Outputting 32MHZ clock on TRACECLK pin

[Patrick]

In the nRF52832 Product Spec v1.4 th the ere are discussions in sections 16.5 and 19.3.10 about being able able to output a divided down version

of the 32MHZ clock on the TRACECLK pin.  We feel we have it setup correctly but we are NOT getting anything on that pin.  Can you give me details on how to properly setup the device so that this works for us.

Thank you.  Patrick Verdon

[Håkon Alseth]

Hi,

 

There's a post on this in the blog section:

https://devzone.nordicsemi.com/b/blog/posts/debugging-nrf52-series-devices-using-trace

And one from Keil as well:

https://devzone.nordicsemi.com/b/blog/posts/nrf52-tutorial-etm-instruction-trace-with-keil-mdk

If you are still getting errors, could you post the output from your IDE?

Kind regards,

Håkon

[Patrick]

These app notes show using the TRACECLK pin in debugging mode.

What we would like to do is on a GPIO (In this case P0_20) output a divided down version of the 

32MHZ input clock.  Ideally 16MHZ but can be slower if the part does NOT support that speed on a GPIO.

How can we setup a GPIO to this?

Thanks.  Pat

[Håkon Alseth]

I think there's some misunderstanding here. The TRACECLK is only enabled when a TRACE enabled debugger is connected, and your device is properly configured by the debugger to output this signal.

Do you want to use TRACE when debugging your project, or do you want to generate a pulse train on a specific GPIO?

If you want to generate a clock pulse on a given GPIO, you can use GPIOTE+PPI+TIMER to obtain this, like this example for the nRF51-series devices:

https://github.com/NordicPlayground/nrf51-8-mhz-gpio-clock/blob/master/main.c

 

Kind regards,

Håkon