CC2640 SPI 用法小计

参考了《CC2640R2F BLE5.0 CC2640R2F SPI驱动实现》

该文章网址https://blog.csdn.net/leconiot/article/details/76808445；

初始化SPI的时候，使用函数SPI_Params_init(SPI_Params *params);

params的默认赋值为

 *      transferMode        = SPI_MODE_BLOCKING
 *      transferTimeout     = SPI_WAIT_FOREVER
 *      transferCallbackFxn = NULL
 *      mode                = SPI_MASTER
 *      bitRate             = 1000000 (Hz)
 *      dataSize            = 8 (bits)
 *      frameFormat         = SPI_POL0_PHA0

其中需要注意的是frameFormat，这是始终采样   

SPI_POL0_PHA0 = 0,    /*!< SPI mode Polarity 0 Phase 0 */
SPI_POL0_PHA1 = 1,    /*!< SPI mode Polarity 0 Phase 1 */
SPI_POL1_PHA0 = 2,    /*!< SPI mode Polarity 1 Phase 0 */
SPI_POL1_PHA1 = 3,    /*!< SPI mode Polarity 1 Phase 1 */
SPI_TI        = 4,    /*!< TI mode (not supported on all
                           implementations) */
SPI_MW        = 5     /*!< Micro-wire mode (not supported on all
                           implementations) */        

根据外设的手册，选择对应的采样相位和极性，否则无法驱动起来硬件

其余的废话不多说，直接上代码：使用SPI一次发送一个字节的程序

SPI_Handle      masterSpi;
SPI_Params      spiParams;
SPI_Transaction transaction;
bool            transferOK;

//SPI初始化
void SPI_open_init(){
    /* Open SPI as master (default) */
    SPI_Params_init(&spiParams);
    spiParams.frameFormat = SPI_POL1_PHA1;
    //spiParams.bitRate = 10000000;
    masterSpi = SPI_open(Board_SPI_MASTER, &spiParams);
    if (masterSpi == NULL) {
        Display_printf(display, 0, 0, "Error initializing master SPI\n");
        while (1);
    }
    else {
        Display_printf(display, 0, 0, "Master SPI initialized\n");
    }

}

//SPI发送

void SPI_WriteByte(uint8_t TxData){
    uint8_t temp[2];
    uint8_t temp1[2] = {0,0};
    temp[0] = TxData；
    transaction.count = 1;
    transaction.txBuf = (void *) temp;
    transaction.rxBuf = (void *) temp1;
    /* Perform SPI transfer */
    transferOK = SPI_transfer(masterSpi, &transaction);
    if (transferOK) {
        //Display_printf(display, 0, 0, "Master send: %x", temp[0]);
    }
    else {
        //Display_printf(display, 0, 0, "Unsuccessful master SPI transfer");
    }

}

//SPI接收

uint8_t SPI_ReadByte(){
    uint8_t temp[2];
    uint8_t temp1[2] = {0,0};
    transaction.count = 1;
    transaction.txBuf = (void *)temp1;
    transaction.rxBuf = (void *) temp;
    /* Perform SPI transfer */
    transferOK = SPI_transfer(masterSpi, &transaction);
    if (transferOK) {
        //Display_printf(display, 0, 0, "Master received: %x", temp[0]);
    }
    else {
        //Display_printf(display, 0, 0, "Unsuccessful master SPI transfer");
    }

    return temp[0];

}

其实写法大同小异，我看到有的文章说发送的时候可以给接收赋值为NULL；

    transaction.txBuf = (void *) temp;
    transaction.rxBuf = NULL;

不知道什么原因，如果这样写，我的外设就驱动不起来，