saikiran cholleti / Mbed 2 deprecated CDMS_COM_INT

vr1.1

Dependencies:   FreescaleIAP mbed-rtos mbed

Fork of CDMS_RTOS_v1_1 by Team Fox

SDCard.cpp@11:d6dc9074075b, 2015-07-06 (annotated)

Committer:
cholletisaik777
Date:
Mon Jul 06 06:25:14 2015 +0000
Revision:
11:d6dc9074075b
Parent:
8:607ae92fa6af
Child:
12:cb3ee1ac3638
changes made

Who changed what in which revision?

UserRevisionLine numberNew contents of line
cholletisaik777 8:607ae92fa6af 1 #include "mbed.h"
cholletisaik777 8:607ae92fa6af 2 #include "mbed_debug.h"
cholletisaik777 0:d6e3d1e21484 3 #include "SDCard.h"
cholletisaik777 8:607ae92fa6af 4 #include "all_funcs.h"
cholletisaik777 0:d6e3d1e21484 5
cholletisaik777 0:d6e3d1e21484 6 SPI spi_SD(PTD6, PTD7, PTD5); // mosi, miso, sclk
pradeepvk2208 2:4c79b3dfef31 7 DigitalOut cs_SD(D2);
cholletisaik777 0:d6e3d1e21484 8
cholletisaik777 7:c270a9e37290 9 int *FCTN_INIT_SD()
cholletisaik777 4:cc85cfaa2086 10 {
cholletisaik777 11:d6dc9074075b 11 all_flags = all_flags|SDCARD_INIT_STATUS;
cholletisaik777 4:cc85cfaa2086 12 int sd_response[2] = {initialise_card(),disk_initialize()};
cholletisaik777 4:cc85cfaa2086 13 return sd_response;
cholletisaik777 4:cc85cfaa2086 14 }
cholletisaik777 4:cc85cfaa2086 15
cholletisaik777 11:d6dc9074075b 16 int FCTN_RD_SD(uint8_t *buffer, uint64_t block_number) {
cholletisaik777 11:d6dc9074075b 17 // set read address for single block (CMD17)
cholletisaik777 11:d6dc9074075b 18 if (cmd(17, block_number * cdv) != 0) {
cholletisaik777 11:d6dc9074075b 19 return 1;
cholletisaik777 11:d6dc9074075b 20 }
cholletisaik777 11:d6dc9074075b 21
cholletisaik777 11:d6dc9074075b 22 // receive the data
cholletisaik777 11:d6dc9074075b 23 read(buffer, 512);
cholletisaik777 11:d6dc9074075b 24 printf("Written Successfully to SDCard\r\n");
cholletisaik777 11:d6dc9074075b 25 return 0;
cholletisaik777 11:d6dc9074075b 26 }
cholletisaik777 11:d6dc9074075b 27
cholletisaik777 11:d6dc9074075b 28 int FCTN_WR_SD(const uint8_t *buffer, uint64_t block_number)
cholletisaik777 11:d6dc9074075b 29 {
cholletisaik777 11:d6dc9074075b 30 // set write address for single block (CMD24)
cholletisaik777 11:d6dc9074075b 31 if (cmd(24, block_number * cdv) != 0) {
cholletisaik777 11:d6dc9074075b 32 return 1;
cholletisaik777 11:d6dc9074075b 33 }
cholletisaik777 11:d6dc9074075b 34
cholletisaik777 11:d6dc9074075b 35 // send the data block
cholletisaik777 11:d6dc9074075b 36 write(buffer, 512);
cholletisaik777 11:d6dc9074075b 37 printf("Written Successfully to SDCard\r\n");
cholletisaik777 11:d6dc9074075b 38 return 0;
cholletisaik777 11:d6dc9074075b 39 }
cholletisaik777 11:d6dc9074075b 40
cholletisaik777 4:cc85cfaa2086 41
cholletisaik777 0:d6e3d1e21484 42 int initialise_card() {
cholletisaik777 0:d6e3d1e21484 43 // Set to 100kHz for initialisation, and clock card with cs_SD = 1
cholletisaik777 0:d6e3d1e21484 44 spi_SD.frequency(100000);
cholletisaik777 0:d6e3d1e21484 45 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 46 for (int i = 0; i < 16; i++) {
cholletisaik777 0:d6e3d1e21484 47 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 48 }
cholletisaik777 0:d6e3d1e21484 49
cholletisaik777 0:d6e3d1e21484 50 // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
cholletisaik777 0:d6e3d1e21484 51 if (cmd(0, 0) != R1_IDLE_STATE) {
cholletisaik777 0:d6e3d1e21484 52 debug("No disk, or could not put SD card in to SPI idle state\r\n");
cholletisaik777 0:d6e3d1e21484 53 return SDCARD_FAIL;
cholletisaik777 0:d6e3d1e21484 54 }
cholletisaik777 0:d6e3d1e21484 55
cholletisaik777 0:d6e3d1e21484 56 // send CMD8 to determine whther it is ver 2.x
cholletisaik777 0:d6e3d1e21484 57 int r = cmd8();
cholletisaik777 8:607ae92fa6af 58 if (r == R1_IDLE_STATE)
cholletisaik777 8:607ae92fa6af 59 {
cholletisaik777 0:d6e3d1e21484 60 printf("Entering v2 bro\r\n");
cholletisaik777 11:d6dc9074075b 61 return initialise_card_v2();
cholletisaik777 8:607ae92fa6af 62 }
cholletisaik777 8:607ae92fa6af 63 else
cholletisaik777 8:607ae92fa6af 64 {
cholletisaik777 0:d6e3d1e21484 65 debug("Not in idle state after sending CMD8 (not an SD card?)\r\n");
cholletisaik777 0:d6e3d1e21484 66 return SDCARD_FAIL;
cholletisaik777 0:d6e3d1e21484 67 }
cholletisaik777 0:d6e3d1e21484 68 }
cholletisaik777 0:d6e3d1e21484 69
cholletisaik777 0:d6e3d1e21484 70 int initialise_card_v2() {
cholletisaik777 0:d6e3d1e21484 71 for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
cholletisaik777 0:d6e3d1e21484 72 wait_ms(50);
cholletisaik777 0:d6e3d1e21484 73 cmd58();
cholletisaik777 0:d6e3d1e21484 74 cmd(55, 0);
cholletisaik777 0:d6e3d1e21484 75 if (cmd(41, 0x40000000) == 0) {
cholletisaik777 0:d6e3d1e21484 76 printf("Yuppie,v2 successful\r\n");
cholletisaik777 0:d6e3d1e21484 77 cmd58();
cholletisaik777 0:d6e3d1e21484 78 debug_if(SD_DBG, "\r\n\rInit: SDCARD_V2\r\n\r");
cholletisaik777 0:d6e3d1e21484 79 cdv = 1;
cholletisaik777 0:d6e3d1e21484 80
cholletisaik777 0:d6e3d1e21484 81 return SDCARD_V2;
cholletisaik777 0:d6e3d1e21484 82 }
cholletisaik777 0:d6e3d1e21484 83 }
cholletisaik777 0:d6e3d1e21484 84
cholletisaik777 0:d6e3d1e21484 85 debug("Timeout waiting for v2.x card\r\n");
cholletisaik777 0:d6e3d1e21484 86 return SDCARD_FAIL;
cholletisaik777 0:d6e3d1e21484 87 }
cholletisaik777 11:d6dc9074075b 88
cholletisaik777 11:d6dc9074075b 89 int disk_initialize() {
cholletisaik777 11:d6dc9074075b 90 int i = initialise_card();
cholletisaik777 11:d6dc9074075b 91 debug_if(SD_DBG, "init card = %d\r\n", i);
cholletisaik777 11:d6dc9074075b 92 sectors = sd_sectors();
cholletisaik777 11:d6dc9074075b 93
cholletisaik777 11:d6dc9074075b 94 // Set block length to 512 (CMD16)
cholletisaik777 11:d6dc9074075b 95 if (cmd(16, 512) != 0) {
cholletisaik777 11:d6dc9074075b 96 debug("Set 512-byte block timed out\r\n");
cholletisaik777 11:d6dc9074075b 97 return 1;
cholletisaik777 11:d6dc9074075b 98 }
cholletisaik777 11:d6dc9074075b 99 else
cholletisaik777 11:d6dc9074075b 100 {
cholletisaik777 11:d6dc9074075b 101 printf("Hey,block init succesful\r\n");
cholletisaik777 11:d6dc9074075b 102 }
cholletisaik777 11:d6dc9074075b 103
cholletisaik777 11:d6dc9074075b 104 spi_SD.frequency(1000000); // Set to 1MHz for data transfer
cholletisaik777 11:d6dc9074075b 105 return 0;
cholletisaik777 11:d6dc9074075b 106 }
cholletisaik777 0:d6e3d1e21484 107
cholletisaik777 0:d6e3d1e21484 108 int cmd(int cmd, int arg) {
cholletisaik777 0:d6e3d1e21484 109 cs_SD = 0;
cholletisaik777 0:d6e3d1e21484 110
cholletisaik777 0:d6e3d1e21484 111 // send a command
cholletisaik777 0:d6e3d1e21484 112 spi_SD.write(0x40 | cmd);
cholletisaik777 0:d6e3d1e21484 113 spi_SD.write(arg >> 24);
cholletisaik777 0:d6e3d1e21484 114 spi_SD.write(arg >> 16);
cholletisaik777 0:d6e3d1e21484 115 spi_SD.write(arg >> 8);
cholletisaik777 0:d6e3d1e21484 116 spi_SD.write(arg >> 0);
cholletisaik777 0:d6e3d1e21484 117 spi_SD.write(0x95);
cholletisaik777 0:d6e3d1e21484 118
cholletisaik777 0:d6e3d1e21484 119 // wait for the repsonse (response[7] == 0)
cholletisaik777 0:d6e3d1e21484 120 for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
cholletisaik777 0:d6e3d1e21484 121 int response = spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 122 if (!(response & 0x80)) {
cholletisaik777 0:d6e3d1e21484 123 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 124 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 125 return response;
cholletisaik777 0:d6e3d1e21484 126 }
cholletisaik777 0:d6e3d1e21484 127 }
cholletisaik777 0:d6e3d1e21484 128 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 129 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 130 return -1; // timeout
cholletisaik777 0:d6e3d1e21484 131 }
cholletisaik777 0:d6e3d1e21484 132
cholletisaik777 0:d6e3d1e21484 133
cholletisaik777 0:d6e3d1e21484 134 int cmd58() {
cholletisaik777 0:d6e3d1e21484 135 cs_SD = 0;
cholletisaik777 0:d6e3d1e21484 136 int arg = 0;
cholletisaik777 0:d6e3d1e21484 137
cholletisaik777 0:d6e3d1e21484 138 // send a command
cholletisaik777 0:d6e3d1e21484 139 spi_SD.write(0x40 | 58);
cholletisaik777 0:d6e3d1e21484 140 spi_SD.write(arg >> 24);
cholletisaik777 0:d6e3d1e21484 141 spi_SD.write(arg >> 16);
cholletisaik777 0:d6e3d1e21484 142 spi_SD.write(arg >> 8);
cholletisaik777 0:d6e3d1e21484 143 spi_SD.write(arg >> 0);
cholletisaik777 0:d6e3d1e21484 144 spi_SD.write(0x95);
cholletisaik777 0:d6e3d1e21484 145
cholletisaik777 0:d6e3d1e21484 146 // wait for the repsonse (response[7] == 0)
cholletisaik777 0:d6e3d1e21484 147 for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
cholletisaik777 0:d6e3d1e21484 148 int response = spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 149 if (!(response & 0x80)) {
cholletisaik777 0:d6e3d1e21484 150 int ocr = spi_SD.write(0xFF) << 24;
cholletisaik777 0:d6e3d1e21484 151 ocr |= spi_SD.write(0xFF) << 16;
cholletisaik777 0:d6e3d1e21484 152 ocr |= spi_SD.write(0xFF) << 8;
cholletisaik777 0:d6e3d1e21484 153 ocr |= spi_SD.write(0xFF) << 0;
cholletisaik777 0:d6e3d1e21484 154 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 155 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 156 return response;
cholletisaik777 0:d6e3d1e21484 157 }
cholletisaik777 0:d6e3d1e21484 158 }
cholletisaik777 0:d6e3d1e21484 159 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 160 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 161 return -1; // timeout
cholletisaik777 0:d6e3d1e21484 162 }
cholletisaik777 0:d6e3d1e21484 163
cholletisaik777 0:d6e3d1e21484 164
cholletisaik777 0:d6e3d1e21484 165 int cmd8() {
cholletisaik777 0:d6e3d1e21484 166 cs_SD = 0;
cholletisaik777 0:d6e3d1e21484 167
cholletisaik777 0:d6e3d1e21484 168 // send a command
cholletisaik777 0:d6e3d1e21484 169 spi_SD.write(0x40 | 8); // CMD8
cholletisaik777 0:d6e3d1e21484 170 spi_SD.write(0x00); // reserved
cholletisaik777 0:d6e3d1e21484 171 spi_SD.write(0x00); // reserved
cholletisaik777 0:d6e3d1e21484 172 spi_SD.write(0x01); // 3.3v
cholletisaik777 0:d6e3d1e21484 173 spi_SD.write(0xAA); // check pattern
cholletisaik777 0:d6e3d1e21484 174 spi_SD.write(0x87); // crc
cholletisaik777 0:d6e3d1e21484 175
cholletisaik777 0:d6e3d1e21484 176 // wait for the repsonse (response[7] == 0)
cholletisaik777 0:d6e3d1e21484 177 for (int i = 0; i < SD_COMMAND_TIMEOUT * 1000; i++) {
cholletisaik777 0:d6e3d1e21484 178 char response[5];
cholletisaik777 0:d6e3d1e21484 179 response[0] = spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 180 if (!(response[0] & 0x80)) {
cholletisaik777 0:d6e3d1e21484 181 for (int j = 1; j < 5; j++) {
cholletisaik777 0:d6e3d1e21484 182 response[i] = spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 183 }
cholletisaik777 0:d6e3d1e21484 184 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 185 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 186 return response[0];
cholletisaik777 0:d6e3d1e21484 187 }
cholletisaik777 0:d6e3d1e21484 188 }
cholletisaik777 0:d6e3d1e21484 189 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 190 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 191 return -1; // timeout
cholletisaik777 0:d6e3d1e21484 192 }
cholletisaik777 0:d6e3d1e21484 193
cholletisaik777 0:d6e3d1e21484 194 uint64_t sd_sectors() {
cholletisaik777 0:d6e3d1e21484 195 uint32_t c_size, c_size_mult, read_bl_len;
cholletisaik777 0:d6e3d1e21484 196 uint32_t block_len, mult, blocknr, capacity;
cholletisaik777 0:d6e3d1e21484 197 uint32_t hc_c_size;
cholletisaik777 0:d6e3d1e21484 198 uint64_t blocks;
cholletisaik777 0:d6e3d1e21484 199
cholletisaik777 0:d6e3d1e21484 200 // CMD9, Response R2 (R1 byte + 16-byte block read)
cholletisaik777 0:d6e3d1e21484 201 if (cmdx(9, 0) != 0) {
cholletisaik777 0:d6e3d1e21484 202 debug("Didn't get a response from the disk\r\n");
cholletisaik777 0:d6e3d1e21484 203 return 0;
cholletisaik777 0:d6e3d1e21484 204 }
cholletisaik777 0:d6e3d1e21484 205
cholletisaik777 0:d6e3d1e21484 206 uint8_t csd[16];
cholletisaik777 0:d6e3d1e21484 207 if (read(csd, 16) != 0) {
cholletisaik777 0:d6e3d1e21484 208 debug("Couldn't read csd response from disk\r\n");
cholletisaik777 0:d6e3d1e21484 209 return 0;
cholletisaik777 0:d6e3d1e21484 210 }
cholletisaik777 0:d6e3d1e21484 211
cholletisaik777 0:d6e3d1e21484 212 // csd_structure : csd[127:126]
cholletisaik777 0:d6e3d1e21484 213 // c_size : csd[73:62]
cholletisaik777 0:d6e3d1e21484 214 // c_size_mult : csd[49:47]
cholletisaik777 0:d6e3d1e21484 215 // read_bl_len : csd[83:80] - the *maximum* read block length
cholletisaik777 0:d6e3d1e21484 216
cholletisaik777 0:d6e3d1e21484 217 int csd_structure = ext_bits(csd, 127, 126);
cholletisaik777 0:d6e3d1e21484 218
cholletisaik777 0:d6e3d1e21484 219 switch (csd_structure) {
cholletisaik777 0:d6e3d1e21484 220 case 0:
cholletisaik777 0:d6e3d1e21484 221 cdv = 512;
cholletisaik777 0:d6e3d1e21484 222 c_size = ext_bits(csd, 73, 62);
cholletisaik777 0:d6e3d1e21484 223 c_size_mult = ext_bits(csd, 49, 47);
cholletisaik777 0:d6e3d1e21484 224 read_bl_len = ext_bits(csd, 83, 80);
cholletisaik777 0:d6e3d1e21484 225
cholletisaik777 0:d6e3d1e21484 226 block_len = 1 << read_bl_len;
cholletisaik777 0:d6e3d1e21484 227 mult = 1 << (c_size_mult + 2);
cholletisaik777 0:d6e3d1e21484 228 blocknr = (c_size + 1) * mult;
cholletisaik777 0:d6e3d1e21484 229 capacity = blocknr * block_len;
cholletisaik777 0:d6e3d1e21484 230 blocks = capacity / 512;
cholletisaik777 0:d6e3d1e21484 231 debug_if(SD_DBG, "\r\n\rSDCard\r\n\rc_size: %d \r\n\rcapacity: %ld \r\n\rsectors: %lld\r\n\r", c_size, capacity, blocks);
cholletisaik777 0:d6e3d1e21484 232 break;
cholletisaik777 0:d6e3d1e21484 233
cholletisaik777 0:d6e3d1e21484 234 case 1:
cholletisaik777 0:d6e3d1e21484 235 cdv = 1;
cholletisaik777 0:d6e3d1e21484 236 hc_c_size = ext_bits(csd, 63, 48);
cholletisaik777 0:d6e3d1e21484 237 blocks = (hc_c_size+1)*1024;
cholletisaik777 0:d6e3d1e21484 238 debug_if(SD_DBG, "\r\n\rSDHC Card \r\n\rhc_c_size: %d\r\n\rcapacity: %lld \r\n\rsectors: %lld\r\n\r", hc_c_size, blocks*512, blocks);
cholletisaik777 0:d6e3d1e21484 239 break;
cholletisaik777 0:d6e3d1e21484 240
cholletisaik777 0:d6e3d1e21484 241 default:
cholletisaik777 0:d6e3d1e21484 242 debug("CSD struct unsupported\r\r\n");
cholletisaik777 0:d6e3d1e21484 243 return 0;
cholletisaik777 0:d6e3d1e21484 244 };
cholletisaik777 0:d6e3d1e21484 245 return blocks;
cholletisaik777 0:d6e3d1e21484 246 }
cholletisaik777 0:d6e3d1e21484 247
cholletisaik777 0:d6e3d1e21484 248 int cmdx(int cmd, int arg) {
cholletisaik777 0:d6e3d1e21484 249 cs_SD = 0;
cholletisaik777 0:d6e3d1e21484 250
cholletisaik777 0:d6e3d1e21484 251 // send a command
cholletisaik777 0:d6e3d1e21484 252 spi_SD.write(0x40 | cmd);
cholletisaik777 0:d6e3d1e21484 253 spi_SD.write(arg >> 24);
cholletisaik777 0:d6e3d1e21484 254 spi_SD.write(arg >> 16);
cholletisaik777 0:d6e3d1e21484 255 spi_SD.write(arg >> 8);
cholletisaik777 0:d6e3d1e21484 256 spi_SD.write(arg >> 0);
cholletisaik777 0:d6e3d1e21484 257 spi_SD.write(0x95);
cholletisaik777 0:d6e3d1e21484 258
cholletisaik777 0:d6e3d1e21484 259 // wait for the repsonse (response[7] == 0)
cholletisaik777 0:d6e3d1e21484 260 for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
cholletisaik777 0:d6e3d1e21484 261 int response = spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 262 if (!(response & 0x80)) {
cholletisaik777 0:d6e3d1e21484 263 return response;
cholletisaik777 0:d6e3d1e21484 264 }
cholletisaik777 0:d6e3d1e21484 265 }
cholletisaik777 0:d6e3d1e21484 266 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 267 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 268 return -1; // timeout
cholletisaik777 0:d6e3d1e21484 269 }
cholletisaik777 0:d6e3d1e21484 270
cholletisaik777 0:d6e3d1e21484 271
cholletisaik777 0:d6e3d1e21484 272 int read(uint8_t *buffer, uint32_t length) {
cholletisaik777 0:d6e3d1e21484 273 cs_SD = 0;
cholletisaik777 0:d6e3d1e21484 274
cholletisaik777 0:d6e3d1e21484 275 // read until start byte (0xFF)
cholletisaik777 0:d6e3d1e21484 276 while (spi_SD.write(0xFF) != 0xFE);
cholletisaik777 0:d6e3d1e21484 277
cholletisaik777 0:d6e3d1e21484 278 // read data
cholletisaik777 0:d6e3d1e21484 279 for (int i = 0; i < length; i++) {
cholletisaik777 0:d6e3d1e21484 280 buffer[i] = spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 281 }
cholletisaik777 0:d6e3d1e21484 282 spi_SD.write(0xFF); // checksum
cholletisaik777 0:d6e3d1e21484 283 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 284
cholletisaik777 0:d6e3d1e21484 285 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 286 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 287 return 0;
cholletisaik777 0:d6e3d1e21484 288 }
cholletisaik777 0:d6e3d1e21484 289
cholletisaik777 0:d6e3d1e21484 290 static uint32_t ext_bits(unsigned char *data, int msb, int lsb) {
cholletisaik777 0:d6e3d1e21484 291 uint32_t bits = 0;
cholletisaik777 0:d6e3d1e21484 292 uint32_t size = 1 + msb - lsb;
cholletisaik777 0:d6e3d1e21484 293 for (int i = 0; i < size; i++) {
cholletisaik777 0:d6e3d1e21484 294 uint32_t position = lsb + i;
cholletisaik777 0:d6e3d1e21484 295 uint32_t byte = 15 - (position >> 3);
cholletisaik777 0:d6e3d1e21484 296 uint32_t bit = position & 0x7;
cholletisaik777 0:d6e3d1e21484 297 uint32_t value = (data[byte] >> bit) & 1;
cholletisaik777 0:d6e3d1e21484 298 bits |= value << i;
cholletisaik777 0:d6e3d1e21484 299 }
cholletisaik777 0:d6e3d1e21484 300 return bits;
cholletisaik777 0:d6e3d1e21484 301 }
cholletisaik777 0:d6e3d1e21484 302
cholletisaik777 0:d6e3d1e21484 303 int write(const uint8_t*buffer, uint32_t length) {
cholletisaik777 0:d6e3d1e21484 304 cs_SD = 0;
cholletisaik777 0:d6e3d1e21484 305
cholletisaik777 0:d6e3d1e21484 306 // indicate start of block
cholletisaik777 0:d6e3d1e21484 307 spi_SD.write(0xFE);
cholletisaik777 0:d6e3d1e21484 308
cholletisaik777 0:d6e3d1e21484 309 // write the data
cholletisaik777 0:d6e3d1e21484 310 for (int i = 0; i < length; i++) {
cholletisaik777 0:d6e3d1e21484 311 spi_SD.write(buffer[i]);
cholletisaik777 0:d6e3d1e21484 312 }
cholletisaik777 0:d6e3d1e21484 313
cholletisaik777 0:d6e3d1e21484 314 // write the checksum
cholletisaik777 0:d6e3d1e21484 315 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 316 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 317
cholletisaik777 0:d6e3d1e21484 318 // check the response token
cholletisaik777 0:d6e3d1e21484 319 if ((spi_SD.write(0xFF) & 0x1F) != 0x05) {
cholletisaik777 0:d6e3d1e21484 320 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 321 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 322 return 1;
cholletisaik777 0:d6e3d1e21484 323 }
cholletisaik777 0:d6e3d1e21484 324
cholletisaik777 0:d6e3d1e21484 325 // wait for write to finish
cholletisaik777 0:d6e3d1e21484 326 while (spi_SD.write(0xFF) == 0);
cholletisaik777 0:d6e3d1e21484 327
cholletisaik777 0:d6e3d1e21484 328 cs_SD = 1;
cholletisaik777 0:d6e3d1e21484 329 spi_SD.write(0xFF);
cholletisaik777 0:d6e3d1e21484 330 return 0;
cholletisaik777 0:d6e3d1e21484 331 }