User guide

24-186
SystemVerilog Testbench Constructs
initial
#1 @ (evt3) $display("evt3 triggerred");
endprogram
The $display system tasks display the following:
evt1 triggerred
evt2 triggerred
evt3 triggerred
IMPORTANT:
When you merge events, the merger takes effect only in
subsequent event controls or wait statements.
In this example, the merging occurred at time 0, the event controls
at time 1, and the triggering of the events at time 2.
Reclaiming Named Events
When you assign the null keyword to a named event, that named
event no longer can synchronize anything. In an event control it might
block forever or not at all. In a wait statement, it is as if the named
event were undefined, and triggering the named event causes no
simulation events.
program prog;
event evt1;
initial
begin
evt1 = null;
#5 -> evt1;
end
initial