SWRU626 December 2025 CC3501E , CC3551E
The Trace Port Interface Unit (TPIU) drives trace data to external pins on a target, so that the Trace Port Analyzer (TPA), which is often part of a debug unit, can capture the trace data.
The TPIU:
Coordinates the stopping of trace capture when it receives a trigger
Inserts source identification information into the trace stream so that trace data can be re-associated with its trace source
Outputs the trace data over trace port pins
Outputs patterns over the trace port. This pattern output is often referred to as TPIU pattern generation. This allows a TPA to tune its capture logic to the trace port, which maximizes the trace data output frequency on the trace port.
TPIU implementation details are found in the Arm CoreSight System-on-Chip SoC-600 Technical Reference Manual.