library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

entity lr4 is
    generic(aw:positive:=8; dw:positive:=128);   -- 2^8=256, 256x128
    Port(
        clk ,we ,en : in std_logic;
        addr : in std_logic_vector(aw-1 downto 0);
        di : in std_logic_vector(dw-1 downto 0);
        do : out std_logic_vector(dw-1 downto 0)
    );
end lr4;

architecture Behavioral of lr4 is

type ram_type is array (0 to 2**aw-1 ) of std_logic_vector (dw-1 downto 0);
signal RAM: ram_type :=(
    x"99",x"88",x"77",x"66",
    x"55",x"44",x"33",x"22",
    x"11",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00",
    x"00",x"00",x"00",x"00"
    );

begin
    process (clk)
    begin
        if rising_edge(clk) then
            if en = '1' then
                if we = '1' then    --write
                    RAM(conv_integer(addr)) <= di;
                end if;
                do <= RAM(conv_integer(addr));
            end if;
        end if;
    end process;
end Behavioral;