Breakthrough technology uses scalable technology to calculate the dynamic voltage drop (DVD) with 100% coverage of all realistic switching combinations and no runtime increase.
SigmaDVD is a novel technology that does not use vectors to achieve 100% coverage of all realistic switching combinations. SigmaDVD replaces traditional vector-based DVD analysis just like STA replaced simulation-based timing. This highly scalable technology allows designers to shrink wasteful safety margins, increase design speeds, and lower project risk.
SigmaDVD provides 100% coverage for dynamic voltage drop (DVD) within short runtimes. Its highly parallelizable analysis eliminates the need for vectors just like STA eliminated them for timing analysis. It can be run at any design stage and generates detailed reports on the root causes of DVD for quick fixes.
How to Achieve 100% Switching Coverage and Identify Root-Causes of DVD
SigmaDVD increases switching coverage from <5% to 100%, which eliminates the risk of missing a worst-case switching event and significantly reduces the wasteful over-design of power supply networks.
Traditional dynamic voltage drop (DVD) signoff relies on simulating multiple cycles of timing vectors (VCD or vectorless). But this catches only a fraction of all possible switching combinations. Increasing the number of simulation cycles takes prohibitively long. Consequently, voltage margins increase to offset the lack of good coverage, which leads to slower performance, and higher power. Even when problems are detected, there is no actionable fixing guidance.
SigmaDVD introduces an entirely novel, breakthrough approach to DVD that eliminates the reliance on vector simulation to give aggressors 100% coverage of all realistic switching combinations. It typically runs in a few hours - about the same time as 20 cycles of traditional DVD simulation. This significantly reduces over-design in power distribution networks and the risk of failure due to a missed worst-case switching event. Less over-design improves chip performance and lowers your power usage.
SigmaDVD is an add-on module to RedHawk-SC that simulates the probability distribution for dynamic voltage drop (DVD) on every instance in a design. SigmaDVD’s analysis includes both self-drop and the voltage drop induced by neighboring cell switching. Its novel analysis technique does not rely on switching vectors, whether from VCD or vector less; it provides 100% switching coverage like how STA timing analysis gives 100% coverage of all timing paths without input vectors.
SigmaDVD is highly parallelizable and runs on hundreds of CPUs in the cloud with linear scalability. The run time is about the same as current vector-based techniques that provide only 5% coverage or less.
Built on accuracy simulation, SigmaDVD provides detailed transient analysis, without approximations or loss of detail.
SigmaDVD’s novel technology covers self-drop and all realistic switching combinations of neighbors for each instance in the design.
SigmaDVD uses 10,000 Monte Carlo simulations to capture all statistically significant combinations of neighbor switching interactions for each instance. Just like STA for timing, this does not require any vector input.
SigmaDVD analyzes each instance in the design and runs in parallel on multiple CPUs with linear scalability. This is excellent for high core utilization in the cloud and means that the runtime is just a few hours – about the same as today’s vector-based approach with 20 cycles.
SigmaDVD’s analysis is an overall DVD frequency distribution and a distribution for each instance, allowing much more refined decision-making for setting limits.
SigmaDVD provides a GUI and reporting to determine the root cause of any voltage drop. This includes the principal causes of the drop, the likelihood of the switching scenario, a list of victims for each significant aggressor, and more. Designers can use this information for targeted fixing.
Because SigmaDVD doesn't rely on vectors as input, it runs at an early design stage, and the results can optimize placement to avoid DVD violations.
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