SDFileSys_with_Rename - Example writing to SD card, sford (original) 21 …

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Doug Wendelboe / Mbed 2 deprecated SDFileSys_with_Rename

Example writing to SD card, sford (original) 21 June 2011: Enhanced by D. Wendelboe to test SD file and directories. Illustrates the following: * rename a file (via copy & delete old). * copy an existing file to a new file. * listing of SD directory names. TODO: Add method to list filenames in a directory. Add a method to return file length.

Dependencies: mbed

SDFileSystem.cpp@1:4a0985d3a848, 2011-06-22 (annotated)

Committer:: YouTahDoug
Date:: Wed Jun 22 16:52:20 2011 +0000
Revision:: 1:4a0985d3a848
Parent:: 0:d0eea54553ed

Who changed what in which revision?

User	Revision	Line number	New contents of line
YouTahDoug	0:d0eea54553ed	1	/* mbed SDFileSystem Library, for providing file access to SD cards
YouTahDoug	0:d0eea54553ed	2	* Copyright (c) 2008-2010, sford
YouTahDoug	0:d0eea54553ed	3	*
YouTahDoug	0:d0eea54553ed	4	* Permission is hereby granted, free of charge, to any person obtaining a copy
YouTahDoug	0:d0eea54553ed	5	* of this software and associated documentation files (the "Software"), to deal
YouTahDoug	0:d0eea54553ed	6	* in the Software without restriction, including without limitation the rights
YouTahDoug	0:d0eea54553ed	7	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
YouTahDoug	0:d0eea54553ed	8	* copies of the Software, and to permit persons to whom the Software is
YouTahDoug	0:d0eea54553ed	9	* furnished to do so, subject to the following conditions:
YouTahDoug	0:d0eea54553ed	10	*
YouTahDoug	0:d0eea54553ed	11	* The above copyright notice and this permission notice shall be included in
YouTahDoug	0:d0eea54553ed	12	* all copies or substantial portions of the Software.
YouTahDoug	0:d0eea54553ed	13	*
YouTahDoug	0:d0eea54553ed	14	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
YouTahDoug	0:d0eea54553ed	15	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
YouTahDoug	0:d0eea54553ed	16	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
YouTahDoug	0:d0eea54553ed	17	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
YouTahDoug	0:d0eea54553ed	18	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
YouTahDoug	0:d0eea54553ed	19	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
YouTahDoug	0:d0eea54553ed	20	* THE SOFTWARE.
YouTahDoug	0:d0eea54553ed	21	*/
YouTahDoug	0:d0eea54553ed	22
YouTahDoug	0:d0eea54553ed	23	/* Introduction
YouTahDoug	0:d0eea54553ed	24	* ------------
YouTahDoug	0:d0eea54553ed	25	* SD and MMC cards support a number of interfaces, but common to them all
YouTahDoug	0:d0eea54553ed	26	* is one based on SPI. This is the one I'm implmenting because it means
YouTahDoug	0:d0eea54553ed	27	* it is much more portable even though not so performant, and we already
YouTahDoug	0:d0eea54553ed	28	* have the mbed SPI Interface!
YouTahDoug	0:d0eea54553ed	29	*
YouTahDoug	0:d0eea54553ed	30	* The main reference I'm using is Chapter 7, "SPI Mode" of:
YouTahDoug	0:d0eea54553ed	31	* http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
YouTahDoug	0:d0eea54553ed	32	*
YouTahDoug	0:d0eea54553ed	33	* SPI Startup
YouTahDoug	0:d0eea54553ed	34	* -----------
YouTahDoug	0:d0eea54553ed	35	* The SD card powers up in SD mode. The SPI interface mode is selected by
YouTahDoug	0:d0eea54553ed	36	* asserting CS low and sending the reset command (CMD0). The card will
YouTahDoug	0:d0eea54553ed	37	* respond with a (R1) response.
YouTahDoug	0:d0eea54553ed	38	*
YouTahDoug	0:d0eea54553ed	39	* CMD8 is optionally sent to determine the voltage range supported, and
YouTahDoug	0:d0eea54553ed	40	* indirectly determine whether it is a version 1.x SD/non-SD card or
YouTahDoug	0:d0eea54553ed	41	* version 2.x. I'll just ignore this for now.
YouTahDoug	0:d0eea54553ed	42	*
YouTahDoug	0:d0eea54553ed	43	* ACMD41 is repeatedly issued to initialise the card, until "in idle"
YouTahDoug	0:d0eea54553ed	44	* (bit 0) of the R1 response goes to '0', indicating it is initialised.
YouTahDoug	0:d0eea54553ed	45	*
YouTahDoug	0:d0eea54553ed	46	* You should also indicate whether the host supports High Capicity cards,
YouTahDoug	0:d0eea54553ed	47	* and check whether the card is high capacity - i'll also ignore this
YouTahDoug	0:d0eea54553ed	48	*
YouTahDoug	0:d0eea54553ed	49	* SPI Protocol
YouTahDoug	0:d0eea54553ed	50	* ------------
YouTahDoug	0:d0eea54553ed	51	* The SD SPI protocol is based on transactions made up of 8-bit words, with
YouTahDoug	0:d0eea54553ed	52	* the host starting every bus transaction by asserting the CS signal low. The
YouTahDoug	0:d0eea54553ed	53	* card always responds to commands, data blocks and errors.
YouTahDoug	0:d0eea54553ed	54	*
YouTahDoug	0:d0eea54553ed	55	* The protocol supports a CRC, but by default it is off (except for the
YouTahDoug	0:d0eea54553ed	56	* first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
YouTahDoug	0:d0eea54553ed	57	* I'll leave the CRC off I think!
YouTahDoug	0:d0eea54553ed	58	*
YouTahDoug	0:d0eea54553ed	59	* Standard capacity cards have variable data block sizes, whereas High
YouTahDoug	0:d0eea54553ed	60	* Capacity cards fix the size of data block to 512 bytes. I'll therefore
YouTahDoug	0:d0eea54553ed	61	* just always use the Standard Capacity cards with a block size of 512 bytes.
YouTahDoug	0:d0eea54553ed	62	* This is set with CMD16.
YouTahDoug	0:d0eea54553ed	63	*
YouTahDoug	0:d0eea54553ed	64	* You can read and write single blocks (CMD17, CMD25) or multiple blocks
YouTahDoug	0:d0eea54553ed	65	* (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
YouTahDoug	0:d0eea54553ed	66	* the card gets a read command, it responds with a response token, and then
YouTahDoug	0:d0eea54553ed	67	* a data token or an error.
YouTahDoug	0:d0eea54553ed	68	*
YouTahDoug	0:d0eea54553ed	69	* SPI Command Format
YouTahDoug	0:d0eea54553ed	70	* ------------------
YouTahDoug	0:d0eea54553ed	71	* Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
YouTahDoug	0:d0eea54553ed	72	*
YouTahDoug	0:d0eea54553ed	73	* +---------------+------------+------------+-----------+----------+--------------+
YouTahDoug	0:d0eea54553ed	74	* \| 01 \| cmd[5:0] \| arg[31:24] \| arg[23:16] \| arg[15:8] \| arg[7:0] \| crc[6:0] \| 1 \|
YouTahDoug	0:d0eea54553ed	75	* +---------------+------------+------------+-----------+----------+--------------+
YouTahDoug	0:d0eea54553ed	76	*
YouTahDoug	0:d0eea54553ed	77	* As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
YouTahDoug	0:d0eea54553ed	78	*
YouTahDoug	0:d0eea54553ed	79	* All Application Specific commands shall be preceded with APP_CMD (CMD55).
YouTahDoug	0:d0eea54553ed	80	*
YouTahDoug	0:d0eea54553ed	81	* SPI Response Format
YouTahDoug	0:d0eea54553ed	82	* -------------------
YouTahDoug	0:d0eea54553ed	83	* The main response format (R1) is a status byte (normally zero). Key flags:
YouTahDoug	0:d0eea54553ed	84	* idle - 1 if the card is in an idle state/initialising
YouTahDoug	0:d0eea54553ed	85	* cmd - 1 if an illegal command code was detected
YouTahDoug	0:d0eea54553ed	86	*
YouTahDoug	0:d0eea54553ed	87	* +-------------------------------------------------+
YouTahDoug	0:d0eea54553ed	88	* R1 \| 0 \| arg \| addr \| seq \| crc \| cmd \| erase \| idle \|
YouTahDoug	0:d0eea54553ed	89	* +-------------------------------------------------+
YouTahDoug	0:d0eea54553ed	90	*
YouTahDoug	0:d0eea54553ed	91	* R1b is the same, except it is followed by a busy signal (zeros) until
YouTahDoug	0:d0eea54553ed	92	* the first non-zero byte when it is ready again.
YouTahDoug	0:d0eea54553ed	93	*
YouTahDoug	0:d0eea54553ed	94	* Data Response Token
YouTahDoug	0:d0eea54553ed	95	* -------------------
YouTahDoug	0:d0eea54553ed	96	* Every data block written to the card is acknowledged by a byte
YouTahDoug	0:d0eea54553ed	97	* response token
YouTahDoug	0:d0eea54553ed	98	*
YouTahDoug	0:d0eea54553ed	99	* +----------------------+
YouTahDoug	0:d0eea54553ed	100	* \| xxx \| 0 \| status \| 1 \|
YouTahDoug	0:d0eea54553ed	101	* +----------------------+
YouTahDoug	0:d0eea54553ed	102	* 010 - OK!
YouTahDoug	0:d0eea54553ed	103	* 101 - CRC Error
YouTahDoug	0:d0eea54553ed	104	* 110 - Write Error
YouTahDoug	0:d0eea54553ed	105	*
YouTahDoug	0:d0eea54553ed	106	* Single Block Read and Write
YouTahDoug	0:d0eea54553ed	107	* ---------------------------
YouTahDoug	0:d0eea54553ed	108	*
YouTahDoug	0:d0eea54553ed	109	* Block transfers have a byte header, followed by the data, followed
YouTahDoug	0:d0eea54553ed	110	* by a 16-bit CRC. In our case, the data will always be 512 bytes.
YouTahDoug	0:d0eea54553ed	111	*
YouTahDoug	0:d0eea54553ed	112	* +------+---------+---------+- - - -+---------+-----------+----------+
YouTahDoug	0:d0eea54553ed	113	* \| 0xFE \| data[0] \| data[1] \| \| data[n] \| crc[15:8] \| crc[7:0] \|
YouTahDoug	0:d0eea54553ed	114	* +------+---------+---------+- - - -+---------+-----------+----------+
YouTahDoug	0:d0eea54553ed	115	*/
YouTahDoug	0:d0eea54553ed	116
YouTahDoug	0:d0eea54553ed	117	#include "SDFileSystem.h"
YouTahDoug	0:d0eea54553ed	118
YouTahDoug	0:d0eea54553ed	119	#define SD_COMMAND_TIMEOUT 5000
YouTahDoug	0:d0eea54553ed	120
YouTahDoug	0:d0eea54553ed	121	SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
YouTahDoug	0:d0eea54553ed	122	FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
YouTahDoug	0:d0eea54553ed	123	_cs = 1;
YouTahDoug	0:d0eea54553ed	124	}
YouTahDoug	0:d0eea54553ed	125
YouTahDoug	0:d0eea54553ed	126	#define R1_IDLE_STATE (1 << 0)
YouTahDoug	0:d0eea54553ed	127	#define R1_ERASE_RESET (1 << 1)
YouTahDoug	0:d0eea54553ed	128	#define R1_ILLEGAL_COMMAND (1 << 2)
YouTahDoug	0:d0eea54553ed	129	#define R1_COM_CRC_ERROR (1 << 3)
YouTahDoug	0:d0eea54553ed	130	#define R1_ERASE_SEQUENCE_ERROR (1 << 4)
YouTahDoug	0:d0eea54553ed	131	#define R1_ADDRESS_ERROR (1 << 5)
YouTahDoug	0:d0eea54553ed	132	#define R1_PARAMETER_ERROR (1 << 6)
YouTahDoug	0:d0eea54553ed	133
YouTahDoug	0:d0eea54553ed	134	// Types
YouTahDoug	0:d0eea54553ed	135	// - v1.x Standard Capacity
YouTahDoug	0:d0eea54553ed	136	// - v2.x Standard Capacity
YouTahDoug	0:d0eea54553ed	137	// - v2.x High Capacity
YouTahDoug	0:d0eea54553ed	138	// - Not recognised as an SD Card
YouTahDoug	0:d0eea54553ed	139
YouTahDoug	0:d0eea54553ed	140	#define SDCARD_FAIL 0
YouTahDoug	0:d0eea54553ed	141	#define SDCARD_V1 1
YouTahDoug	0:d0eea54553ed	142	#define SDCARD_V2 2
YouTahDoug	0:d0eea54553ed	143	#define SDCARD_V2HC 3
YouTahDoug	0:d0eea54553ed	144
YouTahDoug	0:d0eea54553ed	145	int SDFileSystem::initialise_card() {
YouTahDoug	0:d0eea54553ed	146	// Set to 100kHz for initialisation, and clock card with cs = 1
YouTahDoug	0:d0eea54553ed	147	_spi.frequency(100000);
YouTahDoug	0:d0eea54553ed	148	_cs = 1;
YouTahDoug	0:d0eea54553ed	149	for(int i=0; i<16; i++) {
YouTahDoug	0:d0eea54553ed	150	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	151	}
YouTahDoug	0:d0eea54553ed	152
YouTahDoug	0:d0eea54553ed	153	// send CMD0, should return with all zeros except IDLE STATE set (bit 0)
YouTahDoug	0:d0eea54553ed	154	if(_cmd(0, 0) != R1_IDLE_STATE) {
YouTahDoug	0:d0eea54553ed	155	fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n");
YouTahDoug	0:d0eea54553ed	156	return SDCARD_FAIL;
YouTahDoug	0:d0eea54553ed	157	}
YouTahDoug	0:d0eea54553ed	158
YouTahDoug	0:d0eea54553ed	159	// send CMD8 to determine whther it is ver 2.x
YouTahDoug	0:d0eea54553ed	160	int r = _cmd8();
YouTahDoug	0:d0eea54553ed	161	if(r == R1_IDLE_STATE) {
YouTahDoug	0:d0eea54553ed	162	return initialise_card_v2();
YouTahDoug	0:d0eea54553ed	163	} else if(r == (R1_IDLE_STATE \| R1_ILLEGAL_COMMAND)) {
YouTahDoug	0:d0eea54553ed	164	return initialise_card_v1();
YouTahDoug	0:d0eea54553ed	165	} else {
YouTahDoug	0:d0eea54553ed	166	fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n");
YouTahDoug	0:d0eea54553ed	167	return SDCARD_FAIL;
YouTahDoug	0:d0eea54553ed	168	}
YouTahDoug	0:d0eea54553ed	169	}
YouTahDoug	0:d0eea54553ed	170
YouTahDoug	0:d0eea54553ed	171	int SDFileSystem::initialise_card_v1() {
YouTahDoug	0:d0eea54553ed	172	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
YouTahDoug	0:d0eea54553ed	173	_cmd(55, 0);
YouTahDoug	0:d0eea54553ed	174	if(_cmd(41, 0) == 0) {
YouTahDoug	0:d0eea54553ed	175	return SDCARD_V1;
YouTahDoug	0:d0eea54553ed	176	}
YouTahDoug	0:d0eea54553ed	177	}
YouTahDoug	0:d0eea54553ed	178
YouTahDoug	0:d0eea54553ed	179	fprintf(stderr, "Timeout waiting for v1.x card\n");
YouTahDoug	0:d0eea54553ed	180	return SDCARD_FAIL;
YouTahDoug	0:d0eea54553ed	181	}
YouTahDoug	0:d0eea54553ed	182
YouTahDoug	0:d0eea54553ed	183	int SDFileSystem::initialise_card_v2() {
YouTahDoug	0:d0eea54553ed	184
YouTahDoug	0:d0eea54553ed	185	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
YouTahDoug	0:d0eea54553ed	186	_cmd(55, 0);
YouTahDoug	0:d0eea54553ed	187	if(_cmd(41, 0) == 0) {
YouTahDoug	0:d0eea54553ed	188	_cmd58();
YouTahDoug	0:d0eea54553ed	189	return SDCARD_V2;
YouTahDoug	0:d0eea54553ed	190	}
YouTahDoug	0:d0eea54553ed	191	}
YouTahDoug	0:d0eea54553ed	192
YouTahDoug	0:d0eea54553ed	193	fprintf(stderr, "Timeout waiting for v2.x card\n");
YouTahDoug	0:d0eea54553ed	194	return SDCARD_FAIL;
YouTahDoug	0:d0eea54553ed	195	}
YouTahDoug	0:d0eea54553ed	196
YouTahDoug	0:d0eea54553ed	197	int SDFileSystem::disk_initialize() {
YouTahDoug	0:d0eea54553ed	198
YouTahDoug	0:d0eea54553ed	199	int i = initialise_card();
YouTahDoug	0:d0eea54553ed	200	// printf("init card = %d\n", i);
YouTahDoug	0:d0eea54553ed	201	// printf("OK\n");
YouTahDoug	0:d0eea54553ed	202
YouTahDoug	0:d0eea54553ed	203	_sectors = _sd_sectors();
YouTahDoug	0:d0eea54553ed	204
YouTahDoug	0:d0eea54553ed	205	// Set block length to 512 (CMD16)
YouTahDoug	0:d0eea54553ed	206	if(_cmd(16, 512) != 0) {
YouTahDoug	0:d0eea54553ed	207	fprintf(stderr, "Set 512-byte block timed out\n");
YouTahDoug	0:d0eea54553ed	208	return 1;
YouTahDoug	0:d0eea54553ed	209	}
YouTahDoug	0:d0eea54553ed	210
YouTahDoug	0:d0eea54553ed	211	_spi.frequency(1000000); // Set to 1MHz for data transfer
YouTahDoug	0:d0eea54553ed	212	return 0;
YouTahDoug	0:d0eea54553ed	213	}
YouTahDoug	0:d0eea54553ed	214
YouTahDoug	0:d0eea54553ed	215	int SDFileSystem::disk_write(const char *buffer, int block_number) {
YouTahDoug	0:d0eea54553ed	216	// set write address for single block (CMD24)
YouTahDoug	0:d0eea54553ed	217	if(_cmd(24, block_number * 512) != 0) {
YouTahDoug	0:d0eea54553ed	218	return 1;
YouTahDoug	0:d0eea54553ed	219	}
YouTahDoug	0:d0eea54553ed	220
YouTahDoug	0:d0eea54553ed	221	// send the data block
YouTahDoug	0:d0eea54553ed	222	_write(buffer, 512);
YouTahDoug	0:d0eea54553ed	223	return 0;
YouTahDoug	0:d0eea54553ed	224	}
YouTahDoug	0:d0eea54553ed	225
YouTahDoug	0:d0eea54553ed	226	int SDFileSystem::disk_read(char *buffer, int block_number) {
YouTahDoug	0:d0eea54553ed	227	// set read address for single block (CMD17)
YouTahDoug	0:d0eea54553ed	228	if(_cmd(17, block_number * 512) != 0) {
YouTahDoug	0:d0eea54553ed	229	return 1;
YouTahDoug	0:d0eea54553ed	230	}
YouTahDoug	0:d0eea54553ed	231
YouTahDoug	0:d0eea54553ed	232	// receive the data
YouTahDoug	0:d0eea54553ed	233	_read(buffer, 512);
YouTahDoug	0:d0eea54553ed	234	return 0;
YouTahDoug	0:d0eea54553ed	235	}
YouTahDoug	0:d0eea54553ed	236
YouTahDoug	0:d0eea54553ed	237	int SDFileSystem::disk_status() { return 0; }
YouTahDoug	0:d0eea54553ed	238	int SDFileSystem::disk_sync() { return 0; }
YouTahDoug	0:d0eea54553ed	239	int SDFileSystem::disk_sectors() { return _sectors; }
YouTahDoug	0:d0eea54553ed	240
YouTahDoug	0:d0eea54553ed	241	// PRIVATE FUNCTIONS
YouTahDoug	0:d0eea54553ed	242
YouTahDoug	0:d0eea54553ed	243	int SDFileSystem::_cmd(int cmd, int arg) {
YouTahDoug	0:d0eea54553ed	244	_cs = 0;
YouTahDoug	0:d0eea54553ed	245
YouTahDoug	0:d0eea54553ed	246	// send a command
YouTahDoug	0:d0eea54553ed	247	_spi.write(0x40 \| cmd);
YouTahDoug	0:d0eea54553ed	248	_spi.write(arg >> 24);
YouTahDoug	0:d0eea54553ed	249	_spi.write(arg >> 16);
YouTahDoug	0:d0eea54553ed	250	_spi.write(arg >> 8);
YouTahDoug	0:d0eea54553ed	251	_spi.write(arg >> 0);
YouTahDoug	0:d0eea54553ed	252	_spi.write(0x95);
YouTahDoug	0:d0eea54553ed	253
YouTahDoug	0:d0eea54553ed	254	// wait for the repsonse (response[7] == 0)
YouTahDoug	0:d0eea54553ed	255	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
YouTahDoug	0:d0eea54553ed	256	int response = _spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	257	if(!(response & 0x80)) {
YouTahDoug	0:d0eea54553ed	258	_cs = 1;
YouTahDoug	0:d0eea54553ed	259	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	260	return response;
YouTahDoug	0:d0eea54553ed	261	}
YouTahDoug	0:d0eea54553ed	262	}
YouTahDoug	0:d0eea54553ed	263	_cs = 1;
YouTahDoug	0:d0eea54553ed	264	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	265	return -1; // timeout
YouTahDoug	0:d0eea54553ed	266	}
YouTahDoug	0:d0eea54553ed	267	int SDFileSystem::_cmdx(int cmd, int arg) {
YouTahDoug	0:d0eea54553ed	268	_cs = 0;
YouTahDoug	0:d0eea54553ed	269
YouTahDoug	0:d0eea54553ed	270	// send a command
YouTahDoug	0:d0eea54553ed	271	_spi.write(0x40 \| cmd);
YouTahDoug	0:d0eea54553ed	272	_spi.write(arg >> 24);
YouTahDoug	0:d0eea54553ed	273	_spi.write(arg >> 16);
YouTahDoug	0:d0eea54553ed	274	_spi.write(arg >> 8);
YouTahDoug	0:d0eea54553ed	275	_spi.write(arg >> 0);
YouTahDoug	0:d0eea54553ed	276	_spi.write(0x95);
YouTahDoug	0:d0eea54553ed	277
YouTahDoug	0:d0eea54553ed	278	// wait for the repsonse (response[7] == 0)
YouTahDoug	0:d0eea54553ed	279	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
YouTahDoug	0:d0eea54553ed	280	int response = _spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	281	if(!(response & 0x80)) {
YouTahDoug	0:d0eea54553ed	282	return response;
YouTahDoug	0:d0eea54553ed	283	}
YouTahDoug	0:d0eea54553ed	284	}
YouTahDoug	0:d0eea54553ed	285	_cs = 1;
YouTahDoug	0:d0eea54553ed	286	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	287	return -1; // timeout
YouTahDoug	0:d0eea54553ed	288	}
YouTahDoug	0:d0eea54553ed	289
YouTahDoug	0:d0eea54553ed	290
YouTahDoug	0:d0eea54553ed	291	int SDFileSystem::_cmd58() {
YouTahDoug	0:d0eea54553ed	292	_cs = 0;
YouTahDoug	0:d0eea54553ed	293	int arg = 0;
YouTahDoug	0:d0eea54553ed	294
YouTahDoug	0:d0eea54553ed	295	// send a command
YouTahDoug	0:d0eea54553ed	296	_spi.write(0x40 \| 58);
YouTahDoug	0:d0eea54553ed	297	_spi.write(arg >> 24);
YouTahDoug	0:d0eea54553ed	298	_spi.write(arg >> 16);
YouTahDoug	0:d0eea54553ed	299	_spi.write(arg >> 8);
YouTahDoug	0:d0eea54553ed	300	_spi.write(arg >> 0);
YouTahDoug	0:d0eea54553ed	301	_spi.write(0x95);
YouTahDoug	0:d0eea54553ed	302
YouTahDoug	0:d0eea54553ed	303	// wait for the repsonse (response[7] == 0)
YouTahDoug	0:d0eea54553ed	304	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
YouTahDoug	0:d0eea54553ed	305	int response = _spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	306	if(!(response & 0x80)) {
YouTahDoug	0:d0eea54553ed	307	int ocr = _spi.write(0xFF) << 24;
YouTahDoug	0:d0eea54553ed	308	ocr \|= _spi.write(0xFF) << 16;
YouTahDoug	0:d0eea54553ed	309	ocr \|= _spi.write(0xFF) << 8;
YouTahDoug	0:d0eea54553ed	310	ocr \|= _spi.write(0xFF) << 0;
YouTahDoug	0:d0eea54553ed	311	// printf("OCR = 0x%08X\n", ocr);
YouTahDoug	0:d0eea54553ed	312	_cs = 1;
YouTahDoug	0:d0eea54553ed	313	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	314	return response;
YouTahDoug	0:d0eea54553ed	315	}
YouTahDoug	0:d0eea54553ed	316	}
YouTahDoug	0:d0eea54553ed	317	_cs = 1;
YouTahDoug	0:d0eea54553ed	318	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	319	return -1; // timeout
YouTahDoug	0:d0eea54553ed	320	}
YouTahDoug	0:d0eea54553ed	321
YouTahDoug	0:d0eea54553ed	322	int SDFileSystem::_cmd8() {
YouTahDoug	0:d0eea54553ed	323	_cs = 0;
YouTahDoug	0:d0eea54553ed	324
YouTahDoug	0:d0eea54553ed	325	// send a command
YouTahDoug	0:d0eea54553ed	326	_spi.write(0x40 \| 8); // CMD8
YouTahDoug	0:d0eea54553ed	327	_spi.write(0x00); // reserved
YouTahDoug	0:d0eea54553ed	328	_spi.write(0x00); // reserved
YouTahDoug	0:d0eea54553ed	329	_spi.write(0x01); // 3.3v
YouTahDoug	0:d0eea54553ed	330	_spi.write(0xAA); // check pattern
YouTahDoug	0:d0eea54553ed	331	_spi.write(0x87); // crc
YouTahDoug	0:d0eea54553ed	332
YouTahDoug	0:d0eea54553ed	333	// wait for the repsonse (response[7] == 0)
YouTahDoug	0:d0eea54553ed	334	for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
YouTahDoug	0:d0eea54553ed	335	char response[5];
YouTahDoug	0:d0eea54553ed	336	response[0] = _spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	337	if(!(response[0] & 0x80)) {
YouTahDoug	0:d0eea54553ed	338	for(int j=1; j<5; j++) {
YouTahDoug	0:d0eea54553ed	339	response[i] = _spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	340	}
YouTahDoug	0:d0eea54553ed	341	_cs = 1;
YouTahDoug	0:d0eea54553ed	342	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	343	return response[0];
YouTahDoug	0:d0eea54553ed	344	}
YouTahDoug	0:d0eea54553ed	345	}
YouTahDoug	0:d0eea54553ed	346	_cs = 1;
YouTahDoug	0:d0eea54553ed	347	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	348	return -1; // timeout
YouTahDoug	0:d0eea54553ed	349	}
YouTahDoug	0:d0eea54553ed	350
YouTahDoug	0:d0eea54553ed	351	int SDFileSystem::_read(char *buffer, int length) {
YouTahDoug	0:d0eea54553ed	352	_cs = 0;
YouTahDoug	0:d0eea54553ed	353
YouTahDoug	0:d0eea54553ed	354	// read until start byte (0xFF)
YouTahDoug	0:d0eea54553ed	355	while(_spi.write(0xFF) != 0xFE);
YouTahDoug	0:d0eea54553ed	356
YouTahDoug	0:d0eea54553ed	357	// read data
YouTahDoug	0:d0eea54553ed	358	for(int i=0; i<length; i++) {
YouTahDoug	0:d0eea54553ed	359	buffer[i] = _spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	360	}
YouTahDoug	0:d0eea54553ed	361	_spi.write(0xFF); // checksum
YouTahDoug	0:d0eea54553ed	362	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	363
YouTahDoug	0:d0eea54553ed	364	_cs = 1;
YouTahDoug	0:d0eea54553ed	365	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	366	return 0;
YouTahDoug	0:d0eea54553ed	367	}
YouTahDoug	0:d0eea54553ed	368
YouTahDoug	0:d0eea54553ed	369	int SDFileSystem::_write(const char *buffer, int length) {
YouTahDoug	0:d0eea54553ed	370	_cs = 0;
YouTahDoug	0:d0eea54553ed	371
YouTahDoug	0:d0eea54553ed	372	// indicate start of block
YouTahDoug	0:d0eea54553ed	373	_spi.write(0xFE);
YouTahDoug	0:d0eea54553ed	374
YouTahDoug	0:d0eea54553ed	375	// write the data
YouTahDoug	0:d0eea54553ed	376	for(int i=0; i<length; i++) {
YouTahDoug	0:d0eea54553ed	377	_spi.write(buffer[i]);
YouTahDoug	0:d0eea54553ed	378	}
YouTahDoug	0:d0eea54553ed	379
YouTahDoug	0:d0eea54553ed	380	// write the checksum
YouTahDoug	0:d0eea54553ed	381	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	382	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	383
YouTahDoug	0:d0eea54553ed	384	// check the repsonse token
YouTahDoug	0:d0eea54553ed	385	if((_spi.write(0xFF) & 0x1F) != 0x05) {
YouTahDoug	0:d0eea54553ed	386	_cs = 1;
YouTahDoug	0:d0eea54553ed	387	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	388	return 1;
YouTahDoug	0:d0eea54553ed	389	}
YouTahDoug	0:d0eea54553ed	390
YouTahDoug	0:d0eea54553ed	391	// wait for write to finish
YouTahDoug	0:d0eea54553ed	392	while(_spi.write(0xFF) == 0);
YouTahDoug	0:d0eea54553ed	393
YouTahDoug	0:d0eea54553ed	394	_cs = 1;
YouTahDoug	0:d0eea54553ed	395	_spi.write(0xFF);
YouTahDoug	0:d0eea54553ed	396	return 0;
YouTahDoug	0:d0eea54553ed	397	}
YouTahDoug	0:d0eea54553ed	398
YouTahDoug	0:d0eea54553ed	399	static int ext_bits(char *data, int msb, int lsb) {
YouTahDoug	0:d0eea54553ed	400	int bits = 0;
YouTahDoug	0:d0eea54553ed	401	int size = 1 + msb - lsb;
YouTahDoug	0:d0eea54553ed	402	for(int i=0; i<size; i++) {
YouTahDoug	0:d0eea54553ed	403	int position = lsb + i;
YouTahDoug	0:d0eea54553ed	404	int byte = 15 - (position >> 3);
YouTahDoug	0:d0eea54553ed	405	int bit = position & 0x7;
YouTahDoug	0:d0eea54553ed	406	int value = (data[byte] >> bit) & 1;
YouTahDoug	0:d0eea54553ed	407	bits \|= value << i;
YouTahDoug	0:d0eea54553ed	408	}
YouTahDoug	0:d0eea54553ed	409	return bits;
YouTahDoug	0:d0eea54553ed	410	}
YouTahDoug	0:d0eea54553ed	411
YouTahDoug	0:d0eea54553ed	412	int SDFileSystem::_sd_sectors() {
YouTahDoug	0:d0eea54553ed	413
YouTahDoug	0:d0eea54553ed	414	// CMD9, Response R2 (R1 byte + 16-byte block read)
YouTahDoug	0:d0eea54553ed	415	if(_cmdx(9, 0) != 0) {
YouTahDoug	0:d0eea54553ed	416	fprintf(stderr, "Didn't get a response from the disk\n");
YouTahDoug	0:d0eea54553ed	417	return 0;
YouTahDoug	0:d0eea54553ed	418	}
YouTahDoug	0:d0eea54553ed	419
YouTahDoug	0:d0eea54553ed	420	char csd[16];
YouTahDoug	0:d0eea54553ed	421	if(_read(csd, 16) != 0) {
YouTahDoug	0:d0eea54553ed	422	fprintf(stderr, "Couldn't read csd response from disk\n");
YouTahDoug	0:d0eea54553ed	423	return 0;
YouTahDoug	0:d0eea54553ed	424	}
YouTahDoug	0:d0eea54553ed	425
YouTahDoug	0:d0eea54553ed	426	// csd_structure : csd[127:126]
YouTahDoug	0:d0eea54553ed	427	// c_size : csd[73:62]
YouTahDoug	0:d0eea54553ed	428	// c_size_mult : csd[49:47]
YouTahDoug	0:d0eea54553ed	429	// read_bl_len : csd[83:80] - the maximum read block length
YouTahDoug	0:d0eea54553ed	430
YouTahDoug	0:d0eea54553ed	431	int csd_structure = ext_bits(csd, 127, 126);
YouTahDoug	0:d0eea54553ed	432	int c_size = ext_bits(csd, 73, 62);
YouTahDoug	0:d0eea54553ed	433	int c_size_mult = ext_bits(csd, 49, 47);
YouTahDoug	0:d0eea54553ed	434	int read_bl_len = ext_bits(csd, 83, 80);
YouTahDoug	0:d0eea54553ed	435
YouTahDoug	0:d0eea54553ed	436	// printf("CSD_STRUCT = %d\n", csd_structure);
YouTahDoug	0:d0eea54553ed	437
YouTahDoug	0:d0eea54553ed	438	if(csd_structure != 0) {
YouTahDoug	0:d0eea54553ed	439	fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n");
YouTahDoug	0:d0eea54553ed	440	return 0;
YouTahDoug	0:d0eea54553ed	441	}
YouTahDoug	0:d0eea54553ed	442
YouTahDoug	0:d0eea54553ed	443	// memory capacity = BLOCKNR * BLOCK_LEN
YouTahDoug	0:d0eea54553ed	444	// where
YouTahDoug	0:d0eea54553ed	445	// BLOCKNR = (C_SIZE+1) * MULT
YouTahDoug	0:d0eea54553ed	446	// MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8)
YouTahDoug	0:d0eea54553ed	447	// BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12)
YouTahDoug	0:d0eea54553ed	448
YouTahDoug	0:d0eea54553ed	449	int block_len = 1 << read_bl_len;
YouTahDoug	0:d0eea54553ed	450	int mult = 1 << (c_size_mult + 2);
YouTahDoug	0:d0eea54553ed	451	int blocknr = (c_size + 1) * mult;
YouTahDoug	0:d0eea54553ed	452	int capacity = blocknr * block_len;
YouTahDoug	0:d0eea54553ed	453
YouTahDoug	0:d0eea54553ed	454	int blocks = capacity / 512;
YouTahDoug	0:d0eea54553ed	455
YouTahDoug	0:d0eea54553ed	456	return blocks;
YouTahDoug	0:d0eea54553ed	457	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	21 Jun 2011
Imports:	110
Forks:	0
Commits:	2
Dependents:	0
Dependencies:	1
Followers:	8

SDFileSystem.cpp@1:4a0985d3a848, 2011-06-22 (annotated)

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