Capacitive Loading; State Clock Violates Overdrive Specification; Unwanted Triggers; Waiting For Trigger - HP E2418A User Manual

Capacitive
Loading
"State Clock
Violates Overdrive
Specification"
I
Note
0
Unwanted
Triggers
"Waiting for
Trigger"
Troubleshooting
A-4
Excessive capacitive loading can cause signals to degrade, resulting in
incorrect capture by the preprocessor interface or system lockup in the
microprocessor. All preprocessor interfaces add additional capacitive
loading. One technique to reduce the capacitive loading is to remove
as many pin protectors, extenders, and adapters as possible.
At least one 16-channel pod in the state analysis measurement stored a
different number of states before trigger than the other pods. This is
usually caused by sending a clocking signal to the state analyzer that
does not meet all of the specified conditions, such as minimum period,
minimum pulse width, or minimum amplitude. Poor pulse shaping
could also cause this problem.
The error message "State Clock Violates Overdrive Specification"
should only occur for HP 1650A,B, HP 1652B, HP 16510A,B, and
HP 16511B Logic Analyzers with the Clock Period field set to
<
60 ns.
If this error message is observed with the Clock Period set to > 60 ns,
you may have a faulty logic analyzer. If a failure is suspected in your
logic analyzer, contact your nearest Hewlett-Packard Sales/Service
Office for information on servicing the instrument.
Unwanted triggers can be caused by unexecuted prefetches. Add the
prefetch queue depth to the trigger address to avoid this problem.
If a trigger pattern is specified, this message indicates that the specified
trigger pattern did not occur. Verify that the triggering pattern is
correctly set.
If a "don't care" trigger condition is set, this message indicates:
• For an HP 16511B Logic Analyzer, only one of the two cards is
receiving its state clock. Refer to "Slow or Missing Clock."
• For an HP 1650A,B, HP 1652B, or HP 16510A,B Logic Analyzer,
the pattern duration is probably set to less than ( <) instead of
greater than ( > ). Since a "don't care" pattern is always true, the
"less than" condition is never satisfied. Set the trace menu
correctly for the measurement that is desired.
HP E2418A
TMS32020/C25 Preprocessor Interface