Inside HDMI CEC: The Little-Known Control Feature

We have covered many attributes of the HDMI interface, including video, power, intelligence and integrity.

But there is still one other line that we have not brought to the table: the CEC line.

Since the activity with this portion of the interface has been somewhat nonexistent, there has not been much of a need to talk about it.

Now, the time has come to look deeper into this portion of the interface, especially since manufacturers are incorporating this feature.

CEC stands for Consumer Electronics Control, a control method developed from the European Scart standard. This has been used for years with great success.

The HDMI CEC system improves upon Scart, allowing different A/V products to work together as total system.

Products that are connected by way of the HDMI interface can interrogate the buss to determine what products are on the line while, at the same time, communicate with them, reducing IR remote functions with fewer key strokes.

Like universal remotes, the system will identify each product when powered up and connect the system with the correct configuration for a true one-button solution.

Based on a one-wire bidirectional system, the CEC line allows all parties (peripherals) to share on this one-wire communication channel.

After Hot Plug detection takes place, all products route their data by way of switching, cables and video conversions to the root of the system -- in this case, the display.

Standards are now in place for manufacturers to incorporate the CEC system.

MORE INFO ON CEC
Panasonic Demos Control over HDMI