}
    else
    {
      /* if the block in the buffer is already assign, then invert it with a spare block */
      if (!(nf_buf[nf_gl_buf_idx].w & 0x8000))                 
      {                                                 
        if ((nf_buf_free[gl_buf_free_idx] & 0x7FFF) == nf_lut_block[nf_zone])
        {
          gl_buf_free_idx++;
          if (gl_buf_free_idx >= nf_spare_block)
          {
            gl_buf_free_idx = 0;
          }      
        }        
        /* invert the block and assign the next 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] & 0x7FFF;
        nf_buf_free[gl_buf_free_idx] = nf_block_to_be_deleted | 0x8000;
        /* block have to be deleted */
        nf_block_used = TRUE;
        /* increase the spare buffer index */
        if ((gl_buf_free_idx++) >= nf_spare_block)
        {
          gl_buf_free_idx = 0;
        }

      }
      else /* The block is not assigned. Nothing to do */
      {
        nf_buf[nf_gl_buf_idx].w &= 0x7FFF;
        nf_block_used = FALSE;
      }
      /* update the max index buffer */
      if (nf_gl_buf_idx > nf_gl_buf_idx_max)
        nf_gl_buf_idx_max = nf_gl_buf_idx;

      /* Update current physical sector */
      nf_current_physical_sector_addr = (Uint32)(nf_buf[nf_gl_buf_idx].w) << 5;
      /* increase the logical block */
      nf_logical_block++;
      /* calculate the redundant block address */
      nf_calc_logical_block();
    }
  }

  Nf_CS_ON();
  if (!gl_cpt_page)
  {
    Nf_wait_busy();
    Nf_write_open_A_area(nf_current_physical_sector_addr, 0x00);
  }
  Nf_wr_byte(b);
  /* Increase internal page counter */
  gl_cpt_page++;                          
  if (((Byte*)&gl_cpt_page)[0] == NF_DATA_SIZE_H) /* check if end of data page */
  {
    nf_update_spare_data();
    Nf_send_command(NF_PAGE_PROGRAM_CMD);
    ((Byte*)&gl_cpt_page)[0] = 0;
    gl_ptr_mem++;
    if (!(((Byte*)&gl_ptr_mem)[3] & NF_BLOCK_MASK)) 
    {
      nf_busy = TRUE;
    }
    else
    {
      ((Byte*)&nf_current_physical_sector_addr)[3]++;
    }
  }

  return OK;
}


/*F**************************************************************************
* NAME: nf_write_sector
*----------------------------------------------------------------------------
* PARAMS:
*   global: gl_ptr_mem
*
* return:
*   write status: OK: write done
*                 KO: write not done
*----------------------------------------------------------------------------
* PURPOSE: 
*   This function is an optimized function that writes nb-sector * 512 bytes
*   from USB controller to NF card
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   nb_sector always >= 1, can not be zero
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
bit nf_write_sector (Uint16 nb_sector)
{
Byte j;

  do
  {   
    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);
      }
      else
      {
        /* if the block in the buffer is already assign, then invert it with a spare block */
        if (!(nf_buf[nf_gl_buf_idx].w & 0x8000))                 
        {                                                 
          if ((nf_buf_free[gl_buf_free_idx] & 0x7FFF) == nf_lut_block[nf_zone])
          {
            gl_buf_free_idx++;
            if (gl_buf_free_idx >= nf_spare_block)
            {
              gl_buf_free_idx = 0;
            }      
          }        
          /* invert the block and assign the next 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] & 0x7FFF;
          nf_buf_free[gl_buf_free_idx] = nf_block_to_be_deleted | 0x8000;
          /* block have to be deleted */
          nf_block_used = TRUE;
          /* increase the spare buffer index */
          if ((gl_buf_free_idx++) >= nf_spare_block)
          {
            gl_buf_free_idx = 0;
          }
        }
        else /* The block is not assigned. Nothing to do */
        {
          nf_buf[nf_gl_buf_idx].w &= 0x7FFF;
          nf_block_used = FALSE;
        }
        /* update the max index buffer */
        if (nf_gl_buf_idx > nf_gl_buf_idx_max)
          nf_gl_buf_idx_max = nf_gl_buf_idx;
  
        /* Update current physical sector */
        nf_current_physical_sector_addr = (Uint32)(nf_buf[nf_gl_buf_idx].w) << 5;
        /* increase the logical block */
        nf_logical_block++;
        /* calculate the redundant block address */
        nf_calc_logical_block();
      }
    }

    Nf_CS_ON();
  
    Nf_wait_busy();
    Nf_write_open_A_area(nf_current_physical_sector_addr, 0x00);

    for (j = 8; j != 0; j--)
    {
      while (!Usb_rx_complete());             /* wait end of reception */
      Nf_wr_byte(Usb_read_byte());            /* write 64 bytes to card */
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Nf_wr_byte(Usb_read_byte());
      Usb_clear_RXOUT_PP();                      /* usb read acknowledgement */
    }
  
    /* Update spare data */
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(((Byte*)&nf_redundant_logical_block_value)[0]);
    Nf_wr_byte(((Byte*)&nf_redundant_logical_block_value)[1]);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(0xFF);
    Nf_wr_byte(((Byte*)&nf_redundant_logical_block_value)[0]);
    Nf_wr_byte(((Byte*)&nf_redundant_logical_block_value)[1]);
  
    Nf_send_command (NF_PAGE_PROGRAM_CMD);
    /* increase gl_ptr_mem : next page */
    gl_ptr_mem++;              
    /* set flag busy */
    if (!(((Byte*)&gl_ptr_mem)[3] & NF_BLOCK_MASK)) 
    {
      nf_busy = TRUE;
    }
    else
    {
      ((Byte*)&nf_current_physical_sector_addr)[3]++;
    }
    nb_sector--;
  }
  while (nb_sector != 0);
  return OK;
}


/*F**************************************************************************
* NAME: nf_format
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*   Address of the format parameter structure in code
*----------------------------------------------------------------------------
* PURPOSE: 
*   This function is called by the fat_format function and returns a pointer
*   to a table containing the format parameters after erasing the NF.
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
s_format * nf_format (void)
{

#define CYL_16  (Uint16)((Uint16)(500) - (MEM_RESERVED_SIZE / (4 * 16)))
#define CYL_32  (Uint16)((Uint16)(500) - (MEM_RESERVED_SIZE / (8 * 16)))
#define CYL_64  (Uint16)((Uint16)(500) - (MEM_RESERVED_SIZE / (8 * 32)))
#define CYL_128 (Uint16)((Uint16)(500) - (MEM_RESERVED_SIZE / (16 * 32)))

code  s_format  nf_tab_format[]=
  {
   /* nb_cylinder, nb_head,  nb_sector, nb_hidden, nb_sector_per_cluster */
    { CYL_16, (Byte)4,  (Byte)16,  (Byte)57,  (Byte)32 }, /* 16MB */
    { CYL_32, (Byte)8,  (Byte)16,  (Byte)51,  (Byte)32 }, /* 32MB */
    { CYL_64, (Byte)8,  (Byte)32,  (Byte)39,  (Byte)32 }, /* 64MB */
    { CYL_128, (Byte)16, (Byte)32,  (Byte)63,  (Byte)32 }, /* 128MB */
  };

code  s_format  nf_tab_format_reserved[]=
  {
   /* nb_cylinder, nb_head,  nb_sector, nb_hidden, nb_sector_per_cluster */
    { (Uint16)500, (Byte)4,  (Byte)16,  (Byte)57,  (Byte)32 }, /* 16MB */
    { (Uint16)500, (Byte)8,  (Byte)16,  (Byte)51,  (Byte)32 }, /* 32MB */
    { (Uint16)500, (Byte)8,  (Byte)32,  (Byte)39,  (Byte)32 }, /* 64MB */
    { (Uint16)500, (Byte)16, (Byte)32,  (Byte)63,  (Byte)32 }, /* 128MB */
  };

  /* Erase all block */
  nf_erase_all_block();

  /* -- NF Type Selection -- */
  if (reserved_disk_space == FALSE)
  {
    if (nf_reserved_space == TRUE)
    {
      nf_mem_size -= MEM_RESERVED_SIZE;
      nf_reserved_space = FALSE;
    }
    return &nf_tab_format[NF_TYPE];
  }
  else
  {
    if (nf_reserved_space == FALSE)
    {
      nf_reserved_space = TRUE;
      nf_mem_size += MEM_RESERVED_SIZE;
    }
    return &nf_tab_format_reserved[NF_TYPE];
  }
}