COM Express: The Next Trend in Embedded Computing Small Form Factors

Rohit Chhabra - COM Express Initiative Manager

Marketing Manager

Intel Infrastructure Processor Division

Overview: Computer-on-Module Methodology Many of today¡¦s most innovative embedded application segments benefit from high levels of processing performance and I/O bandwidth in extremely compact form factors. Legacy interfaces including Peripheral Component Interconnect Extended (PCI-X) and Accelerated Graphics Port (AGP) can no longer satisfy the requirements of leading-edgeapplications in medical imaging, retail point-of-sale and advertising terminals, gaming, and industrial automation.

Meeting the requirements of these embedded market segments will require platform developers to gradually replace legacy parallel interfaces entirely with low-voltage differential signaling (LVDS) interfaces, while taking advantage ofthe performance gains enabled by new generations of processors and chipsets.

The continuing evolution of processors and the emergence of the current generation of high-speed serial differential interfaces confront embedded developers with the problem of how to implement these new capabilities while maintaining focus on their core business. Clearly, the task of engineering a new single-board computer (SBC) for eachnew generation of processors, or to implement faster buses, is an extremely expensive and time-consuming proposition.It can also place an added burden on already thinly stretched engineering resources.

Computer-on-Module, or ¡§COM¡¨ methodology, has become a well-accepted way to implement many of the mostdemanding embedded solutions. COM can be simply defined as a module that contains all the components needed for a bootable host computer, packaged as an off-the-shelf component. System expansion and customization for each solution is implemented on an application-specific carrier board. Together, the COM and carrier board deliver the functionalityof a single-board computer.

As the COM approach has gained in popularity, the embedded industry has recognized the need for an open COM standard to provide the advantages of modular, off-the-shelf building blocks. In addition, the industry saw the need for astandard that would enable a smooth transition from legacy interfaces, such as PCI and AGP, to legacy-free LVDS interfaces, including PCI Express*, Serial ATA and Serial Digital Video Out (SDVO). The answer is the COM Express specification from the PCI Industrial Computer Manufacturers Group (PICMG). WithCOM Express products beginning to appear in 2005, embedded developers interested in fast time to revenue shouldlearn more about this robust, embedded industry standard.

COM Advantages

Small and rugged, Computer-on-Module implementations are ideal for a broad range of embedded applications wherethey fit mechanically, economically, and functionally, and where other form factors such as add-in cards cannot be used. For embedded developers the advantages of the COM methodology include faster time to market, better control over form-fit-function, reduced development cost and risk, and lower total cost of ownership through scalability.

Perhaps the greatest reason embedded developers have been attracted to the COM methodology is that it lets them focustheir engineering resources on meeting core business requirements, without having to worry about how to implement new generations of processors and evolving I/O technologies.

Volatile demand fluctuations and intense competition are facts of life in the embedded world, and the COM approachenables system manufacturers to efficiently respond to competitive forces and meet new requirements by modifying their existing designs and expanding their product portfolios. This is especially true of embedded products with 5-to-10-year lifecycles whose compute performance and I/O capabilities must also be kept up to date.

The compelling advantages of the COM approach have given rise to a large base of suppliers who are working to meet the growing demand for COM modules and carrier boards. According to VDC, the COM and carrier board market segment is predicted to grow 54 percent annually through 2006 (source: Venture Development Corporation research, January 2004). ¡§Because of the interest generated by the COM approach, the embedded commercial segment is ready for a newstandard that makes the computer-on-module an interchangeable component,¡¨ said Jennifer Zickel, product marketingmanager at RadiSys Corporation.

While the COM approach has grown in popularity, it has also engendered a proliferation of potentially incompatible COM products. In 2004, this situation prompted the industry to begin work on an open industry standard, known as COM Express.

COM Express COM Express is the PICMG industry standard for Computer-on-Modules, developed with embedded industryparticipation under the sponsorship of Intel, Kontron, PFU, and RadiSys. The goals of the COM Express standards effort include the creation of specifications for small-form-factor modules to satisfy all performance segments of the embedded industry.

For example, high-performance segments can use COM Express to replace PCI-X and AGP with PCI Express and replace parallel ATA with Serial ATA. COM Express alsoprovides a bridge between legacy-free and legacy functions by incorporating optional PCI and IDE interfaces. According to Wade Clowes, vice president and general manager of RadiSys Commercial Segment, ¡§COM Expressmakes it an order of magnitude easier to configure a range of embedded products. RadiSys customers will be able tooffer a line of products from low-end to high-end, using the same carrier board and swapping-out the COM module.¡¨

COM Express is designed to help accelerate development in some of today¡¦s most dynamic application segments: ¡E Retail and advertising¡Xelectronic billboards, interactive kiosks and shopping carts¡E Medical¡XC-Arm real-time imaging and 3D/4D ultrasound devices¡E Test and measurement¡Xbus and protocol analyzers and automated test equipment ¡E Gaming, entertainment and hospitality¡Xhigh-definition, media-rich gaming platforms ¡E Industrial automation¡Xnondestructive testers, 4D microscopy, volumetric imagers and real-time data analyzers¡E Military/government and security¡Xunmanned vehicles, training simulators and portable tactical communications (C4) devicesIn each of these market segments COM Express safeguards R&D investments and lowers total cost of ownership (TCO) by enabling designers to partition commodity host-processor COM Express modules from proprietary, value-addedplatform building blocks, including Field Programmable Gate Arrays (FPGAs) and specialty I/Os.

By improving form-fit-function in specific applications, COM Express modules can help minimize current and future design risks. It can help cut development time and costs during the initial phase of product development, while providing the scalability needed to cost-effectively implement value-added innovations over the multiyear lifecycle of anembedded platform. Functional Overview COM Express is designed as a CPU-agnostic standard that will enable the embedded industry to adopt all-LVDS interfaces, while maintaining support for legacy interfaces.

Source: Intel - www.intel.com/technology/magazine/

COM Express Modules
Mini-ITX Motherboards
MB879 - LGA775 Pentium^® 4, ATI Xpress 200 Mini-ITX (NEW)
MB899 - Socket 478 Core^® 2 Duo Mini-ITX with Intel^® 945GM chipset
MB899X - Socket 478 Core^® 2 Duo Mini-ITX MB with Intel^® 945GM w/ 4 COM, PCI-E(x16)
MB896 - Socket 479 Pentium^® M Mini-ITX with Intel^® 915GM
MB890 - Socket 479/Pentium^® M-based 855GME Mini-ITX
MB850 - Socket 478 Intel^® 845GV Mini-ITX
MB877 - LGA775 Pentium^® 4, ATI RS400M Mini-ITX
MB870 - Socket 478 Pentium^® 4, ATI RS300M Mini-ITX
MB770 - VIA Eden-V4 CN700 Mini-ITX with VGA, 10/100 LAN
MB720 - VIA Eden/C3 CN400 Mini-ITX Motherboard, with VGA, 10/100 LAN, optional GbE, 1394, TV out
MB740 - SiS 741CX Socket A AMD Geode NX Mini-ITX (NEW)
MB500 - AMD Geode LX Mini-ITX with AMD CS5536 Chipset (NEW)
MB860 - Transmeta Efficeon Mini-ITX