
RCPU
REFERENCE MANUAL
DEVELOPMENT SUPPORT
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MOTOROLA
8-9
ternal to the processor:
1. Enter debug mode, either immediately out of reset or using the debug mode
request.
2. Program the hardware to break on the event that marks the start of the trace
window using the control registers defined in
8.8 Development Support
Registers
.
3. Enable debug mode entry for the programmed breakpoint in the debug en-
able register (DER).
4. Return to the regular code run.
5. The hardware generates a breakpoint when the programmed event is de-
tected, and the machine enters debug mode.
6. Program the hardware to break on the event that marks the end of the trace
window.
7. Assert VSYNC.
8. Return to the regular code run. The first report on the VF pins is a VSYNC
(VF[0:2] = 011).
9. The external hardware starts sampling the program trace information upon
the report on the VF pins of VSYNC.
10. The hardware generates a breakpoint when the programmed event is de-
tected, and the machine enters debug mode.
11. Negate VSYNC.
12. Return to the regular code run. The first report on the VF pins is a VSYNC
(VF[0:2] = 011).
13. The external hardware stops sampling the program trace information upon
the report on the VF pins of VSYNC.
A second method allows the trace window to be synchronized to internal processor
events without stopping execution and entering debug mode at the two events.
1. Enter debug mode, either immediately out of reset or using the debug mode
request.
2. Program a watchpoint for the event that marks the start of the trace window
using the control registers defined in
8.8 Development Support Registers
.
3. Program a second watchpoint for the event that marks the end of the trace
window.
4. Return to regular code execution by exiting debug mode.
5. The watchpoint logic signals the starting event by asserting the appropriate
watchpoint pin.
6. Upon detecting the first watchpoint, assert VSYNC using the development
port serial interface.
7. The external program trace hardware starts sampling the program trace in-
formation upon the report on the VF pins of VSYNC.
8. The watchpoint logic signals the ending event by asserting the appropriate
watchpoint pin.
9. Upon detecting the second watchpoint, negate VSYNC using the develop-
ment port serial interface.
10. The external program trace hardware stops sampling the program trace in-
formation upon the report on VF[0:1] of VSYNC.
F
Freescale Semiconductor, Inc.
n
.