nf.c

一个可作为mp3播放器固件的代码集,包括解码,播放,控制,任务管理等.

*----------------------------------------------------------------------------
* PARAMS:
*   pos: address of the logic sector to read (size 512 bytes)
*
* return:
*   Update memory for reading
*----------------------------------------------------------------------------
* PURPOSE:
*   Low level memory read update
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE: 
*----------------------------------------------------------------------------
* REQUIREMENTS: 
*****************************************************************************/
bit nf_read_open (Uint32 pos)
{
Uint16 physical_block;

  if (nf_lut_modified)
  {
    nf_reassign_block();
    nf_lut_modified = FALSE;
  }

  gl_ptr_mem = pos;
  gl_cpt_page = 0;

  /* Determine the logical block value */
  nf_logical_block = gl_ptr_mem >> 6;                 /* 64 pages by block */
  nf_zone = 0;

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

  /* Calculate the address where are the physical block value */
  gl_address  = (Uint32)(lut_block[nf_zone]) << 5;      /* 32 * lut block                               */
  gl_address += ((Uint32)(nf_logical_block) >> 7);      /* logical block / 128 = page number of the lut */
  gl_address += ((Uint32)(lut_index[nf_zone])<<3);      /* lut index * 8 = offset for beginning of lut  */

  /* Open the look-up table */
  Nf_CS_EVEN();       
  Nf_wait_busy_even();
  if (nf_logical_block & 0x40)                              /* 64 logical blocks by part of lut page        */
  {
    Nf_send_command_even(NF_READ_B_AREA_CMD);               /* 2nd half page                                */
    Nf_send_address_even( (nf_logical_block & 0x3F) << 2);  /* 4Bytes for one logical block                 */
  }
  else
  {
    Nf_send_command_even(NF_READ_A_AREA_CMD);               /* first half page */
    Nf_send_address_even((nf_logical_block & 0x3F) << 2);
  }

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

  /* Read the physical even block number */
  ((Byte*)&physical_block)[0] = Nf_rd_byte_even();
  ((Byte*)&physical_block)[1] = Nf_rd_byte_even();
  /* Calculate the physical even sector address */
  nf_current_physical_sector_addr_even = ((Uint32)(physical_block) << 5) + ((((Byte*)&gl_ptr_mem)[3] & 0x3F) >> 1) + (((Byte*)&gl_ptr_mem)[3]  & 0x01);
  /* Read the physical odd block number */
  ((Byte*)&physical_block)[0] = Nf_rd_byte_even();
  ((Byte*)&physical_block)[1] = Nf_rd_byte_even();
  /* Calculate the physical odd sector address */
  nf_current_physical_sector_addr_odd = ((Uint32)(physical_block) << 5) + ((((Byte*)&gl_ptr_mem)[3] & 0x3F) >> 1); 

  if (((Byte*)&gl_ptr_mem)[3]  & 0x01)
  {
    nf_parity_bit = NF_ODD;
  }
  else
  {
    nf_parity_bit = NF_EVEN;
  }

  return OK;
}


/*F**************************************************************************
* NAME: nf_read_close
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Low level memory read close
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE: 
*----------------------------------------------------------------------------
* REQUIREMENTS: 
*****************************************************************************/
void nf_read_close (void)
{
}



/*F*************************************************************************
* NAME: nf_read_byte
*---------------------------------------------------------------------------
* PARAMS:
*
* return:
*   Data read from memory
*---------------------------------------------------------------------------
* PURPOSE:
*   Low level memory read function
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE: 
*----------------------------------------------------------------------------
* REQUIREMENTS: 
****************************************************************************/
Byte nf_read_byte (void)
{
Byte b;
  if (!gl_cpt_page)
  {
    if (nf_parity_bit == NF_ODD)
    {
      Nf_active_ODD();
      Nf_wait_busy_odd();
      Nf_read_open_A_area_odd(nf_current_physical_sector_addr_odd, 0x00);
      b = Nf_rd_byte_odd();

    }
    else
    {
      Nf_active_EVEN();
      Nf_wait_busy_even();
      Nf_read_open_A_area_even(nf_current_physical_sector_addr_even, 0x00);
      b = Nf_rd_byte_even();
    }
  }
  else
  {
    b = (nf_parity_bit == NF_ODD) ? Nf_rd_byte_odd() : Nf_rd_byte_even();
  }

  gl_cpt_page++;
  
  if (((Byte*)&gl_cpt_page)[0]  == 0x02)                  /* end of page        */               
  {
    gl_ptr_mem++;                                         /* new page           */
    ((Byte*)&gl_cpt_page)[0] = 0;                         /* start at column 0  */
    if ( !(((Byte*)&gl_ptr_mem)[3] & 0x3F) )              /* New block ?        */
    {
      nf_read_open(gl_ptr_mem);
    }
    else
    {
      nf_parity_bit = ~nf_parity_bit;
      if (nf_parity_bit == NF_ODD)
      {
        ((Byte*)&nf_current_physical_sector_addr_even)[3]++;
        //nf_current_physical_sector_addr_even++;
      }
      else
      {
        ((Byte*)&nf_current_physical_sector_addr_odd)[3]++;
        //nf_current_physical_sector_addr_odd++;
      }
    }
  }
  return b;
}


/*F**************************************************************************
* NAME: nf_read_sector
*----------------------------------------------------------------------------
* PARAMS:
*   global: gl_ptr_mem
*
* return: OK read done
*         KO read failure
*----------------------------------------------------------------------------
* PURPOSE: 
*   This function is an optimized function that writes 512 bytes from NF
*   to USB controller 
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
bit nf_read_sector(Uint16 nb_sector)
{
Byte i;
bit begin_ping_pong = TRUE;
  do
  {
    if (nf_parity_bit == NF_ODD)
    {
      Nf_active_ODD();
      Nf_wait_busy_odd();
      Nf_read_open_A_area_odd(nf_current_physical_sector_addr_odd, 0x00);
      ((Byte*)&nf_current_physical_sector_addr_odd)[3]++;
      //nf_current_physical_sector_addr_odd++;
      for (i = 8; i != 0; i--)
      {
        Usb_write_byte(Nf_rd_byte_odd());            /* read 64 bytes from card */
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        Usb_write_byte(Nf_rd_byte_odd());
        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 */    
      }

    }
    else
    {
      Nf_active_EVEN();
      Nf_wait_busy_even();
      Nf_read_open_A_area_even(nf_current_physical_sector_addr_even, 0x00);
      ((Byte*)&nf_current_physical_sector_addr_even)[3]++;
      //nf_current_physical_sector_addr_even++;
      for (i = 8; i != 0; i--)
      {
        Usb_write_byte(Nf_rd_byte_even());            /* read 64 bytes from card */
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());
        Usb_write_byte(Nf_rd_byte_even());