The FM25C041U is a 4K (4,096) bit serial interface CMOS EEPROM (Electrically Erasable Programmable Read-Only Memory). This device fully conforms to the SPI 4-wire protocol which uses Chip Select (/CS), Clock (SCK), Data-in (SI) and Dataout (SO) pins to synchronously control data transfer between the SPI microcontroller and the EEPROM. In addition, the serial interface allows a minimal pin count, packaging designed to simplify PC board layout requirements and offers the designer a variety of low voltage and low power options.