BUY DS1216F https://www.utsource.net/itm/p/7420486.html
IC SMART/ROM 3V 64/256/1M 32DIP
Description: The DS1216F is a nonvolatile static RAM (NVRAM) with a built-in real-time clock/calendar. Features: Low power CMOS technology 32K x 8 static RAM Real-time clock/calendar Battery-backed operation Automatic power-fail detect and switch Automatic write protect Automatic power-on reset Automatic data write Automatic data read Automatic data write protect Automatic data read protect Automatic data write enable Automatic data read enable Automatic data write disable Automatic data read disable Automatic data write/read protect Automatic data write/read enable Automatic data write/read disable Automatic data write/read cycle Automatic data write/read cycle enable Automatic data write/read cycle disable Automatic data write/read cycle protect Automatic data write/read cycle enable/disable Applications: Automotive Industrial control Networking Telecommunications Medical Security systems Home automation (For reference only)