A computer-on-module (COM) is a type of
single-board computer
A single-board computer (SBC) is a complete computer built on a single circuit board, with microprocessor(s), memory, input/output (I/O) and other features required of a functional computer. Single-board computers are commonly made as demonstrat ...
(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
A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs ( processor cores) along with memory and programma ...
in nature. It is very similar to a
system on module
A system on a module (SoM) is a board-level circuit that integrates a system function in a single module. It may integrate digital and analog functions on a single board. A typical application is in the area of embedded systems. Unlike a sing ...
(SOM).
Design
COMs are complete
embedded computers built on a single
circuit board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich stru ...
.
[Typical COM product line]
/ref> The design is centered on a microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
with RAM, input/output
In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...
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
A peripheral or peripheral device is an auxiliary device used to put information into and get information out of a computer. The term ''peripheral device'' refers to all hardware components that are attached to a computer and are controlled by th ...
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 system
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' ...
s. As a COM is very compact and highly integrated, even complex CPUs, including multi-core technology, can be realized on a COM.
Some devices also incorporate field-programmable gate array
A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term '' field-programmable''. The FPGA configuration is generally specified using a hardware ...
(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
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich str ...
.[Technologic Systems FPGA based COM modules]
/ref>
A "computer-on-module" is also called a "system-on-module" (SOM).
History
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.
Dr. Gordon Kruberg, founder and CEO of Gumstix, is credited for creating the first COM, predating the next recognizable COM entries by almost 18 months.
Gumstix ARM Linux Machine number is 373, established 9 September 2003, while Kontron's is 735, established 18 April 2005, and Keith & Koep's (now part of SECO["Garz & Fricke (incl. Keith & Koep) now part of SECO"]
SECO Northern Europe) is 776, established 20 June 2005. Boards numbered below 373 were larger and single board computers as opposed to modules, for example, the Itsy, a tiny hand-held device based on the StrongARM.
The rapid development paradigm (COM + expansion board) Dr. Kruberg established has been at the heart of leading edge development since then and used at leading consumer products companies worldwide.
COM's have proven useful in launching entire industries requiring rapid development efforts. For example, in 2005 Apple used a Gumstix COM to test the original iPhone concept.
Benefits
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. However, this only works if the board-to-board connection between the COM and its carrier remains compatible between upgrades.
Other benefits of using COM products instead of ground-up development include reducing time to market (TTM), risk reduction, cost savings, choice of a variety of CPUs, reduced requirements and time for customer design, and the ability to conduct both hardware and software development simultaneously.[Computer on Modules - Technical Reference Manuals]
/ref>
See also
* COM Express
COM Express, a computer-on-module (COM) form factor, is a highly integrated and compact computer that can be used in a design application much like an integrated circuit component. Each module integrates core CPU and memory functionality, the co ...
* CoreExpress
* Embedded System Module
* ESMexpress
* ETX (form factor)
* Qseven
* SMARC
* XTX
XTX is a computer-on-module (COM) standard for x86-based embedded devices. XTX adds PCI-Express, SATA, and LPC
LPC may refer to:
Science and technology
* Linear predictive coding, a method used in audio signal processing and speech processing
* ...
References
External links
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Microcomputers
Embedded systems