DS12887A
FEATURES
- Drop- in replacement for IBM AT puter clock/calendar
- Pin patible with the MC146818B and DS1287A
- 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, days, day of the week, date, month, and year with leap year pensation valid up to 2100
- Binary or BCD representation of time, calendar, and alarm
- 12- or 24- hour clock with AM and PM in 12- hour mode
- Daylight Savings Time option
- Selectable between Motorola and Intel bus timing
- Multiplex bus for pin efficiency
- Interfaced with software as 128 RAM locations
- 14 bytes of clock and control registers
- 114 bytes of general purpose RAM
- Programmable square wave output signal
- Bus- patible 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...
