I/O Is Key to Expanding SFF-Board Applications

By Robert A. Burckle, Vice President, WinSystems

Faster, smaller, cheaper, low power, and networked: That is the direction of embedded computers. With the Atom, Intel has made significant boosts to functionality and performance while minimizing power for its processor and chipsets. The initial success of these processors lies in the fact that they don’t sacrifice processing performance in favor of lower electrical power and elaborate cooling solutions. With the addition of more real-world I/O interfaces, the number of embedded applications will continue to proliferate—especially in the areas of industrial control, transportation, security, communications, and military/commercial-off-the-shelf (COTS).

With the shortage of skilled, knowledgeable hardware and software engineers to work on an ever-growing number of embedded- systems projects, companies are rapidly moving from proprietary in-house designs to small-form-factor (SFF) boards as system components. The reason for this design-approach methodology is that a company can focus upon its core competency by emphasizing areas where they can add value rather than reinvent the computer hardware again and again. Choosing an SFF board as a building-block component increases reliability while getting the product to market quicker. At the same time, it leverages the vast software infrastructure supporting PCs. From a hardware perspective, I/O is an unheralded yet key element to interface each unique application to an off-the-shelf SFF-board solution.

Recognizing this I/O-centric design approach, a new industrystandards group called the Small Form Factor Special Interest Group (SFF-SIG) was formed in the fall of 2007. The group’s philosophy is to embrace the latest technologies while maintaining legacy compatibility and enabling transition solutions to next-generation interfaces. Its goal is to charter a course to develop, adopt, and promote circuitboard specifications and related technologies that will help electronics equipment manufacturers and integrators reduce the overall size of their next-generation systems. Uniquely, the SFF-SIG separates interconnect technology from form-factor specifications. In doing so, it enables enormous flexibility in the design of products based on the SFF-SIG standards while ensuring interoperability.

In the first year of operation, the SFF-SIG introduced SUMIT, a board-to-board I/O interconnect standard for embedded systems using two 52-pin, high-density (0.025-in.-pitch) connectors. The SUMIT (pronounced “sum it”) interface specification targets next-generation, low-power, expandable single-board computers (SBCs). It maps well to the new, single-chip chipsets from manufacturers of sub-10-W designs. At the same time, SUMIT closely follows the trend of replacing parallel interfaces with high-speed serial interfaces.

With a blend of high-bandwidth PCI Express lanes, Universal Serial Bus (USB) ports, and lower-speed multiplexed and serial buses, SUMIT can be added to a variety of board form factors. It also is flexible and compact enough to meet a very broad range of application requirements. Unifying the expansion interfaces of many SBC form factors has the potential to consolidate I/O ecosystems, which could improve economies of scale for I/O.

Next, the SFF-SIG introduced COMIT, which stands for Computer On Module Interconnect Technology. COMIT is aimed at SFF processor modules and baseboards leveraging the latest ultra-mobile and moderate power-processor/chipset combinations. This enabling technology allows the design of tiny processor modules to fit within the footprint of industry-standard SFF boards like EBX, EPIC, and PC/104 or any other standard or custom-designed baseboards.

COMIT is a high-speed, 240-pin connector system that supports the most common serial-I/O and legacy interfaces available from modern, low-power chipsets as designed by Intel with its Atom processor. This technology can be used to support different processors, as a single baseboard allows easy migration to future processors for performance/feature enhancement or obsolescence mitigation. The purpose is to provide a compact, stackable COM solution for future embedded-systems designs that are suitable for industrial environments using the newest low-power chipsets.

Embedded-systems designers are asking for simple, modular ways to implement emerging low-power, high-speed processors and their various I/O requirements without sacrificing packaging and legacy issues. Systems supporting SUMIT- and COMIT-based boards can develop stacking expansion-I/O modules using standard SFF technologies.

Robert A. Burckle is vice president of WinSystems, a designer and manufacturer of embedded computer hardware. He has over 30 years of electronics experience in the embedded market. Burckle has an MBA in marketing from North Texas State University and both a master and bachelor degree in electrical engineering from the University of Louisville.