System Development and Debugging
MPC885 PowerQUICC Family Reference Manual, Rev. 2
53-6
Freescale Semiconductor
possible to use the internal breakpoints hardware with the debug mode. This method is available only when
debug mode is enabled. For more information on debug mode, see
Section 53.3, “Development System
Interface.”
The following is a possible set of steps that enable the user to synchronize the trace window to the internal
core events:
1. Enter debug mode, either immediately out of reset or using the debug mode request.
2. Program hardware to break on the event that marks the start of the trace window using the registers
defined in
Section 53.2, “Watchpoints and Breakpoints Support.”
3. Enable debug mode entry for the breakpoint programmed in the DER (see
Table 53-25
).
4. Return to the regular code run (refer to
Section 53.3.1.7, “Exiting Debug Mode”
).
5. The hardware generates a breakpoint when the event in question is detected and the machine enters
debug mode (refer to
Section 53.3.1.2, “Entering 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 VSYNC (VF = 0b011).
9. The external hardware starts sampling the program trace information after the VF pins indicate
VSYNC.
10. The hardware generates a breakpoint when the event in question is detected and the machine enters
debug mode.
11. Negate VSYNC.
12. Return to the regular code run (issue an rfi). The first encoding on the VF pins is VSYNC (VF =
0b011).
13. External hardware stops sampling the program trace information after recognizing VSYNC
on the VF pins.
53.1.5.3
Detecting the Trace Window Start Address
When using back trace, latching of VF, VFLS, and the address of the cycles marked program trace cycle
should all start immediately after the negation of reset. The start address is the first address in the program
trace cycle buffer. When using window trace, latching of VF, VFLS, and the address of the cycles marked
as program trace cycle should all start immediately after the first VSYNC is recognized on the VF pins.
The start address of the trace window should be calculated according to the first two VF pin reports.
Assume VF1 and VF2 are the first two VF pin reports and T1 and T2 are the two addresses of the first two
cycles marked with the program trace cycle attribute that were latched in the trace buffer. Use
Table 53-5
to calculate the trace window start address.
Summary of Contents for PowerQUICC MPC870
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Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
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Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
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Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
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