Series Cut Crystal Ball or Parallel Cut Crystal Ball? -----Original Message----- From: Lawrence Lile [mailto:llile@TOASTMASTER.COM] Sent: Friday, June 14, 2002 10:47 AM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [PIC]: Will an unprogrammed chip oscillate? Series cut .. Parallel cut - How does one figure out which applies to the crystal in question. I just looked at EVERY crystal in Digikey, and NONE (i.e. diddlysquat, Nada, Nichts, Nyet, Zip, Zilcho) specify whether the crystal is parallel or serial cut. Now there are a few that allude to "When run in parallel mode.." "Effective series resistance" And one has a whole paragraph of rubber language which basically says "Your Mileage May Vary" when run in parallel or series mode, but none of them just come right out and say one or the other. I guess the correct method is to use a CRYSTAL ball. --Lawrence ----- Original Message ----- From: "Brendan Moran" To: Sent: Thursday, June 13, 2002 5:33 PM Subject: Re: [PIC]: Will an unprogrammed chip oscillate? > It could be that what you were using before is a parallel cut crystal, since > there is a section in the 16F87x manual stating that only series cut > crystals will operate. I'd imagine that all the PICs are the same that way, > though I haven't checked. > > At least, that's my best guess. > > --Brendan > > ----- Original Message ----- > From: "Lawrence Lile" > To: > Sent: Thursday, June 13, 2002 3:22 PM > Subject: Re: [PIC]: Will an unprogrammed chip oscillate? > > > > After fixing a few crossed ICSP wires, the chip programs and verifies OK. > > > > Well, the plot thickens. I had a 4 MHz crystal and two capacitors (22 pF, > > IIRC), and still could not get my PIC to oscillate. > > > > I replaced the crystal and caps with a 4 MHZ packaged ceramic resonator > with > > internal caps, and the oscillator strarts fine. > > > > So what causes one kind of crystal to not oscilate with the PIC, another > to > > work OK? I've never really run into this before. > > > > --Lawrence > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body