• Skip to main content
  • Skip to search
  • Skip to footer
Cadence Home
  • This search text may be transcribed, used, stored, or accessed by our third-party service providers per our Cookie Policy and Privacy Policy.

  1. Community Forums
  2. PCB Design
  3. How to change rise and fall time in Stimulus Edit of Si...

Stats

  • Locked Locked
  • Replies 1
  • Subscribers 164
  • Views 12950
  • Members are here 0
More Content
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

How to change rise and fall time in Stimulus Edit of SigXplorer

archive
archive over 17 years ago

I'm using SigXplorer of Cadence SPB 15.2 to simulate the signal integrity. After extracting the topology, I need to define the stimulus. In the dialog of 'IO Cell Stimulus Edit', the stimulus could be customized. But the rise time and fall time are fixed(Tr 2.737 ns and Tf 3.357 ns). The question is how to modify them?

Thank you in advance

HappySniper


Originally posted in cdnusers.org by HappySniper
  • ScreenShot.JPG
  • View
  • Hide
  • Cancel
  • archive
    archive over 17 years ago

    Tr and Tf are derived directly from the "dt" parameter in your model's DML file (or the [Ramp] keyword in the original IBIS) which gives the 20-80% rise/fall times. As such, the values in the form are derived from the equation dt/0.6. Change the dt value, reload the libraries, and you'll see the Tr and Tf values change to whatever you want.

    That said, many models/simulations are insensitive to changes in Tr/Tf - but that depends on your application.

    Donald


    Originally posted in cdnusers.org by Donald Telian
    • 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.

© 2025 Cadence Design Systems, Inc. All Rights Reserved.

  • Terms of Use
  • Privacy
  • Cookie Policy
  • US Trademarks
  • Do Not Sell or Share My Personal Information