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

In the case where the index of the nested array is constant it is easy as you say. In fact for the (fairly common) case where the array is contained within a single bank I believe you can do:

 mov fsr,#idx
 mov w,#arr1
 add w,ind
 mov fsr,w


it is a little more exciting which the index of the nested array is variable to arr1[arr2[i]] = 42 but still not impossible:


[code]
arr1 equ $3a 
arr2 equ $5a 
i equ $a 
val equ $8 
org 0 
reset Start 
Start:  

; Preamble to allow 'stepping through' in SXSIM
mov i,#2 
mov fsr,#arr2+2 
mov ind,#3 
mov val,#$42 
; Attempting arr1[arr2[i]] = val - arr1[arr2[2]] - arr1[3] in test = $3d 
mov w,#arr2  

; requires a bank instruction here if i not 'already available'
add w,i 
mov fsr,w 
mov w,#arr1 
add w,ind 
mov fsr,w  

; Job done - line below as a 'proof'
mov ind,val 


 

As in Peter's post if Arr1 or Arr2 span banks it is a little uglier ....

 

David[/code]

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


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=328791#m328825

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

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2009 (http://www.dotNetBB.com)