Проблема с программированием МК

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/delay.h>
#define F_CPU 8000000UL

unsigned char S=1;
unsigned char F=3;
unsigned char A;

void EEPROM_write(unsigned int uiAddress, unsigned char ucData)
{
/* Wait for completion of previous write */
while(EECR & (1<<EEWE))
;
/* Set up Address and Data Registers */
EEAR = uiAddress;
EEDR = ucData;
/* Write logical one to EEMWE */
EECR |= (1<<EEMWE);
/* Start eeprom write by setting EEWE */
EECR |= (1<<EEWE);
}

unsigned char EEPROM_read(unsigned int uiAddress)
{
/* Wait for completion of previous write */
while(EECR & (1<<EEWE))
;
/* Set up Address Register */
EEAR = uiAddress;
/* Start eeprom read by writing EERE */
EECR |= (1<<EERE);
/* Return data from Data Register */
return EEDR;
}

int main(void)
{
DDRA = 0xff;
DDRC = 0x00;
PORTC= 0b01;

PORTA=0x0, PORTA |= 1<<0;
_delay_ms(10);

sei();

EEPROM_write(0x3E, F);

A=EEPROM_read(0x3E);

if (A>2) S=A;

while(1)
{

if (S==1) PORTA=0x0, PORTA |= 1<<0;
if (S==2) PORTA=0x0, PORTA |= 1<<1;
if (S==3) PORTA=0x0, PORTA |= 1<<2;
if (S==4) PORTA=0x0, PORTA |= 1<<3;
if (S==5) PORTA=0x0, PORTA |= 1<<4;
if (S==6) PORTA=0x0, PORTA |= 1<<5;
if (S>6) PORTA=0xff;
}
}