[gta02-core] U490{1,2,3} diagrams

Werner Almesberger werner at openmoko.org
Thu Jun 11 21:48:15 CEST 2009

Rene Harder wrote:
> I just played a little bit with the PCB  Layout editor and the way you
> associate the footprints in kicad. Yes you really can link against any
> footprint, for example a battery symbol to an atmel controller package,
> and the DRC was not even complaining about the unconnected pins of the
> footprint. Is that the way how it supposed to be?

Hmm, yes. Missing connections will be flagged, but if you have extra
pins/pads that just do nothing, KiCad will let you have that.

> Well, that's true but if there are no pin numbers we only need different
> footprints for each vendor, like TI_SN74AUP1G00_DSBGA,
> NXP_74AUP1G00_TSSOP5 etc.

Aiii ... vendor-specific footprints with different numbering. Very
very dangerous ... If you really make a footprint for each device,
that would work. But then, you normally want one for each package,
so that would be TSSOP5 or NXP_TSSOP5.

There's a freakish exception every once in a while (particularly
those where data sheet and real package don't quite agree), but
for "standard" footprints, we shouldn't have to optimize by
vendor or even chips. And altering the numbering is almost
guaranteed to cause mistakes.

> For now, I would go with this, maybe we'll find a better solution later.
> It should be easy for us to change the name, if necessary.

Perfect. So it seems we have all the symbols now ? A number of
them still need reviewing. I'll have a look at issues [1] through

- Werner

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