IVP wrote:
>> With Fosc =3D 48MHz
>>    =20
>
> The OP said the PICDEM FSUSB has a 20MHz crystal. I'm not
> familiar with that board. Can it be changed to 48MHz ?
>  =20
The picdem FS USB has a PIC18F4550. Due to the USB the
PIC18f4550 has a rather unusual clock block. Normally*
the incoming clock is divided down to 4MHz, then multiplied
up to 96MHz then divided down again for the USB and
primary clock.

So with this chip it's perfectly normal to have a 20 MHz
crystal and yet have a "primary clock" of 48 MHz.

* You can also bypass the 96 MHz pll and drive core and/or
USB directly off the oscilator but I don't think i've ever seen it done

--=20
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