szkielet INT

//enable clock PIO for advanced PIO operation
AT91C_BASE_PMC->PMC_PCER = (1<<AT91C_ID_PIOA);
//External INT----------------------------------------------
AT91C_BASE_PIOA->PIO_PDR = SW1 |SW2;
AT91C_BASE_PIOA->PIO_ODR = SW1 |SW2;
AT91C_BASE_PIOA->PIO_CODR= SW1 |SW2;
AT91C_BASE_PIOA->PIO_PPUER= SW1 |SW2;
AT91C_BASE_PIOA->PIO_ASR = SW1 |SW2;
AT91C_BASE_PIOA->PIO_OWDR = SW1 |SW2;
AT91C_BASE_AIC->AIC_SMR[AT91C_ID_PIOA] = AT91C_AIC_SRCTYPE_INT_POSITIVE_EDGE | 0;
AT91C_BASE_AIC->AIC_SVR[AT91C_ID_PIOA] = (unsigned int)ex_int_handler;
AT91C_BASE_PIOA->PIO_IFER = SW1 |SW2;
io_status = AT91C_BASE_PIOA->PIO_ISR;
AT91C_BASE_AIC->AIC_IECR =  (1 << AT91C_ID_PIOA);
AT91C_BASE_PIOA->PIO_IER = SW1 | SW2;


void ex_int_handler (void)            //ex INT
{
io_status = AT91C_BASE_PIOA->PIO_ISR;   //reset interrupts
....
}