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The DS1388 I C real-time clock (RTC), supervisor, and
EEPROM is a multifunction device that provides a
clock/calendar, programmable watchdog timer, power-
supply monitor with reset, and 512 bytes of EEPROM.
The clock provides hundredths of seconds, seconds,
minutes, and hours, and operates in 24-hour or 12-hour
format with an AM/PM indicator. The calendar provides
day, date, month, and year information. The date at the
end of the month is automatically adjusted for months
with fewer than 31 days, including corrections for leap
year. A watchdog timer provides a reset for an unre-
sponsive microprocessor. It is programmable in 10ms
intervals from 0.01 to 99.99 seconds. A temperature-
compensated voltage reference and comparator circuit
. If a primary power failure is
monitors the status of V
CC
detected, the device automatically switches to the
backup supply and drives the reset output to the active
state. The backup supply maintains time and date
operation in the absence of V . When V returns to
CC CC
nominal levels, the reset is held low for a period to allow
the power supply and processor to stabilize. The
device also has a pushbutton reset controller, which
debounces a reset input signal. The device is
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accessed through an I C serial interface.
Applications
Portable Instruments
Point-of-Sale Equipment
Network Interface Cards
Wireless Equipment