The PCF85363A is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption and with automatic switching to battery on main power loss. The RTC can also be configured as a stop-watch (elapsed time counter). Three time log registers triggered from battery switch-over as well as input driven events. Featuring clock output and two independent interrupt signals, two alarms, I²C interface and quartz crystal calibration, 64 byte battery backed-up RAM.