Remote 8-Bit I2C And SMBus Low-Power I/O Expander With Interrupt Output, Reset, And Config Registers

The PCA9538 consists of one 8-bit Configuration (input or output selection), Input Port, Output Port, and Polarity Inversion (active high or active low) Registers At power on, the I/Os are configured as inputs. However, the system master 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 master. By Texas Instruments