AT91C_BASE_SYS->PIOA_IDR = 0xffffffff;
   // AT91C_BASE_US0->US_IER = AT91C_US_RXRDY;
    //* Disable the interrupt on the interrupt controller
    AT91C_BASE_AIC->AIC_IDCR = 1<<AT91C_ID_US0;
    //* Save the interrupt handler routine pointer and the interrupt priority
    AT91C_BASE_AIC->AIC_SVR[AT91C_ID_US0] = (unsigned int) RX_interrapt;
    //* Store the Source Mode Register
    AT91C_BASE_AIC->AIC_SMR[AT91C_ID_US0] = AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 2 ;
    //* Clear the interrupt on the interrupt controller
    AT91C_BASE_AIC->AIC_ICCR = 1<<AT91C_ID_US0;
    
    AT91C_BASE_AIC->AIC_IECR = 0x1 << AT91C_ID_US0;

void RX_interrapt (void)
{


    status = AT91C_BASE_US0->US_CSR;
                status = AT91C_BASE_US0->US_RHR;
    
     AT91C_BASE_US0->US_CR = AT91C_US_RSTSTA;
                 AT91C_BASE_SYS->AIC_EOICR = 0;
}

__data_handler:
        ldr  pc,[pc,#+24]            ;; Data abort

__irq void RX_interrapt (void)