The DS1553 is a full-function, year-2000-compliant (Y2KC) real-time clock/calendar (RTC) with an RTC alarm, watchdog timer, power-on reset, battery
monitor, and "8k x 8 nonvolatile static RAM (NV SRAM)." User access to all registers within the DS1553 is accomplished with a bytewide interface as shown in
Figure 1. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour BCD format. Corrections for day of month and
leap year are made automatically.