topic aw16 external oscillator circuit doesn't work???? in 8-bit Microcontrollers

aw16 external oscillator circuit doesn't work????

allegropro — Tue, 10 Jul 2007 10:45:07 GMT

Now i am using mc9s08aw16 in my project,and the footprint is qfp44.

But i have problem with it,the external oscillator circuit doesn't work,and i test the EXTAL and XTAL signal,but cann't find any oscillating wave.I designed the schematic from the demo MC9s08aw60,i think i cann't make a mistake.

please help me!

any other have encounted this problem?

please share your experience!

Re: aw16 external oscillator circuit doesn't work????

mylim — Tue, 10 Jul 2007 16:03:38 GMT

Hi allegropro,

Did you try using a scope to probe at the crystal? If it doesnt show anything.. by changing a crystal will solve the problem.

Secondly, is the value of the crystal u choose correct?

Hope these help.

Regards,

mingyee

Re: aw16 external oscillator circuit doesn't work????

thisobj — Tue, 10 Jul 2007 19:11:55 GMT

Hello Allegropro,

Have you configured the clock generation registers to use the external crystal? If so, perhaps you could post your configuration code here. Also, the layout for the xtal circuit is somewhat critical. This issue was discussed at some length in the following thread:

http://forums.freescale.com/freescale/board/message?board.id=8BITCOMM&thread.id=6599

Frank