MCU:STM32F303VC

在SPI通信中，可以同時(shí)開啟發(fā)送和接收DMA請(qǐng)求，自動(dòng)數(shù)據(jù)的發(fā)送和接收，完成數(shù)據(jù)的交換

基本步驟是：

1. 配置好SPI相應(yīng)引腳功能

2. 配置和初始化SPI

3. 初始化DMA

4. 片選信號(hào)選擇要通信的設(shè)備

5. 打開DMA

對(duì)應(yīng)DMA通道：SPI1_RX---DMA1_Channel2；SPI1_TX---DMA1_Channel3

代碼：

#define L3GD20_SPI_TDR (u32)(SPI1_BASE+0x0C)

#define L3GD20_SPI_RDR (u32)(SPI1_BASE+0x0C)

u8 SPI_TXBUFFER[7]={0xE8,0x00,0x00,0x00,0x00,0x00,0x00};

u8 SPI_RXBUFFER[7]={0};

void SPI_DMA_Test(void)

{

SPI_GPIO_Config()；

SPI_Config()；//見上一篇博客

SPI_DMA_Config();

GPIO_ResetBit(GPIOE,GPIO_Pin_3);//片選信號(hào)

//打開DMA

SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, ENABLE);

SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Tx, ENABLE);

DMA_Cmd(DMA1_Channel2, ENABLE);

DMA_Cmd(DMA1_Channel3, ENABLE);

}

void SPI_DMA_Config(void)

{

DMA_InitTypeDef DMA_InitStruct;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

DMA_StructInit(&DMA_InitStruct);

DMA_DeInit(DMA1_Channel2);

DMA_DeInit(DMA1_Channel3);

DMA_InitStruct.DMA_PeripheralBaseAddr = L3GD20_SPI_TDR;

DMA_InitStruct.DMA_MemoryBaseAddr = (uint32_t )SPI_TXBUFFER;

DMA_InitStruct.DMA_DIR = DMA_DIR_PeripheralDST;

DMA_InitStruct.DMA_BufferSize =7;

DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;

DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

DMA_InitStruct.DMA_Mode = DMA_Mode_Circular;

DMA_InitStruct.DMA_Priority = DMA_Priority_VeryHigh;

DMA_InitStruct.DMA_M2M = DMA_M2M_Disable;

DMA_Init(DMA1_Channel3, &DMA_InitStruct);

DMA_InitStruct.DMA_PeripheralBaseAddr = L3GD20_SPI_RDR;

DMA_InitStruct.DMA_MemoryBaseAddr = (uint32_t )SPI_RXBUFFER;

DMA_InitStruct.DMA_DIR = DMA_DIR_PeripheralSRC;

DMA_Init(DMA1_Channel2, &DMA_InitStruct);

}

處理數(shù)據(jù)時(shí)只需要讀取緩沖區(qū)的數(shù)據(jù)即可，不需要額外的程序去讀取，節(jié)省資源，用起來方便。