On Fri, 2010-08-06 at 17:19 +0200, Stefan Salewski wrote: > > I have to think about it, thanks! >
The current status of my mind: Having net classes in gschem would make all much easier. We can start drawing schematics as now. Then we define a set (or load existing) of net classes, each class can define parameters like trace width, clearance, maximum length, maybe impedance... First we select all nets and assign a default class. Then we select a other class and click on all nets which should be a member of this class (power3.3V, power5.0V, gnd, fast signals, slow signals, sensitive analog signals, traces with maximum total length, ...). The classes of nets can be marked by colors, we go on until all nets have the correct class. If we can transfer this class information into PCB and assign it to the pins of the nets, then we do not have to care much about routing style in PCB program. Click on a pin, and traces with correct routing style will start drawing. Seems to be easy and fast. And the autorouter can use all this information. (Of course we may overwrite parameters of traces in PCB program when it is necessary.) With these net classes the concept of virtual layers or layer groups in PCB may be obsolete. Traces of each net class are drawn in a unique color. If we decide that copper layer 3 is for power supply, we select that real copper layer and start drawing traces. Nets for different voltages will get different colors and parameters, if we have defined special net classes for each voltage in gschem. One more idea: Maybe we can have subnets in gschem, which connects two pins and ensures that the pins have a maximum distance to each other. So we can ensure that a bypass capacitor is close to its OpAmp on the PCB board. Auto-Placer may use that information. Best wishes, Stefan Salewski _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
