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 demonst ...
(SBC), a subtype of an
embedded computer
An embedded system is a specialized 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 em ...
system. An extension of the concept of
system on chip (SoC) and
system in package
A system in a package (SiP) or system-in-package is a number of integrated circuits (ICs) enclosed in one chip carrier package or encompassing an IC package substrate that may include passive components and perform the functions of an entire sys ...
(SiP), COM lies between a full-up
computer
A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...
and a
microcontroller
A microcontroller (MC, uC, or μC) or microcontroller unit (MCU) is a small computer on a single integrated circuit. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Pro ...
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 computer
An embedded system is a specialized 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 em ...
s built on a single
circuit board
A printed circuit board (PCB), also called printed wiring board (PWB), is a laminated sandwich structure of conductive and insulating layers, each with a pattern of traces, planes and other features (similar to wires on a flat surface) ...
.
[Typical COM product line]
/ref> The design is centered on a microprocessor
A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...
with RAM
Ram, ram, or RAM most commonly refers to:
* A male sheep
* Random-access memory, computer memory
* Ram Trucks, US, since 2009
** List of vehicles named Dodge Ram, trucks and vans
** Ram Pickup, produced by Ram Trucks
Ram, ram, or RAM may also ref ...
, input/output
In computing, input/output (I/O, i/o, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, such as another computer system, peripherals, or a human operator. Inputs a ...
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 device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...
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 specialized 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 e ...
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 (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 called printed wiring board (PWB), is a Lamination, laminated sandwich structure of electrical conduction, conductive and Insulator (electricity), insulating layers, each with a pattern of traces, planes ...
.[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
Gumstix is an American multinational corporation headquartered in Redwood City, California. It develops and manufactures small system boards comparable in size to a stick of gum. In 2003, when it was first fully functional, it used ARM architect ...
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
In commerce, time to market (TTM) is the length of time it takes from a product being conceived until its being available for sale. The reason that time to market is so important is that being late erodes the addressable market into which produ ...
(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 is a form factor for computer-on-modules (COMs), which are highly integrated and compact computers that can be used in design applications much like integrated circuit components. Each module integrates core CPU and memory functionali ...
* CoreExpress
CoreExpress modules are complete computer-on-module (COM) highly integrated, compact computers that can be used in an embedded computer board design, much like an integrated circuit component. COMs integrate CPU, memory, graphics, and BIOS, and c ...
* Embedded System Module
Embedded System Module, or ESM, is a compact computer-on-module (COM) standard. An ESM module typically includes a CPU processor, memory, module-specific I/O interfaces and a number of basic front I/O connectors. They can be plugged on a carrier bo ...
* ESMexpress ESMexpress is a computer-on-module (COM) standard. It is a complete processor module that currently supports several low-power Intel and PowerPC platforms. Every module has a CPU, as well as memory and a range of serial communication interfaces such ...
* ETX (form factor)
ETX, standing for Embedded Technology eXtended, is an integrated and compact computer-on-module (COM) form factor, which can be used in a design application much like an integrated circuit component. Each ETX COM integrates core CPU and memo ...
* Qseven
Qseven, a computer-on-module (COM) form factor, is a small, highly integrated computer module that can be used in a design application much like an integrated circuit component. It is smaller than other computer-on-module standards such as COM E ...
* SMARC
* XTX
References
External links
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Microcomputers
Embedded systems