A KiCad schematic split into sub-sheets that act like functions, with named input/output pins. Used by CapnKernel for main + PSU + level translator.
How it looks
Real image: the CORE3588 schematic, exported by KiCad (shown in greys)
The top sheet of the CORE3588 schematic, as KiCad draws it: just two boxes, each standing for a whole sub-sheet. (The lines crossing them are the page frame.)
1Sheet box "P1": opens 1_P1.kicad_sch, where the whole circuit lives.
2Sheet box "block3 3V3": a second sub-sheet (empty in this version).
How it works
Where it fits
Each box is a sub-sheet; inside, nets can also be joined by name with a global label. The whole thing still makes one netlist.