CompactPCI is a

computer bus In computer architecture, a bus (historically also called a data highway or databus) is a communication system that transfers data between components inside a computer or between computers. It encompasses both hardware (e.g., wires, optical ...

interconnect for industrial computers, combining a Eurocard-type connector and PCI 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 to connect s ...

. The connector pin assignments are standardized by the

PICMG PICMG, or PCI Industrial Computer Manufacturers Group, is a consortium of over 140 companies in the fields of computer science and engineering. Founded in 1994, the group was originally formed to adapt PCI technology for use in high-performanc ...

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 a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somet ...

. 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; ) is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies. IEC standards cover a vast range of ...

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, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as Peripher ...

and PXI respectively. The abbreviations cPCI, CPCI, cPCIe, and CPCIe are colloquial terms and are not officially used by PICMG.

References

External links

* {{DEFAULTSORT:Compactpci Peripheral Component Interconnect Computer standards Open standards PICMG standards

See also

References

External links