USBMSD example using an SD card
Dependents: USBMSD_SD_HelloWorld_FRDM-KL25Z USBMSD_SD_HelloWorld_Mbed USBMSD_SD_HelloWorld_FRDM-KL25Z V09_01h ... more
Revision 2:055119ccf5a7, committed 2013-01-21
- Comitter:
- samux
- Date:
- Mon Jan 21 10:40:05 2013 +0000
- Parent:
- 1:923991b026e7
- Commit message:
- use latest SDFilesystem library
Changed in this revision
USBMSD_SD.cpp | Show annotated file Show diff for this revision Revisions of this file |
USBMSD_SD.h | Show annotated file Show diff for this revision Revisions of this file |
diff -r 923991b026e7 -r 055119ccf5a7 USBMSD_SD.cpp --- a/USBMSD_SD.cpp Sun Dec 11 15:52:35 2011 +0000 +++ b/USBMSD_SD.cpp Mon Jan 21 10:40:05 2013 +0000 @@ -1,5 +1,5 @@ -/* mbed USBMSD_SD Library, for providing file access to SD cards - * Copyright (c) 2008-2010, sford +/* mbed Microcontroller Library + * Copyright (c) 2006-2012 ARM Limited * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal @@ -16,28 +16,27 @@ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. */ - /* Introduction * ------------ * SD and MMC cards support a number of interfaces, but common to them all * is one based on SPI. This is the one I'm implmenting because it means - * it is much more portable even though not so performant, and we already + * it is much more portable even though not so performant, and we already * have the mbed SPI Interface! * - * The main reference I'm using is Chapter 7, "SPI Mode" of: + * The main reference I'm using is Chapter 7, "SPI Mode" of: * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf * * SPI Startup * ----------- * The SD card powers up in SD mode. The SPI interface mode is selected by - * asserting CS low and sending the reset command (CMD0). The card will + * asserting CS low and sending the reset command (CMD0). The card will * respond with a (R1) response. * - * CMD8 is optionally sent to determine the voltage range supported, and - * indirectly determine whether it is a version 1.x SD/non-SD card or + * CMD8 is optionally sent to determine the voltage range supported, and + * indirectly determine whether it is a version 1.x SD/non-SD card or * version 2.x. I'll just ignore this for now. * * ACMD41 is repeatedly issued to initialise the card, until "in idle" @@ -51,21 +50,21 @@ * The SD SPI protocol is based on transactions made up of 8-bit words, with * the host starting every bus transaction by asserting the CS signal low. The * card always responds to commands, data blocks and errors. - * - * The protocol supports a CRC, but by default it is off (except for the + * + * The protocol supports a CRC, but by default it is off (except for the * first reset CMD0, where the CRC can just be pre-calculated, and CMD8) - * I'll leave the CRC off I think! - * - * Standard capacity cards have variable data block sizes, whereas High + * I'll leave the CRC off I think! + * + * Standard capacity cards have variable data block sizes, whereas High * Capacity cards fix the size of data block to 512 bytes. I'll therefore * just always use the Standard Capacity cards with a block size of 512 bytes. * This is set with CMD16. * - * You can read and write single blocks (CMD17, CMD25) or multiple blocks + * You can read and write single blocks (CMD17, CMD25) or multiple blocks * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When - * the card gets a read command, it responds with a response token, and then + * the card gets a read command, it responds with a response token, and then * a data token or an error. - * + * * SPI Command Format * ------------------ * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC. @@ -81,7 +80,7 @@ * SPI Response Format * ------------------- * The main response format (R1) is a status byte (normally zero). Key flags: - * idle - 1 if the card is in an idle state/initialising + * idle - 1 if the card is in an idle state/initialising * cmd - 1 if an illegal command code was detected * * +-------------------------------------------------+ @@ -93,7 +92,7 @@ * * Data Response Token * ------------------- - * Every data block written to the card is acknowledged by a byte + * Every data block written to the card is acknowledged by a byte * response token * * +----------------------+ @@ -108,22 +107,26 @@ * * Block transfers have a byte header, followed by the data, followed * by a 16-bit CRC. In our case, the data will always be 512 bytes. - * + * * +------+---------+---------+- - - -+---------+-----------+----------+ - * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] | + * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] | * +------+---------+---------+- - - -+---------+-----------+----------+ */ - #include "USBMSD_SD.h" +#include "mbed_debug.h" #define SD_COMMAND_TIMEOUT 5000 +#define SD_DBG 0 + USBMSD_SD::USBMSD_SD(PinName mosi, PinName miso, PinName sclk, PinName cs) : - _spi(mosi, miso, sclk), _cs(cs) { - _cs = 1; - //no init - _status = 0x01; - connect(); + _spi(mosi, miso, sclk), _cs(cs) { + _cs = 1; + + //no init + _status = 0x01; + + connect(); } #define R1_IDLE_STATE (1 << 0) @@ -139,7 +142,6 @@ // - v2.x Standard Capacity // - v2.x High Capacity // - Not recognised as an SD Card - #define SDCARD_FAIL 0 #define SDCARD_V1 1 #define SDCARD_V2 2 @@ -147,90 +149,93 @@ int USBMSD_SD::initialise_card() { // Set to 100kHz for initialisation, and clock card with cs = 1 - _spi.frequency(100000); + _spi.frequency(100000); _cs = 1; - for(int i=0; i<16; i++) { + for (int i = 0; i < 16; i++) { _spi.write(0xFF); } - // send CMD0, should return with all zeros except IDLE STATE set (bit 0) - if(_cmd(0, 0) != R1_IDLE_STATE) { - fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n"); + if (_cmd(0, 0) != R1_IDLE_STATE) { + debug("No disk, or could not put SD card in to SPI idle state\n"); return SDCARD_FAIL; } - + // send CMD8 to determine whther it is ver 2.x int r = _cmd8(); - if(r == R1_IDLE_STATE) { + if (r == R1_IDLE_STATE) { return initialise_card_v2(); - } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { + } else if (r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { return initialise_card_v1(); } else { - fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n"); + debug("Not in idle state after sending CMD8 (not an SD card?)\n"); return SDCARD_FAIL; } } int USBMSD_SD::initialise_card_v1() { - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - _cmd(55, 0); - if(_cmd(41, 0) == 0) { + for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) { + _cmd(55, 0); + if (_cmd(41, 0) == 0) { + cdv = 512; + debug_if(SD_DBG, "\n\rInit: SEDCARD_V1\n\r"); return SDCARD_V1; } } - - fprintf(stderr, "Timeout waiting for v1.x card\n"); + + debug("Timeout waiting for v1.x card\n"); return SDCARD_FAIL; } int USBMSD_SD::initialise_card_v2() { - - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - _cmd(55, 0); - if(_cmd(41, 0) == 0) { + for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) { + wait_ms(50); + _cmd58(); + _cmd(55, 0); + if (_cmd(41, 0x40000000) == 0) { _cmd58(); + debug_if(SD_DBG, "\n\rInit: SDCARD_V2\n\r"); + cdv = 1; return SDCARD_V2; } } - - fprintf(stderr, "Timeout waiting for v2.x card\n"); + + debug("Timeout waiting for v2.x card\n"); return SDCARD_FAIL; } int USBMSD_SD::disk_initialize() { - int i = initialise_card(); -// printf("init card = %d\n", i); -// printf("OK\n"); - + debug_if(SD_DBG, "init card = %d\n", i); _sectors = _sd_sectors(); - + // Set block length to 512 (CMD16) - if(_cmd(16, 512) != 0) { - fprintf(stderr, "Set 512-byte block timed out\n"); + if (_cmd(16, 512) != 0) { + debug("Set 512-byte block timed out\n"); return 1; } - + _spi.frequency(5000000); // Set to 5MHz for data transfer + // OK _status = 0x00; + return 0; } -int USBMSD_SD::disk_write(const char *buffer, int block_number) { +int USBMSD_SD::disk_write(const uint8_t *buffer, uint64_t block_number) { // set write address for single block (CMD24) - if(_cmd(24, block_number * 512) != 0) { + if (_cmd(24, block_number * cdv) != 0) { return 1; } - + // send the data block - _write(buffer, 512); - return 0; + _write(buffer, 512); + return 0; } -int USBMSD_SD::disk_read(char *buffer, int block_number) { +int USBMSD_SD::disk_read(uint8_t *buffer, uint64_t block_number) { // set read address for single block (CMD17) - if(_cmd(17, block_number * 512) != 0) { + if (_cmd(17, block_number * cdv) != 0) { return 1; } @@ -241,13 +246,13 @@ int USBMSD_SD::disk_status() { return _status; } int USBMSD_SD::disk_sync() { return 0; } -int USBMSD_SD::disk_sectors() { return _sectors; } +uint64_t USBMSD_SD::disk_sectors() { return _sectors; } + // PRIVATE FUNCTIONS - int USBMSD_SD::_cmd(int cmd, int arg) { - _cs = 0; - + _cs = 0; + // send a command _spi.write(0x40 | cmd); _spi.write(arg >> 24); @@ -255,11 +260,11 @@ _spi.write(arg >> 8); _spi.write(arg >> 0); _spi.write(0x95); - + // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { + for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) { int response = _spi.write(0xFF); - if(!(response & 0x80)) { + if (!(response & 0x80)) { _cs = 1; _spi.write(0xFF); return response; @@ -270,8 +275,8 @@ return -1; // timeout } int USBMSD_SD::_cmdx(int cmd, int arg) { - _cs = 0; - + _cs = 0; + // send a command _spi.write(0x40 | cmd); _spi.write(arg >> 24); @@ -279,11 +284,11 @@ _spi.write(arg >> 8); _spi.write(arg >> 0); _spi.write(0x95); - + // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { + for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) { int response = _spi.write(0xFF); - if(!(response & 0x80)) { + if (!(response & 0x80)) { return response; } } @@ -294,7 +299,7 @@ int USBMSD_SD::_cmd58() { - _cs = 0; + _cs = 0; int arg = 0; // send a command @@ -304,16 +309,15 @@ _spi.write(arg >> 8); _spi.write(arg >> 0); _spi.write(0x95); - + // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { + for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) { int response = _spi.write(0xFF); - if(!(response & 0x80)) { + if (!(response & 0x80)) { int ocr = _spi.write(0xFF) << 24; ocr |= _spi.write(0xFF) << 16; ocr |= _spi.write(0xFF) << 8; ocr |= _spi.write(0xFF) << 0; -// printf("OCR = 0x%08X\n", ocr); _cs = 1; _spi.write(0xFF); return response; @@ -325,7 +329,7 @@ } int USBMSD_SD::_cmd8() { - _cs = 0; + _cs = 0; // send a command _spi.write(0x40 | 8); // CMD8 @@ -334,18 +338,18 @@ _spi.write(0x01); // 3.3v _spi.write(0xAA); // check pattern _spi.write(0x87); // crc - + // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) { + for (int i = 0; i < SD_COMMAND_TIMEOUT * 1000; i++) { char response[5]; response[0] = _spi.write(0xFF); - if(!(response[0] & 0x80)) { - for(int j=1; j<5; j++) { - response[i] = _spi.write(0xFF); - } - _cs = 1; - _spi.write(0xFF); - return response[0]; + if (!(response[0] & 0x80)) { + for (int j = 1; j < 5; j++) { + response[i] = _spi.write(0xFF); + } + _cs = 1; + _spi.write(0xFF); + return response[0]; } } _cs = 1; @@ -353,115 +357,117 @@ return -1; // timeout } -int USBMSD_SD::_read(char *buffer, int length) { +int USBMSD_SD::_read(uint8_t *buffer, uint32_t length) { _cs = 0; - + // read until start byte (0xFF) - while(_spi.write(0xFF) != 0xFE); - + while (_spi.write(0xFF) != 0xFE); + // read data - for(int i=0; i<length; i++) { + for (int i = 0; i < length; i++) { buffer[i] = _spi.write(0xFF); } _spi.write(0xFF); // checksum _spi.write(0xFF); - - _cs = 1; + + _cs = 1; _spi.write(0xFF); return 0; } -int USBMSD_SD::_write(const char *buffer, int length) { +int USBMSD_SD::_write(const uint8_t*buffer, uint32_t length) { _cs = 0; // indicate start of block _spi.write(0xFE); // write the data - for(int i=0; i<length; i++) { + for (int i = 0; i < length; i++) { _spi.write(buffer[i]); } // write the checksum - _spi.write(0xFF); + _spi.write(0xFF); _spi.write(0xFF); - - // check the repsonse token - if((_spi.write(0xFF) & 0x1F) != 0x05) { + + // check the response token + if ((_spi.write(0xFF) & 0x1F) != 0x05) { _cs = 1; - _spi.write(0xFF); + _spi.write(0xFF); return 1; } - + // wait for write to finish - while(_spi.write(0xFF) == 0); - - _cs = 1; + while (_spi.write(0xFF) == 0); + + _cs = 1; _spi.write(0xFF); return 0; } -static int ext_bits(char *data, int msb, int lsb) { - int bits = 0; - int size = 1 + msb - lsb; - for(int i=0; i<size; i++) { - int position = lsb + i; - int byte = 15 - (position >> 3); - int bit = position & 0x7; - int value = (data[byte] >> bit) & 1; +static uint32_t ext_bits(unsigned char *data, int msb, int lsb) { + uint32_t bits = 0; + uint32_t size = 1 + msb - lsb; + for (int i = 0; i < size; i++) { + uint32_t position = lsb + i; + uint32_t byte = 15 - (position >> 3); + uint32_t bit = position & 0x7; + uint32_t value = (data[byte] >> bit) & 1; bits |= value << i; } return bits; } -int USBMSD_SD::_sd_sectors() { - +uint64_t USBMSD_SD::_sd_sectors() { + uint32_t c_size, c_size_mult, read_bl_len; + uint32_t block_len, mult, blocknr, capacity; + uint32_t hc_c_size; + uint64_t blocks; + // CMD9, Response R2 (R1 byte + 16-byte block read) - if(_cmdx(9, 0) != 0) { - fprintf(stderr, "Didn't get a response from the disk\n"); + if (_cmdx(9, 0) != 0) { + debug("Didn't get a response from the disk\n"); return 0; } - char csd[16]; - if(_read(csd, 16) != 0) { - fprintf(stderr, "Couldn't read csd response from disk\n"); + uint8_t csd[16]; + if (_read(csd, 16) != 0) { + debug("Couldn't read csd response from disk\n"); return 0; } - + // csd_structure : csd[127:126] // c_size : csd[73:62] // c_size_mult : csd[49:47] // read_bl_len : csd[83:80] - the *maximum* read block length - + int csd_structure = ext_bits(csd, 127, 126); - int c_size = ext_bits(csd, 73, 62); - int c_size_mult = ext_bits(csd, 49, 47); - int read_bl_len = ext_bits(csd, 83, 80); - -// printf("CSD_STRUCT = %d\n", csd_structure); - if(csd_structure != 0) { - fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); - return 0; - } - - // memory capacity = BLOCKNR * BLOCK_LEN - // where - // BLOCKNR = (C_SIZE+1) * MULT - // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8) - // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12) - - int block_len = 1 << read_bl_len; - int mult = 1 << (c_size_mult + 2); - int blocknr = (c_size + 1) * mult; - capacity = blocknr * block_len; - - int blocks = capacity / 512; + switch (csd_structure) { + case 0: + cdv = 512; + c_size = ext_bits(csd, 73, 62); + c_size_mult = ext_bits(csd, 49, 47); + read_bl_len = ext_bits(csd, 83, 80); + + block_len = 1 << read_bl_len; + mult = 1 << (c_size_mult + 2); + blocknr = (c_size + 1) * mult; + capacity = blocknr * block_len; + blocks = capacity / 512; + debug_if(SD_DBG, "\n\rSDCard\n\rc_size: %d \n\rcapacity: %ld \n\rsectors: %lld\n\r", c_size, capacity, blocks); + break; + case 1: + cdv = 1; + hc_c_size = ext_bits(csd, 63, 48); + blocks = (hc_c_size+1)*1024; + debug_if(SD_DBG, "\n\rSDHC Card \n\rhc_c_size: %d\n\rcapacity: %lld \n\rsectors: %lld\n\r", hc_c_size, blocks*512, blocks); + break; + + default: + debug("CSD struct unsupported\r\n"); + return 0; + }; return blocks; } - - -int USBMSD_SD::disk_size() { - return capacity; -}
diff -r 923991b026e7 -r 055119ccf5a7 USBMSD_SD.h --- a/USBMSD_SD.h Sun Dec 11 15:52:35 2011 +0000 +++ b/USBMSD_SD.h Mon Jan 21 10:40:05 2013 +0000 @@ -53,12 +53,13 @@ */ USBMSD_SD(PinName mosi, PinName miso, PinName sclk, PinName cs); virtual int disk_initialize(); - virtual int disk_write(const char *buffer, int block_number); - virtual int disk_read(char *buffer, int block_number); virtual int disk_status(); + virtual int disk_read(uint8_t * buffer, uint64_t block_number); + virtual int disk_write(const uint8_t * buffer, uint64_t block_number); virtual int disk_sync(); - virtual int disk_sectors(); - virtual int disk_size(); + virtual uint64_t disk_sectors(); + + virtual uint64_t disk_size(){return _sectors*512;}; protected: @@ -70,16 +71,16 @@ int initialise_card_v1(); int initialise_card_v2(); - int _read(char *buffer, int length); - int _write(const char *buffer, int length); - int _sd_sectors(); - int _sectors; + int _read(uint8_t * buffer, uint32_t length); + int _write(const uint8_t *buffer, uint32_t length); + uint64_t _sd_sectors(); + uint64_t _sectors; - int capacity; - int _status; + uint8_t _status; SPI _spi; DigitalOut _cs; + int cdv; }; #endif