void Spi1Exec(INT8U *tx, INT8U *rx, INT16U rxtx, INT8U target)
{
   ....
        if(rxtx)
        {
            pSPI1->SPI_RPR = (INT32U)rx;
            pSPI1->SPI_RCR = rxtx;
            pSPI1->SPI_PTCR = AT91C_PDC_RXTEN | AT91C_PDC_TXTEN;
            while( !( pSPI1->SPI_SR & AT91C_SPI_ENDRX ) );
            pSPI1->SPI_PTCR = AT91C_PDC_RXTDIS | AT91C_PDC_TXTDIS;
        }
}

    // Check if there is a "stuck" byte in receive register
    if (AT91C_BASE_SPI->SPI_SR & (AT91C_SPI_OVRES | AT91C_SPI_RDRF))
     i=AT91C_BASE_SPI->SPI_RDR;

    // Set up reception of input buffer
    AT91F_SPI_ReceiveFrame(AT91C_BASE_SPI,(char*) &SPIInput[0],sizeof(SPIInput),0,0);

    // Fire transmittion and reception
    AT91F_SPI_SendFrame(AT91C_BASE_SPI,(char*) &OutputBuf[0],sizeof(OutputBuf),0,0);
    // Wait until the reception is finished
    while(!((AT91C_BASE_SPI->SPI_SR) & AT91C_SPI_RXBUFF))
     vTaskDelay(portTICK_RATE_MS * 5);

    // Process input
    .....