Stats

  • Locked Locked
  • Replies 1
  • Subscribers 64
  • Views 11224
  • 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

Virtuoso: cloning vs unit cell

AshutoshLayout

Hi,

Can anyone confirm for the large layout database, will the top level hierarchy with unit cell kind of instances repeated 1000s of time load faster or the cloned synchronous groups repeated the same amount of time load faster?

I know that if we use unit cells, we loose the xl-connectivity and there are other demerits of it. But, only from a layout loading point of view which would load faster and why?

  • If there are a very large number of instances/objects which are cloned, then I would expect the hierarchical approach to be faster to load - mainly because there would be fewer objects in the resulting layout. If the unit cell has (say) 20 instances and 30 shapes (say), then 1,000 clones means you have 20,000 instances and 30,000 shapes in the cellView. If you have an actual unit cell, then there are only 1,000 instances plus 20 instances plus 30 shapes to load overall - so much less data.

    If there are relatively few instances/shapes within the cloned unit then the difference is going to be smaller.

    Note that the hierarchical approach may not be that bad because you can use transparent instances to still consider the connectivity through the hierarchy. 

    Andrew

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.