PIC Microcontoller Math Method

Multiply 16x16 bit macro from Bob Fehrenbach, Scott Dattalo

Posted to PICList Mon Aug 4 10:17:59 1997

;*******************************************************************
; Double Precision Multiplication
;
; n_2 : n_1 * n_4 : n_3 -> q_4:q_3:q_2:q_1
;
; Standard shift and add.
; Execution time: 215 to 295 clock cycles.
; Code space: 22 locations
;
; Cleaned up and corrected version from Microchip Ap note by BF.
; Note: Ap note has errors! Additional mods by Scott Dattalo.
;
;*******************************************************************


mpy16b16: macro
local m1, m2
	clrf q_4
	clrf q_3
	clrf q_2
	clrf q_1
	bsf q_2, 7
m1:
	rrf n_2, f
	rrf n_1, f
	skpc
	goto m2
	movf n_3, w
	addwf q_3, f
	movf n_4, w
	skpnc
	incfsz n_4, w
	addwf q_4, f
m2:
	rrf q_4, f
	rrf q_3, f
	rrf q_2, f
	rrf q_1, f
	skpc
	goto m1

endm

file: /Techref/microchip/math/mul/16x16bfsd.htm, 1KB, , updated: 2000/2/11 14:52, local time: 2024/11/22 04:16,

^{3.149.23.123:LOG IN}

©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="http://sxlist.com/techref/microchip/math/mul/16x16bfsd.htm"> PIC Microcontoller Math Method Multiply 16x16 bit macro</A>

Did you find what you needed?

Welcome to sxlist.com!

Site supported by
sales, advertizing,
& kind contributors
just like you!
Please don't rip/copy
(here's why
Copies of the site on CD
are available at minimal cost.