[HYknight]

Chào các bác !!!
Em cũng đang ngâm cứu về SDCard
Nhưng hiện tại em mới chỉ khởi tạo cho thẻ mà không được
Reset thì thẻ vẫn trả về được Reponse R1 = 0x01
Đây là code và shematic
Mong các bác xem và giúp đỡ em

//Chuong trinh giao tiep voi SD card --------------------------
//  ------------ main.c ------------------------------
#include <18F452.h>
#fuses hs,nowdt,nolvp
#use delay (clock = 12000000)
#include <LCD_HYknight.C>
#include <def_18f452.c>
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,ERRORS)
#include <SDCard.c>


void main()
     {   
      SETUP_ADC_PORTS(NO_ANALOGS);
      SETUP_SPI (SPI_MASTER |  SPI_SS_DISABLED |SPI_H_TO_L| SPI_CLK_DIV_4 | SPI_XMIT_L_TO_H);
 
      TRISA = 0X00 ;
      TRISC = 0X93;
      TRISB = 0XF0;
      TRISD = 0X0F;
      TRISE = 0X00;
      CS=1;
      
     
      LCD_INIT();
      
      PRINTF("\r\n**** Doc ghi SD card - HYknight - CFOC **** ");      
      PRINTF("\r\n");
      DELAY_MS(2000);
      
      PRINTF("\r\ Khoi tao Card..... ");
      PRINTF("\r\n");
      DELAY_MS(2000);


      if(mmc_init()== 0)
       {
         printf("> Khoi tao card thanh cong...\r\n>");
         DELAY_MS(2000);
       }
      else
       {
      printf("> Khong khoi tao duoc, xin moi khoi tao lai...!\r\n");
      LCD_PUTCHAR("Khong kt duoc");

       }
    


      }

// --------------- SDCard.c ----------------------
// -----------------------------------------------

#DEFINE CS  rc2 // chip select for MMC
#DEFINE SDO rc5
#DEFINE CLK rc3
#DEFINE SDI rc4

void send_6byte(int8 cmd, int16 argh, int16 argl, int8 crc7);
int mmc_init();

char str[600];
CHAR CH;

int8 HIGH(long data)
{
   int8 modi;
   modi = data>>8;
   return(modi);
}

int8 LOW(long data)
{
   int8 modi;
   modi = data;
   return(modi);
}

void send_6byte(int8 cmd, int16 argh, int16 argl, int8 crc7)
{
   spi_write(cmd);
   spi_write(make8(argh,1));
   spi_write(make8(argh,0));
   spi_write(make8(argl,1));
   spi_write(make8(argh,0));
   spi_write(crc7);
}

int mmc_response(unsigned char response)
{
        unsigned long count = 0xFFFF;           // 16bit repeat, it may be possible to shrink this to 8 bit but there is not much point

        while(SPI_READ(0xFF) != response && --count > 0);

        if(count==0) return 1;                  // loop was exited due to timeout
        else return 0;                          // loop was exited before timeout
}

int mmc_init()
   {
      int i;
      *0x94 |= 0x40;                          // set CKE = 1 - clock idle low
      *0x14 &= 0xEF;                          // set CKP = 0 - data valid on rising edge
      
      CS =1;                    // set cs = 1 (off)
      SPI_WRITE(0xFF);
      for(i=0;i<16;i++)                       // initialise the MMC card into SPI mode by sending clks on
      {
        SPI_WRITE(0xFF);
      }
      
      CS =0;                    // set cs = 0 (on) tells card to go to spi mode when it receives reset
      send_6byte(0x40,0,0,0x95);
      
      for(i= 0; i< 100; i++)
         {
            if(spi_read(0x00)== 0x01)
            {
               break;
            }
         }
         
      if(i>= 100) // Check for Time-out Error
         {
            return(1);
         }
         
      printf("CMD40 OK (R1= 0x01)\n\r");
      DELAY_MS(2000);
      //  ----------> Den day van duoc
      
      send_6byte(0x55, 0, 0, 0xff);
      send_6byte(0x41, 0, 0, 0xff);
     
      
      for(i= 0; i<255; i++)
         {
            if(spi_read(0x00)== 0x00)
            {
               break;
            }
            
         }
          
      if(i>=255)        
         {
            return(1);
         }
         
      
      printf("CMD41 OK (R1= 0x00)\n\r");
      DELAY_MS(2000);
     
      return (0);
       
   }