On Thu, 17 Sep 1998, Clewer,Brian wrote:

> I need to use even parity, 1 stop bit with 7 data bits.  I can quite
> easily transmit 8 data bits and no parity but my question is "what would
> be the best way of implementing even parity and 7 data bits."  Has
> anybody got a snippet of code I could look at (or even pseudo code) or
> maybe a web site to goto?

Very sneaky and efficient parity generators were posted here, but for a
serial routine, I'd implement it by toggling a flag bit in a register in
the serializer proper, where a decision is already made. After the 7th bit
send the LSB in the flag byte as parity. Set the flag byte to 1 for even
(0 for odd)  at entry and increment it for each 1 transmitted. You may
have to adjust the timing in the serializer loop for the added
instruction.


any optimizers ? <g>

Peter