Bdm Command Set; Bdm Command Summary - Motorola ColdFire MCF5281 User Manual

Background Debug Mode (BDM)

29.5.3 BDM Command Set

Table 29-17 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.
Command Mnemonic
Read A/D /
RAREG
register
RDREG
Write A/D /
WAREG
register
WDREG
Read memory
READ
location
Write memory
WRITE
location
Dump
DUMP
memory block
Fill memory
FILL
block
Resume
GO
execution
No operation
NOP
Read control
RCREG
register
Write control
WCREG
register
Read debug
RDMREG
module
register
Write debug
WDMREG
module
register
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
29-20
Table 29-17. BDM Command Summary
Description
Read the selected address or data register and return the
results through the serial interface.
Write the data operand to the specified address or data
register.
Read the data at the memory location specified by the
longword address.
Write the operand data to the memory location specified
by the longword address.
Used with to dump large blocks of memory. An
READ
initial is executed to set up the starting address of
READ
the block and to retrieve the first result. A
command retrieves subsequent operands.
Used with to fill large blocks of memory. An
WRITE
initial is executed to set up the starting address of
WRITE
the block and to supply the first operand. A
command writes subsequent operands.
The pipeline is flushed and refilled before resuming
instruction execution at the current PC.
Perform no operation; may be used as a null command.
Read the system control register.
Write the operand data to the system control register.
Read the debug module register.
Write the operand data to the debug module register.
NOP
MCF5282 User's Manual
DUMP
FILL
and return the illegal command response.
CPU Command
Section
1
State
Halted 29.5.3.3.1 0x218 {A/D,
Reg[2:0]}
Halted 29.5.3.3.2 0x208 {A/D,
Reg[2:0]}
Steal 29.5.3.3.3 0x1900—byte
0x1940—word
0x1980—lword
Steal 29.5.3.3.4 0x1800—byte
0x1840—word
0x1880—lword
Steal 29.5.3.3.5 0x1D00—byte
0x1D40—word
0x1D80—lword
Steal 29.5.3.3.6 0x1C00—byte
0x1C40—word
0x1C80—lword
Halted 29.5.3.3.7 0x0C00
Parallel 29.5.3.3.8 0x0000
Halted 29.5.3.3.9 0x2980
Halted 29.5.3.3.10 0x2880
Parallel 29.5.3.3.11 0x2D {0x4
DRc[4:0]}
Parallel 29.5.3.3.12 0x2C {0x4
DRc[4:0]}
MOTOROLA
(Hex)
2
2