Description
The FM31xxx is a family of integrated devices that includes the most commonly needed functions for processor-based systems. Major features include nonvolatile memory available in various sizes, realtime clock, low-VDD reset, watchdog timer, nonvolatile event counter, lockable 64-bit serial number area, and general purpose comparator that can be used for an early power-fail (NMI) interrupt or other purpose. The family operates from 2.7 to 5.5V.

FEATUREs
High Integration Device Replaces Multiple Parts
•  Serial Nonvolatile Memory
•  Real-time Clock (RTC)
•  Low Voltage Reset
•  Watchdog Timer
•  Early Power-Fail Warning/NMI
•  Two 16-bit Event Counters
•  Serial Number with Write-lock for Security

Ferroelectric Nonvolatile RAM
•  4Kb, 16Kb, 64Kb, and 256Kb versions
•  Unlimited Read/Write Endurance
•  10 year Data Retention
•  NoDelayô Writes

Real-time Clock/Calendar
•  Backup Current under 1 µA
•  Seconds through Centuries in BCD format
•  Tracks Leap Years through 2099
•  Uses Standard 32.768 kHz Crystal (6pF)
•  Software Calibration
•  Supports Battery or Capacitor Backup

Processor Companion
•  Active-low Reset Output for VDDand Watchdog
•  Programmable VDDReset Trip Point
•  Manual Reset Filtered and De-bounced
•  Programmable Watchdog Timer
•  Dual Battery-backed Event Counter Tracks System Intrusions or other Events
•  Comparator for Early Power-Fail Interrupt
•  64-bit Programmable Serial Number with Lock

Fast Two-wire Serial Interface
•  Up to 1 MHz Maximum Bus Frequency
•  Supports Legacy Timing for 100 kHz & 400 kHz
•  Device Select Pins for up to 4 Memory Devices
•  RTC, Supervisor Controlled via 2-wire Interface

Easy to Use Configurations
•  Operates from 2.7 to 5.5V
•  Small Footprint 14-pin SOIC
•  Low Operating Current
•  -40°C to +85°C Operation