mmc.c

sd卡＋VS1003模块＋M16组成的mp3 VS1003模块使用www.icdev.com.cn的

#include "mmc.h"

/*==========================================================
//	function:	spi mode send and receive data
//	Parameter:	data		send data
//	return:		u8			receive data
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcSendByte(unsigned char data)
{
	unsigned char tmp;
	SPDR = data;
	while( !(SPSR & (1 << SPIF)) );	
	tmp = SPDR;
	return tmp;
}

/*==========================================================
//	function:	send command to mmc card
//	Parameter:	*cmd		command 6bytes(cmd,d,d,d,d,crc)
//	return:		u8			return data
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcWriteCmd(unsigned char *cmd)
{
	unsigned char tmp;
	unsigned char retry=0;
	mmcDisable();
	mmcSendByte(0xFF);
	mmcEnable();

	for(tmp = 0; tmp < 6; tmp++)		//command send
	{
		mmcSendByte(*cmd++);
	}

	tmp = 0xFF;
	while(tmp == 0xFF)
	{
		tmp = mmcSendByte(0xFF);		//wait return value
		if(retry++ > 100)
		{
			break;
		}
	}
	return(tmp);
}

/*==========================================================
//	function:	mmc init
//	Parameter:	void
//	return:		u8			init return
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcIni(void)
{
	unsigned char retry=0;
	unsigned char tmp;
	unsigned char cmd[] = {0x40,0x00,0x00,0x00,0x00,0x95};
	DDRB |= MMC_MSK;
	PORTB |= MMC_CS;
	DDRA &= ~(MMC_DET);
	SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR0) | (1 << SPR1);

	mmcDisable();
	for(tmp = 0; tmp < 200; tmp++)		//little wait
	{
		asm("NOP");
	}
	for(tmp = 0; tmp < 0x0F; tmp++)		//min 74 clock
	{
		mmcSendByte(0xFF);
	}

	while(mmcWriteCmd(cmd) != 1)		//step 1,CMD0,return 1
	{
		if(retry++ > 200)
		{
			return 1;
		}
	}

	retry=0;
	cmd[0] = 0x41;
	cmd[5] = 0xFF;
	while(mmcWriteCmd(cmd) != 0)		//step 2,CMD1,return 0
	{
		if(retry++ > 200)
		{
			return 2;
		}
	}

	SPCR &= ~((1 << SPR0) | (1 << SPR1));
	SPSR |= (1 << SPI2X);				//full speed spi

	mmcDisable();
	return 0;
}

/*==========================================================
//	function:	Write a sector,512 bytes
//	Parameter:	addr		sector serial
//				*buff		data buffer
//	return:		u8			write return
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcWriteSector(unsigned long addr,unsigned char *buff)
{
	unsigned char tmp;
	unsigned int i;
	unsigned char cmd[] = {0x58,0x00,0x00,0x00,0x00,0xFF}; 

	addr = addr<<9;	// *512
	cmd[1] = ((addr & 0xFF000000) >>24 );
	cmd[2] = ((addr & 0x00FF0000) >>16 );
	cmd[3] = ((addr & 0x0000FF00) >>8 );

	tmp = mmcWriteCmd(cmd);				//CMD24
	if(tmp != 0)
	{
		return tmp;
	}
	for(i = 0; i < 100; i++)			//send dummy
	{
		mmcSendByte(0xFF);
	}
	mmcSendByte(0xFE);					//send data start token
	for(i = 0; i < 0x200; i++)			//send data
	{
		mmcSendByte(*buff++);
	}
	mmcSendByte(0xFF);
	mmcSendByte(0xFF);					//write 16-bit CRC (dummy values)

	while(0xFF != mmcSendByte(0xFF));
	mmcDisable();
	return 0;
}

/*==========================================================
//	function:	read data
//	Parameter:	*cmd		command 6bytes
//				*buff		read data buffer
//				size		read data size
//	return:		void
//	date:		2006/10/18
//	note:		none
==========================================================*/
void mmcReadBlock(unsigned char *cmd,unsigned char *buff,unsigned int size)
{
	unsigned int i;
	asm("cli");
	if(mmcWriteCmd(cmd) != 0)
	{
		return;
	}
	while(0xFE != mmcSendByte(0xFF));
	for(i = 0; i < size; i++)
	{
		*buff++ = mmcSendByte(0xFF);
	}
	mmcSendByte(0xFF);
	mmcSendByte(0xFF);
	mmcDisable();
	asm("sei");
	return;
}

/*==========================================================
//	function:	read 1 sector data,512 bytes 
//	Parameter:	addr		sector serial
//				*buff		read data buffer
//	return:		u8			always return 0
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcReadSector(unsigned long addr,unsigned char *buff)
{
	unsigned char cmd[] = {0x51,0x00,0x00,0x00,0x00,0xFF}; 

	addr = addr<<9;
	cmd[1] = ((addr & 0xFF000000) >>24 );
	cmd[2] = ((addr & 0x00FF0000) >>16 );
	cmd[3] = ((addr & 0x0000FF00) >>8 );
	mmcReadBlock(cmd,buff,512);
	return 0;
}

/*==========================================================
//	function:	read card cid
//	Parameter:	*buff		cid buffer(03,53,44,53,44,...)
//	return:		u8			always return 0
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcReadCid(unsigned char *buff)
{
	unsigned char cmd[] = {0x4A,0x00,0x00,0x00,0x00,0xFF}; 

	mmcReadBlock(cmd,buff,16);

	return 0;
}

/*==========================================================
//	function:	read card csd
//	Parameter:	*buff		csd buffer(P3.5.3)
//	return:		u8			always return 0
//	date:		2006/10/18
//	note:		none
==========================================================*/
unsigned char mmcReadCsd(unsigned char *buff)
{
	unsigned char cmd[] = {0x49,0x00,0x00,0x00,0x00,0xFF}; 

	mmcReadBlock(cmd,buff,16);

	return 0;
}