Almost every application in production today can benefit from or already requires a unique identifier or serial number. This number allows identification and tracking for multiple purposes including node identity， build control， version control， customer tracking and authenticity check. Building and maintaining an infrastructure to assign and maintain the serialization of products， particularly in high-volume production lines across multiple locations， can be challenging. The Atmel? AT24CS series of devices helps resolve this problem by including a unique， factory-programmed， read-only 128-bit Serial Number that can help customers simplify inventory control of mass production lines and enhance product traceability. The CS family comes in multiple EEPROM array densities from 1Kb through 64Kb. As an application’s needs grow over time and greater memory densities are required， the 128-bit Serial Number contained within any CS series Serial EEPROM product remains unique， enabling the value to remain distinctive across the entire portfolio of customer applications. The AT24CS series maintains all of the features that make serial EEPROMs a must-have element in most designs， including 1 million cycle write endurance， 100-year data retention， byte write capability， and very low active and standby current consumption