View ds1315 datasheet:

DS1315 Phantom Time Chip www.dalsemi.com FEATURES PIN ASSIGNMENT Real time clock keeps track of hundredths of seconds, seconds, minutes, hours, days, date VCC1 1 16 X1 of the month, months, and years 2 15 VCC0 X2 Adjusts for months with fewer than 31 days 3 14 BAT2 WE Automatic leap year correction valid up to 2100 BAT1 4 13 RST No address space required to communicate GND 5 12 OE with RTC D 6 11 CEI Provides nonvolatile controller functions for Q 7 10 CEO battery backup of SRAM Supports redundant battery attachment for 8 9 ROM/RAM GND high–reliability applications 16-Pin DIP (300-mil) Full ±10% VCC operating range +3.3 volt or +5 volt operation VCC1 X1 1 16 Industrial (–45°C to +85°C) operating temperature ranges available X2 2 15 VCC0 Drop i