sdcard Class Reference

#include <sdcard.h>

Public Member Functions
void	sel ()
void	desel ()
void	sd_delay (byte n)
void	cmd (byte cmd, uint32_t lba=0, uint8_t crc=0x95)
byte	R1 ()
byte	sdR3 (uint32_t &ocr)
byte	sdR7 ()
void	appcmd (byte cc, uint32_t lba=0)
uint8_t	begin (byte p)
void	cmd17 (uint32_t off)
void	rdn (byte *d, uint32_t off, uint16_t n)
uint32_t	rd4 (uint32_t off)
uint16_t	rd2 (uint32_t off)
byte	rd (uint32_t off)

Data Fields
byte	pin
byte	ccs
byte	type
uint16_t	sectors_per_cluster
uint16_t	reserved_sectors
uint16_t	max_root_dir_entries
uint16_t	sectors_per_fat
uint16_t	cluster_size
uint32_t	root_dir_first_cluster
uint32_t	o_partition
uint32_t	o_fat
uint32_t	o_root
uint32_t	o_data

Detailed Description

Definition at line 57 of file sdcard.h.

Member Function Documentation

appcmd()

void sdcard::appcmd ( byte  cc, uint32_t  lba = 0  )

inline

Definition at line 123 of file sdcard.h.

                                         {
    cmd(55); R1();
    cmd(cc, lba);
  }

begin()

uint8_t sdcard::begin ( byte  p )

inline

Definition at line 128 of file sdcard.h.

  {
    uint16_t cts=2000;
    pin = p;
 
    pinMode(pin, OUTPUT);
    SPI.begin();
    SPI.setClockDivider(SPI_CLOCK_DIV64);
    desel();
 
    delay(10);      // wait for boot
    sd_delay(10);   // deselected, 80 pulses
 
    // Tty.printf("Attempting card reset... ");
    // attempt reset
    byte r1,r;
    do
    {       // reset, enter idle
      cmd(0);
      do
      {      
         if(cts>0) cts--; else 
         {
           desel();
           return  0;
         }  
       }while ((r = SPI.transfer(0xff)) & 0x80);
      desel();
      SPI.transfer(0xff);   // trailing byte
      r1 = r;
    }while(r1!=1);
    // Tty.printf("reset ok\n");
 
    byte sdhc = 0;
    cmd(8, 0x1aa, 0x87);
    r1 = sdR7();
    sdhc = (r1 == 1);
 
    // Tty.printf("card %s SDHC\n", sdhc ? "is" : "is not");
 
    // Tty.printf("Sending card init command... ");
    while (1) {
      appcmd(41, sdhc ? (1UL << 30) : 0); // card init
      r1 = R1();
      if ((r1 & 1) == 0)
        break;
      delay(100);
    }
    // Tty.printf("OK\n");
 
    if (sdhc) {
      cmd(58);
      uint32_t OCR;
      sdR3(OCR);
      ccs = 1UL & (OCR >> 30);
      // Tty.printf("OCR register is %#010lx\n", long(OCR));
    } else {
      ccs = 0;
    }
    // Tty.printf("ccs = %d\n", ccs);
 
    byte type_code = rd(0x1be + 0x4);
    switch (type_code) {
      default:
        type = FAT16;
        break;
      case 0x0b:
      case 0x0c:
        type = FAT32;
        break;
    }
    // Tty.printf("Type code %#02x means FAT%d\n", type_code, (type == FAT16) ? 16 : 32);
 
    o_partition = 512L * rd4(0x1be + 0x8);
    sectors_per_cluster = rd(o_partition + 0xd);
    reserved_sectors = rd2(o_partition + 0xe);
    cluster_size = 512L * sectors_per_cluster;
 
    // Tty.printf("Bytes per sector:    %d\n", rd2(o_partition + 0xb));
    // Tty.printf("Sectors per cluster: %d\n", sectors_per_cluster);
 
    if (type == FAT16) {
      max_root_dir_entries = rd2(o_partition + 0x11);
      sectors_per_fat = rd2(o_partition + 0x16);
      o_fat = o_partition + 512L * reserved_sectors;
      o_root = o_fat + (2 * 512L * sectors_per_fat);
      // data area starts with cluster 2, so offset it here
      o_data = o_root + (max_root_dir_entries * 32L) - (2L * cluster_size); 
    } else {
      uint32_t sectors_per_fat = rd4(o_partition + 0x24);
      root_dir_first_cluster = rd4(o_partition + 0x2c);
      uint32_t fat_begin_lba = (o_partition >> 9) + reserved_sectors;
      uint32_t cluster_begin_lba = (o_partition >> 9) + reserved_sectors + (2 * sectors_per_fat);
 
      o_fat = 512L * fat_begin_lba;
      o_root = (512L * (cluster_begin_lba + (root_dir_first_cluster - 2) * sectors_per_cluster));
      o_data = (512L * (cluster_begin_lba - 2 * sectors_per_cluster));
    }
    return 1;
  }

cmd()

void sdcard::cmd ( byte  cmd, uint32_t  lba = 0, uint8_t  crc = 0x95  )

inline

Definition at line 69 of file sdcard.h.

                                                           {
#if VERBOSE
    Serial.print("cmd ");
    Serial.print(cmd, DEC);
    Serial.print(" ");
    Serial.print(lba, HEX);
    Serial.println();
#endif
 
    sel();
    SPI.transfer(0xff);
    SPI.transfer(0x40 | cmd);
    SPI.transfer(0xff & (lba >> 24));
    SPI.transfer(0xff & (lba >> 16));
    SPI.transfer(0xff & (lba >> 8));
    SPI.transfer(0xff & (lba));
    SPI.transfer(crc);
    SPI.transfer(0xff);
  }

cmd17()

void sdcard::cmd17 ( uint32_t  off )

inline

Definition at line 228 of file sdcard.h.

                           {
    if (ccs)
      cmd(17, off >> 9);
    else
      cmd(17, off & ~511L);
    R1();
    sel();
    while (SPI.transfer(0xff) != 0xfe)
      ;
  }

desel()

void sdcard::desel ( )

inline

Definition at line 60 of file sdcard.h.

               {
    digitalWrite(pin, HIGH);
    SPI.transfer(0xff); // force DO release
  }

R1()

byte sdcard::R1 ( )

inline

Definition at line 89 of file sdcard.h.

  {     // read response R1
    byte r;
    
   while ((r = SPI.transfer(0xff)) & 0x80);
      desel();
      SPI.transfer(0xff);  
    return r;
  }

rd()

byte sdcard::rd ( uint32_t  off )

inline

Definition at line 263 of file sdcard.h.

                        {
    byte r;
    rdn((byte*)&r, off, sizeof(r));
    return r;
  }

rd2()

uint16_t sdcard::rd2 ( uint32_t  off )

inline

Definition at line 257 of file sdcard.h.

                             {
    uint16_t r;
    rdn((byte*)&r, off, sizeof(r));
    return r;
  }

rd4()

uint32_t sdcard::rd4 ( uint32_t  off )

inline

Definition at line 251 of file sdcard.h.

                             {
    uint32_t r;
    rdn((byte*)&r, off, sizeof(r));
    return r;
  }

rdn()

void sdcard::rdn ( byte *  d, uint32_t  off, uint16_t  n  )

inline

Definition at line 238 of file sdcard.h.

                                              {
    cmd17(off);
    uint16_t i;
    uint16_t bo = (off & 511);
    for (i = 0; i < bo; i++)
      SPI.transfer(0xff);
    for (i = 0; i < n; i++)
      *d++ = SPI.transfer(0xff);
    for (i = 0; i < (514 - bo - n); i++)
      SPI.transfer(0xff);
    desel();
  }

sd_delay()

void sdcard::sd_delay ( byte  n )

inline

Definition at line 64 of file sdcard.h.

                        {
    while (n--)
      SPI.transfer(0xff);
  }

sdR3()

byte sdcard::sdR3 ( uint32_t &  ocr )

inline

Definition at line 99 of file sdcard.h.

                           {  // read response R3
    uint32_t r;
    while ((r = SPI.transfer(0xff)) & 0x80)
      ;
    for (byte i = 4; i; i--)
      ocr = (ocr << 8) | SPI.transfer(0xff);
    SPI.transfer(0xff);   // trailing byte
 
    desel();
    return r;
  }

sdR7()

byte sdcard::sdR7 ( )

inline

Definition at line 111 of file sdcard.h.

              {  // read response R3
    uint32_t r;
    while ((r = SPI.transfer(0xff)) & 0x80)
      ;
    for (byte i = 4; i; i--)
      // Serial.println(SPI.transfer(0xff), HEX);
      SPI.transfer(0xff);
    desel();
 
    return r;
  }

sel()

void sdcard::sel ( )

inline

Definition at line 59 of file sdcard.h.

{ digitalWrite(pin, LOW); }

Field Documentation

ccs

byte sdcard::ccs

Definition at line 269 of file sdcard.h.

cluster_size

uint16_t sdcard::cluster_size

Definition at line 276 of file sdcard.h.

max_root_dir_entries

uint16_t sdcard::max_root_dir_entries

Definition at line 274 of file sdcard.h.

o_data

uint32_t sdcard::o_data

Definition at line 283 of file sdcard.h.

o_fat

uint32_t sdcard::o_fat

Definition at line 281 of file sdcard.h.

o_partition

uint32_t sdcard::o_partition

Definition at line 280 of file sdcard.h.

o_root

uint32_t sdcard::o_root

Definition at line 282 of file sdcard.h.

pin

byte sdcard::pin

Definition at line 268 of file sdcard.h.

reserved_sectors

uint16_t sdcard::reserved_sectors

Definition at line 273 of file sdcard.h.

root_dir_first_cluster

uint32_t sdcard::root_dir_first_cluster

Definition at line 277 of file sdcard.h.

sectors_per_cluster

uint16_t sdcard::sectors_per_cluster

Definition at line 272 of file sdcard.h.

sectors_per_fat

uint16_t sdcard::sectors_per_fat

Definition at line 275 of file sdcard.h.

type

byte sdcard::type

Definition at line 271 of file sdcard.h.

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The documentation for this class was generated from the following file:

• D:/eclipse-workspace/BridgeTek/EveApps/EveApps/common/application/Arduino/sdcard.h