Ashkan Vakil

dblp:233/8112 · DBLP profile ↗
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4ranked-venue papers
2as first author
3since 2021 · last 2022
0000-0002-5029-8330ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Systems, architecture and hardware · 4 · 2 first-author · 3 since 2021
YearPublicationVenuePosition
2022 RAPTA: A Hierarchical Representation Learning Solution For Real-Time Prediction of Path-Based Static Timing Analysis
abstract
This paper presents RAPTA, a customized Representation-learning Architecture for automation of feature engineering and predicting the result of Path-based Timing-Analysis early in the physical design cycle. RAPTA offers multiple advantages compared to prior work: 1) It has superior accuracy with errors std ranges 3.9ps~16.05ps in 32nm technology. 2) RAPTA's architecture does not change with feature-set size, 3) RAPTA does not require manual input feature engineering. To the best of our knowledge, this is the first work, in which Bidirectional Long Short-Term Memory (Bi-LSTM) representation learning is used to digest raw information for feature engineering, where generation of latent features and Multilayer Perceptron (MLP) based regression for timing prediction can be trained end-to-end.
Tanmoy Chowdhury, Ashkan Vakil, Banafsheh S. Latibari, Sayed Aresh Beheshti-Shirazi, Ali Mirzaeian, Xiaojie Guo 0002, Sai Manoj Pudukotai Dinakarrao, Houman Homayoun, Ioannis Savidis, Liang Zhao 0002, Avesta Sasan
ACM Great Lakes Symposium on VLSI2
2021 Learning Assisted Side Channel Delay Test for Detection of Recycled ICs
abstract
With the outsourcing of design flow, ensuring the security and trustworthiness of integrated circuits has become more challenging. Among the security threats, IC counterfeiting and recycled ICs have received a lot of attention due to their inferior quality, and in turn, their negative impact on the reliability and security of the underlying devices. Detecting recycled ICs is challenging due to the effect of process variations and process drift occurring during the chip fabrication. Moreover, relying on a golden chip as a basis for comparison is not always feasible. Accordingly, this paper presents a recycled IC detection scheme based on delay side-channel testing. The proposed method relies on the features extracted during the design flow and the sample delays extracted from the target chip to build a Neural Network model using which the target chip can be truly identified as new or recycled. The proposed method classifies the timing paths of the target chip into two groups based on their vulnerability to aging using the information collected from the design and detects the recycled ICs based on the deviation of the delay of these two sets from each other.
Ashkan Vakil, Farzad Niknia, Ali Mirzaeian, Avesta Sasan, Naghmeh Karimi
ASP-DAC1
2021 A Reinforced Learning Solution for Clock Skew Engineering to Reduce Peak Current and IR Drop
abstract
This paper purposes a Reinforcement Learning solution for peak current reduction by clock skew engineering. The reinforcement learning agent learns how to adjust each register's clock arrival time to maximize the clock arrival's distribution. The use of reinforcement learning allows us to explore optimization opportunities in clock tree synthesis beyond the heuristic algorithms used in modern EDA tools. Our experimental results support this claim as we report over 35% drop in peak current and major reduction in IR drop (from package to transistor) in the selected benchmarks. The agent explores despite creating timing violations and receives a large negative reward for its action. The agent, however, can receive a bonus reward in the future if the timing violation was fixed later by adjusting the clock arrival time of other registers, resulting in a broader spread in clock arrival distribution.
Sayed Aresh Beheshti-Shirazi, Ashkan Vakil, Sai Manoj Pudukotai Dinakarrao, Ioannis Savidis, Houman Homayoun, Avesta Sasan
ACM Great Lakes Symposium on VLSI2
2019 IR-ATA: IR annotated timing analysis, a flow for closing the loop between PDN design, IR analysis & timing closure
abstract
This paper presents IR-ATA, a novel flow for modeling the timing impact of IR drop during the physical design and timing closure of an ASIC chip. We first illustrate how the current and conventional mechanism for budgeting the IR drop and voltage noise (by using hard margins) lead to sub-optimal design. Consequently, we propose a new approach for modeling and margining against voltage noise, such that each timing path is margined based on its own topology and its own view of voltage noise. By having such a path based margining mechanism, the margins for IR drop and voltage noise for most timing paths in the design are safely relaxed. The reduction in the margin increases the available timing slack that could be used for improving the power, performance, and area of a design. Finally, we illustrate how IR-ATA could be used to track the timing impact of physical or PDN changes, allowing the physical designers to explore tradeoffs that were previously, for lack of methodology, not possible.
Ashkan Vakil, Houman Homayoun, Avesta Sasan
ASP-DAC1