer of a sample (1 or 2 bytes) from the Rx shift
register to the Rx FIFO.
0
RxRDY Receiver ready (in UART or modem modes).
0 The CPU has read the receiver buffer and no characters remain in the FIFO after this read.
1 One or more characters were received and are waiting in the receiver buffer FIFO.
14.3.7 UART Clock-Select Registers (UCSRn)
The UART clock-select registers (UCSRn) select an external clock on the TIN input
(divided by 1 or 16) or a prescaled CLKIN as the clocking source for the transmitter and
receiver. See Section 14.5.1, “Transmitter/Receiver Clock Source.” UCSR1 is used in
UART mode only. The transmitter and receiver can use different clock sources. To use
CLKIN for both, set UCSRn to 0xDD.
7
Field
4
3
RCS
Reset
0000_0000
R/W
Write only
Address
0
TCS
MBAR + 0x1C4 (UCSR0), 0x204 (UCSR1)
Figure 14-8. UART Clock-Select Register (UCSRn)
Table 14-8 describes UCSRn fields.
Table 14-8. UCSRn Field Descriptions
Bits
Name
7–4
RCS
Receiver clock select. Selects the clock source for the receiver channel.
1101 Prescaled CLKIN
1110 TIN divided by 16
1111 TIN
Description
3–0
TCS
Transmitter clock select. Selects the clock source for the transmitter channel.
1101 Prescaled CLKIN
1110 TIN divided by 16
1111 TIN
14.3.8 Receive Samples Available Register (RSMP)
The receive samples available register (RSMP), Figure 14-9, shows the current byte count
for the Rx FIFO. It is in UART1 only and can be used in both UART and modem modes.
14-12
MCF5407 User’s Manual
Register Descriptions
7
5
4
0
Field
—
RSMP
Reset
—
0_0000
R/W
Read only
Address
MBAR + 0x206
Figure 14-9. Receive Samples Available Register (RSMP)
Table 14-9 describes RSMP fields.
Table 14-9. RSMP Field Descriptions
Bits
Name
7–5
—
4–0
RSMP
Description
Reserved, should be cleared.
Number of bytes in the Rx FIFO.
14.3.9 Transmit Space Available Register (TSPC)
The transmit space available register (TSPC), Figure 14-10, shows available bytes in Tx
FIFO. TSPC supports UART1 only and can be used in UART and modem modes.
7
5
Field
—
Reset
—
4
0
TSPC
0_0000
R/W
Read only
Address
MBAR + 0x207
Figure 14-10. Tx Space Available Register (TSPC)
Table 14-10 describes TSPC fields.
Table 14-10. TSPC Field Descriptions
Bits
Name
7–5
—
4–0
TSPC
Description
Reserved, should be cleared.
Number of empty bytes in the Tx FIFO.
14.3.10 UART Command Registers (UCRn)
The UART command registers (UCRn), Figure 14-11, supply commands to the UART in
both UART and modem modes. Only multiple commands that do not conflict can be
specified in a single write to a UCRn. For example, RESET TRANSMITTER and ENABLE
TRANSMITTER cannot be specified in one command.
Chapter 14. UART Modules
14-13
Register Descriptions
7
Field
6
4
—
3
MISC
Reset
2
1
TC
0
RC
0000_0000
R/W
Write only
Address
MBAR + 0x1C8, 0x208
Figure 14-11. UART Command Register (UCRn)
Table 14-11 describes UCRn fields and commands. Examples in Section 14.5.2,
“Transmitter and Receiver Operating Modes,” show how these commands are used.
Table 14-11. UCRn Field Descriptions
Bits
7
Value
Command
—
—
6–4
Description
Reserved, should be cleared.
MISC Field (This field selects a single command.)
000
NO COMMAND
—
001
RESET MODE
Causes the mode register pointer to point to UMR1n.
REGISTER POINTER
010
RESET RECEIVER
Immediately disables the receiver, clears USRn[FFULL,RxRDY], and reinitializes
the receiver FIFO pointer. No other registers are altered. Because it places the
receiver in a known state, use this command instead of RECEIVER DISABLE when
reconfiguring the receiver.
011
RESET
In UART mode, immediately disables the transmitter and clears
USRn[TxEMP,TxRDY]. No other registers are altered. Because it places the
transmitter in a known state, use this command instead of TRANSMITTER DISABLE
when reconfiguring the transmitter. When UART1 is in modem mode, TxEMP is
not cleared by this soft reset. It is cleared the same way as the Rx overflow bit,
by a RESET ERROR STATUS command.
TRANSMITTER
100
RESET ERROR
STATUS
101
RESET BREAK–
CHANGE INTERRUPT
14-14
In UART mode, clears USRn[RB,FE,PE,OE]. Also used in block mode to clear all
error bits after a data block is received. When UART1 is in modem mode, this
command also clears TxEMP.
Clears the delta break bit, UISRn[DB]. This command has no effect in modem
mode.
110
START BREAK
Forces TxD low. If the transmitter is empty, the break may be delayed up to one
bit time. If the transmitter is active, the break starts when character transmission
completes. The break is delayed until any character in the transmitter shift
register is sent. Any character in the transmitter holding register is sent after the
break. The transmitter must be enabled for the command to be accepted. This
command ignores the state of CTS and has no effect in modem mode.
111
STOP BREAK
Causes TxD to go high (mark) within two bit times. Any characters in the
transmitter buffer are sent.
MCF5407 User’s Manual
Register Descriptions
Table 14-11. UCRn Field Descriptions (Continued)
Bits
Value
Command
3–2
Description
TC Field (This field selects a single command)
00
NO ACTION TAKEN
Causes the transmitter to stay in its current mode: if the transmitter is enabled, it
remains enabled; if the transmitter is disabled, it remains disabled.
01
TRANSMITTER
Enables operation of the channel’s transmitter. USRn[TxEMP,TxRDY] are set. If
the transmitter is already enabled, this command has no effect.
For UART1 in modem mode, Tx FIFO can be loaded while the transmitter is
disabled, unlike in UART mode. Therefore, this command does not affect the
behavior of TxRDY. It does not automatically set TxRDY and TxEMP; however, if
no data is written to the Tx FIFO, TxEMP is set at the first frame sync after the
transmitter is enabled.
In AC ‘97 mode, TxEMP is set if Tx FIFO is empty, the transmitter is enabled, the
receiver detects a coded ready condition, and a frame sync occurs before
samples are written to the Tx FIFO.
ENABLE
10
TRANSMITTER
DISABLE
11
—
1–0
Terminates transmitter operation and clears USRn[TxEMP,TxRDY]. If a character
is being sent when the transmitter is disabled, transmission completes before the
transmitter becomes inactive. If the transmitter is already disabled, the command
has no effect.
In modem mode, the transmitter does not clear USRn[TxRDY] unless UART1 is
in remote loop-back or auto-echo mode. This is because in modem mode, unlike
in UART mode, the Tx FIFO may be loaded while the Tx is disabled.
Reserved, do not use.
RC (This field selects a single command)
00
NO ACTION TAKEN
Causes the receiver to stay in its current mode. If the receiver is enabled, it
remains enabled; if disabled, it remains disabled.
01
RECEIVER ENABLE
If the UART module is not in multidrop mode (UMR1n[PM] ≠ 11), RECEIVER
ENABLE enables the channel's receiver and forces it into search-for-start-bit state.
If the receiver is already enabled, this command has no effect.
10
RECEIVER DISABLE
Disables the receiver immediately. Any character being received is lost. The
command does not affect receiver status bits or other control registers. If the
UART module is programmed for local loop-back or multidrop mode, the receiver
operates even though this command is selected. If the receiver is already
disabled, the command has no effect.
When UART1 is in modem mode, if the receiver is disabled while a character is
being received, reception completes before the receiver becomes inactive.
11
—
Reserved, do not use.
14.3.11 UART Receiver Buffers (URBn)
The receiver buffer for UART0 contains one serial shift register and three receiver holding
registers, which act as a FIFO. RxD is connected to the serial shift register. The CPU reads
from the top of the stack while the receiver shifts and updates from the bottom when the
shift register is full (see Figure 14-29). RB contains the character in the receiver.
Chapter 14. UART Modules
14-15
Register Descriptions
7
0
Field
RB
Reset
0000_0000
R/W
Read only
Address
MBAR + 0x1CC
Figure 14-12. UART Receiver Buffer for UART0 (URB0)
Figure 14-13 shows the configuration of URB1.
31
24
Field
RB[31:24]
Reset
23
16
15
RB[23:16]
8
7
RB[15:8]
0
RB[7:0]
0000_0000_0000_0000_0000_0000_0000_0000
R/W
Read only
Address
MBAR + 0x20C
Figure 14-13. UART Receiver Buffer for UART1 (URB1)
14.3.12 UART Transmitter Buffers (UTBn)
The transmitter buffer for UART0 consists of the transmitter holding register and the
transmitter shift register. The holding register accepts characters from the bus master if
channel’s USRn[TxRDY] is set. A write to the transmitter buffer clears TxRDY, inhibiting
any more characters until the shift register can accept more data. When the shift register is
empty, it checks if the holding register has a valid character to be sent (TxRDY = 0). If there
is a valid character, the shift register loads it and sets USRn[TxRDY] again. Writes to the
transmitter buffer when the channel’s TxRDY = 0 and when the transmitter is disabled have
no effect on the transmitter buffer.
Figure 14-14 shows UTB0. TB contains the character in the transmitter buffer.
7
0
Field
TB
Reset
0000_0000
R/W
Address
Write only
MBAR + 0x1CC
Figure 14-14. UART Transmitter Buffer for UART0 (UTB0)
The transmitter buffer in UART1 consists of the transmitter shift register and the Tx FIFO,
as described in Section 14.5.2.6, “FIFOs in UART1.” The Tx FIFO in UART1 accepts
characters/samples from the bus master if there is room for them in the FIFO. A write to the
transmitter buffer clears TxRDY if the number of bytes in the FIFO exceeds the threshold
level in TXLVL. When the shift register is empty, it checks if the FIFO has a valid
character/sample to be sent. Valid characters are loaded into the shift register. Unlike UART
14-16
MCF5407 User’s Manual
Register Descriptions
mode, in modem mode the Tx FIFO in UART1 can be loaded while the Tx is disabled. For
UART1, FIFOs can be accessed as longwords.
Figure 14-15 shows the configuration of the UTB1. These bits contain the samples in the
transmitter buffer for UART1.
31
24
Field
23
16
TB[31:24]
15
8
TB[23:16]
Reset
7
0
TB[15:8]
TB[7:0]
0000_0000_0000_0000_0000_0000_0000_0000
R/W
Write only
Address
MBAR + 0x20C
Figure 14-15. UART Transmitter Buffer for UART1 (UTB1)
14.3.13 UART Input Port Change Registers (UIPCRn)
The input port change registers (UIPCRn), Figure 14-16, hold the current state and the
change-of-state for CTS.
7
Field
Reset
5
—
3
1
111
0000
0
R/W
Address
4
COS
0
CTS
11
CTS
Read only
MBAR + 0x1D0 (UIPCR0), 0x210 (UIPCR1)
Figure 14-16. UART Input Port Change Register (UIPCRn)
Table 14-12 describes UIPCRn fields.
Table 14-12. UIPCRn Field Descriptions
Bits Name
7–5
—
4
COS
3–1
—
0
CTS
Description
Reserved, should be cleared.
Change of state (high-to-low or low-to-high transition). Not used in modem mode.
0 No change-of-state since the CPU last read UIPCRn. Reading UIPCRn clears UISRn[COS].
1 A change-of-state longer than 25–50 µs occurred on the CTS input. UACRn can be programmed to
generate an interrupt to the CPU when a change of state is detected.
Reserved, should be cleared.
Current state. Starting two serial clock periods after reset, CTS reflects the state of CTS. If CTS is
detected asserted at that time, COS is set, which initiates an interrupt if UACRn[IEC] is enabled. This
bit is not used in modem mode.
0 The current state of the CTS input is asserted.
1 The current state of the CTS input is negated.
14.3.14 UART Auxiliary Control Register (UACRn)
The UART auxiliary control registers (UACRn), Figure 14-12, control the input enable.
Chapter 14. UART Modules
14-17
Register Descriptions
7
1
Field
—
Reset
0
IEC
0000_0000
R/W
Write only
Address
MBAR + 0x1D0 (UACR0), 0x210 (UACR1)
Figure 14-17. UART Auxiliary Control Register (UACRn)
Table 14-13 describes UACRn fields.
Table 14-13. UACRn Field Descriptions
Bits
Name
7–1
—
0
IEC
Description
Reserved, should be cleared.
Input enable control. This bit is not used in modem mode.
0 Setting the corresponding UIPCRn bit has no effect on UISRn[COS].
1 UISRn[COS] is set and an interrupt is generated when the UIPCRn[COS] is set by an external
transition on the CTS input (if UIMRn[COS] = 1).
14.3.15 UART Interrupt Status/Mask Registers
(UISRn/UIMRn)
The UART interrupt status registers (UISRn), Figure 14-18, provide status for all potential
interrupt sources. UISRn contents are masked by UIMRn. If corresponding UISRn and
UIMRn bits are set, the internal interrupt output is asserted. If a UIMRn bit is cleared, the
state of the corresponding UISRn bit has no effect on the output.
NOTE:
True status is provided in the UISRn regardless of UIMRn
settings. UISRn is cleared when the UART module is reset.
7
Field
Reset
R/W
Address
COS
6
3
—
2
1
0
DB
FFULL/RxRDY
TxRDY
0000_0000
Read only
MBAR + 0x1D4 (UISR0), 0x214 (UISR1); MBAR + 0x1D4 (UIMR0), 0x214 (UIMR1)
Figure 14-18. UART Interrupt Status/Mask Registers (UISRn/UIMRn)
Table 14-14 describes UISRn and UIMRn fields.
14-18
MCF5407 User’s Manual
Register Descriptions
Table 14-14. UISRn/UIMRn Field Descriptions
Bits
7
Name
Description
COS
Change-of-state. Not used by UART1 in modem mode.
0 UIPCRn[COS] is not selected.
1 Change-of-state occurred on CTS and was programmed in UACRn[IEC] to cause an interrupt.
6–3
—
Reserved, should be cleared.
2
DB
Delta break. Not used by UART1 in modem mode.
0 No new break-change condition to report. Section 14.3.10, “UART Command Registers (UCRn),”
describes the RESET BREAK-CHANGE INTERRUPT command.
1 The receiver detected the beginning or end of a received break.
1
FFULL/ RxRDY (receiver ready) if UMR1n[FFULL/RxRDY] = 0; FIFO full (FFULL) if UMR1n[FFULL/RxRDY]
RxRDY = 1. Duplicate of USRn[FFULL/RxRDY]. Used by UART1 in modem mode. If FFULL is enabled for
UART0 or UART1, DMA channels 2 or 3 are respectively interrupted when the FIFO is full.
0
TxRDY
Transmitter ready. This bit is the duplication of USRn[TxRDY]. Used by UART1 in modem mode.
0 The transmitter holding register was loaded by the CPU or the transmitter is disabled. Characters
loaded into the transmitter holding register when TxRDY = 0 are not sent.
1 The transmitter holding register is empty and ready to be loaded with a character.
14.3.16 UART Divider Upper/Lower Registers (UDUn/UDLn)
The UDUn registers (formerly called UBG1n) holds the MSB, and the UDLn registers
(formerly UBG2n) hold the LSB of the preload value. UDUn and UDLn concatenate to
provide a divider to CLKIN for transmitter/receiver operation, as described in
Section 14.5.1.2.1, “CLKIN Baud Rates.”
7
0
Field
Divider MSB
Reset
0000_0000
R/W
R/W
Address
MBAR + 0x1D8 (UDU0), 0x218 (UDU1)
Figure 14-19. UART Divider Upper Register (UDUn)
7
0
Field
Divider LSB
Reset
0000_0000
R/W
Address
R/W
MBAR + 0x1DC (UDL0), 0x21C (UDL1)
Figure 14-20. UART Divider Lower Register (UDLn)
NOTE:
The minimum value that can be loaded on the concatenation of
UDUn with UDLn is 0x0002. Both UDUn and UDLn are
write-only and cannot be read by the CPU.
Chapter 14. UART Modules
14-19
Register Descriptions
14.3.17 UART Interrupt Vector Register (UIVRn)
The UIVRn, Figure 14-21, contain the 8-bit internal interrupt vector number (IVR).
7
0
Field
IVR
Reset
0000_1111
R/W
R/W
Address
MBAR + 0x1F0 (UIVR0), 0x230 (UIVR1)
Figure 14-21. UART Interrupt Vector Register (UIVRn)
Table 14-15 describes UIVRn fields.
Table 14-15. UIVRn Field Descriptions
Bits
Name
Description
7–0
IVR
Interrupt vector. Indicates the vector number where the address of the exception handler for the
specified interrupt is located. UIVRn is reset to 0x0F, indicating an uninitialized interrupt condition.
14.3.18 UART Input Port Register (UIPn)
The UART input port registers (UIPn), Figure 14-22, show the current state of the CTS
input when the processor is in UART mode.
7
1
Field
—
Reset
1111_1111
R/W
Read only
Address
0
CTS
MBAR + 0x1F4 (UIP0), 0x234 (UIP1)
Figure 14-22. UART Input Port Register (UIPn)
Table 14-16 describes UIPn fields.
Table 14-16. UIPn Field Descriptions
Bits
Name
7–1
—
0
CTS
14-20
Description
Reserved, should be cleared.
Current state. The CTS value is latched and reflects the state of the input pin when UIPn is read.
Note: This bit has the same function and value as UIPCRn[RTS].
0 The current state of the CTS input is logic 0.
1 The current state of the CTS input is logic 1.
When UART1 is in modem mode, CTS toggles when a frame sync occurs. It is used during testing to
synchronize test code running on the CPU with frames transferred on the serial interface.
MCF5407 User’s Manual
UART Module Signal Definitions
14.3.19 UART Output Port Data Registers (UOP1n/UOP0n)
In UART mode, the RTS output can be asserted by writing a 1 to UOP1n[RTS] and negated
by writing a 1 to UOP0n[RTS]. UOP registers have no effect in modem mode. See
Figure 14-23.
7
1
Field
—
Reset
0
RTS
0000_0000
R/W
Write only
Addr
UART0: MBAR + 0x1F8 (UOP1), 0x1FC (UOP0); UART1 0x238 (UOP1), 0x23C (UOP0)
Figure 14-23. UART Output Port Data 1 Register (UOP1/UOP0)
Table 14-17 describes UOP1 fields.
Table 14-17. UOP1/UOP0 Field Descriptions
Bits
Name
Description
7–1
—
Reserved, should be cleared.
0
RTS
Output port parallel output. Controls assertion (UOP1)/negation (UOP0) of RTS output.
0 Not affected.
1 Asserts RTS (UOP1). Negates RTS (UOP0).
14.4 UART Module Signal Definitions
Figure 14-24 shows both the external and internal signal groups.
CLKIN
or
External Clock (TIN)
Clock Source
Generator
UART Module
Internal Bus
Output Port
RTS
Input Port
CTS
Four-Character
Receive Buffer
RxD
Two-Character
Transmit Buffer
TxD
Control
Interface
to CPU
Address Bus
Internal
Control
Logic
Data
To Interrupt
Controller
(SIM)
External
Interface
Signals
IRQ
Figure 14-24. UART Block Diagram Showing External and Internal Interface Signals
Chapter 14. UART Modules
14-21
UART Module Signal Definitions
An internal interrupt request signal (IRQ) is provided to notify the interrupt controller of an
interrupt condition. The output is the logical NOR of unmasked UISRn bits. The interrupt
level of a UART module is programmed in the interrupt controller in the system integration
module (SIM). The UART can use the autovector for the programmed interrupt level or
supply the vector from the UIVRn when the UART interrupt is acknowledged.
The interrupt level, priority, and auto-vectoring capability is programmed in SIM register
ICR4 for UART0 and ICR5 for UART1. See Section 9.2.1, “Interrupt Control Registers
(ICR0–ICR9).”
Note that the UARTs can also automatically transfer data by using the DMA rather than
interrupting the core. When UIMR[FFULL] is 1 and a receiver’s FIFO is full, it can send
an interrupt to a DMA channel so the FIFO data can be transferred to memory. Note also
that UART0 and UART1’s interrupt requests are connected to DMA channel 2 and
channel 3, respectively.
Table 14-18 briefly describes the UART module signals.
NOTE:
The terms ‘assertion’ and ‘negation’ are used to avoid
confusion between active-low and active-high signals.
‘Asserted’ indicates that a signal is active, independent of the
voltage level; ‘negated’ indicates that a signal is inactive.
Table 14-18. UART Module Signals
Signal
Description
Transmitter
Serial Data
Output (TxD)
In UART mode, TxD is held high (mark condition) when the transmitter is disabled, idle, or operating
in the local loop-back mode. Data is shifted out on TxD on the falling edge of the clock source, with
the least significant bit (lsb) sent first. For UART1 in modem mode, TxD is held low when the
transmitter is disabled or idle. Data is shifted out on TxD on the rising edge of the clock signal driving
UART1’s CTS input. UART1 transfers can be specified as either lsb or msb first.
Receiver
Serial Data
Input (RxD)
Data received on RxD is sampled on the rising edge of the clock source, with the lsb received first.
For UART1 in modem mode, data received on RxD is sampled on the falling edge of the clock signal
driving UART1’s CTS input. UART1 transfers can be specified as either lsb or msb first.
Clear-toSend (CTS)
This input can generate an interrupt on a change of state. For UART1 in modem mode, CTS must be
driven by the serial bit clock from the external CODEC or AC ‘97 controller.
Request-toSend (RTS)
This output can be programmed to be negated or asserted automatically by either the receiver or the
transmitter. When connected to a transmitter’s CTS, RTS can control serial data flow. For UART1 in
AC ‘97 mode, RTS serves as the frame sync or start-of-frame (SOF) output to the external AC ‘97
controller. When this mode is used, the AC ‘97 BIT_CLK, which is input on CTS, is divided by 256.
Timer Input
(TIN1)
When UART1 in modem mode is used as an 8- or 16-bit CODEC interface, TIN1 must be driven by
the frame sync or SOF output from the external CODEC. SOF is sampled on the falling edge of the
bit clock driving CTS. TIN1 can still be used in all timer modes except capture mode when UART1 is
being used as an 8- or 16-bit CODEC interface. See Table 14-26.
Figure 14-25 shows a signal configuration for a UART/RS-232 interface.
14-22
MCF5407 User’s Manual
Operation
UART
RS-232 Transceiver
RTS
DI2
CTS
DO2
TxD
DI1
RxD
DO1
Figure 14-25. UART/RS-232 Interface
Figure 14-26 shows a signal configuration for a UART1/CODEC interface.
UART1
MC143416 CODEC
TIN1
SSYNC0
CTS
SCLK0
TxD
SRx0
RxD
STx0
Figure 14-26. UART1/CODEC Interface
Figure 14-27 shows a signal configuration for a UART1/CODEC interface. An MCF5407
general-purpose I/O (GPIO) is used as a reset to the AC ‘97 device.
UART1
AC ’97
RTS
FRAME SYNC
CTS
BIT_CLK
TxD
SDATA_OUT
RxD
SDATA_IN
GPIO
RESET
Figure 14-27. UART1/AC ’97 Interface
14.5 Operation
This section describes operation of the clock source generator, transmitter, and receiver.
14.5.1 Transmitter/Receiver Clock Source
CLKIN serves as the basic timing reference for the clock source generator logic, which
consists of a clock generator and a programmable 16-bit divider dedicated to the UART.
The clock generator cannot produce standard baud rates if CLKIN is used, so the 16-bit
divider should be used.
Chapter 14. UART Modules
14-23
Operation
14.5.1.1 Programmable Divider
As Figure 14-28 shows, the UART transmitter and receiver can use the following clock
sources:
•
•
An external clock signal on the TIN pin that can be divided by 16. When not divided,
TIN provides a synchronous clock mode; when divided by 16, it is asynchronous.
CLKIN supplies an asynchronous clock source that is divided by 32 and then
divided by the 16-bit value programmed in UDUn and UDLn. See Section 14.3.16,
“UART Divider Upper/Lower Registers (UDUn/UDLn).”
The choice of TIN or CLKIN is programmed in the UCSR.
TOUT
On-Chip
Timer Module
TIN
UART
Clocking sources programmed in UCSR
TxD
Tx Buffer
x1
Prescaler
TIN
x16
Prescaler
TIN
Tx
Rx
Clock
Generator
RxD
16-Bit
Divider
x32
Prescaler
Rx Buffer
CLKIN
Figure 14-28. Clocking Source Diagram
NOTE:
If TIN is a clocking source for either the timer or UART, as is
the case for UART1 used as an 8- or 16-bit CODEC interface,
the timer module cannot use TIN for timer capture.
14.5.1.2 Calculating Baud Rates
The following sections describe how to calculate baud rates.
14.5.1.2.1 CLKIN Baud Rates
When CLKIN is the UART clocking source, it goes through a divide-by-32 prescaler and
then passes through the 16-bit divider of the concatenated UDUn and UDLn registers.
Using a 54-MHz CLKIN, the baud-rate calculation is as follows:
14-24
MCF5407 User’s Manual
Operation
54MHz
Baudrate = -----------------------------------[ 32 × divider ]
Let baud rate = 9600; the divider can be calculated as follows:
54MHz
Divider = ----------------------------- = 176 ( decimal ) = 0x00B0
[ 32 × 9600 ]
Therefore UDUn = 0x00 and UDLn = 0xB0.
14.5.1.2.2 External Clock
An external source clock (TIN) can be used as is or divided by 16.
Externalclockfrequency
Baudrate = --------------------------------------------------------------------16or1
14.5.2 Transmitter and Receiver Operating Modes
Figure 14-29 is a functional block diagram of the transmitter and receiver showing the
command and operating registers, which are described generally in the following sections
and described in detail in Section 14.3, “Register Descriptions.”
UART0
UART Command Register (UCR0)
UART
Transmitter Buffer
(UTB0)
(2 Registers)
W
UART Mode Register 1 (UMR1)
R/W
UART Mode Register 2 (UMR2)
R/W
UART Status Register (USR0)
R
Transmitter Holding Register
W
External
Interface
TXD
Transmitter Shift Register
Receiver Holding Register 1
Receiver Holding Register 2
R
FIFO (32-byte
FIFOs on
UART1)
Receiver Holding Register 3
UART Receive
Buffer (URB0)
(4 Registers)
Receiver Shift Register
RXD
Figure 14-29. Transmitter and Receiver Functional Diagram
Chapter 14. UART Modules
14-25
Operation
14.5.2.1 Transmitting in UART Mode
The transmitter is enabled through the UART command register (UCRn). When it is ready
to accept a character, the UART sets USRn[TxRDY]. The transmitter converts parallel data
from the CPU to a serial bit stream on TxD. It automatically sends a start bit followed by
the programmed number of data bits, an optional parity bit, and the programmed number
of stop bits. The lsb is sent first. Data is shifted from the transmitter output on the falling
edge of the clock source.
After the stop bits are sent, if no new character is in the transmitter holding register, the TxD
output remains high (mark condition) and the transmitter empty bit, USRn[TxEMP], is set.
Transmission resumes and TxEMP is cleared when the CPU loads a new character into the
UART transmitter buffer (UTBn). If the transmitter receives a disable command, it
continues until any character in the transmitter shift register is completely sent.
If the transmitter is reset through a software command, operation stops immediately (see
Section 14.3.10, “UART Command Registers (UCRn)”). The transmitter is reenabled
through the UCRn to resume operation after a disable or software reset.
If the clear-to-send operation is enabled, CTS must be asserted for the character to be
transmitted. If CTS is negated in the middle of a transmission, the character in the shift
register is sent and TxD remains in mark state until CTS is reasserted. If the transmitter is
forced to send a continuous low condition by issuing a SEND BREAK command, the
transmitter ignores the state of CTS.
If the transmitter is programmed to automatically negate RTS when a message transmission
completes, RTS must be asserted manually before a message is sent. In applications in
which the transmitter is disabled after transmission is complete and RTS is appropriately
programmed, RTS is negated one bit time after the character in the shift register is
completely transmitted. The transmitter must be manually reenabled by reasserting RTS
before the next message is to be sent.
Figure 14-30 shows the functional timing information for the transmitter.
14-26
MCF5407 User’s Manual
Operation
C1 in transmission
C11
TxD
C2
C3
C4
Break
C6
Transmitter
Enabled
USRn[TxRDY]
internal
module
select
W2
W
W
C11
C2
C3 Start
break
W
W
W
C4 Stop
break
W
W
C5
not
transmitted
C6
CTS3
RTS4
Manually asserted
by BIT-SET command
Manually
asserted
1 Cn = transmit characters
2 W = write
3 UMR2n[TxCTS] = 1
4 UMR2n[TxRTS] = 1
Figure 14-30. Transmitter Timing Diagram
14.5.2.2 Transmitter in Modem Mode (UART1)
After a hardware reset, UART1 is in UART mode. UART1 can be put in one of the modem
modes by writing the appropriate value for MODCTL[MODE], as described in
Section 14.3.4, “Modem Control Register (MODCTL).” The other MODCTL fields should
be initialized at the same time. Set the Tx FIFO threshold as described in Section 14.3.5,
“Tx FIFO Threshold Register (TXLVL).”
The serial bit clock is always an input to UART1 in modem mode (on CTS). For an 8- or
16-bit CODEC, the frame sync is also an input to UART1 (on TIN1). However for an
AC ‘97 controller, UART1 provides the frame sync (on RTS). Figure 14-31 shows an
example timing for UART1-CODEC interfaces (lsb first).
CTS
TIN1
Frame Sync
TxD
D0
D1
D2
D14
D15
RxD
D0
D1
D2
D14
D15
Figure 14-31. 16-Bit CODEC Interface Timing (lsb First)
Chapter 14. UART Modules
14-27
Operation
Figure 14-32 is an example timing diagram for the UART1-CODEC interface (msb first).
CTS
TIN1
Frame Sync
TxD
D7
D6
D5
D1
D0
RxD
D7
D6
D5
D1
D0
Figure 14-32. 8-Bit CODEC Interface Timing (msb First)
Figure 14-33 shows an example timing diagram for the UART1-AC ‘97 interface.
CTS
RTS
TxD
Frame Sync
bit1
bit2
Frame Sync
bit13 bit14 bit15 bit16
20
bits
Slot 2
RxD
bit1
bit2
bit13 bit14 bit15 bit16
20
bits
Slot 2
Slot 1
20
bits
Slot 3
20
bits
Slot 3
20
bits
Slot 13
20
Slot 1
bits
Slot 13
Slot 1
Frame
Figure 14-33. AC ‘97 Interface Timing
For more information about interfacing to an AC ‘97 controller, refer to the Audio
CODEC ‘97 Component Specification.
When interfaced to an 8- or 16-bit CODEC (MODCTL[MODE] = 01 or 10), UART1 starts
to send a sample either during the 1-bit clock cycle after the rising edge of frame sync,
according to the value of MODCTL[DTS1]. The width of the frame sync pulse makes no
difference. MODCTL[SHDIR] controls whether bits are shifted out msb or lsb first. After
the 8- or 16-bit sample is sent, zeros are sent until the next frame sync.
When interfacing to an AC ‘97 controller (MODCTL[MODE] = 11), UART1 starts to
transmit time slot 1 data one bit-clock cycle after the rising edge of frame sync, regardless
of the value of MODCTL[DTS1]. However, MODCTL[SHDIR] must be 0, because the
shift order must be msb first. UART1 divides the bit clock by 256 to generate a frame sync
pulse that is high for 16-bit clock cycles. The transmitter sends zeros until the receiver
detects the CODEC-ready condition (a 1 in the first bit of a new frame).
Because Rx data is sampled on the falling edge of the bit clock, for transmit purposes, the
frame has already started when the receiver detects a CODEC-ready condition. For this
reason, transmission starts at the next frame sync after the CODEC-ready condition is
detected. UART1 stops transmission at the end of the frame in which the first bit of the
received frame is detected low (CODEC not ready). During transmission, UART1 fills each
of the 13 time slots of the AC ‘97 frame with samples from the Tx FIFO.
14-28
MCF5407 User’s Manual
Operation
14.5.2.2.1 AC ‘97 Low-Power Mode
A general-purpose I/O (GPIO) must be used as an AC ‘97 reset output pin. UART1
monitors the first three time slots of each Tx frame to detect the power-down condition for
the AC ‘97 digital interface. The power-down condition is detected as follows:
1. The first 3 bits of slot 1 must be set, indicating that the Tx frame and slots 1 and 2
are valid.
2. Slot 2 holds the address of the power-down register (0x26) in the external AC ‘97
device.
3. Slot 3 contains a 1 in the fourth bit (bit 12/PR4 in power-down register 1), as defined
in the AC ’97 specification.
Low-power mode can be left through either a warm or cold reset. The CPU performs a
warm reset by setting MODCTL[AWR] for at least 1 µs. This negates RTS, which is used
as the frame sync output in AC ‘97 mode. The CPU performs a cold reset in two steps:
1. Writes a 0 to whichever GPIO is being used as the active low AC ‘97 reset pin for
the minimum time specified in the AC ‘97 specification.
2. Writes a 0 to UART1’s MODCTL[ACRB] (bit 7). The CPU sets this bit after writing
a 1 to the GPIO used for the AC ‘97 reset pin.
Step 2 is required so UART1 knows when an AC ‘97 cold reset is occurring.
14.5.2.3 Receiver
The receiver is enabled through its UCRn, as described in Section 14.3.10, “UART
Command Registers (UCRn).” Figure 14-34 shows receiver functional timing.
Chapter 14. UART Modules
14-29
Operation
TxD
C1
C2
C3
C4
C5
C6
C7
C8
C6, C7, and C8 will be lost
Receiver
Enabled
USRn[RxRDY]
USRn[FFULL]
internal
module
select
Status
Data
C5 will
be lost
(C1)
(C2) (C3) (C4)
Reset by
command
Overrun
USRn[OE]
RTS4
Status Status Status
Data Data Data
Manually asserted first time,
automatically negated if overrun occurs
UOP0[RTS] = 1
Automatically asserted
when ready to receive
Figure 14-34. Receiver Timing
When the receiver detects a high-to-low (mark-to-space) transition of the start bit on RxD,
the state of RxD is sampled each 16× clock for eight clocks, starting one-half clock after
the transition (asynchronous operation) or at the next rising edge of the bit time clock
(synchronous operation). If RxD is sampled high, the start bit is invalid and the search for
the valid start bit begins again.
If RxD is still low, a valid start bit is assumed and the receiver continues sampling the input
at one-bit time intervals, at the theoretical center of the bit, until the proper number of data
bits and parity, if any, is assembled and one stop bit is detected. Data on the RxD input is
sampled on the rising edge of the programmed clock source. The lsb is received first. The
data is then transferred to a receiver holding register and USRn[RxRDY] is set. If the
character is less than eight bits, the most significant unused bits in the receiver holding
register are cleared.
After the stop bit is detected, the receiver immediately looks for the next start bit. However,
if a non-zero character is received without a stop bit (framing error) and RxD remains low
for one-half of the bit period after the stop bit is sampled, the receiver operates as if a new
start bit were detected. Parity error, framing error, overrun error, and received break
conditions set the respective PE, FE, OE, RB error and break flags in the USRn at the
received character boundary and are valid only if USRn[RxRDY] is set.
If a break condition is detected (RxD is low for the entire character including the stop bit),
a character of all zeros is loaded into the receiver holding register (RHR) and
USRn[RB,RxRDY] are set. RxD must return to a high condition for at least one-half bit
time before a search for the next start bit begins.
14-30
MCF5407 User’s Manual
Operation
The receiver detects the beginning of a break in the middle of a character if the break
persists through the next character time. If the break begins in the middle of a character, the
receiver places the damaged character in the Rx FIFO stack and sets the corresponding
USRn error bits and USRn[RxRDY]. Then, if the break lasts until the next character time,
the receiver places an all-zero character into the Rx FIFO and sets USRn[RB,RxRDY].
14.5.2.4 UART1 in UART Mode
After a hardware reset, UART1 is in UART mode and differs from UART0 only with
respect to receiver overrun, which is a function of Rx FIFO depth. UART0 has an effective
depth of 4 bytes counting the Rx shift register, whereas UART1 has an effective depth of
33 bytes counting the Rx shift register. As a result, an overrun error won’t occur in UART1
until 34 bytes are received without a CPU read from the Rx FIFO. In UART0, an overrun
error would occur after 5 bytes are received without a CPU read from the Rx FIFO. In all
other respects, UART1 in UART mode operates identically to UART0.
14.5.2.4.1 Receiver in Modem Mode (UART1)
After a hardware reset, UART1 is in UART mode. Modem modes are chosen by setting
MODCTL[MODE]. Other MODCTL fields should be initialized at the same time, as
described in Section 14.3.4, “Modem Control Register (MODCTL).” Set the Rx FIFO
threshold as described in Section 14.3.3, “Rx FIFO Threshold Register (RXLVL).”
The serial bit clock is always an input to UART1 in modem mode (on CTS). When
interfacing to an 8- or 16-bit CODEC, the frame sync is also an input to UART1 (on TIN1).
However when an AC ‘97 controller is used, UART1 provides the frame sync (on RTS).
Figure 14-31 on page 14-27 and Figure 14-32 on page 14-28 show timing diagrams for the
UART1-CODEC interfaces. Figure 14-33 shows an example timing diagram for the
UART1-AC ‘97 interface.
When an 8- or 16-bit CODEC is specified (MODCTL[MODE] = 01 or 10), UART1 starts
to receive a sample either at the rising edge of frame sync or 1 bit clock cycle after the rising
edge of frame sync, according to the value of MODCTL[DTS1]. The width of the frame
sync pulse makes no difference. MODCTL[SHDIR] controls whether the sample is shifted
in msb or lsb first. After the 8- or 16-bit sample is received, the receiver shift register shuts
off until the next frame sync occurs.
When an AC ‘97 controller is specified (MODCTL[MODE] = 11), UART1 starts to receive
time slot 1 data one bit-clock cycle after the rising edge of frame sync, regardless of the
MODCTL[DTS1] value. However, MODCTL[SHDIR] must be 0 because the shift order
must be msb first. Until the receiver detects the CODEC ready condition (a 1 in the first bit
of a new frame), no data is put into the Rx FIFO for that frame. When a CODEC ready
condition is detected, the receiver starts loading the Rx FIFO with the received time slot
samples and continues to do so until a 0 is received in the first bit of a new frame.
Chapter 14. UART Modules
14-31
Operation
14.5.2.5 FIFO Stack in UART0
The FIFO stack is used in the UART’s receiver buffer logic. The stack consists of three
receiver holding registers. The receive buffer consists of the FIFO and a receiver shift
register connected to the RxD (see Figure 14-29). Data is assembled in the receiver shift
register and loaded into the top empty receiver holding register position of the FIFO. Thus,
data flowing from the receiver to the CPU is quadruple-buffered.
In addition to the data byte, three status bits, parity error (PE), framing error (FE), and
received break (RB), are appended to each data character in the FIFO; OE (overrun error)
is not appended. By programming the ERR bit in the channel’s mode register (UMR1n),
status is provided in character or block modes.
USRn[RxRDY] is set when at least one character is available to be read by the CPU. A read
of the receiver buffer produces an output of data from the top of the FIFO stack. After the
read cycle, the data at the top of the FIFO stack and its associated status bits are popped and
the receiver shift register can add new data at the bottom of the stack. The FIFO-full status
bit (FFULL) is set if all three stack positions are filled with data. Either the RxRDY or
FFULL bit can be selected to cause an interrupt.
The two error modes are selected by UMR1n[ERR] as follows:
•
•
In character mode (UMR1n[ERR] = 0, status is given in the USRn for the character
at the top of the FIFO.
In block mode, the USRn shows a logical OR of all characters reaching the top of
the FIFO stack since the last RESET ERROR STATUS command. Status is updated as
characters reach the top of the FIFO stack. Block mode offers a data-reception speed
advantage where the software overhead of error-checking each character cannot be
tolerated. However, errors are not detected until the check is performed at the end of
an entire message—the faulting character is not identified.
In either mode, reading the USRn does not affect the FIFO. The FIFO is popped only when
the receive buffer is read. The USRn should be read before reading the receive buffer. If all
three receiver holding registers are full, a new character is held in the receiver shift register
until space is available. However, if a second new character is received, the contents of the
the character in the receiver shift register is lost, the FIFOs are unaffected, and USRn[OE]
is set when the receiver detects the start bit of the new overrunning character.
To support flow control, the receiver can be programmed to automatically negate and assert
RTS, in which case the receiver automatically negates RTS when a valid start bit is detected
and the FIFO stack is full. The receiver asserts RTS when a FIFO position becomes
available; therefore, overrun errors can be prevented by connecting RTS to the CTS input
of the transmitting device.
14-32
MCF5407 User’s Manual
Operation
NOTE:
The receiver can still read characters in the FIFO stack if the
receiver is disabled. If the receiver is reset, the FIFO stack, RTS
control, all receiver status bits, and interrupt requests are reset.
No more characters are received until the receiver is reenabled.
14.5.2.6 FIFOs in UART1
For UART1, FIFOs can be accessed as longwords. Other properties are as follows:
•
•
•
8-bit CODEC mode (MODCTL[MODE] = 01):
— Can access FIFOs either one, two, or four 1-byte samples at a time.
— For one-sample accesses, the sample occupies internal data bus bits 31–24.
For two-sample accesses, the samples occupy internal data bus bits 31–16.16-bit
CODEC mode (MODCTL[MODE] = 10):
— Can access FIFOs one or two 2-byte samples at a time.
— For one-sample accesses, the sample occupies internal data bus bits 31–16.
AC ‘97 mode (MODCTL[MODE] = 11):
— Must access FIFOs one sample at a time
— Because time slot 1 has 16 bits, compared to 20 for all other time slots in a frame,
time slot 1 data occupies internal data bus bits 31–16.
— All 20-bit time slots occupy internal data bus bits 31–12 for Tx and Rx FIFOs.
— In addition, when the Rx FIFO is being read, a 1 in internal data bus bit 11 marks
this sample as the first time slot of a new frame.
The Tx FIFO functions as follows:
•
•
AC ‘97 mode—Tx FIFO is effectively a 16 x 20 dual-port RAM to hold sixteen
20-bit AC ‘97 time slots. One sample/time slot is written to Tx FIFO per internal bus
cycle.
For all other modes the Tx FIFO is effectively 8 x 32.
— 8-bit CODEC or as a UART—Tx FIFO can hold thirty-two 8-bit samples. One,
two, or four bytes/samples can be written to Tx FIFO per internal bus cycle.
— 16-bit CODEC—Tx FIFO can hold sixteen 16-bit samples. Either one or two
16-bit samples can be written to Tx FIFO per internal bus cycle.
The Rx FIFO functions as follows:
•
AC ‘97 mode—Rx FIFO is effectively a 16 x 21 dual-port RAM to hold sixteen
20-bit AC ‘97 time slots. The extra flag bit is set to indicate the first time slot of a
new AC ‘97 frame. One sample/time slot is read from Rx FIFO per internal bus
cycle.
Chapter 14. UART Modules
14-33
Operation
•
For all other modes, the Rx FIFO is effectively 8 x 32.
— 8-bit CODEC or as a UART—Rx FIFO holds thirty-two 8-bit samples. One, two,
or four bytes/samples can be read from the Rx FIFO per internal bus cycle.
— 16-bit CODEC—Rx FIFO holds sixteen 16-bit samples. Either one or two 16-bit
samples can be read from the Rx FIFO per internal bus cycle.
14.5.3 Looping Modes
The UART can be configured to operate in various looping modes as shown in Figure 14-34
on page 14-30. These modes are useful for local and remote system diagnostic functions
and can be used by UART1 in modem mode as well as UART mode. The modes are
described in the following paragraphs and in Section 14.3, “Register Descriptions.”
The UART’s transmitter and receiver should be disabled when switching between modes.
The selected mode is activated immediately upon mode selection, regardless of whether a
character is being received or transmitted.
14.5.3.1 Automatic Echo Mode
In automatic echo mode, shown in Figure 14-35, the UART automatically resends received
data bit by bit. The local CPU-to-receiver communication continues normally, but the
CPU-to-transmitter link is disabled. In this mode, received data is clocked on the receiver
clock and resent on TxD. The receiver must be enabled, but the transmitter need not be.
RxD Input
Rx
CPU
Disabled
Tx
Disabled
TxD Input
Figure 14-35. Automatic Echo
Because the transmitter is inactive, USRn[TxEMP,TxRDY] are inactive and data is sent as
it is received. Received parity is checked but is not recalculated for transmission. Character
framing is also checked, but stop bits are sent as they are received. A received break is
echoed as received until the next valid start bit is detected.
14.5.3.2 Local Loop-Back Mode
Figure 14-36 shows how TxD and RxD are internally connected in local loop-back mode.
This mode is for testing the operation of a local UART module channel by sending data to
the transmitter and checking data assembled by the receiver to ensure proper operations.
Rx
Disabled
RxD Input
Disabled
TxD Input
CPU
Tx
Figure 14-36. Local Loop-Back
14-34
MCF5407 User’s Manual
Operation
Features of this local loop-back mode are as follows:
•
•
•
•
Transmitter and CPU-to-receiver communications continue normally in this mode.
RxD input data is ignored
TxD is held marking
The receiver is clocked by the transmitter clock. The transmitter must be enabled,
but the receiver need not be.
14.5.3.3 Remote Loop-Back Mode
In remote loop-back mode, shown in Figure 14-37, the channel automatically transmits
received data bit by bit on the TxD output. The local CPU-to-transmitter link is disabled.
This mode is useful in testing receiver and transmitter operation of a remote channel. For
this mode, the transmitter uses the receiver clock.
Because the receiver is not active, received data cannot be read by the CPU and error status
conditions are inactive. Received parity is not checked and is not recalculated for
transmission. Stop bits are sent as they are received. A received break is echoed as received
until the next valid start bit is detected.
Disabled
Rx
Disabled
RxD Input
Disabled
TxD Input
CPU
Disabled
Tx
Figure 14-37. Remote Loop-Back
14.5.4 Multidrop Mode
Setting UMR1n[PM] programs the UART to operate in a wake-up mode for multidrop or
multiprocessor applications. In this mode, a master can transmit an address character
followed by a block of data characters targeted for one of up to 256 slave stations.
Although slave stations have their channel receivers disabled, they continuously monitor
the master’s data stream. When the master sends an address character, the slave receiver
channel notifies its respective CPU by setting USRn[RxRDY] and generating an interrupt
(if programmed to do so). Each slave station CPU then compares the received address to its
station address and enables its receiver if it wishes to receive the subsequent data characters
or block of data from the master station. Slave stations not addressed continue monitoring
the data stream. Data fields in the data stream are separated by an address character. After
a slave receives a block of data, its CPU disables the receiver and repeats the process.
Chapter 14. UART Modules
14-35
Operation
Functional timing information for multidrop mode is shown in Figure 14-38.
Master Station
A/D
TxD
ADD1 1
A/D
A/D
C0
ADD2 1
Transmitter
Enabled
USRn[TxRDY]
internal
module
select
UMR1n[PM] = 11
UMR1n[PT] = 1
ADD 1
C0
UMR1n[PT] = 0
ADD 2
UMR1n[PT] = 2
Peripheral Station
RxD
A/D
A/D
0
ADD1 1
A/D
C0
A/D
A/D
ADD2 1
0
Receiver
Enabled
USRn[RxRDY]
internal
module
select
UMR1n[PM] = 11
UMR1n[PM] = 11
ADD 1
Status Data
(C0)
Status Data
(ADD 2)
Figure 14-38. Multidrop Mode Timing Diagram
A character sent from the master station consists of a start bit, a programmed number of
data bits, an address/data (A/D) bit flag, and a programmed number of stop bits. A/D = 1
indicates an address character; A/D = 0 indicates a data character. The polarity of A/D is
selected through UMR1n[PT]. UMR1n should be programmed before enabling the
transmitter and loading the corresponding data bits into the transmit buffer.
In multidrop mode, the receiver continuously monitors the received data stream, regardless
of whether it is enabled or disabled. If the receiver is disabled, it sets the RxRDY bit and
loads the character into the receiver holding register FIFO stack provided the received A/D
bit is a one (address tag). The character is discarded if the received A/D bit is zero (data
tag). If the receiver is enabled, all received characters are transferred to the CPU through
the receiver holding register stack during read operations.
In either case, the data bits are loaded into the data portion of the stack while the A/D bit is
loaded into the status portion of the stack normally used for a parity error (USRn[PE]).
Framing error, overrun error, and break detection operate normally. The A/D bit takes the
place of the parity bit; therefore, parity is neither calculated nor checked. Messages in this
mode may still contain error detection and correction information. One way to provide error
14-36
MCF5407 User’s Manual
Operation
detection, if 8-bit characters are not required, is to use software to calculate parity and
append it to the 5-, 6-, or 7-bit character.
14.5.5 Bus Operation
This section describes bus operation during read, write, and interrupt acknowledge cycles
to the UART module.
14.5.5.1 Read Cycles
The UART module responds to reads with byte data. Reserved registers return zeros.
14.5.5.2 Write Cycles
The UART module accepts write data as bytes. Write cycles to read-only or reserved
registers complete normally without exception processing, but data is ignored.
NOTE:
The UART module is accessed by the CPU with zero wait
states, as CLKIN is used for the UART module.
14.5.5.3 Interrupt Acknowledge Cycles
The UART module supplies the interrupt vector in response to a UART IACK cycle. If
UIVRn is not initialized to provide a vector number, a spurious exception is taken if an
interrupt is generated. This works in conjunction with the interrupt controller, which allows
a programmable priority level.
14.5.6 Programming
The software flowchart, Figure 14-39, consists of the following:
•
•
UART module initialization—These routines consist of SINIT and CHCHK (sheets
1 and 2). Before SINIT is called at system initialization, the calling routine allocates
2 words on the system stack. On return to the calling routine, SINIT passes UART
status data on the stack. If SINIT finds no errors, the transmitter and receiver are
enabled. SINIT calls CHCHK to perform the checks. When called, SINIT places the
UART in local loop-back mode and checks for the following errors:
— Transmitter never ready
— Receiver never ready
— Parity error
— Incorrect character received
I/O driver routine—This routine (sheets 4 and 5) consists of INCH, the terminal
input character routine which gets a character from the receiver, and OUTCH, which
sends a character to the transmitter.
Chapter 14. UART Modules
14-37
Operation
•
Interrupt handling—Consists of SIRQ (sheet 4), which is executed after the UART
module generates an interrupt caused by a change-in-break (beginning of a break).
SIRQ then clears the interrupt source, waits for the next change-in-break interrupt
(end of break), clears the interrupt source again, then returns from exception
processing to the system monitor.
14.5.6.1 UART Module Initialization Sequence
NOTE:
UART module registers can be accessed by word or byte
operations, but only data byte D[7:0] is valid.
Table 14-19 shows the UART module initialization sequence.
Table 14-19. UART Module Initialization Sequence
Register
Setting
UCRn
Reset the receiver and transmitter—UART or modem modes.
Reset the mode pointer (MISC[2–0] = 0b001)—UART or modem modes.
UIVRn
Program the vector number for a UART module interrupt—UART or modem modes.
UIMRn
Enable the preferred interrupt sources—UART or modem modes.
UACRn
Initialize the input enable control (IEC bit)—UART mode only.
UCSRn
Select the receiver and transmitter clock. Use timer as source if required—UART mode only.
UMR1n
If preferred, program operation of receiver ready-to-send (RxRTS bit)—UART mode only.
Select receiver-ready or FIFO-full notification (RxRDY/FFULL bit)—UART or modem modes.
Select character or block error mode (ERR bit)—UART mode only.
Select parity mode and type (PM and PT bits)—UART mode only.
Select number of bits per character (B/Cx bits)—UART mode only.
UMR2n
Select the mode of operation (CMx bits)—UART or modem modes.
If preferred, program operation of transmitter ready-to-send (TxRTS)—UART mode only.
If preferred, program operation of clear-to-send (TxCTS bit)—UART mode only.
Select stop-bit length (SBx bits)—UART mode only.
RXLVL
UART1 only, UART or modem modes—Choose Rx FIFO full threshold level.
TXLVL
UART1 only, UART or modem modes—Choose Tx FIFO empty threshold level.
MODCTL Modem mode only
Choose the desired modem mode.
Choose whether msb or lsb is to be transferred first.
Choose 0- or 1-bit delay between rising edge of frame sync and first bit of time slot 1.
Choose 1 or 2 DMA channels to service UART1.
Activate/deactivate AC ‘97 warm and cold resets.
UCRn
Enable the receiver and transmitter—UART or modem modes.
14-38
MCF5407 User’s Manual
Operation
ENABLE
ENABLA
SERIAL MODULE
SINIT
ANY
ERRORS
?
INITIATE:
Y
N
CHANNEL
INTERRUPTS
ENABLE RECEIVER
CHK1
CALL CHCHK
SAVE CHANNEL
STATUS
ASSERT
REQUEST TO SEND
SINITR
RETURN
Figure 14-39. UART Mode Programming Flowchart (Sheet 1 of 5)
Chapter 14. UART Modules
14-39
Operation
CHCHK
CHCHK
PLACE CHANNEL IN
LOCAL LOOPBACK
MODE
ENABLE
TRANSMITTER CLEAR
STATUS WORD
TxCHK
N
IS
TRANSMITTER
READY
?
N
Y
WAITED
TOO LONG
?
Y
SET TRANSMITTERNEVER-READY FLAG
Y
SET RECEIVERNEVER-READY FLAG
N
Y
SNDCHR
SEND CHARACTER
TO TRANSMITTER
RxCHK
N
HAS
CHARACTER BEEN
RECEIVED
?
N
WAITED
TOO LONG
?
Y
A
B
Figure 14-39. UART Mode Programming Flowchart (Sheet 2 of 5)
14-40
MCF5407 User’s Manual
Operation
B
A
FRCHK
RSTCHN
HAVE
FRAMING ERROR
?
N
Y
DISABLE
TRANSMITTER
RESTORE
TO ORIGINAL MODE
SET FRAMING
ERROR FLAG
PRCHK
RETURN
HAVE
PARITY ERROR
?
N
Y
SET PARITY
ERROR FLAG
A
CHRCHK
GET CHARACTER
FROM RECEIVER
SAME AS
TRANSMITTED
CHARACTER
?
Y
N
SET INCORRECT
CHARACTER FLAG
B
Figure 14-39. UART Mode Programming Flowchart (Sheet 3 of 5)
Chapter 14. UART Modules
14-41
Operation
INCH
SIRQ
ABRKI
WAS
IRQ CAUSED
BY BEGINNING
OF A BREAK
?
Y
N
DOES
CHANNEL A
RECEIVER HAVE A
CHARACTER
?
N
Y
PLACE CHARACTER
IN D0
CLEAR CHANGE-INBREAK STATUS BIT
ABRKI1
HAS
END-OF-BREAK
IRQ ARRIVED
YET
?
RETURN
N
Y
CLEAR CHANGE-INBREAK STATUS BIT
REMOVE BREAK
CHARACTER FROM
RECEIVER FIFO
REPLACE RETURN
ADDRESS ON SYSTEM
STACK AND MONITOR
WARM START ADDRESS
SIRQR
RTE
Figure 14-39. UART Mode Programming Flowchart (Sheet 4 of 5)
14-42
MCF5407 User’s Manual
Operation
OUTCH
IS
TRANSMITTER
READY
?
N
Y
SEND CHARACTER
TO TRANSMITTER
RETURN
Figure 14-39. UART Mode Programming Flowchart (Sheet 5 of 5)
Chapter 14. UART Modules
14-43
Operation
14-44
MCF5407 User’s Manual
Chapter 15
Parallel Port (General-Purpose I/O)
This chapter describes the operation and programming model of the parallel port pin
assignment, direction-control, and data registers. It includes a code example for setting up
the parallel port.
15.1 Parallel Port Operation
The MCF5407 parallel port module has 16 signals, which are programmed as follows:
•
•
•
The pin assignment register (PAR) selects the function of the 16 multiplexed pins.
Port A data direction register (PADDR) determines whether pins configured as
parallel port signals are inputs or outputs.
The Port A data register (PADAT) shows the status of the parallel port signals.
The operations of the PAR, PADDR, and PADAT are described in the following sections.
15.1.1 Pin Assignment Register (PAR)
The pin assignment register (PAR), which is part of the system integration module (SIM),
defines how each PAR bit determines each pin function, as shown in Figure 15-1.
15
14
13
12
11
10
9
8
7
Field PAR15 PAR14 PAR13 PAR12 PAR11 PAR10 PAR9 PAR8 PAR7
6
5
4
2
1
0
PAR5 PAR4 PAR3
PAR2 PAR1 PAR0
PP6
PP5
PP2
PAR[n] = 0 PP15
PP14
PP13
PP12
PP11
PP10
PP9
PP8
PP7
PAR[n] = 1
A30
A29
A28
A27
A26
A25
A24
TIP DREQ0 DREQ1 TM2
A31
3
PAR6
PP4
PP3
PP1
PP0
TM1/ TM0/ TT1
DACK1 DACK0
TT0
Reset Determined by driving D4/ADDR_CONFIG with a 1 or 0 when RSTI negates. The system is configured as
PP[15:0] if D4 is low; otherwise alternate pin functions selected by PAR[n] = 1 are used.
R/W
Address
R/W
Address MBAR + 0x004
Figure 15-1. Parallel Port Pin Assignment Register (PAR)
If PP[9:8]/A[25:24] are unavailable because A[25:0] are needed for external addressing,
PP[15:10]/A[31:26] can be configured as general-purpose I/O. Table 15-1 summarizes
MCF5407 parallel port pins, described in detail in Chapter 17, “Signal Descriptions.”
Chapter 15. Parallel Port (General-Purpose I/O)
15-1
Parallel Port Operation
Table 15-1. Parallel Port Pin Descriptions
Pin
Description
PP[15:8]/
A[31:24]
MSB of the address bus/parallel port. Programmed through PAR[15–8]. If a PAR bit is 0, the associated
pin functions as a parallel port signal. If a bit is 1, the pin functions as an address bus signal. If all pins
are address signals, as much as 4 Gbytes of memory space are available.
TIP/PP7
Transfer-in-progress output/parallel port bit 7. Programmed through PAR[7]. Assertion indicates a bus
transfer is in progress; negation indicates an idle bus cycle if the bus is still granted to the processor.
Note that TIP is held asserted on back-to-back bus cycles.
DREQ[1:0]/ DMA request inputs/two bits of the parallel port. Programmed through PAR[6–5]. These inputs are
PP[6:5]
asserted by a peripheral device to request a DMA transfer.
TM[2:0]/
PP[4:2]/
DACK[1:0]
Transfer type outputs/parallel port bits 4–2. Programmed through PAR[4–2]. For DMA transfers, these
signals provide acknowledge information or can be programmed to function as DMA acknowledge
signals. For emulation transfers, TM[2:0] indicate user or data transfer types. For CPU space transfers,
TM[2:0] are low. For interrupt acknowledge transfers, TM[2:0] carry the interrupt level being
acknowledged.
TT[1:0]/
PP[1:0]
Transfer type outputs/parallel port bits 1–0. Programmed through PAR[1–0].
When the MCF5407 is bus master, it outputs these signals. They indicate the current bus access type.
15.1.2 Port A Data Direction Register (PADDR)
The PADDR determines the signal direction of each parallel port pin programmed as a
general-purpose I/O port in the PAR.
15
0
Field
PADDR
Reset
0000_0000_0000_0000
R/W
R/W
Address
Address MBAR + 0x244
Figure 15-2. Port A Data Direction Register (PADDR)
Table 15-2 describes PADDR fields.
Table 15-2. PADDR Field Description
Bits
Name
15–0
PADDR
Description
Data direction bits. Each data direction bit selects the direction of the signal as follows:
0 Signal is defined as an input.
1 Signal is defined as an output.
15.1.3 Port A Data Register (PADAT)
The PADAT value for inputs corresponds to the logic level at the pin; for outputs, the value
corresponds to the logic level driven onto the pin. Note the following:
•
15-2
PADAT has no effect on pins not configured for general-purpose I/O.
MCF5407 User’s Manual
Parallel Port Operation
•
•
PADAT settings do not affect inputs. PADAT bit values determine the corresponding
logic levels of pins configured as outputs.
PADAT can be written to anytime. A read from PADAT returns values of
corresponding pins configured as general-purpose I/O in the PAR and designated as
inputs by the PADDR.
15
0
Field
PADAT
Reset
0000_0000_0000_0000
R/W
R/W
Address
Address MBAR+0x248
Figure 15-3. Port A Data Register (PADAT)
Table 15-3 shows relationships between PADAT bits and parallel port pins when PADAT is
accessed. The effect differs when the parallel port pin is an input or output.
The following results occur when a parallel port pin is configured as an input:
•
•
When the PADAT is read, the value returned is the logic value on the pin.
When the PADAT is written, the register contents are updated without affecting the
logic value on the pin.
The following results occur when a parallel port pin is configured as an output:
•
•
When the PADAT is read, the register contents are returned and the pin is the logic
value of the register.
When the PADAT is written, the register contents are updated and the pin is the logic
value of the register.
These relationships are also described in Table 15-3.
Table 15-3. Relationship between PADAT Register and Parallel Port Pin (PP)
PP Status PADAT R/W
Read
Effect on PADAT
Effect on PP
Register bit value is the pin’s logic value
No effect. Source of logic value
Input
Write
Register contents updated
No effect on the logic value at the pin
Read
Register contents are returned
Pin is the logic value of the register bit
Write
Register contents updated
Pin is the logic value of the register bit
Output
NOTE:
Although external devices cannot access the MCF5407’s
on-chip memories or MBAR, they can access any parallel port
module registers in the SIM.
Chapter 15. Parallel Port (General-Purpose I/O)
15-3
Parallel Port Operation
15.1.4 Code Example
The following code example shows how to set up the parallel port. Here, PP[7:0] are
general-purpose I/O, PP[3:0] are inputs, and PP[7:4] are outputs.
15-4
MBARx
PAR
PADDR
PADAT
EQU
EQU
EQU
EQU
0x00010000
MBARx+0x004
MBARx+0x244
MBARx+0x248
move.l
movec
move.w
move.w
move.w
move.w
move.b
move.b
#MBARx,D0
D0, MBAR
#0x00FF,D0
D0,PAR
#0x00F0,D0
D0,PADDR
#0xA0,D0
D0,PADAT
;because MBAR is an internal register, MBARx is used as
;label for the memory map address
;set up the PAR. PP[7:0] set up as I/O
;set PP[7:4] as outputs; PP[3:0] as inputs
;0xA0 written into PADAT; PP[7:4] being outputs,
;PP[7:4] becomes 1010; i.e. PP7, PP5 = 1 and
;PP6, PP4 = 0
MCF5407 User’s Manual
Part IV
Hardware Interface
Intended Audience
Part IV is intended for hardware designers who need to know the functions and electrical
characteristics of the MCF5407 interface. It includes a pinout, and both electrical and
functional descriptions of the MCF5407 signals. It also describes how these signals interact
to support the variety of bus operations shown in timing diagrams.
Contents
Part IV contains the following chapters:
•
•
•
•
•
Chapter 16, “Mechanical Data,” provides a functional pin listing and package
diagram for the MCF5407.
Chapter 17, “Signal Descriptions,” provides an alphabetical listing of MCF5407
signals. This chapter describes the MCF5407 signals. In particular, it shows which
are inputs or outputs, how they are multiplexed, which signals require pull-up
resistors, and the state of each signal at reset.
Chapter 18, “Bus Operation,” describes data transfers, error conditions, bus
arbitration, and reset operations. It describes transfers initiated by the MCF5407 and
by an external bus master, and includes detailed timing diagrams showing the
interaction of signals in supported bus operations. Note that Chapter 11,
“Synchronous/Asynchronous DRAM Controller Module,” describes DRAM cycles.
Chapter 19, “IEEE 1149.1 Test Access Port (JTAG),” describes configuration and
operation of the MCF5407 JTAG test implementation. It describes the use of JTAG
instructions and how to disable JTAG functionality.
Chapter 20, “Electrical Specifications,” describes AC and DC electrical
specifications and thermal characteristics for the MCF5407. Because additional
speeds may have become available since the publication of this book, consult
Motorola’s ColdFire web page, http://www.motorola.com/coldfire, to confirm that
this is the latest information.
Part IV. Hardware Interface
IV-i
Suggested Reading
The following literature may be helpful with respect to the topics in Part IV:
•
•
IEEE Standard Test Access Port and Boundary-Scan Architecture
IEEE Supplement to Standard Test Access Port and Boundary-Scan Architecture
(1149.1)
Acronyms and Abbreviations
Table IV-i describes acronyms and abbreviations used in Part IV.
Table IV-i. Acronyms and Abbreviated Terms
Term
Meaning
BDM
Background debug mode
BIST
Built-in self test
BSDL
Boundary-scan description language
DMA
Direct memory access
DSP
Digital signal processing
EDO
Extended data output (DRAM)
GPIO
General-purpose I/O
I2C
Inter-integrated circuit
IEEE
Institute for Electrical and Electronics Engineers
IPL
Interrupt priority level
JEDEC
Joint Electron Device Engineering Council
JTAG
Joint Test Action Group
LSB
Least-significant byte
lsb
Least-significant bit
MAC
Multiple accumulate unit
MBAR
Memory base address register
MSB
Most-significant byte
msb
Most-significant bit
Mux
Multiplex
PCLK
Processor clock
PLL
Phase-locked loop
POR
Power-on reset
PQFP
Plastic quad flat pack
IV-ii
MCF5407 User’s Manual
Table IV-i. Acronyms and Abbreviated Terms (Continued)
Term
Meaning
RISC
Reduced instruction set computing
Rx
Receive
SIM
System integration module
TAP
Test access port
TTL
Transistor-to-transistor logic
Tx
Transmit
Part IV. Hardware Interface
IV-iii
IV-iv
MCF5407 User’s Manual
Chapter 16
Mechanical Data
This chapter provides a function pin listing and package diagram for the MCF5407. See the
website [http://www.motorola.com/coldfire] for any updated information.
16.1 Package
The MCF5407 is assembled in a 208-pin, thermally enhanced plastic QFP package.
16.2 Pinout
The MCF5407 pinout is detailed in the following tables, including the primary and
secondary functions of multiplexed signals. Additional columns indicate the output drive
capability of each pin, whether it is internally synchronized, and if the signal can change
on a negative clock transition. Note that the pin names IVCC and EVCC indicate which
pins require 1.8- and 3.3-V power inputs, respectively.
These tables show MCF5407 pin numbers, including signal multiplexing. Additional
columns indicate the direction, description, and output drive capability of each pin.
Table 16-1. Pins 1–52 (Left, Top-to-Bottom)
Pin
Alternate
Function
I/O
Description
Drive
(mA)
No
Name
1
IVCC
—
—
1.8-V power input
—
2
A0
—
I/O
Address bus bit
8
3
A1
—
I/O
Address bus bit
8
4
GND
—
—
Ground pin
—
5
A2
—
I/O
Address bus bit
8
6
A3
—
I/O
Address bus bit
8
7
EVCC
—
—
3.3-V power input
—
8
A4
—
I/O
Address bus bit
8
9
A5
—
I/O
Address bus bit
8
10
GND
—
—
Ground pin
—
11
A6
—
I/O
Address bus bit
8
Chapter 16. Mechanical Data
16-1
Pinout
Table 16-1. Pins 1–52 (Left, Top-to-Bottom) (Continued)
Pin
No
16-2
Name
Alternate
Function
I/O
Description
Drive
(mA)
12
A7
—
I/O
Address bus bit
8
13
EVCC
—
—
3.3-V power input
—
14
A8
—
I/O
Address bus bit
8
15
A9
—
I/O
Address bus bit
8
16
A10
—
I/O
Address bus bit
8
17
GND
—
—
Ground pin
—
18
A11
—
I/O
Address bus bit
8
19
A12
—
I/O
Address bus bit
8
20
A13
—
I/O
Address bus bit
8
21
EVCC
—
—
3.3-V power input
—
22
A14
—
I/O
Address bus bit
8
23
A15
—
I/O
Address bus bit
8
24
A16
—
I/O
Address bus bit
8
25
GND
—
—
Ground pin
—
26
A17
—
I/O
Address bus bit
8
27
A18
—
I/O
Address bus bit
8
28
A19
—
I/O
Address bus bit
8
29
EVCC
—
—
3.3-V power input
—
30
A20
—
I/O
Address bus bit
8
31
A21
—
I/O
Address bus bit
8
32
A22
—
I/O
Address bus bit
8
33
GND
—
—
Ground pin
—
34
A23
—
I/O
Address bus bit
8
35
PP8
A24
I/O
Parallel port bit/Address bus bit
8
36
PP9
A25
I/O
Parallel port bit/Address bus bit
8
37
EVCC
—
—
3.3-V power input
—
38
PP10
A26
I/O
Parallel port bit/Address bus bit
8
39
PP11
A27
I/O
Parallel port bit/Address bus bit
8
40
PP12
A28
I/O
Parallel port bit/Address bus bit
8
—
41
GND
—
—
Ground pin
42
PP13
A29
I/O
Parallel port bit/Address bus bit
8
43
PP14
A30
I/O
Parallel port bit/Address bus bit
8
44
PP15
A31
I/O
Parallel port bit/Address bus bit
8
45
EVCC
—
—
3.3-V power input
—
46
SIZ0
—
I/O
Size attribute
8
MCF5407 User’s Manual
Pinout
Table 16-1. Pins 1–52 (Left, Top-to-Bottom) (Continued)
Pin
No
Name
Alternate
Function
I/O
Description
Drive
(mA)
47
SIZ1
—
I/O
Size attribute
8
48
GND
—
—
Ground pin
—
49
OE
—
O
Output enable for chip selects
8
50
CS0
—
O
Chip select
8
51
CS1
—
O
Chip select
8
52
EVCC
—
—
3.3-V power input
—
Table 16-2. Pins 53–104 (Bottom, Left-to-Right)
Pin
Alternate
Function
I/O
GND
—
—
Ground pin
—
54
CS2
—
O
Chip select
8
55
CS3
—
O
Chip select
8
56
CS4
—
O
Chip select
8
No
Name
53
Description
Drive
(mA)
57
IVCC
—
—
1.8-V power input
—
58
CS5
—
O
Chip select
8
59
CS6
—
O
Chip select
8
60
CS7
—
O
Chip select
8
61
GND
—
—
Ground pin
—
62
AS
—
I/O
Address strobe
8
63
R/W
—
I/O
Read/Write
8
64
TA
—
I/O
Transfer acknowledge
8
65
EVCC
—
—
3.3-V power input
—
66
TS
—
I/O
Transfer start
8
67
RSTI
—
I
Reset
—
68
IRQ7
—
I
Interrupt request
—
69
GND
—
—
Ground pin
—
70
IRQ5
IRQ4
I
Interrupt request
—
71
IRQ3
IRQ6
I
Interrupt request
—
72
IRQ1
IRQ2
I
Interrupt request
—
73
IVCC
—
—
1.8-V power input
—
74
BR
—
O
Bus request
8
75
BD
—
O
Bus driven
8
76
BG
—
I
Bus grant
—
Chapter 16. Mechanical Data
16-3
Pinout
Table 16-2. Pins 53–104 (Bottom, Left-to-Right) (Continued)
Pin
No
1
16-4
Name
Alternate
Function
I/O
Description
Drive
(mA)
77
GND
—
—
Ground pin
—
78
TOUT1
—
O
Timer output
8
79
TOUT0
—
O
Timer output
8
80
TIN0
—
I
Timer input
—
81
EVCC
—
—
3.3-V power input
—
82
TIN1
—
I
Timer input
—
83
RAS0
—
O
DRAM row address strobe
16
84
RAS1
—
O
DRAM row address strobe
16
85
GND
—
—
Ground pin
—
86
CAS0
—
O
DRAM column address strobe
16
87
CAS1
—
O
DRAM column address strobe
16
88
CAS2
—
O
DRAM column address strobe
16
89
EVCC
—
—
3.3-V power input
—
90
CAS3
—
O
DRAM column address strobe
16
91
DRAMW
—
O
DRAM write
16
92
SRAS
—
O
SDRAM row address strobe
16
93
GND
—
—
Ground pin
—
94
SCAS
—
O
SDRAM column address strobe
16
95
SCKE
—
O
SDRAM clock enable
16
96
BE0
BWE0
O
Byte enable/byte write enable
8
97
EVCC
—
—
3.3-V power input
—
98
BE1
BWE1
O
Byte enable/byte write enable
8
99
BE2
BWE2
O
Byte enable/byte write enable
8
100
BE3
BWE3
O
Byte enable/byte write enable
8
101
GND
—
—
Ground pin
—
102
SCL
—
I/OD 1 Serial clock line
8
103
SDA
—
I/OD 1 Serial data line
8
104
GND
—
—
Ground pin
OD: Open-drain output
MCF5407 User’s Manual
—
Pinout
Table 16-3. Pins 105–156 (Right, Bottom-to-Top)
Pin
No
Name
105
IVCC
Alternate
Function
I/O
—
—
Description
1.8-V power input
Drive
(mA)
—
106
D31
—
I/O
Data bus
8
107
D30
—
I/O
Data bus
8
108
D29
—
I/O
Data bus
8
109
GND
—
—
Ground pin
—
110
D28
—
I/O
Data bus
8
111
D27
—
I/O
Data bus
8
112
D26
—
I/O
Data bus
8
113
EVCC
—
—
3.3-V power input
—
114
D25
—
I/O
Data bus
8
115
D24
—
I/O
Data bus
8
116
D23
—
I/O
Data bus
8
117
GND
—
—
Ground pin
—
118
D22
—
I/O
Data bus
8
119
D21
—
I/O
Data bus
8
120
D20
—
I/O
Data bus
8
121
EVCC
—
—
3.3-V power input
—
122
D19
—
I/O
Data bus
8
123
D18
—
I/O
Data bus
8
124
D17
—
I/O
Data bus
8
125
GND
—
—
Ground pin
—
126
D16
—
I/O
Data bus
8
127
D15
—
I/O
Data bus
8
128
D14
—
I/O
Data bus
8
129
EVCC
—
—
3.3-V power input
—
130
D13
—
I/O
Data bus
8
131
D12
—
I/O
Data bus
8
132
D11
—
I/O
Data bus
8
133
GND
—
—
Ground pin
—
134
D10
—
I/O
Data bus
8
135
D9
—
I/O
Data bus
8
136
D8
—
I/O
Data bus
8
137
EVCC
—
—
3.3-V power input
—
138
D7
CS_CONF2
I/O
Data bus/Chip select configuration
8
Chapter 16. Mechanical Data
16-5
Pinout
Table 16-3. Pins 105–156 (Right, Bottom-to-Top) (Continued)
Pin
No
Name
Alternate
Function
I/O
Description
Drive
(mA)
139
D6
CS_CONF1
I/O
Data bus/Chip select configuration
8
140
D5
CS_CONF0
I/O
Data bus/Chip select configuration
8
141
GND
—
—
Ground pin
—
142
D4
ADDR_CONF
I/O
Data bus/Address configuration
8
143
D3
BE_CONFIG0
I/O
Data bus/Byte enable configuration
8
144
D2
DIVIDE2
I/O
Data bus/Divide control PCLK:CLKIN
8
145
EVCC
—
—
3.3-V power input
—
146
D1
DIVIDE1
I/O
Data bus/Divide control PCLK:CLKIN
8
147
D0
DIVIDE0
I/O
Data bus/Divide control PCLK:CLKIN
8
Ground pin
—
148
GND
—
—
149
DSCLK
TRST
I
Debug serial clock/JTAG Reset
—
150
TCK
TCK
I
JTAG clock
—
151
DSO
TDO
O
Debug serial out/JTAG data out
8
152
IVCC
—
—
1.8-V power input
—
153
DSI
TDI
I
Debug serial input/JTAG data in
—
154
BKPT
TMS
I
Debug breakpoint/JTAG mode select
—
155
HIZ
—
I
High impedance override
—
156
GND
—
—
Ground pin
—
Table 16-4. Pins 157–208 (Top, Right-to-Left)
Pin
16-6
Alternate
Function
I/O
IVCC
—
—
158
CTS1
—
159
RTS1
—
160
RXD1
—
I
161
TXD1
—
O
UART1 transmit data
8
162
GND
—
—
Ground pin
—
—
No
Name
157
Description
Drive
(mA)
1.8-V power input
—
I
UART1 clear-to-send
—
O
UART1 request-to-send
8
UART1 receive data
—
163
CTS0
—
I
UART0 clear-to-send
164
RTS0
—
O
UART0 request-to-send
8
165
RXD0
—
I
UART0 receive data
—
166
TXD0
—
O
UART0 transmit data
8
167
EVCC
—
—
3.3-V power input
—
MCF5407 User’s Manual
Pinout
Table 16-4. Pins 157–208 (Top, Right-to-Left) (Continued)
Pin
Alternate
Function
I/O
No
Name
168
EDGESEL
—
I
169
GND
—
—
Description
Drive
(mA)
SDRAM bus clock edge select
—
Ground pin
—
170
BCLKO
—
O
Bus clock output
16
171
IVCC
—
—
1.8-V power input
—
172
RSTO
—
O
Processor reset output
8
173
GND
—
—
Ground pin
—
174
CLKIN
—
I
Clock input
—
175
IVCC
—
—
1.8-V power input
—
176
MTMOD0
—
I
JTAG/BDM select (Tie high or low)
—
177
MTMOD1
—
I
Tie high or low
—
178
PGND
—
—
PLL ground pin
—
179
NC
—
O
180
PVCC
—
—
181
MTMOD2
—
I
182
MTMOD3
—
I
Tie high or low
—
183
GND
—
—
Ground pin
—
184
PSTCLK
—
O
Processor status clock
8
—
1.8-V filter supply for PLL
—
Tie high or low
—
185
IVCC
—
—
1.8-V power input
—
186
PSTDDATA0
—
O
Processor status/debug data
8
187
PSTDDATA1
—
O
Processor status/debug data
8
188
GND
—
—
Ground pin
—
189
PSTDDATA2
—
O
Processor status/debug data
8
190
PSTDDATA3
—
O
Processor status/debug data
8
191
EVCC
—
—
3.3-V power input
—
192
PSTDDATA4
—
O
Processor status/debug data
8
193
PSTDDATA5
—
O
Processor status/debug data
8
194
GND
—
—
Ground pin
—
195
PSTDDATA6
—
O
Processor status/debug data
8
196
PSTDDATA7
—
O
Processor status/debug data
8
197
IVCC
—
—
1.8-V power input
—
198
PP7
TIP
I/O
Parallel port bit/transfer in progress
8
199
PP6
DREQ0
I/O
Parallel port bit/DMA request
8
200
PP5
DREQ1
I/O
Parallel port bit/DMA request
8
201
GND
—
—
Ground pin
—
202
PP4
TM2
I/O
Parallel port bit/Transfer modifier
8
Chapter 16. Mechanical Data
16-7
Mechanical Diagram
Table 16-4. Pins 157–208 (Top, Right-to-Left) (Continued)
Pin
1
Alternate
Function
I/O
PP3
TM1/DACK11
I/O
Parallel port bit/Transfer modifier/DMA acknowledge
8
204
PP2
TM0/DACK01
I/O
Parallel port bit/Transfer modifier/DMA acknowledge
8
205
EVCC
—
—
3.3-V power input
—
206
PP1
TT1
I/O
Parallel port bit/Transfer type
8
207
PP0
TT0
I/O
Parallel port bit/Transfer type
8
208
GND
—
—
Ground pin
—
No
Name
203
Description
When the internal DMA is used, PP3 and PP2 (PP[3:2]/TM[1:0]) can be programmed to a third
function, (DACK[1:0]), which indicates DMA acknowledge.
16.3 Mechanical Diagram
Figure 16-1 is a mechanical diagram of the 208-pin QFP MCF5407.
16-8
MCF5407 User’s Manual
Drive
(mA)
GND
PP0
PP1
EVCC
PP2
PP3
PP4
GND
PP5
PP6
PP7
IVCC
PSTDDATA7
PSTDDATA6
GND
PSTDDATA5
PSTDDATA4
EVCC
PSTDDATA3
PSTDDATA2
GND
PSTDDATA1
PSTDDATA0
IVCC
PSTCLK
GND
MTMOD3
MTMOD2
PVCC
NC
PGND
MTMOD1
MTMOD0
IVCC
CLKIN
GND
RSTO
IVCC
BCLKO
GND
EDGESEL
EVCC
TXD0
RXD0
RTS0
CTS0
GND
TXD1
RXD1
RTS1
CTS1
IVCC
Case Drawing
156
160
165
170
175
180
185
190
205
1
IVCC
A0
A1
GND
A2
A3
EVCC
A4
A5
GND
A6
A7
EVCC
A8
A9
A10
GND
A11
A12
A13
EVCC
A14
A15
A16
GND
A17
A18
A19
EVCC
A20
A21
A22
GND
A23
PP8
PP9
EVCC
PP10
PP11
PP12
GND
PP13
PP14
PP15
EVCC
SIZ0
SIZ1
GND
OE
CS0
CS1
EVCC
195
157
200
208
GND
HIZ
BKPT
DSI
IVCC
DSO
TCK
DSCLK
GND
D0
D1
EVCC
D2
D3
D4
GND
D5
D6
D7
EVCC
D8
D9
D10
GND
D11
D12
D13
EVCC
D14
D15
D16
GND
D17
D18
D19
EVCC
D20
D21
D22
GND
D23
D24
D25
EVCC
D26
D27
D28
GND
D29
D30
D31
IVCC
155
5
150
10
145
15
140
20
135
25
130
30
125
35
120
40
115
45
110
100
95
90
85
80
75
70
65
52
60
55
50
105
104
GND
CS2
CS3
CS4
IVCC
CS5
CS6
CS7
GND
AS
R/W
TA
EVCC
TS
RSTI
IRQ7
GND
IRQ5
IRQ3
IRQ1
IVCC
BR
BD
BG
GND
TOUT1
TOUT0
TIN0
EVCC
TIN1
RAS0
RAS1
GND
CAS0
CAS1
CAS2
EVCC
CAS3
DRAMW
SRAS
GND
SCAS
SCKE
BE0
EVCC
BE1
BE2
BE3
GND
SCL
SDA
GND
53
105
Figure 16-1. Mechanical Diagram
16.4 Case Drawing
Figure 16-2 and Figure 16-3 show the MCF5407 case drawings.
Chapter 16. Mechanical Data
16-9
Case Drawing
Figure 16-2. MCF5407 Case Drawing (General View)
16-10
MCF5407 User’s Manual
Case Drawing
View A: Three Places
Section A-A: 160 Places Rotated 90° CW
View B
Figure 16-3. Case Drawing (Details)
The dimensions in Figure 16-2 and Figure 16-3 are referenced in Table 16-5.
Table 16-5. Dimensions
Dimension (Millimeters)
Reference
Minimum
Maximum
A
—
4.10
A1
0.25
0.50
A2
3.20
3.60
b
0.17
0.27
b1
0.17
0.23
c
0.09
0.20
c1
0.09
0.16
D
30.60 BSC
Chapter 16. Mechanical Data
16-11
Case Drawing
Table 16-5. Dimensions (Continued)
Dimension (Millimeters)
Reference
Minimum
D1
28.00 BSC
e
0.50 BSC
E
30.60 BSC
E1
28.00 BSC
L
0.45
L1
R1
16-12
Maximum
0.75
1.30 REF
0.08
—
R2
0.08
0.25
S
0.20
—
ϑ
0*
8*
ϑ1
0*
—
ϑ2
5*
16*
MCF5407 User’s Manual
Chapter 17
Signal Descriptions
This chapter describes MCF5407 signals. It includes an alphabetical listing of signals,
showing multiplexing, whether it is an input or output to the MCF5407, the state at reset,
and whether a pull-up resistor should be used. The following chapter, Chapter 18, “Bus
Operation,” describes how these signals interact.
NOTE:
The terms ‘assertion’ and ‘negation’ are used to avoid
confusion when dealing with a mixture of active-low and
active-high signals. The term ‘asserted’ indicates that a signal
is active, independent of the voltage level. The term ‘negated’
indicates that a signal is inactive.
Active-low signals, such as SRAS and TA, are indicated with
an overbar.
17.1 Overview
Figure 17-1 shows the block diagram of the MCF5407 with the signal interface.
Chapter 17. Signal Descriptions
17-1
Overview
ColdFire V4 Core
2
2
Bus
Interface
Test
Controller
Debug Module
PSTDDATA[7:0]
2 2-Kbyte SRAMs
32
DIV
External
to Internal
Bus
8
2
8
4
Chip
Selects
8
MAC
8-Kbyte 16-Kbyte
D-Cache I-Cache
Parallel
Port1
Internal Bus Arbiter
Interrupt
Controller
1 Parallel
2 I2C
port pins (PPn) are multiplexed with other bus functions as shown.
is a Philips proprietary interface.
Figure 17-1. MCF5407 Block Diagram with Signal Interfaces
Table 17-1 lists the MCF5407 signals grouped by functionality.
17-2
MCF5407 User’s Manual
I2C
Module 2
SDA
SCL
2
2
Dual
Timer
Module
TOUT[1:0]
UART1
Serial
I/O
(synch)
TxD0
RxD0
RTS0
CTS0
TxD1
RxD1
RTS1
CTS1
PLL
UART0
Serial
I/O
TIN[1:0]
DMA
Module
2
DRAM
Controller
System
Integration
Module
(SIM)
2
2
4
DREQ[1:0]/
PP[6:5]
BCLKO
CLKIN
PSTCLK
4
TDI/DSI
TRST/DSCLK
A[23:0]
CS[7:0]
BE[3:0]/BWE[3:0]
OE
IRQ7
IRQ5
IRQ3
IRQ1
RAS[1:0]
CAS[3:0]
DRAMW
SRAS
SCAS
SCKE
EDGESEL
JTAG
Port
TMS/BKPT
24
A[31:24]/PP[15:8]
TM[2:0]/PP[4:2]
MTMOD[3:0]
HIZ
TDO/DSO
TCK
DACK[1:0]/
PP[3:2]
BR
BG
BD
RSTI
RSTO
AS
TA
TS
TT[1:0]]/PP[1:0]
SIZ[1:0]
R/W
TIP/PP7
D[31:0]
Overview
Table 17-1. MCF5407 Signal Index
Signal Name
Abbreviation
Function
I/O
Reset
Pull-Up Page
17-7
Section 17.2, “MCF5407 Bus Signals”
Address
A[31:0]
32-bit address bus. A[4:2] indicate
the interrupt level for external
interrupts.
I/O
Three
state
17-7
Data
D[31:0]
Data bus. D[7:0] are loaded at reset
for bus configuration.
I/O
Three
state
17-8
Read/Write
R/W
Identifies read and write transfers
I/O
Three
state
Size
SIZ[1:0]
Indicates the data transfer size
I/O
Three
state
17-8
Transfer start
TS
Indicates the start of a bus transfer
I/O
Three
state
17-9
Address strobe
AS
Indicates a bus cycle has been
initiated and address is stable
I/O
Three
state
Up
17-9
Transfer acknowledge
TA
Assertion terminates transfer
synchronously
I/O
Three
state
Up
17-9
Transfer in progress
TIP/PP7
Indicates a bus cycle is in progress;
multiplexed with PP7
O
Parallel
port
17-10
Transfer type
TT[1:0]
Indicates transfer type: normal, CPU
space, emulator mode, or DMA;
multiplexed with PP[1:0]
O
Parallel
port
17-10
Transfer modifier
TM[2:0]
Provides transfer modifier
information; multiplexed with
TM2/PP4 and
TM[1:0]/PP[3:2]/DACK[1:0]
O
Parallel
port
17-10
Up
17-8
17-12
Section 17.3, “Interrupt Control Signals”
Interrupt request
IRQ7, IRQ5,
IRQ3, IRQ1
Four external interrupts are set to
default levels 1,3,5,7; user-alterable.
I
—
Up
17-12
17-12
Section 17.4, “Bus Arbitration Signals”
Bus request
BR
Indicates processor needs bus
O
High
Bus grant
BG
Arbiter asserts to grant mastership.
I
—
Bus driven
BD
Indicates processor is driving bus
O
High
17-12
Note
1
17-12
17-13
17-13
Section 17.5, “Clock and Reset Signals”
Reset in
RSTI
Processor reset input
I
—
Clock input
CLKIN
Input used to clock internal logic
I
—
17-13
Bus clock out
BCLKO
Bus clock reference output
O
—
17-13
Reset out
RSTO
Processor reset output
O
Low
17-13
Auto-acknowledge
configuration 2
AA_CONFIG
Controls auto acknowledge timing
for CS0 at reset
I
—
17-14
Port size configuration 2 PS_CONFIG[1:0] Controls port size for CS0 at reset
I
—
User cfg 17-14
Chapter 17. Signal Descriptions
Up
17-13
17-3
Overview
Table 17-1. MCF5407 Signal Index (Continued)
Signal Name
Address configuration
Abbreviation
2
Function
I/O
Reset
Pull-Up Page
ADDR_CONFIG
Programs parallel I/O ports
I
—
User cfg 17-15
BE[3:0] configuration
BE_CONFIG
Programs byte enable pins
I
—
User cfg 17-15
Divide control PCLK to
CLKIN 2
DIVIDE[2:0]
Selects CLKIN/PCLK ratio
I
—
User cfg 17-15
17-15
Section 17.6, “Chip-Select Module Signals”
Chip selects[7:0]
CS[7:0]
Enables peripherals at programmed
addresses; CS0 provides boot ROM
selection.
O
High
17-15
Byte enable[3:0]/
Byte write enable[3:0]
BE[3:0]/
BWE[3:0]
BE[3:0] select bytes in memory.
Programmed at reset for CS0
O
High
17-16
Output enable
OE
Output enable for chip select read
cycles
O
High
17-16
17-16
Section 17.7, “DRAM Controller Signals”
Row address strobe
RAS[1:0]
DRAM row address strobe
O
High
Column address strobe
CAS[3:0]
DRAM column address strobe
O
High
17-16
DRAM write
DRAMW
Asserted for DRAM write; negated
for DRAM read
O
High
17-16
Synchronous column
address strobe
SCAS
SDRAM column address strobe
O
High
17-17
Synchronous row
address strobe
SRAS
SDRAM row address strobe
O
High
17-17
Synchronous clock
enable
SCKE
Clock enable for external SDRAM
O
Low
17-17
Synchronous edge
select
EDGESEL
Timing select for external SDRAM
I
—
17-16
User cfg 17-17
17-17
Section 17.8, “DMA Controller Module Signals”
DMA request
DREQ[1:0]
External DMA transfer request;
multiplexed with PP[6:5]
I
—
17-17
DMA acknowledge
DACK[1:0]
Indicates DMA transfer terminated;
multiplexed with TM[1:0]/PP[3:2]
O
Parallel
port
17-18
17-18
Section 17.9, “Serial Module Signals”
Receive data
RxD[1:0]
Receive serial data input for UART
I
—
17-19
Transmit data
TxD[1:0]
Transmit serial data output for UART
O
High
17-18
Request-to-send
RTS[1:0]
UART asserts when ready to
receive data query.
O
High
17-19
Clear-to-send
CTS[1:0]
Signals UART that data can be sent
to peripheral
I
—
17-19
17-19
Section 17.10, “Timer Module Signals”
Timer input
17-4
TIN[1:0]
Clock input to timer or trigger to
timer value capture logic
MCF5407 User’s Manual
I
—
17-19
Overview
Table 17-1. MCF5407 Signal Index (Continued)
Signal Name
Timer outputs
Abbreviation
TOUT[1:0]
Function
Outputs waveform or pulse.
I/O
Reset
O
High
Pull-Up Page
17-19
17-19
Section 17.11, “Parallel I/O Port (PP[15:0])”
Parallel port
PP[15:0]
Interfaces with I/O; multiplexed with
bus address and attribute signals.
I/O
Input
17-19
Section 17.12, “I2C Module Signals”
I2C
Serial clock line
SCL
Clock signal for
Serial data line
SDA
Serial data port for I2C operation
17-20
operation
I/O
Open
drain
Up
17-20
I/O
Open
drain
Up
17-20
17-20
Section 17.13, “Debug and Test Signals”
Motorola test mode
MTMOD0
Puts processor in functional or
emulator mode
I
—
Motorola test mode
MTMOD[3:1]
Reserved
I
—
Down
17-20
High impedance
HIZ
Assertion three-states all outputs
I
—
Up
17-20
Processor clock out
PSTCLK
Output clock used for PSTDDATA
O
—
17-21
Displays captured processor data
and breakpoint status
O
Driven
17-21
Processor status/debug PSTDDATA[7:0]
data
User cfg 17-20
17-21
Section 17.14, “Debug Module/JTAG Signals”
Test clock
TCK
Clock signal for IEEE 1149.1 JTAG
I
—
Low
17-22
Test reset/
Development serial
clock
TRST/DSCLK
Asynchronous reset for JTAG;
debug module clock input
I
—
Up
17-21
Test mode select/
Breakpoint
TMS/BKPT
TMS (JTAG)/hardware breakpoint
(debug)
I
—
Up
17-21
Test data input/
Development serial
input
TDI/DSI
Multiplexed serial input for the JTAG
or background debug module
I
—
Up
17-22
Test data output/
Development serial
output
TDO/DSO
Multiplexed serial output for the
JTAG or background debug module
O
Driven
1
2
17-22
If there is no arbiter, BG should be tied low; otherwise, it should be negated.
These data pins are sampled at reset for configuration.
Table 17-2 lists signals in alphabetical order by abbreviated name.
Table 17-2. MCF5407 Alphabetical Signal Index
Abbreviation
AA_CONFIG
Signal Name
Auto-acknowledge configuration
Function
Clock/reset
ADDR_CONFIG
Address configuration
Clock/reset
AS
Address strobe
Bus
Chapter 17. Signal Descriptions
I/O
Page
I
17-14
I
17-15
I/O
17-9
17-5
Overview
Table 17-2. MCF5407 Alphabetical Signal Index (Continued)
Abbreviation
Signal Name
Function
I/O
Page
A[31:0]
Address
Bus
I/O
17-7
BCLKO
Bus clock out
Clock/reset
O
17-13
BD
Bus driven
Bus arbitration
O
17-13
Chip select
O
17-16
BE[3:0]/BWE[3:0] Byte enable[3:0]/Byte write enable[3:0]
BG
Bus grant
Bus arbitration
I
17-12
BR
Bus request
Bus arbitration
O
17-12
CAS[3:0]
Column address strobe
DRAM
O
17-16
CLKIN
Clock input
Clock/reset
I
17-13
CS[7:0]
Chip selects[7:0]
UART
O
17-15
CTS[1:0]
Clear-to-send
Serial module
I
17-19
DACK[1:0]
DMA acknowledge
DMA
O
17-18
DIVIDE[2:0]
Divide control PCLK to CLKIN
Clock/reset
I
17-15
DRAMW
DRAM write
DRAM
O
17-16
DREQ[1:0]
DMA request
DMA
I
17-17
D[31:0]
Data
Bus
I/O
17-8
EDGESEL
Sync edge select
DRAM
I
17-17
HIZ
High impedance
Debug
I
17-20
IRQ7, IRQ5,
IRQ3, IRQ1
Interrupt request
Interrupt control
I
17-12
MTMOD[3:0]
Motorola test mode
Debug
I
17-20
OE
Output enable
Chip select
O
17-16
PP[15:0]
Parallel port
Parallel port
I/O
17-19
PSTCLK
Processor clock out
Debug
O
17-20
PSTDDATA[7:0]
Processor status/debug data
Debug
O
17-20
Clock/reset
I
17-14
PS_CONFIG[1:0] Port size configuration
R/W
Read/Write
Bus
I/O
17-8
RAS[1:0]
Row address strobe
DRAM
O
17-16
RSTI
Reset In
Clock/reset
I
17-13
RSTO
Reset Out
Clock/reset
O
17-13
RTS[1:0]
Request-to-send
Serial module
O
17-19
RxD[1:0]
Receive data
Serial module
I
17-19
SCAS
Synchronous column address strobe
DRAM
O
17-17
SCKE
Synchronous clock enable
DRAM
O
17-17
SCL
Serial clock line
I2C
I/O
17-20
SDA
Serial data line
I2C
I/O
17-20
SIZ[1:0]
Size
Bus
I/O
17-8
17-6
MCF5407 User’s Manual
MCF5407 Bus Signals
Table 17-2. MCF5407 Alphabetical Signal Index (Continued)
Abbreviation
Signal Name
Function
I/O
Page
SRAS
Synchronous row address strobe
DRAM
O
17-17
TA
Transfer acknowledge
Bus
I/O
17-9
TCK
Test clock
JTAG
I
17-22
TDI/DSI
Test data input/Development serial input
JTAG
I
17-22
TDO/DSO
Test data output/Development serial output
JTAG
O
17-22
TIN[1:0]
Timer input
Timer
I
17-19
TIP
Transfer in progress
Bus
O
17-10
TMS/BKPT
Test mode select/Breakpoint
JTAG
I
17-21
TM[2:0]
Transfer modifier
Bus
O
17-10
TOUT[1:0]
Timer outputs
Timer
O
17-19
TRST/DSCLK
Test reset/Development serial clock
JTAG
I
17-21
TS
Transfer start
Bus
I/O
17-9
TT[1:0]
Transfer type
Bus
O
17-10
TxD[1:0]
Transmit data
Serial module
O
17-18
17.2 MCF5407 Bus Signals
The bus signals provide the external bus interface to the MCF5407.
17.2.1 Address Bus
The address bus provides the address of the byte or most-significant byte (MSB) of the
word or longword being transferred. The address lines also serve as the DRAM addressing,
providing multiplexed row and column address signals. When an external device has
ownership of the MCF5407 bus, the device must drive the address bus and assert TS or AS
to indicate the start of a bus cycle. During an interrupt acknowledge access, A[4:2] indicate
the interrupt level being acknowledged.
17.2.1.1 Address Bus (A[23:0])
The lower 24 bits of the address bus become valid when TS is asserted. A[4:2] indicate the
interrupt level during interrupt acknowledge cycles.
17.2.1.2 Address Bus (A[31:24]/PP[15:8])
These multiplexed pins can serve as the most-significant byte of the address bus, or as the
most-significant byte of the parallel port. Programming the PAR in the system integration
module (SIM) determines the function of each of these eight multiplexed pins. These pins
are programmable on a bit-by-bit basis.
Chapter 17. Signal Descriptions
17-7
MCF5407 Bus Signals
•
•
A[31:24]—Pins are configured as address bits by setting corresponding PAR bits;
they represent the most-significant address bus bits. As much as 4 Gbytes of
memory are available when all of these pins are programmed as address signals.
PP[15:8]—Pins are configured as parallel port signals by clearing corresponding
PAR bits; these represent the most-significant parallel port bits.
17.2.2 Data Bus (D[31:0])
The data bus is bidirectional and non-multiplexed. Data is sampled by the MCF5407 on the
rising CLKIN edge. The data bus port width, wait states, and internal termination are
initially defined for the boot chip select by D[7:0] during reset. The port width for each chip
select and DRAM bank are programmable. The data bus uses a default configuration if none
of the chip selects or DRAM bank match the address decode. The default configuration is
a 32-bit port with external termination and burst-inhibited transfers. The data bus can
transfer byte, word, or longword data widths. All 32 data bus signals are driven during
writes, regardless of port width and operand size.
D[7:0] are used during reset initialization as inputs to configure the functions as described
in Table 17-3. They are defined in Section 17.5.5, “Data/Configuration Pins (D[7:0]).”
Table 17-3. Data Pin Configuration
Pin
D7
Function
Section
Auto-acknowledge configuration
(AA_CONFIG)
Section 17.5.5.2, “D7—Auto Acknowledge Configuration
(AA_CONFIG)”
D[6:5] Port size configuration (PS_CONFIG[1:0])
Section 17.5.5.3, “D[6:5]—Port Size Configuration
(PS_CONFIG[1:0])”
D4
Address configuration (ADDR_CONFIG/D4) Section 17.5.6, “D4—Address Configuration
(ADDR_CONFIG)”
D3
Byte enable configuration (BE_CONFIG)
D[2:0] Divide control (DIVIDE[2:0])
Section 17.5.5.4, “D3—Byte-Enable Configuration
(BE_CONFIG)”
Section 17.5.6.1, “D[2:0]—Divide Control (DIVIDE[2:0])”
17.2.3 Read/Write (R/W)
When the MCF5407 is the bus master, it drives the R/W signal to indicate the direction of
subsequent data transfers. It is driven high during read bus cycles and driven low during
write bus cycles. This signal is an input during an external master access.
17.2.4 Size (SIZ[1:0])
When it is the bus master, the MCF5407 outputs these signals to indicate the requested data
transfer size. Table 17-4 shows the definition of the bus request size encodings. When the
MCF5407 device is not the bus master, these signals function as inputs.
Note that for misaligned transfers, SIZ[1:0] indicate the size of each transfer. For example,
17-8
MCF5407 User’s Manual
MCF5407 Bus Signals
if a longword access occurs at a misaligned offset of 0x1, a byte is transferred first (SIZ[1:0]
= 01), a word is next transferred at offset 0x2 (SIZ[1:0] = 10), then the final byte is
transferred at offset 0x4 (SIZ[1:0] = 01).
For aligned transfers larger than the port size, SIZ[1:0] behaves as follows:
•
•
If bursting is used, SIZ[1:0] stays at the size of transfer.
If bursting is inhibited, SIZ[1:0] first shows the size of the transfer and then shows
the port size.
Table 17-4. Bus Cycle Size Encoding
SIZ[1:0]
Port Size
00
Longword
01
Byte
10
Word
11
Line
For burst-inhibited transfers, SIZ[1:0] changes with each TS assertion to reflect the next
transfer size. For transfers to port sizes smaller than the transfer size, SIZ[1:0] indicates the
size of the entire transfer on the first access and the size of the current port transfer on
subsequent transfers. For example, for a longword write to an 8-bit port, SIZ[1:0] = 00 for
the first byte transfer and 01 for the next three.
17.2.5 Transfer Start (TS)
The MCF5407 asserts TS during the first clock cycle when address and attributes (TM, TT,
TIP, R/W, and SIZ) are valid. TS is negated in the following clock cycle. When the
MCF5407 is not the bus master, TS is an input.
17.2.6 Address Strobe (AS)
Address strobe (AS) is asserted to indicate when the address is stable at the start of a bus
cycle. The address and attributes are guaranteed to be valid during the entire period that AS
is asserted. This signal is asserted and negated on the falling edge of the clock. When the
MCF5407 is not the bus master, AS is an input.
17.2.7 Transfer Acknowledge (TA)
When the MCF5407 is bus master, the external system drives this input to terminate the bus
transfer. The bus continues to be driven until this synchronous signal is asserted. For write
cycles, the processor continues to drive data one clock after TA is asserted. During read
cycles, the peripheral must continue to drive data until TA is recognized.
If all bus cycles support fast termination, TA can be tied low. However, note that TA cannot
be tied low if potential external bus masters are present. The MCF5407 drives TA for an
Chapter 17. Signal Descriptions
17-9
MCF5407 Bus Signals
external master access. This condition is indicated by the AM bit in the chip-select mask
register (CSMR) being cleared. See Chapter 10, “Chip-Select Module.”
17.2.8 Transfer In Progress (TIP/PP7)
The TIP/PP7 pin is programmed in the PAR to serve as the transfer-in-progress output or
as a parallel port bits. The TIP output is asserted indicating a bus transfer is in progress. It
is negated during idle bus cycles if the bus is still granted to the processor. It is three-stated
for external master accesses. Note that TIP is held asserted on back-to-back bus cycles.
17.2.9 Transfer Type (TT[1:0]/PP[1:0])
The TT[1:0]/PP[1:0] pins are programmed in the PAR to serve as the transfer type outputs
or as two parallel port bits. When the MCF5407 is bus master and TT[1:0] are enabled,
these signals are driven as outputs only. If an external master owns the bus and TT[1:0] are
enabled, these pins are three-stated by the MCF5407 and can be driven by the external
master. Table 17-5 shows the definition of the encodings.
Table 17-5. Bus Cycle Transfer Type Encoding
TT[1:0]
Transfer Type
00
Normal access
01
DMA access
10
Emulator access
11
CPU space or interrupt acknowledge
17.2.10 Transfer Modifier (TM[2:0]/PP[4:2]/DACK[1:0])
The TM[2:0]/PP[4:2] pins are programmed in the PAR to serve as the transfer modifier
outputs or as three parallel port bits. These outputs provide supplemental information for
each transfer type; see Table 17-6 through Table 17-10.
When the MCF5407 is the bus master and TM[2:0] are enabled, these signals are driven as
outputs only. If an external device is bus master and TM[2:0] are enabled, these pins are
three-stated by the MCF5407 and can be driven by the external master.
Table 17-6. TM[2:0] Encodings for TT = 00 (Normal Access)
TM[2:0]
000
Cache push access
001
User data access
010
User code access
011–100
101
17-10
Transfer Modifier
Reserved
Supervisor data access
MCF5407 User’s Manual
MCF5407 Bus Signals
Table 17-6. TM[2:0] Encodings for TT = 00 (Normal Access) (Continued)
TM[2:0]
Transfer Modifier
110
Supervisor code access
111
Reserved
As shown in Table 17-7, if the DMA is bus master (TT = 01), TM[2:0] indicate the type of
DMA access and provide the DMA acknowledgement information for channels 0 and 1. In
addition, TM[1:0] are multiplexed with DMA acknowledge signals for channels 0 and 1.
NOTE:
When TT= 01, the TM2 encoding is independent from TM[1:0]
encoding.
Table 17-7. TM2 Encoding for DMA as Master (TT = 01)
TM2
Transfer Modifier Encoding
0
Single-address access negated
1
Single-address access
Table 17-8. TM[1:0] Encoding for DMA as Master (TT = 01)
TM[1:0]
Transfer Modifier Encoding
00
DMA acknowledges negated
01
DMA acknowledge, channel 0
10
DMA acknowledge, channel 1
11
Reserved
Table 17-9 shows TM[2:0] encodings for emulator mode accesses.
Table 17-9. TM[2:0] Encodings for TT = 10 (Emulator Access)
TM[2:0]
000–100
Transfer Modifier
Reserved
101
Emulator mode data access
110
Emulator mode code access
111
Reserved
The TM signals indicate user or data transfer types during emulation transfers, while for
interrupt acknowledge transfers, the TM signals carry the interrupt level being
acknowledged; see Table 17-10.
Chapter 17. Signal Descriptions
17-11
Interrupt Control Signals
Table 17-10. TM[2:0] Encodings for TT = 11 (Interrupt Level)
TM[2:0]
Transfer Modifier
000
CPU Space
001
Interrupt level 1 acknowledge
010
Interrupt level 2 acknowledge
011
Interrupt level 3 acknowledge
100
Interrupt level 4 acknowledge
101
Interrupt level 5 acknowledge
110
Interrupt level 6 acknowledge
111
Interrupt level 7 acknowledge
17.3 Interrupt Control Signals
The interrupt control signals supply the external interrupt level to the MCF5407 device.
17.3.1 Interrupt Request (IRQ1/IRQ2, IRQ3/IRQ6, IRQ5/IRQ4,
and IRQ7)
The IRQ1, IRQ3, IRQ5, and IRQ7 signals are the default interrupt request signals (IRQn).
However, by setting the appropriate bit in the interrupt port assignment register (IRQPAR),
IRQ1, IRQ3, and IRQ5 can be changed to function as IRQ2, IRQ6, and IRQ4, respectively.
See Section 9.2.4, “Interrupt Port Assignment Register (IRQPAR).”
17.4 Bus Arbitration Signals
The bus arbitration signals provide the external bus arbitration control for the MCF5407.
17.4.1 Bus Request (BR)
The BR output indicates to an external arbiter that the processor is requesting to be bus
master for one or more bus cycles. BR is negated when the MCF5407 begins an access to
the external bus with no other internal accesses pending. BR remains negated until another
internal request occurs.
17.4.2 Bus Grant (BG)
An external arbiter asserts the BG input to indicate that the MCF5407 can take control of
the bus on the next rising edge of CLKIN. When the arbiter negates BG, the MCF5407 will
release the bus as soon as the current transfer completes. The external arbiter must not grant
the bus to any other master until both BD and BG are negated.
17-12
MCF5407 User’s Manual
Clock and Reset Signals
17.4.3 Bus Driven (BD)
The MCF5407 asserts BD to indicate that it is the current master and is driving the bus. The
MCF5407 behaves as follows:
•
•
•
•
If the MCF5407 is the bus master but is not using the bus, BD is asserted.
If the MCF5407 loses mastership during a transfer, it completes the last transfer of
the access, negates BD, and three-states all bus signals on the rising edge of CLKIN.
If the MCF5407 loses bus mastership during an idle clock cycle, it three-states all
bus signals on the rising edge of CLKIN.
BD cannot be negated unless BG is negated.
17.5 Clock and Reset Signals
The clock and reset signals configure the MCF5407 and provide interface signals to the
external system.
17.5.1 Reset In (RSTI)
Asserting RSTI causes the MCF5407 to enter reset exception processing. When RSTI is
recognized, BR and BD are negated and the address bus, data bus, TT, SIZ, R/W, AS, and
TS are three-stated. RSTO is asserted automatically when RSTI is asserted.
17.5.2 Clock Input (CLKIN)
CLKIN is the MCF5407 input clock frequency to the on-board phase-locked-loop (PLL)
clock generator. CLKIN is used to internally clock or sequence the MCF5407 internal bus
interface at a selected multiple of the input frequency used for internal module logic.
CLKIN should be used as the bus timing reference.
17.5.3 Bus Clock Output (BCLKO)
The internal PLL generates BCLKO. It has the same frequency as CLKIN, which is used
as the bus timing reference by the external devices. BCLKO is provided for compatibility
with earlier devices.
17.5.4 Reset Out (RSTO)
After RSTI is asserted, the PLL temporarily loses its lock, during which time RSTO is
asserted. When the PLL regains its lock, RSTO negates again. This signal can be used to
reset external devices.
Chapter 17. Signal Descriptions
17-13
Clock and Reset Signals
17.5.5 Data/Configuration Pins (D[7:0])
This section describes data pins, D[7:0], that are read at reset for configuration. Table 17-11
shows pin assignments.
Table 17-11. Data Pin Configuration
Pin
Function
D7
Auto-acknowledge configuration (AA_CONFIG)
D[6:5]
Port size configuration (PS_CONFIG[1:0])
D4
Address configuration (ADDR_CONFIG/D4)
D3
Byte enable configuration (BE_CONFIG)
D[2:0]
Divide control (DIVIDE[2:0])
17.5.5.1 D[7:5,3]—Boot Chip-Select (CS0) Configuration
D[7:5,3] determine defaults for the global chip select (CS0), the only chip select valid at
reset. These signals correspond to bits in chip-select configuration register 0 (CSCR0).
17.5.5.2 D7—Auto Acknowledge Configuration (AA_CONFIG)
At reset, the enabling and disabling of auto acknowledge for boot CS0 is determined by the
logic level driven on D7 at the rising edge of RSTI. AA_CONFIG is multiplexed with D7
and sampled only at reset. The D7 logic level is reflected as the reset value of CSCR[AA].
Table 17-12 shows how the D7 logic level corresponds to the auto acknowledge timing for
CS0 at reset. Note that auto acknowledge can be disabled by driving a logic 0 on D7 at reset.
Table 17-12. D7 Selection of CS0 Automatic Acknowledge
D7 (CSCR0[AA])
Boot CS0 AA
0
Disabled
1
Enabled with 15 wait states
17.5.5.3 D[6:5]—Port Size Configuration (PS_CONFIG[1:0])
The default port size value of the boot CS0 is determined by the logic levels driven on
D[6:5] at the rising edge of RSTI, which are reflected as the reset value of CSCR[PS]. Table
17-13 shows how the logic levels of D[6:5] correspond to the CS0 port size at reset.
Table 17-13. D6 and D5 Selection of CS0 Port Size
17-14
D[6:5] (CSCR0[PS])
Boot CS0 Port Size
00
32-bit port
01
8-bit port
1x
16-bit port
MCF5407 User’s Manual
Chip-Select Module Signals
17.5.5.4 D3—Byte-Enable Configuration (BE_CONFIG)
The default byte-enable mode of the boot CS0 is determined by the logic level driven on
D3 at the rising edge of RSTI. This logic level is reflected as the reset value of
CSCR0[BEM]. Table 17-13 shows how the logic levels of D[6:5] correspond to the port
size for CS0 at reset.
Table 17-14. D3/BE_CONFIG, BE[3:0] Boot Configuration
D3 (CSCR0[BEM])
Boot CS0 Byte Enable Configuration
0
Neither BE nor BWE is asserted for read. BWE is generated for data write only.
1
BE is asserted for read; BWE is asserted for write.
17.5.6 D4—Address Configuration (ADDR_CONFIG)
The address configuration signal (ADDR_CONFIG) programs the PAR of the parallel I/O
port to be either parallel I/O or to be the upper address bus bits along with various attribute
and control signals at reset to give the user the option to access a broader addressing range
of memory if desired. ADDR_CONFIG is multiplexed with D4 and its configuration is
sampled at reset as shown in Table 17-15.
Table 17-15. D4/ADDR_CONFIG, Address Pin Assignment
D4/ADDR_CONFIG
PAR Configuration at Reset
0
PP[15:0], defaulted to inputs upon reset
1
A[31:24]/TIP/DREQ[1:0]/TM[2:0]/TT[1:0]
17.5.6.1 D[2:0]—Divide Control (DIVIDE[2:0])
The divide control input bus, DIVIDE[2:0], indicates the CLKIN/PCLK ratio. These
signals are sampled on the rising edge of RSTI to indicate the ratios described in
Chapter 20, “Electrical Specifications.”
17.6 Chip-Select Module Signals
The MCF5407 device provides eight programmable chip-select signals that can directly
interface with SRAM, EPROM, EEPROM, and peripherals. These signals are asserted and
negated on the falling edge of the clock.
17.6.1 Chip-Select (CS[7:0])
Each chip select can be programmed for a base address location and for masking addresses,
port size and burst-capability indication, wait-state generation, and internal/external
termination.
Reset clears all chip select programming; CS0 is the only chip select initialized out of reset.
CS0 is also unique because it can function at reset as a global chip select that allows boot
Chapter 17. Signal Descriptions
17-15
DRAM Controller Signals
ROM to be selected at any defined address space. Port size and termination (internal vs.
external) for boot CS0 are configured by the levels on D[7:5,3] on the rising edge of RSTI,
as described in Section 17.5.5.1, “D[7:5,3]—Boot Chip-Select (CS0) Configuration.”
The chip-select implementation is described in Chapter 10, “Chip-Select Module.”
17.6.2 Byte Enables/Byte Write Enables (BE[3:0]/BWE[3:0])
The four byte enables are multiplexed with the MCF5407 byte-write-enable signals. Each
pin can be individually programmed through the chip-select control registers (CSCRs). For
each chip select, assertion of byte enables for reads and byte-write enables for write cycles
can be programmed. Alternatively, users can program byte-write enables to assert on writes
and no byte enable assertion for read transfers.
17.6.3 Output Enable (OE)
The output enable (OE) signal is sent to the interfacing memory and/or peripheral to enable
a read transfer. OE is asserted only when a chip select matches the current address decode.
17.7 DRAM Controller Signals
The DRAM signals in the following sections interface to external DRAM. DRAM with
widths of 8, 16, and 32 bits are supported and can access as much as 512 Mbytes of DRAM.
17.7.1 Row Address Strobes (RAS[1:0])
The row address strobes (RAS[1:0]) interface to RAS inputs on industry-standard
ADRAMs. When SDRAMs are used, these signals interface to the chip-select lines of the
SDRAMs within a memory block. Thus, there is one RAS line for each memory block
(because the MCF5407 supports only two memory blocks).
17.7.2 Column Address Strobes (CAS[3:0])
The column address strobes (CAS[3:0]) interface to CAS inputs on industry-standard
DRAMs. These provide CAS for a given ADRAM block. When SDRAMs are used, CAS
signals control the byte enables for standard SDRAMs (referred to as DQMx). CAS3
accesses the LSB and CAS0 accesses the MSB of data.
17.7.3 DRAM Write (DRAMW)
The DRAM write signal (DRAMW) is asserted to signify that a DRAM write cycle is
underway. A read bus cycle is indicated by the negation of DRAMW.
17-16
MCF5407 User’s Manual
DMA Controller Module Signals
17.7.4 Synchronous DRAM Column Address Strobe (SCAS)
The synchronous DRAM column address strobe (SCAS) is registered during synchronous
mode to route directly to the SCAS signal of SDRAMs.
17.7.5 Synchronous DRAM Row Address Strobe (SRAS)
The synchronous DRAM row address strobe output (SRAS) is registered during
synchronous mode to route directly to the SRAS signal of external SDRAMs.
17.7.6 Synchronous DRAM Clock Enable (SCKE)
The synchronous DRAM clock enable output (SCKE) is registered during synchronous
mode to route directly to the SCKE signal of external SDRAMs. This signal provides the
clock enable to the SDRAM.
17.7.7 Synchronous Edge Select (EDGESEL)
The synchronous edge select input (EDGESEL) helps select additional output hold times
for signals that interface to external SDRAMs. It provides the following three modes of
operation for SDRAM control signals:
•
•
•
When EDGESEL is tied high, SDRAM control signals change on the rising edge of
CLKIN.
When EDGESEL is tied low, SDRAM control signals change on the falling edge of
CLKIN.
When EDGESEL is tied to the external clock (normally buffered CLKIN), which
drives the SDRAM and other devices, SDRAM signals are generated within the
MCF5407 make a transition on the rising edge of the SDRAM clock. See
Figure 11-14 on page 11-19. This loop-back configuration provides additional
output hold time for MCF5407 interface signals provided to the SDRAM. In this
case, the SDRAM clock operates at the CLKIN frequency, with a possible slight
phase delay.
17.8 DMA Controller Module Signals
The DMA controller module uses the signals in the following subsections to provide
external request for either a source or destination.
17.8.1 DMA Request (DREQ[1:0]/PP[6:5])
The DMA request pins (DREQ[1:0]/PP[6:5]) can serve as the DMA request inputs or as
two bits of the parallel port, as determined by individually programmable bits in the PAR.
These inputs are asserted by a peripheral device to request an operand transfer between that
peripheral and memory by either channel 0 or 1 of the on-chip DMA.
Chapter 17. Signal Descriptions
17-17
Serial Module Signals
17.8.2 Transfer Modifier/DMA Acknowledge
(TM[2:0]/DACK[1:0])
Although the MCF5407 provides similar encodings on TM[2:0], DMA acknowledgement
pins (DACK[1:0]) are now combined with PP[3:2]/TM[1:0], resulting in three-to-one
multiplexed signals, PP[3:2]/TM[1:0]/DACK[1:0]. TM2 is still multiplexed only with PP4.
When properly connected, TM[2:0] can be used in MCF5407 designs as on MCF5307
designs, or DACK[1:0] can be used for DMA transfers, as shown in Figure 17-2.
MCF5307 Function
Pin
Pin
MCF5407 Function
Single/dual cycle access
TM0
TM0
DMA 0 acknowledge
DMA 0 acknowledge configuration
TM1
TM1
DMA 1 acknowledge
DMA 1 acknowledge configuration
TM2
TM2
Single/dual cycle access
Figure 17-2. MCF5307 to MCF5407 TM[2:0] Pin Remapping
To enable DACK[1:0], first enable TM[1:0] through the PAR and then program the
interrupt assignment register (IRQPAR) in the MCF5407 SIM module to enable bits 0–1.
When IRQPAR[ENBDACK1] = 1 and PAR is programmed to enable TM1, DACK1 for
DMA channel 1 is driven in place of TM1 for DMA transfers. Clearing ENBDACK1
disables this function and only the TM1 encoding is driven. Likewise, setting ENBDACK0
enables DACK0 to be driven; clearing ENBDACK0 disables this function and drives the
TM0 encoding.
Although the MCF5407 TM[2:0] signals can drive DMA access encoding, the bit positions
of these encodings differ from the MCF5307. Single-address access indication is now
encoded on TM2 when the PAR is set to enable the transfer modifier signal and an external
master or DMA transfer is occurring. This encoding is driven by TM0 on the MCF5307. In
addition, DMA acknowledge encodings are driven on TM[1:0] on the MCF5407, as
opposed to TM[2:1] on the MCF5307.
17.9 Serial Module Signals
The signals in the following sections are used to transfer serial data between the two UART
modules and external peripherals.
17.9.1 Transmitter Serial Data Output (TxD)
In UART mode, TxD is held high (mark condition) when the transmitter is disabled, idle,
or operating in the local loop-back mode. Data is shifted out least-significant bit (lsb) first
on TxD on the falling edge of the clock source. For UART1 in modem mode, TxD is held
low when the transmitter is disabled or idle. Data is shifted out on TxD on the rising edge
of the clock signal driving UART1’s CTS input. UART1 transfers can be specified as either
lsb or msb first.
17-18
MCF5407 User’s Manual
Timer Module Signals
17.9.2 Receiver Serial Data Input (RxD)
Data received on RxD is sampled on the rising edge of the clock source, with the lsb
received first. For UART1 in modem mode, data received on RxD is sampled on the falling
edge of the clock signal driving UART1’s CTS input. UART1 transfers can be specified as
either lsb or msb first.
17.9.3 Clear to Send (CTS)
This input can generate an interrupt on a change of state. For UART1 in modem mode, CTS
must be driven by the serial bit clock from the external CODEC or AC97 controller.
17.9.4 Request to Send (RTS)
This output can be programmed to be negated or asserted automatically by either the
receiver or the transmitter. When connected to a transmitter’s CTS, RTS can control serial
data flow. For UART1 in AC97 mode, RTS serves as the frame sync or start of frame (SOF),
output to the external AC97 controller. When this mode is used, the AC97 BIT_CLK, which
is input on CTS, is divided by 256.
17.10 Timer Module Signals
The signals in the following sections are external interfaces to the two general-purpose
MCF5407 timers. These 16-bit timers can capture timer values, trigger external events or
internal interrupts, or count external events.
17.10.1 Timer Inputs (TIN[1:0])
TIN[1:0] can be programmed as clocks that cause events in the counter and prescalers.
They can also cause captures on the rising edge, falling edge, or both edges.
17.10.2 Timer Outputs (TOUT1, TOUT0)
The programmable timer outputs (TOUT1 and TOUT0) pulse or toggle on various timer
events.
17.11 Parallel I/O Port (PP[15:0])
This 16-bit bus is dedicated for general-purpose I/O. The parallel port is multiplexed with
the A[31:24], TT[1:0], TM[2:0], TIP, and DREQ[1:0]. These 16 bits are programmed for
functionality with the PAR in the SIM.
The system designer controls the reset value of this register by driving D4 with a 1 or 0 on
the rising edge of RSTI (reset input to MCF5407 device). At reset, the system is configured
as PP[15:0] if D4 is 0; otherwise alternate pin functions selected by PAR = 1 are used.
Chapter 17. Signal Descriptions
17-19
I2C Module Signals
Motorola recommends that D4 be driven during reset to a logic level.
17.12 I2C Module Signals
The I2C module acts as a two-wire, bidirectional serial interface between the MCF5407 and
peripherals with an I2C interface (such as LED controller, A-to-D converter, or D-to-A
converter). Devices connected to the I2C must have open-drain or open-collector outputs.
17.12.1 I2C Serial Clock (SCL)
The bidirectional, open-drain I2C serial clock signal (SCL) is the clock signal for I2C
module operation. The I2C module controls this signal when the bus is in master mode; all
I2C devices drive this signal to synchronize I2C timing.
17.12.2 I2C Serial Data (SDA)
The bidirectional, open-drain I2C serial data signal (SDA) is the data input/output for the
serial I2C interface.
17.13 Debug and Test Signals
The signals in this section interface with external I/O to provide processor status signals.
17.13.1 Test Mode (MTMOD[3:0])
The test mode signals choose between multiplexed debug module and JTAG signals. If
MTMOD0 is low, the part is in normal and background debug mode (BDM); if it is high,
it is in normal and JTAG mode. All other MTMOD values are reserved; MTMOD[3:1]
should be tied to ground and MTMOD[3:0] should not be changed while RSTI is negated.
17.13.2 High Impedance (HIZ)
The assertion of HIZ forces all output drivers to high-impedance state. The timing on HIZ
is independent of the clock. Note that HIZ does not override the JTAG operation;
TDO/DSO can be forced to high impedance by asserting TRST.
17.13.3 Processor Clock Output (PSTCLK)
The internal PLL generates this output signal, and is the processor clock output that is used
as the timing reference for the debug bus timing (PSTDDATA[7:0]). PSTCLK is at the
same frequency as the core processor and cache memory.
17-20
MCF5407 User’s Manual
Debug Module/JTAG Signals
17.13.4 Processor Status Debug Data (PSTDDATA[7:0])
Processor status data outputs indicate both processor status and captured address and data
values. They operate at half the processor’s frequency, using PSTCLK. Given that real-time
trace information appears as a sequence of 4-bit data values, there are no alignment
restrictions; that is, PST values and operands may appear on either PSTDDATA[7:0]
nibble. The upper nibble, PSTDDATA[7:4], is most significant. See Chapter 5, “Debug
Support.”
17.14 Debug Module/JTAG Signals
The MCF5407 complies with the IEEE 1149.1a JTAG testing standard. JTAG test pins are
multiplexed with background debug pins. Except for TCK, these signals are selected by the
value of MTMOD0. If MTMOD0 is high, JTAG signals are chosen; if it is low, debug
module signals are chosen. MTMOD0 should be changed only while RSTI is asserted.
17.14.1 Test Reset/Development Serial Clock
(TRST/DSCLK)
If MTMOD0 is high, TRST is selected. TRST asynchronously resets the internal JTAG
controller to the test logic reset state, causing the JTAG instruction register to choose the
bypass instruction. When this occurs, JTAG logic is benign and does not interfere with
normal MCF5407 functionality.
Although TRST is asynchronous, Motorola recommends that it makes an
asserted-to-negated transition only while TMS is held high. TRST has an internal pull-up
resistor so if it is not driven low, it defaults to a logic level of 1. If TRST is not used, it can
be tied to ground or, if TCK is clocked, to VDD. Tying TRST to ground places the JTAG
controller in test logic reset state immediately. Tying it to VDD causes the JTAG controller
(if TMS is a logic level of 1) to eventually enter test logic reset state after 5 TCK clocks.
If MTMOD0 is low, DSCLK is selected. DSCLK is the development serial clock for the
serial interface to the debug module. The maximum DSCLK frequency is 1/5 CLKIN. See
Chapter 5, “Debug Support.”
17.14.2 Test Mode Select/Breakpoint (TMS/BKPT)
If MTMOD0 is high, TMS is selected. The TMS input provides information to determine
the JTAG test operation mode. The state of TMS and the internal 16-state JTAG controller
state machine at the rising edge of TCK determine whether the JTAG controller holds its
current state or advances to the next state. This directly controls whether JTAG data or
instruction operations occur. TMS has an internal pull-up resistor so that if it is not driven
low, it defaults to a logic level of 1. But if TMS is not used, it should be tied to VDD.
If MTMOD0 is low, BKPT is selected. BKPT signals a hardware breakpoint to the
Chapter 17. Signal Descriptions
17-21
Debug Module/JTAG Signals
processor in debug mode. See Chapter 5, “Debug Support.”
17.14.3 Test Data Input/Development Serial Input (TDI/DSI)
If MTMOD0 is high, TDI is selected. TDI provides the serial data port for loading the
various JTAG boundary scan, bypass, and instruction registers. Shifting in data depends on
the state of the JTAG controller state machine and the instruction in the instruction register.
Shifts occur on the TCK rising edge. TDI has an internal pull-up resistor, so when not
driven low it defaults to high. But if TDI is not used, it should be tied to VDD.
If MTMOD0 is low, DSI is selected. DSI provides the single-bit communication for debug
module commands. See Chapter 5, “Debug Support.”
17.14.4 Test Data Output/Development Serial Output
(TDO/DSO)
If MTMOD0 is high, TDO is selected. The TDO output provides the serial data port for
outputting data from JTAG logic. Shifting out data depends on the JTAG controller state
machine and the instruction in the instruction register. Data shifting occurs on the falling
edge of TCK. When TDO is not outputting test data, it is three-stated. TDO can be
three-stated to allow bused or parallel connections to other devices having JTAG.
If MTMOD0 is low, DSO is selected. DSO provides single-bit communication for debug
module responses. See Chapter 5, “Debug Support.”
17.14.5 Test Clock (TCK)
TCK is the dedicated JTAG test logic clock independent of the MCF5407 processor clock.
Various JTAG operations occur on the rising or falling edge of TCK. Holding TCK high or
low for an indefinite period does not cause JTAG test logic to lose state information. If TCK
is not used, it must be tied to ground.
17-22
MCF5407 User’s Manual
Chapter 18
Bus Operation
This chapter describes data-transfer operations, error conditions, bus arbitration, and reset
operations. It describes transfers initiated by the MCF5407 and by an external bus master,
and includes detailed timing diagrams showing the interaction of signals in supported bus
operations. Chapter 11, “Synchronous/Asynchronous DRAM Controller Module,”
describes DRAM cycles.
18.1 Features
The following list summarizes bus operation features:
•
•
•
•
•
•
•
Up to 32 bits of address and data
8-, 16-, and 32-bit port sizes
Byte, word, longword, and line size transfers
Bus arbitration for external devices
Burst and burst-inhibited transfer support
Internal termination for core and DMA bus cycles
External termination of bus cycles controlled by an external bus master
Note that, throughout this manual, an overbar indicates an active-low signal.
18.2 Bus and Control Signals
Table 18-1 summarizes MCF5407 bus signals described in Chapter 17, “Signal
Descriptions.”
Table 18-1. ColdFire Bus Signal Summary
Signal Name
AS
A[31:0]
BE/BWE 1
CS[7:0]
1
D[31:0]
Description
MCF5407 Master
External Master
Edge
Address strobe
O
I
Falling
Address bus
O
I
Rising
Byte enable/Byte write enable
O
O
Falling
Chip selects
O
O
Falling
Data bus
I/O
I/O
Rising
Chapter 18. Bus Operation
18-1
Bus Characteristics
Table 18-1. ColdFire Bus Signal Summary (Continued)
Signal Name
IRQ[7,5,3,1]
MCF5407 Master
External Master
Edge
Interrupt request
I
I
Rising
OE 1
Output enable
O
I
Falling
R/W
Read/write
O
I
Rising
Transfer size
O
I
Rising
TA
Transfer acknowledge
I
O
Rising
TIP
Transfer in progress
O
Three-state
Rising
Transfer modifier
O
Three-state
Rising
TS
Transfer start
O
I
Rising
TT[1:0]
Transfer type
O
Three-state
Rising
SIZ[1:0]
TM[2:0]
1
Description
These signals change after the falling edge. In Chapter 20, “Electrical Specifications,” these signals are specified
off the rising edge because CLKIN is squared up internally.
18.3 Bus Characteristics
The MCF5407 uses an input clock signal (CLKIN) to generate its internal clock and
outputs BCLKO, which is provided for backwards compatibility for MCF5307 designs.
CLKIN is the bus clock rate, where all bus operations are synchronous to the rising edge of
CLKIN. Some of the bus control signals (BE/BWE, OE, CSx, and AS) are synchronous to
the falling edge, shown in Figure 18-1. Bus characteristics may differ somewhat for
interfacing with external DRAM.
CLKIN
tvo
tho
Rising-Edge
Signals
tvo
tho
Falling-Edge
Signals
tsi
thi
Inputs
tvo=Propagation delay of signal relative to CLKIN edge
tho=Output hold time relative to CLKIN edge
tsi =Required input setup time relative to CLKIN edge
thi=Required input hold time relative to CLKIN edge
Figure 18-1. Signal Relationship to CLKIN for Non-DRAM Access
18.4 Data Transfer Operation
Data transfers between the MCF5407 and other devices involve the following signals:
18-2
MCF5407 User’s Manual
Data Transfer Operation
•
•
•
•
•
Address bus (A[31:0])
Data bus (D[31:0])
Control signals (TS and TA)
AS, CSx, OE, BE/BWE
Attribute signals (R/W, SIZ, TT, TM, and TIP)
The address bus, write data, TS, and all attribute signals change on the rising edge of
CLKIN. Read data is latched into the MCF5407 on the rising edge of CLKIN. AS, CSx,
OE, and BE/BWE change on the falling edge.
The MCF5407 bus supports byte, word, and longword operand transfers and allows
accesses to 8-, 16-, and 32-bit data ports. Transfer parameters such as port size, the number
of wait states for the external slave being accessed, and whether internal transfer
termination is enabled, can be programmed in the chip-select control registers (CSCRs) and
DRAM control registers (DACRs).
For aligned transfers larger than the port size, SIZ[1:0] behaves as follows:
•
•
If bursting is used, SIZ[1:0] stays at the size of transfer.
If bursting is inhibited, SIZ[1:0] first shows the size of the transfer and then shows
the port size.
Table 18-2 shows encoding for SIZ[1:0].
Table 18-2. Bus Cycle Size Encoding
SIZ[1:0]
Port Size
00
Longword
01
Byte
10
Word
11
Line
Figure 18-2 shows the byte lanes that external memory should be connected to and the
sequential transfers if a longword is transferred for three port sizes. For example, an 8-bit
memory should be connected to D[31:24] (BE0). A longword transfer takes four transfers
on D[31:24], starting with the MSB and going to the LSB.
Chapter 18. Bus Operation
18-3
Data Transfer Operation
BE1
BE2
BE3
D[31:24]
D[23:16]
D[15:8]
D[7:0]
32-Bit Port
Memory
Byte 0
Byte 1
Byte 2
Byte 3
16-Bit Port
Memory
Byte 0
Byte 1
Byte 2
Byte 3
Byte Enable
Processor
External
Data Bus
8-Bit Port
Memory
BE0
Driven with
indeterminate values
Byte 0
Byte 1
Byte 2
Driven with
indeterminate values
Byte 3
Figure 18-2. Connections for External Memory Port Sizes
The timing relationships between CLKIN and chip select (CS[7:0]), byte enable/byte write
enables (BE/BWE[3:0]), and output enable (OE) are similar to their relationships with
address strobe (AS) in that all transitions occur during the low phase of CLKIN. However,
as shown in Figure 18-3, differences in on-chip signal routing and external loading may
prevent signals from asserting simultaneously.
CLKIN
CS[7:0]
BE/BWE[3:0]
AS, OE
Figure 18-3. Chip-Select Module Output Timing Diagram
18.4.1 Bus Cycle Execution
When a bus cycle is initiated, the MCF5407 first compares its address with the base address
and mask configurations programmed for chip selects 0–7 (CSCR0–CSCR7) and for
DRAM blocks 0 and 1 address and control registers (DACR0 and DACR1). If the driven
address matches a programmed chip select or DRAM block, the appropriate chip select is
asserted or the DRAM block is selected using the specifications programmed in the
respective configuration register. Otherwise, the following occurs:
•
•
•
18-4
If the address and attributes do not match in CSCR or DACR, the MCF5407 runs an
external burst-inhibited bus cycle with a default of external termination on a 32-bit
port.
If an address and attribute match in multiple CSCRs, the matching chip-select
signals are driven; however, the MCF5407 runs an external burst-inhibited bus cycle
with external termination on a 32-bit port.
If an address and attribute match both DACRs or a DACR and a CSCR, the operation
is undefined.
MCF5407 User’s Manual
Data Transfer Operation
Table 18-3 shows the type of access as a function of match in the CSCRs and DACRs.
Table 18-3. Accesses by Matches in CSCRs and DACRs
Number of CSCR Matches
Number of DACR Matches
Type of Access
0
0
External
Defined by CSCRs
1
0
Multiple
0
External, burst-inhibited, 32-bit
0
1
Defined by DACRs
1
1
Undefined
Multiple
1
Undefined
0
Multiple
Undefined
1
Multiple
Undefined
Multiple
Multiple
Undefined
Basic bus operations occur in three clocks, as follows:
1. During the first clock, the address, attributes, and TS are driven. AS is asserted at the
falling edge of the clock to indicate that address and attributes are valid and stable.
2. Data and TA are sampled during the second clock of a bus-read cycle. During a read,
the external device provides data and is sampled at the rising edge at the end of the
second bus clock. This data is concurrent with TA, which is also sampled at the
rising clock edge.
During a write, the MCF5407 drives data from the rising clock edge at the end of the
first clock to the rising clock edge at the end of the bus cycle. Wait states can be
added between the first and second clocks by delaying the assertion of TA. TA can
be configured to be generated internally through the DACRs and CSCRs. If TA is
not generated internally, the system must provide it externally.
3. The last clock of the bus cycle uses what would be an idle clock between cycles to
provide hold time for address, attributes, and write data. Figure 18-6 and
Figure 18-8 show the basic read and write operations.
18.4.2 Data Transfer Cycle States
The data transfer operation in the MCF5407 is controlled by an on-chip state machine. Each
bus clock cycle is divided into two states. Even states occur when CLKIN is high and odd
states occur when CLKIN is low. The state transition diagram for basic and fast-termination
read and write cycles is shown in Figure 18-4.
Chapter 18. Bus Operation
18-5
Data Transfer Operation
Next Cycle
S0
S5
S1
Basic
Read/Write
Fast
Termination
S4
S2
Wait
States
S3
Figure 18-4. Data Transfer State Transition Diagram
Table 18-4 describes the states as they appear in subsequent timing diagrams. Note that the
TT[1:0], TM[2:0], and TIP functions are chosen in the PAR, as described in Section 15.1.1,
“Pin Assignment Register (PAR).”
Table 18-4. Bus Cycle States
State
Cycle
CLKIN
Description
S0
All
High
The read or write cycle is initiated. On the rising edge of CLKIN, the MCF5407
places a valid address on the address bus, asserts TIP, and drives R/W high for
a read and low for a write, if these signals are not already in the appropriate
state. The MCF5407 asserts TT[1:0], TM[2:0], SIZ[1:0], and TS on the rising
edge of CLKIN.
S1
All
Low
AS asserts on the falling edge of CLKIN, indicating that the address and
attributes are stable. The appropriate CSx, BE/BWE, and OE signals assert on
the CLKIN falling edge.
Fast termination
S2
Read/write
(skipped for fast
termination)
TA must be asserted during S1. Data is made available by the external device
and is sampled on the rising edge of CLKIN with TA asserted.
High
Write
S3
Read/write
(skipped for fast
termination)
The data bus is driven out of high impedance as data is placed on the bus on
the rising edge of CLKIN.
Low
Read
S4
All
Read (including
fast termination)
18-6
TS is negated on the rising edge of CLKIN.
The MCF5407 waits for TA assertion. If TA is not sampled as asserted before
the rising edge of CLKIN at the end of the first clock cycle, the MCF5407 inserts
wait states (full clock cycles) until TA is sampled as asserted.
Data is made available by the external device on the falling edge of CLKIN and
is sampled on the rising edge of CLKIN with TA asserted.
High
The external device should negate TA.
The external device can stop driving data after the rising edge of CLKIN.
However, data could be driven up to S5.
MCF5407 User’s Manual
Data Transfer Operation
Table 18-4. Bus Cycle States (Continued)
State
S5
Cycle
CLKIN
S5
Low
Description
AS, CS, BE/BWE, and OE are negated on the CLKIN falling edge. The
MCF5407 stops driving address lines and R/W on the rising edge of CLKIN,
terminating the read or write cycle. At the same time, the MCF5407 negates
TT[1:0], TM[2:0], TIP, and SIZ[1:0] on the rising edge of CLKIN.
Note that the rising edge of CLKIN may be the start of S0 for the next access
cycle; in this case, TIP remains asserted and R/W may not transition,
depending on the nature of the back-to-back cycles.
Read
The external device stops driving data between S4 and S5.
Write
The data bus returns to high impedance on the rising edge of CLKIN. The rising
edge of CLKIN may be the start of S0 for the next access.
NOTE:
An external device has at most two CLKIN cycles after the start
of S4 to three-state the data bus after data is sampled in S3. This
applies to basic read cycles, fast-termination cycles, and the
last transfer of a burst.
18.4.3 Read Cycle
During a read cycle, the MCF5407 receives data from memory or from a peripheral device.
Figure 18-5 is a read cycle flowchart.
System
MCF5407
1.
Set R/W to read
2.
Place address on A[31:0]
3.
Assert TT[1:0], TM[2:0], TIP,
and SIZ[1:0]
4.
Assert TS
5.
Assert AS
6.
Negate TS
1.
1.
1.
Decode address and select the
appropriate slave device.
2.
Drive data on D[31:0]
3.
Assert TA
1.
Negate TA.
2.
Stop driving D[31:0]
Sample TA low and latch data
Start next cycle
Figure 18-5. Read Cycle Flowchart
The read cycle timing diagram is shown in Figure 18-6.
NOTE:
In the following timing diagrams, TA waveforms apply for chip
selects programmed to enable either internal or external
Chapter 18. Bus Operation
18-7
Data Transfer Operation
termination. TA assertion should look the same in either case.
S0
S1
S2
S3
S4
S5
CLKIN
R/W
TT[1:0], TM[2:0]
SIZ[1:0], A[31:0]
TIP
TS
AS, CSx
BEx, OE
Read
D[31:0]
TA
Figure 18-6. Basic Read Bus Cycle
Note the following characteristics of a basic read:
•
•
•
In S3, data is made available by the external device on the falling edge of CLKIN
and is sampled on the rising edge of CLKIN with TA asserted.
In S4, the external device can stop driving data after the rising edge of CLKIN.
However, data could be driven up to S5.
For a read cycle, the external device stops driving data between S4 and S5.
States are described in Table 18-4.
18.4.4 Write Cycle
During a write cycle, the MCF5407 sends data to memory or to a peripheral device. The
write cycle flowchart is shown in Figure 18-7.
18-8
MCF5407 User’s Manual
Data Transfer Operation
System
MCF5407
1.
Set R/W to write
2.
Place address on A[31:0]
3.
Assert TT[1:0], TM[2:0], TIP,
and SIZ[1:0]
4.
Assert TS
5.
Assert AS
6.
Place data on D[31:0]
7.
Negate TS
1.
Sample TA low
1.
Tree-state D[31:0]
2.
Start next cycle
1.
Decode address
2.
Store data on D[31:0]
3.
Assert TA
1.
Negate TA
Figure 18-7. Write Cycle Flowchart
The write cycle timing diagram is shown in Figure 18-8.
S0
S1
S2
S3
S4
S5
CLKIN
A[31:0], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BWEx
Write
D[31:0]
TA
Figure 18-8. Basic Write Bus Cycle
Table 18-4 describes the six states of a basic write cycle.
18.4.5 Fast-Termination Cycles
Two clock-cycle transfers are supported on the MCF5407 bus. In most cases, this is
impractical to use in a system because the termination must take place in the same half
clock during which AS is asserted. Because this is atypical, it is not referred to as the
zero-wait-state case but is called the fast-termination case. A fast-termination cycle is one
in which an external device or memory asserts TA as soon as TS is detected. This means
that the MCF5407 samples TA on the rising edge of the second cycle of the bus transfer.
Figure 18-9 shows a read cycle with fast termination. Note that fast termination cannot be
used with internal termination.
Chapter 18. Bus Operation
18-9
Data Transfer Operation
S0
S1
S4
S5
CLKIN
A[31:0],TT[1:0]
TM[2:0, SIZ[1:0]]
R/W
TIP
TS
AS, CSx
BEx, OE
Read
D[31:0]
TA
Figure 18-9. Read Cycle with Fast Termination
Figure 18-10 shows a write cycle with fast termination.
S0
S1
S4
S5
CLKIN
A[31:0], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BWEx, OE
D[31:0]
Write
TA
Figure 18-10. Write Cycle with Fast Termination
18.4.6 Back-to-Back Bus Cycles
The MCF5407 runs back-to-back bus cycles whenever possible. For example, when a
longword read is started on a word-size bus, the processor performs two back-to-back word
read accesses. Back-to-back accesses are distinguished by the continuous assertion of TIP
throughout the cycle. Figure 18-11 shows a read back-to-back with a write.
18-10
MCF5407 User’s Manual
Data Transfer Operation
S0
S1
S2
S3
S4
S5
S0
S1
S2
S3
S4
S5
CLKIN
A[31:0], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BE/BWEx
OE
Read
D[31:0]
Write
TA
Figure 18-11. Back-to-Back Bus Cycles
Basic read and write cycles are used to show a back-to-back cycle, but there is no restriction
as to the type of operations to be placed back to back. The initiation of a back-to-back cycle
is not user definable.
18.4.7 Burst Cycles
The MCF5407 can be programmed to initiate burst cycles if its transfer size exceeds the
size of the port it is transferring to. For example, with bursting enabled, a word transfer to
an 8-bit port would take a 2-byte burst cycle for which SIZ[1:0] = 10 throughout. A line
transfer to a 32-bit port would take a 4-longword burst cycle, for which SIZ[1:0] = 11
throughout.
The MCF5407 bus can support 2-1-1-1 burst cycles to maximize cache performance and
optimize DMA transfers. A user can add wait states by delaying termination of the cycle.
The initiation of a burst cycle is encoded on the size pins. For burst transfers to smaller port
sizes, SIZ[1:0] indicates the size of the entire transfer. For example, if the MCF5407 writes
a longword to an 8-bit port, SIZ[1:0] = 00 for the first byte transfer and does not change.
CSCRs are used to enable bursting for reads, writes, or both. MCF5407 memory space can
be declared burst-inhibited for reads and writes by clearing the appropriate
CSCRx[BSTR,BSTW]. A line access to a burst-inhibited region is broken into separate
port-width accesses. Unlike a burst access, SIZ[1:0] = 11 only for the first port-width
access; for the remaining accesses, SIZ[1:0] reflects the port width, with individual
accesses separated by AS negations. The address changes if internal termination is used but
does not change if external termination is used, as shown in Figure 18-12 and Figure 18-14.
Chapter 18. Bus Operation
18-11
Data Transfer Operation
18.4.7.1 Line Transfers
A line is a 16-byte-aligned, 16-byte value. Despite the alignment, a line access may not
begin on the aligned address; therefore, the bus interface supports line transfers on multiple
address boundaries. Table 18-5 shows allowable patterns for line accesses.
Table 18-5. Allowable Line Access Patterns
A[3:2]
Longword Accesses
00
0–4–8–C
01
4–8–C–0
10
8–C–0–4
11
C–0–4–8
18.4.7.2 Line Read Bus Cycles
Figure 18-12 shows line read with zero wait states. The access starts like a basic read bus
cycle with the first data transfer sampled on the rising edge of S4, but the next pipelined
burst data is sampled a cycle later on the rising edge of S6. Each subsequent pipelined data
burst is single cycle until the last one, which can be held for up to 2 CLKIN cycles after TA
is asserted. Note that AS and CSx are asserted throughout the burst transfer. This example
shows the timing for external termination, which differs only from the internal termination
example in Figure 18-13 in that the address lines change only at the beginning (assertion of
TS and TIP) and end (negation of TIP) of the transfer.
S0
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10 S11 S12
CLKIN
A[31:0], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BE/BWEx, OE
D[31:0]
Read
Read
Read
Read
TA
Figure 18-12. Line Read Burst (2-1-1-1), External Termination
Figure 18-13 shows timing when internal termination is used.
18-12
MCF5407 User’s Manual
Data Transfer Operation
S0
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10 S11 S12
CLKIN
A[31:0]
TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BE/BWEx, OE
Read
D[31:0]
Read
Read
Read
TA
Figure 18-13. Line Read Burst (2-1-1-1), Internal Termination
Figure 18-14 shows a line access read with one wait state programmed in CSCRx to give
the peripheral or memory more time to return read data. This figure follows the same
execution as a zero-wait state read burst with the exception of an added wait state.
.
S0 S1 S2 S3
WS
S4 S5
WS
S6 S7
WS
S8 S9
WS
S10S11S12S13
CLKIN
A[31:0], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BE/BWEx, OE
D[31:0]
Read
Read
Read
Read
TA
Figure 18-14. Line Read Burst (3-2-2-2), External Termination
Figure 18-15 shows a burst-inhibited line read access with fast termination. The external
device executes a basic read cycle while determining that a line is being transferred. The
external device uses fast termination for subsequent transfers.
Chapter 18. Bus Operation
18-13
Data Transfer Operation
S0
S1
S2 S3 S4 S5 S0 S1 S4 S5
S0 S1 S4 S5
S0 S1 S4 S5
A[3:2] = 10
A[3:2] = 11
S6 S7
CLKIN
A[3:2] = 00
A[31:0]
A[3:2] = 01
R/W
TT[1:0]
TM[2:0]
TIP
SIZ[1:0]
Line
Longword
TS
AS, CSx
BE/BWEx, OE
D[31:0]
Read
Read
Read
Read
Fast
Fast
Fast
TA
Basic
Figure 18-15. Line Read Burst-Inhibited, Fast, External Termination
18.4.7.3 Line Write Bus Cycles
Figure 18-16 shows a line access write with zero wait states. It begins like a basic write bus
cycle with data driven one clock after TS. The next pipelined burst data is driven a cycle
after the write data is registered (on the rising edge of S6). Each subsequent burst takes a
single cycle. Note that as with the line read example in Figure 18-12, AS and CSx remain
asserted throughout the burst transfer. This example shows the behavior of the address lines
for both internal and external termination. Note that with external termination, address
lines, like SIZ, TT, and TM, hold the same value for the entire transfer.
S0
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
CLKIN
A[31:0]
Internal Termination
A[31:0]
External Termination
SIZ[1:0]
TM[1:0], TT[1:0]
R/W, TIP
TS
AS, CSx
OE, BE/BWE
D[31:0]
Write
Write
Write
Write
TA
Figure 18-16. Line Write Burst (2-1-1-1), Internal/External Termination
18-14
MCF5407 User’s Manual
Data Transfer Operation
Figure 18-17 shows a line burst write with one wait-state insertion.
S0 S1 S2 S3
WS
S4 S5
WS
S6 S7
WS
S8 S9
WS
S10S11
CLKIN
A[31:0]
R/W, TIP
TM[2:0], TT[1:0]
SIZ[1:0]
TS
AS, CSx
OE, BWE
Write
D[31:0]
Write
Write
Write
TA
Figure 18-17. Line Write Burst (3-2-2-2) with One Wait State, Internal Termination
Figure 18-18 shows a burst-inhibited line write. The external device executes a basic write
cycle while determining that a line is being transferred. The external device uses fast
termination to end each subsequent transfer.
S0
S1
S2 S3 S4 S5 S0 S1 S4 S5
S0 S1 S4 S5
S0 S1 S4 S5
A[3:2] = 10
A[3:2] = 11
CLKIN
A[31:0]
A[3:2] = 00
A[3:2] = 01
R/W, TIP
TT[1:0]
TM[2:0]
SIZ[1:0]
Longword
Line
TS
AS, CSx
OE, BWE
D[31:0]
Write
Write
Write
Write
TA
Basic
Fast
Fast
Fast
Figure 18-18. Line Write Burst-Inhibited, Internal Termination
18.4.7.4 Transfers Using Mixed Port Sizes
Figure 18-19 shows timing for a longword read from an 8-bit port using external
termination. Figure 18-20 shows the same transfer with internal termination. For both,
SIZ[1:0] change only at the start of a new transfer because this burst is implemented as one
Chapter 18. Bus Operation
18-15
Misaligned Operands
transfer.
S0
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10 S11 S12
CLKIN
A[31:0], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BE/BWEx, OE
Read
Read
D[31:0]
Read
Read
TA
Figure 18-19. Longword Read from an 8-Bit Port, External Termination
Note that with external termination, address signals do not change. With internal
termination, Figure 18-20, A[1:0] increment for the same longword transfer.
S0
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10 S11 S12
CLKIN
A[1:0]
A[31:2], TT[1:0]
TM[2:0], SIZ[1:0]
R/W
TIP
TS
AS, CSx
BE/BWEx, OE
D[31:0]
Read
Read
Read
Read
TA
Figure 18-20. Longword Read from an 8-Bit Port, Internal Termination
18.5 Misaligned Operands
Because operands, unlike opcodes, can reside at any byte boundary, they are allowed to be
misaligned. A byte operand is properly aligned at any address, a word operand is
misaligned at an odd address, and a longword is misaligned at an address not a multiple of
four. Although the MCF5407 enforces no alignment restrictions for data operands
(including program counter (PC) relative data addressing), additional bus cycles are
required for misaligned operands.
18-16
MCF5407 User’s Manual
Bus Errors
Instruction words and extension words (opcodes) must reside on word boundaries.
Attempting to prefetch a misaligned instruction word causes an address error exception.
The MCF5407 converts misaligned, cache-inhibited operand accesses to multiple aligned
accesses. Figure 18-21 shows the transfer of a longword operand from a byte address to a
32-bit port. In this example, SIZ[1:0] specify a byte transfer and a byte offset of 0x1. The
slave device supplies the byte and acknowledges the data transfer. When the MCF5407
starts the second cycle, SIZ[1:0] specify a word transfer with a byte offset of 0x2. The next
two bytes are transferred in this cycle. In the third cycle, byte 3 is transferred. The byte
offset is now 0x0, the port supplies the final byte, and the operation is complete.
31
24 23
16 15
87
0
A[2:0]
Transfer 1
—
Byte 0
—
—
001
Transfer 2
—
—
Byte 1
Byte 2
010
Transfer 3
Byte 3
—
—
—
100
Figure 18-21. Example of a Misaligned Longword Transfer (32-Bit Port)
If an operand is cacheable and is misaligned across a cache-line boundary, both lines are
loaded into the cache. The example in Figure 18-22 differs from the one in Figure 18-21 in
that the operand is word-sized and the transfer takes only two bus cycles.
31
24 23
16 15
87
0
A[2:0]
Transfer 1
—
—
—
Byte 0
001
Transfer 2
Byte 0
—
—
—
100
Figure 18-22. Example of a Misaligned Word Transfer (32-Bit Port)
NOTE:
External masters using internal MCF5407 chip selects and
default memory control signals must initiate aligned transfers.
18.6 Bus Errors
The MCF5407 has no bus monitor. If the auto-acknowledge feature is not enabled for the
address that generates the error, the bus cycle can be terminated by asserting TA or by using
the software watchdog timer. If it is required that the MCF5407 handle a bus error
differently, an interrupt handler can be invoked by asserting an interrupt to the core along
with TA when the bus error occurs.
18.7 Interrupt Exceptions
A peripheral device uses the interrupt-request signals (IRQx) to signal the core to take an
interrupt exception when it needs the MCF5407 or is ready to send information to it. The
interrupt transfers control to an appropriate routine.
Chapter 18. Bus Operation
18-17
Interrupt Exceptions
The MCF5407 has the following two levels of interrupt masking:
•
•
Interrupt mask registers in the SIM compare interrupt inputs with programmable
interrupt mask levels. The SIM outputs only unmasked interrupts.
The status register uses a 3-bit interrupt priority mask. The core recognizes only
interrupt requests of higher priority than the value in the mask. See Section 2.2.2.1,
“Status Register (SR).”
NOTE:
To mask a level 1–6 interrupt source, write a higher-level SR
interrupt mask before setting IMR. Then restore the mask to its
previous value. Do not mask a level 7 interrupt source.
The MCF5407 continuously samples and synchronizes external interrupt inputs. An
interrupt request must be held for at least two consecutive CLKIN periods to be considered
valid. To guarantee that the interrupt is recognized, the request level must be maintained
until the MCF5407 acknowledges the interrupt with an interrupt-acknowledge cycle.
NOTE:
Interrupt levels 1–7 are level-sensitive. Level 7 is also
edge-triggered. See Section 18.7.1, “Level 7 Interrupts.”
The MCF5407 takes an interrupt exception for a pending interrupt within one instruction
boundary after processing any higher-priority pending exception. Thus, the MCF5407
executes at least one instruction in an interrupt exception handler before recognizing
another interrupt request.
If autovector generation is used for internal interrupts (ICRn[AVEC] = 1), the interrupt
acknowledge vector is generated internally and no interrupt acknowledge cycle is generated
on the external bus.
If autovector generation is used for external interrupts, no interrupt acknowledge cycle is
shown on the external bus (AS is not asserted) unless AVR[BLK] is 0. Consequently, the
external interrupt must be cleared in the interrupt service routine. See Section 9.2.2,
“Autovector Register (AVR).”
18.7.1 Level 7 Interrupts
Level 7 interrupts are nonmaskable and are handled differently than other interrupts.
Level 7 interrupts are edge triggered by a transition from a lower priority request to the
level 7 request. Interrupts at all other levels are level sensitive. Therefore, if IRQ7 remains
asserted, the MCF5407 recognizes only one level 7 interrupt because only one transition
from a lower level request to a level 7evel 7 request occurred. For the processor to
recognize two consecutive level 7 interrupts, one of the following must occur:
18-18
MCF5407 User’s Manual
Interrupt Exceptions
•
•
The interrupt request on the interrupt control pins is raised to level 7 and stays there
until an interrupt-acknowledge cycle begins. The level later drops but then returns to
level 7, causing a second transition on the interrupt control lines.
The interrupt request on the interrupt control pins is raised to level 7 and stays there.
If the level 7 interrupt routine lowers the mask level, a second level 7 interrupt is
recognized without a transition of the interrupt control pins. After the level 7 routine
completes, the MCF5407 compares the mask level to the request level on the IRQx
signals. Because the mask level is lower than the requested level, the interrupt mask
is set back to level 7. To ensure it is recognized, the level 7 request on IRQ7 must be
held until the second interrupt-acknowledge bus cycle begins.
18.7.2 Interrupt-Acknowledge Cycle
When the MCF5407 processes an interrupt exception, it performs an interruptacknowledge bus cycle to obtain the vector number that contains the starting location of the
interrupt exception handler. The interrupt-acknowledge bus cycle is a read transfer that
differs from normal read cycles in the following respects:
•
•
•
•
•
TT[1:0] = 0x3 to indicate a CPU space or acknowledge bus cycle.
TM[2:0] = the level of interrupt being acknowledged.
A[31:5] = 0x7F_FFFF.
A[4:2] = the interrupt request level being acknowledged (same as TM[2:0]).
A[1:0] = 00.
During the interrupt-acknowledge bus cycle (a read cycle), the responding device places the
vector number on D[31:24] and the cycle is terminated normally with TA. Figure 18-23 is
a flow diagram for an interrupt-acknowledge cycle terminated with TA.
Chapter 18. Bus Operation
18-19
Bus Arbitration
MCF5407
SYSTEM
1.
Drive 0x7FFFFF on A[31:5]
2.
Drive 0x0 on A[1:0]
3.
Drive interrupt level on A[4:2]
4.
Drive R/W to read (R/W = 1)
5.
Drive SIZ[1:0] to indicate byte (SIZ[1:0] = 01)
6.
Drive TT[1:0] and TM[2:0] to indicate interrupt
acknowledge (TT[1:0] = 11; TM[2:0] = interrupt
level)
7.
Assert TS for one CLKIN cycle
1.
Negate TS
2.
Drive TM[2:0] to indicate interrupt
acknowledge (TM[2:0] = interrupt level)
1.
Decode address and select the appropriate slave
device.
1.
Read and store data (D[31:24])
2.
Drive data on D[31:24]
2.
Recognize the transfer is done
3.
Assert TA for one CLKIN cycle
Figure 18-23. Interrupt-Acknowledge Cycle Flowchart
18.8 Bus Arbitration
The MCF5407 bus protocol gives either the MCF5407 or an external device access to the
external bus. If more than one external device uses the bus, an external arbiter can prioritize
requests and determine which device is bus master. When the MCF5407 is bus master, it
uses the bus to fetch instructions and transfer data to and from external memory. When an
external device is bus master, the MCF5407 can monitor the external master’s transfers and
interact through its chip-select, DRAM control, and transfer termination signals. See
Section 10.4.1.3, “Chip-Select Control Registers (CSCR0–CSCR7),” and Chapter 11,
“Synchronous/Asynchronous DRAM Controller Module.”
Two-wire bus arbitration is used where the MCF5407 shares the bus with a single external
device. This mode uses BG and BD. The external device can ignore BR. Three-wire mode
is used where the MCF5407 shares the bus with multiple external devices. This requires an
external bus arbiter and uses BG, BD, and BR. In either mode, the MCF5407 bus arbiter
operates synchronously and transitions between states on the rising edge of CLKIN.
Table 18-6 shows the four arbitration states the MCF5407 can be in during bus operation.
Table 18-6. MCF5407 Arbitration Protocol States
State
Master
Bus
BD
Reset
None
Not
driven
Negated
The MCF5407 enters reset state from any other state when RSTI or
software watchdog reset is asserted. If both are negated, the MCF5407
enters implicit or external device mastership state, depending on BG.
Implicit
master
MCF5407
Not
driven
Negated
The MCF5407 is bus master (BG input is asserted) but is not ready to
begin a bus cycle. It continues to three-state the bus until an internal bus
request.
18-20
Description
MCF5407 User’s Manual
General Operation of External Master Transfers
Table 18-6. MCF5407 Arbitration Protocol States (Continued)
State
Master
Bus
Explicit
master
MCF5407
External
master
External
BD
Description
Driven Asserted The MCF5407 is explicit bus master when BG is asserted and at least
one bus cycle has been initiated. It asserts BD and retains explicit
mastership until BG is negated even if no active bus cycles are executed.
It releases the bus at the end of the current bus cycle, then negates BD
and three-states the bus signals.
Not
driven
Negated
An external device is bus master (BG negated to MCF5407). The
MCF5407 can assert OE, CS[7:0], BE/BWE[3:0], TA, and all DRAM
controller signals (RAS[1:0], CAS[3:0], SRAS, SCAS, DRAMW, SCKE).
If the MCF5407 is the only possible master, BG can be tied to GND—no arbiter is needed.
18.8.1 Bus Arbitration Signals
Bus arbitration signal timings in Table 18-7 are referenced to the system clock, which is not
considered a bus signal. Clock routing is expected to meet application requirements.
Table 18-7. ColdFire Bus Arbitration Signal Summary
Signal
I/O
Description
BR
O
Bus request. Indicates to an external arbiter that the processor needs to become bus master. BR is
negated when the MCF5407 begins an access to the external bus with no other internal accesses
pending. BR remains negated until another internal request occurs.
BG
I
Bus grant. An external arbiter asserts BG to indicate that the MCF5407 can control the bus at the
next rising edge of CLKIN. When the arbiter negates BG, the MCF5407 must release the bus as
soon as the current transfer completes. The external arbiter must not grant the bus to any other
device until both BD and BG are negated.
BD
O
Bus driven. The MCF5407 asserts BD to indicate it is current master and is driving the bus. If it loses
bus mastership during a transfer, it completes the last transfer of the current access, negates BD,
and three-states all bus signals on the rising edge of CLKIN. If it loses mastership during an idle
clock cycle, it three-states all bus signals on the rising edge of CLKIN.
18.9 General Operation of External Master Transfers
An external master asserts its hold signal (such as HOLDREQ) when it executes a bus
cycle, driving BG high and forcing the MCF5407 to hold all bus requests. During an
external master cycle, the MCF5407 can provide memory control signals (OE, CS[7:0],
BE/BWE[3:0], RAS[1:0], CAS[3:0]) and TA while the external master drives the address
and data bus and other required bus control signals. When the external master asserts TS or
AS to the MCF5407, the beginning of a bus cycle is identified and the MCF5407 starts
decoding the address driven.
Note the following regarding external master accesses:
Chapter 18. Bus Operation
18-21
General Operation of External Master Transfers
•
For the MCF5407 to assert a CSx during external master accesses, CSMRn[AM]
must be set. External master hits use the corresponding CSCRn settings for
auto-acknowledge, byte enables, and wait states. See Section 10.4.1.3, “Chip-Select
Control Registers (CSCR0–CSCR7).”
To enable DRAM control signals during external master accesses, DCMRn[AM]
must be set.
During external master bus cycles, either TS or AS (but not both) should be driven
to the MCF5407. Driving both during a bus cycle causes indeterminate results.
•
•
External master transfers that use the MCF5407 to drive memory control signals and TA
are like normal MCF5407 transfers. Figure 18-24 shows timing for basic back-to-back bus
cycles during an external master transfer.
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
CLKIN
A[31:0], TT[1:0]
SIZ[1:0], TM[2:0]
R/W
TIP
TS
AS
CS 1
BE/BWE 1
D[31:0]
TA 1
BR 2
BG, BD 2
HOLDREQ
External Master
1 Depending on programming, these signals may or may not be driven
2 This signal is driven by the processor for an external master transfer.
by the processor.
Figure 18-24. Basic No-Wait-State External Master Access
R/W is asserted high for reads and low for writes; otherwise, the transfers are the same. In
Figure 18-24, the MCF5407 chip select’s internal transfer acknowledge is enabled and the
MCF5407 drives TA as an output after a programmed number of wait states.
18-22
MCF5407 User’s Manual
General Operation of External Master Transfers
NOTE:
Bus timing diagrams for external master transfers are not valid
for on-chip internal four-channel DMA accesses on the
MCF5407.
Timing diagrams describe transactions in general terms of bus
cycles (Cn) rather than the states (Sn) used in the bus diagrams.
Table 18-8 defines the cycles for Figure 18-24.
Table 18-8. Cycles for Basic No-Wait-State External Master Access
Cycle
C1
Definition
The external master asserts HOLDREQ, signaling the MCF5407 to hold bus requests. BD should not be
asserted. The external master drives address, TS, R/W, TT[1:0], TM[2:0], TIP, and SIZ[1:0] as MCF5407
inputs.
C2–C3 The MCF5407 decodes the external master’s address and control signals to identify the proper chip select
and byte enable assertion. The external master negates TS in C2.
C4
On the falling edge of CLKIN, the MCF5407 asserts the appropriate chip select for the external master
access along with the appropriate byte enables.
C5
On the rising edge of CLKIN, data is driven onto the bus by the device selected by CS. On the rising edge,
the MCF5407 asserts TA to indicate the cycle is complete.
C6
TA negates on the rising edge of CLKIN. On the falling edge, the MCF5407 negates the chip select and
byte enables and the next cycle can begin.
C7
The external master negates TIP on the rising edge of CLKIN.
C8
The external device retains bus mastership and drives the address bus, TS, R/W, TT[1:0], TM[2:0], TIP, and
SIZ[1:0] as inputs to the MCF5407.
C9
The MCF5407 decodes the external master’s address and control signals to identify the proper chip select
and byte enable assertion. The external master negates TS. The MCF5407 asserts BR on the rising edge of
CLKIN, signalling that it wants to arbitrate for the bus when the current cycle completes.
C10
The MCF5407 continues to decode the external device’s address and control signals to identify the proper
chip select and byte enable assertion.
C11
On the falling edge of CLKIN, the MCF5407 asserts the appropriate chip select for the external master
access along with the appropriate byte enables.
Figure 18-25 shows a burst line access for an external master transfer with the chip select
set to no-wait states and with internal transfer-acknowledge assertion enabled.
Chapter 18. Bus Operation
18-23
General Operation of External Master Transfers
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
CLKIN
A[31:0]
R/W
TT[1:0], TM[2:0]
SIZ[1:0]
TIP
TS
AS, BR 2
CS 1
BE/BWE 1
D[31:0]
TA 1
BG, BD 2
HOLDREQ
External Master
1 Depending on programming, these signals may or may not be driven by the
2 These signals are driven by the processor for an external master transfer.
processor.
Figure 18-25. External Master Burst Line Access to 32-Bit Port
Table 18-9 defines the cycles for Figure 18-25.
Table 18-9. Cycles for External Master Burst Line Access to 32-Bit Port
Cycle
Definition
C1
The external device is bus master and asserts HOLDREQ, indicating to the MCF5407 to hold all bus
requests. In other words, BD should not be asserted. The external master drives address, TS, R/W, TT[1:0],
TM[2:0], TIP, and SIZ[1:0] as inputs to the MCF5407. SIZ[1:0] inputs indicate a line transfer. The MCF5407
is not asserting BR.
C2–C3
The MCF5407 decodes the external device’s address and control signals to identify the proper chip-select
and byte-enable assertion. The external device negates TS in C2. Address and R/W are latched in the
MCF5407 on the rising edge of CLKIN in C2. After C2, the address and R/W are ignored for the rest of the
burst transfer.
C4
On the falling edge of CLKIN, the MCF5407 asserts the appropriate chip select for the external device
access along with the appropriate byte enables.
C5
On the rising edge of CLKIN, data is driven onto the bus by the device selected by CS. The MCF5407
asserts TA on the rising edge of CLKIN, indicating the first data transfer is complete.
18-24
MCF5407 User’s Manual
General Operation of External Master Transfers
Table 18-9. Cycles for External Master Burst Line Access to 32-Bit Port (Continued)
Cycle
Definition
C6–C8
No-wait state data transfers 2–4 occur on the rising edges of CLKIN. TA continues to be asserted indicating
completion of each transfer. TIP, CSx, and BE/BWE[3:0] are driven.
C9
TA negates on the rising edge of CLKIN along with external device’s negation of TIP. On the falling edge,
the MCF5407 negates chip select and byte enables, creating an opportunity for another cycle to begin.
18.9.1 Two-Device Bus Arbitration Protocol (Two-Wire
Mode)
Two-wire mode bus arbitration lets the MCF5407 share the external bus with a single
external bus device without requiring an external bus arbiter. Figure 18-26 shows the
MCF5407 connecting to an external device using the two-wire mode. The MCF5407 BG
input is connected to the HOLDREQ output of the external device; the MCF5407 BD
output is connected to the HOLDACK input of the external device. Because the external
device controls the state of HOLDREQ, it controls when the MCF5407 is granted the bus,
giving the MCF5407 lower priority.
BG
HOLDREQ
HOLDACK
BD
BR
A[31:0]
A[31:0]
D[31:0]
TS
R/W
SIZ[1:0]
TA
D[31:0]
TS
R/W
SIZ[1:0]
TA
External Bus Master
MCF5407
To/from external memory and control
Figure 18-26. MCF5407 Two-Wire Mode Bus Arbitration Interface
When the external device is not using the bus, it negates HOLDREQ, driving BG low and
granting the bus to the MCF5407. When the MCF5407 has an internal bus request pending
and BG is low, the MCF5407 drives BD low, negating HOLDACK to the external device.
When the external bus device needs the external bus, it asserts HOLDREQ, driving BG
high, requesting the MCF5407 to release the bus. If BG is negated while a bus cycle is in
progress, the MCF5407 releases the bus at the completion of the bus cycle. Note that the
MCF5407 considers the individual transfers of a burst or burst-inhibited access to be a
single bus cycle and does not release the bus until the last transfer of the series completes.
When the bus has been granted to the MCF5407, one of two situations can occur. In the first
case, if the MCF5407 has an internal bus request pending, the MCF5407 asserts BD to
indicate explicit bus mastership and begins the pending bus cycle by asserting TS. As
Chapter 18. Bus Operation
18-25
General Operation of External Master Transfers
shown in Figure 18-25, the MCF5407 continues to assert BD until the completion of the
bus cycle. If BG is negated by the end of the bus cycle, the MCF5407 negates BD. While
BG is asserted, BD remains asserted to indicate the MCF5407 is master, and it continuously
drives the address bus, attributes, and control signals.
s
C1
C2
C3
C4
C5
C6
C7
C8
C9
CLKIN
A[31:0], TT[1:0]
SIZ[1:0], TM[2:0]
R/W
TIP
TS
AS
D[31:0]
TA
BG
BD
External Master
MCF5407
Figure 18-27. Two-Wire Bus Arbitration with Bus Request Asserted
In the second situation, the bus is granted to the MCF5407, but it does not have an internal
bus request pending, so it takes implicit bus mastership. The MCF5407 does not drive the
bus and does not assert BD if the bus has an implicit master. If an internal bus request is
generated, the MCF5407 assumes explicit bus mastership. If explicit mastership was
assumed because an internal request was generated, the MCF5407 immediately begins an
access and asserts BD.
In Figure 18-28, the external device is bus master during C1 and C2. During C3 the external
device releases control of the bus by asserting BG to the MCF5407. At this point, there is
an internal access pending so the MCF5407 asserts BD during C4 and begins the access.
Thus, the MCF5407 becomes the explicit external bus master. Also during C4, the external
device removes the grant from the MCF5407 by negating BG. As the current bus master,
the MCF5407 continues to assert BD until the current transfer completes. Because BG is
negated, the MCF5407 negates BD during C9 and three-states the external bus, thereby
returning external bus mastership to the external device.
18-26
MCF5407 User’s Manual
General Operation of External Master Transfers
C1
C2
C3
C4
C5
C6
C7
C8
C9
CLKIN
A[31:0], TT[1:0]
SIZ[1:0], TM[2:0]
R/W
TIP
TS
AS
D[31:0]
TA
BG
BD
Implicit
Mastership
External Master
Explicit
Mastership
MCF5407
Figure 18-28. Two-Wire Implicit and Explicit Bus Mastership
In Figure 18-28, the external device is master during C1 and C2. It releases bus control in
C3 by asserting BG to the MCF5407. During C4 and C5, the MCF5407 is implicit master
because no internal access is pending. In C5, an internal bus request becomes pending,
causing the MCF5407 to become explicit bus master in C6 by asserting BD. In C7, the
external device removes the bus grant to the MCF5407. The MCF5407 does not release the
bus (the MCF5407 continues to assert BD) until the transfer ends.
NOTE:
The MCF5407 can start a transfer in the clock cycle after BG
is asserted. The external master must not assert BG to the
MCF5407 while driving the bus or the part may be damaged.
Figure 18-29 is a MCF5407 bus arbitration state diagram. States are described in
Table 18-6.
Chapter 18. Bus Operation
18-27
General Operation of External Master Transfers
A1
A2
Reset
A4
A3
B1
External
Master
D1
Implicit
Master
D3
D2
D4
B3
B2
B4
C3
C5
Explicit
Master
C1
C2
C4
Figure 18-29. MCF5407 Two-Wire Bus Arbitration Protocol State Diagram
Table 18-10 describes the two-wire bus arbitration protocol transition conditions.
Table 18-10. MCF5407 Two-Wire Bus Arbitration Protocol Transition Conditions
Present
State
Condition
Label
RSTI
Software Watchdog
Reset
BG
Bus
Request
Transfer in
Progress
End of
Cycle1
Next
State
A1
A2
—
—
—
—
—
Reset
A2
N3
A
—
—
—
—
Reset
A3
N
N
N
—
—
—
EM 4
A4
N
N
A
—
—
—
Implicit mas
B1
N
N
N
—
—
—
EM
B2
N
N
A
—
—
—
Explicit mas
B3
N
N
A
N
—
—
Implicit mas
B4
N
N
A
A
—
—
Explicit mas
C1
N
N
A
—
—
—
Explicit mas
C2
N
N
N
—
—
—
Explicit mas
C3
N
N
N
—
N
—
EM
C4
N
N
N
—
A
N
Explicit mas
C5
N
N
N
—
A
A
EM
D1
N
N
N
—
—
—
EM mas
D2
N
N
A
—
—
—
Explicit mas
D3
N
N
A
N
—
—
Implicit mas
D4
N
N
A
A
—
—
Explicit mas
Reset
Implicit
Master
Explicit
Master
External
Master
18-28
MCF5407 User’s Manual
General Operation of External Master Transfers
1
Both normal terminations and terminations due to bus errors generate an end of cycle. Bus cycles resulting from
a burst-inhibited transfer are considered part of that original transfer.
2 A means asserted.
3 N means negated.
4 EM means external master.
18.9.2 Multiple External Bus Device Arbitration Protocol
(Three-Wire Mode)
Three-wire mode lets the MCF5407 share the external bus with multiple external devices.
This mode requires an external arbiter to assign priorities to each potential master and to
determine which device accesses the external bus. The arbiter uses the MCF5407 bus
arbitration signals, BR, BD, and BG, to control use of the external bus by the MCF5407.
The MCF5407 requests the bus from the external bus arbiter by asserting BR when the core
requests an access. It continues to assert BR until after the transfer starts. It can negate BR
at any time regardless of the BG status. If the MCF5407 is granted the bus when an internal
bus request is generated, it asserts BD and the access begins immediately. The MCF5407
always drives BR and BD, which cannot be directly wire-ORed with other devices.
The external arbiter asserts BG to grant the bus to MCF5407, which can begin a bus cycle
after the next rising edge of CLKIN. If BG is negated during a bus cycle, the MCF5407
releases the bus when the cycle completes. To guarantee that the bus is released, BG must
be negated before the rising edge of the CLKIN in which the last TA is asserted. Note that
the MCF5407 treats any series of burst or a burst-inhibited transfers as a single bus cycle
and does not release the bus until the last transfer of the series completes.
When the MCF5407 is granted the bus after it asserts BR, one of two things can occur. If
the MCF5407 has an internal bus request pending, it asserts BD, indicating explicit bus
mastership, and begins the pending bus cycle by asserting TS. The MCF5407 continues to
assert BD until the external bus arbiter negates BG, after which BD is negated at the
completion of the bus cycle. As long as BG is asserted, BD remains asserted to indicate that
the MCF5407 is bus master, and the MCF5407 continuously drives the address bus,
attributes, and control signals.
If no internal request is pending, the MCF5407 takes implicit bus mastership. It does not
drive the bus and does not assert BD if the bus has an implicit master. If an internal bus
request is generated, the MCF5407 assumes explicit bus mastership and immediately
begins an access and asserts BD. Figure 18-30 shows implicit and explicit bus mastership
due to generation of an internal bus request.
Chapter 18. Bus Operation
18-29
General Operation of External Master Transfers
C1
C2
C3
C4
C5
C6
C7
C8
C9
CLKIN
A[31:0], TT[1:0]
SIZ[1:0], TM[2:0]
R/W
TIP
TS
AS
D[31:0]
TA
BR
BG
BD
Implicit
Mastership
External Master
Explicit
Mastership
MCF5407
Figure 18-30. Three-Wire Implicit and Explicit Bus Mastership
In Figure 18-30, the external device is bus master during C1 and C2, releasing control in
C3, at which time the external arbiter asserts BG to the MCF5407. During C4 and C5, the
MCF5407 is implicit master because no internal access is pending. In C5, an internal bus
request becomes pending, causing the MCF5407 to take explicit bus mastership in C6 by
asserting BR and BD. In C7, the external device removes the bus grant to the MCF5407.
The MCF5407 does not release the bus (the MCF5407 asserts BD) until the transfer ends.
NOTE:
The MCF5407 can start a transfer in the CLKIN cycle after BG
is asserted. The external arbiter should not assert BG to the
MCF5407 until the previous external master stops driving the
bus. Asserting BG during another external master’s transfer
may damage the part.
18-30
MCF5407 User’s Manual
General Operation of External Master Transfers
C1
C2
C3
C4
C5
C6
C7
C8
C9
CLKIN
A[31:0], TT[1:0]
SIZ[1:0], TM[2:0]
R/W
TIP
TS
AS
D[31:0]
TA
BR
BG
BD
External
Master
MCF5407
Figure 18-31. Three-Wire Bus Arbitration
In Figure 18-31, the external device is bus master during C1 and C2. During C2, the
MCF5407 requests the external bus because of a pending internal transfer. On C3, the
external releases mastership and the external arbiter grants the bus to the MCF5407 by
asserting BG. At this point, an internal is access pending so the MCF5407 asserts BD
during C4 and begins the access. Thus, the MCF5407 becomes the explicit bus master. Also
during C4, the external arbiter removes the grant from the MCF5407 by negating BG.
Because the MCF5407 is bus master, it continues to assert BD until the current transfer
completes. Because BG is negated, the MCF5407 negates BD during C9 and three-states
the external bus, thereby passing mastership to an external device.
The MCF5407 can assert BR to signal the external arbiter that it needs the bus. However,
there is no guarantee that when the bus is granted to the MCF5407 that a bus cycle will be
performed. At best, BR must be used as a status output that indicates when the MCF5407
needs the bus, but not as an indication that the MCF5407 is in a certain bus arbitration state.
Figure 18-32 is a high-level state diagram for MCF5407 bus arbitration protocol.
Table 18-6 describes the four states shown in Figure 18-32.
Chapter 18. Bus Operation
18-31
General Operation of External Master Transfers
A1
A2
Reset
A4
A3
D1
B1
External
Master
Implicit
Master
D3
D2
D4
B3
B2
B4
C3
C5
Explicit
Master
C1
C2
C4
Figure 18-32. Three-Wire Bus Arbitration Protocol State Diagram
Table 18-11 lists conditions that cause state transitions.
Table 18-11. Three-Wire Bus Arbitration Protocol Transition Conditions
Current
State
Reset
Implicit
master
18-32
Software
Watchdog
Reset
BG
Bus
Request
Transfer
in
Progress
End of
Cycle 1
Next State
Asserted
—
—
—
—
—
Reset
Negated
Asserted
—
—
—
—
Reset
Condition
Label
RSTI
A1
A2
A3
Negated
Negated
Negated
—
—
—
EM
A4
Negated
Negated
Asserted
—
—
—
Implicit
master
B1
Negated
Negated
Negated
—
—
—
External
device
master
B2
Negated
Negated
Asserted
—
—
—
Explicit
master
B3
Negated
Negated
Asserted
Negated
—
—
Implicit
master
B4
Negated
Negated
Asserted
Asserted
—
—
Explicit
master
MCF5407 User’s Manual
Reset Operation
Table 18-11. Three-Wire Bus Arbitration Protocol Transition Conditions (Continued)
Current
State
Condition
Label
RSTI
Software
Watchdog
Reset
BG
Bus
Request
Transfer
in
Progress
End of
Cycle 1
Explicit
master
C1
Negated
Negated
Asserted
—
—
—
Explicit
master
C2
Negated
Negated
Negated
—
—
—
Explicit
master
C3
Negated
Negated
Negated
—
Negated
—
External
device
master
C4
Negated
Negated
Negated
—
Yes
Negated
Explicit
master
C5
Negated
Negated
Negated
—
Yes
Yes
External
device
master
D1
Negated
Negated
Negated1
—
—
—
External
device
master
D2
Negated
Negated
Asserted
—
—
—
Explicit
master
D3
Negated
Negated
Asserted
Negated
—
—
Implicit
master
D4
Negated
Negated
Asserted
Asserted
—
—
Explicit
master
External
master
1
Next State
Both normal terminations and terminations due to bus errors generate an end of cycle. Bus cycles resulting from
a burst-inhibited transfer are considered part of that original transfer.
The bus arbitration state diagram can be used for the MCF5407 three-wire bus arbitration
protocol to approximate the high-level behavior of the MCF5407. It is assumed that all TS
or AS signals in a system are tied together and each bus device’s BD and BR signals are
connected individually to the external arbiter. The external arbiter must ensure that any
external masters will have released the bus after the next rising edge of CLKIN before
asserting BG to the MCF5407. The MCF5407 does not monitor external bus master
operation regarding bus arbitration.
NOTE:
The MCF5407 can start a transfer on the rising edge of CLKIN
the cycle after BG is asserted. The external arbiter should not
assert BG to the MCF5407 until the previous external master
stops driving the bus or the part may be damaged.
18.10 Reset Operation
The MCF5407 supports two types of reset. Asserting RSTI resets the entire MCF5407. A
software watchdog reset resets everything but the internal PLL module.
Chapter 18. Bus Operation
18-33
Reset Operation
18.10.1 Master Reset
To perform a master reset, an external device asserts RSTI. When power is applied to the
system, external circuitry should assert RSTI for a minimum of 16 CLKIN cycles after
EVcc and IVcc are within tolerance. Figure 18-33 is a functional timing diagram of the
master reset operation, showing relationships among E/IVcc, RSTI, mode selects, and bus
signals. CLKIN must be stable by the time E/IVcc reach the minimum operating
specification. See Section 20.1.1, “Supply Voltage Sequencing and Separation Cautions.”
CLKIN should start oscillating as E/IVcc are ramped up to clear out contention internal to
the MCF5407 caused by the random states of internal flip-flops on power up. RSTI is
internally synchronized for two CLKIN cycles before being used and must meet the
specified setup and hold times in relationship to CLKIN to be recognized.
>16 CLKIN cycles
50K CLKIN cycles
PLL lock time
CLKIN
EVCC, IVCC
RSTI
RSTO
D[7:0]
Bus Signals
BR
BD
Figure 18-33. Master Reset Timing
During the master reset period, all signals capable of being three-stated are driven to a
high-impedance; all others are negated. When RSTI negates, all bus signals remain in a
high-impedance state until the MCF5407 is granted the bus and the core begins the first bus
cycle for reset exception processing. A master reset causes any bus cycle (including DRAM
refresh cycle) to terminate and initializes registers appropriately for a reset exception.
Note that during reset D[7:0] are sampled on the negating edge of RSTI for initial
MCF5407 configurations listed in Table 18-12.
18-34
MCF5407 User’s Manual
Reset Operation
Table 18-12. Data Pin Configuration
Pin
D7
D[6:5]
Function
Auto-Acknowledge Configuration (AA_CONFIG)
Port Size Configuration (PS_CONFIG[1:0])
D4
Address Configuration (ADDR_CONFIG/D4)
D3
Byte Enable Configuration (BE_CONFIG)
D[2:0]
Divide Control (DIVIDE[2:0])
See Section 17.5.5, “Data/Configuration Pins (D[7:0]).” Motorola recommends that the
data pins be driven rather than using a weak pull-up or pull-down resistor. Table 17-1 lists
the encoding of these pins sampled at reset.
After RSTI is negated, 32 bits of CPU configuration information are loaded into data
register D0 and 32 bits of internal memory information are loaded in D1. Because D0 and
D1 are uninitialized on previous ColdFire devices, this feature allows users to identify the
MCF5407 through software. Values D1 = 0x0630_0530 and D0 = 0xCF4x_C012 identify
the MCF5407, where x identifies the core revision number (0x1 for the initial device).
18.10.2 Software Watchdog Reset
A software watchdog reset is performed if the executing software does not provide the
correct write data sequence with the enable-control bit set. This reset helps prevent runaway
software or unterminated bus cycles. Figure 18-34 is a functional timing diagram of the
software watchdog reset operation, showing RSTO and bus signal relationships.
>16 CLKS
50K CLKIN
Cycle Lock Time
>10 CLKS
CLKIN
BCLKO
PSTCLK
RSTI
D[7:0]
D[7:0] latched on rising edge of CLKIN
RSTO
Figure 18-34. Software Watchdog Reset Timing
Chapter 18. Bus Operation
18-35
Reset Operation
During the software watchdog reset period, all signals that can be are driven to a
high-impedance state; all those that cannot be are negated. When RSTO negates, bus
signals remain in a high-impedance state until the MCF5407 is granted the bus and the
ColdFire core begins the first bus cycle for reset exception processing.
18-36
MCF5407 User’s Manual
Chapter 19
IEEE 1149.1 Test Access Port (JTAG)
This chapter describes configuration and operation of the MCF5407 JTAG test
implementation. It describes the use of JTAG instructions and provides information on how
to disable JTAG functionality.
19.1 Overview
The MCF5407 dedicated user-accessible test logic is fully compliant with the publication
Standard Test Access Port and Boundary-Scan Architecture, IEEE Standard 1149.1. Use the
following description in conjunction with the supporting IEEE document listed above. This
section includes the description of those chip-specific items that the IEEE standard requires
as well as those items specific to the MCF5407 implementation.
The MCF5407 JTAG test architecture supports circuit board test strategies based on the
IEEE standard. This architecture provides access to all data and chip control pins from the
board-edge connector through the standard four-pin test access port (TAP) and the JTAG
reset pin, TRST. Test logic design is static and is independent of the system logic except
where the JTAG is subordinate to other complimentary test modes, as described in
Chapter 5, “Debug Support.” When in subordinate mode, JTAG test logic is placed in reset
and the TAP pins can be used for other purposes, as described in Table 19-1.
The MCF5407 JTAG implementation can do the following:
•
•
•
•
•
Perform boundary-scan operations to test circuit board electrical continuity
Bypass the MCF5407 by reducing the shift register path to a single cell
Set MCF5407 output drive pins to fixed logic values while reducing the shift register
path to a single cell
Sample MCF5407 system pins during operation and transparently shift out the result
Protect MCF5407 system output and input pins from backdriving and random
toggling (such as during in-circuit testing) by placing all system pins in highimpedance state
NOTE:
IEEE Standard 1149.1 may interfere with system designs that do
not incorporate JTAG capability. Section 19.6, “Disabling IEEE
Standard 1149.1 Operation,” describes precautions for ensuring
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
19-1
JTAG Signal Descriptions
that this logic does not affect system or debug operation.
Figure 19-1 is a block diagram of the MCF5407 implementation of the 1149.1 IEEE
standard. The test logic includes several test data registers, an instruction register,
instruction register control decode, and a 16-state dedicated TAP controller.
Test Data Registers
V+
TDI
Boundary Scan Register
M
U
X
ID Code
Bypass
3-Bit Instruction Decode
3-Bit Instruction Register
M
U
X
TDO
V+
TMS
TCK
TAP
V+
TRST
Figure 19-1. JTAG Test Logic Block Diagram
19.2 JTAG Signal Descriptions
JTAG operation on the MCF5407 is enabled when MTMOD0 is high (logic 1), as described
in Table 19-1. Otherwise, JTAG TAP signals, TCK, TMS, TDI, TDO, and TRST, are
interpreted as the debug port pins. MTMOD0 should not be changed while RSTI is
asserted.
19-2
MCF5407 User’s Manual
TAP Controller
Table 19-1. JTAG Pin Descriptions
Pin
Description
TCK
Test clock. The dedicated JTAG test logic clock is independent of the MCF5407 processor clock. Various
JTAG operations occur on the rising or falling edge of TCK. Internal JTAG controller logic is designed such
that holding TCK high or low indefinitely does cause the JTAG test logic to lose state information. If TCK is
not used, it should be tied to ground.
TMS/
BKPT
Test mode select (MTMOD0 high)/breakpoint (MTMOD0 low). TMS provides the JTAG controller with
information to determine the test operation mode. The states of TMS and of the internal 16-state JTAG
controller state machine at the rising edge of TCK determine whether the JTAG controller holds its current
state or advances to the next state. This directly controls whether JTAG data or instruction operations
occur. TMS has an internal pull-up, so if it is not driven low, its value defaults to a logic level of 1. If TMS is
not used, it should be tied to VDD. BKPT signals a hardware breakpoint to the processor in debug mode.
See Chapter 5, “Debug Support.”
TDI/DSI
Test data input (MTMOD0 high)/development serial input (MTMOD0 low). TDI provides the serial data port
for loading the JTAG boundary-scan, bypass, and instruction registers. Shifting in of data depends on the
state of the JTAG controller state machine and the instruction in the instruction register. This shift occurs on
the rising edge of TCK. TDI has an internal pull-up so if it is not driven low its value defaults to a logical 1. If
TDI is not used, it should be tied to VDD.
DSI provides single-bit communication for debug module commands. See Chapter 5, “Debug Support.”
TDO/
DSO
Test data output (MTMOD0 high)/development serial output (MTMOD0 low). TDO is the serial data port for
outputting data from JTAG logic. Shifting data out depends on the state of the JTAG controller state
machine and the instruction currently in the instruction register. This shift occurs on the falling edge of TCK.
When not outputting test data, TDO is three-stated. It can also be placed in three-state mode to allow
bussed or parallel connections to other devices having JTAG. DSO provides single-bit communication for
debug module commands. See Chapter 5, “Debug Support.”
TRST/ Test reset (MTMOD0 high)/development serial clock (MTMOD0 low). As TRST, this pin asynchronously
DSCLK resets the internal JTAG controller to the test logic reset state, causing the JTAG instruction register to
choose the IDCODE instruction. When this occurs, all JTAG logic is benign and does not interfere with
normal MCF5407 functionality. Although this signal is asynchronous, Motorola recommends that TRST
make only an asserted-to-negated transition while TMS is held at a logic 1 value. TRST has an internal
pull-up; if it is not driven low its value defaults to a logic level of 1. However, if TRST is not used, it can
either be tied to ground or, if TCK is clocked, to VDD. The former connection places the JTAG controller in
the test logic reset state immediately; the latter connection eventually puts the JTAG controller (if TMS is a
logic 1) into the test logic reset state after 5 TCK cycles.
DSCLK is the development serial clock for the serial interface to the debug module.The maximum DSCLK
frequency is 1/2 the CLKIN frequency. See Chapter 5, “Debug Support.”
19.3 TAP Controller
The state of TMS at the rising edge of TCK determines the current state of the TAP
controller. The TAP controller can follow two basic two paths, one for executing JTAG
instructions and the other for manipulating JTAG data based on JTAG instructions. The
various states of the TAP controller are shown in Figure 19-2. For more detail on each state,
see the IEEE Standard 1149.1 JTAG document. Note that regardless of the TAP controller
state, test-logic-reset can be entered if TMS is held high for at least five rising edges of
TCK. Figure 19-2 shows the JTAG TAP controller state machine.
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
19-3
JTAG Register Descriptions
1
Test-Logic-Reset
TLR
0
Run-Test-Idle
0
<-- Value of TMS at rising edge of TCK
1
1
1
Select-IR-Scan
SeIR
Select-DR-Scan
SeDR
RTI
0
0
1
1
Capture-DR
CaDR
Capture-IR
CaIR
0
0
Shift-IR
Shift-DR
ShDR
0
1
1
Exit1-DR
Exit1-IR
1
E1DR
0
Pause-DR
PaDR
Pause-IR
PaIR
0
1
0
1
0
Exit2-DR
E2DR
Exit2-IR
E2IR
1
1
Update-DR
UpDR
1
1
E1IR
0
0
0
ShIR
0
Update-IR
UpIR
1
0
Figure 19-2. JTAG TAP Controller State Machine
19.4 JTAG Register Descriptions
The following sections describe the JTAG registers implemented on the MCF5407.
19-4
MCF5407 User’s Manual
JTAG Register Descriptions
19.4.1 JTAG Instruction Shift Register
The MCF5407 IEEE Standard 1149.1 implementation uses a 3-bit instruction-shift register
(IR) without parity. This register transfers its value to a parallel hold register and applies
one of six instructions on the falling edge of TCK when the TAP state machine is in
Update-IR state. To load instructions into the shift portion of the register, place the serial
data on TDI before each rising edge of TCK. The msb of the instruction shift register is the
bit closest to the TDI pin, and the lsb is the bit closest to TDO.
Table 19-2 describes customer-usable instructions.
Table 19-2. JTAG Instructions
Instruction
Class
IR
Description
EXTEST
(EXT)
Required
000 Selects the boundary-scan register. Forces all output pins and bidirectional pins
configured as outputs to the preloaded fixed values (with the SAMPLE/PRELOAD
instruction) and held in the boundary-scan update registers. EXTEST can also
configure the direction of bidirectional pins and establish high-impedance states on
some pins. EXTEST becomes active on the falling edge of TCK in the Update-IR state
when the data held in the instruction-shift register is equivalent to octal 0.
IDCODE
(IDC)
Optional
001 Selects the IDCODE register for connection as a shift path between TDI and TDO.
Interrogates the MCF5407 for version number and other part identification. The
IDCODE register is implemented in accordance with IEEE Standard 1149.1 so the lsb
of the shift register stage is set to logic 1 on the rising edge of TCK following entry into
the capture-DR state. Therefore, the first bit shifted out after selecting the IDCODE
register is always a logic 1. The remaining 31-bits are also set to fixed values. See
Section 19.4.2, “IDCODE Register.”
IDCODE is the default value in the IR when a JTAG reset occurs by either asserting
TRST or holding TMS high while clocking TCK through at least five rising edges and
the falling edge after the fifth rising edge. A JTAG reset causes the TAP state machine
to enter test-logic-reset state (normal operation of the TAP state machine into the
test-logic-reset state also places the default value of octal 1 into the instruction
register). The shift register portion of the instruction register is loaded with the default
value of octal 1 in Capture-IR state and a TCK rising edge occurs.
SAMPLE/
PRELOAD
(SMP)
Required
100 Provides two separate functions. It obtains a sample of the system data and control
signals at the MCF5407 input pins and before the boundary-scan cell at the output
pins. This sampling occurs on the rising edge of TCK in the capture-DR state when an
instruction encoding of octal 4 is in the instruction register. Sampled data is observed
by shifting it through the boundary-scan register to TDO by using shift-DR state. The
data capture and shift are transparent to system operation. The users must provide
external synchronization to achieve meaningful results because there is no internal
synchronization between TCK and CLK.
SAMPLE/PRELOAD also initializes the boundary-scan register update cells before
selecting EXTEST or CLAMP. This is done by ignoring data shifted out of TDO while
shifting in initialization data. The Update-DR state in conjunction with the falling edge
of TCK can then transfer this data to the update cells. This data is applied to external
outputs when an instruction listed above is applied.
HIGHZ
(HIZ)
Optional
101 Anticipates the need to backdrive outputs and protects inputs from random toggling
during board testing. Selects the bypass register, forcing all output and bidirectional
pins into high-impedance.
HIGHZ goes active on the falling edge of TCK in the Update-IR state when instruction
shift register data held is equivalent to octal 5.
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
19-5
JTAG Register Descriptions
Table 19-2. JTAG Instructions (Continued)
Instruction
Class
IR
Description
CLAMP
(CMP)
Optional
110 Selects the bypass register and asserts functional reset while forcing all output and
bidirectional pins configured as outputs to fixed, preloaded values in the
boundary-scan update registers. Enhances test efficiency by reducing the overall shift
path to one bit (the bypass register) while conducting an EXTEST type of instruction
through the boundary-scan register. CLAMP becomes active on the falling edge of
TCK in the Update-IR state when instruction-shift register data is equivalent to octal 6.
BYPASS
(BYP)
Required
111 Selects the single-bit bypass register, creating a single-bit shift register path from TDI
to the bypass register to TDO. Enhances test efficiency by reducing the overall shift
path when a device other than the MCF5407 is under test on a board design with
multiple chips on the overall 1149.1 defined boundary-scan chain. The bypass register
is implemented in accordance with 1149.1 so the shift register stage is set to logic 0
on the rising edge of TCK following entry into the capture-DR state. Therefore, the first
bit shifted out after selecting the bypass register is always a logic 0 (to differentiate a
part that supports an IDCODE register from a part that supports only the bypass
register).
BYPASS goes active on the falling edge of TCK in the Update-IR state when
instruction shift register data is equivalent to octal 7.
The IEEE Standard 1149.1 requires the EXTEST, SAMPLE/PRELOAD, and BYPASS
instructions. IDCODE, CLAMP, and HIGHZ are optional standard instructions that the
MCF5407 implementation supports and are described in the IEEE Standard 1149.1.
19.4.2 IDCODE Register
The MCF5407 includes an IEEE Standard 1149.1-compliant JTAG identification register,
IDCODE, which is read by the MCF5407 JTAG instruction encoded as octal 1.
31
30
29
28
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
1
1
7
6
5
4
3
2
1
0
9
8
7
6
5
4
3
2
1
0
9
8
7
6
5
4
3
2
1
0
Version Number
0 1 0 0 1 1 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 1 1 1 0 1
(0000 for initial MCF5407 device)
Figure 19-3. IDCODE Register
Table 19-3 describes IDCODE bit assignments.
Table 19-3. IDCODE Bit Assignments
Bits
Description
31–28
Version number. Indicates the revision number of the MCF5407
27–22
Design center. Indicates the ColdFire design center
21–12
Device number. Indicates an MCF5407
11–1
Indicates the reduced JEDEC ID for Motorola. Joint Electron Device Engineering Council (JEDEC)
Publication 106-A and Chapter 11 of the IEEE Standard 1149.1 give more information on this field.
0
Identifies this as the JTAG IDCODE register (and not the bypass register) according to the IEEE Standard
1149.1
19-6
MCF5407 User’s Manual
JTAG Register Descriptions
19.4.3 JTAG Boundary-Scan Register
The MCF5407 model includes an IEEE Standard 1149.1-compliant boundary-scan register
connected between TDI and TDO when the EXTEST or SAMPLE/PRELOAD instructions
are selected. This register captures signal data on the input pins, forces fixed values on the
output pins, and selects the direction and drive characteristics (a logic value or high
impedance) of the bidirectional and three-state pins. Table 19-4 shows MCF5407
boundary-scan register bits.
Table 19-4. Boundary-Scan Bit Definitions
Bit
Cell Type
Pin Type
Bit
Cell Type
0
O.Ctl
PP0 enable
Pin Cell
—
120
O.Pin
BE0
Pin Cell
1
O.Pin
PP0
I/O
121
O.Pin
SCKE
O
2
I.Pin
PP0
I/O
122
O.Pin
SCAS
O
3
IO.Ctl
PP1 enable
—
123
O.Pin
SRAS
O
4
O.Pin
PP1
I/O
124
O.Pin
DRAMW
O
5
I.Pin
PP1
I/O
125
O.Pin
CAS3
O
6
IO.Ctl
PP2 enable
—
126
O.Pin
CAS2
O
7
O.Pin
PP2
I/O
127
O.Pin
CAS1
O
8
I.Pin
PP2
I/O
128
O.Pin
CAS0
O
9
IO.Ctl
PP3 enable
—
129
O.Pin
RAS1
O
10
O.Pin
PP3
I/O
130
O.Pin
RAS0
O
11
I.Pin
PP3
I/O
131
I.Pin
TIN1
I
12
IO.Ctl
PP4 enable
—
132
I.Pin
TIN0
I
13
O.Pin
PP4
I/O
133
O.Pin
TOUT0
O
14
I.Pin
PP4
I/O
134
O.Pin
TOUT1
O
15
IO.Ctl
PP5 enable
—
135
I.Pin
BG
I
16
O.Pin
PP5
I/O
136
O.Pin
BD
O
17
I.Pin
PP5
I/O
137
O.Pin
BR
O
18
IO.Ctl
PP6 enable
—
138
I.Pin
IRQ1
I
19
O.Pin
PP6
I/O
139
I.Pin
IRQ3
I
20
I.Pin
PP6
I/O
140
I.Pin
IRQ5
I
21
IO.Ctl
PP7 enable
—
141
I.Pin
IRQ7
I
22
O.Pin
PP7
I/O
142
I.Pin
RSTI
I
23
I.Pin
PP7
I/O
143
O.Pin
TS
I/O
24
O.Pin
PSTDDATA7
O
144
I.Pin
TS
I/O
25
O.Pin
PSTDDATA6
O
145
IO.Ctl
TA enable
—
26
O.Pin
PSTDDATA5
O
146
O.Pin
TA
I/O
27
O.Pin
PSTDDATA4
O
147
I.Pin
TA
I/O
28
O.Pin
PSTDDATA3
O
148
O.Pin
R/W
I/O
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
Pin Type
O
19-7
JTAG Register Descriptions
Table 19-4. Boundary-Scan Bit Definitions
Bit
Cell Type
29
O.Pin
30
O.Pin
31
O.Pin
PSTDDATA0
O
151
32
O.Pin
PSTCLK
O
152
33
I.Pin
CLKIN
I
153
O.Pin
34
IO.Ctl
RSTO enable
—
154
35
O.Pin
RSTO
I/O
155
36
I.Pin
RSTO
I/O
156
37
O.Pin
BCLKO
O
157
38
I.Pin
EDGESEL
I
39
O.Pin
TXD0
40
I.Pin
RXD0
41
O.Pin
RTS0
42
I.Pin
CTS0
43
O.Pin
TXD1
44
I.Pin
45
O.Pin
46
I.Pin
CTS1
I
166
I.Pin
PP15
I/O
47
I.Pin
HIZ
I
167
O.Pin
PP15
I/O
48
IO.Ctl
Data enable
—
168
IO.Ctl
PP14 enable
—
49
O.Pin
D0
I/O
169
I.Pin
PP14
I/O
50
I.Pin
D0
I/O
170
O.Pin
PP14
I/O
51
O.Pin
D1
I/O
171
IO.Ctl
PP13 enable
—
52
I.Pin
D1
I/O
172
I.Pin
PP13
I/O
53
O.Pin
D2
I/O
173
O.Pin
PP13
I/O
54
I.Pin
D2
I/O
174
IO.Ctl
PP12 enable
—
55
O.Pin
D3
I/O
175
I.Pin
PP12
I/O
56
I.Pin
D3
I/O
176
O.Pin
PP12
I/O
57
O.Pin
D4
I/O
177
IO.Ctl
PP11 enable
—
58
I.Pin
D4
I/O
178
I.Pin
PP11
I/O
59
O.Pin
D5
I/O
179
O.Pin
PP11
I/O
60
I.Pin
D5
I/O
180
IO.Ctl
PP10 enable
—
61
O.Pin
D6
I/O
181
I.Pin
PP10
I/O
62
I.Pin
D6
I/O
182
O.Pin
PP10
I/O
63
O.Pin
D7
I/O
183
IO.Ctl
PP9 enable
—
64
I.Pin
D7
I/O
184
I.Pin
PP9
I/O
19-8
Pin Cell
Pin Type
Bit
Cell Type
PSTDDATA2
O
149
I.Pin
R/W
I/O
PSTDDATA1
O
150
O.Pin
AS
I/O
I.Pin
AS
I/O
O.Pin
CS7
O
CS6
O
O.Pin
CS5
O
O.Pin
CS4
O
O.Pin
CS3
O
O.Pin
CS2
O
158
O.Pin
CS1
O
O
159
O.Pin
CS0
O
I
160
O.Pin
OE
O
O
161
O.Pin
SIZ1
I/O
I
162
I.Pin
SIZ1
I/O
O
163
O.Pin
SIZ0
I/O
RXD1
I
164
I.Pin
SIZ0
I/O
RTS1
O
165
IO.Ctl
PP15 enable
—
MCF5407 User’s Manual
Pin Cell
Pin Type
JTAG Register Descriptions
Table 19-4. Boundary-Scan Bit Definitions
Bit
Cell Type
Pin Cell
Pin Type
Bit
Cell Type
Pin Cell
65
O.Pin
D8
I/O
185
O.Pin
PP9
I/O
66
I.Pin
D8
I/O
186
IO.Ctl
PP8 enable
—
67
O.Pin
D9
I/O
187
I.Pin
PP8
I/O
68
I.Pin
D9
I/O
188
O.Pin
PP8
I/O
69
O.Pin
D10
I/O
189
IO.Ctl
TS/R/W/SIZ enable
—
70
I.Pin
D10
I/O
190
IO.Ctl
Address enable
—
71
O.Pin
D11
I/O
191
O.Pin
A23
I/O
72
I.Pin
D11
I/O
192
I.Pin
A23
I/O
73
O.Pin
D12
I/O
193
O.Pin
A22
I/O
74
I.Pin
D12
I/O
194
I.Pin
A22
I/O
75
O.Pin
D13
I/O
195
O.Pin
A21
I/O
76
I.Pin
D13
I/O
196
I.Pin
A21
I/O
77
O.Pin
D14
I/O
197
O.Pin
A20
I/O
78
I.Pin
D14
I/O
198
I.Pin
A20
I/O
79
O.Pin
D15
I/O
199
O.Pin
A19
I/O
80
I.Pin
D15
I/O
200
I.Pin
A19
I/O
81
O.Pin
D16
I/O
201
O.Pin
A18
I/O
82
I.Pin
D16
I/O
202
I.Pin
A18
I/O
83
O.Pin
D17
I/O
203
O.Pin
A17
I/O
84
I.Pin
D17
I/O
204
I.Pin
A17
I/O
85
O.Pin
D18
I/O
205
O.Pin
A16
I/O
86
I.Pin
D18
I/O
206
I.Pin
A16
I/O
87
O.Pin
D19
I/O
207
O.Pin
A15
I/O
88
I.Pin
D19
I/O
208
I.Pin
A15
I/O
89
O.Pin
D20
I/O
209
O.Pin
A14
I/O
90
I.Pin
D20
I/O
210
I.Pin
A14
I/O
91
O.Pin
D21
I/O
211
O.Pin
A13
I/O
92
I.Pin
D21
I/O
212
I.Pin
A13
I/O
93
O.Pin
D22
I/O
213
O.Pin
A12
I/O
94
I.Pin
D22
I/O
214
I.Pin
A12
I/O
95
O.Pin
D23
I/O
215
O.Pin
A11
I/O
96
I.Pin
D23
I/O
216
I.Pin
A11
I/O
97
O.Pin
D24
I/O
217
O.Pin
A10
I/O
98
I.Pin
D24
I/O
218
I.Pin
A10
I/O
99
O.Pin
D25
I/O
219
O.Pin
A9
I/O
100
I.Pin
D25
I/O
220
I.Pin
A9
I/O
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
Pin Type
19-9
Restrictions
Table 19-4. Boundary-Scan Bit Definitions
Bit
Cell Type
101
O.Pin
102
I.Pin
103
104
105
Pin Cell
Pin Type
Bit
Cell Type
Pin Cell
Pin Type
D26
I/O
221
O.Pin
A8
I/O
D26
I/O
222
I.Pin
A8
I/O
O.Pin
D27
I/O
223
O.Pin
A7
I/O
I.Pin
D27
I/O
224
I.Pin
A7
I/O
O.Pin
D28
I/O
225
O.Pin
A6
I/O
106
I.Pin
D28
I/O
226
I.Pin
A6
I/O
107
O.Pin
D29
I/O
227
O.Pin
A5
I/O
I/O
108
I.Pin
D29
I/O
228
I.Pin
A5
109
O.Pin
D30
I/O
229
O.Pin
A4
I/O
110
I.Pin
D30
I/O
230
I.Pin
A4
I/O
111
O.Pin
D31
I/O
231
O.Pin
A3
I/O
112
I.Pin
D31
I/O
232
I.Pin
A3
I/O
113
O.Pin
SDA
OD
233
O.Pin
A2
I/O
114
I.Pin
SDA
I
234
I.Pin
A2
I/O
115
O.Pin
SCL
OD
235
O.Pin
A1
I/O
116
I.Pin
SCL
I
236
I.Pin
A1
I/O
117
O.Pin
BE3
O
237
O.Pin
A0
I/O
118
O.Pin
BE2
O
238
I.Pin
A0
I/O
119
O.Pin
BE1
O
19.4.4 JTAG Bypass Register
The IEEE Standard 1149.1-compliant bypass register creates a single-bit shift register path
from TDI to the bypass register to TDO when the BYPASS instruction is selected.
19.5 Restrictions
Test logic design is static, so TCK can be stopped in high or low state with no data loss.
However, system logic uses a different system clock not internally synchronized to TCK.
Operation mixing 1149.1 test logic with system functional logic that uses both clocks must
coordinate and synchronize these clocks externally to the MCF5407.
19.6 Disabling IEEE Standard 1149.1 Operation
There are two ways to use the MCF5407 without IEEE Standard 1149.1 test logic being
active:
19-10
MCF5407 User’s Manual
Obtaining the IEEE Standard 1149.1
•
Nonuse of JTAG test logic by either nontermination (disconnection) or intentionally
fixing TAP logic values. The following issues must be addressed if IEEE Standard
1149.1 logic is not to be used when the MCF5407 is assembled onto a board.
— IEEE Standard 1149.1 test logic must remain transparent and benign to the
system logic during functional operation. To ensure that the part enters the
test-logic-reset state requires either connecting TRST to logic 0 or connecting
TCK to a source that supplies five rising edges and a falling edge after the fifth
rising edge. The recommended solution is to connect TRST to logic 0.
— TCK has no internal pull-up as is required on TMS, TDI, and TRST; therefore,
it must be terminated to preclude mid-level input values. Figure 19-4 shows pin
values recommended for disabling JTAG with the MCF5407 in JTAG mode.
VDD
•
TMS/BKPT
TDI/DSI
•
TRST/DSCLK
•
TCK
Note: MTMOD0 high allows JTAG mode.
Figure 19-4. Disabling JTAG in JTAG Mode
•
Disabling JTAG test logic by holding MTMOD0 low during reset (debug mode).
This allows the IEEE Standard 1149.1 test controller to enter test-logic-reset state
when TRST is internally asserted to the controller. TAP pins function as debug mode
pins. In JTAG mode, inputs TDI/DSI, TMS/BKPT, and TRST/DSCLK have internal
pull-ups enabled. Figure 19-5 shows pin values recommended for disabling JTAG in
debug mode.
TDI/DSI
Debug Interface
TMS/BKPT
TRST/DSCLK
TCK
Note: MTMOD0 low prohibits JTAG.
Figure 19-5. Disabling JTAG in Debug Mode
19.7 Obtaining the IEEE Standard 1149.1
The IEEE Standard 1149.1 JTAG specification is a copyrighted document and must be
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
19-11
Obtaining the IEEE Standard 1149.1
obtained directly from the IEEE:
IEEE Standards Department
445 Hoes Lane
P.O. Box 1331
Piscataway, NJ 08855-1331
USA
http://stdsbbs.ieee.org/
FAX: 908-981-9667
Information: 908-981-0060 or 1-800-678-4333
19-12
MCF5407 User’s Manual
Chapter 20
Electrical Specifications
This chapter describes the AC and DC electrical specifications and thermal characteristics
for the MCF5407. Note that this information was correct at the time this book was
published. As process technologies improve, there is a likelihood that this information may
change. To confirm that this is the latest information, see Motorola’s ColdFire webpage,
http://www.motorola.com/coldfire.
20.1 General Parameters
Table 20-1 lists maximum and minimum ratings for supply and operating voltages and
storage temperature. Operating outside of these ranges may cause erratic behavior or
damage to the processor.
Table 20-1. Absolute Maximum Ratings
Rating
Symbol
Value
Units
External (I/O pads) supply voltage (3.3-V power pins)
EVcc
Internal logic supply voltage
IVcc
-0.3 to +4.0
-0.5 to +2.0 1, 2
V
PLL supply voltage
PVcc
-0.5 to +2.0 2, 3
V
Internal logic supply voltage, input voltage level
Vin
-0.5 to +3.6 4
V
Storage temperature range
Tstg
-55 to +150
oC
V
1
IVcc must not exceed EVcc
IVcc and PVcc must not differ by more than 0.5 V
3 PV must not exceed EV
cc
cc
4 V must not exceed EV
in
cc
2
Table 20-2 lists junction and ambient operating temperatures.
Table 20-2. Operating Temperatures
Characteristic
Maximum operating junction temperature
Symbol
Value
Units
Tj
TBD
oC
1
oC
Maximum operating ambient temperature
TAmax
70
Minimum operating ambient temperature
TAmin
0
1
oC
This published maximum operating ambient temperature should be used only as a system design guideline. All
device operating parameters are guaranteed only when the junction temperature lies within the specified range.
Chapter 20. Electrical Specifications
20-1
General Parameters
Table 20-3 lists DC electrical operating temperatures. This table is based on an operating
voltage of EVcc = 3.3 Vdc ± 0.3 Vdc and IVcc of 1.8 ± 0.15 Vdc.
Table 20-3. DC Electrical Specifications
Characteristic
Symbol
Min
Max
Units
EVcc
3.0
3.6
V
V
External (I/O pads) operation voltage range
1
IVcc
1.65
1.95
PVcc
1.65
1.95
V
Input high voltage
VIH
2.0
3.6
V
Internal logic operation voltage range
PLL operation voltage range 1
Input low voltage
VIL
-0.5
0.8
V
Input signal undershoot
—
—
0.8
V
Input signal overshoot
—
—
0.8
V
Input leakage current @ 0.5/2.4 V during normal operation
Iin
—
20
µA
ITSI
—
20
µA
Signal low input current, VIL = 0.8 V 2
IIL
0
1
mA
Signal high input current, VIH = 2.0 V 2
IIH
0
1
mA
VOH
2.4
—
V
VOL
—
0.5
V
Load capacitance (all outputs)
CL
—
50
pF
Capacitance 5, Vin = 0 V, f = 1 MHz
CIN
—
TBD
pF
High impedance (three-state) leakage current @ 0.5/2.4 V during
normal operation
Output high voltage IOH = 8 mA
3,
16 mA
4
Output low voltage IOL = 8 mA 3, 16 mA 4
1
2
3
4
5
IVcc and PVcc should be at the same voltage.
BKPT/TMS, DSI/TDI, DSCLK/TRST
D[31:0], A[23:0], PP[15:0],TS, TA, SIZ[1:0], R/W, BR, BD, RSTO, AS, CS[7:0], BE[3:0], OE, PSTCLK,
PSTDDATA[7:0], DSO, TOUT[1:0], SCL, SDA, RTS[1:0], TXD[1:0]
BCLKO, RAS[1:0], CAS[3:0], DRAMW, SCKE, SRAS, SCAS
Capacitance CIN is periodically sampled rather than 100% tested.
20-2
MCF5407 User’s Manual
General Parameters
20.1.1 Supply Voltage Sequencing and Separation Cautions
DC Power Supply Voltage
Figure 20-1 shows two situations to avoid in sequencing the IVcc and EVcc supplies.
EVcc
3.3V
2
1.8V
Supplies Stable
IVcc, PVcc
1
0
Time
Notes:
1
2
IVcc, PVcc rising before EVcc
EVcc rising much faster than IVcc, PVcc
Figure 20-1. Supply Voltage Sequencing and Separation Cautions
IVcc should not be allowed to rise early (1). This is usually avoided by running the regulator
for the IVcc supply (1.8 V) from the voltage generated by the 3.3-V EVcc supply
(Figure 20-2). This keeps IVcc from rising faster than EVcc.
IVcc should not rise so late that a large voltage difference is allowed between the two
supplies (2). Typically this situation is avoided by using external discrete diodes in series
between supplies as shown in Figure 20-2. The series diodes forward bias when the
difference between EVcc and IVcc reaches approximately 2.1V, causing IVcc to rise as EVcc
ramps up. When the IVcc regulator begins proper operation, the difference between supplies
should not exceed 1.5 V and conduction through the diode chain reduces to essentially
leakage current. During supply sequencing, the following general relationship should be
adhered to: EVcc ≥ IVcc ≥ (EVcc - 2.1 V). The PLL Vdd (PVcc) supply should comply with
these constraints just as IVcc does. In practice, PVcc is typically connected directly to IVcc
with some filtering.
Chapter 20. Electrical Specifications
20-3
Clock Timing Specifications
3.3 V
Regulator
Supply
EVcc
1.8 V
Regulator
IVcc, PVcc
Figure 20-2. Example Circuit to Control Supply Sequencing
20.2 Clock Timing Specifications
Table 20-4 shows the MCF5407 PLL encodings. Note that they differ from the MCF5307
DIVIDE[1:0] encodings.
Table 20-4. Divide Ratio Encodings
D[2:0]/DIVIDE[2:0]
Input Clock (MHz)
Multiplier
011
40.0–54.0
3
120.0–162
60.0–81.0
100
25.0–40.5
4
100.0–162
50.0–81.0
101
25.0–32.4
5
125.0–162
67.5–81.0
110
25.0–27.0
6
150.0–162
75.0–81.0
00x–010
Core Clock (MHz)
PSTCLK (MHz)
Reserved
111
Reserved
Figure 20-3 correlates CLKIN and core clock frequencies for the 3x–6x multipliers.
CLKIN
Core Clock
3x
40
54
120
162
4x
25
40.5
100
162
5x
25
32.4
125
162
6x
25 27
25
30
CLKIN (MHz)
150
35
40
45
50
55
100
110
120
Core Clock (MHz)
130
140
150
162
160
170
Figure 20-3. CLKIN-to-Core Clock Frequency Ranges
Table 20-5 lists specifications for the clock timing parameters shown in Figure 20-4 and
Figure 20-5. Motorola recommends that CLKIN be used for the system clock. BCLKO is
provided only for compatibility with slower MCF5307 designs. Regardless of the CLKIN
frequency driven at power-up, CLKIN (and BCLKO) have the same ratio value to the
20-4
MCF5407 User’s Manual
Clock Timing Specifications
PCLK. Although either signal can be used as a clock reference, CLKIN leaves more room
to meet the bus specifications than BCLKO, which is generated as a phase-aligned signal
to CLKIN.
Table 20-5. Clock Timing Specification
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
18.5
Note 1
nS
C1
CLKIN cycle time
C2
CLKIN rise time (0.5V to 2.4 V)
—
2
nS
C3
CLKIN fall time (2.4V to 0.5 V)
—
2
nS
C4
CLKIN duty cycle (at 1.5 V)
C5
PSTCLK cycle time
C6
PSTCLK duty cycle (at 1.5 V)
C7
BCLKO cycle time
C8
BCLKO duty cycle (at 1.5 V)
C9
CLKIN to BCLKO
1
40
60
%
12.3
Note 1
nS
40
60
%
18.5
Note
1
nS
45
55
%
-1.5
1.5
nS
The PLL low-frequency limit depends on the clock divide ratio chosen. See Table 20-4.
Figure 20-4 shows timings for the parameters listed in Table 20-5.
C1
C3
C4
CLKIN
C4
C2
C7
C9
BCLKO
C8
C8
Note: Input and output AC timing specifications are measured to CLKIN with a 50-pF load capacitance (not
including pin capacitance).
Figure 20-4. Clock Timing
Figure 20-5 shows PSTCLK timings for parameters listed in Table 20-5.
Chapter 20. Electrical Specifications
20-5
Input/Output AC Timing Specifications
C5
C6
PSTCLK
C6
Figure 20-5. PSTCLK Timing
20.3 Input/Output AC Timing Specifications
Table 20-6 lists specifications for parameters shown in Figure 20-6 and Figure 20-7. Note
that inputs IRQ[7,5,3,1], BKPT, and AS are synchronized internally; that is, the logic level
is validated if the value does not change for two consecutive rising CLKIN edges. Setup
and hold times must be met only if recognition on a particular clock edge is required.
Table 20-6. Input AC Timing Specification
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
B1 1
Valid to CLKIN rising (setup)
7.5
—
nS
B2 1
CLKIN rising to invalid (hold)
1.0
—
nS
2
Valid to CLKIN rising (setup)
0
—
nS
B4 2
CLKIN rising to invalid (hold)
0.5(C1) + 1.3
—
nS
B5 3
CLKIN to input high impedance
—
2
Bus clock
B6
CLKIN to EDGESEL delay
0
5.0
nS
B3
1
Inputs: BG, TA, A[23:0], PP[15:0], SIZ[1:0], R/W, TS, EDGESEL, D[31:0],
IRQ[7,5,3,1], and BKPT
2 Inputs: AS
3 Inputs: D[31:0]
Table 20-7 lists specifications for timings in Figure 20-6, Figure 20-7, and Figure 20-13.
Although output signals that share a specification number have approximately the same
timing, due to loading differences, they do not necessarily change at the same time.
However, they have similar timings; that is, minimum and maximum times are not mixed.
Table 20-7. Output AC Timing Specification
Num
54 MHz CLKIN
Characteristic
Min
20-6
B10 1,2,3
CLKIN rising to valid
B11 3,4,5
CLKIN rising to invalid (hold)
B12 6,7
CLKIN to high impedance (three-state)
Units
Max
—
84
nS
—
10 5
nS
1.0 5
—
nS
—
10
nS
MCF5407 User’s Manual
Input/Output AC Timing Specifications
Table 20-7. Output AC Timing Specification (Continued)
Num
54 MHz CLKIN
Characteristic
Units
Min
Max
—
0.5(C1) +8.0 9
nS
—
0.5(C1) +10.0 10
nS
0.5(C1) + 1.0
—
nS
—
12
nS
B13 8,2,3
CLKIN rising to valid
B14 8,2,3
CLKIN rising to invalid (hold)
B15 2,3
EDGESEL to valid
B16 2,3
EDGESEL to invalid (hold)
2
—
nS
H1
HIZ to high impedance
—
60
nS
H2
HIZ to low Impedance
—
60
nS
1
2
3
4
5
6
7
8
9
10
Outputs that change only on rising edge of CLKIN: RSTO, TS, BR, BD, TA, R/W, SIZ[1:0], PP[7:0]
(and PP[15:8] when configured as parallel port outputs).
Outputs that can change on either CLKIN edge depending only on EDGESEL: D[31:0], A[23:0],
SCKE, SRAS, SCAS, and DRAMW and on PP[15:8] when individually configured as A[31:24]
outputs.
Outputs that can change on either CLKIN edge depending upon EDGESEL and the interface
operating mode (DRAM/SDRAM): RAS[1:0], CAS[3:0]
SRAS, SCAS, DRAMW, RAS[1:0], CAS[3:0]
D[31:0], A[23:0], TM[2:0], TT[1:0], SIZ[1:0], R/W, TIP, TS, BR, BD, and TA and PP[15:8] when
individually configured as A[31:24] outputs.
High impedance (three-state): D[31:0]
Outputs that transition to high impedance due to bus arbitration: A[23:0], R/W, SIZ[1:0], TS, AS,
and TA, and PP[15:8] when individually configured as A[31:24] outputs.
Outputs that change only on falling edge of CLKIN: AS, CS[7:0], BE[3:0], OE
SRAS, SCAS, DRAMW, RAS[1:0], CAS[3:0], AS, CS[7:0], BE[3:0], OE
D[31:0], A[23:0], TM[2:0], TT[1:0], SIZ[1:0], R/W, TIP, and TS and on PP[15:8] when individually
configured as A[31:24] outputs.
Note that these figures show two representative bus operations and do not attempt to show
all cases. For explanations of the states, S0–S5, see Section 18.4, “Data Transfer
Operation.” Note that Figure 20-7 does not show all signals that apply to each timing
specification. See the previous tables for a complete listing.
Figure 20-6 shows AC timings for normal read and write bus cycles.
Chapter 20. Electrical Specifications
20-7
Input/Output AC Timing Specifications
S0
CLKIN
S1
S2
S3
S4
S5
S0
S1
S2
S3
S4
S5
B11
B10
A[31:0]
TM[2:0]
TT[1:0]
SIZ[1:0]
R/W
B11
TS
TIP
B14
B13
AS, CS, OE
BE/BWE[3:0]
B12
B2
B10
D[31:0]
B1
B5
TA
Figure 20-6. AC Timings—Normal Read and Write Bus Cycles
Figure 20-7 shows timings for a read cycle with EDGESEL tied to buffered CLKIN.
20-8
MCF5407 User’s Manual
Input/Output AC Timing Specifications
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
CLKIN
B6
EDGESEL
B15
Row
A[31:0]
Column
TS
B16
SRAS
B15
SCAS 1
B16
DRAMW
B1
D[31:0]
B16
B2
RAS
B16
CAS
ACTV
1 DACR[CASL]
NOP
READ
NOP
NOP
PALL
NOP
=2
Figure 20-7. SDRAM Read Cycle with EDGESEL Tied to Buffered CLKIN
Figure 20-8 shows an SDRAM write cycle with EDGESEL tied to buffered CLKIN.
Chapter 20. Electrical Specifications
20-9
Input/Output AC Timing Specifications
0
1
2
3
4
5
6
7
8
9
10
11
12
CLKIN
B6
EDGESEL
B15
Row
A[31:0]
Column
TS
B16
SRAS
B15
SCAS 1
B16
DRAMW
B15
D[31:0]
B16
RAS
B16
CAS
NOP
ACTV
1 DACR[CASL]
WRITE
NOP
PALL
=2
Figure 20-8. SDRAM Write Cycle with EDGESEL Tied to Buffered CLKIN
Figure 20-9 shows an SDRAM read cycle with EDGESEL tied high.
20-10
MCF5407 User’s Manual
Input/Output AC Timing Specifications
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CLKIN
B10
Row
A[31:0]
Column
TS
B11
SRAS
B10
SCAS 1
B11
DRAMW
B1
D[31:0]
B11
B2
RAS
B11
CAS
ACTV
1 DACR[CASL]
NOP
READ
NOP
NOP
PALL
=2
Figure 20-9. SDRAM Read Cycle with EDGESEL Tied High
Figure 20-10 shows an SDRAM write cycle with EDGESEL tied high.
Chapter 20. Electrical Specifications
20-11
Input/Output AC Timing Specifications
0
1
2
3
4
5
6
7
8
9
10
11
12
CLKIN
B10
Row
A[31:0]
Column
TS
B11
SRAS
B10
SCAS1
B11
DRAMW
B10
D[31:0]
B11
RAS
B11
CAS
ACTV
1 DACR[CASL]
NOP
WRITE
NOP
PALL
=2
Figure 20-10. SDRAM Write Cycle with EDGESEL Tied High
Figure 20-11 shows an SDRAM read cycle with EDGESEL tied low.
20-12
MCF5407 User’s Manual
Input/Output AC Timing Specifications
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CLKIN
B13
Row
A[31:0]
Column
TS
B14
SRAS
B13
SCAS1
B14
DRAMW
B1
D[31:0]
B14
B2
RAS
B14
CAS
ACTV
1 DACR[CASL]
NOP
READ
NOP
NOP
PALL
=2
Figure 20-11. SDRAM Read Cycle with EDGESEL Tied Low
Figure 20-12 shows an SDRAM write cycle with EDGESEL tied low.
Chapter 20. Electrical Specifications
20-13
Input/Output AC Timing Specifications
0
1
2
3
4
5
6
7
8
9
10
11
12
CLKIN
B13
Row
A[31:0]
Column
TS
B14
SRAS
B13
SCAS1
B14
DRAMW
B13
D[31:0]
B14
RAS
B14
CAS
ACTV
1 DACR[CASL]
NOP
WRITE
NOP
PALL
=2
Figure 20-12. SDRAM Write Cycle with EDGESEL Tied Low
Figure 20-13 shows AC timing showing high impedance.
HIZ
H1
OUTPUTS
Figure 20-13. AC Output Timing—High Impedance
20-14
MCF5407 User’s Manual
H2
Reset Timing Specifications
20.4 Reset Timing Specifications
Table 20-8 lists specifications for the reset timing parameters shown in Figure 20-14.
Table 20-8. Reset Timing Specification
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
R1 1
Valid to CLKIN (setup)
7.5
—
nS
R2
CLKIN to invalid (hold)
1.0
—
nS
R3
RSTI to invalid (hold)
1.0
—
nS
1
RSTI and D[7:0] are synchronized internally. Setup and hold times
must be met only if recognition on a particular clock is required.
Figure 20-14 shows reset timing for the values in Table 20-8.
CLKIN
R1
RSTI
R2
D[7:0]
R1
R3
Note: Mode selects are registered on the rising CLKIN edge before the cycle in which RSTI is
recognized as being negated.
Figure 20-14. Reset Timing
Chapter 20. Electrical Specifications
20-15
Debug AC Timing Specifications
20.5 Debug AC Timing Specifications
Table 20-9 lists specifications for the debug AC timing parameters shown in Figure 20-16.
Table 20-9. Debug AC Timing Specification
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
D1
PSTDDATA to PSTCLK setup
4.5
—
nS
D2
PSTCLK to PSTDDATA hold
4.5
—
nS
D3
DSI-to-DSCLK setup
1
—
PSTCLKs
D4 1
DSCLK-to-DSO hold
4
—
PSTCLKs
D5
DSCLK cycle time
5
—
PSTCLKs
1
DSCLK and DSI are synchronized internally. D4 is measured from the
synchronized DSCLK input relative to the rising edge of PSTCLK.
Figure 20-15 shows real-time trace timing for the values in Table 20-9.
PSTCLK
D1
D2
PSTDDATA[7:0]
Figure 20-15. Real-Time Trace AC Timing
Figure 20-16 shows BDM serial port AC timing for the values in Table 20-9.
PSTCLK
D5
DSCLK
D3
DSI
Current
Next
D4
DSO
Past
Figure 20-16. BDM Serial Port AC Timing
20-16
MCF5407 User’s Manual
Current
Timer Module AC Timing Specifications
20.6 Timer Module AC Timing Specifications
Table 20-10 lists specifications for timer module AC timing parameters shown in
Figure 20-17.
Table 20-10. Timer Module AC Timing Specification
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
T1
TIN cycle time
3
—
Bus clocks
T2
TIN valid to CLKIN (input setup)
7.5
—
nS
T3
CLKIN to TIN invalid (input hold)
1.0
—
nS
T4
CLKIN to TOUT valid (output valid)
—
10
nS
T5
CLKIN to TOUT invalid (output hold)
1.0
—
nS
T6
TIN pulse width
1
—
Bus clocks
T7
TOUT pulse width
1
—
Bus clocks
Figure 20-17 shows timings for Table 20-10.
CLKIN
T6
TIN
T2
T3
TIN
T1
T7
TOUT
T4
T5
Figure 20-17. Timer Module AC Timing
Chapter 20. Electrical Specifications
20-17
I2C Input/Output Timing Specifications
20.7 I2C Input/Output Timing Specifications
Table 20-11 lists specifications for the I2C input timing parameters shown in Figure 20-18.
Table 20-11. I2C Input Timing Specifications between SCL and SDA
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
I1
Start condition hold time
2
—
Bus clocks
I2
Clock low period
8
—
Bus clocks
I3
SCL/SDA rise time (VIL = 0.5 V to VIH = 2.4 V)
—
1
mS
I4
Data hold time
0
—
nS
I5
SCL/SDA fall time (VIH = 2.4 V to VIL = 0.5 V)
—
1
mS
I6
Clock high time
4
—
Bus clocks
I7
Data setup time
0
—
nS
I8
Start condition setup time (for repeated start condition only)
2
—
Bus clocks
I9
Stop condition setup time
2
—
Bus clocks
Table 20-12 lists specifications for the I2C output timing parameters shown in
Figure 20-18.
Table 20-12. I2C Output Timing Specifications between SCL and SDA
54 MHz CLKIN
Num
I11
Characteristic
Start condition hold time
I21
Clock low period
I3 2
SCL/SDA rise time (VIL = 0.5 V to VIH = 2.4 V)
Units
Min
Max
6
—
Bus clocks
Bus clocks
10
—
Note 2
Note 2
I4 1
Data hold time
7
—
I5 3
SCL/SDA fall time (VIH = 2.4 V to VIL = 0.5 V)
—
3
nS
I6 1
Clock high time
10
—
Bus clocks
Bus clocks
I7 1
Data setup time
2
—
Bus clocks
I8 1
Start condition setup time (for repeated start condition only)
20
—
Bus clocks
Stop condition setup time
10
—
Bus clocks
I9
1
1
Programming IFDR with the maximum frequency (IFDR = 0x20) results in the minimum output timings listed
here. The I2C interface is designed to scale the data transition time, moving it to the middle of the SCL low
period. The actual position is affected by the prescale and division values programmed in IFDR.
2 Because SCL and SDA are open-collector-type outputs, which the processor can only actively drive low, the time
SCL or SDA takes to reach a high level depends on external signal capacitance and pull-up resistor values.
3 Specified at a nominal 50-pF load.
Figure 20-18 shows timing for the values in Table 20-11 and Table 20-12.
20-18
MCF5407 User’s Manual
UART Module AC Timing Specifications
I2
I6
I5
SCL
I1
I4
I3
I8
I9
I7
SDA
Figure 20-18. I2C Input/Output Timings
20.8 UART Module AC Timing Specifications
Table 20-13 lists specifications for UART module AC timing parameters in Figure 20-19.
Table 20-13. UART Module AC Timing Specifications
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
U1
RXD valid to CLKIN (input setup)
7.5
—
U2
CLKIN to RXD invalid (input hold)
1.0
—
nS
nS
U3
CTS valid to CLKIN (input setup)
7.5
—
nS
U4
CLKIN to CTS invalid (input hold)
1.0
—
nS
U5
CLKIN to TXD valid (output valid)
—
10
nS
U6
CLKIN to TXD invalid (output hold)
1.0
—
nS
U7
CLKIN to RTS valid (output valid)
—
10
nS
U8
CLKIN to RTS invalid (output hold)
1.0
—
nS
U9
CTS high time
38
—
nS
U10
CTS low time
38
—
nS
U11
CTS rising to TxD valid
—
20
nS
U12
RxD setup to CTS falling
10
—
nS
U13
RxD hold from CTS falling
—
5
nS
U14
TxD to RxD (remote loop back)
—
15
nS
U15
TIN1 setup to CTS falling
10
—
nS
U16
TIN1 hold from CTS falling
—
5
nS
U17
CTS rising to RTS asserted
—
20
nS
Figure 20-19 shows UART0 and UART1 timing for the values in Table 20-13.
Chapter 20. Electrical Specifications
20-19
UART Module AC Timing Specifications
CLKIN
U1
RXD
U2
U3
CTS
U4
U5
TXD
U6
U7
RTS
U8
Figure 20-19. UART0 and UART1 Module AC Timing—UART Mode
Figure 20-19 shows timing for UART1 in 8- and 16-bit CODEC mode.
20-20
MCF5407 User’s Manual
UART Module AC Timing Specifications
U9
U10
CTS/
Serial bit clock
U11
TxD
U14
U12
U13
RxD
TIN1/
Frame sync
U15
U16
Figure 20-20. UART1 in 8- and 16-bit CODEC Mode
Figure 20-21 shows timing for UART1 in AC ‘97 mode.
U9
U10
CTS/
Bit clock
U17
RTS/
Frame sync
Figure 20-21. UART1 in AC ‘97 Mode
Chapter 20. Electrical Specifications
20-21
Parallel Port (General-Purpose I/O) Timing Specifications
20.9 Parallel Port (General-Purpose I/O) Timing
Specifications
Table 20-14 lists specifications for general-purpose I/O timing parameters in Figure 20-22.
Table 20-14. General-Purpose I/O Port AC Timing Specifications
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
P1
PP valid to CLKIN (input setup)
7.5
—
nS
P2
CLKIN to PP invalid (input hold)
1.0
—
nS
P3
CLKIN to PP valid (output valid)
—
10
nS
P4
CLKIN to PP invalid (output hold)
1.0
—
nS
Figure 20-22 shows general-purpose I/O timing.
CLKIN
P1
PP IN
P2
P3
PP OUT
P4
Figure 20-22. General-Purpose I/O Timing
20-22
MCF5407 User’s Manual
DMA Timing Specifications
20.10 DMA Timing Specifications
Table 20-14 lists specifications for DMA timing parameters shown in Figure 20-22.
Table 20-15. DMA AC Timing Specifications
54 MHz CLKIN
Num
Characteristic
Units
Min
Max
M1
DREQ valid to CLKIN (input setup)
7.5
—
nS
M2
CLKIN to DREQ invalid (input hold)
1.0
—
nS
M3
CLKIN to DACK valid (output valid)
—
10
nS
M4
CLKIN to DACK invalid (output hold)
1.0
—
nS
Figure 20-23 shows DMA AC timing.
CLKIN
M1
DREQ
M4
M2
M3
DACK
Figure 20-23. DMA Timing
Chapter 20. Electrical Specifications
20-23
IEEE 1149.1 (JTAG) AC Timing Specifications
20.11 IEEE 1149.1 (JTAG) AC Timing Specifications
Table 20-16 lists specifications for JTAG AC timing parameters shown in Figure 20-24.
Table 20-16. IEEE 1149.1 (JTAG) AC Timing Specifications
Num
Characteristic
—
TCK frequency of operation
Units
Min
Max
0
10
MHz
nS
J1
TCK cycle time
100
—
J2a
TCK clock pulse high width (measured at 1.5 V)
40
—
nS
J2b
TCK clock pulse low width (measured at 1.5 V)
40
—
nS
J3a
TCK fall time (VIH = 2.4 V to VIL = 0.5V)
—
5
nS
J3b
TCK rise time (VIL = 0.5v to VIH = 2.4V)
—
5
nS
J4
TDI, TMS to TCK rising (input setup)
10
—
nS
J5
TCK rising to TDI, TMS invalid (hold)
15
—
nS
J6
Boundary scan data valid to TCK (setup)
10
—
nS
J7
TCK to boundary-scan data invalid (hold)
15
—
nS
J8
TRST pulse width (asynchronous to clock edges)
15
—
—
J9
TCK falling to TDO valid (signal from driven or
three-state)
—
30
nS
J10
TCK falling to TDO high impedance
—
30
nS
J11
TCK falling to boundary scan data valid (signal from
driven or three-state)
—
30
nS
J12
TCK falling to boundary scan data high impedance
—
30
nS
Figure 20-24 shows JTAG timing.
20-24
All
Frequencies
MCF5407 User’s Manual
IEEE 1149.1 (JTAG) AC Timing Specifications
J3a
J1
TCK
J2b
J2a
J3b
J4
TDI, TMS
J5
J6
BOUNDARY
SCAN DATA
INPUT
J7
TRST
J8
J9
TDO
J10
BOUNDARY
SCAN DATA
OUTPUT
J11
J12
Figure 20-24. IEEE 1149.1 (JTAG) AC Timing
Chapter 20. Electrical Specifications
20-25
IEEE 1149.1 (JTAG) AC Timing Specifications
20-26
MCF5407 User’s Manual
Appendix A
Migrating from the ColdFire MCF5307 to
the MCF5407
This appendix highlights the differences between the MCF5307B and MCF5407. Users of
the MCF5307 and MCF5307A should use this document in conjunction with the MCF5307
User's Manual Mask Set Addendum. For additional information, see the MCF5407
Integrated ColdFire Microprocessor Product Brief.
A.1 Overview
Customers using the integrated peripherals of the MCF5307 can access the same features
on the MCF5407 with the added advantage of increased cache and RAM memories as well
as an enhanced instruction set architecture (ISA), DMA, synchronous UART, and debug
functionality. Decreased voltage requirements allow designers to take advantage of other
low-voltage components on the board for an integrated, low-power system.
To migrate designs from the MCF5307 to the MCF5407, note the minor differences
between these code-compatible processors in the initialization code, power supplies, and
clock inputs. This document describes the differences between the processors and outlines
the steps to upgrade the design. Table A-1 is a quick reference chart of these differences.
Table A-1. Differences between MCF5307 and MCF5407
Feature
MCF5307
MCF5407
Reference
Version core
ColdFire Version 3 (V3)
ColdFire Version 4
—
MIPS
70 MIPS at 90-MHz core
clock
233 MIPS at 162-MHz core clock
—
Instruction set
Baseline ColdFire ISA Rev A
is used in Version 2 and
Version 3 core.
ColdFire ISA Rev B which includes certain
instruction enhancements and some instruction
additions; V2/V3 ISA Rev A is
upward-compatible with ISA Rev B.
Section A.2,
“Instruction Set
Additions”
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-1
Instruction Set Additions
Table A-1. Differences between MCF5307 and MCF5407
Feature
Caches
MCF5307
MCF5407
Reference
8-Kbyte unified cache
16-Kbyte instruction cache
8-Kbyte data cache
Two cache access control
registers (ACR0/ACR1)
ACR0/ACR1 configure data space;
ACR2/ACR3 configure instruction space
4-Kbyte SRAM
Two independently configurable 2-Kbyte
SRAMs
No cache locking
Ability to lock all or half of the caches to prevent
instructions or data from being cast out. This is
useful for deterministic code.
DMA acknowledge assertion
is encoded on TM[2:0].
DACK[1:0] multiplexed on TM[1:0] can be
programmed as separate DMA acknowledge
signals.
DMA TM[2:0] encodings are different from
MCF5307 DMA TM[2:0] encodings.
DMA byte count register
(BCR) can be programmed
to be 16 or 24 bits.
BCR is 24 bits only.
UART
Both UARTs have identical
functionality. No support for
synchronous mode.
UART0 is identical to the MCF5307 UARTs;
UART1 has been enhanced to provide
synchronous operation and a CODEC interface
for soft modem support.
Section A.5, “UART
Enhancements”
Timing
relationships
All signal timing with respect
to BCLKO; CLKIN rise time =
5 nS.
All signal timings with respect to CLKIN
(BCLKO support provides compatibility with
MCF5307 designs.)
Tighter negative edge bus specifications due to
duty cycle; CLKIN rise time = 2 nS.
Section A.6.1,
“Phase-Locked
Loop (PLL),” and
Section A.6, “Timing
Differences”
Reset
initialization
Need to drive D[7:0]/
AA, PS[1:0],
ADDR_CONFIG,
FREQ[1:0], DIVIDE[1:0]
Need to drive D[7:0]/AA, PS[1:0],
ADDR_CONFIG, BE_CONFIG, DIVIDE[2:0]
Section A.7, “Reset
Initialization
Modifications”
Debug
module
Debug Revision B. Separate
PST[3:0] and DDATA[3:0]
Debug Revision C—Adds breakpoint registers,
normal interrupt request service during debug,
and combines debug signals into
PSTDDATA[7:0]
Section A.8,
“Revision C Debug”
Voltage input
changes
Drives minimum 2.4 V;
accepts 5-V input
Drives minimum 2.4 V; accepts 3.3-V input
Requires 3.3-V operating
voltage
Requires 1.8-V and 3.3-V operating voltages
Section A.9,
“Voltage Input
Changes”
Standard MCF5307 pinout
Compatible with MCF5307 pinout except for
power-pad input assignment
DMA
modifications
Pin
assignment
Section A.3,
“Enhanced
Memories”
Section A.4,
“On-Chip DMA
Modifications”
Section A.11,
“Pin-Assignment
Compatibility”
A.2 Instruction Set Additions
The MCF5407 implements Revision B (Rev B) of the ColdFire instruction set, which adds
instructions and enhances existing ISA Revision A (Rev A) opcodes to support byte- and
A-2
MCF5407 User’s Manual
Enhanced Memories
word-sized operands and position-independent code. Existing MCF5307 code is
completely upward compatible with the MCF5407. However, designers may incorporate
the instruction set additions and enhancements, especially when upgrading 68K code that
references 8- and 16-bit short operands.
The following list summarizes new and enhanced instructions of Rev B ISA:
•
•
New instructions:
— INTOUCH loads instructions one cache block at a time for use with cache
locking.
— MOV3Q.L moves 3-bit immediate data to the destination location.
— MVS.{B,W} moves the sign-extended source operand to the destination register.
— MVZ.{B,W} zero-fills the source operand and moves it to the destination
register.
— SATS.L updates bit 31 of the destination register depending on the CCR
overflow bit.
— TAS.B tests and sets byte operand being addressed.
Enhancements to existing Revision A instructions:
— Longword support for branch instructions (Bcc, BRA, BSR)
— Byte and word support for compare instructions (CMP, CMPI)
— Byte and longword support for MOVE where the source is of type #<data> and
the destination is of type d16(Ax); that is, move.b #<data>, d16(Ax)
Refer to Section 2.9, “ColdFire Instruction Set Architecture Enhancements” for details of
these additions and enhancements.
A.3 Enhanced Memories
With the introduction of a Harvard memory architecture in the Version 4 core design, the
MCF5407 has separate instruction and data caches. The 16-Kbyte instruction cache and
8-Kbyte data cache greatly improve performance on existing systems. On-chip RAMs are
also provided to work with the caches. For more details see, Chapter 4, “Local Memory”.
The MCF5307 configuration contains an 8-Kbyte unified cache with a 4-Kbyte SRAM.
Configuration registers for these memories include one cache control register (CACR), two
access control registers (ACR0 and ACR1), and one RAM base address register
(RAMBAR). With the enhanced memory sizes of the MCF5407, more configuration
registers have been provided. The new MOVEC register map for the MCF5407 memory
configuration registers is given in Table A-2.
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-3
On-Chip DMA Modifications
Table A-2. MOVEC CPU Space Register Map
Rc[1:0]
1
Register Definition
0x002
Cache control register (CACR)
0x004
Cache access control register 0 (ACR0; data cache)
0x005
Cache access control register 1 (ACR1; data cache)
0x006
Cache access control register 2 (ACR2; instruction cache)
0x007
Cache access control register 3 (ACR3; instruction cache)
0xC04
RAM base address register 0 (RAMBAR0) 1
0xC05
RAM base address register 1 (RAMBAR1) 1
Either or both of the RAMBAR registers can be configured for instructions or data through
an additional bit, RAMBARn[D/I].
Note that the existing functionality has not changed; new registers and new bits in existing
registers have been added to support the enhanced memories and control for the new branch
cache. One of the two 2-Kbyte SRAMs can be dedicated to support the instruction cache,
and the other can support the data cache. Many designs use one SRAM block as a system
stack and the other to hold important interrupt service routines.
The SRAM can also function as a ROM by programming it as a data block while loading
configuration information to it and then reprogramming it as a read-only instruction block.
The two MCF5407 SRAM blocks can be programmed to provide a contiguous 4-Kbyte
memory map similar to the MCF5307’s single contiguous 4-Kbyte SRAM.
A.4 On-Chip DMA Modifications
The MCF5407 integrates the four-channel DMA used in the MCF5307 with changes to pin
multiplexing, DMA byte transfer count, and the encoding of transfer acknowledgement.
The MCF5307 provides DMA acknowledgement encodings for channels 0 and 1 through
the transfer modifier pins, TM[2:1], which are multiplexed with PP[4:3]. For clarification
on MCF5307 signal multiplexing, see the pinout tables in the mechanical specifications
chapter of the MCF5307 User’s Manual. The MCF5307 also indicates a DMA single
address access through transfer modifier pin TM0, multiplexed with PP2. For more details
see, Chapter 12, “DMA Controller Module”.
When the pin assignment register (PAR) is programmed to enable the TM signals, the
encodings listed in Table A-3 and Table A-4 are driven during transfers by the internal
DMA channels of the MCF5307. The condition TT[1:0] = 01 indicates an access by either
an internal DMA or an external device.
Table A-3. TM[2:1] Encoding for MCF5307 Internal DMA as Master (TT = 01)
TM[2:1]
A-4
Transfer Modifier Encoding
00
DMA acknowledges negated
01
DMA acknowledge, channel 0
MCF5407 User’s Manual
UART Enhancements
Table A-3. TM[2:1] Encoding for MCF5307 Internal DMA as Master (TT = 01) (ConTM[2:1]
Transfer Modifier Encoding
10
DMA acknowledge, channel 1
11
Reserved
Table A-4. TM0 Encoding for MCF5307 Internal DMA as Master (TT = 01)
TM0
Transfer Modifier Encoding
0
Dual address access
1
Single address access
Although the MCF5407 provides similar encodings on TM[2:0], dedicated DMA
acknowledgement pins (DACK[1:0]) have been added. Thus, DACK[1:0] are now
combined with PP[3:2]/TM[1:0], resulting in a three-to-one multiplexed signal,
PP[3:2]/TM[1:0]/DACK[1:0]. TM2 is still multiplexed only with PP4. For further
clarification on the multiplexing, see the pinout tables in Section A.11, “Pin-Assignment
Compatibility.” When properly connected, TM[2:0] can be used in MCF5407 designs as on
MCF5307 designs or DACK[1:0] can be used for DMA transfers, as shown in Figure A-1.
MCF5307 Function
Pin
Pin
MCF5407 Function
Single/dual cycle access
TM0
TM0
DMA 0 acknowledge
DMA 0 acknowledge configuration
TM1
TM1
DMA 1 acknowledge
DMA 1 acknowledge configuration
TM2
TM2
Single/dual cycle access
Figure A-1. MCF5307 to MCF5407 TM[2:0] Pin Remapping
For further details see Section 12.2, “DMA Signal Description”.
Although TM[2:0] can still drive DMA access encoding, the bit positions of these
encodings are different from the MCF5307. The MCF5407 encodes single-address
accesses on TM2 when the PAR is set to enable the transfer modifier signal and an external
master or DMA transfer is occurring. This encoding is driven by TM0 on the MCF5307.
Again, more details can be found in Section 12.2, “DMA Signal Description”.
Designers who use MCF5307 DMA channels should also note that the MCF5407 DMA
byte count registers (BCRs) for channels 0–3 exclusively support a 24-bit byte count. A
16-bit byte count register is no longer supported; therefore, MPARK[BCR24BIT] has been
removed.
A.5 UART Enhancements
The MCF5407 contains two UARTs that act independently. One of the UARTs on the
MCF5407 has been enhanced to provide synchronous operation and a CODEC interface for
soft modem support. Each UART can be clocked by the system bus clock, eliminating the
need for an external crystal. For more details see, Chapter 14, “UART Modules”.
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-5
Timing Differences
The UART module interfaces directly to the CPU as shown in Figure A-2. The UART
module consists of the following major functional areas:
•
•
•
•
Serial communication channel
16-bit timer for baud-rate generation
Internal channel control logic
Interrupt control logic
UART
Internal Channel
Control Logic
CTS
Serial
Communications
Channel
RTS
RxD
TxD
System Integration
Module (SIM)
Interrupt
Controller
Interrupt Control
Logic
16-Bit Timer for
Baud-Rate
Generation
CLKIN
or
External clock (TIN)
Figure A-2. Simplified Block Diagram
In addition, UART1 has been enhanced to provide a CODEC interface for soft modem
support. UART1 can be programmed to provide any one of the following functions:
•
•
The original UART (identical to UART0)
Three modem modes, (see Section 14.5.2.2, “Transmitter in Modem Mode
(UART1) for more details)”:
— An 8-bit CODEC interface
— A 16-bit CODEC interface
— An audio CODEC 97 (AC97) digital interface controller
A.6 Timing Differences
This section explains timing relationships within phase-locked loop registers.
A.6.1 Phase-Locked Loop (PLL)
The PLL for the MCF5407 is enhanced to support faster processor clock (PCLK)
frequencies. The MCF5307 supports PCLK frequencies of 66.7 and 90 MHz with a clock
input (CLKIN) of 1/2 PCLK. The MCF5407 offers a larger range of clock input ratios and
a higher performance processor clock. For more details see Section 7.1.1, “PLL:PCLK
Ratios” and Chapter 20, “Electrical Specifications”.
The MCF5407 PLL module is shown in Figure A-3.
A-6
MCF5407 User’s Manual
Timing Differences
CLKIN (to on-chip peripherals)
BCLKO
PCLK (to core)
CLKIN
DIVIDE[2:0]
Debug Module
÷2
PLL
RSTI
RSTO
Figure A-3. PLL Module
PSTCLK
(= PCLK/2)
Similar to the MCF5307 functionality, the MCF5407 samples clock ratio encodings on the
lower data bits of the bus at reset to determine the CLKIN-to-PCLK ratio at which the
device runs. These bits are DIVIDE[1:0] on the MCF5307 and are multiplexed with data
bits D[1:0]. Because the MCF5407 offers more divide ratio combinations than the
MCF5307, three input bits, D[2:0]/DIVIDE[2:0], have been provided to offer more
programming options at reset. Also, note that only specific CLKIN ranges are allowed for
each divide ratio on the MCF5407.
Table A-5 shows the new encodings. Note that they differ from the MCF5307 DIVIDE[1:0]
encodings.
Table A-5. Divide Ratio Encodings
D[2:0]/DIVIDE[2:0]
Multiplier
00x–010
Reserved
011
3
100
4
101
5
110
6
111
Reserved
A.6.2 Timing Relationships
For both the MCF5307 and MCF5407, the user provides the clock input signal (CLKIN),
which is also used for on-chip peripherals, as shown in Figure A-3. This signal is also the
reference from which other clock frequencies are derived, including the bus clock output
signal (BCLKO), which on the MCF5407 is provided for compatibility with MCF5307
designs. BCLKO is generated by the PLL and MCF5307 designs should use BCLKO as the
bus timing reference for external devices; MCF5407 designs should use CLKIN. On the
MCF5407, the CLKIN frequency can be 1/3, 1/4, 1/5, or 1/6 of the PCLK. Furthermore,
depending on the MCF5307 configuration, the BCLKO-to-PCLK ratio may not be the same
as the CLKIN-to-PCLK ratio. For more details see Section 20.2, “Clock Timing
Specifications”.
On the MCF5407, the user-provided CLKIN should be used as the bus clock for the system.
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-7
Reset Initialization Modifications
BCLKO runs at the same frequency as CLKIN and is offered as an optional timing
reference for backwards compatibility for lower-speed MCF5307 designs.
Regardless of the CLKIN frequency driven at power-up, CLKIN and BCLKO have the
same ratio value to PCLK. Although designers can use either BCLKO or CLKIN as a clock
reference, Motorola recommends using CLKIN because it leaves more room to meet bus
specifications than BCLKO, which is generated as a phase-aligned signal to CLKIN. An
MCF5307 user should consider switching to a CLKIN reference clock when upgrading to
the MCF5407 if board frequencies exceed 50 MHz.
Although the CLKIN duty cycle remains the same for the MCF5307 and MCF5407, use
caution when interfacing signals on the falling edge of CLKIN with only a 4-nS window at
high frequencies. Also, note that the MCF5407 input rise time is reduced to 2 nS (5 nS in
the MCF5307). For designers who choose to reference signals from CLKIN only, BCLKO
can be disabled to save power. For details see Section 7.2.3, “Reduced-Power Mode”.
A.7 Reset Initialization Modifications
Like the MCF5307, the MCF5407 samples a group of eight input signals, D[7:0], on the
rising edge of CLKIN before the rising edge of RSTI to determine the reset configuration
of the global chip select, the address bus, and PLL. However, unlike the MCF5307, the
frequency range encodings are not sampled on D[3:2], which are replaced by two other
reset configuration inputs. First, the CLKIN-to-PCLK ratio allows more combinations.
This extra bit is now sampled on D2 so that the clock ratio programming bits encompass
D[2:0]/DIVIDE[2:0].
Second, a new reset configuration bit, BE_CONFIG, is now multiplexed with D3 in the
MCF5407. This bit enables the four byte enables for the global chip select, CS0, for reads
and writes or writes only, depending on the bit value sampled at reset, as shown in
Table A-10.
Table A-6 shows the multiplexing of D[7:0] for the MCF5307 and the MCF5407.
Table A-6. D[7:0] Multiplexing
Data Pins
MCF5307
MCF5407
D7
AA
D[6:5]
PS[1:0]
D4
ADDR_CONFIG
D3
FREQ1
BE_CONFIG, BE[3:0]
D2
FREQ0
DIVIDE2
D1
DIVIDE1
D0
DIVIDE0
Table A-7 through Table A-10 list the various reset encodings for the configuration signals
A-8
MCF5407 User’s Manual
Reset Initialization Modifications
multiplexed with D[7:3]. See for D[2:0]/DIVIDE[2:0] encodings sampled at reset. Note
that Table A-7 and Table A-8 configure the global, or boot, CS0 that is used to access boot
ROM out of reset. CS0 is the only chip select active out of reset until other chip selects
become valid. Both the wait states and port size of boot memory accessed by boot CS0 are
programmed through these bits.
Table A-7. D7/AA, Automatic Acknowledge of Boot CS0
D7/AA
Boot CS0 AA Configuration at Reset
0
Disabled
1
Enabled with 15 wait states
Table A-8 shows configurations for D[6:5]/PS[1:0].
Table A-8. D[6:5]/PS[1:0], Port Size of Boot CS0
D[6:5]/PS[1:0]
Boot CS0 Port Size at Reset
00
32-bit port
01
8-bit port
1x
16-bit port
Table A-9 initializes the pin assignment register of the parallel I/O port to be either parallel
I/O or to be the upper address bus bits along with various attribute and control signals at
reset to give the user the option to access a broader addressing range of memory, if desired.
Table A-9. D4/ADDR_CONFIG, Address Pin Assignment
D4/ADDR_CONFIG
Configuration Pin Assignment Register at Reset
0
PP[15:0], defaulted to inputs upon reset
1
ADDR[31:24]/TIP/DREQ[1:0]/TM[2:1]
Table A-10 shows configurations for D3/BE_CONFIG. Because some boot memories
require byte enables to be active only during writes, the functionality of byte enables,
BE[3:0], can be programmed at reset.
Table A-10. D3/BE_CONFIG, BE[3:0] Boot Configuration
D3/BE_CONFIG
Configuration of Byte Enables for Boot CS0
0
BE[3:0] are enabled as byte write enables only
1
BE[3:0] are enabled as byte enables for reads and writes
D[2:0]/DIVIDE[2:0] configurations are shown in Table A-5.
After RSTI is negated, 32 bits of CPU configuration information are loaded into data
register D0 and 32 bits of internal memory information are loaded in D1. Because these
registers are completely uninitialized on previous ColdFire devices, this feature allows
users to identify the MCF5407 through software. Values D1 = 0x0630_0530 and D0 =
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-9
Revision C Debug
0xCF4x_C012 identify the MCF5407, where x identifies the core revision number (0x1 for
the initial device).
A.8 Revision C Debug
A number of enhancements to the original ColdFire debug functions were requested by
customers and third-party tool developers. As a result, an expanded set of debug functions
was implemented in the Version 4 ColdFire and named Revision C, or simply Debug C.
Most of the enhancements are included in the MCF5407 debug module and are primarily
related to improvements in the real-time debug capabilities.
A.8.1 Debug Interrupts and Interrupt Requests
in Emulator Mode
In the Debug B ColdFire implementation of the MCF5307, the response to a user-defined
breakpoint trigger can be configured as one of three possibilities:
•
•
•
The breakpoint trigger can be displayed on the PSTDDATA bus with no internal
reaction to the trigger. The trigger state information is displayed on PSTDDATA in
all situations.
The breakpoint trigger can force the processor to halt and allow BDM activities.
The breakpoint trigger can generate a special debug interrupt to allow real-time
systems to quickly process the interrupt and return to normal system executing as
rapidly as possible.
The occurrence of a debug interrupt exception is treated as a special type of interrupt. It is
considered to be higher in priority than all normal interrupt requests and has special
processor status values to indicate externally that this interrupt occurred.
Additionally, the execution of the debug interrupt service routine is forced to be
interrupt-inhibited by the processor hardware. Optionally, it is capable of mapping all
instruction and data references while in this service routine into a separate address space,
so that an emulator can define the routine dynamically.
Current processor implementations include a state bit, invisible to software, that defines this
emulator mode of operation. Note that the interrupt mask level is not modified during the
processing of a debug interrupt.
In response to customers with real-time embedded systems asking for the ability to service
normal interrupt requests while processing the debug interrupt service routine, this feature
has been incorporated in the Revision C debug. To provide this function and service any
number of normal interrupt requests, including the possibility of nested interrupts, the
processor state signaling emulator mode is now included as part of the exception stack
A-10
MCF5407 User’s Manual
Revision C Debug
frame, shown in Figure A-4.
31
A7→
+ 0x04
28
Format
27
26
FS[3–2]
25
18
Vector[7–0]
17
16
15
FS[1–0]
0
Status Register
Program counter[31:0]
Figure A-4. Exception Stack Frame Form
As part of the Debug C enhancement, the operation of the debug interrupt is modified as
follows:
•
•
•
1.
2.
3.
4.
The occurrence of the breakpoint trigger, configured to generate a debug interrupt,
is treated exactly as before. The debug interrupt is treated as a higher priority
exception relative to the normal interrupt requests encoded on the interrupt priority
input signals.
At the appropriate sample point, the processor initiates debug interrupt exception
processing. This event is signaled externally by the generation of a unique PST value
(PST = 0xD) asserted for multiple cycles. The processor sets the emulator mode
state bit as part of this processing.
All normal interrupt requests are evaluated and sampled once per instruction during
the debug interrupt service routine. If an exception is detected, the processor takes
the following steps:
In response to the new exception, the processor saves a copy of the current value of
the emulator mode state bit and then exits emulator mode by clearing the actual
state.
The new exception stack frame sets bit 1 of the fault status field, using the saved
emulator mode bit, indicating that execution while the processor is in emulator mode
was interrupted. This corresponds to bit [17] of the longword at the top of the system
stack.
Control is passed to the appropriate exception handler.
When the exception handler is complete, a Return From Exception (RTE)
instruction is executed. During the processing of the RTE, the FS1 bit is reloaded
from the system stack. If FS1 = 1, the processor sets the emulator mode state and
resumes execution of the original debug interrupt service routine. This is signaled
externally by the generation of the PST value that originally identified the
occurrence of a debug interrupt exception, that is, PST = 0xD.
Implementation of this revised debug interrupt handling fully supports the servicing of any
number of normal interrupt requests while in a debug interrupt service routine. The
emulator mode state bit is essentially changed to a program-visible value, stored into
memory when the exception stack frame is created, and loaded from memory by the RTE
instruction.
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-11
Revision C Debug
A.8.2 On-Chip Breakpoint Registers
The Debug B core debug module included three basic types of on-chip breakpoint registers:
•
•
•
A 32-bit PC breakpoint register and a 32-bit PC breakpoint mask
Two 32-bit address registers, which can be used to specify a single address or a range
of addresses
A 32-bit data breakpoint register and a 32-bit data breakpoint mask
The mask registers can be used to “don’t care” the equivalent bits in the breakpoint
registers.
Additions to the breakpoint implementation are as follows:
•
•
•
Three more 32-bit PC breakpoint registers
Two more 32-bit address registers (ABLR1, ABHR1) plus an attribute register
(AATR1) and mask register, which can be used to specify a single address or a range
of addresses
One more 32-bit data breakpoint register and a 32-bit data breakpoint mask
The addition of these new breakpoint registers also requires the appropriate control and
configuration functions be added to the debug programming model. The affected BDM
command and new register formats are described below. The revised BDM command is
write debug module register (WDMREG).
A.8.2.1 Write Debug Module Register (WDMREG)
The operand (longword) data is written to the specified debug module register. All 32 bits
of the register are altered by the write operation. The debug module’s programming model
can be accessed either from the serial BDM communication channel or from the processor’s
execution of the supervisor-mode WDEBUG instruction. DSCLK must be inactive while
WDEBUG executes.
Figure A-5 defines the operand data format.
15
14
13
0x2
12
11
10
9
8
7
0xC
6
0x4
5
4
3
2
DRc
D[31:16]
D[15:0]
Figure A-5. Write Debug Module Register Command (WDMREG)
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MCF5407 User’s Manual
1
0
Revision C Debug
Table A-11 describes the DRc encoding for the debug registers.
Table A-11. Definition of DRc Encoding—Write
DRc (hex)
0x00
0x01–0x04
Debug Register Definition
Abbreviation
Initial State (hex)
CSR
0x0000
Configuration/Status
—
—
0x05
BDM address attributes
BAAR
0x0005
0x06
Bus attributes and mask
AATR
0x0005
0x07
Trigger definition
TDR
0x0000
0x08
PC breakpoint
PBR
—
0x09
PC breakpoint mask
0x0A–0x0B
Reserved
PBMR
—
—
—
Reserved
0x0C
Operand address high breakpoint
ABHR
—
0x0D
Operand address low breakpoint
ABLR
—
0x0E
Data breakpoint
DBR
—
0x0F
Data breakpoint mask
0x10–0x15
DBMR
—
—
—
Reserved
0x16
Bus attributes and mask 1
AATR1
0x0005
0x17
Extended trigger definition
XTDR
0x0000
0x18
PC breakpoint 1
PBR1
0x0000
0x19
Reserved
0x1A
PC breakpoint 2
—
—
PBR2
0x0000
PBR3
0x0000
0x1B
PC breakpoint 3
0x1C
Operand address high breakpoint 1
ABHR1
—
0x1D
Operand address low breakpoint 1
ABLR1
—
0x1E
Data breakpoint 1
DBR1
—
0x1F
Data breakpoint mask 1
DBMR1
—
Command Sequence:
WDMREG
???
MS DATA
"NOT READY"
LS DATA
"NOT READY"
XXX
"ILLEGAL"
NEXT CMD
"NOT READY"
NEXT CMD
"CMD COMPLETE"
Figure A-6. WDMREG Command Sequence
Operand Data:
Longword data is written into the specified debug register. Data is supplied most
significant word first.
Result Data:
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-13
Revision C Debug
Command complete status (0x0FFFF) is returned when register write is complete.
A.8.3 Debug Programming Model
In addition to existing BDM commands that provide access to the processor’s registers and
the memory subsystem, the debug module contains a number of registers to support the
required functionality. These registers are treated as 32-bit quantities, regardless of the
number of bits in the implementation. The debug control registers (DRc) are addressed
using a 5-bit value as part of two new BDM commands (WDREG and RDREG). These values
are shown in Table A-11.
These registers are also accessible from the processor’s supervisor programming model
through the execution of the WDEBUG instruction. Thus, the breakpoint hardware within
the debug module can be accessed by the external development system using the serial
interface or by the operating system running on the processor core. It is the software’s
responsibility to guarantee that all accesses to these resources are serialized and are
logically consistent. The hardware provides a locking mechanism in the CSR to allow the
external development system to disable any attempted writes by the processor to the
breakpoint registers (setting IPW).
The following sections describe the newly added breakpoint registers in Debug C.
A.8.3.1 Address Breakpoint 1 Registers (ABLR1, ABHR1)
The 32-bit address breakpoint 1 registers define an upper (ABHR1) and a lower (ABLR1)
boundary for a region in the operand logical address space of the processor that can be used
as part of the trigger. The ABLR1 and ABHR1 values are compared with the ColdFire CPU
core address signals, as defined by the setting of the trigger definition register (TDR) and
the extended trigger definition register (XTDR).
A.8.3.2 Address Attribute Breakpoint Register 1 (AATR1)
The address attribute breakpoint register 1 (AATR1) defines the address attributes and a
mask associated with ABLR1 and ABHR1 to be matched in the trigger. The AATR1 value
is compared with the ColdFire CPU core address attribute signals, as defined by the setting
of the TDR and XTDR. The format of the AATR1 is the same as the AATR register. For
more details about these registers see Section 5.4.1, “Address Attribute Trigger Registers
(AATR, AATR1)”.
A.8.3.3 Program Counter Breakpoint Registers 1–3 (PBR1–PBR3)
Each of the program counter (PC) breakpoint registers (PBR, PBR1–PBR3) defines an
instruction address that can be used as part of the trigger. PBRn registers are compared with
the processor’s program counter register when the appropriate valid bit is asserted and TDR
is configured appropriately. For more details about these registers see Section 5.4.6,
“Program Counter Breakpoint/Mask Registers (PBR, PBR1, PBR2, PBR3, PBMR)”.
A-14
MCF5407 User’s Manual
Revision C Debug
The results of all PC breakpoint registers, PBR/PBMR, PBR1, PBR2, and PBR3, are
logically summed to form a single PC breakpoint trigger signal.
•
•
PBRn[31:1] = program counter breakpoint address
PBRn[0] = valid bit
A.8.3.4 Data Breakpoint Register 1 (DBR1, DBMR1)
The data breakpoint register 1 (DBR1) defines a specific data pattern that can be used as
part of a trigger. The DBR1 value is masked by DBMR1, allowing only those bits in DBR1
that have a corresponding zero in DBMR1 to be compared with the ColdFire CPU core data
signals, as defined in the TDR and the XTDR.
The data breakpoint registers support both aligned and misaligned operand references. The
relationship between the processor core address, the access size, and the corresponding
location within the 32-bit core data bus is defined in the DBR and DBMR description.
A.8.3.5 Extended Trigger Definition Register (XTDR)
The XTDR enables the operation as defined by the new breakpoint registers, ABHR1,
ABLR1, AATR1, DBR1, and DBMR1, within the debug module and operates in
conjunction with the trigger definition register (TDR). The added breakpoint logic can be
included as a one- or two-level trigger; XTDR[29–18] define second-level triggers and
XTDR[13–2] define first-level triggers. The definition of the XTDR register is exactly the
same as the TDR for the control of the ABHR1, ABLR1, DBR1 and DBMR1 breakpoint
registers. The XTDR is cleared on reset. For more details about this register see
Section 5.4.8, “Extended Trigger Definition Register (XTDR)”.
A.8.4 Debug Interrupt Exception Vectors
In the Debug B revision, if the occurrence of a hardware breakpoint is configured to
generate a debug interrupt, this exception is mapped to vector number 12 (0x030). The
actual debug interrupts can be broadly classified into two groups—PC breakpoints and all
other types. A PC breakpoint is treated in a precise manner—exception recognition and
processing are initiated before the instruction at the given address is executed. Conversely,
all other breakpoint events are recognized on the given internal bus transaction, but are
made pending to the processor and sampled like other interrupt conditions. As a result,
these types of interrupts are imprecise by nature.
In response to a customer request that PC breakpoints be distinguishable from other type
of trigger events, the debug interrupt exception vector is expanded in Debug C of the
MCF5407 to two unique entries, shown in Table A-12, where the occurrence of a PC
breakpoint generates the 0x034 vector. In the case of a two-level trigger, the last breakpoint
event determines the exception vector.
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-15
Revision C Debug
Table A-12. Debug C Exception Vector Assignments
Vector
Vector Offset
Stacked Program Counter
Assignment
12
0x030
Next
Non-PC-breakpoint debug interrupt
13
0x034
Next
PC-breakpoint debug Interrupt
A.8.5 Processor Status and Debug Data Output Signals
The Debug B architecture defines processor status, PST[3:0] and debug data DDATA[3:0]
signals, which provide information to support real-time trace. In the Debug B design, these
signals are output at the processor frequency.
For the Debug C definition, however, the PST and DDATA are combined and redefined to
operate at half the processor’s operating frequency (provided by PSTCLK). Therefore,
PSTDDATA[7:0] are used to output both processor status and captured debug data values.
For more details, including single-cycle instruction timing examples, see Section 5.2.1,
“Processor Status/Debug Data (PSTDDATA[7:0]).”
A PST marker and its data display are transmitted contiguously. Except for this
transmission, the IDLE status (0x0) may appear any time. Again, given the real-time trace
information appears as a sequence of 4-bit values, there are no alignment restrictions. That
is, PST values and operands may appear on either nibble of PSTDDATA.
In Debug B, the DDATA outputs display the status of the internal breakpoint registers when
they are not displaying captured data values. For the Debug C design, any change to this
breakpoint state is identified by a PST marker and then the new state value. Specifically, the
marker for this breakpoint state change is a single assertion of the value 0xD. Usually, the
0xD status is asserted for multiple cycles, indicating entry into emulator mode in response
to a debug interrupt exception. For Debug C, the posting of the 0xD status can signal
multiple events, based on the next value.
if the PSTDDATA stream includes {0xD, 0x2}
then Breakpoint state changed to Waiting for Level 1 Trigger
if the PSTDDATA stream includes {0xD, 0x4}
then Breakpoint state changed to Level 1 Breakpoint Triggered
if the PSTDDATA stream includes {0xD, 0xA}
then Breakpoint state changed to Waiting for Level 2 Trigger
if the PSTDDATA stream includes {0xD, 0xC}
then Breakpoint state changed to Level 2 Breakpoint Triggered
if the PSTDDATA stream includes {0xD, 0xD}
then Entry into Emulator Mode
Table A-13 shows the revised definition of the processor status encodings, where the values
of {0xC–0xF} are usually asserted for multiple cycles. The behavior of the 0xD value was
described previously. The PSTDDATA values of 0x2 and 0x6 are formerly reserved values
now needed to support the Version 4 operand execution pipeline.
A-16
MCF5407 User’s Manual
Voltage Input Changes
Table A-13. Version 4 Debug C Processor Status Encodings
PSTDDATA Value
Definition
0x0
Continue execution
0x1
Begin execution of one instruction
0x2
Begin execution of two instructions
0x3
Entry into user-mode
0x4
Begin execution of PULSE or WDDATA instruction
0x5
Begin execution of taken branch
0x6
Begin execution of an instruction plus a taken branch
0x7
Begin execution of RTE instruction
0x8
Begin 1-byte data transfer on PSTDDATA
0x9
Begin 2-byte data transfer on PSTDDATA
0xA
Begin 3-byte data transfer on PSTDDATA
0xB
Begin 4-byte data transfer on PSTDDATA
0xC
Exception processing
0xD
Breakpoint state change, or entry into emulator mode
0xE
Processor is stopped, waiting for interrupt
0xF
Processor is halted
A.8.6 Debug C Summary
The preceding section describes additional functionality requested by ColdFire customers
and third-party developers. The Debug C enhancements are designed to retain backward
compatibility with the previous definition.
A.9 Voltage Input Changes
Although the MCF5407 logic operates at 1.8 V, the device pads are standard
TTL-compatible and therefore can drive a 2.4-V minimum output and accepts a 3.3-V
input. Thus, the MCF5407 requires both 1.8- and 3.3-V power supplies. This specification
differs from the MCF5307, which operates at 3.3 V with 5-V-tolerant I/O pads. Although
the power and ground pin assignment are the same for both the MCF5307 and MCF5407,
the power pin allocation of the MCF5407 is divided between 1.8- and 3.3-V supply levels.
Thus, two power rails are necessary to supply power to the MCF5407.
Note that the MCF5407 meets the EIA/JEDEC standard for 1.8-V power supply voltage
and interface requirements. See the JEDEC standard (EIA/JESD8-7, February 1997).
A.10 PLL Power Supply Filter Circuit
To ensure PLL stability, the power supply to the PLL power pin should be filtered using a
Appendix A. Migrating from the ColdFire MCF5307 to the MCF5407
A-17
Pin-Assignment Compatibility
circuit similar to the one shown in Figure A-7. The circuit should be as close as possible to
the PLL power pin to ensure maximum noise filtering. This filter design can be used for
both the MCF5307 and MCF5407.
.
Vdd
10 Ω
PLL power pin
10 µF
0.1 µF
Figure A-7. PLL Power Supply Filter Circuit
A.11 Pin-Assignment Compatibility
The MCF5407 pinout is identical to the MCF5307 except for the power pin allocation and
PSTDDATA[7:0], which make available the contents of processor status, PST[3:0], and
debug data, DDATA[3:0]. Therefore, when designing-in the MCF5407, note which power
pins require 1.8 V and which require 3.3 V. The MCF5407 footprint is the same as the
MCF5307, which is a 208-pin plastic quad flat pack (QFP).
A-18
MCF5407 User’s Manual
Appendix B
List of Memory Maps
Table B-1. SIM Registers
MBAR
Offset
0x000
0x004
[31:24]
[23:16]
[15:8]
[7:0]
Reset status register
(RSR) [p. 6-5]
System protection
control register
(SYPCR) [p. 6-8]
Software watchdog
interrupt vector register
(SWIVR) [p. 6-9]
Software watchdog
service register (SWSR)
[p. 6-9]
Interrupt port
assignment register
(IRQPAR) [p. 9-7]
Reserved
Pin assignment register (PAR) [p. 6-10]
0x008
PLL control (PLLCR)
[p. 7-3]
Reserved
0x00C
Default bus master park
register (MPARK)
[p. 6-11]
Reserved
0x010–
0x03C
Reserved
Table B-2. Interrupt Controller Registers
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
Interrupt Registers [p. 9-3]
0x040
Interrupt pending register (IPR) [p. 9-6]
0x044
Interrupt mask register (IMR) [p. 9-6]
0x048
Reserved
Autovector register
(AVR) [p. 9-5]
Interrupt Control Registers (ICRs) [p. 9-3]
0x04C
Software watchdog
timer (ICR0) [p. 6-6]
Timer0 (ICR1) [p. 9-2]
Timer1 (ICR2) [p. 9-3]
I2C (ICR3) [p. 9-3]
0x050
UART0 (ICR4) [p. 9-3]
UART1 (ICR5) [p. 9-3]
DMA0 (ICR6) [p. 9-3]
DMA1 (ICR7) [p. 9-3]
0x054
DMA2 (ICR8) [p. 9-3]
DMA3 (ICR9) [p. 9-3]
Appendix B. List of Memory Maps
Reserved
B-1
Table B-3. Chip-Select Registers
MBAR
Offset
0x080
0x084
[31:24]
[23:16]
[15:8]
[7:0]
Reserved1
Chip-select address register—bank 0 (CSAR0)
[p. 10-6]
Chip-select mask register—bank 0 (CSMR0) [p. 10-7]
0x088
Reserved1
Chip-select control register—bank 0 (CSCR0)
[p. 10-8]
0x08C
Chip-select address register—bank 1 (CSAR1)
[p. 10-6]
Reserved1
0x090
Chip-select mask register—bank 1 (CSMR1) [p. 10-7]
0x094
Reserved1
Chip-select control register—bank 1 (CSCR1)
[p. 10-8]
0x098
Chip-select address register—bank 2 (CSAR2)
[p. 10-6]
Reserved1
0x09C
Chip-select mask register—bank 2 (CSMR2) [p. 10-7]
0x0A0
Reserved1
Chip-select control register—bank 2 (CSCR2)
[p. 10-8
0x0A4
Chip-select address register—bank 3 (CSAR3)
[p. 10-6]
Reserved1
0x0A8
Chip-select mask register—bank 3 (CSMR3) [p. 10-7]
0x0AC
Reserved1
Chip-select control register—bank 3 (CSCR3)
[p. 10-8]
0x0B0
Chip-select address register—bank 4 (CSAR4)
[p. 10-6]
Reserved1
0x0B4
Chip-select mask register—bank 4 (CSMR4) [p. 10-7]
0x0B8
Reserved1
Chip-select control register—bank 4 (CSCR4)
[p. 10-8]
0x0BC
Chip-select address register—bank 5 (CSAR5)
[p. 10-6]
Reserved1
0x0C0
Chip-select mask register—bank 5 (CSMR5) [p. 10-7]
0x0C4
Reserved
Chip-select control register—bank 5 (CSCR5)
[p. 10-8]
0x0C8
Chip-select address register—bank 6 (CSAR6)
[p. 10-6]
Reserved1
0x0CC
Chip-select mask register—bank 6 (CSMR6) [p. 10-7]
0x0D0
Reserved1
Chip-select control register—bank 6 (CSCR6)
[p. 10-8]
0x0D4
Chip-select address register—bank 7 (CSAR7)
[p. 10-6]
Reserved1
0x0D8
0x0DC
B-2
Chip-select mask register—bank 7 (CSMR7) [p. 10-7]
Reserved1
Chip-select control register—bank 7 (CSCR7)
[p. 10-8
MCF5407 User’s Manual
Table B-3. Chip-Select Registers (Continued)
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x080
0x084
Chip-select mask register—bank 0 (CSMR0) [p. 10-7]
0x088
Reserved1
Chip-select control register—bank 0 (CSCR0)
[p. 10-8]
0x08C
Chip-select address register—bank 1 (CSAR1)
[p. 10-6]
Reserved1
0x090
Chip-select mask register—bank 1 (CSMR1) [p. 10-7]
0x094
Reserved1
Chip-select control register—bank 1 (CSCR1)
[p. 10-8]
0x098
Chip-select address register—bank 2 (CSAR2)
[p. 10-6]
Reserved1
0x09C
Chip-select mask register—bank 2 (CSMR2) [p. 10-7]
0x0A0
Reserved1
Chip-select control register—bank 2 (CSCR2)
[p. 10-8]
0x0A4
Chip-select address register—bank 3 (CSAR3)
[p. 10-6]
Reserved1
0x0A8
Chip-select mask register—bank 3 (CSMR3) [p. 10-7]
0x0AC
Reserved1
Chip-select control register—bank 3 (CSCR3)
[p. 10-8]
0x0B0
Chip-select address register—bank 4 (CSAR4)
[p. 10-6]
Reserved1
0x0B4
Chip-select mask register—bank 4 (CSMR4) [p. 10-7]
Reserved1
0x0B8
1
Reserved1
Chip-select address register—bank 0 (CSAR0)
[p. 10-6]
Chip-select control register—bank 4 (CSCR4)
[p. 10-8]
Addresses not assigned to a register and undefined register bits are reserved for expansion. Write accesses to
these reserved address spaces and reserved register bits have no effect.
Table B-4. DRAM Controller Registers
MBAR
Offset
0x100
[31:24]
[23:16]
[15:8]
DRAM control register (DCR) [p. 11-3]
[7:0]
Reserved
0x104
Reserved
0x108
DRAM address and control register 0 (DACR0) [p. 11-3]
0x10C
DRAM mask register block 0 (DMR0) [p. 11-3]
0x110
DRAM address and control register 1 (DACR1) [p. 11-3]
0x114
DRAM mask register block 1 (DMR1) [p. 11-3]
Appendix B. List of Memory Maps
B-3
Table B-5. General-Purpose Timer Registers
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x140
Timer 0 mode register (TMR0) [p. 13-3]
0x144
Timer 0 reference register (TRR0) [p. 13-4]
Reserved
0x148
Timer 0 capture register (TCR0) [p. 13-4]
Reserved
0x14C
0x150
Reserved
Timer 0 counter (TCN0) [p. 13-5]
Reserved
Reserved
Timer 0 event register
(TER0) [p. 13-5]
Reserved
0x180
Timer 1 mode register (TMR1) [p. 13-3]
0x184
Timer 1 reference register (TRR1) [p. 13-4]
Reserved
0x188
Timer 1 capture register (TCR1) [p. 13-4]
Reserved
0x18C
0x190
Reserved
Timer 1 counter (TCN1) [p. 13-5]
Reserved
Reserved
Timer 1 event register
(TER1) [p. 13-5]
Reserved
Table B-6. UART0 Control Registers
MBAR
Offset
[31:24]
[23:16]
UART0 Control Registers
0x1C0
UART mode
registers1—(UMR1n)
[p. 14-5], (UMR2n)
[p. 14-7]
—
0x1C4
(Read) UART status
registers—(USRn)
[p. 14-10]
—
(Write) UART
clock-select
register1—(UCSRn)
[p. 14-12]
—
(Read) Do not access2
—
0x1C8
(Write) UART command —
registers—(UCRn)
[p. 14-13]
0x1CC
(Read) UART receiver
buffers—(URBn)
[p. 14-15]
—
(Write) UART transmitter —
buffers—(UTBn)
[p. 14-16]
B-4
MCF5407 User’s Manual
[15:8]
[7:0]
Table B-6. UART0 Control Registers (Continued)
MBAR
Offset
[31:24]
[23:16]
(Read) UART input port
change
registers—(UIPCRn)
[p. 14-17]
—
(Write) UART auxiliary
control
registers1—(UACRn)
[p. 14-17]
—
(Read) UART interrupt
status
registers—(UISRn)
[p. 14-18]
—
(Write) UART interrupt
mask
registers—(UIMRn)
[p. 14-18]
—
0x1D8
UART divider upper
registers—(UDUn)
[p. 14-19]
—
0x1DC
UART divider lower
registers—(UDLn)
[p. 14-19]
—
0x1E0–
0x1EC
Do not access2
—
0x1F0
UART interrupt vector
register—(UIVRn)
[p. 14-20]
—
0x1F4
(Read) UART input port
registers—(UIPn)
[p. 14-20]
—
0x1D0
0x1D4
2
—
2
(Read) Do not access
—
(Write) UART output
port bit set command
registers—(UOP1n3)
[p. 14-21]
—
(Write) Do not access
0x1F8
0x1FC
(Read) Do not access
2
—
(Write) UART output
port bit reset command
registers—(UOP0n3)
[p. 14-21]
—
[15:8]
[7:0]
1
UMR1n, UMR2n, UCSRn, and UACRn[BRG] should be changed only after the receiver/transmitter is issued a
software reset command. That is, if channel operation is not disabled, undesirable results may occur.
2 This address is for factory testing. Reading this location results in undesired effects and possible incorrect
transmission or reception of characters. Register contents may also be changed.
Appendix B. List of Memory Maps
B-5
3
Address-triggered commands
Table B-7. UART1 Control Registers
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
UART1 Control Registers
0x200
UART mode
registers1—(UMR1n)[p.
14-5], (UMR2n) [p. 14-7
Rx FIFO threshold
register—(RXLVL)
[p. 14-8]
Modem control
register—(MODCTL)
[p. 14-9]
Tx FIFO threshold
register—(TXLVL)
[p. 14-10]
0x204
(Read) UART status
registers—(USRn)
[p. 14-10]
—
(Read) Rx samples
available
register—(RSMP)
[p. 14-12]
(Read) Tx space
available
register—(TSPC)
[p. 14-13]
(Write) UART
clock-select
register1—(UCSRn)
[p. 14-12]
0x208
(Read) Do not access2
—
(Write) UART command —
registers—(UCRn)
[p. 14-13]
0x20C
(Read) UART receiver buffers—(URBn) [p. 14-15]
(Write) UART transmitter buffers—(UTBn) [p. 14-16]
(Read) UART input port
change
registers—(UIPCRn)
[p. 14-17]
—
(Write) UART auxiliary
control
registers1—(UACRn)
[p. 14-17]
—
(Read) UART interrupt
status
registers—(UISRn)
[p. 14-18]
—
(Write) UART interrupt
mask
registers—(UIMRn)
[p. 14-18]
—
0x218
UART divider upper
registers—(UDUn)
[p. 14-19]
—
0x21C
UART divider lower
registers—(UDLn)
[p. 14-19]
—
0x220–
0x22C
Do not access2
—
0x210
0x214
B-6
MCF5407 User’s Manual
Table B-7. UART1 Control Registers (Continued)
MBAR
Offset
[31:24]
[23:16]
0x230
UART interrupt vector
register—(UIVRn)
[p. 14-20]
—
0x234
(Read) UART input port
registers—(UIPn)
[p. 14-20]
—
2
(Write) Do not access
0x238
2
[15:8]
[7:0]
—
(Read) Do not access
—
(Write) UART output
port bit set command
registers—(UOP1n3)
[p. 14-21]
—
(Read) Do not access
2
—
(Write) UART output
port bit reset command
registers—(UOP0n3)
[p. 14-21]
—
0x200
UART mode
registers4—(UMR1n)
[p. 14-5], (UMR2n)
[p. 14-7]
Rx FIFO threshold
register—(RXLVL)
[p. 14-10] (UART1 only)
Modem control
register—(MODCTL)
[p. 14-9] (UART1 only)
Tx FIFO threshold
register—(TXLVL)
[p. 14-10] (UART1 only)
0x204
(Read) UART status
registers—(USRn)
[p. 14-10]
—
(Read) Rx samples
available
register—(RSMP)
[p. 14-12] (UART1 only)
(Read) Tx space
available
register—(TSPC)
[p. 14-13] (UART1 only)
0x23C
(Write) UART
clock-select
register1—(UCSRn)
[p. 14-12]
1
UMR1n, UMR2n, UCSRn, and UACRn[BRG] should be changed only after the receiver/transmitter is issued a
software reset command. That is, if channel operation is not disabled, undesirable results may occur.
2 This address is for factory testing. Reading this location results in undesired effects and possible incorrect
transmission or reception of characters. Register contents may also be changed.
3 Address-triggered commands
4 UMR1n, UMR2n, UCSRn, and UACRn[BRG] should be changed only after the receiver/transmitter is issued a
software reset command. That is, if channel operation is not disabled, undesirable results may occur.
Table B-8. Parallel Port Memory Map
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x244
Parallel port data direction register (PADDR)
[p. 15-2]
Reserved
0x248
Parallel port data register (PADAT) [p. 15-2]
Reserved
Appendix B. List of Memory Maps
B-7
Table B-9. I2C Interface Memory Map
MBAR
Offset
[31:24]
[23:16]
[15:8]
0x280
I2C address register
(IADR) [p. 8-6]
Reserved
0x284
I2C frequency divider
register (IFDR) [p. 8-6]
Reserved
0x288
I2C control register
(I2CR) [p. 8-7]
Reserved
0x28C
I2C status register
(I2SR) [p. 8-8]
Reserved
0x290
I2C data I/O register
(I2DR) [p. 8-9]
Reserved
[7:0]
Table B-10. DMA Controller Registers
MBAR
Offset
[31:24]
[23:16]
[15:8]
0x300
Source address register 0 (SAR0) [p. 12-7]
0x304
Destination address register 0 (DAR0) [p. 12-7]
0x308
DMA control register 0 (DCR0) [p. 12-8]
0x30C
Reserved
Byte count register 0 (BCR0) [p. 12-7]
0x310
DMA status register 0
(DSR0) [p. 12-10]
Reserved
0x314
DMA interrupt vector
register 0 (DIVR0)
[p. 12-11]
Reserved
0x340
Source address register 1 (SAR1) [p. 12-7]
0x344
Destination address register 1 (DAR1) [p. 12-7]
0x348
DMA control register 1 (DCR1) [p. 12-8]
0x34C
Reserved
Byte count register 1 (BCR1) [p. 12-7]
0x350
DMA status register 1
(DSR1) [p. 12-10]
Reserved
0x354
DMA interrupt vector
register 1 (DIVR1)
[p. 12-11]
Reserved
0x380
Source address register 2 (SAR2) [p. 12-7]
0x384
Destination address register 2 (DAR2) [p. 12-7]
0x388
DMA control register 2 (DCR2) [p. 12-8]
0x38C
Reserved
Byte count register 2 (BCR2) [p. 12-7]
0x390
DMA status register 2
(DSR2) [p. 12-10]
Reserved
B-8
MCF5407 User’s Manual
[7:0]
Table B-10. DMA Controller Registers (Continued)
MBAR
Offset
0x394
[31:24]
DMA interrupt vector
register 2 (DIVR2)
[p. 12-11]
[23:16]
[15:8]
Reserved
0x3C0
Source address register 3 (SAR3) [p. 12-7]
0x3C4
Destination address register 3 (DAR3) [p. 12-7]
0x3C8
[7:0]
DMA control register 3 (DCR3) [p. 12-8]
0x3CC
Reserved
Byte count register 3 (BCR3) [p. 12-7]
0x3D0
DMA status register 3
(DSR3) [p. 12-10]
Reserved
0x3D4
DMA interrupt vector
register 3 (DIVR3)
[p. 12-11]
Reserved
Appendix B. List of Memory Maps
B-9
B-10
MCF5407 User’s Manual
Glossary of Terms and Abbreviations
The glossary contains an alphabetical list of terms, phrases, and abbreviations used in this
book.
A
Architecture. A detailed specification of requirements for a processor or
computer system. It does not specify details of how the processor or
computer system must be implemented; instead it provides a
template for a family of compatible implementations.
Autovector. A method of determining the starting address of the service
routine by fetching the value from a lookup table internal to the
processor instead of requesting the value from the system.
B
Branch folding. The replacement with target instructions of a branch
instruction and any instructions along the not-taken path when a
branch is either taken or predicted as taken.
Branch prediction.The process of guessing whether a branch will be taken.
Such predictions can be correct or incorrect; the term ‘predicted’ as
it is used here does not imply that the prediction is correct
(successful). Branch resolution.The determination of whether a
branch is taken or not taken. A branch is said to be resolved when the
processor can determine which instruction path to take. If the branch
is resolved as predicted, the instructions following the predicted
branch that may have been speculatively executed can complete (see
completion). If the branch is not resolved as predicted, instructions
on the mispredicted path, and any results of speculative execution,
are purged from the pipeline and fetching continues from the
nonpredicted path.
Burst. A multiple-beat data transfer.
C
Cache. High-speed memory containing recently accessed data and/or
instructions (subset of main memory).
Cache coherency. An attribute wherein an accurate and common view of
memory is provided to all devices that share the same memory
Glossary of Terms and Abbreviations
Glossary-1
system. Caches are coherent if a processor performing a read from
its cache is supplied with data corresponding to the most recent value
written to memory or to another processor’s cache.
Cache flush. An operation that removes from a cache any data from a
specified address range. This operation ensures that any modified
data within the specified address range is written back to main
memory.
Cache line. The smallest unit of consecutive data or instructions that is stored
in a cache. For ColdFire processors a line consists of 16 bytes.
Caching-inhibited. A memory update policy in which the cache is bypassed
and the load or store is performed to or from main memory.
Cast outs. Cache lines that must be written to memory when a cache miss
causes a cache line to be replaced.
Clear. To cause a bit or bit field to register a value of zero. See also Set.
Copyback. A cache memory update policy in which processor write cycles
are directly written only to the cache. External memory is updated
only indirectly, for example, when a modified cache line is cast out
to make room for newer data.
E
Effective address (EA). The 32-bit address specified for an instruction.
Exception. A condition encountered by the processor that requires special,
supervisor-level processing.
Exception handler. A software routine that executes when an exception is
taken. Normally, the exception handler corrects the condition that
caused the exception, or performs some other meaningful task (that
may include aborting the program that caused the exception). The
address for each exception handler is identified by an exception
vector defined by the ColdFire architecture.
F
Fetch. The act of retrieving instructions from either the cache or main
memory and making them available to the instruction unit.
Flush. An operation that causes a modified cache line to be invalidated and
the data to be written to memory.
H
Glossary-2
Harvard architecture. An architectural model featuring separate caches for
instruction and data.
MCF5407 User’s Manual
H
I
Illegal instructions. A class of instructions that are not implemented for a
particular processor. These include instructions not defined by the
ColdFire architecture.
Implementation. A particular processor that conforms to the ColdFire
architecture, but may differ from other architecture-compliant
implementations for example in design, feature set, and
implementation of optional features. The ColdFire architecture has
many different implementations.
Imprecise mode. A memory access mode that allows write accesses to a
specified memory region to occur out of order.
Instruction queue. A holding place for instructions fetched from the current
instruction stream.
Instruction latency. The total number of clock cycles necessary to execute
an instruction and make the results of that instruction available.
Interrupt. An asynchronous exception. On ColdFire processors, interrupts
are a special case of exceptions. See also asynchronous exception.
Invalid state. State of a cache entry that does not currently contain a valid
copy of a cache line from memory.
L
L
Least-significant bit (lsb). The bit of least value in an address, register, data
element, or instruction encoding.
Least-significant byte (LSB). The byte of least value in an address, register,
data element, or instruction encoding.
Longword. A 32-bit data element
M
Master. A device able to initiate data transfers on a bus. Bus mastering refers
to a feature supported by some bus architectures that allow a
controller connected to the bus to communicate directly with other
devices on the bus without going through the CPU.
Memory coherency. An aspect of caching in which it is ensured that an
accurate view of memory is provided to all devices that share system
memory.
Modified state. Cache state in which only one caching device has the valid
data for that address.
Glossary of Terms and Abbreviations
Glossary-3
Most-significant bit (msb). The highest-order bit in an address, registers,
data element, or instruction encoding.
Most-significant byte (MSB). The highest-order byte in an address,
registers, data element, or instruction encoding.
N
O
P
Nop. No-operation. A single-cycle operation that does not affect registers or
generate bus activity.
Overflow. An condition that occurs during arithmetic operations when the
result cannot be stored accurately in the destination register(s). For
example, if two 16-bit numbers are multiplied, the result may not be
representable in 16 bits.
Pipelining. A technique that breaks operations, such as instruction
processing or bus transactions, into smaller distinct stages or tenures
(respectively) so that a subsequent operation can begin before the
previous one completes.
Precise mode. A memory access mode that ensures that all write accesses to
a specified memory region occur in order.
S
Set (v) To write a nonzero value to a bit or bit field; the opposite of clear. The
term ‘set’ may also be used to generally describe the updating of a
bit or bit field.
Set (n). A subdivision of a cache. Cacheable data can be stored in a given
location in any one of the sets, typically corresponding to its lowerorder address bits. Because several memory locations can map to the
same location, cached data is typically placed in the set whose cache
line corresponding to that address was used least recently. See Setassociativity.
Set-associativity. Aspect of cache organization in which the cache space is
divided into sections, called sets. The cache controller associates a
particular main memory address with the contents of a particular set,
or region, within the cache.
Slave. The device addressed by a master device. The slave is identified in the
address tenure and is responsible for supplying or latching the
requested data for the master during the data tenure.
Static branch prediction. Mechanism by which software (for example,
compilers) can hint to the machine hardware about the direction a
branch is likely to take.
Glossary-4
MCF5407 User’s Manual
Superscalar machine. A machine that can issue multiple instructions
concurrently from a conventional linear instruction stream.
Supervisor mode. The privileged operation state of a processor. In
supervisor mode, software, typically the operating system, can
access all control registers and can access the supervisor memory
space, among other privileged operations.
System memory. The physical memory available to a processor.
T
Tenure. A tenure consists of three phases: arbitration, transfer, termination.
There can be separate address bus tenures and data bus tenures.
Throughput. The measure of the number of instructions that are processed
per clock cycle.
Transfer termination. The successful or unsuccessful conclusion of a data
transfer.
U
Underflow. A condition that occurs during arithmetic operations when the
result cannot be represented accurately in the destination register.
User mode. The operating state of a processor used typically by application
software. In user mode, software can access only certain control
registers and can access only user memory space. No privileged
operations can be performed.
V
W
Word. A 16-bit data element.
Write-through. A cache memory update policy in which all processor write
cycles are written to both the cache and memory.
Glossary of Terms and Abbreviations
Glossary-5
Glossary-6
MCF5407 User’s Manual
INDEX
A
C
Addressing mode summary, 2-15
Arbitration
between masters, 6-14
bus control, 6-11
for internal transfers, 6-12
Architecture
Harvard memory, 2-6
instruction set
additions, 2-18
enhancements, 2-36
Cache
configuration register, 2-12
registers, access control, 2-12
Chip-select module
8-, 16-, and 32-bit port sizing, 10-4
enable signals, 17-15
operation, 10-2
general, 10-3
global, 10-4
overview, 10-1
registers, 10-5, 10-6, B-2
code example, 10-9
control, 10-8
mask, 10-7
signals, 10-1
Clock
PLL control, 6-10
ColdFire core
exception stack frame definition, A-11
features and enhancements, 2-1
Condition code register, 2-9
CPU STOP instruction, 6-10
B
Branch acceleration, 2-4
Branch instruction execution
timing, 2-30
Bus arbitration control, 6-11
Bus master park register, 6-11
Bus operation
bus errors, 18-17
characteristics, 18-2
control signals, 18-1
data transfer
back-to-back cycles, 18-10
burst cycles
line read bus, 18-12
line transfers, 18-12
line write bus, 18-14
mixed port sizes, 18-15
overview, 18-11
cycle execution, 18-4
cycle states, 18-5
fast-termination cycles, 18-9
operation, 18-2
read cycle, 18-7
write cycle, 18-8
external master transfers
general, 18-21
two-device arbitration protocol, 18-25
two-wire mode, 18-25
features, 18-1
interrupt exceptions, 18-17
misaligned operands, 18-16
reset operation
master, 18-34
overview, 18-33
software watchdog, 18-35
D
Data registers, A-13
Debug
module enhancements, 2-6
system interface, 1-12
DMA controller module
byte count registers, 12-7
programming model, 12-5
signal description, 12-2
source address registers, 12-7
transfer overview, 12-4
DRAM controller
asynchronous mode signals, 11-4
asynchronous operation
burst page mode, 11-12
continuous page mode, 11-13
extended data out, 11-15
general, 11-4
register set, 11-4
general guidelines, 11-8
non-page mode, 11-11
refresh operation, 11-16
registers, 11-3
Index
Index-1
INDEX
address and control, 11-5
mask, 11-7
signals, 17-16
synchronous operation, 11-16
address and control registers, 11-20
address multiplexing, 11-23
auto-refresh, 11-31
burst page mode, 11-27
continuous page mode, 11-29
controller signals, synchronous mode, 11-17
edge select, 11-18
general guidelines, 11-23
initialization, 11-32
interfacing, 11-27
mask registers, 11-22
mode register settings, 11-33
register set, 11-19
self-refresh, 11-32
E
Electrical specifications
cautions, 20-3
clock timing, 20-4
debug AC timing, 20-16
DMA timing, 20-23
general parameters, 20-1
I2C input/output timing, 20-18
input/output AC timing specifications, 20-6
JTAG AC timing, 20-24
parallel port timing, 20-22
reset timing, 20-15
timer module AC timing, 20-17
UART module AC timing, 20-19
Exception processing
overview, 2-31
processor exceptions, 2-34
stack frame definition, 2-32
Execution timings
miscellaneous, 2-29
one operand, 2-26
two operands, 2-27
F
Features
process, 1-7
summary, 1-4
H
Harvard memory architecture, 2-6
I
I2C
Index-2
address register, 8-6
arbitration procedure, 8-4
clock stretching, 8-5
clock synchronization, 8-5
control register, 8-7
data I/O register, 8-9
features, 8-1
frequency divider register, 8-6
handshaking, 8-5
interface memory map, B-8
lost arbitration, 8-13
overview, 8-1
programming examples, 8-10
programming model, 8-6
protocol, 8-3
repeated START generation, 8-12
slave mode, 8-13
software response, 8-11
START generation, 8-10
status register, 8-8
STOP generation, 8-12
system configuration, 8-3
timing specifications, 20-18
IEEE Standard 1149.1 Test Access Port, see JTAG
Instruction execution times, 2-29
Instruction set
architecture additions, 2-18
architecture enhancements, 2-36
branch acceleration, 2-4
fetch pipeline, 2-4
MAC summary, 3-4
MAC unit execution times, 3-5
summary, 2-15, 2-19
Integer data formats, 2-13
Integer data formats in memory, 2-14
Integer data formats in registers, 2-13
Interrupt controller
autovector register, 9-5
overview, 9-1
pending and mask registers, 9-6
port assignment register, 9-7
J
JTAG
AC timing, 20-24
obtaining IEEE Standard 1149.1, 19-11
overview, 19-1
registers
boundary scan, 19-7
bypass, 19-10
descriptions, 19-4
IDCODE, 19-6
instruction shift, 19-5
restrictions, 19-10
MCF5407 User’s Manual
INDEX
Pipelines, 2-2
instruction fetch, 2-4
operand execution, 2-4
PLL, 7-2
clock control for STOP, 6-10
clock frequency relationships, 7-4
clock-multiplied, 2-2
control register, 7-3
modes
normal, 7-2
reduced power, 7-3
operation, 7-2
overview, 7-1
port list, 7-4
power supply filter circuit, 7-6
reset/initialization, 7-2
timing relationships, 7-4
Power supply
filter circuit, 7-6
Program counter, 2-9
Programming models
MAC, 2-10
overview, 2-7
registers, 1-15
SIM, 6-3
summary, B-1
supervisor, 2-10
user, 2-8
signal descriptions, 19-2
TAP controller, 19-3
test logic disabling, 19-10
M
MAC
data representation, 3-4
hardware support, 2-5
instruction execution timings, 3-5
instruction set summary, 3-4
operation, 3-3
programming model, 2-10, 3-2
Mask registers
DRAM, 11-7, 11-22
MBAR, 6-4
Mechanical data, 16-1
case drawing, 16-9
diagram, 16-8
pinout, 16-1
Memory
integer data formats, 2-14
SIM register, 6-3
Modules, 1-7
base address register, 2-12
core description, 1-7
debug, 2-6
DMA controller, 1-9
DRAM controller, 1-9
I2C, 1-11
PLL, 1-13
system interface, 1-11
16-bit parallel port, 1-12
chip selects, 1-11
debug, 1-12
external bus, 1-11
interrupt controller, 1-12
JTAG, 1-12
Timer, 1-11
UARTs, 1-10
MOVE instructions timing, 2-25
R
RAM base address registers, 2-12
Registers
A0–A6, 2-9
A7, 2-9
AATR, 5-10
access control, 2-12
address, 2-9
AVR, 9-5
BAAR, 5-12
bus master park, 6-11
cache configuration, 2-12
CACR, 2-12
CCR, 2-9
chip-select
control, 10-8
mask, 10-7
module, 10-5
condition code, 2-9
CSR, 5-13
D0–D7, 2-8
data, 2-8, A-13
DMA byte count, 12-7
DMA source address, 12-7
DRAM
O
Opcodes
illegal handling, 2-5
P
Parallel port
code example, 15-4
data direction register, 15-2
data register, 15-2
operation, 15-1
Pin assignment register, 6-10, 15-1
Index
Index-3
INDEX
asynchronous
address and control, 11-5
DACR, 11-5
DCR, 11-4
DMR, 11-7
mode signals, 11-4
general operation, 11-3
synchronous
DACR, 11-20
DCR, 11-19
DMR, 11-22
mode settings, 11-33
2
IC
address, 8-6
control, 8-7
data I/O, 8-9
frequency divider, 8-6
status, 8-8
I2CR, 8-7
I2DR, 8-9
I2SR, 8-8
IADR, 8-6
IFDR, 8-6
integer data formats in, 2-13
interrupt controller
autovector, 9-5
pending and mask, 9-6
port assignment, 9-7
IPR and IMR, 9-6
IRQPAR, 9-7
JTAG
boundary scan, 19-7
bypass, 19-10
descriptions, 19-4
IDCODE, 19-6
instruction shift, 19-5
MBAR, 2-12, 6-4
MODCTL, 14-9
module base address, 2-12
MPARK, 6-11
PADAT, 15-2
PADDR, 15-2
PAR, 6-10, 15-1
parallel port
data, 15-2
pin assignment, 15-1
PBR, 5-16
pin assignment, 6-10
PLL control, 7-3
PLLCR, 7-3
programming model, 1-15
RAM base address, 2-12
RAMBAR, 2-12
RAREG/RDREG, 5-30
Index-4
RCREG, 5-42
RDMREG, 5-44
reset status, 6-5
RSMP, 14-12
RSR, 6-5
RXLVL, 14-8
SDRAM mode initialization, 11-38
SIM
base address, 6-4
memory map, 6-3
software watchdog interrupt, 6-9
SR, 2-11
status, 2-11
supervisor, 1-16, 1-16
SWIVR, 6-9
SWSR, 6-9
SYPCR, 6-8
system protection control, 6-8
TCR, 13-4
TDR, 5-18
TER, 13-5
timer module
capture, 13-4
event, 13-5
mode, 13-3
reference, 13-4
TMR, 13-3
TSPC, 14-13
TXLVL, 14-10
UACR, 14-17
UART modules, 14-3–14-21
UCR, 14-13
UCSR, 14-12
UDU/UDL, 14-19
UIP, 14-20
UIPCR, 14-17
UISR, 14-18
UIVR, 14-20
user, 1-15
VB, 2-12
vector base, 2-12
WAREG/WDREG, 5-31
WCREG, 5-43
WDMREG, 5-45
XTDR, 5-19
RSTI timing, 7-5
S
SDRAM
block diagram and major components, 11-2
controller registers, B-3
DACR initialization, 11-35
DCR initialization, 11-35
definitions, 11-2
MCF5407 User’s Manual
INDEX
interrupt request, 17-12
JTAG, 19-2
parallel I/O port, 17-19
read/write, 17-8
reset in, out, 17-13
serial module
clear to Send, 17-19
general, 17-18
receiver serial data input, 17-19
request to send, 17-19
transmitter serial data output, 17-18
size, 17-8
timer module, 17-19
transfer
acknowledge, 17-9
in progress, 17-10
modifier, 17-10
start, 17-9
Signals
overview, 17-1
SIM
features, 6-1
programming model, 6-3
register memory map, 6-3
Software watchdog
interrupt vector register, 6-9
service register, 6-9
timer, 6-6
Stack pointer, 2-9, 2-9
Status register, 2-11
Supervisor
programming model, 2-10
registers, 1-16
System protection control register, 6-8
DMR initialization, 11-37
example, 11-34
initialization code, 11-39
interface configuration, 11-34
mode register initialization, 11-38
overview, 11-1
Signal descriptions, 17-1
address bus, 17-7
address configuration, 17-15
address strobe, 17-9
bus
arbitration, 17-12
clock output, 17-13
data, 17-8
driven, 17-13
grant, 17-12
request, 17-12
chip-select module, 17-15
clock and reset, 17-13
clock input, 17-13
data bus, 17-8
data/configuration pins, 17-14
debug
high impedance, 17-20
JTAG, 17-21
processor clock output, 17-20
processor status debug data, 17-21
test
clock, 17-22
mode, 17-20
overview, 17-20
debug module/JTAG
test data input/development serial input, 17-22
test data output/development serial output, 17-22
test mode select/breakpoint, 17-21
test reset/development serial clock, 17-21
divide control, 17-15
DMA controller module
general, 17-17
transfer modifier/acknowledge, 17-18
DRAM controller
address strobes, 17-16
overview, 17-16
synchronous
clock enable, 17-17
column address strobe, 17-17
edge select, 17-17
row address strobe, 17-17
synchronous edge select, 17-17
write, 17-16
I2C module
general, 17-20
serial clock, 17-20
serial data, 17-20
interrupt control signals, 17-12
T
Timer module
calculating time-out values, 13-7
capture registers, 13-4
code example, 13-6
counters, 13-5
event registers, 13-5
general-purpose programming model, 13-2
general-purpose units, 13-2
mode registers, 13-3
reference registers, 13-4
Timing
branch instruction execution, 2-30
MAC unit instructions, 3-5
MOVE instructions, 2-25
one operand, 2-26
PLL, 7-4
RSTI, 7-5
two operands, 2-27
Index
Index-5
INDEX
Transfers
internally generated, 6-12
U
UART Modules
register description and programming
register description
UART module programming model (table
14-1), B-4
UART modules
bus operation, 14-37
interrupt acknowledge cycles, 14-37
read cycles, 14-37
write cycles, 14-37
clock source
baud rates, 14-24
controm registers, B-6
external clock, 14-25
FIFO stack in UART0, 14-32
initialization sequence, 14-38
looping modes, 14-34
automatic echo, 14-34
local loop-back, 14-34
remote loop-back mode, 14-35
mode registers, 14-5
multidrop mode, 14-35
programming, 14-37
receiver, 14-29
receiver in modem mode, 14-31
register descriptions, 14-3
serial overview, 14-2
signal definitions, 14-21
simplified block diagram, A-6
transmitter and receiver modes, 14-25
transmitter in modem mode, 14-27
transmitter/receiver clock source, 14-23
transmitting in UART mode, 14-26
UART1 in UART mode, 14-31
User registers, 1-15
V
Vector base register, 2-12
Index-6
MCF5407 User’s Manual
Overview
Part I: MCF5407 Processor Core
1
Part I
ColdFire Core
2
Hardware Multiply/Accumulate (MAC) Unit
3
Local Memory
4
Debug Support
5
Part II: System Integration Module (SIM)
Part II
SIM Overview
6
Phase-Locked Loop (PLL)
7
I2C
Module
8
Interrupt Controller
9
Chip-Select Module
10
Synchronous/Asynchronous DRAM Controller Module
11
Part III: Peripheral Module
Part III
DMA Controller Module
12
Timer Module
13
UART Modules
14
Parallel Port (General-Purpose I/O)
15
Part IV: Hardware Interface
Part IV
Mechanical Data
16
Signal Descriptions
17
Bus Operation
18
IEEE 1149.1 Test Access Port (JTAG)
19
Electrical Specifications
20
Appendix A: Migration
A
Appendix B: Memory Map
B
Glossary of Terms and Abbreviations
GLO
Index
IND
IND
B
GLO
IND
1
Part I
Overview
Part I: MCF5407 Processor Core
2
ColdFire Core
3
Hardware Multiply/Accumulate (MAC) Unit
4
Local Memory
5
Debug Support
Part II
Part II: System Integration Module (SIM)
6
SIM Overview
7
Phase-Locked Loop (PLL)
8
I2C Module
9
Interrupt Controller
10
Chip-Select Module
11
Synchronous/Asynchronous DRAM Controller Module
Part III
Part III: Peripheral Module
12
DMA Controller Module
13
Timer Module
14
UART Modules
15
Parallel Port (General-Purpose I/O)
Part IV
Part IV: Hardware Interface
16
Mechanical Data
17
Signal Descriptions
18
Bus Operation
19
IEEE 1149.1 Test Access Port (JTAG)
20
Electrical Specifications
A
Appendix A: Migration
B
Appendix B: Memory Map
GLO
Glossary of Terms and Abbreviations
IND
Index