USBMSD SD card Hello World for Mbed platforms
Dependencies: mbed USBMSD_SD USBDevice
USBDevice/USBMSD/USB_SDcard.cpp@4:980e6470dcce, 2011-11-12 (annotated)
- Committer:
- samux
- Date:
- Sat Nov 12 17:53:04 2011 +0000
- Revision:
- 4:980e6470dcce
- Child:
- 6:126c4d980196
will try to find a solution to init before connecting devices
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
samux |
4:980e6470dcce | 1 | /* mbed USB_SDcard Library, for accessing SD cards |
samux |
4:980e6470dcce | 2 | * Copyright (c) 2008-2010, sford |
samux |
4:980e6470dcce | 3 | * |
samux |
4:980e6470dcce | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
samux |
4:980e6470dcce | 5 | * of this software and associated documentation files (the "Software"), to deal |
samux |
4:980e6470dcce | 6 | * in the Software without restriction, including without limitation the rights |
samux |
4:980e6470dcce | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
samux |
4:980e6470dcce | 8 | * copies of the Software, and to permit persons to whom the Software is |
samux |
4:980e6470dcce | 9 | * furnished to do so, subject to the following conditions: |
samux |
4:980e6470dcce | 10 | * |
samux |
4:980e6470dcce | 11 | * The above copyright notice and this permission notice shall be included in |
samux |
4:980e6470dcce | 12 | * all copies or substantial portions of the Software. |
samux |
4:980e6470dcce | 13 | * |
samux |
4:980e6470dcce | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
samux |
4:980e6470dcce | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
samux |
4:980e6470dcce | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
samux |
4:980e6470dcce | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
samux |
4:980e6470dcce | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
samux |
4:980e6470dcce | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
samux |
4:980e6470dcce | 20 | * THE SOFTWARE. |
samux |
4:980e6470dcce | 21 | */ |
samux |
4:980e6470dcce | 22 | |
samux |
4:980e6470dcce | 23 | #include "USB_SDcard.h" |
samux |
4:980e6470dcce | 24 | |
samux |
4:980e6470dcce | 25 | #define SD_COMMAND_TIMEOUT 5000 |
samux |
4:980e6470dcce | 26 | |
samux |
4:980e6470dcce | 27 | USB_SDcard::USB_SDcard(PinName mosi, PinName miso, PinName sclk, PinName cs): |
samux |
4:980e6470dcce | 28 | _spi(mosi, miso, sclk), _cs(cs) { |
samux |
4:980e6470dcce | 29 | _cs = 1; |
samux |
4:980e6470dcce | 30 | init(); |
samux |
4:980e6470dcce | 31 | } |
samux |
4:980e6470dcce | 32 | |
samux |
4:980e6470dcce | 33 | #define R1_IDLE_STATE (1 << 0) |
samux |
4:980e6470dcce | 34 | #define R1_ERASE_RESET (1 << 1) |
samux |
4:980e6470dcce | 35 | #define R1_ILLEGAL_COMMAND (1 << 2) |
samux |
4:980e6470dcce | 36 | #define R1_COM_CRC_ERROR (1 << 3) |
samux |
4:980e6470dcce | 37 | #define R1_ERASE_SEQUENCE_ERROR (1 << 4) |
samux |
4:980e6470dcce | 38 | #define R1_ADDRESS_ERROR (1 << 5) |
samux |
4:980e6470dcce | 39 | #define R1_PARAMETER_ERROR (1 << 6) |
samux |
4:980e6470dcce | 40 | |
samux |
4:980e6470dcce | 41 | // Types |
samux |
4:980e6470dcce | 42 | // - v1.x Standard Capacity |
samux |
4:980e6470dcce | 43 | // - v2.x Standard Capacity |
samux |
4:980e6470dcce | 44 | // - v2.x High Capacity |
samux |
4:980e6470dcce | 45 | // - Not recognised as an SD Card |
samux |
4:980e6470dcce | 46 | |
samux |
4:980e6470dcce | 47 | #define SDCARD_FAIL 0 |
samux |
4:980e6470dcce | 48 | #define SDCARD_V1 1 |
samux |
4:980e6470dcce | 49 | #define SDCARD_V2 2 |
samux |
4:980e6470dcce | 50 | #define SDCARD_V2HC 3 |
samux |
4:980e6470dcce | 51 | |
samux |
4:980e6470dcce | 52 | int USB_SDcard::initialise_card() { |
samux |
4:980e6470dcce | 53 | // Set to 100kHz for initialisation, and clock card with cs = 1 |
samux |
4:980e6470dcce | 54 | _spi.frequency(100000); |
samux |
4:980e6470dcce | 55 | _cs = 1; |
samux |
4:980e6470dcce | 56 | for(int i=0; i<16; i++) { |
samux |
4:980e6470dcce | 57 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 58 | } |
samux |
4:980e6470dcce | 59 | |
samux |
4:980e6470dcce | 60 | // send CMD0, should return with all zeros except IDLE STATE set (bit 0) |
samux |
4:980e6470dcce | 61 | if(_cmd(0, 0) != R1_IDLE_STATE) { |
samux |
4:980e6470dcce | 62 | fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n"); |
samux |
4:980e6470dcce | 63 | return SDCARD_FAIL; |
samux |
4:980e6470dcce | 64 | } |
samux |
4:980e6470dcce | 65 | |
samux |
4:980e6470dcce | 66 | // send CMD8 to determine whther it is ver 2.x |
samux |
4:980e6470dcce | 67 | int r = _cmd8(); |
samux |
4:980e6470dcce | 68 | if(r == R1_IDLE_STATE) { |
samux |
4:980e6470dcce | 69 | return initialise_card_v2(); |
samux |
4:980e6470dcce | 70 | } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { |
samux |
4:980e6470dcce | 71 | return initialise_card_v1(); |
samux |
4:980e6470dcce | 72 | } else { |
samux |
4:980e6470dcce | 73 | fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n"); |
samux |
4:980e6470dcce | 74 | return SDCARD_FAIL; |
samux |
4:980e6470dcce | 75 | } |
samux |
4:980e6470dcce | 76 | } |
samux |
4:980e6470dcce | 77 | |
samux |
4:980e6470dcce | 78 | int USB_SDcard::initialise_card_v1() { |
samux |
4:980e6470dcce | 79 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
samux |
4:980e6470dcce | 80 | _cmd(55, 0); |
samux |
4:980e6470dcce | 81 | if(_cmd(41, 0) == 0) { |
samux |
4:980e6470dcce | 82 | return SDCARD_V1; |
samux |
4:980e6470dcce | 83 | } |
samux |
4:980e6470dcce | 84 | } |
samux |
4:980e6470dcce | 85 | |
samux |
4:980e6470dcce | 86 | fprintf(stderr, "Timeout waiting for v1.x card\n"); |
samux |
4:980e6470dcce | 87 | return SDCARD_FAIL; |
samux |
4:980e6470dcce | 88 | } |
samux |
4:980e6470dcce | 89 | |
samux |
4:980e6470dcce | 90 | int USB_SDcard::initialise_card_v2() { |
samux |
4:980e6470dcce | 91 | |
samux |
4:980e6470dcce | 92 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
samux |
4:980e6470dcce | 93 | _cmd(55, 0); |
samux |
4:980e6470dcce | 94 | if(_cmd(41, 0) == 0) { |
samux |
4:980e6470dcce | 95 | _cmd58(); |
samux |
4:980e6470dcce | 96 | return SDCARD_V2; |
samux |
4:980e6470dcce | 97 | } |
samux |
4:980e6470dcce | 98 | } |
samux |
4:980e6470dcce | 99 | |
samux |
4:980e6470dcce | 100 | fprintf(stderr, "Timeout waiting for v2.x card\n"); |
samux |
4:980e6470dcce | 101 | return SDCARD_FAIL; |
samux |
4:980e6470dcce | 102 | } |
samux |
4:980e6470dcce | 103 | |
samux |
4:980e6470dcce | 104 | int USB_SDcard::init() { |
samux |
4:980e6470dcce | 105 | |
samux |
4:980e6470dcce | 106 | int i = initialise_card(); |
samux |
4:980e6470dcce | 107 | // printf("init card = %d\n", i); |
samux |
4:980e6470dcce | 108 | // printf("OK\n"); |
samux |
4:980e6470dcce | 109 | |
samux |
4:980e6470dcce | 110 | _sectors = _sd_sectors(); |
samux |
4:980e6470dcce | 111 | |
samux |
4:980e6470dcce | 112 | // Set block length to 512 (CMD16) |
samux |
4:980e6470dcce | 113 | if(_cmd(16, 512) != 0) { |
samux |
4:980e6470dcce | 114 | fprintf(stderr, "Set 512-byte block timed out\n"); |
samux |
4:980e6470dcce | 115 | return 1; |
samux |
4:980e6470dcce | 116 | } |
samux |
4:980e6470dcce | 117 | |
samux |
4:980e6470dcce | 118 | _spi.frequency(1000000); // Set to 1MHz for data transfer |
samux |
4:980e6470dcce | 119 | return 0; |
samux |
4:980e6470dcce | 120 | } |
samux |
4:980e6470dcce | 121 | |
samux |
4:980e6470dcce | 122 | int USB_SDcard::blockWrite(uint8_t * buffer, uint16_t block_number) { |
samux |
4:980e6470dcce | 123 | // set write address for single block (CMD24) |
samux |
4:980e6470dcce | 124 | if(_cmd(24, block_number * 512) != 0) { |
samux |
4:980e6470dcce | 125 | return 1; |
samux |
4:980e6470dcce | 126 | } |
samux |
4:980e6470dcce | 127 | |
samux |
4:980e6470dcce | 128 | // send the data block |
samux |
4:980e6470dcce | 129 | _write((const char *)buffer, 512); |
samux |
4:980e6470dcce | 130 | return 0; |
samux |
4:980e6470dcce | 131 | } |
samux |
4:980e6470dcce | 132 | |
samux |
4:980e6470dcce | 133 | int USB_SDcard::blockRead(uint8_t * buffer, uint16_t block_number) { |
samux |
4:980e6470dcce | 134 | // set read address for single block (CMD17) |
samux |
4:980e6470dcce | 135 | if(_cmd(17, block_number * 512) != 0) { |
samux |
4:980e6470dcce | 136 | return 1; |
samux |
4:980e6470dcce | 137 | } |
samux |
4:980e6470dcce | 138 | |
samux |
4:980e6470dcce | 139 | // receive the data |
samux |
4:980e6470dcce | 140 | _read((char *)buffer, 512); |
samux |
4:980e6470dcce | 141 | return 0; |
samux |
4:980e6470dcce | 142 | } |
samux |
4:980e6470dcce | 143 | |
samux |
4:980e6470dcce | 144 | int USB_SDcard::disk_status() { return 0; } |
samux |
4:980e6470dcce | 145 | int USB_SDcard::disk_sync() { return 0; } |
samux |
4:980e6470dcce | 146 | int USB_SDcard::disk_sectors() { return _sectors; } |
samux |
4:980e6470dcce | 147 | |
samux |
4:980e6470dcce | 148 | // PRIVATE FUNCTIONS |
samux |
4:980e6470dcce | 149 | |
samux |
4:980e6470dcce | 150 | int USB_SDcard::_cmd(int cmd, int arg) { |
samux |
4:980e6470dcce | 151 | _cs = 0; |
samux |
4:980e6470dcce | 152 | |
samux |
4:980e6470dcce | 153 | // send a command |
samux |
4:980e6470dcce | 154 | _spi.write(0x40 | cmd); |
samux |
4:980e6470dcce | 155 | _spi.write(arg >> 24); |
samux |
4:980e6470dcce | 156 | _spi.write(arg >> 16); |
samux |
4:980e6470dcce | 157 | _spi.write(arg >> 8); |
samux |
4:980e6470dcce | 158 | _spi.write(arg >> 0); |
samux |
4:980e6470dcce | 159 | _spi.write(0x95); |
samux |
4:980e6470dcce | 160 | |
samux |
4:980e6470dcce | 161 | // wait for the repsonse (response[7] == 0) |
samux |
4:980e6470dcce | 162 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
samux |
4:980e6470dcce | 163 | int response = _spi.write(0xFF); |
samux |
4:980e6470dcce | 164 | if(!(response & 0x80)) { |
samux |
4:980e6470dcce | 165 | _cs = 1; |
samux |
4:980e6470dcce | 166 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 167 | return response; |
samux |
4:980e6470dcce | 168 | } |
samux |
4:980e6470dcce | 169 | } |
samux |
4:980e6470dcce | 170 | _cs = 1; |
samux |
4:980e6470dcce | 171 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 172 | return -1; // timeout |
samux |
4:980e6470dcce | 173 | } |
samux |
4:980e6470dcce | 174 | int USB_SDcard::_cmdx(int cmd, int arg) { |
samux |
4:980e6470dcce | 175 | _cs = 0; |
samux |
4:980e6470dcce | 176 | |
samux |
4:980e6470dcce | 177 | // send a command |
samux |
4:980e6470dcce | 178 | _spi.write(0x40 | cmd); |
samux |
4:980e6470dcce | 179 | _spi.write(arg >> 24); |
samux |
4:980e6470dcce | 180 | _spi.write(arg >> 16); |
samux |
4:980e6470dcce | 181 | _spi.write(arg >> 8); |
samux |
4:980e6470dcce | 182 | _spi.write(arg >> 0); |
samux |
4:980e6470dcce | 183 | _spi.write(0x95); |
samux |
4:980e6470dcce | 184 | |
samux |
4:980e6470dcce | 185 | // wait for the repsonse (response[7] == 0) |
samux |
4:980e6470dcce | 186 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
samux |
4:980e6470dcce | 187 | int response = _spi.write(0xFF); |
samux |
4:980e6470dcce | 188 | if(!(response & 0x80)) { |
samux |
4:980e6470dcce | 189 | return response; |
samux |
4:980e6470dcce | 190 | } |
samux |
4:980e6470dcce | 191 | } |
samux |
4:980e6470dcce | 192 | _cs = 1; |
samux |
4:980e6470dcce | 193 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 194 | return -1; // timeout |
samux |
4:980e6470dcce | 195 | } |
samux |
4:980e6470dcce | 196 | |
samux |
4:980e6470dcce | 197 | |
samux |
4:980e6470dcce | 198 | int USB_SDcard::_cmd58() { |
samux |
4:980e6470dcce | 199 | _cs = 0; |
samux |
4:980e6470dcce | 200 | int arg = 0; |
samux |
4:980e6470dcce | 201 | |
samux |
4:980e6470dcce | 202 | // send a command |
samux |
4:980e6470dcce | 203 | _spi.write(0x40 | 58); |
samux |
4:980e6470dcce | 204 | _spi.write(arg >> 24); |
samux |
4:980e6470dcce | 205 | _spi.write(arg >> 16); |
samux |
4:980e6470dcce | 206 | _spi.write(arg >> 8); |
samux |
4:980e6470dcce | 207 | _spi.write(arg >> 0); |
samux |
4:980e6470dcce | 208 | _spi.write(0x95); |
samux |
4:980e6470dcce | 209 | |
samux |
4:980e6470dcce | 210 | // wait for the repsonse (response[7] == 0) |
samux |
4:980e6470dcce | 211 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
samux |
4:980e6470dcce | 212 | int response = _spi.write(0xFF); |
samux |
4:980e6470dcce | 213 | if(!(response & 0x80)) { |
samux |
4:980e6470dcce | 214 | int ocr = _spi.write(0xFF) << 24; |
samux |
4:980e6470dcce | 215 | ocr |= _spi.write(0xFF) << 16; |
samux |
4:980e6470dcce | 216 | ocr |= _spi.write(0xFF) << 8; |
samux |
4:980e6470dcce | 217 | ocr |= _spi.write(0xFF) << 0; |
samux |
4:980e6470dcce | 218 | // printf("OCR = 0x%08X\n", ocr); |
samux |
4:980e6470dcce | 219 | _cs = 1; |
samux |
4:980e6470dcce | 220 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 221 | return response; |
samux |
4:980e6470dcce | 222 | } |
samux |
4:980e6470dcce | 223 | } |
samux |
4:980e6470dcce | 224 | _cs = 1; |
samux |
4:980e6470dcce | 225 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 226 | return -1; // timeout |
samux |
4:980e6470dcce | 227 | } |
samux |
4:980e6470dcce | 228 | |
samux |
4:980e6470dcce | 229 | int USB_SDcard::_cmd8() { |
samux |
4:980e6470dcce | 230 | _cs = 0; |
samux |
4:980e6470dcce | 231 | |
samux |
4:980e6470dcce | 232 | // send a command |
samux |
4:980e6470dcce | 233 | _spi.write(0x40 | 8); // CMD8 |
samux |
4:980e6470dcce | 234 | _spi.write(0x00); // reserved |
samux |
4:980e6470dcce | 235 | _spi.write(0x00); // reserved |
samux |
4:980e6470dcce | 236 | _spi.write(0x01); // 3.3v |
samux |
4:980e6470dcce | 237 | _spi.write(0xAA); // check pattern |
samux |
4:980e6470dcce | 238 | _spi.write(0x87); // crc |
samux |
4:980e6470dcce | 239 | |
samux |
4:980e6470dcce | 240 | // wait for the repsonse (response[7] == 0) |
samux |
4:980e6470dcce | 241 | for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) { |
samux |
4:980e6470dcce | 242 | char response[5]; |
samux |
4:980e6470dcce | 243 | response[0] = _spi.write(0xFF); |
samux |
4:980e6470dcce | 244 | if(!(response[0] & 0x80)) { |
samux |
4:980e6470dcce | 245 | for(int j=1; j<5; j++) { |
samux |
4:980e6470dcce | 246 | response[i] = _spi.write(0xFF); |
samux |
4:980e6470dcce | 247 | } |
samux |
4:980e6470dcce | 248 | _cs = 1; |
samux |
4:980e6470dcce | 249 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 250 | return response[0]; |
samux |
4:980e6470dcce | 251 | } |
samux |
4:980e6470dcce | 252 | } |
samux |
4:980e6470dcce | 253 | _cs = 1; |
samux |
4:980e6470dcce | 254 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 255 | return -1; // timeout |
samux |
4:980e6470dcce | 256 | } |
samux |
4:980e6470dcce | 257 | |
samux |
4:980e6470dcce | 258 | int USB_SDcard::_read(char *buffer, int length) { |
samux |
4:980e6470dcce | 259 | _cs = 0; |
samux |
4:980e6470dcce | 260 | |
samux |
4:980e6470dcce | 261 | // read until start byte (0xFF) |
samux |
4:980e6470dcce | 262 | while(_spi.write(0xFF) != 0xFE); |
samux |
4:980e6470dcce | 263 | |
samux |
4:980e6470dcce | 264 | // read data |
samux |
4:980e6470dcce | 265 | for(int i=0; i<length; i++) { |
samux |
4:980e6470dcce | 266 | buffer[i] = _spi.write(0xFF); |
samux |
4:980e6470dcce | 267 | } |
samux |
4:980e6470dcce | 268 | _spi.write(0xFF); // checksum |
samux |
4:980e6470dcce | 269 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 270 | |
samux |
4:980e6470dcce | 271 | _cs = 1; |
samux |
4:980e6470dcce | 272 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 273 | return 0; |
samux |
4:980e6470dcce | 274 | } |
samux |
4:980e6470dcce | 275 | |
samux |
4:980e6470dcce | 276 | int USB_SDcard::_write(const char *buffer, int length) { |
samux |
4:980e6470dcce | 277 | _cs = 0; |
samux |
4:980e6470dcce | 278 | |
samux |
4:980e6470dcce | 279 | // indicate start of block |
samux |
4:980e6470dcce | 280 | _spi.write(0xFE); |
samux |
4:980e6470dcce | 281 | |
samux |
4:980e6470dcce | 282 | // write the data |
samux |
4:980e6470dcce | 283 | for(int i=0; i<length; i++) { |
samux |
4:980e6470dcce | 284 | _spi.write(buffer[i]); |
samux |
4:980e6470dcce | 285 | } |
samux |
4:980e6470dcce | 286 | |
samux |
4:980e6470dcce | 287 | // write the checksum |
samux |
4:980e6470dcce | 288 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 289 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 290 | |
samux |
4:980e6470dcce | 291 | // check the repsonse token |
samux |
4:980e6470dcce | 292 | if((_spi.write(0xFF) & 0x1F) != 0x05) { |
samux |
4:980e6470dcce | 293 | _cs = 1; |
samux |
4:980e6470dcce | 294 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 295 | return 1; |
samux |
4:980e6470dcce | 296 | } |
samux |
4:980e6470dcce | 297 | |
samux |
4:980e6470dcce | 298 | // wait for write to finish |
samux |
4:980e6470dcce | 299 | while(_spi.write(0xFF) == 0); |
samux |
4:980e6470dcce | 300 | |
samux |
4:980e6470dcce | 301 | _cs = 1; |
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4:980e6470dcce | 302 | _spi.write(0xFF); |
samux |
4:980e6470dcce | 303 | return 0; |
samux |
4:980e6470dcce | 304 | } |
samux |
4:980e6470dcce | 305 | |
samux |
4:980e6470dcce | 306 | static int ext_bits(char *data, int msb, int lsb) { |
samux |
4:980e6470dcce | 307 | int bits = 0; |
samux |
4:980e6470dcce | 308 | int size = 1 + msb - lsb; |
samux |
4:980e6470dcce | 309 | for(int i=0; i<size; i++) { |
samux |
4:980e6470dcce | 310 | int position = lsb + i; |
samux |
4:980e6470dcce | 311 | int byte = 15 - (position >> 3); |
samux |
4:980e6470dcce | 312 | int bit = position & 0x7; |
samux |
4:980e6470dcce | 313 | int value = (data[byte] >> bit) & 1; |
samux |
4:980e6470dcce | 314 | bits |= value << i; |
samux |
4:980e6470dcce | 315 | } |
samux |
4:980e6470dcce | 316 | return bits; |
samux |
4:980e6470dcce | 317 | } |
samux |
4:980e6470dcce | 318 | |
samux |
4:980e6470dcce | 319 | int USB_SDcard::_sd_sectors() { |
samux |
4:980e6470dcce | 320 | |
samux |
4:980e6470dcce | 321 | // CMD9, Response R2 (R1 byte + 16-byte block read) |
samux |
4:980e6470dcce | 322 | if(_cmdx(9, 0) != 0) { |
samux |
4:980e6470dcce | 323 | fprintf(stderr, "Didn't get a response from the disk\n"); |
samux |
4:980e6470dcce | 324 | return 0; |
samux |
4:980e6470dcce | 325 | } |
samux |
4:980e6470dcce | 326 | |
samux |
4:980e6470dcce | 327 | char csd[16]; |
samux |
4:980e6470dcce | 328 | if(_read(csd, 16) != 0) { |
samux |
4:980e6470dcce | 329 | fprintf(stderr, "Couldn't read csd response from disk\n"); |
samux |
4:980e6470dcce | 330 | return 0; |
samux |
4:980e6470dcce | 331 | } |
samux |
4:980e6470dcce | 332 | |
samux |
4:980e6470dcce | 333 | // csd_structure : csd[127:126] |
samux |
4:980e6470dcce | 334 | // c_size : csd[73:62] |
samux |
4:980e6470dcce | 335 | // c_size_mult : csd[49:47] |
samux |
4:980e6470dcce | 336 | // read_bl_len : csd[83:80] - the *maximum* read block length |
samux |
4:980e6470dcce | 337 | |
samux |
4:980e6470dcce | 338 | int csd_structure = ext_bits(csd, 127, 126); |
samux |
4:980e6470dcce | 339 | int c_size = ext_bits(csd, 73, 62); |
samux |
4:980e6470dcce | 340 | int c_size_mult = ext_bits(csd, 49, 47); |
samux |
4:980e6470dcce | 341 | int read_bl_len = ext_bits(csd, 83, 80); |
samux |
4:980e6470dcce | 342 | |
samux |
4:980e6470dcce | 343 | // printf("CSD_STRUCT = %d\n", csd_structure); |
samux |
4:980e6470dcce | 344 | |
samux |
4:980e6470dcce | 345 | if(csd_structure != 0) { |
samux |
4:980e6470dcce | 346 | fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); |
samux |
4:980e6470dcce | 347 | return 0; |
samux |
4:980e6470dcce | 348 | } |
samux |
4:980e6470dcce | 349 | |
samux |
4:980e6470dcce | 350 | // memory capacity = BLOCKNR * BLOCK_LEN |
samux |
4:980e6470dcce | 351 | // where |
samux |
4:980e6470dcce | 352 | // BLOCKNR = (C_SIZE+1) * MULT |
samux |
4:980e6470dcce | 353 | // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8) |
samux |
4:980e6470dcce | 354 | // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12) |
samux |
4:980e6470dcce | 355 | |
samux |
4:980e6470dcce | 356 | int block_len = 1 << read_bl_len; |
samux |
4:980e6470dcce | 357 | int mult = 1 << (c_size_mult + 2); |
samux |
4:980e6470dcce | 358 | int blocknr = (c_size + 1) * mult; |
samux |
4:980e6470dcce | 359 | int capacity = blocknr * block_len; |
samux |
4:980e6470dcce | 360 | |
samux |
4:980e6470dcce | 361 | int blocks = capacity / 512; |
samux |
4:980e6470dcce | 362 | |
samux |
4:980e6470dcce | 363 | return blocks; |
samux |
4:980e6470dcce | 364 | } |