Datasheet

5-16 MCF5307 User’s Manual
Background Debug Mode (BDM)
5.5 Background Debug Mode (BDM)
The ColdFire Family implements a low-level system debugger in the microprocessor
hardware. Communication with the development system is handled through a dedicated,
high-speed serial command interface. The ColdFire architecture implements the BDM
controller in a dedicated hardware module. Although some BDM operations, such as CPU
register accesses, require the CPU to be halted, other BDM commands, such as memory
accesses, can be executed while the processor is running.
5.5.1 CPU Halt
Although many BDM operations can occur in parallel with CPU operations, unrestricted
BDM operation requires the CPU to be halted. The sources that can cause the CPU to halt
are listed below in order of priority:
1. A catastrophic fault-on-fault condition automatically halts the processor.
28–22
12–6
EDx Setting an EDx bit enables the corresponding data breakpoint condition based on the size and placement
on the processor’s local data bus. Clearing all EDx bits disables data breakpoints.
28/12 EDLW Data longword. Entire processor’s local data bus.
27/11 EDWL Lower data word.
26/10 EDWU Upper data word.
25/9 EDLL Lower lower data byte. Low-order byte of the low-order word.
24/8 EDLM Lower middle data byte. High-order byte of the low-order word.
23/7 EDUM Upper middle data byte. Low-order byte of the high-order word.
22/6 EDUU Upper upper data byte. High-order byte of the high-order word.
21/5 DI Data breakpoint invert. Provides a way to invert the logical sense of all the data breakpoint comparators.
This can develop a trigger based on the occurrence of a data value other than the DBR contents.
20–18/
4–2
EAx Enable address bits. Setting an EA bit enables the corresponding address breakpoint. Clearing all three
bits disables the breakpoint.
20/4 EAI Enable address breakpoint inverted. Breakpoint is based outside the range between ABLR and
ABHR.
19/3 EAR Enable address breakpoint range. The breakpoint is based on the inclusive range defined by
ABLR and ABHR.
18/2 EAL Enable address breakpoint low. The breakpoint is based on the address in the ABLR.
17/1 EPC Enable PC breakpoint. If set, this bit enables the PC breakpoint.
16/0 PCI Breakpoint invert. If set, this bit allows execution outside a given region as defined by PBR and PBMR to
enable a trigger. If cleared, the PC breakpoint is defined within the region defined by PBR and PBMR.
Table 5-14. TDR Field Descriptions (Continued)
Bits Name Description
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