Tom Rogers wrote:

>Sipke de Leeuw wrote:
>>
>> Hello all,
>>
>> I think someone else has ask this question before, but I didn't read any
>> answers. What kind of crystal do we need for building the extern part of the
>> oscillator for a PIC: serial or parallel ??
>> (&etc.)
>
>I didn't see any answers, either, so try this:
>
>Basicly, a crystal is a crystal. Size & cut changes the LC model numbers
>to a degree, but there is really no major physical difference between
>series and parallel parts. What is different is the circuit used to
>oscillate the crystal during calibration (or at least the type intended
>when in use). I usually think of most common ic oscillator architectures
>as being series, but the truth is that for microprocessor use I don't
>think I've ever seen a frequency difference, which is subtle in any
>case. Almost any modern small crystal will oscillate just fine with
>almost any modern ic, so you can pretty well relax and follow the
>manufacturers' suggestions for external parts.

Ok, I can explain my problem a little more. For my application using a PIC
(84) a need the processor running at exactly 8 MHz +- 30 ppm. At this point
it is necessary, I think, to know whether the crystal is made to oscillate
in a serie or parallel circuit. I can't find the answer in the datasheets of
the PIC's.

Greetings:                           ... Sipke de Leeuw ...