Floorplanning consistent with partial-clustering on the sequence-pair

We propose a placement algorithm that cooperatively optimizes the wire-length and area, all on the sequence-pair. Wire-length minimization is pursued in the clustering stage, called partial clustering, in which modules are merged into the clusters according to the ratio-connectivity. Some modules are left as free-modules that are not so strongly connected to other modules. Area minimization is pursued by an iterative-improvement in which the move is partially hierarchical that exchanges the labels of free-modules, modules in the clusters, and clusters. In experiments, a behavior is clearly observed that free-modules creep into and out of clusters, adjusting the niches and humps in the clusters for area minimization with little effect on the wire-length.