Motorola MPC533 Reference Manual page 978

Program Trace
Program trace synchronization messages provide the full address (without leading zeros)
and ensure that development tools fully synchronize with program trace regularly.
Synchronization messages provide a reference address for subsequent BTMs, in which only
the unique portion of the program trace address is transmitted.
For program trace synchronization to work, the ICTRL register
(refer to Table 21.6.11) must be programmed such that show
cycle will be performed for all changes in the program flow
(ISCTL field = 01) if the PTM bit is set to 0. If the PTM bit is
set to 1, ISCTL can be programmed to any value except no
show cycles (ISCTL field = 11).
It is also recommended that the USIU be programmed to ignore instruction show cycles so
as to not impact U-bus performance; set SIUMCR[NOSHOW]. Synchronization will only
occur at changes in program flow boundaries, and cannot be forced by the READI module.
Synchronizations on errors, overflows, as well as periodic synchronizations will not be
deterministic to the nearest instruction, but to the next taken change in program flow. The
start of program trace (enabled via any means) will be also deferred to the next change in
program flow.
Program trace synchronization messages are of the following types:
• Direct branch
• Indirect branch
• Direct branch with compressed code
• Indirect branch with compressed code
• Resource full
22.3.2.4.1 Direct Branch Synchronization Message
The program trace direct branch synchronization message has the following formats
depending on how the PTSM bit in the MC register is configured:
[6 bits]
TCODE (11)
Figure 22-23. Direct Branch Synchronization Message Format (PTSM = 0)
22-46
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
NOTE
[1 bit]
Messages Cancelled
Max Length = 30 bits
Min Length = 8 bits
MPC533 Reference Manual
[1 – 23 bits]
Full target address
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