NXP PCA9537DPZ

PCA9537DPZ is a 4-bit I²C-bus and SMBus low power I/O port with interrupt and reset. It provides 4bits of general purpose parallel input/output (GPIO) expansion with interrupt and reset for I²C-bus/SMBus applications. It was developed to enhance the NXP Semiconductors family of I²C-bus I/O expanders. I/O expanders provide a simple solution when additional I/O is needed for ACPI power switches, sensors, push-buttons, LEDs, fans, etc. It consists of a 4bit Configuration register (input or output selection), 4bit input port register, 4bit output port register and a 4bit polarity inversion register (active HIGH or active LOW operation). The system controller can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding input port or output port register. The polarity of the input port register can be inverted with the polarity inversion register. All registers can be read by the system controller.