The MAX7306/MAX7307 ports P2, P3, and P4 can be configured as inputs, push-pull outputs, and open-drain outputs. Port P1 can be configured as a general-purpose input, open-drain output, or an open-drain INT output. Ports P2 and P3 can be configured as OSCIN and OSCOUT, respectively. The MAX7306/MAX7307 include an internal oscillator for PWM, blink, and key debounce, or to cascade multiple MAX7306/MAX7307s. The external clock can be used to set a specific PWM and blink timing. The RST input asynchronously clears the 2-wire interface and terminates a bus lockup involving the MAX7306/MAX7307.