汇编学习笔记(13)MOVZA、MOVSX,XCHG练习

          TITLE Data Transfer Example
INCLUDE irvine32.inc

.data

val1 WORD 1000h
val2 WORD 2000h
arrayB BYTE 10h,20h,30h,40h,50h
arrayW WORD 100H,200H,300H
arrayD DWORD 100000h,20000H

.code

main PROC
    
    ;MOVZX(move with zero-extend)
    
         mov bx,0A69Bh
         movzx,eax,bx          ;0000A69BH
         movzx edx,bl          ;00000009H
         movzx,cx,bl           ;0009H
         
         ;MOVSX(move with sign-extend) 没搞懂
         
         mov bx,0A69BH
         movsx eax,bx         ;FFFFA69BH
         movsx edx,bl         ;FFFFFF9BH
         mov b1,7BH           ;bx=FF7BH
         mov cx,bl            ;cx=007BH 
         
         
         ;XCHG(exchange data)
         mov ax,val1          ;ax=1000h
         XCHG ax,val2         ;ax=2000h,val2=1000h
         mov val1,ax          ;val1=2000h
         
         ;直接偏移寻址
         
         mov al,arrayB         ;ax=0010h
         mov al,[arrayB+1]     ;ax=0020h
         mov al,[arrayB+2]     ;ax=0030H
         
         ;如果是字就加2,双字就加4
         
main endp