Multiprocessor System-on-chip Research Articles

Secure Video Streaming Using Dedicated Hardware

The purpose of this article is to present a system that enhances the security, efficiency, and reconfigurability of an Internet-of-Things (IoT) system used for surveillance and monitoring. A Multi-Processor System-On-Chip (MPSoC) composed of Central Processor Unit (CPU) and Field-Programmable Gate Array (FPGA) is proposed for increasing the security and the frame rate of a smart IoT edge device. The private encryption key is safely embedded in the FPGA unit to avoid being exposed in the Random Access Memory (RAM). This allows the edge device to securely store and authenticate the key, protecting the data transmitted from the same Integrated Circuit (IC). Additionally, the edge device can simultaneously publish and route a camera stream using a lightweight communication protocol, achieving a frame rate of 14 frames per Second (fps). The performance of the MPSoC is compared to a NVIDIA Jetson Nano (NJN) and a Raspberry Pi 4 (RPI4) and it is found that the RPI4 is the most cost-effective solution but with lower frame rate, the NJN is the fastest because it can achieve higher frame-rate but it is not secure, and the MPSoC is the optimal solution because it offers a balanced frame rate and it is secure because it never exposes the secure key into the memory. The proposed system successfully addresses the challenges of security, scalability, and efficiency in an IoT system used for surveillance and monitoring. The Rivest-Shamir-Adleman (RSA) encryption key is securely stored and authenticated, and the edge device is able to simultaneously publish and route a camera stream feed high-definition images at 14 fps. The proposed system enhances the security, efficiency, and reconfigurability of an IoT system used for surveillance and monitoring. The RSA encryption key is effectively protected by the implementation of an MPSoC with Programmable Logic (PL), which also allows for faster processing and data transmission.

Machine learning in run-time control of multicore processor systems

Abstract Modern embedded and cyber-physical applications consist of critical and non-critical tasks co-located on multiprocessor systems on chip (MPSoCs). Co-location of tasks results in contention for shared resources, resulting in interference on interconnect, processing units, storage, etc. Hence, machine learning-based resource managers must operate even non-critical tasks within certain constraints to ensure proper execution of critical tasks. In this paper we demonstrate and evaluate countermeasures based on backup policies to enhance rule-based reinforcement learning to enforce constraints. Detailed experiments reveal the CPUs’ performance degradation caused by different designs, as well as their effectiveness in preventing constraint violations. Further, we exploit the interpretability of our approach to further improve the resource manager’s operation by adding designers’ experience into the rule set.

Application Level Resource Scheduling for Deep Learning Acceleration on MPSoC

Deep Neutral Networks (DNNs) have been widely used in many applications, such as self-driving cars, natural language processing (NLP), image classification, visual object recognition, and so on. Field-programmable gate array (FPGA) based Multiprocessor System on a Chip (MPSoC) is recently considered one of the popular choices for deploying DNN models. However, the limited resource capacity of MPSoC imposes a challenge for such practical implementation. Recent studies revealed the trade-off between the “resources consumed" vs. the “performance achieved". Taking a cue from these findings, we address the problem of efficient implementation of deep learning into the resource-constrained MPSoC in this paper, where each deep learning network is run with different service levels based on resource usage (where a higher service level implies higher performance with increased resource consumption). To this end, we propose a heuristic-based strategy, Application Wise Level Selector (AWLS), for selecting service levels to maximize the overall performance subject to a given resource bound. AWLS can achieve higher performance within a constrained resource budget under various simulation scenarios. Further, we verify the proposed strategy using an AMD-Xilinx Zynq UltraScale+ XCZU9EG SoC. Using a framework designed to deploy multi-DNN on multi-DPUs (Deep Learning Units), it is proved that an optimal solution is achieved from the algorithm, which obtains the highest performance (Frames Per Second) using the same resource budget.

Lazy Load Scheduling for Mixed-criticality Applications in Heterogeneous MPSoCs

Newly emerging multiprocessor system-on-a-chip (MPSoC) platforms provide hard processing cores with programmable logic (PL) for high-performance computing applications. In this article, we take a deep look into these commercially available heterogeneous platforms and show how to design mixed-criticality applications such that different processing components can be isolated to avoid contention on the shared resources such as last-level cache and main memory. Our approach involves software/hardware co-design to achieve isolation between the different criticality domains. At the hardware level, we use a scratchpad memory (SPM) with dedicated interfaces inside the PL to avoid conflicts in the main memory. At the software level, we employ a hypervisor to support cache-coloring such that conflicts at the shared L2 cache can be avoided. In order to move the tasks in/out of the SPM memory, we rely on a DMA engine and propose a new CPU-DMA co-scheduling policy, called Lazy Load , for which we also derive the response time analysis. The results of a case study on image processing demonstrate that the contention on the shared memory subsystem can be avoided when running with our proposed architecture. Moreover, comprehensive schedulability evaluations show that the newly proposed Lazy Load policy outperforms the existing CPU-DMA scheduling approaches and is effective in mitigating the main memory interference in our proposed architecture.

X-Stream: Accelerating streaming segments on MPSoCs for real-time applications

We are witnessing a race to meet the ever-growing computation requirements of emerging AI applications to provide perception and control in autonomous vehicles — e.g., self-driving cars and UAVs. To remain competitive, vendors are packing more processing units (CPUs, programmable logic, GPUs, and hardware accelerators) into next-generation multiprocessor systems-on-a-chip (MPSoC). As a result, modern embedded platforms are achieving new heights in peak computational capacity. Unfortunately, however, the collateral and inevitable increase in complexity represents a major obstacle for the development of correct-by-design safety-critical real-time applications. Due to the ever-growing gap between fast-paced hardware evolution and comparatively slower evolution of real-time operating systems (RTOS), there is a need for real-time oriented full-platform management frameworks to complement traditional RTOS designs.In this work, we propose one such framework, namely the X-Stream framework, for the definition, synthesis, and analysis of real-time workloads targeting state-of-the-art accelerator-augmented embedded platforms. Our X-Stream framework is designed around two cardinal principles. First, computation and data movements are orchestrated to achieve predictability by design. For this purpose, iterative computation over large data chunks is divided into subsequent segments. These segments are then streamed leveraging the three-phase execution model (load, execute and unload). Second, the framework is workflow-centric: system designers can specify their workflow and the necessary code for workflow orchestration is automatically generated.In addition to automating the deployment of user-defined hardware-accelerated workloads, X-Stream supports the deployment of some computation segments on traditional CPUs. Finally, X-Stream allows the definition of real-time partitions. Each partition groups applications belonging to the same criticality level and that share the same set of hardware resources, with support for preemptive priority-driven scheduling. Conversely, freedom from interference for applications deployed in different partitions is guaranteed by design. We provide a full-system implementation that includes RTOS integration and showcase the proposed X-Stream framework on a Xilinx Ultrascale+ platform by focusing on a matrix-multiplication and addition kernel use-case.

A Reliability System Evaluation Model of NoC Communication with Crosstalk Analysis from Backend to Frontend

Network on chip (NoC) is the main solution to the communication bandwidth of a multi-processor system on chip (MPSoC). NoC also brings more route requirements and is highly prone to errors caused by crosstalk. Crosstalk has become a major design problem in deep-submicron NoC communication design. Hence, a crosstalk error model and corresponding reliable system with error correction code (ECC) are required to make NoC communication reliable. In this paper, a reliability system evaluation model (RSE) of NoC communication with analysis from backend to frontend has been proposed. In the backend, a crosstalk error rate model (CER) is established with a three-wire RLC coupling model and timing constraints. The CER is used to establish functional relations between interconnect spacing, length and signal frequency, and test system reliability. In the frontend, a reliability system performance model (RSP) is established with a CER, reliability method cost and bandwidth. The RSE summarizes the frontend and backend model. In order to verify the RSE model, we propose a reliability system with a hybrid automatic repeat request technique (RSHARQ). Simulation demonstrates that the CER model is close to real circuit design. Through the CER and RSP model, the performance of RSHARQ could be simulated.

Virtualization of accelerators in embedded systems for mixed-criticality: RPU exploitation for fusion diagnostics and control

The need for computing systems featuring high performance, safety, security, and predictability requirements, has become essential for fusion diagnostics and control. In this scenario, the next-generation Multiprocessors System-On-Chip (MPSoCs) characterized by modern processors and hardware accelerators can expand the potential of control infrastructure. To enhance the usability, performance, and dependability of these new technologies and to reduce the deployment cost, the concept of virtualization sees its first application in embedded systems. This work aims to propose three high-level architectural solutions that leverage virtualization to exploit accelerators and Real-Time Processing Units (RPUs) present on MPSoCs to realize Mixed-Criticality Systems (MCSs). That is, systems capable to manage on a single chip real-time tasks for critical automatic control together with other value-added services on the same hardware. The problems to be solved to implement these proposals will be explained in detail to guide future works. To highlight the potential of virtualization for real-time embedded systems in fusion science scenarios we explore some use cases regarding Vertical Stabilization (VS) algorithms for plasma magnetic control that can benefit from the proposed solutions.

DTS-100G — a versatile heterogeneous MPSoC board for cryogenic sensor readout

Heterogeneous devices such as the Multi-Processor System-on-Chip (MPSoC) from Xilinx are extremely valuable in custom instrumentation systems. This contribution presents the joint development of a heterogeneous MPSoC board called DTS-100G by DESY and KIT. The board is built around a Xilinx Zynq Ultrascale+ chip offering all available high-speed transceivers using QSFP28, 28 Gbps FireFly, FMC, and FMC+ interfaces. The board is not designed for a particular application, but can be used as a generic DAQ platform for a variety of physics experiments. The DTS-100G board was successfully developed, built and commissioned. ECHo-100k is the first experiment which will employ the board. This contribution shows the system architecture and explains how the DTS-100G board is a crucial component in the DAQ chain.

Vector Extensions in COTS Processors to Increase Guaranteed Performance in Real-Time Systems

The need for increased application performance in high-integrity systems such as those in avionics is on the rise as software continues to implement more complex functionalities. The prevalent computing solution for future high-integrity embedded products is multi-processor systems-on-chip (MPSoC) processors. MPSoCs include central processing unit (CPU) multicores that enable improving performance via thread-level parallelism. MPSoCs also include generic accelerators (graphics processing units [GPUs]) and application-specific accelerators. However, the data processing approach (DPA) required to exploit each of these underlying parallel hardware blocks carries several open challenges to enable the safe deployment in high-integrity domains. The main challenges include the qualification of its associated runtime system and the difficulties in analyzing programs deploying the DPA with out-of-the-box timing analysis and code coverage tools. In this work, we perform a thorough analysis of vector extensions (VExts) in current commercial off-the-shelf (COTS) processors for high-integrity systems. We show that VExts prevent many of the challenges arising with parallel programming models and GPUs. Unlike other DPAs, VExts require no runtime support, prevent design race conditions that might arise with parallel programming models, and have minimum impact on the software ecosystem, enabling the use of existing code coverage and timing analysis tools. We develop vectorized versions of neural network kernels and show that the NVIDIA Xavier VExts provide a reasonable increase in guaranteed application performance of up to 2.7x. Our analysis contends that VExts are the DPA approach with arguably the fastest path for adoption in high-integrity systems.

Design and Performance Analysis of Low Latency Routing Algorithm based NoC for MPSoC

The Network on Chip is appropriate where System-on-Chip technology is scalable and adaptable. The Network on Chip is a new communication architecture with a number of benefits, including scalability, flexibility, and reusability, for applications built on Multiprocessor System on a Chip (MPSoC). However, the design of efficient NoC fabric with high performance is critically complex because of its architectural parameters. Identifying a suitable scheduling algorithm to resolve arbitration among ports to obtain high-speed data transfer in the router is one of the most significant phases while designing a Network on chip based Multiprocessor System on a Chip. Low latency, throughput, space utilization, energy consumption, and reliability for Network on chip fabric are all determined by the router. The performance of the NoC system is hampered by the deadlock issues that plague conventional routing algorithms. This work develops a novel routing algorithm to address the deadlock problem. In this paper, a deterministic shortest path deadlock-free routing method is developed based on the analysis of the Turn Model. In the 2D-mesh structure, the algorithm uses separate routing methods for the odd and even columns. This minimizes the number of paths for a single channel, congestion, and latency. Two test scenarios—one with and one without a load test—were used to evaluate the proposed model. For a zero-load network, three clock cycles are utilized to transfer the packets. For the load network, five clocks are utilized to transfer the packets. The latency is measured for both cases without load and with load test and the corresponding latency is 3ns and 7ns respectively.The proposed method has an 18.57Mbps throughput. The area and power utilization for the proposed method are 69% (IO utilization) and 0.128W respectively. In order to validate the proposed method, the latency is compared with existing work and 50% latency is reduced both with and without congestion load.

An Optimal DPM Based Energy-Aware Task Scheduling for Performance Enhancement in Embedded MPSoC

Minimizing the energy consumption to increase the life span and performance of multiprocessor system on chip (MPSoC) has become an integral chip design issue for multiprocessor systems. The performance measurement of computational systems is changing with the advancement in technology. Due to shrinking and smaller chip size power densities on-chip are increasing rapidly that increasing chip temperature in multi-core embedded technologies. The operating speed of the device decreases when power consumption reaches a threshold that causes a delay in complementary metal oxide semiconductor (CMOS) circuits because high on-chip temperature adversely affects the life span of the chip. In this paper an energy-aware dynamic power management technique based on energy aware earliest deadline first (EA-EDF) scheduling is proposed for improving the performance and reliability by reducing energy and power consumption in the system on chip (SOC). Dynamic power management (DPM) enables MPSOC to reduce power and energy consumption by adopting a suitable core configuration for task migration. Task migration avoids peak temperature values in the multi-core system. High utilization factor ( on central processing unit (CPU) core consumes more energy and increases the temperature on-chip. Our technique switches the core by migrating such task to a core that has less temperature and is in a low power state. The proposed EA-EDF scheduling technique migrates load on different cores to attain stability in temperature among multiple cores of the CPU and optimized the duration of the idle and sleep periods to enable the low-temperature core. The effectiveness of the EA-EDF approach reduces the utilization and energy consumption compared to other existing methods and works. The simulation results show the improvement in performance by optimizing 4.8% on 9%, 16%, 23% and 25% at 520 MHz operating frequency as compared to other energy-aware techniques for MPSoCs when the least number of tasks is in running state and can schedule more tasks to make an energy-efficient processor by controlling and managing the energy consumption of MPSoC.

Energy-Efficient Scheduling Based on Task Migration Policy Using DPM for燞omogeneous MPSoCs

Increasing the life span and efficiency of Multiprocessor System on Chip (MPSoC) by reducing power and energy utilization has become a critical chip design challenge for multiprocessor systems. With the advancement of technology, the performance management of central processing unit (CPU) is changing. Power densities and thermal effects are quickly increasing in multi-core embedded technologies due to shrinking of chip size. When energy consumption reaches a threshold that creates a delay in complementary metal oxide semiconductor (CMOS) circuits and reduces the speed by 10%–15% because excessive on-chip temperature shortens the chip’s life cycle. In this paper, we address the scheduling & energy utilization problem by introducing and evaluating an optimal energy-aware earliest deadline first scheduling (EA-EDF) based technique for multiprocessor environments with task migration that enhances the performance and efficiency in multiprocessor system-on-chip while lowering energy and power consumption. The selection of core and migration of tasks prevents the system from reaching its maximum energy utilization while effectively using the dynamic power management (DPM) policy. Increase in the execution of tasks the temperature and utilization factor on-chip increases that dissipate more power. The proposed approach migrates such tasks to the core that produces less heat and consumes less power by distributing the load on other cores to lower the temperature and optimizes the duration of idle and sleep times across multiple CPUs. The performance of the EA-EDF algorithm was evaluated by an extensive set of experiments, where excellent results were reported when compared to other current techniques, the efficacy of the proposed methodology reduces the power and energy consumption by 4.3%–4.7% on a utilization of 6%, 36% & 46% at 520 & 624 MHz operating frequency when particularly in comparison to other energy-aware methods for MPSoCs. Tasks are running and accurately scheduled to make an energy-efficient processor by controlling and managing the thermal effects on-chip and optimizing the energy consumption of MPSoCs.

MPSoC design and implementation using microblaze soft core processor architecture for faster execution of arithmetic application

The research paper presents the design methodology with novel task distribution technique on multi-processor system on chip (MPSoC) for speeding up the execution of arithmetic application. Utilisation of multiple soft core processors on field programmable gate array (FPGA) reduces the overload of adding external hardware to a system. Parallel processing of soft core processor with proposed task distribution technique makes any application to execute at faster rate. This task distribution based speed enhancement technique for arithmetic application is very feasible and appealing to the modern applications like neural networks, fuzzy logic, algorithms of machine learning etc. Experimentation on such architecture with arithmetic application shows significant increase in speed of operation with respect to conventional design. This is implemented using Microblaze soft core processor architecture on Xilinx Virtex 5 FPGA board.

Modeling and Simulation Challenges and Solutions in Cooling Systems for Nanoscale Integrated Circuits [Feature

The power density in modern Integrated Circuits (ICs) is tremendous. For example, Multi-Processor Systems-on-Chip (MPSoCs) nowadays undergo temperature swings of 40 degrees in 100 milliseconds or less, with rapidly emerging and vanishing sub-millimeter hot spots. As such, not only a simulation-based cooling assessment is vital, but one has to simulate the on-chip thermal phenomena jointly with the heat dissipation system - historically, a challenge. In recent years, however, the idea of coupling traditional 3D chip simulators with heat dissipation models written in Equation-Based Modeling (EBM) languages has proven to be a game changer. EBM languages allow one to compose a model by assembling components described in terms of Differential and Algebraic Equations (DAE) and have the simulation code generated automatically. In this article, we take a tutorial viewpoint on the matter just sketched, to put the reader in the position of exploiting the above technology. We also present the first nucleus of a model library for cooling systems, that we release as free software for the scientific and engineering community.

The CTH Network: An NoC Platform for Scalable and Energy Efficient Application Mapping Solution

Multi-threaded design of the applications has given a new dimension to the execution concurrency. The Network-on-Chip (NoC) infrastructure has evolved as the communication backbone in multiprocessor System-on-Chips (MPSoCs) to exploit Thread-Level Parallelism (TLP). Mapping the threads of various applications on the processing cores is crucial in utilizing the resources of a many-core system. An application's performance depends primarily on the mapping strategy. However, the performance of an application gets influenced significantly by the underlying network architecture of the NoC. The present work proposes a run-time application mapping technique based on the Cube-Tree-Hybrid (CTH) topology focusing on the traffic load balancing across the network. The mapping overhead decreased significantly by exploiting the low network diameter of CTH with its high scalability and path diversity, projecting a 31% reduction in normalized execution time over the prevalent algorithms on the existing mapping platforms. Rigorous experimentation with varying application and network sizes is carried out across mesh, ZMesh, torus, and Mest-of-Tree (MoT) networks. The experimental observations project that the proposed algorithm results in sustainable application performance with 15%-21% gain in the overall energy consumption over the existing state-of-the-art techniques across various benchmark workloads.

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.

Run-Time Remapping Algorithm of Dataflow Actors on NoC-Based Heterogeneous MPSoCs

Multiprocessor system-on-chip (MPSoC) platforms have been emerging as the main solution to cope with processor frequency ceiling and power density issues while still improving performances. Then, network-on-chip (NoC) has been adopted to provide the increasing number of processors with the required communication bandwidth as well as with the necessary flexibility. Video processing and streaming applications are adopting dynamic dataflow model of computation as the need for high performance parallel computing is growing. Dataflow applications executed on modern MPSoC-based architectures are becoming increasingly dynamic and more data-dependent. Different tasks execute concurrently with significant modifications in their workloads and resource demanding over time depending on the input data. Hence, adopting any static or offline dynamic scheduling for mapping tasks will not cope with the computation variations. This article introduces an original run-time mapping algorithm based on the Move Based (MB) method targeting a dedicated heterogeneous NoC-based MPSoC architecture to achieve workload balancing and optimized communication traffic. The performance of the proposed algorithm is verified by conducting cycle-accurate SystemC simulations of the adopted NoC implementing a real MPEG4-SP decoder. The obtained results reveal the effectiveness of our proposed algorithm. For various real-life videos, the proposed algorithm systematically succeeded to enhance significantly the performance.

Using Pattern of On-Off Routers and Links and Router Delays to Protect Network-on-Chip Intellectual Property

Intellectual Property (IP) reuse is a well known practice in chip design processes. Nowadays, network-on-chips (NoCs) are increasingly used as IP and sold by various vendors to be integrated in a multiprocessor system-on-chip (MPSoC). However, IP reuse exposes the design to IP theft, and an attacker can launch IP stealing attacks against NoC IPs. With the growing adoption of MPSoC, such attacks can result in huge financial losses. In this article, we propose four NoC IP protection techniques using fingerprint embedding: ON-OFF router-based fingerprinting (ORF), ON-OFF link-based fingerprinting (OLF), Router delay-based fingerprinting (RTDF), and Row delay-based fingerprinting (RWDF). ORF and OLF techniques use patterns of ON-OFF routers and links, respectively, while RTDF and RWDF techniques use router delays to embed fingerprints. We show that all of our proposed techniques require much less hardware overhead compared to an existing NoC IP security solution (square spiral routing) and also provide better security from removal and masking attacks. In particular, our proposed techniques require between 40.75% and 48.43% less router area compared to the existing solution. We also show that our solutions do not affect the normal packet latency and hence do not degrade the NoC performance.

Stereo: Assignment and Scheduling in MPSoC Under Process Variation by Combining Stochastic and Decomposition Approaches

Aggressive scaling in integrated circuits creates new challenges such as an increase in power density, temperature, and especially process variation in designing Multiprocessor Systems-on-Chip (MPSoC). While most of the previous works attempt to mitigate the process variation effects at the system level, the eventual design still suffers from the variability of frequency and leakage power. In this paper, we propose a method called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Stereo</i> that combines <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</u> tochas <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</u> ic and d <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</u> composition to solve task assignment and scheduling under p <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</u> oc <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</u> ss variati <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</u> n in MPSoCs. In our previous work, we formulated a Mixed Integer Linear Programming (MILP) problem for variation-aware task assignment and scheduling to optimize energy consumption while meeting the real-time constraints. To capture the stochastic behavior of process variation, we employed a chance-constrained programming technique to turn the problem into a corresponding stochastic optimization that can be solved by typical ILP solvers. However, it had a scalability problem. To address this issue, in this work, we leverage a Logic-based Benders Decomposition (LBD) approach to improve the running time for finding an optimal solution of assignments and schedulings under process variation phenomenon). We carried out extensive experiments using Embedded System Synthesis Benchmarks Suite (E3S). The experimental results of the Stereo method evince considerable improvements compared to the baseline method in terms of performance-yield and run-time. The Stereo-based MILP method ameliorates performance-yield up to 2× and run-time by 532×. Moreover, for manifold applications, the Stereo-based LBD method archives 3.47×-91.49× run-time improvement compared to the Stereo-based MILP approach and is capable of assigning and scheduling of more than 50 tasks on 9 processors.

A Novel Hybrid Hexagonal Star Topology for On-Chip Interconnection Networks

Network-on-Chip (NoC) is an emerging and efficient on-chip interconnection network. NoC is expected to be the communication backbone of next-generation Multi-processor System-on-Chip (MPSoC) architectures. Topology is a crucial design aspect of NoC, as it affects the performance of the interconnection network. This paper proposes a novel, scalable, hybrid Hexagonal Star (HS) topology for on-chip interconnection networks. Properties of the proposed topology have been explored and compared with those of Mesh, Torus and Honeycomb Mesh topologies. The performance of the Hexagonal Star topology has been evaluated and compared with that of Mesh topology for different scenarios. The comparative studies of topological properties have indicated that the proposed topology can be a potential choice for on-chip interconnection networks. The simulation results have shown that the proposed topology outperforms Mesh topology in terms of latency for low traffic loads. For different traffic patterns and traffic loads, HS topology has registered a reduction of packet latency ranging from 15% to 50% and from 9% to 23% for 18 nodes and 32 nodes, respectively, compared to Mesh topology.