CoreExpress modules are complete
computer-on-module
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 microco ...
(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
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the ...
, and common I/O interfaces. The interfaces are modern, using only digital buses such as
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common ...
,
Serial ATA
SATA (Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard t ...
,
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
,
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...
, and HD audio (
Intel High Definition Audio
Intel High Definition Audio (IHDA) (also called HD Audio or development codename Azalia) is a specification for the audio sub-system of personal computers. It was released by Intel in 2004 as the successor to their AC'97 PC audio standard.
Featur ...
). All signals are accessible on a high-density, high-speed, 220-pin connector. Although most implementations use
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
processors, the specification is open for different CPU modules.
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 by LiPPERT Embedded Computers and standardized by the
Small Form Factor Special Interest Group
The Small Form Factor Special Interest Group (SFF-SIG, pronounced ''ess-eff-eff-sig'') is an international non-profit standards body focused on modular computer hardware technologies used in embedded and small form factor computers and controller ...
in March 2010.
Size and mechanics
The specification defines a board size of 58 mm × 65 mm, slightly smaller than a
credit card
A credit card is a payment card issued to users (cardholders) to enable the cardholder to pay a merchant for goods and services based on the cardholder's accrued debt (i.e., promise to the card issuer to pay them for the amounts plus the o ...
and small enough to allow a carrier board in standard
PC/104-Plus format.
The module can be embedded into a
heat spreader
A heat spreader transfers energy as heat from a hotter source to a colder heat sink or heat exchanger. There are two thermodynamic types, passive and active. The most common sort of passive heat spreader is a plate or block of material having hi ...
, which distributes the component-generated heat onto a larger surface area. In low power applications, this distribution may be enough for complete thermal
dissipation
In thermodynamics, dissipation is the result of an irreversible process that takes place in homogeneous thermodynamic systems. In a dissipative process, energy (internal, bulk flow kinetic, or system potential) transforms from an initial form to a ...
.
In higher power applications, the heat spreader presents a thermal interface for mating to additional heat
dissipating components such as finned
heat sink
A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, th ...
s. 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 the
electromagnetic Interference
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electros ...
containment design.
Specification
The specification is hosted by the Small Form Factors Special Interest Group and is available on their website.
Revision 2.1 was released on February 23, 2010.
See also
*
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 boa ...
*
Computer-on-module
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 microco ...
*
Computer form factor
Form factor is a hardware design aspect that defines and prescribes the size, shape, and other physical specifications of components, particularly in electronics. A form factor may represent a broad class of similarly sized components, or it may ...
*
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'' as ...
References
External links
CoreExpress website
{{DEFAULTSORT:Coreexpress
Motherboard form factors
Computer hardware standards