Patent ID: 7002378

Claim:
An apparatus for detecting a valid data strobe contained within a strobe signal, the apparatus comprising: a voltage detector to detect whether a measured voltage level of the strobe signal is above or below a preselected threshold level and to provide an output in response thereto; a sample and hold unit coupled to the voltage detector to sample and hold the strobe signal detected by the voltage detector; a sampling clock unit coupled to the sample and hold unit to generate a sampling clock signal, wherein the sampling clock signal sets a sampling frequency of the strobe signal for the sample and hold unit, wherein the sampling frequency determines a measurement accuracy of the strobe signal, and wherein the strobe signal is sampled by the sample and hold unit at a time that corresponds to either a rising edge or a falling edge of the sampling clock signal; and a valid strobe detector coupled to the sample and hold unit to detect a valid strobe signal upon receiving a predetermined number of consecutive valid strobe signal samples from the sample and hold unit, wherein the consecutive strobe signal samples are taken at a time that corresponds to either a rising edge or a falling edge of the sampling clock signal.