Myke Predko says:
Yesterday, I needed snippets of code which which will increment/decrement the "w" register without affecting any of the other registers in a 12C508.
For Increment, I came up with:xorlw 0x0FF ; Get 1s Complement of Number addwf Reg, w ; w = Reg + (w^0x0FF) subwf Reg, w ; w = Reg + ((Reg + (w^0x0FF))^0x0FF) + 1 ; w = w + 1
and for Decrement:subwf Reg, w ; w = Reg + (2^0x0FF) + 1 xorlw 0x0FF ; Get 1s Complement of Result addwf Reg, w ; w = w - 1
"Reg" can be any Register in the PICMicro which cannot change during the course of the three instructions (in the low-end PICMicros, this is any port other than the timer and I/O ports).
|file: /Techref/microchip/12countw.htm, 1KB, , updated: 1999/6/22 09:49, local time: 2017/10/23 19:52,
|©2017 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?|
<A HREF="http://www.piclist.com/techref/microchip/12countw.htm"> microchip 12countw</A>
|Did you find what you needed?|
PICList 2017 contributors:
o List host: MIT, Site host massmind.org, Top posters @20171023 RussellMc, Van Horn, David, James Cameron, Sean Breheny, IVP, alan.b.pearce, Neil, David C Brown, Bob Blick, Denny Esterline,
* 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 www.piclist.com!