MCF548x Reference Manual, Rev. 3
8-32 Freescale Semiconductor

Unassigned command opcodes are reserved by Freescale. All unused command formats within any

revision level perform a NOP and return the illegal command response.

Table 8-24. BDM Command Summary

Command Mnemonic Description CPU
State1
1General 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.
Section Command
(Hex)
Read A/D
register
rareg/
rdreg
Read the selected address or data register and
return the results through the serial interface.
Halted 8.5.3.3.1 0x218 {A/D,
Reg[2:0]}
Write A/D
register
wareg/
wdreg
Write the data operand to the specified address or
data register.
Halted 8.5.3.3.2 0x208 {A/D,
Reg[2:0]}
Read
memory
location
read Read the data at the memory location specified by
the longword address.
Steal 8.5.3.3.3 0x1900—byte
0x1940—word
0x1980—lword
Write
memory
location
write Write the operand data to the memory location
specified by the longword address.
Steal 8.5.3.3.4 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 8.5.3.3.5 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 8.5.3.3.6 0x1C00—byte
0x1C40—word
0x1C80—lword
Resume
execution
go The pipeline is flushed and refilled before resuming
instruction execution at the current PC.
Halted 8.5.3.3.7 0x0C00
No operation nop Perform no operation; may be used as a null
command.
Parallel 8.5.3.3.8 0x0000
Output the
current PC
sync_pc Capture the current PC and display it on the
PSTDDATA output pins.
Parallel 8.5.3.3.9 0x0001
Read control
register
rcreg Read the system control register. Halted 8.5.3.3.11 0x2980
Write control
register
wcreg Write the operand data to the system control
register.
Halted 8.5.3.3.15 0x2880
Read debug
module
register
rdmreg Read the debug module register. Parallel 8.5.3.3.16 0x2D {0x42
DRc[4:0]}
20x4 is a three-bit field.
Write debug
module
register
wdmreg Write the operand data to the debug module
register.
Parallel 8.5.3.3.17 0x2C {0x42
DRc[4:0]}