According to one embodiment, a system for controlling an in-vehicle device is provided. The system has an in-vehicle device and an electronic control unit. The electronic control unit generates control signals to control the in-vehicle device and transmits the generated control signals to the in-vehicle device. The in-vehicle device has a semiconductor integrated circuit and a semiconductor memory circuit. The semiconductor integrated circuit is capable of performing a plurality of functional operations. The semiconductor memory circuit stores pieces of setting information necessary to perform the respective functional operations. The electronic control unit has a designation signal generation unit to output designation signals as the control signals. Each of the designation signals designates one of the pieces of setting information to be read from the semiconductor memory circuit. The semiconductor integrated circuit receives the designated one of the pieces of setting information which is read from the semiconductor memory circuit.