Re: gEDA-user: How to deal with single/dual parts?

[Peter Clifton <pcjc2@xxxxxxxxx>]

On Wed, 2009-11-18 at 14:31 -0600, Bill Gatliff wrote:
> Steven Michalske wrote:

> * a schematic "symbol" represents some or all of a "component"
> * a "component" might satisfy the functionality indicated by more than
> one symbol
> * a "component" comes in one or more "footprints"
You're clearly thinking of PCB layout _____^

> * "footprints" are used by more than one component
> * schematic hierarchy symbols are just collections of "symbols"

Think at the netlist / design hierarchy level, with arbitrary
technology, the possibilities of the tool-kit really open up then.

See this old diagram Peter B and I drew:

http://geda.seul.org/wiki/geda:data_structure_design_discussion?s=data%
20structure

The diagram is somewhat conceptually different from gEDA, especially in
the fact that it treats attributes as a primitive entity belonging to a
circuit, circuit instance, net or Mport - gEDA just requires you to
place some text define the attribute and its contents. In gEDA, they
notionally belong to a symbol instance, net, or pin.

The core of the diagram (blue and yellow) would apply as a hierarchical
design / netlist representation _without_ the need for any schematic.
That was its real purpose - defining the logic required in a
hierarchical netlist representation.


I would call any non-graphical entity a "circuit" with "Mports" (a
gnetman term). Symbols either represent sub-circuits defined logically
by more schematics, or instantiations of physical devices, VHDL
primitives, VHDL code, ....

"Symbols" are a graphical representation of "circuits", such as to be
able to connect instances of those circuits using schematics.

For chips / components on a board layout, ports correspond to device
pins, and the nets connecting them correspond to tracks.

NB: I don't just see gEDA useful for schematics / VHDL / IC design
though.. I draw all kinds of logical diagrams with it. Some make sense
represented as a hierarchy.

I can imagine a netlist of a "simulink" type digram being used to define
a system for simulation - where "nets" represent abstract signals,
rather than electrical connectivity.


> Man, the scripts to make all the above work just sound like a
> connect-the-dots type of exercise.  But the computer scientist that
> isn't in me just isn't jumping up and down going "oooh, I know! I
> know!!" just yet.  :)
> 
> The good news is, perhaps, that implementing a workflow based on the
> above should be possible with the current gaf tools.  It's really just
> an exercise in not using functionality in the existing tools that are
> trying to implement certain cases of the above already.
> 
> Does any of this sound familiar to anyone?  Solved problem anywhere we
> can look to for inspiration?
> 
> 
> b.g.
> 




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