File content as of revision 0:f3870f76a890:

#include "mbed.h"
#include "stdint.h"

SPI Card(p5, p6, p7);
    //mosi, miso, sck
DigitalOut cs(p8);
    //chip select

unsigned char OCR[4];
    //operating condition register
unsigned char CSD[16];
    //card-specific data register
bool Version;
    //card version, low for 1, high for 2
bool Capacity;
    //low for low-capacity, high for high-capacity
bool CRCMode;
    //low to disable CRCs, high to enable CRCs
unsigned char CommandCRCTable[256];
    //CRC7 lookup table
unsigned char DataCRCTable[512];
    //CRC CCITT lookup table
unsigned char Workspace[5];
    //generic information holder

//////////////////////////////
DigitalOut led1(LED1);
DigitalOut led2(LED2);
DigitalOut led3(LED3);
DigitalOut led4(LED4);
Serial Computer(USBTX, USBRX);
    //for testing
//////////////////////////////

bool Initialize();
bool Write(unsigned int Address, unsigned char* Data);
bool Read(unsigned int Address, unsigned char* Data);
void Command(unsigned char Index, unsigned int Argument, unsigned char* Response);
char CommandCRC(unsigned char* IndexPtr, unsigned int* ArgumentPtr);
void DataCRC(unsigned short Length, unsigned char* Data, unsigned char* Result);
void GenerateCRCTable(unsigned char Size, unsigned long long Generator, unsigned char* Table);

int main()
{
/////////////////////
    led1 = 0;
    led2 = 0;
    led3 = 0;
    led4 = 0;
    Computer.baud(9600);
        //for testing
    unsigned char wdata[512];
    unsigned char rdata[512];
    int testaddress = 9;
/////////////////////
    
    //Initialize();
    
    /*for(unsigned short j = 0; j < 512; j++)
    {
        wdata[j] = 0x00;
    }
    Write(testaddress, wdata);
    Read(testaddress, rdata);
    for(unsigned short j = 0; j < 512; j++)
    {
        Computer.putc(rdata[j]);
    }
    for(unsigned short j = 0; j < 512; j++)
    {
        wdata[j] = 0x00 + j;
    }
    Write(testaddress, wdata);
    Read(testaddress, rdata);
    for(unsigned short j = 0; j < 512; j++)
    {
        Computer.putc(rdata[j]);
    }*/

/////////////////////
    if (Initialize())
    {
        while(1)
        {
            led1 = !led1;
            wait_ms(250);
            led2 = !led2;
            wait_ms(250);
            led3 = !led3;
            wait_ms(250);
            led4 = !led4;
            wait_ms(250);
        }
    }//victory dance
    else
    {
        while(1)
        {
            
            led1 = !led1;
            led2 = !led2;
            led3 = !led3;
            led4 = !led4;
            wait_ms(250);
        }
    }//failure
        //for testing
/////////////////////
}

bool Initialize()
{
    Card.frequency(100000);
        //set universal speed
    cs = 1;
        //chip select is active low
    CRCMode = 1;
        //turn cyclic redundancy checks on

    GenerateCRCTable(1, 137, CommandCRCTable);
        //generate the command crc lookup table
        //(generator polynomial x^7 + x^3 + 1 converts to decimal 137)
    GenerateCRCTable(2, 69665, DataCRCTable);
        //generate the command crc lookup table
        //(generator polynomial x^16 + x^12 + x^5 + 1 converts to decimal 69665)
            
    for (unsigned char j = 0; j < 16; j++)
    {
        Card.write(0xFF);
    }
        //perform specified power up sequence
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(0, 0, Workspace);
            //send command 0 to put the card into SPI mode
        if (Workspace[0] == 0x01)
            //check for idle mode
        { break; }
        if (j == 8191)
        { return 0; }
    }
    Computer.putc(0x1F);
    Computer.putc(Workspace[0]);
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(8, 426, Workspace);
            //voltage bits are 0x01 for 2.7V - 3.6V,
            //check pattern 0xAA, [00,00,01,AA] = 426
        if ((Workspace[0] == 0x05) || ((Workspace[0] == 0x01) &&
            ((Workspace[3] & 0x0F) == 0x01) && (Workspace[4] == 0xAA)))
            //check version, voltage acceptance, and check pattern
        { break; }
        if (j == 8191)
        { return 0; }
    }
    Version = Workspace[0] == 0x01;
        //store card version
    Computer.putc(0x3F);
    Computer.putc(Workspace[0]);
    Computer.putc(Version);
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(58, 0, Workspace);
            //check the OCR
        if ((Workspace[0] == 0x01) && ((Workspace[2] & 0x20) || (Workspace[2] & 0x10)))
            //check for correct operating voltage 3.3V
        { break; }
        if (j == 8191)
        { return 0; }
    }
    Computer.putc(0x4F);
    Computer.putc(Workspace[0]);
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(59, 1, Workspace);
            //send command 59 to turn on CRCs
    Computer.putc(Workspace[0]);
        if (Workspace[0] == 0x01)
        { break; }
        if (j == 8191)
        { return 0; }
    }
    Computer.putc(0x2F);
    Computer.putc(Workspace[0]);
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(55, 0, Workspace);
            //specify application-specific command
        Command(41, 1073741824, Workspace);
            //specify host supports high capacity cards
            //[40,00,00,00] = 1073741824
        if (Workspace[0] == 0x00)
            //check if card is ready
        { break; }
        if (j == 8191)
        { return 0; }
    }
    Computer.putc(0x5F);
    Computer.putc(Workspace[0]);
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(58, 0, Workspace);
            //check the OCR again
        if ((Workspace[0] == 0x00) && (Workspace[1] & 0x80))
        { break; }
        if (j == 8191)
        { return 0; }
    }
    for (unsigned char j = 0; j < 4; j++)
    {
        OCR[j] = Workspace[j + 1];
    }
        //record OCR
    Capacity = (OCR[0] & 0x40) == 0x40;
        //record capacity
    Computer.putc(0x6F);
    Computer.putc(Workspace[0]);
    Computer.putc(Capacity);
    
    for (unsigned int j = 0; j < 8192; j++)
    {
        Command(9, 0, Workspace);
            //read the card-specific data register
        cs = 0;
        for (unsigned int k = 0; k < 8192; k++)
        {
            if (Card.write(0xFF) == 0xFE)
            { break; }
        }
            //get to the start-data-block token
        for (unsigned char k = 0; k < 16; k++)
        {
            CSD[k] = Card.write(0xFF);
        }
        Workspace[3] = Card.write(0xFF);
        Workspace[4] = Card.write(0xFF);
        cs = 1;
        Card.write(0xFF);
        DataCRC(16, CSD, Workspace);
            //calculate the CSD data CRC
        Workspace[0] = 0;
        for (unsigned char k = 0; k < 15; k++)
        {
            Workspace[0] = CommandCRCTable[Workspace[0]] ^ CSD[k];
        }
        Workspace[0] = CommandCRCTable[Workspace[0]] | 0x01;
        if ((Workspace[0] == CSD[15]) && (Workspace[1] == Workspace[3]) && (Workspace[2] == Workspace[4]))
        { break; }
        if (j == 8191)
        { return 0; }
    }
    Computer.putc(0x7F);
    Computer.putc(Workspace[0]);
    Computer.putc(CSD[3] & 0x7F);
    
    if (((CSD[3] & 0x07) > 2) || ((CSD[3] & 0x7F) > 0x32))
    {
        Card.frequency(25000000);
            //maximum speed is given at 25MHz
    }
    else
    {
       Workspace[0] = 1;
        for (unsigned char j = 0; j < (CSD[3] & 0x07); j++)
        {
            Workspace[0] *= 10;
                //the first three bits are a power of ten multiplier for speed
        }
        switch (CSD[3] & 0x78)
        {
            case 0x08: Card.frequency(Workspace[0] * 100000); break;
            case 0x10: Card.frequency(Workspace[0] * 120000); break;
            case 0x18: Card.frequency(Workspace[0] * 140000); break;
            case 0x20: Card.frequency(Workspace[0] * 150000); break;
            case 0x28: Card.frequency(Workspace[0] * 200000); break;
            case 0x30: Card.frequency(Workspace[0] * 250000); break;
            case 0x38: Card.frequency(Workspace[0] * 300000); break;
            case 0x40: Card.frequency(Workspace[0] * 350000); break;
            case 0x48: Card.frequency(Workspace[0] * 400000); break;
            case 0x50: Card.frequency(Workspace[0] * 450000); break;
            case 0x58: Card.frequency(Workspace[0] * 500000); break;
            case 0x60: Card.frequency(Workspace[0] * 550000); break;
            case 0x68: Card.frequency(Workspace[0] * 600000); break;
            case 0x70: Card.frequency(Workspace[0] * 700000); break;
            case 0x78: Card.frequency(Workspace[0] * 800000); break;
            default: break;
                //read the csd card speed bits and speed up card operations
        }
    }
    
    if (!Version)
    {
        for (unsigned int j = 0; j < 8192; j++)
        {
            Command(16, 512, Workspace);
                //set data-block length to 512 bytes
            if (Workspace[0] == 0x00)
            { break; }
            if (j == 8191)
            { return 0; }
        }
    }
    Computer.putc(0x8F);
    Computer.putc(Workspace[0]);
        ////////////////////////////////////////////implement data block sizing later
    return 1;
}

bool Write(unsigned int Address, unsigned char* Data)
{
    if (Capacity)
    {
        for (unsigned int j = 0; j < 8192; j++)
        {
            Command(24, Address, Workspace);
            if (Workspace[0] == 0x00)
            { break; }
            if (j == 8191)
            { return 0; }
        }
    }
    else
    {
        for (unsigned int j = 0; j < 8192; j++)
        {
            Command(24, Address * 512, Workspace);///////////implement block length
            if (Workspace[0] == 0x00)
            { break; }
            if (j == 8191)
            { return 0; }
        }
    }
    cs = 0;
    Card.write(0xFE);
        //start data block token
    for (unsigned short j = 0; j < 512; j++)
    {
        Card.write(Data[j]);
            //write the data
    }
    DataCRC(512, Data, Workspace);
    Card.write(Workspace[1]);
    Card.write(Workspace[2]);
    for (unsigned int j = 0; j < 8192; j++)
    {
        Workspace[0] = Card.write(0xFF);
        if ((Workspace[0] & 0x1F) == 0x05)
        { break; }
    }
    while (!Card.write(0xFF));
    cs = 1;
    Card.write(0xFF);
    if ((Workspace[0] & 0x1F) == 0x05)
    { return 1; }
    else
    {
        for (unsigned int j = 0; j < 8192; j++)
        {
            Command(13, 0, Workspace);
            if (Workspace[0] == 0x00)
            { break; }
        }
        return 0;
    }
}

bool Read(unsigned int Address, unsigned char* Data)
{
    if (Capacity)
    {
        for (unsigned int j = 0; j < 8192; j++)
        {
            Command(17, Address, Workspace);
            if (Workspace[0] == 0x00)
            { break; }
            if (j == 8191)
            { return 0; }
        }
    }
    else
    {
        for (unsigned int j = 0; j < 8192; j++)
        {
            Command(17, Address * 512, Workspace);///////////implement block length
            if (Workspace[0] == 0x00)
            { break; }
            if (j == 8191)
            { return 0; }
        }
    }
    cs = 0;
    for (unsigned int j = 0; j < 8192; j++)
    {
        if (Card.write(0xFF) == 0xFE)
        { break; }
    }
    for (unsigned short j = 0; j < 512; j++)
    {
        Data[j] = Card.write(0xFF);
    }
    Workspace[3] = Card.write(0xFF);
    Workspace[4] = Card.write(0xFF);
    cs = 1;
    Card.write(0xFF);
    DataCRC(512, Data, Workspace);
    if ((Workspace[1] == Workspace[3]) && (Workspace[2] == Workspace[4]))
    { return 1; }
    else
    { return 0; }
}

void Command(unsigned char Index, unsigned int Argument, unsigned char* Response)
{
    cs = 0;
        //assert chip select low to synchronize command
    Card.write(0x40 | Index);
        //the index is assumed valid, commands start with "01b"
    Card.write(((char*)&Argument)[3]);
    Card.write(((char*)&Argument)[2]);
    Card.write(((char*)&Argument)[1]);
    Card.write(((char*)&Argument)[0]);
        //send the argument bytes in order from MSB to LSB (mbed is little endian)
    if (CRCMode)
    { Card.write(CommandCRC(&Index, &Argument)); }
    else
    { Card.write(0x00); }
        //send the command CRC
    for (unsigned int j = 0; j < 8192; j++)
    {
        Response[0] = Card.write(0xFF);
            //clock the card high to let it run operations, the first byte will be
            //busy (all high), the response will be sent some time later
        if (!(Response[0] & 0x80))
            //check for a response by testing if the first bit is low
        { break; }
    }
    if ((Index == 8) || (Index == 13) || (Index == 58))
    {
        for (unsigned char j = 1; j < 5; j++)
        {
            Response[j] = Card.write(0xFF);
        }
            //get the rest of the response
    }
    cs = 1;
        //assert chip select high to synchronize command
    Card.write(0xFF);
        //clock the deselected card high to complete processing for some cards
}
    
char CommandCRC(unsigned char* IndexPtr, unsigned int* ArgumentPtr)
{
    return
        CommandCRCTable[
            CommandCRCTable[
                CommandCRCTable[
                    CommandCRCTable[
                        CommandCRCTable[
                            *IndexPtr | 0x40
                        ] ^ ((char*)ArgumentPtr)[3]
                    ] ^ ((char*)ArgumentPtr)[2]
                ] ^ ((char*)ArgumentPtr)[1]
            ] ^ ((char*)ArgumentPtr)[0]
        ] | 0x01;
        //using a CRC table, the CRC result of a byte is equal to the byte in the table at the
        //address equal to the input byte, a message CRC is obtained by successively XORing these
        //with the message bytes
}

void DataCRC(unsigned short Length, unsigned char* Data, unsigned char* Result)
{
    Result[1] = 0x00;
    Result[2] = 0x00;
        //initialize result carrier
    for (int i = 0; i < Length; i++)
        //step through each byte of the data to be checked
    {
        Result[0] = Result[1];
            //record current crc lookup for both bytes
        Result[1] = DataCRCTable[2 * Result[0]] ^ Result[2];
            //new fist byte result is XORed with old second byte result
        Result[2] = DataCRCTable[(2 * Result[0]) + 1] ^ Data[i];
            //new second byte result is XORed with new data byte
    }
    for (int i = 0; i < 2; i++)
        //the final result must be XORed with two 0x00 bytes.
    {
        Result[0] = Result[1];
        Result[1] = DataCRCTable[2 * Result[0]] ^ Result[2];
        Result[2] = DataCRCTable[(2 * Result[0]) + 1];
    }
}

void GenerateCRCTable(unsigned char Size, unsigned long long Generator, unsigned char* Table)
{
    unsigned char Index[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
        //this will hold information from the generator; the position indicates the
        //order of the encountered 1, the value indicates its position in the
        //generator, the 9th entry indicates the number of 1's encountered
    for (int i = 0; i < 64; i++)
    {
        if (((char*)&Generator)[7] & 0x80)
        { break; }
        Generator = Generator << 1;
            //shift generator so that the first bit is high
    }
    for (unsigned char k = 0; k < Size; k++)
    {
        Table[k] = 0x00;
            //initialize the first CRC bytes
    }
    for (unsigned char i = 0; i < 8; i++)
        //increment through each generator bit
    {
        if ((0x80 >> i) & ((unsigned char*)&Generator)[7])
            //if a 1 is encountered in the generator
        {
            Index[Index[8]] = i;
            Index[8]++;
                //record its order and location and increment the counter
        }
        for (unsigned char j = 0; j < (0x01 << i); j++)
            //each bit increases the number of xor operations by a power of 2
        {
            for (unsigned char k = 0; k < Size; k++)
                //we need to perform operations for each byte in the CRC result
            {
                Table[(Size * ((0x01 << i) + j)) + k] = Table[(Size * j) + k];
                    //each new power is equal to all previous entries with an added xor
                    //on the leftmost bit and each succeeding 1 on the generator
                for (unsigned char l = 0; l < Index[8]; l++)
                    //increment through the encountered generator 1s
                {
                    Table[(Size * ((0x01 << i) + j)) + k] ^= (((unsigned char*)&Generator)[7-k] << (i + 1 - Index[l]));
                    Table[(Size * ((0x01 << i) + j)) + k] ^= (((unsigned char*)&Generator)[6-k] >> (7 - i + Index[l]));
                        //xor the new bit and the new generator 1s
                }
            }
        }
    }
}