UNI EN ISO 9001 CERT. N. 9105.CAEN VME course for beginners Carlo Tintori Kolkata-Mumbai May 2009

UNI EN ISO 9001 CERT. N. 9105.CAEN

VME course for beginnersCarlo Tintori

Kolkata-Mumbai May 2009

May 2009 VME course for beginners 2

Reproduction, transfer, distribution of part or all of the contents in this document in any form without prior written permission of CAEN S.p.A. is prohibited

indexindexindexindex

• Cap. 1: Introduction to the VME standards

• Cap. 2: VME architecture and protocols

• Cap. 3: Setting up a VME acquisition system

• Cap. 4: Examples of Software for VME systems



preamblepreamble

CAEN has been designing VME boards for more than 20 years; today our VME products are the result of the long experience in the field of physics applications and the interaction with our customers all over the world. This presentation describes general characteristics and features of the VME bus that can be applied to any VME product available on the market. However, it reflects our know-how and our view of the VME standards. The course focuses on the issues that we consider more related to the physics applications and it can not be considered as an exhaustive VME treatise.The practical examples will be done using CAEN modules, drivers and libraries

Chapter 1--------------------------------

Introduction to the VME standards



What is VMEWhat is VME• VMEbus is a master-slave computer architecture

• VME stands for VERSA-Module Eurocard

• the standard defines electrical and mechanical specifications

• it was introduced in 1981 for industrial, commercial and military applications

• VITA (VME International Trade Association) is the organisation whose purpose is to promote and develop the VME



VME at a glanceVME at a glance

VME crate (chassis)

smart fan units

VME master VME slavespower supply

backplane



• Unlike NIM and CAMAC, the VME was created for the industry and not for physics applications

• However, the North American, European and Japanese physics communities have joined to work with the VITA and found the VME International Physics Association (VIPA)

• Two standards have been created: VME/V430 (1990) and VME64xP (1998)

VME for physicsVME for physics



The standards: VMEThe standards: VME

• Born in 1981

• 3-row P1/P2 connectors type DIN-96pin

• 32 bit wide Address and Data buses

• Bandwidth up to 40MBytes/s (BLT)

• Power Supplies: +5, 12

• Up to 21 card slots can be used in a single backplane

VME (IEEE-1014-1987)

P1

P2

DIN-96pin Connector



The standards: VME64The standards: VME64

• Born in 1989

• Same mechanics as the VME

• Fully backwards compatible

• 64 bit wide multiplexed Address and Data buses

• Bandwidth up to 80MBytes/s (MBLT)

VME64 (ANSI/VITA 1-1994)

P1

P2



The standards: V430The standards: V430

• Born in 1990

• Additional 3-row PAUX connector type DIN-30pin

• Geographical Addressing

• Dedicated trigger and clock lines

• Extra Power Supplies: -5, -2, 15

• Not fully compatible with VME64!!!

VME/V430 (CERN)

P1

P2

PAUX



The standards: VME64xThe standards: VME64x

• Born in 1996

• 5-row P1/P2 connectors (160 pins)

• P0 connector (metric 95 pins, optional)

• Bandwidth up to 160 MBytes/s (2eVME)

• Geographical Addressing

• Power Supplies: +5, 12, +3.3, +48, u.d.

• Live Insertion, ESD-EMC features

VME64x (VITA 1.1-1997)

P1

P2

P0



5 row P1/P2 connectors5 row P1/P2 connectors• BACKWARD AND FORWARD COMPATIBILITY

thanks to the mechanical design of the 5-row connectors, older legacy boards will fit into new backplanes (and vice-versa)

Precharge pins

96 pinrow a,b,c

+ 64 pinrow d,z



VME64X mechanicsVME64X mechanics

• IEEE Std 1101.10-1996• ESD-EMC shielding panel• Anticipated ground connection• Alignment pins• Insertion-Extraction handles• Keying (prevents damages due

to incompatible power supply)

• Warning: VME64 and VME64x boards and backplanes can always mate; however, VME64x boards may not fit the mechanics of the VME64 crates



The standards: VME64xPThe standards: VME64xP

• Fully compatible with VME64x

• Definition of power supplies in P0 connector

• Some options are made mandatory

• Definition of 9U board size

• Special transfer protocols for Physics (Chained Block Transfer, MultiCast…)

• NOT A NEW STANDARD!!!

VME64xP (VIPA) (VITA 23-1998)

P1

P2

P0



The standards: 2eSSTThe standards: 2eSST

• Born in 1997 (VME320 backplane by Arizona Digital, Inc.)

• Same mechanics as the VME64x

• Implemented 2eSST protocol for high speed data transfer

• Bandwidth up to 320 MBytes/s (2eSST) std VME64x backplanes

• New backplanes layout which reduces parasitic capacitance and inductance up to 1GByte

VME2eSST (VITA 1.5-2003)

P1

P2

P0



The standards: VXS (VITA 41)

The standards: VXS (VITA 41)

VXS: VME Switched Serial (VITA 41)• Transition to the legacy parallel bus to one or more

high speed serial links (switched fabric)

• High speed new P0 connector designed to support up to 6Gbps

• Backwards compatibility with the VMEbus ecosystem

• Definition of multiple interconnect technologies:• VITA 41.1: InfiniBand

• VITA 41.2: Serial RapidIO

• VITA 41.3: 1000BaseCX Ethernet

• VITA 41.4: PCI Express

• VITA 41.5: Aurora

• 45 GB/s with today’s fabric speeds (could grow to 180 GB/s)!



Payload and Switch boardsPayload and Switch boards

Payload boardSwitch board

Alignment and Protocol Keying

example of dual star backplane

New high-speed P0 (different from P0 in VME64x)

different backplane topologies are available



Example of VXS productsExample of VXS products



The standards: VPX (VITA 46)The standards: VPX (VITA 46)

• New 7-row connector rated for signalling rates up to 6.25Gbps

• High speed serial connectivity• PMC and XMC mezzanines• Ruggedized solutions• Conduction cooling• Mainly used for military

applications

VITA46



Hybrid backplanesHybrid backplanes

• Concept of a hybrid backplane is fundamental to VITA 46

• Retain customers existing $$$ investment in VME boards

• Accepts all existing VME modules - with and without P0 connector

VME64x

VXS

VITA 46



VME MechanicsVME Mechanics

3U P1

160 x 100 mm

P06U

P1

P2

160 x 233 mm

P1

P0

P2

P3

P4

J1/P1 DIN 96 pins3 rows x 32

J1/P1 & J2/P2 DIN 160 pins5 rows x 32

J0/P0 J4/P4 metric 95 pins5+2 rows x 19 (2 mm)

J5/P5 metric 110 pinsJ6/P6 metric 125 pins

VME64XP9U

P1

P0

P2

P5P4

P6367 X 400 mm



Rear Transition ModulesRear Transition Modules

P1

P2

Backplane

3U transition module

6U VME module

• 3U, 6U and even 9U size• 64 user defined lines

available on P2• Further free lines on the 5

rows connectors• Can be used to implement

an auxiliary bus in parallel to the VME



• +5V is always available with high current (200A or more)• ±12V is always available but the current may be rather low;

sometimes DC-DC converters are used to generate ±12V from +5V (CAEN does that for some modules)

• +3.3V is available in VME64x only on the external rows; it should not be used in case of backward compatibility (not used by CAEN)

• +48V is available in VME64x only and is normally used for the switching DC-DC converters (not used by CAEN)

• -5V and -2V (mainly for ECL) can be taken either from JAUX (V430 version only) or from internal DC-DC converters. It is recommended not to use them for compatibility reasons.

• ±15V from JAUX only; It is recommended not to use them for compatibility reasons.

Power suppliesPower supplies



Transfer rateTransfer rate

• As the VME is an asynchronous bus, the bandwidth indicated is a theoretical limit

• Usually the actual transfer rate is less than 50% of the bandwidth• Except Synchronous 2eSST: 95% protocol efficency (~ 300 MB/sec)

40

80

40

160

160

320

20

40

20

80

80

300

0 50 100 150 200 250 300 350

VME (BLT)

VME64 (BLT)

VME/V430 (BLT)

VME64x (2eVME)

VME64xP (2eVME)

VME2SST (2eSST)

Theoretical Max Band (MB/s) Practical Max Band (MB/s)



The standards: summary

The standards: summary

Year Protocol Band (MB/s)

P1/P2 PAUX P0 Power Supplies

VME

1981 BLT 40 3 x 32 - - +5, 12

VME64 1989 MBLT 80 3 x 32 - - +5, 12

VME/V430 1990 MBLT 80 3 x 32 3 x 10 - +5, 12,

-5, -2, 15

VME64x

1996 2eVME 160 5 x 32 - 5 x 19 +5, 12, +3.3,

+48, ud

VME64xP

1996 2eVME 160 5 x 32 - 5 x 19 +5, 12, +3.3, +48, -5, -2, ud

VME2SST

1997 2eSST 320 5 x 32 - 5 x 19 +5, 12, +3.3,

+48, ud



VME Ref.VME Ref.• VMEbus Handbook by Wade Peterson,

published by VITA A readable reiteration of the VMEbus specifications with much background material

• VMEbus International Trade Association (VITA) 126 Members (CAEN & CERN) http://www.vita.com/

• CERN documentation: http://atlas.web.cern.ch/Atlas/GROUPS/FRONTEND/VMEbus/

• VITA Standards Organisation – VSO http://www.vita.com/vso

• ftp.caen.it username: caenvme passwd: bitto12

Documents

UNI EN ISO 9001 CERT. N. 9105.CAEN VME course for beginners Carlo Tintori Kolkata-Mumbai May 2009