• 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. Digital Implementation
  3. Max Transition Violations in CTS report

Stats

  • Locked Locked
  • Replies 2
  • Subscribers 92
  • Views 16981
  • 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

Max Transition Violations in CTS report

Bardia B
Bardia B over 11 years ago

Hi,

I use Automatic gated CTS, and it is recommended by my foundry to set maxsinktran and maxbuftran to 2ns. Also I've found that the required maxtran is 4ns by my library.

 After running CTS, there are some max tran violations in the CTS report for some of my clocks. like below: 

Max. Rise Sink Tran            : 2335.1(ps)             2000(ps)            

However I do not see any violations in the postCTS timedesign report.  Is this because this is still below 4ns which is the global target for max tran?

 should I take these max tran violations in the CTS report seriously?

 How can I remove this violations during CTS?

 Also another interesting point is that after running CTS for one of my clocks, I got the following report: 

 ###############################################################

# Complete Clock Tree Timing Report

#

# CLOCK: PCLK

#

# Mode: preRoute

#

# Delay Corner information

# Analysis View       : func_max

# Delay Corner Name   : corner_max

# RC Corner Name      : ams_rc_corner_wc

# Analysis View       : func_min

# Delay Corner Name   : corner_min

# RC Corner Name      : ams_rc_corner_bc

###############################################################

 

 

Nr. of Subtrees                : 5

Nr. of Sinks                   : 672

Nr. of Buffer                  : 32

Nr. of Level (including gates) : 8

Root Rise Input Tran           : 0.1(ps)

Root Fall Input Tran           : 0.1(ps)

Max trig. edge delay at sink(R): CoeffMEM/Reg_in_reg[9]/CP 5064.6(ps)

Min trig. edge delay at sink(R): CoeffMEM/C2_mem_reg[17][6]/CP 4775.7(ps)

 

                                 (Actual)               (Required)          

Rise Phase Delay               : 4775.7~5064.6(ps)      1000~10000(ps)      

Fall Phase Delay               : 4329.3~4991.3(ps)      1000~10000(ps)      

Trig. Edge Skew                : 288.9(ps)              200(ps)             

Rise Skew                      : 288.9(ps)              

Fall Skew                      : 662(ps)                

Max. Rise Buffer Tran          : 1223.2(ps)             2000(ps)            

Max. Fall Buffer Tran          : 834.3(ps)              2000(ps)            

Max. Rise Sink Tran            : 1094.5(ps)             2000(ps)            

Max. Fall Sink Tran            : 776.9(ps)              2000(ps)            

Min. Rise Buffer Tran          : 113(ps)                0(ps)               

Min. Fall Buffer Tran          : 105.1(ps)              0(ps)               

Min. Rise Sink Tran            : 601.4(ps)              0(ps)               

Min. Fall Sink Tran            : 477.9(ps)              0(ps)               

 

view func_max : skew = 288.9ps (required = 200ps)

view func_min : skew = 197.9ps (required = 200ps)

 

 

 

 

***** Max Transition Time Violation *****

 

Pin Name                         (Actual)               (Required)          

-------------------------------------------------------------------

PCLK__L1_I0/A                    [4008 2176.2](ps)      2000(ps)            

PCLK__L1_I1/A                    [4008 2176.2](ps)      2000(ps)            

 

 

 

***** NO Min Transition Time Violation *****

 

***** NO Max Capacitance Violation *****

 

***** NO Max_Fanout Violation *****

 

***** NO AC Irms Limit Violation *****

 

as you see above, in the Max Rise/Fall Buffer Tran the maximum transition is met, but at the end it reports two pin names which violate the transition time. I don't how this makes sense! 

 So again here this violation does not exist in the timedesign report of postCTS even though it is larger than 4ns!!!

So can you help me with these issues?

 Thank you so much in advance,

Bardia 

  • Cancel
Parents
  • Bardia B
    Bardia B over 11 years ago
    Thanks Shawn for your help!
    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Reply
  • Bardia B
    Bardia B over 11 years ago
    Thanks Shawn for your help!
    • 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