Stats

  • Locked Locked
  • Replies 1
  • Subscribers 91
  • Views 13149
  • 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

about bufferTreeSynthesis ??

icmaple

if Net resetn connects RN port of many different SDFF ( X2 X4 ..) ,  when i use bufferTreeSynthesis cmd, Need I use its option: -leafPorts for thest different SDFF.?   bufferTreeSynthesis consider what type of Pin/Port as Leafport by default??   

  • I'm curious why you're using bufferTreeSynthesis instead of allowing optDesign to automatically buffer these nets? Do you want the skew to be balanced between the flops the net drives?  Or does the net connect to an always-on power domain?  If not, bufferTreeSynthesis may not be the best option for dealing with these high fanout nets.

    bufferTreeSynthesis considers clock pins on instances (according to .lib and/or .lef markings) leafPorts by default, similarly as does CTS.  So, it's possible that you don't need to specify any leafPorts at all.

    That said, I did some testing and I see that the leafPort option appears to not handle wildcards:

    bufferTreeSynthesis -nets clk -bufList BUFX1 -leafPorts *FF*/CK
    **WARN: (SOCCK-664):    The LeafPort + *FF*/CK is an invalid name.
     
    bufferTreeSynthesis -nets clk -bufList BUFX1 -leafPorts {SDFFSHQX1/CK SEDFFX1/CK}
    ->This works

    Therefore, it appears that you need to specify each drive strength in your list of leafPorts.

    Hope this helps,
    Bob

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.