There are two configurations of the TPIU:
A configuration that supports ITM debug trace.
A configuration that supports both ITM and ETM debug trace.
If your implementation requires no trace support then the TPIU might not be present.
If your Cortex-M4 system uses the optional ETM component, the TPIU configuration supports both ITM and ETM debug trace. See the ETM-M4 Technical Reference Manual.