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Abstract-Negative bias temperature instability (NBTI) in PMOS transistors has become a major reliability concern in present-day digital circuit design. Further, with the recent introduction of Hf-based high-k dielectrics for gate leakage reduction, positive bias temperature instability (PBTI), the dual effect in NMOS transistors, has also reached significant levels. Consequently, designs are required to build in substantial guardbands in order to guarantee reliable operation over the lifetime of a chip, and these involve large area and power overheads. In this paper, we begin by proposing the use of adaptive body bias (ABB) and adaptive supply voltage (ASV) to maintain optimal performance of an aged circuit, and demonstrate its advantages over a guardbanding technique such as synthesis. We then present a hybrid approach, utilizing the merits of both ABB and synthesis, to ensure that the resultant circuit meets the performance constraints over its lifetime, and has a minimal area and power overhead, as compared with a nominally designed circuit.

There is a growing trend of using cloud environments for ever growing storage and data processing needs. However, adopting a cloud computing paradigm may have positive as well as negative effects on the data security of service consumers. This paper primarily aims to highlight the major security issues existing in current cloud computing environments. We carry out a survey to investigate the security mechanisms that are enforced by major cloud service providers. We also propose a risk analysis approach that can be used by a prospective cloud service for analyzing the data security risks before putting his confidential data into a cloud computing environment.

We report on an all-optical XNOR-gate using simultaneous Four-Wave Mixing (FWM) and Cross-Gain Modulation (XGM) in a semiconductor optical amplifier (SOA). FWM generates the bitwise AND output corresponding to the two input data streams while XGM is used to generate the NOR output. These two outputs are combined using a coupler to obtain the final XNOR output. Error-free operation for RZ data with <2dB power-penalty is reported.

The development of a scalable and user-friendly SPICE model is a key aspect of exploring the potential of spin-transfer torque MRAM (STT-MRAM). A self-contained magnetic tunnel junction (MTJ) SPICE model is proposed in this work which can reproduce realistic MTJ characteristics based on user-defined input parameters such as length, width, and thickness. Using the propose model, scalability studies of both inplane and perpendicular MTJs can be performed across different technology nodes with minimal effort, which differentiates this model from most previously reported models.