Digital-multimedia interface grows up
By Brian Dipert -- EDN, January 22, 2004
Please note: This piece has been updated from its print counterpart.
The January 2003 CES (Consumer Electronics Show) in Las Vegas marked the debut of HDMI (High Definition Multimedia Interface), the CE-tuned, high-resolution, multichannel, audio-inclusive version of DVI-HDCP (Digital Video Interface-High Bandwidth Digital Content Protection). HDMI dictates different cabling and connectors from those that DVI uses, and HDMI can also carry both RGB and component video. DVI (and HDMI) semiconductor pioneer Silicon Image's earlier PanelLink A/V proof-of-concept prototypes modulated the audio bit stream on the pixel clock. In contrast, HDMI squeezes the audio data into the video signals' blanking intervals in an approach reminiscent of competitors' proposals (see "A/V integration in a wire, no 'fire' required," EDN, Feb 1, 2001, pg. 20). HDMI channels can transport either uncompressed PCM audio or, via the IEC61937 standard, compressed audio in Dolby Digital, DTS, and other formats. Version 1.0 of the HDMI specification had been published one month earlier, in December 2002, and Silicon Image unveiled first-generation, single-port SiI 9190 transmitter and SiI 9993 receiver chips at the 2003 conference.
At this month's 2004 CES, Silicon Image released second-generation chips, and HDMI expanded its silicon-supplier base. Silicon Image's HDMI product triumvirate, which the company is branding as PanelLink Cinema, comprises the $11.40 (10,000) SiI 9030 transmitter and the $10.70 SiI 9021 and $14.10 SiI 9031 dual-port receivers. The SiI 9030 builds on its SiI 9190 predecessor by transmitting as many as 7.1 channels of surround-sound audio at a 96-kHz sampling rate or dual-channel audio at 192 kHz, by supporting resolutions as high as 1280×1024-pixel, progressive-scan SXGA and by offering an additional I2C Master port to implement the DDC bus. The SiI 9021 receiver targets use in displays, whereas the SiI 9031 with its HDMI-repeater capability aims at audio/video gear. Both HDMI receivers match the SiI 9030 in audio- and video-resolution capabilities, and the company schedules all three chips to be available in sample quantities by the end of this quarter.
When an industry standard reaches critical mass and momentum, large consumer-electronics companies invariably turn to their semiconductor subsidiaries to develop chips for the sibling systems divisions. Such seems to be the case with Toshiba, which is unveiling its own HDMI $13.50 (10,000) TC90701FG transmitter and $15 TC90700FG dual-port receiver; a package- and pinout-compatible, single-port variant of the receiver is also available. The company is now shipping both chips in sample quantities and schedules them for volume production in the second quarter. It'll be interesting to see how successful Toshiba is in selling its chips to potential system competitors. (See Picture.)
Silicon Image, 1-408-616-4000, www.siliconimage.com.
Toshiba, 1-949-455-2000, http://chips.toshiba.com.
