;鍵盤控制的0802液晶顯示程序。
;***************************************************************************
;*  sxj1974@163.com		     (51c51 test web)     www.8951.com     *
;*  Create by :石學(xué)軍      www.51c51.com 更多例程請登陸網(wǎng)站        	   *
;***************************************************************************

	RS EQU P2.0
	RW EQU P2.1
	E EQU P2.2
	mov p3,#0ffh
	MOV P0,#01H	;清除屏幕
	ACALL ENABLE
	MOV P0,#38H	;8位點(diǎn)陣
	ACALL ENABLE
	MOV P0,#0FH	;開顯示
	ACALL ENABLE
	MOV P0,#06H	;移動光標(biāo)
	ACALL ENABLE
	MOV P0,#80H	;顯示位置
	ACALL ENABLE
l3:	mov p0,#01h
	acall enable
	mov dptr,#table1 ;送第一句話
	call write1
	call enable
	mov p0,#01h
	ljmp l1
l4:	mov p0,#01h
	acall enable
	mov dptr,#table2 ;送第二句話
	call write1
	call enable
	mov p0,#01h
	ljmp l1
l5:	mov p0,#01h
	acall enable
	mov dptr,#table3 ;送第三句話
	call write1
	acall enable
	mov p0,#01h
	ljmp l1
	l6:mov p0,#01h
	acall enable
	mov dptr,#table4  ;送第四句話
	call write1
	acall enable
	mov p0,#01h
	ljmp l1
l1:	jnb p3.3,l3     ;監(jiān)測鍵盤
	jnb p3.4,l4
	jnb p3.5,l5
	JNB P3.2,L6
	jmp l1
ENABLE:			;送命令
	CLR RS
	CLR RW
	CLR E
	ACALL DELAY
	SETB E
	RET
write1:			;送字符串
	mov r1,#00h
	a1:mov a,r1
	movc a,@a+dptr
	call write2
	inc r1
	cjne a,#00h,a1	;以00H做字符串結(jié)束標(biāo)志
	ret
write2:			;送單個字符
	mov p0,a
	setb rs
	clr rw
	clr e
	call delay
	setb e
	ret
delay:                  ;延時子程序
	mov r7,#255
	d1:mov r6,#255
	d2:djnz r6,d2
	djnz r7,d1
	ret
;以下每個表格都是一句話,以00H作為每句話的結(jié)尾.
table1: db "8951.COM",00H
table2: db "GO-51C51",00H
table3: db "27529065",00H
Table4: db "HELLO...",00H

end