Re: gEDA-user: wishful UI

[Stefan Salewski <mail@xxxxxxxxxxxx>]

On Sat, 2010-08-14 at 00:48 +0200, Dietmar Schmunkamp wrote:
> 
> Stefan,
> 
> I looked at your suggestions about netclasses and I like them.

Indeed currently I am still looking for a good reason against that
proposal. My best candidates: It is not too useful for small projects,
and it is some work to implement.

> What I
> would like to add (and this adds complexity, too), is the notion of
> differential pair (two wires should be same length, but the actual
> length basically is a don't care) or busses and control signals
> (industry standard SDRAM's etc where you have delay constraints of an
> entire bus vs. a single control signal).

Sure! I tried to mention that type short by writing:

>More or less related to this problem are attributes defining pairs of
>traces for differential signals: Maybe we can assign attributes like
>"SigA@1" and "SigA@2" indicating the pair, which should have a defined
>trace separation and equal length on PCB board. (A similar notation may
>be useful to indicate buses and allow pinswap in the schematic).

I have to admit that I do not know much about "differential pairs" now,
but it is very important...

> Furthermore I have a little objection towards " No chance for unskilled
> people or autorouters", I agree with "unskilled people", but at least a
> subset of the requirements can be translated to autorouter attributes,
> e.g. impedance easily translates to geometry for a defined layer stack
> (including base material, copper width ... ) while other attributes you
> suggest ("short") would only be applicable to an autoplacer (or skilled
> people).
> I know that the target to add net classes AND to support them with
> auto[route|place|...] is very challenging, but nevertheless I think that
> it's worth a try/start a discusssion.
> 
I agree.

I guess it would be no great deal for smart (but very busy) people like
Peter C. and DJ, to implement the basic concept. For people not familiar
with the internals of gschem and PCB like me it may take very long...

Best regards

Stefan Salewski




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