Re: [piclist] Re: Is PIC timing ultra accurate?


Jan 31 12:54 PM

 


----------------------------

#4343 Jan 31 12:54 PM

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.



----------------------------

#4347 Jan 31 2:49 PM

XT



--- honamos@... 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.

>

>





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----------------------------

#4348 Jan 31 3:19 PM

When I put it on XT, it doesn't work at all. Right now, i have it on

INT....

ideas?

--- In piclist@yahoogroups.com, John Remington jrem123@y...> wrote:

> 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.

> >

> >

>

>

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----------------------------

#4349 Jan 31 3:20 PM

Nope. Use EC and you will gain the use of RA6!

--- In piclist@yahoogroups.com, John Remington jrem123@y...> wrote:

> 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.

> >

> >

>

>

---------------

> Do you Yahoo!?

> Yahoo! SiteBuilder - Free web site building tool. Try it!

> webhosting.yahoo.com/ps/sb/



----------------------------

#4350 Jan 31 3:14 PM

It depends on what freq Osc your using. From page93, table 14-2 of the PIC16F62X datasheet (which I assume you forgot tomention that you read but were confused :) ),  Mode       Freq    LP           32kHz or 200kHzXT           100kHz, 2MHz or 4MHzHS           8MHz, 10MHz or 20MHz You need to refer to the data sheet because youmust include capacitors on each leg of the XTAL. The tables give the appropriatevalues. There is also a similar table if your using a ceramic resonatorcircuit. Scott Kellish ----- Original Message -----From:John RemingtonTo: piclist@yahoogroups.comSent: Saturday, January 31, 2004 5:49PMSubject: Re: [piclist] PIC Timing

XT

--- honamos@... wrote:> I need touse an External Oscilator for my 16F628.  Which setting > should Iuse? LP, XT, HS, EC?> > What else do I need to do?>

> Thanks for any help.> >



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----------------------------

#4351 Jan 31 4:44 PM

doesn't this all depend on what he means by external oscillator? If

he means crystal or resonator, then this answer is correct but if he

wants to generate the clock elsewhere and pump it into the pic, then

EC is the way to go.

--- In piclist@yahoogroups.com, "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: piclist@yahoogroups.com

> 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.

> >

> >

>

>

---------------

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----------------------------

#4354 Jan 31 6:44 PM

Your right in that it depends on what he wants touse as a clock. He said "external osc", but if he's going to use a clock derivedelsewhere than EC would be used. He really needs to read the datasheet as all(most) of the answers are right there. Scott----- Original Message -----From:PhilTo: piclist@yahoogroups.comSent: Saturday, January 31, 2004 7:44PMSubject: [piclist] Re: PIC Timing

doesn't this all depend on what he means by externaloscillator?  If he means crystal or resonator, then this answer iscorrect but if he wants to generate the clock elsewhere and pump it intothe pic, then EC is the way to go.

--- In piclist@yahoogroups.com, "ScottKellish" skellish@c...> wrote:>It depends on what freq Osc your using. From page 93, table 14-2 of thePIC16F62X datasheet (which I assume you forgot to mention that you readbut were confused :) ), > >Mode        Freq    >LP            32kHz or200kHz>XT            100kHz,2MHz or 4MHz>HS            8MHz,10MHz or 20MHz> > You need to refer to the data sheet becauseyou must include capacitors on each leg of the XTAL. The tables give theappropriate values. There is also a similar table if your using a ceramic

resonator circuit.> > Scott Kellish>

>   ----- Original Message ----- >   From:John Remington >   To: piclist@yahoogroups.com

>   Sent: Saturday, January 31, 2004 5:49PM>   Subject: Re: [piclist] PIC Timing> >

>   XT> >   --- honamos@y...wrote:>   > I need to use an External Oscilator for my16F628.  Which setting >   > should I use? LP,XT, HS, EC?>   > >   > What else do Ineed to do?>   > >   > Thanks for anyhelp.>   > >   > > >

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----------------------------

#4355 Jan 31 6:57 PM

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 piclist@yahoogroups.com, "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: piclist@yahoogroups.com

> 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.

> >

> >

>

>

---------------

> Do you Yahoo!?

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----------------------------

#4357 Jan 31 7:28 PM

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@... 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 piclist@yahoogroups.com, "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: piclist@yahoogroups.com

> > 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.

> > >

> > >

> >

> >

---------------

> > Do you Yahoo!?

> > Yahoo! SiteBuilder - Free web site building tool. Try it!

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> instructions

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> > ADVERTISEMENT

> >

> >

> >

> >

> >

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>





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----------------------------

#4358 Jan 31 9:07 PM

Hey Chad,

I'm using a crystal. A 4MHz crystal...



What now?



Thanks for your help.

Shamoon

--- In piclist@yahoogroups.com, 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 piclist@yahoogroups.com, "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: piclist@yahoogroups.com

> > > 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.

> > > >

> > > >

> > >

> > >

---------------

> > > Do you Yahoo!?

> > > Yahoo! SiteBuilder - Free web site building tool. Try it!

> > > webhosting.yahoo.com/ps/sb/

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> > >

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the

> > instructions

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> > > Yahoo! Groups Sponsor

> > > ADVERTISEMENT

> > >

> > >

> > >

> > >

> > >

> > >

---------------

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Terms of

> >

> > Service.

> >

> >

>

>

> =====

> My software has no bugs. Only undocumented features.

>

---------------

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----------------------------

#4359 Jan 31 9:59 PM

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 piclist@yahoogroups.com, honamos@y... wrote:

> Hey Chad,

> I'm using a crystal. A 4MHz crystal...

>

> What now?

>

> Thanks for your help.

> Shamoon

>

> --- In piclist@yahoogroups.com, 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 piclist@yahoogroups.com, "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: piclist@yahoogroups.com

> > > > 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.

> > > > >

> > > > >

> > > >

> > > >

---------------

> > > > Do you Yahoo!?

> > > > Yahoo! SiteBuilder - Free web site building tool. Try it!

> > > > webhosting.yahoo.com/ps/sb/

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> > > >

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> the

> > > instructions

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> > > > Yahoo! Groups Sponsor

> > > > ADVERTISEMENT

> > > >

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> > > >

> > > >

> > > >

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> Terms of

> > >

> > > Service.

> > >

> > >

> >

> >

> > =====

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

> >

---------------

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> > webhosting.yahoo.com/ps/sb/







----------------------------

#4360 Jan 31 10:24 PM

:-p Is that Shamoon again? One more day until the blessed event

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 phil1960us@...> 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 piclist@yahoogroups.com, honamos@y... wrote:

> > Hey Chad,

> > I'm using a crystal. A 4MHz crystal...

> >

> > What now?

> >

> > Thanks for your help.

> > Shamoon

> >

> > --- In piclist@yahoogroups.com, 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 piclist@yahoogroups.com, "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: piclist@yahoogroups.com

> > > > > 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.

> > > > > >

> > > > > >

> > > > >

> > > > >

---------------

> > > > > Do you Yahoo!?

> > > > > Yahoo! SiteBuilder - Free web site building tool. Try it!

> > > > > webhosting.yahoo.com/ps/sb/

> > > > >

> > > > >

> > > > > to unsubscribe, go to www.yahoogroups.com and follow

>

> > the

> > > > instructions

> > > > >

> > > > >

> > > > > Yahoo! Groups Sponsor

> > > > > ADVERTISEMENT

> > > > >

> > > > >

> > > > >

> > > > >

> > > > >

> > > > >

> > > >

---------------

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> > --

> > > > ----------

> > > > > Yahoo! Groups Links

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> > > > > a.. To visit your group on the web, go to:

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> > Terms of

> > > >

> > > > Service.

> > > >

> > > >

> > >

> > >

> > > =====

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

> > >

---------------

> > > Do you Yahoo!?

> > > Yahoo! SiteBuilder - Free web site building tool. Try it!

> > > webhosting.yahoo.com/ps/sb/

>

>





=====

My software has no bugs. Only undocumented features.



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----------------------------

#7464 Oct 24, 2004

I need to supply a DAC with a clock of 11.2896MHz. Would a PIC (such as a 16F84-20 running a 20MHzcrystal) be able to supply such a frequency and if so what sort of accuracywould it be able to obtain? Thanks,Nigel



----------------------------

#7465 Oct 24, 2004

--- In piclist@yahoogroups.com, "Nigel Symes" symesbris@h...> wrote: > I need to supply a DAC with a clock of 11.2896 MHz.

>

> Would a PIC (such as a 16F84-20 running a 20MHz crystal) be able to

supply such a frequency and if so what sort of accuracy would it be

able to obtain? >

> Thanks,

> Nigel



Nigel,



PIC timing is as accurate (basically anyway) as the component used as

it's clock (in this case the 20 MHz crystal). However, since each

instruction takes 4 clock cycles (except instructions that modify

Program Counter), a PIC running at 20 MHz would not be able to output

an 11+ MHz signal.



----------------------------

#7466 Oct 24, 2004

Digi-Key sells 11.2896 MHz crystals for about $1. And 11.2896 MHz

oscillators for just a bit more.



Mike



--- In piclist@yahoogroups.com, "Nigel Symes" symesbris@h...> wrote:

> I need to supply a DAC with a clock of 11.2896 MHz.

>

> Would a PIC (such as a 16F84-20 running a 20MHz crystal) be able to

supply such a frequency and if so what sort of accuracy would it be

able to obtain?

>

> Thanks,

> Nigel



----------------------------

#7467 Oct 24, 2004

----- Original Message -----

From: Nigel Symes

To: piclist@yahoogroups.com

Sent: Sunday, October 24, 2004 1:47 PM

Subject: [piclist] Is PIC timing ultra accurate?





I need to supply a DAC with a clock of 11.2896 MHz.



Would a PIC (such as a 16F84-20 running a 20MHz crystal) be able to supply

such a frequency and if so what sort of accuracy would it be able to obtain?



No. You could get an 11.2896 MHz crystal made and use that for both the PIC

and the DAC.



Leon



----------------------------

#7468 Oct 24, 2004

> Message: 1

> Date: Sun, 24 Oct 2004 22:47:02 +1000

> From: "Nigel Symes" symesbris@...>

> Subject: Is PIC timing ultra accurate?

>

> I need to supply a DAC with a clock of 11.2896 MHz.

>

> Would a PIC (such as a 16F84-20 running a 20MHz crystal) be able to

> supply such a frequency and if so what sort of accuracy would it be able

> to obtain?

>

> Thanks,

> Nigel

>

> [This message contained attachments]

>

>

>

No. U can use a simple gate based oscillator with a 11.2896 MHz crystal



Regards..

--

Ing. Germ.n Hern.ndez Castillo

Union Temporal Seguridad Cartagena



----------------------------

#7470 Oct 24, 2004

--- In piclist@yahoogroups.com, "Leon Heller" leon.heller@d...> wrote:

...

>

> No. You could get an 11.2896 MHz crystal made and use that for both

the PIC

> and the DAC.



I agree that this is the prefered solution. iirc, there is an issue

of loading but I dont remember where I saw that plus I'm not sure how

two devices can both drive a single crystal. a similar approach is to

use external clock mode (dunno if F84 has it but suggest he moves to

628A which does, is pin compatible, cheaper and more memory). create

an oscillator and feed both at 11.2896 MHz. page 95 and 96 of the

627A/628A/648A datasheet show how to do this in detail.



----------------------------

#7471 Oct 24, 2004

Yep - I stuffed up. I thought I needed to supply aDAC (a cs4334 to be precise) with a specific frequency to oversample some audio.Thankfully the MP3 decoder I'm using (STA013) provides the requiredfrequency. I did find a place, www.foxonline.com that sell variable(adjustable) oscillators for US$15. But I don't need them now. Thanks,Nigel----- Original Message -----From:PhilTo: piclist@yahoogroups.comSent: Monday, October 25, 2004 2:04PMSubject: [piclist] Re: Is PIC timingultra accurate?



--- In piclist@yahoogroups.com, "LeonHeller" leon.heller@d...>wrote:...> > No. You could get an 11.2896 MHz crystal madeand use that for boththe PIC > and the DAC.

I agree thatthis is the prefered solution.  iirc, there is an issueof loading butI dont remember where I saw that plus I'm not sure howtwo devices can bothdrive a single crystal.  a similar approach is touse external clockmode (dunno if F84 has it but suggest he moves to628A which does, is pincompatible, cheaper and more memory).  createan oscillator and feedboth at 11.2896 MHz.  page 95 and 96 of the627A/628A/648A datasheetshow how to do this in detail.





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