a.c

40个练习程序（坚持）.rar

#include <AT89X51.H>
unsigned int t02s;
unsigned char t05ms;
bit flag;
void main (void)
{
TMOD=0x01;
TH0=(65536-500)/256;
TL0=(65536-500)%256;
TR0=1;
EA=1;
ET0=1;
while(1);

}


void t0(void) interrupt 1 using 0
{TH0=(65536-500)/256;
TL0=(65536-500)%256;
t02s++;
if(t02s==400)
{t02s=0;
flag=~flag;
}
if (flag==0);{
P1_0=~P1_0;}
if (flag==1)
{P1_0=1;}
}