新手求助啊，TF卡发送CMD17之后，无法接到0xFE应答

只看该作者 · 2012-5-8 09:12

各位高手好，小弟最近才入手STM32，在调试SD卡和TF卡时候，遇上了如题的问题，目前SD卡读写一切正常，但是调试TF卡（套了个SD卡套）时，发送CMD17命令之后，始终无法得到0xFE的应答，总是超时退出，请大家帮忙分析一下是什么原因，万分感谢！！！
等待应答函数如下：
SD_Error TFSD_ReadBlock(uint8_t* pBuffer, uint32_t ReadAddr, uint16_t BlockSize)
{
  uint32_t i = 0;
  SD_Error rvalue = SD_RESPONSE_FAILURE;
  static u8 temp = 0;

  /*!< SD chip select low */
  SD_CS = EN_CS;

  /*!< Send CMD17 (SD_CMD_READ_SINGLE_BLOCK) to read one block */
  TFSD_SendCmd(CMD17, ReadAddr, 0xFF);

  /*!< Check if the SD acknowledged the read block command:
                              R1 response (0x00: no errors) */
  temp = TFSD_GetResponse(SD_RESPONSE_NO_ERROR);
  if (!temp)
  {
/*!< Now look for the data token to signify the start of the data */
if (!TFSD_GetResponse(0xFE))
{
   /*!< Read the SD block data : read NumByteToRead data */
   for (i = 0; i < BlockSize; i++)
   {
      /*!< Save the received data */
      *pBuffer = SD_ReadByte();
      *
      /*!< Point to the next location where the byte read will be saved */
      pBuffer++;
   }
   /*!< Get CRC bytes (not really needed by us, but required by SD) */
   SD_ReadByte();
   SD_ReadByte();
   /*!< Set response value to success */
   rvalue = SD_RESPONSE_NO_ERROR;
}
  }
  /*!< SD chip select high */
  SD_CS = DIS_CS;

  /*!< Send dummy byte: 8 Clock pulses of delay */
  SD_WriteByte(0xFF);

  /*!< Returns the reponse */
  return rvalue;
}

SD_Error TFSD_GetResponse(uint8_t Response)
{

uint32_t Count = 0xFFFFF;

while ((SD_ReadByte() != Response) && Count)

{

Count--;

}

if (Count == 0)

{

return SD_RESPONSE_FAILURE;

}

else

{

return SD_RESPONSE_NO_ERROR;

}
}