CoreExpress modules are completecomputer-on-module (COM) highly integrated, compact computers that can be used in an embedded computer board design, much like an integrated circuit component. COMs integrateCPU, memory, graphics, andBIOS, and common I/O interfaces.[1] The interfaces are modern, using only digital buses such asPCI Express,Serial ATA,Ethernet,USB, and HD audio (Intel High Definition Audio). All signals are accessible on a high-density, high-speed, 220-pin connector. Although most implementations useIntel processors, the specification is open for different CPU modules.[2]
CoreExpress modules are mounted on a custom carrier board, containing the peripherals required for the specific application. In this way, small but highly specialized computer systems can be built.
The CoreExpress form factor was originally developed byLiPPERT Embedded Computers[3][4] and standardized by theSmall Form Factor Special Interest Group (SFF-SIG) in March 2010.[5][6] It was competing with other standards likeCOM Express orQseven.[7] Initially adopted by the German LiPPERT and the Swiss companyDIGITAL-LOGIC[8] (which has meanwhile been bought byKontron),[6] it was later backed up by more than eight vendors[6] including Syslogic.
The specification defines a board size of 58 mm × 65 mm, slightly smaller than acredit card and small enough to allow a carrier board in standardPC/104-Plus format.[1][9]
The module can be embedded into aheat spreader, which distributes the component-generated heat onto a larger surface area. In low power applications, this distribution may be enough for complete thermaldissipation.
In higher power applications, the heat spreader presents a thermal interface for mating to additional heatdissipating components such as finnedheat sinks. Heat spreaders are simpler and more rugged to connect to than the heat generating components underneath. This simplifies mechanical design for the system builder, but can be less efficient than a complete purpose-built thermal solution.
In a complete system, heat spreaders can be part of theelectromagnetic interference containment design.
The specification is hosted by the SFF-SIG and is available on their website.Revision 2.1 was released on 23 February 2010.[10]