MCXA153VLF internal clock frequency

_Ferrari_ — Tue, 24 Jun 2025 07:27:29 GMT

Dear all,

I'm developing a project based on the MCXA153VLF CPU, equipped with an external Crystal Oscillator. I'm using a 16MHz Crystal oscillator.

I would like to know if he FIRC (fast internal reference clock) can be sincronized with external clock in order to use internal 96MHz clock, generated by FIRC, as main clock.

Is it possible to use the "highlighted block" (int the red ellipse) to syncronize FIRC with external clock ? if so, how to do it ?

if not how to syncronize the FIRC with the external clock ?

Thank you very much for your help and cooperation

regards

Re: MCXA153VLF internal clock frequency

Harry_Zhang — Thu, 26 Jun 2025 03:07:13 GMT

Hi @_Ferrari_

Yes — the FIRC in the MCXA153 can be auto-trimmed using the external crystal oscillator (SOSC) as a reference clock.

This is supported and described in section 22.6.3.2 "FIRC auto trim example" of the MCXA153 reference Manual.

Harry

topic Re: MCXA153VLF internal clock frequency in MCX Microcontrollers

MCXA153VLF internal clock frequency

Re: MCXA153VLF internal clock frequency