stm32 spi dma发送

在STM32中使用DMA发送SPI数据可以提高效率和可靠性。下面是一个简单的示例代码，演示如何使用DMA发送SPI数据：

#include "stm32f4xx.h"

#define BUFFER_SIZE  10

uint8_t tx_buffer[BUFFER_SIZE] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A};

void DMA2_Stream3_IRQHandler(void)
{
  if (DMA_GetITStatus(DMA2_Stream3, DMA_IT_TCIF3))
  {
    DMA_ClearITPendingBit(DMA2_Stream3, DMA_IT_TCIF3);
    // DMA transfer complete
  }
}

int main(void)
{
  // Enable the DMA2 clock
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);

  // Enable the SPI1 clock
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);

  // Enable GPIO clock
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

  // Configure SPI pins
  GPIO_InitTypeDef GPIO_InitStruct;
  GPIO_StructInit(&GPIO_InitStruct);
  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStruct);

  // Configure DMA for SPI1 TX
  DMA_InitTypeDef DMA_InitStruct;
  DMA_StructInit(&DMA_InitStruct);
  DMA_InitStruct.DMA_Channel = DMA_Channel_3;
  DMA_InitStruct.DMA_DIR = DMA_DIR_MemoryToPeripheral;
  DMA_InitStruct.DMA_Memory0BaseAddr = (uint32_t)tx_buffer;
  DMA_InitStruct.DMA_BufferSize = BUFFER_SIZE;
  DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t)&SPI1->DR;
  DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
  DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
  DMA_InitStruct.DMA_Mode = DMA_Mode_Normal;
  DMA_InitStruct.DMA_Priority = DMA_Priority_High;
  DMA_InitStruct.DMA_FIFOMode = DMA_FIFOMode_Disable;
  DMA_InitStruct.DMA_MemoryBurst = DMA_MemoryBurst_Single;
  DMA_InitStruct.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
  DMA_Init(DMA2_Stream3, &DMA_InitStruct);

  // Enable DMA interrupt
  NVIC_InitTypeDef NVIC_InitStruct;
  NVIC_InitStruct.NVIC_IRQChannel = DMA2_Stream3_IRQn;
  NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStruct);

  // Configure SPI1
  SPI_InitTypeDef SPI_InitStruct;
  SPI_StructInit(&SPI_InitStruct);
  SPI_InitStruct.SPI_Direction = SPI_Direction_1Line_Tx;
  SPI_InitStruct.SPI_Mode = SPI_Mode_Master;
  SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStruct.SPI_CPOL = SPI_CPOL_Low;
  SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge;
  SPI_InitStruct.SPI_NSS = SPI_NSS_Soft;
  SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
  SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_Init(SPI1, &SPI_InitStruct);

  // Enable SPI1
  SPI_Cmd(SPI1, ENABLE);

  // Enable DMA2 Stream3
  DMA_Cmd(DMA2_Stream3, ENABLE);

  while (1)
  {
    // Wait for DMA transfer complete
    while (DMA_GetFlagStatus(DMA2_Stream3, DMA_FLAG_TCIF3) == RESET);

    // Clear DMA transfer complete flag
    DMA_ClearFlag(DMA2_Stream3, DMA_FLAG_TCIF3);

    // Reset DMA counter
    DMA_SetCurrDataCounter(DMA2_Stream3, BUFFER_SIZE);

    // Start DMA transfer
    DMA_Cmd(DMA2_Stream3, ENABLE);
  }
}

在这个示例代码中，DMA2的Stream3被配置为SPI1的传输通道。使用SPI1发送的数据存储在一个大小为10的缓冲区中。DMA中断用于通知传输何时完成。在主循环中，当DMA传输完成时，DMA计数器被重置并启动新的DMA传输。