2 The DS1388 I C real-time clock (RTC), supervisor, and EEPROM is a multifunction device that provides a clock/calendar, programmable watchdog timer, power- supply monitor with reset, and 512 bytes of EEPROM. The clock provides hundredths of seconds, seconds, minutes, and hours, and operates in 24-hour or 12-hour format with an AM/PM indicator. The calendar provides day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. A watchdog timer provides a reset for an unre- sponsive microprocessor. It is programmable in 10ms intervals from 0.01 to 99.99 seconds. A temperature- compensated voltage reference and comparator circuit . If a primary power failure is monitors the status of V CC detected, the device automatically switches to the backup supply and drives the reset output to the active state. The backup supply maintains time and date operation in the absence of V . When V returns to CC CC nominal levels, the reset is held low for a period to allow the power supply and processor to stabilize. The device also has a pushbutton reset controller, which debounces a reset input signal. The device is 2 accessed through an I C serial interface. Applications Portable Instruments Point-of-Sale Equipment Network Interface Cards Wireless Equipment