A method of calibrating a first clock signal using a second clock signal and a plurality of calibration periods may include generating incremented counter values at a counter responsive to edges of the second clock signal. For at least two of the plurality of calibration periods, an initial incremented counter value from the counter may be stored in memory at an initial edge of the first clock signal for the respective calibration period, a final incremented counter value may be stored in memory at a final edge of the clock signal for the respective calibration period, and the at least two of the plurality of calibration periods may be overlapping with different initial and final edges of the first clock signal. For each of the plurality of calibration periods, a number of edges of the second clock signal occurring during the respective calibration period may be determined using the initial and final incremented counter values stored in memory. A relationship between the first and second clock signals may be determined using a sum of a number of edges of the second clock signal occurring during each of the plurality of calibration periods and using a sum of a number of first clock signal cycles occurring during each of the plurality of calibration periods.