CC2640 SPI 用法小计

最新推荐文章于 2025-06-20 13:06:18 发布

迎風吹頭髮

最新推荐文章于 2025-06-20 13:06:18 发布

阅读量5.7k

点赞数 1

CC 4.0 BY-SA版权

分类专栏： SPI小记文章标签： SPI

本文链接：https://blog.youkuaiyun.com/farsight_2098/article/details/86505544

SPI小记专栏收录该内容

2 篇文章

订阅专栏

本文详细介绍了CC2640R2F芯片中SPI接口的驱动实现，包括SPI参数初始化、发送与接收字节的函数编写。重点解析了frameFormat参数的选择，确保与外设手册一致，以正确驱动硬件。

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

该文章网址https://blog.youkuaiyun.com/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，