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Re: gEDA-user: A couple o' questions



Would it be useful to have an intermediate decision? When people are designing symbols, maybe they can set an attribute to "not connected", so that DRC can report on pins that are not normally (ok, I have to do this, bear with the negative logic...) that are not normally "not connected" and ignore those pins that are set to normally not connected.

David Logan

Stuart Brorson wrote:

Place and connect to those pins the noconnection symbol
(misc/nc-*-1.sym). This will connect that pins to the net
"NoConnection", which is not checked in the DRC.



vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv


However, be aware that
gnetlist and gsch2pcb will conect those non-connected pins together.
We have to find a way to avoid this, but it is to be done yet.


^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Actually, I am very disturbed by this, and have been for some time.
We encourage newbies to put a NC symbol on no-connect pins so the
design passes a DRC check. However, this symbol causes all the NC pins
to be connected together. This is not a good idea, particularly since
it's an easy trap for newbies to get snared by.


Some NC pins are actually test pins on chips which shouldn't be
connected to anything lest some strange operational mode be triggered
in the chip.


I'd personally prefer that the DRC simply not report unconnected pins
-- a usually harmless thing -- than encourage a practice which can
inadvertently lead to bad boards simply to pass a DRC.  The DRC is
supposed to prevent errors, not cause them!  Perhaps disable this
feature until the appropriate fixes are rendered in the netlisting
backends and in gsch2pcb????

Stuart