Re: Simulation of inverter

[cfk]

Thank you Steve. Now, I can set the power supply voltage for my VDD and set
the net names for the nets connected to my hybrid inverter in layout form
combined with Spice parts, and it creates a valid looking spice netlist with
everything connected as I expect. Now for the next question. Would I expect
the writing of the spice deck to also write the parisitic capacitances?
Perhaps in my naivety, I just dont quite understand yet. I was thinking that
the inverter itself would have some appreciable parasitic capacitance and
series poly resistance. Basically, the place I am trying to go is to
understand some of the relationships between geometry and speed. I have
spent some time reading a couple of books on layout and I can see some of
the relationships, but I am so far thwarted by my attempts to get them out
of the layout writing of the spice deck option.

    Again, thanks for getting me to the next stage. I promise to do my
homework and not trivialize the questions in this forum. I am, however,
thinking that the questions and answers may help others in my situation who
are just starting to try to use Electric and any hints, kinks, examples and
other information will tend to make the use of the software you have created
more widespread.

Charles

----- Original Message -----
From: "Steven Rubin" <address@hidden>
To: "cfk" <address@hidden>
Cc: <address@hidden>
Sent: Friday, January 17, 2003 3:59 PM
Subject: Re: Simulation of inverter


>
> >It appears I got ahead of myself, so I am taking a step back and trying
to
> >understand some simpler concepts before I go off into EDIF & Verilog
> >never-never land. This morning, I created a simple {lay} facet using the
> >inverter from the MOSIS library in an attempt to duplicate figure 11-11
in
> >Mr. Rubin's book and see if I could write a spice deck. After a shile I
> >actually am able to find that I can put an inverter on the drawing,
change
> >technologies to SchematicAnalog and put a few Spice parts such as a DC
> >pulse, load resistor and DC power supply on the drawing. The trick to
> >hooking them up seems to end the wire creation on the Spice part where
the
> >terminals on the pulse generator and DC supply are not as obvious as on a
> >resistor.
> >
> >I can then write a simulator spice deck and see that I have connected
> >everything with a pulse generator to an inverter, a resistor load on the
> >inverter output and a DC voltage source to VDD on the inverter. That is
> >really good.
> >
> >I was able to change the resistor value by double-clicking on it. I would
> >appreciate some guidance in changing the value of the pulse generator or
> >the DC voltage source as double-clicking doesnt do it and although I can
> >see its value of 0V with info->Attributes->Define, I cannot change it
yet.
>
> When you double-click on the DC voltage source, you get the "generalized
> Getinfo" dialog for nodes.  But if you expand that dialog (click "more" to
> see it in a larger form) then there is a list in the lower half.  The list
> can show connections or Parameters.  Select "Parameters" and the
parameters
> of the DC voltage source will appear, able to be selected and modified.
>
> >I also would like to name my nets. Electric gives me default net names
> >like net1, net2, net3, etc, but normally, I like to name the nets in a
> >design. I suspect that there is merely some simple command that I have
not
> >figured out yet that lets me name the nets in a design.
>
> Double click on any arc on that net and give it a name.  That names the
> net.  So does creating an export on any node on that network.
>
>     -Steve
>
>