A signal generator consistent with certain embodiments of the invention has a reference clock (34) producing a periodic sequence of reference clock output pulses. A window generator (38) generates a plurality of time windows through which a selected plurality of the reference clock output pulses are selectively passed as windowed pulses so that the windowed pulses form a selected pattern of pulses. A programmable delay (46) has resolution of delay that has finer time granularity in delay than the period of the clock output pulses. The programmable delay (46) delays each of the windowed pulses by a programmed delay time to thereby provide a timing correction to the windowed pulses to produce an output pattern of pulses.