Tuesday, August 29, 2006

YAST - Yet Another STA Tool

I'm initially puzzled when an EDA vendor fields a new tool to take on Synopsys PrimeTime, e.g., Incentia Timing Analysis and Constraint Management Software Adopted by Ambarella.

PrimeTime is one of Synopsys highest-quality, most trouble-free tools. The main gripe I have with PT is that it can only tell you about timing problems -- it doesn't fix them! Hence, a cottage industry of home-grown scripts and supplementary tools exists to take PT reports and generate ECOs to fix the violations.

However, some of the features in this TimeCraft tool sound pretty attractive, and give me second thoughts about assuming nothing can beat PrimeTime. Attractive features include

  • MSV support
  • "multi-task capability for multi-corner and multi-mode analysis"
  • Advanced OCV features
  • Constraint Manager


Sandeep said...

"multi-task" - I doubt they can do that without partitioning the design in some way (something like what Nassda used to do).

John, your gripe about PT is a problem we have thought about in the past. For a tool to do what you want, it must INFER timing exceptions (false paths, multicycle paths) - not an easy job

I'm curious what do you do to manage ECO's? Do you go for a respin?

John said...

It is interesting to infer exceptions, but why is it necessary for timing closure? People close timing all the time with manually-created SDC files.

Regarding handling of ECOs, I am referring to the home-grown or supplementary script/tool generating a change list or new netlist which is then implemented by the production P&R tool like physopt, Astro, etc.

Kiran Bulusu said...

going for re-spin is too costly and definetly ur marketing folks will not appreciate it as they might miss their deadlines...one metholdology for managing ECO's is hack ur netlist and do ECO, do formal verification and if it passes, go ahead with rest of the ur schedule. Parallely depending on what changed, ur Front end signoff or backend end team can do re-spin of the design. ur schedule is not affected...