Lyra: A New Approach to Geometric Layout Rule Checking

Lyra is a layout rule checking program for Manhattan VLSI circuits. In Lyra, rules are specified in terms of constraints that must hold at certain corners in the design. The corner-based mechanism permits a wide variety of rules to be specified easily, including rules involving asymmetric constructs such as transistor overhangs. Lyra's mechanism also has locality, which can be exploited to construct incremental and/or hierarchical checkers. A rule compiler translates symbolic rules into efficient code for checking those rules, and permits the system to be retargeted for different processes.