TDA4VE-Q1: Trace32 interface usage

Hello Xingyu,

CPU loading for a core on the TDA4VE can be determined using TRACE32.  The method to do this will depend on which core/s need profiling and which software is running on that core.  Load can be measured using sample based, trace based, or instrumentation based methods.  There are multiple and different interfaces available to accomplish this.  In this thread you are asking about the external trace method.  The external trace method likely can give the most detailed timing information but has the most cost in board space and tool type needed.  Maximum information is gotten when all the signals listed above are used in conjunction with an external PowerTRACE3 system.  TI's EVM does export these signals using a MIPI-60 debug header. It is possible to get loading information with a subset of the signals but how many are needed depends on which core and the speed of the core.  If too few signals are used underruns resulting in data holes can happen.

In addition to external trace, use of internal trace or snooped PC's can give CPU loading using TRACE32.  For most RTOS and HLOS the PERF or SNOOPER command groups can be used to determine loading.  The snooped PC method is sample based so it will have accuracy limitations but it can be valuable for development and requires no external TRC signal usage (it only needs the standard JTAG hook up).