Background Debug Mode (BDM)
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 8-35

8.5.3.3 Command Set Descriptions

The following sections describe the commands summarized in Table 8-24.
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 8.5.2, “BDM Serial Interface,” describes the receive packet format.
Freescale reserves unassigned command opcodes for future expansion. Unused command formats in any
revision level perform a NOP and return an illegal command response.
8.5.3.3.1 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:
Command Sequence:
Figure 8-24. 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.
8.5.3.3.2 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.
15 1211 87 432 0
Command 0x2 0x1 0x8 A/D Register
Result D[31:16]
D[15:0]
Figure 8-23. RAREG/RDREG Command Format
RAREG/RDREG
???
NEXT CMD
LS RESULT
NEXT CMD
’NOT READY’
XXX
BERR
XXX
MS RESULT