资 源 简 介
The FM31xx is a family of integrated devices thatincludes the most commonly needed funcTIons forprocessor-based systems. Major features includenonvolaTIle memory available in various sizes, realTImeclock, low-VDD reset, watchdog TImer,nonvolatile event counter, lockable 64-bit serialnumber area, and general purpose comparator thatcan be used for an early power-fail (NMI) interrupt orother purpose. The family operates from 2.7 to 5.5V.Each FM31xx provides nonvolatile RAM available insizes including 4Kb, 16Kb, 64Kb, and 256Kb versions. Fast write speed and unlimited endurance allow the memory to serve as extra RAM or conventional nonvolatile storage. This memory is truly nonvolatile rather than battery backed.The real-time clock (RTC) provides time and date information in BCD format. It can be permanently powered from external backup voltage source, either a battery or a capacitor. The timekeeper uses a common external 32.768 kHz crystal and provides a calibration mode that allows software adjustment of timekeeping accuracy.