VPX
Encyclopedia
VPX, formerly known as VITA 46, is an ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....

 standard (ANSI/VITA 46.0-2007) that provides VMEbus-based systems with support for switched fabric
Switched fabric
Switched fabric, switching fabric, or just fabric, is a network topology where network nodes connect with each other via one or more network switches . The term is popular in telecommunication, Fibre Channel storage area networks and other high-speed networks, including InfiniBand...

s over a new high speed connector. Defined by the VITA (VME
VMEbus
VMEbus 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. It is physically based on Eurocard sizes, mechanicals and connectors , but uses its own signalling system,...

 International Trade Association) working group (composed of major companies such as Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

, Curtiss-Wright
Curtiss-Wright
The Curtiss-Wright Corporation was the largest aircraft manufacturer in the United States at the end of World War II, but has evolved to largely become a component manufacturer, specializing in actuators, aircraft controls, valves, and metalworking....

, Elma Electronic
Elma Electronic
Elma Electronic is a publicly traded Swiss electronics company founded in 1960 and based in Wetzikon, Switzerland. The company has 5 product divisions: Systems Platforms, Backplanes, Enclosures & Components, Rotary Switches, and Cabinet Enclosures. The largest segment is systems packaging solutions...

, GE Intelligent Platforms, Kontron
Kontron
Kontron AG is a German-based multinational company which designs and manufactures embedded computer modules, boards and systems.Kontron AG serves OEMs, system integrators and application providers of different market segments...

, Mercury Computer Systems
Mercury Computer Systems
Mercury Computer Systems, Inc. provides high-performance embedded, real-time digital signal and image processing solutions.Mercury designs and builds embedded multicomputers, which may be considered to be either loosely coupled NUMA computers or tightly coupled clusters. Despite being marketed as...

 and Northrop Grumman
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...

), it has been designed specifically with defense applications in mind, with an enhanced module standard that enables applications and platforms with superior performance. VPX retains VME’s existing 6U
Rack unit
A rack unit or U is a unit of measure used to describe the height of equipment intended for mounting in a 19-inch rack or a 23-inch rack...

 and 3U form factors, supporting existing PCI Mezzanine Card
PCI mezzanine card
A PCI Mezzanine Card or PMC is a printed circuit board manufactured to the IEEE P1386.1 standard. This standard combines the electrical characteristics of the PCI bus with the mechanical dimensions of the Common Mezzanine Card or CMC format .A mezzanine connector connects two parallel printed...

 and XMC mezzanines (PMC with high-speed serial fabric interconnect), and maintaining the maximum possible compatibility with VMEbus.

New generations of embedded computing systems based on the VPX standard reflect the growing significance of high speed serial switched fabric
Switched fabric
Switched fabric, switching fabric, or just fabric, is a network topology where network nodes connect with each other via one or more network switches . The term is popular in telecommunication, Fibre Channel storage area networks and other high-speed networks, including InfiniBand...

 interconnects such as PCI Express
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...

, RapidIO
RapidIO
The RapidIO architecture is a high-performance packet-switched, interconnect technology for interconnecting chips on a circuit board, and also circuit boards to each other using a backplane...

, Infiniband
InfiniBand
InfiniBand is a switched fabric communications link used in high-performance computing and enterprise data centers. Its features include high throughput, low latency, quality of service and failover, and it is designed to be scalable...

 and 10 Gigabit Ethernet
10 Gigabit Ethernet
The 10 gigabit Ethernet computer networking standard was first published in 2002. It defines a version of Ethernet with a nominal data rate of 10 Gbit/s , ten times faster than gigabit Ethernet.10 gigabit Ethernet defines only full duplex point to point links which are generally connected by...

. These technologies are replacing traditional parallel communications
Parallel communications
In telecommunication and computer science, parallel communication is a method of sending several data signals simultaneously over several parallel channels...

 bus architectures for local communications, because they offer significantly greater capability. Switched fabrics provide an optimum technology to support the implementation of multiprocessing
Multiprocessing
Multiprocessing is the use of two or more central processing units within a single computer system. The term also refers to the ability of a system to support more than one processor and/or the ability to allocate tasks between them...

 systems that require the fastest possible communications between multiple processors (e.g., digital signal processing applications). VPX gives the large existing base of VMEbus users access to these switched fabrics.

Technologies called for in VPX include:
  • Both 3U and 6U formats
  • New 7-row high speed connector rated up to 6.25 Gbit/s
  • Choice of high speed serial fabrics
  • PMC, FMC (VITA 57) and XMC (VITA 42) mezzanines
  • Hybrid backplanes to accommodate VME64, VXS and VPX boards

Specification

In common with other similar standards, VPX comprises a ‘base line’ specification, which defines the basic mechanical and electrical elements of VPX, together with a series of ‘dot level’ specifications, one or more of which must be implemented to create a functional module. The specifications and their current status are as follows:
Basic module
VITA 46.0 VPX Base Standard - ANSI ratified
VITA 46.1 VMEbus Signal Mapping on VPX - ANSI ratified
VITA 46.3 Serial RapidIO(tm) on VPX Fabric Connector - VITA draft standard for trial use
VITA 46.4 PCI Express on VPX Fabric Connector - VITA draft standard for trial use
VITA 46.6 Gigabit Ethernet Control Plane on VPX - draft
VITA 46.7 Ethernet on VPX Fabric Connector - VITA draft standard for trial use
VITA 46.9 PMC/XMC/Ethernet Signal Mapping to 3U/6U on VPX - draft
VITA 46.10 Rear transition module on VPX - draft
VITA 46.11 System Management on VPX - draft
VITA 46.12 Fiber Optic Interface on VPX - Now VITA 66
VITA 46.13 Fibre channel on VPX - planned
VITA 46.20 Switch slot definition on VPX - draft
VITA 46.21 Distributed switching topologies - draft

Connector

The single biggest difference between today’s VMEbus boards and VPX boards is that VPX boards use a new connector, developed by Tyco Electronics
Tyco Electronics
TE Connectivity, Ltd., previously known as Tyco Electronics, Ltd., and formerly a segment of Tyco International, is a leading global provider of engineered electronic components, network solutions, undersea telecommunication systems, and specialty products for customers in more than 150 countries...

 and known as the MultiGig RT2. This means that VPX boards cannot be used in a standard VMEbus chassis, although the use of hybrid chassis is foreseen by the VPX standard. A 6U VPX board features six 16-column 7-row RT2 connectors and one 8-column 7-row RT2 connector, while a 3U board features two 16-column 7-row RT2 connectors and one 8-column 7-row RT2 connector.

Also new for VPX boards are alignment/keying blocks which are designed to be sufficiently robust to prevent pin stubbing. The blocks also provide card keying and a safety ground. A 6U board has three such keying blocks, while a 3U board has two.

The MultiGig RT2 connector is specifically designed to enable high performance. It accomplishes this through a 7-row 16-wafer (wafers can be power, differential or single-ended) that delivers highly controlled impedance, minimal insertion loss and less than 3% crosstalk at transfer rates up to 6.25 Gbit/s. The new connector enables a 6U VPX board to feature a total of 707 non-power electrical contacts and a total of 464 signal contacts. The latter are usable as:
  • 64 signals implemented as 32 high speed differential pairs for core fabric
  • 104 VME64 signals
  • 268 for user I/O including 128 high speed differential pairs (giving a total of 160 high speed differential pairs)
  • 28 for system utilities or spares


The connector is designed to allow a typical stiffening bar and a standard length PMC.

Power and ruggedization

A VMEbus slot is limited to a maximum of 90 watts at 5 volts. VPX raises this to 115 watts at the same voltage, or up to 384 watts at 12 volts or 768 watts at 48 volts. The specification of 6U VPX calls for computer cooling
Computer cooling
Computer cooling is required to remove the waste heat produced by computer components, to keep components within their safe operating temperature limits.Various cooling methods help to improve processor performance or reduce the noise of cooling fans....

 via a conduction-cooled envelope compliant with the IEEE standard IEEE-1101.2, which is compatible with existing enclosures. Provision is also made for air-cooling via an IEEE 1101.1/10 form factor version.

For more stringent cooling requirements, the REDI (Ruggedized Enhanced Design Implementation – previously known as VITA 48) standard describes how to implement layout techniques to better support cooling methodologies on specific form factors. This provides a specification not only for ESD metal covers on two sides of VPX boards, but also for forced air, conduction- and liquid-cooling implementations. REDI also addresses spray cooling. To allow for greater power and heat dissipation, REDI includes provision for increased board-to-board spacing and increased board thickness.

Products

A number of manufacturers have announced products based on the VPX standard, in both 3U and 6U form factors. These include single board computers (based on both Intel and PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...

 architectures), Multiprocessors, Graphics processors, FPGA-based processing modules, mass storage, switches, and complete integrated subsystems. Today, VPX is a mature standard, with second- and third generation products coming to market. VPX has also been designed in to a number of high profile military programs.

OpenVPX

The working group was formed in January 2009 to develop a system level specification that addressed interoperability improvements for the VITA 46 (VPX) specification. The goal was to Improve the interoperability of COTS 3U and 6U VPX boards through the implementation of predefined system topologies, and thus to lower the risk of adoption, expand the addressable market for VPX solutions, increase the market opportunities, and accelerate the deployment of VPX solutions into defense related applications.

The OpenVPX System Specification describes the technical implementation details for 3U and 6U VPX payload and switch modules, backplane topologies, and chassis products, which provides clear guidance on how to build interoperable computing and communication platforms. Widespread adoption of OpenVPX will ultimately create a healthy ecosystem of interoperable components and systems providing customers with the benefits of reuse, choice of best of breed, faster time-to-market, lower risk technology refresh, and a more competitive marketplace.

OpenVPX should be seen as a development of, and complementary to, VPX. The OpenVPX System Specification was ratified by ANSI in June 2010.

See also

  • VMEbus
    VMEbus
    VMEbus 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. It is physically based on Eurocard sizes, mechanicals and connectors , but uses its own signalling system,...

  • CompactPCI
    CompactPCI
    A CompactPCI system is a 3U or 6U Eurocard-based industrial computer, where all boards are connected via a passive PCI backplane. The connector pin assignments are standardized by the PICMG US and PICMG Europe organizations. PICMG stands for PCI Industrial Computers Manufacturers Group...

  • CompactPCI Serial (serial, high-speed successor of CompactPCI)

External links

Standards
  • VITA VPX and REDI Standards


Tutorials

Overviews

Reference Guide
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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