Stats

Locked Locked
Replies 5
Subscribers 164
Views 14855
Members are here 0

Length Matching rule

Hi,
I've topology for databus like

Driver----------1.Res.2-----------Receiver

Min and Max Length From Dri to Res pin.1 is given.Similarly, for Res pin 2 to Receiver also, min-max length given.
So in EC, in Propagation delay tab,I fixed this min and max length for both the segments.
My doubt is how to fix rules for length matching within a group(bus) and between groups.
In Relative propagation delay tab, I defined two rules.to fix the tolerance value for the above two segments.I think this will work only for signals within a bus.How to fix length tolerance to match signals between buses?
Under Scope, we've "Local" , "Global" and "Bus".Can anyone of you please explain how to use this?
I gone through the tutorial but still not get a clear knowledge in this.
Your help is extremely needed.
Thanks in advance.

Originally posted in cdnusers.org by harish.mellacheruvu@hcl.in

archive over 17 years ago

It would help with all of your posts if you stated what version and product you are running.
Regards,
BillZ
EMA Design Automation

Originally posted in cdnusers.org by BillZ_EMA
Cancel
Vote Up 0 Vote Down

Cancel
archive over 17 years ago

Hi,

Iam using Allegro V15.7

Originally posted in cdnusers.org by harish.mellacheruvu@hcl.in
Cancel
Vote Up 0 Vote Down

Cancel
archive over 17 years ago

Local scope is used for matching within a (x)net only. Think of a net topology with a branch where you want the the branches to match one another but you don't care about matching to any other nets.

Global scope is for matching net to net. In your example, you may want to match Drvr to Rcvr for every net in a group or bus.

Local and Global are the only 2 scopes that exist at the net level. Bus scope can only be set at the ECSet level and controls how the Match Groups are created when the ECSet is mapped. Sounds like you might be trying to constrain a memeory interface. Bus scope was designed to cut down on the number of ECSets need to constrain an interface. It will create a separate MG for each set of nets (with a scope of global) grouped in a bus (by appending the bus name to the MG name in the ECSet). It allows for a single ECSet to be applied to several buses rather than using many identical ECSets that only differ by the MG name in the ECSet. For more detail see the following paper from CDNLive SJ 2007: Session 8.14: "How to use SPB 15.7 to Simplify Your DDR Constraints" by Mike Veal

Originally posted in cdnusers.org by den
Cancel
Vote Up 0 Vote Down

Cancel
archive over 17 years ago

Somone just pointed out to me that Mike's paper might not be included in the zip file of the proceedings for CDNLive SiliconValley 2007 (5_SPB.zip). Best way to get it is to navigate to the SPB tab for the 2007 proceedings:

http://cdnusers.org/CDNLive/SiliconValley2007Proceedings/tabid/419/Default.aspx?topic=Silicon-package-board%20co-design

Mike's paper is 2nd from the bottom.

Regards,
Dennis Nagle
Cadence

Originally posted in cdnusers.org by den
Cancel
Vote Up 0 Vote Down

Cancel
archive over 17 years ago

Thanks Den.
This will help me.

Originally posted in cdnusers.org by harish.mellacheruvu@hcl.in
Cancel
Vote Up 0 Vote Down

Cancel

Cadence Guidelines

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.