VPX, also known as VITA 46, is 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. VPX provides VMEbus-based systems with support for switched fabrics over a new high speed connector. Defined by the VMEbus International Trade Association (VITA) working group starting in 2003, it was first demonstrated in 2004, and became an ANSI standard in 2007. [1]
VPX was intended to address shortcomings in scalability and performance on both sides of the bus to bus bridging technology. The goal was to include newer faster VMEbus standards and new generations of PCI bus standards.
The VMEbus International Trade Association (VITA) working group, formed in March 2003, was composed of companies such as ADLINK, Boeing, Curtiss-Wright, Elma Electronic, GE Intelligent Platforms, Kontron, Mercury Computer Systems, and Northrop Grumman, it was designed with defense applications in mind, with an enhanced module standard that enables applications and platforms with superior performance. VPX retained VME's Eurocard form factors, which are based on multiples of three rack units: 3U means three rack units, and 6U six rack units. It supported PCI Mezzanine Card (PMC) and XMC mezzanines (PMC with high-speed serial fabric interconnect), and maintaining the maximum possible compatibility with VMEbus.
New generations of embedded systems reflected the growing significance of high speed serial switched fabric interconnects such as PCI Express, RapidIO, Infiniband and 10 Gigabit Ethernet. These technologies are replacing traditional parallel communications bus architectures for local communications, because they offer significantly greater capability. Switched fabrics technology supports the implementation of multiprocessing systems that require the fastest possible communications between multiple processors, such as digital signal processing applications. VPX gives the existing base of VMEbus users access to these switched fabrics.
VPX technology was presented at a VMEbus International Trade Association (VITA) trade show in 2004, by a company called American Logic Machines USA. [2] Products were announced as early as 2006. [3] [4]
Technologies in VPX include:
The VPX standard was updated in 2013 and 2019. [5]
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 status[ when? ] are:
| Title | Status | |
|---|---|---|
| VITA 46.0 | VPX Baseline Standard | ANSI ratified |
| VITA 46.1 | VMEbus Signal Mapping on VPX | ANSI ratified |
| VITA 46.3 | Serial RapidIO on VPX Fabric Connector | ANSI ratified |
| VITA 46.4 | PCI Express® on VPX Fabric Connector | ANSI ratified |
| VITA 46.6 | Gigabit Ethernet Control Plane on VPX | ANSI ratified |
| VITA 46.7 | Ethernet on VPX Fabric Connector | ANSI ratified |
| VITA 46.9 | PMC/XMC Rear I/O Fabric Signal Mapping on 3U and 6U VPX Modules Standard | ANSI ratified |
| VITA 46.10 | Rear Transition Module for VPX | ANSI ratified |
| VITA 46.11 | System Management on VPX | ANSI ratified |
| VITA 46.12 | Fiber Optic Interface on VPX | Now VITA 66 |
| VITA 46.13 | Fiber Channel on VPX | Planned |
| VITA 46.20 | Switch Slot Definition on VPX | Draft |
| VITA 46.21 | Distributed Switching Topologies | Draft |
The single biggest difference between original VMEbus boards and VPX boards is a new connector, developed by Tyco Electronics and known as the MultiGig RT2 which was used in VXS. [6] Amphenol Aerospace has since developed their RVPX line of connectors capable of speeds up to 32 Gb/s. [7] 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/RVPX connectors and one 8-column 7-row RT2/RVPX connector, while a 3U board features two 16-column 7-row RT2/RVPX connectors and one 8-column 7-row RT2/RVPX 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 signaling 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:
The connector is designed to allow a typical stiffening bar and a standard length PMC.
The VITA 62 section of the VPX standard allows for more flexibility in maximizing power capability of the system, as compared to the old VMEbus standards. "When the shared pins are utilized with multiple supplies, there are no real limitations on achievable power levels," states Patrick Shaw the chair of VITA 62. [8]
Removing wasted heat is always one of the primary objectives related to the power supply of a system. The specification of 6U VPX calls for computer cooling 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.
Manufacturers[ who? ] 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 architectures), multiprocessors, graphics processors, FPGA-based processing modules, mass storage, switches, and complete integrated subsystems, which started appearing around 2007. [9] [10]
The OpenVPX working group was formed in January 2009 to develop a system-level specification that addressed interoperability improvements for VPX. Three years after being called a "standard", most VPX products still had to have all components supplied by a single source. [11] The United States Department of Defense, in particular, mandated improved interoperability of parts of different vendors. [12] In October, 2009, the specification was submitted as VITA 65, and products were demonstrated at the Milcom 2009 conference. [13] In December 2009, the 28 member companies formed an alliance for marketing their products. [14]
The OpenVPX System Specification describes technical implementation details for 3U and 6U VPX payload and switch modules, backplane topologies, and chassis products, which provides guidance on how to build interoperable computing and communication systems. OpenVPX was a development of, and complementary to, VPX. The OpenVPX System Specification was ratified by ANSI in June 2010. By 2011, it was seen as replacing older forms of VMEbus. [15] SOSA aims to guarantee interoperability between equipment adhering to the VPX standard from different vendors. [16] [17]
Eurocard is an IEEE standard format for printed circuit board (PCB) cards that can be plugged together into a standard chassis which, in turn, can be mounted in a 19-inch rack. The chassis consists of a series of slotted card guides on the top and bottom, into which the cards are slid so they stand on end, like books on a shelf. At the spine of each card is one or more connectors which plug into mating connectors on a backplane that closes the rear of the chassis.
Myrinet, ANSI/VITA 26-1998, is a high-speed local area networking system designed by the company Myricom to be used as an interconnect between multiple machines to form computer clusters.
VMEbus is a computer bus standard physically based on Eurocard sizes.
Futurebus is a computer bus standard designed to replace all local bus connections in a computer, including the CPU, plug-in cards, and even some LAN links between machines. The project started in 1979 and was completed in 1987, but then went through a redesign until 1994. It has seen little real-world use, although custom implementations are still designed.
A PCI Mezzanine Card or PMC is a printed circuit board assembly 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.
Electronic test equipment is used to create signals and capture responses from electronic devices under test (DUTs). In this way, the proper operation of the DUT can be proven or faults in the device can be traced. Use of electronic test equipment is essential to any serious work on electronics systems.
CompactPCI is a computer bus interconnect for industrial computers, combining a Eurocard-type connector and PCI signaling and protocols. Boards are standardized to 3U or 6U sizes, and are typically interconnected via a passive backplane. 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.
VME eXtensions for instrumentation bus refers to standards for automated test based upon VMEbus. VXI defines additional bus lines for timing and triggering as well as mechanical requirements and standard protocols for configuration, message-based communication, multi-chassis extension, and other features. In 2004, the 2eVME extension was added to the VXI bus specification, giving it a maximum data rate of 160 MB/s.
Multibus is a computer bus standard used in industrial systems. It was developed by Intel Corporation and was adopted as the IEEE 796 bus.
The STEbus is a non-proprietary, processor-independent, computer bus with 8 data lines and 20 address lines. It was popular for industrial control systems in the late 1980s and early 1990s before the ubiquitous IBM PC dominated this market. STE stands for STandard Eurocard.
A system on a module (SoM) is a board-level circuit that integrates a system function in a single module. It may integrate digital and analog functions on a single board. A typical application is in the area of embedded systems. Unlike a single-board computer, a SoM serves a special function like a system on a chip (SoC). The devices integrated in the SoM typically requires a high level of interconnection for reasons such as speed, timing, bus width, etc. There are benefits in building a SoM, as for SoC; one notable result is to reduce the cost of the base board or the main PCB. Two other major advantages of SoMs are design-reuse and that they can be integrated into many embedded computer applications.
M-Modules are a mezzanine standard mainly used in industrial computers. Being mezzanines, they are always plugged on a carrier printed circuit board (PCB) that supports this format. The modules communicate with their carrier over a dedicated bus, and can have all kinds of special functions.
Stackable Unified Module Interconnect Technology (SUMIT) is a connector between expansion buses independent of motherboard form factor. Boards featuring SUMIT connectors are usually used in "stacks" where one board sits on top of another. It was published by the Small Form Factor Special Interest Group.
CompactPCI PlusIO is an extension to the PICMG 2.0 CompactPCI industrial standard for modular computer systems. CompactPCI PlusIO was officially adopted by the PCI Industrial Computer Manufacturers Group PICMG 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 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.
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, CompactPCI Serial uses only serial point-to-point connections. CompactPCI Serial was officially adopted by the PCI Industrial Computer Manufacturers Group PICMG as PICMG CPCI-S.0 CompactPCI Serial in March 2011. Its mechanical concept is based on the proven standards of IEEE 1101-1-1998 and IEEE 1101-10-1996. CompactPCI Serial includes different connectors that permit very high data rates. The new technology standard succeeding parallel CompactPCI comprises another specification called PICMG 2.30 CompactPCI PlusIO. This is why CompactPCI Serial and CompactPCI PlusIO as a whole were also called CompactPCI Plus. PICMG's first working title of CompactPCI Serial was CPLUS.0. CompactPCI Serial backplanes and chassis are developed by Schroff, Elmа, and Pixus Technologies companies, as for the CompactPCI Serial board level electronics – they are developed by MEN Mikro Elektronik, Fastwel, EKF, Emerson Embedded Computing, ADLINK, and Kontron.
Hybricon Corporation is a provider of systems packaging serving the military, aerospace, homeland security, medical and high-end Industrial markets and develops embedded computing systems using OpenVPX, VPX, VXS, VMEbus, VME64X, CompactPCI, rugged MicroTCA, and custom bus structures.
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 serving the military, aerospace, homeland security, medical and industrial markets. The Elma Bustronic division develops backplanes, including VME320, which was the world's fastest VME backplane in 1997. Elma Bustronic also develops backplanes in OpenVPX, VMEbus, VME64X, CompactPCI, MicroTCA, and custom bus structures. Elma is an executive member of the PCI Industrial Computer Manufacturers Group (PICMG), VME International Trade Association, and member of the OpenVPX Industry Working Standards Group.
FPGA Mezzanine Card (FMC) is an ANSI/VITA 57.1 standard that defines I/O mezzanine modules with connection to an FPGA or other device with re-configurable I/O capability. It specifies a low profile connector and compact board size for compatibility with several industry standard slot card, blade, low profile motherboard, and mezzanine form factors.
VMEBus Switched Serial, commonly known as VXS, is an ANSI standard that improves the performance of standard parallel VMEbus by enhancing it to support newer switched serial fabrics. The base specification defines all common elements of the standard, while "dot"-specifications define extensions which use specific serial fabrics or additional functionality. VXS is backward compatible with VMEBus. It is defined by the VME International Trade Association (VITA) working group.
The RAD5500 is a radiation-hardened 64-bit processor core design created by BAE Systems Electronics, Intelligence & Support based on the PowerPC e5500 designed by IBM and Freescale Semiconductor. Successor of the RAD750, the RAD5500 processor platform is for use in high radiation environments experienced on board satellites and spacecraft.
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Interfaces are listed by their speed in the (roughly) ascending order, so the interface at the end of each section should be the fastest.  Category | |
