The RX4111CEA3 is a real-time clock module featuring an SPI-bus 4-wire interface with integrated frequency-adjusted 32.768 kHz crystal oscillator and automatic power switching function. It operates over a temperature range of -40°C to +105°C with an operating supply voltage of 1.6 V to 5.5 V, consuming only 100 nA typical backup current at 3 V. The module provides comprehensive timekeeping capabilities including 8-time stamp function (from year to 1/256 seconds), alarm interruption programmable from year to second, and wakeup timer function selectable from 244 µs to 32 years. Additional features include clock output frequency selection (32.768 kHz, 1024 Hz, or 1 Hz), auto-repeat wakeup timer with watchdog capability, and self-monitoring interruption detection for crystal oscillation stop, VBAT low, and VDD low conditions. The compact 3.2 × 2.5 mm package with 1.0 mm maximum thickness makes it ideal for portable devices, IoT applications, and systems requiring precise timekeeping with minimal power consumption and battery backup capability.