> I haven't looked at the app note, but most writeups about crystal caps > I've > seen have a big flaw in that they ignore the output impedence of the > driver. > >From the comments here, it seems this app note is no different. They do mention how to check the oscillation margin, and drive level, which pretty much covers that. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist