Cadence® system design and verification solutions, integrated under our Verification Suite, provide the simulation, acceleration, emulation, and management capabilities.
Verification Suite Related Products A-Z
Cadence® digital design and signoff solutions provide a fast path to design closure and better predictability, helping you meet your power, performance, and area (PPA) targets.
Full-Flow Digital Solution Related Products A-Z
Cadence® custom, analog, and RF design solutions can help you save time by automating many routine tasks, from block-level and mixed-signal simulation to routing and library characterization.
Overview Related Products A-Z
Driving efficiency and accuracy in advanced packaging, system planning, and multi-fabric interoperability, Cadence® package implementation products deliver the automation and accuracy.
Cadence® PCB design solutions enable shorter, more predictable design cycles with greater integration of component design and system-level simulation for a constraint-driven flow.
An open IP platform for you to customize your app-driven SoC design.
Comprehensive solutions and methodologies.
Helping you meet your broader business goals.
A global customer support infrastructure with around-the-clock help.
More Support Log In
24/7 Support - Cadence Online Support
Locate the latest software updates, service request, technical documentation, solutions and more in your personalized environment.
Cadence offers various software services for download. This page describes our offerings, including the Allegro FREE Physical Viewer.
The Cadence Academic Network helps build strong relationships between academia and industry, and promotes the proliferation of leading-edge technologies and methodologies at universities renowned for their engineering and design excellence.
Participate in CDNLive
A huge knowledge exchange platform for academia to network with industry. We are looking for academic speakers to talk about their research to the industry attendees at the Academic Track at CDNLive EMEA and Silicon Valley.
Come & Meet Us @ Events
A huge knowledge exchange platform for academia. We are looking for academic speakers to talk about their research to industry attendees.
Americas University Software Program
Join the 250+ qualified Americas member universities who have already incorporated Cadence EDA software into their classrooms and academic research projects.
EMEA University Software Program
In EMEA, Cadence works with EUROPRACTICE to ensure cost-effective availability of our extensive electronic design automation (EDA) tools for non-commercial activities.
Apply Now For Jobs
If you are a recent college graduate or a student looking for internship. Visit our exclusive job search page for interns and recent college graduate jobs.
Cadence is a Great Place to do great work
Learn more about our internship program and visit our careers page to do meaningful work and make a great impact.
Get the most out of your investment in Cadence technologies through a wide range of training offerings.
Overview All Courses Asia Pacific EMEANorth America
Instructor-led training [ILT] are live classes that are offered in our state-of-the-art classrooms at our worldwide training centers, at your site, or as a Virtual classroom.
Online Training is delivered over the web to let you proceed at your own pace, anytime and anywhere.
Exchange ideas, news, technical information, and best practices.
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.
It's not all about the technology. Here we exchange ideas on the Cadence Academic Network and other subjects of general interest.
Cadence is a leading provider of system design tools, software, IP, and services.
I have a design that has several diff pairs. I have been asked to make them the same length within .005" (5 mil). I can't figure out how to use the constraint manager to do this. When using the propogation delay, it says it doesn't apply to diff pairs..... ?
I am using Allegro 16.0 XL
OK, looks like I found what I needed EXCEPT........how do I undock the "heads up" display?
In reply to pitbull107:
In reply to oldmouldy:
I found that setting under "ETCH". However, it still won't fly out or display a docked heads up display........anything else I can try?
Also, once I enabled the above, I no longer get any tuning (like trombone, etc) even though I have all those settings setup.
When I did'nt have those heads up settings on at all, I could get the tromboning to work, but no way to see how the tuning is progressing.
Just tried 16,5 XL legacy with this same brd. No flyout, no docked heads up display.I checked the user pref and it is set to be "ON".. I don't get it. Is it the type of Allegro editor affect this? I.E. XL vs SI, etc???
Yes but with an XL license you have enought tools. What Constraint Manager rules are set. Heads up display will only display for Total Etch Length, Static Phase and Rel Prop Delays...
In reply to steve:
I don't have them set. I just set 5mil/7mil/5mil diff pair. How/what do I set for total length? They (the diff pairs) are not a straight across routing. Some are jogged around connector pins.
Do I have to query each pair and set for the longest wire?
Best is to set the diff pairs up correctly. Take a look at:- http://www.parallel-systems.co.uk/images/PDF/diffpairs_definition.pdf
Thanks for the info! BTW, there is no BGA in my design, only paired through hole connectors where video signals go between pin pairs (same pin numbers on both connectors). One connector on top and the paired one on the bottom mirrored.
So I guess that only defining trace width and spacing for each diff pair in constraint manager is not sufficient? (No, I have not done this type of wiring before, still learning...I am not a EE)
So, basically, I just need to make sure each diff pair (separately) have their trace lengths macth within 5 mil. Do I still need to do all the other setup in Constraint Manager for this?
Make sure you have your DRC modes ON for Propagation Delay, Relative Propagation Delay and All Differential Pair Checks. Go to Setup > Constraints > Modes and under the Electrical Modes category to turn them On or Off. If they are Off then it will not be DRC checked and the Dynamic Timing feedback window will not be displayed.
It is starting to sound like you are looking to match the members of the diff pair to each other by 5mils (Phase Tolerance). If that is the case you need to define the Phase Tolerance as 5mils to control the matching between the members of the pair. You can do it thru Constraint Manager or attach the DIFFP_PHASE_TOL property to the diff pair nets with a value of 5 mils.
If you need to have all the Diff Pairs match to each other you will need to use Relative Propagation Delay and add all them to a Match Group with a Tolerance. (but it sounds like you are looking for jus a Phase Tolerance).
Hope this helps,Mike Catrambone
In reply to mcatramb91:
Yes, only to each pair, not to all pairs together. Now, another stupid question: I have already routed the diff pairs. Can I now (after setting the constraint phase tolerance), just use the "delay tune" to adjust the diff pairs? Or do I have to delete the diff pairs and start again?
No stupid questions, no need to delete/reroute - you can just use Delay Tune to adjust the Diff Pairs, just remember to check "Single trace mode" from the Right mouse button so you delay just one diff pair member.
Just as a test, I set the phase tol to 5 mil on one set of diff pairs. Then I tried to tune using single trace mode, and nothing happens. If I turn off single trace mode, then I get tuning and the flyout window is bordered in red.
I can email the brd file. So what am I doing wrong? BTW 16.0 XL
The only thing that I could think of is that the diff pair is either routed on another layer or has a dangling trace (stub) hanging of the trace somewhere. I have seen the tool go crazy in those situations when dealing with Diff Pairs so I figured I would mention it.
Tried everything and I am staring to think what I am trying to do just will not work.
A diff pair set to 5/7/5 (5mil wire width with 7mil spacing)
One of the traces is 1008.42 mil long....the other is 1040.06
I set the DIFFP_PHASE_TOL to 5mils ( I think this means that both etch lengths have to be within 5 mils of each other, correct?)
When I try to tune using the DELAY TUNE (in single trace mode), the accordian gives a drc as soon as I try to increase it's length or amplitude. In dual trace mode, no drcs, but no adjustment to make both traces "equal in length" within 5mil.
So.....is it possible to tune this diff pair at 5 mil DIFFP_PHASE_TOL *and* containing a defined diff pair GAP of 5mil????
If not, then what would be a reasonable tolerence of the lengths?