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Chapter 9: Solving Problems
If you see negative time or negative states in the trace list
If you see negative time or negative states in the
trace list
If counter overflow occurs during a deep analyzer trace measurement, you may see
a count of negative time or negative states in the trace list. This is a normal
condition. It indicates that the counter value stored with the reference state was
greater than the counter value stored with the present state. In absolute time counts,
negative times will continue to be seen until a state is captured whose counter value
is greater than the trigger state counter value. In relative time counts, negative time
should only be seen beside the first state captured after the counter overflows.
If the analyzer won't trigger
Instruction fetches from cache memory aren't visible to the analyzer. You can
disable the cache while using the analyzer by answering no to the configuration
question "Enable the 68040 instruction and data cache?" (Use the modify
configuration command to access this configuration question.) Reenable the cache
to improve performance when you're finished using the analyzer.
The analyzer can be configured to trace background monitor execution, foreground
monitor and target program execution, or both background and foreground
operations. If you trace only background monitor execution, the analyzer will not
see any foreground cycles and will not trigger the trace. (Use the modify
configuration command to access this configuration question.)
The MC68040 emulator only fetches instructions on long word boundaries (least
significant hex digit of address is 0, 4, 8, or C). However, program labels can be
aligned on word boundaries between long word boundaries. If you try to trace on a
label located on a non-long-word boundary, the emulation-bus analyzer will never
trigger because the address will never appear on the address bus. To mask an
address so that it is on a long word boundary, use the long_aligned keyword with
trace specifications.
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