DS12885/DS12885Q/DS12885T
Real-Time Clock
www.maxim-ic.com
www.maxim-ic.com
FEATURES
§ Drop-in replacement for IBM AT computer
clock/calendar
PIN ASSIGNMENT (Top View)
§ Pin configuration closely matches
MC146818B and DS1285
§ Counts seconds, minutes, hours, days, day of
the week, date, month, and year with leap-
year compensation valid up to 2100
§ Binary or BCD representation of time,
calendar, and alarm
§ 12-hour or 24-hour clock with AM and PM in
12-hour mode
§ Daylight Savings Time option
§ Selectable between Motorola and Intel bus
timing
§ Multiplex bus for pin efficiency
§ Interfaced with software as 128 RAM
locations
DS12885Q
28 PLCC
§ 14 bytes of clock and control registers
§ 114 bytes of general purpose RAM
§ Programmable square-wave output signal
bus-compatible interrupt signals (IRQ )
§ Three interrupts are separately software-
maskable and testable
§ Time-of-day alarm once/second to once/day
§ Periodic rates from 122ms to 500ms
§ End-of-clock update cycle
§ Optional 28-pin PLCC surface mount package
or 32-pin TQFP
DS12885T
32 TQFP
§ Optional industrial temperature range
available
§ Underwriters Laboratory (UL) recognized
Package Dimension Information
http://www.maxim-ic.com/TechSupport/DallasPackInfo.htm
Note:Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here: http://www.maxim-ic.com/errata.
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