Memory Map/Register Definition
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 8-9

8.4 Memory Map/Register Definition

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 (write only). Thus, the breakpoint hardware in the debug module can be read or written by the

external development system using the debug serial interface or written 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 WDEBUG instruction is used to access

debug module registers or the resulting behavior is undefined.

These registers, shown in Figure 8-5, are treated as 32-bit quantities, regardless of the number of

implemented bits.

Figure 8-5. Debug Programming Model

ABLR1
ABHR1
AATR1
PC breakpoint 1 register
PC breakpoint 3 register
PC breakpoint mask register
PC breakpoint register
Data breakpoint register
Data breakpoint mask register
Data breakpoint 1 register
Data breakpoint mask 1 register
Trigger definition register
Extended trigger definition registerXTDR
Configuration/status register
BDM address attributes register
PC breakpoint 2 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. 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
Address attribute trigger register
Address low breakpoint register
Address high breakpoint register
Address 1 attribute trigger register
Address low breakpoint 1 register
Address high breakpoint 1 register
31 15 7 0
31 15 7 0
31 15 7 0
31 15 0
31 15 0
31 15 0
31 15 0
31 15
31 15 0
31 15 0
31 15 0
31 15 0
31 15 0
31 15 0
AATR
ABLR
ABHR
BAAR
CSR
DBR
DBMR
PBR
DBR1
DBMR1
PBR1
PBR2
PBR3
PBMR
TDR