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A computer-on-module (COM) is a type of single-board computer (SBC), a subtype of an embedded computer system. An extension of the concept of system on chip (SoC) and system in package (SiP), CoM lies between a full-up computer and a microcontroller in nature. It is very similar to a system on module (SOM).


COMs are complete embedded computers built on a single circuit board.[1] The design is centered on a microprocessor with RAM, input/output controllers and all other features needed to be a functional computer on the one board. However, unlike a single-board computer, the COM usually lacks the standard connectors for any input/output peripherals to be attached directly to the board.

The module usually needs to be mounted on a carrier board (or "baseboard") which breaks the bus out to standard peripheral connectors. Some CoMs also include peripheral connectors. Some can be used without a carrier.

A COM solution offers a dense package computer system for use in small or specialized applications requiring low power consumption or small physical size as is needed in embedded systems. As a COM is very compact and highly integrated, even complex CPUs, including multi-core technology, can be realized on a COM.

Using a carrier board is a benefit in many cases, as it can implement special I/O interfaces, memory devices, connectors or form factors. Separating the design of the carrier board and CoM makes design concepts more modular, if needed. A carrier tailored to a special application may involve high design overhead by itself. If the actual processor and main I/O controllers are located on a COM, it is much easier, for example, to upgrade a CPU component to the next generation, without having to redesign a very specialized carrier as well. This can save costs and shorten development times. On the other hand, this only works if the board-to-board connection between the CoM and its carrier remains compatible between upgrades.

Some devices also incorporate field-programmable gate array (FPGA) components. FPGA-based functions can be added as IP cores to the COM itself or to the carrier card. Using FPGA IP cores adds to the modularity of a COM concept, because I/O functions can be adapted to special needs without extensive rewiring on the printed circuit board.[2]


The terms "Computer-On-Module" and "COM" were coined by VDC Research Group, Inc. (formerly Venture Development Corporation) to describe this class of embedded computer boards.[citation needed]

Dr. Gordon Kruberg,[3] founder and CEO of Gumstix, created the first CoM.[4][5] Gumstix's ARM Linux Machine is #373 and dated September 9, 2003, as compared to the next recognizable COM's entry of #735 dated April 18, 2005, a gap of over 19 months. Note that boards numbered below 373 were larger, single board computers as opposed to modules, for example, the Itsy, a tiny hand-held device based on the StrongARM.[6]

The rapid development paradigm (COM + expansion board) Dr. Kruberg established has been instrumental to research and development since then and has proven useful in launching industries requiring rapid development efforts, for example, Apple Inc. used a Gumstix COM to test original iPhone concept in 2005.[7]

The term became more notable upon industry standardization of the COM Express format.

Benefits of computer modules[edit]

There are many benefits to using COM products instead of ground-up development.[8] These benefits include reducing time to market (TTM), reduction in risk, cost savings, choice of a variety of CPUs, reduced requirements and time for customer design, and an ability to conduct both hardware and software development at once.

See also[edit]


  1. ^
  2. ^ Technologic Systems FPGA based COM modules
  3. ^ "About Gumstix, Inc. | Gumstix, Inc". Gumstix, Inc. Retrieved 2016-05-06.
  4. ^ "A Linux Machine For Your Collar - Slashdot". Retrieved 2016-05-06.
  5. ^ "Launch" (PDF). Launch. Gumstix. May 14, 2004.
  6. ^ "Machines". Machines.
  7. ^ Vogelstein, Fred (2013-11-12). Dogfight: How Apple and Google Went to War and Started a Revolution. Macmillan. ISBN 9780374711009.
  8. ^ Computer on Modules - Technical Reference Manuals