Non-blocking delayed clocking system for domino logic

Abstract

A non-blocking multiple-phase clocking system for use with domino-type dynamic logic provides clock phases with overlapping evaluation phases to a circuit including a several cascaded dynamic logic gates. The circuit also includes a first flip-flop that is coupled to provide input signal(s) to the first dynamic logic gate of the cascade and a second flip-flop that is coupled to receive output signal(s) from the last dynamic logic gate of the cascade. The clocking system provides a first clock phase to the first dynamic logic gate, a second clock phase to the second dynamic logic gate and so on. A timing analysis is performed of each logic path in the circuit to determine the arrival time of each critical input signals to each dynamic logic gate. The delay between adjacent clock phase is then predetermined so that each dynamic logic gate enters its evaluation phase before the critical input signal(s) to the particular dynamic logic gate arrives. This adjustment of the clock phases maximizes the logic evaluation speed of the dynamic logic circuit.