Subversion Repositories am9080_cpu_based_on_microcoded_am29xx_bit-slices

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-- Company: 

-- Engineer: 

-- 

-- Create Date: 09/20/2017 11:51:21 PM

-- Design Name: 

-- Module Name: Am25139 - Behavioral

-- Project Name: 

-- Target Devices: 

-- Tool Versions: 

-- Description: 

-- 

-- Dependencies: 

-- 

-- Revision:

-- Revision 0.01 - File Created

-- Additional Comments:

-- 

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

-- Uncomment the following library declaration if using

-- arithmetic functions with Signed or Unsigned values

--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating

-- any Xilinx leaf cells in this code.

--library UNISIM;

--use UNISIM.VComponents.all;

entity Am25139 is

    Port ( nG1 : in STD_LOGIC;

           B1 : in STD_LOGIC;

           A1 : in STD_LOGIC;

           nY1 : out STD_LOGIC_VECTOR (3 downto 0);

           nG2 : in STD_LOGIC;

           B2 : in STD_LOGIC;

           A2 : in STD_LOGIC;

           nY2 : out STD_LOGIC_VECTOR (3 downto 0));

end Am25139;

architecture Behavioral of Am25139 is

signal sel1, sel2: std_logic_vector(1 downto 0);

begin

sel1 <= B1 & A1;

sel2 <= B2 & A2;

decoder1: process(nG1, sel1)

begin

    if (nG1 = '0') then

        case sel1 is

            when "00" =>

                nY1 <= "1110"; -- 0

            when "01" =>

                nY1 <= "1101"; -- 1

            when "10" =>

                nY1 <= "1011"; -- 2

            when "11" =>

                nY1 <= "0111"; -- 3

            when others =>

                                        null;

        end case;

    else

        nY1 <= "1111";

    end if;

end process;

decoder2: process(nG2, sel2)

begin

    if (nG2 = '0') then

        case sel2 is

            when "00" =>

                nY2 <= "1110"; -- 0

            when "01" =>

                nY2 <= "1101"; -- 1

            when "10" =>

                nY2 <= "1011"; -- 2

            when "11" =>

                nY2 <= "0111"; -- 3

            when others =>

                                        null;

        end case;

    else

        nY2 <= "1111";

    end if;

end process;

end Behavioral;