Method of synchronizing signals of a pulse generator

Abstract

A digital architecture for a pulse generator provides a method of synchronizing signals of the pulse generator. The pulse generator has a timebase card, a microprocessor and a plurality of pulse cards. The microprocessor controls the parameters of the timebase card and pulse cards, and the timebase card provides a common master clock signal to all of the pulse cards determined by a triggerable voltage controlled oscillator that has two sources of frequency control voltage, an internal DAC for absolute frequency and a frequency comparison circuit for synchronization with an external timebase. The pulse cards produce pulses, either singly or in bursts, with the leading and trailing edges being separately positionable using quantum, sliver and vernier controls. A pattern RAM on each pulse card provides a pulse pattern that provides an approximation of the desired pulses to one quantum, and repeated iterations through the pattern RAM provide bursts of pulses. Pattern RAMs on different pulse cards, where one pattern is related to the other by a power of two, may be synchronized since both channels use the same master clock from the timebase card. Likewise a burst of pulses may be synchronized with the external timebase since the master clock is synchronized with the external timebase, with a frame sync input signal being used to determine the relative phase between the burst of pulses and the external timebase.