please dont rip this site

Atmel AVR Microcontroller Basic Math Code Library

for Multiplication

Multiply 8 bits by 8 bits in software based on code from

; 8bit x 8bit signed multiply
; Register variables:
;  Call:  var10 = 8bit multiplicand
;         var11 = <don't care>
;         var20 = 8bit multiplier
;         lc    = <don't care> (high register must be allocated)
;  Result:var1[1:0] = 16bit result of var10 * var20
;         var20     = <not changed>
;         lc        = 0
; Size  = 24 words
; Clock = 80 cycles (+ret)
; Stack = 0 byte

mul08s:		clr	lc
		tst	var10
		brpl	PC+3
		inc	lc
		neg	var10
		tst	var20
		brpl	PC+3
		inc	lc
		neg	var20
		bst	lc,0
		sub	var11,var11	;initialize variables
		ldi	lc,9		; lc = 9;
		brcc	PC+2		;---- calcurating loop
		add	var11,var20	;
		ror	var11		;
		ror	var10		;
		dec	lc		;if (--lc > 0)
		brne	PC-5		; continue loop;
		brtc	PC+5
		com	var10
		com	var11
		adc	var10,lc
		adc	var11,lc

file: /Techref/atmel/avr/mul8x8sws-ec.htm, 1KB, , updated: 2007/9/14 16:52, local time: 2024/7/20 23:54,

 ©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=""> Atmel AVR, atmega, Microcontroller, embedded controller, math 8x8 signed</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?


Welcome to!


Welcome to!