----------------------------------------------------------------------------- -- Copyright (C) 2005 IMEC - -- - -- Redistribution and use in source and binary forms, with or without - -- modification, are permitted provided that the following conditions - -- are met: - -- - -- 1. Redistributions of source code must retain the above copyright - -- notice, this list of conditions and the following disclaimer. - -- - -- 2. Redistributions in binary 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. - -- - -- 3. Neither the name of the author nor the names of contributors - -- may be used to endorse or promote products derived from this - -- software without specific prior written permission. - -- - -- THIS CODE IS PROVIDED BY THE AUTHOR 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. - -- - ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- -- File : tb_stack.vhd ----------------------------------------------------------------------------- -- Description : Testbench for stack of the Micro6 -- -------------------------------------------------------------------------- -- Author : Osman Allam -- Date : 07/02/2006 -- Version : 1.0 -- Change history : ----------------------------------------------------------------------------- -- This code was developed by Osman Allam during an internship at IMEC, -- in collaboration with Geert Vanwijnsberghe, Tom Tassignon en Steven -- Redant. The purpose of this code is to teach students good VHDL coding -- style for writing complex behavioural models. ----------------------------------------------------------------------------- library IEEE; use IEEE.std_logic_1164.all; use IEEE.numeric_std.all; entity tb_stack is end entity; architecture test of tb_stack is signal clk : std_logic; signal rst : std_logic; signal en : std_logic; signal d : std_logic_vector (7 downto 0); signal push : std_logic; signal pop : std_logic; signal q : std_logic_vector (7 downto 0); component stack is port ( clk : in std_logic; rst : in std_logic; en : in std_logic; d : in std_logic_vector; push : in std_logic; pop : in std_logic; q : out std_logic_vector); end component; signal EndOfSim : boolean := false; constant clkPeriod : time := 10 ns; constant dutyCycle : real := 0.5; procedure t_push ( data : in std_logic_vector; signal d : out std_logic_vector; signal en : out std_logic; signal push : out std_logic) is begin d <= data; en <= '1'; push <= '1'; wait until falling_edge (clk); en <= '0'; push <= '0'; wait until falling_edge (clk); end procedure; procedure t_pop ( data_expected : in std_logic_vector; signal en : out std_logic; signal pop : out std_logic) is begin en <= '1'; pop <= '1'; wait until falling_edge (clk); en <= '0'; pop <= '0'; wait until falling_edge (clk); assert (q = data_expected) report "Popping doesn't work correctly"; end procedure; begin UUT: stack port map (clk, rst, en, d, push, pop, q); clock: process begin clk <= '0'; wait for (1.0 - dutyCycle) * clkPeriod; clk <= '1'; wait for dutyCycle * clkPeriod; if EndOfSim then wait; end if; end process; process begin en <= '0'; pop <= '0'; push <= '0'; -- Testing the reset signal wait for 23 ns; rst <= '1'; wait for 1 ns; assert (q = (q'range => '0')) report "Reset doesn't reset the stack"; wait for 50 ns; rst <= '0'; wait until falling_edge (clk); -- allign rest of inputs with falling edge of clk -- Pushing 00001100 into the stack t_push ("00001100", d, en, push); -- Stack contents -- 00: 00001100 04: 00000000 08: 00000000 12: 00000000 -- 01: 00000000 05: 00000000 09: 00000000 13: 00000000 -- 02: 00000000 06: 00000000 10: 00000000 14: 00000000 -- 03: 00000000 07: 00000000 11: 00000000 15: 00000000 -- Stack pointer: 01 -- Poping a word from the stack t_pop ("00001100", en, pop); -- Stack contents -- 00: 00001100 04: 00000000 08: 00000000 12: 00000000 -- 01: 00000000 05: 00000000 09: 00000000 13: 00000000 -- 02: 00000000 06: 00000000 10: 00000000 14: 00000000 -- 03: 00000000 07: 00000000 11: 00000000 15: 00000000 -- Stack pointer: 00 -- Popping again from the empty stack returns the same value but doesn't -- change the stack status (contents and pointer) t_pop ("00001100", en, pop); -- Stack contents -- 00: 00001100 04: 00000000 08: 00000000 12: 00000000 -- 01: 00000000 05: 00000000 09: 00000000 13: 00000000 -- 02: 00000000 06: 00000000 10: 00000000 14: 00000000 -- 03: 00000000 07: 00000000 11: 00000000 15: 00000000 -- Stack pointer: 00 -- Pushing 11001100 into the stack t_push ("11001100", d, en, push); -- Pushing 00110011 into the stack t_push ("00110011", d, en, push); -- Pushing 10101010 into the stack t_push ("10101010", d, en, push); -- Pushing 01010101 into the stack t_push ("01010101", d, en, push); -- Stack contents -- 00: 11001100 04: 00000000 08: 00000000 12: 00000000 -- 01: 00110011 05: 00000000 09: 00000000 13: 00000000 -- 02: 10101010 06: 00000000 10: 00000000 14: 00000000 -- 03: 01010101 07: 00000000 11: 00000000 15: 00000000 -- Stack pointer: 04 -- Poping a word from the stack t_pop ("01010101", en, pop); -- Poping a word from the stack t_pop ("10101010", en, pop); -- Poping a word from the stack t_pop ("00110011", en, pop); -- Poping a word from the stack t_pop ("11001100", en, pop); -- Stack contents -- 00: 11001100 04: 00000000 08: 00000000 12: 00000000 -- 01: 00110011 05: 00000000 09: 00000000 13: 00000000 -- 02: 10101010 06: 00000000 10: 00000000 14: 00000000 -- 03: 01010101 07: 00000000 11: 00000000 15: 00000000 -- Stack pointer: 00 -- Filling up the stack with (pushing 16 values) t_push ("00000011", d, en, push); t_push ("00000111", d, en, push); t_push ("00001011", d, en, push); t_push ("00001111", d, en, push); t_push ("00010011", d, en, push); t_push ("00010111", d, en, push); t_push ("00011011", d, en, push); t_push ("00011111", d, en, push); t_push ("00100011", d, en, push); t_push ("00100111", d, en, push); t_push ("00101011", d, en, push); t_push ("00101111", d, en, push); t_push ("00110011", d, en, push); t_push ("00110111", d, en, push); t_push ("00111011", d, en, push); t_push ("00111111", d, en, push); -- Stack contents -- 00: 00000011 04: 00010011 08: 00100011 12: 00110011 -- 01: 00000111 05: 00010111 09: 00100111 13: 00110111 -- 02: 00001011 06: 00011011 10: 00101011 14: 00111011 -- 03: 00001111 07: 00011111 11: 00101111 15: 00111111 -- Stack pointer: 16 -- Pushing additional data shouldn't change the stack status t_push ("01000011", d, en, push); t_push ("01000111", d, en, push); -- Stack contents << THE SAME >> -- 00: 00000011 04: 00010011 08: 00100011 12: 00110011 -- 01: 00000111 05: 00010111 09: 00100111 13: 00110111 -- 02: 00001011 06: 00011011 10: 00101011 14: 00111011 -- 03: 00001111 07: 00011111 11: 00101111 15: 00111111 -- Stack pointer: 16 -- Popping the entire stack contents t_pop ("00111111", en, pop); t_pop ("00111011", en, pop); t_pop ("00110111", en, pop); t_pop ("00110011", en, pop); t_pop ("00101111", en, pop); t_pop ("00101011", en, pop); t_pop ("00100111", en, pop); t_pop ("00100011", en, pop); t_pop ("00011111", en, pop); t_pop ("00011011", en, pop); t_pop ("00010111", en, pop); t_pop ("00010011", en, pop); t_pop ("00001111", en, pop); t_pop ("00001011", en, pop); t_pop ("00000111", en, pop); t_pop ("00000011", en, pop); -- Stack contents -- 00: 00000011 04: 00010011 08: 00100011 12: 00110011 -- 01: 00000111 05: 00010111 09: 00100111 13: 00110111 -- 02: 00001011 06: 00011011 10: 00101011 14: 00111011 -- 03: 00001111 07: 00011111 11: 00101111 15: 00111111 -- Stack pointer: 00 -- Additional pops shouldn't change the stack status t_pop ("00000011", en, pop); t_pop ("00000011", en, pop); -- Stack contents << THE SAME >> -- 00: 00000011 04: 00010011 08: 00100011 12: 00110011 -- 01: 00000111 05: 00010111 09: 00100111 13: 00110111 -- 02: 00001011 06: 00011011 10: 00101011 14: 00111011 -- 03: 00001111 07: 00011111 11: 00101111 15: 00111111 -- Stack pointer: 00 report "Simulation completed"; EndOfSim <= true; wait; end process; end architecture;