Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());
      Usb_write_byte(Nf_rd_byte());

      if (begin_ping_pong)
      {
        begin_ping_pong = FALSE;
      }
      else
      {
        while (!Usb_tx_complete());         /* wait end of transfer */
        Usb_clear_TXCMPL();                 /* ack transfer */
      }
      Usb_set_TXRDY();                      /* start usb transfer */    
    }
  
    gl_ptr_mem++;                           /* new page */
    Nf_CS_OFF();
    if (! ( ((Byte*)&gl_ptr_mem)[3] & NF_BLOCK_MASK ) )               /* New block ? */
    {
      nf_read_open(gl_ptr_mem);
    }
    else
    {
      nf_current_physical_sector_addr++;
    }
    nb_sector--;
  }
  while (nb_sector != 0);

  while (!Usb_tx_complete());               /* wait end of last transfer */
  Usb_clear_TXCMPL();                       /* ack transfer */

  return OK;
}


/*F**************************************************************************
* NAME: nf_write_open
*----------------------------------------------------------------------------
*----------------------------------------------------------------------------
* PARAMS:
*   pos: address of the the next write data
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Low level memory write update
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
bit nf_write_open (Uint32 pos)
{
Byte i;
Byte j;
bit change_zone = FALSE;

  gl_ptr_mem = pos;
  gl_cpt_page = 0;

  /* Determine the logical block value */
  nf_logical_block = (gl_ptr_mem >> 5);
  nf_zone = 0;

  while (nf_logical_block > 999)
  {
    nf_logical_block -= 1000;
    nf_zone++;
  }
  Nf_CS_ON();

  if (nf_zone != nf_old_zone)
  {
    change_zone = TRUE;
    if (nf_lut_modified)
    { /* save old lut */
      i = nf_old_zone;
      nf_old_zone = nf_zone;
      nf_zone = i;
      nf_reassign_block();
      nf_lut_modified = FALSE;
      nf_zone = nf_old_zone;
    }
    else
    { /* update old zone value */
      nf_old_zone = nf_zone;
    }
    nf_block_min = 0xFFFF;
    gl_buf_free_idx = 0;
  }

  if ((nf_logical_block >= nf_block_min) && (nf_logical_block < (nf_block_min + NF_BUFFER_SIZE - 5)))
  { /* we don't have to update the buffer */
    nf_calc_logical_block();
    nf_gl_buf_idx = nf_logical_block - nf_block_min;
  }
  else 
  { /* we have to update the buffer */
    /* Store the look up table block address */
    nf_look_up_table_block =  nf_lut_block[nf_zone];
    /* If LUT have been modified */
    if (nf_lut_modified)           
    {
      nf_reassign_block();                  /* update the LUT */
    }
    /* Calculate the address for LUT access */
    gl_address = ((Uint32)(nf_look_up_table_block)<<5) + ((Uint32)(nf_logical_block) >> 8);
    gl_address += (Uint32)(nf_lut_index[nf_zone])<<2;
    /* Calculate the redundant block address value */
    nf_calc_logical_block();
    i = nf_logical_block;
    /* For the current zone, initialize the number of spare block */
    nf_spare_block = nf_spare_block_number[nf_zone];
    /* Calculate the low and the high block stored in the buffer */
    nf_block_min = nf_logical_block;
    nf_block_max = ((nf_logical_block + NF_BUFFER_SIZE) > 999) ? (1000 - nf_logical_block) : NF_BUFFER_SIZE;

    /* Open the look-up table */
    Nf_wait_busy();     
    if (((Byte*)&nf_logical_block)[1] & 0x80)
    {
      Nf_send_command(NF_READ_B_AREA_CMD);  /* 2nd half page */
      Nf_send_address((nf_logical_block << 1) - 256);
    }
    else
    {
      Nf_send_command(NF_READ_A_AREA_CMD);  /* first half page */
      Nf_send_address(nf_logical_block << 1);
    }

    Nf_send_address (((Byte*)&gl_address)[3]);     /* 2nd address cycle         */
    Nf_send_address (((Byte*)&gl_address)[2]);     /* 3rd address cycle         */
    if (NF_4_CYCLE_ADDRESS_BIT)                    /* Size of card >= 64Mbytes ?*/
      Nf_send_address ( ((Byte*)&gl_address)[1] ); /* 4th address cycle         */
  
    Nf_wait_busy();

    for (j = 0; j < nf_block_max ; j++)
    {
      /* Read conversion table : 64 datas */
      nf_buf[j].b[0] = Nf_rd_byte();
      nf_buf[j].b[1] = Nf_rd_byte();
      i++;
      if (i == 0)
      {
        gl_address++;
        Nf_read_open_A_area(gl_address, 0x00);
      }
    }
  
    if (change_zone)        /* If it is a new zone, then load the spare buffer */
    {
      /* Check for used block : first, read in the LUT the free physical block */
      gl_address = ((Uint32)(nf_look_up_table_block)<<5) + 3;
      gl_address += (Uint32)(nf_lut_index[nf_zone])<<2;
      Nf_read_open_B_area(gl_address, 208);
      for (i = 0; i <= (nf_spare_block); i++)
      {
        nf_buf_free[i] = (Uint16)(Nf_rd_byte()<<8);
        nf_buf_free[i] +=  Nf_rd_byte();
      }
    }
    nf_gl_buf_idx = 0;           /* initialize index for main buffer */
    nf_gl_buf_idx_max = 0;       /* initialize the max index for the buffer */
  }
  
  /* if block is already assigned, then invert with a spare block */
  nf_block_used = (!(nf_buf[nf_gl_buf_idx].w & 0x8000)) ? TRUE : FALSE;
  if (nf_block_used)
  {
    if ((nf_buf_free[gl_buf_free_idx] & 0x7FFF) == nf_look_up_table_block)
    {
      gl_buf_free_idx++;
      if (gl_buf_free_idx >= nf_spare_block)
      {
        gl_buf_free_idx = 0;
      }      
    }
    /* assign block to be deleted */
    nf_block_to_be_deleted = nf_buf[nf_gl_buf_idx].w;
    nf_buf[nf_gl_buf_idx].w = nf_buf_free[gl_buf_free_idx];
    nf_buf_free[gl_buf_free_idx++] = nf_block_to_be_deleted | 0x8000;
    /* increase the index for spare block buffer */
    if (gl_buf_free_idx >= nf_spare_block)
    {
      gl_buf_free_idx = 0;
    }
  }

  /* Mark block as assigned */
  nf_buf[nf_gl_buf_idx].w &= 0x7FFF;       

  if (nf_gl_buf_idx > nf_gl_buf_idx_max)
    nf_gl_buf_idx_max = nf_gl_buf_idx;

  /* Update the current physical sector address */
  nf_current_physical_sector_addr = ((Uint32)(nf_buf[nf_gl_buf_idx].w) << 5);

  if (nf_block_used)                        /* Fisrt block already used block ?  */
  { 
    nf_copy_block_head();                   /* Copy the first part of the block  */
  }
  else                                 
  { 
    nf_init_spare();                        /* else init spare data for new logical block  */
  }

  nf_busy = FALSE;                          /* Clear flag busy */
  nf_lut_modified = TRUE;
  /* Set LUT as modified */
  gl_address = ((Uint32)(nf_look_up_table_block)<<5);
  gl_address += (Uint32)(nf_lut_index[nf_zone])<<2;
  Nf_wait_busy();
  Nf_write_open_C_area(gl_address, 0x00);
  Nf_wr_byte(0x00);                         /* Reset first byte */
  Nf_send_command(NF_PAGE_PROGRAM_CMD);     /* Send program command to the device */
  
  return OK; 
}


/*F**************************************************************************
* NAME: nf_write_close
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Low level memory write close: release NF 
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
bit nf_write_close (void)
{ 
  Nf_CS_ON();
  if (gl_cpt_page)
  {
    while (((Byte*)&gl_cpt_page)[0] != NF_DATA_SIZE_H)
    {
      gl_cpt_page++;
      Nf_wr_byte(0x00);
    }
    nf_update_spare_data();
    Nf_send_command(NF_PAGE_PROGRAM_CMD);
    ((Byte*)&gl_cpt_page)[0] = 0;
    gl_ptr_mem++;
    ((Byte*)&nf_current_physical_sector_addr)[3]++;
  }

  /* Copy last part of a block if the block was assigned */
  if (nf_block_used)
  {
    if (((Byte*)&gl_ptr_mem)[3] & NF_BLOCK_MASK) 
      nf_copy_block_tail();
    nf_block_erase((Uint32)(nf_block_to_be_deleted) << 5);    /* Erase old block */
  }
  Nf_CS_OFF();
  return OK;
}


/*F**************************************************************************
* NAME: nf_write_byte
*----------------------------------------------------------------------------
* PARAMS:
*   b: data to write
*
* RETURN:
*   write status: OK: write done
*                 KO: write not done
*
*----------------------------------------------------------------------------
* PURPOSE:
*   Low level memory write function
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
bit nf_write_byte (Byte b)
{
  if (nf_busy)
  {
    nf_busy = FALSE;
    /* If previous block have to de deleted */
    if (nf_block_used)       
    {
      nf_block_erase((Uint32)(nf_block_to_be_deleted) << 5);
    }
    /* increase the main buffer index */
    nf_gl_buf_idx++;
    /* if zone change */
    if (nf_gl_buf_idx >= nf_block_max)
    {
      nf_write_open(gl_ptr_mem);