A method of operating a source driver, a display driving circuit, and a method of operating the display driving circuit are provided. The method of operating the source driver including a receiver, includes determining a parameter value of the receiver for optimizing a receiving of the receiver, through training, and transmitting the parameter value to a timing controller external to the source driver. The method of operating the source driver further includes, based on an abnormal state occurring in the receiving of the receiver, receiving the transmitted parameter value from the timing controller, and optimizing the receiving of the receiver based on the received parameter value.