EiED Online>> Board And Bus Show: Take 2

Jan. 31, 2005
The Bus and Board Show was only two days long, but there was more going on than could be covered in a single issue of EIED Online. Take a look at this wrap up of the latest VME and AdvancedTCA advancements.

The Bus and Board show is finally over, and I have had a chance to look over my notes and download the photos from my camera. First down was a photo of Ray Alderman (Fig. 1). Ray runs the show and is looking to put on another with a military bent-Military Embedded Electronic and Computing Conference (MEECC). Check out the Bus and Board show for conference proceedings and presentations.

Keeping Cool In Long Beach It was cool to be cool at the show. Although no one was selling a water-based cooling solution, there were a host of demonstrations presenting different techniques to handle the 200-W limit for AdvancedTCA (ATCA). That is 2.4 kW for a full rack with a dozen boards not counting the switches. At this point 200 W is the limit, but designers want more. These new approaches may handle up to 1000 W per board. Things keep going in cycles. Water cooling was big many years ago on mainframes.

Schroff/Pentair was showing the more conventional piped cooling system that hits the hot spots (Fig. 2 and Fig. 3). A production version will be a lot cleaner, but this version shows how to go with the flow. Very low drip connectors are already available, so it's just a matter of reserving space on the backplane for the liquid source and sink.

Radstone and Parker Hannifin had a demo that showed a variety of approaches, including a spray cooling system (Fig. 4). This requires significant changes to the board because it must now be sealed. But there are advantages, including a simpler system implementation. Radstone and Parker Hannifin also announced the HRU-1000 Heat Rejection Unit, a liquid-cooled system for air transport rack (ATR) designs (Fig. 5).

VME Standards 2eSST has come to fruition. A significant number of boards and backplanes are employing the 320-Mbyte/s parallel bus standard. The big discussion this time around, though, was between VITA 41 and VITA 46. VITA 41 retains the parallel VME bus while adding a switch fabric to the mix. Additional standards for InfiniBand (41.1), Serial Rapid IO (41.2), Gigabit Ethernet (41.3), and PCI Express (41.4) exist. Dave French of SBS gave a presentation on VXS/VITA 4.1.

Dave Compston from Radstone provided a counterpoint for VITA 46 in his presentation. It looks like both are going to be around for awhile, although VITA 46 boards will not be showing up until the end of the year or early next year. The majority of developers seem to fit into one camp or the other depending upon the performance requirements. Not surprising considering how VITA 46's new form factor was designed to fit existing customer requirements. The architecture will be useful in high-bandwidth applications like software-defined radio and radar. Hybrid backplanes were shown that combine VME64 support with VITA 46 boards.

John Wemekamp, CTO of Curtiss-Wright, presented the VITA 46 workshop that addressed the "Why, What, and Where" of VITA 46. The new standard utilizes a Tyco connector with seven rows of 16 wafer blocks to provide differential pairs for the switch fabric and application I/O. There are 128 pairs available for application use. They are distributed across the switch fabric connectors. There is even support for optical connections. This is definitely a high-end platform.

Keep It Simple Maintenance in a military environment is critical. Much of the current electronic support employs a three-level maintenance approach where systems are removed in the field and sent to an intermediate shop where the bad board is identified and replaced. The board is then sent back for repair.

Jim Robles, Senior Technology Fellow at Boeing, presented the session "Two Level Maintenance versus the Use of COTS Assemblies: An Implementation Issue for Modern Fighters, Helicopters and Ground Vehicles." It was definitely enlightening.

Switching to a two-level maintenance schedule can cut costs by 50% through elimination of the intermediate level and reducing the cost and complexity of backup systems. It requires a system to identify the board that needs to be replaced. Instead of subsystems, a supply of replacement boards is required. Mr. Robles stressed the need electro-static-discharge (ESD) handling protection. This would require more robust card designs.

Serial RapidIO I had a nice discussion with Ian Scott, the new executive director of the RapidIO Trade Association. For those following RapidIO, Serial RapidIO is right around the corner. Expect a flood of new chips and boards in the latter part of the year. The critical factor is Serial RapidIO switches. I talked with Tundra, but I can't provide you with a lot of details right now. One thing you can count on though is the availability of Serial RapidIO switches from a number of sources.

Serial RapidIO is one case where the holdup is in the fabric, or the switches to be more specific. A number of products already address Serial RapidIO, but these employ FPGAs for the interface. This is actually a hedge that most vendors in this space are taking because FPGAs are also suitable for implementing other serial switch fabric interfaces, such as InfiniBand. What will be exciting, though, is the Serial RapidIO support in processors and DSPs. Many of the implementations will use single lane (1x) connections allowing very compact chips. This is the same approach taken with PCI Express where many systems only use 1x connections.

What of parallel RapidIO? It's not going away, but it never achieved widespread adoption. Its simple, high-performance interface fits in some areas, like military applications, and it has even been found on the backplane although it was never really designed to go there. That was going to be the purview of Serial RapidIO.

In any case, you can still find parallel RapidIO on some microcontrollers. It is easily supported in FPGAs, but don't expect to hear much about it in the future. Serial RapidIO will become synonymous with RapidIO in about a year.

I was going to include some more of the new products I saw at the show, but I saved them for Electronic Design's new products section. Check it out for the latest in COTS. I will also be taking a closer look at advanced mezzanine cards (AMCs) in our print publication. As usual, mezzanine cards of all types were out in force at the show. AMC is the new standard that is employed in Advanced TCA.

One last item worth mentioning: PowerPC designers should check out the www.power.org site. Robert Negre of Thales provided a good overview of the site and the latest PowerPC products. The site is designed for developers and marketers.

No more Bus and Board till next year. I promise. The next EIED Online takes a look at a new way to build circuit boards. Stay tuned.

Related Links Bus and Board Show

Military Embedded Electronics and Computing Conference

Parker Aerospace


Pentair Electronic Packaging




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