Re: gEDA-user: blue sky ideas - written down finally

[Dave N6NZ <n6nz@xxxxxxxx>]

On Dec 27, 2009, at 9:16 AM, DJ Delorie wrote:

> 
>> On the pin mapping subject I miss an example of the power pins of a
>> rail-to-rail opamp, just to nail these troublemakers down as well (sometimes
>> I get Vss hitched to ground instead of the negative voltage rail).
> 
> Power pins are not special in my plan, they're just pins.  If they're
> not connected to a symbol, they show up in the "other pins" table, by
> name, and you can connect them to whatever you want.  I.e. there are
> NO MORE implied net connections.  You just don't need the "power
> symbols" any more.
> 
OK, DJ, just so I understand what you are saying here... let's run a scenario:

User creates a schematic with some op amps and some logic.  It's a pretty crazy mix of technologies.  User has chosen a methodology where infrastructure is not shown in the schematic.  User creates a netlist.

Now, someplace there is an "other pins" table -- where is this exactly?  It contains (package,pin) duples of the form:
U01 V+
U01 V-
U01 GND
U02 VCC
U02 GND
U03 VCC3v3
U03 GND
U04 VCC1v8
U04 GND
... and so forth

User now needs to somehow specify that U01 GND is connected to analog ground, U01 V+ and V- to analog power rails.  U01 GND, U02 GND, U03 GND and U04 GND are connected to digital ground. U02 VCC is connected to 5V, U03 VCC3v3 is connected to 3v3 power, and U04 VCC1v8 s connected to 1v8 power.  So is this in some attribute table or something?

I'm not suggesting that the above methodology is wise -- IMHO it is a confusing methodology in the long run.  But I think it should be supported. I'm unclear what you expect the above user to type and where, though.

-dave



_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user