To reduce power consumption of a display device. A sequence of supply of video signals to a plurality of pixels included in an active matrix display device is controlled. For example, a supply sequence is controlled so that the potentials of the video signals supplied to a plurality of pixels are in ascending order or in descending order. This enables a reduction in the amount of charge and discharge of electric charge of signal lines which supply video signals to a plurality of pixels. Consequently, power consumption of the display device can be reduced.