Method and apparatus for controlling a variable frequency controlled oscillator.

摘要

A system for steering mutually phase-locked time-of-day (TOD) clocks in unison to a higher-precision reference clock. Periodically the count stored by a TOD counter responsive to one of the TOD clocks is compared with a reference count to provide an error signal. A proportional correction signal derived from the error signal is applied together with an offset to each of the TOD clocks to adjust the clock frequencies and thereby steer the TOD count toward the reference count. The steering offset is dynamically adjusted in such a manner that, when the offset signal is applied alone as a correction signal, the frequencies of the TOD clocks track that of the reference clock. <IMAGE>