mmc.c

this is a source code for usinf sd card with PIC

#define MMC_BLOCK_LENGTH 512 /* Taille d'un bloc. */

//*************** VARIABLES GLOBALES ***************//

unsigned short mmc_temp[4]; /* Variable temporaire. */

#define mmc_int (*(unsigned int*)(&mmc_temp[0]))
#define mmc_long (*(unsigned long*)(&mmc_temp[0]))

//*************** MACROS ***************//

#define mmc_enable() /* Active le p閞iph閞ique. */ \
\
    portc.f2 = 0

#define mmc_disable() /* D閟active le p閞iph閞ique. */ \
\
    portc.f2 = 1

#define mmc_read() /* Lit un octet dans le bloc ouvert. */ \
\
    spi_read(0xFF)

#define mmc_write(B) /* Ecrit un octet dans le bloc ouvert. */ \
\
    spi_write(B)

//*************** FONCTIONS "PRIVEES" ***************//

#define mmc_send_command(CMD,ADDR,CRC) /* Envoie une commande
                                        * au p閞iph閞ique. */ \
\
    spi_write(0xFF); \
    spi_write(CMD); \
    mmc_long = ADDR; \
    spi_write(highest(mmc_long)); \
    spi_write(higher(mmc_long)); \
    spi_write(hi(mmc_long)); \
    spi_write(lo(mmc_long)); \
    spi_write(CRC)
    
#define mmc_wait_response(RESP) /* Attend une r閜onse du p閞iph閞ique. */ \
\
    mmc_int = 0xFFFF; \
\
    while( (spi_read(0xFF) != RESP) && (--mmc_int > 0))

#define mmc_response_ok() /* Vrai si la r閜onse est celle attendue. */ \
\
    (mmc_int > 0)

//*************** FONCTIONS "PUBLIQUES" ***************//

#define mmc_init_inline() /* Fonction d'initialisation. */ \
\
    unsigned short i; \
\
    trisc = 0b10010000; \
    portc = 0b00000000; \
\
    spi_init_advanced(MASTER_OSC_DIV4, \
        DATA_SAMPLE_END,CLK_IDLE_HIGH,HIGH_2_LOW); \
\
    mmc_disable(); \
\
    for( i = 0; i < 10; ++i) spi_write(0xFF); \
\
    mmc_enable(); \
\
    mmc_send_command(0x40,0x00,0x95); \
\
    mmc_wait_response(0x01); \
    if( !mmc_response_ok()) return 1; \
\
    i = 0; \
\
    while(1) { \
\
        mmc_wait_response(0x00); \
        if( mmc_response_ok()) break; \
        if( i++ == 0xFF) return 1; \
        mmc_send_command(0x41,0x00,0xFF); \
    } \
\
    mmc_disable(); \
\
    spi_write(0xFF); \
\
    mmc_enable(); \
\
    mmc_send_command(0x50,MMC_BLOCK_LENGTH,0xFF); \
\
    mmc_wait_response(0x00); \
    if( !mmc_response_ok()) return 1; \
\
    mmc_disable()

unsigned short mmc_init() {

    mmc_init_inline();
    return 0;
}

#define mmc_open_read_block_inline(BLK) /* Ouvre un bloc pour la lecture. */ \
\
	mmc_enable(); \
\
	mmc_send_command(0x51,(BLK) * MMC_BLOCK_LENGTH,0xFF); \
\
    mmc_wait_response(0x00); \
    if( !mmc_response_ok()) return 1; \
\
    mmc_wait_response(0xFE); \
    if( !mmc_response_ok()) return 1

unsigned short mmc_open_read_block(unsigned long block) {

    mmc_open_read_block_inline(block);
    return 0;
}

#define mmc_open_write_block_inline(BLK) /* Ouvre un bloc pour l'閏riture. */ \
\
	mmc_enable(); \
\
	mmc_send_command(0x58,(BLK) * MMC_BLOCK_LENGTH,0xFF); \
\
    mmc_wait_response(0x00); \
    if( !mmc_response_ok()) return 1; \
\
    spi_write(0xFF); \
    spi_write(0xFF); \
    spi_write(0xFE)
    
unsigned short mmc_open_write_block(unsigned long block) {

    mmc_open_write_block_inline(block);
    return 0;
}

#define mmc_write_verif_inline() /* V閞ifie que l'閏riture est ok. */ \
\
    mmc_wait_response(0x00); \
    if( !mmc_response_ok()) return 1; \
\
    mmc_wait_response(0xFF); \
    if( !mmc_response_ok()) return 1; \
\
    while( spi_read(0xFF) < 0xFF)
    
unsigned short mmc_write_verif() {

    mmc_write_verif_inline();
    return 0;
}

#define mmc_close_block_inline() /* Ferme le dernier bloc ouvert. */ \
\
	spi_read(0xFF); \
	spi_read(0xFF); \
    mmc_disable(); \
	spi_write(0xFF)

void mmc_close_block() {

    mmc_close_block_inline();
}