Restrictive design rules (RDRs) have been introduced as a simplified layout optimization method to better enable resolution enhancement techniques in ultra-deep submicron designs (16). In this paper, we study the technology migration problem for designs with strong RET-driven layout restrictions, i.e., RDR constraints, which require devices (gates) to be placed on a coarse pitch and in a single orientation. In particular, we study the legalization problem with on-pitch constraints for devices with an objective of minimum layout perturbation. The problem can be formulated as an integer linear programming (ILP) problem with a set of stringent integer constraints, and it can be approximated as a mixed integer linear programming (MILP) problem. Instead of using an MILP solver to solve it, we propose a two-stage method --- first the target on-pitch positions for gates are computed and second the original problem is relaxed to a linear programming problem. Library cell layouts designed in a technology with conventional ground rules have been migrated successfully to a technology with RDRs using our approach.

An increasingly important trend in the engineering of complex systems is the design of component integration standards. Such standards define rules of interaction and shared communication infrastructure that permit composition of systems out of independently-developed parts. A problem with these standards is that it is often difficult to understand exactly what they require and provide, and to analyze them in order to understand their deeper properties. In this paper we use our experience in modeling the High Level Architecture (HLA) for Distributed Simulation to show how one can capture the structured protocol inherent in an integration standard as a formal architectural model that can be analyzed to detect anomalies, race conditions, and deadlocks.