Stats

  • Locked Locked
  • Replies 1
  • Subscribers 91
  • Views 14953
  • 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

Real DRV and Total DRV

naderi

 Hi all,

 Could someone please tell me the difference between "Real DRV" and "Total DRV"?

Also, how the maximum cap and transition can be defined?

Post_route summary showes the following and I wonder how to fix the DRVs.

+--------------------+---------+---------+---------+---------+---------+---------+
|     Setup mode     |   all   | reg2reg | in2reg  | reg2out | in2out  | clkgate |
+--------------------+---------+---------+---------+---------+---------+---------+
|           WNS (ns):|  0.129  |  0.251  |  0.129  |  1.176  |   N/A   |   N/A   |
|           TNS (ns):|  0.000  |  0.000  |  0.000  |  0.000  |   N/A   |   N/A   |
|    Violating Paths:|    0    |    0    |    0    |    0    |   N/A   |   N/A   |
|          All Paths:|2.48e+05 |1.24e+05 |1.24e+05 |    3    |   N/A   |   N/A   |
+--------------------+---------+---------+---------+---------+---------+---------+

Density: 76.000%
Real DRV (fanout, cap, tran): (5072, 0, 0)
Total DRV (fanout, cap, tran): (7556, 49, 125327)
------------------------------------------------------------
 

Thanks,

Ali

Parents

  • Hi Ali,

    I found the following solution via a Sourcelink search for "real drv" that explains the difference between Real and Total DRV:

    http://sourcelink.cadence.com/docs/db/kdb/2005/Dec/11210732.html

    In short, optimization cranks away on things it can fix: data signals (as opposed to clock nets), things that aren't marked FIXED/dont_touch etc.  The Real DRV is reported along withTotal DRV to give you a feel for how good of a job optDesign is doing repairing the things that it is attempting to repair.

    Maximum Cap and Transition can come from 2 sources: The .lib and the SDCs.

    Hope this helps,
    Bob

Reply

  • Hi Ali,

    I found the following solution via a Sourcelink search for "real drv" that explains the difference between Real and Total DRV:

    http://sourcelink.cadence.com/docs/db/kdb/2005/Dec/11210732.html

    In short, optimization cranks away on things it can fix: data signals (as opposed to clock nets), things that aren't marked FIXED/dont_touch etc.  The Real DRV is reported along withTotal DRV to give you a feel for how good of a job optDesign is doing repairing the things that it is attempting to repair.

    Maximum Cap and Transition can come from 2 sources: The .lib and the SDCs.

    Hope this helps,
    Bob

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.