SECOND	EQU		30H
TCOUNT	EQU		31H
KCOUNT	EQU		32H
KEY		BIT		P3.7
		ORG		00H
		SJMP	START
		ORG		0BH
		LJMP	INT_T0
START:	MOV		DPTR,#TABLE
		MOV		P0,#3FH
		MOV		P2,#3FH		   ;開始,數碼管顯示"00"
		MOV		SECOND,#00H
		MOV		TCOUNT,#00H
		MOV		KCOUNT,#00H
		MOV		TMOD,#01H	   ;定時器0工作在方式1
		MOV		TL0,#(65536-50000)/256
		MOV		TH0,#(65536-50000) MOD	256
	K1:	JB		KEY,$		   ;等待按鍵
		LCALL	DELAY
		JB		KEY,$
		MOV		A,KCOUNT
		CJNE	A,#00H,K2	   ;判斷按鍵次數
		SETB	TR0			   ;第1次按鍵,啟動定時器
		MOV		IE,#82H
		JNB		KEY,$
		INC		KCOUNT		   ;按鍵抬起,按鍵次數值加1
		LJMP	K1
	K2:	CJNE	A,#01H,K3
		CLR		TR0			   ;第2次按鍵,關閉定時器
		MOV		IE,#00H
		JNB		KEY,$
		INC		KCOUNT		   ;按鍵抬起,按鍵次數值加1
		LJMP	K1
	K3:	CJNE	A,#02H,K1	   ;第3次按鍵,返回初始狀態
		JNB		KEY,$
		LJMP	START
INT_T0:	MOV 	TH0,#(65536-50000)/256
		MOV 	TL0,#(65536-50000) MOD 256
		INC		TCOUNT
		MOV		A,TCOUNT
		CJNE	A,#2,I2		   ;是否計夠0.1秒
		MOV		TCOUNT,#00H	
		INC		SECOND
		MOV		A,SECOND
		CJNE	A,#100,I1	   ;是否計夠10秒
		MOV		SECOND,#00H
	I1:	MOV		A,SECOND
		MOV		B,#10
		DIV		AB
		MOVC	A,@A+DPTR	   ;顯示時間
		MOV		P0,A
		MOV		A,B
		MOVC	A,@A+DPTR
		MOV		P2,A
	I2:	RETI				
TABLE: 	DB 		3FH,06H,5BH,4FH,66H
		DB		6DH,7DH,07H,7FH,6FH
DELAY:	MOV		R6,#20
D1:		MOV		R7,#250
		DJNZ	R7,$
		DJNZ	R6,D1
		RET
		END