SOURCE: Epson Toyocom Corp.

November 25, 2008 08:30 ET

Epson Toyocom's U.S.-Based Timing Products Division Develops Real-Time Clock Module With Time-Stamp Function

EL SEGUNDO, CA--(Marketwire - November 25, 2008) - Epson Toyocom Corporation's U.S.-based Timing Products Division today announced the development of the RX-5412SF, a real-time clock module equipped with a time-stamp function for recording and storing the times and dates of abnormal events such as system errors and warning signals. Commercial development is scheduled for the first half of 2009.

The time-stamp function built into the RX-5412SF detects and records signals generated when an error or emergency event occurs. Time-stamping improves system reliability and can be applied in a wide range of fields, from quality control to security. The demand for time-stamping has been accelerating in recent years, driven by, among other things, an intensified interest in security technologies in response to the spread of a diverse range of computer crimes, and by public concern about the safety and traceability of food supplies.

Time-stamping generally is provided by microprocessor systems. However, with CPU resources limited, the task of developing complex software that is also reliable has been a major burden. To alleviate this burden, Epson Toyocom developed the RX-5412SF real-time clock module so that time-stamping can easily be incorporated into a system. In addition to giving customers added freedom in the use of CPU resources and reducing time and effort spent in software development, the RX-5412SF will help save costs and improve system reliability.

The RX-5412SF has four input pins and can record the date and time along with identifying information for each pin. This RTC module is also loaded with a host of other features, including general-purpose memory, a 256-byte SRAM chip that can be used as a time-stamp memory, a watchdog timer(1), a general-purpose timer and power switching.

Despite this abundance of features, the module has a low-power design and consumes only 0.5 µA of current. A backup battery enables timekeeping and time-stamping to continue even if a system goes down on a weekend, at night, or during a power failure. The RX-5412SF will thus offer enhanced reliability while simultaneously allowing downsizing of batteries.

Main specifications
Item                          Specification
Supply voltage                2.5 V to 5.5 V
Clock voltage                 1.4 V to 5.5 V
Standby current consumption   0.5 µA (Typ.) / 3 V
Frequency precision           5+/-23 x 10-6
Interface                     4-wire serial
External dimensions           10.2 x 5.4 x 2.0t mm (24-pin SSOP)

Main Features

--  Full calendar and clock functions with automatic leap year correction
--  Built-in 32.768 kHz crystal unit eliminates the need for clock accuracy
--  Alarms settable for dates, days of the week, hours and minutes
--  A fixed-cycle timer that can be set for any time between 244.14
    micro-seconds and 4095 minutes
--  Power switching function for automatically switching to a backup power
    source when the voltage of the main power supply drops
--  Built-in general-purpose memory and 256-bytes of RAM that can be used
    for time-stamp memory
--  Capable of 4-input event detection with adjustable chattering-free(2)
    sensitivity, and able to output interrupt signals during input
--  Watchdog timer settable from 1.95 ms to 468.75 ms


(1) Watchdog timer

A function that monitors whether a system is operating normally. A watchdog timer uses a regular signal that is sometimes called a "watchdog operation" to determine whether a system is hung up, and can then reset the system and restore normal operations if the system is in an abnormal state.

(2) Chattering-free

The operation of a push-button switch generates a phenomenon called "chattering." Chattering is caused by electrical signals being generated many times by repeated electrical contact within a very short period of time when a switch is turned on or off. An operation to generate one signal ends up generating multiple signals, causing errors when directly connected to an electric circuit. The chattering-free input circuit deals with this phenomenon by using a filter circuit designed to eliminate short signals under a certain duration contained within the input of a switch signal.

About Epson Toyocom Corporation

Epson Toyocom Corporation (Epson Toyocom) is the global leader in quartz devices. Epson Toyocom maintains its leadership position through technological innovation and expertise in three critical device categories -- timing, sensing, and optical devices; and through the development of combinations of products in each of these segments. The company and its more than 12,000 employees market its products to customers worldwide through sales and marketing affiliates around the world including Epson Electronics America, Inc. in El Segundo, California.

About Epson Electronics America, Inc.

The Timing Products Business Unit of Epson Electronics America, Inc. (EEA) is the North American sales, marketing, and engineering arm of Epson Toyocom Corporation (Epson Toyocom) and provides a wide array of crystals, oscillators, real-time clock modules, SAW products, optical devices and gyro sensors. Based in El Segundo, California, the EEA group has more than 40 sales representative offices nationwide and a growing network of exclusive distributors. For more information, please visit and click on the Epson Toyocom center box. Both Epson Toyocom and EEA are part of the Seiko Epson Group, which consists of 109 companies around the world.

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