Stats

  • Locked Locked
  • Replies 8
  • Subscribers 90
  • Views 19817
  • 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

Peak and average IR drop analysis mode

archive

Hello,

I am not sure about what means peak and average IR drop mode analysis in Encounter. What of these two analysis modes should be considered for power plan optimization?

I have a small block design (5K gates) operating at very low frequency (640 KHz) and there is a big difference between the results of these two analysis modes:

  • worst IR drop average analysis: 9.8035e-05 v

  • worst IR drop peak analysis: 4.3088e-01 v

Is average analysis frequency dependent? But voltage drop is not event dependent and so can cause timing problems also at low frequencies?

Thanks in advance.

 


Originally posted in cdnusers.org by clsantos
Parents

  • Hello EngHan,

    I found only these definitions about peak and average IR drop analysis in Encounter documentation:
    AVERAGE: Displays a gradient of the average IR drop during the entire analysis period. Use this type of analysis to identify potential areas of power deficiency within the design.
    PEAK: Displays a gradient that shows the largest IR drop during the analysis period. Use this type of analysis to identify IR drop that is caused by local switching activity.
    But these definitions don't clarify my doubts...
    If average IR drop is calculated over an entire clock period, this analysis mode should mislead delay problems due voltage drop at low frequencies?
    I think that if switching activity, and so voltage drop, will occur only at the time around clock event , so it is better consider peak than average IR drop analysis... Is it right?

    Regards,
    Cristiano.


    Originally posted in cdnusers.org by clsantos
Reply

  • Hello EngHan,

    I found only these definitions about peak and average IR drop analysis in Encounter documentation:
    AVERAGE: Displays a gradient of the average IR drop during the entire analysis period. Use this type of analysis to identify potential areas of power deficiency within the design.
    PEAK: Displays a gradient that shows the largest IR drop during the analysis period. Use this type of analysis to identify IR drop that is caused by local switching activity.
    But these definitions don't clarify my doubts...
    If average IR drop is calculated over an entire clock period, this analysis mode should mislead delay problems due voltage drop at low frequencies?
    I think that if switching activity, and so voltage drop, will occur only at the time around clock event , so it is better consider peak than average IR drop analysis... Is it right?

    Regards,
    Cristiano.


    Originally posted in cdnusers.org by clsantos
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.