EM78P447自收发光电检测

;***********************************************************************
;              自收发光电检测.dt
;***********************************************************************

 PORT5    ==        0x05                ;定义端口5,6,7
 PORT6    ==        0x06
 PORT7    ==        0x07
;-----------------------------------------------------------------------
 IOCE     ==        0x0E                ;定义WDT控制寄存器IOCE
;-----------------------------------------------------------------------
 DLY1     ==        12                  ;定义延时置数单元DLY1，DLY2，DLY3,DLY4
 DLY2     ==        13
 DLY3     ==        14
 DLY4     ==        15         
 BUFFER   ==        16                  ;定义暂存器BUFFER，存放当前输出
;-----------------------------------------------------------------------
          ORG       0X00

 INIT:    MOV       A,@0X11             ;关闭看门狗功能
          IOW       IOCE
          MOV       A,@0XFF             ;设定PORT5全部为输入
          IOW       PORT5               
          MOV       A,@0X00             ;设定PORT6、PORT7全部为输出
          IOW       PORT6               
          IOW       PORT7               
          MOV       A,@0XFF             ;设置暂存器BUFFER初值，
          MOV       BUFFER,A
          MOV       PORT7,A             ;PORT7输出指示LED全暗
          MOV       A,@0X00
          MOV       PORT6,A             ;PORT6输出低电平，熄灭光电发射管
    
 GDCHECK: MOV       A,@0XFF         ;PORT6输出高电平，点亮光电发射管
          MOV       PORT6,A
          CALL      DL10                ;发射时间维持5ms左右
          MOV       A,PORT5             ;从PORT5读入光电接收管状态
          AND       A,@0B00000111       ;屏蔽高5位，只保留3位
          XOR       A,@0XFF             ;光电接收管状态值反向
          MOV       BUFFER,A            ;送暂存器BUFFER保存
          MOV       A,@0X00             ;PORT6输出低电平，熄灭光电发射管
          MOV       PORT6,A

 DISPLAY: MOV       A,BUFFER            ;发光二极管显示光电接收状态值
          MOV       PORT7,A
          CALL      DELAY               ;采样延时
          JMP       GDCHECK             ;继续进行自收发光电信号检测
;-----------------------------------------------------------------------
 DELAY:   MOV       A,@1                ;延时，需要调整
          MOV       DLY3,A              ;1
 DEL:     MOV       A,@10               ;1*(DLY3)
          MOV       DLY2,A              ;1*(DLY3)
 INNER2   MOV       A,@250              ;1*(DLY3)*(DLY2)
          MOV       DLY1,A              ;1*(DLY3)*(DLY2)
 INNER1:  DJZ       DLY1                ;1*(DLY3)*(DLY2)*(DLY1)
          JMP       INNER1              ;1*(DLY3)*(DLY2)*(DLY1)
          DJZ       DLY2                ;1*(DLY3)*(DLY2)
          JMP       INNER2              ;1*(DLY3)*(DLY2)
          DJZ       DLY3                ;1*(DLY3)
          JMP       DEL                 ;1*(DLY3)
          RET                           ;延时返回
;-----------------------------------------------------------------------
 DL10:    MOV       A,2                 ;延时5ms左右，需要调整
          MOV       DLY4,A
 INNER3:  DJZ       DLY4
          JMP       INNER3
          RET        
          EOP