#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;
}