40Mhz

[Armando Herjim]

Hello everybody!!

Does anybody know if the Pic 18F4550 works with a 40 Mhz crystal in HS mode?? If not, does anybody has a hint??

Thanks to all of you.

[Pic_User]

Hi Armando,

I haven't used the PIC18F4550, yet.

Take a look at this thread:
http://www.picbasic.co.uk/forum/showthread.php?t=4086

Is this a 40MHz crystal (I.E. one requiring parallel caps) or is it a 40MHz TTL
clock oscillator?

Above 25MHz, you'll need a TTL type clock oscillator. HS and HSPLL support
up to 25MHz primary osc.

Make sure you have the latest verion of the 4550 data sheet rev DS39632C
and look in the electrical characteristics section at table 28-8, parameter 1A.

With a 40MHz TTL type clock oscillator, and EC or ECIO oscillator modes, it
should work fine.


CONFIG PLLDIV=10,CPUDIV=OSC1_PLL2,USBDIV=2,FOSC=ECIO_EC

-Adam-