Konfiguracja RTT w SAM7 S256 do odczytu temperatury co sekundę

                   if (0 != (AT91C_BASE_RTTC->RTTC_RTSR & AT91C_RTTC_RTTINC))
                      {
                        rtt_irq_handler();
                      }
                /* End the interrupt in the AIC. */
                AT91C_BASE_AIC->AIC_EOICR = 0;

void
rtt_irq_handler (void)
{
  rtt_sys_time = AT91C_BASE_RTTC->RTTC_RTVR;                                              // Update system timer (clear rtt irq).

  if (0 == (rtt_sys_time % 2))
    {
      AT91C_BASE_PIOA->PIO_CODR = 0x00000004;
    }
  else
    {
      AT91C_BASE_PIOA->PIO_SODR = 0x00000004;
    }
}

void pitIsr(void);
void PIT_init(void)
{
	uint32_t dummy;
	AT91C_BASE_PITC->PITC_PIMR= ~(AT91C_PITC_PITEN | AT91C_PITC_PITIEN);
	while (AT91C_BASE_PITC->PITC_PIVR & AT91C_PITC_CPIV ) {};
	dummy=AT91C_BASE_PITC->PITC_PIVR;
	const uint8_t PIT_IRQ_PRIORITY = 5;
	AT91F_AIC_ConfigureIt ( AT91C_BASE_AIC , AT91C_ID_SYS , PIT_IRQ_PRIORITY , AT91C_AIC_SRCTYPE_INT_POSITIVE_EDGE , pitIsr );
	AT91F_AIC_EnableIt ( AT91C_BASE_AIC , AT91C_ID_SYS );
	
	AT91C_BASE_PITC->PITC_PIMR=( 0xFFFFE | AT91C_PITC_PITEN | AT91C_PITC_PITIEN);
	
	
}
void pitIsr(void)
{
uint32_t status;
uint32_t dummy1;
	if(AT91C_BASE_PITC->PITC_PIMR | AT91C_PITC_PITIEN)
	{
		status=AT91C_BASE_PITC->PITC_PISR;
		AT91C_BASE_PITC->PITC_PIMR= ~( AT91C_PITC_PITIEN);
		if(status & AT91C_PITC_PITS)
		{
			dummy1=AT91C_BASE_PITC->PITC_PIVR;
			lcdCls();
			lcdLocate(1,0);
			lcdText("123456789012345");
			delay_ms(1000);
			lcdCls();
			
		}
		AT91C_BASE_PITC->PITC_PIMR= ( AT91C_PITC_PITIEN);
	}
}