FM32278 Datasheet, PDF (1/21 Pages) Ramtron International Corporation – 5V Integrated Processor Companion with Memory

FM32278/276/274/272
5V Integrated Processor Companion with Memory
Features
High Integration Device Replaces Multiple Parts
• Serial Nonvolatile Memory
• Low Voltage Reset
• Watchdog Timer
• Early Power-Fail Warning/NMI
• Two 16-bit Event Counters
• Serial Number with Write-lock for Security
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
Ferroelectric Nonvolatile RAM
• 4Kb, 16Kb, 64Kb, and 256Kb versions
• Unlimited Read/Write Endurance
• 45 year Data Retention
• NoDelay™ Writes
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
• Companion Controlled via 2-wire Interface
Easy to Use Configurations
• Operates from 4.0 to 5.5V
• 14-pin “Green”/RoHS SOIC package (-G)
• Pin Compatible with FM3127x Series
• Low Operating Current
• -40°C to +85°C Operation
• Underwriters Laboratory (UL) Recognized
Description
The FM3227x 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, 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 4.0 to 5.5V.
The FM3227x family is software and pinout
compatible with the FM3127x family which also
includes a real-time clock. The common features
allow a system design that easily can be assembled
with or without timekeeping by simply selecting the
FM3127x or FM3227x, respectively.
Each FM3227x 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 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.
A general-purpose comparator compares an external
input pin to the onboard 1.2V reference. This is
useful for generating a power-fail interrupt (NMI) but
can be used for any purpose. The family also includes
a programmable 64-bit serial number that can be
locked making it unalterable.
Additionally the FM3227x offers a dual event
counter that tracks the number of rising or falling
edges detected on dedicated input pins. The counter
can optionally be battery backed and even battery
operated by attaching a backup power source to the
VBAK pin. If VBAK is connected to a battery or
capacitor, then events will be counted even in the
absence of V_DD.
This product conforms to specifications per the terms of the Ramtron
standard warranty. The product has completed Ramtron’s internal
qualification testing and has reached production status.
Rev. 3.0
Feb. 2009
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, [phone]
http://www.ramtron.com
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