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K70F150M and external 12MHz oscillator

Question asked by Alexander Bazhaev on Feb 20, 2014
Latest reply on Feb 28, 2014 by Jorge_Gonzalez

Hi all. I'm trying to initialize K70F150M, which uses external 12MHz oscillator at XTAL1 and external XTAL32 32kHz.

MCGOUTCLK supposed to be 150 MHz, target mode - PEE, selected PLL - PLL0.

 

I want initialize k70 like in it's datasheet, example #1

Here are my modes sequency: FEI-> FBE-> PBE-> PEE.

Here are PLL0 frequency dividers:

12MHz * 1 * 25 = 150 MHz, so

PRDIV0=0x00u

VDIV0 = 0x09u

I have a problem configuring C1

Example text: "C1[FRDIV] set to 3'b100, or divide-by-512 because 8 MHz / 512 = 31.25 kHz which is in the 31.25 kHz to 39.0625 kHz range required by the FLL."

But I have 12 MHz oscillator, so 12 Mhz / 512 = 23.4kHz, 12MHz/256=46.8kHz

So I don't have any dividers to get frequency in the secified range. What value I have to set in?

 

Whole initialization code is in attachment #1

Example's screenshot are in the attachments #2 and #3.

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