Yes, two PICs can share a single oscillator. Actually, you can use one P= IC as the oscillator MASTER and connect the other(s) to it as SLAVEs. Th= e oscillator circuit on the chip is basically an inverter biased into the= linear region between Hi and Lo (this is way oversimplified, but serves for disc= ussion). Of the two OSCILLATOR pins, one is Input and the other is Outpu= t - on the PICs I have examined (not all, by any means) Osc1 is the INPUT= and Osc2 is the OUTPUT. Connect your cheap ($1 - $2) crystal or (cheaper= ) ceramic resonator between Osc1 and Osc2 as usual - this PIC is the Mast= er. Then connect Osc2 of the Master PIC to Osc1 of the Slave PIC - you ma= y want to put a 1K resistor in series to reduce excess capacitance at the= Master's output. I have done this several times, even driving several "e= xtra" chips with the common clock output. Roy J. Gromlich -- Original Message -- From: Matt Redmond To: PICLIST@MITVMA.MIT.EDU Send: 2004-04-21 Subject: [PIC]: Two PICs share an oscillator? Maybe silly question, but can two PICs share an oscillator? If so, how m= ight one accomplish this? I ask because 'Jason S' mentioned dividing functionality among several uC= s and it occurred to me that you could end up spending more on oscillators than= on the 12F629s themselves! Thanks! -matt redmond -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics