mmc.h

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/*! \file mmc.h \brief MultiMedia and SD Flash Card Interface. */
//*****************************************************************************
//
// File Name    : 'mmc.h'
// Title        : MultiMedia and SD Flash Card Interface
// Author       : Pascal Stang - Copyright (C) 2004
// Created      : 2004.09.22
// Revised      : 2004.09.22
// Version      : 0.1
// Target MCU   : Atmel AVR Series
// Editor Tabs  : 4
//
/// \ingroup driver_hw
/// \defgroup mmc MultiMedia and SD Flash Card Interface (mmc.c)
/// \code #include "mmc.h" \endcode
/// \par Description
///     This library offers some simple functions which can be used
///     to read and write data on a MultiMedia or SecureDigital (SD) Flash
///     Card.  Although MM and SD Cards are designed to operate with their own
///     special bus wiring and protocols, both types of cards also provide a
///     simple SPI-like interface mode which is exceptionally useful when 
///     attempting to use the cards in embedded systems.
///
/// \par Wiring
///     To work with this library, the card must be wired to the SPI port of
///     the Atmel microcontroller as described below.  Typical cards can
///     operate at up to 25MHz maximum SPI clock rate (thus faster than most
///     AVR's maximum SPI clock rate).
/// <pre>
///       _________________
///      /  1 2 3 4 5 6 78 |    <- view of MMC/SD card looking at contacts
///     / 9                |    Pins 8 and 9 are present only on SD cards
///     |    MMC/SD Card   |
///     |                  |
///     /\/\/\/\/\/\/\/\/\/\
///     1 - CS   (chip select)          - wire to any available I/O pin(*)
///     2 - DIN  (data in, card<-host)  - wire to SPI MOSI pin
///     3 - VSS  (ground)               - wire to ground
///     4 - VDD  (power, 3.3V only?)    - wire to power (MIGHT BE 3.3V ONLY!)
///     5 - SCLK (data clock)           - wire to SPI SCK pin
///     6 - VSS  (ground)               - wire to ground
///     7 - DOUT (data out, card->host) - wire to SPI MISO pin
///
///     (*) you must define this chip select I/O pin in mmcconf.h
/// </pre>
/// \note This code is currently below version 1.0, and therefore is considered
/// to be lacking in some functionality or documentation, or may not be fully
/// tested.  Nonetheless, you can expect most functions to work.
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************
//@{

#ifndef MMC_H
#define MMC_H

#include "global.h"

// constants/macros/typdefs
// MMC commands (taken from sandisk MMC reference)
#define MMC_GO_IDLE_STATE           0       ///< initialize card to SPI-type access
#define MMC_SEND_OP_COND            1       ///< set card operational mode
#define MMC_SEND_CSD                9       ///< get card's CSD
#define MMC_SEND_CID                10      ///< get card's CID
#define MMC_SEND_STATUS             13
#define MMC_SET_BLOCKLEN            16      ///< Set number of bytes to transfer per block
#define MMC_READ_SINGLE_BLOCK       17      ///< read a block
#define MMC_WRITE_BLOCK             24      ///< write a block
#define MMC_PROGRAM_CSD             27
#define MMC_SET_WRITE_PROT          28
#define MMC_CLR_WRITE_PROT          29
#define MMC_SEND_WRITE_PROT         30
#define MMC_TAG_SECTOR_START        32
#define MMC_TAG_SECTOR_END          33
#define MMC_UNTAG_SECTOR            34
#define MMC_TAG_ERASE_GROUP_START   35      ///< Sets beginning of erase group (mass erase)
#define MMC_TAG_ERARE_GROUP_END     36      ///< Sets end of erase group (mass erase)
#define MMC_UNTAG_ERASE_GROUP       37      ///< Untag (unset) erase group (mass erase)
#define MMC_ERASE                   38      ///< Perform block/mass erase
#define MMC_CRC_ON_OFF              59      ///< Turns CRC check on/off
// R1 Response bit-defines
#define MMC_R1_BUSY                 0x80    ///< R1 response: bit indicates card is busy
#define MMC_R1_PARAMETER            0x40
#define MMC_R1_ADDRESS              0x20
#define MMC_R1_ERASE_SEQ            0x10
#define MMC_R1_COM_CRC              0x08
#define MMC_R1_ILLEGAL_COM          0x04
#define MMC_R1_ERASE_RESET          0x02
#define MMC_R1_IDLE_STATE           0x01
// Data Start tokens
#define MMC_STARTBLOCK_READ         0xFE    ///< when received from card, indicates that a block of data will follow
#define MMC_STARTBLOCK_WRITE        0xFE    ///< when sent to card, indicates that a block of data will follow
#define MMC_STARTBLOCK_MWRITE       0xFC
// Data Stop tokens
#define MMC_STOPTRAN_WRITE          0xFD
// Data Error Token values
#define MMC_DE_MASK                 0x1F
#define MMC_DE_ERROR                0x01
#define MMC_DE_CC_ERROR             0x02
#define MMC_DE_ECC_FAIL             0x04
#define MMC_DE_OUT_OF_RANGE         0x04
#define MMC_DE_CARD_LOCKED          0x04
// Data Response Token values
#define MMC_DR_MASK                 0x1F
#define MMC_DR_ACCEPT               0x05
#define MMC_DR_REJECT_CRC           0x0B
#define MMC_DR_REJECT_WRITE_ERROR   0x0D

// functions

//! Initialize AVR<->MMC hardware interface.
/// Prepares hardware for MMC access.
void mmcInit(void);

//! Initialize the card and prepare it for use.
/// Returns zero if successful.
u08 mmcReset(void);

//! Send card an MMC command.
/// Returns R1 result code.
u08 mmcSendCommand(u08 cmd, u32 arg);

//! Read 512-byte sector from card to buffer
/// Returns zero if successful.
u08 mmcRead(u32 sector, u08* buffer);

//! Write 512-byte sector from buffer to card
/// Returns zero if successful.
u08 mmcWrite(u32 sector, u08* buffer);

//! Internal command function.
/// Issues a generic MMC command as specified by cmd and arg.
u08 mmcCommand(u08 cmd, u32 arg);

#endif
//@}

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