How to collect the event while the registers on DWT overflow?

[Lingjun Kong]

Posted on August 28, 2017 at 15:12

ARMv7M has provided a tracing unit for debugging: The Data Watchpoint and Trace unit. but it has only 8bit counter for such as CPICNT. how do you use it to count a piece of code?

#stm32f7 #dwt #dwt->cyccnt #stm32f7-discovery #cpi

[Tesla DeLorean]

Posted on August 28, 2017 at 15:40

Monitor it frequently?

[Lingjun Kong]

Posted on August 28, 2017 at 16:03

You mean scan the register periodically? I'm afraid it will impact the normal order of the code and the accuracy of the result.

[Tesla DeLorean]

Posted on August 28, 2017 at 17:49

Such is life, ARM tends to use the minimum gates to achieve the maximum result, most people are never using the DWT beyond debugging on the bench. If you need some industrial grade profiling consider getting a trace pod, last time I checked they ran $1200