CLOCK SELECTION CONTROL CIRCUIT

摘要

TITLE CLOCK SELECTION CONTROL CIRCUIT A circuit which controls the selection and activation of one of a plurality of clock circuits arranged in copies. Selection circuitry is used to detect failure of an on-line clock circuit, scan a plurality of available clock circuits in a predetermined sequence and place the next available properly operating clock circuit on line. Control circuitry prevents erroneous clock selection during power-up/ power down operations and enables predetermined clock circuit copies to be disabled.