This document provides an overview of VME and VPX standards for modular computing systems. It discusses the origins and evolution of VME, including its initial development based on Eurocard and VERSAbus standards. Key features of VME are described such as its modular design, interconnect standards, and support for real-time control applications. Enhancements to VME including VME64 and VME64x are summarized. The document then provides a brief introduction to the transition from VME to the newer VPX standard and OpenVPX specification.
1. New Trends with VME/VPX – Part 1
An historical perspective with a look at the future
2. Overview
Part 1
• VME: how it all started
• VME: motivations
• VME: electrical features
• VME: mechanical features
• VME: enhancements (VME64,
2eSST, etc)
• VME64: An example - Advme8028
• VME64x + 2eSST: An example -
Advme8027
• VME: CPU architectures
Part 2
• From VME to VPX
• VPX - OpenVPX
• OpenVPX: basics
• OpenVPX: MultiGig RT2
connector
• OpenVPX: planes and profiles
• OpenVPX: 2 level maintenance
• OpenVPX: an example
3. VME: how it all started
1980: Motorola + Mostek + Signetics
VME begins as the sum of two standards:
Eurocard (mechanical) + VERSAbus (electrical)
In that moment, many different proprietary solutions existed
Lack of standardization was inhibiting cross-compatibility, etc
With VME, an open standard was created.
Its adoption generated a multibillion market that is still very strong.
Being open, VME has been adopted by a significant number of
vendors that offer interoperable platforms
4. VME: motivations
VME promised and delivered great value to the customer:
• Simple maintenance
• Rugged and reliable systems
• Lots of flexibility in configurations
• Interoperability
• Support for real time control
These qualities have made VME a choice in many high end and
long term applications, including: defense, transportation, medical,
aerospace, high end industrial
5. VME: electrical features
Historically, the first concept of VME was very close to an
extension of the Motorola 68K CPU
It gradually became standardized and incorporated some important
features (IEEE-1014-1987):
• 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.
6. VME: mechanical features
VME is a backplane pluggable standard that has been designed
with the Eurocard form factors (IEEE 1101.1):
• 3U, 6U or 9U height – 9U not common today
• Single or double width (1 or two slots)
• Length: 160mm or 340mm
• One backplane can have up to 21 slots (19”)
6U
P1
P2
3U P1
7. VME: mechanical features
In VME, two types of connectors to the backplane are defined:
96 pins (VME and VME64) or 160 pins (VME64x)
P1 (3U&6U) P2 (6U only)
VME, VME64 96 pins (16D+24A) 96 pins (16D+8A ext; 64
user defined)
VME64x 160 pins (more user I/O) 160 pins (more user I/O)
Note: The 68K CPU had 32/32 internal busses, but 24/16 external busses
VME, VME64
VME64x
Note: VME64x allows also one 95 pin connector (P0) for high speed signals
9. VME: enhancements (VME64, 2eSST, etc)
VME has been improved and extended over time; some examples:
• VME64 (ANSI/VITA 1-1994)
– 64D/64A for 6U boards.
– 32D/ 40A for 3U boards.
– Twice the bandwidth (up to 80 Mbytes/sec).
– Automatic 'plug-and-play' features.
• VME64x (1997)
– A new 160 pin connector family.
– A 95 pin P0/J0 connector.
– 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.
• VME320 [2eSST] (1997/98)
– 320MB/s and new backplane technology
10. VME64: An example - Advme8028 6U with
Intel® Atom™ CPU
Eurotech Advme8028 is a VME64 board
VME, VME64 96 pins
PMC slots
11. VME64x + 2eSST: An example -
Advme8027 6U with Intel® Core 2 Duo™
Eurotech Advme8027 is a VME64x board with 2eSST support
VME64x 160 pins
PMC slotsXMC slots
12. VME: CPU architectures
VME was born to support the Motorola 68K, but it is versatile:
• PPC
– PPC based designs are very popular
– E.g. Altivec support (PPC) + VME ruggedness and easy maintenance = great
success in Defense applications
• X86
– Many designs have incorporated x86 CPUs
– Large software base and lots of tools
For examples of VME boards, please check: www.eurotech.com