------------------------------------------------------------------------------  This file is a part of the GRLIB VHDL IP LIBRARY--  Copyright (C) 2004 GAISLER RESEARCH----  This program is free software; you can redistribute it and/or modify--  it under the terms of the GNU General Public License as published by--  the Free Software Foundation; either version 2 of the License, or--  (at your option) any later version.----  See the file COPYING for the full details of the license.--------------------------------------------------------------------------------- Entity: 	mmulru-- File:	mmulru.vhd-- Author:	Konrad Eisele, Jiri Gaisler, Gaisler Research-- Description:	MMU LRU logic------------------------------------------------------------------------------library ieee;use ieee.std_logic_1164.all;library grlib;use grlib.amba.all;use grlib.stdlib.all;library gaisler;use gaisler.devices.all;use gaisler.libiu.all;use gaisler.libcache.all;use gaisler.leon3.all;use gaisler.mmuconfig.all;use gaisler.mmuiface.all;entity mmulru is  generic (    entries  : integer := 8    );    port (    rst   : in std_logic;    clk   : in std_logic;    lrui  : in mmulru_in_type;    lruo  : out mmulru_out_type     );end mmulru;architecture rtl of mmulru is  constant entries_log : integer := log2(entries);    component mmulrue   generic (    position : integer;    entries  : integer := 8    );  port (    rst      : in std_logic;    clk      : in std_logic;    lruei    : in mmulrue_in_type;    lrueo    : out mmulrue_out_type   );  end component;  type lru_rtype is record    bar   : std_logic_vector(1 downto 0);    clear : std_logic_vector(M_ENT_MAX-1 downto 0);        -- pragma translate_off    reinit : std_logic;    pos    : std_logic_vector(entries_log-1 downto 0);    -- pragma translate_on  end record;    signal c,r   : lru_rtype;  signal lruei : mmulruei_a (entries-1 downto 0);  signal lrueo : mmulrueo_a (entries-1 downto 0);begin    p0: process (clk, rst, r, c, lrui, lrueo)    variable v : lru_rtype;    variable reinit : std_logic;    variable v_lruei_clk : std_logic;    variable pos : std_logic_vector(entries_log-1 downto 0);    variable touch : std_logic;  begin    v := r;    -- #init    reinit := '0';    v_lruei_clk := rst;        --# eather element in luri or element 0 to top    pos := lrui.pos(entries_log-1 downto 0);    touch := lrui.touch;    if (lrui.touchmin) = '1' then      pos := lrueo(0).pos(entries_log-1 downto 0);      touch := '1';    end if;          for i in entries-1 downto 0 loop      lruei(i).pos(entries_log-1 downto 0)   <= pos;      lruei(i).touch <= touch;      lruei(i).clear <= r.clear((entries-1)-i);  -- reverse order    end loop;        lruei(entries-1).fromleft  <= '0';    lruei(entries-1).fromright <= lrueo(entries-2).movetop;    lruei(entries-1).right(entries_log-1 downto 0)     <= lrueo(entries-2).pos(entries_log-1 downto 0);        for i in entries-2 downto 1 loop      lruei(i).left(entries_log-1 downto 0)      <= lrueo(i+1).pos(entries_log-1 downto 0);      lruei(i).right(entries_log-1 downto 0)     <= lrueo(i-1).pos(entries_log-1 downto 0);      lruei(i).fromleft  <= lrueo(i+1).movetop;      lruei(i).fromright <= lrueo(i-1).movetop;    end loop;        lruei(0).fromleft <= lrueo(1).movetop;    lruei(0).fromright  <= '0';    lruei(0).left(entries_log-1 downto 0)     <= lrueo(1).pos(entries_log-1 downto 0);    if not (r.bar = lrui.mmctrl1.bar) then      reinit := '1';    end if;    -- pragma translate_off        -- pragma translate_on    if (rst) = '0' then       v.bar := lrui.mmctrl1.bar;       reinit := '1';    end if;    if (reinit) = '1' then      v.bar := lrui.mmctrl1.bar;      v.clear := (others => '0');      case lrui.mmctrl1.bar is        when "01"  =>            v.clear(1 downto 0)  := "11";  -- reverse order        when "10"  =>            v.clear(2 downto 0)  := "111";  -- reverse order        when "11"  =>            v.clear(4 downto 0)  := "11111"; -- reverse order        when others =>            v.clear(0)  := '1';       end case;    end if;    --# drive signals          -- pragma translate_off    v.reinit := reinit;    v.pos    := pos;    -- pragma translate_on        lruo.pos  <= lrueo(0).pos;    c <= v;      end process p0;    p1: process (clk)  begin if rising_edge(clk) then r <= c; end if;  end process p1;  --# lru entries  lrue0: for i in entries-1 downto 0 generate    l1 : mmulrue      generic map ( position => i,                    entries => entries )      port map (rst, clk, lruei(i), lrueo(i));  end generate lrue0;end rtl;