mmc.h

实现了avr下对sd卡的读写,支持文件存取,删除的功能

//*****************************************************************************
//
// 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   |
//	    |                  |
//	    X X X X X X X X X X 
//	    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
//
//*****************************************************************************
//-------------------------------------------------------------------------
// 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 num 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 begin 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: 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
//-------------------------------------------------------------------------
struct MMC_VOLUME_INFO{				//MMC/SD Card info
  uint32_t  size_MB;
  uint8_t   sector_multiply;
  uint32_t  sector_count;
  uint8_t   name[6];
};
//-------------------------------------------------------------------------
// 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.
uint8_t mmcReset(void);
//-------------------------------------------------------------------------
//! Send card an MMC command. Returns R1 result code.
uint8_t mmcSendCommand(uint8_t cmd, uint32_t arg);
//-------------------------------------------------------------------------
//! Read 512-byte sector from card to buffer Returns zero if successful.
uint8_t mmcRead(uint32_t sector, uint8_t* buffer);
//-------------------------------------------------------------------------
//! Write 512-byte sector from buffer to card Returns zero if successful.
uint8_t mmcWrite(uint32_t sector, uint8_t* buffer);
//-------------------------------------------------------------------------
//! Internal command function.Issues a generic MMC command.
uint8_t mmcCommand(uint8_t cmd, uint32_t arg);
//-------------------------------------------------------------------------
void MMC_get_volume_info(void);
//-------------------------------------------------------------------------