R&D Report 1974-17 : The generation of video synchronising pulses and test waveforms by digital synthesis: Timing errors caused by quantising distortion P.A. Ratcliff
Digital waveform-synthesis produces interval timing errors, or wave-shape distortion, when generation of transitions is required at intervals which are not integer multiples of the sampling clock period. A rule has been evolved to determine the timing accuracy with which a digital system, with quantisation limitations, is capable of generating waveform transitions. Synchronising-pulse edges and 2T pulses have been generated at intervals of 1/16 of a clock-period, using a sampling clock-rate of thrice colour-subcarrier frequency. A synchronising-pulse jitter of less than +/- 2.5 ns is obtainable, and tests on a video tape recorder indicate that this amount of jitter is satisfactory.