The FM25640 is a 64-kilobit nonvolatile memory employing an advanced ferroelectric process. A ferroelectric random access memory or FRAM is nonvolatile but operates in other respects as a RAM. It provides reliable data retention for 45 years while eliminating the complexities, overhead, and system level reliability problems caused by EEPROM and other nonvolatile memories. Unlike serial EEPROMs, the FM25640 performs write operations at bus speed. No write delays are incurred. Data is written to the memory array immediately after it has been successfully transferred to the device. The next bus cycle may commence immediately. In addition, the product offers substantial write endurance compared with other nonvolatile memories. The FM25640 is capable of supporting up to 1012 read/write cycles -- far more than most systems will require from a serial memory. These capabilities make the FM25640 ideal for nonvolatile memory applications requiring frequent or rapid writes. Examples range from data collection, where the number of write cycles may be critical, to demanding industrial controls where the long write time of EEPROM can cause data loss. The FM25640 provides substantial benefits to users of serial EEPROM, in a hardware drop-in replacement. The FM25640 uses the high-speed SPI bus, which enhances the high-speed write capability of FRAM technology. The specifications are guaranteed over an industrial temperature range of -40°C to +85°C.