1entity test is
2end test;
3
4architecture only of test is
5  signal s : bit;
6begin
7  s  <= '1' after 10 ns, '0' after 20 ns, '1' after 30 ns, '0' after 40 ns;
8  p: process
9  begin
10    wait for 1 ns;
11    assert not(s'event) report "TEST FAILED - 'event active" severity failure;
12   wait for 25 ns;
13 --   s <= '1';
14--    wait for 0 ns;
15    assert s = '0' report "TEST FAILED - s has not changed  to 0 yet!" severity failure;
16    --wait for 10 ns;
17    wait for 4 ns;
18    assert s = '1' report "TEST FAILED - s has not changed  to 1 yet!" severity failure;
19    assert (s'event) report "TEST FAILED - 'event not tripped" severity failure;
20    report "TEST PASSED";
21    wait;
22  end process;
23end architecture only;
24