COM Express platform based on the Intel Atom processor

This article introduces the CXB-A945M, a new COMExpress module based on the power-saving Intel Atom processor N270. This standard platform specifically addresses applications requiring the same range of I/O options as typically implemented with the Intel 82945/ICH-7M chipset.

Thanks to the small die size and extremely low power consumption, the latest Intel Atom processor technology enables new innovative applications in the embedded computingmarket. It is no surprise that many manufacturers of embedded computing platforms have already announcedmodules based on the Z5x0. These products however usually offer fewer interfaces than typical COMExpress applications require. As a result,manymodules lack enough PCI Express channels ormiss the previously achieved graphics performance.MSC, as amarket leader of COMExpress solutions, again demonstrates with the new product its strong position, offering best-in-class innovative design approaches.

An important trend for industrial applications is the move towards fanless operation. Numerous high performance applications with matching I/O performance are waiting to be realized without an active heat sink on standard COM Express modules. The new Intel Atom processor technologymeets these requirements and enables a wide range of fanless applications. While the maximum power dissipation of the Intel Celeron 440 CPU architecture is specified with 27Wat 1.86 GHz, the comparable value of the Intel Atom processor is only 2.5W at 1.6 GHz. Previouslymost fanless applications were based on low or ultra-low voltage processor versions e.g. the Celeron ULV 423. Even those CPUs lose in the performance/watt comparison, as Intel demonstrated at the design conference in San Francisco late August.

These devices often do not match the cost budget of industrial applications, requiring customers to bite the bullet and revert to the standard Celeron devices, frequently leaving the performance underutilized while requiring extra effort to cool the systemdown. Intel’s first Atom platform consists of the Intel Atom processor Z530 (Silverthorne) running at a clock rate of 1.6 GHz, and the Intel systemcontroller hub US15W. This complete platform is specified with a thermal design power (TPD) of 6.3 watt. The processor is manufactured on a 45nmprocess and placed in a small formfactor package. The traditional north and south bridge are combined to the complex system controller hub (SCH) within one package. The Intel graphicsmedia accelerator 500 (GMA 500), amemory- and I/O controller are part of this SCHdevice. Intel high definition audio and hardware video decode acceleration are also supported. This low-end solution will also become available on the emerging Qseven standard by the end of this year.

In comparison to the Intelmainstreammobile solution with three chips: CPU, north bridge and south bridge, the number of I/O interfaces offered by the two-chip solution is significantly reduced. In hand-held applications this is not a concern, since low power consumption and battery lifetime are the key factors addressed with this two-chip platform. For industrial application in a 24/7 operation environment however, the number of possible systemextensions is a crucial factor. The two-chip platform does not seemthe right fit for such applications as additional interface controllers cannot fill the connectivity gap without a performance impact, making it obvious that the Atom Z5x0 platform has not been specified with I/O demanding industrial applications in mind.

With the Atom N270 CPU, Intel opened up a completely new path. Still supporting the 82945-based three-chip solution, the CPU manufacturer addresses the industry need for affordable flexible solutions.

With the new Intel Atom platform the advantages of the processor N270 are combined with the I/O-rich Intel 82945GME/ICH7 bridge technology. The Atom N270 (Diamondville) processor is specified with a TDP of 2.5W which is equivalent to the TDP of the AtomZ530 processor. Other than the Z5x0, the N270 interfaces to well-established bridge chips. Therefore the power can still be dissipated with a passive heatsink. The complete three-chip Atom N270 platform requires typically 10-12W, still allowing fanless operation. A comparable solution based on a classic ULV processor version will definitely result in higher nominal power dissipation. Thanks to the wide range of interfaces and the support for DVI/LVDS or a PCIe x16 port for external graphic adapters, the platform allows easy extensions not possible with most other Atom on COM Express implementations available today.

The new CXB-A945M is based on the Atomprocessor and is available in the most commonly used COM Express basic form factor. The board format of 125mmx95mmoffers similar features to theMSC CXB-CD945 product, while consuming only a third of the power compared to the Intel Celeron M 440 implementation. The new boards support exactly the same type and number of interfaces as the existing designs. This compatibility allows easy interchangeability of COM Express compatible modules based on the Intel 82945GME chipset, and helps to protect systeminvestments while still allowing to take advantage of reduced power dissipation and cost reductions through high volumes.

The MSC CXB-A945M module family provides five PCI Express 1x Lanes and is perfectly suited for applications requiring a wide range of interfaces.The number of unswitched PCI Express channels is crucial factor, since the technology is based on a point-to-point interconnect. Eight USB 2.0 ports allow maximum flexibility to connect peripheral devices to the module. Gigabit Ethernet network access is realized via the Intel® 82573L Gigabit LAN controller. For mass storage two SATA ports with up to 150 Mbytes/s and an enhanced IDE port are provided.

Mainmemory of up to 2Gbytes is supported by the chipset on a SO-DIMM socket. The Intel 82945GME chipset also integrates the graphics media accelerator 950, and offers excellent 3D graphic performance at the highest available frequency suited for applications running resolutions higher than 1280x1024 under standard operating systems. Two independent displays with a resolution of up to 1600x1200 pixel (LVDS 24 -bit, dual channel) and an analog VGA output are also supported by the 82945GME chipset. For even higher demands on the graphic performance, the PCI Express graphics (PEG) port can be utilized to plug in third party graphic adapters.

Like all new COMExpress modules offered by MSC, the CXB-A945Mboard provides leading edge security functions based on the specifications of the Trusted Computing Group (TCG). These security functions protect the customer know-how by preventing copying ormodification of the system software. The implementation is based on the MicroCore-BIOS from Phoenix Technologies, with extensions to the Infineon trusted platformmodule TPM1.2 SLB 9635 for hardware-based security. The COM Express platformoperates underWindows XP (embedded) and Linux operating systems. For evaluation and design-in supportMSC offers a baseboard with all common PC interfaces. Main target applications of Intel Atomprocessor- based COM Express platforms are industrial control applications like Panel PCs and humanmachine interfaces, and control systems that are operated in 24/7 environments without a fan. Other applications can be found in home automation, POS and POI systems, medical devices and automotive applications.

published in: boards & solutions 10/2008 [PDF 316KB]

By Bernhard Andretzky, MSC