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Re: gEDA-user: gschem: directly connecting two nets?

On Mon, 24 Jan 2011 13:31:28 +0900
John Doty <jpd@xxxxxxxxx> wrote:

> On Jan 24, 2011, at 11:57 AM, Kai-Martin Knaak wrote:
> > Steven Michalske wrote:
> > 
> >> We would also need a way to force the chosen name of the net to choose
> >> when merging nets.  e.g.  When you merge a net named power with a net
> >> named 3v3_power, who wins?
> > 
> > If a two pin symbol mediates the fusion, this would be determined 
> > by the connections to the symbol. The symbol would comprise a win-pin 
> > and a loose-pin. The winner would be the net that is connected to the 
> > win-pin. 
> Works for the simplest case:
> net1                 net2
> -----------(WP,LP)------------
> The combined net would be "net1".
> But a little more complicated:
> net1                 net2              net3
> -----------(WP,LP)------------(LP,WP)---------
> Is this "net1" or "net3"?

Although I don't foresee using this feature myself, I'd say to do this:

Logically sort the symbols first by connection order, then by instantiation order.  Whatever symbol last had a connection made to it would be the symbol which takes precedence, unless there are two or more symbols that share that honor.  In that latter case, jusr use the winner/loser pins from the most recently-instantiated symbol.

So in the above, if the two symbols are added left-first, then the right-most symbol would govern the connection, and the winner would be "net3", since that net falls on the second symbol's "winner" pin.

In the circular path KMK mentioned, the first and last symbols added to the circuit would end up getting connected together at the same moment by a single net, so those two would share the "last connection made" status.  So, the last one before the loop repeats would govern the connection, since it was the last one to be instantiated.

"There are some things in life worth obsessing over.  Most
things aren't, and when you learn that, life improves."
Vanessa Ezekowitz <vanessaezekowitz@xxxxxxxxx>

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