Wire Length Analysis For Unequal Sized Recursive Min-Cut Placement Using Different Net Weighting Scheme
In this paper, different net weighting schemes are examined for a new method of min-cut partitioning for VLSI
placement. Traditional min-cut placers use equal sized partitioning at each level for VLSI placement. They use either bisection
or quadrisection to divide the circuit. This paper gives an introduction to a new method of partitioning called unequal sized
partitioning. In this method of unequal sized min-cut partitioning the circuit is divided into unequal sized partitions at each
level. This paper analyses the placement results of different net weighting schemes for unequal sized partitioning to minimize
the total wire length. Firstly an introduction to unequal sized recursive partitioning and net weighting schemes are presented.
Then these schemes are applied to MCNC benchmark circuits for different partition ratios ranging from 0.1 to 0.9. The results
prove that all the net weighting schemes do not give optimal wire lengths for balanced partitioning. Each circuit has optimal
wire length at different partition ratio for a different net weighting scheme. Finally this paper suggests the need for unequal
sized partitioning which improves the wire length significantly as compared to the conventional balanced partitioning.
Keywords- Hypergraph, Min-cut Algorithm, Net Weighting, Placement, Unequal Sized Partitioning.