Long term use of TRACECLK

[Michaud]

Hello dev zone !

I shall design a compact hardware solution wich is cost sensitive.

I need to use a NRF52832QFAA,  I need to provide a 16mhz clock to a hardware peripheral. In this case i expect to save a quartz footprint and BOM impact.

1 - In my interpretation, it's not possible to use a PWM à 16Mhz using the 32Mhz HFXO ?

2- Could i use the TRACECLK PIN and TRACEPORTSPEED configuration register to produce this clock source ?

2.1- It's a debug mode, is it possible to activate this mode during product lifecycle ?

2.2- Wich restriction are inherent to this mode ?

Thanks for your support, 

Regards

[Sigurd]

Hi,

1 - In my interpretation, it's not possible to use a PWM à 16Mhz using the 32Mhz HFXO ?

 Your interpretation is correct. That is not possible.

2- Could i use the TRACECLK PIN and TRACEPORTSPEED configuration register to produce this clock source ?

I did some quick tests with this, and I was only able to get the TRACECLK to output 16Mhz when the debugger was attached. The duty cycle was varying between 65% to 75% , and the frequency was varying between 15.62 MHz and 16.67 MHz

So you will need to use a separate crystal for the external device.

[Michaud]

Thanks for your quick tests and response.

So , i need a 16Mhz or an Hardware tips ...