/****************************************************************************
Interrupt Timer2 (Display)
****************************************************************************/

ISR(TIMER2_OVF_vect)
{
	if (STATUS_DISPLAY & (1<<0)) //new Data UP&DOWN
	{
		if (istart_DISPLAYUP > iend_DISPLAYUP) 
		{
			PORTA &= ~(1<<RS);
			STATUS_DISPLAY &= ~(1<<0);
			STATUS_DISPLAY |= (1<<2);
			
			PORTA |= (1<<E);
			PORTD = istart_DISPLAYDOWN;
			PORTD |= (1<<7);
			PORTA &= ~(1<<E);
		}
		
		else
		{
			PORTA |= (1<<RS);
			PORTA |= (1<<E);
			PORTD = DISPLAY_DataUP[istart_DISPLAYUP];
			if (PORTD == 0) {PORTD = Z_LEER;}
			PORTA &= ~(1<<E);
			istart_DISPLAYUP ++;
		}
	}
	
	else if (STATUS_DISPLAY & (1<<1)) //new Data UP
	{
		PORTA |= (1<<RS);
		PORTA |= (1<<E);
		PORTD = DISPLAY_DataUP[istart_DISPLAYUP];
		if (PORTD == 0) {PORTD = Z_LEER;}
		PORTA &= ~(1<<E);
		istart_DISPLAYUP ++;
		
		if (istart_DISPLAYUP > iend_DISPLAYUP)
		{
			STATUS_DISPLAY &= ~(1<<1);
			STATUS10 &= ~(1<<2);
			if (STATUS_DISPLAY != 0) {STATUS00 |= (1<<2); TCCR2B &= ~(1<<CS21);}
			else //zum Beenden von Timer2
			{
				TCCR2B &= ~(1<<CS21);
				PORTA &= ~((1<<RW) | (1<<RS));
				PORTD = 0;
				DDRD = 0;
			}
		}
	}
	
	else if (STATUS_DISPLAY & (1<<2)) //new Data DOWN
	{
		PORTA |= (1<<RS);
		PORTA |= (1<<E);
		PORTD = DISPLAY_DataDOWN[istart_DISPLAYDOWN - 0x40];
		if (PORTD == 0) {PORTD = Z_LEER;}
		PORTA &= ~(1<<E);
		istart_DISPLAYDOWN ++;
		
		if (istart_DISPLAYDOWN > iend_DISPLAYDOWN)
		{
			STATUS_DISPLAY &= ~(1<<2);
			STATUS10 &= ~(1<<2);
			if (STATUS_DISPLAY != 0) {STATUS00 |= (1<<2); TCCR2B &= ~(1<<CS21);}
			else //zum Beenden von Timer2
			{
				TCCR2B &= ~(1<<CS21);
				PORTA &= ~((1<<RW) | (1<<RS));
				PORTD = 0;
				DDRD = 0;
			}
		}
	}
	
	else if (STATUS_DISPLAY & (1<<3)) //activate Cursor
	{
		switch (STATUS_DISPLAYCURSOR)
		{
		case 0: //POS_DISPLAYCURSOR gesetzt
			PORTA &= ~(1<<RS);
			PORTA |= (1<<E);
			PORTD = 0b00001111;
			PORTA &= ~(1<<E);
			STATUS_DISPLAYCURSOR = 1;
		break;
		
		case 1: //Cursor gesetzt
			PORTA |= (1<<RS);
			if (POS_DISPLAYCURSOR < 0x40)
			{
				PORTA |= (1<<E);
				PORTD = DISPLAY_DataUP[POS_DISPLAYCURSOR];
				if (PORTD == 0) {PORTD = Z_LEER;}
				PORTA &= ~(1<<E);
			}
			else
			{
				PORTA |= (1<<E);
				PORTD = DISPLAY_DataDOWN[POS_DISPLAYCURSOR - 0x40];
				if (PORTD == 0) {PORTD = Z_LEER;}
				PORTA &= ~(1<<E);
			}
			STATUS_DISPLAYCURSOR = 2;
		break;
		
		case 2: //Zeichen gesetzt
			PORTA &= ~(1<<RS);
			PORTA |= (1<<E);
			PORTD = 0b00010000;
			PORTA &= ~(1<<E);
			STATUS_DISPLAYCURSOR = 3;
		break;
		
		case 3: //Cursor geshiftet nach links
			STATUS_DISPLAY &= ~(1<<3);
			STATUS10 &= ~(1<<2);
			if (STATUS_DISPLAY != 0) {STATUS00 |= (1<<2); TCCR2B &= ~(1<<CS21);}
			else //zum Beenden von Timer2
			{
				TCCR2B &= ~(1<<CS21);
				PORTA &= ~((1<<RW) | (1<<RS));
				PORTD = 0;
				DDRD = 0;
			}
		break;
		}
	}
	
//if (STATUS00 == 0) {PORTB |= (1<<LED_rot);}
	
	else //zum Beenden von Timer2
	{
			TCCR2B &= ~(1<<CS21);
			STATUS10 &= ~(1<<2);
			PORTA &= ~((1<<RW) | (1<<RS));
			PORTD = 0;
			DDRD = 0;
	} 
	TCNT2 = TCNT2_StartValue;
}