EEPROM, 512K bit, 64K x 8bit, Serial SPI, 20MHz, SOIC, 8 Pins - 

The 25LC512-I/SN is a 512Kbit serial Electrically Erasable Programmable Read-only Memory (EEPROM) 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. Communication to the device can be paused via the hold pin (HOLD). While the device is paused, transitions on its inputs will be ignored, with the exception of Chip Select, allowing the host to service higher priority interrupts.