CodeWarrior for MCUのトピックPEMicro TraceLink trace ends prematurely

PEMicro TraceLink trace ends prematurely

robertgrimshaw — Wed, 26 Jul 2017 01:37:31 GMT

I'm having a problem using my PEMicro Tracelink with CodeWarrior, attempting to trace the execution of firmware on a Cortex-M0+. The trace ends prematurely, well before the 128Mb of configured trace buffer is filled. Oddly, each trace seems to stop after a different number of trace records, sometimes in the 3k range, sometime in the 5k range. When the trace stops, it halts the processor and drops me into the debugger at a return from a function, in code that I was expecting to be running.

I have the "Trace Max Buffer Size" option set to 128 Mb in the target settings, and in the Trace and Profile settings I have the "Trace Buffer Size" set to 0x2000, with "Continuous" selected.

I'm tracing third-party code, so I'm stuck without source, but I can set a breakpoint where I want to begin trace and that works well. The problem is that the assembly should clearly be looping for a very long time but something is happening that exits the loop and I want to know what. Interrupts are disabled, but I was hoping a trace would catch an interrupt if that was the culprit and I was simply misunderstanding the assembly.

Thanks in advance for the assistance.

Re: PEMicro TraceLink trace ends prematurely

Carlos_Mendoza — Thu, 27 Jul 2017 21:58:37 GMT

Hi Robert,

Is this problem of the trace ending prematurely just happening with this project? Which CodeWarrior version are you using? I think that the following posts created by our colleague Erich Styger might be helpful for you:

First Steps with the P&E Tracelink | MCU on Eclipse

Debugging ARM Cortex-M0+ Hard Fault with MTB Trace | MCU on Eclipse

Hope it helps!

Best Regards,
Carlos Mendoza
Technical Support Engineer

Re: PEMicro TraceLink trace ends prematurely

robertgrimshaw — Fri, 18 Aug 2017 18:37:54 GMT

I never did get to the bottom of this, but the premature trace stops may have been occurring when the watchdog timer was resetting the chip. Code I added was not servicing the timer and this was causing resets. I got no indication of that in CodeWarrior, but that may have been what was happening.

Re: PEMicro TraceLink trace ends prematurely

Carlos_Mendoza — Fri, 18 Aug 2017 19:22:44 GMT

Hi Robert,

I agree with you, the watchdog reset was most likely causing the trace to stop.

Best Regards,
Carlos Mendoza
Technical Support Engineer