MultiMedia Card low level Functions. More...

#include <avr/io.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include "types.h"
#include "mmc.h"
#include "delay.h"
#include "main.h"
#include "uart.h"
#include "vs1001.h"

Include dependency graph for mmc.c:

Go to the source code of this file.

Defines
#define	MMC_C
Functions
void	SpiInit (void)
	Setup Pin configuration of SPI bus for the AVR.
uint8	SpiByte (unsigned char byte)
	Main SPI routine transmits a byte and receives a byte simultaneously received byte is returned if you only want to read a byte, put a dummy (say 0xff) in the transmit slot.
uint8	MMCGet (void)
	Retrieve data from then MMC.
void	MMCCommand (unsigned char command, uint8 px, uint8 py, uint8 pz)
	Send a control command to the MMC.
uint8	MMC_Reset (void)
	Perform a Hardware then software reset of the MMC.
uint8	MMC_Detect (void)
	Checks if there is a memory card in the slot This requires a pull down resistor on the CS line of about 100K.
uint16	MMC_Check (void)
	Send the get status command to the MMC and returns the result.
uint8	MMC_Read (uint32 lba)
	Grab the Serial number & info from the card.
Variables
uint8	mmc_sbuf [512]
	512 byte sector buffer in internal RAM
uint8	mmc_scratch [32]
	32 byte Scratch buffer for CSD/CID/ ops

Detailed Description

MultiMedia Card low level Functions.

Author:: Nick Lott brokentoaster@users.sf.net

Date:: September 2004

Id:: mmc.c,v 1.18 2009/01/10 22:40:12 brokentoaster Exp

This file represents a convergence of a number of code snippets found on the web, some of the Yampp system by Jesper Hansen and the work done by Sylvain.Bissonnette@microsyl.com. The goal is to produce an adaptable library for doing low level MMC activities over the SPI bus. This code was written with the Atmega169V in mind (aka "Butterfly"). http://butterflymp3.sf.net

For details Concerning the MMC spec see www.sandisk.com. I refered to "SanDisk MultiMediaCard and Reduced-Size MultiMediaCard Product Manual" Doc No. 80-36-00320 v1.0 during the writing of this code.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

History:

24-26 Sep 2004: Initial write and port of functions collected over last few months

March 2005: Add new improvements based around Circuit cellar article. Updated Comments for Doxygen

Definition in file mmc.c.

Define Documentation

#define MMC_C

Definition at line 50 of file mmc.c.

Function Documentation

uint16 MMC_Check ( void )

Send the get status command to the MMC and returns the result.

Returns:: 2 byte value from MMC status register

Definition at line 281 of file mmc.c.

References MMC_CS, MMC_PORT, MMC_SEND_STATUS, MMCCommand(), MMCGet(), SBI, and SpiByte().

Referenced by handle_mmc(), and MMC_tester().

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uint8 MMC_Detect ( void )

Checks if there is a memory card in the slot This requires a pull down resistor on the CS line of about 100K.

Returns:: FALSE card not detected; TRUE card detected

Definition at line 251 of file mmc.c.

References FALSE, MMC_CS, MMC_DDR, MMC_PIN, MMC_PORT, and TRUE.

Referenced by handle_mmc().

uint8 MMC_Read ( uint32 lba )

Grab the Serial number & info from the card.

Returns status response from card. if successful CID is in mmc_scratch[1..16]

Returns:: byte response from the CID command Retrieves the CSD Register from the mmc and stores it in mmc_scratch[1..17]; Status response from cmd Calculates the capacity of the MMC in blocks; uint32 capacity of MMC in blocks or -1 in error; Read the OEM/Manufcatures MMC Name into the scratchpad.; status of MMC from SEND_CID cmd.

Definition at line 422 of file mmc.c.

References CBI, MMC_CS, MMC_PORT, MMC_READ_SINGLE_BLOCK, mmc_sbuf, MMC_SEND_STATUS, MMC_STARTBLOCK_READ, MMCCommand(), MMCGet(), SBI, and SpiByte().

Referenced by FAT_tester(), init_HW(), and MMC_tester().

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uint8 MMC_Reset ( void )

Perform a Hardware then software reset of the MMC.

Returns:: 00 if reset successful; FF if reset unsuccessful

Definition at line 200 of file mmc.c.

References MMC_CS, MMC_PORT, MMCCommand(), MMCGet(), SBI, and SpiByte().

Referenced by FAT_tester(), handle_mmc(), init_mmc_fat(), MMC_tester(), and streaming().

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void MMCCommand	(	unsigned char	command,
		uint8	px,
		uint8	py,
		uint8	pz
	)

Send a control command to the MMC.

send one byte of 0xff, then issue command + params + (fake) crc eat up the one command of nothing after the CRC Clears the MMC_CS and BSYNC_PIN lines. MMC must be de-selected outside of this code !!

Parameters: