A circuit and method has a processing unit, a master clock generator for providing a master clock and a plurality of phase-locked loops, each providing a respective clock signal. A plurality of dynamically variable delay circuits each has a plurality of predetermined delay amounts. Clocked circuits are coupled to respective clock signals provided by respective phase-locked loops. A performance detector is coupled to receive the clock signals for determining a center of a quiet zone for at least one of the plurality of phase-locked loops. The phase-locked loops are turned off and on and a respective one of the plurality of dynamically variable delay circuits is set to have a new predetermined value of delay which adjusts an edge of the master clock to a location that permits the data processing system to operate near substantially the center of the quiet zone.