Can someone please tell me about the design rules? I am looking at skywater130nm pdk and grules. In grules I see [“via3”][“met4”] = {“min_enclosure”: 0.65} but I can't find this in the sky130 design rules. I think the corresponding rule in sky130 is (m3.4). However, (m3.4) says “Via2 must be enclosed by Met3 by at least ...AL 0.065 µm”.

@Kento Takeuchi Good point. Looking at the rules, I think about half of the metal enclosure rules (upper metal to lower via) are backwards. via3 will never enclose met4 so even though the value

0.65

is 10x bigger than it should be it will never be checked. I suspect that instead of

grulesobj["via3"]["met4"] = {"min_enclosure": 0.65}

the rule should be (looks like all the distances are rounded up to the nearest 0.01).

grulesobj["met4"]["via3"] = {"min_enclosure": 0.07} #m3.4

Can you create a pull request for the changes? These are the other changes I see.

grulesobj["poly"]["mcon"] = {"min_enclosure": 0.08, "min_separation": 0.06} #licon.8a

instead of

grulesobj["poly"]["mcon"] = {"min_enclosure": 0.05, "min_separation": 0.06}

These rules don’t make sense and can be removed, I think.

grulesobj["mcon"]["poly"] = {"min_enclosure": 0.08}
grulesobj["mcon"]["met1"] = {"min_enclosure": 0.08}
grulesobj["via1"]["met2"] = {"min_enclosure": 0.06}
grulesobj["via2"]["met3"] = {"min_enclosure": 0.09}
grulesobj["via3"]["met4"] = {"min_enclosure": 0.65}
grulesobj["via4"]["met5"] = {"min_enclosure": 0.07}

These currently empty rules should probably be added:

grulesobj["met1"]["mcon"] = {"min_enclosure": 0.08} #li.5.-
grulesobj["met2"]["via1"] = {"min_enclosure": 0.06} #m1.5
grulesobj["met3"]["via2"] = {"min_enclosure": 0.09} #m2.5
grulesobj["met4"]["via3"] = {"min_enclosure": 0.07} #m3.4 (as previously stated)
grulesobj["met5"]["via4"] = {"min_enclosure": 0.07} #m4.3

@mehdi Can someone from your glayout team verify this?

Thank you. I will create a pull request.

I can take a look, thank you for pointing this out!!

OK Chetanya Goyal Thank you.