The STMPE801 is a GPIO (General Purpose Input/Output) port expander that can interface with a main digital ASIC via the two-line bidirectional bus (I2C). A separate GPIO Expander IC is often used in Mobile-Multimedia platforms to solve the problems of the limited amounts of GPIOs usually available on the Digital Engine. The STMPE801 offers great flexibility as each I/O is configurable as input or output. This device has been designed with very low quiescent current and includes a wake-up feature for each I/O to optimize the power consumption of the IC.