Is

capm.2b_a

checked by Magic ? And does it mean you can't have a MiM cap met3 closer than 1.2u of any other met3 ? Does that include any orther met3 from another MiM cap ?

Magic does not check this rule correctly, and we have updated the klayout rule deck to. . . maybe. . . check this rule correctly. I may be able to implement the rule correctly in magic now that I understand it. The MiM cap rules in the open source documentation are not the right rules for the sky130 process (they belong to a MiM cap used on some other variant of the original S8 process). The bottom plate spacing rule requires checking the distance from an imaginary rectangle made from expanding the CAPM layer by some amount, then ensuring at least 1.2um spacing from that imaginary rectangle to the nearest facing edge of metal3 not belonging to the same net.

Any chance to get the text / origina DRC doc for the actual MiM caps ? Because I just spent a couple of days working on a design packing MiM caps as densely as I could and now I can scrap it 😕

Unfortunately the best DRC documentation (from S130) only says "capm bottom plate minimum spacing >= 1.2um". No other information whatsoever. I had to figure out the rest from the Calibre rule deck, but I'm not so familiar with Calibre syntax so it's still not entirely clear to me how it's implemented.