This 16-bit I/O expander for the two-line bidirectional bus (I2C) is designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL ...

The MCP23S18 is device that provides 16-bit, general purpose parallel I/O expansion for SPI applications. It contains multiple 8-bit configuration registers for input, output and polarity selection.