#include <avr/io.h> 

int main (void) 
{ 

DDRB &= ~( 1 << PB0 ); //PB0 Eingang 
DDRB &= ~( 1 << PB1 ); //PB1 Eingang
PORTB |= ( 1 << PB0 ); //Pull up an
PORTB |= ( 1 << PB1 ); //Pull up an
DDRC &= ~( 1 << PC2 ); //PC2 Eingang 
DDRC &= ~( 1 << PC3 ); //PC3 Eingang
PORTC |= ( 1 << PC2 ); //Pull up an
PORTC |= ( 1 << PC3 ); //Pull up an
DDRC |= ( 1 << PC0 ); //PC0 Ausgang 
DDRC |= ( 1 << PC1 ); //PC1 Ausgang

void del_ms(int n)//delay n ms
{
int x;
  while(n--){
    x=1300;       //empirically determined  factor  8 MHz
    while(x--);
  }
}

while(1) 
{ 
if (PINB & (1 << PB0))//wenn PB0 High ist... 
{ 
PORTC |= (1 << PC0); //PC0 High
 del_ms(1024);
}
if (PINB & (1 << PB1))//wenn PB1 High ist... 
{ 
PORTC |= (1 << PC1); //PC1 High
 del_ms(1024);
} 
if (PINC & (1 << PC2))//wenn PC2 High ist... 
{ 
PORTC |= (1 << PC0); //PC0 High
 del_ms(1024);
} 
if (PINC & (1 << PC3))//wenn PC3 High ist... 
{ 
PORTC |= (1 << PC1); //PC1 High 
del_ms(1024);
} 

// Eine Schleife 
if (!(PINB & (1 << PB0))) //wenn PB0 Low ist... 
{ 
PORTC &= ~(1 << PC0); //PC0 Low 
} 
if (!(PINB & (1 << PB1))) //wenn PB1 Low ist... 
{ 
PORTC &= ~(1 << PC1); //PC1 Low 
}
if (!(PINC & (1 << PC2))) //wenn PC2 Low ist... 
{ 
PORTC &= ~(1 << PC0); //PC0 Low 
} 
if (!(PINC & (1 << PC3))) //wenn PC3 Low ist... 
{ 
PORTC &= ~(1 << PC1); //PC1 Low 
}

} 

return 0; 
}