Discussed is a timing controller. The timing controller includes a receiver, a converter, an aligner, and an EPI transmitter. The receiver receives input RGB data from an external system. The converter converts the input RGB data into input WRGB data. The aligner converts one of W, R, G, and B data, composing the input WRGB data, into 0 to generate conversion WRGB data having bits less than the total number of bits composing the W, R, G, and B data. The EPI transmitter generates WRGB data by adding dummy bits to the conversion WRGB data, and outputs the WRGB data to a source driver IC.