#include "reg51.h"


  
sbit P1_0=P1^0;
sbit P1_1=P1^1;
sbit P1_2=P1^2;

          sbit P0_0=P0^0;
sbit P0_1=P0^1;
sbit P0_2=P0^2;
sbit P0_3=P0^3;
sbit P0_4=P0^4;
sbit P0_5=P0^5;
sbit P0_6=P0^6;
sbit P0_7=P0^7;

void mdelay(unsigned int delaytime)
{  unsigned int k=0;
   for(;delaytime>0;delaytime--)

{  for(k=0;k<500;k++)
    {;}
}
}






void main  ()
{   unsigned char k;

        P1_0=1;  
     P1_1=0;
    P1_2=0;
   
       
   for(;;)
{
        P3=0x0f;
    k=P3|0xfe;
       
       
       

        if(k!=0xff)
         
       
       
   {
      P0_0=~P0_0;
      mdelay(20  );
      P0_0=~P0_0;

      P0_1=~P0_1;
       mdelay(20  );
      P0_1=~P0_1;

     P0_2=~P0_2;
        mdelay(20  );
    P0_2=~P0_2;


     P0_3=~P0_3;
     mdelay(20  );
    P0_3=~P0_3;

    P0_4=~P0_4;
    mdelay(20  );
    P0_4=~P0_4;

    P0_5=~P0_5;
     mdelay(20  );
      P0_5=~P0_5;

    P0_6=~P0_6;
    mdelay(20  );
    P0_6=~P0_6;

    P0_7=~P0_7;
    mdelay(20  );
    P0_7=~P0_7;

}  

       
}


}