Synerchip Reveals Aim with New AV Interface 'DIVA'

Jun 9, 2008
Naoki Asakawa, Nikkei Electronics

Synerchip Inc, a fabless chip company, and major Chinese consumer-electronics makers proposed "DIVA" (digital interface for video & audio), a high-speed AV interface standard that vies with the HDMI (See related article).

The executive chairman of Synerchip is David Lee, who, as a former president and CEO of Silicon Image Inc, was deeply involved in establishing the HDMI. After contributing to the diffusion of the HDMI, he set out to develop an AV interface that might come next to the HDMI.

The DIVA's transmission rate of video and audio signals is 13.5Gbps, slightly higher than the HDMI's 10.2Gbps. However, the DIVA is capable of bidirectional transmission at 2.25Gbps at the same time.

"By merging multimedia and data communication over a single interface, the DIVA standard is poised take digital home networking to a new level, fulfilling the promise of making DTV the center of the home entertainment network," Lee said in a press release.

What kind of strategies are they developing to compete with the HDMI, which is holding an established position as an industry standard? We interviewed Steve Yum, senior director of Product Planning, Synerchip. (Interviewer: Naoki Asakawa)

Could you describe the specifications of the DIVA? How are they different from those of the HDMI?

Yum: It has two features. First, a dedicated band is used for bidirectional transmission. The DIVA has a total transmission rate of 18Gbps, which was realized by bundling four twisted-pair wires capable of 4.5Gbps transmission each. Three of the four wires are used for video and audio signals, and one for bidirectional data transmission.

Therefore, the DIVA has a transmission rate of 13.5Gbps for video and audio signals and a rate of 2.25Gbps for each direction of the data transmission. Currently, the HDMI has a transmission rate of only 1Kbps for bidirectional transmission.

Second, it is possible to cut the price of cable. The HDMI has 19 connector pins so that it is partly compatible with the DVI. But the DIVA has only eight connector pins because it transmits data with four twisted-pair wires.

In addition to consolidating the role of traditional connector pins into 2.25Gbps data communication, the DIVA reduced the number of pins by using 8B/10B as a modulation method and omitting the pins for clock. Though we will finalize the specifications of the cable and connector pins from now, we have already confirmed that the DIVA can transmit HDTV videos with a CAT6a Ethernet cable in an experiment.

Why did you add a high-speed bidirectional communication function to the AV interface?

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Why did you add a high-speed bidirectional communication function to the AV interface?

Yum: It is to construct a home network among appliances connected to one another with DIVA cables. In the past, to construct a home network, we had to connect home appliances by using Ethernet cables or wireless LAN in addition to HDMI cables. With the DIVA, all we have to do is to connect appliances with cables.

For example, by using a TV set as a hub and connecting it to an STB, recorder, game console, PC and so forth with DIVA cables, it is possible to enable them to mutually communicate with, send AV data to and operate one another. Also, it will be easier to get connected to the Internet, and DLNA can be used on the DIVA network.

The HDMI is already seen as the industry's de facto standard. What kind of strategies do you have to compete with the HDMI?

Yum: Our aim is not to compete directly against any particular standard. Our aim is to create a new home audio/video networking standard. We are in cooperation with major consumer-electronics makers in China. In digital equipment in China, analog interfaces are still used to transmit HDTV videos. So, the HDMI has not become widely used yet. In addition, China is trying to establish its own specification. So, we aim to have the DIVA selected as China's own specification for a start.

We like to finalize the specification by the end of 2008 and ship transmitter and receiver chip sets in 2009 or 2010. Also, we have a plan to develop a bridge LSI that can interconvert DIVA signals and HDMI signals.

Correction Notice: We changed the title of the article and part of the second-to-last paragraph because they turned out to be misleading.