CompactPCI Plus and rear I/O

Version 1


    Author: Andreas Lenkisch, Principal Engineer Backplanes at Schroff GmbH, Straubenhardt, Germany


    CompactPCI Plus is a new standardisation project by the PCI Industrial Manufacturers Group (PICMG) that defines a successor architecture for the CompactPCI bus.


    The principal features of this project are:


    •  the introduction of the serial interface currently provided by chipsets, such as PCIe, USB, SATA and Ethernet,
    • the development of a low-cost architecture that will also give former IPC users access to this robust and modular world,
    •  the creation of a flexible architecture that provides the appropriate infrastructure for a wide range of application situations without high cost overheads, and
    • the retaining of the CompactPCI ecosystem by creating a soft migration path from CompactPCI to CompactPCI Plus.

    CompactPCI Plus naturally also supports rear I/O.


    The peripheral CompactPCI Plus slot now requires only a small connector with 6 rows of contacts for power and signals. The remainder of the single-height euroboard remains free for user-defined I/O and offers 128 differential contact pairs or 384 contacts in total. This is significantly more than in 32-bit CompactPCI.


    In 6U systems with double-height euroboards the entire upper section of the euroboard remains, as with CompactPCI, available for user-defined I/O. The new solution however features some substantial advantages.


    While in CompactPCI both boards, front and rear, were linked via the backplane, in the new architecture both boards are inserted directly into one another. This does away with both a multilayered backplane in the I/O area and also the transfer connector onto it. Not only does this reduce costs; it also makes the system more flexible. There is no prescribed connector; this can be selected freely to suit economic and technical requirements.


    In mechanical terms everything remains as previously; as before, the large building blocks of 19" technology can be used.