mci.Command

#include <file_config.h>

BOOL Command  (
     U8   cmd,           /* Command code for SD Card    */
     U32  arg,           /* Command Argument            */
     U32  resp_type,     /* Command Response type       */
     U32* rp);           /* Buffer to recive a response */

The function Command sends a command to the Flash memory card.

The parameter cmd is one of the available SD/MMC Commands. The parameter arg is a 32-bit SD Command argument. The parameter resp_type specifies the expected response type:

The parameter rp is a pointer to a buffer to store the response.

The function is part of the MCI Driver. The prototype is defined in the file File_Config.h. Developers must customize the function.

• __TRUE - on success.
• __FALSE - on failure.

mci.BusMode, mci.BusSpeed, mci.BusWidth, mci.CheckMedia, mci.Delay, mci.Init, mci.ReadBlock, mci.SetDma, mci.UnInit, mci.WriteBlock

/* MCI Device Driver Control Block */
MCI_DRV mci0_drv = {
  Init,
  UnInit,
  Delay,
  BusMode,
  BusWidth,
  BusSpeed,
  Command,
  ReadBlock,
  WriteBlock,
  NULL,
  CheckMedia
};

/* Send a Command to Flash card and get a response. */
static BOOL Command (U8 cmd, U32 arg, U32 resp_type, U32 *rp)  {
  U32 cmdval,stat;

  cmd   &= 0x3F;
  cmdval = 0x400 | cmd;
  switch (resp_type)  {
    case RESP_SHORT:
      cmdval |= 0x40;
      break;
    case RESP_LONG:
      cmdval |= 0xC0;
      break;
  }
  MCI_ARGUMENT = arg;
  MCI_COMMAND  = cmdval;                               /* Send the command. */

  if (resp_type == RESP_NONE)  {
    while (MCI_STATUS & MCI_CMD_ACTIVE);               /* Wait until command finished. */
    MCI_CLEAR = 0x7FF;
    return (__TRUE);
  }

  for (;;)  {
    stat = MCI_STATUS;
    if (stat & MCI_CMD_TIMEOUT)  {
      MCI_CLEAR = stat & MCI_CLEAR_MASK;
      return (__FALSE);
    }
    if (stat & MCI_CMD_CRC_FAIL)  {
      MCI_CLEAR = stat & MCI_CLEAR_MASK;
      if ((cmd == SEND_OP_COND)      ||
          (cmd == SEND_APP_OP_COND)  ||
          (cmd == STOP_TRANS))  {
        MCI_COMMAND = 0;
        break;
      }
      return (__FALSE);
    }
    if (stat & MCI_CMD_RESP_END)  {
      MCI_CLEAR = stat & MCI_CLEAR_MASK;
      break;
    }
  }
  if ((MCI_RESP_CMD & 0x3F) != cmd)  {
    if ((cmd != SEND_OP_COND)     &&
        (cmd != SEND_APP_OP_COND) &&
        (cmd != ALL_SEND_CID)     &&
        (cmd != SEND_CSD))         {
      return (__FALSE);
    }
  }

  rp[0] = MCI_RESP0;                                   /* Read MCI response registers */
  if (resp_type == RESP_LONG) {
    rp[1] = MCI_RESP1;
    rp[2] = MCI_RESP2;
    rp[3] = MCI_RESP3;
  }
  return (__TRUE);
}