riscv_adder_tb.vhd

-------------------------------------------------------------------------------
-- Project  ELE8304 : Circuits intégrés à très grande échelle
-------------------------------------------------------------------------------
-- File     riscv_adder_tb.vhd
-- Authors  Titouan Luard <luardtitouan@gmail.com> 
--          Yann Roberge <yann.roberge@polymtl.ca> 
-- Lab      GRM - Polytechnique Montreal
-- Date     2021-11-05
-------------------------------------------------------------------------------
-- Brief    Full adder, supports sign-extension, addition-subtraction,
--          signed and unsigned.
-------------------------------------------------------------------------------
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use ieee.math_real.all;

library work;
use work.riscv_pkg.all;

entity riscv_adder_tb is
end riscv_adder_tb;

architecture tb of riscv_adder_tb is

    constant N   : positive := 32;

    signal a    : std_logic_vector(N-1 downto 0);
    signal b    : std_logic_vector(N-1 downto 0);
    signal sign : std_logic;
    signal sub  : std_logic;
    signal sum  : std_logic_vector(N downto 0);

    constant PERIOD   : time := 10 ns;

begin

  -- DUT
  dut: entity work.riscv_adder
    generic map (
      N => N
    )
    port map (
      i_a    => a,
      i_b    => b,
      i_sign => sign,
      i_sub  => sub,
      o_sum  => sum
    );

  -- Main TB process
  p_main : process
  begin
    -- Vecteurs de tests

    report "BEGIN SIMULATION";

    report "Unsigned addition";
    a <= std_logic_vector(to_unsigned(12345, a'length));
    b <= std_logic_vector(to_unsigned(2345,  b'length));
    sign <= '0';
    sub <= '0';
    wait for PERIOD;
    assert sum = std_logic_vector(to_unsigned(12345 + 2345, sum'length))
      report "unsigned addition error" severity error;
    wait for PERIOD;

    report "Signed addition";
    a <= std_logic_vector(to_signed(12345, a'length));
    b <= std_logic_vector(to_signed(-2346, b'length));
    sign <= '1';
    sub <= '0';
    wait for PERIOD;
    assert sum = std_logic_vector(to_signed(12345 - 2346, sum'length))
      report "signed addition error" severity error;
    wait for PERIOD;

    report "Unsigned subtraction";
    a <= std_logic_vector(to_unsigned(12345, a'length));
    b <= std_logic_vector(to_unsigned(2346, b'length));
    sign <= '0';
    sub <= '1';
    wait for PERIOD;
    assert sum = std_logic_vector(to_unsigned(12345 - 2346, sum'length))
      report "signed addition error" severity error;
    wait for PERIOD;

    report "Signed subtraction";
    a <= std_logic_vector(to_signed(12345, a'length));
    b <= std_logic_vector(to_signed(-2346, b'length));
    sign <= '1';
    sub <= '1';
    wait for PERIOD;
    assert sum = std_logic_vector(to_signed(12345 + 2346, sum'length))
      report "signed addition error" severity error;
    wait for PERIOD;

    report "SIMULATION DONE";
    wait;
  end process p_main;

end architecture tb;