topic Re: Clocking K64 @120MHz using 32KHz IRC? in Kinetis Microcontrollers

Clocking K64 @120MHz using 32KHz IRC?

nitinharish — Wed, 13 May 2015 13:52:29 GMT

Folks

Is it possible to run K64 @120MHz using 32KHz internal IRC Reference (refereed as slow clock in K64 manual) ?

Re: Clocking K64 @120MHz using 32KHz IRC?

mjbcswitzerland — Wed, 13 May 2015 14:00:56 GMT

Nitin

32kHz RTC can only be used by the FLL (not by the PLL, because its value is too low for the PLL's minimum input of 2MHz).

The highest FLL factor is 2929, which limits the speed to 32768 x 2929 = 95.977472MHz

When using the FLL the USB clock should be either from IRC48M (suitable for device mode but not host) or from an external source since the FLL output is not suitable for USB (high jitter which doesn't fulfil the USB specification).

Regards

Mark

Kinetis: µTasker Kinetis support

K64: µTasker Kinetis FRDM-K64F support / µTasker Kinetis TWR-K64F120M support

For the complete "out-of-the-box" Kinetis experience and faster time to market

Re: Clocking K64 @120MHz using 32KHz IRC?

nitinharish — Wed, 13 May 2015 14:11:54 GMT

mjbcswitzerland, thanks for your blessings. I figured that out from the manual and your web page but thought you might have figured some trick out.

Thanks for the answer.

Re: Clocking K64 @120MHz using 32KHz IRC?

nitinharish — Wed, 13 May 2015 14:25:58 GMT

mjbcswitzerland, please follow me in the freescale community (that is the only way I can send you a private message).

I am interested in buying a utasker commercial license for kinetis (specially K60 and K64).

Can you please quote a price (with full support email and phone) ?

My email, I will send you in private message.

Thanks and Regards

Nitin Harish

Re: Clocking K64 @120MHz using 32KHz IRC?

mjbcswitzerland — Wed, 13 May 2015 19:22:05 GMT

Nitin

I did as you asked.

Regards

Mark

mark (at) utasker.com