Method and apparatus for glitch-free control of a delay-locked loop in a network device

Abstract

A method of controlling a delay-locked loop (DLL) module is disclosed. The method includes the steps of receiving a clock signal, comparing the received clock signal with a reference clock signal to determine whether a required phase difference between the signals is within specified tolerances, producing a correction signal when the required phase difference between the received clock and reference clock signals is not within the specified tolerances, utilizing the correction signal to change a delay setting and forwarding the correction signal to slave DLL modules in communication with the DLL module. The comparing, producing, utilizing and forwarding steps are performed only after a period of time has elapsed from a prior incidence of the comparing, producing, utilizing and forwarding steps, where the period of time is sufficient to allow the DLL to settle and no extraneous results are produced.