void Init_Ports (void) {
    DDRB  = (1<<DDB5)|(1<<DDB3)|(1<<DDB2)|(1<<DDB1)|(1<<DDB0);
    PORTB = (1<<PB4)|(1<<PB2);

    DDRC  =  (1<<DDC5)|(1<<DDC4)|(1<<DDC3)|(1<<DDC2)|(1<<DDC0);
    PORTC =  (1<<PC1);

    DDRD  = (1<<DDD7)|(1<<DDD6)|(1<<DDD5)|(1<<DDD4)|(1<<DDD3)|(1<<DDD1)|(1<<DDD0);
    PORTD = (1<<PD2)|(1<<PD1);
}

// Timer/Counter 1 initialization
// Clock source: System Clock
// Clock value: 8000,000 kHz
// Mode: Fast PWM top=ICR1
// OC1A output: Inverted
// OC1B output: Non-Inv.
// Noise Canceler: Off
// Input Capture on Falling Edge
// Timer1 Overflow Interrupt: Off
// Input Capture Interrupt: Off
// Compare A Match Interrupt: Off
// Compare B Match Interrupt: Off
TCCR1A=0xE2;
TCCR1B=0x19;
TCNT1H=0x00;
TCNT1L=0x00;
ICR1H=0x00;
ICR1L=0x3F;
OCR1AH=0x00;
OCR1AL=0x1F;
OCR1BH=0x00;
OCR1BL=0x1F;

TCCR1A |= (1 << FOC1A);

void EEPROMWrite(INT16U uiAddress, INT08U ucData) {

    while(EECR & (1<<EEWE))                                     // Wait for completion of previous write /
;
    EEAR = uiAddress;                                           // Set up address and data registers /
    EEDR = ucData;
    EECR |= (1<<EEMWE);                                         // Write logical one to EEMWE /
    EECR |= (1<<EEWE);                                          // Start eeprom write by setting EEWE /
}


INT08U EEPROMRead(INT16U uiAddress) {

    while(EECR & (1<<EEWE))                                     // Wait for completion of previous write /
;
    EEAR = uiAddress;                                           // Set up address register /
    EECR |= (1<<EERE);                                          // Start eeprom read by writing EERE /
    return EEDR;                                                // Return data from data register /
}

...
            for(i=0; i<8; i++) {
                EEPROMWrite(i, (INT08U)tmp2);
                tmp2 >>= 8;
            }


            for (i=0; i < 8; i++)
                UARTTransmitByte ( EEPROMRead(i) );
            
...

    
__disable_interrupt();
...
__enable_interrupt();

char temp = SREG;
__disable_interrupt();
...
SREG = temp;

unsigned short Addr = (unsigned short)main;
((void(*)(void))Addr)();

#include <stdint.h>  // И не нужно придумывать свои типы вроде UINT8U
__eeprom uint8_t My_data[8];

void test()
{

    for(uint_fast8_t i = 0; i < sizeof(My_data) / sizeof(My_data[0]); ++i)
          My_data[i] = i;

    for(uint_fast8_t i = 0; i < sizeof(My_data) / sizeof(My_data[0]); ++i)
          UARTTransmitByte(My_data[i]);
}

ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
// тут код блока с атомарным доступом
}