In this paper we propose an efficient cluster refinement approach for macro
-cell placement. The algorithm selects a cluster of blocks dynamically, and
finds an optimal solution for all the blocks in the cluster simultaneously
. This is different from previous zone refinement approach which optimizes
the allocation of one single block in each operation. Experimental results
on the MCNC benchmark circuits show that the approach achieves excellent ar
ea utilization while minimizing the wire length at the same rime.