The MAX7314 I2CTM-compatible serial interfaced peripheral provides microprocessors with 16 I/O ports plus one output-only port and one input-only port. Each I/O port can be individually configured as either an open-drain current-sinking output rated at 50mA and 5.5V, or a logic input with transition detection. The output-only port can be assigned as an interrupt output for transition detection. The outputs are capable of driving LEDs, or providing logic outputs with external resistive pullup up to 5.5V.