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 8K x 8 of static RAM

   – 14 bytes of clock and control registers

   – 50 bytes of general and control registers

   – Separate 8K 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 (DS1495/DS1495S) or stand alone module with embedded lithium battery and crystal (DS1497)