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  Helper package with useful functions

--! @author Markus Fehrenz

--! @date   2011/12/02

--!

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

package pkg_helper is

        --!

        --! Return the log_2 of an natural value, i.e. the number of bits required

        --! to represent this unsigned value.

        --!

        function no_bits_natural(value_in : natural) return natural;

        --! Return maximum of two input values

        function max(value_in_a, value_in_b : natural) return natural;

end pkg_helper;

package body pkg_helper is

        function no_bits_natural(value_in: natural) return natural is

                variable v_n_bit : unsigned(31 downto 0);

        begin

                if value_in = 0 then

                        return 0;

                end if;

                v_n_bit := to_unsigned(value_in, 32);

                for i in 31 downto 0 loop

                        if v_n_bit(i) = '1' then

                                return i + 1;

                        end if;

                end loop;

                return 1;

        end no_bits_natural;

        function max(value_in_a, value_in_b : natural) return natural is

        begin

                if value_in_a > value_in_b then

                        return value_in_a;

                else

                        return value_in_b;

                end if;

        end function;

end pkg_helper;