Re: Circuit Board Design Programmer with a "don't care"
- From: Mark Borgerson <mborgerson@xxxxxxxxxxx>
- Date: Fri, 23 Nov 2007 10:51:26 -0800
In article <o8x1j.23367$j7.443829@xxxxxxxxxxxxxx>, toe@xxxxxxxxxxx
says...
If you're doing a multi-layer board with VCC or ground as a middle
I'm designing a circuit, and there's a couple of points in the
circuit where I can't leave unused pins floating, so I either connect
them to Vcc or to ground. What I would prefer though is being able to
mark them as "don't care", meaning that they can be connected to _either_
of Vcc or ground, depending on which route is shortest on the circuit
board.
Do you know of any applications that have this feature? I'm using
Protel 99 SE at the moment, and I don't know whether it can.
layer, routing a pin to either is just a short route and a via.
This gets complicated only when traces are dense enough to preclude
vias at your convenience. Even on 2-layer boards, I usually flood
the bottom layer with copper attached to ground, so ground connections
with a via are my most common solution.
Sometimes you can decide the level by simply examining the proximity
of other ground or Vcc pins. But I do like the idea of having
the autorouter make the decision. AFAIK, it doesn't work that way
in PADS 2007, so I still have to make the decisions myself.
Mark Borgerson
.
- References:
- Circuit Board Design Programmer with a "don't care"
- From: Tomás Ó hÉilidhe
- Circuit Board Design Programmer with a "don't care"
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