The MCP23S18-E/MJ is a 16-bit I/O Expander for high speed SPI? compatible interface. The MCP23X18 device provides 16-bit, general purpose parallel I/O expansion for I2C bus or SPI applications. The two devices differ only in the serial interface. The MCP23X18 consists of multiple 8-bit configuration registers for input, output and polarity selection. The system master can enable the I/Os as either inputs or outputs by writing the I/O configuration bits. The data for each input or output is kept in the corresponding input or output 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. The 16-bit I/O port functionally consists of two 8-bit ports (PORTA and PORTB).
Low standby current as low as 1μA
High-speed I2C? interface up to 3.4MHz
Single hardware address pin, voltage input to allow up to eight devices on the bus
Configurable interrupt output pins - Configurable as active-high, active-low or open-drain
