Glossary

Deck

A YAML file of rules for one PDK subsystem (e.g. metal2.yml). See PDK authoring guide.

Suite

A named, curated selection of rules imported from one or more decks, optionally restricted to a whitelist of rule ids per deck. Selected with --suite (mutually exclusive with --deck). See PDK authoring guide.

Rule

One entry in a deck: an id, a check type, one or more layers, a value, and optional params/text/ignore. See PDK authoring guide.

Check

The algorithm a rule’s check: field selects (e.g. min_space, min_density) — see Check reference for the full reference.

Layer

A named alias for a GDS (gds_layer, gds_datatype) pair, declared in a PDK’s layer table. Rules and virtual-layer definitions reference layers by name.

Virtual layer

A derived layer computed from drawn (or other virtual) layers via a boolean, selection or morphological operator, declared in pdk.yml. See Virtual layers.

Eager (virtual layer)

A virtual layer computed once, up front, as ordinary boundaries in the layout — because a whole-layout check reads it, or its op only exists that way. See Virtual layers.

Lazy (virtual layer)

A virtual layer registered with the tiled merge cache and built per tile on first use; every virtual layer, unless a rule needs it eager. See Virtual layers and Architecture.

FlatLayout

The whole requested top cell’s geometry (boundaries and text labels), with every StructRef/ArrayRef resolved to top-cell coordinates by composing affine transforms down the hierarchy. See Architecture.

Tile

A fixed-size (20 µm) square region of the chip; the unit the merge cache merges, composes and stitches independently, in parallel. See Architecture.

Halo

The margin of geometry around a tile’s core that its local merge sees, so a shape straddling the tile boundary is computed correctly. Sized per layer, from the largest distance any rule measures on it. See Architecture.

Core

The tile’s own (non-halo) rectangle — the region whose merged output actually belongs to that tile, as opposed to geometry only visible for halo purposes. See Architecture.

Region stitching

Reconstructing a layer’s whole connected regions (area, marker point, or a predicate) from independently-computed tile-local pieces, by joining pieces whose shared tile-core edge shows continuous coverage. See Architecture.

Net-aware check

A check that needs electrical connectivity (which shapes are the same net), e.g. the antenna-ratio family and a min_space gated on net. Requires the PDK’s connectivity: graph and runs unless --no-connectivity is passed. See antenna_ratio, min_space.

Connectivity graph

A PDK’s declared list of connector (via/contact) layers and the conductor layers each one electrically bridges, used to extract nets from geometry alone. See PDK authoring guide.

Marker

One reported violation’s geometry in a .lyrdb report: an edge, a point, or none (a global/whole-chip check). See Reports and markers.

lyrdb

KLayout’s XML report-database format, written by --report and loadable in KLayout’s Marker Browser. See Reports and markers.