On Mon, 3 Mar 2008 09:16:27 -0800 (PST), Mark_Galeck
<mark_galeck_spam_magnet@yahoo.com> wrote:

>Hello,  I am a software eng and I have a purely hardware question;
>hope that some hardware engs here can comment.
>
>Does it exist now (or if not, does it make sense that someone will
>design) a CPU board with more than one VME bus?  Thank you.
>

One do get things like VME-VME bridges. This probably can be designed
as a CPU board with two VME busses. 

Regards
  Anton Erasmus

On Mar 3, 9:16 am, Mark_Galeck <mark_galeck_spam_mag...@yahoo.com>
wrote:

> Hello,  I am a software eng and I have a purely hardware question;
> hope that some hardware engs here can comment.
>
> Does it exist now (or if not, does it make sense that someone will
> design) a CPU board with more than one VME bus?  Thank you.
>
> Mark Galeck

Mark

Has it been done? I don't know of any.
Could it be done? I expect so.
(Would it be standards compliant? I don't know.)
Does it make sense? Not as a single PCB with VME pinout connectors
that plug into a COTS motherboard(s). But a module? Maybe.

In the 90s I worked on a dual VME bus box that had several octal DSP
boards with a hypercube serial port interconnect spanning the two VME
sections. The application was a frequency domain beamformer. One VME
bus had the bandwidth for input or output but not both, so two VMEs.
OC-3 links brought data into and out of the box. The CPUs just set up
the DSPs and IO cards, so CPU wasn't the scarce resource, but there
were no COTS dual VME CPU PCBs or modules at the time.

Dale B. Dalrymple
http://dbdimages.com

Tim Wescott wrote:
> Mark_Galeck wrote:
>> Hello,  I am a software eng and I have a purely hardware question;
>> hope that some hardware engs here can comment.
>>
>> Does it exist now (or if not, does it make sense that someone will
>> design) a CPU board with more than one VME bus?  Thank you.
>>
> There may be such a thing, but it would certainly be oddball.
> 
> I don't believe that there is a VME specification for multiple busses in 
> one box (someone will correct me soon enough if I'm wrong).  Strictly 
> speaking, if there isn't such a critter specified then what you are 
> asking for isn't possible.
> 

There are, or at least were. That is what the "Bus-Instance" number 
specifies (zero would be a single-bus system):

http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R7F-TE_html/CHPTR004.HTM


> Tell us what you're trying to do, and perhaps someone will have sensible 
> suggestions about how it could be achieved.
> 


-- 
Regards, Joerg

http://www.analogconsultants.com/

Mark_Galeck wrote:
> Hello,  I am a software eng and I have a purely hardware question;
> hope that some hardware engs here can comment.
> 
> Does it exist now (or if not, does it make sense that someone will
> design) a CPU board with more than one VME bus?  Thank you.
> 
There may be such a thing, but it would certainly be oddball.

I don't believe that there is a VME specification for multiple busses in 
one box (someone will correct me soon enough if I'm wrong).  Strictly 
speaking, if there isn't such a critter specified then what you are 
asking for isn't possible.

Tell us what you're trying to do, and perhaps someone will have sensible 
suggestions about how it could be achieved.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html

Hello,  I am a software eng and I have a purely hardware question;
hope that some hardware engs here can comment.

Does it exist now (or if not, does it make sense that someone will
design) a CPU board with more than one VME bus?  Thank you.

Mark Galeck