Здравствуйте!
Необходимо получить данные с MMC карты памяти...Подключил к ATmega16 схема:
Помогите написать программу..получить первые данные...а далее сам постараюсь разобраться...

ИМХО, лучше взять ATMega16L или использовать нормальный преобразователь уровней.

Сначала добейтесь ответа 0x01 на CMD0 (0x40, 0x0, 0x0, 0x0, 0x0, 0x95). Примеров полно в нете.

Немоглы бы вы привести пример кода...?

Посмотрите EFSL, например.

Научитесь пользоваться поиском по форуму - тема поднималась и обсуждалась много раз.

http://elm-chan.org/docs/mmc/mmc_e.html
http://elm-chan.org/fsw/ff/00index_e.html

вот еще библиотеку нашел:

/// MMC/SD Library. CopyLefted from Procyon AVRlib
/// _________________
/// / 1 2 3 4 5 6 78 | <- view of MMC/SD card looking at contacts
/// / 9 | Pins 8 and 9 are present only on SD cards
/// | MMC/SD Card |
/// | |
/// /\/\/\/\/\/\/\/\/\/\
/// 1 - CS (chip select) - wire to any available I/O pin(*)
/// 2 - DIN (data in, card<-host) - wire to SPI MOSI pin
/// 3 - VSS (ground) - wire to ground
/// 4 - VDD (power, 3.3V only?) - wire to power (MIGHT BE 3.3V ONLY!)
/// 5 - SCLK (data clock) - wire to SPI SCK pin
/// 6 - VSS (ground) - wire to ground
/// 7 - DOUT (data out, card->host) - wire to SPI MISO pin
/// 8,9 (SD card only) - PullUP to VDD

#define MMC_CS_PORT PORTB
#define MMC_CS_DDR DDRB
#define MMC_CS_PIN 0

// function prototypes

// SPI interface initializer
void spiInit(void);

// spiSendByte(unsigned char data) waits until the SPI interface is ready
// and then sends a single byte over the SPI port. This command
// does not receive anything.
void spiSendByte(unsigned char data);

// spiTransferByte(unsigned char data) waits until the SPI interface is ready
// and then sends a single byte over the SPI port. The function also
// returns the byte that was received during transmission.
unsigned char spiTransferByte(unsigned char data);

// spiTransferWord(unsigned char data) works just like spiTransferByte but
// operates on a whole word (16-bits of data).
unsigned int spiTransferWord(unsigned int data);

// global variables
volatile unsigned char spiTransferComplete;

// access routines
void spiInit()
{
unsigned char zzz;
// setup SPI I/O pins
PORTB.5=1; // set SCK hi
DDRB.5=1; // set SCK as output
DDRB.4=0; // set MISO as input
DDRB.3=1; // set MOSI as output
DDRB.2=1; // SS must be output for Master mode to work

SPCR.4=1;
// clock = f/16
SPCR.0=0;
SPCR.1=0;
SPSR.0=0;
// select clock phase positive-going in middle of data
SPCR.3=0;
// Data order MSB first
SPCR.5=0;
// enable SPI
SPCR.6=1;

// clear status
zzz=SPSR;
spiTransferComplete = 255;

}

void spiSendByte(unsigned char data)
{
while(!((SPSR) & (1<< SPSR.7)));
spiTransferComplete = 0;
SPDR=data;
}

unsigned char spiTransferByte(unsigned char data)
{
// send the given data
spiTransferComplete = 0;

SPDR=data;
while ((SPSR & (1<<7))==0);
spiTransferComplete = 255;
return SPDR;

}



// constants/macros/typdefs
// MMC commands (taken from sandisk MMC reference)
#define MMC_GO_IDLE_STATE 0 ///< initialize card to SPI-type access
#define MMC_SEND_OP_COND 1 ///< set card operational mode
#define MMC_SEND_CSD 9 ///< get card's CSD
#define MMC_SEND_CID 10 ///< get card's CID
#define MMC_SEND_STATUS 13
#define MMC_SET_BLOCKLEN 16 ///< Set number of bytes to transfer per block
#define MMC_READ_SINGLE_BLOCK 17 ///< read a block
#define MMC_WRITE_BLOCK 24 ///< write a block
#define MMC_PROGRAM_CSD 27
#define MMC_SET_WRITE_PROT 28
#define MMC_CLR_WRITE_PROT 29
#define MMC_SEND_WRITE_PROT 30
#define MMC_TAG_SECTOR_START 32
#define MMC_TAG_SECTOR_END 33
#define MMC_UNTAG_SECTOR 34
#define MMC_TAG_ERASE_GROUP_START 35 ///< Sets beginning of erase group (mass erase)
#define MMC_TAG_ERARE_GROUP_END 36 ///< Sets end of erase group (mass erase)
#define MMC_UNTAG_ERASE_GROUP 37 ///< Untag (unset) erase group (mass erase)
#define MMC_ERASE 38 ///< Perform block/mass erase
#define MMC_CRC_ON_OFF 59 ///< Turns CRC check on/off
// R1 Response bit-defines
#define MMC_R1_BUSY 0x80 ///< R1 response: bit indicates card is busy
#define MMC_R1_PARAMETER 0x40
#define MMC_R1_ADDRESS 0x20
#define MMC_R1_ERASE_SEQ 0x10
#define MMC_R1_COM_CRC 0x08
#define MMC_R1_ILLEGAL_COM 0x04
#define MMC_R1_ERASE_RESET 0x02
#define MMC_R1_IDLE_STATE 0x01
// Data Start tokens
#define MMC_STARTBLOCK_READ 0xFE ///< when received from card, indicates that a block of data will follow
#define MMC_STARTBLOCK_WRITE 0xFE ///< when sent to card, indicates that a block of data will follow
#define MMC_STARTBLOCK_MWRITE 0xFC
// Data Stop tokens
#define MMC_STOPTRAN_WRITE 0xFD
// Data Error Token values
#define MMC_DE_MASK 0x1F
#define MMC_DE_ERROR 0x01
#define MMC_DE_CC_ERROR 0x02
#define MMC_DE_ECC_FAIL 0x04
#define MMC_DE_OUT_OF_RANGE 0x04
#define MMC_DE_CARD_LOCKED 0x04
// Data Response Token values
#define MMC_DR_MASK 0x1F
#define MMC_DR_ACCEPT 0x05
#define MMC_DR_REJECT_CRC 0x0B
#define MMC_DR_REJECT_WRITE_ERROR 0x0D

// functions

//! Initialize AVR<->MMC hardware interface.
/// Prepares hardware for MMC access.
void mmcInit(void);

//! Initialize the card and prepare it for use.
/// Returns zero if successful.
unsigned char mmcReset(void);

//! Send card an MMC command.
/// Returns R1 result code.
unsigned char mmcSendCommand(unsigned char cmd, unsigned long arg);

//! Read 512-byte sector from card to buffer
/// Returns zero if successful.
unsigned char mmcRead(unsigned long sector, unsigned char* buffer);

//! Write 512-byte sector from buffer to card
/// Returns zero if successful.
unsigned char mmcWrite(unsigned long sector, unsigned char* buffer);

//! Internal command function.
/// Issues a generic MMC command as specified by cmd and arg.
unsigned char mmcCommand(unsigned char cmd, unsigned long arg);


void mmcInit(void)
{
// initialize SPI interface
spiInit();
// release chip select
DDRB.0=1;
PORTB.0=1;
}

unsigned char mmcReset(void)
{
unsigned char retry,rn;
unsigned char r1=0;


retry = 0;
do
{
// send dummy bytes with CS high before accessing
for (rn=0; rn<74;rn++) spiTransferByte(0xFF);
delay_ms(1);
// resetting card, go to SPI mode
r1 = mmcSendCommand(MMC_GO_IDLE_STATE, 0);
// do retry counter
retry++;
if(retry>10) return 255;
} while(r1 != 0x01);

retry = 0;
do
{
// initializing card for operation
r1 = mmcSendCommand(MMC_SEND_OP_COND, 0);
// do retry counter
retry++;
if(retry>250) return 254;
} while(!(r1==0));

// turn off CRC checking to simplify communication
//r1 = mmcSendCommand(MMC_CRC_ON_OFF, 0);

// set block length to 512 bytes
r1 = mmcSendCommand(MMC_SET_BLOCKLEN, 512);

// return success
return 0;
}

unsigned char mmcSendCommand(unsigned char cmd, unsigned long arg)
{
unsigned char r1;

// assert chip select
PORTB.0=0;
// issue the command
r1 = mmcCommand(cmd, arg);
// release chip select
PORTB.0=1;

return r1;
}

unsigned char mmcRead(unsigned long sector, unsigned char* buffer)
{
unsigned char r1;
unsigned int i;

// assert chip select
PORTB.0=0;
// issue command
r1 = mmcCommand(MMC_READ_SINGLE_BLOCK, sector<<9);
// check for valid response
if(r1 != 0x00)
return r1;
// wait for block start
while(spiTransferByte(0xFF) != MMC_STARTBLOCK_READ);
// read in data
for(i=0; i<0x200; i++)
{
*buffer++ = spiTransferByte(0xFF);
}
// read 16-bit CRC
spiTransferByte(0xFF);
spiTransferByte(0xFF);
// release chip select
PORTB.0=1;
// return success
return 0;
}

unsigned char mmcWrite(unsigned long sector, unsigned char* buffer)
{
unsigned char r1;
unsigned int i;

// assert chip select
PORTB.0=0;
// issue command
r1 = mmcCommand(MMC_WRITE_BLOCK, sector<<9);
// check for valid response
if(r1 != 0x00)
return r1;
// send dummy
spiTransferByte(0xFF);
// send data start token
spiTransferByte(MMC_STARTBLOCK_WRITE);
// write data
for(i=0; i<0x200; i++)
{
spiTransferByte(*buffer++);
}
// write 16-bit CRC (dummy values)
spiTransferByte(0xFF);
spiTransferByte(0xFF);
// read data response token
r1 = spiTransferByte(0xFF);
if( (r1&MMC_DR_MASK) != MMC_DR_ACCEPT)
return r1;
// wait until card not busy
while(!spiTransferByte(0xFF));
// release chip select
PORTB.0=1;
// return success
return 0;
}

unsigned char mmcCommand(unsigned char cmd, unsigned long arg)
{
unsigned char r1;
unsigned char retry=0;
// send command
spiTransferByte(cmd | 0x40);
spiTransferByte(arg>>24);
spiTransferByte(arg>>16);
spiTransferByte(arg>>8);
spiTransferByte(arg);
spiTransferByte(0x95); // crc valid only for MMC_GO_IDLE_STATE
// end command
// wait for response
// if more than 8 retries, card has timed-out
// return the received 0xFF
while((r1 = spiTransferByte(0xFF)) == 0xFF)
if(retry++ > 8) break;
// return response
return r1;
}

Мы все рады за Вас, но:
1. Лучше ограничиться ссылкой или прикрепить файл.
2. Пользуйтесь тегами [сode][/сode] для оформления кода.
3. Какой реакции Вы ждете от остальных?

подскажите...

unsigned char t;
while(1)
{
mmcInit();
t=mmcReset();
printf ("%c",t);
}


или перед этом всем еше spiInit нада?

spiInit() вызывается в mmcInit(), так что не надо.

mmcInit() я бы из цикла вынес.

что то карта вообще не отвечает....

А сигналы идут? Если осциллоскопом посмотреть...