Integrated circuit with real time, elapsed time, and cycle counter clocks

An integrated circuit which includes not only a real time clock, but also an elapsed time counter, and a third counter. The elapsed time counter measures the total number of seconds during which a system has been powered up. The third counter is a "cycle counter," which measures the number of times a power cycle (power-up and power-down) has occurred. Thus, by reading the cycle counter and the elapsed time indicator, the general power history of a system can readily be determined, even if the system itself has totally failed. This integrated circuit is battery backed, and is advantageously combined with a system for which power history must be maintained.