RTC IC with 400 kHz I2C interface in bare die package.

The PCF8564A is a CMOS real-time clock and calendar optimized for low power consumption. A programmable clock output, interrupt output and voltage low detector are also provided. All addresses and data are transferred serially via a two-line bidirectional I²C-bus. Maximum bus speed is 400 kbit/s. The built-in word address register is incremented automatically after each written or read data byte.