Motorola ColdFire MCF5281 - Manual (Page 625)

Debug Support
Freescale Semiconductor 30-7
NOTE
Debug control registers can be written by the external development system
or the CPU through the WDEBUG instruction.
CSR is write-only from the programming model. It can be read or written
through the BDM port using the
RDMREG and WDMREG commands.
30.4.1 Revision A Shared Debug Resources
In the Revision A implementation of the debug module, certain hardware structures are shared between
BDM and breakpoint functionality as shown in
Table 30-4 .
Thus, loading a register to perform a specific function that shares hardware resources is destructive to the
shared function. For example, a BDM command to access memory overwrites an address breakpoint in
ABHR. A BDM write command overwrites the data breakpoint in DBR.
30.4.2 Address Attribute Trigger Register (AATR)
The AATR, shown in Figure 30-5 , defines address attributes and a mask to be matched in the trigger. The
register value is compared with address attribute signals from the processor’s local high-speed bus, as
defined by the setting of the trigger definition register (TDR).
Table 30-3. BDM/Breakpoint Registers
DRc[4–0] Register Name Abbreviation Initial State Page
0x00 Configuration/status register CSR 0x00010_0000 p. 30-10
0x01–0x05 Reserved — — —
0x06 Address attribute trigger register AATR 0x0000_0005 p. 30-7
0x07 Trigger definition register TDR 0x0000_0000 p. 30-14
0x08 Program counter breakpoint register PBR — p. 30-13
0x09 Program counter breakpoint mask register PBMR — p. 30-13
0x0A–0x0B Reserved — — —
0x0C Address breakpoint high register ABHR — p. 30-9
0x0D Address breakpoint low register ABLR — p. 30-9
0x0E Data breakpoint register DBR — p. 30-12
0x0F Data breakpoint mask register DBMR — p. 30-12
Table 30-4. Rev. A Shared BDM/Breakpoint Hardware
Register BDM Function Breakpoint Function
AATR Bus attributes for all memory commands Attributes for address breakpoint
ABHR Address for all memory commands Address for address breakpoint
DBR Data for all BDM write commands Data for data breakpoint
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3