An integrated circuit includes a clock control circuit coupled to a reference clock signal node and a plurality of circuits including a voltage regulator, a digital circuit, and an analog circuit. The voltage regulator, in operation, supplies a regulated voltage. The clock control circuit, in operation, generates a system clock. Input/output interface circuitry is coupled to the plurality of circuits and a common input/output node. The input/output interface circuitry, in operation, selectively couples one of the plurality of circuits to the common input/output node.