Multi-processor SoC design methodology using a concept of two-layer hardware-dependent software

Multiprocessor System on Chip (MPSoC) technology can present an interesting solution to reduce the computational time of complex applications. Execute the H.264/AVC encoder on MPSoC architecture, is becoming an interesting point of research that can mitigate its algorithmic complexity and to resolve the real time constraints. In this paper, we present an efficient MPSoC architecture for the intra prediction process which is an important module of the H.264/AVC video encoder, using Data Level Parallelism (DLP) partitioning. This architecture is tested on an open platform for MPSoC architectures virtual designing (SoCLiB), and validated on FPGA technology. Experimental results show a gain of 74% in term of encoding speed when using four processors for coding a High Definition Video sequence (HDV) compared to uni-processor architecture.

Embedded System plays a vital role in consumer Industry. Complex applications need systems which contains multiple heterogeneous processors, running in parallel to speed up the system. Also due to area constraints, the processors are evolved in a single System on Chip called Multiprocessor System on Chip (MPSoC). The system should be reusable and debuggable, hence the designers designed and developed Reconfigurable MPSoCs rather than Application Specific Integrated Circuits (ASIC) in Field Programmable Gate Arrays (FPGA). Multiprocessor System on Chip (MPSoC) platform plays a vital role in parallel processor architecture design. However the growth of number of processing elements in one chip, task decomposition and scheduling become major bottlenecks of MPSoC architecture. To execute the applications, the application software is splitted as tasks and mapped to the different available processors and scheduled the tasks as when to execute in the available processors when the resources are ready. Selection of most suitable candidates for execution in a particular processor is very much important. Hardware related tasks are executed in different hardware accelerators and software tasks in processors. The area occupied by the schedulers in memory is more in internal memory. For scheduling these tasks, a programmable hardware is developed as hardware scheduler in the reconfigurable MPSoC using NIOS II processor. The algorithm for optimized scheduling in the target architecture is proposed. The literature survey is made with the hardware scheduler and new target MPSoC architecture. Quartus II version 12.1 and SOPC Builder are used to configure the NIOS II processer. Nios II EDS software tool has been used to build the application code.

This paper presents methods for automatic generation of models of Transducer, a highly flexible communication module for interfacing Multiprocessor System-on-Chip (MPSoC) components. We describe the transducer architecture, comprising the bus interface, high-level communication controllers and buffer management blocks. The well-defined architecture of the transducer enables automatic generation of its Transaction-level and Register-transfer level (RTL) models. Moreover, the simple interface of the transducer provides for a well-defined software interface, making it easy to update the software after changes in MPSoC platform. Our experimental results show that MPSoC design for industrial-size applications, such as MP3 decoder and JPEG encoder, greatly benefits from automatic generation of transducer models. We found productivity gains of 9-23× due to significant savings in modeling effort. On the quality axis, we show that MPSoC communication design using automatically generated transducers has very little overhead in communication delay over a fully connected point-to-point communication architecture. Finally, we show that our automatically generated TLMs greatly reduce the system-level modeling time and provide a fast executable model for early functional validation.

In modern complex systems-on-chip (SoC), software as an integral part of the SoC is gaining more and more importance. With increasing SoC complexity, SoC designers are facing an increasing complexity in the system's architecture other than the HW issues alone. The intricacy of the software needed to run on such devices is increasing tremendously as well. The challenges regarding design flow, design automation and verification cannot be solved looking at the HW aspects of the design alone. There is a big need for SoC designers to understand both their classical - the HW - world, and the world of embedded software as well. Particular attention needs to be paid on questions like: how to deal with IP reuse that is composed of HW and SW; how does SW affect the design flow; how to enable portability across hardware platforms, different application domains, and so forth. This paper introduces embedded software for SoC and EDA designers, and tries to raise their awareness on software issues they are directly impacted by. However, both classical HW designers and embedded software designers have a lot to teach each other, therefore mutual understanding is crucial for solving the SoC design challenges. In the last part of this paper, the concept of hardware dependent software (HdS) is introduced, and how HdS can help to solve some of the issues mentioned before.

Power reduction in Multiprocessor System-on-Chip (MPSoC) is a key design challenge today. In this paper, we present an approach to power reduction for homogeneous SIMD MPSoC platforms. The technique involves the use of dynamic voltage scaling and power management of voltage islands. The basic idea is to have different supply voltage for different instructions: slow instructions run at the higher voltage levels while fast instructions run at lower voltages to save on power. We use a reconfigurable MPSoC architecture, namely MorphoSys, as a vehicle to demonstrate the approach, although the methods are suitable for other SIMD MPSoC architectures. A number of image processing benchmarks are manually mapped to the hardware to demonstrate the power reduction. The results show energy savings from 12% up to 24% for the specified benchmarks using the proposed approach.

Multiprocessor Systems-on-Chip (MPSoCs) are a promising solution to fulfill the requirements of high performance computing applications, such as image processing or bioinformatics. Many different MPSoC architectures are introduced by industry and academics, such as Intel's Single Cloud Computer (SCC) or IBM's Cell. To achieve a high efficiency on such MPSoCs a high computing performance in the processing elements (PE) is not the only parameter. The bandwidth of the memory and especially the on-chip communication infrastructure are extremely important to achieve the requirements of the applications. Furthermore, for embedded System-on-Chip solutions, flexibility is extremely important for providing a good tradeoff between performance and power consumption. Especially, for general purpose MPSoCs, designed for a wide range of applications with different communication demands, this flexibility is essential for a good energy efficiency. A simple bus or Network-on-Chip (NoC) with fixed bandwidth and communication paradigm is not sufficient in this varying application scenario and its design space. In this paper novel features for the heterogeneous and runtime adaptive Star-Wheels Network-on-Chip are presented. This Network-on-Chip is used within a runtime adaptive MPSoC, which enables to tailor processors and accelerators to the requirements of the applications. For optimizing the Star-Wheels Network-on-Chip and its communication protocol at runtime to the application requirement the following novel features have been added: the combination of the circuit- and the packet-switched communication paradigm and an algorithm-based placement of the processing elements within the NoC. The integration of the novel algorithm into the design methodology and the exploitation of the novel features within the special purpose runtime operating system of a runtime adaptive MPSoC are also introduced.

Daedalus is a system-level design flow for the design of multiprocessor system-on-chip (MP-SoC) based embedded multimedia systems. It offers a fully integrated tool-flow in which design space exploration (DSE), system-level synthesis, application mapping, and system prototyping of MP-SoCs are highly automated. In this paper, we describe our first industrial deployment experiences with the Daedalus framework. Daedalus is currently being deployed in the early stages of the design of an image compression system for very high resolution cameras targeting medical appliances. In this context, we performed a DSE study with a JPEG encoder application, which exploits both task and data parallelism. This application was mapped onto a range of different MP-SoC architectures. We achieved a performance speed-up of up to 20x compared to a single processor system. In addition, the results show that the Daedalus high-level MP-SoC models accurately predict the overall system performance, i.e., the performance error is around 5%.

Inter-core communication introduces overheads in task schedules on Multiprocessor System-on-Chips (MPSoCs). Inter-core communication overhead not only negatively impacts the timing performance but also significantly degrades the memory usage for streaming applications running on MPSoC architectures. By minimizing inter-core communication overhead, a shorter period can be applied and system performance (e.g., throughput, memory usage) can be improved. In this paper, we focus on solving the problem of minimizing inter-core communication overhead for streaming applications on bus-based MPSoCs. The objective is to minimize inter-core communication overhead while minimizing the overall memory usage. To solve the problem, we first let tasks with intra-period data dependencies transform to inter-period data dependencies so as to overlap the execution of computation and inter-core communication tasks. By doing this, inter-core communication overhead can be effectively removed. To minimize the overall memory usage, we then perform schedulability analysis and obtain the bounds of the times needed to reschedule each task. Based on the schedulability analysis, we formulate the scheduling problem as an integer linear programming (ILP) model and obtain an optimal schedule. In addition, we propose a heuristic approach to efficiently obtain a near-optimal solution. We conduct experiments on a set of benchmarks from both real-life streaming applications and synthetic task graphs. The experimental results show that the proposed approach can significantly reduce the schedule length and improve the memory usage compared with the previous work.

In this paper, an overview of reconfigurability is presented with some design recommendations. Besides, a design flow of a Reconfigurable System on Chip (RSoC) is studied for an application case: the implementation of two different controllers on Multiprocessor SoC (MPSoC) architecture using the FPGA Virtex-II Pro. A runtime partial reconfiguration is adopted to switch between them. A predictive internal state definition allows a soft commutation between controllers. Experimental results confirm the adopted approach efficiency and give satisfying performance.

Reconfigurable technologies are getting popular as an instrument not only for verification and prototyping but also for commercial implementation of Multi-Processor System-on-Chip (MPSoC) architectures. These systems, in particular Network-on-Chip (NoC) based ones, have emerged as a design strategy to cope with increased requirements and complexity of modern applications. However, the increasing heterogeneity, coupled with possibility of reconfiguration, makes security become one of major concerns in MPSoC design. In this work, we show a solution for FPGA based designs against one of the most widespread types of attacks - code injection. Our response to tackle this challenge is given in form of Stack Protection Unit (SPU) embedded into processing cores. MicroBlaze soft-core processor serves as a case study for verification of the proposed solution in FPGA technology.

C/C++-based languages such as SystemC or SpecC can be used for both hardware and software description by raising the level of abstraction for hardware. This paper proposes techniques for fast and accurate high-level co-simulation for multithread and multiprocessor SoC design using SystemC for hardware and legacy C with RTOS (real-time operating system) API for software. Automatically modified legacy C synchronizes with SystemC clock events, and communicates with other modules through IO (input/output) variables and transaction level bus models. Generic RTOS scheduler and POS1X APIs are also provided for the real-time application. About three times faster co-simulation speed than the ISS-based co-simulation along with various profiling data with 95% accuracy were achieved.

The performances of System on Chip (SoC) and the Field Programmable Gate Array (FPGA) particularly, are increasing continually. Due to the growing complexity of modern embedded control systems, the need of more performance digital devices is evident. Recent FPGA technology makes it possible to include processor cores into the FPGA chip, which ensures more flexibility for digital controllers. Indeed, greater functionality of hardware and system software, Real-Time (RT) platforms and distributed subsystems are demanded. In this chapter, a design concept of FPGA based controller with Hardware/Software (Hw/Sw) codesign is proposed. It is applied for electrical machine drives. There are discussed different MultiProcessor SoC (MPSoC) architectures with Hw peripherals for the implementation on FPGA-based embedded processor cores. Hw accelerators are considered in the design to enhance the controller speed performance and reduce power consumption. Test and validation of this control system are performed on a RT motor emulator implemented on the same FPGA. Experimental results, carried on a real prototyping platform, are given in order to analyze the performance and efficiency of discussed architecture designs helping to support hard RT constraints.Request access from your librarian to read this chapter's full text.

The design of a Multiprocessor System-on-Chip (MPSoC) is a complex task, including steps as application development, platform configuration, code generation, task mapping onto the platform and debugging. An integrated environment covering most of these steps is a gap in the literature. The present work first details an MPSoC architecture, which supports the execution of distributed applications, including an operating system enabling multitask execution at each processing element. The MPSoC is heterogeneous, due to the support to different processor architectures. Then, a framework able to cover the design steps previously mentioned is presented. The framework enables the design space exploration for applications to be executed in the MPSoC, varying for example the number and type of processors, the memory size, the task mapping. Results demonstrate the correct operation for different MPSoC configurations, generated from the proposed framework. Such open-source framework enables the research community to investigate new subjects related to MPSoC and Network on Chip (NoC) design, as well as evaluate distributed applications in a multiprocessor environment.

This article proposes an original design flow for the fast prototyping of image processing on a MP-SoC (MultiProcessors System on Chip) architecture. Developing processors network systems tailored to a particular application domain is critical and design-time consuming in order to achieve highperformance customized solutions. The effectiveness of such approaches largely depends on the availability of an ad hoc design methodology. This paper illustrates a new design flow that enables to instantiate a generic Homogeneous Network of Communicating Processors (called HNCP) tailored for a targeted application. The HNCP is generated with a tool that avoids fastidious manual editing operations for the designer. Specific lightweight communication functions have been developed to fasten the programming of the MP-SoC network. A case study (image texture analyzes) is presented to illustrate the proposed MP-SoC design methodology and enables to focus on architecture exploration, instantiated scheme of parallelization and timing performance.

This article proposes an original methodology for the fast prototyping of image processing on a generic MP-SoC (Multi-Processors System on Chip) architecture. To define a processors network adapted to a particular application is critical and design-time consuming in order to achieve high-performance customized solutions. The effectiveness of such approaches largely depends on the availability of an ad hoc design methodology. This paper illustrates a new methodology that enables to instantiate a generic Homogeneous Network of Communicating Processors (called HNCP) tailored for a targeted application. The HNCP is generated with a tool that avoids fastidious manual editing operations for the designer. Specific lightweight communication functions have been developed to fasten the programming of the MP-SoC network. A case study (image texture analyzes) is presented to illustrate the proposed MP-SoC design methodology and enables to focus on architecture exploration, instantiated scheme of parallelization and timing performance.