Forums

PIC Timing

Started by Unknown January 31, 2004
you know, shamoon, this is a bit like the movie Groundhog Day. About
a month ago, you had exactly the same questions and got exactly the
same answers. Since you obviously haven't solved your problem, you
should try a different tack. Maybe get an o'scope and see if the
crystal is oscillating or break down and buy a prebuilt proto board
like one of the MELabs LabX boards.

--- In , honamos@y... wrote:
> Hey Chad,
> I'm using a crystal. A 4MHz crystal...
>
> What now?
>
> Thanks for your help.
> Shamoon
>
> --- In , Chad Russel <chadrussel@y...> wrote:
> > If you have an oscillator and not a crystal, the you don't need
any
> > capacitors. Just hook it up to the OSCIN or OSC1 pin and set the
> PIC
> > to HS, XT or LP.
> >
> > --- honamos@y... wrote:
> > > Well,
> > > I have a 4MHz Oscillator. I tried XT, but it doesn't work. It
> only
> > > works on INTRC(IN) for some reason. I have the appropriate
> capacitor
> > >
> > > values for XT, but it still doesn't work.
> > >
> > > Ideas?
> > >
> > > Shamoon
> > > --- In , "Scott Kellish" <skellish@c...>
> > > wrote:
> > > > It depends on what freq Osc your using. From page 93, table
14-
> 2 of
> > >
> > > the PIC16F62X datasheet (which I assume you forgot to mention
> that
> > > you read but were confused :) ),
> > > >
> > > > Mode Freq
> > > > LP 32kHz or 200kHz
> > > > XT 100kHz, 2MHz or 4MHz
> > > > HS 8MHz, 10MHz or 20MHz
> > > >
> > > > You need to refer to the data sheet because you must include
> > > capacitors on each leg of the XTAL. The tables give the
> appropriate
> > > values. There is also a similar table if your using a ceramic
> > > resonator circuit.
> > > >
> > > > Scott Kellish
> > > >
> > > > ----- Original Message -----
> > > > From: John Remington
> > > > To:
> > > > Sent: Saturday, January 31, 2004 5:49 PM
> > > > Subject: Re: [piclist] PIC Timing
> > > >
> > > >
> > > > XT
> > > >
> > > > --- honamos@y... wrote:
> > > > > I need to use an External Oscilator for my 16F628. Which
> > > setting
> > > > > should I use? LP, XT, HS, EC?
> > > > >
> > > > > What else do I need to do?
> > > > >
> > > > > Thanks for any help.
> > > > >
> > > > >
> > > >
> > > >
> > > > __________________________________
> > > >
> > > >
> > > > to unsubscribe, go to http://www.yahoogroups.com and follow
> the
> > > instructions
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > ----------------------------
--
> --
> > > ----------
> > > > Yahoo! Groups Links
> > > >
> > > > a.. To
> > >
> > >
> >
> >
> > =====
> > My software has no bugs. Only undocumented features.
> >
> > __________________________________
> >




:-p Is that Shamoon again? One more day until the blessed event
http://www.punxsutawneyphil.com/ My sister lives about an hour away,
and has threatened to take him out on Monday with her .30-06.

Same spiel as before. Leads to xtal as short as possible. Parallel
cut crystal. Use the crystal manufacturer's recommended capacitors.
Don't try to power your coffee pot also with the output of the xtal.
It's hard to keep these things from oscillating when they are not
supposed to. :-p

Good luck,
Chad
--- Phil <> wrote:
> you know, shamoon, this is a bit like the movie Groundhog Day. About
>
> a month ago, you had exactly the same questions and got exactly the
> same answers. Since you obviously haven't solved your problem, you
> should try a different tack. Maybe get an o'scope and see if the
> crystal is oscillating or break down and buy a prebuilt proto board
> like one of the MELabs LabX boards.
>
> --- In , honamos@y... wrote:
> > Hey Chad,
> > I'm using a crystal. A 4MHz crystal...
> >
> > What now?
> >
> > Thanks for your help.
> > Shamoon
> >
> > --- In , Chad Russel <chadrussel@y...>
> wrote:
> > > If you have an oscillator and not a crystal, the you don't need
> any
> > > capacitors. Just hook it up to the OSCIN or OSC1 pin and set the
>
> > PIC
> > > to HS, XT or LP.
> > >
> > > --- honamos@y... wrote:
> > > > Well,
> > > > I have a 4MHz Oscillator. I tried XT, but it doesn't work. It
>
> > only
> > > > works on INTRC(IN) for some reason. I have the appropriate
> > capacitor
> > > >
> > > > values for XT, but it still doesn't work.
> > > >
> > > > Ideas?
> > > >
> > > > Shamoon
> > > > --- In , "Scott Kellish" <skellish@c...>
> > > > wrote:
> > > > > It depends on what freq Osc your using. From page 93, table
> 14-
> > 2 of
> > > >
> > > > the PIC16F62X datasheet (which I assume you forgot to mention
> > that
> > > > you read but were confused :) ),
> > > > >
> > > > > Mode Freq
> > > > > LP 32kHz or 200kHz
> > > > > XT 100kHz, 2MHz or 4MHz
> > > > > HS 8MHz, 10MHz or 20MHz
> > > > >
> > > > > You need to refer to the data sheet because you must include
> > > > capacitors on each leg of the XTAL. The tables give the
> > appropriate
> > > > values. There is also a similar table if your using a ceramic
> > > > resonator circuit.
> > > > >
> > > > > Scott Kellish
> > > > >
> > > > > ----- Original Message -----
> > > > > From: John Remington
> > > > > To:
> > > > > Sent: Saturday, January 31, 2004 5:49 PM
> > > > > Subject: Re: [piclist] PIC Timing
> > > > >
> > > > >
> > > > > XT
> > > > >
> > > > > --- honamos@y... wrote:
> > > > > > I need to use an External Oscilator for my 16F628. Which
>
> > > > setting
> > > > > > should I use? LP, XT, HS, EC?
> > > > > >
> > > > > > What else do I need to do?
> > > > > >
> > > > > > Thanks for any help.
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > > __________________________________
> > > > >
> > > > >
> > > > > to unsubscribe, go to http://www.yahoogroups.com and follow
>
> > the
> > > > instructions
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> ----------------------------
> --
> > --
> > > > ----------
> > > > > Yahoo! Groups Links
> > > > >
> > > > > a.. To
> > > >
> > > >
> > >
> > >
> > > =====
> > > My software has no bugs. Only undocumented features.
> > >
> > > __________________________________
> > >
>


=====
My software has no bugs. Only undocumented features.

__________________________________