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Re: New part file format document.


>> It does need a way of telling the schematic capture how to choose a
>> look for a component. However, I think the functionality is allowed
>> for in the current spec already. The different versions can be
>> alternatives, then it is down to the GUI design to make these
>> alternatives easy to select on a per-component instance basis which
>> I'm sure is possible, and if I remember rightly desired by Jean-Pierre
>> for large logic designs too for selecting deMorgan.
>> So I think this is already covered, I hadn't thought about using
>> alternatives for this in the part spec. This also covers different
>> pinouts for processors that are available in different packages.
>> The only thing not covered for me then would be one schematic pin to
>> many footprint pins support. I can't see a nice way of doing that yet.
>> It's only a nice-to-have anyway, and that's only my opinion which
>> generally seems to differ from most others! ;)
> Conceptually its a merge action so the syntax would look like:
> (pin_merge PIN_LIST)
> The part and schematic editors would only display the first pin in the list.
> The schematic net list generator would electrically connect all of the pins in
> the list.
> The other option is to tell the schematic editor to merge all power pins with
> the same name.  So all pins named GND, VCC, etc. would be merged into a single
> pin for display purposes.  This behavior could even be applied per component
> and saved a part of the yet to be written new schematic file format.
> My preference would be to make this an option in the schematic editor since it
> doesn't really effect the part itself.  It only effects how the part is
> displayed.  Anyone else have any thoughts.
> Wayne

What about something along the lines of:

(pin_clone NUMBER NUMBER)

Given one power pin, the other power pins that are electrically
connected will be exactly the same pin, only duplicated/cloned.

Schematic capture can display the defined pin as per normal, and pin
clones can be added to the pin number; perhaps in brackets after the
first defined pin number or something - having all the pin numbers
visible is pretty essential I think*. This is easy to write if you're
writing the pin definitions by hand, and in the GUI a clones text
field could be a comma delimited list of pins that are clones of the
visibly defined pin.

Does that sound reasonable? I think the code behind that should feel
fairly sane and not too messy. The netlist generator can check for
clones of a pin pretty easily and connect the clones to the same net.

I think this sounds sane, but I also agree this could probably dealt
with in some way by the schematic editor too.

* One of the first checks of nearly any board I do is to quickly scope
around looking at the VCC / VDD levels, etc. just making sure all
power pins are powered and are at the right level.

Best Regards,