On Wed, 6 Dec 2000, William wrote:

> Hi, all piclisters.
>
>     How to write a even parity checking algorithm?
> My data will be 7-bit (LSB) for ASCII data, and the
> 8th bit will reserse for even-parity bit checking.

Here's a variation of Payson's (with the same verbose comments)


   bcf    byte_to_send,7
   swapf  byte_to_send,w
   xorwf  byte_to_send,w
   movwf  t
   rlf    t,f
   rlf    t,f
   xorwf  t,f
   rlf    t,w
   xorwf  t,w
   andlw  0x80
   iorwf  byte_to_send,w  ; use xor for odd parity

Scott

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