apparatus for synchronizing a clock signal to a pulse comprises a clock signal generator for generating a first clock signal having a frequency equal to that of a desired clock signal . a delay circuit to which the first clock signal is fed generates a number of time delayed versions of the first clock signal , each time delay being less than the period of the first clock signals . logic compares the time delayed versions of the first clock signal and the original clock signal at the time of occurrence of the pulse and selects as the desired clock signal , a version of the first clock signal which has changed state close to the time of occurence of the pulse .