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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