#define SETBIT(PORT,PIN) (PORT |= 1<<PIN)
#define CLRBIT(PORT,PIN) (PORT &= ~(1<<PIN))

#define ISRXFHIGH ( PINC & (1<<RXF) )
#define ISRXFLOW ( !ISRXFHIGH) 
#define ISTXEHIGH ( PINC & (1<<TXE) ) 
#define ISTXELOW ( !ISTXEHIGH) 
#define READFROMDATABUS ( ( (PINB & 0x03) << 6 ) | ( (PIND & 0xfc) >> 2) )
#define ISBUTTONPRESSED (!((PINC & (1<<BUTTON))>>BUTTON))

#define MAKEDATABUSINPUT {DDRB &= ~((1 << 0) | (1<<1));  DDRD &= ~0xfc; PORTB |= (1 << 0) | (1<<1);  PORTD |= 0xfc; }
#define MAKEDATABUSOUTPUT { DDRB |= (1 << 0) | (1<<1); DDRD |= 0xfc; }

#define PUTONDATABUS(x) {PORTB = (PORTB & 0xfc) | (x&0xc0)>>6 ; PORTD = (PORTD & 0x03) | (x&0x3f)<<2;   }