> IC 4.4.3
> Dear All,
> I often use(d) the .MEASure command in hspice for getting some
> characteristics out of a circuit. Is there a way that I can tell Analog
> Artist to do the same?
> e.g. taking an inverter, measuring the cell delay, varying the supply
> voltage, measuring the cell delay again, and finally plotting a graph cell
> delay vs. supply voltage.
> I know I can do this using ALTER and MEAS in an include file to Analog
> Artist and I get the data into an external file, but I am just wondering
> whether someone has an idea how I could get that characteristic straight on
> the screen in Analog Artist.
> cheers, Kurt.
Hi, Kurt!
It is much more convinient to do this task in Analog Artist. Because
for HSPICE if you want to plot something like that you should include
.MEAS command before simulation. So you must think over thoroughly
before simulation what kind of information you will want to see after
simulation. But sometimes it is very difficult to predict that. Using
Analog Artist Parametric Analysis with calculator tool you can get any
information after simulation.
Now about above mentioned task. Set DC voltage for Vcc source as
variable. Add this variable and it's default value to variable list.
Choose Parametric analysis tool. Pick up this Vcc variable as sweeping
variable. Run Analysis from Parametric analysis window (not from
Analog Artist window). When the analysis is finished open calculator
wndows click VT button and two nodes (supposed to be a delayed output
and an input) in schematic window. After that choose Special Function
-> Delay and fill in a poping up window. You should set threshold
levels, edge numbers and edge kinds (rising or falling) both for
output and input. After that click plot or erplot and you will see how
you delay varies with Vcc.
Best regards
Vladimir Fomin.
by