#include "reg51.h"
unsigned int cd,dd;
unsigned char cc,ee;
sbit LED0=P1^0;
void led_int() interrupt 1 using 0
{
TH0=(65536-5000)/256;
TL0=(65536-5000)%256;
TR0=1;
dd++;
if(dd==2)
{
if((cc==0x50)&&(ee==0)){cd=0;}
if((cc==0)&&(ee==0x50)){cd=1;}
if(cd){cc++;ee--;}
else {cc--;ee++;}
dd=0;
}
}
void delay(unsigned int i)
{
unsigned int j;
while(i--)
{
for(j=0;j<0x10;j++);
}
}
void main()
{
cc=0;
ee=0x50;
TMOD=0x01;
TH0=(65536-5000)/256;
TL0=(65536-5000)%256;
EA=1;
ET0=1;
TR0=1;
while(1)
{
LED0=1;
delay(ee);
LED0=0;
delay(cc);
}
}