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-- Copyright (C) 2002 Morgan Kaufmann Publishers, Inc
-- This file is part of VESTs (Vhdl tESTs).
-- VESTs 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.
-- VESTs is distributed in the hope that it will be useful, but WITHOUT
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-- for more details.
-- You should have received a copy of the GNU General Public License
-- along with VESTs; if not, write to the Free Software Foundation,
-- Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
entity processor_node is
end entity processor_node;
-- code from book
architecture dataflow of processor_node is
-- not in book
subtype word is bit_vector(31 downto 0);
type word_vector is array (natural range <>) of word;
function resolve_unique ( drivers : word_vector ) return word is
begin
if drivers'length > 0 then
return drivers(drivers'left);
else
return X"00000000";
end if;
end function resolve_unique;
-- end not in book
signal address_bus : resolve_unique word bus;
-- . . .
-- not in book
signal cache_miss, dirty, replace_section,
snoop_hit, flag_update : bit := '0';
constant tag_section0 : bit_vector(11 downto 0) := X"000";
constant tag_section1 : bit_vector(11 downto 0) := X"001";
constant set_index : bit_vector(15 downto 0) := X"6666";
constant snoop_address : word := X"88888888";
-- end not in book
begin
cache_to_address_buffer : block ( cache_miss = '1' and dirty = '1' ) is
begin
address_bus <= guarded
tag_section0 & set_index & B"0000" when replace_section = '0' else
tag_section1 & set_index & B"0000";
end block cache_to_address_buffer;
snoop_to_address_buffer : block ( snoop_hit = '1' and flag_update = '1' ) is
begin
address_bus <= guarded snoop_address(31 downto 4) & B"0000";
end block snoop_to_address_buffer;
-- . . .
-- not in book
stimulus : process is
begin
wait for 10 ns;
dirty <= '0'; cache_miss <= '1', '0' after 5 ns; wait for 10 ns;
dirty <= '1'; cache_miss <= '1', '0' after 5 ns; wait for 10 ns;
replace_section <= '1';
cache_miss <= '1', '0' after 5 ns; wait for 10 ns;
flag_update <= '0'; snoop_hit <= '1', '0' after 5 ns; wait for 10 ns;
flag_update <= '1'; snoop_hit <= '1', '0' after 5 ns; wait for 10 ns;
wait;
end process stimulus;
-- end not in book
end architecture dataflow;
-- end code from book
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