The NXP PCF8593 is a CMOS1 clock and calendar circuit, optimized for low power consumption. Addresses and data are transferred serially via the two line bidirectional I2C bus. The built in word address register is incremented automatically after each written or read data byte. The built in 32.768 kHz oscillator circuit and the first 8 bytes of the RAM are used for the clock, calendar, and counter functions.

Space saving SO8 package
Slave addresses: A3h for reading, A2h for writing