Sampling timebase system

Abstract

A sampling timebase system uses the frequency stable clock signal present in digital systems to accurately reconstruct waveforms that are synchronous with the clock signal. The sampling timebase system provides a strobe signal having a precisely controlled time delay relative to a trigger event. An interval counter is programmed to count a specified number of the cycles of the clock signal, providing for coarse time delay adjustment of the strobe signal in time increments determined by the period of the clock signal. A fine delay generator triggered by the terminal count of the interval counter provides for fine adjustment of the time delay of the strobe signal. The interval counter and fine delay generator are programmable to progressively vary the time delay between the strobe signal and the trigger event relative to cycles of the waveform. The strobe signals, when applied to a sampler, enable sufficient samples to be acquired to reconstruct selected segments of the waveform. An optional prescaler included in the sampling timebase system divides the frequency of the applied clock signal when the clock signal is beyond the operating frequency of the interval counter or the fine delay generator.