Download radiant: 20230314 - iCEbreaker with Radiant

Make sure you have added the license, and configured the environment variable.

Open radiant, create a project, add the next sources counter.vhd:

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity counter is
  generic (
    WIDTH : positive := 8
  );
  port (
    clk   : in  std_logic;
    rst_n : in  std_logic;              -- active-low reset
    en    : in  std_logic;
    q     : out std_logic_vector(WIDTH-1 downto 0)
  );
end entity;

architecture rtl of counter is
  signal cnt : unsigned(WIDTH-1 downto 0) := (others => '0');
begin
  process(clk)
  begin
    if rising_edge(clk) then
      if rst_n = '0' then
        cnt <= (others => '0');
      elsif en = '1' then
        cnt <= cnt + 1;
      end if;
    end if;
  end process;

  q <= std_logic_vector(cnt);
end architecture;

And create another one called tb_counter.vhd

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity tb_counter is
end entity;

architecture sim of tb_counter is
  constant WIDTH : positive := 8;

  signal clk   : std_logic := '0';
  signal rst_n : std_logic := '0';
  signal en    : std_logic := '0';
  signal q     : std_logic_vector(WIDTH-1 downto 0);

begin
  -- DUT
  dut: entity work.counter
    generic map ( WIDTH => WIDTH )
    port map (
      clk   => clk,
      rst_n => rst_n,
      en    => en,
      q     => q
    );

  -- 100 MHz clock (10 ns period)
  clk <= not clk after 5 ns;

  -- Stimulus
  process
  begin
    -- hold reset low briefly
    rst_n <= '0';
    en    <= '0';
    wait for 50 ns;

    -- release reset
    rst_n <= '1';
    wait for 20 ns;

    -- enable counting
    en <= '1';
    wait for 200 ns;

    -- pause counting
    en <= '0';
    wait for 50 ns;

    -- count again
    en <= '1';
    wait for 100 ns;

    -- done
    assert false report "Simulation finished" severity failure;
  end process;

end architecture;

Add the two sources, and then configure the simulation wizard. Select the correct top part.