This part is a kind of semiconductor called DS1225AD.

Function of this product has 64k Nonvolatile SRAM.

Manufacturers : Dallas

Image and pinout :

Some of the text within the PDF file :

DS1225AB/AD 64k Nonvolatile SRAM www.dalsemi.com FEATURES 10 years minimum data retention in the absence of external power Data is automatically protected during power loss Directly replaces 8k x 8 volatile static RAM or EEPROM Unlimited write cycles Low-power CMOS JEDEC standard 28-pin DIP package Read and write access times as fast as 70 ns Lithium energy source is electrically disconnected to retain freshness until power is applied for the first time Full ±10% VCC operating range (DS1225AD) Optional ±5% VCC operating range (DS1225AB) Optional industrial temperature range of -40°C to +85°C, designated IND PIN ASSIGNMENT NC A12 A7 A6 A5 A4 A3 A2 A1 A0 DQ0 DQ1 DQ2 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 VCC WE NC A8 A9 A11 OE A10 CE DQ7 DQ6 DQ5 [ ... ]

DS1225AD PDF Datasheet Download