Subject: | |
From: | |
Date: | Sun, 18 May 1997 14:10:22 -0400 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
dkorf wrote:
>
... snip ...
> I'd love to compare notes with you sometime on this. I think we need
> to address this as an industry. I have been working with the CAD
> software suppliers to raise their awareness of what a test point is.
> It turns out, they don't really have a clue.
> ... snip ...
Dana,
I very much agree about the whole-industry perspective, as well as
the CAD supplier angle. The problem actually goes deeper than
just the test perspective, all the way back to EDRC. Most systems
cannot easily identify the endpoints you seek, at least partially
due to the same obstacle designers are in need of controlling: the
overall topology of a net.
To handle high-speed digital interconnect properly, we must know
and verify the allowable end-points of a net (sources, stubs, and
terminations). I believe these are one and the same as the test
points you seek.
We can vouch for how difficult this is to determine without carry-
ing and analyzing the full pin-use descriptions. In porting route
data between two CAD platforms that use entirely different models
to describe etch topology, we found it quite difficult to ascertain
and translate the intent with 100% accuracy. This is especially
true when either the target or the source do not have an inherent
basis for determining what is the "proper" topology. This sounds
to me like the missing link in creating a good test file, no?
My personal belief is that we won't have a satisfactory answer to
this until CAD systems start recognizing a higher level of element
type than "pin", "via" and "line". That may be a long time coming.
Meanwhile, best to all!
--
Jeff Seeger Applied CAD Knowledge Inc
Chief Technical Officer Tyngsboro, MA 01879
[log in to unmask] 508 649 9800
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]> *
* with <subject: subscribe/unsubscribe> and no text in the body. *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] *
***************************************************************************
|
|
|