library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL; 

entity decoder_3_8_TB is

end decoder_3_8_TB;

architecture Behavior of decoder_3_8_TB is

   
    component decoder_3_8
        Port ( A    : in  STD_LOGIC_VECTOR (2 downto 0);
               EN_L : in  STD_LOGIC;
               Y    : out STD_LOGIC_VECTOR (7 downto 0));
    end component;

    -- Signals to connect to the UUT (Unit Under Test)
    signal A_tb    : STD_LOGIC_VECTOR (2 downto 0) := "000";
    signal EN_L_tb : STD_LOGIC := '1';
    signal Y_tb    : STD_LOGIC_VECTOR (7 downto 0);

  
    function to_bstring(slv : std_logic_vector) return string is
        variable result : string(1 to slv'length);
        variable idx    : integer := 1;
    begin
       
        for i in slv'range loop
            case slv(i) is
                when '0' => result(idx) := '0';
                when '1' => result(idx) := '1';
                when others => result(idx) := 'X'; 
            end case;
            idx := idx + 1;
        end loop;
        return result;
    end function;

 begin

    
    UUT: decoder_3_8 Port map (
          A => A_tb,
          EN_L => EN_L_tb,
          Y => Y_tb
        );

   
    stim_proc: process
        variable i : integer;
    begin
       
        EN_L_tb <= '1';
        A_tb <= "101"; 
        wait for 10 ns;
        report "--- DECODER DISABLED ---";
        
        report "EN_L=" & std_logic'image(EN_L_tb) & "  Input A2,A1,A0= " & to_bstring(A_tb) & 
                   " | Output Y7...Y0= " & to_bstring(Y_tb) & LF & " ";
	
		wait for 10 ns;
        report "--- DECODER ENABLED ---";
        
        EN_L_tb <= '0';
        for i in 0 to 7 loop
            
            A_tb <= std_logic_vector(to_unsigned(i, 3));
            wait for 10 ns; 
           	         
            report "EN_L=" & std_logic'image(EN_L_tb) & "  Input A2,A1,A0= " & to_bstring(A_tb) & 
                   " | Output Y7...Y0= " & to_bstring(Y_tb) & LF & " ";
           
        end loop;
    
        report "Simulation Complete.";
        wait; 
    end process;

end Behavior;