@ SD & MMC Spezialisten

void find_highest_song_number(void){

int32 clust_high;

int32 eocmark;

  root_ccl= BPB_RootClus;

  clust_high=0;

  do{

    root_p_cl=root_ccl;

    root_ccl=readfat(root_p_cl);

//    printf("cluster seek:%4LX   ",root_ccl);

    eocmark=root_ccl & 0x0FFFFFFF;

    clust_high++;

  }while(eocmark<0x0fffffef);

  highestsong=clust_high * BPB_SecPerClus;

  highestsong=  highestsong*16;

  highestsong--;

}

int32 readfat(int32 fatoffset){

int16 temp;

int32 tempb;

char los;

  temp=0;

  fatoffset=fatoffset*2;

  los = *(((char*)&fatoffset)+0);  //the bottom byte of the address goes directly to a word in the FAT

  fatoffset=fatoffset / 256; 

  fatoffset+=fatstart;

  if(mmc_open_block(fatoffset)==1){

    putc('^');

//    printf("fat retry...");

    if(mmc_open_block(fatoffset)==1){

      putc('&');

      mmc_init(0);

//      printf("fat RETRY...");

      if(mmc_open_block(fatoffset)==1){

        putc('*');

        mmc_init(0);

//        printf("fat LOOKS BAD...");

        if(mmc_open_block(fatoffset)==1){

          printf("problem reading fat table, quitting chain. Sorry!");

          return 0xffffffff;

          songkill=1;

        }

      }

    }

  }

  mmc_skip(los);

  mmc_read();

  temp = ((int16) data_hi * 256)+ (int16) data_lo;

  mmc_read();//for fat32, four bytes per entry

  tempb=0;

  tempb = ((int16) data_hi * 256)+ (int16) data_lo;

  tempb=tempb<<16;

  tempb=tempb+(int32) temp;

  mmc_skip(255-(los));//trouble???

  mmc_read();

  mmc_read();

  mmc_close_block();

  return tempb;

}

char mmc_open_block(int32 block_number){

char tries,i;

int32 block_number_temp;

  for(tries=0;tries<10;tries++){

    SSPCON1=throttle;

    block_number_temp=block_number*512;

//    PUTC(13);PUTC(10);

//    printf("opening boolach");

//    printf("try:%u",tries);

    SPI_WRITE(0xFF);

    SPI_WRITE(0xFF);

    MMCSS=0;                     // set MMCSS = 0 (on)

//    SPI_WRITE(0xFF);

//    SPI_WRITE(0xFF);

    SPI_WRITE(0x51);                // send mmc read single block command

    SPI_WRITE(*(((char*)&block_number_temp)+3)); // arguments are address

    SPI_WRITE(*(((char*)&block_number_temp)+2));

    SPI_WRITE(*(((char*)&block_number_temp)+1));

    SPI_WRITE(0x00);

    SPI_WRITE(0xFF);                // checksum is no longer required but we always send 0xFF

    if((mmc_response(0x00))==0){//((mmc_response(0x00))==0){

      if((mmc_response(0xFE))==0){

        return(0);  

      }

  //    printf("NOFENOFE");

      for(i=0;i<255;i++){

        SPI_WRITE(0xFF);

        SPI_WRITE(0xFF);

      }

    }

    MMCSS=1;            // set MMCSS = 1 (off)

    SPI_WRITE(0xFF);// give mmc the clocks it needs to finish off

    SPI_WRITE(0xFF);// give mmc the clocks it needs to finish off

//    SPI_WRITE(0xFF);// give mmc the clocks it needs to finish off

//    SPI_WRITE(0xFF);// give mmc the clocks it needs to finish off

//    printf("minorcrash%d",tries);

//    if((throttle==mmc_high_speed)&(tries>3)){throttle=mmc_med_speed; printf("now med speed");}

//    else if((throttle==mmc_med_speed)&(tries>5)){throttle=mmc_low_speed; printf("now low speed");}

//    mmc_init(0);

  }

//  puts("MMC crash in: mmc open block.\n\r");

  return 1;

}

void mmc_close_block(void){

//printf("close block");

  SPI_READ(0xFF);                 // CRC bytes that are not needed

  SPI_READ(0xFF);

  MMCSS=1;            // set MMCSS = 1 (off)

  SPI_WRITE(0xFF);                // give mmc the clocks it needs to finish off

       SPI_WRITE(0xff);

//       SPI_WRITE(0xff);

  //     SPI_WRITE(0xff);

}

void mmc_skip(char count){

  for (;count>0;count--){

    SPI_WRITE(0xFF);

    SPI_WRITE(0xFF);

  }

}