Thanks to everyone who chimed in, it got me thinking through the problem better. I think I am doing the calculations correctly but some of the baud rates I'd chosen must have had too much of an error. I am able to run at 9600 with 8 bit, BRGH=3D0, BRG=3D78 and at 115200 with = 8bit BRGH=3D1, BRG=3D25. I tried to run 9600 with 8bit BRGH=3D1, BRG=3D311 with no luck. This is all still using 48MHz. Thanks again Bill On Fri, Mar 23, 2012 at 7:26 AM, wrote: > > > A 'hexadecimal' crystal is more suitable for common baud rates, but > > whether you can or do use one depends on the functional priorities. For > > example if a microsecond timer is more important than comms, then a > > 20MHz would be preferable (for the 200ns cycles). You might have to > > compromise somewhere > > > > An 18.432MHz crystal in the calculations > > > > ((18432000/115200)/16)-1 > > > > =3D 9.000000, no error > > > > There is also a 19.something that gives exact baud rates (19.66088? or > something like that). The other option would be to 'overclock' slightly a= t > twice 12.288 which is also an exact baud rate frequency (hence it tended = to > be used as the standard frequency for 8080 CPUs). > > > -- > Scanned by iCritical. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 This e-mail, including any attachments, is intended solely for the person or entity to which it is addressed and may contain confidential, proprietary and/or non-public material. Except as stated above, any review, re-transmission, dissemination or other use of, or taking of any action in reliance upon this information by persons or entities other than an intended recipient is prohibited. If you receive this in error, please so notify the sender and delete the material from any media and destroy any printouts or copies. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .