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
