（圖一）



  （圖二）
/********************************************************************************************************************
函數(shù)名：unsigned char mmc_command(unsigned char *comm,unsigned char retuen_dat)
功能：向sd卡寫命令
返回： 1- >操作失敗 0->成功
********************************************************************************************************************/
unsigned char mmc_command(unsigned char *comm,unsigned char retuen_dat)
{
unsigned char n,temp,count,n_count;
count = 0;
do
{
SSEL_D(0);
for(n=0;n<6;n++)
SPI_Send_Dat(*comm++);
for(n_count=0;n_count<5;n_count++)
{
temp = SPI_Receiver_Dat();
if(temp == retuen_dat)break;
}
SSEL_D(1);
SPI_Send_Dat(0xff);
if(count>100) return 1;
}while(temp!=retuen_dat);
return 0;
}
/*******************************************************************************************************
函數(shù)名：void mmc_init(void)
功能：初始化sd卡
返回： 無
*******************************************************************************************************/
void mmc_init(void)
{
unsigned char command_dat[6];
unsigned char n;
for(n=0;n<6;n++) command_dat[n] = 0;
SPI_Init();
for(n=0;n<16;n++)
SPI_Send_Dat(0xff);//圖一 同步用至少74個(gè)周期
command_dat[0] = 0x40;
command_dat[5] = 0x95;
mmc_command(command_dat,0x01);//圖二
command_dat[0] = 0x41;
command_dat[5] = 0xff;
mmc_command(command_dat,0x00);//圖二
}







/*******************************************************************************************************
函數(shù)名：void write_mmc_dat(unsigned char *comm,unsigned char *dat,unsigned int len)
功能：向sd寫數(shù)據(jù)（底層）
返回： 無
*******************************************************************************************************/
void write_mmc_dat(unsigned char *comm,unsigned char *dat,unsigned int len)
{
 unsigned char n,temp,n_count;//,count;
unsigned int count;
 count = 0;
  for(count=0;count<5;count++)
  {
    SSEL_D(1);
    SPI_Send_Dat(0xff);
    SSEL_D(0);
    for(n=0;n<6;n++)
    SPI_Send_Dat(*comm++);
    for(n_count=0;n_count<5;n_count++)
    {
     temp =  SPI_Receiver_Dat();
     if(temp == 0)break;
    }
              if(temp == 0)break;
  }
       SPI_Send_Dat(0xff);
      SPI_Send_Dat(0xff);
     SPI_Send_Dat(0xfE);//開始寫
      for(count=0;count<len;count++)
  {
    SPI_Send_Dat(*dat);
    dat++;
  }   
       SPI_Send_Dat(0xff);
         SPI_Send_Dat(0xff);
         temp =  SPI_Receiver_Dat();
   if( temp&0x1f!=0x05);//寫失敗
   SSEL_D(1);
   SPI_Send_Dat(0xff);
} 
/*******************************************************************************************************
函數(shù)名：void write_mmc_dat(unsigned char *comm,unsigned char *dat,unsigned int len)
功能：向sd寫數(shù)據(jù)
返回： 無
*******************************************************************************************************/
void  MMCWdBolckOne(unsigned long addr,unsigned char *buffer)
{
  unsigned char command_dat[6];
  command_dat[0] = 0x40 + 24;              // READ SINGLE BLOCK
     addr <<=  9;                                      // addr*512,取512的整數(shù)倍
  command_dat[1] = (addr >> 24);
  command_dat[2] = (addr >> 16);
  command_dat[3] = (addr >> 8);
  command_dat[4] = (addr >> 0);
     command_dat[5] = 0;
  write_mmc_dat(command_dat,buffer,512);
}



/*******************************************************************************************************
函數(shù)名：void write_mmc_dat(unsigned char *comm,unsigned char *dat,unsigned int len)
功能：向sd讀數(shù)據(jù)（底層）
返回： 無
*******************************************************************************************************/
void read_mmc_dat(unsigned char *comm,unsigned char *dat,unsigned int len)
{
 unsigned char n,temp,count,n_count;
 count = 0;
  for(count=0;count<5;count++)
  {
    SSEL_D(1);
    SPI_Send_Dat(0xff);
    SSEL_D(0);
    for(n=0;n<6;n++)
    SPI_Send_Dat(*comm++);
    for(n_count=0;n_count<5;n_count++)
    {
     temp =  SPI_Receiver_Dat();
     if(temp == 0)break;
    }
             if(temp == 0)break;
  }
  for(n_count=0;n_count<50;n_count++)
  {
   temp =  SPI_Receiver_Dat();
   if(temp == 0xfe)break;
  }
    while(len--)
  {
   *dat =  SPI_Receiver_Dat();
    dat++;
  }   
   SPI_Send_Dat(0xff);
         SPI_Send_Dat(0xff);
   SSEL_D(1);
   SPI_Send_Dat(0xff);
}
/*******************************************************************************************************
函數(shù)名：void write_mmc_dat(unsigned char *comm,unsigned char *dat,unsigned int len)
功能：讀sd寫數(shù)據(jù)
返回： 無
*******************************************************************************************************/
void MMCRdBolckOne(unsigned long addr,unsigned char *buffer,unsigned int len)
{
  unsigned char command_dat[6];
  command_dat[0] = 0x40 + 17;                     // READ SINGLE BLOCK
  addr <<=  9;                                     // addr*512,取512的整數(shù)倍
  command_dat[1] = (addr >> 24);
  command_dat[2] = (addr >> 16);
  command_dat[3] = (addr >> 8);
  command_dat[4] = (addr >> 0);
     command_dat[5] = 0;
  read_mmc_dat(command_dat,buffer,len);
}
 
#define SCK_IO(x)  (x?(P1=0X0f):(P1=0X0f))//1->輸出  0->輸入
#define MOSI_IO(x) (x?(P1=0X0f):(P1=0X0f))
#define MISO_IO(x) (x?(P1=0X0f):(P1=0X0f))
#define SSEL_IO(x) (x?(P1=0X0f):(P1=0X0f))
 
#define SCK_D(x)  (x?(P1|=0X01):(P1&=0XFE))
#define MOSI_D(x) (x?(P1|=0X02):(P1&=0XFD))
#define SSEL_D(X) (X?(P1|=0X08):(P1&=0XF7))
#define MISO_I()  (P1&0X04)
/**********************************************
模式零           spi 寫數(shù)據(jù)
***********************************************/
void SPI_Send_Dat(unsigned char dat)
{
 unsigned char n;
 for(n=0;n<8;n++)
 {
  SCK_D(0);
  if(dat&0x80)MOSI_D(1);
  else MOSI_D(0);
  dat<<=1;
  SCK_D(1);
 }
  SCK_D(0);
}
/*********************************************
模式零        spi  讀數(shù)據(jù)
*********************************************/
unsigned char SPI_Receiver_Dat(void)
{
 unsigned char n ,dat,bit_t;
 for(n=0;n<8;n++)
 {
  SCK_D(0);
  dat<<=1;
  if(MISO_I())dat|=0x01;
  else dat&=0xfe;
  SCK_D(1);
 }
  SCK_D(0);
  return dat;
}
void SPI_Init(void)
{
SCK_IO(1)   ; 
MOSI_IO(1)  ;
MISO_IO(0)  ; 
SSEL_IO(1)  ; 
SSEL_D(1);
MOSI_D(1);
SCK_D(0);
}

  
上行為寫    下行為讀
code unsigned char  leab[512] = {0x55,0xaa,2,3,4,5,6,7,8,9};
unsigned char rmmc[16];
main()
{
unsigned char i;
Time_Count0_Init(0 ,1);     //10ms時(shí)基
start_time0();         //開啟定時(shí)器0
Time_Count1_Init(0,2);    //用于產(chǎn)生9600串口波特率
start_time1() ;       //開啟定時(shí)器1
Uart_Config(1);          //配置串口
interrupt_Open();      //打開中斷
mmc_init();
 MMCWdBolckOne(0,leab);
 for(i=0;i<16;i++)
  Send_Data(leab[i]);
 MMCRdBolckOne(0x00,rmmc,10);
  for(i=0;i<16;i++)
  Send_Data(rmmc[i]);
while (1);
}

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