Biblio
With increasing integration in SoCs, the Network-on-Chip (NoC) connecting cores and accelerators is of paramount importance to provide low-latency and high-throughput communication. Due to limits to scaling of electrical wires in terms of energy and delay, especially for long multi-mm distances on-chip, alternate technologies such as Wireless Network-on-Chip (WNoC) have shown promise. WNoCs can provide low-latency one-hop broadcasts across the entire chip and can augment point-to-point multi-hop signaling over traditional wired NoCs. Thus, there has been a recent surge in research demonstrating the performance and energy benefits of WNoCs. However, little to no work has studied the additional security and fault tolerance challenges that are unique to WNoCs. In this work, we study potential threats related to denial-of-service, spoofing, and eavesdropping attacks in WNoCs, due to malicious hardware trojans or faulty wireless components. We introduce Prometheus, a dropin solution inside the network interface that provides protection from all three attacks, while adhering to the strict area, power and latency constraints of on-chip systems.
The hybrid microgrid is attracting great attention in recent years as it combines the main advantages of the alternating current (AC) and direct current (DC) microgrids. It is one of the best candidates to support a net-zero energy community. Thus, this paper investigates and compares different hybrid AC/DC microgrid configurations that are suitable for a net-zero energy community. Four different configurations are compared with each other in terms of their impacts on the overall system reliability, expandability, load shedding requirements, power sharing issues, net-zero energy capability, number of the required interface converters, and the requirement of costly medium-voltage components. The results of the investigations indicate that the best results are achieved when each building is enabled to supply its critical loads using an independent AC microgrid that is interfaced to the DC microgrid through a dedicated interface converter.
Hardware Trojan (HT) detection methods based on the side channel analysis deeply suffer from the process variations. In order to suppress the effect of the variations, we devise a method that smartly selects two highly correlated paths for each interconnect (edge) that is suspected to have an HT on it. First path is the shortest one passing through the suspected edge and the second one is a path that is highly correlated with the first one. Delay ratio of these paths avails the detection of the HT inserted circuits. Test results reveal that the method enables the detection of even the minimally invasive Trojans in spite of both inter and intra die variations with the spatial correlations.
This paper introduces a hardware Trojan detection method using Chip ID which is generated by Relative Time-Delays (RTD) of sensor chains and the effectiveness of RTD is verified by post-layout simulations. The rank of time-delays of the sensor chains would be changed in Trojan-inserted chip. RTD is an accurate approach targeting to all kinds of Trojans, since it is based on the RELATIVE relationship between the time-delays rather than the absolute values, which are hard to be measured and will change with the fabricate process. RTD needs no golden chip, because the RELATIVE values would not change in most situations. Thus the genuine ID can be generated by simulator. The sensor chains can be inserted into a layout utilizing unused spaces, so RTD is a low-cost solution. A Trojan with 4x minimum NMOS is placed in different places of the chip. The behavior of the chip is obtained by using transient based post-layout simulation. All the Trojans are detected AND located, thus the effectiveness of RTD is verified.
Interconnect opens are known to be one of the predominant defects in nanoscale technologies. Automatic test pattern generation for open faults is challenging, because of their rather unstable behavior and the numerous electrical parameters which need to be considered. Thus, most approaches try to avoid accurate modeling of all constraints like the influence of the aggressors on the open net and use simplified fault models in order to detect as many faults as possible or make assumptions which decrease both complexity and accuracy. Yet, this leads to the problem that not only generated tests may be invalidated but also the localization of a specific fault may fail - in case such a model is used as basis for diagnosis. Furthermore, most of the models do not consider the problem of oscillating behavior, caused by feedback introduced by coupling capacitances, which occurs in almost all designs. In [1], the Robust Enhanced Aggressor Victim Model (REAV) and in [2] an extension to address the problem of oscillating behavior were introduced. The resulting model does not only consider the influence of all aggressors accurately but also guarantees robustness against oscillating behavior as well as process variations affecting the thresholds of gates driven by an open interconnect. In this work we present the first diagnostic classification algorithm for this model. This algorithm considers all constraints enforced by the REAV model accurately - and hence handles unknown values as well as oscillating behavior. In addition, it allows to distinguish faults at the same interconnect and thus reducing the area that has to be considered for physical failure analysis. Experimental results show the high efficiency of the new method handling circuits with up to 500,000 non-equivalent faults and considerably increasing the diagnostic resolution.
As the interconnect delay is becoming a larger fraction of the clock cycle time, the conventional global stalling mechanism, which is used to correct error in general synchronous circuits, would be no longer feasible because of the expensive timing cost for the stalling signal to travel across the circuit. In this paper, we propose recovery-based resilient latency-insensitive systems (RLISs) that efficiently integrate error-recovery techniques with latency-insensitive design to replace the global stalling. We first demonstrate a baseline RLIS as the motivation of our work that uses additional output buffer which guarantees that only correct data can enter the output channel. However this baseline RLIS suffers from performance degradations even when errors do not occur. We propose a novel improved RLIS that allows erroneous data to propagate in the system. Equipped with improved queues that prevent accumulation of erroneous data, the improved RLIS retains the system performance. We provide theoretical study that analyzes the impact of errors on system performance and the queue sizing problem. We also theoretically prove that the improved RLIS performs no worse than the global stalling mechanism. Experimental results show that the improved RLIS has 40.3% and even 3.1% throughput improvements compared to the baseline RLIS and the infeasible global stalling mechanism respectively, with less than 10% hardware overhead.
Power network is important part of national comprehensive energy resources transmission system in the way of energy security promise and the economy society running. Meanwhile, because of many industries involved, the development of grid can push national innovation ability. Nowadays, it makes the inner of smart grid flourish that material science, computer technique and information and communication technology go forward. This paper researches the function and modality of smart grid on energy, geography and technology dimensions. The analysis on the technology dimension is addressed on two aspects which are network control and interaction with customer. The mapping relationship between functions fo smart grid and eight key technologies, which are Large-capacity flexible transmission technology, DC power distribution technology, Distributed power generation technology, Large-scale energy storage technology, Real-time tracking simulation technology, Intelligent electricity application technology, The big data analysis and cloud computing technology, Wide-area situational awareness technology, is given. The research emphasis of the key technologies is proposed.