Evanescent Waveguide Sensor for On-Chip Biomolecular Detection

This work presents analysis and development of an evanescent waveguide sensor system, which integrates an amorphous silicon photodiode and a glass-diffused waveguide. Design of the system includes a study of thickness and refractive index of the transparent electrode of the diode, which are crucial parameters for the optimization of the optical coupling between the waveguide and the photodetector. Preliminary electro-optical measurements on the fabricated device show excellent system performances, and suggest its use for on-chip detection in lab-on-chip applications

An Energy-Efficient Reconfigurable Circuit Switched Network-on-Chip

Network-on-Chip (NoC) is an energy-efficient on-chip communication architecture for multi-tile System-on-Chip (SoC) architectures. The SoC architecture, including its run-time software, can replace inflexible ASICs for future ambient systems. These ambient systems have to be flexible as well as energy-efficient. To find an energy-efficient solution for the communication network we analyze three wireless applications. Based on their communication requirements we observe that revisiting of the circuit switching techniques is beneficial. In this paper we propose a new energy-efficient reconfigurable circuit-switched Network-on-Chip. By physically separating the concurrent data streams we reduce the overall energy consumption. The circuit-switched router has been synthesized and analyzed for its power consumption in 0.13 ¿m technology. A 5-port circuit-switched router has an area of 0.05 mm2 and runs at 1075 MHz. The proposed architecture consumes 3.5 times less energy compared to its packet-switched equivalen

PowerPack: Energy Profiling and Analysis of High-Performance Systems and Applications

Energy efficiency is a major concern in modern high-performance computing system design. In the past few years, there has been mounting evidence that power usage limits system scale and computing density, and thus, ultimately system performance. However, despite the impact of power and energy on the computer systems community, few studies provide insight to where and how power is consumed on high-performance systems and applications. In previous work, we designed a framework called PowerPack that was the first tool to isolate the power consumption of devices including disks, memory, NICs, and processors in a high-performance cluster and correlate these measurements to application functions. In this work, we extend our framework to support systems with multicore, multiprocessor-based nodes, and then provide in-depth analyses of the energy consumption of parallel applications on clusters of these systems. These analyses include the impacts of chip multiprocessing on power and energy efficiency, and its interaction with application executions. In addition, we use PowerPack to study the power dynamics and energy efficiencies of dynamic voltage and frequency scaling (DVFS) techniques on clusters. Our experiments reveal conclusively how intelligent DVFS scheduling can enhance system energy efficiency while maintaining performance

TrustShadow: Secure Execution of Unmodified Applications with ARM TrustZone

The rapid evolution of Internet-of-Things (IoT) technologies has led to an emerging need to make it smarter. A variety of applications now run simultaneously on an ARM-based processor. For example, devices on the edge of the Internet are provided with higher horsepower to be entrusted with storing, processing and analyzing data collected from IoT devices. This significantly improves efficiency and reduces the amount of data that needs to be transported to the cloud for data processing, analysis and storage. However, commodity OSes are prone to compromise. Once they are exploited, attackers can access the data on these devices. Since the data stored and processed on the devices can be sensitive, left untackled, this is particularly disconcerting. In this paper, we propose a new system, TrustShadow that shields legacy applications from untrusted OSes. TrustShadow takes advantage of ARM TrustZone technology and partitions resources into the secure and normal worlds. In the secure world, TrustShadow constructs a trusted execution environment for security-critical applications. This trusted environment is maintained by a lightweight runtime system that coordinates the communication between applications and the ordinary OS running in the normal world. The runtime system does not provide system services itself. Rather, it forwards requests for system services to the ordinary OS, and verifies the correctness of the responses. To demonstrate the efficiency of this design, we prototyped TrustShadow on a real chip board with ARM TrustZone support, and evaluated its performance using both microbenchmarks and real-world applications. We showed TrustShadow introduces only negligible overhead to real-world applications.Comment: MobiSys 201