stm32 memory map读写RAM stm32读写sd卡

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墨染心语 2024-03-23 11:14:50

文章标签 stm32 arm 嵌入式硬件单片机驱动开发 文章分类 机器学习人工智能

读取SD卡的函数分析就此就结束了。接下来就是分析文件系统了，以方便读取SD卡中的有用数据本篇文章对SD卡的操作基于

STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\SDIO\uSDCard

之中的文件。

🚩 参考文件：STM32F10x_StdPeriph_Lib_V3.5.0(STM32标准库)

主要的问题就是，本篇读、写操作其实无用，只是示例。写入了一堆乱七八糟的数据又读了一堆乱七八糟的数据。

SD测试函数

擦除测试

单块读写操作

多块读写操作

SD测试函数

直接在主函数中调用函数！

void SD_Test(void)
{

  if((Status = SD_Init()) != SD_OK)    //初始化失败
  {
    STM_EVAL_LEDOn(LED4);     //点亮LED4
  }
        
  while((Status == SD_OK)     //无错误
     && (SDCardOperation != SD_OPERATION_END)    //SD卡不在写状态
     && (SD_Detect() == SD_PRESENT))    //SD卡是否插入
  {
    switch(SDCardOperation)    //判断执行那个测试
    {
      /*-------------------------- SD Erase Test ---------------------------- */
      case (SD_OPERATION_ERASE):
      {
        SD_EraseTest();
        SDCardOperation = SD_OPERATION_BLOCK;
        break;
      }
      /*-------------------------- SD Single Block Test --------------------- */
      case (SD_OPERATION_BLOCK):
      {
        SD_SingleBlockTest();
        SDCardOperation = SD_OPERATION_MULTI_BLOCK;
        break;
      }       
      /*-------------------------- SD Multi Blocks Test --------------------- */
      case (SD_OPERATION_MULTI_BLOCK):
      {
        SD_MultiBlockTest();
        SDCardOperation = SD_OPERATION_END;
        break;
      }              
    }
  }
}

擦除测试

擦除前0x00~512*10的部分。

/**
  * @brief  Tests the SD card erase operation.
  * @param  None
  * @retval None
  */
void SD_EraseTest(void)
{
  /*------------------- Block Erase ------------------------------------------*/
  if (Status == SD_OK)
  {
    /* Erase NumberOfBlocks Blocks of WRITE_BL_LEN(512 Bytes) */
    Status = SD_Erase(0x00, (BLOCK_SIZE * NUMBER_OF_BLOCKS));    //擦除地址
  }

  if (Status == SD_OK)
  {
    /* 进行多块读操作 */    //第一个参数为数据缓冲区，起始地址，数据块大小，数据块数
    Status = SD_ReadMultiBlocks(Buffer_MultiBlock_Rx, 0x00, BLOCK_SIZE, NUMBER_OF_BLOCKS);

    /* Check if the Transfer is finished */
    Status = SD_WaitReadOperation();    //等待DMA读完

    /* Wait until end of DMA transfer */
    while(SD_GetStatus() != SD_TRANSFER_OK);    //SD传输不正常则等待
  }

  /* Check the correctness of erased blocks */
  if (Status == SD_OK)
  {
    /* 检查缓冲区的所有值是否都等于零。 */    //第一个参数为数据缓冲区，第二个为大小
    EraseStatus = eBuffercmp(Buffer_MultiBlock_Rx, MULTI_BUFFER_SIZE);
  }
  
  if(EraseStatus == PASSED)    //擦除成功
  {
    STM_EVAL_LEDOn(LED1);
  }
  else    //擦除失败
  {
    STM_EVAL_LEDOff(LED1);
    STM_EVAL_LEDOn(LED4);    
  }
}

其中，检测数据的函数：

/**
  * @brief  Checks if a buffer has all its values are equal to zero.
  * @param  pBuffer: buffer to be compared.
  * @param  BufferLength: buffer's length
  * @retval PASSED: pBuffer values are zero
  *         FAILED: At least one value from pBuffer buffer is different from zero.
  */
TestStatus eBuffercmp(uint8_t* pBuffer, uint32_t BufferLength)
{
  while (BufferLength--)
  {
    /* In some SD Cards the erased state is 0xFF, in others it's 0x00 */
    if ((*pBuffer != 0xFF) && (*pBuffer != 0x00))
    {
      return FAILED;
    }

    pBuffer++;
  }

  return PASSED;
}

单块读写操作

/**
  * @brief  Tests the SD card Single Blocks operations.
  * @param  None
  * @retval None
  */
void SD_SingleBlockTest(void)
{
  /*------------------- Block Read/Write --------------------------*/
  /* Fill the buffer to send */
  /* 用用户预定义的数据填充缓冲区 */ 
  Fill_Buffer(Buffer_Block_Tx, BLOCK_SIZE, 0x320F);

  if (Status == SD_OK)
  {
    /* Write block of 512 bytes on address 0 */    //数据缓冲区，写入地址，块大小
    Status = SD_WriteBlock(Buffer_Block_Tx, 0x00, BLOCK_SIZE);
    /* Check if the Transfer is finished */
    Status = SD_WaitWriteOperation();    //等待SDIO DMA数据传输完成。
    while(SD_GetStatus() != SD_TRANSFER_OK);
  }

  if (Status == SD_OK)
  {
    /* Read block of 512 bytes from address 0 */    //数据缓冲区，读取地址，块大小
    Status = SD_ReadBlock(Buffer_Block_Rx, 0x00, BLOCK_SIZE);
    /* Check if the Transfer is finished */
    Status = SD_WaitReadOperation();
    while(SD_GetStatus() != SD_TRANSFER_OK);
  }

  /* Check the correctness of written data */
  if (Status == SD_OK)
  {
    TransferStatus1 = Buffercmp(Buffer_Block_Tx, Buffer_Block_Rx, BLOCK_SIZE);
  }
  
  if(TransferStatus1 == PASSED)    //写成功，检测读和写的数据相同
  {
    STM_EVAL_LEDOn(LED2);
  }
  else    //写失败，读和写的数据不同
  {
    STM_EVAL_LEDOff(LED2);
    STM_EVAL_LEDOn(LED4);    
  }
}

处理数据缓冲区的函数

/**
  * @brief  Fills buffer with user predefined data.
  * @param  pBuffer: pointer on the Buffer to fill
  * @param  BufferLength: size of the buffer to fill
  * @param  Offset: first value to fill on the Buffer
  * @retval None
  */
void Fill_Buffer(uint8_t *pBuffer, uint32_t BufferLength, uint32_t Offset)
{
  uint16_t index = 0;

  /* Put in global buffer same values */
  for (index = 0; index < BufferLength; index++)
  {
    pBuffer[index] = index + Offset;    //其实就是瞎写数据
  }
}

检测数据函数

主要判断写数据缓冲区和读数据缓冲区数据是否相等。

/**
  * @brief  Compares two buffers.
  * @param  pBuffer1, pBuffer2: buffers to be compared.
  * @param  BufferLength: buffer's length
  * @retval PASSED: pBuffer1 identical to pBuffer2
  *         FAILED: pBuffer1 differs from pBuffer2
  */
TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint32_t BufferLength)
{
  while (BufferLength--)
  {
    if (*pBuffer1 != *pBuffer2)
    {
      return FAILED;
    }

    pBuffer1++;
    pBuffer2++;
  }

  return PASSED;
}

多块读写操作

/**
  * @brief  Tests the SD card Multiple Blocks operations.
  * @param  None
  * @retval None
  */
void SD_MultiBlockTest(void)
{
  /*--------------- Multiple Block Read/Write ---------------------*/
  /* Fill the buffer to send */
  /* 用用户预定义的数据填充缓冲区 */ 
  Fill_Buffer(Buffer_MultiBlock_Tx, MULTI_BUFFER_SIZE, 0x0);

  if (Status == SD_OK)
  {
    /* Write multiple block of many bytes on address 0 */
    // 数据缓冲区、写入地址、块大小、块数量
    Status = SD_WriteMultiBlocks(Buffer_MultiBlock_Tx, 0x00, BLOCK_SIZE, NUMBER_OF_BLOCKS);
    /* Check if the Transfer is finished */
    Status = SD_WaitWriteOperation();
    while(SD_GetStatus() != SD_TRANSFER_OK);
  }

  if (Status == SD_OK)
  {
    /* Read block of many bytes from address 0 */
    // 数据缓冲区、写入地址、块大小、块数量
    Status = SD_ReadMultiBlocks(Buffer_MultiBlock_Rx, 0x00, BLOCK_SIZE, NUMBER_OF_BLOCKS);
    /* Check if the Transfer is finished */
    Status = SD_WaitReadOperation();
    while(SD_GetStatus() != SD_TRANSFER_OK);
  }

  /* Check the correctness of written data */
  if (Status == SD_OK)
  {
    /* 检查读写缓冲区数据是否相同 */
    TransferStatus2 = Buffercmp(Buffer_MultiBlock_Tx, Buffer_MultiBlock_Rx, MULTI_BUFFER_SIZE);
  }
  
  if(TransferStatus2 == PASSED)    //成功
  {
    STM_EVAL_LEDOn(LED3);
  }
  else    //失败
  {
    STM_EVAL_LEDOff(LED3);
    STM_EVAL_LEDOn(LED4);    
  }
}

处理缓冲区、检测数据函数和单个块读写操作相同。

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