CompactPCI PlusIO is an extension to the PICMG 2.0

CompactPCI CompactPCI is a computer bus 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. The co ...

industrial standard for modular computer systems. CompactPCI PlusIO was officially adopted by the PCI Industrial Computer Manufacturers Group

PICMG PICMG, or PCI Industrial Computer Manufacturers Group, is a consortium of over 140 companies. Founded in 1994, the group was originally formed to adapt PCI technology for use in high-performance telecommunications, military, and industrial comp ...

as PICMG 2.30 CompactPCI PlusIO in November 2009. Being 100% compatible with CompactPCI, PICMG 2.30 defines a migration path to the future

CompactPCI Serial CompactPCI Serial is an industrial standard for modular computer systems. It is based on the established PICMG 2.0 CompactPCI standard, which uses the parallel PCI bus for communication among a system's card components. In contrast to this, Compact ...

standard. It defines a fixed rear I/O pin assignment that focuses on modern, fast serial point-to-point connections. The new technology succeeding parallel CompactPCI comprises both CompactPCI Serial and CompactPCI PlusIO.

History

The CompactPCI standard uses one main bus connector, J1, and defines user I/O pins and a 64-bit extension for the legacy PCI bus on connector J2. J1 and J2 are the only connectors on 3 U single Eurocards. The CompactPCI definition for 6U double Eurocards includes additional connectors (J3, J4, J5) for rear I/O. A true rear I/O standard, however, exists only for J3 – through the PICMG 2.16 CompactPCI Packet Switching Backplane specification that defines

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 ...

interfaces at the

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 ...

of 6U cards. Fast serial point-to-point connections have become the state-of-the-art technology and are gradually replacing the classic bus architecture in computers. Also, 3U-based systems are very popular because of their small footprint. This is especially true for modular embedded applications, for example in the field of communications. As a result, several manufacturers tried to implement their own rear I/O concepts using the J2 connector, but had no standard to make their J2 pin assignments compatible with other cards. Another approach to realize serial high-speed interfaces were so-called

switched fabric Switched fabric or switching fabric is a network topology in which network Node (networking), nodes interconnect via one or more network switches (particularly crossbar switches). Because a switched fabric network spreads network traffic across m ...

s, which used additional switches and bridges to connect to each other. This involved higher costs and still provided solutions that were too specialized to be compatible with each other. The CompactPCI standard as it is does not offer a standardized solution for the kind of modular connectivity requested for the future. The additional PICMG 2.30 CompactPCI PlusIO specification provides this connectivity on the well-known platform of CompactPCI. It stays compatible with but extends the existing standard by a new definition of the rear J2 connector, adding a number of serial interfaces to provide fast and standardized rear I/O also on 3U format. Through these serial point-to-point connections, CompactPCI PlusIO also bridges the gap between parallel CompactPCI and the serial

standard.

Interfaces

PICMG 2.30 CompactPCI PlusIO standardizes the following interfaces at the rear J2 connector: * 4 x

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 ...

(one lane each) * 2 x

1000BASE-T In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use i ...

* 4 x

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 ...

2.0 * 4 x

SATA 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 to ...

/ SAS

Backplane Connectors

The PICMG 2.30 extension introduces a new J2 connector type on the plug-in board, an Ultra Hard Metric (UHM) connector with virtual coaxial box shielding technology, which reduces

crosstalk In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel. Crosstalk is usually caused by undesired capacitive, induc ...

at high speeds. This connector supports high frequencies of 5 Gbit/s, even when mated with the CompactPCI-standard unshielded 2-mm hard-metric headers. The matching P2 backplane connector remains the same as for CompactPCI, as do the J1/P1 connectors.

Compatibility with Legacy CompactPCI and CompactPCI Serial

PICMG 2.30 gives the J2 pins a fixed interface functionality. This makes 64-bit bus communication impossible. The new J2 connector type itself is 100% compatible with the legacy one. The J1 bus connector conforms with the CompactPCI definition. In all, CompactPCI PlusIO is 100% compatible with legacy 32-bit CompactPCI in 3U and 6U format (single and double Eurocards). At the same time, its serial rear I/O connectivity and higher-speed connector form a bridge towards future CompactPCI Serial system architecture. Hybrid backplanes support several cards of the three different standards PICMG 2.0, 2.30, and CPCI-S.0.

References

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External links