An integrated circuit module has a common function known good integrated circuit die with selectable functions. The selectable functions are selected during packaging of the known good integrated circuit die. The known good integrated circuit die is mounted to a second level substrate. The second level substrate has wiring connections to the input/output pads of the known good integrated circuit die that select desired input functions and output functions. Further, the wiring connections on the second level substrate provide signal paths to transfer signals to the desired input function and signals from the desired output function, and signals to and from the common functions. Also, the wiring connections form connections between the input/output pads and external circuitry. To select the desired input functions and the desired output functions, appropriate logic states are applied to input/output pads connected to a function selector to configure a functional operation of the integrated circuit module. The second level module substrate has connector pins to provide physical and electrical connections between the external circuitry and the wiring connections on the second level substrate.