Felix Collins/PEC/NZ wrote:
>
> Hi,
> I'm very new to the PICnic and have a question that may be a bit simple for
 the
> group.  However I can't find anything in the FAQ's.
>
> The problem is that the transmitter seems to be inverting all the signals.  It
> seems to idle high, but the start bit, data and stop bits are all in the wrong
> polarity (start bit is high and stop bit is low).  The receiver also seems to
> be working incorrectly as it doesn't correctly receive data being sent.
>
> I can't find anything in the documentation about polarity inversion or
> anything.  Am I just missing something really obvious?  This application is
> just for inter-processor comms between a 3v DSP and a 16C63 pic.  I'm running
> it at 312.5 kiloBaud, 1 start, 8 data, no parity, 1 stop.
>
> Thanks for any suggestions,
> Felix

Felix,

There is a known problem with the UART's in the PIC16C6X series when
running at high baud rates. Check out the errata sheets on the Microchip
site for more information and possible work-arounds. As for the polarity
inversion, I'm not sure what your problem is. I'm assuming that you are
not going through a level-converter (like a MAX232) since this is
inter-processor communication.

Hope this helps.

Greg Maki