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--         FILE NAME: bclrrom.vhdl

--       ENTITY NAME: bclr_rom

-- ARCHITECTURE NAME: basic

--          REVISION: A

--

--       DESCRIPTION: 8 byte x 8 bit ROM 

--                    For Bit clear translations

--

-- Written by John Kent for the mc6805 processor

--

library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_arith.all;

use ieee.std_logic_unsigned.all;

entity bclr_rom is

  port (

    addr   : in   std_logic_vector(2 downto 0);

    data   : out  std_logic_vector(7 downto 0)

  );

end entity bclr_rom;

architecture basic of bclr_rom is

  constant width   : integer := 8;

  constant memsize : integer := 8;

  type bclr_rom_array is array(0 to memsize-1) of std_logic_vector(width-1 downto 0);

  constant bclr_rom_data : bclr_rom_array :=

  ( "11111110",

    "11111101",

    "11111011",

    "11110111",

    "11101111",

    "11011111",

    "10111111",

    "01111111"

         );

begin

   data <= bclr_rom_data(conv_integer(addr));

end architecture basic;