mmc_sd.c

mp3量不要让站长把时间都花费在为您修正说明上。压缩包解压时不能有密码。系统会自动删除debug和release目录

	}
	//等待操作完		//wait no busy
	while(!SPI_WriteByte(0xff))if(retry++ > ACCESS_TIMEOUT){SPI_CS_Deassert;return 1;}

	SPI_CS_Deassert;
	SPI_WriteByte(0xff);// extra 8 CLK

	return 0;
}


/* return number of max block, in case of 512bytes per unit */
uint32 MMC_SD_ReadCapacity()
{
	uint8 r1;
	uint16 i;
	uint16 temp;
	uint8 buffer[16];
	uint32 Capacity;
	uint32 retry =0;
	//uint8 retry=0;

	//if(address_mode==BLOCK_MODE) return 0; /*currently I do not have the spec. so do not kown how to calculate the capacity*/
	
	//SPI_High();		/* Use High Speed SPI*/

	r1 = MMC_SD_SendCommandCRC_NoDeassert(9, 0,0);//写命令	//send command  //READ CSD
	if(r1 != 0x00)
		return r1;

	SPI_CS_Assert;
	while(SPI_WriteByte(0xff) != 0xfe)if(retry++ > ACCESS_TIMEOUT){SPI_CS_Deassert;return 1;}

	
	for(i=0;i<16;i++)
	{
		buffer[i]=SPI_WriteByte(0xff);
	}	

	SPI_WriteByte(0xff);
	SPI_WriteByte(0xff);
	
	SPI_WriteByte(0xff);
	
	SPI_CS_Deassert;

	SPI_WriteByte(0xff);// extra 8 CLK

	if((buffer[0]&0xc0)==0x40)
	{
		Capacity =  (((uint32)buffer[8])<<8 + (uint32)buffer[9] +1)*(uint32)1024;
		return Capacity;
	}

/*********************************/
//	C_SIZE
	i = buffer[6]&0x03;
	i<<=8;
	i += buffer[7];
	i<<=2;
	i += ((buffer[8]&0xc0)>>6);

/**********************************/
//  C_SIZE_MULT

	r1 = buffer[9]&0x03;
	r1<<=1;
	r1 += ((buffer[10]&0x80)>>7);


/**********************************/
// BLOCKNR

	r1+=2;

	temp = 1;
	while(r1)
	{
		temp*=2;
		r1--;
	}
	
	Capacity = ((uint32)(i+1))*((uint32)temp);

/////////////////////////
// READ_BL_LEN

	i = buffer[5]&0x0f;

/*************************/
//BLOCK_LEN

	temp = 1;
	while(i)
	{
		temp*=2;
		i--;
	}
/************************/


/************** formula of the capacity ******************/
//
//  memory capacity = BLOCKNR * BLOCK_LEN
//	
//	BLOCKNR = (C_SIZE + 1)* MULT
//
//           C_SIZE_MULT+2
//	MULT = 2
//
//               READ_BL_LEN
//	BLOCK_LEN = 2
/**********************************************/

//The final result
	
	Capacity *= (uint32)temp;	 
	return Capacity/512;		
}


#if 0
/* SD card initialization, include reset and configuration */
uint8 MMC_SD_Init(void)
{
	uint8 i;
	uint8 retry = 0;
	uint8 r1 = 0;
	#if 0
	AT91PS_SPI pSPI      = AT91C_BASE_SPI;
	AT91PS_PMC pPMC      = AT91C_BASE_PMC;
	
	MMC_SD_PORT_INI;	/* Port Initialize */

	/* disable PIO from controlling MOSI, MISO, SCK (=hand over to SPI) */
	pPIO->PIO_PDR = AT91C_PA12_MISO | AT91C_PA13_MOSI | AT91C_PA14_SPCK;
	/* set pin-functions in PIO Controller */
	pPIO->PIO_ASR = AT91C_PA12_MISO | AT91C_PA13_MOSI | AT91C_PA14_SPCK;

	/* enable peripheral clock for SPI ( PID Bit 5 ) */
	pPMC->PMC_PCER = ( 1 << AT91C_ID_SPI ); /* n.b. IDs are just bit-numbers */

	/* SPI enable and reset */
	pSPI->SPI_CR = AT91C_SPI_SPIEN | AT91C_SPI_SWRST;

	/* SPI mode: master, fixed periph. sel., FDIV=0, fault detection disabled */
	pSPI->SPI_MR  = AT91C_SPI_MSTR | AT91C_SPI_PS_FIXED | AT91C_SPI_MODFDIS;

	/* set PCS for fixed select, in this program we do not use select of the SPI */
	/* We control the select ourself, so the default cs is 0, but we never use it */
	pSPI->SPI_MR &= 0xFFF0FFFF; /* clear old PCS - redundant (AT91lib) */
	pSPI->SPI_MR |= ( (0<<16) & AT91C_SPI_PCS ); /* set PCS */
	pSPI->SPI_CSR[0] = AT91C_SPI_NCPHA | AT91C_SPI_BITS_8;
#endif

	SPI1_CS_GPIO();		
	SPI1_CS_OUT();
		SPI_CS_Deassert;	
		
	PINSEL1 &= ~((0x03 << 2) + (0x03 << 4) + (0x03 << 6)); 
	PINSEL1 |=  (0x02 << 2) + (0x02 << 4) + (0x02 << 6);
	
	SSPCR0 = (0x00 << 8) |              			// SCR=0  
            (0x00 << 7) |             				// CPHA =0时钟输出相位,仅SPI模式有效 
            (0x00 << 6) |              				// CPOL =0时钟输出极性,仅SPI模式有效
            (0x00 << 4) |              				// FRF =00 帧格式 00=SPI,01=SSI,10=Microwire,11=保留
            (0x07 << 0);               				// DSS  数据长度,0000-0010=保留,0011=4位,0111=8位,1111=16位

    SSPCR1 = (0x00 << 3) |              			// SOD  从机输出禁能,1=禁止,0=允许
            (0x00 << 2) |              				// MS   主从选择,0=主机,1=从机
            (0x01 << 1) |              				// SSE  SSP使能,1=允许SSP与其它设备通信
            (0x00 << 0);               				// LBM  回写模式
             
	/* set SPI clock speed */
	SPI_Low();
#if 0
	/* Enable SPI interface */
	pSPI->SPI_CR = AT91C_SPI_SPIEN;
	
#endif

	do
	{
		for(i=0;i<10;i++) SPI_WriteByte(0xff);
		r1 = MMC_SD_SendCommand(0, 0);//发idle命令	//send idle command
		retry++;
		if(retry>0xfe) return 1;//超时退出		//time out
	} while(r1 != 0x01);	


	retry = 0;
	do
	{
		r1 = MMC_SD_SendCommand(1, 0);//发active命令	//send active command
		retry++;
		if(retry>0xfe) return 1;//超时退出		//time out
	} while(r1);
	
	SPI_High();		/* Use High Speed SPI*/
	
	r1 = MMC_SD_SendCommand(59, 0);//关crc		//disable CRC

	r1 = MMC_SD_SendCommand(16, 512);//设扇区大小512	//set sector size to 512
	return 0;//正常返回		//normal return
}

//读一个扇区		//read one sector
uint8 MMC_SD_ReadSingleBlock(uint32 sector, uint8* buffer)
{
	uint8 r1;
	uint16 i;
	uint16 retry=0;

	SPI_High();		/* Use High Speed SPI*/

	r1 = MMC_SD_SendCommand(17, sector<<9);//读命令	//read command
	
	if(r1 != 0x00)
		return r1;

	SPI_CS_Assert;
	//等数据的开始	//wait to start recieve data
	while(SPI_WriteByte(0xff) != 0xfe)
	{
		if(retry++ > 0xfffe)
		{
			SPI_CS_Deassert;
			return 1;
		}
	}
	
	for(i=0; i<512; i++)//读512个数据	//read 512 bytes
	{
		*buffer++ = SPI_WriteByte(0xff);
	}

	SPI_WriteByte(0xff);//伪crc    //dummy crc
	SPI_WriteByte(0xff);
	
	SPI_CS_Deassert;
	SPI_WriteByte(0xff);// extra 8 CLK

	return 0;
}


//写一个扇区		//wirite one sector //not used in this application
uint8 MMC_SD_WriteSingleBlock(uint32 sector, uint8* buffer)
{
	uint8 r1;
	uint16 i;
	uint16 retry=0;
	
	SPI_High();		/* Use High Speed SPI*/

	r1 = MMC_SD_SendCommand(24, sector<<9);//写命令	//send command
	if(r1 != 0x00)
		return r1;

	SPI_CS_Assert;
	
	SPI_WriteByte(0xff);
	SPI_WriteByte(0xff);
	SPI_WriteByte(0xff);

	SPI_WriteByte(0xfe);//发开始符			//send start byte "token"
	
	for(i=0; i<512; i++)//送512字节数据		//send 512 bytes data
	{
		SPI_WriteByte(*buffer++);
	}
	
	SPI_WriteByte(0xff);			//dummy crc
	SPI_WriteByte(0xff);
	
	r1 = SPI_WriteByte(0xff);
	
	if( (r1&0x1f) != 0x05)//等待是否成功	//judge if it successful
	{
		SPI_CS_Deassert;
		return r1;
	}
	//等待操作完		//wait no busy
	while(SPI_WriteByte(0xff) != 0x00)
	{
		if(retry++ > 0xfffe)
		{
			SPI_CS_Deassert;
			return 1;
		}
	}
	SPI_CS_Deassert;
	SPI_WriteByte(0xff);// extra 8 CLK

	return 0;
}



uint32 MMC_SD_ReadCapacity(void)
{
	uint8 r1;
	uint16 i;
	uint16 temp;
	uint8 buffer[16];
	uint32 Capacity;
	uint16 retry =0;
	//uint8 retry=0;

	SPI_High();		/* Use High Speed SPI*/

	r1 = MMC_SD_SendCommand(9, 0);//写命令	//send command  //READ CSD
	if(r1 != 0x00)
		return r1;
	
	SPI_CS_Assert;

	while(SPI_WriteByte(0xff) != 0xfe)
	{
		if(retry++ > 0xfffe)
		{
			SPI_CS_Deassert;
			return 1;
		}
	}
	
	for(i=0;i<16;i++)
	{
		buffer[i]=SPI_WriteByte(0xff);
	}	

	SPI_WriteByte(0xff);
	SPI_WriteByte(0xff);
	
	SPI_WriteByte(0xff);
	
	SPI_CS_Deassert;

	SPI_WriteByte(0xff);// extra 8 CLK

/*********************************/
//	C_SIZE
	i = buffer[6]&0x03;
	i<<=8;
	i += buffer[7];
	i<<=2;
	i += ((buffer[8]&0xc0)>>6);

/**********************************/
//  C_SIZE_MULT

	r1 = buffer[9]&0x03;
	r1<<=1;
	r1 += ((buffer[10]&0x80)>>7);


/**********************************/
// BLOCKNR

	r1+=2;

	temp = 1;
	while(r1)
	{
		temp*=2;
		r1--;
	}
	
	Capacity = ((uint32)(i+1))*((uint32)temp);

/////////////////////////
// READ_BL_LEN

	i = buffer[5]&0x0f;

/*************************/
//BLOCK_LEN

	temp = 1;
	while(i)
	{
		temp*=2;
		i--;
	}
/************************/


/************** formula of the capacity ******************/
//
//  memory capacity = BLOCKNR * BLOCK_LEN
//	
//	BLOCKNR = (C_SIZE + 1)* MULT
//
//           C_SIZE_MULT+2
//	MULT = 2
//
//               READ_BL_LEN
//	BLOCK_LEN = 2
/**********************************************/

//The final result
	
	Capacity *= (uint32)temp;	 
	return Capacity;		
}
#endif