單片機60S倒計時匯編語言

ORG 0000H

AJMP MAIN

ORG 000BH

AJMP INTT0

ORG 0030H

MAIN: MOV R7,#60

MOV R6,#00H

MOV DPTR,#TABLE

MOV TMOD,#01H

MOV TL0,#0B0H

MOV TH0,#3CH ;設置定時器工作方式、初值

SETB EA

SETB ET0

SETB TR0

NEXT: MOV A,R7

MOV B,#0AH

DIV AB

SETB P1.3

MOVC A,@A+DPTR

MOV P0,A

CLR P1.4 ;開啟shi位顯示

ACALL DELAY

MOV A,B

SETB P1.4

MOVC A,@A+DPTR

MOV P0,A

CLR P1.3 ;開啟ge位顯示

ACALL DELAY

CJNE R6,#14H,NEXT

MOV R6,#00H

DEC R7

CJNE R7,#0FFH,NEXT

SJMP MAIN

INTT0:MOV TL0,#0B0H ;中斷服務程序

MOV TH0,#3CH

INC R6

RETI

DELAY:MOV R5,#02H ;延時子程序

LOOP:MOV R4,#02H

DJNZ R4,$

DJNZ R5,LOOP

RET

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

END