DS1216F Datasheet PDF - Dallas Semiconductor -> Maxim Integrated

GENERAL DESCRIPTION
The DS1216 SmartWatch RAM and SmartWatch ROM sockets are 600-mil-wide DIP sockets with a built-in CMOS watch function, an NV RAM controller circuit, and an embedded lithium energy
source. The sockets provide an NV RAM solution for memory sized from 2K x 8 to 512K x 8 with
package sizes from 26 pins to 32 pins. When a socket is mated with a CMOS SRAM, it provides a
complete solution to problems associated with memory volatility and uses a common energy source to maintain time and date.

FEATURES
  Keeps Track of Hundredths of Seconds, Seconds, Minutes, Hours, Days, Date of the Month, Months, and Years
  Converts Standard 2K x 8 Up to 512K x 8 CMOS Static RAMs into Nonvolatile Memory
  Embedded Lithium Energy Cell Maintains Watch Information and Retains RAM Data
  Watch Function is Transparent to RAM Operation
  Automatic Leap Year Compensation Valid Up to 2100
  Lithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time
  Proven Gas-Tight Socket Contacts
  Full ±10% Operating Range
  Accuracy Better Than ±1 Minute/Month at +25°C