Re: gEDA-user: hierarchical schematics

[mcmahill@mtl.mit.edu]

On Thu, 8 Feb 2001, Ales Hvezda wrote:

> Hi,
> 
> 	Ah excellent, a user question on the geda-user list. :-)
> 
> >
> >are hierarchical schematics supported under gschem?
> 
> 
> 	Yes.  The netlister also supports the creation of flat hierarchical
> netlists.

oh cool.  now I really must take the time to learn gschem and friends.


> >and if so, how about parameterized subcircuits.  Ie, can I make a
> >subcircuit with some component values that are specified when in
> >instantiate the subcircuit?
> 
> 
> 	This is not supported, however if you elaborate on how you would
> specify something like this and how it might behave, you might corrupt my
> mind a bit. :)

I haven't totally thought it through, but one idea which comes to mind is
that you leave certain component values or properties (I'm thinking of
transistor dimensions) as variables, or perhaps a function.  for example I
might make a subcircuit which is a CMOS inverter where I specify W/L for
the pmos device to be N*2.8/0.6 and the nmos device N*1.4/0.6.  Now when
I instantiate the inverter in a higher level schematic, I assign a value
of N to each instance.  That way I can do N=1 and get a minimum sized
inverter or N=16 and get a 16x sized one. 

But the hierarchical part is the biggie and sounds like its covered.  


any users out there who use gschem and gnetlist for ic schematics?  

-Dan