sd_test.c

mmc/sd卡的实现源码

/*
 * Project name:
     SD_Test (Demonstration of SD Library usage)
 * Copyright:
     (c) MikroElektronika, 2005.
 * Description:
     This project demonstrates usage of the SD Library routines, to access,
     read to and write from the SD (Secure Dicital) card storage media.
     Upon initialization, this example stores some data on the SD card and in-
     forms the user about the activity status.
 * Test configuration:
     MCU:             PIC18F452
     Dev.Board:       EasyPIC2
     Oscillator:      HS, 8.000 MHz
     Ext. Modules:    MMC_SD
     SW:              mikroC v2.0.0.2
 * NOTES:
     - This example works on PIC18 MCUs only.
*/
unsigned char SD_Send_Command(unsigned char partial_cmm, unsigned long address, unsigned char CRC);
unsigned char SD_Read_Sector_No_Offset(unsigned long sector, char* data);
unsigned char SD_Init(char* data);
unsigned char SD_Read_Sector(unsigned long sector, char* data);
unsigned char SD_Write_Sector(unsigned long sector, char *data);
unsigned char SD_Read_CID(char * data_for_registers);
unsigned char SD_Read_CSD(char * data_for_registers);


// if defined, we have a debug messages on PC terminal
#define RS232_debug 1

// universal variables
unsigned int px, k; // universal for loops and other stuff

// Variables for SD routines
unsigned char data[512]; // Buffer for MMC sector reading/writing
unsigned char data_for_registers[16]; // buffer for CID and CSD registers


// RS232 communication variables
unsigned char received_character;
unsigned long sector_address;
unsigned char first_byte, second_byte, third_byte, fourth_byte;
unsigned char serial_buffer[2];
unsigned char serial_pointer;

// --------------------- Example vvvv ------------------------------------------

// Display byte in hex
void printhex(unsigned char i)
{
  unsigned char hi,lo;
  hi = i & 0xF0;               // High nibble
  hi = hi >> 4;
  hi = hi + '0';
  if (hi>'9') hi = hi + 7;
  lo = (i & 0x0F) + '0';       // Low nibble
  if (lo>'9') lo=lo+7;
  USART_Write(hi);
  USART_Write(lo);
}

void main()
{
  unsigned int i;

  PORTC = 0;
  #ifdef RS232_debug
    USART_Init(19200);
  #endif

  TRISC = 0b11010011;
  #ifdef RS232_debug
    USART_Write('P'); // Report PIC presence
    USART_Write('I'); //
    USART_Write('C'); //
    USART_Write('-'); //
    USART_Write('S'); //
    USART_Write('t'); //
    USART_Write('a'); //
    USART_Write('r'); //
    USART_Write('t'); //
    USART_Write('e'); //
    USART_Write('d'); //
    USART_Write(13);  //
    USART_Write(10);  //
  #endif

  // Beffore all, we must initialise a MMC card
  i = SD_Init(data);

  #ifdef RS232_debug
    if(i == 1)
    {
      USART_Write('S'); // Report MMC card presence
      USART_Write('D');
      USART_Write(' ');
      USART_Write('I');
      USART_Write('n');
      USART_Write('i');
      USART_Write('t');
      USART_Write('-');
      USART_Write('O');
      USART_Write('K');
      USART_Write(13);
      USART_Write('O');
      USART_Write('f');
      USART_Write('f');
      USART_Write('s');
      USART_Write('e');
      USART_Write('t');
      USART_Write('=');
      USART_Write('0');
      USART_Write('x');
      USART_Write(13);
      USART_Write(10);
    }
    if(i == 0)
    {
      USART_Write('S'); // Report error
      USART_Write('D');
      USART_Write('C');
      USART_Write('I');
      USART_Write('n');
      USART_Write('i');
      USART_Write('t');
      USART_Write('-');
      USART_Write('E');
      USART_Write('r');
      USART_Write('r');
      USART_Write(13);
      USART_Write(10);
    }
  #endif

  for(i=0; i<=511; i++) data[i] = 0; // Fill MMC buffer with zerross
  //i = SD_Write_Sector(0, data);

  #ifdef RS232_debug
    if(i == 0)
    {
      Usart_Write('U');
      Usart_Write('p');
      Usart_Write('i');
      Usart_Write('s');
      Usart_Write('-');
      Usart_Write('O');
      Usart_Write('K');
    }
    else  // ako nije u redu.....
    {
      Usart_Write('U');
      Usart_Write('p');
      Usart_Write('i');
      Usart_Write('s');
      Usart_Write('-');
      Usart_Write('E');
      Usart_Write('r');
      Usart_Write('r');
    }                                                    // pisi O, ako nije N
    USART_Write(13);
    USART_Write(10);
  #endif

  // Reading of CID and CSD register on MMC card.....
  #ifdef RS232_debug
    i = SD_Read_CID(data_for_registers);
    if(i == 0)
    {
      for(k=0; k<=15; k++)
      {
        printhex(data_for_registers[k]);
        if(k!=15) USART_Write('-');
      }
      USART_Write(13);
    }
    else
    {
      Usart_Write('C');
      Usart_Write('I');
      Usart_Write('D');
      Usart_Write('-');
      Usart_Write('E');
      Usart_Write('r');
      Usart_Write('r');
    }
    i == SD_Read_CSD(data_for_registers);
    if(i == 0)
    {
      for(k=0; k<=15; k++)
      {
        printhex(data_for_registers[k]);
        if(k!=15) USART_Write('-');
      }
      USART_Write(13);
      USART_Write(10);
    }
    else
    {
      Usart_Write('C');
      Usart_Write('S');
      Usart_Write('D');
      Usart_Write('-');
      Usart_Write('E');
      Usart_Write('r');
      Usart_Write('r');
    }
  #endif

  // Variables initialisation
  serial_pointer = 0;

  // MAIN loop
  while(1)
  {
    if (USART_Data_Ready())
    {
      serial_buffer[serial_pointer] = USART_Read();    // Get the received character
      serial_pointer++;
      if(serial_pointer>1)
      {
        serial_pointer = 0;
        //get 4 bytes to generate address
        if(serial_buffer[0] == 'S') first_byte  = serial_buffer[1];
        if(serial_buffer[0] == 's') second_byte = serial_buffer[1];
        if(serial_buffer[0] == 'E') third_byte  = serial_buffer[1];
        if(serial_buffer[0] == 'e') fourth_byte = serial_buffer[1];
        if(serial_buffer[0] == 'R') // Read Memory command
        {
          if(serial_buffer[1] == 'r')
          {
            sector_address = ((long)first_byte << 24) + ((long)second_byte << 16) +
                             ((long)third_byte << 8)  + ((long)fourth_byte);
            i = SD_Read_Sector(sector_address, data);
            if(i == 0)
            {
              for(k=0; k<512; k++)
              {
                printhex(data[k]);
                USART_Write(' ');
                if(((k+1) % 16)==0)
                {
                  USART_Write(' ');
                  //printhex(k);
                  for(px=(k-15); px<=k; px++)
                  {
                    if((data[px]>33) && (data[px]<126))
                    {
                      USART_Write(data[px]);
                    }
                    else
                    {
                      USART_Write('.');
                    }
                  }
                  USART_Write(13);
                }
              }
              USART_Write(13);  //
              USART_Write(10);
            }
            else
            {
              USART_Write('R');  //
              USART_Write('d');
              USART_Write('-');
              USART_Write('E');
              USART_Write('r');
              USART_Write('r'); //
            }
          }
        }
        if(serial_buffer[0] == 'W') // Write data command
        {
          if(serial_buffer[1] == 'w')
          {
            //generate 32-bit sector address
            sector_address = ((long)first_byte << 24) + ((long)second_byte << 16) +
                             ((long)third_byte << 8)  + ((long)fourth_byte);
            for(k=0; k<512; k++) data[k] = received_character;// fill RAM buffer with character received
            i = SD_Write_Sector(sector_address, data); // ...and write the buffer down into the MMC
            if(i != 0)
            {
              USART_Write('W');  // Write-Error
              USART_Write('r');
              USART_Write('-');
              USART_Write('E');
              USART_Write('r');
              USART_Write('r');
            }
            else
            {
              USART_Write('W');  // Write OK
              USART_Write('r');
              USART_Write('-');
              USART_Write('O');
              USART_Write('K');
            }
          }
        }
        if(serial_buffer[0] == 'C')
        {
          received_character = serial_buffer[1];
        }
      }
    }
  }
}