9.7.1. Capturing trace after an event and stopping

Two things must happen before trace capture can be stopped:

Figure 9.2 shows a possible time-line of events where an event of interest, referred to as a trigger event, causes some trace that must be captured and thereafter the trace capture device can be stopped.

When one trace source is used, there is no requirement to flush the system. Instead, the length of the trigger counter delay can be increased to enable more trace to be generated, thereby pushing out historical information.

The trigger event at time t1 is signaled to the TPIU through the cross-triggering system. The trace source which generated the trigger event might also embed some trigger information in its trace stream at this point.

The TPA only registers a trigger at time t3, when it is safe to stop trace capture. The TPIU embeds a trigger in the formatted trace stream at this time, and signals a trigger on tracectl if it is in bypass or normal mode.

Figure 9.2. Capturing trace after an event and stopping

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In Figure 9.2, the action that causes trace capture to be stopped at time t3 can be one of the following:

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