Sequence-Pair Based Compaction under Equi-Length Constraint

Equi-length constraints are widely used for a substitution for IR-drop or skew constraints. This paper provides a linear programming formulation for compaction with equi-length constraints, where the authors make use of multi-SP that is an extension of sequence-pair to multi-layer layouts. Since multi-SP stores horizontal relations and vertical ones among modules and wires in the same data structure, it enables us to simultaneously impose constraints on both horizontal and vertical directions. Furthermore, the paper provides extensions to IR-drop and skews constraints. In experiments, the authors applied the LP-base compaction to artificial instances of power routing and LCD I/O routing, and showed the promising results