Pre-Production
FM31256/FM3164
FM3116/FM3104
Integrated Processor Companion with Memory
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
Virtually Unlimited Read/Write Endurance
38 year Data Retention (+75C)
NoDelay™ Writes
Real-time Clock/Calendar
Backup Current 1.4
A
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 V
DD
and Watchdog
Programmable V
DD
Reset Trip Point
Manual Reset Filtered and Debounced
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 “Green” SOIC (-G)
Low Operating Current
-40C to +85C Operation
Description
The FM31xx 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, real-
time 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.
Each FM31xx provides nonvolatile RAM available in
sizes 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
This is a product in the pre-production phase of development. Device
characterization is complete and Ramtron does not expect to change
the specifications. Ramtron will issue a Product Change Notice if any
specification changes are made.
Rev. 2.1
Sept. 2011
calibration mode that allows software adjustment of
timekeeping accuracy.
The processor companion includes commonly needed
CPU support functions. Supervisory functions
include a reset output signal controlled by either a
low VDD condition or a watchdog timeout. /RST
goes active when VDD drops below a programmable
threshold and remains active for 100 ms after VDD
rises above the trip point. A programmable watchdog
timer runs from 100 ms to 3 seconds. The watchdog
timer is optional, but if enabled it will assert the reset
signal for 100 ms if not restarted by the host before
the timeout. A flag-bit indicates the source of the
reset.
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, (719) 481-7000
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RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
