SD卡开发 单片机读写SD卡 模拟SPI总线的子程序

qujian1120

模拟SPI总线的子程序：
sbit CS=P1^0;
sbit CLK= P1^1;
sbit DATaI=P1^2;
sbit DATaO=P1^3;
#define SD_Disable() CS=1 //Disable CS
#define SD_Enable() CS=0 //Enable CS
unsigned char SPI_TransferByte(unsigned char val)
{
  unsigned char BitCounter;
  for(BitCounter=8; BiCounter!=0; BitCounter--)
  {
    CLK=0; DATaI=0; // write
    if(val&0x80) DATaI=1;
    val<<=1; CLK=1;
    if(DATaO)val|=1; // read
  }
  CLK=0;
  return val;
}


初始化SD卡的子程序
unsigned char SD_Init(void)
{
  unsigned char retry,temp;
  unsigned char i;
   for (i=0;i<0x0f;i++)
   { SPI_TransferByte(0xff); //delay }
    SD_Enable(); //Enable Chip select
    SPI_TransferByte(SD_RESET); //send a reset command
    SPI_TransferByte(0x00);
    SPI_TransferByte(0x00);
    SPI_TransferByte(0x00);         
    SPI_TransferByte(0x00);
    SPI_TransferByte(0x95);
    SPI_TransferByte(0xff);
    SPI_TransferByte(0xff);
    retry=0;
    do
    {
        temp=Write_Command_SD(SD_INIT,0); //Send the initialization command
        retry++;
        if(retry==100) //retry 100 times
        {
              SD_Disable(); //disable chip select
              return(INIT_CMD1_ERROR); //If retry fails returns an error number
        }
     }while(temp!=0);
     SD_Disable(); //disable card
     return(TRUE); //return success
}
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chocoer

有没有完整的SD.h?