#include <mega8.h>
// I2C Bus functions
#asm
   .equ __i2c_port=0x12 ;PORTD
   .equ __sda_bit=0
   .equ __scl_bit=1
#endasm
#include <i2c.h>

// DS1307 Real Time Clock functions
#include <ds1307.h>

char hour, min, sec;
char tmp, flag;

// External Interrupt 0 service routine
interrupt [EXT_INT0] void ext_int0_isr(void)
{
// Place your code here
flag=~flag;
}

// Timer2 overflow interrupt service routine
interrupt [TIM2_OVF] void timer2_ovf_isr(void)
{
// Place your code here

}

// Timer2 output compare interrupt service routine
interrupt [TIM2_COMP] void timer2_comp_isr(void)
{
// Place your code here

}



void main(void)
{
// Declare your local variables here

// Input/Output Ports initialization
// Port B initialization
// Func7=Out Func6=Out Func5=Out Func4=Out Func3=Out Func2=Out Func1=Out Func0=Out 
// State7=0 State6=0 State5=0 State4=0 State3=0 State2=0 State1=0 State0=0 
PORTB=0x00;
DDRB=0xFF;

// Port C initialization
// Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=Out 
// State6=T State5=T State4=T State3=T State2=T State1=T State0=0 
PORTC=0x00;
DDRC=0x01;

// Port D initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In 
// State7=P State6=P State5=P State4=T State3=T State2=T State1=T State0=T 
PORTD=0xE0;
DDRD=0x00;

// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: 125,000 kHz
// Mode: Fast PWM top=0xFF
// OC2 output: Disconnected
ASSR=0x00;
TCCR2=0x4C;
TCNT2=0x00;
OCR2=0x00;

// External Interrupt(s) initialization
// INT0: On
// INT0 Mode: Rising Edge
// INT1: Off
GICR|=0x40;
MCUCR=0x03;
GIFR=0x40;

// Timer(s)/Counter(s) Interrupt(s) initialization
TIMSK=0xC0;

// I2C Bus initialization
i2c_init();

// DS1307 Real Time Clock initialization
// Square wave output on pin SQW/OUT: On
// Square wave frequency: 1Hz
tmp = rtc_read(0x00);
tmp &=~(1<<7);
rtc_write(0x00, tmp); // включение ds1307 бит 7 ноль
tmp = rtc_read(0x02);
tmp &=~(1<<6);
rtc_write(0x02, tmp); // бит 6 ноль - 24 часовой режим
rtc_init(0,1,0);
rtc_get_time (&hour, &min, &sec);

// Global enable interrupts
#asm("sei")

while (1)
      {
      // Place your code here
      if(flag==1)PORTB=0x18;
      }
}