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 layer operations.

Eager (virtual layer)

The default virtual-layer evaluation mode: computed once, up front, as ordinary boundaries. See Virtual layer operations.

Lazy (virtual layer)

The mode: lazy virtual-layer evaluation mode: registered with the tiled merge cache and built per tile on first use. See Virtual layer operations 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. Requires the PDK’s connectivity: graph and runs unless --no-connectivity is passed. See antenna_ratio.

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.