DoubleDabble.vhd

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;
use IEEE.std_logic_misc.all;
use IEEE.std_logic_unsigned.all;

entity DoubleDabble is
    Port (Clk_in: IN STD_LOGIC;
         Data_in: IN STD_LOGIC_VECTOR(7 DOWNTO 0);
            H_out: OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
            T_out: OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
            U_out: OUT STD_LOGIC_VECTOR(3 DOWNTO 0));
end DoubleDabble;

architecture Behavioral of DoubleDabble is
    begin
    Main: process(Clk_in)
    variable count : STD_LOGIC_VECTOR(3 DOWNTO 0) := "0000";
     variable IP : STD_LOGIC_VECTOR (19 DOWNTO 0);
        begin
        if Rising_Edge(Clk_in) then
                if count = "0000" then
                    IP(7 DOWNTO 0) := Data_in;
                    IP(19 DOWNTO 8) := "000000000000";
                    H_out(3 DOWNTO 0) <= "0000";
                    T_out(3 DOWNTO 0) <= "0000";
                    U_out(3 DOWNTO 0) <= "0000";
                    count := count + '1';
                elsif count < "1000" then
                    IP := IP (18 DOWNTO 0) & '0';
                    count := count + '1';
                        if unsigned(IP(19 DOWNTO 16)) >= 5 then
                            IP(19 DOWNTO 16) := IP(19 DOWNTO 16) + "0011";
                        end if;
                        if unsigned(IP(15 DOWNTO 12)) >= 5 then
                            IP(15 DOWNTO 12) := IP(15 DOWNTO 12) + "0011";
                        end if;
                        if unsigned(IP(11 DOWNTO 8)) >= 5 then
                            IP(11 DOWNTO 8) := IP(11 DOWNTO 8) + "0011";
                        end if;
                        H_out(3 DOWNTO 0) <= IP(19 DOWNTO 16);
                        T_out(3 DOWNTO 0) <= IP(15 DOWNTO 12);
                        U_out(3 DOWNTO 0) <= IP(11 DOWNTO 8);
                elsif count = "1000" then
                    IP := IP (18 DOWNTO 0) & '0';
                    count := count + '1';
                    H_out(3 DOWNTO 0) <= IP(19 DOWNTO 16);
                    T_out(3 DOWNTO 0) <= IP(15 DOWNTO 12);
                    U_out(3 DOWNTO 0) <= IP(11 DOWNTO 8);
                end if;
        end if;
    end process Main;
end Behavioral;