Subversion Repositories product_code_iterative_decoder

-- ------------------------------------------------------------------------
-- Copyright (C) 2005 Arif Endro Nugroho
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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;