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diff --git a/testsuite/gna/issue301/src/branch_distance.vhd b/testsuite/gna/issue301/src/branch_distance.vhd
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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  Branch distance calculation unit.
+--! @author Markus Fehrenz
+--! @date   2011/08/04
+--!
+--! @details Each branch has to be calculated only once.
+--!          The branch calculations are configured with a generic.
+--!          There is no limitation in branch calculations.
+--!
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+library dec_viterbi;
+use dec_viterbi.pkg_param.all;
+use dec_viterbi.pkg_param_derived.all;
+use dec_viterbi.pkg_types.all;
+
+
+entity branch_distance is
+	generic(
+		EDGE_WEIGHT : in std_logic_vector(0 to NUMBER_PARITY_BITS - 1)
+	);
+	port(
+		clk                 : in std_logic;
+		rst                 : in std_logic;
+
+		--
+		-- Input LLR values
+		--
+		s_axis_input_tvalid : in  std_logic;
+		s_axis_input_tdata  : in  t_input_block;
+		s_axis_input_tlast  : in  std_logic;
+		s_axis_input_tready : out std_logic;
+
+
+		--
+		-- Output branch metrics, going to ACS unit.
+		--
+		m_axis_output_tvalid : out std_logic;
+		m_axis_output_tdata  : out std_logic_vector(BW_BRANCH_RESULT - 1 downto 0);
+		m_axis_output_tlast  : out std_logic;
+		m_axis_output_tready : in  std_logic
+	);
+end entity branch_distance;
+
+
+architecture rtl of branch_distance is
+
+	signal m_axis_output_tvalid_int : std_logic;
+	signal s_axis_input_tready_int  : std_logic;
+
+begin
+
+	-- We are ready, when we are allowed to write to the output, or the output is idle.
+	s_axis_input_tready_int <= '1' when m_axis_output_tready = '1' else
+	                           '0';
+
+	-- Connect internal versions of signal to output port.
+	s_axis_input_tready   <= s_axis_input_tready_int;
+	m_axis_output_tvalid  <= m_axis_output_tvalid_int;
+
+
+	-- Calculation of specific branch distance with a geometric distance function.
+	pr_branch : process(clk) is
+		variable v_branch_result : integer;
+	begin
+	if rising_edge(clk) then
+		if rst = '1' then
+			m_axis_output_tvalid_int <= '0';
+			m_axis_output_tdata      <= (others => '0');
+			m_axis_output_tlast      <= '0';
+		else
+
+			if m_axis_output_tvalid_int = '1' and m_axis_output_tready = '1' then
+				m_axis_output_tvalid_int <= '0';
+				m_axis_output_tlast      <= '0';
+			end if;
+
+			if s_axis_input_tready_int = '1' and s_axis_input_tvalid = '1' then
+				v_branch_result := 0;
+
+				for i in NUMBER_PARITY_BITS - 1 downto 0 loop
+
+					--
+					-- Either the value is added or subtracted, depending on
+					-- the current branch metric we are computing.
+					--
+					if EDGE_WEIGHT(i) = '0' then
+						v_branch_result := v_branch_result + to_integer(s_axis_input_tdata(i));
+					else
+						v_branch_result := v_branch_result - to_integer(s_axis_input_tdata(i));
+					end if;
+				end loop;
+				m_axis_output_tdata <= std_logic_vector(to_signed(v_branch_result, BW_BRANCH_RESULT));
+				m_axis_output_tvalid_int <= '1';
+				m_axis_output_tlast      <= s_axis_input_tlast;
+			end if;
+
+		end if;
+	end if;
+	end process pr_branch;
+
+end architecture rtl;