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Initiative targets COM Express interoperability

Apr 11, 2007 — by LinuxDevices Staff — from the LinuxDevices Archive — views

Three embedded hardware vendors have launched an initiative aimed at improving interoperability among COM Express modules and carrier boards. Adlink, Ampro, and Congatec invite other module vendors and system integrators to join their “COM Express PNP” (plug-and-play) initiative, which has already published extensive documentation, including a free implementation guide.

COM Express module and baseboard
(Click to enlarge)

COM Express is a PICMG standard for small single-board computers that integrate processor(s), memory, and flash into a component-like “computer-on-module” (COM). In theory, COMs reduce the engineering effort required to build embedded electronics, by supplying those sub-systems where electrical tolerances are the most exacting as a simple super-component.

In practice, though, the COM Express standard offers “great flexibility,” with two different module sizes, and five different pin-out types. It also permits “certain freedom in power sequencing, I/O definition, and other criteria,” which PnP Initiative proponents said are “often a limitation for the interchangeability from one vendor to the other.”

The group said its 119-page implementation guide fully details circuitry that OEMs (original equipment manufacturers) can use to ensure module interchangeability, when designing COM Express modules. Additionally, a complete set of schematics for a full-featured carrier board is available.

According to Ampro director of marketing Colin McCracken, the guide helps to “standardize and clarify things that are not [sufficiently] specific” in the COM Express standard.

Both the design guide and carrier board schematics are free to download and use. Module suppliers and system integrators supporting the implementation are entitled to a free company listing on the COM Express PnP website — where additional details can be found.

Interestingly, Kontron, the creator of ETX and ETX Express, from which COM Express sprang, does not appear to be participating in the initiative.

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