The ISL12029 device is a low power real time clock with clock/calender, power-fail indicator, clock output and crystal compensation, two periodic or polled alarms (open drain output), intelligent battery backup switching, CPU Supervisor, integrated 512 x 8 bit EEPROM configured in 16 byte per page. The oscillator uses an external, low-cost 32.768kHz crystal. The real time clock tracks time with separate registers for hours, minutes, and seconds. The device has calendar registers for date, month, year and day of the week. The calendar is accurate through 2099, with automatic leap year correction.