IC Validator offers step up in physical designer's productivity

Recently, Synopsys Inc. introduced an IC Validator design rule checking/layout verification signoff (DRC/LVS) for in-design physical verification and signoff for advanced designs at 45nm and below.

Said to provide a step up in physical designer productivity, it is architected to deliver the high accuracy necessary for leading-edge process nodes, superior scalability for efficient utilization of available hardware, and ease-of-use.

What does IC Validator do?
According to Sanjay Bali, Director of Marketing, Physical Verification & DFM, Synopsys, the IC Validator is a complete physical verification tool, performing increasingly complex DRC and LVS sign-off checks.

It has been specifically architected for in-design physical verification. This means: the place-and-route engineers can run DRC and practical DFM steps alongside place and route within the familiar IC Compiler physical design environment.

And, why need for such a solution? He added that three key summary challenges are driving the need for a new approach and hence the new tool. These are:
a) Increase in complexity and count of manufacturing rules.
b) Unabated growth on design complexity.
c) Increasing DFM challenges, which just cannot be handled in a post processing approach.

Currently, the solution is aimed at 45nm and below as these nodes largely represent the challenges listed above.

Enhancing physical designer's productivity
Three key tenants of the IC Validator that offer improved physical designer productivity are:
a) High accuracy necessary for leading-edge process nodes.
b) Superior scalability for efficient utilization of available hardware. And,
c) Ease of use with seamless integration of IC Validator and IC Compiler

Bali said: "The IC Validator has been architected from the ground up for in-design physical verification. In-design physical verification enables place-and-route engineers to accelerate the time to tapeout by enabling sign-off quality physical verification from within implementation or physical design. Physical designers designing with IC Compiler can now benefit from the in-design physical verification approach with the push of a button, incurring minimal overhead cost to eliminate surprises late in the design.

"With the verify-as-you-go approach replacing the implement-then-verify approach, physical designers can significantly reduce iteration count, eliminate streamouts and streamins, and accelerate time to tapeout. In addition, the integration enables several productivity enhancing flows like incremental DRC verification, incremental metal fill flows and ECO flows -- all leading to significant reduction in time to tapeout."

It would be interesting to determine or know by approximately what percent is the total physical verification time reduced, and what all does it cover in the process?

Bali added that in extreme cases, finding and fixing DRC violations can easily impact the schedules by a few weeks! The key here is that physical designers typically wait until the final stages of the tapeout to run physical verification. Inevitably, the schedule at this point is squeezed and the cost of fixing the error is high.

"With a sign-off quality physical verification tool integrated into the physical design environment, place-and-route engineers can verify as they implement and eliminate late surprises while speeding up the total physical verification turnaround time. In addition, the outcome of this process is a sign-off clean design.

Production ready!
The Synopsys IC Validator is also said to 'production ready!" What exactly does that mean?

The IC Validator has been successfully used to tapeout designs at several chip manufacturers, said Bali. In addition, it is currently being used for production designs at Nvidia and Toshiba. Besides other leading foundry's and chip manufactures it is also qualified by TSMC for 40nm and 28nm process nodes.

For those interested, Toshiba already has Synopsys as its key EDA partner, and NVIDIA adopted the IC Validator for sign-off physical verification, within days of its launch! More are bound to follow!

Saving design spins!
Will the IC Validator approach be able to save design spins? How much is the physical design cycle time reduced?

With the in-design physical verification, place-and-route engineers will be able to run sign-off quality DRC checks, timing aware and sign-off quality metal fill, all within the familiar IC Compiler environment. Linear scalability for efficient use of hardware, sign-off accuracy and integration with IC Compiler will enable productivity enhancing flows like auto detect and autofix, incremental verification flows -- all can significantly reduce time to tapeout.

How can it help in avoiding the painful sign-off failure-to-physical-redesign iterations that are increasingly common below 90nm?

With the seamless integration of the IC Validator with the IC Compiler, physical designers can now verify the design as they implement for manufacturing sign-off accuracy.

Incremental DRC's strength
How good is the incremental design-rule checker (DRC)? Is it really parallelized for the multicore servers?

According to Bali, incremental flows are one of the strongest tenants of IC Validator. To improve physical designer productivity, rule-based only or layer-based only incremental verification runs can be initiated from within IC Compiler.

He said: "For ECO validation, the IC Validator supports window or an area-based incremental verification approach to speed up surgical checks. The incremental flows are meant to be quick, but the IC Validator has multicore capability to further speed up the process."

The IC Validator discovers and fixes design rule violations within the global context of the design as well. How is this made possible?

With the in-design physical verification, the IC Validator can accurately and automatically identify DRC violation and automatically provide fix guidance to IC Compiler to fix the violation and then re-verify it again.

Handling metal fills and design changes
Operations typically performed during physical verification, such as metal fills, may trigger additional design changes to achieve timing closure. How is this handled by the IC Validator?

Bali said that the prevailing post-processing oriented DFM flows introduce excessive and lengthy discover-fix iterations. Metal fill insertion, a mandatory DFM step at the advanced nodes, exemplifies this issue.

"Physical designers stream out the timing closed post-fill design for signoff validation and then stream it back in to fix any signoff errors flagged during physical verification. This multi-hour discover-fix loop is typically repeated per block till the post-fill design is both signoff qualified and timing clean.

"With in-design physical verification, the IC Validator and IC Compiler address the challenges of DFM, within the place-and-route environment. The seamless integration enables a single pass metal fill flow that is timing aware and of signoff quality and is void of expensive streamouts and streamins," he added.