DescriptionAll addresses and data are transferred serially via a two-line bidirectional I²C-bus. Maximum bus speed is 400 kbit/s. The register address is incremented automatically after each written or read data byte.Real Time Clock Module (RTC) PCF8563 FeaturesProvides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystalCentury flagClock operating voltage: