scasw.asm

来自「汇编语言 参考书 包含作业与答案 从入门到精通 通俗易懂」· 汇编 代码 · 共 57 行

; This sample shows how
; to use SCASW instruction
; to find a WORD (2 bytes).

#make_COM#

; COM file is loaded at 100h
; prefix:
    ORG 100h

; set forward direction:
    CLD

; set counter to data size:
    MOV CX, 4

; load string address
; into ES:DI
    MOV AX, CS
    MOV ES, AX
    LEA DI, dat1

; we will look for the 9012h
; word in data string:
    MOV AX, 9012h

    REPNE   SCASW

    JZ  found

not_found:

; "No" - not found!
    MOV AL, 'N'
    MOV AH, 0Eh
    INT 10h

    JMP exit_here
found:

; "Yes" - found!
    MOV AL, 'Y'
    MOV AH, 0Eh
    INT 10h

; DI contains the
; offset of 9012h word:
    DEC DI  

exit_here:
    RET

dat1 DW 1234h, 5678h, 9012h, 3456h


END