These devices combines two popular functions, Supply Voltage Supervision and Serial E2PROM Memory in one package. This combination lowers system cost, reduces board space requirements, and increases reliability. The user's system is protected from low voltage conditions by the devices low Vcc detection circuitry. When Vcc falls below the minimum Vcc trip point, the system is reset. RESET/RESET is asserted until Vcc returns to proper operating levels and stabilizes. The memory portion of the device is a CMOS Serial E2PROM array with Xicor's Block LockTM Protection. The array is internally organized as x 8. The device features a Serial Peripheral Interface (SPI) and software protocol allowing operation on a simple four-wire bus. The device utilizes Xicor's proprietary Direct WriteTM cell, providing a minimum endurance of 100,000 cycles per sector and a minimum data retention of 100 years.