Frequently Asked Questions
comp.arch.bus.vmebus

1. J2/P2 Rows A and C are user defined. They are specified in the VXIbus which is one reason why the VXIbus and VMEbus are not totally compatible.

2. A01 to A31 is the address bus. Notice it is similar to the MC68000 scheme ie without A0. DS0* and DS1* (DS = Data Strobe) specify the upper or lower portion of the data bus. (rather than having a A0) See the FAQ for comp.sys.m68k for a discussion of this issue.

3. * means an active low signal.

D) VME64 - a new standard

The regular VMEbus standard accommodates 32 bit address and data buses. Data transfers are 32, 16 and 8 bytes wide. One type of data transfer, called a Block Transfer, allow up to 256 bytes to be transferred with only the start address placed on the address bus once. For the rest of the transfer, the address bus is idle. The VME64 standard utilizes this unused bandwidth to enable 64 bit block transfers. The lower 32 bits are placed on the regular D0 to D31 and the upper 32 bits placed on the idle address bus A01 to A31.

The VME64 standard adds many other advanced features. VME64 is a VITA Standard. This standard, which has recently gained ANSI approval, is backwards compatible with existing VMEbus boards.

For more information: http://www.vita.com/jvita.html

There is a VME64 Reflector (mailing list). To subscribe, Email to majordomo@syspac.com leaving the subject line blank with the following command in the body: of the message: subscribe vita
You will receive confirmation of your subscription and to send a message to others send your Email message to vita@syspac.com.

Back to What's New!

3) The VXIbus - Technical Information

A) The VXIbus - Introduction

The VXIbus is an instrumentation bus based on the VMEbus, the Eurocard and standards such as IEEE 488.2 and the HP GPIB (General Purpose Instrumentation Bus). It is an open architecture and is useful for automated test systems and data collection. The issue of electromagnetic radiation is part of the VXIbus specification. VXIbus is an acronym for "VMEbus eXtensions for Instrumentation". The VXIbus was announced in 1987.

The VXIbus expands on the VMEbus so the two bus specifications are very similar. TTL and ECL trigger lines, a local bus and an analogue summing bus are among the added features. The December 1988 issue of "VMEbus Systems" contains a good outline of the VXIbus. The Spring 1995 issue of "VXIjournal" is a VXIbus Buyer's Guide.

B) The VXIbus - Description

There are two more board sizes in addition to the VMEbus single and double sizes:

       Size      Height    Dimensions (mm)     Connectors        Slot Spacing
       ----------------------------------------------------------------------
       A         Single    100 x 160           P1                  0.8 inch
       B         Double    233 x 160           P1 & opt P2         0.8 inch
       C         Double    233 x 340           P1 & opt P2         1.2 inch
       D         Triple    366 x 340           P1, opt P2,P3       1.2 inch

       ======================================================================

Notes:

1. opt = optional

2. P1, P2 & P3 are the same 96 pin DIN connector as in the VMEbus.

3. The increased width of the C and D sizes are to accommodate thick analogue modules and EMI shielding.
   

Reasons why the VMEbus and the VXIbus specifications are not totally compatible include:

1. conflicts may arise depending on the use of the A & C rows on P2.

2. VMEbus Double height boards are not as deep as VXIbus size C.

3. The VMEbus has no configuration registers while the VXIbus does.

C) DIN Connector Assignments

P1 and P2-B (the centre row) have the same pin assignments as the VMEbus and are listed above. The outside 2 rows of P2 are specified in the VXIbus. In the VMEbus specification, these two rows are user defined. Since Slot 0 on the backplane is reserved for a system timing module, P2-A has slightly different assignments than for Slots 1 to 12. P2-C has essentially the same assignments for all slots.

to be continued.....

4) Information Sources

A) VMEbus Systems Magazine

       25875 Jefferson                  (Advertising and Business Offices)
       St. Clair Shores                  The Editorial Offices are at Micrology
       Michigan, 48081                   listed below.

       (313) 774-8180
       (313) 774-8182 (FAX)

This magazine is free to qualified VMEbus systems users and specifiers in the United States and Canada. There is a subscription fee applicable for other countries. This magazine contains industry news, informative articles and useful advertisements. Back issues are available from Micrology. See http://www.primenet.com/~magpub for more information.
The December 1994 issue is a useful Buyer's Guide.

B) VXI Journal

       Business Offices              Editorial Offices

       25875 Jefferson               11051 Pinto Drive
       St. Clair Shores              Fountain Hills
       Michigan, 48081               Arizona, 85268

       (313) 774-8180                (602) 837-3756
       (313) 774-8182 (FAX)          (602) 837-3768 (FAX)

VXIJournal is published by the people at the VMEbus Magazine at the same addresses as listed above. Subscriptions are free to qualified users of the VXIbus or GPIB in Canada or the USA.

C) Real Time Engineering

A new magazine, Real Time Engineering, is also published by Micrology in Arizona. The Spring 1995 edition is a Buyer's Guide.

To get a subscription request form for any of these three magazines, send Email to John Black, Editor (micrology@aol.com) or contact the offices in Michigan.

The Web site for these three magazines is : http://www.primenet.com/~magpub

D) Micrology pbt, Inc.

2618 S. Shannon Drive
Tempe, Arizona 85282

(602) 967-5581
(602) 968-3446 (FAX)
(602) 968-9265 (Real Time Engineering Magazine)
micrology@aol.comJohn Black

A VXIbus Buyer's Guide - $33

Back issues of VMEbus Systems Magazine are available for $4 each.
Email micrology@aol.com and request a listing.

The Systems Engineer's Handbook:
A guide to building VMEbus and VXIbus systems:

John Black has edited this hard cover text that covers the VMEbus and VXIbus thoroughly. This is an easy to read book that contains the complete VMEbus and VXIbus specifications and information on graphics, disk interfaces, Ethernet, image processing and interfacing to external devices such as stepping motors...and much more.

It is now available directly from Micrology for US$59.95 + $7 shipping.
excellent. - even better at this lower price !

(602) 966-5936 or FAX (608) 968-3446

Back to What's New!

E) VITA - VMEbus International Trade Association

       VITA                                         VITA Europe
       10229 North Scottsdale Rd                    P.O. Box 192
       Suite B                                      5300 AD Zaltbommel
       Scottsdale, Arizona 85253                    The Netherlands
       (602)  951-8866                              31.4180.14661 (or .16593)

       (602) 951-0720 (FAX)                         31.4180.15115  (FAX)

       John Rynearson                               Zoltan Hunor
       Technical Director                           Director VITA
       VITA USA                                     Europe
       techdir@vita.com                             hunor@knoware.nl

World Wide Web site: http://www.vita.com

VITA is the world-wide association of VMEbus users and manufacturers and as such organizes global promotion of the VMEbus including exhibitions, seminars and courses. Vita does not test and approve components but is a full member of ANSI and promotes standards of interest to the community. VITA publishes various magazines and manuals about the VMEbus.
In Europe, VITA has a mailing list of 100,000 engineers.

VMEbus Handbook $53 VMEbus Specification $32

The Handbook provides information for programmers, system integrators, engineers. It is written by Wade Peterson in an easy-to-read style. It contains information on the VMEbus from a general outline to hardware specifics. There are schematic diagrams and many photographs of representative VMEbus components. This book also addresses the VME64 specification and the Futurebus+ bridge and is recommended.

The VMEbus Specification book is the complete specification list. These two books provide the information needed to understand the VMEbus system and are worth the moderate cost.

VITA also publishes a Buyer's Guide for $55 (or $110 a year).

VITA now offers a free quarterly news publication, the VITA Journal, on a complimentary subscription basis to qualified residents of the United States. It contains member and industry news and the activities of the VITA Standards Organization.

F) Computer Design

Computer Design is a magazine that contains VMEbus advertisements with articles about computer design in general. It is free to qualified readers by contacting Ron Kalusa at ronk@pennwell.com.

Back to What's New!

G) Test & Measurement World

This magazine will feature the VXIbus starting in January 1996. The February issue will feature an article on using VMEbus slave cards in a VXIbus system. It is free to qualified personnel.

275 Washington Street
Newton, Massachusets 02158
Phone (617) 558-4671
FAX (617) 558-4470
Email: tmw@cahners.com

Back to What's New!

H) The Manufacturers

There are many manufacturers of VMEbus computer modules worldwide. Refer to any of the Buyer's Guides listed above or post to comp.arch.bus.vmebus for more information. Many manufacturers are getting Internet Email addresses. They note them in their advertisements in the magazines listed above.

Many VMEbus CPU boards have a built-in monitor program similar to the TUTOR monitor and have a RS-232 port that can be hooked up to a terminal or a host computer. Programs can be entered with the provided simple assembler/disassembler and executed. Peripheral devices can be attached easily to these boards. These boards are often available used and the older ones with 68000/10 CPUs have a low cost(<$50) and is a good way to become acquainted with the VMEbus. See the FAQ for comp.sys.m68k.

I) Unadvertised ftp and WWW Sites

Motorola

• http://motserv.indirect.com
  
• http://www.mot.com
  
• http://design-net.com/datacom - info on MC68302 and 68360.

• http://freeware.aus.sps.mot.com/index.html(for html)
  
• ftp://freeware.aus.sps.mot.com (Motorola BBS)
  
• ftp://pirs.aus.sps.mot.com(129.38.233.1) (AESOP & DR. BUB)
  

------------------------------------------------------------------

Other Interesting Links:

VITA - http://www.vita.com

Heurikon - http://www.heurikon.com(nifty daily cartoons)

Dallas Semiconductor - http://www.dalsemi.com (Postscript data sheets)

Maximum Strategy Inc. - http://www.maxstrat.com (disk arrays)

Hitex Corporation - In-circuit Emulators http://www.hitex.com/ for California or in Europe: http://www.ba-karlsruhe.de/automation

Introl Corporation: http://www.introl.com
Introl is offering a non-commercial license for their US$2,000 C compiler. This is the full version - it is not crippled. It comes with an instruction manual. It is available for MS-DOS and Windows95 for this special offer. See their homepage for more information.
Back to What's New!

FAQ - comp.sys.m68k: for information on the Motorola M680x0 and MC683xx

http://www.hitex.com/automation/FAQ/m68k California
http://www.ee.ualberta.ca/archive/m68kfaq.html Western Canada
ftp://nyquist.ee.ualberta.ca/pub/motorola/m68kfaq
http://www.ba-karlsruhe.de/automation/FAQ/m68k Germany

5) Answers to Frequently Asked Questions

A) VMEbus Interface Components

A frequently asked question is "are there any easy-to-use devices to provide a VMEbus interface to my computer design?". Two suppliers of chips to do these tasks are Cypress and Newbridge .

Newbridge Microsystems

The VME64 (SCV64) controller chip provides a 64 bit VMEbus interface from the local bus. This chip has a built-in DMA controller, VMEbus address decoder and local bus burst modes. It is a 299 pin PGA ($308CDN) or a 304 pin PQFP ($256CDN) package.

Newbridge also makes a PCI to VMEbus interface ("UNIVERSE")($US160 @ 1K) and Futurebus+ interface chips ("LIFE"). A new part, "TROOPER" is a low cost ($40 1995 @ 1K) slave-only VMEbus interface chip. Available June 1995. The SCV64 and "TROOPER" are fabricated by Motorola.

The "SPANNER" is now in production. This is a MC68040 to PCI bridge chip. This is Newbridge's introductory offering in this area.

(800) 267-7231 (North America), (613) 592-0714 in Canada
(408) 258-3600 in California.

Email addresses:
nms-inquire@newbridge.com for general inquiries or nms-support@newbridge.com for technical support.

<prices may be inaccurate> The SCV64 (33 Mhz QFP) has been reported as costing US$ 332 (qty=5), US$ 287 (25) and US$ 248 (100).

Cypress Semiconductor

Cypress manufactures a series of useful VMEbus integrated circuits:

VIC64 - an enhanced VIC068. All the features of the VIC068 plus MBLT support. (Multiplexed Block Transfer) Provides a direct connection to the M68K family and mappable to others. VME64 compliant (64 bit block transfers - rates up to 70 mbytes/sec). 144TQFP, 144PPGA, 144CPGA, 160PQFP, 160CQFP. $US 142 (Qty 100)

VIC068 - VMEbus Interface Controller - provides VMEbus controller functions between a CPU and the external VMEbus. VMEbus SYSCON (system controller), interrupt handler, local DMA and a DRAM controller. 32/16/8 bit transfers. 144TQFP, 144PPGA, 144CPGA, 160PQFP, 160CQFP. $US 113 (Qty 100)

VAC068 - VMEbus Address Controller - forms a complete VMEbus master/slave interface when used with the VIC068.
144PPGA, 144CPGA, 160PQFP, 160CQFP. $US 91 (Qty 100)

CY7C960 - Slave VMEbus Interface Controller - VME64 (64/32/16/8 bit data transfers), auto-slot ID, DMA, DRAM controller with refresh. 80 mbyte/sec Block Transfers. CR/CSR support (used for Auto-slot identification to determine which slot a participating module is in).
64TQFP, 64CQFP, 68CPGA. $US 29

CY7C961 - based on the CY960 - includes local and remote VMEbus Master capability. on-chip DMA.
100 TQFP, 100CQFP. $US 47 (Qty 100)

CY7C964 - Bus Interface Logic Circuit - a companion part to the products listed above. This 8 bit part is used to drive the upper three bytes of the VMEbus data and address buses. Three devices are needed for VIC068 and VIC64 and four with the CY7C960/961. The VIC64 and VIC068 directly drive the lower bytes. The purpose of this part is to simplify the interfacing of the board logic by providing various counters, latches, comparators and drivers.
64TQFP, 64CQFP, 68CPGA. $US 19 (Qty 100)

        San Jose, California, U.S.A        Toronto, CANADA.

       Phone (408) 943-2600               Phone (416) 620-7276
       FAX   (408) 943-2741               FAX   (416) 620-7279
       vmebus@cypress.com                 Ed Dupuis (ead@cypress.com)
       BBS: (408) 943-2954 (1200 to 19.2k, 8N1)

B) Battery Clocks - MK48TO2B-xx

Some VMEbus CPU boards contain a clock IC with an integral battery such as the MOSTEK MK48TO2B-25. The battery in this device is supposed to last for five years, then the entire chip must be replaced. It seems the manufacturers expected these boards to become obsolete when they became 5 years old.

The MK48TO2B-25 is being discontinued and has been replaced by the M48TO2-200PC1. Mauser Electronics <(800) 346-6873 or (817)483- 4422> nor Arrow have any MK48Ts and the M48Ts have a delivery time of 8 to 14 weeks. MOSTEK is apparently now owned by SGS-Thompson who will be replacing the MK48TO2B with a 2 piece part called the "SnapHat". The IC proper and the battery/crystal are replaced separately. This information is provided by Gerry Belanger and Dennis Johnson.

Dallas Semiconductor makes the Timekeeper series of clock chips. Their US phone number is (214) 450-0448 or (800) 336-6933.

The Dallas DS1642 may replace the Mostek MK48TO2B-25. The DS1642 is available in speeds of 120 or 150 nsec. It is available directly from Dallas Semiconductor for about US$17 plus shipping with a delivery time of 4 to 6 weeks. Dallas credit card orders for the USA - (800) 336-6933. Dallas suggests that Newark Electronics may have this item in stock. (800) 463-9275 CANADA number only.(?)
The postscript datasheet for this part is: ftp://ftp.dalsemi.com/pub/datasheets/1642.ps

How to add an external battery:

The MK48TO2B-25 Mostek real time clock consists of a standard 24 pin DIP with a black plastic cap attached to its top. This plastic rectangular cap contains the clock crystal and the battery.

This cap is attached to the chip body at each end only with a potting material that appears to be an epoxy. If you put the MKT48 up to a light source you should be able to see a gap between the plastic cap and the DIP. Notice that the cap is glued to the DIP only at the ends and then only in the centre of the ends. ie where the half-circle is molded into a DIP to indicate where pins 1 and 24 are and at the corresponding place at the other end.

The wires for the crystal and the battery pass through this potting material on each side of the potting material. The crystal wires are at the pin # 1 and 24 end of the DIP and the battery is at the pin # 12 and 13 end. These wires do not necessarily connect to these pins.

The idea is to cut through the potting material, disconnect the positive internal battery wire and solder a new battery to the wire coming out of the DIP nearest to pin 13 and the other to pin 12 (ground) of the DIP.

The positive (+) wire is towards pin 13 (but is not connected to it). Ground is pin 12 (the external pin on the DIP).

I found a hacksaw blade the ideal tool to slowly cut through the potting material. From time to time I would probe in the cut spot with a voltmeter (gnd to pin 12) to see if I had reached the positive wire. Even though the battery is near death, mine measured 0.9 volts which is enough to detect. Then I continued cutting and scratching until the wire was exposed. The rest is easy. Cut the wire in two and solder the positive terminal of the new battery to the lower wire (ie the one that comes out of the DIP). The wire is not microscopic and relatively easy to work with once exposed.

A picture would be worth a million words, nay, a -billion- at this point. Once you have done one, it would be easy to do many. I used a small 3 volt clock battery that had two tabs spot welded on it.
Works great for me! Good Luck!

Please send suggestions for this article to r.boys@genie.geis.com
The original idea for this was provided by Michael Coughlin at MIT.

C) Where does the name "VME" come from?

In case you are new to this newsgroup..... an article written by John Black:

Motorola proposed that the three companies jointly support the VERSAbus backplane. However, both Mostek and Signetics rejected that proposal, saying that the VERSAbus board size was much too large. In response to that objection, Motorola proposed that the (much smaller) Eurocard board size be used. A backplane could then be designed with the VERSAbus electrical specifications and the Eurocard mechanical specifications. Motorola suggested that new board products (based on this new backplane) be called VERSAmodule Eurocards, which could be abbreviated "VME".

Both Mostek and Signetics were satisfied with the choice of the Eurocard mechanical standard, but they objected to the "VERSAmodule Eurocard" name, since Motorola had already trademarked the name "VERSAmodule".

Eventually this difficulty was overcome when the three companies agreed that the name VMEbus would be placed in the public domain, and that if anybody asked what VME meant; they would say....

"VME?...Oh, it doesn't stand for anything in particular".

6) PROFILES:

The purpose of this section is to profile some of the products of various manufacturers to give an idea of what is available to the designer and the state of the market. This section will be rotated and previous sections will be archived.

Most Friendly Contributors:

       Andy Fraser         Ontario
       John Black          Arizona
       Michael Coughlin    Massachusets  (sold me my first VME board!)
       Gerry Belanger      Connecticut
       Dennis H. Johnson   ??
       Bosco Chan          Ontario
       Michael Bodine      Ilinois

and more to come.....

Please send all comments to:

Robert Boys
73 Knightswood Blvd.
Guelph, Ontario
CANADA
N1E 3W6

r.boys@genie.geis.com or rboys@best.com

Back to What's New!

Hitex Development Tools
2055 Gateway Place Suite 400
San Jose, California
USA
95110

(800) 45-hitex
Phone - (408) 451-3986
FAX - (408) 441-9486