A technology for transmitting a training signal with a pattern that enables high-speed data transmission in a training process performed before transmission of video data is disclosed. A method of receiving data in a display driving device according to one of the various embodiments of the present disclosure can include receiving a first training signal transmitted from a display processing device; generating a clock signal based on the first training signal; confirming a second training signal transmitted from the display processing device based on the generated clock signal; and confirming data transmitted from the display processing device based on the second training signal.