Luis:

This comes up every once in a while and is likely to be in the 
archives somewhere.

The last time I answered the question, I came up with these.  I 
didn't assemble or test them, but no one complained that they failed 
to work...

To increment one byte:

    INCF    REG 

    MOVLW   0x06
    ADDWF   REG
    SKPDC
    SUBWF   REG 

    MOVLW   0x60
    ADDWF   REG
    SKPC
    SUBWF   REG

To decrement one byte:

    MOVLW   1
    SUBWF   REG

    MOVLW   0x06
    SKPDC
    XORWF   REG

    MOVLW   0x60
    SKPC
    XORWF   REG

The Carry flag is valid after each of those, so first inc/dec the low 
byte, then use the carry to decide whether to inc/dec the high byte.

-Andy

=== Andrew Warren - fastfwd@ix.netcom.com

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist