Fast logic restructuring exploring fanout-reconvergent structures and extended symmetry detections

Rewiring is a logic restructuring technique proved to possess a theoretically complete capability for logic transformations. This technique can be even more powerful if well integrated with today´s EDA flow for deep-submicron technology where wiring delay well dominates. In this paper, we will show that a structural factor yielding rewiring patterns is probably mainly rooted from the nature of fanout-reconvergent structures abundant in combinational Boolean networks. Here, we analyze the implication properties for such fanout-reconvergent structures for quick identifications of alternative wires together with an extended symmetry detection scheme for finding more swappable wires. In this fast rewiring engine, the number of alternative wires found can be over 50% of that found by an extensive ATPG-based rewiring tool, REWIRE; however with an only 2% runtime.