kicad-developers team mailing list archive

[Tomasz Wlostowski <tomasz.wlostowski@xxxxxxx>]

On 14.07.2014 22:12, Jean-Paul Louis wrote:
> To me, the netlist is one representation of the design.
> The schematic is an electrical engineering view of the netlist,
> The BOARD is the physical instance of the netlist.

Yep, but it needs not hold the netlist as a separate entity (which would 
have to be updated every time something gets changed on the board).

> So the BOARD needs to know about the net list for connectivity of the 
> elements, and other constraints like impedances, crosstalk, EMI, etc..

Both schematic and BOARD objects constitute a netlist, but for 
forward/backannotation we need much less information than what is stored 
in them. That IMHO justifies the need for a generic NETLIST class, 
understandable by both eeschema and pcbnew.

Cheers,
Tom

> My $0.02,
> Jean-Paul
> AC9GH
>
>
> On Jul 14, 2014, at 3:49 PM, Tomasz Wlostowski <tomasz.wlostowski@xxxxxxx> wrote:
>
> > On 14.07.2014 19:59, Dick Hollenbeck wrote:
> >
> > > Specifically in this case, the question should have been asked:
> > >
> > > "does the BOARD need to know about the NETLIST, or does the NETLIST need to know about the
> > > BOARD?'
> > Dick,
> >
> > IMHO neither needs to know about the existence of the other.
> >
> > NETLIST can be extracted from the board by a separate entity (say, BOARD_NETLISTER). Same for the schematic netlist.
> >
> > BOARD can be updated by looking at the differences between NETLISTs made by these two entities. Same for the schematic - the differences just trigger different actions. Change of a footprint in SCH->PCB direction would trigger a reload of the footprint and replacing corresponding primitives in the BOARD. In reverse direction, it would merely change the FPID attribute of the schematic part.
> >
> > IMHO it's just a matter of refactoring the BOARD::ReloadNetlist into smaller chunks (each of them responding for a particular change, with the knowledge of how to update the underlying model) and writing a much simpler (just doing pin/part swaps + footprint backannotation) class for eeschema.
> >
> > No files involved, just as you said.
> >
> > Cheers,
> > Tom
> >
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