SDCard.h

00001 //mbed Microcontroller Library
00002 //SDCard Interface
00003 //Copyright 2010
00004 //Thomas Hamilton
00005 
00006 #ifndef SDCardLibrary
00007 #define SDCardLibrary
00008 
00009 #include "stdint.h"
00010 #include "mbed.h"
00011 #include "FATFileSystem.h"
00012 
00013 class SDCard : public FATFileSystem
00014 {
00015     private:
00016         SPI DataLines;
00017         DigitalOut ChipSelect;
00018             //physical chip interface
00019 
00020         unsigned int t;
00021             //timeout counter
00022         unsigned int Timeout;
00023             //timeout limit
00024         bool CRCMode;
00025             //low: CRCs disabled, high: CRCs enabled
00026         bool Capacity;
00027             //low: low-capacity, high: high-capacity
00028         bool Version;
00029             //low: version 1, high: version 2
00030         unsigned char Status;
00031             //0x00: Ready, 0x01: not initialized
00032         unsigned char FSR[64];
00033             //function status register
00034         unsigned char CSD[16];
00035             //card-specific data register
00036         unsigned char OCR[4];
00037             //operating conditions register
00038         unsigned char DataCRCTable[512];
00039             //CRC16 CCITT lookup table
00040         unsigned char CommandCRCTable[256];
00041             //CRC7 SD command lookup table
00042 
00043         unsigned char Initialize();
00044             //complete all initialization operations
00045         void Command(unsigned char Index,
00046             unsigned int Argument, unsigned char* Response);
00047             //sends the SD command with the given Index and Argument to the SD
00048             //card and stores the SD Response
00049         void CommandCRC(unsigned char* IndexPtr,
00050             unsigned int* ArgumentPtr, unsigned char* Result);
00051             //calculates the SD proprietary CRC7 result of an SD command
00052             //(composed of a command index and argument) and stores the one-
00053             //byte solution in Result
00054         void DataCRC(
00055             unsigned short Length, unsigned char* Data, unsigned char* Result);
00056             //calculates the CRC16 CCITT result of the number of bytes in Data
00057             //given by Length and stores the two-byte solution in Result
00058             //assumes DataCRCTable has already been calculated
00059         void GenerateCRCTable(unsigned char Size,
00060             unsigned long long Generator, unsigned char* Table);
00061             //pre-calculates CRC results from the given Generator for efficient
00062             //checking; assumes pre-allocated Table is large enough to hold the
00063             //number of bytes given in Size
00064 
00065         virtual unsigned char disk_initialize();
00066         virtual unsigned char disk_status();
00067         virtual unsigned char disk_read(unsigned char* buff,
00068             unsigned long sector, unsigned char count);
00069         virtual unsigned char disk_write(const unsigned char* buff,
00070             unsigned long sector, unsigned char count);
00071         virtual unsigned char disk_sync();
00072         virtual unsigned long disk_sector_count();
00073         virtual unsigned short disk_sector_size();
00074         virtual unsigned long disk_block_size();
00075             //FAT system virtual functions that are called by the FAT module
00076 
00077     public:
00078         SDCard(PinName mosi, PinName miso, PinName sck, PinName cs,
00079             const char* DiskName);
00080             //constructor needs SPI pins, DigitalOut pins, and a directory name
00081         virtual ~SDCard();
00082             //destructor deallocates tables and registers
00083         unsigned char Format(unsigned int AllocationUnit);
00084             //formats the card FAT with given AllocationUnit in sectors; the
00085             //maximum is 32768 sectors
00086         unsigned char Log(unsigned char Control, unsigned char Data);
00087             //multipurpose single-byte raw data-logging method with three modes
00088             //Control   description
00089             //  0       synchronizes card and resets internal counter to
00090             //              finalize read or write operations
00091             //  1       successively write Data to a raw byte address in order
00092             //              starting at address 0
00093             //  2       successively read and return a raw data byte in order
00094             //              starting at address 0
00095             //return byte from sync or write operations and input Data of sync
00096             //or read operations are not used; writing with this function will
00097             //deformat the drive
00098         unsigned char Write(unsigned int Address, unsigned char* Data);
00099             //write the first 512 byte sector of Data to the card at the given
00100             //Address
00101         unsigned char Write(unsigned int Address,
00102             unsigned char SectorCount, unsigned char* Data);
00103             //write the first given SectorCount of 512 byte sectors of Data to
00104             //the card at the given Address
00105         unsigned char Read(unsigned int Address, unsigned char* Data);
00106             //read the first 512 byte sector from card at the given Address
00107             //into Data
00108         unsigned char Read(unsigned int Address,
00109             unsigned char SectorCount,  unsigned char* Data);
00110             //read the first given SectorCount of 512 byte sectors from the
00111             //card at the given Address into Data
00112         unsigned char SelectCRCMode(bool Mode);
00113             //toggle CRC mode; low: CRCs disabled, high: CRCs enabled, default:
00114             //CRCs disabled
00115         void SetTimeout(unsigned int Retries);
00116             //change the number of retries for interface functions; increase if
00117             //lines are unreliable; default: 1024, minimum: 1024
00118 };
00119 
00120 #endif