REAL TIME CLOCK USING COMPUTER AND SEPARATE COUNTING MEANS

摘要

A method and apparatus for maintaining a real time clock normally incremented by a CPU when power is provided thereto and maintained by a separate counting means when power is removed from the CPU, the separate counting means powered independently of the CPU power source. A method and apparatus is also disclosed for synchronizing the separate counting means such that the real time clock maintained by the CPU may be updated for the time interval in which the CPU was inoperative without loss of real time clock accuracy.