What is the effect of this delayed statement in the following process?

Question

Hi guys in the following process how the delayed assignment should be interpreted?

clk_process : process
begin
        clk <= '0','1' after 5 ns;
        wait for 10 ns;
end process;

Is it intepreted as...

clk is set to '0' for 5 ns then i changes into '1' and after 10 ns it is set again to '0'? or it is simply '0' for 5 ns and '1' for 5 ns?

I'm a bit confused...

You can shorten it to `clk <= not clk after 5 ns;` :). – Paebbels Sep 07 '15 at 12:41 — Paebbels, Sep 07 '15 at 12:41

score 3 · Accepted Answer · answered Sep 07 '15 at 11:07

3

The process has no sensitivity list, and a wait statement. It will therefore run repeatedly. The following stages can be seen:

The end result is a clock, starting at '0', with a period of 10 ns.

answered Sep 07 '15 at 11:07

scary_jeff

So it is (0,0 ns), (1, 5 ns), (0, 10 ns), (1, 15 ns), ... and so on? – user8469759 Sep 07 '15 at 11:09
A 15 char "yes" – scary_jeff Sep 07 '15 at 12:20

1 Answers1