Method and apparatus for testing high-speed circuits based on slow-speed signals

摘要

Techniques and circuits for testing high-speed circuits using slow-speed input signals. Various designs for a “stimulus” generator are provided, which is capable of generating a high-speed stimulus based on, or in response to, one or more input signals. In one design, the generator includes two edge detectors coupled to a latch. Each edge detector receives a respective set of input signals and provides an intermediate signal. The latch receives the two intermediate signals from the two edge detectors and generates the output signal, which has a particular waveform pattern generated based on the active (e.g., leading) transitions in the two sets of input signals provided to the two edge detectors. In another design, the generator includes a ring oscillator that is enabled by one input signal, and further initiated by a pulse on another input signal provided to an input of a latch used to implement the oscillator.