...目的是让蜂鸣器一秒响一次。最好能有解释,没有也无所谓

发布网友 发布时间：2024-04-08 20:47

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热心网友 时间：2024-04-23 07:47

两个子程序均实现延时1秒的功能，实现方式略有不同，但机制是一样的。
 
 
        CODE  SEGMENT
              ASSUME    CS:CODE
              ORG       100H
      START:  PUSH      CS
              POP       DS
              PUSH      CS
              POP       ES
              MOV       CX,10
              MOV       DL,7        ; 蜂鸣
        @00:
              MOV       AH,2
              INT       21H
              CALL      DELAY_PROC
              LOOP      @00
              
              MOV       AH,4CH
              INT       21H

     DELAY1S  PROC      NEAR
              PUSH      AX
              PUSH      CX
              PUSH      DX
              PUSH      SI
              PUSH      DI
              PUSHF
              MOV       AH,0
              INT       1AH
              MOV       SI,CX
              MOV       DI,DX
     @DELAY:
              MOV       AH,0
              INT       1AH
              SUB       DX,DI
              SBB       CX,SI
              CMP       DX,18       ; 延时1秒
              JB        @DELAY
              POPF
              POP       DI
              POP       SI
              POP       DX
              POP       CX
              POP       AX
              RET
     DELAY1S  ENDP
  ;================================================================
  DELAY_PROC  PROC      NEAR
              PUSH      ES
              PUSH      DX
              MOV       DX,40H
              MOV       ES,DX
              MOV       DX,ES:[006CH]
              ADD       DX,18       ; 延时1秒
    DELAY10:
              CMP       ES:[006CH],DX
              JBE       DELAY10
              POP       DX
              POP       ES
              RET
  DELAY_PROC  ENDP
       
      
        CODE  ENDS
              END       START