UPD4991A Description
DATA SHEET MOS INTEGRATED CIRCUIT µPD4991A 4-BIT PARALLEL I/O CALENDAR CLOCK The µPD4991A is a CMOS integrated circuit that has the ability to input/output 4-bit parallel time data and calendar data to/from a microputer and includes an alarm function. Its reference oscillation frequency is 32.768 kHz. Hour, minute, second, year, month, day, and date data is stored internally.
UPD4991A Key Features
- Time (hour, minute, and second) and calendar (leap year, year, month, day, and date) counters
- Leap year can be automatically identified or set
- 12- and 24-hour modes selectable
- 4-bit parallel input/output in BCD data format
- Alarm function (hour, minute, second, month, day, date)
- One of 0.1, 1.0, 10, 30, and 60-s interval timer outputs selectable
- One of 2048, 1024, 64, 16, 1 Hz, 1-pulse output, and H→L output selectable as alarm coincidence output
- Upward patible with µPD4991
- Low power consumption: 2 µA typ. (VDD = 2.4 V)