In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Coriolis wrote:

Nick,
 

Bookmark this page: [url=http://www.sxlist.com/techref/scenix/constdivmul_help.htm]http://www.sxlist.com/techref/scenix/constdivmul_help.htm[/url]

 

It is a web form to generate code to multiply a variable by a constant value (in your case 0.15625). It was designed before the advent of SX/B so the code it spits out is in assembler, but it shouldn't require to much effort to convert.

 

For your example it generated the following code:

 



[code]

; ACC = ACC * 0.15625
; Temp = TEMP
; ACC size = 8 bits
; Error = 0.5 %
; Bytes order = little endian
; Round = no

; ALGORITHM:
; Clear accumulator
; Add input / 8 to accumulator
; Add input / 32 to accumulator
; Move accumulator to result
;
; Approximated constant: 0.15625, Error: 0 %

;     Input: ACC0, 8 bits
;    Output: ACC0, 6 bits
; Code size: 11 instructions

ACC0	DS	1

;copy accumulator to temporary
	mov	w, ACC0


;shift accumulator right 2 times
	clc
	rr	ACC0
	clc
	rr	ACC0

;add temporary to accumulator
	add	ACC0, w

;shift accumulator right 3 times
	rr	ACC0
	clc
	rr	ACC0
	clc
	rr	ACC0</PRE> 
[/code]

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=83746#m83758

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2005 (http://www.dotNetBB.com)