CompactPCI is a
computer bus
In computer architecture, a bus (shortened form of the Latin '' omnibus'', and historically also called data highway or databus) is a communication system that transfers data between components inside a computer, or between computers. This ex ...
interconnect for industrial computers, combining a
Eurocard-type connector and
PCI
PCI may refer to:
Business and economics
* Payment card industry, businesses associated with debit, credit, and other payment cards
** Payment Card Industry Data Security Standard, a set of security requirements for credit card processors
* Pro ...
signaling and protocols.
Boards are standardized to 3
U or 6U sizes, and are typically interconnected via a passive
backplane
A backplane (or "backplane system") is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used as a backbo ...
. The connector pin assignments are standardized by the
PICMG US and PICMG Europe organizations. The connectors and the electrical rules allow for eight boards in a PCI segment. Multiple bus segments are allowed with
bridges
A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, whic ...
.
[
]
Unlike the original Eurocard solutions such as
VME, which use connectors with a 0.1 inch (2.54 mm) pin spacing, CompactPCI cards use metric connectors with a 2-millimeter pin spacing, designed to the
IEC
The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...
1076 standard. 3U boards have a 110-pin connector (J1), which carries the 32-bit PCI bus signals, and an optional 110-pin connector (J2), which carries either user-defined I/O or the upper 32 bits of an optional 64-bit PCI bus. 6U cards have an identical J1, a J2 that is always used for 64-bit PCI, as well as J3, J4, and J5 connectors for a variety of uses either as user-defined I/O or specified signaling such as Telephony and/or
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 ...
signaling. Hot-plugging is a supported feature of CompactPCI. Some of the pins are slightly longer to provide proper grounding when devices are inserted and removed.
The backplanes can be designed for 3.3 V VIO or 5 V VIO operation. These are differentiated by having 'Cadmium Yellow' coloured key for 3.3V or 'Brilliant Blue' colour for 5V operation. If the CompactPCI card operates on a particular VIO voltage the card shall have the respective coloured coding key. If the card is compatible with both voltages then it may not have any coding key. The image above illustrates a 5 V VIO 8-slot backplane.
CompactPCI was initially ratified as PICMG 2.0 in late 1995 as a passive backplane for PCI signaling. The 2.x series of specifications from PICMG provide support for a variety of technologies including Hot Swap (PICMG 2.1), Telephony signaling (PICMG 2.5) and most notably the expansion of the architecture to include switched Ethernet (PICMG 2.16).
Originally designed to support the PCI signaling protocol (and hence the name "CompactPCI"), CompactPCI has grown to include a variety of technologies centered on the application of the 2mm HM connector on the 3U and 6U form factor. In fact many systems are implemented with no PCI bus on the backplane, such as those implemented with switched Ethernet board interconnection (PICMG 2.16).
A drawback of the design is that the signal pins can become bent when a new device is inserted.
Related standards include CompactPCI Express and CompactPXI, which follow a similar concept, but substitute the protocols and signaling of
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 ...
and
PXI
PCI eXtensions for Instrumentation (PXI) is one of several modular electronic instrumentation platforms in current use. These platforms are used as a basis for building electronic test equipment, automation systems, and modular laboratory instru ...
respectively.
The abbreviations cPCI, CPCI, cPCIe, and CPCIe are colloquial terms and are not officially used by PICMG.
See also
*
CompactPCI Serial
*
CompactPCI PlusIO
*
PXI
PCI eXtensions for Instrumentation (PXI) is one of several modular electronic instrumentation platforms in current use. These platforms are used as a basis for building electronic test equipment, automation systems, and modular laboratory instru ...
*
MicroTCA or Advanced Mezzanine Card
*
Mini PCI
Peripheral Component Interconnect (PCI) is a local computer bus for attaching hardware devices in a computer and is part of the PCI Local Bus standard. The PCI bus supports the functions found on a processor bus but in a standardized format th ...
*
VMEbus
VMEbus (Versa Module Europa or Versa Module Eurocard bus) is a computer bus standard, originally developed for the Motorola 68000 line of CPUs, but later widely used for many applications and standardized by the IEC as ANSI/IEEE 1014-1987. I ...
*
VPX
VPX (Virtual Path Cross-Connect), also known as VITA 46, refers to a set of standards for connecting components of a computer (known as a computer bus), commonly used by defense contractors.
Some are ANSI standards such as ANSI/VITA 46.0–2019.
...
References
External links
*
{{DEFAULTSORT:Compactpci
Peripheral Component Interconnect
Computer standards
Open standards
PICMG standards