On Jan 8, 2010, at 10:18 AM, Dave N6NZ wrote: > > On Jan 8, 2010, at 8:57 AM, John Eaton wrote: > >> >>> Pinlabel is for humans, and for hierarchy. Pinseq is a unique >>> numerical identifier for the "pin", independent of the footprint if >>> any (not all symbols correspond to parts with footprints). >>> >> So slotting lets the PCB designer exchange one 2 input Nand gate >> for >> another in the same or different package. > > Among other things. I use it to split up complex parts into > multiple symbols, for instance power and other infrastructure on > its own symbol that can go on the relevant page.
You don't need slotting for that. Just have multiple symbols with same refdes. > >> Swapping lets them swap >> the two inputs pins. How does the pinseq number do both at the same >> time? > > It doesn't. Swapping pins isn't really supported. slotdef attributes are really a general pin mapping mechanism, so you can specify pin swaps by having every permutation as a "slot" in the symbol (DJ apparently uses this technique). Or, you can attach a customized slotdef= attribute to an instance and change the mapping to whatever you want. > DJ proposed a new mechanism in the "Blue Sky" document. The biggest problem with the existing mechanism is that it gets in the way of reuse. Layout-specific data like pin and slot assignments does not belong in reusable source schematics. It also doesn't play well with hierarchy, as a slotted components cannot cannot be shared between blocks, and power arrangements cannot be separated from the signal flow in a hierarchical schematic. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ [email protected] _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
