-- (C) Copyright Collin J. Doering 2015
--
-- 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 3 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, see .
-- File: alu_tb.vhdl
-- Author: Collin J. Doering
-- Date: May 22, 2015
library IEEE;
use IEEE.std_logic_1164.all;
-- A testbench has no ports.
entity alu_tb is
end alu_tb;
architecture alu_tb_arch of alu_tb is
-- Declaration of the component that will be instantiated.
component alu
port (x, y : in std_logic_vector(15 downto 0);
zx, nx, zy, ny, f, no : in std_logic;
cout : out std_logic_vector(15 downto 0);
zr, ng : out std_logic);
end component;
-- Specifies which entity is bound with the component.
for alu_0: alu use entity work.alu;
-- Signals
signal x, y, cout : std_logic_vector(15 downto 0);
signal zx, nx, zy, ny, f, no, zr, ng : std_logic;
begin
-- Component instantiation.
alu_0: alu port map (x, y, zx, nx, zy, ny, f, no, cout, zr, ng);
-- This process does the real job.
process
type pattern_type is record
-- The inputs of the alu.
x, y : std_logic_vector(15 downto 0);
zx, nx, zy, ny, f, no : std_logic;
-- The expected outputs of the alu.
cout : std_logic_vector(15 downto 0);
zr, ng : std_logic;
end record;
-- The patterns to apply.
type pattern_array is array (natural range <>) of pattern_type;
constant patterns : pattern_array :=
(("0000000000000000", "1111111111111111", '1', '0', '1', '0', '1', '0', "0000000000000000", '1', '0'),
("0000000000000000", "1111111111111111", '1', '1', '1', '1', '1', '1', "0000000000000001", '0', '0'),
("0000000000000000", "1111111111111111", '1', '1', '1', '0', '1', '0', "1111111111111111", '0', '1'),
("0000000000000000", "1111111111111111", '0', '0', '1', '1', '0', '0', "0000000000000000", '1', '0'),
("0000000000000000", "1111111111111111", '1', '1', '0', '0', '0', '0', "1111111111111111", '0', '1'),
("0000000000000000", "1111111111111111", '0', '0', '1', '1', '0', '1', "1111111111111111", '0', '1'),
("0000000000000000", "1111111111111111", '1', '1', '0', '0', '0', '1', "0000000000000000", '1', '0'),
("0000000000000000", "1111111111111111", '0', '0', '1', '1', '1', '1', "0000000000000000", '1', '0'),
("0000000000000000", "1111111111111111", '1', '1', '0', '0', '1', '1', "0000000000000001", '0', '0'),
("0000000000000000", "1111111111111111", '0', '1', '1', '1', '1', '1', "0000000000000001", '0', '0'),
("0000000000000000", "1111111111111111", '1', '1', '0', '1', '1', '1', "0000000000000000", '1', '0'),
("0000000000000000", "1111111111111111", '0', '0', '1', '1', '1', '0', "1111111111111111", '0', '1'),
("0000000000000000", "1111111111111111", '1', '1', '0', '0', '1', '0', "1111111111111110", '0', '1'),
("0000000000000000", "1111111111111111", '0', '0', '0', '0', '1', '0', "1111111111111111", '0', '1'),
("0000000000000000", "1111111111111111", '0', '1', '0', '0', '1', '1', "0000000000000001", '0', '0'),
("0000000000000000", "1111111111111111", '0', '0', '0', '1', '1', '1', "1111111111111111", '0', '1'),
("0000000000000000", "1111111111111111", '0', '0', '0', '0', '0', '0', "0000000000000000", '1', '0'),
("0000000000000000", "1111111111111111", '0', '1', '0', '1', '0', '1', "1111111111111111", '0', '1'),
("0000000000010001", "0000000000000011", '1', '0', '1', '0', '1', '0', "0000000000000000", '1', '0'),
("0000000000010001", "0000000000000011", '1', '1', '1', '1', '1', '1', "0000000000000001", '0', '0'),
("0000000000010001", "0000000000000011", '1', '1', '1', '0', '1', '0', "1111111111111111", '0', '1'),
("0000000000010001", "0000000000000011", '0', '0', '1', '1', '0', '0', "0000000000010001", '0', '0'),
("0000000000010001", "0000000000000011", '1', '1', '0', '0', '0', '0', "0000000000000011", '0', '0'),
("0000000000010001", "0000000000000011", '0', '0', '1', '1', '0', '1', "1111111111101110", '0', '1'),
("0000000000010001", "0000000000000011", '1', '1', '0', '0', '0', '1', "1111111111111100", '0', '1'),
("0000000000010001", "0000000000000011", '0', '0', '1', '1', '1', '1', "1111111111101111", '0', '1'),
("0000000000010001", "0000000000000011", '1', '1', '0', '0', '1', '1', "1111111111111101", '0', '1'),
("0000000000010001", "0000000000000011", '0', '1', '1', '1', '1', '1', "0000000000010010", '0', '0'),
("0000000000010001", "0000000000000011", '1', '1', '0', '1', '1', '1', "0000000000000100", '0', '0'),
("0000000000010001", "0000000000000011", '0', '0', '1', '1', '1', '0', "0000000000010000", '0', '0'),
("0000000000010001", "0000000000000011", '1', '1', '0', '0', '1', '0', "0000000000000010", '0', '0'),
("0000000000010001", "0000000000000011", '0', '0', '0', '0', '1', '0', "0000000000010100", '0', '0'),
("0000000000010001", "0000000000000011", '0', '1', '0', '0', '1', '1', "0000000000001110", '0', '0'),
("0000000000010001", "0000000000000011", '0', '0', '0', '1', '1', '1', "1111111111110010", '0', '1'),
("0000000000010001", "0000000000000011", '0', '0', '0', '0', '0', '0', "0000000000000001", '0', '0'),
("0000000000010001", "0000000000000011", '0', '1', '0', '1', '0', '1', "0000000000010011", '0', '0'));
begin
-- Check each pattern.
for i in patterns'range loop
-- Set the inputs.
x <= patterns(i).x;
y <= patterns(i).y;
zx <= patterns(i).zx;
nx <= patterns(i).nx;
zy <= patterns(i).zy;
ny <= patterns(i).ny;
f <= patterns(i).f;
no <= patterns(i).no;
-- Wait for the results.
wait for 1 ns;
-- Check the outputs.
assert cout = patterns(i).cout
report "bad alu output" severity error;
assert zr = patterns(i).zr
report "bad alu zr control bit output" severity error;
assert ng = patterns(i).ng
report "bad alu ng control bit output" severity error;
end loop;
assert false report "end of test" severity note;
-- Wait forever; this will finish the simulation.
wait;
end process;
end alu_tb_arch;