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DESCRIPTION
The DS1315 Phantom Time Chip is a
combination of a CMOS timekeeper and a
nonvolatile memory controller. In the absence of
power, an external battery maintains the
timekeeping operation and provides power for a
CMOS static RAM. The watch keeps track of
hundredths of seconds, seconds, minutes, hours,
day, date, month, and year information. The last
day of the month is automatically adjusted for
months with fewer than 31 days, including leap
year correction. The watch operates in one of two
formats: a 12-hour mode with an AM/PM
indicator or a 24-hour mode. The nonvolatile
controller supplies all the necessary support
circuitry to convert a CMOS RAM to a
nonvolatile memory. The DS1315 can be
interfaced with either RAM or ROM without
leaving gaps in memory.
PIN CONFIGURATIONS
Pin Configurations continued at end of data sheet.
FEATURES
Real-Time Clock Keeps Track of Hundredths
of Seconds, Seconds, Minutes, Hours, Days,
Date of the Month, Months, and Years
Automatic Leap Year Correction Valid Up to
2100
No Address Space Required to Communicate
with RTC
Provides Nonvolatile Controller Functions for
Battery Backup of SRAM
Supports Redundant Battery Attachment for
High-Reliability Applications
Full ±10% VCC Operating Range
+3.3V or +5V Operation
Industrial (-40°C to +85°C) Operating
Temperature Ranges Available
PIN DESCRIPTION
X1, X2 - 32.768kHz Crystal Connection
- Write Enable
BAT1 - Battery 1 Input
GND - Ground
D - Data Input
Q - Data Output
ROM/
- ROM/RAM Mode Select
- Chip Enable Output
- Chip Enable Input
- Output Enable
- Reset
BAT2 - Battery 2 Input
VCC0 - Switched Supply Output
VCC1 - Power Supply Input
Phant