HDMI Rev. 1.4: Out of the Ether…Ethernet Added

Submitted by DPL Labs Staff on Wed, 09/02/2009 - 19:54

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Regardless of how you feel about it…HDMI™ specification revision 1.4 (Rev. 1.4) is now upon us. And 1.4 adds so much more, with significant new features designed to prepare the industry’s foremost digital signaling solution for the future. Perhaps most intriguing, revision 1.4 arrives with Ethernet capability as one of its main attractions and a prime point of interest for systems integrators and custom installers. We trust this article will answer many questions and help position your company to take maximum advantage of one possible electronic future.

Ethernet History

Originally developed in Xerox’s fabled PARC facility in the mid-‘70s, Ethernet, contrary to popular lore, is not a single method of computer-to-computer communication even though it was defined in 1984 under the IEEE’s 802.3 standard.

Rather, Ethernet has evolved over the years and is now an enormously flexible set of standards that allows LANs (local area networks composed on several – or many – computers) to transmit and share data of all kinds. Today, LANs often incorporate consumer electronics components.

HDMI and Ethernet

HDMI, originally backed by Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson, and Toshiba, came to the consumer electronics market in stages (see the chart at the end of this article for the introduction date and chief features of previous versions). In May, 2009, version 1.4 appeared. Among other features, 1.4 promises full Ethernet capability within a single HDMI cable that formerly carried only content and authentication data.

HDMI 1.4 aims to make LAN connections far less complicated than previously possible. It also seeks to facilitate adaptation of Ethernet so that home entertainment systems and other components of the “whole house” universe can share a common command path and protocol.

Although some advanced Ethernet systems now use Cat 5 cable or glass fiber to reach speeds of 1 Gb/sec and greater, HDMI 1.4 supports only the more conventional – and far more widely used – 10/100 Mb/sec full duplex data speeds, Ethernet’s “data packet” structure, and a “twisted pair” signal path.

Backwards Compatibility

At the outset, you should know that HDMI 1.4 is fully backwards compatible with earlier HDMI versions. Thus a 1.4-enabled component will communicate with a 1.0 – 1.3 system or component. However, specific 1.4 features – including Ethernet, 3D TV, and others – will not be available to the rest of the system.

Cable Questions

Ethernet-via-HDMI demands an Ethernet-ready HDMI cable. Differences between Ethernet-ready and non-Ethernet cables rest in the way HDMI was able to add Ethernet capability without changing the 19-pin connector used for previous HDMI versions.

Although HDMI is reluctant to divulge specifics, differences include a redefined use for the “reserve pin” on the standard HDMI connector as well as some reduced signal levels to enable full duplex signaling on yet another active wire made into a twisted pair.

This will initially add some confusion when choosing a cable. In addition to desired video resolution and consequent bandwidth requirements which are identical to Rev 1.3, a system designer will now need to specify “Ethernet” or “non-Ethernet” varieties. Here are the new choices:

Category 1 (standard) cables with bandwidth of 74.5 MHz rated for 1080i or 720p with and without Ethernet capability
Category 2 (high speed) cables rated at 340 MHz for resolutions up 1600p – again, with and without Ethernet capability.

IC Questions

Aside from the cable itself, are there any other impediments to using 1.4’s Ethernet capabilities? The answer to that is an emphatic “yes!”

HDMI 1.4 requires a new higher speed chip set similar to Sil9334 transmitter in a source component and a Sil9387 port processor in downstream components. Thus, there can be no firmware updates to make earlier HDMI versions 1.4-compliant.

What’s the Significance of Ethernet via HDMI?

The major significance is simpler and less time-consuming system hookups for both installers and consumers. With both media transmission and Ethernet’s IP-based capabilities handled via a single cable, initial system configuration and troubleshooting should be easier.

Although many audio and video components now come with the ubiquitous RJ-45 connector for separate Ethernet cables, HDMI hopes this duplication will gradually disappear and leave even more rear panel real estate for less-crowded system connections.

Content distribution will also be less complex. Games, Blu-ray players, DVRs, etc. can share content in its native format for recording or storage. (Note that HDCP-encrypted content remains protected.)

Conflicts, Anyone?

Is there a need for another way to implement overall system control? After all, we already have the CEC (Consumer Electronics Control) system and the simpler and royalty-free DisplayPort connections favored by the computer industry.

These questions will be answered by the marketplace. However, we point out that, given HDMI’s growth since Version 1.0 appeared in December of 2002, the future seems favorably disposed to welcome 1.4.

When?

We may see 1.4-compliant prototypes at CEDIA’s 2009 Expo in September. However, it seems more likely that they will appear at 2010’s January WCES. Delivery of actual production pieces will depend on the engineering resources manufacturers can bring to bear on the new HDMI version as well as the supply of transmitter and port processor chips Silicon Image and others will deliver.

If everything goes will, we may see production products hitting the market in Q1 to Q2 of 2010.

Read This Fine Print, Please!

Is Ethernet mandated for all HDMI 1.4 products? Absolutely not!

As we’ve already seen with earlier HDMI versions, many of the claimed advantages are left to the manufacturers to implement. So be prepared for some nominally 1.4-compliant products to come to market without Ethernet capability.

HDMI is asking – but not mandating – that Ethernet-capable components identify all Ethernet-capable ports with an HEC logo (HDMI Ethernet Channel). Read the owner’s manual of any component you may be considering. There are also some very specific nomenclature required for cables that must be printed on each compliant Rev 1.4 cable. We may not see that change until September 1, 2009.

Preparing For the Future

If you’re not already familiar with Ethernet capability as it pertains to home entertainment systems, start studying. Finding knowledge sources isn’t hard. (You’re already at one of the best.)

Second, begin to develop “scripts” to present Ethernet benefits to potential customers. A prepared presentation is always a more convincing one.

But for now, put those scripts in a locked desk drawer. It will be quite a few months before Ethernet-ready HDMI 1.4 comes to market. But it is coming.

Be ready!