In accordance with an embodiment, a method of detecting a phase difference between a first signal and a second signal include latching a state of the first signal using the second signal as a clock to produce a first latched signal, latching a state of the second signal using the first signal as a clock to produce a second latched signal summing the first latched signal and the second latched signal to produce an indication of whether the first signal is leading or lagging the second signal.