Chapter 5. Debug Support
5-21
Background Debug Mode (BDM)
5.5.3.2 Command Sequence Diagrams
The command sequence diagram in Figure 5-16 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.
Figure 5-16. 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.
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
SEQUENCE TAKEN IF
OPERATION HAS NOT
COMPLETED
DATA UNUSED FROM
THIS TRANSFER
SEQUENCE TAKEN IF
ILLEGAL COMMAND
IS RECEIVED BY DEBUG MODULE
RESULTS FROM PREVIOUS COMMAND
RESPONSES FROM THE DEBUG MODULE
NONSERIAL-RELATED ACTIVITY
MS ADDR
"NOT READY"
XXX
"ILLEGAL"
LS ADDR
"NOT READY"
NEXT CMD
"NOT READY"
READ (LONG)
???
NEXT CMD
"NOT READY"
XXX
"NOT READY"
XXXXX
XXX
BERR
MS RESULT
NEXT CMD
LS RESULT
READ
MEMORY
LOCATION
NEXT
COMMAND
CODE
SEQUENCE TAKEN IF BUS
ERROR OCCURS ON
MEMORY ACCESS
HIGH- AND LOW-ORDER
16 BITS OF RESULT
XXX
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Страница 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...