Edge Generator-Based Phase Locked Loop Reference Clock Generator for Automated Test System

摘要

An automatic test system configured for generating a periodic signal of a programmable frequency. The automatic test system may comprise a clock, an edge generator coupled to the clock, a phase locked loop, and a delay adjustment circuit. The edge generator may comprise an edge generator output, an enable input and a delay input. The edge generator may produce at the edge generator output a signal with a delay relative to an edge of the clock specified by a value at the delay input in each cycle of the clock for which the enable input is asserted. The phase locked loop may comprise a reference input and a phase locked loop output configured to provide the periodic signal of the programmable frequency. The delay adjustment circuit may comprise an accumulator that may increase in value by a programmed amount for each cycle of the clock.