A fail-operational/fail-operational fault tolerant clock includes a voting core comprised of triple redundant clock modules (30, 40, 50) and a floating hot spare module (60). Each module includes a voter (84) and fault detection, identification and reconfiguration circuitry (82) which operates to substitute...http://www.google.de/patents/US5537583?utm_source=gb-gplus-sharePatent US5537583 - Method and apparatus for a fault tolerant clock with dynamic reconfiguration
