1 Waking Up an HDMI Sink Device

HDMI is a de facto interface standard in consumer electronics and the most successful and easiest video and audio connector in the industry. Most digital TVs, monitors, and video display equipment have one or more HDMI ports. Video source equipment such as set-top boxes, gaming consoles, Blu-ray Disk™ players, notebooks, and mobile video sources support HDMI as well. HDMI supports a supplemental specification, Consumer Electronics Control (CEC), to control the HDMI source and sink in HDMI-connected equipment. CEC provides the same ‘language’ between the HDMI equipment allowing users to easily control them. Figure 1-1 shows the high-level HDMI1.4/2.0 interconnection, including a CEC line.

CEC is one of the 19 HDMI connector pins and CEC has a electrical and protocol specification. A number of different messages and operation code (opcode) are used for the best user experience so that users can use only one remote controller to control both HDMI source and HDMI sink devices. For instance, if an HDMI source and sink are in standby mode and the user wants to wake up both of them, the following power-on function code can be used to switch on the HDMI devices by pressing the power button on the remote controller. This can wake up both the HDMI source and sink devices. More advanced user-controlled CEC messages are available, refer to the CEC specification in HDMI 2.0, or older version specifications.