int main ()
{  
  
  //switch configuration
  //select the direction register  of port k :0x107
  //make the directio register of port k as input by 0x00
 //select the input port address of portk :0x106
 //Imp for switch or mechanical button//
 //pull down of pin
 //take care of masking
 //debouncing

 
  volatile char *dir_k , *input_port_k , x ;
  volatile long t;
  dir_k = 0x107;
  *dir_k = 0x00;
  input_port_k = 0x106;

 //LED configuration
 //select the direction register of portf :0x30
 //make the directio register of port f as output by 0xff
 //select the output port adress of portf :0x31
 

  volatile char *dir_f, *out_f;
   dir_f = 0x30;
   *dir_f =0x01;
   out_f = 0x31;
  
  
 //if switch is pressd the led should glow
  while(1)
  {
    //read the value of switch
    x = *input_port_k;

    //if Switch is pressed at portk the LED at port f should glow
    //i.e if *input_port_k gets HIGH value LED should Glow
    if((x & 0x01) == 0x01) //here masking is done 
      { 
        for(t = 0 ; t<5000 ; t++);//debounce time to give time to output of swith 
        *out_f = 0x03;              // to get stable
        
      } 
    else
      *out_f = 0x00;   
      
    
  }


  return 0;



  }