/*********************************************************

        +-----------------------------------------+
        |              SD卡模塊                   |
        +-----------------------------------------+
使用UART0串口SPI模式控制SD卡存儲  端口選擇 P3.0/STE=1  
    P3.1/SIMO=2  P3.2/SOMI=7  P3.3/UCLK=5   vcc(3.3)=4  
    Gnd=3,6
SD卡的底層驅(qū)動程序，主控芯片為msp340-149；
其他的微處理器(帶SPI接口的)只需稍加修改即可適用；

             ->產(chǎn)品咨詢 QQ:461693690 
		       MSN:ly461693690@hotmail.com
	                    
說明：SD卡模塊 通過測試，確保其正確性與穩(wěn)定性，請放心使用，
      			  
***********************************************************/
#include "MMC_SD.h"

void open_xt1(void)            //設(shè)置時鐘為8M晶振
{
  BCSCTL1 &= ~XT2OFF;
  char n;
  do
  {
    IFG1 &= ~OFIFG;
    for(n=0xee;n>0;n--)
      ;
  }
  while((IFG1&OFIFG)!=0);    
  BCSCTL2 |= SELM_2 + SELS; 
  
}

/* spi low speed, below 400KHz */
void SPI_Low(void)
{ BCSCTL2 |= DIVS_1; 
  UCTL0=SWRST;//開啟設(shè)置
  UTCTL0|=SSEL1+STC;//選擇SMCLK
  UCTL0|=CHAR+SYNC+MM;//8為數(shù)據(jù) SPI模式
  UBR00=0x03;//波特率設(shè)置 
  UBR10=0X00;
  UMCTL0=0X00;
  ME1|=USPIE0;//使能SPI
  UCTL0&=~SWRST;//關(guān)閉設(shè)置
 
}

/* spi high speed, not exceed 25MHz */
void SPI_High(void)
{
  open_xt1();
  UCTL0=SWRST;//開啟設(shè)置
  UTCTL0=SSEL1+STC;//選擇SMCLK
  UCTL0|=CHAR+SYNC+MM;//8為數(shù)據(jù) SPI模式
  UBR00=0x03;//波特率設(shè)置 
  UBR10=0X00;
  UMCTL0=0X00;
  ME1|=USPIE0;//使能SPI
  UCTL0&=~SWRST;//關(guān)閉設(shè)置
 
}


/* read and write one byte , full duplex */
uint8 SPI_WriteByte(uint8 val)
{  
   while((IFG1&UTXIFG0)==0);//等待...直到發(fā)送中斷標志位置位
   TXBUF0=val;
   while((IFG1&URXIFG0)==0);//等待...直到接受緩存數(shù)據(jù)滿  再取回數(shù)據(jù)
   return (RXBUF0);
}


/* sd send command */ 
uint8 MMC_SD_SendCommand(uint8 cmd, uint32 arg)
{
	uint8 r1;
	uint8 retry=0;
	
	SPI_WriteByte(0xff);
	SPI_CS_Assert;
	
	SPI_WriteByte(cmd | 0x40);	/* send command */
	SPI_WriteByte(arg>>24);
	SPI_WriteByte(arg>>16);
	SPI_WriteByte(arg>>8);
	SPI_WriteByte(arg);
	SPI_WriteByte(0x95);
	
	while((r1 = SPI_WriteByte(0xff)) == 0xff)	/* wait response */
		if(retry++ > 0xfe) break;				/* time out error */

	return r1;								/* return state */
}

/* SD card initialization, include reset and configuration */
uint8 MMC_SD_Init(void)
{
	uint8 i;
	uint8 retry = 0;
	uint8 r1 = 0;
	
	P3SEL|=0X0e;//0000 1110 P3.0.1.2.3選擇第二功能
        P3DIR|=0X0B;//0000 1011	                          /* Port Initialize */
        
	SPI_Low();			                  /* SPI intialize */
	
	do
	 {
	   for(i=0;i<10;i++) SPI_WriteByte(0xff);
	   r1 = MMC_SD_SendCommand(0, 0);//發(fā)idle命令	//send idle command
	   retry++;
	   if(retry>0xfe) return 1;//超時退出		//time out
	  } while(r1 != 0x01);	
        SPI_CS_Deassert;
	SPI_WriteByte(0xff);				// extra 8 CLK

	retry = 0;
        
	do
	 {
	   r1 = MMC_SD_SendCommand(1, 0);              //發(fā)active命令	
	   retry++;
	   if(retry>0xfe) return 1;                    //超時退出		
	  } while(r1);
	SPI_CS_Deassert;
	SPI_WriteByte(0xff);				// extra 8 CLK
        
	SPI_High();		                        /* Use High Speed SPI*/
	
	r1 = MMC_SD_SendCommand(59, 0);                //關(guān)crc		
        SPI_CS_Deassert;
	SPI_WriteByte(0xff);				// extra 8 CLK

	r1 = MMC_SD_SendCommand(16, 512);               //設(shè)扇區(qū)大小512	
        
        SPI_CS_Deassert;
	SPI_WriteByte(0xff);				// extra 8 CLK
	return 0;                                      //正常返回		
}

//讀一個扇區(qū)		//read one sector
uint8 MMC_SD_ReadSingleBlock(uint32 sector, uint8* buffer)
{
	uint8 r1;
	uint16 i;
	uint16 retry=0;

	r1 = MMC_SD_SendCommand(17, sector<<9);          //讀命令	
	
	if(r1 != 0x00)
		return r1;
        
	//等數(shù)據(jù)的開始	//wait to start recieve data
	while(SPI_WriteByte(0xff) != 0xfe)if(retry++ > 0xfffe){SPI_CS_Deassert;return 1;}

	for(i=0; i<512; i++)                             //讀512個數(shù)據(jù)	
	{
		*buffer++ = SPI_WriteByte(0xff);
	}

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

	return 0;
}


//寫一個扇區(qū)		//wirite one sector //not used in this application
uint8 MMC_SD_WriteSingleBlock(uint32 sector, uint8* buffer)
{
	uint8 r1;
	uint16 i;
	uint16 retry=0;

	r1 = MMC_SD_SendCommand(24, sector<<9);        //寫命令
	if(r1 != 0x00)
		return r1;
	
	SPI_WriteByte(0xff);
	SPI_WriteByte(0xff);
	SPI_WriteByte(0xff);

	SPI_WriteByte(0xfe);                          //發(fā)開始符			
	
	for(i=0; i<512; i++)                          //送512字節(jié)數(shù)據(jù)		
	{
		SPI_WriteByte(*buffer++);
	}
	
	SPI_WriteByte(0xff);			    //偽crc  
	SPI_WriteByte(0xff);
	
	r1 = SPI_WriteByte(0xff);
	
	if( (r1&0x1f) != 0x05)                     //等待是否成功	
	{
		SPI_CS_Deassert;
		return r1;
	}
	//等待操作完		
	while(!SPI_WriteByte(0xff))if(retry++ > 0xfffe){SPI_CS_Deassert;return 1;}

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

	return 0;
}



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

	r1 = MMC_SD_SendCommand(9,0);                //寫命令	
	if(r1 != 0x00)
		return r1;

	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_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;		
}