4.8. Trace FIFO overflow

A single cycle on the processor can generate more trace than the PTM can output in this time. Therefore, the PTM includes a FIFO to buffer trace data. This FIFO can overflow if a large volume of trace is generated. The PFT protocol handles FIFO overflow as follows:

While tracing is stopped because of FIFO overflow, all PTM resources continue to operate. This means that any trigger condition, such as a trigger generated by the address comparators, can be detected and output after the FIFO has emptied and tracing restarted.

Any source that can request a periodic synchronization of the PTM can force the PTM to behave as if the FIFO had overflowed. See Forced overflow.

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