A device for communications over a multimedia communication interface. The device can be a source device including a scrambling circuit that receives control data associated with multimedia data to be transmitted over the multimedia channel of the multimedia communication interface, and generates scrambled control codes based on the control data. An encoding circuit generates transition minimized control codes based on the scrambled control codes. The device transmits the transition minimized control codes to a sink device via the multimedia channel. The sink device may also decode and de-scramble the transition minimized control codes received from the source device via the multimedia channel.