The X25097 is a CMOS 8K-bit serial E2PROM, internally organized as 1024 x 8. The X25097 features a Serial Peripheral Interface (SPI) and software protocol allowing operation on a simple four-wire bus. The bus signals are a clock input (SCK) plus separate data in (SI) and data out (SO) lines. Access to the device is controlled through a chip select (CS) input, allowing any number of devices to share the same bus. IDLock is a programmble locking mechanism which allows the user to lock system ID and parametric data in different portions of the E 2 P ROM memory space, ranging from as little as one page to as much as 1/2 of the total array. The X25097 also features a WP pin that can be used for hardwire protection of the part, disabling all write attempts, as well as a Write Enable Latch that must be set before a write operation can be initiated. The X25097 utilizes Xicor's proprietary Direct WriteTM cell, providing a minimum endurance of 100,000 cycles per byte and a minimum data retention of 100 years.