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--!
--! 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;
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