Drop-In Replacement for IBM AT Computer
Clock/Calendar
♦
RTC Counts Seconds, Minutes, Hours, Day, Date,
Month, and Year with Leap Year Compensation
Through 2099
♦
Binary or BCD Time Representation
♦
12-Hour or 24-Hour Clock with AM and PM in
12-Hour Mode
♦
Daylight Saving Time Option
♦
Selectable Intel or Motorola Bus Timing
♦
Interfaced with Software as 128 RAM Locations
♦
14 Bytes of Clock and Control Registers
♦
114 Bytes of General-Purpose, Battery-Backed
RAM (113 Bytes in the DS12C887 and
DS12C887A)
♦
RAM Clear Function (DS12885, DS12887A, and
DS12C887A)
♦
Interrupt Output with Three Independently
Maskable Interrupt Flags
♦
Time-of-Day Alarm Once Per Second to Once
Per Day
♦
Periodic Rates from 122μs to 500ms
♦
End-of-Clock Update Cycle Flag
♦
Programmable Square-Wave Output
♦
Automatic Power-Fail Detect and Switch Circuitry
♦
Optional 28-Pin PLCC Surface Mount Package or
32-Pin TQFP (DS12885)
♦
Optional Encapsulated DIP (EDIP) Package with
Integrated Crystal and Battery (DS12887,
DS12887A, DS12C887, DS12C887A)
♦
Optional Industrial Temperature Range Available
♦
Underwriters Laboratory (UL) Recognized
DS12885/DS12887/DS12887A/DS12C887/DS12C887A
Real-Time Clock
______________________________________________
Maxim Integrated Products
1
DS12885
DS83C520
R/W
AS
GND
X2
X1
V
CC
V
CC
CRYSTAL
DS
V
BAT
AD(0–7)
SQW
RESET
IRQ
RCLR
CS
MOT
Typical Operating Circuit
Rev 3; 2/07
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or
visit Maxim’s website at www.maxim-ic.com.
Pin Configurations and Ordering Information appear at end of data sheet.
