[PCB_FORUM] Re: Difference between "delta" and "tolerance" in Relative Propagation Delay
- From: "Austin Franklin" <austin@xxxxxxxxxxxx>
- To: <icu-pcb-forum@xxxxxxxxxxxxx>
- Date: Sat, 12 Mar 2005 11:16:36 -0500
Hi Julian,
Let's see if I understand your explanation. If I want the clock to be, as
you say, 1" longer than the matched length of the group (which is, say,
+-100) I would use delta of 1000 on the clock line only to increase it's
length, and the rest of the group has a tolerance of 100. In this case,
setting the clock as a target would not work, as you can't specify an
offset...and delta is really an offset.
So, tolerance is +- whatever value is there....delta is absolute, as in, if
you specify a delta -1000, that signal will be shorter than the other
members of match group by 1 inch, if you specify a delta of 1000, that
signal will be longer than the group by 1".
Is that was you were getting at? If so, I'll have to think a bit more about
that, but it seems a reasonable methodology of specifying that case. Thanks
for the explanation!
Regards,
Austin
> -----Original Message-----
> From: Julian Ungureanu (jungurea) [mailto:jungurea@xxxxxxxxx]
> Sent: Saturday, March 12, 2005 10:17 AM
> To: icu-pcb-forum@xxxxxxxxxxxxx
> Subject: [PCB_FORUM] Re: Difference between "delta" and "tolerance" in
> Relative Propagation Delay
>
>
> Austin,
> I believe Delta is meant to be used when you have a say bus and
> you attached
> a match length
> Group; you include in your group the clock that goes along with
> the data bus
> let's say.
> You want the clock to be skewed by 1" say. So all the nets are
> part of that
> matched group, included the clock; but the clock has Delta of 1".
> The whole group has a tolerance of 100 mils.
>
> My 2 cents,
> Julian
>
> -----Original Message-----
> From: Austin Franklin [mailto:austin@xxxxxxxxxxxx]
> Sent: Friday, March 11, 2005 7:39 PM
> To: icu-pcb-forum@xxxxxxxxxxxxx
> Subject: [PCB_FORUM] Difference between "delta" and "tolerance"
> in Relative
> Propagation Delay
>
> Hi,
>
> What is the functional difference between "delta" and "tolerance" in the
> constraint manager "relative propagation delay" worksheet? The examples
> (and explanations) they give seem like they could be implemented with
> either...
>
> For example:
>
> three signals A, B, C. Say C is target of 1", and I want a
> length match of
> .1 on A & B to C. I could set either delta OR tolerance to .1,
> and get what
> I want.
>
> Again, three signals, A, B, C. C target of 1". I set delta to .1, and
> tolerance to 10 mils. What is different doing that than simply setting
> either delta or tolerance to 110?
>
> Regards,
>
> Austin
>
>
> -----------------------------------------------------------
> To subscribe/unsubscribe:
> Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx
> with a subject of subscribe or unsubscribe
>
> To view the archives of this list please login at
//www.freelists.org.
Our list name is icu-pcb-forum or go to
//www.freelists.org/archives/icu-pcb-forum/
Problems or Questions:
Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx
Want to post a job listing ? DON'T DO IT HERE!
Better yet, join our jobs listing forum.
SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx
POST: icu-jobs-forum@xxxxxxxxxx
-----------------------------------------------------------
-----------------------------------------------------------
To subscribe/unsubscribe:
Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx
with a subject of subscribe or unsubscribe
To view the archives of this list please login at
//www.freelists.org. Our list name is icu-pcb-forum
or go to //www.freelists.org/archives/icu-pcb-forum/
Problems or Questions:
Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx
Want to post a job listing ? DON'T DO IT HERE!
Better yet, join our jobs listing forum.
SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx
POST: icu-jobs-forum@xxxxxxxxxx
-----------------------------------------------------------
-----------------------------------------------------------
To subscribe/unsubscribe:
Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx
with a subject of subscribe or unsubscribe
To view the archives of this list please login at
//www.freelists.org. Our list name is icu-pcb-forum
or go to //www.freelists.org/archives/icu-pcb-forum/
Problems or Questions:
Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx
Want to post a job listing ? DON'T DO IT HERE!
Better yet, join our jobs listing forum.
SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx
POST: icu-jobs-forum@xxxxxxxxxx
-----------------------------------------------------------
Other related posts:
