Automatic design of domain-specific instructions for low-power processors

This paper explores hardware specialization of low­ power processors to improve performance and energy efficiency. Our main contribution is an automated framework that analyzes instruction sequences of applications within a domain at the loop body level and identifies exactly and partially-matching sequences across applications that can become custom instructions. Our framework transforms sequences to a new code abstraction, a Merging Diagram, that improves similarity identification, clusters alike groups of potential custom instructions to effectively reduce the search space, and selects merged custom instructions to efficiently exploit the available customizable area. For a set of 11 media applications, our fast framework generates instructions that significantly improve the energy-delay product and speed­ up, achieving more than double the savings as compared to a technique analyzing sequences within basic blocks. This paper shows that partially-matched custom instructions, which do not significantly increase design time, are crucial to achieving higher energy efficiency at limited hardware areas

Reconfigurable Antenna Systems: Platform implementation and low-power matters

Antennas are a necessary and often critical component of all wireless systems, of which they share the ever-increasing complexity and the challenges of present and emerging trends. 5G, massive low-orbit satellite architectures (e.g. OneWeb), industry 4.0, Internet of Things (IoT), satcom on-the-move, Advanced Driver Assistance Systems (ADAS) and Autonomous Vehicles, all call for highly flexible systems, and antenna reconfigurability is an enabling part of these advances. The terminal segment is particularly crucial in this sense, encompassing both very compact antennas or low-profile antennas, all with various adaptability/reconfigurability requirements. This thesis work has dealt with hardware implementation issues of Radio Frequency (RF) antenna reconfigurability, and in particular with low-power General Purpose Platforms (GPP); the work has encompassed Software Defined Radio (SDR) implementation, as well as embedded low-power platforms (in particular on STM32 Nucleo family of micro-controller). The hardware-software platform work has been complemented with design and fabrication of reconfigurable antennas in standard technology, and the resulting systems tested. The selected antenna technology was antenna array with continuously steerable beam, controlled by voltage-driven phase shifting circuits. Applications included notably Wireless Sensor Network (WSN) deployed in the Italian scientific mission in Antarctica, in a traffic-monitoring case study (EU H2020 project), and into an innovative Global Navigation Satellite Systems (GNSS) antenna concept (patent application submitted). The SDR implementation focused on a low-cost and low-power Software-defined radio open-source platform with IEEE 802.11 a/g/p wireless communication capability. In a second embodiment, the flexibility of the SDR paradigm has been traded off to avoid the power consumption associated to the relevant operating system. Application field of reconfigurable antenna is, however, not limited to a better management of the energy consumption. The analysis has also been extended to satellites positioning application. A novel beamforming method has presented demonstrating improvements in the quality of signals received from satellites. Regarding those who deal with positioning algorithms, this advancement help improving precision on the estimated position

Fracturable DSP block for multi-context reconfigurable architectures

Multi-context architectures like NATURE enable low-power applications to leverage fast context switching for improved energy efficiency and lower area footprint. The NATURE architecture incorporates 16-bit reconfigurable DSP blocks for accelerating arithmetic computations, however, their fixed precision prevents efficient re-use in mixed-width arithmetic circuits. This paper presents an improved DSP block architecture for NATURE, with native support for temporal folding and run-time fracturability. The proposed DSP block can compute multiple sub-width operations in the same clock cycle and can dynamically switch between sub-width and full-width operations in different cycles. The NanoMap tool for mapping circuits onto NATURE is extended to exploit the fracturable multiplier unit incorporated in the DSP block. We demonstrate the efficiency of the proposed dynamically fracturable DSP block by implementing logic-intensive and compute-intensive benchmark applications. Our results illustrate that the fracturable DSP block can achieve a 53.7% reduction in DSP block utilization and a 42.5% reduction in area with a 122.5% reduction in power-delay product without exploiting logic folding. We also observe an average reduction of 6.43% in power-delay product for circuits that utilize NATURE’s temporal folding compared to the existing full precision DSP block in NATURE, leading to highly compact, energy efficient designs

FPGA dynamic and partial reconfiguration : a survey of architectures, methods, and applications

Dynamic and partial reconfiguration are key differentiating capabilities of field programmable gate arrays (FPGAs). While they have been studied extensively in academic literature, they find limited use in deployed systems. We review FPGA reconfiguration, looking at architectures built for the purpose, and the properties of modern commercial architectures. We then investigate design flows, and identify the key challenges in making reconfigurable FPGA systems easier to design. Finally, we look at applications where reconfiguration has found use, as well as proposing new areas where this capability places FPGAs in a unique position for adoption

Design Space Exploration and Resource Management of Multi/Many-Core Systems

The increasing demand of processing a higher number of applications and related data on computing platforms has resulted in reliance on multi-/many-core chips as they facilitate parallel processing. However, there is a desire for these platforms to be energy-efficient and reliable, and they need to perform secure computations for the interest of the whole community. This book provides perspectives on the aforementioned aspects from leading researchers in terms of state-of-the-art contributions and upcoming trends