The DS1302time measurement chip with charge retention function contains a real-time clock/calendar and a real-time 31 bytes static RAM. He communicates with a micro-processor via a simple serial interface. The real-time clock/calendar provides details of the real-time to seconds, minutes, hours, day, date, month and year. In months with less than 31 days, the automatic change of date at the end of the month, and leap years are taken into account. The watch can either be used in 24-hour format or the 12 hour format with AM/PM display.This text is machine translated.