嵌入式開發中經常會用到對外部SD卡進行相關的讀寫操作。下圖是CPU硬件連接示意圖

引腳配置瑞如下：

void SD_LowLevel_DeInit(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure;
  
  /*!< Disable SDIO Clock */
  SDIO_ClockCmd(DISABLE);

  /*!< Set Power State to OFF */
  SDIO_SetPowerState(SDIO_PowerState_OFF);

  /*!< DeInitializes the SDIO peripheral */
  SDIO_DeInit();

  /*!< Disable the SDIO AHB Clock */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_SDIO, DISABLE);

  /*!< Configure PC.08, PC.09, PC.10, PC.11, PC.12 pin: D0, D1, D2, D3, CLK pin */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOC, &GPIO_InitStructure);

  /*!< Configure PD.02 CMD line */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
  GPIO_Init(GPIOD, &GPIO_InitStructure);
}

DMA部分配置如下:

void SD_LowLevel_DMA_TxConfig(uint32_t *BufferSRC, uint32_t BufferSize)
{

  DMA_InitTypeDef DMA_InitStructure;

  DMA_ClearFlag(SD_SDIO_DMA_FLAG_TC | SD_SDIO_DMA_FLAG_TE | SD_SDIO_DMA_FLAG_HT | SD_SDIO_DMA_FLAG_GL);

  /*!< DMA2 Channel4 disable */
  DMA_Cmd(SD_SDIO_DMA_CHANNEL, DISABLE);

  /*!< SDIO DMA CHANNEL Config */
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)SDIO_FIFO_ADDRESS;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)BufferSRC;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
  DMA_InitStructure.DMA_BufferSize = BufferSize / 4;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
  DMA_InitStructure.DMA_Priority = DMA_Priority_High;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
  DMA_Init(SD_SDIO_DMA_CHANNEL, &DMA_InitStructure);

  DMA_ITConfig(SD_SDIO_DMA_CHANNEL, DMA_IT_TC, ENABLE);

  /*!< SDIO DMA CHANNEL enable */
  DMA_Cmd(SD_SDIO_DMA_CHANNEL, ENABLE);  
}



void SD_LowLevel_DMA_RxConfig(uint32_t *BufferDST, uint32_t BufferSize)
{
  DMA_InitTypeDef DMA_InitStructure;

  DMA_ClearFlag(SD_SDIO_DMA_FLAG_TC | SD_SDIO_DMA_FLAG_TE | SD_SDIO_DMA_FLAG_HT | SD_SDIO_DMA_FLAG_GL);

  /*!< SDIO DMA CHANNEL disable */
  DMA_Cmd(SD_SDIO_DMA_CHANNEL, DISABLE);

  /*!< SDIO DMA CHANNEL Config */
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)SDIO_FIFO_ADDRESS;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)BufferDST;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
  DMA_InitStructure.DMA_BufferSize = BufferSize / 4;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
  DMA_InitStructure.DMA_Priority = DMA_Priority_High;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
  DMA_Init(SD_SDIO_DMA_CHANNEL, &DMA_InitStructure);

  DMA_ITConfig(SD_SDIO_DMA_CHANNEL, DMA_IT_TC, ENABLE);

  /*!< SDIO DMA CHANNEL enable */
  DMA_Cmd(SD_SDIO_DMA_CHANNEL, ENABLE);  
}


  
  

uint32_t SD_DMAEndOfTransferStatus(void)
{
  return (uint32_t)DMA_GetFlagStatus(DMA2_FLAG_TC4);
}

SDIO函數中斷部分

///sd卡狀態判斷
void SDCARD_Config(void)
{
	SD_Error Status = SD_OK;
	Status = SD_Init();	        //初始化SDIO
	if (Status != SD_OK)
	{
		Display_ErrorWithoutSD((u8 *)"No_SDCard");
	}
	SDCARD_NVIC_Config();	
}



//中斷配置 部分

void SDCARD_NVIC_Config(void)
{
	NVIC_InitTypeDef NVIC_InitStructure;

	/* Configure the NVIC Preemption Priority Bits */
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

	NVIC_InitStructure.NVIC_IRQChannel = SDIO_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
}



中斷函數
void SDIO_IRQHandler(void)
{
	/* Process All SDIO Interrupt Sources */
	SD_ProcessIRQSrc();
}

審核編輯：符乾江