新建dingshi text file.txt

基于89S52单片机的4位led显示程序

	ORG	0000H
	AJMP	MAIN
	ORG	000BH
	LJMP	INT
	ORG	0030H
MAIN:		
	MOV	R4,	#10
	MOV	TMOD,	#01H
	MOV	TH0,	#3CH
	MOV	TL0,	#0B0H		
	SETB	ET0		
	SETB	EA
	SETB 	TR0

;减计数处值
	MOV 	R5,	#99
	MOV 	A,	R5
	MOV 	B,	#10
	DIV 	AB
	MOV 	70H,	A
	MOV 	71H,	B
;加计数
	MOV	R1,	#00

	MOV 	A,	R1
	MOV 	B,	#10
	DIV 	AB
	MOV 	72H,	A
	MOV 	73H,	B

TT:	LCALL 	DIR
	AJMP 	TT
;占用R4,R5
INT:
	DJNZ 	R4,	NEXT 
	MOV	R4,	#10
	DEC	R5
	INC 	R1
	MOV 	A,	R5
	MOV 	B,	#10
	DIV 	AB
	MOV 	70H,	A
	MOV 	71H,	B
	
	MOV 	A,	R1
	MOV 	B,	#10
	DIV 	AB
	MOV 	72H,	A
	MOV 	73H,	B
NEXT:
	MOV TH1,#3CH
	MOV TL0,#0B0H
	RETI

;占用R0,R2,R3
DIR:

	MOV	DPTR,	#TAB
	MOV 	R0,	#70H
	MOV	R3,	#04H
	MOV 	R2,	#7FH

LP:
	MOV 	A,	@R0
	MOVC 	A,	@A+DPTR
	MOV 	P0,	A
	MOV 	P2,	R2
	MOV 	A,	R2
	RR 	A
	MOV 	R2,	A
	INC 	R0
	ACALL 	DELAY
	DJNZ 	R3,	LP
	RET

;占用R6,R7
DELAY:	MOV R6,#4
LOOP1:	MOV R7,#250
LOOP2:	DJNZ R7,LOOP2
	DJNZ R6,LOOP1
	RET

TAB:	DB	0C0H,	0F9H,	0A4H,	0B0H,	99H,	92H,	82H,	0F8H,	80H,	90H
	END