The MAX7323 2-wire serial-interfaced peripheral features eight I/O ports. Four ports are push-pull outputs and the other four are open-drain I/O ports, independent of supply voltage. The four I/O ports configured as inputs are continuously monitored for state changes (transition detection). State changes are indicated by the open-drain INT output. The interrupt is latched, allowing detection of transient changes. When the MAX7323 is subsequently accessed through the serial interface, any pending interrupt is cleared.