US Patent 7825689 Functional-input sequential circuit

An exemplary functional input sequential circuit for reducing the setup time of input signals. The functional sequential circuit includes a tri-state inverter having an input signal and two control signals. The transmission circuit receives a control signal from a combinational logic circuit that performs a logical operation on a second input signal and a clock signal. The output of the transmission circuit is coupled to a digital storage element. Further, a control circuit is coupled to the digital storage element in order to force a value on the digital storage element when no input signal is received from the transmission circuit. The control circuit is also controlled by the second input signal and a clock signal.