On May 8, 2010, at 10:43 AM, kai-martin knaak wrote: > DJ Delorie wrote: > >> >> Had an idea about back-annotating pin swaps. > > Why is this on the devel list, where mere users are not allowed to write and > hardly read? > > >> The big "issue" is figuring out how to back-annotate from pcb to >> gschem. So... why do we need to? > > Because a schematic should contain the information on which slot a symbol > corresponds to. > > >> gschem need not know about physical packages or pins, ever, unless you >> want to back-annotate a whole board (or merge the pinmap into a >> separate set of schematics for reference). > > gschem may not need to know, but I need to, when I look at the schematic. > > A pretty common scenario with my kind of analog prtojects: For some reason I > know, there is a problem with a certain analog switch. This switch happens > to be one of the four slots of IC7. The value of the slot attribute is > visible on the schematic and says it is number 1. Thus I know, I have to > poke at pin 1-3 of IC7 for debugging. > If the slotting information would reside in the layout only, I'd have to > back-engineer form the actual tracks on the layout which pins to look at. > > >> How confused would gschem get if we omitted pin numbers from it >> completely?
gschem doesn't get confused, but gnetlist does. > > Me, the reader of the schematic would be quite confused. I deliberately have > pin numbers printed on the schematic for more complex ICs. This helps a lot > during debugging stage of prototypes. It provides a convenient way to know > at what pin to stick the scope probe. For a clean flow, I'd want the annotated schematics that go into the documentation to be distinct from the source schematics that I edit. I emphatically reject "back-annotation" as a serious problem for reuse and automated flow. Others have other ideas, so any facility should support both flavors of annotation. Of course, a well factored facility would make this trivial. But, for example, wiring it into gschem would problematic. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ j...@noqsi.com _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user