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Coarse-grained reconfigurable arrays (CGRAs) are programmable hardware platforms that can be used to realize application-specific accelerators for higher performance and energy efficiency. A CGRA is a 2D array of configurable logic blocks & interconnect, where the logic blocks are typically large & ALU-like, and the interconnect is word-wide. CGRA-ME is a software framework that enables the modelling and exploration of CGRA architectures, as well as research on CGRA CAD algorithms. With CGRA-ME, an architect can specify a CGRA architecture at a high level of abstraction. A set of applications can be mapped onto the architecture to assess the mappability, power, performance and cost. CGRA-ME also allows one to generate synthesizable Verilog RTL for the modelled CGRA, permitting its implementation as an ASIC or FPGA overlay. In this paper, we describe the CGRA-ME framework [5] and overview its capabilities and current limitations. We discuss ongoing and prior research conducted with the framework, as well as outline future plans. We believe CGRA-ME will be a valuable contribution to the community, enabling new research on CGRA CAD & architectures.

This paper will describe high performance interface building blocks, compare their networking features and show how they may be used in small and large systems especially as they apply to SpaceVPX modules. Emphasis will be placed on their SpaceWire and other networking capabilities.1

Network-On-Chip design has been an active area of academic research for two decades, but many proposed ideas have not been adopted in real chips because they have complex behavior or create significant risks in chip implementation. For this reason, many existing chips just employ fast, replicated vanilla dimension-ordered mesh NoCs. However, these networks do not come close to utilizing the full available VLSI wiring capabilities, and propagate packets at speeds that are significantly below the raw speed of wires.The ideal network would not require any custom circuits, and would decompose easily into a hierarchical CAD flow consisting of a top-level design instantiating a mesh of identical hardened tiles with short-wire neighbor connections.At the same time, this ideal network would easily scale to efficiently utilize the majority of the available chip wiring resources, and would offer a mechanism for scaling this wire usage up or down based on available bandwidth. Packets would spend a significant fraction of their time in wire delay rather than router delay. Finally, the NoC would be simple to understand.This paper proposes Ruche Networks, which fulfill these requirements. They are based on simple 2-D mesh networks but amplify the NoC bandwidth and reduce NoC diameter of tiled architectures by adding long-range physical channels from each tile to other tiles on the same row or column. The more distant the connections, the greater the bandwidth of the network and the lower the diameter. The distance is typically increased until all of the physical VLSI wiring bandwidth have been absorbed.We explain the rational for this "ruching" and provide a simple methodology for designing and implementing these networks using a standard cell VLSI CAD flow.In this paper, we show the steps involved in ruching the HammerBlade Manycore’s mesh networks; these steps can easily apply to other designs.

Deep neural networks (DNNs) have been successfully applied to a great variety of applications, ranging from small IoT devices to large scale services in a data center. In order to improve the efficiency of processing these DNN models, dedicated hardware accelerators are required for all these scenarios. Theoretically, there exists an optimized acceleration architecture for each application. However, considering the cost of chip design and corresponding tool-chain development, researchers need to trade off between efficiency and generality. In this work, we demonstrate that it is practical to use a unified architecture, called Ascend, to support those applications, ranging from IoT devices to data-center services. We provide a lot of design details to explain that the success of Ascend relies on contributions from different levels. First, heterogeneous computing units are employed to support various DNN models. And the datapath is adapted according to the requirement of computing and data access. Second, when scaling the Ascend architecture from a single core to a cluster containing thousands of cores, it involves design efforts, such as memory hierarchy and system level integration. Third, a multi-tier compiler, which provides flexible choices for developers, is the last critical piece. Experimental results show that using accelerators based on the Ascend architecture can achieve comparable or even better performance in different applications. In addition, various chips based on the Ascend architecture have been successfully commercialized. More than 100 million chips have been used in real products.

This "success story" panel illustrates how next generation video applications are enabled on PCs today using consumer integrated and discrete GPUs launched in 2020. Intel's XeLP graphics technology with dedicated media hardware powers the integrated graphics in Intel's latest client processor, Tiger Lake, and Intel's first entry-level mainstream discrete graphics card, DG1. XeLP graphics in Tiger Lake and DG1 has democratized access to high performance implementations of the latest emerging video codec standards. Three topics will be covered: (i) 8K HEVC/AV1 Playback with Content Adaptive Power Optimization; (ii) Ludicrous Speed HEVC Encoding with Integrated + Discrete GPU; and (iii) MPEG Immersive Video (MIV) Playback on DG1.

Despite tremendous advancement of digital IC design automation tools over the last few decades, analog IC layout is still heavily manual which is very tedious and error-prone. This paper will first review the history, challenges, and current status of analog IC layout automation. Then, we will present MAGICAL, a human-intelligence inspired, fully-automated analog IC layout system currently being developed under the DARPA IDEA program. It starts from an unannotated netlist, performs automatic layout constraint extraction and device generation, then performs placement and post-placement optimization, followed by routing to obtain the final GDSII layout. Various analytical, heuristic, and machine learning algorithms will be discussed. MAGICAL has obtained promising preliminary results. We will conclude the paper with further discussions on challenges and future directions for fully-automated analog IC layout.

Wavelength-routed optical network-on-chip (WRONoC) design consists of topological and physical synthesis. It covers many interacting design aspects such as wavelength assignment, message routing, network construction, component placement, and waveguide routing. Due to the high complexity of the design problem, current manual design usually trades optimality for scalability and feasibility, which results in performance degradation and waste of resources. In this paper, we will present an overview of the existing design automation approaches that have demonstrated their effectiveness in customizing and optimizing application-specific WRONoC designs, and of the potential design automation directions to address a wider range of design challenges. We will also discuss the advantages of comprehensive optimization considering multiple design aspects simultaneously, and the possible barriers that need to be removed to achieve this goal.

The increasing complexity of modern Integrated Circuits (ICs) leads to systems composed of various different Intellectual Property (IPs) blocks, known as System-on-Chip (SoC). Such complexity requires strong expertise from engineers, that rely on expansive commercial EDA tools. To overcome such a limitation, an automated open-source logic synthesis flow is required. In this context, this work proposes LSOracle: a novel automated mixed logic synthesis framework. LSOracle is the first to exploit state-of-the-art And-Inverter Graph (AIG) and Majority-Inverter Graph (MIG) logic optimizers and relies on a Deep Neural Network (DNN) to automatically decide which optimizer should handle different portions of the circuit. To do so, LSOracle applies $k-way$ partitioning to split a DAG into multiple partitions and uses a to chose the best-fit optimizer. Post-tech mapping ASIC results, targeting the 7nm ASAP standard cell library, for a set of mixed-logic circuits, show an average improvement in area-delay product of 6.87% (up to 10.26%) and 2.70% (up to 6.27%) when compared to AIG and MIG, respectively. In addition, we show that for the considered circuits, LSOracle achieves an area close to AIGs (which delivered smaller circuits) with a similar performance of MIGs, which delivered faster circuits.

This paper reviews the results of recent researches aimed to extend the standard-cell based digital design flow to analog building blocks, so that to enhance scalability, reconfigurability and portability across technology nodes and to reduce design effort, time-to-market and costs. In this framework, the application of the proposed fully digital design approach to a wake up oscillator and to a Digital-to-Analog Converter, which are two building blocks widely employed in IoT sensor nodes, is illustrated in detail.

Neuromorphic chips are electronic hardware mimicking neurons in human brain in an electronic structure. These ASICs (Application Specific Integrated Circuits) provide artificial neural networks with computational power comparatively higher than most neural networks generated by software algorithms. 'CM1K' is an electronic chip in this family of products. It has a parallel neural network of 1024 neurons. These neurons provide K-Nearest Neighbor (KNN) data classification. The chip requires to be embedded in an electronic system to access all its capabilities. This paper deliver a novel hardware system embedding CM1K neuromorphic chip. The system was implemented in image and video frame analysis for evaluation. The results prove that the system could benefit various applications including security, asset management, home appliances, mail sorting and manufacturing. Since the embedded system provide opportunity to integrate AI in to simple electronics, it helps on extending AI applications.

The fifth generation of mobile communications (5G) is expected to dramatically improve performance compared to preceding standards by offering very high bandwidths and low latencies. To provide this performance, heavy processing is required and must meet strong timing constraints. Reconfigurable computing, managing processing in software and exploiting reconfigurable hardware acceleration, is an innovative approach that should be considered for 5G for its capacity to combine high throughput and high flexibility. This paper presents a case study for Orthogonal Frequency Division Multiplexing (OFDM) computation reconfigurable offloading onto an Field Programmable Gate Array (FPGA). The implementation is based on Open Computing Language (OpenCL) that represents a versatile solution, as this language can be compiled for several architectures, provided that a Host+Accelerator structure is used. The objective of our study is to demonstrate that, by means of hardware offloading, the 5G architecture resources can reach high computational load, avoiding processing stalls and latency increase. Results show that around 15% of the software processing can be freed through hardware acceleration and reallocated to support other tasks.

In this paper, we present full-chip designs and their power, performance, and area (PPA) metrics using the ASAP7 process design kit (PDK) and library. Reliable cell library is a key element in evaluating new technological options such as monolithic 3D (M3D) ICs. Given an RTL, we conduct synthesis and place/route to obtain commercial-quality 2D and M3D IC designs and compare PPA. The ASAP7 library is highly useful to build high-quality designs that accurately reflect 7nm technology node. In addition, the full front-end and back-end access provided in ASAP7 allows us to see the impact of various device and interconnect parameters at the full-chip level for both 2D and monolithic 3D ICs. This work demonstrates the critical role of an academic PDK and library in enabling high-quality research in disruptive technologies such as M3D integration.

This work discusses the ASAP7 predictive process design kit (PDK) and associated standard cell library. The necessity for multi-patterning (MP) techniques at advanced nodes results in the standard cell and SRAM architecture becoming entangled with design rules, mandating design-technology co-optimization (DTCO). This paper discusses the DTCO process involving standard cell physical design. An assumption of extreme ultraviolet (EUV) lithography availability in the PDK allows bi-directional M1 geometries that are difficult with MP. Routing and power distribution schemes for self-aligned quadruple patterning (SAQP) friendly, high density standard cell based blocks are shown. Restrictive design rules are required and supported by the automated place and route (APR) setup. Supporting sub-20 nm dimensions with academic tool licenses is described. The APR (QRC techfile) extraction shows high correlation with the Calibre extraction deck. Finally, use of the PDK for academic coursework and research is discussed.

Standard cell libraries are the foundation for the entire back-end design and optimization flow in modern application-specific integrated circuit designs. At 7nm technology node and beyond, standard cell library design and optimization is becoming increasingly difficult due to extremely complex design constraints, as described in the ASAP7 process design kit (PDK). Notable complexities include discrete transistor sizing due to FinFETs, complicated design rules from lithography and restrictive layout space from modern standard cell architectures. The design methodology presented in this paper enables efficient and high-quality standard cell library design and optimization with the ASAP7 PDK. The key techniques include exhaustive transistor sizing for cell timing optimization, transistor placement with generalized Euler paths and back-end design prototyping for library-level explorations.

This paper investigates the multi-broker based network control and management paradigm for realizing scalable and cost-effective service provisioning in multi-domain software-defined optical networks. Experimental results verify the feasibility of the proposal and demonstrate ∼ 7.6× blocking reduction comparing with the conventional single-broker based solution.

Domain-Specific Languages (DSLs) provide a high-level and domain-specific abstraction to describe algorithms within a certain domain concisely. Since a DSL separates the algorithm description from the actual target implementation, it offers a high flexibility among heterogeneous hardware targets, such as CPUs and GPUs. With the recent uprise of promising High-Level Synthesis (HLS) tools, like Vivado HLS and Altera OpenCL, FPGAs are becoming another attractive target architecture. Particularly in the domain of image processing, applications often come with stringent requirements regarding performance, energy efficiency, and power, for which FPGA have been proven to be among the most suitable architectures. In this work, we present the Hipacc framework, a DSL and source-to-source compiler for image processing. We show that domain knowledge can be captured to generate tailored implementations for C-based HLS from a common high-level DSL description targeting FPGAs. Our approach includes FPGA-specific memory architectures for handling point and local operators, as well as several high-level transformations. We evaluate our approach by comparing the resulting hardware accelerators to GPU implementations, generated from exactly the same DSL source code.

Spiking Neural Network based brain-inspired computing paradigms are becoming increasingly popular tools for various cognitive tasks. The sparse event-driven processing capability enabled by such networks can be potentially appealing for implementation of low-power neural computing platforms. However, the parallel and memory-intensive computations involved in such algorithms is in complete contrast to the sequential fetch, decode, execute cycles of conventional von-Neumann processors. Recent proposals have investigated the design of spintronic “in-memory” crossbar based computing architectures driving “spin neurons” that can potentially alleviate the memory-access bottleneck of CMOS based systems and simultaneously offer the prospect of low-power inner product computations. In this article, we perform a rigorous system-level simulation study of such All-Spin Spiking Neural Networks on a benchmark suite of 6 recognition problems ranging in network complexity from 10k–7.4M synapses and 195–9.2k neurons. System level simulations indicate that the proposed spintronic architecture can potentially achieve ∼1292× energy efficiency and ∼ 235× speedup on average over the benchmark suite in comparison to an optimized CMOS implementation at 45nm technology node.

Hybrid systems combine Large-Area Electronics (LAE) with high-performance technologies (e.g., silicon CMOS) [1]. With architectural concepts for hybrid systems broadening to match the range of emerging applications, this paper examines modular approaches for multi-sheet, multi-technology integration. It identifies the interfaces required as a critical backbone. For interfaces associated with various system functionalities (sensing, processing, powering), specific approaches are surveyed and analyzed, taking from insights derived from several previous experimental demonstrations of complete hybrid systems.

Latency, Area, and Power are three important metrics that a VLSI designer wants to optimize. However, often one of these may have to be optimized at the cost of another or the other two. Depending on the application scenario, choice of the metric to optimize is made. In this paper, we consider hardware implementations of a number of cryptographic primitives and present a number of optimizations. We consider three areas of cryptoengineering. They are building physical unclonable functions (PUFs), implementing encryption/decryption algorithms, and side channel proof crypto implementations. The techniques we employ range from area optimization through customized multiplexer design, fusing multiple operations into a single hardware element, folding and unrolling of iterative algorithms, creating reconfigurable implementations to achieve multiple operations with the same set of hardware elements, to techniques of obfuscation to defeat fault injection based attacks on the crypto implementation. All the proposed and existing designs are implemented with 45 nm CMOS library.

The explosion of big data applications imposes severe challenges of data processing speed and scalability on traditional computer systems. However, the performance of the von Neumann machine is greatly hindered by the increasing performance gap between CPU and memory, motivating the active research on new or alternative computing architectures. As one important instance, neuromorphic computing systems inspired by the working mechanism of human brains have gained considerable attention. In this work, we propose a heterogeneous computing system with neuromorphic computing accelerators (NCAs) that are built with emerging memristor technology. In the proposed system, NCA is designed to speed up the artificial neural network (ANN) executions in many high-performance applications by leveraging the extremely efficient mixed-signal computation capability of nanoscale memristor-based crossbar (MBC) arrays. The hierarchical MBC arrays of the NCA can be flexibly configured to different ANN topologies through the help of an analog Network-on-Chip (A-NoC). A general approach which translates the target codes within a program to the corresponding NCA instructions is also developed to facilitate the utilization of the NCA. Our simulation results show that compared to the baseline general purpose processor, the proposed heterogeneous system can achieve on average 18.2x performance speedup and 20.1x energy reduction over nine representative applications while constraining the computation accuracy degradation within an acceptable range.

This paper presents aspects of process technology applicable to FPGAs. Overdrive of transistors for routing pass gates is an important performance and reliability factor. Random variation effects are significant for small arrays of configuration RAM, but small impact on performance. We discuss challenges for CRAM and switch replacement using novel technologies.

This paper introduces a novel methodology to adapt the microarchitecture of a processor at run-time. The goal is to tailor the internal architecture to the requirements of an application and the data to be processed. The latter parameter is normally not known at design time. This leads to the development of more general purpose processors which are capable to handle the data to be processed in any case. With the novel approach which keeps the microarchitecture of a processor flexible, the processor can start as a general purpose device and end up with a specific parameterization, comparable with application specific processor architectures. Furthermore, the increased degree of freedom which is enabled through the approach for a novel quality of processors is described.

This paper presents a behavioral synthesis method for asynchronous circuits with bundled-data implementation. This paper extends a behavioral synthesis method for synchronous circuits so that an RTL model of bundled-data implementation is synthesized from a behavioral description specified by a restricted C language. Finally, this paper evaluates our method for several benchmarks through a tool implementation.

Scalable Video Coding provides temporal, spatial and quality scalability using layers within the encoded bitstream. This feature allows the encoded bitstream to be adapted to different devices and heterogeneous networks. This paper proposes a technique to convert an H.264/AVC bitstream in Baseline profile to a scalable stream which provides temporal scalability. Applying the presented approach, a reduction of 65% of coding complexity is achieved while maintaining the coding efficiency.

This tutorial paper surveys recent developments in parallel computer architecture, focusing on the field-programmable gate array and the graphics processor. We aim to illustrate the potential of these architectures for the type of high-speed numerical computation required in on-line optimization for model predictive control. While significant performance advantages can be gained by migrating existing control algorithms to these processor architectures, in order to realise their full potential, further research is needed at the boundary of control theory, digital electronics, and computer architecture. We survey some of the open questions in this area.

Dirty paper code (DPC) can be used in a number of communication network applications; broadcast channels, multiuser interference channels and ISI channels to name a few. We study various implementation bottlenecks and issues with implementing a DPC pre-coder based on nested trellis technique. The aim is to achieve a practical hardware realization of the precoder for wireless LAN/DSL applications. We describe the architectural development process and realization of the precoder on a Xilinx Virtex 2V8000 FPGA. To the best of our knowledge this is the first reported DPC pre-coder hardware implementation.

OpenMP has gained wide popularity as an API for parallel programming on shared memory and distributed shared memory platforms. It is also a promising candidate to exploit the emerging multicore, multithreaded processors. In addition, there is an increasing trend to combine OpenMP with MPI to take full advantage of mainstream supercomputers consisting of clustered SMPs. All of these require that attention be paid to the quality of the compiler's translation of OpenMP and the flexibility of runtime support. Many compilers and runtime libraries have an internal cost model that helps evaluate compiler transformations, guides adaptive runtime systems, and helps achieve load balancing. But existing models are not sufficient to support OpenMP, especially on new platforms. In this paper we present our experience adapting the cost models in OpenUH, a branch of Open64, to estimate the execution cycles of parallel OpenMP regions using knowledge of both software and hardware. Our OpenMP cost model reuses major components from Open64, along with extensions to consider more OpenMP details. Preliminary evaluations of the model are presented using kernel benchmarks. The challenges and possible extensions for modeling OpenMP on multicore platforms are also discussed.

Published version

The paper describes architectural enhancements to Xilinx FPGAs that provide better support for the creation of dynamically reconfigurable designs. These are augmented by a new design methodology that uses pre-routed IP cores for communication between static and dynamic modules and permits static designs to route through regions otherwise reserved for dynamic modules. A new CAD tool flow to automate the methodology is also presented. The new tools initially target the Virtex-II, Virtex-II Pro and Virtex-4 families and are derived from Xilinx's commercial CAD tools

The usage of mobile devices rose enormously. Their integration into complex interacting systems leads to new software architectures. This paper shows the general design considerations of service-oriented systems integrating mobile devices, together with its motivation. We identify a smaller granularity of design components - tasks for service invocation - and examine their distribution between mobile device and not mobile components of the software system.

Designing a product line architecture can be approached from scratch or by deducing it after having built a series of similar products. We hereby present a different approach where we designed a product line architecture after only one product was built. Given MCC+, a product for consistency checking of different diagrams in a UML model, we identified the variabilities it should manage in order to be useful for a variety of modeling tools, obtaining a product line MCC-SPL. We accordingly upgraded the original architecture to a product line architecture (PLA). We verified how well the proposed PLA generalizes the single product architecture using a simple yet well known product line architecture assessment method. We also validated the usefulness of the just designed PLA by porting the tool to a different modeling platform.