Re: gEDA-user: gnetlist and attributes

[Svenn Are Bjerkem <svenn@bjerkem.de>]

On Monday 25 November 2002 20:21, wolfgang buesser wrote:
> 'Model=NMOS W=3.2um L=0.8um AD=6E-12 AS=6E-12' as
> value
> attribute.
> Is there no posibility to enter this into separate
> attributes with the chance to have default values?

And even better: Having calculated attributes. In IC
design, specially analog, there are loads of transistors
that may have different W/L relation. Many high-end
simulators (like spectre) are pretty sensitive to some
of the less obvious parameters like drain and source
geometries. These numbers must either be calculated by
hand and entered, or there are standard "shoot from the
hip" values. After layout, there are backannotated 
transistor geometries available.

It is for me more interesting to change the W and the L
of a transistor, and have gnetlist calculate the rest
so that my simulation is more accurate. Sometimes there 
is a lot of WL changement, and each time recalculate the
other stuff is a hassle.

Of course, IC design is a lot different than PCB design
and there are other needs, but there is no reason why
it should not be possible to replace cadence virtuoso
composer for schematic capture. (It is stone age tech
in a motif wrapping)

-- 
Svenn Bjerkem