You might consider using a 32Khz crystal for timekeeping and the internal RC 
oscillator for operation. You can calibrate your baud rate divisor using the 
known speed of the 32Khz oscillator.

-- Bob Ammerman
RAm Systems

----- Original Message ----- 
From: "Mike Harrison" <mike@whitewing.co.uk>
>I have a slightly odd requirement for what can be considered to be a comms 
>logger - needs to wake a
> few times a sec, look for some data, and if received, record a couple of 
> bytes & timestamp it. Only
> need 2 IO's, must be very low avarage power (2032  coin cell )
> I can't run everything on a 32K xtal as I need higher speed to do the 
> comms - a T1 oscillator would
> be usaeble but the lower-end 8/14 pin PICs I've looked at so far don't do 
> T1 oscillators. The
> ability to turn off the 32K osc for storage would be an advantage

You might consider using a 32Khz crystal for timekeeping and the internal RC 
oscillator for operation. You can calibrate your baud rate divisor using the 
known speed of the 32Khz oscillator.

-- Bob Ammerman
RAm Systems

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