Semi-individual wire-length prediction with application to logic synthesis

Abstract

A new concept for wire-length prediction, the semi-individual wire-length prediction, is introduced. Structural metrics, such as mutual contraction and net range, are used to predict which interconnects have a tendency to be long or short in the final layout. The very good correlation of the prelayout measures with the postlayout interconnect lengths is demonstrated. The prelayout wire-length-prediction techniques are applied in logic synthesis, targeting wiring cost, and congestion minimization. This paper focuses on technology mapping and fan-out optimization. Experiments on LGSyn93 and ITC'99 benchmark suites show that the wire-length-prediction-based technology mapping and fan-out-optimization algorithms produce layout-friendly netlists. After placement and global routing, the netlists yield smaller total wire length, are more routable, and achieve better timing than the netlists obtained using traditional logic-synthesis flow in SIS.