Line 1... |
Line 1... |
--!
|
--!
|
--! Copyright (C) 2011 - 2012 Creonic GmbH
|
--! Copyright (C) 2011 - 2014 Creonic GmbH
|
--!
|
--!
|
--! This file is part of the Creonic Viterbi Decoder, which is distributed
|
--! This file is part of the Creonic Viterbi Decoder, which is distributed
|
--! under the terms of the GNU General Public License version 2.
|
--! under the terms of the GNU General Public License version 2.
|
--!
|
--!
|
--! @file
|
--! @file
|
Line 47... |
Line 47... |
|
|
architecture rtl of trellis_traceback is
|
architecture rtl of trellis_traceback is
|
|
|
signal current_node : unsigned(BW_TRELLIS_STATES - 1 downto 0);
|
signal current_node : unsigned(BW_TRELLIS_STATES - 1 downto 0);
|
signal m_axis_output_tvalid_int : std_logic;
|
signal m_axis_output_tvalid_int : std_logic;
|
signal s_axis_input_last_tuser_d1 : std_logic;
|
|
signal s_axis_input_tready_int : std_logic;
|
signal s_axis_input_tready_int : std_logic;
|
|
|
begin
|
begin
|
s_axis_input_tready_int <= '1' when m_axis_output_tready = '1' or m_axis_output_tvalid_int = '0' else
|
s_axis_input_tready_int <= '1' when m_axis_output_tready = '1' or m_axis_output_tvalid_int = '0' else
|
'0';
|
'0';
|
s_axis_input_tready <= s_axis_input_tready_int;
|
s_axis_input_tready <= s_axis_input_tready_int;
|
|
|
m_axis_output_tvalid <= m_axis_output_tvalid_int;
|
m_axis_output_tvalid <= m_axis_output_tvalid_int;
|
|
|
|
|
-- Traceback the ACS local path decisions and output the resulting global path.
|
-- Traceback the ACS local path decisions and output the resulting global path.
|
pr_traceback : process(clk) is
|
pr_traceback : process(clk) is
|
begin
|
begin
|
if rising_edge(clk) then
|
if rising_edge(clk) then
|
if rst = '1' then
|
if rst = '1' then
|
m_axis_output_tvalid_int <= '0';
|
m_axis_output_tvalid_int <= '0';
|
m_axis_output_tdata <= '0';
|
m_axis_output_tdata <= '0';
|
m_axis_output_tlast <= '0';
|
m_axis_output_tlast <= '0';
|
m_axis_output_last_tuser <= '0';
|
m_axis_output_last_tuser <= '0';
|
s_axis_input_last_tuser_d1 <= '0';
|
|
current_node <= (others => '0');
|
current_node <= (others => '0');
|
else
|
else
|
m_axis_output_tlast <= s_axis_input_tlast;
|
|
s_axis_input_last_tuser_d1 <= s_axis_input_last_tuser;
|
if m_axis_output_tready = '1' then
|
m_axis_output_last_tuser <= s_axis_input_last_tuser;
|
m_axis_output_tvalid_int <= '0';
|
|
end if;
|
|
|
-- calculate the decoded bit with an shift register
|
-- calculate the decoded bit with an shift register
|
if s_axis_input_last_tuser_d1 = '0' then
|
|
if s_axis_input_tvalid = '1' and s_axis_input_tready_int = '1' then
|
if s_axis_input_tvalid = '1' and s_axis_input_tready_int = '1' then
|
current_node <= current_node(BW_TRELLIS_STATES - 2 downto 0)
|
|
& s_axis_input_tdata(to_integer(current_node(BW_TRELLIS_STATES - 1 downto 0)));
|
m_axis_output_tlast <= s_axis_input_tlast;
|
m_axis_output_tdata <= current_node(BW_TRELLIS_STATES - 1);
|
m_axis_output_last_tuser <= s_axis_input_last_tuser;
|
end if;
|
|
else
|
|
current_node <= to_unsigned(0, BW_TRELLIS_STATES);
|
|
end if;
|
|
-- handle tvalid output signal
|
-- handle tvalid output signal
|
if s_axis_input_window_tuser = '1' then
|
if s_axis_input_window_tuser = '1' then
|
m_axis_output_tvalid_int <= '1';
|
m_axis_output_tvalid_int <= '1';
|
|
m_axis_output_tdata <= current_node(BW_TRELLIS_STATES - 1);
|
|
end if;
|
|
|
|
-- last value of current window?
|
|
if s_axis_input_last_tuser = '1' then
|
|
current_node <= to_unsigned(0, BW_TRELLIS_STATES);
|
else
|
else
|
m_axis_output_tvalid_int <= '0';
|
current_node <= current_node(BW_TRELLIS_STATES - 2 downto 0)
|
|
& s_axis_input_tdata(to_integer(current_node(BW_TRELLIS_STATES - 1 downto 0)));
|
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
end process pr_traceback;
|
end process pr_traceback;
|
end architecture rtl;
|
end architecture rtl;
|