Hello,
I'm having problems interfacing a MT8880(dtmf tranciever) with a PIC
16F628. I'm not 100% sure, but I think my problem stems from the fact that the two chips run at a different clock rate. I have my ~3.5MHz crystal hooked up to the MT8880 as the datasheet calls for, but my PIC has an internal clock that is a bit faster I think? What I tried to do is insert a bunch of NOPs between PIC instructions so the MT8880 has time to see everything, but I have had no success.
Does inserting NOPs sound correct, or am I missing something?? Also, does anyone have some suggestions as to what I should check and how to debug?
Thanks for the help.