知道VME或VXI总线的有吗？

cdhqh

知道VME或VXI总线的有吗？

iamchine

在学校学接口总线时倒是学过VME总线，但工作后没接触过，早还给老师了。刚从网上搜到一个概述性介绍，感觉不错，摘贴如下：
                       VMEbus Applications
VMEbus is used in a wide variety of applications. In many cases, the VMEbus system design has been tailored to support specialized applications as well. Some of the most popular include:
Industrial controls: factory automation, robotics, injection molding machines, automotive body assembly and painting, sawmill controls, metal working, steel manufacturing, cardboard cutters and many others.
Military: battlefield command & control systems, ground and flight radar control systems, tank and gun controls, communications, avionics and many others.
Aerospace: avionics, fly-by-wire control systems, in-flight video servers, spacecraft experiment control, missile countdown sequencers, and many others. In 1998 the Mars Pathfinder used a VMEbus computer to control spacecraft operation on the planet Mars.
Transportation: railway controls, smart highway systems and light-rail transit systems.
Telecom: advanced intelligent node (AIN) switch gear, cellular telephone base stations, satellite uplink and downlinks and telephone switches. VMEbus live insertion capabilities were also designed for this application.
Simulation: aircraft flight, earthquake, metal fatigue and various military simulation systems.
Medical: CATSCAN imaging, MRI imaging and various acoustical systems.
High Energy Physics: particle accelerators, particle detectors.
General business: network routers, servers, copy machines and high-speed printers.
              Original VMEbus (IEEE-1014-1987)
The original VMEbus specification (IEEE-1014-1987) has a robust set of features. These are just a subset of the current VMEbus offerings, but included:
MASTER/SLAVE architecture.
Asynchronous bus (no clocks are used to coordinate data transfers).
Variable speed handshaking protocol.
Non-multiplexed bus.
Addressing range between 16 and 32-bits.
Data path widths of between 8 and 32-bits.
Bandwidths up to 40 Mbyte/second.
Multiprocessing capability.
Interrupt capability.
Wide variety of mechanical hardware based on the IEEE 1101 standard.
Up to 21 card slots can be used in a single backplane.
Noteworthy functions include (up to) 32-bit address and data buses, multiprocessing capability and seven level interrupt protocol. Both the address and data buses can be dynamically configured (i.e. they change widths automatically). This allows system expansion as microcomputer technology grows. It also handles data transfer speeds to 40 Mbytes/second.
VMEbus uses a master-slave architecture. Functional modules called masters transfer data to and from functional modules called slaves. Since many masters can reside on the bus it is called a multiprocessing bus. Before a master can transfer data it must first acquire the bus using a central arbiter. This arbiter is part of a module called the system controller. Its function is to determine which master gets access to the bus. All bus activity takes place on five sub-buses. These are called the Data Transfer Bus, the Data Transfer Arbitration Bus, the Priority Interrupt Bus, the Utility bus and the Serial Bus.
VMEbus is an asynchronous bus. That means that there are no clocks used coordinate data transfers. Data is passed between modules using interlocked handshaking signals. The cycle speed of each transfer is set by the slowest module participating in the cycle.
The maximum speed of asynchronous buses is limited by the propagation delay of signals across backplanes and through buffer ICs. A VMEbus backplane can be up to 500 mm (19.68") in length and can have relatively high inductive and capacitive loads on the signal traces. If VMEbus were synchronous, it would probably have a system clock speed of around 10 MHz. This allows about 100 nanoseconds for a signal to propagate from a master at one end of a bus, through the backplane and interface ICs, and then back again.
As we'll see shortly, the basic capabilities of VMEbus have been greatly expanded since its inception. These enhancements have taken the form of VME64, VME64x and VME320 technologies.
                                 VME64
The most recent version of VMEbus is the ANSI/VITA 1-1994, which is also known as VME64. Since its approval in 1995, a variety of boards and chips have been introduced to support the new standard. As the next generation architecture for VMEbus, VME64 promises to extend the life of VMEbus well into the 21st century. The new standard offers a much-needed 'face-lift', with enhancements such as higher bandwidths, larger address spaces and easier-to-use cards.
VME64 is a mechanical and electrical 'superset' of the original IEEE 1014-1987 standard. It offers new features such as:
Larger, 64-bit data path for 6U boards.
Larger, 64-bit addressing range for 6U boards.
32-bit data and 40-bit addressing modes for 3U boards.
Twice the bandwidth (up to 80 Mbytes/sec).
Lower noise connector system.
Cycle retry capability.
Bus LOCK cycles.
First slot detector.
Automatic 'plug-and-play' features.
Configuration ROM / CSR capability.
Re-definition of SERCLK and SERDAT pins.
Actually, the term 'VME64' is something of a misnomer, as all VMEbus modules that conform to the IEEE-1014-1987 are now considered to be VME64 compliant (regardless of their data transfer capability). For example, a 16 or 32-bit CPU board designed under the older specification can be (correctly) identified as VME64 compatible.
All of the enhancements under VME64 and VME64x are optional. New products work in conjunction with older 'legacy' boards, thereby providing a smooth upgrade path for system integrators.
                  The VME64 Extensions (VME64x)
In 1997 the VITA Standards Organization (VSO) adopted a superset to the VME64 standard. The new standard is called the VME64 Extensions (VME64x). VME64x adds new capabilities such as:
A new 160 pin connector family.
A 95 pin P0/J0 connector.
3.3 V power supply pins.
More +5 VDC power supply pins.
Geographical addressing.
Higher bandwidth bus cycles (up to 160 Mbytes/sec).
141 more user-defined I/O pins.
Rear plug-in units (transition modules).
Live insertion / hot-swap capability.
Injector / ejector locking handles.
EMC (ElectroMagnetic Compatible) front panels.
ESD (Electrostatic Discharge) features.
The VME64x standard also lays the groundwork for the High Availability and Live Insertion (Hot Swap) VME64x standards. These are emerging standards, and will not be covered in great detail in this FAQ.
All legacy VME and VME64 modules are forward compatible to VME64x backplanes and sub-racks. That means that older bus modules can be plugged into newer systems.
In general, the reverse is also true. Bus modules designed to the VME64x standard are also backward compatible with older backplanes and subracks. For example, the new 160 pin connectors can be plugged into an older backplane. However, there are a few exceptions to this. For example, if a board requires the new +3.3 VDC power supplies, then it will not work in an older backplane (which does not have these power pins).
The VME64x standard describes many optional features. However, the standard insists that a minimum set of features be present on boards and backplanes before they are considered to be VME64x compliant. All of the other features in the standard are considered optional. For example, the minimum features that must be present on 6U modules include:
160 pin connectors.
All defined grounds must be connected (row 'd' is optional).
The minimum features that must be present on a 6U backplane include:
160 pin connectors.
All defined grounds must be connected.
Monolithic PCB (i.e. must include both J1 and J2 connectors).
Geographical address pins.
Must route and terminate all VME64 and VME64x bused signal lines.
Power connection and distribution for +5V, +3.3V, +/- 12V, +/- V1, +/- V2 and VPC.
If rear (user defined) I/O pins are supported, then the rear connections must comply with the IEEE 101.11 rear I/O transition board standard.
                              VME320
In 1997 a modified VMEbus architecture called VME320 was released by Arizona Digital, Inc. The VME320 architecture was designed for operation at over 320 Mbyte/second, and peak bandwidths of over 500 Mbyte/second. VME320 uses a new backplane design and bus protocol. It is a proprietary architecture, and the inventors claim to have patent protection on the backplane technology within the United States of America. However, VMEbus modules can be designed, built and sold without license.
The VME320 backplane uses a 'star' interconnection method to speed up the VMEbus backplane itself. All of the interconnections on the backplane are connected together at the middle slot of the backplane. In a nutshell, the idea behind this backplane is that the leading edges of signals, propagating from slot-to-slot, will effectively pass through only one slot on the way to their destination. This allows tighter skew delays on the backplane, thereby speeding up the system.
The VME320 concept uses a new bus protocol called 2eSST. The protocol allows VME320 compatible modules to interact at much higher speeds.
                         VMEbus Software
VMEbus has the largest software base of any computer architecture. That's quite a claim, but it is supported by the fact that there are over 103 known, commercial operating systems running on VMEbus. Other, proprietary operating systems are also known to exist. Table 2 shows just a few examples.

The VMEbus standards themselves have little to say about software. However, there have been an increased emphasis on software standards within the VMEbus community. The Embedded Software Association (ESOFTA) also has additional information about these topics.
          VMEbus Data Transfer Speeds
VMEbus is quite fast, especially in it's most recent manifestations. In fact, it is arguably the fastest of all of the popular microcomputer buses, and certainly the fastest among the 'big commercial backplane buses' (i.e. > 8 slots). Table 3 shows the typical, maximum data transfer speeds that can be achieved between VMEbus modules. The actual data transfer rate of a VMEbus module may be slower than that shown in the Table. The user is advised to contact the board manufacturer for more details.

Table 3. Maximum Data Transfer Speeds
Topology               Bus Cycle          Maximum Speed
VMEbus IEEE-1014         BLT               40 Mbyte/sec
VME64                    MBLT              80 Mbyte/sec
VME64x                   2eVME             160 Mbyte/sec
VME320                   2eSST             320 - 500+Mbyte/sec
更详细的大家可以看http://www.vita.com/vmefaq/#anchor233940

kingfreedom

VME用得很少,通用性不强,
我了解到的这种结构与CPU结构有关.
目前在军用上较多.很昂贵
现在的趋势采用CPCI架构