要求：在原来跑马灯的基础上，增加时间中断和外部中断来实现跑马灯的顺序。
#include<reg52.h>
#include <intrins.h>
sbit P32 = P3^2;
unsigned char flag=0; //设置标志位（0/1） 1为左移
unsigned char LED;
unsigned char count=0;
void delayms(unsigned char ms)
{
unsigned char i;
while(ms--)
{
for(i = 0; i < 120; i++);
}
}
void timer0() interrupt 1
{
TH0=(65535-50000)/256;
TL0=(65535-50000)%256;
count++;
if(count==20)
{
count=0;
flag=!flag;
}
}
void waibu() interrupt 0
{
flag=!flag;
}
void main()
{
//时间中断打开
TMOD=0x11;
IE=0x83; //EA=1； ET0=1;
TR0=1;
//外部中断打开
//IE=0x81;
//EA=1;
//EX0=1;
IT0=1; //为1是边沿触发，为0是电平触发
TH0=(65535-50000)/256;
TL0=(65535-50000)%256;
LED = 0x01;
P1 = LED;
while(1)
{
if(flag==1)
{
while(1){
if(P1!=0x80)
{
LED=LED<<1;
P1 = LED;
delayms(250);
//n++;
}
else if(P1==0x80)
{
//n=0;
LED=0x01;
P1=LED;
delayms(250);
}
if(flag==0)
break;
}
}
else
{
while(1)
{
if(P1!=0x01)
{
LED=LED>>1;
P1 = LED;
delayms(250);
}
else if(P1==0x01)
{
LED=0x80;
P1=LED;
delayms(250);
}
if(flag==1)
break;
}
}
}
}
