Matrix user forums

I'm looking to replace the 20MHz crystal on my HP-488-02 development board with a 40MHz crystal. Can you tell me who your supplier is for that part so that I can get one in the same package? Also, do you know of any reason offhand why a 40MHz crystal might not work with the board?

Hello

Which PICmicro device are you looking to drive with the 40MHz crystal? Most of the PICmicro devices will not be unable to run at this speed.

PIC 18F258

I don't think the chip will have a problem, because its UART baud specs include the possibility of running off a 40MHz oscillator. I was more wondering if anything else on the board (the PPP firmware or something) might object to the frequency increase.

Hello

Yes you are correct these devices do support the 40MHz clock. Thats great not spotted that before. You can also use a lower speed clock and use the onboard PLL to boost the program frequency if you wish. There should not be any issues with using a 40MHz clock onboard our hardware. The PPP chip has its own oscillator so you should not run into any problems.

Ok, thanks for the info. If you can, would you mind telling me who your manufacturer is for the onboard crystal?

Hello

I normally buy ACT

http://www.rapidonline.com/searchresult ... kw=90-1080

or Truxtal

http://www.rapidonline.com/searchresult ... kw=90-3257

However it looks like these manufacturers do not go as high as you would like.

Remember you can always buy a 10MHz crystal and then enable the onboard 4x PLL to boost this speed up to the 40MHz. This can be done through the expert chip configuration screen.