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Full Adder using a 3-to-8 Decoder in VHDL

  1. Nov 30, 2008 #1
    I need to design a full adder using a 3-to-8 decoder.

    I have the code for the 3-to-8 decoder but don't know how to use it as a full adder.
    Please help. Thanks

    //3-to-8 Decoder

    Code (Text):

    library ieee;
    use ieee.std_logic_1164.all;
    use ieee.numeric_std.all;

    entity Decoder is
       port (
          A : in unsigned(2 downto 0);
          Y : out unsigned(7 downto 0));
    end Decoder;

    architecture Logic1 of Decoder is

       type TableType is array (0 to 7) of unsigned(7 downto 0);

       constant Table : TableType :=
          ( "00000001", "00000010", "00000100", "00001000",
            "00010000", "00100000", "01000000", "10000000");


       Y <= Table(to_integer(A));

    end Logic1;
  2. jcsd
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