使用CC1310Launch Pad的SPI，调用SPI_transfer()成功后无返回数值。

// From board.c
PIN_Config BoardGpioInitTable[] = {
    Board_CSN_0   | PIN_GPIO_OUTPUT_EN | PIN_GPIO_HIGH   | PIN_PUSHPULL,   // Ensure SPI slave 0 is not selected
    Board_CSN_1   | PIN_GPIO_OUTPUT_EN | PIN_GPIO_HIGH   | PIN_PUSHPULL    // Ensure SPI slave 1 is not selected
}
const *** ***[CC2650_SPICOUNT] = {
{   // Use SPI0 module with default chip select on Board_CSN_0
    .baseAddr = SSI0_BASE,
    .intNum = INT_SSI0,
    .intPriority = ~0,
    .swiPriority = 0,
    .defaultTxBufValue = 0,
    .powerMngrId = PERIPH_SSI0,
    .rxChannelIndex = UDMA_CHAN_SSI0_RX,
    .txChannelIndex = UDMA_CHAN_SSI0_TX,
    .mosiPin = Board_SPI0_MOSI,
    .misoPin = Board_SPI0_MISO,
    .clkPin = Board_SPI0_CLK,
    .csnPin = Board_CSN_0
}
// From your_application.c
static void taskFxn(UArg a0, UArg a1)
{
    SPI_Handle handle;
    SPI_Params params;
    SPI_Transaction transaction;
    PIN_Id csnPin1  = PIN_ID(Board_CSN_1);
    uint8_t txBuf[] = "Hello World";    // Transmit buffer
    // Init SPI and specify non-default parameters
    SPI_Params_init(&params);
    params.bitRate     = 1000000;
    params.frameFormat = SPI_POL1_PHA1;
    params.mode        = SPI_MASTER;
    // Configure the transaction
    transaction.count = sizeof(txBuf);
    transaction.txBuf = txBuf;
    transaction.rxBuf = NULL;
    // Open the SPI and perform transfer to the first slave
    handle = SPI_open(Board_SPI, &params);
    SPI_transfer(handle, &transaction);
    // Then switch chip select pin and perform transfer to the second slave
    SPI_control(handle, ***, &csnPin1);
    SPI_transfer(handle, &transaction);
}