msd.c

STM32不完全手册 例程源码 29个

//  /* Byte 14 */
//  MSD_cid->ManufactDate = (CID_Tab[13] & 0x0F) << 8;
//  /* Byte 15 */
//  MSD_cid->ManufactDate |= CID_Tab[14];
//  /* Byte 16 */
//  MSD_cid->msd_CRC = (CID_Tab[15] & 0xFE) >> 1;
//  MSD_cid->Reserved2 = 1;
//
//  /* Return the reponse */
//  return rvalue;
//}

/*******************************************************************************
* Function Name  : MSD_SendCmd
* Description    : Send 5 bytes command to the MSD card.
* Input          : - Cmd: the user expected command to send to MSD card
*                  - Arg: the command argument
*                  - Crc: the CRC
* Output         : None
* Return         : None
*******************************************************************************/
void MSD_SendCmd(u8 Cmd, u32 Arg, u8 Crc)
{
  u32 i = 0x00;
  u8 Frame[6];

  /* Construct byte1 */
  Frame[0] = (Cmd | 0x40);
  /* Construct byte2 */
  Frame[1] = (u8)(Arg >> 24);
  /* Construct byte3 */
  Frame[2] = (u8)(Arg >> 16);
  /* Construct byte4 */
  Frame[3] = (u8)(Arg >> 8);
  /* Construct byte5 */
  Frame[4] = (u8)(Arg);
  /* Construct CRC: byte6 */
  Frame[5] = (Crc);

  /* Send the Cmd bytes */
  for (i = 0; i < 6; i++)
  {
    MSD_WriteByte(Frame[i]);
  }
}

/*******************************************************************************
* Function Name  : MSD_GetDataResponse
* Description    : Get MSD card data response.
* Input          : None
* Output         : None
* Return         : The MSD status: Read data response xxx0<status>1
*                   - status 010: Data accecpted
*                   - status 101: Data rejected due to a crc error
*                   - status 110: Data rejected due to a Write error.
*                   - status 111: Data rejected due to other error.
*******************************************************************************/
u8 MSD_GetDataResponse(void)
{
  u32 i = 0;
  u8 response, rvalue;

  while (i <= 64)
  {
    /* Read resonse */
    response = MSD_ReadByte();
    /* Mask unused bits */
    response &= 0x1F;

    switch (response)
    {
      case MSD_DATA_OK:
      {
        rvalue = MSD_DATA_OK;
        break;
      }

      case MSD_DATA_CRC_ERROR:
        return MSD_DATA_CRC_ERROR;

      case MSD_DATA_WRITE_ERROR:
        return MSD_DATA_WRITE_ERROR;

      default:
      {
        rvalue = MSD_DATA_OTHER_ERROR;
        break;
      }
    }
    /* Exit loop in case of data ok */
    if (rvalue == MSD_DATA_OK)
      break;
    /* Increment loop counter */
    i++;
  }
  /* Wait null data */
  while (MSD_ReadByte() == 0);
  /* Return response */
  return response;
}

/*******************************************************************************
* Function Name  : MSD_GetResponse
* Description    : Returns the MSD response.
* Input          : None
* Output         : None
* Return         : The MSD Response: - MSD_RESPONSE_FAILURE: Sequence failed
*                                    - MSD_RESPONSE_NO_ERROR: Sequence succeed
*******************************************************************************/
u8 MSD_GetResponse(u8 Response)
{
  u32 Count = 0xFFF;

  /* Check if response is got or a timeout is happen */
  while ((MSD_ReadByte() != Response) && Count)
  {
    Count--;
  }

  if (Count == 0)
  {
    /* After time out */
    return MSD_RESPONSE_FAILURE;
  }
  else
  {
    /* Right response got */
    return MSD_RESPONSE_NO_ERROR;
  }
}

/*******************************************************************************
* Function Name  : MSD_GetStatus
* Description    : Returns the MSD status.
* Input          : None
* Output         : None
* Return         : The MSD status.
*******************************************************************************/
u16 MSD_GetStatus(void)
{
  u16 Status = 0;

  /* MSD chip select low */
  SD_CS=0;
  /* Send CMD13 (MSD_SEND_STATUS) to get MSD status */
  MSD_SendCmd(MSD_SEND_STATUS, 0, 0xFF);

  Status = MSD_ReadByte();
  Status |= (u16)(MSD_ReadByte() << 8);

  /* MSD chip select high */
  SD_CS=1;
  /* Send dummy byte 0xFF */
  MSD_WriteByte(DUMMY);

  return Status;
}

/*******************************************************************************
* Function Name  : MSD_GoIdleState
* Description    : Put MSD in Idle state.
* Input          : None
* Output         : None
* Return         : The MSD Response: - MSD_RESPONSE_FAILURE: Sequence failed
*                                    - MSD_RESPONSE_NO_ERROR: Sequence succeed
*******************************************************************************/
u8 MSD_GoIdleState(void)
{
  /* MSD chip select low */
  SD_CS=0;
  /* Send CMD0 (GO_IDLE_STATE) to put MSD in SPI mode */
  MSD_SendCmd(MSD_GO_IDLE_STATE, 0, 0x95);

  /* Wait for In Idle State Response (R1 Format) equal to 0x01 */
  if (MSD_GetResponse(MSD_IN_IDLE_STATE))
  {
    /* No Idle State Response: return response failue */
    return MSD_RESPONSE_FAILURE;
  }
  /*----------Activates the card initialization process-----------*/
  do
  {
    /* MSD chip select high */
    SD_CS=1;
    /* Send Dummy byte 0xFF */
    MSD_WriteByte(DUMMY);

    /* MSD chip select low */
    SD_CS=0;

    /* Send CMD1 (Activates the card process) until response equal to 0x0 */
    MSD_SendCmd(MSD_SEND_OP_COND, 0, 0xFF);
    /* Wait for no error Response (R1 Format) equal to 0x00 */
  }
  while (MSD_GetResponse(MSD_RESPONSE_NO_ERROR));

  /* MSD chip select high */
  SD_CS=1;
  /* Send dummy byte 0xFF */
  MSD_WriteByte(DUMMY);
 	SPIx_SetSpeed(SPI_SPEED_4);//设置到低速模式
  return MSD_RESPONSE_NO_ERROR;
}

/*******************************************************************************
* Function Name  : MSD_WriteByte
* Description    : Write a byte on the MSD.
* Input          : Data: byte to send.
* Output         : None
* Return         : None.
*******************************************************************************/
void MSD_WriteByte(u8 Data)
{
	u8 retry=0;				 
	while((SPI1->SR&1<<1)==0)//等待发送区空	
	{
		retry++;
		if(retry>200)return;
	}			  
	SPI1->DR=Data;	 	  //发送一个byte 
	retry=0;
	while((SPI1->SR&1<<0)==0) //等待接收完一个byte  
	{
		retry++;
		if(retry>200)return ;
	}	  						    
	retry= SPI1->DR;          //返回收到的数据	 
}

/*******************************************************************************
* Function Name  : MSD_ReadByte
* Description    : Read a byte from the MSD.
* Input          : None.
* Output         : None
* Return         : The received byte.
*******************************************************************************/
u8 MSD_ReadByte(void)
{				  
	u8 retry=0;				 
	while((SPI1->SR&1<<1)==0)//等待发送区空	
	{
		retry++;
		if(retry>200)return 0;
	}			  
	SPI1->DR=0XFF;	 	  //发送一个byte 
	retry=0;
	while((SPI1->SR&1<<0)==0) //等待接收完一个byte  
	{
		retry++;
		if(retry>200)return 0;
	}	  						    
	return SPI1->DR;          //返回收到的数据		 
}
 

/******************* (C) COPYRIGHT 2010 STMicroelectronics *****END OF FILE****/