Subversion Repositories uart_fiber

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

entity spdif_to_RX is

    Port ( iCLK : in  STD_LOGIC;

           optic_in : in  STD_LOGIC;

           RX : out  STD_LOGIC;

                          learn_out : out  STD_LOGIC

                          );

end spdif_to_RX;

architecture Behavioral of spdif_to_RX is

--low pass

signal q1 : STD_LOGIC;

signal q2 : STD_LOGIC;

signal samp : STD_LOGIC;

--RX generator

signal samp2 : STD_LOGIC;

signal cnt : natural range 0 to 63;

signal learn : STD_LOGIC;

--constant periode_1_max : natural := (20+7);

--constant periode_0_min : natural := (40-7);

signal RX2 : STD_LOGIC;

begin

learn_out<=learn;

input_low_pass:process (iCLK)

begin

if (iCLK'event and iCLK= '1') then

        q1<=q2;

        q2<=optic_in;

        if(q1=q2)then

                samp<=q1;

        end if;

end if;

end process;

fiber_decoder:process (iCLK)

begin

if (iCLK'event and iCLK= '1') then

        samp2<=samp;

        if(samp2/=samp and samp=learn) then

                if(cnt>33) then

                        RX<='0'; --shift 0

                        RX2<='0';

                elsif (cnt<=20) then

                        RX<=RX2;        --shift1

                        RX2<='1';

                elsif(cnt<27)then

                        RX2<='1';       --shift already done, reload diffr. value

                else

                        learn<=not learn;

                end if;

                cnt<=0;

        else

                if(cnt=20) then

                        RX<=RX2;

                end if;

                if(cnt<63) then

                        cnt<=cnt+1;

                end if;

        end if;

end if;

end process;

end Behavioral;