Samuel Mokrani
USBMSD example using an SD card
Dependents: USBMSD_SD_HelloWorld_FRDM-KL25Z USBMSD_SD_HelloWorld_Mbed USBMSD_SD_HelloWorld_FRDM-KL25Z V09_01h ... more
USBMSD_SD.cpp@1:923991b026e7, 2011-12-11 (annotated)
- Committer:
- samux
- Date:
- Sun Dec 11 15:52:35 2011 +0000
- Revision:
- 1:923991b026e7
- Parent:
- 0:de50a209c5a9
- Child:
- 2:055119ccf5a7
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| samux | 0:de50a209c5a9 | 1 | /* mbed USBMSD_SD Library, for providing file access to SD cards |
| samux | 0:de50a209c5a9 | 2 | * Copyright (c) 2008-2010, sford |
| samux | 0:de50a209c5a9 | 3 | * |
| samux | 0:de50a209c5a9 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| samux | 0:de50a209c5a9 | 5 | * of this software and associated documentation files (the "Software"), to deal |
| samux | 0:de50a209c5a9 | 6 | * in the Software without restriction, including without limitation the rights |
| samux | 0:de50a209c5a9 | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| samux | 0:de50a209c5a9 | 8 | * copies of the Software, and to permit persons to whom the Software is |
| samux | 0:de50a209c5a9 | 9 | * furnished to do so, subject to the following conditions: |
| samux | 0:de50a209c5a9 | 10 | * |
| samux | 0:de50a209c5a9 | 11 | * The above copyright notice and this permission notice shall be included in |
| samux | 0:de50a209c5a9 | 12 | * all copies or substantial portions of the Software. |
| samux | 0:de50a209c5a9 | 13 | * |
| samux | 0:de50a209c5a9 | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| samux | 0:de50a209c5a9 | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| samux | 0:de50a209c5a9 | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| samux | 0:de50a209c5a9 | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| samux | 0:de50a209c5a9 | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| samux | 0:de50a209c5a9 | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| samux | 0:de50a209c5a9 | 20 | * THE SOFTWARE. |
| samux | 0:de50a209c5a9 | 21 | */ |
| samux | 0:de50a209c5a9 | 22 | |
| samux | 0:de50a209c5a9 | 23 | /* Introduction |
| samux | 0:de50a209c5a9 | 24 | * ------------ |
| samux | 0:de50a209c5a9 | 25 | * SD and MMC cards support a number of interfaces, but common to them all |
| samux | 0:de50a209c5a9 | 26 | * is one based on SPI. This is the one I'm implmenting because it means |
| samux | 0:de50a209c5a9 | 27 | * it is much more portable even though not so performant, and we already |
| samux | 0:de50a209c5a9 | 28 | * have the mbed SPI Interface! |
| samux | 0:de50a209c5a9 | 29 | * |
| samux | 0:de50a209c5a9 | 30 | * The main reference I'm using is Chapter 7, "SPI Mode" of: |
| samux | 0:de50a209c5a9 | 31 | * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf |
| samux | 0:de50a209c5a9 | 32 | * |
| samux | 0:de50a209c5a9 | 33 | * SPI Startup |
| samux | 0:de50a209c5a9 | 34 | * ----------- |
| samux | 0:de50a209c5a9 | 35 | * The SD card powers up in SD mode. The SPI interface mode is selected by |
| samux | 0:de50a209c5a9 | 36 | * asserting CS low and sending the reset command (CMD0). The card will |
| samux | 0:de50a209c5a9 | 37 | * respond with a (R1) response. |
| samux | 0:de50a209c5a9 | 38 | * |
| samux | 0:de50a209c5a9 | 39 | * CMD8 is optionally sent to determine the voltage range supported, and |
| samux | 0:de50a209c5a9 | 40 | * indirectly determine whether it is a version 1.x SD/non-SD card or |
| samux | 0:de50a209c5a9 | 41 | * version 2.x. I'll just ignore this for now. |
| samux | 0:de50a209c5a9 | 42 | * |
| samux | 0:de50a209c5a9 | 43 | * ACMD41 is repeatedly issued to initialise the card, until "in idle" |
| samux | 0:de50a209c5a9 | 44 | * (bit 0) of the R1 response goes to '0', indicating it is initialised. |
| samux | 0:de50a209c5a9 | 45 | * |
| samux | 0:de50a209c5a9 | 46 | * You should also indicate whether the host supports High Capicity cards, |
| samux | 0:de50a209c5a9 | 47 | * and check whether the card is high capacity - i'll also ignore this |
| samux | 0:de50a209c5a9 | 48 | * |
| samux | 0:de50a209c5a9 | 49 | * SPI Protocol |
| samux | 0:de50a209c5a9 | 50 | * ------------ |
| samux | 0:de50a209c5a9 | 51 | * The SD SPI protocol is based on transactions made up of 8-bit words, with |
| samux | 0:de50a209c5a9 | 52 | * the host starting every bus transaction by asserting the CS signal low. The |
| samux | 0:de50a209c5a9 | 53 | * card always responds to commands, data blocks and errors. |
| samux | 0:de50a209c5a9 | 54 | * |
| samux | 0:de50a209c5a9 | 55 | * The protocol supports a CRC, but by default it is off (except for the |
| samux | 0:de50a209c5a9 | 56 | * first reset CMD0, where the CRC can just be pre-calculated, and CMD8) |
| samux | 0:de50a209c5a9 | 57 | * I'll leave the CRC off I think! |
| samux | 0:de50a209c5a9 | 58 | * |
| samux | 0:de50a209c5a9 | 59 | * Standard capacity cards have variable data block sizes, whereas High |
| samux | 0:de50a209c5a9 | 60 | * Capacity cards fix the size of data block to 512 bytes. I'll therefore |
| samux | 0:de50a209c5a9 | 61 | * just always use the Standard Capacity cards with a block size of 512 bytes. |
| samux | 0:de50a209c5a9 | 62 | * This is set with CMD16. |
| samux | 0:de50a209c5a9 | 63 | * |
| samux | 0:de50a209c5a9 | 64 | * You can read and write single blocks (CMD17, CMD25) or multiple blocks |
| samux | 0:de50a209c5a9 | 65 | * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When |
| samux | 0:de50a209c5a9 | 66 | * the card gets a read command, it responds with a response token, and then |
| samux | 0:de50a209c5a9 | 67 | * a data token or an error. |
| samux | 0:de50a209c5a9 | 68 | * |
| samux | 0:de50a209c5a9 | 69 | * SPI Command Format |
| samux | 0:de50a209c5a9 | 70 | * ------------------ |
| samux | 0:de50a209c5a9 | 71 | * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC. |
| samux | 0:de50a209c5a9 | 72 | * |
| samux | 0:de50a209c5a9 | 73 | * +---------------+------------+------------+-----------+----------+--------------+ |
| samux | 0:de50a209c5a9 | 74 | * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 | |
| samux | 0:de50a209c5a9 | 75 | * +---------------+------------+------------+-----------+----------+--------------+ |
| samux | 0:de50a209c5a9 | 76 | * |
| samux | 0:de50a209c5a9 | 77 | * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95) |
| samux | 0:de50a209c5a9 | 78 | * |
| samux | 0:de50a209c5a9 | 79 | * All Application Specific commands shall be preceded with APP_CMD (CMD55). |
| samux | 0:de50a209c5a9 | 80 | * |
| samux | 0:de50a209c5a9 | 81 | * SPI Response Format |
| samux | 0:de50a209c5a9 | 82 | * ------------------- |
| samux | 0:de50a209c5a9 | 83 | * The main response format (R1) is a status byte (normally zero). Key flags: |
| samux | 0:de50a209c5a9 | 84 | * idle - 1 if the card is in an idle state/initialising |
| samux | 0:de50a209c5a9 | 85 | * cmd - 1 if an illegal command code was detected |
| samux | 0:de50a209c5a9 | 86 | * |
| samux | 0:de50a209c5a9 | 87 | * +-------------------------------------------------+ |
| samux | 0:de50a209c5a9 | 88 | * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle | |
| samux | 0:de50a209c5a9 | 89 | * +-------------------------------------------------+ |
| samux | 0:de50a209c5a9 | 90 | * |
| samux | 0:de50a209c5a9 | 91 | * R1b is the same, except it is followed by a busy signal (zeros) until |
| samux | 0:de50a209c5a9 | 92 | * the first non-zero byte when it is ready again. |
| samux | 0:de50a209c5a9 | 93 | * |
| samux | 0:de50a209c5a9 | 94 | * Data Response Token |
| samux | 0:de50a209c5a9 | 95 | * ------------------- |
| samux | 0:de50a209c5a9 | 96 | * Every data block written to the card is acknowledged by a byte |
| samux | 0:de50a209c5a9 | 97 | * response token |
| samux | 0:de50a209c5a9 | 98 | * |
| samux | 0:de50a209c5a9 | 99 | * +----------------------+ |
| samux | 0:de50a209c5a9 | 100 | * | xxx | 0 | status | 1 | |
| samux | 0:de50a209c5a9 | 101 | * +----------------------+ |
| samux | 0:de50a209c5a9 | 102 | * 010 - OK! |
| samux | 0:de50a209c5a9 | 103 | * 101 - CRC Error |
| samux | 0:de50a209c5a9 | 104 | * 110 - Write Error |
| samux | 0:de50a209c5a9 | 105 | * |
| samux | 0:de50a209c5a9 | 106 | * Single Block Read and Write |
| samux | 0:de50a209c5a9 | 107 | * --------------------------- |
| samux | 0:de50a209c5a9 | 108 | * |
| samux | 0:de50a209c5a9 | 109 | * Block transfers have a byte header, followed by the data, followed |
| samux | 0:de50a209c5a9 | 110 | * by a 16-bit CRC. In our case, the data will always be 512 bytes. |
| samux | 0:de50a209c5a9 | 111 | * |
| samux | 0:de50a209c5a9 | 112 | * +------+---------+---------+- - - -+---------+-----------+----------+ |
| samux | 0:de50a209c5a9 | 113 | * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] | |
| samux | 0:de50a209c5a9 | 114 | * +------+---------+---------+- - - -+---------+-----------+----------+ |
| samux | 0:de50a209c5a9 | 115 | */ |
| samux | 0:de50a209c5a9 | 116 | |
| samux | 0:de50a209c5a9 | 117 | #include "USBMSD_SD.h" |
| samux | 0:de50a209c5a9 | 118 | |
| samux | 0:de50a209c5a9 | 119 | #define SD_COMMAND_TIMEOUT 5000 |
| samux | 0:de50a209c5a9 | 120 | |
| samux | 0:de50a209c5a9 | 121 | USBMSD_SD::USBMSD_SD(PinName mosi, PinName miso, PinName sclk, PinName cs) : |
| samux | 0:de50a209c5a9 | 122 | _spi(mosi, miso, sclk), _cs(cs) { |
| samux | 0:de50a209c5a9 | 123 | _cs = 1; |
| samux | 1:923991b026e7 | 124 | //no init |
| samux | 1:923991b026e7 | 125 | _status = 0x01; |
| samux | 0:de50a209c5a9 | 126 | connect(); |
| samux | 0:de50a209c5a9 | 127 | } |
| samux | 0:de50a209c5a9 | 128 | |
| samux | 0:de50a209c5a9 | 129 | #define R1_IDLE_STATE (1 << 0) |
| samux | 0:de50a209c5a9 | 130 | #define R1_ERASE_RESET (1 << 1) |
| samux | 0:de50a209c5a9 | 131 | #define R1_ILLEGAL_COMMAND (1 << 2) |
| samux | 0:de50a209c5a9 | 132 | #define R1_COM_CRC_ERROR (1 << 3) |
| samux | 0:de50a209c5a9 | 133 | #define R1_ERASE_SEQUENCE_ERROR (1 << 4) |
| samux | 0:de50a209c5a9 | 134 | #define R1_ADDRESS_ERROR (1 << 5) |
| samux | 0:de50a209c5a9 | 135 | #define R1_PARAMETER_ERROR (1 << 6) |
| samux | 0:de50a209c5a9 | 136 | |
| samux | 0:de50a209c5a9 | 137 | // Types |
| samux | 0:de50a209c5a9 | 138 | // - v1.x Standard Capacity |
| samux | 0:de50a209c5a9 | 139 | // - v2.x Standard Capacity |
| samux | 0:de50a209c5a9 | 140 | // - v2.x High Capacity |
| samux | 0:de50a209c5a9 | 141 | // - Not recognised as an SD Card |
| samux | 0:de50a209c5a9 | 142 | |
| samux | 0:de50a209c5a9 | 143 | #define SDCARD_FAIL 0 |
| samux | 0:de50a209c5a9 | 144 | #define SDCARD_V1 1 |
| samux | 0:de50a209c5a9 | 145 | #define SDCARD_V2 2 |
| samux | 0:de50a209c5a9 | 146 | #define SDCARD_V2HC 3 |
| samux | 0:de50a209c5a9 | 147 | |
| samux | 0:de50a209c5a9 | 148 | int USBMSD_SD::initialise_card() { |
| samux | 0:de50a209c5a9 | 149 | // Set to 100kHz for initialisation, and clock card with cs = 1 |
| samux | 0:de50a209c5a9 | 150 | _spi.frequency(100000); |
| samux | 0:de50a209c5a9 | 151 | _cs = 1; |
| samux | 1:923991b026e7 | 152 | for(int i=0; i<16; i++) { |
| samux | 0:de50a209c5a9 | 153 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 154 | } |
| samux | 0:de50a209c5a9 | 155 | |
| samux | 0:de50a209c5a9 | 156 | // send CMD0, should return with all zeros except IDLE STATE set (bit 0) |
| samux | 0:de50a209c5a9 | 157 | if(_cmd(0, 0) != R1_IDLE_STATE) { |
| samux | 0:de50a209c5a9 | 158 | fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n"); |
| samux | 0:de50a209c5a9 | 159 | return SDCARD_FAIL; |
| samux | 0:de50a209c5a9 | 160 | } |
| samux | 0:de50a209c5a9 | 161 | |
| samux | 0:de50a209c5a9 | 162 | // send CMD8 to determine whther it is ver 2.x |
| samux | 0:de50a209c5a9 | 163 | int r = _cmd8(); |
| samux | 0:de50a209c5a9 | 164 | if(r == R1_IDLE_STATE) { |
| samux | 0:de50a209c5a9 | 165 | return initialise_card_v2(); |
| samux | 0:de50a209c5a9 | 166 | } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { |
| samux | 0:de50a209c5a9 | 167 | return initialise_card_v1(); |
| samux | 0:de50a209c5a9 | 168 | } else { |
| samux | 0:de50a209c5a9 | 169 | fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n"); |
| samux | 0:de50a209c5a9 | 170 | return SDCARD_FAIL; |
| samux | 0:de50a209c5a9 | 171 | } |
| samux | 0:de50a209c5a9 | 172 | } |
| samux | 0:de50a209c5a9 | 173 | |
| samux | 0:de50a209c5a9 | 174 | int USBMSD_SD::initialise_card_v1() { |
| samux | 0:de50a209c5a9 | 175 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| samux | 0:de50a209c5a9 | 176 | _cmd(55, 0); |
| samux | 0:de50a209c5a9 | 177 | if(_cmd(41, 0) == 0) { |
| samux | 0:de50a209c5a9 | 178 | return SDCARD_V1; |
| samux | 0:de50a209c5a9 | 179 | } |
| samux | 0:de50a209c5a9 | 180 | } |
| samux | 0:de50a209c5a9 | 181 | |
| samux | 0:de50a209c5a9 | 182 | fprintf(stderr, "Timeout waiting for v1.x card\n"); |
| samux | 0:de50a209c5a9 | 183 | return SDCARD_FAIL; |
| samux | 0:de50a209c5a9 | 184 | } |
| samux | 0:de50a209c5a9 | 185 | |
| samux | 0:de50a209c5a9 | 186 | int USBMSD_SD::initialise_card_v2() { |
| samux | 0:de50a209c5a9 | 187 | |
| samux | 0:de50a209c5a9 | 188 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| samux | 0:de50a209c5a9 | 189 | _cmd(55, 0); |
| samux | 0:de50a209c5a9 | 190 | if(_cmd(41, 0) == 0) { |
| samux | 0:de50a209c5a9 | 191 | _cmd58(); |
| samux | 0:de50a209c5a9 | 192 | return SDCARD_V2; |
| samux | 0:de50a209c5a9 | 193 | } |
| samux | 0:de50a209c5a9 | 194 | } |
| samux | 0:de50a209c5a9 | 195 | |
| samux | 0:de50a209c5a9 | 196 | fprintf(stderr, "Timeout waiting for v2.x card\n"); |
| samux | 0:de50a209c5a9 | 197 | return SDCARD_FAIL; |
| samux | 0:de50a209c5a9 | 198 | } |
| samux | 0:de50a209c5a9 | 199 | |
| samux | 0:de50a209c5a9 | 200 | int USBMSD_SD::disk_initialize() { |
| samux | 0:de50a209c5a9 | 201 | |
| samux | 0:de50a209c5a9 | 202 | int i = initialise_card(); |
| samux | 0:de50a209c5a9 | 203 | // printf("init card = %d\n", i); |
| samux | 0:de50a209c5a9 | 204 | // printf("OK\n"); |
| samux | 0:de50a209c5a9 | 205 | |
| samux | 0:de50a209c5a9 | 206 | _sectors = _sd_sectors(); |
| samux | 0:de50a209c5a9 | 207 | |
| samux | 0:de50a209c5a9 | 208 | // Set block length to 512 (CMD16) |
| samux | 0:de50a209c5a9 | 209 | if(_cmd(16, 512) != 0) { |
| samux | 0:de50a209c5a9 | 210 | fprintf(stderr, "Set 512-byte block timed out\n"); |
| samux | 0:de50a209c5a9 | 211 | return 1; |
| samux | 0:de50a209c5a9 | 212 | } |
| samux | 0:de50a209c5a9 | 213 | |
| samux | 0:de50a209c5a9 | 214 | _spi.frequency(5000000); // Set to 5MHz for data transfer |
| samux | 1:923991b026e7 | 215 | // OK |
| samux | 1:923991b026e7 | 216 | _status = 0x00; |
| samux | 0:de50a209c5a9 | 217 | return 0; |
| samux | 0:de50a209c5a9 | 218 | } |
| samux | 0:de50a209c5a9 | 219 | |
| samux | 0:de50a209c5a9 | 220 | int USBMSD_SD::disk_write(const char *buffer, int block_number) { |
| samux | 0:de50a209c5a9 | 221 | // set write address for single block (CMD24) |
| samux | 0:de50a209c5a9 | 222 | if(_cmd(24, block_number * 512) != 0) { |
| samux | 0:de50a209c5a9 | 223 | return 1; |
| samux | 0:de50a209c5a9 | 224 | } |
| samux | 0:de50a209c5a9 | 225 | |
| samux | 0:de50a209c5a9 | 226 | // send the data block |
| samux | 0:de50a209c5a9 | 227 | _write(buffer, 512); |
| samux | 0:de50a209c5a9 | 228 | return 0; |
| samux | 0:de50a209c5a9 | 229 | } |
| samux | 0:de50a209c5a9 | 230 | |
| samux | 0:de50a209c5a9 | 231 | int USBMSD_SD::disk_read(char *buffer, int block_number) { |
| samux | 0:de50a209c5a9 | 232 | // set read address for single block (CMD17) |
| samux | 0:de50a209c5a9 | 233 | if(_cmd(17, block_number * 512) != 0) { |
| samux | 0:de50a209c5a9 | 234 | return 1; |
| samux | 0:de50a209c5a9 | 235 | } |
| samux | 0:de50a209c5a9 | 236 | |
| samux | 0:de50a209c5a9 | 237 | // receive the data |
| samux | 0:de50a209c5a9 | 238 | _read(buffer, 512); |
| samux | 0:de50a209c5a9 | 239 | return 0; |
| samux | 0:de50a209c5a9 | 240 | } |
| samux | 0:de50a209c5a9 | 241 | |
| samux | 1:923991b026e7 | 242 | int USBMSD_SD::disk_status() { return _status; } |
| samux | 0:de50a209c5a9 | 243 | int USBMSD_SD::disk_sync() { return 0; } |
| samux | 0:de50a209c5a9 | 244 | int USBMSD_SD::disk_sectors() { return _sectors; } |
| samux | 0:de50a209c5a9 | 245 | |
| samux | 0:de50a209c5a9 | 246 | // PRIVATE FUNCTIONS |
| samux | 0:de50a209c5a9 | 247 | |
| samux | 0:de50a209c5a9 | 248 | int USBMSD_SD::_cmd(int cmd, int arg) { |
| samux | 0:de50a209c5a9 | 249 | _cs = 0; |
| samux | 0:de50a209c5a9 | 250 | |
| samux | 0:de50a209c5a9 | 251 | // send a command |
| samux | 0:de50a209c5a9 | 252 | _spi.write(0x40 | cmd); |
| samux | 0:de50a209c5a9 | 253 | _spi.write(arg >> 24); |
| samux | 0:de50a209c5a9 | 254 | _spi.write(arg >> 16); |
| samux | 0:de50a209c5a9 | 255 | _spi.write(arg >> 8); |
| samux | 0:de50a209c5a9 | 256 | _spi.write(arg >> 0); |
| samux | 0:de50a209c5a9 | 257 | _spi.write(0x95); |
| samux | 0:de50a209c5a9 | 258 | |
| samux | 0:de50a209c5a9 | 259 | // wait for the repsonse (response[7] == 0) |
| samux | 0:de50a209c5a9 | 260 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| samux | 0:de50a209c5a9 | 261 | int response = _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 262 | if(!(response & 0x80)) { |
| samux | 0:de50a209c5a9 | 263 | _cs = 1; |
| samux | 0:de50a209c5a9 | 264 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 265 | return response; |
| samux | 0:de50a209c5a9 | 266 | } |
| samux | 0:de50a209c5a9 | 267 | } |
| samux | 0:de50a209c5a9 | 268 | _cs = 1; |
| samux | 0:de50a209c5a9 | 269 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 270 | return -1; // timeout |
| samux | 0:de50a209c5a9 | 271 | } |
| samux | 0:de50a209c5a9 | 272 | int USBMSD_SD::_cmdx(int cmd, int arg) { |
| samux | 0:de50a209c5a9 | 273 | _cs = 0; |
| samux | 0:de50a209c5a9 | 274 | |
| samux | 0:de50a209c5a9 | 275 | // send a command |
| samux | 0:de50a209c5a9 | 276 | _spi.write(0x40 | cmd); |
| samux | 0:de50a209c5a9 | 277 | _spi.write(arg >> 24); |
| samux | 0:de50a209c5a9 | 278 | _spi.write(arg >> 16); |
| samux | 0:de50a209c5a9 | 279 | _spi.write(arg >> 8); |
| samux | 0:de50a209c5a9 | 280 | _spi.write(arg >> 0); |
| samux | 0:de50a209c5a9 | 281 | _spi.write(0x95); |
| samux | 0:de50a209c5a9 | 282 | |
| samux | 0:de50a209c5a9 | 283 | // wait for the repsonse (response[7] == 0) |
| samux | 0:de50a209c5a9 | 284 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| samux | 0:de50a209c5a9 | 285 | int response = _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 286 | if(!(response & 0x80)) { |
| samux | 0:de50a209c5a9 | 287 | return response; |
| samux | 0:de50a209c5a9 | 288 | } |
| samux | 0:de50a209c5a9 | 289 | } |
| samux | 0:de50a209c5a9 | 290 | _cs = 1; |
| samux | 0:de50a209c5a9 | 291 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 292 | return -1; // timeout |
| samux | 0:de50a209c5a9 | 293 | } |
| samux | 0:de50a209c5a9 | 294 | |
| samux | 0:de50a209c5a9 | 295 | |
| samux | 0:de50a209c5a9 | 296 | int USBMSD_SD::_cmd58() { |
| samux | 0:de50a209c5a9 | 297 | _cs = 0; |
| samux | 0:de50a209c5a9 | 298 | int arg = 0; |
| samux | 0:de50a209c5a9 | 299 | |
| samux | 0:de50a209c5a9 | 300 | // send a command |
| samux | 0:de50a209c5a9 | 301 | _spi.write(0x40 | 58); |
| samux | 0:de50a209c5a9 | 302 | _spi.write(arg >> 24); |
| samux | 0:de50a209c5a9 | 303 | _spi.write(arg >> 16); |
| samux | 0:de50a209c5a9 | 304 | _spi.write(arg >> 8); |
| samux | 0:de50a209c5a9 | 305 | _spi.write(arg >> 0); |
| samux | 0:de50a209c5a9 | 306 | _spi.write(0x95); |
| samux | 0:de50a209c5a9 | 307 | |
| samux | 0:de50a209c5a9 | 308 | // wait for the repsonse (response[7] == 0) |
| samux | 0:de50a209c5a9 | 309 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| samux | 0:de50a209c5a9 | 310 | int response = _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 311 | if(!(response & 0x80)) { |
| samux | 0:de50a209c5a9 | 312 | int ocr = _spi.write(0xFF) << 24; |
| samux | 0:de50a209c5a9 | 313 | ocr |= _spi.write(0xFF) << 16; |
| samux | 0:de50a209c5a9 | 314 | ocr |= _spi.write(0xFF) << 8; |
| samux | 0:de50a209c5a9 | 315 | ocr |= _spi.write(0xFF) << 0; |
| samux | 0:de50a209c5a9 | 316 | // printf("OCR = 0x%08X\n", ocr); |
| samux | 0:de50a209c5a9 | 317 | _cs = 1; |
| samux | 0:de50a209c5a9 | 318 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 319 | return response; |
| samux | 0:de50a209c5a9 | 320 | } |
| samux | 0:de50a209c5a9 | 321 | } |
| samux | 0:de50a209c5a9 | 322 | _cs = 1; |
| samux | 0:de50a209c5a9 | 323 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 324 | return -1; // timeout |
| samux | 0:de50a209c5a9 | 325 | } |
| samux | 0:de50a209c5a9 | 326 | |
| samux | 0:de50a209c5a9 | 327 | int USBMSD_SD::_cmd8() { |
| samux | 0:de50a209c5a9 | 328 | _cs = 0; |
| samux | 0:de50a209c5a9 | 329 | |
| samux | 0:de50a209c5a9 | 330 | // send a command |
| samux | 0:de50a209c5a9 | 331 | _spi.write(0x40 | 8); // CMD8 |
| samux | 0:de50a209c5a9 | 332 | _spi.write(0x00); // reserved |
| samux | 0:de50a209c5a9 | 333 | _spi.write(0x00); // reserved |
| samux | 0:de50a209c5a9 | 334 | _spi.write(0x01); // 3.3v |
| samux | 0:de50a209c5a9 | 335 | _spi.write(0xAA); // check pattern |
| samux | 0:de50a209c5a9 | 336 | _spi.write(0x87); // crc |
| samux | 0:de50a209c5a9 | 337 | |
| samux | 0:de50a209c5a9 | 338 | // wait for the repsonse (response[7] == 0) |
| samux | 0:de50a209c5a9 | 339 | for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) { |
| samux | 0:de50a209c5a9 | 340 | char response[5]; |
| samux | 0:de50a209c5a9 | 341 | response[0] = _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 342 | if(!(response[0] & 0x80)) { |
| samux | 0:de50a209c5a9 | 343 | for(int j=1; j<5; j++) { |
| samux | 0:de50a209c5a9 | 344 | response[i] = _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 345 | } |
| samux | 0:de50a209c5a9 | 346 | _cs = 1; |
| samux | 0:de50a209c5a9 | 347 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 348 | return response[0]; |
| samux | 0:de50a209c5a9 | 349 | } |
| samux | 0:de50a209c5a9 | 350 | } |
| samux | 0:de50a209c5a9 | 351 | _cs = 1; |
| samux | 0:de50a209c5a9 | 352 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 353 | return -1; // timeout |
| samux | 0:de50a209c5a9 | 354 | } |
| samux | 0:de50a209c5a9 | 355 | |
| samux | 0:de50a209c5a9 | 356 | int USBMSD_SD::_read(char *buffer, int length) { |
| samux | 0:de50a209c5a9 | 357 | _cs = 0; |
| samux | 0:de50a209c5a9 | 358 | |
| samux | 0:de50a209c5a9 | 359 | // read until start byte (0xFF) |
| samux | 0:de50a209c5a9 | 360 | while(_spi.write(0xFF) != 0xFE); |
| samux | 0:de50a209c5a9 | 361 | |
| samux | 0:de50a209c5a9 | 362 | // read data |
| samux | 0:de50a209c5a9 | 363 | for(int i=0; i<length; i++) { |
| samux | 0:de50a209c5a9 | 364 | buffer[i] = _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 365 | } |
| samux | 0:de50a209c5a9 | 366 | _spi.write(0xFF); // checksum |
| samux | 0:de50a209c5a9 | 367 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 368 | |
| samux | 0:de50a209c5a9 | 369 | _cs = 1; |
| samux | 0:de50a209c5a9 | 370 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 371 | return 0; |
| samux | 0:de50a209c5a9 | 372 | } |
| samux | 0:de50a209c5a9 | 373 | |
| samux | 0:de50a209c5a9 | 374 | int USBMSD_SD::_write(const char *buffer, int length) { |
| samux | 0:de50a209c5a9 | 375 | _cs = 0; |
| samux | 0:de50a209c5a9 | 376 | |
| samux | 0:de50a209c5a9 | 377 | // indicate start of block |
| samux | 0:de50a209c5a9 | 378 | _spi.write(0xFE); |
| samux | 0:de50a209c5a9 | 379 | |
| samux | 0:de50a209c5a9 | 380 | // write the data |
| samux | 0:de50a209c5a9 | 381 | for(int i=0; i<length; i++) { |
| samux | 0:de50a209c5a9 | 382 | _spi.write(buffer[i]); |
| samux | 0:de50a209c5a9 | 383 | } |
| samux | 0:de50a209c5a9 | 384 | |
| samux | 0:de50a209c5a9 | 385 | // write the checksum |
| samux | 0:de50a209c5a9 | 386 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 387 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 388 | |
| samux | 0:de50a209c5a9 | 389 | // check the repsonse token |
| samux | 0:de50a209c5a9 | 390 | if((_spi.write(0xFF) & 0x1F) != 0x05) { |
| samux | 0:de50a209c5a9 | 391 | _cs = 1; |
| samux | 0:de50a209c5a9 | 392 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 393 | return 1; |
| samux | 0:de50a209c5a9 | 394 | } |
| samux | 0:de50a209c5a9 | 395 | |
| samux | 0:de50a209c5a9 | 396 | // wait for write to finish |
| samux | 0:de50a209c5a9 | 397 | while(_spi.write(0xFF) == 0); |
| samux | 0:de50a209c5a9 | 398 | |
| samux | 0:de50a209c5a9 | 399 | _cs = 1; |
| samux | 0:de50a209c5a9 | 400 | _spi.write(0xFF); |
| samux | 0:de50a209c5a9 | 401 | return 0; |
| samux | 0:de50a209c5a9 | 402 | } |
| samux | 0:de50a209c5a9 | 403 | |
| samux | 0:de50a209c5a9 | 404 | static int ext_bits(char *data, int msb, int lsb) { |
| samux | 0:de50a209c5a9 | 405 | int bits = 0; |
| samux | 0:de50a209c5a9 | 406 | int size = 1 + msb - lsb; |
| samux | 0:de50a209c5a9 | 407 | for(int i=0; i<size; i++) { |
| samux | 0:de50a209c5a9 | 408 | int position = lsb + i; |
| samux | 0:de50a209c5a9 | 409 | int byte = 15 - (position >> 3); |
| samux | 0:de50a209c5a9 | 410 | int bit = position & 0x7; |
| samux | 0:de50a209c5a9 | 411 | int value = (data[byte] >> bit) & 1; |
| samux | 0:de50a209c5a9 | 412 | bits |= value << i; |
| samux | 0:de50a209c5a9 | 413 | } |
| samux | 0:de50a209c5a9 | 414 | return bits; |
| samux | 0:de50a209c5a9 | 415 | } |
| samux | 0:de50a209c5a9 | 416 | |
| samux | 0:de50a209c5a9 | 417 | int USBMSD_SD::_sd_sectors() { |
| samux | 0:de50a209c5a9 | 418 | |
| samux | 0:de50a209c5a9 | 419 | // CMD9, Response R2 (R1 byte + 16-byte block read) |
| samux | 0:de50a209c5a9 | 420 | if(_cmdx(9, 0) != 0) { |
| samux | 0:de50a209c5a9 | 421 | fprintf(stderr, "Didn't get a response from the disk\n"); |
| samux | 0:de50a209c5a9 | 422 | return 0; |
| samux | 0:de50a209c5a9 | 423 | } |
| samux | 0:de50a209c5a9 | 424 | |
| samux | 0:de50a209c5a9 | 425 | char csd[16]; |
| samux | 0:de50a209c5a9 | 426 | if(_read(csd, 16) != 0) { |
| samux | 0:de50a209c5a9 | 427 | fprintf(stderr, "Couldn't read csd response from disk\n"); |
| samux | 0:de50a209c5a9 | 428 | return 0; |
| samux | 0:de50a209c5a9 | 429 | } |
| samux | 0:de50a209c5a9 | 430 | |
| samux | 0:de50a209c5a9 | 431 | // csd_structure : csd[127:126] |
| samux | 0:de50a209c5a9 | 432 | // c_size : csd[73:62] |
| samux | 0:de50a209c5a9 | 433 | // c_size_mult : csd[49:47] |
| samux | 0:de50a209c5a9 | 434 | // read_bl_len : csd[83:80] - the *maximum* read block length |
| samux | 0:de50a209c5a9 | 435 | |
| samux | 0:de50a209c5a9 | 436 | int csd_structure = ext_bits(csd, 127, 126); |
| samux | 0:de50a209c5a9 | 437 | int c_size = ext_bits(csd, 73, 62); |
| samux | 0:de50a209c5a9 | 438 | int c_size_mult = ext_bits(csd, 49, 47); |
| samux | 0:de50a209c5a9 | 439 | int read_bl_len = ext_bits(csd, 83, 80); |
| samux | 0:de50a209c5a9 | 440 | |
| samux | 0:de50a209c5a9 | 441 | // printf("CSD_STRUCT = %d\n", csd_structure); |
| samux | 0:de50a209c5a9 | 442 | |
| samux | 0:de50a209c5a9 | 443 | if(csd_structure != 0) { |
| samux | 0:de50a209c5a9 | 444 | fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); |
| samux | 0:de50a209c5a9 | 445 | return 0; |
| samux | 0:de50a209c5a9 | 446 | } |
| samux | 0:de50a209c5a9 | 447 | |
| samux | 0:de50a209c5a9 | 448 | // memory capacity = BLOCKNR * BLOCK_LEN |
| samux | 0:de50a209c5a9 | 449 | // where |
| samux | 0:de50a209c5a9 | 450 | // BLOCKNR = (C_SIZE+1) * MULT |
| samux | 0:de50a209c5a9 | 451 | // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8) |
| samux | 0:de50a209c5a9 | 452 | // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12) |
| samux | 0:de50a209c5a9 | 453 | |
| samux | 0:de50a209c5a9 | 454 | int block_len = 1 << read_bl_len; |
| samux | 0:de50a209c5a9 | 455 | int mult = 1 << (c_size_mult + 2); |
| samux | 0:de50a209c5a9 | 456 | int blocknr = (c_size + 1) * mult; |
| samux | 0:de50a209c5a9 | 457 | capacity = blocknr * block_len; |
| samux | 0:de50a209c5a9 | 458 | |
| samux | 0:de50a209c5a9 | 459 | int blocks = capacity / 512; |
| samux | 0:de50a209c5a9 | 460 | |
| samux | 0:de50a209c5a9 | 461 | return blocks; |
| samux | 0:de50a209c5a9 | 462 | } |
| samux | 0:de50a209c5a9 | 463 | |
| samux | 0:de50a209c5a9 | 464 | |
| samux | 0:de50a209c5a9 | 465 | int USBMSD_SD::disk_size() { |
| samux | 0:de50a209c5a9 | 466 | return capacity; |
| samux | 0:de50a209c5a9 | 467 | } |