SD Card Interface class. Log raw data bytes to memory addresses of your choice, or format the card and use the FAT file system to write files.
SDCard.cpp@0:f3870f76a890, 2010-07-18 (annotated)
- Committer:
- Blaze513
- Date:
- Sun Jul 18 21:26:24 2010 +0000
- Revision:
- 0:f3870f76a890
- Child:
- 1:94c648931f84
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Blaze513 | 0:f3870f76a890 | 1 | #include "SDCard.h" |
Blaze513 | 0:f3870f76a890 | 2 | |
Blaze513 | 0:f3870f76a890 | 3 | SDCard::SDCard(PinName mosi, PinName miso, PinName sck, PinName cs) |
Blaze513 | 0:f3870f76a890 | 4 | : DataLines(mosi, miso, sck), ChipSelect(cs), CRCMode(1) |
Blaze513 | 0:f3870f76a890 | 5 | { |
Blaze513 | 0:f3870f76a890 | 6 | DataLines.frequency(100000); |
Blaze513 | 0:f3870f76a890 | 7 | //set universal speed |
Blaze513 | 0:f3870f76a890 | 8 | ChipSelect.write(1); |
Blaze513 | 0:f3870f76a890 | 9 | //chip select is active low |
Blaze513 | 0:f3870f76a890 | 10 | GenerateCRCTable(1, 137, CommandCRCTable); |
Blaze513 | 0:f3870f76a890 | 11 | //generate the command crc lookup table |
Blaze513 | 0:f3870f76a890 | 12 | //(generator polynomial x^7 + x^3 + 1 converts to decimal 137) |
Blaze513 | 0:f3870f76a890 | 13 | GenerateCRCTable(2, 69665, DataCRCTable); |
Blaze513 | 0:f3870f76a890 | 14 | //generate the command crc lookup table |
Blaze513 | 0:f3870f76a890 | 15 | //(generator polynomial x^16 + x^12 + x^5 + 1 converts to decimal 69665) |
Blaze513 | 0:f3870f76a890 | 16 | Initialize(); |
Blaze513 | 0:f3870f76a890 | 17 | //send card initialization sequence |
Blaze513 | 0:f3870f76a890 | 18 | } |
Blaze513 | 0:f3870f76a890 | 19 | |
Blaze513 | 0:f3870f76a890 | 20 | bool SDCard::Write(unsigned int Address, unsigned char* Data) |
Blaze513 | 0:f3870f76a890 | 21 | { |
Blaze513 | 0:f3870f76a890 | 22 | if (Capacity) |
Blaze513 | 0:f3870f76a890 | 23 | { |
Blaze513 | 0:f3870f76a890 | 24 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 25 | { |
Blaze513 | 0:f3870f76a890 | 26 | Command(24, Address, Workspace); |
Blaze513 | 0:f3870f76a890 | 27 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 28 | { break; } |
Blaze513 | 0:f3870f76a890 | 29 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 30 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 31 | } |
Blaze513 | 0:f3870f76a890 | 32 | } |
Blaze513 | 0:f3870f76a890 | 33 | else |
Blaze513 | 0:f3870f76a890 | 34 | { |
Blaze513 | 0:f3870f76a890 | 35 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 36 | { |
Blaze513 | 0:f3870f76a890 | 37 | Command(24, Address * 512, Workspace);///////////implement block length |
Blaze513 | 0:f3870f76a890 | 38 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 39 | { break; } |
Blaze513 | 0:f3870f76a890 | 40 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 41 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 42 | } |
Blaze513 | 0:f3870f76a890 | 43 | } |
Blaze513 | 0:f3870f76a890 | 44 | ChipSelect.write(0); |
Blaze513 | 0:f3870f76a890 | 45 | DataLines.write(0xFE); |
Blaze513 | 0:f3870f76a890 | 46 | //start data block token |
Blaze513 | 0:f3870f76a890 | 47 | for (unsigned short j = 0; j < 512; j++) |
Blaze513 | 0:f3870f76a890 | 48 | { |
Blaze513 | 0:f3870f76a890 | 49 | DataLines.write(Data[j]); |
Blaze513 | 0:f3870f76a890 | 50 | //write the data |
Blaze513 | 0:f3870f76a890 | 51 | } |
Blaze513 | 0:f3870f76a890 | 52 | DataCRC(512, Data, Workspace); |
Blaze513 | 0:f3870f76a890 | 53 | DataLines.write(Workspace[1]); |
Blaze513 | 0:f3870f76a890 | 54 | DataLines.write(Workspace[2]); |
Blaze513 | 0:f3870f76a890 | 55 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 56 | { |
Blaze513 | 0:f3870f76a890 | 57 | Workspace[0] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 58 | if ((Workspace[0] & 0x1F) == 0x05) |
Blaze513 | 0:f3870f76a890 | 59 | { break; } |
Blaze513 | 0:f3870f76a890 | 60 | } |
Blaze513 | 0:f3870f76a890 | 61 | while (!DataLines.write(0xFF)); |
Blaze513 | 0:f3870f76a890 | 62 | ChipSelect.write(1); |
Blaze513 | 0:f3870f76a890 | 63 | DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 64 | if ((Workspace[0] & 0x1F) == 0x05) |
Blaze513 | 0:f3870f76a890 | 65 | { return 1; } |
Blaze513 | 0:f3870f76a890 | 66 | else |
Blaze513 | 0:f3870f76a890 | 67 | { |
Blaze513 | 0:f3870f76a890 | 68 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 69 | { |
Blaze513 | 0:f3870f76a890 | 70 | Command(13, 0, Workspace); |
Blaze513 | 0:f3870f76a890 | 71 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 72 | { break; } |
Blaze513 | 0:f3870f76a890 | 73 | } |
Blaze513 | 0:f3870f76a890 | 74 | return 0; |
Blaze513 | 0:f3870f76a890 | 75 | } |
Blaze513 | 0:f3870f76a890 | 76 | } |
Blaze513 | 0:f3870f76a890 | 77 | |
Blaze513 | 0:f3870f76a890 | 78 | bool SDCard::Read(unsigned int Address, unsigned char* Data) |
Blaze513 | 0:f3870f76a890 | 79 | { |
Blaze513 | 0:f3870f76a890 | 80 | if (Capacity) |
Blaze513 | 0:f3870f76a890 | 81 | { |
Blaze513 | 0:f3870f76a890 | 82 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 83 | { |
Blaze513 | 0:f3870f76a890 | 84 | Command(17, Address, Workspace); |
Blaze513 | 0:f3870f76a890 | 85 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 86 | { break; } |
Blaze513 | 0:f3870f76a890 | 87 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 88 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 89 | } |
Blaze513 | 0:f3870f76a890 | 90 | } |
Blaze513 | 0:f3870f76a890 | 91 | else |
Blaze513 | 0:f3870f76a890 | 92 | { |
Blaze513 | 0:f3870f76a890 | 93 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 94 | { |
Blaze513 | 0:f3870f76a890 | 95 | Command(17, Address * 512, Workspace);///////////implement block length |
Blaze513 | 0:f3870f76a890 | 96 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 97 | { break; } |
Blaze513 | 0:f3870f76a890 | 98 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 99 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 100 | } |
Blaze513 | 0:f3870f76a890 | 101 | } |
Blaze513 | 0:f3870f76a890 | 102 | ChipSelect.write(0); |
Blaze513 | 0:f3870f76a890 | 103 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 104 | { |
Blaze513 | 0:f3870f76a890 | 105 | if (DataLines.write(0xFF) == 0xFE) |
Blaze513 | 0:f3870f76a890 | 106 | { break; } |
Blaze513 | 0:f3870f76a890 | 107 | } |
Blaze513 | 0:f3870f76a890 | 108 | for (unsigned short j = 0; j < 512; j++) |
Blaze513 | 0:f3870f76a890 | 109 | { |
Blaze513 | 0:f3870f76a890 | 110 | Data[j] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 111 | } |
Blaze513 | 0:f3870f76a890 | 112 | Workspace[3] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 113 | Workspace[4] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 114 | ChipSelect.write(1); |
Blaze513 | 0:f3870f76a890 | 115 | DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 116 | DataCRC(512, Data, Workspace); |
Blaze513 | 0:f3870f76a890 | 117 | if ((Workspace[1] == Workspace[3]) && (Workspace[2] == Workspace[4])) |
Blaze513 | 0:f3870f76a890 | 118 | { return 1; } |
Blaze513 | 0:f3870f76a890 | 119 | else |
Blaze513 | 0:f3870f76a890 | 120 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 121 | } |
Blaze513 | 0:f3870f76a890 | 122 | |
Blaze513 | 0:f3870f76a890 | 123 | bool SDCard::Initialize() |
Blaze513 | 0:f3870f76a890 | 124 | { |
Blaze513 | 0:f3870f76a890 | 125 | for (unsigned char j = 0; j < 16; j++) |
Blaze513 | 0:f3870f76a890 | 126 | { |
Blaze513 | 0:f3870f76a890 | 127 | DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 128 | } |
Blaze513 | 0:f3870f76a890 | 129 | //perform specified power up sequence |
Blaze513 | 0:f3870f76a890 | 130 | |
Blaze513 | 0:f3870f76a890 | 131 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 132 | { |
Blaze513 | 0:f3870f76a890 | 133 | Command(0, 0, Workspace); |
Blaze513 | 0:f3870f76a890 | 134 | //send command 0 to put the card into SPI mode |
Blaze513 | 0:f3870f76a890 | 135 | if (Workspace[0] == 0x01) |
Blaze513 | 0:f3870f76a890 | 136 | //check for idle mode |
Blaze513 | 0:f3870f76a890 | 137 | { break; } |
Blaze513 | 0:f3870f76a890 | 138 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 139 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 140 | } |
Blaze513 | 0:f3870f76a890 | 141 | |
Blaze513 | 0:f3870f76a890 | 142 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 143 | { |
Blaze513 | 0:f3870f76a890 | 144 | Command(59, 1, Workspace); |
Blaze513 | 0:f3870f76a890 | 145 | //send command 59 to turn on CRCs |
Blaze513 | 0:f3870f76a890 | 146 | if (Workspace[0] == 0x01) |
Blaze513 | 0:f3870f76a890 | 147 | { break; } |
Blaze513 | 0:f3870f76a890 | 148 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 149 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 150 | } |
Blaze513 | 0:f3870f76a890 | 151 | |
Blaze513 | 0:f3870f76a890 | 152 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 153 | { |
Blaze513 | 0:f3870f76a890 | 154 | Command(8, 426, Workspace); |
Blaze513 | 0:f3870f76a890 | 155 | //voltage bits are 0x01 for 2.7V - 3.6V, |
Blaze513 | 0:f3870f76a890 | 156 | //check pattern 0xAA, [00,00,01,AA] = 426 |
Blaze513 | 0:f3870f76a890 | 157 | if ((Workspace[0] == 0x05) || ((Workspace[0] == 0x01) && |
Blaze513 | 0:f3870f76a890 | 158 | ((Workspace[3] & 0x0F) == 0x01) && (Workspace[4] == 0xAA))) |
Blaze513 | 0:f3870f76a890 | 159 | //check version, voltage acceptance, and check pattern |
Blaze513 | 0:f3870f76a890 | 160 | { break; } |
Blaze513 | 0:f3870f76a890 | 161 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 162 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 163 | } |
Blaze513 | 0:f3870f76a890 | 164 | Version = Workspace[0] == 0x01; |
Blaze513 | 0:f3870f76a890 | 165 | //store card version |
Blaze513 | 0:f3870f76a890 | 166 | |
Blaze513 | 0:f3870f76a890 | 167 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 168 | { |
Blaze513 | 0:f3870f76a890 | 169 | Command(58, 0, Workspace); |
Blaze513 | 0:f3870f76a890 | 170 | //check the OCR |
Blaze513 | 0:f3870f76a890 | 171 | if ((Workspace[0] == 0x01) && ((Workspace[2] & 0x20) || (Workspace[2] & 0x10))) |
Blaze513 | 0:f3870f76a890 | 172 | //check for correct operating voltage 3.3V |
Blaze513 | 0:f3870f76a890 | 173 | { break; } |
Blaze513 | 0:f3870f76a890 | 174 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 175 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 176 | } |
Blaze513 | 0:f3870f76a890 | 177 | |
Blaze513 | 0:f3870f76a890 | 178 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 179 | { |
Blaze513 | 0:f3870f76a890 | 180 | Command(55, 0, Workspace); |
Blaze513 | 0:f3870f76a890 | 181 | //specify application-specific command |
Blaze513 | 0:f3870f76a890 | 182 | Command(41, 1073741824, Workspace); |
Blaze513 | 0:f3870f76a890 | 183 | //specify host supports high capacity cards |
Blaze513 | 0:f3870f76a890 | 184 | //[40,00,00,00] = 1073741824 |
Blaze513 | 0:f3870f76a890 | 185 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 186 | //check if card is ready |
Blaze513 | 0:f3870f76a890 | 187 | { break; } |
Blaze513 | 0:f3870f76a890 | 188 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 189 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 190 | } |
Blaze513 | 0:f3870f76a890 | 191 | |
Blaze513 | 0:f3870f76a890 | 192 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 193 | { |
Blaze513 | 0:f3870f76a890 | 194 | Command(58, 0, Workspace); |
Blaze513 | 0:f3870f76a890 | 195 | //check the OCR again |
Blaze513 | 0:f3870f76a890 | 196 | if ((Workspace[0] == 0x00) && (Workspace[1] & 0x80)) |
Blaze513 | 0:f3870f76a890 | 197 | { break; } |
Blaze513 | 0:f3870f76a890 | 198 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 199 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 200 | } |
Blaze513 | 0:f3870f76a890 | 201 | for (unsigned char j = 0; j < 4; j++) |
Blaze513 | 0:f3870f76a890 | 202 | { |
Blaze513 | 0:f3870f76a890 | 203 | OCR[j] = Workspace[j + 1]; |
Blaze513 | 0:f3870f76a890 | 204 | } |
Blaze513 | 0:f3870f76a890 | 205 | //record OCR |
Blaze513 | 0:f3870f76a890 | 206 | Capacity = (OCR[0] & 0x40) == 0x40; |
Blaze513 | 0:f3870f76a890 | 207 | //record capacity |
Blaze513 | 0:f3870f76a890 | 208 | |
Blaze513 | 0:f3870f76a890 | 209 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 210 | { |
Blaze513 | 0:f3870f76a890 | 211 | Command(9, 0, Workspace); |
Blaze513 | 0:f3870f76a890 | 212 | //read the card-specific data register |
Blaze513 | 0:f3870f76a890 | 213 | ChipSelect.write(0); |
Blaze513 | 0:f3870f76a890 | 214 | for (unsigned int k = 0; k < 8192; k++) |
Blaze513 | 0:f3870f76a890 | 215 | { |
Blaze513 | 0:f3870f76a890 | 216 | if (DataLines.write(0xFF) == 0xFE) |
Blaze513 | 0:f3870f76a890 | 217 | { break; } |
Blaze513 | 0:f3870f76a890 | 218 | } |
Blaze513 | 0:f3870f76a890 | 219 | //get to the start-data-block token |
Blaze513 | 0:f3870f76a890 | 220 | for (unsigned char k = 0; k < 16; k++) |
Blaze513 | 0:f3870f76a890 | 221 | { |
Blaze513 | 0:f3870f76a890 | 222 | CSD[k] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 223 | } |
Blaze513 | 0:f3870f76a890 | 224 | Workspace[3] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 225 | Workspace[4] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 226 | ChipSelect.write(1); |
Blaze513 | 0:f3870f76a890 | 227 | DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 228 | DataCRC(16, CSD, Workspace); |
Blaze513 | 0:f3870f76a890 | 229 | //calculate the CSD data CRC |
Blaze513 | 0:f3870f76a890 | 230 | Workspace[0] = 0; |
Blaze513 | 0:f3870f76a890 | 231 | for (unsigned char k = 0; k < 15; k++) |
Blaze513 | 0:f3870f76a890 | 232 | { |
Blaze513 | 0:f3870f76a890 | 233 | Workspace[0] = CommandCRCTable[Workspace[0]] ^ CSD[k]; |
Blaze513 | 0:f3870f76a890 | 234 | } |
Blaze513 | 0:f3870f76a890 | 235 | Workspace[0] = CommandCRCTable[Workspace[0]] | 0x01; |
Blaze513 | 0:f3870f76a890 | 236 | if ((Workspace[0] == CSD[15]) && (Workspace[1] == Workspace[3]) && (Workspace[2] == Workspace[4])) |
Blaze513 | 0:f3870f76a890 | 237 | { break; } |
Blaze513 | 0:f3870f76a890 | 238 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 239 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 240 | } |
Blaze513 | 0:f3870f76a890 | 241 | |
Blaze513 | 0:f3870f76a890 | 242 | if (((CSD[3] & 0x07) > 2) || ((CSD[3] & 0x7F) > 0x32)) |
Blaze513 | 0:f3870f76a890 | 243 | { |
Blaze513 | 0:f3870f76a890 | 244 | DataLines.frequency(25000000); |
Blaze513 | 0:f3870f76a890 | 245 | //maximum speed is given at 25MHz |
Blaze513 | 0:f3870f76a890 | 246 | } |
Blaze513 | 0:f3870f76a890 | 247 | else |
Blaze513 | 0:f3870f76a890 | 248 | { |
Blaze513 | 0:f3870f76a890 | 249 | Workspace[0] = 1; |
Blaze513 | 0:f3870f76a890 | 250 | for (unsigned char j = 0; j < (CSD[3] & 0x07); j++) |
Blaze513 | 0:f3870f76a890 | 251 | { |
Blaze513 | 0:f3870f76a890 | 252 | Workspace[0] *= 10; |
Blaze513 | 0:f3870f76a890 | 253 | //the first three bits are a power of ten multiplier for speed |
Blaze513 | 0:f3870f76a890 | 254 | } |
Blaze513 | 0:f3870f76a890 | 255 | switch (CSD[3] & 0x78) |
Blaze513 | 0:f3870f76a890 | 256 | { |
Blaze513 | 0:f3870f76a890 | 257 | case 0x08: DataLines.frequency(Workspace[0] * 100000); break; |
Blaze513 | 0:f3870f76a890 | 258 | case 0x10: DataLines.frequency(Workspace[0] * 120000); break; |
Blaze513 | 0:f3870f76a890 | 259 | case 0x18: DataLines.frequency(Workspace[0] * 140000); break; |
Blaze513 | 0:f3870f76a890 | 260 | case 0x20: DataLines.frequency(Workspace[0] * 150000); break; |
Blaze513 | 0:f3870f76a890 | 261 | case 0x28: DataLines.frequency(Workspace[0] * 200000); break; |
Blaze513 | 0:f3870f76a890 | 262 | case 0x30: DataLines.frequency(Workspace[0] * 250000); break; |
Blaze513 | 0:f3870f76a890 | 263 | case 0x38: DataLines.frequency(Workspace[0] * 300000); break; |
Blaze513 | 0:f3870f76a890 | 264 | case 0x40: DataLines.frequency(Workspace[0] * 350000); break; |
Blaze513 | 0:f3870f76a890 | 265 | case 0x48: DataLines.frequency(Workspace[0] * 400000); break; |
Blaze513 | 0:f3870f76a890 | 266 | case 0x50: DataLines.frequency(Workspace[0] * 450000); break; |
Blaze513 | 0:f3870f76a890 | 267 | case 0x58: DataLines.frequency(Workspace[0] * 500000); break; |
Blaze513 | 0:f3870f76a890 | 268 | case 0x60: DataLines.frequency(Workspace[0] * 550000); break; |
Blaze513 | 0:f3870f76a890 | 269 | case 0x68: DataLines.frequency(Workspace[0] * 600000); break; |
Blaze513 | 0:f3870f76a890 | 270 | case 0x70: DataLines.frequency(Workspace[0] * 700000); break; |
Blaze513 | 0:f3870f76a890 | 271 | case 0x78: DataLines.frequency(Workspace[0] * 800000); break; |
Blaze513 | 0:f3870f76a890 | 272 | default: break; |
Blaze513 | 0:f3870f76a890 | 273 | //read the CSD card speed bits and speed up card operations |
Blaze513 | 0:f3870f76a890 | 274 | } |
Blaze513 | 0:f3870f76a890 | 275 | } |
Blaze513 | 0:f3870f76a890 | 276 | |
Blaze513 | 0:f3870f76a890 | 277 | if (!Version) |
Blaze513 | 0:f3870f76a890 | 278 | { |
Blaze513 | 0:f3870f76a890 | 279 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 280 | { |
Blaze513 | 0:f3870f76a890 | 281 | Command(16, 512, Workspace); |
Blaze513 | 0:f3870f76a890 | 282 | //set data-block length to 512 bytes |
Blaze513 | 0:f3870f76a890 | 283 | if (Workspace[0] == 0x00) |
Blaze513 | 0:f3870f76a890 | 284 | { break; } |
Blaze513 | 0:f3870f76a890 | 285 | if (j == 8191) |
Blaze513 | 0:f3870f76a890 | 286 | { return 0; } |
Blaze513 | 0:f3870f76a890 | 287 | } |
Blaze513 | 0:f3870f76a890 | 288 | } |
Blaze513 | 0:f3870f76a890 | 289 | ////////////////////////////////////////////implement data block sizing later |
Blaze513 | 0:f3870f76a890 | 290 | return 1; |
Blaze513 | 0:f3870f76a890 | 291 | } |
Blaze513 | 0:f3870f76a890 | 292 | |
Blaze513 | 0:f3870f76a890 | 293 | void SDCard::Command(unsigned char Index, unsigned int Argument, unsigned char* Response) |
Blaze513 | 0:f3870f76a890 | 294 | { |
Blaze513 | 0:f3870f76a890 | 295 | ChipSelect.write(0); |
Blaze513 | 0:f3870f76a890 | 296 | //assert chip select low to synchronize command |
Blaze513 | 0:f3870f76a890 | 297 | DataLines.write(0x40 | Index); |
Blaze513 | 0:f3870f76a890 | 298 | //the index is assumed valid, commands start with "01b" |
Blaze513 | 0:f3870f76a890 | 299 | DataLines.write(((char*)&Argument)[3]); |
Blaze513 | 0:f3870f76a890 | 300 | DataLines.write(((char*)&Argument)[2]); |
Blaze513 | 0:f3870f76a890 | 301 | DataLines.write(((char*)&Argument)[1]); |
Blaze513 | 0:f3870f76a890 | 302 | DataLines.write(((char*)&Argument)[0]); |
Blaze513 | 0:f3870f76a890 | 303 | //send the argument bytes in order from MSB to LSB (mbed is little endian) |
Blaze513 | 0:f3870f76a890 | 304 | if (CRCMode) |
Blaze513 | 0:f3870f76a890 | 305 | { DataLines.write(CommandCRC(&Index, &Argument)); } |
Blaze513 | 0:f3870f76a890 | 306 | else |
Blaze513 | 0:f3870f76a890 | 307 | { DataLines.write(0x00); } |
Blaze513 | 0:f3870f76a890 | 308 | //send the command CRC |
Blaze513 | 0:f3870f76a890 | 309 | for (unsigned int j = 0; j < 8192; j++) |
Blaze513 | 0:f3870f76a890 | 310 | { |
Blaze513 | 0:f3870f76a890 | 311 | Response[0] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 312 | //clock the card high to let it run operations, the first byte will be |
Blaze513 | 0:f3870f76a890 | 313 | //busy (all high), the response will be sent some time later |
Blaze513 | 0:f3870f76a890 | 314 | if (!(Response[0] & 0x80)) |
Blaze513 | 0:f3870f76a890 | 315 | //check for a response by testing if the first bit is low |
Blaze513 | 0:f3870f76a890 | 316 | { break; } |
Blaze513 | 0:f3870f76a890 | 317 | } |
Blaze513 | 0:f3870f76a890 | 318 | if ((Index == 8) || (Index == 13) || (Index == 58)) |
Blaze513 | 0:f3870f76a890 | 319 | { |
Blaze513 | 0:f3870f76a890 | 320 | for (unsigned char j = 1; j < 5; j++) |
Blaze513 | 0:f3870f76a890 | 321 | { |
Blaze513 | 0:f3870f76a890 | 322 | Response[j] = DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 323 | } |
Blaze513 | 0:f3870f76a890 | 324 | //get the rest of the response |
Blaze513 | 0:f3870f76a890 | 325 | } |
Blaze513 | 0:f3870f76a890 | 326 | ChipSelect.write(1); |
Blaze513 | 0:f3870f76a890 | 327 | //assert chip select high to synchronize command |
Blaze513 | 0:f3870f76a890 | 328 | DataLines.write(0xFF); |
Blaze513 | 0:f3870f76a890 | 329 | //clock the deselected card high to complete processing for some cards |
Blaze513 | 0:f3870f76a890 | 330 | } |
Blaze513 | 0:f3870f76a890 | 331 | |
Blaze513 | 0:f3870f76a890 | 332 | char SDCard::CommandCRC(unsigned char* IndexPtr, unsigned int* ArgumentPtr) |
Blaze513 | 0:f3870f76a890 | 333 | { |
Blaze513 | 0:f3870f76a890 | 334 | return |
Blaze513 | 0:f3870f76a890 | 335 | CommandCRCTable[ |
Blaze513 | 0:f3870f76a890 | 336 | CommandCRCTable[ |
Blaze513 | 0:f3870f76a890 | 337 | CommandCRCTable[ |
Blaze513 | 0:f3870f76a890 | 338 | CommandCRCTable[ |
Blaze513 | 0:f3870f76a890 | 339 | CommandCRCTable[ |
Blaze513 | 0:f3870f76a890 | 340 | *IndexPtr | 0x40 |
Blaze513 | 0:f3870f76a890 | 341 | ] ^ ((char*)ArgumentPtr)[3] |
Blaze513 | 0:f3870f76a890 | 342 | ] ^ ((char*)ArgumentPtr)[2] |
Blaze513 | 0:f3870f76a890 | 343 | ] ^ ((char*)ArgumentPtr)[1] |
Blaze513 | 0:f3870f76a890 | 344 | ] ^ ((char*)ArgumentPtr)[0] |
Blaze513 | 0:f3870f76a890 | 345 | ] | 0x01; |
Blaze513 | 0:f3870f76a890 | 346 | //using a CRC table, the CRC result of a byte is equal to the byte in the table at the |
Blaze513 | 0:f3870f76a890 | 347 | //address equal to the input byte, a message CRC is obtained by successively XORing these |
Blaze513 | 0:f3870f76a890 | 348 | //with the message bytes |
Blaze513 | 0:f3870f76a890 | 349 | } |
Blaze513 | 0:f3870f76a890 | 350 | |
Blaze513 | 0:f3870f76a890 | 351 | void SDCard::DataCRC(unsigned short Length, unsigned char* Data, unsigned char* Result) |
Blaze513 | 0:f3870f76a890 | 352 | { |
Blaze513 | 0:f3870f76a890 | 353 | Result[1] = 0x00; |
Blaze513 | 0:f3870f76a890 | 354 | Result[2] = 0x00; |
Blaze513 | 0:f3870f76a890 | 355 | //initialize result carrier |
Blaze513 | 0:f3870f76a890 | 356 | for (int i = 0; i < Length; i++) |
Blaze513 | 0:f3870f76a890 | 357 | //step through each byte of the data to be checked |
Blaze513 | 0:f3870f76a890 | 358 | { |
Blaze513 | 0:f3870f76a890 | 359 | Result[0] = Result[1]; |
Blaze513 | 0:f3870f76a890 | 360 | //record current crc lookup for both bytes |
Blaze513 | 0:f3870f76a890 | 361 | Result[1] = DataCRCTable[2 * Result[0]] ^ Result[2]; |
Blaze513 | 0:f3870f76a890 | 362 | //new fist byte result is XORed with old second byte result |
Blaze513 | 0:f3870f76a890 | 363 | Result[2] = DataCRCTable[(2 * Result[0]) + 1] ^ Data[i]; |
Blaze513 | 0:f3870f76a890 | 364 | //new second byte result is XORed with new data byte |
Blaze513 | 0:f3870f76a890 | 365 | } |
Blaze513 | 0:f3870f76a890 | 366 | for (int i = 0; i < 2; i++) |
Blaze513 | 0:f3870f76a890 | 367 | //the final result must be XORed with two 0x00 bytes. |
Blaze513 | 0:f3870f76a890 | 368 | { |
Blaze513 | 0:f3870f76a890 | 369 | Result[0] = Result[1]; |
Blaze513 | 0:f3870f76a890 | 370 | Result[1] = DataCRCTable[2 * Result[0]] ^ Result[2]; |
Blaze513 | 0:f3870f76a890 | 371 | Result[2] = DataCRCTable[(2 * Result[0]) + 1]; |
Blaze513 | 0:f3870f76a890 | 372 | } |
Blaze513 | 0:f3870f76a890 | 373 | } |
Blaze513 | 0:f3870f76a890 | 374 | |
Blaze513 | 0:f3870f76a890 | 375 | void SDCard::GenerateCRCTable(unsigned char Size, unsigned long long Generator, unsigned char* Table) |
Blaze513 | 0:f3870f76a890 | 376 | { |
Blaze513 | 0:f3870f76a890 | 377 | unsigned char Index[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0}; |
Blaze513 | 0:f3870f76a890 | 378 | //this will hold information from the generator; the position indicates the |
Blaze513 | 0:f3870f76a890 | 379 | //order of the encountered 1, the value indicates its position in the |
Blaze513 | 0:f3870f76a890 | 380 | //generator, the 9th entry indicates the number of 1's encountered |
Blaze513 | 0:f3870f76a890 | 381 | for (int i = 0; i < 64; i++) |
Blaze513 | 0:f3870f76a890 | 382 | { |
Blaze513 | 0:f3870f76a890 | 383 | if (((char*)&Generator)[7] & 0x80) |
Blaze513 | 0:f3870f76a890 | 384 | { break; } |
Blaze513 | 0:f3870f76a890 | 385 | Generator = Generator << 1; |
Blaze513 | 0:f3870f76a890 | 386 | //shift generator so that the first bit is high |
Blaze513 | 0:f3870f76a890 | 387 | } |
Blaze513 | 0:f3870f76a890 | 388 | for (unsigned char k = 0; k < Size; k++) |
Blaze513 | 0:f3870f76a890 | 389 | { |
Blaze513 | 0:f3870f76a890 | 390 | Table[k] = 0x00; |
Blaze513 | 0:f3870f76a890 | 391 | //initialize the first CRC bytes |
Blaze513 | 0:f3870f76a890 | 392 | } |
Blaze513 | 0:f3870f76a890 | 393 | for (unsigned char i = 0; i < 8; i++) |
Blaze513 | 0:f3870f76a890 | 394 | //increment through each generator bit |
Blaze513 | 0:f3870f76a890 | 395 | { |
Blaze513 | 0:f3870f76a890 | 396 | if ((0x80 >> i) & ((unsigned char*)&Generator)[7]) |
Blaze513 | 0:f3870f76a890 | 397 | //if a 1 is encountered in the generator |
Blaze513 | 0:f3870f76a890 | 398 | { |
Blaze513 | 0:f3870f76a890 | 399 | Index[Index[8]] = i; |
Blaze513 | 0:f3870f76a890 | 400 | Index[8]++; |
Blaze513 | 0:f3870f76a890 | 401 | //record its order and location and increment the counter |
Blaze513 | 0:f3870f76a890 | 402 | } |
Blaze513 | 0:f3870f76a890 | 403 | for (unsigned char j = 0; j < (0x01 << i); j++) |
Blaze513 | 0:f3870f76a890 | 404 | //each bit increases the number of xor operations by a power of 2 |
Blaze513 | 0:f3870f76a890 | 405 | { |
Blaze513 | 0:f3870f76a890 | 406 | for (unsigned char k = 0; k < Size; k++) |
Blaze513 | 0:f3870f76a890 | 407 | //we need to perform operations for each byte in the CRC result |
Blaze513 | 0:f3870f76a890 | 408 | { |
Blaze513 | 0:f3870f76a890 | 409 | Table[(Size * ((0x01 << i) + j)) + k] = Table[(Size * j) + k]; |
Blaze513 | 0:f3870f76a890 | 410 | //each new power is equal to all previous entries with an added xor |
Blaze513 | 0:f3870f76a890 | 411 | //on the leftmost bit and each succeeding 1 on the generator |
Blaze513 | 0:f3870f76a890 | 412 | for (unsigned char l = 0; l < Index[8]; l++) |
Blaze513 | 0:f3870f76a890 | 413 | //increment through the encountered generator 1s |
Blaze513 | 0:f3870f76a890 | 414 | { |
Blaze513 | 0:f3870f76a890 | 415 | Table[(Size * ((0x01 << i) + j)) + k] ^= (((unsigned char*)&Generator)[7-k] << (i + 1 - Index[l])); |
Blaze513 | 0:f3870f76a890 | 416 | Table[(Size * ((0x01 << i) + j)) + k] ^= (((unsigned char*)&Generator)[6-k] >> (7 - i + Index[l])); |
Blaze513 | 0:f3870f76a890 | 417 | //xor the new bit and the new generator 1s |
Blaze513 | 0:f3870f76a890 | 418 | } |
Blaze513 | 0:f3870f76a890 | 419 | } |
Blaze513 | 0:f3870f76a890 | 420 | } |
Blaze513 | 0:f3870f76a890 | 421 | } |
Blaze513 | 0:f3870f76a890 | 422 | } |