單片機匯編實驗七：掃描鍵盤及液晶顯示實驗
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//初始化液晶屏程序段
INTE: CLR P1.1 //讀寫選擇端口清零
CLR P2.6 //關閉數碼管
CLR P2.7
MOV A,#0X38
CALL WRITE_COM
CALL DELAY
MOV A,#0X0E
CALL WRITE_COM
CALL DELAY
CALL DELAY
MOV A,#0X06
CALL WRITE_COM
CALL DELAY
CALL DELAY
MOV A,#0X01
CALL WRITE_COM
CALL DELAY
CALL DELAY
MOV A,#0X80
CALL WRITE_COM
CALL DELAY0
RET
//10ms延時函數
DELAY:MOV R7,#0FFH
DELY1:MOV R6,#02AH
DELY2:NOP
DJNZ R6,DELY2
DJNZ R7,DELY1
RET
//5ms延時函數
DELAY0:MOV R7,#0FEH
DELY10:MOV R6,#02FH
DELY20:NOP
DJNZ R6,DELY2
DJNZ R7,DELY1
RET
//寫命令函數
WRITE_COM:
MOV P0,A //暫定A為數據傳輸寄存器
CLR P1.0 //打開命令選擇端口
CLR P1.1 //打開寫選擇端口
CLR P2.5 //液晶使能端
CALL DELAY //10MS
SETB P2.5 //液晶使能端
CALL DELAY //10MS
CLR P2.5 //液晶使能端
RET
// 寫數據函數
WRITE_DATE:
MOV P0,A //暫定A為數據傳輸寄存器
SETB P1.0 //液晶數據/命令選擇端口
CLR P1.1 //讀寫選擇端口
CLR P2.5 //液晶使能端
CALL DELAY //10MS
SETB P2.5 //液晶使能端
CALL DELAY //10MS
CLR P2.5 //液晶使能端
RET
TABLE: DB 30H,31H,32H,33H,34H,35H,36H,37H,38H,39H,41H,42H,43H,44H,45H,46H,47H
END
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