Date: Wednesday 29 March 2017
Time: 10:00 - 10:30
Location / Room: IP sessions (in front of rooms 4A and 5A)

Interactive Presentations run simultaneously during a 30-minute slot. A poster associated to the IP paper is on display throughout the morning. Additionally, each IP paper is briefly introduced in a one-minute presentation in a corresponding regular session, prior to the actual Interactive Presentation. At the end of each afternoon Interactive Presentations session the award 'Best IP of the Day' is given.

Label	Presentation Title Authors
IP2-1	COMPACT MODELING AND CIRCUIT-LEVEL SIMULATION OF SILICON NANOPHOTONIC INTERCONNECTS Speaker: Yuyang Wang, UC Santa Barbara, US Authors: Rui Wu, Yuyang Wang, Zeyu Zhang, Chong Zhang, Clint Schow, John Bowers and Kwang-Ting Cheng, UC Santa Barbara, US Abstract Nanophotonic interconnects have been playing an increasingly important role in the datacom regime. Greater integration of silicon photonics demands modeling and simulation support for design validation, optimization and design space exploration. In this work, we develop compact models for a number of key photonic devices, which are extensively validated by the measurement data of a fabricated optical network-on-chip (ONoC). Implemented in SPICE-compatible Verilog-A, the models are used in circuit-level simulations of full optical links. The simulation results match well with the measurement data. Our model library and simulation approach enable the electro-optical (EO) co-simulation, allowing designers to include photonic devices in the whole system design space, and to co-optimize the transmitter, interconnect, and receiver jointly. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-2	A TRUE RANDOM NUMBER GENERATOR BASED ON PARALLEL STT-MTJS Speaker: Yuanzhuo Qu, University of Alberta, CA Authors: Yuanzhuo Qu1, Jie Han1, Bruce Cockburn1, Yue Zhang2, Weisheng Zhao2 and Witold Pedrycz1 1University of Alberta, CA; 2Beihang University, CN Abstract Random number generators are an essential part of cryptographic systems. For the highest level of security, true random number generators (TRNG) are needed instead of pseudo-random number generators. In this paper, the stochastic behavior of the spin transfer torque magnetic tunnel junction (STT-MTJ) is utilized to produce a TRNG design. A parallel structure with multiple MTJs is proposed that minimizes device variation effects. The design is validated in a 28-nm CMOS process with Monte Carlo simulation using a compact model of the MTJ. The National Institute of Standards and Technology (NIST) statistical test suite is used to verify the randomness quality when generating encryption keys for the Transport Layer Security or Secure Sockets Layer (TLS/SSL) cryptographic protocol. This design has a generation speed of 177.8 Mbit/s, and an energy of 0.64 pJ is consumed to set up the state in one MTJ. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-3	ENABLING AREA EFFICIENT RF ICS THROUGH MONOLITHIC 3D INTEGRATION Speaker: Panagiotis Chaourani, KTH, Royal Institute of Technology, Stockholm, SE Authors: Panagiotis Chaourani, Per-Erik Hellström, Saul Rodriguez, Raul Onet and Ana Rusu, KTH, Royal Institute of Technology, SE Abstract The Monolithic 3D (M3D) integration technology has emerged as a promising alternative to dimensional scaling thanks to the unprecedented integration density capabilities and the low interconnect parasitics that it offers. In order to support technological investigations and enable future M3D circuits, M3D design methodologies, flows and tools are essential. Prospective M3D digital applications have attracted a lot of scientific interest. This paper identifies the potential of M3D RF/analog circuits and presents the first attempt to demonstrate such circuits. Towards this, a M3D custom design platform, which is fully compatible with commercial design tools, is proposed and validated. The design platform includes process characteristics, device models, LVS and DRC rules and a parasitic extraction flow. The envisioned M3D structure is built on a commercial CMOS process that serves as the bottom tier, whereas a SOI process is used as top tier. To validate the proposed design flow and to investigate the potential of M3D RF/analog circuits, a RF front-end design for Zig-Bee WPAN applications is used as case-study. The M3D RF front-end circuit achieves 35.5 % area reduction, while showing similar performance with the original 2D circuit. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-4	RECONFIGURABLE THRESHOLD LOGIC GATES USING OPTOELECTRONIC CAPACITORS Speaker: Baris Taskin, Drexel University, US Authors: Ragh Kuttappa, Lunal Khuon, Bahram Nabet and Baris Taskin, Drexel University, US Abstract This paper investigates the integration of optoelectronic devices with CMOS threshold logic gates to design reconfigurable Boolean functions. The weight of the optoelectronic device can be altered by changing the optical power which is used to reconfigure the threshold logic (TL) gate. The proposed optoelectronic capacitor based TL (OECTL) gates are designed for i) simplistic AND/NAND gates and OR/NOR gates with large fan-in and ii) linearly separable Boolean functions that can be reconfigured to other linearly separable Boolean functions, constrained in reconfiguration by the specifics of TL operation. SPICE simulations in 65nm bulk CMOS technology with a Verilog-A model for the optoelectronic capacitor demonstrate i) AND/NAND gates and OR/NOR gates are 2X faster as fan0in increases and consumes low power ii) Boolean function can be reconfigured with 0.58X smaller delay and 0.46X lesser power of standard CMOS. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-5	I-BEP: A NON-REDUNDANT AND HIGH-CONCURRENCY MEMORY PERSISTENCY MODEL Speaker: Yuanchao Xu, Capital Normal University, CN Authors: Yuanchao Xu, Zeyi Hou, Junfeng Yan, Lu Yang and Hu Wan, Capital Normal University, CN Abstract Byte-addressable, non-volatile memory (NVM) technologies enable fast persistent updates but incur potential data inconsistency upon a failure. Recent proposals present several persistency models to guarantee data consistency. However, they fail to express the minimal persist ordering as a result of inducing unnecessary ordering constraints. In this paper, we propose i-BEP, a non-redundant high concurrency memory persistency model, which expresses epoch dependency via persist directed acyclic graph instead of program order. Additionally, we propose two techniques, background persist and deferred eviction, to enhance the performance of i-BEP. We demonstrate that i-BEP can improve the performance by 15% for typical data structures on average over buffered epoch persistency (BEP) model. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-6	SPMS: STRAND BASED PERSISTENT MEMORY SYSTEM Speaker: Shuo Li, National University of Defense Technology, CN Authors: Shuo Li1, Peng Wang2, Nong Xiao1, Guangyu Sun2 and Fang Liu1 1National University of Defense Technology, CN; 2Peking University, CN Abstract Emerging non-volatile memories enable persistent memory, which offers the opportunity to directly access persistent data structures residing in main memory. In order to keep persistent data consistent in case of system failures, most prior work relies on persist ordering constraints which incurs significant overheads. Strand persistency minimizes persist ordering constraints. However, there is still no proposed persistent memory design based on strand persistency due to its implementation complexity. In this work, we propose a novel persistent memory system based on strand persistency, called SPMS. SPMS consists of cacheline-based strand group tracking components, a volatile strand buffer and ultra-capacitors incorporated in persistent memory modules. SPMS can track each strand and guarantee its atomicity. In case of system failures, committed strands buffered in the strand buffer can be flushed back to persistent memory within the residual energy window provided by the ultra-capacitors. Our evaluations show that SPMS outperforms the state-of-the-art persistent memory system by 6.6\% and has slightly better performance than the baseline without any consistency guarantee. What's more, SPMS reduces the persistent memory write traffic by 30\%, with the help of the strand buffer. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-7	ARCHITECTING HIGH-SPEED COMMAND SCHEDULERS FOR OPEN-ROW REAL-TIME SDRAM CONTROLLERS Speaker: Leonardo Ecco, TU Braunschweig, DE Authors: Leonardo Ecco1 and Rolf Ernst2 1Institute of Computer and Network Engineering, TU Braunschweig, DE; 2TU Braunschweig, DE Abstract As SDRAM modules get faster and their data buses wider, researchers proposed the use of the open-row policy in command schedulers for real-time SDRAM controllers. While the real-time properties of such schedulers have been thoroughly investigated, their hardware implementation was not. Hence, in this paper, we propose a highly-parallel and multi-stage architecture that implements a state-of-the open-row real-time command scheduler. Moreover, we evaluate such architecture from the hardware overhead and performance perspectives. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-8	AUTOMATIC EQUIVALENCE CHECKING FOR SYSTEMC-TLM 2.0 MODELS AGAINST THEIR FORMAL SPECIFICATIONS Speaker: Mehran Goli, University of Bremen, DE Authors: Mehran Goli, Jannis Stoppe and Rolf Drechsler, University of Bremen, DE Abstract The necessity to handle the increasing complexity of digital circuits has led to the usage of more and more abstract design paradigms. In particular, the Electronic System Level (ESL) has become an area of active research and industrial application, especially via SystemC and its Transaction Level Modeling (TLM) framework. Additionally, the usage of formal specification languages such as the Unified Modeling Language (UML) prior to the implementation (even at higher abstraction levels) is now a broadly accepted workflow. Utilizing this layered approach leaves the translation from the specification to the implementation to the designer, leaving the question unanswered how the equivalence of these should be verified. This paper proposes a novel, non-intrusive and broadly applicable approach to automatically validate the equivalence of the structural and behavioral information of a SystemC-TLM 2.0 model and its formal specification. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-9	(Best Paper Award Candidate) HEAD-MOUNTED SENSORS AND WEARABLE COMPUTING FOR AUTOMATIC TUNNEL VISION ASSESSMENT Speaker: Josue Ortiz, Complutense University of Madrid, ES Authors: Yuchao Ma and Hassan Ghasemzadeh, Washington State University, US Abstract As the second leading cause of blindness worldwide, glaucoma impacts a large population of individuals over 40. Although visual acuity often remains unaffected in early stages of the disease, visual field loss, expressed by tunnel vision condition, gradually increases. Glaucoma often remains undetected until it has moved into advanced stages. In this paper, we introduce a wearable system for automatic tunnel vision detection using head-mounted sensors and machine learning techniques. We develop several tasks, including reading and observation, and estimate visual field loss by analyzing user's head movements while performing the tasks. An integrated computational module takes sensor signals as input, passes the data through several automatic data processing phases, and returns a final result by merging task-level predictions. For validation purposes, a series of experiments is conducted with 10 participants using tunnel vision simulators. Our results demonstrate that the proposed system can detect mild and moderate tunnel visions with an accuracy of 93.3% using a leave-one-subject-out analysis. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-10	(Best Paper Award Candidate) RETRODMR: TROUBLESHOOTING NON-DETERMINISTIC FAULTS WITH RETROSPECTIVE DMR Speaker: Ting Wang, The Chinese University of Hong Kong, HK Authors: Ting Wang1, Yannan Liu1, Qiang Xu1, Zhaobo Zhang2, Zhiyuan Wang2 and Xinli Gu2 1The Chinese University of Hong Kong, HK; 2Huawei Technologies, Inc., US Abstract The most notorious faults for diagnosis in post-silicon validation are those that manifest themselves in a non-deterministic manner with system-level functional tests, where errors randomly appear from time to time even when applying the same workloads. In this work, we propose a novel diagnostic framework that resorts to dual-modular redundancy (DMR) for troubleshooting non-deterministic faults, namely RetroDMR. To be specific, we log the essential events (e.g., the sequence of thread migration) in the faulty run to record the mapping relationship between threads and their corresponding execution units. Then in the following diagnosis runs, we apply redundant multithreading (RMT) technique to reduce error detection latency, while at the same time we try to follow the thread migration sequence of the original run whenever possible. By doing so, RetroDMR significantly improves the reproduction rate and diagnosis resolution for non-deterministic faults, as demonstrated in our experimental results. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-11	CRITICAL PATH - ORIENTED THERMAL AWARE X-FILLING FOR HIGH UN-MODELED DEFECT COVERAGE Speaker: Fotios Vartziotis, Computer Engineering, T.E.I. of Epirus, Greece, GR Authors: FOTIOS VARTZIOTIS1 and Chrysovalantis Kavousianos2 1TEI of Epirus, University of Ioannina, GR; 2Department of Computer Science and Engineering, University of Ioannina, GR Abstract The thermal activity during testing can be considerably reduced by applying power-oriented filling of the unspecified bits of test vectors. However, traditional power-oriented X-fill methods do not correlate the thermal activity with delay failures, and they consume all the unspecified bits to reduce the power dissipation at every region of the core. Therefore, they adversely affect the un-modeled defect coverage of the generated test vectors. The proposed method identifies the unspecified bits that are more critical for delay failures, and it fills them in such a way as to create a thermal safe neighborhood around the most critical regions of the core. For the rest of the unspecified bits a probabilistic model based on output deviations is adopted to increase the un-modeled defect coverage of the test vectors. Experimental results show that the thermal activity and the inter-connection delays of critical regions of the core are comparable to those of the power-oriented X-fill methods, while the un-modeled defect coverage is as high as that of the random-fill method. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-12	A COMPREHENSIVE METHODOLOGY FOR STRESS PROCEDURES EVALUATION AND COMPARISON FOR BURN-IN OF AUTOMOTIVE SOC Speaker: Paolo Bernardi, Politecnico di Torino, IT Authors: Paolo Bernardi1, Davide Appello2, Giampaolo Giacopelli2, Alessandro Motta2, Alberto Pagani2, Giorgio Pollaccia3, Christian Rabbi2, Marco Restifo1, Priit Ruberg4, Ernesto Sanchez1, Claudio Maria Villa2 and Federico Venini1 1Politecnico di Torino, IT; 2STMicroelectronics, IT; 3STMicroelectonics, IT; 4Tallinn University of Technology, EE Abstract Environmental and electrical stress phases are commonly applied to automotive devices during manufacturing test. The combination of thermal and electrical stress is used to give rise to early life latent failures that can be naturally found in a population of devices by accelerating aging processes through Burn-In test phases. This paper provides a methodology to evaluate and compare the stress procedures to be run during Burn-In; the proposed method takes into account several factors such as circuit activity, chip surface temperature and current consumption required by the stress procedure, and also considers Burn-In flow and tester limitations. A specific metric called Stress Coverage is suggested summing up all the stress contributions. Experimental results are gathered on an automotive device, showing the comparison between scan-based and functional stress run by a massively parallelized test equipment; reported figures and tables quantify the differences between the two approaches in terms of stress. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-13	ENERGY EFFICIENT STOCHASTIC COMPUTING WITH SOBOL SEQUENCES Speaker: Siting Liu, University of Alberta, CA Authors: Siting Liu and Jie Han, University of Alberta, CA Abstract Energy efficiency presents a significant challenge for stochastic computing (SC) due to the long random binary bit streams required for accurate computation. In this paper, a type of low discrepancy (LD) sequences, the Sobol sequence, is considered for energy-efficient implementations of SC circuits. The use of Sobol sequences improves the output accuracy of a stochastic circuit with a reduced sequence length compared to the use of another type of LD sequences, the Halton sequence, and conventional LFSR-generated pseudorandom sequences. The use of Sobol sequences leads to a similar or higher accuracy than using Halton sequences for basic arithmetic operations. Sobol sequence generators cost less energy than the Halton counterparts when multiple random sequences are required in a circuit, thus the use of Sobol sequences can lead to a higher energy efficiency in an SC circuit than using Halton sequences. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-14	LOGIC ANALYSIS AND VERIFICATION OF N-INPUT GENETIC LOGIC CIRCUITS Speaker: Hasan Baig, Technical University of Denmark, DK Authors: Hasan Baig and Jan Madsen, Technical University of Denmark, DK Abstract Nature is using genetic logic circuits to regulate the fundamental processes of life. These genetic logic circuits are triggered by a combination of external signals, such as chemicals, proteins, light and temperature, to emit signals to control other gene expressions or metabolic pathways accordingly. As compared to electronic circuits, genetic circuits exhibit stochastic behavior and do not always behave as intended. Therefore, there is a growing interest in being able to analyze and verify the logical behavior of a genetic circuit model, prior to its physical implementation in a laboratory. In this paper, we present an approach to analyze and verify the Boolean logic of a genetic circuit from the data obtained through stochastic analog circuit simulations. The usefulness of this analysis is demonstrated through different case studies illustrating how our approach can be used to verify the expected behavior of an n-input genetic logic circuit. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-15	A NOVEL WAY TO EFFICIENTLY SIMULATE COMPLEX FULL SYSTEMS INCORPORATING HARDWARE ACCELERATORS Speaker: Nikolaos Tampouratzis, Technical University of Crete, GR Authors: Nikolaos Tampouratzis1, Konstantinos Georgopoulos2 and Ioannis Papaefstathiou3 1Technical University of Crete, GR; 2Telecommunication Systems Institute, Technical University of Crete, GR; 3Technical university of Crete, GR Abstract The breakdown of Dennard scaling coupled with the persistently growing transistor counts severally increased the importance of application-specific hardware acceleration; such an approach offers significant performance and energy benefits compared to general-purpose solutions. In order to thoroughly evaluate such architectures, the designer should perform a quite extensive design space exploration so as to evaluate the tradeoffs across the entire system. The design, until recently, has been predominantly done using Register Transfer Level (RTL) languages such as Verilog and VHDL, which, however, lead to a prohibitively long and costly design effort. In order to reduce the design time a wide range of both commercial and academic High-Level Synthesis (HLS) tools have emerged; most of those tools, handle hardware accelerators that are described in synthesisable SystemC. The problem today, however, is that most simulators used for evaluating the complete user applications (i.e. full-system CPU/Mem/Peripheral simulators) lack any type of SystemC accelerator support. Within this context this paper presents a novel simulation environment comprised of a generic SystemC accelerator and probably the most widely known fullsystem simulator (i.e. GEM5). The proposed system is the only solution supporting the very important feature of global synchronization across the integrated simulation; furthermore it has been evaluated based on two different computationallyintensive use cases and the final results demonstrate that the presented approach is orders of magnitude faster than the existing ones. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-16	AUTOMATIC ABSTRACTION OF MULTI-DISCIPLINE ANALOG MODELS FOR EFFICIENT FUNCTIONAL SIMULATION Speaker: Franco Fummi, Università degli Studi di Verona, IT Authors: Enrico Fraccaroli1, Michele Lora1 and Franco Fummi2 1University of Verona, IT; 2Universita' di Verona, IT Abstract Multi-discipline components introduce problems when inserted within virtual platforms of Smart Systems for functional validation. This paper lists the most common emerging problems and it proposes a set of solutions to them. It presents a set of techniques, unified in an automatic abstraction methodology, useful to achieve fast analog mixed-signal simulation even when different physical disciplines and modeling styles are combined into a single analog model. The paper makes use of a complex case study.It deals with multiple-discipline descriptions, non-electrical conservative models, non-linear equation systems, and mixed time/frequency domain models. The original component behavior has been modeled in Verilog-AMS by using electrical, mechanical and kinematic equations. Then, it has been abstracted and integrated within a virtual platform of a mixed-signal smart system for efficient functional simulation. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-17	NOVEL MAGNETIC BURN-IN FOR RETENTION TESTING OF STTRAM Speaker: Swaroop Ghosh, Pennsylvania State University, US Authors: Mohammad Nasim Imtiaz Khan, Anirudh Iyengar and Swaroop Ghosh, Pennsylvania State University, US Abstract Spin-Transfer Torque RAM (STTRAM) is an emerging Non-Volatile Memory (NVM) technology that has drawn significant attention due to complete elimination of bitcell leakage. However, it brings new challenges in characteriz-ing the retention time of the array during test. Significant shift of retention time under static (process variation (PV)) and dynamic (voltage, temperature fluctuation) variability furthers this issue. In this paper, we propose a novel mag-netic burn-in (MBI) test which can be implemented with minimal changes in the existing test flow to enable STTRAM retention testing at short test time. The magnetic burn-in is also combined with thermal burn-in (MBI+BI) for further compression of retention and test time. Simula-tion results indicate MBI with 220Oe (at 25C) can improve the test time by 3.71x1013 X while MBI+BI with 220Oe at 125C can improve the test time by 1.97x1014X. Download Paper (PDF; Only available from the DATE venue WiFi)
IP2-19	AUTOMATIC CONSTRUCTION OF MODELS FOR ANALYTIC SYSTEM-LEVEL DESIGN SPACE EXPLORATION PROBLEMS Speaker: Seyed-Hosein Attarzadeh-Niaki, Shahid Beheshti University (SBU), IR Authors: Seyed-Hosein Attarzadeh-Niaki1 and Ingo Sander2 1Shahid Beheshti University (SBU), IR; 2KTH Royal Institute of Technology, SE Abstract Due to the variety of application models and also the target platforms used in embedded electronic system design, it is challenging to formulate a generic and extensible analytic design-space exploration (DSE) framework. Current approaches support a restricted class of application and platform models and are difficult to extend. This paper proposes a framework for automatic construction of system-level DSE problem models based on a coherent, constraint-based representation of system functionality, flexible target platforms, and binding policies. Heterogeneous semantics is captured using constraints on logical clocks. The applicability of this method is demonstrated by constructing DSE problem models from different combinations of application and platforms models. Time-triggered and untimed models of the system functionality and heterogeneous target platforms are used for this purpose. Another potential advantage of this approach is that constructed models can be solved using a variety of standard and ad-hoc solvers and search heuristics. Download Paper (PDF; Only available from the DATE venue WiFi)