max_nets_under¶

Net-aware. How many different nets one marker may cover: the regions of layers[1] under each region of layers[0] are resolved to nets, and a marker covering more than value of them is reported.

Semantics¶

GF180’s NAT.6 is the rule this exists for — “two or more COMPs at different potential are not allowed under the same NAT layer”. Upstream builds the different-potential pairs with a net-aware spacing helper and asks which markers touch them; counting the nets under the marker is what the rule says, and reaches the same answer.

Each conductor region is placed under whichever marker region holds its marker point. A region whose net does not resolve counts as a net of its own, so an unresolved lookup can only ever cost a false positive, never a false clean.

Layers¶

layers[0] — the marker.
layers[1] — what lies beneath it and is counted.

Parameters¶

net_of (a layer param): Optional. The conductor the nets are looked up on, when what is counted is a derived layer — NAT.6 counts the active under the marker, an intersection, which is in no connect graph. Defaults to layers[1].

Violation markers¶

One point marker per marker region over the limit, at its marker.

KLayout equivalent¶

None directly; upstream’s construction through a net-aware spacing helper.

Example¶

- id: NAT.6
  check: max_nets_under
  layers: [nat, nat6_comp]
  value: 1.0
  layer_params:
    net_of: comp