TIME-OF-DAY PERIPHERAL CIRCUIT.

The MC146818 Real-Time Clock plus RAM peripheral integrated circuit is described. It combines three unique features: a complete time-of-day clock with alarm and one hundred year calendar, a programmable periodic interrupt and square wave generator, and 50 bytes of low power static RAM. The IC uses high-speed CMOS technology which consumes little power while interfacing to 1 MHz processor buses. The MC146818 is designed to interface to multiplexed buses and incorporates a unique circuit which allows direct connection to processors using multiplexed bus schemes. Another version, the MC146819, is provided to connect to standard non-multiplexed bus schemes.