Network-on-Chip Architecture Research Articles

Performance and energy evaluation of dynamic adaptive deterministic routing algorithm for multicore architectures

Chip Multiprocessors (CMPs) leverage multiple processing units to improve computational speed and efficiency. Routing algorithms in NoC (Network-on-Chip) architectures ensure efficient data communication between these units, addressing challenges such as congestion, latency, and power consumption. This paper delves into an extensive analysis of the performance evaluation concerning the Dynamic Adaptive Deterministic (DyAD) routing for Network-on-Chip (NoC) and Wireless Network-on-Chip (WiNoC) configurations within the framework of a 64-core and 100-core multicore architecture. The evaluation involved a congestion threshold analysis of data transmission latency, the efficiency of network data throughput, and the amount of energy consumed. To substantiate our conclusions, we conducted simulations of the 64-core and 100-core mesh-based NoC and WiNoC architectures under the Video Image Processing System (VIPS) benchmark workload. These simulations were executed utilizing the Noxim simulator, a well-recognized tool acclaimed for its capacity to provide cycle-accurate simulations. Analyzing the simulation outcomes, it becomes evident that the DyAD routing approach for the 64-core and 100-core WiNoC architecture performs better in terms of network performance. It is characterized by enhanced capabilities at higher Packet Injection Rate (PIR) saturation loads, improved network throughput, and minimized latencies. This dominance is evident from its ability to handle heavier workloads and achieve lower delays in the investigated VIPS workload situations, compared to the 64-core and 100-core NoC multicore architecture.

Exploring distance-based wireless transceiver placements for wireless network-on-chip architecture with deterministic routing algorithms

Network-on-chip (NoC) technology is crucial for integrating multiple embed-ded computing cores onto a single chip. Consequently, this has led to the de-velopment of the wireless network-on-chip (WiNoC) concept, seen as a promis-ing strategy to overcome scalability issues in communication systems withinchips for future many-core architectures. This research analyses the impactof wireless transceiver subnet clustering on the hundred-core mesh-structuredWiNoC architecture. The study aims to examine the effects of distance-basedwireless transceiver placements on the transmission delay, network throughput,and energy consumption within a mesh wireless NoC architecture featuring ahundred cores, under specific routing strategies: X-Y, west-first, negative-first,and north-last. This research investigates the impact of positioning radio sub-nets at the farthest, farther, nearest, and closest positions within an architectureequipped with four wireless transceivers. The Noxim simulator was utilised tosimulate the analysed wireless transceiver placements within the hundred-coremesh-structured WiNoC designs, with the objective of validating the results.The architecture with the wireless transceivers positioned at midway proxim-ity (nearer and further) demonstrated the best performance, as evidenced by thelowest latencies for all evaluated deterministic routing algorithms, according tothe simulation outcomes.

A high-level simulator for Network-on-Chip

This study presents a high-level simulator for Network-on-Chip (NoC), designed for many-core architectures, and integrated with the PlatEMO platform. The motivation for developing this tool arose from the need to evaluate the behavior of application mapping algorithms and the routing, both aspects are essential in the implementation and design of NoC architectures. This analysis underscored the importance of having effective NoC simulators as tools that allow for studying and comparing various network technologies while ensuring a controlled simulation environment. During this investigation and evaluation, some simulators, such as Noxim, NoCTweak, and NoCmap, among others, offered configurable parameters for application traffic, options to synthetically define topology and packet traffic patterns. Additionally, they include mapping options that optimize latency and energy consumption, routing algorithms, technological settings such as the CMOS process, and measurement options for evaluating performance metrics such as throughput and power usage. However, while these simulators meet detailed technical demands, they are mostly restricted to analyzing the low-level elements of the architecture, thus hindering quick and easy under- standing for non-specialists. This insight underscored the challenge in developing a tool that balances detailed analysis with a comprehensive learning perspective, considering the specific restrictions of each simulator analyzed. Experiments demonstrated the proposed simulator efficacy in handling algorithms like GA, PSO, and SA variant, and, surprisingly, revealed limitations of the XY algorithm in Mesh topologies, indicating the need for further investigation to confirm these findings. Future work will expand the simulator functionalities, incorporating a broader range of algorithms and performance metrics, to establish it as an indispensable tool for research and development in NoCs.

Breaking On-Chip Communication Anonymity using Flow Correlation Attacks

Network-on-Chip (NoC) is widely used to facilitate communication between components in sophisticated System-on-Chip (SoC) designs. Security of the on-chip communication is crucial because exploiting any vulnerability in shared NoC would be a goldmine for an attacker that puts the entire computing infrastructure at risk. We investigate the security strength of existing anonymous routing protocols in NoC architectures, making two pivotal contributions. Firstly, we develop and perform a machine learning (ML)-based flow correlation attack on existing anonymous routing techniques in Network-on-Chip (NoC) systems, revealing that they provide only packet-level anonymity. Secondly, we propose a novel, lightweight anonymous routing protocol featuring outbound traffic tunneling and traffic obfuscation. This protocol is designed to provide robust defense against ML-based flow correlation attacks, ensuring both packet-level and flow-level anonymity. Experimental evaluation using both real and synthetic traffic demonstrates that our proposed attack successfully deanonymizes state-of-the-art anonymous routing in NoC architectures with high accuracy (up to 99%) for diverse traffic patterns. It also reveals that our lightweight anonymous routing protocol can defend against ML-based attacks with minor hardware and performance overhead.

Design of Area Efficient Network-On-Chip Router: A Comprehensive Review

The number of uses for cutting-edge technologies has led to a further growth in a single chip's computational capacity. In this case, several applications want to build on a single chip for computing resources. As a result, connecting the IP cores becomes yet another difficult chore. The many-core System-On-Chips (SoCs) are being replaced by Network-On-Chip (NoC) as an on-chip connectivity option. As a result, the Network on Chip was created as a cutting-edge framework for those networks inside the System on Chip. Modern multiprocessor architectures would benefit more from a NoC architecture as its communication backbone. The most important components of any network structure are its topologies, routing algorithms, and router architectures. NoCs use the routers on each node to route traffic. Circuit complexity, high critical path latency, resource usage, timing, and power efficiency are the primary shortcomings of conventional NoC router architecture. It has been difficult to build a high-performance, low-latency NoC with little area overhead. This paper surveys previous methods and strategies for NoC router topologies and study of general router architecture and its components. Analysis is carried out to understand and work for a low latency, low power consumption, and high performance NoC router design that can be employed with a wide range of FPGA families. In the current work, we are structuring a modified four port router with the goals of low area and high performance operation.

Probability-based mapping approach for an application-aware networks-on-chip architectures

In a digital and automation era, on-chip multi-core architecture plays a vital role in effective communication in the field of very large-scale integrated circuits (VLSI). In this paper, we propose a unique mapping approach in which a probability-based core selection from the application benchmark into the center to eccentric way of placement of cores in the standard network architecture improves the performance of networks-on-chip (NoC). The proposed approach utilizes a structured mapping strategy, in contrast to the random mapping. This characteristic renders the proposed method a robust solution for a diverse range of NoC architectures irrespective of scale. The proposed approach provides better quality of service (QoS) with optimal total communication bandwidth and average hop count. The performance of the proposed mapping approach is validated with various experiments over standard and real-time benchmarks. The investigation results indicate that the total communication cost over real-time NoC benchmarks for the proposed mapping approach offers 43.06%, 22.75%, and 16.69% average improvement over CastNet, NMAP, and mapGtoM respectively. Furthermore, we adopt uniform geometric and shuffled traffic patterns to identify the latency and throughput of the proposed probability-based mapping approach. The investigation results indicate that the proposed mapping approach outperforms existing mapping procedures.

Network on Chip and Its Low Power Techniques

The advent of Network-On-Chip (NoC) architecture has significantly revolutionized the design of complex System-On-Chip (SoC) systems by providing scalable and efficient communication infrastructures. NoC architectures offer advantages such as high bandwidth; low latency and better scalability compared with traditional bus-based communication architectures. However, the ever-increasing demand for higher performance and lower power consumption poses significant challenges for NoC designers. This article reviews the basic architectures and design issues of NoCs with SoCs and further extended with research challenges and low power techniques. Key Words: Network-On-Chip, System-On-Chip, latency and scalability

NEXUS: A 28nm 3.3pJ/SOP 16-Core Spiking Neural Network with a Diamond Topology for Real-Time Data Processing.

The realization of brain-scale spiking neural networks (SNNs) is impeded by power constraints and low integration density. To address these challenges, multi-core SNNs are utilized to emulate numerous neurons with high energy efficiency, where spike packets are routed through a network-on-chip (NoC). However, the information can be lost in the NoC under high spike traffic conditions, leading to performance degradation. This work presents NEXUS, a 16-core SNN with a diamond-shaped NoC topology fabricated in 28-nm CMOS technology. It integrates 4096 leaky integrate-and-fire (LIF) neurons with 1M 4-bit synaptic weights, occupying an area of 2.16 mm2. The proposed NoC architecture is scalable to any network size, ensuring no data loss due to contending packets with a maximum routing latency of 5.1μs for 16 cores. The proposed congestion management method eliminates the need for FIFO in routers, resulting in a compact router footprint of 0.001 mm2. The proposed neurosynaptic core allows for increasing the processing speed by up to 8.5× depending on input sparsity. The SNN achieves a peak throughput of 4.7 GSOP/s at 0.9 V, consuming a minimum energy per synaptic operation (SOP) of 3.3 pJ at 0.55 V. A 4-layer feed-forward network is mapped onto the chip, classifying MNIST digits with 92.3% accuracy at 8.4Kclassification/ s and consuming 2.7-μJ/classification. Additionally, an audio recognition task mapped onto the chip achieves 87.4% accuracy at 215-μJ/classification.

DEMAP: differential evolution mapping for network on chip optimization

Network-on-chip (NoC) is a new paradigm for system-on-chip (SoC) design, which facilitates the interconnection and integration of complex components. Since this technology is still new, significant research efforts are needed to accelerate and simplify the design phases. Mapping is a critical phase in the NoC design process, as a mismatch of application software components can significantly impact the final system's performance. Therefore, it is essential to develop automated tools and methods to ensure this step. The main objective of this project is to develop a new approach that can be used to map applications on the NoC architecture to reduce communication costs. To achieve this goal, we have opted for an optimization algorithm, specifically the differential evolution algorithm.

Design and Implementation of High QoS 3D-NoC using Modified Double Particle Swarm Optimization on FPGA

One technique to overcome the exponential growth bottleneck is to increase the number of cores on a processor, although having too many cores might cause issues including chip overheating and communication blockage. The problem of the communication bottleneck on the chip is presently effectively resolved by networks-on-chip (NoC). A 3D stack of chips is now possible, thanks to recent developments in IC manufacturing techniques, enabling to reduce of chip area while increasing chip throughput and reducing power consumption. The automated process associated with mapping applications to form three-dimensional NoC architectures is a significant new path in 3D NoC research. This work proposes a 3D NoC partitioning approach that can identify the 3D NoC region that has to be mapped. A double particle swarm optimization (DPSO) inspired algorithmic technique, which may combine the characteristics having neighbourhood search and genetic architectures, also addresses the challenge of a particle swarm algorithm descending into local optimal solutions. Experimental evidence supports the claim that this hybrid optimization algorithm based on Double Particle Swarm Optimisation outperforms the conventional heuristic technique in terms of output rate and loss in energy. The findings demonstrate that in a network of the same size, the newly introduced router delivers the lowest loss on the longest path. Three factors, namely energy, latency or delay, and throughput, are compared between the suggested 3D mesh ONoC and its 2D version. When comparing power consumption between 3D ONoC and its electronic and 2D equivalents, which both have 512 IP cores, it may save roughly 79.9% of the energy used by the electronic counterpart and 24.3% of the energy used by the latter. The network efficiency of the 3D mesh ONoC is simulated by DPSO in a variety of configurations. The outcomes also demonstrate an increase in performance over the 2D ONoC. As a flexible communication solution, Network-On-Chips (NoCs) have been frequently employed in the development of multiprocessor system-on-chips (MPSoCs). By outsourcing their communication activities, NoCs permit on-chip Intellectual Property (IP) cores to communicate with one another and function at a better level. The important components in assigning application duties, distributing the work to the IPs, and coordinating communication among them are mapping and scheduling methods. This study aims to present an entirely advanced form of research in the area of 3D NoC mapping and scheduling applications, grouping the results according to various parameters and offering several suggestions for further research.

A Performance Constrained Metaheuristic Algorithm for 2D Mesh Based NoC

Integrating large number of Intellectual Property (IP) cores onto a single chip has been made possible with the technology scaling and shrinking in the size of transistors. This has led designers to create a scalable and flexible on-chip network infrastructure – Network on Chip (NoC). Mapping application graphs on multiple cores of NoC architecture is one of the challenging research problems. The all in all performance of NoC network depends primarily on an efficient and cost-effective mapping technique which optimizes several performance metrics. These metrics primarily consists of communication cost, energy, throughput, latency, power dissipation and simulation time. A metaheuristic state-of-the-art nature inspired mapping approach for NoC's called Hunger Games Search Algorithm (HGSA) has been introduced in this research work. The devised algorithm minimizes NoC energy and power consumption based on six standard available embedded application benchmarks. Experimental results demonstrate that the presented technique outperforms as compared to other existing nature-inspired meta-heuristic application mapping approaches.

Securing Network-on-chips Against Fault-injection and Crypto-analysis Attacks via Stochastic Anonymous Routing

Network-on-chip (NoC) is widely used as an efficient communication architecture in multi-core and many-core System-on-chips (SoCs). However, the shared communication resources in an NoC platform, e.g., channels, buffers, and routers, might be used to conduct attacks compromising the security of NoC-based SoCs. Most of the proposed encryption-based protection methods in the literature require leaving some parts of the packet unencrypted to allow the routers to process/forward packets accordingly. This reveals the source/destination information of the packet to malicious routers, which can be exploited in various attacks. For the first time, we propose the idea of secure, anonymous routing with minimal hardware overhead to encrypt the entire packet while exchanging secure information over the network. We have designed and implemented a new NoC architecture that works with encrypted addresses. The proposed method can manage malicious and benign failures at NoC channels and buffers by bypassing failed components with a situation-driven stochastic path diversification approach. Hardware evaluations show that the proposed security solution combats the security threats at the affordable cost of 1.5% area and 20% power overheads chip-wide.

WHYPE: A Scale-Out Architecture With Wireless Over-the-Air Majority for Scalable In-Memory Hyperdimensional Computing

Hyperdimensional computing (HDC) is an emerging computing paradigm that represents, manipulates, and communicates data using long random vectors known as hypervectors. Among different hardware platforms capable of executing HDC algorithms, in-memory computing (IMC) has shown promise as it is very efficient in performing matrix-vector multiplications, which are common in the HDC algebra. Although HDC architectures based on IMC already exist, how to scale them remains a key challenge due to collective communication patterns that these architectures required and that traditional chip-scale networks were not designed for. To cope with this difficulty, we propose a scale-out HDC architecture called WHYPE, which uses wireless in-package communication technology to interconnect a large number of physically distributed IMC cores that either encode hypervectors or perform multiple similarity searches in parallel. In this context, the key enabler of WHYPE is the opportunistic use of the wireless network as a medium for over-the-air computation. WHYPE implements an optimized source coding that allows receivers to calculate the bit-wise majority of multiple hypervectors (a useful operation in HDC) being transmitted concurrently over the wireless channel. By doing so, we achieve a joint broadcast distribution and computation with a performance and efficiency unattainable with wired interconnects, which in turn enables massive parallelization of the architecture. Through evaluations at the on-chip network and complete architecture levels, we demonstrate that WHYPE can bundle and distribute hypervectors faster and more efficiently than a hypothetical wired implementation, and that it scales well to tens of receivers. We show that the average error rate of the majority computation is low, such that it has negligible impact on the accuracy of HDC classification tasks.

SeVNoC: Security Validation of System-on-Chip Designs With NoC Fabrics

Modern System-on-Chip (SoC) designs include a variety of Network-on-Chip (NoC) fabrics to implement coordination and communication of integrated hardware intellectual property (IP) blocks. An important class of security vulnerabilities involves a rogue hardware IP interfering with this communication to compromise the integrity of the system. Such interference includes message mutation, misdirection, delivery prevention, or IP masquerading, among others. In this article, we propose a scalable RTL-level SoC validation scheme, SeVNoC, for the systematic detection of security violations in inter-IP communications for SoC designs with NoC fabrics. Given a target security property to be validated, SeVNoC entails extraction of the control-flow graph of the relevant SoC, which is analyzed through a security property-based model comparison, without incurring state-space explosion. Our experiments on full-scale realistic SoC designs with multiple IPs and NoC architecture indicate that SeVNoC detects security violations in NoC communications with near-perfect accuracy, within only a few minutes.

Hardware Trojan Detection and Mitigation in NoC using Key authentication and Obfuscation Techniques

Today's Multiprocessor System-on-Chip (MPSoC) contains many cores and integrated circuits. Due to the current requirements of communication, we make use of Network-on-Chip (NoC) to obtain high throughput and low latency. NoC is a communication architecture used in the processor cores to transfer data from source to destination through several nodes. Since NoC deals with on-chip interconnection for data transmission, it will be a good prey for data leakage and other security attacks. One such way of attacking is done by a third-party vendor introducing Hardware Trojans (HTs) into routers of NoC architecture. This can cause packets to traverse in wrong paths, leak/extract information and cause Denial-of-Service (DoS) degrading the system performance. In this paper, a novel HT detection and mitigation approach using obfuscation and key-based authentication technique is proposed. The proposed technique prevents any illegal transitions between routers thereby protecting data from malicious activities, such as packet misrouting and information leakage. The proposed technique is evaluated on a 4x4 NoC architecture under synthetic traffic pattern and benchmarks, the hardware model is synthesized in Cadence Tool with 90nm technology. The introduced Hardware Trojan affects 8% of packets passing through infected router. Experimental results demonstrate that the proposed technique prevents those 10-15% of packets infected from the HT effect. Our proposed work has negligible power and area overhead of 8.6% and 2% respectively.

Optimized shortest path algorithm for on-chip board processor in large scale networks

In this paper, we present TriBA (Triplet based) NoC (network on-chip) architecture with 40 nodes referred as TriBA-NoC. TriBA-NoC is implemented in a multi-core 40 tile DDR-3 hardware. The nodes in the TriBA-NoC are connected through recursive triplets. We carried out the performance analysis in network simulator (NS-3) using several perspectives. We adopted TR-132 shortest routing path algorithm with novel router architecture for TriBA-NoC systems. The results of average packet latency for various patterns of traffic of a 40-core TriBA-NoC model are demonstrated. The results of the proposed 40-core TriBA-NoC model achieved better performances while compared to the TriBA.

Performance evaluation of modified mesh-based NoC architecture

With the advancement of technology in the field of VLSI, it is possible to integrate several computing elements onto a single chip. The performance of these single bus-based models still suffers from scalability on large-scale platforms. Therefore, network-on-chip (NoC) architecture integrating multiple cores in a single chip has emerged as an alternative. An efficient mapping is one of the most essential activities in high-performance multi-processor architectures. This research paper proposes an efficient core mapping and modified 2-D mesh NoC architecture. Every core is connected to the two routers via a network interface. In an efficient core mapping algorithm, the mapping region is selected based on Core Efficient Region (CER), which can improve the processor performance. The proposed core mapping algorithm is applied to the multimedia benchmarks. The experimental results show that the efficient core mapping algorithm outperforms the communication energy and performance when compared with other recent mapping algorithms.

Anticipative QoS Control: A Self-Reconfigurable On-Chip Communication.

A self-reconfigurable Network-on-Chip (NoC) architecture that supports anticipative Quality of Service (QoS) control with penetrative switch ability is proposed to enhance the performance of bidirectional-channel NoC communication while supporting prioritized packet transmission services. The anticipative QoS control not only allows each communication channel to be dynamically self-configured to transmit flits in either direction for a better channel utilization of on-chip hardware resources, but also enhances the latency performance for QoS services. The proposed anticipative control is based on penetratingly observing channel direction requests of routers that is two hops away from the current one. The added ability enables a router to allocate high-priority packets to a dedicated virtual channel and then rapidly bypass it to the next destination router. The provided flexibility of packet switch promises better channel bandwidth utilization, lower packet delivery latency, and furthermore guarantees the high-priority packets being served with a better QoS. Accordingly, in this paper, an enhanced NoC architecture supporting the hybrid anticipative QoS, penetrative switch, and bidirectional-channel control, namely Anticipative QoS Bidirectional-channel NoC (AQ-BiNoC) is presented. Tested with cycle-accurate synthetic traffic patterns, significant performance enhancement has been observed when the proposed AQ-BiNoC architecture is compared against conventional NoC designs.

ASCENT: Communication Scheduling for SDF on Bufferless Software-Defined NoC

Bufferless software-defined network-on-chip (NoC) is a promising alternative to conventional dynamic routing as it offers predictable data movement with real-time guarantees. Existing time-division multiplexing (TDM)-based mechanisms for predictability assume the worst-case communication pattern (e.g., all-to-all) and compute a fixed schedule wherein the cores can only communicate during the allocated time slots. These approaches lead to low application throughput as they cannot adapt to application characteristics. In this article, we present an application specific, non-TDM-based communication scheduling mechanism for bufferless software-defined NoCs. We choose the synchronous dataflow (SDF) model of computation to represent the input streaming applications. We propose ASCENT, a novel offline approach that takes the SDF-specified streaming application and the NoC architecture as input, exploits the task interactions and the timing information in the SDF, and generates the task-to-core mapping and communication schedule that is represented compactly in hardware. ASCENT achieves <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.8\times $ </tex-math></inline-formula> better performance on average than existing TDM-based NoCs and manages to achieve the performance of an ideal dynamically routed NoC, yet ensuring predictability.

SMA: A constructive partitioning based mapping approach for Networks-on-Chip

This paper proposes a constructive partitioning approach as an effective mapping approach for 2D Networks-on-Chip. Cluster-based mapping approach offers a promising improvement on the fastest initial mapping against the standard Networks-on-Chip (NoC) architecture. In this paper, the spectral partitioning algorithm is adopted for the fastest mapping with NoC, named SMA. The proposed spectral partitioning-based mapping approach (SMA) explores the efficacious NoC mapping concerning communication bandwidth, average hop counts, and total power consumption NoC architecture. The experimental analysis indicates that the proposed SMA outperforms existing partitioning approaches.