TAU Contest 2015

TAU 2015 Contest: Incremental Timing and Incremental CPPR

TAU 2015 would like to invite students to participate in this year's contest on Incremental Timing and Incremental Common Path Pessimism Removal (CPPR) analysis.

Among timing analysis applications, timing-driven operations are imperative for the success of optimization flows, such as placement, routing, logic synthesis, and physical synthesis. Optimization transforms change the design, and therefore have the potential to significantly affect timing information. As such, timing must be kept current to ensure slack integrity and timing closure, and updating timing information quickly and accurately is crucial for reasonable turnaround time and performance. The goals of this year's TAU contest are:

  • increase awareness of incremental timing analysis
  • create a framework where timing needs to be re-validated after a set of transforms on a design
  • encourage incremental and multithreaded approaches
  • introduce incremental common path pessimism removal (CPPR) analysis
  • create an evaluation environment to measure the performance of incremental timing analysis with CPPR in terms of memory, runtime, and accuracy
  • facilitate a unified academic timing engine that can be used to perform timing analysis and enable timing-driven flows

For reference, CPPR was the contest topic from the TAU 2014 Contest.


Top performers will receive monetary prizes as well as plaques commemorating their achievements. Congratulations to all the winners! More Pictures from TAU: TAU 2015 Pictures

TAU logo

First Place: Team iTimerC 2.0

Team Members: Pei-Yu Lee, Cheng-Ruei Li, Wei-Lun Chiu, Yu-Ming Yang, and Iris Hui-Ru Jiang

University: National Chiao Tung University, Taiwan

Representative: Pei-Yu Lee

Second Place: Team UI-Timer 2.0

Team Members: Tsung-Wei Huang and Martin D. F. Wong

University: University of Illinois at Urbana-Champaign, USA

Representative: Tsung-Wei Huang

Third Place: Team iitRACE (winners unable to attend in person)

Team Members: Chaitanya Peddawad, Aman Goel, Dheeraj B, Nitin Chandrachoodan

University: India Institute of Technology, Madras, India

Representative: Ramprasanth S

Participation [The contest registration is now closed. If you have any questions, please contact tau <dot> contest <at> gmail <dot> com.]

If you are interested in participating, please send an email to tau <dot> contest <at> gmail <dot> com with the following information by November 15th, 2014:

  • Name(s)
  • School/University
  • Contact email(s)
  • Advisor name [if applicable]
  • Team Name [optional]

Important Dates

All dates below are tentative.

Updates and Announcements

TAU 2015 Pictures | Presentation | Results

  • March 16, 2015 [Front Page][Resources]: Uploaded contest presentation, results, pictures, and benchmarks/utilities from TAU 2015. Congratulations to all the winners!
  • February 25, 2015 [Front Page]: The final binary contest submission has been closed. See you all at TAU 2015!
  • February 19, 2015 [Resources]: Uploaded additional associated .spef files.
  • February 18, 2015 [Resources]: Uploaded two additional .ops files.
  • February 16, 2015 [Front Page][Resources]: Extended the final submission date to February 20th; update tau_crc32d16N.tar.gz with the same pin caps for early and late.
  • February 9, 2015 [Resources]: Updated contest_file_formats.pdf to remove the semi-colon after report_worst_paths in the output.
  • February 8, 2015 [Resources]: Updated benchmarks to reflect correct slew propagation, fixed report_worst_paths to print data paths, uploaded simplified output comparer.
  • February 5, 2015 [Resources]: Updated FAQ regarding potential mismatch of positive slack values in golden output.
  • February 4, 2015 [Resources]: Updated ispd and crc32d16N benchmarks for correct RAT and slack setup values; uploaded new benchmark netcard.
  • January 30, 2015 [Resources]: Updated ispd and crc32d16N benchmarks for clock inverters; uploaded two verbose ispd .ops / .output files.
  • January 22, 2015 [Resources]: Posted an additional benchmark that has clock inverters.
  • January 19, 2015 [Resources]: Corrected clock pin RAT and slack computation in contest_education.pdf.
  • January 18, 2015 [Resources]: Correct some golden results regarding slack and critical paths.
  • January 13, 2015 [Resources]: Fixed golden output for sequential benchmarks where first set of reports had pre-CPPR values; updated contest_education.pdf to clarify to only consider CPPR credit if the path is failing.
  • January 8, 2015 [Resources]: Fixed a bug in asserting RATs for golden output in all benchmarks. We apologize for any inconvenience.
  • January 6, 2015 [Resources]: Corrected Equation 25 in contest_education.pdf.
  • January 5, 2015 [Resources]: Updated c17, s400, wb_dma benchmarks to include the AT/RAT/slack values of every pin before and after every batch of operations, corrected large values to be the correct undefined values.
  • January 5, 2015 [Resources][FAQ]: Updated contest_file_formats.pdf to clarify the correct command is insert_net, not create_net; updated FAQ.
  • December 16, 2014 [Resources]: Updated contest_education.pdf to highlight updates with color.
  • December 15, 2014 [Resources][FAQ]: Updated contest_education.pdf to clarify CL computation for combinational cells; updated FAQ.
  • December 12, 2014 [Resources]: Updated ispd benchmarks to fix hold test on "ms00f10" element (related pin "ck"); updated some existing benchmarks with more extensive .ops/.output files; updated contest_education.pdf to reflect RAT calculation for clock pins of sequential elements.
  • December 10, 2014 [Resources][FAQ]: Uploaded a new set of benchmarks, and updated FAQ.
  • December 8, 2014 [Resources][FAQ]: Fixed minor typo in contest_file_formats.pdf, changed "Start instances" to "Start cells" in vga_lcd.v (inside vga_lcd.tar.gz), and updated FAQ.
  • December 2, 2014 [Resources]: Uploaded new sets of benchmarks based on the TAU 2013 designs.
  • November 25, 2014 [Resources]: Modified vga_lcd.v to say "Start cells" instead of "Start instances".
  • November 24, 2014 [Resources]: Uploaded new benchmark vga_lcd that is substantially more complex than simple. Warning: large file size.
  • November 19, 2014 [Resources]: Updated golden results for simple (simpleout.output in simple.tar.gz) to reflect correct beta calculation.
  • November 12, 2014 [Resources]X2: Updated simple.tar.gz to reflect .timing and golden results.
  • November 12, 2014 [Resources]: Updated contest_file_formats.pdf and contest_education.pdf.
  • November 11, 2014 [Resources]X2: Updated contest_file_formats.pdf (see updates); updated simple.tar.gz with more in-depth .ops file and golden results.
  • November 10, 2014 [Resources]X2: Updated contest_file_formats.pdf to reflect early and late libs; updated simple.tar.gz accordingly.
  • November 7, 2014 [Resources]: Updated contest_file_formats.pdf include path type for report_worst_paths.
  • October 31, 2014 [Resources]: Updated simple.timing (in simple.tar.gz) to load to the output pins; updated contest_file_formats.pdf to reflect output loads.
  • October 30, 2014 [Resources]: Updated simple.timing (in simple.tar.gz) to add the arrival times of tau2015_clk and slews; updated contest_file_formats.pdf to reflect input slews.
  • October 8, 2014 [Resources]: Updated simple.lib (in simple.tar.gz) to change 'CK' to 'ck' in the FF definition.
  • October 1, 2014 [Main Page]: Contest documentation has been released; registration is now open.

Contest Organizers

  • Jin Hu, IBM Corp. (Contact: jinhu <at> us<dot> ibm <dot>com)
  • Greg Schaeffer, IBM Corp. (Contact: gmschaef <at> us <dot> ibm <dot> com)
  • Vibhor Garg, Cadence (Contact: gargv <at> cadence <dot> com)

TAU 2015 Committee (TAU 2015)

  • Igor Keller, Cadence [General Chair]
  • Debjit Sinha, IBM Corp. [Technical Chair]
  • Chirayu Amin, Intel [Past Chair]


For any questions, concerns, or feedback regarding the contest, please email tau <dot> contest <at> gmail <dot> com.


  • Winners of the PATMOS 2011 Contest (from NTU) for providing their source NTUTimer
  • Jobin Jacob Kavalam, Neel Gala and Nitin Chandrachoodan for providing the source code of IITimer (winner of the TAU 2013 Contest)
  • Tsung-Wei Huang for providing the source code of UI-Timer (winner of the TAU 2014 Contest)