Can kinetis mcu KL4x operate on a lower frequency than 48MHz ?

[satsok_n]

I want to operate mcu KL4x on a lower frequency than the normal 48MHz. Is it possible ?

[jorge_a_vazquez]

Hi Kostas Nomikos

Yes, it is possible. Are you using KL43 or KL46? These two devices have different clock module (MCG and MCG-lite). I recommend you the following link:

https://www.nxp.com/files-static/training_pdf/28973_S08_MCG_WBT.pdf 

It is for MCG and it explains in detail the different clock modes. Actually, out of reset, Kinetis devices work in FEI mode which doesn't run to the 48MHz.

I highly recommend you SDK software tools, You can download it from

https://mcuxpresso.nxp.com 

It includes a clock config tool where you can set the frequency that needs.

Hope this information could help you, please don't hesitate to contact me if you have any other question about this.

Have a great day,
TIC

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[satsok_n]

I am using KL46Z. Thanks for your help, much appreciated.

[mjbcswitzerland]

Kostas

There are various clocking options:

See some references for the KL46 at
http://www.utasker.com/kinetis/FRDM-KL46Z.html
http://www.utasker.com/kinetis/TWR-KL46Z48M.html

including simulation of the operation and clock settings.

Regards

Mark