SD/MMC Disk Drivers

The Embedded SDK contains two different disk drivers for accessing SD/MMC cards depending upon the physical interface that is available to access the card.

Multimedia Card Interface (MCI)

The multimedia card interface (MCI) disk driver uses an on-chip peripheral of communicating with the card using a 4-wire or 8-wire bus. Although the multimedia card interface provides better performance, it is only supported on MCU's that have a dedicated peripheral for accessing SD/MMC cards.

#include "FS/Disk/disk_mci.h"
#include <assert.h>

static MCIDISK disk;                    /* Allocate the disk driver */

void APP_Function(void)
{
    STATUS status;


    status = MCIDISK_Create(&disk,      /* Create and initialize the disk driver */
                            0);         /* The MCI peripheral port number */

    assert(status == SUCCESS);


    status = DISK_Mount(&disk.base);    /* Mount and initialize the card */
    assert(status == SUCCESS);
}

SPI Interface

The multimedia card SPI disk driver uses a standard SPI port for communicating with a SD/MMC card. The SPI disk driver can be used with any MCU that has an available SPI port.

#include "FS/Disk/disk_mci.h"
#include <assert.h>

static SPI spi;                             /* Allocate the SPI port */
static MCSPIDISK disk;                      /* Allocate the disk driver */

void APP_Function(void)
{
    STATUS status;


    status = SPI_Open(&spi,                 /* Open the SPI port */
                      0,                    /* Port number 0 */
                      10000000,             /* Initial clock frequency of 10Mhz */         
                      SPI_DEFAULT);         /* Default clock polarity and phase */
                      
    status = MCSPIDISK_Create(&disk,        /* Create and initialize the disk driver */
                              &spi,         /* A pointer to the SPI port to be used */
                              P0_3);        /* Use pin P0.3 as the chip-select */

    assert(status == SUCCESS);

    status = DISK_Mount(&disk.base);        /* Mount and initialize the card */
    assert(status == SUCCESS);
}