Re: gEDA-user: mixed 5.0/3.3/1.8 V designs?

[John Griessen <john_g@cibolo.com>]

On Thursday 11 July 2002 04:19 am, mcmahill@mtl.mit.edu wrote:
> Given that the power supply connections for many of the logic symbols in
> the gaf library are implicit (not shown, considered evil by some) whats
> the way to mix different digital supply voltages in the same design and be
> fairly certain of not having the wrong ones connected?

It's not evil, just special case....   the usual way to deal with this is to 
create a library symbol with explicit pwr gnd, (or even transistor material 
substrate ), connections, and to create named versions of power and ground 
like vcca  vccd  gnda gndd.    Separate substrate connectioins might make 
sense when designing analog silicon on insulator, or memory SOI circuits.

John Griessen