DS1387 EDIP-24

RAMified Real Time Clock 4K x 8

FEATURES
• Upgraded IBM AT computer clock/calendar with
4K x 8 extended RAM
• Totally nonvolatile with over 10 years of operation in
the absence of power
• Counts seconds, minutes, hours, day of the week,
date, month and year with leap year compensation
• Binary or BCD representations of time, calendar and
alarm
• 12– or 24–hour clock with AM and PM in 12–hour
mode
• Daylight Savings Time option
• Multiplex bus for pin efficiency
• Interfaced with software as 64 user RAM locations
plus 4K x 8 of static RAM
– 14–bytes of clock and control registers
– 50–bytes of general purpose RAM
– 4K x 8 SRAM accessible by using separate control pins
• 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 122 µs to 500 ms
– End–of–clock update cycle
• Available as chip (DS1385 or DS1385S) or stand
alone module with embedded lithium battery and
crystal (DS1387)