A new hierarchical layout compactor using simplified graph models

A new hierarchy-preserving hierarchical compactor which can be used with either 1-D or 2-D leafcell compaction techniques has been developed. The compactor is applicable to hierarchical layouts which consist of a number of arrays of identical cells. The hierarchy is maintained throughout the compaction process so that all the instances of a subarray of identical cells have the same shape after compaction. A hierarchical compactor based on the suggested simplified graph model has been developed and experimental results on several benchmark examples showed that the proposed method was satisfactory