On Fri, 11 Oct 2002, David Duffy wrote:

> >Russell McMahon wrote:
> > > A ceramic resonator has ample accuracy to guarantee the required
> > accuracy if
> > > used at both ends.
>
> Vasile:
> >   I'll retranslate a little this phrase:
> >
> >   A ceramic resonator *might* have the accuracy to guarantee if used at
> >both ends. Is much better if slow rate are used.
>
> As has been said many times before, the accuracy is NOT dependent
> on the baud rate. Its a percentage thing.

  Ok, maybe I misunderstand the translation of "accuracy" which according
to my Webster's is:
  -- the condition or quality of being true,
     correct, or exact; precision; exactness.
I had yesterday a problem with choosing an "accurate" ceramic resonators
and I can assure you, in my PIC-PC connection, a slow rate may work with a
"wrong value" resonator and a high rate not, using the same basic code
which is working perfectly with a Xtal.
Everything depends if the samples are or not taken at the middle of the
receptioned bit value. And I'm not talking about using USART but
bit-banged.


 I use ceramic resonators all
> the time, from 4MHz & 1200 baud to 20MHz & 115200 baud without
> any problems. Sometimes from PC<->PIC and sometimes PIC<->PIC.
> I all comes down to the starting error percentage & variations caused
> by temperature. Most of my equipment operates in the 10-60 degrees
> (Celcius) range so my results may be better than some. :-)
> David...
>
> ___________________________________________
> David Duffy        Audio Visual Devices P/L
> U8, 9-11 Trade St, Cleveland 4163 Australia
> Ph: +61 7 38210362   Fax: +61 7 38210281
> New Web: www.audiovisualdevices.com.au
> ___________________________________________
>
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