The RS5C372A is a CMOS type real-time clock which is connected to the CPU via 2-wires and capable of serialtransmission of clock and calendar data to the CPU.The RS5C372A can generate various periodic interrupt clock pulses lasting for long period (one month), andalarm interrupt can be made by days of the week, hours, and minutes by two incorporated systems. Since an oscillationcircuit is driven at a constant voltage, it undergoes fluctuations of few voltage and consequently offers low currentconsumption (TYP. 0.5μA at 3V). It also provides an oscillator halt sensing function applicable for data validationat power-on and other occasions and 32-kHz clock output for an external micro computer. (Nch. open drain output)The product also incorporates a time trimming circuit that adjusts the clock with higher precision by adjustingany errors in crystal oscillator frequencies based on signals from the CPU. The crystal oscillator may be selectedfrom 32.768kHz or 32.000kHz types. Integrated into an ultra compact and ultra thin 8 pin SSOP package, theRS5C372A is the optimum choice for equipment requiring small sized and low power consuming products.