用DMA模式读写SD卡

carmen523

用DMA模式读写SD卡 [复制链接]

不好意思， 我知道这个问题问了很多次，可是我是一个新手，没有办法做到。

我模仿了以下的程式：

https://bbs.eeworld.com.cn/thread-250154-2-1.html

这是我的Code：

void WriteBlock_DMA(void){

//__IO uint32_t Status = 0;

uint8_t write_data[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};

//SD_Init();

//Status = SD_WriteBlock(write_data, 0x00, SD_BLOCK_SIZE);

DMA_InitTypeDef DMA_TestStructure;

SD_Error rvalue = SD_RESPONSE_FAILURE;

SD_Init();

SD_CS_LOW();

//Enables the DMA1 peripheral clock.

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

//Configuration of the DMA1 Channel4 - SPI2_RX

DMA_DeInit(DMA1_Channel5);

  DMA_TestStructure.DMA_PeripheralBaseAddr = (uint32_t)SD_SPI_DR_Address;

  DMA_TestStructure.DMA_MemoryBaseAddr = (uint32_t)write_data;

  DMA_TestStructure.DMA_DIR = DMA_DIR_PeripheralDST;

  DMA_TestStructure.DMA_BufferSize = SD_BLOCK_SIZE;

  DMA_TestStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

  DMA_TestStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

  DMA_TestStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

  DMA_TestStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;

  DMA_TestStructure.DMA_Mode = DMA_Mode_Normal;

  DMA_TestStructure.DMA_Priority = DMA_Priority_High;

  DMA_TestStructure.DMA_M2M = DMA_M2M_Disable;

  DMA_Init(DMA1_Channel5, &DMA_TestStructure);

SD_SendCmd(SD_CMD_SET_BLOCKLEN,SD_BLOCK_SIZE,0x00); 

  SD_ReadByte();

  SD_ReadByte();

SPI_I2S_DMACmd(SD_SPI, SPI_I2S_DMAReq_Tx, ENABLE);

//DMA_ClearFlag(DMA1_FLAG_TC4);

SD_SendCmd(SD_CMD_WRITE_SINGLE_BLOCK, 0x00, 0xFF);

if (!SD_GetResponse(SD_RESPONSE_NO_ERROR))

  {

    /*!< Send a dummy byte */

    SD_WriteByte(SD_DUMMY_BYTE);

    /*!< Send the data token to signify the start of the data */

    SD_WriteByte(0xFE);

    

DMA_Cmd(DMA1_Channel5, ENABLE);

while (!DMA_GetFlagStatus(DMA1_FLAG_TC5));

while(SPI_I2S_GetFlagStatus(SD_SPI, SPI_I2S_FLAG_TXE) == RESET);

SD_ReadByte();

    SD_ReadByte();

    /* Read data response */

    if (SD_GetDataResponse() == SD_DATA_OK)

    {

        rvalue = SD_RESPONSE_NO_ERROR;

    }

}

SD_CS_HIGH();  

SD_WriteByte(SD_DUMMY_BYTE);

DMA_Cmd(DMA1_Channel5, DISABLE);

}

程式一直停在if (SD_GetDataResponse() == SD_DATA_OK)，请问各位高手我有哪里没有考虑到的吗？