Periodic signal measurement using statistical sampling

A fully-digital probabilistic measurement methodology in which a periodic signal generated on an IC device is sampled multiple times during a test period, with the asserted/de-asserted state of the periodic signal determined during each sampling event. A statistically significant number of sampling events are executed according to a reference signal frequency that is uncorrelated to the IC's system clock, whereby each successive sampling event involves detecting an essentially random associated phase of the periodic signal such that the probability of detecting an asserted state during any given sampling event is proportional to the duty cycle of the periodic signal. A first count value records the number of sampling events in which the periodic signal is asserted, and a second count value records the total number of sampling events performed, whereby a ratio of these two count values provides a statistical measurement of the periodic signal's duty cycle.