Px.4 - Px.0口线连接5个LED灯LED4 - LED0;KEY1键为启动按键,连接外部中断1;KEY2键为急停按键,连接外部中断0。按要求进行硬件接线,并利用定时器T0和外部中断编写程序实现如下功能:(1)程序运行开始LED灯全灭,KEY1键按下,触发外部中断1,LED灯开始按要求的顺序点亮:即使5个LED灯间隔0.6s,按以下顺序循环点亮:亮灭灭灭灭,灭亮灭灭灭,灭灭亮灭灭,灭灭灭亮灭,灭灭灭灭亮,如此循环;(2)KEY2 键按下,触发外部中断0,使5个LED灯全亮。(晶振频率为12MHz)
单片机源程序如下:
ORG 00H
AJMP MAIN
ORG 03H
AJMP JITING
ORG 13H
AJMP WAIBU
ORG 0BH
AJMP DINGSHIQI
ORG 30H
MAIN:
MOV TMOD,#01H
MOV TH0,#15H
MOV TL0,#0A0H
SETB EA
SETB EX0
SETB IT0
SETB ET0
SETB EX1
SETB IT1
MOV R4,#10
SJMP $
ORG 50H
WAIBU:
MOV A,#0FEH
MOV P0,A
SETB TR0
RETI
ORG 60H
DINGSHIQI:
MOV TH0,#15H
MOV TL0,#0A0H
DJNZ R4,EXIT
MOV R4,#10
RL A
CJNE A,#11011111B,TIAO
MOV A,#0FEH
RETI
ORG 70H
TIAO:
MOV P0,A
EXIT:RETI
ORG 80H
JITING:
MOV A,#00H
MOV P0,A
RETI
END |