Article ID: 103488255

Published date: 13 Dec 2017

Last updated: -

Applies to: CoreSight Debug and Trace

Question

I want to capture trace in my CoreSight ETB while not clocking the CoreSight TPIU but my trace stalls.

Answer

The CoreSight Components TRM, Section 6.2 gives the following requirement for the Replicator:

It is a requirement of the attached trace sinks to set their ATREADY signal when they are disabled. This enables the replicator to operate as a pass-through to the remaining enabled trace sink."

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0314f/Chdbdcjh.html

The procedure for disabling the TPIU is to stop it by use of bits [12] and [6] of the Formatter and Flush Control Register, per the final Note in section 8.6.10 of the CoreSight Components TRM.

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0314f/Cbahcjai.html

This will result in the ATREADY being 'parked' so as to avoid backing up the ATB, as indicated in the second bullet point under section 8.13.1.

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0314f/Cbajbjgc.html

Once the TPIU is correctly stopped, TRACECLKIN may be stopped without backing up the ATB channel in the Replicator.

Related information

N/A