See Also

If You Have a Problem

No Setup/Hold field on format screenNo Setup/Hold field on format screen

The HP 16540 and 16541 (A and D models), or HP 16542A logic analyzer cards are not calibrated. Refer to your logic analyzer reference manual for procedures to calibrate the cards.

No activity on activity indicators

On the HP 16510A Logic Analyzer, check the fuse that allows power to the preprocessor interface.

On other logic analyzers, check for loose cables, board connections, and preprocessor interface connections.

Check for bent or damaged pins on the preprocessor probe.

Capacitive loading

Excessive capacitive loading can degrade signals, resulting in incorrect capture by the preprocessor interface, or system lockup in the microprocessor. All preprocessor interfaces add additional capacitive loading, as can custom probe fixtures you design for your application.

Careful layout of your target system can minimize loading problems and result in better margins for your design. This is especially important for systems that are running at frequencies greater than 50 MHz.

Remove as many pin protectors, extenders, and adapters as possible.

If multiple preprocessor interface solutions are available, try using one with lower capacitive loading.

Chapter 6 lists some application notes that discuss the problems of probing high-speed digital systems.

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