MM58174A

MM58174A Microprocessor-Compatible Real-Time Clock May 1991 MM58174A Microprocessor-Compatible Real-Time Clock General Description The MM58174A is a low-threshold metal-gate CMOS circuit that functions as a real-time clock and calendar in bus-oriented microprocessor systems The device includes an interrupt timer which may be programmed to one of three times Timekeeping is maintained down to 2 2V to allow low power standby battery operation The timebase is generated from a 32768 Hz crystal-controlled oscillator Y Y Y Y Y TTL compatible Low power standby operation (2 2V 10 mA) Low cost internally biased oscillator Low cost 16-pin dual-in-line package Available for commercial and military temperature ranges Applications Y Y Y Y Y Y Y Y Features Y Y Y Y Y Y Microprocessor compatible Tenths of seconds seconds tens of seconds minutes tens of minutes day of week days tens of days months tens of months independent registers Automatic leap year calculation Internal pull-ups to safeguard data Protection for read during data changing Independent interrupt system with open drain output Point-of-sale terminals Word processors Teller terminals Event recorders Microprocessor-controlled instrumentation Microprocessor time clock TV VCR reprogramming Intelligent telephone Block Diagram TL F 6681 – 1 FIGURE 1 TRI-STATE is a registered trademark of National Semiconductor Corporation C1995 National Semiconductor Corporation TL F 6681 RRD-B30M105 Printed in U S A Absolute Maximum Rati...