On Tue, 14 Nov 2006 23:18:12 -0000, "Przemyslaw Lopaciuk" wrote:

>Hi,
>I'm using PIC18F8621 with 40 MHz crystal and I've just tested it with an oscilloscope.
>The odd thing is that it shows that the frequency is about 13MHz on both outputs (X1 and X2).
>What could be the reason of it? Load capacitance? 
> 
>I would be very grateful for every advice.
> 

As I read the datasheet, without the PLL, the max crystal frequency is
limited to 25 MHz in HS mode. To get 40 MHz operation, you'd need to
use a 10 MHz crystal with the PLL enabled (HS+PLL in the configuration
bits).


Regards, Bob

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