#include <avr/io.h>          
  #define serpin 3
  
  int main(void) 
  {  
      unsigned char x;
      unsigned char rega = 0;
  
      ddrc &= ~(1<<serpin);  
      
    for(x = 0;x < 8; x++)  
    {
       rega = rega >> 1;  
        rega |= (pinc &(1<<serpin)) << (7-serpin);
    }            
      return 0;
  }