Christopher Head wrote:

> I implemented what Linux calls the CRC-CCITT (I translated from the
> Linux source), which is a 16-bit CRC, on a PIC18F4550. My implementation
> takes 24 instruction cycles and 24 words of Flash for the basic "add
> one byte to accumulated CRC" operation.

There are two 17 word versions of the CRC-CCITT here:

http://www.dattalo.com/technical/software/pic/crc_1021.asm

Both can be reduced to 16 words for the 18F family by replacing the two
consecutive RLF's with one RLNCF.

There are some other PIC CRC routines here:

http://www.dattalo.com/technical/software/pic/crc.php

Scott
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