CLOCK FREQUENCY COORDINATION FOR ELECTROMAGNETIC COMPATIBILITY

摘要

A method for selecting fundamental clock frequencies in order to achieve electromagnetic compatibility in electronic products which employ a plurality of clocks. The method requires first selecting an ideal frequency for each clock in the product. Then, and until the goal of avoiding coinciding harmonics is complete, the method includes the steps of computing all harmonics of all clock frequencies chosen, determining a minimum difference tolerable in the chosen frequencies and their harmonics for sufficient minimization of electromagnetic interference, and determining if the harmonics of the chosen frequencies coincide impermissibly within the frequency range. If there exists coincidence of harmonics within the predetermined minimum range, then the fundamental frequency of at least one of the clocks corresponding to an interfering harmonic must be adjusted to eliminate the interference. With the altered fundamental frequency, the steps of computing harmonics, determining if coincidence occurs, and adjusting the fundamental frequency is repeated.