gEDA-dev: [PATCH] GAF: Solve the "transistor problem"

[Bernd Jendrissek]

On 8/7/07, John Doty <jpd at wispertel.net> wrote:
> > components".  Their only purpose is to provide slots for abstract
> > symbols, so
> > that your abstract symbols can inherit attributes like refdes=U100,
> > and that
> > your abstract symbols' pins can be numbered properly according to
> > the part.
>
> I am concerned that this will complicate symbol creation and
> modification, a process already daunting to newbies.

Yes, currently the only way to create these first-class SLOT objects
is by applying your text editor skills to a symbol file.

> You're using pinseq, an attribute already overloaded, as it also
> represents pin order in SPICE netlist format (and perhaps others). So
> your method is likely to yield symbols whose assignments conflict
> with those needed for simulation or ASIC design using SPICE netlists.

I didn't know about these other uses of pinseq.  You *can* just keep
the normal numerical pinseq attributes, but I'd far rather have
human-readable names for pin functions providing the mapping from
abstract pin to pinnumber.  It will be good for the UI of a SLOT
editor.

> > symbols to the gate slots of a 74LS00.  You can force the dialog to
> > let you
> > choose slots with conflicting attributes, by disabling the
> > "Compatible"
> > button.  The "Hijack" button (off by default) lets you select slots
> > which are
> > already occupied by other abstract symbols.
>
> Sounds complicated.

Bah ;)  Select, eS, cursor up/down, Enter, and your symbol is
re-slotted.  How complicated is that?

> > (*) Currently the translation is to "die pin number", which refers
> > to a specific pad on a piece of silicon.
>
> The majority of my symbols don't represent pieces of silicon with
> pads (although some represent individual pads!).

There doesn't *have* to be a second mapping from silicon pad to
package pin.  I just wanted to future-proof my struct member names for
when I make it possible for a PLCC and TQFP version of the same chip
to be represented by the same component symbol.

> This seems to represent a specific vision of how gEDA is to be used.
> But for me, gEDA's critical strength is its flexibility and
> adaptability to a wide variety of design flows. Your change might be
> a good thing, but *please* do not complicate usage, especially usage
> "outside the box".

Like DJ said, I'm not outlawing anything.  You can stick to editing
your schematic with ed (which is the standard editor) if you like. ;)

Let me know how you feel about the slot chooser interface when you run
gschem on gnetlist/tests/324.sch.  Select the op-amp and invoke
'edit-slot' (e-shiftS).

Thanks for your feedback; I'll change to using, hmm, pinfunction= as
the human-readable attribute that will provide the mapping to
pinnumber.