Hi, i have a circuit with 2 PIC12F629 with crystal oscillator 4 MHz. I have currently 2 crystal 4 MHz ( one PIC12F629 - one crystal 4 MHz ). It is possible using 1 crystal 4 MHz for both PIC 12F629 ?
Thanks.
Fero
Do you have a crystal, using the PIC's own oscillator, or a 'crystal oscillator' module?. If the latter, then the answer is 'yes'. Most of these have a 'fanout' of perhaps 4 or more, and will drive two PIC's inputs without problems. If the former, then the answer is less certain. I can be made to work (you program the second PIC into EC mode, and connect it's CKIN pin to the CKOUT of the first chip). However the extra load, and capacitance, may require you to adjust the drive to the crystal, and may cause the frequency to shift slightly. Look at the Microchip application note 'AN949', and the note near the end of this.
Best Wishes
A tiny logic 74HCU04 would put that to rights.
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