• 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. Custom IC Design
  3. Questions on Grid and DBU in Virtuoso layout editor

Stats

  • Locked Locked
  • Replies 2
  • Subscribers 126
  • Views 18197
  • Members are here 0
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

Questions on Grid and DBU in Virtuoso layout editor

winever
winever over 12 years ago

Hi everybody,

Could anyone tell me the exact definition of Grid and DBU(database unit) in Virtuoso layout editor? What do they refer to respectively? What should be taken into consideration when setting these two parameters or can I set them arbitrarily? Some references on the internet say that the DBU is the minimum resolution unit of a layout and for a standard GDSII stream file, it should be set to 0.001um. And the Grid size is proportional to the minimum electron-beam-spot size used to create the masks. It seems that these two terms are critical when doing layout design, for they are related to masks fabrication. But what do they exactly refer to? I am still confused now. Could anyone explain these two terms to me in detail and offer me some advice on how to set the value of these two terms? I really appreciate it for you help.

 

Regards,

Winever.   

  • Cancel
Parents
  • Marc Heise
    Marc Heise over 12 years ago

     Hi Winever,

     

    DBU  are Database Units , thats the resolution your layout data is stored with in the Database. The value you are actually set is called DBUperUU ( Database Units per User Unit ) . A user unit is usually 1um , a DBUperUU of 2000 which is common these days would lead to 1um/2000 = 0.5nm database resolution.

    This is not necessarily your drawing grid, which you allready described correctly as the resolution your mask creator can handle.

     

    Regards,

    Marc

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Reply
  • Marc Heise
    Marc Heise over 12 years ago

     Hi Winever,

     

    DBU  are Database Units , thats the resolution your layout data is stored with in the Database. The value you are actually set is called DBUperUU ( Database Units per User Unit ) . A user unit is usually 1um , a DBUperUU of 2000 which is common these days would lead to 1um/2000 = 0.5nm database resolution.

    This is not necessarily your drawing grid, which you allready described correctly as the resolution your mask creator can handle.

     

    Regards,

    Marc

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Children
No Data

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