#include <avr/io.h>        
  
  int main(void) 
  {  
      unsigned char bcdbyte;
      unsigned char w = '4';
      unsigned char z = '7';
      ddrb = 0xff ;    
      w = w & 0x0f;    
      w = w << 4;      
      z = z & 0x0f;    
      bcdbyte = w | z;  
      portb = bcdbyte;
  
    return 0;
  }