On Thu, Feb 12, 2009 at 8:43 PM, Dan McMahill <[email protected]> wrote: > What do you have in mind? What should the calculations provide? How > would you want to access them?
I have a range of things on my wish list. I originally thought it would be best to include at least the first few of these in PCB (ctrl-R on a trace and get all of the impedance information pcb has for it), but running the pcb file (or an extracted file) through an external tool would be fine too. Bearing in mind that I just started thinking about this today, here is my wishlist, in the order I think it would be sensible to implement them: 1) select a trace and get length, area, number of vias, number of pads 2) ability to provide a stackup file which can be matched with pcb layers. 3) Specify an impedance for a route type and have pcb calculate the required width 4) Designate XY pairs and critical nets 5) DRC warning if XY pair is separated or something may significantly affect trace impedance (like running a trace over a discontinuity in the ground plane) for routes with a specified impedance. 6) Ability to assign load impedances to pads generically (applied to all pads) and specifically, possibly semiautomatic based on pin type. 7) Ability to specify timing constraints for a net and have DRC verify this based on above. 8) Calculate a matrix of mutual impedances between all nets, highlight critical nets 9) calculate resonant frequencies of nets and image planes, give warnings when additional bypass and decoupling might be required. 10) extract pcb characteristics and back-annotate to a netlist for functional simulation. I've only done three boards with geda/pcb and I still very much consider myself a novice, so some of these may be much more difficult than I think or less useful than I'd hope. -Jeff. > > > -Dan > > > > > > _______________________________________________ > geda-user mailing list > [email protected] > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
