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Aug. 1998
Serial RTC with Alarm and Timer
RTC
-
4573
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Built-in frequency adjusted 32.768KHz crystal oscillator
·
Serial interface that can be controlled through three signal lines
·
Week , Day , hour , and minute alarm interrupt functions
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Interval timer interrupt function that can be set with an interval ranging from 1/4096th of a second to 255minutes
·
Dual dedicated interrupt outputs for software maskable alarms and for timers
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Functions that detect halting of crystal oscillation, and when the time is being updated
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Automatic leap year compensation function
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Wide interface voltage range, from 1.6 to 5.5V
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Wide timing voltage range, from 1.6 to 5.5V
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Low current consumption : 0.5
m
A/3V (typ.)
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Small SOP package suited for high-density mounting
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Overview
This module is a serial interface-type real-time clock with a crystal oscillator on chip. This module includes clock
and calendar circuitry (from seconds to years) with automatic leap year compensation, alarms, and timer interrupt
functions, as well as functions that detect when oscillation is halted, the time is being updated. The serial
interface permits control through three signal lines, keeping the number of ports required on the system side to a
minimum. Because the small SOP package can be used in high-density mounting, this module is ideal for
portable telephones, hand-held terminals, and other compact electronic equipment.
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Block Diagram
INTERRUPTS
CONTROLLER
ALARM
REGISTER
OSC
/ TIRQ
BUS
INTERFACE
CIRCUIT
SHIFT REGISTER
DATA
CLK
C E0
32.768KHz
CONTROL
REGISTER
DIVIDER
CLOCK and
CALENDAR
CONTROL LINE
/ AIRQ
C E1
OUTPUT
CONTROLLER
FOUT
TIMER
REGISTER
