----- Original Message ----- 
From: "Roger Weichert" <rweicher@bigpond.net.au>
To: "Microcontroller discussion list - Public." <piclist@mit.edu>
Sent: Tuesday, September 22, 2009 6:51 PM
Subject: Re: [PIC] Basic question on 'RRF' command


> Hi again Howard,
>
> Does adding  '0'  to the program counter cause any problems?
>
> Regards,   Roger

No. The program counter is always pointing at the _next_ instruction. Thus, 
adding zero to it is effectively a NOP. Program execution just continues 
with the very next instruction.

    ADDWF    PCL,F        ; add to program counter
    GOTO    A                   ; we come here if W was zero
    GOTO    B                   ; and here if W was one
    ...etc.

NOTE: You must be careful not to span a page boundary ( a multiple of 0x100 
instructions ) with the above construct because only the least significant 
byte of the program counter is affected by the ADDWF instruction.

-- Bob Ammerman 

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