Re: gEDA-user: wishful UI

[John Griessen <john@xxxxxxxxxxxxxx>]

John Griessen wrote:
> Rick Collins wrote:
> > How would you make use of "subnets" that would be useful that you 
> > can't do with just nets?

After my last post, I saw you could argue, "You can do that with just nets.",
and I see your point that from a schematic view a net is a net, and most
of the use of the concept of subnets is in layout.

In case you mean "How would you make use of "subnets" in the schematic view?",
here's another case:

A net is a net, except when it is connected to something...  Suppose we want to
tell an autorouter to make certain pins, capacitor pins, routed closely?
You could define a subnet by tagging a net like VCC partially like this:
Use select-and-add-attributes to tag one pin of a cap and one pin of a chip
with a name unique to the schematic, and with attribute route-priority-closest,
then go to  another cap also connected to VCC and do likewise.

There you have two subnets doing something very useful for automation
on a schematic alone.  No need to define physical regions on a layout to
have a meaning.

And we see that a net isn't a net everywhere.  At each end, (and nets can
have any number of ends, not just two), the part where it connects to
something else is always different from the rest.  The layout correspondence
is pin or pad at the ends of the net, and trace everywhere else.

Sure, I"m talking about obvious stuff, but it's not to suggest anyone's
slow on this list, just that autorouters and other automatons are slow
on the uptake, even if they're faster at counting than Rainman.
Subnet definitions would be most valuable for "slow witted" but
speedy and cheap-to-hire autorouters.

John Griessen


_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user