Hierarchical stress parameter annotation

Abstract

In an embodiment, the design flow is modified to avoid the flattening process but still accurately annotate the transistors with stress parameters. The location-based stress parameters may be generated, but may not be provided to the LVS tool. Instead, a hierarchical LVS process may be performed, black-boxing lower level blocks that already have stress parameter assignments, preserving hierarchy, etc. The output database from LVS thus includes a cross reference between layout devices and schematic devices, as well as locations of the schematic devices. The database may then be queried for the transistors in the non-flattened design, and the stress parameters may be assigned to the transistors based on the location-based stress parameters. In this fashion the stress parameters may be assigned to the desired transistors, permitting annotation of these parameters into the schematics, without flattening the design and doing unnecessary work on blocks to be skipped.