Gbps interfaces target automotive appications
PARIS — Not long ago, the mobile industry was the master who led chip vendors around on a leash, commanding them to sit, heel, and roll over. Lately, the leash has been passed on to the automotive industry.
Level 4 and Level 5 autonomous vehicle designers are asking for in-vehicle connectivity at multi-gigabit speed, to which a host of industry alliances and standards bodies — ranging from Networking for Autonomous Vehicles (NAV) Alliance to MIPI and HDBaseT group — are all saying that they are ready to roll over.
Fully automated vehicles are, of course, not here yet. But their heavy reliance on high-resolution sensors including vision, lidars, and radars is destined to vastly expand the volume of data that must pass through vehicles. This prospect compels every industry group that has ever developed high-speed connectivity technologies for data centers, enterprise infrastructure, or professional studios to see golden opportunity in the automotive market.
Last week, MIPI Alliance, a group who started by developing interface specifications for the mobile industry, revealed preparations to address high-speed data interface specs in the automotive industry. It has already initiated development of an MIPI A-PHY specification to meet 12 to 24 gigabits per second (Gbps) of a physical layer up to 15 meters. MIPI A-PHY v1.0 is expected to be available to developers in late 2019.
Just last month, HDBaseT group announced that Denso joined as a “contributor member.”
HDBaseT — originally a consumer electronics and commercial connectivity standard for transmission of uncompressed HD video, audio, power, home networking, Ethernet, USB, and some control signals over a CAT 5 cable — now has an automotive variant called HDBaseT Automotive.
In a recent interview with EE Times, Micha Risling, senior vice president and head of the automotive unit at Valens Semiconductor, said, “HDBaseT can now deliver 2-Gbps bandwidth over unshielded twisted pair — a cheaper, more flexible, and easier to install cable” — while it readies for “future versions enabling 4/8/12/16 Gbps.”
Also, there is NAV, an industry alliance consisting of chip vendors Aquantia, Nvidia and Bosch, Continental, and Volkswagen. The group’s big advantage is said to be that it’s moving in lockstep with IEEE Ethernet group to develop IEEE Multi-Gig Automotive Ethernet PHY. The force behind this movement is Aquantia, a chip vendor that set itself apart from others by pioneering high-speed, multi-gigabit Ethernet technologies now used by data centers (10/25/100 GbE) and enterprise infrastructure (2.5/5/10 GbE).
In an interview with EE Times last week, Amir Bar-Niv, vice president of marketing for automotive products at Aquantia, acknowledged, “There had been a vacuum” in the automotive industry — where no multi-gig automotive Ethernet existed. That, in turn, created an opening for other players to come in and pitch proprietary solutions, he explained. But now that the IEEE Multi-Gig Automotive Ethernet PHY standard is well on its way, “I no longer see a vacuum,” he said.
In Aquantia’s mind, the adoption of the Multi-Gig Automotive Ethernet by OEMs and Tier Ones is almost a forgone conclusion.
After all, with the latest addition of Automotive Multi-Gig Ethernet PHY, the automotive industry is aware that it can take advantage of many existing Ethernet attributes, according to Aquantia. Such blessings include “multiple vendors and low cost” and features such as “switching, synchronous, AVB/TSN, security, and topologies,” said the company.
Are they complementary?
It’s important to note, however, that not all long-reach automotive interfaces are created equal. MIPI’s automotive efforts, for example, differs from HDBaseT, observed Ian Riches, director for the Automotive Electronics service at Strategy Analytics. MIPI A-PHY “is a point-to-point asynchronous link. Huge bandwidth in one direction, limited in the other. It’s a simple data pipe and doesn’t natively support USB, Ethernet, and power like HDBaseT.”
Nonetheless, MIPI will compete with other multi-gig connectivity like Automotive Ethernet “for connecting a high-bandwidth source (e.g., a camera) to a central controller,” said Riches.
Asked to compare these competing connectivity solutions, Riches said: “Ethernet is great if you want a network. HDBaseT allows support for things such as power transmission, USB, etc. MIPI A-PHY is a more direct competitor for proprietary LVDS solutions such as APIX, FPD-Link, GMSL, etc. It’s ideal for simply moving data from one place to another, with a limited back channel for control.”
>> Continue reading page two of this article on our sister site, EE Times: "Robocar data glut unsettles I/F specs."