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Re: gEDA-user: preferred power connection style?

Xtian Xultz wrote:
> 
> What you do when you have more than one +5V power supply on the same
> circuit?
> 

	I agree that it as problem, but to draw the power lines is also a
problem for some components that have more than one slot, such as logic
ports (7400, for example).  You do not want the power lines drawn. Even
if you admit to draw the power lines, you do want to draw them in just
one of the ports belonging to the same chip, since if you draw them in
all ports, you will have more pins in the drawing than in the physial
device.

	Usually digital circuits have just one Vcc or Vdd line (it does not
need to be +5V) for all components. Of course, there are exceptions and
thats the why I agree that to use NET attribute can cause problems, but
I think that to draw all the power lines is a worst problem.

> And when you have a +5V line to a analog circuit that use some digital
> components, like a double ramp A/D converter? It is a problem, huh?

	Not at all. For the digital components the NET attribute are used and
the power lines are not drawn. For the analog components the power lines
are drawn and connected through the "power components" (those Vcc and
GND symbols).

> You can edit the component, change the net= attribute to the correct
> power line (and have a correct netlist) but for maintenance pourposes,
> its a problem, becaus the printed diagram doesnt show the net=
> attribute.

	I agree with you. Different things should appear to be different. To
have more than one "implicit" power net is a bad idea.

> 
> The best half term I found is the power boxes...
> 

		
	I'm sorry, but I am not sure what are you calling power boxes. Could
you explain further?

> Em Qua, 2003-02-19 ās 10:29, Walter Fetter Lages escreveu:
> >       My rule-of-thumb is: If it is a digital device, use the NET attribute.
> > If it is an analog device, draw the power pins.


-- 
[ ]s

Walter Fetter Lages       <mailto:w.fetter@ieee.org>
<http://www.eletro.ufrgs.br/~fetter>