Microchip have me confuddled on choosing the clock source for the 16F690=20
chip.=20

They state on page 109 (111 in pdf numbering) under note 4:

When the device frequency is greater than 1 MHz, the FRC clock source is=20
only recommended if the conversion will be performed during Sleep.

And yet, all public code including Microchips' that I've seen use the FRC,=
=20
most recently the code in their new Pic starter kit uses the FRC, they are=
=20
using the internal 8MHz oscillator, but that is well, eight times over=20
1MHz.

 I will be using an 11.059MHz crystal and therefore a /32 prescaler will=20
bring the clock into the ADC frequency range.

I just can't get my head around why they recommend against using it and=20
then do so themselves (Microchip demo code reputation notwithstanding).=20
Surely the internal FRC will have less jitter and noise?

Colin=20
--
cdb,  on 9/07/2011






--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.