Re: gEDA: design decisions: PCB<->schematic

[Charles Lepple <clepple-at-NOSPAMghz_dot_cc>]

On Friday, November 22, 2002, at 02:10  PM, Egil Kvaleberg wrote:

> Which sort of reminds me of an old idea of mine: Whereas a schematic
> drawing is super for visualizing analog circuits and also some digital
> circuits (gate logic, for instance), it is in fact pretty unsuited for
> drawing various types of processor systems, for instance. In this case,
> a textual specification would be better, listing the components, and
> then describing the signals and which components they connect.

Agreed. I used gschem to design a system that hooks up to a TI 'C6711 
DSK, and rather than draw the bus, I just used a bunch of off-page 
connectors attached to each device. (The DSK bus connector symbols were 
generated by a script.) Then, when I needed to prototype the system, I 
just created a netlist by listing the different gschem schematics on 
the command line of gnetlist. The same can be done with hierarchical 
components.

The problem with implementing Egil's suggestion (as I understand it) is 
that if you are joining nets together with some sort of list or table, 
you would run into a arbitrarily low limit of how many nets you can 
rename in gnetlist (64, IIRC... can't find the patch at the moment).

If, however, you attach the same net name to each bit on the bus (e.g. 
D0, D1 instead of FLASH_D0 or whatever), things should work.

-- 
Charles Lepple <clepple@ghz.cc>
http://www.ghz.cc/charles/