Does supply voltage effect baud rate?

When operating within the rated voltages of a pic 12F683 does the supply voltage effect the generated baud rate?

I'm struggling with series comms using a 12F683 at 4mhz sending 8N1 data using serout N9600.

I have a logic analyser and it reports the baud rate as 8696 which is around 10% off and I think causing my data corruption.

I have had this working before with a 4mhz clock for months. very odd? Any ideas?

If you have PBP 2.60 and are using SEROUT, you should apply the "A" patch that was released last week.
http://melabs.com/support/patches.htm

It fixes the SEROUT/IN baud rate.

Thanks for that i was pulling my hair out! It was working when compiled with earlier version :mad:

What exactly is the issue with it that has been corrected?

Several things have been corrected, including those that were listed on the "Issues" page.
http://melabs.com/support/pbpissues.htm

SERIN/OUT is the 4th one down ... (Commands affected: SERIN/SEROUT)

Can 9600 baud rate be supported at 4MHz?
I read 2400 is the safe option and in some cases 4800 can be supported at MAX.