-- ---------------------------------------------------------------------------
-- SRAM 61256 (32Kx8) - Simplified behavioral SRAM            -- TEST BENCH --
-- ---------------------------------------------------------------------------
--
--  File        : 'sram61256_testbench.vhd'
--  Author      :  Lars Larsson 
-- 
--  Date        :  February 15, 1999
--
--  Description :  The design is a behavioral SRAM model 61256 (MSM52256, ...)
--
--  Hint        :  Package simulation (file 'simulation.vhd') is required. Run
--                 simulation over 1000 ns.
-- 
-- -----------------------------------------------------------------------------
--
-- Copyright (C) 1999 Lars Larsson, Dept. of Computer Science
--                                  University of Hamburg
--                                  Vogt-Koelln-Str. 30
--                                  D - 22041 Hamburg, Germany
--                                  larsson@informatik.uni-hamburg.de
--                                  http://tech-www.informatik.uni-hamburg.de/~larsson
--
-- 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.
--
-- This program 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 this program; 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;

library work;
use work.simulation.all;

entity sram61256_testbench is
end sram61256_testbench;

architecture simulate of sram61256_testbench is

  constant T_AA : time := 15 ns;   -- Address Acces Time
  constant T_CO : time := 15 ns;   -- nCS Access Time

  signal address_s                 : std_logic_vector (14 downto 0);
  signal data_s, idata_s, odata_s  : std_logic_vector (7 downto 0);
  signal nwe_s,ncs_s,noe_s         : std_logic;

  -- signal t_access : time :=  0 ns;

  begin

  tristate_p : process ( odata_s, nwe_s, noe_s )
               begin
                 if (nwe_s='0') then
                         data_s <= odata_s;
                     else 
                         data_s <= (others=>'Z');
                 end if;
               end process;

  idata_s <= data_s;

  sim_p : process 
          begin
            noe_s<='0';
            nwe_s<='1';  ncs_s<='1'; address_s<="000000000000000"; odata_s<="00000000";  wait for 100 ns;

            nwe_s<='0';  ncs_s<='1'; address_s<="000000000000000"; odata_s<="00000000";  wait for 100 ns;
                         ncs_s<='0'; wait for 20 ns;
            nwe_s<='0';  ncs_s<='1'; address_s<="000000000000001"; odata_s<="00000001";  wait for 100 ns;
                         ncs_s<='0'; wait for 20 ns;
                         ncs_s<='1'; wait for 20 ns;
            nwe_s<='1';  ncs_s<='1'; address_s<="000000000000000"; odata_s<="00000000";  wait for 100 ns;
                         ncs_s<='0'; wait for 20 ns;
            nwe_s<='1';  ncs_s<='1'; address_s<="000000000000001"; odata_s<="00000000";  wait for 100 ns;
                         ncs_s<='0'; wait for 20 ns;
            nwe_s<='1';  ncs_s<='1'; address_s<="000000000000010"; odata_s<="00000000";  wait for 100 ns;
                         ncs_s<='0'; wait for 20 ns;
            nwe_s<='1';  ncs_s<='1'; address_s<="000000000000011"; odata_s<="00000000";  wait for 100 ns;
          wait;
         end process;
 
    sram_i : sram61256 port map ( nwe_s,ncs_s,noe_s,address_s,data_s );

end simulate;

-- ============================ CONFIGURATION ============================

configuration sram61256_testbench_cfg of sram61256_testbench is
  for simulate
  end for;
end sram61256_testbench_cfg;

-- ======================== END OF CONFIGURATION =========================

<div align="center"><br /><script type="text/javascript"><!--
google_ad_client = "pub-7293844627074885";
//468x60, Created at 07. 11. 25
google_ad_slot = "8619794253";
google_ad_width = 468;
google_ad_height = 60;
//--></script>
<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script><br />&nbsp;</div>