Notion of Time

Just like SystemVerilog, time comes in ESDL in two forms. You can
specify time in absolute form complete with a unit. In this form, the
value of time is stored as a 64-bit value and the unit is stored as a
byte enum. Since they are clubbed together in form of a structure,
Time specified in this form takes 128 bits (16 bytes) of data.

More often, you would want to look at time as an integral value. ESDL
uses a wrapper struct named SimTime for such integral modeling of
time. SimTime gets the absolute sense only in conjunction with time
precision used by the simulation. Since ESDL allows multiple simulator
instances running on parallel threads, time precision is tagged with a
simulator instance.