The CAT25010/20/40 is a 1K/2K/4K Bit SPI Serial CMOS EEPROM internally organized as 128x8/256x8/ 512x8 bits. Catalyst's advanced CMOS Technology substantially reduces device power requirements. The CAT25010/20/40 features a 16-byte page write buffer. The device operates via the SPI bus serial interface and is enabled though a Chip Select (CS). The HOLD pin may be used to suspend any serial communication without resetting the serial sequence. The CAT25010/ 20/40 is designed with software and hardware write protection features including Block Write protection.