Subversion Repositories viterbi_decoder_axi4s

--!

--! Copyright (C) 2011 - 2014 Creonic GmbH

--!

--! This file is part of the Creonic Viterbi Decoder, which is distributed

--! under the terms of the GNU General Public License version 2.

--!

--! @file

--! @brief Parameters

--! @author Markus Fehrenz

--! @date 2011/07/01

--!

--! @details This is the configuration file of the Viterbi decoder.

--!          Any changes for parameters should be done here.

--!          Changing parameters somewhere else may result in a malicious

--!          behavior.

--!

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

package pkg_param is

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

        -- Convolutional Code Parameters --

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

        --

        -- Set the number of parity values

        -- This has to correspond to PARITY_POLYNOMIALS

        --

        constant NUMBER_PARITY_BITS : natural := 2;

        type t_parity is array (NUMBER_PARITY_BITS - 1 downto 0) of natural;

        --

        -- Set parity polynoms in decimal notation

        -- NUMBER_PARITY_BITS has to correspond to the number of elements

        -- Examples: WiFi : [121,91] or [121,91,101]

        --           CDMA : [491,369] or [367,435,369] or [501,441,331,315]

        --           GSM  : [27,19] or [27,21,31]

        --           DAB  : [91,121,101,91]

        --           WiMAX: [91,121,117]

        --

        constant PARITY_POLYNOMIALS   : t_parity := (121,91);

        --

        -- Set a recursive polynomial

        -- Set to 0 if no recursion is used

        -- Setting this arbitrary may result in a worse error correction ability

        --

        constant FEEDBACK_POLYNOMIAL : natural := 0;

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

        -- Architecture Parameters --

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

        --

        -- Set bit width of LLR input

        -- Recommended values: 3 or 4

        --

        constant BW_LLR_INPUT : natural := 4;

        --

        -- Set the maximum window length which shall be allowed at runtime.

        -- Recommended: at least 6 * constraint length

        --

        constant MAX_WINDOW_LENGTH : natural := 96;

        --

        -- Set to 'true' if distributed RAM shall be used

        -- Set to 'false' if block RAM shall be used

        --

        constant DISTRIBUTED_RAM : boolean := true;

end package pkg_param;