Folded circuit synthesis: min-area logic synthesis using dual-edge-triggered flip-flops

Abstract

The area required by combinational logic of a sequential circuit based on standard flip-flops can be reduced by identifying subcircuits that are identical. Pairs of matching subcircuits can then be replaced by circuits in which dual-edge-triggered flip-flops operate on multiplexed data at the rising and falling edges of the clock signal. We show how to modify the Boolean network describing a combinational logic to increase the opportunities for folding, without affecting its function. Experiments with benchmark circuits achieved an average reduction in circuit area of 18%.