51单片机汇编四个数码管三个按键加一减一复位

DAT		EQU 30H
DCNT		EQU 34H
SCANLED		EQU 35H
ORG 0000H
LJMP MAIN
ORG 000BH
LJMP T0ISR
ORG 0030H
MAIN:
		MOV SP,#5FH
		MOV TMOD,#01H
		MOV TH0,#0D8H
		MOV TL0,#0F0H
		MOV P2,#00H
		MOV SCANLED,#0
		MOV 30H,#0
		MOV 31H,#0
		MOV 32H,#0
		MOV 33H,#0
		SETB EA
		SETB ET0
		SETB TR0
LOOP:		
		JB P3.0,LOOP1
		JNB P3.0,$
		INC 30H
		MOV A,30H
		CJNE A,#10,LOOP
		MOV 30H,#0
		INC 31H
		MOV A,31H
		CJNE A,#10,LOOP
		MOV 31H,#0
		INC 32H
		MOV A,32H
		CJNE A,#10,LOOP
		MOV 32H,#0
		INC 33H
		MOV A,33H
		CJNE A,#10,LOOP
		MOV 33H,#0
		SJMP LOOP
LOOP1:
		JB P3.1,LOOP2
		JNB P3,2,$
		MOV A,30H
		JNZ LOOP10
		MOV 30H,#9
		MOV A,31H
		JNZ LOOP11
		MOV 31H,#9
		MOV A,32H
		JNZ LOOP12
		MOV 32H,#9
		MOV A,33H
		JNZ LOOP13
		MOV 33H,#9
		SJMP LOOP
LOOP10:
		DEC A
		MOV 30H,A
		SJMP LOOP
LOOP11:
		DEC A
		MOV 31H,A
		SJMP LOOP
LOOP12:
		DEC A
		MOV 32H,A
		SJMP LOOP
LOOP13:
		DEC A
		MOV 33H,A
		SJMP LOOP
LOOP2:
		MOV 30H,#0
		MOV 31H,#0
		MOV 32H,#0
		MOV 33H,#0
		LJMP LOOP
;--------------------
DELAY:
		MOV R3,#50
DELAY1:
		MOV R4,#100
		DJNZ R4,$
		DJNZ R3,DELAY1
		DJNZ R2,DELAY
		RET
;--------------------
T0ISR:
		PUSH ACC
		CLR TR0
		MOV TH0,#0D8H
		MOV TL0,#0F0H
		SETB TR0
		MOV DPTR,#LEDTAB
T000:						;数字显示
		MOV R0,#DAT
		MOV A,SCANLED
		ADD A,R0
		MOV R0,A
		MOV A,SCANLED
		JNZ T001
		MOV P2,#01H
		SJMP T0DIS
T001:
		DEC A
		JNZ T002
		MOV P2,#02H
		SJMP T0DIS
T002:
		DEC A
		JNZ T003
		MOV P2,#04H
		SJMP T0DIS
T003:
		MOV P2,#08H
T0DIS:
		MOV A,@R0
		MOVC A,@A+DPTR
		CPL A
		MOV P0,A
		INC SCANLED
		MOV A,SCANLED
		ANL A,#03H
		MOV SCANLED,A
		POP ACC
		RETI
;--------------------
LEDTAB:	
		DB 0C0H	;"0"	00H
		DB 0F9H	;"1"	01H
		DB 0A4H	;"2"	02H
		DB 0B0H	;"3"	03H
		DB 99H	;"4"	04H
		DB 92H	;"5"	05H
		DB 82H	;"6"	06H
		DB 0F8H	;"7"	07H
		DB 80H	;"8"	08H
		DB 90H	;"9"	09H
		DB 88H	;"A"	0AH
		DB 83H	;"B"	0BH
		DB 0C6H	;"C"	0CH
		DB 0A1H	;"D"	0DH
		DB 86H	;"E"	0EH
		DB 8EH	;"F"	0FH
		DB 0FFH	;" "	10H
;--------------------
END