M48T86_07 Datasheet, PDF (1/36 Pages) STMicroelectronics – 5.0 V PC real-time clock

Features
■ Drop-in replacement for PC computer
clock/calendar
■ Counts seconds, minutes, hours, days, day of
the week, date, month, and year with leap year
compensation
■ Clock accuracy better than ±1 minute per
month
■ Interfaced with software as 128 RAM locations:
– 14 bytes of clock and control registers
– 114 bytes of general purpose RAM
■ Selectable bus timing (Intel/Motorola)
■ Three interrupts are separately software-
maskable and testable
– Time-of-day alarm (once/second to
once/day)
– Periodic rates from 122µs to 500ms
– End-of-clock update cycle
■ Programmable square wave output
■ 10 years of data retention and clock operation
in the absence of power
■ Self-contained battery and crystal in the caphat
dip package
■ Packaging includes a 28-lead SOIC and
Snaphat^® top (to be ordered separately)
■ SOIC package provides direct connection for a
snaphat top contains the battery and crystal
■ Pin and function compatible with bq3285/7A
and DS12887
M48T86
5.0 V PC real-time clock
24
1
PCDIP24 (PC)
Battery/Crystal
CAPHAT
SNAPHAT (SH)
Battery/Crystal
28
1
SOH28 (MH)
February 2007
Rev 5
1/36
www.st.com
1