SPI (SPIM_PutArray())

Are there any thing I miss here?

Yes, you are too fast. The PutArray() API is non-blocking when the transmit buffer is large enough. So your reading GetTxBufferSize() just shows that the complete transfer to the slave is not done yet.

Bob

void SPIM_1_PutArray(const uint8 buffer[], uint8 byteCount)                                                                    

{

    uint8 bufIndex;

    bufIndex = 0u;

    while(byteCount > 0u)

    {

        /* Wait until TX FIFO has a place */

        while(0u == (SPIM_1_TX_STATUS_REG & SPIM_1_STS_TX_FIFO_NOT_FULL))

        {

        }

        /* Put data element into the TX FIFO */

        CY_SET_REG8(SPIM_1_TXDATA_PTR, txData);

        bufIndex++;

        byteCount--;

    }

}