This FAQ explains the three main error types encountered during trace recording and provides troubleshooting steps.

FIFOFULL

A FIFOFULL occurs when the trace sources produce data faster than the trace infrastructure (the chip/interface) can process it. This results in lost trace packets.

You can search for FIFOFULL errors in the trace recording using the following command:

Trace.Find FIFOFULL /ALL

To resolve a FIFOFULL, you must either increase the bandwidth or decrease the data volume:

1. Increase Bandwidth:

• Ensure the trace clock is running at the maximum supported frequency.

• Use the highest available port speed and bus width.

2. Decrease Data Volume:

• Disable unused sources: Turn off trace sources not required for your current debug session (e.g., disable data trace if only instruction trace is needed).

• Use Filters: Apply selective program and/or data trace by using trace filters (TraceEnable, TraceData, TraceON, TraceOFF). Refer for more information to the description of the command Break.Set in the General Commands Reference Guide B.

• Some processor architectures allow stalling the CPU or suppress the output of the data flow information if a FIFO overflow is likely to happen.

HARDERROR

A HARDERROR indicates that the captured trace data is invalid or corrupted.

Common Causes & Troubleshooting:

• Setup/hold time violations or signal capturing failures.

• The trace port is multiplexed with other I/O functions, preventing valid data capture.

• The target frequency is set too high for the current trace configuration.

• An incorrect version of the PowerTrace module is being used.

FLOWERROR

A FLOWERROR indicates that the captured trace data is logically inconsistent with the current state of the target memory.

Common Causes:

• The trace data itself is invalid (often a secondary effect of a HARDERROR).

• Missing task switches in the trace in case of OS trace

• Memory contents have changed (e.g. self modifying code)

You can search for FLOWERROR occurrences in the trace recording using the following command:

Trace.Find FLOWERROR /ALL