Subversion Repositories product_code_iterative_decoder

-- ------------------------------------------------------------------------

-- Copyright (C) 2005 Arif Endro Nugroho

-- All rights reserved.

-- 

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-- 2. Redistributions in binary form must reproduce the above copyright

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-- THIS SOFTWARE IS PROVIDED BY ARIF ENDRO NUGROHO "AS IS" AND ANY EXPRESS

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-- ------------------------------------------------------------------------

library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_arith.all;

use ieee.std_logic_unsigned.all;

entity analyze is

   port (

      clear   : in  bit;

      start   : in  bit;

      match   : in  bit_vector (3 downto 0);

      col_0   : out integer;

      col_1   : out integer;

      col_2   : out integer;

      col_3   : out integer;

      result  : out integer

      );

end analyze;

architecture analyzer of analyze is

signal col_0_int  : integer range 0 to 19999;

signal col_1_int  : integer range 0 to 19999;

signal col_2_int  : integer range 0 to 19999;

signal col_3_int  : integer range 0 to 19999;

signal result_int : integer range 0 to 19999;

begin

process (start,clear)

begin

if (clear = '1') then

   col_0_int  <= 0;

   col_1_int  <= 0;

   col_2_int  <= 0;

   col_3_int  <= 0;

   result_int <= 0;

-- sample at rising edge then show the result at falling edge.

elsif (start = '1' and start'event) then

   if (match(0) = '0') then

      if (col_0_int < 19999) then

         col_0_int <= col_0_int + 1;

      else

         col_0_int <= 0;

      end if;

   end if;

   if (match(1) = '0') then

      if (col_1_int < 19999) then

         col_1_int <= col_1_int + 1;

      else

         col_1_int <= 0;

      end if;

   end if;

   if (match(2) = '0') then

      if (col_2_int < 19999) then

         col_2_int <= col_2_int + 1;

      else

         col_2_int <= 0;

      end if;

   end if;

   if (match(3) = '0') then

      if (col_3_int < 19999) then

         col_3_int <= col_3_int + 1;

      else

         col_3_int <= 0;

      end if;

   end if;

end if;

result_int <= col_0_int + col_1_int + col_2_int + col_3_int;

end process;

result   <= result_int;

col_0    <= col_0_int;

col_1    <= col_1_int;

col_2    <= col_2_int;

col_3    <= col_3_int;

end analyzer;