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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
library ieee; use ieee.std_logic_1164.all;
entity bus_module is
port ( synch : inout std_ulogic; -- . . . );
-- not in book
other_port : in std_ulogic := 'U' );
-- end not in book
end entity bus_module;
--------------------------------------------------
-- not in book
library ieee; use ieee.std_logic_1164.all;
entity bus_based_system is
end entity bus_based_system;
-- end not in book
architecture top_level of bus_based_system is
signal synch_control : std_logic;
-- . . .
begin
synch_control_pull_up : synch_control <= 'H';
bus_module_1 : entity work.bus_module(behavioral)
port map ( synch => synch_control, -- . . . );
-- not in book
other_port => open );
-- end not in book
bus_module_2 : entity work.bus_module(behavioral)
port map ( synch => synch_control, -- . . . );
-- not in book
other_port => open );
-- end not in book
-- . . .
end architecture top_level;
architecture behavioral of bus_module is
begin
behavior : process is
-- . . .
-- not in book
constant Tdelay_synch : delay_length := 10 ns;
constant wait_delay : delay_length := 100 ns;
-- end not in book
begin
synch <= '0' after Tdelay_synch;
-- . . .
-- not in book
wait for wait_delay;
-- end not in book
-- ready to start operation
synch <= 'Z' after Tdelay_synch;
wait until synch = 'H';
-- proceed with operation
-- . . .
end process behavior;
end architecture behavioral;
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