According to an embodiment, in a display device, pixels have memories respectively. A signal supply circuit includes a mode control circuit, and switches into a first mode or a second mode to supply digital data pieces to sub-pixels. In the first mode, the circuit receives from the outside first video data pieces corresponding to n sub-pixels, and supplies digital data pieces for the n sub-pixels to corresponding memories. In the second mode, the signal supply circuit receives from the outside second video data pieces corresponding to m sub-pixels fewer than n sub-pixels, and supplies digital data pieces for the n sub-pixels to corresponding memories based on the second video data pieces.