HP 64780A, User Manual

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Making Complex Trace Measurements
You can have the analyzer record bus activity by simply using the trace command
without any options. But this doesn’t use the analyzer effectively for two reasons:
•
the trace memory may fill before the program reaches the states of interest.
•
you may have to search through a long trace list to find a few states pertinent
to your measurement problem.
The HP 64700 analyzer has trigger and sequence capabilities that help solve these
problems. These tools act as a filter for processor bus activity that allows the
analyzer to capture only the states you want to see in the measurement.
A trigger tells the analyzer to identify a certain bus state as a point of reference in
the trace of states. A sequence is a more complex specification that specifies a
series of bus states that must be found to satisfy the trigger.
This section tells you how to get the most out of the HP 64700 analyzer by using
trigger and sequence specifications. It also describes additional measurement tools
to help you get more information from the trace.
Many of the options in this section can be combined one or more times. See the
trace syntax in Chapter 11, "Emulator/Analyzer Interface Commands", for more
information.
Expressions are an important part of trace specifications because they specify the
numeric or logical values that the analyzer matches for trigger and storage.
Expressions are represented by the <expression> symbol in this chapter. Refer to
Chapter 11, "Emulator/Analyzer Interface Commands", for specifics on expression
syntax.
Expressions in Trace Commands
When modifying the analysis specification, you can enter expressions that consist
of values, symbols, and operators.
Values Values are numbers in hexadecimal, decimal, octal, or binary. These
number bases are specified by the following characters:
B b Binary (example: 10010110b).
Chapter 7: Using the Emulation-Bus Analyzer
Making Complex Trace Measurements
206