RC oscillator

[admin]

Hello,

     I'm trying to use MC68HC908JK3 with RC oscillator but it doesn't work.

     I set the 7th bit of PTAPUER but the problem continuous the same.

     I've used RC oscillator with QT4, QY, JK8 but with JK3 I've never got success.

     Does somebody knows the answer?

Thanks a lot.

Edson

[peg]

Hi Edson,

I have used the RC JK1 successfully in a product using the RC oscillator. But these things are no longer made. From memory there is nothing special to do.

Regards Peg

[peg]

After a little further investigation, I think you may be trying to use the RC osc on a HC part. With the QY/QT the RC osc is a selectable option on the standard part and only requires one R external. With the JK/L 8 the RC osc is a selectable option that requires an ext R/C.

With the JK/JL 1 or 3 the RC osc only exists on the HRC part and this is the one that is discontinued! The HC version needs a crystal. The HRC requires an external R/C.

I got caught out with the dropping of the HRC part and have recently recieved some HC versions and I am going to try to glue a crystal on to the existing PCB as I sell a whopping 5 a year to one customer (so I am not going to produce another PCB).

Regards Peg