A fast fanout optimization algorithm for near-continuous buffer libraries

This paper presents a gain-based fanout optimization algorithm for near-continuous buffer libraries. A near-continuous buffer library contains many buffers in a wide range of discrete sizes and each buffer ofa specific type satisfies a size-independent delay equation. The new fanout algorithm is derived from an optimal algorithm to a special fanout optimization problem for continuous libraries. The gainbased technique constructs fanout trees which have better timing at similar area cost. Since no combinatorial search over buffer sizes or fanout tree topologies is used, our execution time is up to 1000 times faster when compared to conventional fanout algorithms.