Microchip Technology 25CS640 64-Kbit SPI Serial EEPROMs provide 64Kbits of Serial EEPROM utilizing the Serial Peripheral Interface (SPI) compatible bus. The devices are organized as 8192 bytes of 8-bits each (8-Kbyte). The Microchip Technology 25CS640 EEPROMs are optimized for use in consumer and industrial applications where reliable and dependable nonvolatile memory storage is essential. The 25CS640 operates across a broad voltage range (1.7V to 5.5V). 25CS640 features a nonvolatile Security register independent of the 64-Kbit main memory array. The first half of the Security register is read-only and contains a factory-programmed, globally unique, 128-bit serial number in the first 16-bytes. The 128-bit read-only serial number is followed by an additional 32 bytes of user-programmable EEPROM.
