A method for functional verification includes transforming an original multiphase circuit design into a phase-abstracted circuit design by identifying cyclical (repetitive) signals in the multiphase circuit design, determining a number of simulation phases for the multiphase circuit design, unwinding the multiphase circuit design by the number of phases to create an unwound design, and then applying logic reduction techniques to the unwound design using the clock-like signals to reduce (simplify) the logic in the unwound design by eliminating unused/unnecessary registers, inputs, outputs, and logic. The resulting phase-abstracted design can then be processed much more efficiently by functional verification engines than the original multiphase circuit design due to the reduced number of registers/inputs.