Re: gEDA-user: Symbol style recommendations

[Mark Rages <markrages@xxxxxxxxx>]

2009/3/19 Peter TB Brett <peter@xxxxxxxxxxxxx>:
> On Thursday 19 March 2009 21:58:59 Josh Jordan wrote:
>> I prefer to use actual pinouts in my schematics for two reasons: It helps
>> you with chip placement because naturally you will tend to place symbols
>> and lines to get the fewest line crossings.  Going to layout after you have
>> already decided the best general position for parts makes it much easier.
>> The second reason is that later on it will be easy to look back to a
>> schematic that has a similar layout as the board and the same pinouts.
>
> We'll have to agree to disagree. When I look at a schematic, I want to be able
> to quickly and easily work out what the circuit is designed to do, and having
> the pins on my symbols arranged by function and bus offset rather than by
> physical position helps a great deal.
>
> What you're doing completely defeats the point of having separate schematic
> and layout diagrams, IMHO.
>
> What do you do about parts that have different pinouts depending on what
> package they're in?
>
>                                     Peter

Of course you use the place the part on the schematic with the pinout
you are using.

When you are troubleshooting a circuit with a scope or analyzer, it
adds an extra decoding step to have the pin order scrambled.  And it
really is annoying when you're trying to look at the schematic to see
where your 64-pin micro has an unused pin free.

The usual problem with having the pins in IC-order is this big rat's
nest of wires running around the chip to get to the pin.  But a better
solution than moving the pins around is using named nets / ports.
This also helps make the intended function of the circuit more
explicit.

Regards,
Mark
markrages@gmail
-- 
Mark Rages, Engineer
Midwest Telecine LLC
markrages@xxxxxxxxxxxxxxxxxxx


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