To provide an active matrix display device in which power consumption of a signal line driver circuit can be suppressed, so that power consumption of the entire memory can be suppressed. A plurality of memory circuits which can write data of a video signal input to a pixel in one line period and can hold the data are provided in a signal line driver circuit of a display device. Then, the data held in each memory circuit is input to a pixel of a corresponding line as a video signal. By providing two or more memory circuits in a driver circuit, pieces of data of video signals corresponding to two or more line periods can be concurrently held in the memory circuits.