The Microchip Technology Inc. 25AA512/25LC512 (25XX512*) is a 512 Kbit serial EEPROM memory with byte-level and page-level serial EEPROM functions. It also features Page, Sector and Chip erase functions typically associated with Flash-based products. These functions are not required for byte or page write operations. The memory is accessed via a simple Serial Peripheral Interface (SPI) compatible serial bus. The bus signals required are a clock input (SCK) plus separate data in (SI) and data out (SO) lines. Access to the device is controlled by a Chip Select (CS) input.