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Debug Module
Command Format:
15
14
13
12
0x2
Table 34-5
shows the definition of the DRc write encoding.
Command Sequence:
WDMREG
???
Operand Data:
Longword data is written into the specified debug register. The data is supplied
most-significant word first.
Result Data:
Command complete status (0xFFFF) is returned when register write is complete.
34.4.2
Real-Time Debug Support
The ColdFire family provides support debugging real-time applications. For these types of embedded
systems, the processor must continue to operate during debug. The foundation of this area of debug support
is that while the processor cannot be halted to allow debugging, the system can generally tolerate the small
intrusions of the BDM inserting instructions into the pipeline with minimal effect on real-time operation.
The debug module provides four types of breakpoints: PC with mask, PC without mask, operand address
range, and data with mask. These breakpoints can be configured into one- or two-level triggers with the
exact trigger response also programmable. The debug module programming model can be written from the
external development system using the debug serial interface or from the processor's supervisor
programming model using the WDEBUG instruction. Only CSR is readable using the external
development system.
34.4.2.1
Theory of Operation
Breakpoint hardware can be configured through TDR[TCR] to respond to triggers by displaying
PSTDDATA, initiating a processor halt, or generating a debug interrupt. As shown in
a breakpoint is triggered, an indication (CSR[BSTAT]) is provided on the PSTDDATA output port of the
DDATA information when it is not displaying captured processor status, operands, or branch addresses.
See
Section 34.4.4.2, "Processor Stopped or Breakpoint State Change (PST =
34-49
Figure 34-47.
BDM Command Format
WDMREG
11
10
9
8
0xC
D[31:16]
D[15:0]
MS DATA
'NOT READY'
'NOT READY'
XXX
'ILLEGAL'
'NOT READY'
Figure 34-48.
Command Sequence
WDMREG
7
6
5
4
1
0
LS DATA
NEXT CMD
'CMD COMPLETE'
NEXT CMD
0xE)."
3
2
1
0
DRc
Table
34-28, when
Freescale Semiconductor
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