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------------------------------------------------------------------------------- -- -- T8039 Microcontroller System -- -- $Id: t8039.vhd,v 1.3 2004-12-03 19:43:12 arniml Exp $ -- -- Copyright (c) 2004, Arnim Laeuger (arniml@opencores.org) -- -- All rights reserved -- -- Redistribution and use in source and synthezised forms, with or without -- modification, are permitted provided that the following conditions are met: -- -- Redistributions of source code must retain the above copyright notice, -- this list of conditions and the following disclaimer. -- -- Redistributions in synthesized form must reproduce the above copyright -- notice, this list of conditions and the following disclaimer in the -- documentation and/or other materials provided with the distribution. -- -- Neither the name of the author nor the names of other contributors may -- be used to endorse or promote products derived from this software without -- specific prior written permission. -- -- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" -- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, -- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR -- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE -- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR -- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF -- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS -- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN -- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) -- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -- POSSIBILITY OF SUCH DAMAGE. -- -- Please report bugs to the author, but before you do so, please -- make sure that this is not a derivative work and that -- you have the latest version of this file. -- -- The latest version of this file can be found at: -- http://www.opencores.org/cvsweb.shtml/t48/ -- ------------------------------------------------------------------------------- library ieee; use ieee.std_logic_1164.all; entity t8039 is port ( xtal_i : in std_logic; reset_n_i : in std_logic; t0_b : inout std_logic; int_n_i : in std_logic; ea_i : in std_logic; rd_n_o : out std_logic; psen_n_o : out std_logic; wr_n_o : out std_logic; ale_o : out std_logic; db_b : inout std_logic_vector( 7 downto 0); t1_i : in std_logic; p2_b : inout std_logic_vector( 7 downto 0); p1_b : inout std_logic_vector( 7 downto 0); prog_n_o : out std_logic ); end t8039; use work.t48_system_comp_pack.t8039_notri; architecture struct of t8039 is signal t0_s : std_logic; signal t0_dir_s : std_logic; signal db_s : std_logic_vector( 7 downto 0); signal db_dir_s : std_logic; signal p2_s : std_logic_vector( 7 downto 0); signal p2_low_imp_s : std_logic; signal p1_s : std_logic_vector( 7 downto 0); signal p1_low_imp_s : std_logic; begin t8039_notri_b : t8039_notri generic map ( -- we don't need explicit gating of input ports -- this is done implicitely by the bidirectional pads gate_port_input_g => 0 ) port map ( xtal_i => xtal_i, reset_n_i => reset_n_i, t0_i => t0_b, t0_o => t0_s, t0_dir_o => t0_dir_s, int_n_i => int_n_i, ea_i => ea_i, rd_n_o => rd_n_o, psen_n_o => psen_n_o, wr_n_o => wr_n_o, ale_o => ale_o, db_i => db_b, db_o => db_s, db_dir_o => db_dir_s, t1_i => t1_i, p2_i => p2_b, p2_o => p2_s, p2_low_imp_o => p2_low_imp_s, p1_i => p1_b, p1_o => p1_s, p1_low_imp_o => p1_low_imp_s, prog_n_o => prog_n_o ); ----------------------------------------------------------------------------- -- Process bidirs -- -- Purpose: -- Assign bidirectional signals. -- bidirs: process (t0_b, t0_s, t0_dir_s, db_b, db_s, db_dir_s, p1_b, p1_s, p1_low_imp_s, p2_b, p2_s, p2_low_imp_s) function open_collector_f(sig : std_logic) return std_logic is variable sig_v : std_logic; begin sig_v := 'Z'; if sig = '0' then sig_v := '0'; end if; return sig_v; end; begin -- Test 0 ----------------------------------------------------------------- if t0_dir_s = '1' then t0_b <= t0_s; else t0_b <= 'Z'; end if; -- Data Bus --------------------------------------------------------------- if db_dir_s = '1' then db_b <= db_s; else db_b <= (others => 'Z'); end if; -- Port 1 ----------------------------------------------------------------- for i in p1_b'range loop p1_b(i) <= open_collector_f(p1_s(i)); end loop; -- if p1_low_imp_s = '1' then -- p1_b <= p1_s; -- else -- p1_b <= (others => 'Z'); -- end if; -- Port 2 ----------------------------------------------------------------- for i in p2_b'range loop p2_b(i) <= open_collector_f(p2_s(i)); end loop; -- if p2_low_imp_s = '1' then -- p2_b <= p2_b_s; -- else -- p2_b <= (others => 'Z'); -- end if; end process bidirs; -- ----------------------------------------------------------------------------- end struct; ------------------------------------------------------------------------------- -- File History: -- -- $Log: not supported by cvs2svn $ -------------------------------------------------------------------------------