PHIFACT-a design space exploration program

PHIFACT is a program to synthesize combinational blocks for performance. This is mainly achieved by design space exploration at logic level. The basic multi-level architecture of the block is gradually constructed during a Boolean phase, where look ahead tools guarantee optimality. During a subsequent local restructuring phase, optimal circuits scattered in subregions of the design space are explored and selected. This is mainly based on a steepest descent method in various directions. Consequently either the complete design space, or selected subregions can be examined. Both progresses are intimately connected, placing PHIFACT in the forefront of logic synthesis tools for performance