Peripheral functions of an integrated circuit device may be pooled and dynamically mapped to available external input-output connections of the integrated circuit device by using a set of configuration registers. To provide system robustness, the configuration registers may implement various levels of write protection, error correction and monitoring circuitry. One or more peripheral output functions may be mapped to one or more external output connections. Not more than one output function may be active at the same time on the same output connection. Outputs and inputs may be mapped to the same external input-output connection with or without the output being controllable for placement into an inactive state, e.g., high impedance or open collector. When the input is required to receive external data over the external input-output connection, the output may be placed into the inactive state.