p12_4.asm

单片机原理与应用实例教程 单片机原理与应用实例教程

		REST	EQU		P0.7
		E		EQU		P3.0
		RW		EQU		P3.1
		RS		EQU		P3.2
		CS1		EQU		P3.6
		CS2		EQU		P3.7
		LCD		EQU		P2

		ORG		0000H
		LJMP	MAIN

		ORG		2000H
PIC1:	DB 	00H, 00H, 00H, 18H, 18H, 00H, 00H, 00H
PIC2:	DB	00H, 00H, 3CH, 24H, 24H, 3CH, 00H, 00H
PIC3:	DB	00H, 7EH, 42H, 42H, 42H, 42H, 7EH, 00H
PIC4:	DB	0FFH,81H, 81H, 81H, 81H, 81H, 81H, 0FFH
		
WAIT:	PUSH 30H
		MOV 30H, A

		MOV LCD, 0FFH   ;空读操作
		SETB RW
		CLR	RS
		SETB E
		MOV A, LCD
		CLR E

		MOV LCD, 0FFH	;第2次读
		CLR	RS
		SETB RW
		SETB E
		MOV A, LCD
		CLR E
		JB ACC.7, WAIT

		MOV A, 30H
		POP 30H
		RET

W_CMD:	ACALL	WAIT
		MOV LCD, A
		CLR		RS
		CLR		RW
		SETB	E
		NOP
		CLR		E
		RET

W_DATA:	ACALL	WAIT
		MOV LCD, A
		SETB	RS
		CLR		RW
		SETB	E
		NOP
		CLR		E
		RET

CLEAR:	MOV 	R0, #0H
CLR1:	MOV 	A, R0			 	;设置页号
		ORL 	A, #10111000B
		ACALL	W_CMD

		MOV 	R1, #0H
		MOV		A,#01000000B
		ACALL	W_CMD
CLR2:	MOV 	A,	#0H
		ACALL	W_DATA
		INC R1
		CJNE R1, #64, CLR2

		INC R0
		CJNE R0, #8, CLR1
		RET

DISPLAY:MOV DPTR, #PIC1
		ACALL	D_PIC
		MOV DPTR, #PIC2
		ACALL	D_PIC
		MOV DPTR, #PIC3
		ACALL	D_PIC
		MOV DPTR, #PIC4
		ACALL	D_PIC
		MOV DPTR, #PIC3
		ACALL	D_PIC
		MOV DPTR, #PIC2
		ACALL	D_PIC
		AJMP DISPLAY
		RET

D_PIC:	MOV		A, #10111100B   ;设置页号
		ACALL	W_CMD
		MOV		A, #01010111B	 ;23列开始显示
		ACALL	W_CMD

		MOV R4, #0
LOOP1:	MOV A, R4
		MOVC A, @A+DPTR
		ACALL	W_DATA
		INC R4
		CJNE R4, #8, LOOP1
		;延迟一段时间
	  	MOV R6, #0FFH
LOOP2:	MOV R7, #07FH
LOOP3:	DJNZ R7, LOOP3
		DJNZ R6, LOOP2
		RET

MAIN:	CLR CS1
		CLR	CS2
		MOV		A, #00111111B	;打开显示
		ACALL	W_CMD

		ACALL	CLEAR
		ACALL	DISPLAY
LOOP:	AJMP	LOOP

		END