EK-TM4c123GXL Launchpad with SD card

Hello Moumita,

Can you share the CCS project?

Regards
Amit

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/908/sd_5F00_card.7z

I have included my project in a .7z format here.

Thanks.

Regards,

Moumita

Hello Moumita

The issue was with the addition of #include "fatfs/port/mmc-dk-tm4c123g.c"

Also after removing the same the next build issue you would encounter is power_on function remaining unresolved. This is handled by the f_open so you do not need to do it in the main file

Regards
Amit

Dear Sir,

I later understood that error. So, I removed the additional include and modified the mmc-dk-tm4c123g.c according to my launchpad. So, currently, even after the program builds without errors, the output is incorrect. Irrespective of whether the SD card is connected or not, the output is FR_OK, and it does not display any list of files contained in the SD card too. What should I do to make it work correctly?

The connections on the SD_card are similar to this:

Just, instead of using Port A, I used Port D definitions (PD0, PD1, PD2, PD3). 

I have attached the modified code herewith.

Thanking you,

Moumita

sd_card.zip

Hello Moumita,

Have you enabled the SSI-1 controller and mapped the entire FatFs to use SSI-1?

Regards
Amit

Yes, I have made the port changes in mmc-ek-tm4c123g.c file as shown here:

/*-----------------------------------------------------------------------*/
/* MMC/SDC (in SPI mode) control module  (C)ChaN, 2007                   */
/*-----------------------------------------------------------------------*/
/* Only rcvr_spi(), xmit_spi(), disk_timerproc() and some macros         */
/* are platform dependent.                                               */
/*-----------------------------------------------------------------------*/


//#include <avr/io.h>
//#include "diskio.h"
#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/ssi.h"
#include "driverlib/sysctl.h"
#include "fatfs/src/diskio.h"

/* Definitions for MMC/SDC command */
#define CMD0    (0x40+0)    /* GO_IDLE_STATE */
#define CMD1    (0x40+1)    /* SEND_OP_COND */
#define CMD8    (0x40+8)    /* SEND_IF_COND */
#define CMD9    (0x40+9)    /* SEND_CSD */
#define CMD10    (0x40+10)    /* SEND_CID */
#define CMD12    (0x40+12)    /* STOP_TRANSMISSION */
#define CMD16    (0x40+16)    /* SET_BLOCKLEN */
#define CMD17    (0x40+17)    /* READ_SINGLE_BLOCK */
#define CMD18    (0x40+18)    /* READ_MULTIPLE_BLOCK */
#define CMD23    (0x40+23)    /* SET_BLOCK_COUNT */
#define CMD24    (0x40+24)    /* WRITE_BLOCK */
#define CMD25    (0x40+25)    /* WRITE_MULTIPLE_BLOCK */
#define CMD41    (0x40+41)    /* SEND_OP_COND (ACMD) */
#define CMD55    (0x40+55)    /* APP_CMD */
#define CMD58    (0x40+58)    /* READ_OCR */


/* Peripheral definitions for EK-TM4C123G board */
// SSI port
#define SDC_SSI_BASE            SSI1_BASE
#define SDC_SSI_SYSCTL_PERIPH   SYSCTL_PERIPH_SSI1

// GPIO for SSI pins
#define SDC_GPIO_PORT_BASE      GPIO_PORTD_BASE
#define SDC_GPIO_SYSCTL_PERIPH  SYSCTL_PERIPH_GPIOF
#define SDC_SSI_CLK             GPIO_PIN_0
#define SDC_SSI_TX              GPIO_PIN_3
#define SDC_SSI_RX              GPIO_PIN_2
#define SDC_SSI_FSS             GPIO_PIN_1
#define SDC_SSI_PINS            (SDC_SSI_TX | SDC_SSI_RX | SDC_SSI_CLK |      \
                                 SDC_SSI_FSS)
/* Port Controls  (Platform dependent) */
//#define SELECT()    PORTB &=~1        /* MMC CS = L */
//#define DESELECT()  PORTB |= 1        /* MMC CS = H */

//#define SOCKPORT    PINB            /* Socket contact port */
//#define SOCKWP      0x20            /* Write protect switch (PB5) */
//#define SOCKINS     0x10            /* Card detect switch (PB4) */

// asserts the CS pin to the card
static
void SELECT (void)
{
    ROM_GPIOPinWrite(SDC_GPIO_PORT_BASE, SDC_SSI_FSS, 0);
}

// de-asserts the CS pin to the card
static
void DESELECT (void)
{
    ROM_GPIOPinWrite(SDC_GPIO_PORT_BASE, SDC_SSI_FSS, SDC_SSI_FSS);
}


/*--------------------------------------------------------------------------

   Module Private Functions

---------------------------------------------------------------------------*/

static volatile
DSTATUS Stat = STA_NOINIT;    /* Disk status */

static volatile
BYTE Timer1, Timer2;    /* 100Hz decrement timer */

static
BYTE CardType;            /* b0:MMC, b1:SDC, b2:Block addressing */

static
BYTE PowerFlag = 0;     /* indicates if "power" is on */


/*-----------------------------------------------------------------------*/
/* Transmit a byte to MMC via SPI  (Platform dependent)                  */
/*-----------------------------------------------------------------------*/

//#define xmit_spi(dat)     SPDR=(dat); loop_until_bit_is_set(SPSR,SPIF)
static
void xmit_spi(BYTE dat)
{
    uint32_t ui32RcvDat;

    ROM_SSIDataPut(SDC_SSI_BASE, dat); /* Write the data to the tx fifo */

    ROM_SSIDataGet(SDC_SSI_BASE, &ui32RcvDat); /* flush data read during the write */
}


/*-----------------------------------------------------------------------*/
/* Receive a byte from MMC via SPI  (Platform dependent)                 */
/*-----------------------------------------------------------------------*/

static
BYTE rcvr_spi (void)
{
    uint32_t ui32RcvDat;

    ROM_SSIDataPut(SDC_SSI_BASE, 0xFF); /* write dummy data */

    ROM_SSIDataGet(SDC_SSI_BASE, &ui32RcvDat); /* read data frm rx fifo */

    return (BYTE)ui32RcvDat;
}

/* Alternative macro to receive data fast */
//#define rcvr_spi_m(dst)    SPDR=0xFF; loop_until_bit_is_set(SPSR,SPIF); *(dst)=SPDR


static
void rcvr_spi_m (BYTE *dst)
{
    *dst = rcvr_spi();
}

/*-----------------------------------------------------------------------*/
/* Wait for card ready                                                   */
/*-----------------------------------------------------------------------*/

static
BYTE wait_ready (void)
{
    BYTE res;


    Timer2 = 50;    /* Wait for ready in timeout of 500ms */
    rcvr_spi();
    do
        res = rcvr_spi();
    while ((res != 0xFF) && Timer2);

    return res;
}

/*-----------------------------------------------------------------------*/
/* Send 80 or so clock transitions with CS and DI held high. This is     */
/* required after card power up to get it into SPI mode                  */
/*-----------------------------------------------------------------------*/
static
void send_initial_clock_train(void)
{
    unsigned int i;
    uint32_t ui32Dat;

    /* Ensure CS is held high. */
    DESELECT();

    /* Switch the SSI TX line to a GPIO and drive it high too. */
    ROM_GPIOPinTypeGPIOOutput(SDC_GPIO_PORT_BASE, SDC_SSI_TX);
    ROM_GPIOPinWrite(SDC_GPIO_PORT_BASE, SDC_SSI_TX, SDC_SSI_TX);

    /* Send 10 bytes over the SSI. This causes the clock to wiggle the */
    /* required number of times. */
    for(i = 0 ; i < 10 ; i++)
    {
        /* Write DUMMY data. SSIDataPut() waits until there is room in the */
        /* FIFO. */
        ROM_SSIDataPut(SDC_SSI_BASE, 0xFF);

        /* Flush data read during data write. */
        ROM_SSIDataGet(SDC_SSI_BASE, &ui32Dat);
    }

    /* Revert to hardware control of the SSI TX line. */
    ROM_GPIOPinTypeSSI(SDC_GPIO_PORT_BASE, SDC_SSI_TX);
}



/*-----------------------------------------------------------------------*/
/* Power Control  (Platform dependent)                                   */
/*-----------------------------------------------------------------------*/
/* When the target system does not support socket power control, there   */
/* is nothing to do in these functions and chk_power always returns 1.   */

static
void power_on (void)
{
    /*
     * This doesn't really turn the power on, but initializes the
     * SSI port and pins needed to talk to the card.
     */

    /* Enable the peripherals used to drive the SDC on SSI */
    ROM_SysCtlPeripheralEnable(SDC_SSI_SYSCTL_PERIPH);
    ROM_SysCtlPeripheralEnable(SDC_GPIO_SYSCTL_PERIPH);

    /*
     * Configure the appropriate pins to be SSI instead of GPIO. The FSS (CS)
     * signal is directly driven to ensure that we can hold it low through a
     * complete transaction with the SD card.
     */
    GPIOPinConfigure(GPIO_PD2_SSI1RX);
	GPIOPinConfigure(GPIO_PD3_SSI1TX);
	GPIOPinConfigure(GPIO_PD0_SSI1CLK);
	GPIOPinConfigure(GPIO_PD1_SSI1FSS);
	ROM_GPIOPinTypeSSI(SDC_GPIO_PORT_BASE, SDC_SSI_TX | SDC_SSI_RX | SDC_SSI_CLK);
    ROM_GPIOPinTypeGPIOOutput(SDC_GPIO_PORT_BASE, SDC_SSI_FSS);

    /*
     * Set the SSI output pins to 4MA drive strength and engage the
     * pull-up on the receive line.
     */
    MAP_GPIOPadConfigSet(SDC_GPIO_PORT_BASE, SDC_SSI_RX, GPIO_STRENGTH_4MA,
                         GPIO_PIN_TYPE_STD_WPU);
    MAP_GPIOPadConfigSet(SDC_GPIO_PORT_BASE, SDC_SSI_CLK | SDC_SSI_TX | SDC_SSI_FSS,
                         GPIO_STRENGTH_4MA, GPIO_PIN_TYPE_STD);

    /* Configure the SSI0 port */
    ROM_SSIConfigSetExpClk(SDC_SSI_BASE, ROM_SysCtlClockGet(),
                           SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, 400000, 8);
    ROM_SSIEnable(SDC_SSI_BASE);

    /* Set DI and CS high and apply more than 74 pulses to SCLK for the card */
    /* to be able to accept a native command. */
    send_initial_clock_train();

    PowerFlag = 1;
}

// set the SSI speed to the max setting
static
void set_max_speed(void)
{
    unsigned long i;

    /* Disable the SSI */
    ROM_SSIDisable(SDC_SSI_BASE);

    /* Set the maximum speed as half the system clock, with a max of 12.5 MHz. */
    i = ROM_SysCtlClockGet() / 2;
    if(i > 12500000)
    {
        i = 12500000;
    }

    /* Configure the SSI0 port to run at 12.5MHz */
    ROM_SSIConfigSetExpClk(SDC_SSI_BASE, ROM_SysCtlClockGet(),
                           SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, i, 8);

    /* Enable the SSI */
    ROM_SSIEnable(SDC_SSI_BASE);
}

static
void power_off (void)
{
	PowerFlag = 0;
}

static
int chk_power(void)        /* Socket power state: 0=off, 1=on */
{
    return PowerFlag;
}



/*-----------------------------------------------------------------------*/
/* Receive a data packet from MMC                                        */
/*-----------------------------------------------------------------------*/

static
BOOL rcvr_datablock (
    BYTE *buff,            /* Data buffer to store received data */
    UINT btr            /* Byte count (must be even number) */
)
{
    BYTE token;


    Timer1 = 100;
    do {                            /* Wait for data packet in timeout of 100ms */
        token = rcvr_spi();
    } while ((token == 0xFF) && Timer1);
    if(token != 0xFE) return FALSE;    /* If not valid data token, retutn with error */

    do {                            /* Receive the data block into buffer */
        rcvr_spi_m(buff++);
        rcvr_spi_m(buff++);
    } while (btr -= 2);
    rcvr_spi();                        /* Discard CRC */
    rcvr_spi();

    return TRUE;                    /* Return with success */
}



/*-----------------------------------------------------------------------*/
/* Send a data packet to MMC                                             */
/*-----------------------------------------------------------------------*/

#if _READONLY == 0
static
BOOL xmit_datablock (
    const BYTE *buff,    /* 512 byte data block to be transmitted */
    BYTE token            /* Data/Stop token */
)
{
    BYTE resp, wc;


    if (wait_ready() != 0xFF) return FALSE;

    xmit_spi(token);                    /* Xmit data token */
    if (token != 0xFD) {    /* Is data token */
        wc = 0;
        do {                            /* Xmit the 512 byte data block to MMC */
            xmit_spi(*buff++);
            xmit_spi(*buff++);
        } while (--wc);
        xmit_spi(0xFF);                    /* CRC (Dummy) */
        xmit_spi(0xFF);
        resp = rcvr_spi();                /* Reveive data response */
        if ((resp & 0x1F) != 0x05)        /* If not accepted, return with error */
            return FALSE;
    }

    return TRUE;
}
#endif /* _READONLY */



/*-----------------------------------------------------------------------*/
/* Send a command packet to MMC                                          */
/*-----------------------------------------------------------------------*/

static
BYTE send_cmd (
    BYTE cmd,        /* Command byte */
    DWORD arg        /* Argument */
)
{
    BYTE n, res;


    if (wait_ready() != 0xFF) return 0xFF;

    /* Send command packet */
    xmit_spi(cmd);                        /* Command */
    xmit_spi((BYTE)(arg >> 24));        /* Argument[31..24] */
    xmit_spi((BYTE)(arg >> 16));        /* Argument[23..16] */
    xmit_spi((BYTE)(arg >> 8));            /* Argument[15..8] */
    xmit_spi((BYTE)arg);                /* Argument[7..0] */
    n = 0xff;
    if (cmd == CMD0) n = 0x95;            /* CRC for CMD0(0) */
    if (cmd == CMD8) n = 0x87;            /* CRC for CMD8(0x1AA) */
    xmit_spi(n);

    /* Receive command response */
    if (cmd == CMD12) rcvr_spi();        /* Skip a stuff byte when stop reading */
    n = 10;                                /* Wait for a valid response in timeout of 10 attempts */
    do
        res = rcvr_spi();
    while ((res & 0x80) && --n);

    return res;            /* Return with the response value */
}


/*-----------------------------------------------------------------------*
 * Send the special command used to terminate a multi-sector read.
 *
 * This is the only command which can be sent while the SDCard is sending
 * data. The SDCard spec indicates that the data transfer will stop 2 bytes
 * after the 6 byte CMD12 command is sent and that the card will then send
 * 0xFF for between 2 and 6 more bytes before the R1 response byte.  This
 * response will be followed by another 0xFF byte.  In testing, however, it
 * seems that some cards don't send the 2 to 6 0xFF bytes between the end of
 * data transmission and the response code.  This function, therefore, merely
 * reads 10 bytes and, if the last one read is 0xFF, returns the value of the
 * latest non-0xFF byte as the response code.
 *
 *-----------------------------------------------------------------------*/

static
BYTE send_cmd12 (void)
{
    BYTE n, res, val;

    /* For CMD12, we don't wait for the card to be idle before we send
     * the new command.
     */

    /* Send command packet - the argument for CMD12 is ignored. */
    xmit_spi(CMD12);
    xmit_spi(0);
    xmit_spi(0);
    xmit_spi(0);
    xmit_spi(0);
    xmit_spi(0);

    /* Read up to 10 bytes from the card, remembering the value read if it's
       not 0xFF */
    for(n = 0; n < 10; n++)
    {
        val = rcvr_spi();
        if(val != 0xFF)
        {
            res = val;
        }
    }

    return res;            /* Return with the response value */
}


/*--------------------------------------------------------------------------

   Public Functions

---------------------------------------------------------------------------*/


/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive                                                 */
/*-----------------------------------------------------------------------*/

DSTATUS disk_initialize (
    BYTE drv        /* Physical drive nmuber (0) */
)
{
    BYTE n, ty, ocr[4];


    if (drv) return STA_NOINIT;            /* Supports only single drive */
    if (Stat & STA_NODISK) return Stat;    /* No card in the socket */

    power_on();                            /* Force socket power on */
    send_initial_clock_train();            /* Ensure the card is in SPI mode */

    SELECT();                /* CS = L */
    ty = 0;
    if (send_cmd(CMD0, 0) == 1) {            /* Enter Idle state */
        Timer1 = 100;                        /* Initialization timeout of 1000 msec */
        if (send_cmd(CMD8, 0x1AA) == 1) {    /* SDC Ver2+ */
            for (n = 0; n < 4; n++) ocr[n] = rcvr_spi();
            if (ocr[2] == 0x01 && ocr[3] == 0xAA) {    /* The card can work at vdd range of 2.7-3.6V */
                do {
                    if (send_cmd(CMD55, 0) <= 1 && send_cmd(CMD41, 1UL << 30) == 0)    break;    /* ACMD41 with HCS bit */
                } while (Timer1);
                if (Timer1 && send_cmd(CMD58, 0) == 0) {    /* Check CCS bit */
                    for (n = 0; n < 4; n++) ocr[n] = rcvr_spi();
                    ty = (ocr[0] & 0x40) ? 6 : 2;
                }
            }
        } else {                            /* SDC Ver1 or MMC */
            ty = (send_cmd(CMD55, 0) <= 1 && send_cmd(CMD41, 0) <= 1) ? 2 : 1;    /* SDC : MMC */
            do {
                if (ty == 2) {
                    if (send_cmd(CMD55, 0) <= 1 && send_cmd(CMD41, 0) == 0) break;    /* ACMD41 */
                } else {
                    if (send_cmd(CMD1, 0) == 0) break;                                /* CMD1 */
                }
            } while (Timer1);
            if (!Timer1 || send_cmd(CMD16, 512) != 0)    /* Select R/W block length */
                ty = 0;
        }
    }
    CardType = ty;
    DESELECT();            /* CS = H */
    rcvr_spi();            /* Idle (Release DO) */

    if (ty) {            /* Initialization succeded */
        Stat &= ~STA_NOINIT;        /* Clear STA_NOINIT */
		set_max_speed();
    } else {            /* Initialization failed */
        power_off();
    }

    return Stat;
}



/*-----------------------------------------------------------------------*/
/* Get Disk Status                                                       */
/*-----------------------------------------------------------------------*/

DSTATUS disk_status (
    BYTE drv        /* Physical drive nmuber (0) */
)
{
    if (drv) return STA_NOINIT;        /* Supports only single drive */
    return Stat;
}



/*-----------------------------------------------------------------------*/
/* Read Sector(s)                                                        */
/*-----------------------------------------------------------------------*/

DRESULT disk_read (
    BYTE drv,            /* Physical drive nmuber (0) */
    BYTE *buff,            /* Pointer to the data buffer to store read data */
    DWORD sector,        /* Start sector number (LBA) */
    BYTE count            /* Sector count (1..255) */
)
{
    if (drv || !count) return RES_PARERR;
    if (Stat & STA_NOINIT) return RES_NOTRDY;

    if (!(CardType & 4)) sector *= 512;    /* Convert to byte address if needed */

    SELECT();            /* CS = L */

    if (count == 1) {    /* Single block read */
        if ((send_cmd(CMD17, sector) == 0)    /* READ_SINGLE_BLOCK */
            && rcvr_datablock(buff, 512))
            count = 0;
    }
    else {                /* Multiple block read */
        if (send_cmd(CMD18, sector) == 0) {    /* READ_MULTIPLE_BLOCK */
            do {
                if (!rcvr_datablock(buff, 512)) break;
                buff += 512;
            } while (--count);
            send_cmd12();                /* STOP_TRANSMISSION */
        }
    }

    DESELECT();            /* CS = H */
    rcvr_spi();            /* Idle (Release DO) */

    return count ? RES_ERROR : RES_OK;
}



/*-----------------------------------------------------------------------*/
/* Write Sector(s)                                                       */
/*-----------------------------------------------------------------------*/

#if _READONLY == 0
DRESULT disk_write (
    BYTE drv,            /* Physical drive nmuber (0) */
    const BYTE *buff,    /* Pointer to the data to be written */
    DWORD sector,        /* Start sector number (LBA) */
    BYTE count            /* Sector count (1..255) */
)
{
    if (drv || !count) return RES_PARERR;
    if (Stat & STA_NOINIT) return RES_NOTRDY;
    if (Stat & STA_PROTECT) return RES_WRPRT;

    if (!(CardType & 4)) sector *= 512;    /* Convert to byte address if needed */

    SELECT();            /* CS = L */

    if (count == 1) {    /* Single block write */
        if ((send_cmd(CMD24, sector) == 0)    /* WRITE_BLOCK */
            && xmit_datablock(buff, 0xFE))
            count = 0;
    }
    else {                /* Multiple block write */
        if (CardType & 2) {
            send_cmd(CMD55, 0); send_cmd(CMD23, count);    /* ACMD23 */
        }
        if (send_cmd(CMD25, sector) == 0) {    /* WRITE_MULTIPLE_BLOCK */
            do {
                if (!xmit_datablock(buff, 0xFC)) break;
                buff += 512;
            } while (--count);
            if (!xmit_datablock(0, 0xFD))    /* STOP_TRAN token */
                count = 1;
        }
    }

    DESELECT();            /* CS = H */
    rcvr_spi();            /* Idle (Release DO) */

    return count ? RES_ERROR : RES_OK;
}
#endif /* _READONLY */



/*-----------------------------------------------------------------------*/
/* Miscellaneous Functions                                               */
/*-----------------------------------------------------------------------*/

DRESULT disk_ioctl (
    BYTE drv,        /* Physical drive nmuber (0) */
    BYTE ctrl,        /* Control code */
    void *buff        /* Buffer to send/receive control data */
)
{
    DRESULT res;
    BYTE n, csd[16], *ptr = buff;
    WORD csize;


    if (drv) return RES_PARERR;

    res = RES_ERROR;

    if (ctrl == CTRL_POWER) {
        switch (*ptr) {
        case 0:        /* Sub control code == 0 (POWER_OFF) */
            if (chk_power())
                power_off();        /* Power off */
            res = RES_OK;
            break;
        case 1:        /* Sub control code == 1 (POWER_ON) */
            power_on();                /* Power on */
            res = RES_OK;
            break;
        case 2:        /* Sub control code == 2 (POWER_GET) */
            *(ptr+1) = (BYTE)chk_power();
            res = RES_OK;
            break;
        default :
            res = RES_PARERR;
        }
    }
    else {
        if (Stat & STA_NOINIT) return RES_NOTRDY;

        SELECT();        /* CS = L */

        switch (ctrl) {
        case GET_SECTOR_COUNT :    /* Get number of sectors on the disk (DWORD) */
            if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16)) {
                if ((csd[0] >> 6) == 1) {    /* SDC ver 2.00 */
                    csize = csd[9] + ((WORD)csd[8] << 8) + 1;
                    *(DWORD*)buff = (DWORD)csize << 10;
                } else {                    /* MMC or SDC ver 1.XX */
                    n = (csd[5] & 15) + ((csd[10] & 128) >> 7) + ((csd[9] & 3) << 1) + 2;
                    csize = (csd[8] >> 6) + ((WORD)csd[7] << 2) + ((WORD)(csd[6] & 3) << 10) + 1;
                    *(DWORD*)buff = (DWORD)csize << (n - 9);
                }
                res = RES_OK;
            }
            break;

        case GET_SECTOR_SIZE :    /* Get sectors on the disk (WORD) */
            *(WORD*)buff = 512;
            res = RES_OK;
            break;

        case CTRL_SYNC :    /* Make sure that data has been written */
            if (wait_ready() == 0xFF)
                res = RES_OK;
            break;

        case MMC_GET_CSD :    /* Receive CSD as a data block (16 bytes) */
            if (send_cmd(CMD9, 0) == 0        /* READ_CSD */
                && rcvr_datablock(ptr, 16))
                res = RES_OK;
            break;

        case MMC_GET_CID :    /* Receive CID as a data block (16 bytes) */
            if (send_cmd(CMD10, 0) == 0        /* READ_CID */
                && rcvr_datablock(ptr, 16))
                res = RES_OK;
            break;

        case MMC_GET_OCR :    /* Receive OCR as an R3 resp (4 bytes) */
            if (send_cmd(CMD58, 0) == 0) {    /* READ_OCR */
                for (n = 0; n < 4; n++)
                    *ptr++ = rcvr_spi();
                res = RES_OK;
            }

        // case MMC_GET_TYPE :    /* Get card type flags (1 byte) */
            // *ptr = CardType;
            // res = RES_OK;
            // break;

        default:
            res = RES_PARERR;
        }

        DESELECT();            /* CS = H */
        rcvr_spi();            /* Idle (Release DO) */
    }

    return res;
}



/*-----------------------------------------------------------------------*/
/* Device Timer Interrupt Procedure  (Platform dependent)                */
/*-----------------------------------------------------------------------*/
/* This function must be called in period of 10ms                        */

void disk_timerproc (void)
{
    BYTE n;


    n = Timer1;                        /* 100Hz decrement timer */
    if (n) Timer1 = --n;
    n = Timer2;
    if (n) Timer2 = --n;

}


/*---------------------------------------------------------*/
/* User Provided Timer Function for FatFs module           */
/*---------------------------------------------------------*/
/* This is a real time clock service to be called from     */
/* FatFs module. Any valid time must be returned even if   */
/* the system does not support a real time clock.          */

DWORD get_fattime (void)
{

    return    ((2007UL-1980) << 25)    // Year = 2007
            | (6UL << 21)            // Month = June
            | (5UL << 16)            // Day = 5
            | (11U << 11)            // Hour = 11
            | (38U << 5)            // Min = 38
            | (0U >> 1)                // Sec = 0
            ;

}

Hello Moumitha,

Then why is GPIOF being enabled?

#define SDC_GPIO_SYSCTL_PERIPH SYSCTL_PERIPH_GPIOF

Regards
Amit

Hello Amit,

I changed the initialization to PortD and tried, without any success. Still, irrespective of whether the SD card is connected or not, the output still is "FR_OK". I am attaching the modified code herewith. 

Thanking you,

Moumita 

7801.sd_card.zip

Hello Moumita

I can give it a try on my DK-TM4C123.

Regards
Amit

Thank you so much. Please let me know the results. If it works correctly, could you please guide me through what has to be done to make it work?

Thanking you,
Moumita

Hello Moumita

The file mmc-ek-tm4c123g.c is missing

Regards
Amit

I had copied the program from my workspace, hence the files were missing. I am sending the include of fatfs library which is present inside third_party folder in Tivaware. This contains all fatfs includes, including mmc-ek-tm4c123g.c.

fatfs.zip

Hello Moumita,

The files ff.c and cc932.c are empty files in the fatfs.zip

Regards
Amit

Here.

5658.fatfs.zip

Hello Moumita

I reviewed the code and the following piece of code shows that the PCTL for the SSI Pins is not being configured. Why is that so?

//GPIOPinConfigure(GPIO_PD2_SSI1RX);
//GPIOPinConfigure(GPIO_PD3_SSI1TX);
//GPIOPinConfigure(GPIO_PD0_SSI1CLK);

Regards
Amit

/*
* Configure the appropriate pins to be SSI instead of GPIO. The FSS (CS)
* signal is directly driven to ensure that we can hold it low through a
* complete transaction with the SD card.
*/


//GPIOPinConfigure(GPIO_PD2_SSI1RX);
//GPIOPinConfigure(GPIO_PD3_SSI1TX);
//GPIOPinConfigure(GPIO_PD0_SSI1CLK);
//GPIOPinConfigure(GPIO_PD1_SSI1FSS);
ROM_GPIOPinTypeSSI(SDC_GPIO_PORT_BASE, SDC_SSI_TX | SDC_SSI_RX | SDC_SSI_CLK);
ROM_GPIOPinTypeGPIOOutput(SDC_GPIO_PORT_BASE, SDC_SSI_FSS);

It was written so in the comments. So we enabled the pins to be SSI and not GPIO. Is this wrong?

Regards,
Moumita

Hello Moumita,

The FSS pin is in GPIO mode. However the SSI's other pin of CLK, RX and TX has to be configured in SSI Mode. The PinTypeSSI configures the other settings for the Pin. The PinConfigure function sets the PCTL value for mux selection

Regards
Amit

I changed the code to this now:

    /*
     * Configure the appropriate pins to be SSI instead of GPIO. The FSS (CS)
     * signal is directly driven to ensure that we can hold it low through a
     * complete transaction with the SD card.
     */
    GPIOPinConfigure(SDC_SSI_RX);
	GPIOPinConfigure(SDC_SSI_TX);
	GPIOPinConfigure(SDC_SSI_CLK);
	GPIOPinConfigure(SDC_SSI_FSS);
	ROM_GPIOPinTypeSSI(SDC_GPIO_PORT_BASE, SDC_SSI_TX | SDC_SSI_RX | SDC_SSI_CLK);
    ROM_GPIOPinTypeGPIOOutput(SDC_GPIO_PORT_BASE, SDC_SSI_FSS);

Currently, I am simply testing what the function f_mount() returns. And again, irrespective of whether the SD card is connected or not, it returns "FR_OK". I am unable to understand why this is happening.

I have posted the changed ccs project and the fatfs folder here.

Thanking you,

Moumita

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/908/fatfs.7zhttps://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/908/8662.sd_5F00_card.7z

Hello Moumita

AFAIK, f_mount will do a logical mounting of the FAT FS. Did you check that actual commands work or not?

Regards
Amit

Yes, using the command line, when I try to display the list of files using the command "ls", it gives Bad command FR_NOT_READY irrespective of whether the sd card is connected or not. I am unable to establish a proper connection with the SD card.

Hello Moumita

Probably next week, I would be able to get back once I have access to the LaunchPad.

Regards
Amit

That would be great. Please let me know where exactly I am going wrong or if there is any alternative way to code the SD card interfacing. Awaiting your reply.

Thanking you,
Moumita

I was debugging step by step and I have understood the problem now specifically. When the function f_open is called, the program is failing at chk_mounted() where it returns "FR_NOT_READY". This happens after disk_initialize() is called:

	fs->fs_type = 0;					/* Clear the file system object */
	fs->drv = LD2PD(vol);				/* Bind the logical drive and a physical drive */
	stat = disk_initialize(fs->drv);	/* Initialize the physical drive */
	if (stat & STA_NOINIT)				/* Check if the initialization succeeded */
		return FR_NOT_READY;			/* Failed to initialize due to no medium or hard error */

This is present in ff.c

So when I am running my current main function in sd_card.c:

int
main(void)
{
    int nStatus;
    FRESULT iFResult;

    //
    // Enable lazy stacking for interrupt handlers.  This allows floating-point
    // instructions to be used within interrupt handlers, but at the expense of
    // extra stack usage.
    //
    ROM_FPULazyStackingEnable();

    //
    // Set the system clock to run at 50MHz from the PLL.
    //
    ROM_SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |
                       SYSCTL_XTAL_16MHZ);

    //
    // Enable the peripherals used by this example.
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0);

    //
    // Configure SysTick for a 100Hz interrupt.  The FatFs driver wants a 10 ms
    // tick.
    //
    ROM_SysTickPeriodSet(ROM_SysCtlClockGet() / 100);
    ROM_SysTickEnable();
    ROM_SysTickIntEnable();

    //
    // Enable Interrupts
    //
    ROM_IntMasterEnable();

    //
    // Initialize the UART as a console for text I/O.
    //
    ConfigureUART();

    //perform SD card operations
    iFResult = f_mount(0, &g_sFatFs);
    if(iFResult != FR_OK)
    {
    	UARTprintf("f_mount error: %s\n", StringFromFResult(iFResult));
    	return(1);
    }
    else
    {
    	UARTprintf("\nMounted SD card\n");
    }

    iFResult = f_open(&g_sFileObject,"data.txt", FA_CREATE_ALWAYS|FA_WRITE);
    if(iFResult != FR_OK)
    {
    	UARTprintf("Error creating file data.txt: %s\n", StringFromFResult(iFResult));
    	return(1);
    }
    else
    {
    	UARTprintf("\nCreated file data.txt\n");
    }
}

It gives the output as follows:

Mounted SD card
Error creating file data.txt: FR_NOT_READY

It would be very helpful if you could point out why this is happening. I am attaching the zipped files of my project and fatfs folder as well.

Thanking you,

Moumita

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/908/4456.sd_5F00_card.7z

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/908/1884.fatfs.7z