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Capturing Data In The Trace Memory
Capture Mode
NOTE
If the Analyzer is set up to fill the trace memory after a trigger event and
the event does not occur, stopping the Analyzer sets an artificial
triggerpoint. The trace memory will then contain 100 % pre-trigger
history. The last captured state is the state before the Analyzer has been
stopped.
Nevertheless, the trace memory can still be empty if no samples were
taken because of the storage qualification.
Capture Mode
The availability of the sequencer depends on the selected capture mode.
The Agilent E2925B testcard provides the following modes for capture
control:
• Standard
In the standard mode, the trace memory trigger and storage qualifier
are directly controlled by pattern terms. Pattern terms are
programmable pattern recognizes. If the programmed pattern is found
on the bus, the pattern term signals
– the trigger to initiate the sampling, or
– the storage qualifier to capture the current sample.
• Sequencer
In the sequencer mode, the trigger sequencer controls the trace
memory’s trigger and storage qualifier. The sequencer detects
sequences of patterns. To detect the patterns, it uses pattern terms as
input. Each state of the sequence can be used to control the
sequencer’s output, trigger and storage qualifier.
• Performance
The performance mode is only available if the PCI Optimizer (option
#200) has been installed.
In the performance mode, the storage qualifier is automatically
programmed as required for performance measurements. A trigger
can be set up to start the measurement.
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Agilent E2925B PCI Analyzer User’s Guide, August 2002