D0 BIT P2.0
D1 BIT P2.1
D2 BIT P2.2
D3 BIT P2.3
D4 BIT P2.4
D5 BIT P2.5
D6 BIT P2.6
D7 BIT P2.7

D EQU P2

RS BIT P1.0
RW BIT P1.1
E BIT P1.2


ORG 0000H
AJMP INITIALIZATION

ORG 0030H

SENDA:
MOV SBUF,A
JNB TI,$
CLR TI
RET

DELAY15: ;精確延時15微秒子程序
	MOV R6,#1
	YS15D:MOV R7,#5
	DJNZ R7,$
	DJNZ R6,YS15D
	RET

DELAY1S: ;精確延時15微秒子程序
	MOV R6,#255
	MOV R5,#10
	YS1SD:MOV R7,#255
	DJNZ R7,$
	DJNZ R6,YS1SD
	DJNZ R5,YS1SD
	RET

WRITE_COM:
CLR RS
CLR RW
MOV D,A
SETB E
CLR E
SETB RW
SETB RS
MOV D,#0FFH
RET

WRITE_DATA:
SETB RS
CLR RW
MOV D,A
SETB E
CLR E
SETB RW
SETB RS
MOV D,#0FFH
RET

WR_CHECK:
MOV D,#11111111B
CLR RS
SETB RW
CLR E
NOP
SETB E
JB D7,WR_CHECK

RET

INITIALIZATION:
MOV TMOD,#20H
MOV TL1,#0E6H
MOV TH1,#0E6H
SETB TR1
MOV SCON,#01010000B
SETB RW
SETB RS


MAIN:
LCALL DELAY15
MOV A,#00111000B
LCALL WRITE_COM
NOP
NOP
NOP
NOP
NOP
LCALL WRITE_COM
NOP
NOP
NOP
NOP
NOP
LCALL WRITE_COM
LCALL WR_CHECK
LCALL WRITE_COM

MOV A,#00001000B;(關閉顯示)
LCALL WR_CHECK
LCALL WRITE_COM

MOV A,#00000001B;(顯示清屏)
LCALL WR_CHECK
LCALL WRITE_COM

MOV A,#00000110B;(顯示光標移動設置)
LCALL WR_CHECK
LCALL WRITE_COM

MOV A,#00001111B;(顯示開及光標設置)
LCALL WR_CHECK
LCALL WRITE_COM

MOV A,#01010100B
LCALL WR_CHECK
LCALL WRITE_DATA

MOV A,#01101110B
LCALL WR_CHECK
LCALL WRITE_DATA

MOV A,#01111000B
LCALL WR_CHECK
LCALL WRITE_DATA

MOV A,#01101110B
LCALL WR_CHECK
LCALL WRITE_DATA

MOV A,#080H
LCALL WR_CHECK
LCALL WRITE_COM

LCALL DELAY1S
MOV A,#01101110B
LCALL WR_CHECK
LCALL WRITE_DATA

LCALL SENDA

END