> movf    <somebyte>,W
> skpnc
> incfsz    <somebyte>,W
> addwf    <resultbyte>,F
>
> As a slick way to do handle carries in an N-byte multiple precision add.
If
> this trick is well-known, it has somehow escaped me. [James: how about a
> section on N-byte arithmetic in the code snippets archive?]

Note that this only works if RESULTBYTE is the last (highest) byte of the
multi-byte number.  The carry generated by this code snippet won't be
correct for use by the next byte.  This is because a carry could occur from
the INCFSZ instruction, which is then lost when the ADDWF instruction
executes.


*****************************************************************
Olin Lathrop, embedded systems consultant in Devens Massachusetts
(978) 772-3129, olin@cognivis.com, http://www.cognivis.com

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