Bob Paddock <[EMAIL PROTECTED]> wrote:

> Yes.  The power pins should also be visible on all parts.  Think field
service 
> while your hunched over in a four foot high dark wet coal mine shaft 
> debugging equipment, because the fiber optic cable looked to much like 
> wire-rope to the coal miners (they where both gray). 

It seems to me that net= attribute values should be visible and editable
for cases like this. I don't think a pin is necessarily the best way to
convey this information: power/return net diagrams tend to be
unilluminating clutter.

In my designs it is often necessary to have different supplies to similar
parts. In mixed signal circuits, one often needs to segregate supplies and
grounds for noise reasons. Power conservation may dictate that idle
subsystems be switched off. Keeping radiation induced latchup from frying
a part may require current limiters or circuit breakers, which in turn may
require dividing circuitry into sections whose normal current draws are
safe.

The days of boards with lots of 74XX parts on a common power supply are
pretty much over. The main applications for MSI are now as glue for
specialized interfaces, and these often require special power
arrangements.

John Doty          "You can't confuse me, that's my job."
MIT-related mail:                       [EMAIL PROTECTED]
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