FEATURES

•Ideal for EISA bus PCs

•Functionally compatible with MC146818 in 32 KHz mode

•Totally nonvolatile with over 10 years of operation in the absence of power

•Self-contained subsystem includes lithium, quartz, and support circuitry

•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

•Interfaced with software as 64 register/RAM locations

plus 4K x 8 of static RAM

– 14 bytes of clock and control registers

– 50 bytes of general and control registers

– Separate 4K x 8 nonvolatile SRAM

•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

•28-pin JEDEC footprint

•Available as chip (DS1395/DS1395S) or stand alone module with embedded lithium battery and crystal (DS1397)