To increase the light detection accuracy, a method for driving an input-output device that includes a first light unit, a second light unit, a display circuit, and Y light detection circuits (Y is a natural number of 2 or more) is proposed. The same light-detection control signal is input to the Y light detection circuits. In a frame period set by a display selection signal, the first light unit is lit by sequentially switching Z light-emitting diodes and emitting light, and the second light unit is lit by making the white light-emitting diode emit light when the first light unit is not lit. In a period when the second light unit is lit, Y pieces of data corresponding to the illuminance of light entering the Y light detection circuits are generated.