topic Re: KV46 : How to get a system/core clock @ 100MHz with 8 MHz crystal in Kinetis Microcontrollers

KV46 : How to get a system/core clock @ 100MHz with 8 MHz crystal

frq04646 — Tue, 16 May 2017 14:23:45 GMT

Hi all,

I'm using board HVP-KV46F150M, with KV46 on it.

KV46 is clocked with external crystal @ 8 MHz, with load capacitors @ 10pF.

I would like to set up system & core clocks to 100 MHz, which is the maximum in RUN mode, according to datasheet.

However, I can't find a configuration matching this requirement when using MCUXpresso Clock Tool.

The reason is that the PLL output frequency must be in range 220 MHz - 480 MHz, and the only way I found to get 100MHz on system/core clock is to have PLL output @ 200 MHz (see attached capture)

Any idea ?

Thanks !

Pierre

Re: KV46 : How to get a system/core clock @ 100MHz with 8 MHz crystal

Alice_Yang — Wed, 17 May 2017 10:11:27 GMT

Hello Pierre,

- It seems if the external crystal is 8Mhz, the PEE mode can not generate core clock with 100MHZ.

From the datasheet we can see the PLL output range is 110MHZ - 240MHZ,

so the range of PLL on Clock configure tool is 220 - 480 , it can't choose 200MHZ.

- You can increase the external crystal, for example 16MHZ:

Hope it helps

Have a great day,
TIC

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Re: KV46 : How to get a system/core clock @ 100MHz with 8 MHz crystal

frq04646 — Wed, 17 May 2017 12:33:47 GMT

Hi Alice,

Thanks for pointing this part of the datasheet out. Answer is clear.

Kind Regards

Pierre