Hybrid schematic structure

I am new to the group and would like to say thanks to the devs for such great software.

Now to the point, I fully understand that KiCAD works best for hierarchical schematic structure and ideally you have one schematic sheet to one hierarchical and most of the time this is fine.

Now consider for example a large microcontroller, the symbol alone may be too large to fit on a single sensibly sized sheet therefore it makes sense to split the symbol and immediately associated components across multiple sheets. I would consider it poor practice to split the symbol across multiple blocks, even if KiCAD annotates correctly in those circumstances, so there is a need to for inter-sheet connection within the block.

KiCAD has no concept of inter-sheet connection other than global labels and that does not work if there are multiple instances. Any thought on how to adress this conundrom?


KiCad right now has no nice solution for this. See https://bugs.launchpad.net/kicad/+bug/1688717

The only workaround i can think of is splitting your sheet into multiple subsheets and connect everything together with hierarchical labels (a bit more work than a proper solution)

I agree with @Rene_Poschl.

Then, you can connect a global label to the pin-sheet outside the hierarchical sheet. This way you can connect different hierarchical sheets without the mess of wires between them and use multiple instances of the same hierarchical sheet. A workaround anyway.

I do not suggest the use of global labels. They have no place in proper hierarchical design as they violate the principle of separated knowledge domains as well as limiting reusability. I would much rather suggest the use of buses.

But i am aware that such pure desing princibles are not really used in electrical engineering at this point in time (they are however heavily used in software design, modern fpga design, soc design and even in digital chip design. In other words: everywhere where you expect multiple people to work on small sub units of complex systems. Or where you build stuff with reusability as a core feature.)

Thanks, this is what I thought although I do see it as a kludge. It is good to see that the issue is at least being discussed even if no solution is in sight. For all KiCADs strengths I do believe that this is an issue that will have to be solved eventually if there is ambition to truely compete as an industrial tool.

I think this is also related to the difficulty in controlling page numbering as discussed in a recent thread, highly atomic hierarchical design is great on a computer where navigation of the hierarchy is easy but rapidly becomes a nightmare as soon as you go to paper with a large and complex design


I also agree in not using global labels. But I received a 40+ sheet and 1000+ component schematic from a client who used them in this particular case and it worked very well.

There were two, sometimes three, levels of hierarchical sheet encapsulation. And as a matter of fact reusability of the inner sheets was a great asset.
Saddly, this approach doesn’t fully solve @stair’s problem, still a workaround.

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.