Obviously setting, or clearing a bit is done with bsf and bcf. Toggleing a bit is done with XOR and a mask. But what if you don't know which bit to set, clear or toggle before the program is compiled?
There are two ways of implementing this operation based on where the input value is relative to the output value. If they are the same (ie the operation is to complement a specific bit), the code to be used is simply:movlw 1 << BitNumber ; Complement Specific Bit for "NOT" xorwf BitRegister, f
If the bit is in another register, then the value stored is the complement of it:bcf Result ; Assume that the Input Bit is Set btfss Bit ; - If it is Set, then Result Correct bsf Result ; Input Bit Reset, Set the Result
|file: /Techref/microchip/math/bit/flipbit.htm, 1KB, , updated: 2004/12/6 12:55, local time: 2018/4/21 01:09,
|©2018 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/math/bit/flipbit.htm"> Toggle or NOT or flip bit number X</A>
|Did you find what you needed?|
PICList 2018 contributors:
o List host: MIT, Site host massmind.org, Top posters @20180421 RussellMc, Van Horn, David, Sean Breheny, Isaac M. Bavaresco, Bob Blick, Neil, David C Brown, alan.b.pearce, Brent Brown, John Gardner,
* 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!