Re: gEDA-user: PCB format wishlist

[John Doty <jpd@xxxxxxxxx>]

On Sep 6, 2010, at 2:49 PM, DJ Delorie wrote:

> 
>> Why have any distinction between "footprint" and other fragments of
>> layout (like hierarchical blocks)?
> 
> Because PCB needs to deal with boards at the semantic level, not just
> the physical level.

Yes. As gschem has to deal with schematics at the semantic level. Yet it manages with little semantic information in its primitives (and could manage with even less).

>  Padstacks have to "exist" at the element level so
> they can be tied to the netlist, for example.  A padstack elsewhere
> has to be managed differently.

But conductors in hierarchical blocks need to be tied to the netlist also. Connections and other relationships between primitives are the responsibility of the composition machinery.

John Doty              Noqsi Aerospace, Ltd.
http://www.noqsi.com/
jpd@xxxxxxxxx




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