PSoC 4 24-Bit Daten am Stück per SPI senden

    /*******************************************************************************

    * Function Name: SPI_SpiUartWriteTxData

    ********************************************************************************

    *

    * Summary:

    *  Places a data entry into the transmit buffer to be sent at the next available

    *  bus time.

    *  This function is blocking and waits until there is space available to put the

    *  requested data in the transmit buffer.

    *

    * Parameters:

    *  txDataByte: the data to be transmitted.

    *

    * Return:

    *  None

    *

    *******************************************************************************/

    void SPI_SpiUartWriteTxData(uint32 txData)

    {

    #if (SPI_INTERNAL_TX_SW_BUFFER_CONST)

        uint32 locHead;

    #endif /* (SPI_INTERNAL_TX_SW_BUFFER_CONST) */

        #if (SPI_CHECK_TX_SW_BUFFER)

        {

            /* Put data directly into the TX FIFO */

            if ((SPI_txBufferHead == SPI_txBufferTail) &&

                (SPI_SPI_UART_FIFO_SIZE != SPI_GET_TX_FIFO_ENTRIES))

            {

                /* TX software buffer is empty: put data directly in TX FIFO */

                SPI_TX_FIFO_WR_REG = txData;

            }

            /* Put data into TX software buffer */

            else

            {

                /* Head index to put data */

                locHead = (SPI_txBufferHead + 1u);

                /* Adjust TX software buffer index */

                if (SPI_TX_BUFFER_SIZE == locHead)

                {

                    locHead = 0u;

                }

                /* Wait for space in TX software buffer */

                while (locHead == SPI_txBufferTail)

                {

                }

                /* TX software buffer has at least one room */

                /* Clear old status of INTR_TX_NOT_FULL. It sets at the end of transfer when TX FIFO is empty. */

                SPI_ClearTxInterruptSource(SPI_INTR_TX_NOT_FULL);

                SPI_PutWordInTxBuffer(locHead, txData);

                SPI_txBufferHead = locHead;

                /* Check if TX Not Full is disabled in interrupt */

                if (0u == (SPI_INTR_TX_MASK_REG & SPI_INTR_TX_NOT_FULL))

                {

                    /* Enable TX Not Full interrupt source to transmit from software buffer */

                    SPI_INTR_TX_MASK_REG |= (uint32) SPI_INTR_TX_NOT_FULL;

                }

            }

        }

        #else

        {

            /* Wait until TX FIFO has space to put data element */

            while (SPI_SPI_UART_FIFO_SIZE == SPI_GET_TX_FIFO_ENTRIES)

            {

            }

            SPI_TX_FIFO_WR_REG = txData;

        }

        #endif

    }