Subversion Repositories wb4pb

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-- This sourcecode is released under BSD license.
-- Please see http://www.opensource.org/licenses/bsd-license.php for details!
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--
-- Copyright (c) 2010, Stefan Fischer <Ste.Fis@OpenCores.org>
-- All rights reserved.
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-- modification, are permitted provided that the following conditions are met:
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--  * Redistributions of source code must retain the above copyright notice, 
--    this list of conditions and the following disclaimer.
--  * Redistributions in binary form must reproduce the above copyright notice,
--    this list of conditions and the following disclaimer in the documentation
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-- filename: picoblaze_wb_gpio_tb.vhd
-- description: testbench for picoblaze_wb_gpio example
-- todo4user: modify stimulus as needed
-- version: 0.0.0
-- changelog: - 0.0.0, initial release
--            - ...
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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
 
 
entity picoblaze_wb_gpio_tb is
end picoblaze_wb_gpio_tb;
 
 
architecture behavioral of picoblaze_wb_gpio_tb is
 
  component picoblaze_wb_gpio is
    port
    (
      p_rst_n_i : in std_logic;
      p_clk_i : in std_logic;
 
      p_gpio_io : inout std_logic_vector(7 downto 0)
    );
  end component;
 
  signal rst_n : std_logic := '0';
  signal clk : std_logic := '1';
 
  signal gpio : std_logic_vector(7 downto 0) := (others => 'Z');
 
  constant PERIOD : time := 20 ns;
 
  signal test_data_in : std_logic_vector(7 downto 4) := (others => '0');
 
begin
 
  -- system signal generation
  rst_n <= '1' after PERIOD*2;
  clk <= not clk after PERIOD/2;
 
  -- 4 bit counting data, changing after some micro seconds
  test_data_in <= std_logic_vector(unsigned(test_data_in) + 1) after 3000 ns;
  -- stimulus at upper gpio nibble
  gpio(7 downto 4) <= test_data_in;
 
  -- design under test instance
  dut : picoblaze_wb_gpio
    port map
    (
      p_rst_n_i => rst_n,
      p_clk_i => clk,
 
      p_gpio_io => gpio
    );
 
end behavioral;