entity roms is
  port (
    address : in  bit_vector (5 downto 0);
    e_n     : in  bit;
    data    : out mux_vector (31 downto 0) bus;
    vdd     : in bit;
    vss     : in bit);
end roms;

architecture data_flow of roms is

  signal rom_out : bit_vector (31 downto 0);

begin

  write_out : block (e_n = '0')
  begin
    data <= guarded rom_out;
  end block;

  with address (5 downto 0) select
  rom_out <=
          X"08000001" when B"100000",
          X"00000021" when B"100001",
          X"400ef800" when B"100010",
          X"00000021" when B"100011",
          X"23ff0004" when B"100100",
          X"03e00008" when B"100101",
          X"42000010" when B"100110",
          X"00000000" when others;

end;