please dont rip this site

PIC Microcontoller Subtraction Math Method

        movf    a1,w 
        subwf   b1,f 

        movf    a2,w 
         incfsz a2,w 
          subwf b2,f 

        movf    a3,w 
         incfsz a3,w 
          subwf b3,f 

        movf    a4,w 
         incfsz a4,w 
          subwf b4,f 

Following on from the multi-byte addition routines by Dwayne Reid and Regulus Berdin this works for 32-bit signed/unsigned subtraction. (only tested in Visual Baisc)

sub32   ;OpD=OpD-OpB
        movf    OpB + 0, W
        subwf   OpD + 0, F

        movf    OpB + 1, W
         incfsz OpB + 1, W
          subwf OpD + 1, F

        movf    OpB + 2, W
         incfsz OpB + 2, W
          subwf OpD + 2, F

        movf    OpB + 3, W
         incfsz OpB + 3, W
          subwf OpD + 3, F


file: /Techref/microchip/math/sub/32bb-drrb.htm, 1KB, , updated: 2016/5/10 10:39, local time: 2024/4/18 02:44,

 ©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE!

<A HREF=""> PIC Microcontoller Subtraction Math Method </A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type a nice message (short messages are blocked as spam) in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.

Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?

  PICList 2024 contributors:
o List host: MIT, Site host, Top posters @none found
- Page Editors: James Newton, David Cary, and YOU!
* Roman Black of Black Robotics donates from sales of Linistep stepper controller kits.
* Ashley Roll of Digital Nemesis donates from sales of RCL-1 RS232 to TTL converters.
* Monthly Subscribers: Gregg Rew. on-going support is MOST appreciated!
* Contributors: Richard Seriani, Sr.

Welcome to!