Library ieee; use ieee.std_logic_1164.all; entity tb_top is end entity; architecture tb of tb_top is signal a,b : std_logic := '0'; signal clk_sys : std_logic; default clock is rising_edge(clk_sys); begin gen_clock_proc : process begin clk_sys <= '1'; wait for 5 ns; clk_sys <= '0'; wait for 5 ns; end process; test_proc : process begin a <= '1'; wait for 50 ns; std.env.finish; end process; my_seq : assert never {a = '1'; b = '1'}[=3]; end architecture tb;