mmc.c

TI公司的MSP430与SD卡连接的驱动

          DMADT_0 |                         /* Single transfer mode */
          DMASBDB |                         /* Byte mode */
          DMAEN;                            /* Enable DMA */

        /* Kick off the transfer by sending the first byte */
        U1TXBUF = 0xFF;
//      while (DMA0CTL & DMAEN) _NOP(); //LPM0;  // wait till done
//      while (DMA0CTL & DMAEN) _EINT(); LPM0;  // wait till done
        _EINT(); LPM0;  // wait till done
#endif
        // get CRC bytes (not really needed by us, but required by MMC)
        spiSendByte(0xff);
        spiSendByte(0xff);
        rvalue = MMC_SUCCESS;
      }
      else
      {
        // the data token was never received
        rvalue = MMC_DATA_TOKEN_ERROR;      // 3
      }
    }
    else
    {
      // the MMC never acknowledge the read command
      rvalue = MMC_RESPONSE_ERROR;          // 2
    }
  }
  else
  {
    rvalue = MMC_BLOCK_SET_ERROR;           // 1
  }
  CS_HIGH ();
  spiSendByte(0xff);
  return rvalue;
}// mmc_read_block



//---------------------------------------------------------------------
//char mmcWriteBlock (const unsigned long address)
char mmcWriteBlock (const unsigned long address, const unsigned long count, unsigned char *pBuffer)
{
  unsigned long i = 0;
  char rvalue = MMC_RESPONSE_ERROR;         // MMC_SUCCESS;
  //  char c = 0x00;

  // Set the block length to read
  if (mmcSetBlockLength (count) == MMC_SUCCESS)   // block length could be set
  {
    // SS = LOW (on)
    CS_LOW ();
    // send write command
    mmcSendCmd (MMC_WRITE_BLOCK,address, 0xFF);

    // check if the MMC acknowledged the write block command
    // it will do this by sending an affirmative response
    // in the R1 format (0x00 is no errors)
    if (mmcGetXXResponse(MMC_R1_RESPONSE) == MMC_R1_RESPONSE)
    {
      spiSendByte(0xff);
      // send the data token to signify the start of the data
      spiSendByte(0xfe);
      // clock the actual data transfer and transmitt the bytes
#ifndef withDMA
      for (i = 0; i < count; i++)
        spiSendByte(pBuffer[i]);            
#else
      /* Get the block */
      /* DMA trigger is UART send */
      DMACTL0 &= ~(DMA0TSEL_15);
      DMACTL0 |= (DMA0TSEL_9);
      /* Source DMA address: the data buffer.  */
      DMA0SA = (unsigned short)pBuffer;
      /* Destination DMA address: the UART send register. */
      DMA0DA = U1TXBUF_;
      /* The size of the block to be transferred */
      DMA0SZ = count;
      /* Configure the DMA transfer*/
      DMA0CTL =
        DMAREQ  |                           /* start transfer */
        DMADT_0 |                           /* Single transfer mode */
        DMASBDB |                           /* Byte mode */
        DMAEN |                             /* Enable DMA */
        DMASRCINCR1 | DMASRCINCR0;          /* Increment the source address */
#endif
      // put CRC bytes (not really needed by us, but required by MMC)
      spiSendByte(0xff);
      spiSendByte(0xff);
      // read the data response xxx0<status>1 : status 010: Data accected, status 101: Data
      //   rejected due to a crc error, status 110: Data rejected due to a Write error.
      mmcCheckBusy();
      rvalue = MMC_SUCCESS;
    }
    else
    {
      // the MMC never acknowledge the write command
      rvalue = MMC_RESPONSE_ERROR;   // 2
    }
  }
  else
  {
    rvalue = MMC_BLOCK_SET_ERROR;   // 1
  }
  // give the MMC the required clocks to finish up what ever it needs to do
  //  for (i = 0; i < 9; ++i)
  //    spiSendByte(0xff);

  CS_HIGH ();
  // Send 8 Clock pulses of delay.
  spiSendByte(0xff);
  return rvalue;
} // mmc_write_block


//---------------------------------------------------------------------
void mmcSendCmd (const char cmd, unsigned long data, const char crc)
{
  char frame[6];
  char temp;
  int i;
  frame[0]=(cmd|0x40);
  for(i=3;i>=0;i--){
    temp=(char)(data>>(8*i));
    frame[4-i]=(temp);
  }
  frame[5]=(crc);
  for(i=0;i<6;i++)
    spiSendByte(frame[i]);
}


//--------------- set blocklength 2^n ------------------------------------------------------
char mmcSetBlockLength (const unsigned long blocklength)
{
  //  char rValue = MMC_TIMEOUT_ERROR;
  //  char i = 0;
  // SS = LOW (on)
  CS_LOW ();
  // Set the block length to read
  //MMC_SET_BLOCKLEN =CMD16
  mmcSendCmd(MMC_SET_BLOCKLEN, blocklength, 0xFF);

  // get response from MMC - make sure that its 0x00 (R1 ok response format)
  if(mmcGetResponse()!=0x00)
  { initMMC();
    mmcSendCmd(MMC_SET_BLOCKLEN, blocklength, 0xFF);
    mmcGetResponse();
  }

  CS_HIGH ();

  // Send 8 Clock pulses of delay.
  spiSendByte(0xff);

  return MMC_SUCCESS;
} // Set block_length


unsigned char spiSendByte(const unsigned char data)
{
  while ((IFG2&UTXIFG1) ==0);   // wait while not ready / for RX
  TXBUF1 = data;         // write
  while ((IFG2 & URXIFG1)==0);   // wait for RX buffer (full)
  return (RXBUF1);
}


// Reading the contents of the CSD and CID registers in SPI mode is a simple
// read-block transaction.
char mmcReadRegister (const char cmd_register, const unsigned char length, unsigned char *pBuffer)
{
  char uc = 0;
  char rvalue = MMC_TIMEOUT_ERROR;

  if (mmcSetBlockLength (length) == MMC_SUCCESS)
  {
    CS_LOW ();
    // CRC not used: 0xff as last byte
    mmcSendCmd(cmd_register, 0x000000, 0xff);

    // wait for response
    // in the R1 format (0x00 is no errors)
    if (mmcGetResponse() == 0x00)
    {
      if (mmcGetXXResponse(0xfe)== 0xfe)
        for (uc = 0; uc < length; uc++)
          pBuffer[uc] = spiSendByte(0xff);  //mmc_buffer[uc] = spiSendByte(0xff);
      // get CRC bytes (not really needed by us, but required by MMC)
      spiSendByte(0xff);
      spiSendByte(0xff);
      rvalue = MMC_SUCCESS;
    }
    else
      rvalue = MMC_RESPONSE_ERROR;
    // CS = HIGH (off)
    CS_HIGH ();

    // Send 8 Clock pulses of delay.
    spiSendByte(0xff);
  }
  CS_HIGH ();
  return rvalue;
} // mmc_read_register


#include "math.h"
unsigned long MMC_ReadCardSize(void)
{
  // Read contents of Card Specific Data (CSD)

  unsigned long MMC_CardSize;
  unsigned short i,      // index
                 j,      // index
                 b,      // temporary variable
                 response,   // MMC response to command
                 mmc_C_SIZE;

  unsigned char mmc_READ_BL_LEN,  // Read block length
                mmc_C_SIZE_MULT;

  CS_LOW ();

  spiSendByte(MMC_READ_CSD);   // CMD 9
  for(i=4; i>0; i--)      // Send four dummy bytes
    spiSendByte(0);
  spiSendByte(0xFF);   // Send CRC byte

  response = mmcGetResponse();

  // data transmission always starts with 0xFE
  b = spiSendByte(0xFF);

  if( !response )
  {
    while (b != 0xFE) b = spiSendByte(0xFF);
    // bits 127:87
    for(j=5; j>0; j--)          // Host must keep the clock running for at
      b = spiSendByte(0xff);


    // 4 bits of READ_BL_LEN
    // bits 84:80
    b =spiSendByte(0xff);  // lower 4 bits of CCC and
    mmc_READ_BL_LEN = b & 0x0F;

    b = spiSendByte(0xff);

    // bits 73:62  C_Size
    // xxCC CCCC CCCC CC
    mmc_C_SIZE = (b & 0x03) << 10;
    b = spiSendByte(0xff);
    mmc_C_SIZE += b << 2;
    b = spiSendByte(0xff);
    mmc_C_SIZE += b >> 6;

    // bits 55:53
    b = spiSendByte(0xff);

    // bits 49:47
    mmc_C_SIZE_MULT = (b & 0x03) << 1;
    b = spiSendByte(0xff);
    mmc_C_SIZE_MULT += b >> 7;

    // bits 41:37
    b = spiSendByte(0xff);

    b = spiSendByte(0xff);

    b = spiSendByte(0xff);

    b = spiSendByte(0xff);

    b = spiSendByte(0xff);

  }

  for(j=4; j>0; j--)          // Host must keep the clock running for at
    b = spiSendByte(0xff);  // least Ncr (max = 4 bytes) cycles after
                               // the card response is received
  b = spiSendByte(0xff);
  CS_LOW ();

  MMC_CardSize = (mmc_C_SIZE + 1);
  // power function with base 2 is better with a loop
  // i = (pow(2,mmc_C_SIZE_MULT+2)+0.5);
  for(i = 2,j=mmc_C_SIZE_MULT+2; j>1; j--)
    i <<= 1;
  MMC_CardSize *= i;
  // power function with base 2 is better with a loop
  //i = (pow(2,mmc_READ_BL_LEN)+0.5);
  for(i = 2,j=mmc_READ_BL_LEN; j>1; j--)
    i <<= 1;
  MMC_CardSize *= i;

  return (MMC_CardSize);

}


char mmc_ping(void)
{
  if (!(P5IN & 0x01))
    return (MMC_SUCCESS);
  else
    return (MMC_INIT_ERROR);
}


#ifdef withDMA
#ifdef __IAR_SYSTEMS_ICC__
#if __VER__ < 200
interrupt[DACDMA_VECTOR] void DMA_isr(void)
#else
#pragma vector = DACDMA_VECTOR
__interrupt void DMA_isr(void)
#endif
#endif

#ifdef __CROSSWORKS__
void DMA_isr(void)   __interrupt[DACDMA_VECTOR]
#endif

#ifdef __TI_COMPILER_VERSION__
__interrupt void DMA_isr(void);
DMA_ISR(DMA_isr)
__interrupt void DMA_isr(void)
#endif
{
  DMA0CTL &= ~(DMAIFG);
  LPM3_EXIT;
}
#endif


//---------------------------------------------------------------------
#endif /* _MMCLIB_C */