{"title":"Theory of Ising Machines and a Common Software Platform for Ising Machines","authors":"Shu Tanaka, Yoshiki Matsuda, N. Togawa","doi":"10.1109/ASP-DAC47756.2020.9045126","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045126","url":null,"abstract":"Ising machines are a new type of non-Neumann computer that specializes in solving combinatorial optimization problems efficiently. The input form of Ising machines is the energy function of the Ising model or quadratic unconstrained binary optimization form, and Ising machines operate to search for a condition to minimize the energy function. We describe the theory of Ising machines and the present status of the Ising machines, software for Ising machines, and applications using Ising machines.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122321335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaqi Gu, Zheng Zhao, Chenghao Feng, Mingjie Liu, Ray T. Chen, D. Pan
{"title":"Towards Area-Efficient Optical Neural Networks: An FFT-based Architecture","authors":"Jiaqi Gu, Zheng Zhao, Chenghao Feng, Mingjie Liu, Ray T. Chen, D. Pan","doi":"10.1109/ASP-DAC47756.2020.9045156","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045156","url":null,"abstract":"As a promising neuromorphic framework, the optical neural network (ONN) demonstrates ultra-high inference speed with low energy consumption. However, the previous ONN architectures have high area overhead which limits their practicality. In this paper, we propose an area-efficient ONN architecture based on structured neural networks, leveraging optical fast Fourier transform for efficient computation. A two-phase software training flow with structured pruning is proposed to further reduce the optical component utilization. Experimental results demonstrate that the proposed architecture can achieve 2.2∼3.7× area cost improvement compared with the previous singular value decomposition-based architecture with comparable inference accuracy.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"20 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114118797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shaobin Ma, Xiaoyi Wang, S. Tan, Liang Chen, Jian He
{"title":"An Adaptive Electromigration Assessment Algorithm for Full-chip Power/Ground Networks","authors":"Shaobin Ma, Xiaoyi Wang, S. Tan, Liang Chen, Jian He","doi":"10.1109/ASP-DAC47756.2020.9045102","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045102","url":null,"abstract":"In this paper, an adaptive algorithm is proposed to perform electromigration (EM) assessment for full-chip power/ground networks. Based on the eigenfunction solutions, the proposed method improves the efficiency by properly selecting the eigenfunction terms and utilizing the closed-form eigenfunctions for commonly seen interconnect wires such as T-shaped or cross-shaped wires. It is demonstrated that the proposed method can trad-off well among the accuracy, efficiency and applicability of the eigenfunction based methods. The experimental results show that the proposed method is about three times faster than the finite difference method and other eigenfunction based methods.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"53 85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114157941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pruthvy Yellu, M. Monjur, Timothy Kammerer, Dongpeng Xu, Qiaoyan Yu
{"title":"Security Threats and Countermeasures for Approximate Arithmetic Computing","authors":"Pruthvy Yellu, M. Monjur, Timothy Kammerer, Dongpeng Xu, Qiaoyan Yu","doi":"10.1109/ASP-DAC47756.2020.9045385","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045385","url":null,"abstract":"Approximate computing (AC) emerges as a promising approach for energy-accuracy trade-off in compute-intensive applications. However, recent work reveals that AC techniques could lead to new security vulnerabilities, which are presented in a format of visionary view. There is a lack of in-depth research on concrete attack models and estimation of the significance of the attacks on approximate arithmetic computing systems. This work presents several practical attack examples and then proposes two attack models with quantitative analysis. Input integrity check and exclusive logic based attack detection methods are proposed to address the attacks on AC systems. The experimental results show that the attack detection failure rate of our method is below $2.2*10^{-3}$ and the area and power overhead is less than 6.8% and 1.5%, respectively.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114309366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vidya A. Chhabria, A. Kahng, Minsoo Kim, U. Mallappa, S. Sapatnekar, Bangqi Xu
{"title":"Template-based PDN Synthesis in Floorplan and Placement Using Classifier and CNN Techniques","authors":"Vidya A. Chhabria, A. Kahng, Minsoo Kim, U. Mallappa, S. Sapatnekar, Bangqi Xu","doi":"10.1109/ASP-DAC47756.2020.9045303","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045303","url":null,"abstract":"Designing an optimal power delivery network (PDN) is a time-intensive task that involves many iterations. This paper proposes a methodology that employs a library of predesigned, stitchable templates, and uses machine learning (ML) to rapidly build a PDN with region-wise uniform pitches based on these templates. Our methodology is applicable at both the floorplan and placement stages of physical implementation. (i) At the floorplan stage, we synthesize an optimized PDN based on early estimates of current and congestion, using a simple multilayer perceptron classifier. (ii) At the placement stage, we incrementally optimize an existing PDN based on more detailed congestion and current distributions, using a convolution neural network. At each stage, the neural network builds a safe-by-construction PDN that meets IR drop and electromigration (EM) specifications. On average, the optimization of the PDN brings an extra 3% of routing resources, which corresponds to a thousands of routing tracks in congestion-critical regions, when compared to a globally uniform PDN, while staying within the IR drop and EM limits.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132763881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Niklas Kochdumper, Ahmad Tarraf, Malgorzata Rechmal, M. Olbrich, L. Hedrich, M. Althoff
{"title":"Establishing Reachset Conformance for the Formal Analysis of Analog Circuits","authors":"Niklas Kochdumper, Ahmad Tarraf, Malgorzata Rechmal, M. Olbrich, L. Hedrich, M. Althoff","doi":"10.1109/ASP-DAC47756.2020.9045120","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045120","url":null,"abstract":"We present the first work on the automated generation of reachset conformant models for analog circuits. Our approach applies reachset conformant synthesis to add nondeterminism to piecewise-linear circuit models so that they enclose all recorded behaviors of the real system. To achieve this, we present a novel technique to compute the required nondeterminism for the piecewise-linear models. The effectiveness of our approach is demonstrated on a real analog circuit. Since the resulting models enclose all measurements, they can be used for formal verification.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"754 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121258102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bayesian Methods for the Yield Optimization of Analog and SRAM Circuits","authors":"Shuhan Zhang, Fan Yang, Dian Zhou, Xuan Zeng","doi":"10.1109/ASP-DAC47756.2020.9045614","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045614","url":null,"abstract":"As the technology node shrinks to the nanometer scale, process variation become one of the most important issues in IC designs. The industry calls for designs with high yield under process variations. Yield optimization is computationally intensive because traditionally it relies on the Monte-Carlo yield estimation. In this paper, we will first review the Bayesian methods that reduce the computational cost of yield estimation and optimization. By applying Bayes’ theorem, maximizing the circuit yield is transformed to identify the design parameters with maximal probability density, conditioning on the event that the corresponding circuit is “pass”. It can thus avoid repetitive yield estimations during optimization. The computational cost can also be reduced by using the Bayesian optimization strategy. By using the Gaussian process surrogate model and adaptive yield estimation, Bayesian optimization can significantly reduce the number of simulations while achieving even comparable yields for analog and SRAM circuits. We further propose a Bayesian optimization approach for yield optimization via maxvalue entropy search in this paper. The proposed max-value entropy search can better explore the state space, and thus reduce the number of circuit simulations while achieving competitive results.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115618209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maedeh Hemmat, Tejash Shah, Yuhua Chen, Joshua San Miguel
{"title":"CRANIA: Unlocking Data and Value Reuse in Iterative Neural Network Architectures","authors":"Maedeh Hemmat, Tejash Shah, Yuhua Chen, Joshua San Miguel","doi":"10.1109/ASP-DAC47756.2020.9045691","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045691","url":null,"abstract":"A common inefficiency in traditional Convolutional Neural Network (CNN) architectures is that they do not adapt to variations in inputs. Not all inputs require the same amount of computation to be correctly classified, and not all of the weights in the network contribute equally to generate the output. Recent work introduces the concept of iterative inference, enabling per-input approximation. Such an iterative CNN architecture clusters weights based on their importance and saves significant power by incrementally fetching weights from off-chip memory until the classification result is accurate enough. Unfortunately, this comes at a cost of increased execution time since some inputs need to go through multiple rounds of inference, negating the savings in energy. We propose Cache Reuse Approximation for Neural Iterative Architectures (CRANIA) to overcome this inefficiency. We recognize that the re-execution and clustering built into these iterative CNN architectures unlock significant temporal data reuse and spatial value reuse, respectively. CRANIA introduces a lightweight cache+compression architecture customized to the iterative clustering algorithm, enabling up to 9 × energy savings and speeding up inference by 5.8 × with only 0.3% area overhead.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121667889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hassaan Saadat, Haris Javaid, A. Ignjatović, S. Parameswaran
{"title":"WEID: Worst-case Error Improvement in Approximate Dividers","authors":"Hassaan Saadat, Haris Javaid, A. Ignjatović, S. Parameswaran","doi":"10.1109/ASP-DAC47756.2020.9045504","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045504","url":null,"abstract":"Approximate integer dividers suffer from unreasonably high worst-case relative errors (such as 50% or 100%), which can adversely affect the application-level output. In this paper, we propose WEID, which is a novel lightweight method to improve the worst-case relative errors in approximate integer dividers. We first present an in-depth analysis to gain insights into the cause of the high worst-case relative error. Based on our insights, we propose a novel method to detect when an error occurs in an approximate divider, and modify the output to reduce the error. Further, we present the hardware realization of WEID method and demonstrate that it can be generically coupled with several state-of-the-art approximate dividers. Our results show that for 32-by-16 dividers, WEID reduces worst-case relative errors from 100% to $sim 20$%, while still achieving $sim 80$% and $sim 70$% reduction in delay and energy compared to an accurate array divider.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122642156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Scaled Population Arithmetic for Efficient Stochastic Computing","authors":"He Zhou, S. Khatri, Jiang Hu, Frank Liu","doi":"10.1109/ASP-DAC47756.2020.9045292","DOIUrl":"https://doi.org/10.1109/ASP-DAC47756.2020.9045292","url":null,"abstract":"We propose a new Scaled Population (SP) based arithmetic computation approach that achieves considerable improvements over existing stochastic computing (SC) techniques. First, SP arithmetic introduces scaling operations that significantly reduce the numerical errors as compared to SC. Experiments show accuracy improvements of a single multiplication and addition operation by $6. 3 times $ and $4. 0 times $, respectively. Secondly, SP arithmetic erases the inherent serialization associated with stochastic computing, thereby significantly improves the computational delays. We design each of the operations of SP arithmetic to take $mathcal{O}$(1) gate delays, and eliminate the need of serially iterating over the bits of the population vector. Our SP approach improves the area, delay and power compared with conventional stochastic computing on an FPGA-based implementation. We also apply our SP scheme on a handwritten digit recognition application (MNIST), improving the recognition accuracy by 32.79% compared to SC.","PeriodicalId":125112,"journal":{"name":"2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122482242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}