IEEE transactions on very large scale integration (VLSI) systems

Simulink ® -based heterogeneous multiprocessor SoC design flow for mixed hardware/software refinement and simulation

Advances in silicon process technology have made it possible to include multiple processor cores on a single die. Billion transistor architectures usually in the form of networks-on-chip present a wide range of challenges in design, microarchitecture, and algorithmic levels with significant impact to system performance and power consumption. In this article, we propose efficient methods and mechanisms that exploit a heterogeneous network-on-chip (NoC) to achieve a power- and thermal-aware coherent system. To this end, we utilize different management techniques which employ dynamic frequency scaling circuitry and power and temperature sensors per node to achieve real-time workload prediction and allocation at node and system level by low-cost threads. The developed heterogeneous multicoprocessing infrastructure is utilized to evaluate diverse policies for power-aware computing in terms of effectiveness and in relation to distributed sensor-conscious management. The proposed reconfigurable architecture supports coprocessor accelerators per node, monitors the program’s power profile on-the-fly, and balances power and thermal behavior at the NoC level. Overall, these techniques form a system exploration methodology using a multi-FPGA emulation platform showing a minimum complexity overhead.

Dynamic Power and Thermal Management of NoC-Based Heterogeneous MPSoCs

This paper presents a framework for high-level power estimation of multiprocessor systems-on-chip (MPSoC) architectures on FPGA. The technique is based on abstract execution profiles, called event signatures, and it operates at a higher level of abstraction than, for example, commonly used instruction-set simulator (ISS)-based power estimation methods and should thus be capable of achieving good evaluation performance. As a consequence, the technique can be very useful in the context of early system-level design space exploration. We integrated the power estimation technique in a system-level MPSoC synthesis framework. Subsequently, using this framework, we designed a range of different candidate architectures which contain different numbers of MicroBlaze processors and compared our power estimation results to those from real measurements on a Virtex-6 FPGA board.

https://pure.uva.nl/ws/files/1862847/125709_377178.pdf

A signature-based power model for MPSoC on FPGA

SAFEPOWER project: Architecture for safe and power-efficient mixed-criticality systems

By allowing parts of the applications to be executed either on soft processors (as software programs) or on customized hard-ware peripherals attached to the processors, FPGAs have made traditional energy estimation techniques inefficient for evaluating various design tradeoffs. In this paper, we propose a high-level simulation-based two-step rapid energy estimation technique for hardware-software codesign using FPGAs. In the first step, a high-level hardware-software cosimulation technique is applied to simulate both the hardware and software components of the target application. High-level simulation results of both software programs running on the processors and the customized hardware peripherals are gathered during the cosimulation process. In the second step, the high-level simulation results of the customized hardware peripherals are used to estimate the switching activities of their corresponding register-transfer/gate level ("low-level") implementations. We use this information to employ an instruction-level energy estimation technique and a domain-specific energy performance modeling technique to estimate the energy dissipation of the complete application. A Matlab/Simulink-based implementation of our approach and two numerical computation applications show that the proposed energy estimation technique can achieve more than 6000x speedup over low-level simulation-based techniques while sacrificing less than 10% estimation accuracy. Compared with the measured results, our experimental results show that the proposed technique achieves an average estimation error of less than 12%.

/pdf/rapid-energy-estimation-for-hardware-software-codesign-using-2fs0k4ib0q.pdf

Rapid energy estimation for hardware-software codesign using FPGAs

Configurable multiprocessor platforms consist of multiple soft processors configured on FPGA devices. They have become an attractive choice for implementing many computing applications. In addition to the various ways of distributing software execution among the multiple soft processors, the application designer can customize soft processors and the connections between them in order to improve the performance of the applications running on the multiprocessor platform. State-of-the-art design tools rely on low-level simulation to explore the various design trade-offs offered by configurable multiprocessor platforms. These low-level simulation based exploration techniques are too time-consuming and can be a major bottleneck to efficient design space exploration on these platforms. We propose a design space exploration technique for configurable multiprocessor platforms using arithmetic-level cycle-accurate hardware--software cosimulation. Arithmetic-level abstractions of the hardware and software execution platforms are created within the proposed cosimulation environment. The configurable multiprocessor platforms are described using these arithmetic-level abstractions. Hardware and software simulators are tightly integrated to concurrently simulate the arithmetic behavior of the multiprocessor platform. The simulation within the integrated simulators are synchronized to provide cycle-accurate simulation results for the complete multiprocessor platform. By doing so, we significantly speed up the cosimulation process for configurable multiprocessor platforms. Exploration of the various hardware-software design trade-offs provided by configurable multiprocessor platforms can be performed within the proposed cycle-accurate cosimulation environment. After the final designs are identified, the corresponding low-level implementations with the desired cycle-accurate arithmetic behavior are generated automatically. For illustrative purposes, we provide an implementation of our approach based on MATLAB/Simulink. We show the cosimulation of two numerical computation applications and one image-processing application on a popular configurable multiprocessor platform within the MATLAB/Simulink-based cosimulation environment. For these three applications, our arithmetic-level cosimulation approach leads to speed-ups in simulation time of up to more than 800x compared with the low-level simulation approaches. The designs of these applications identified using our arithmetic-level cosimulation approach achieve execution time speed-ups up to 5.6x, compared with other designs considered in our experiments.

Design space exploration using arithmetic-level hardware--software cosimulation for configurable multiprocessor platforms

A cooperative management scheme for power efficient implementations of real-time operating systems on field-programmable gate-array (FPGA)-based soft processors is presented. Dedicated power management hardware peripherals are tightly coupled to a soft processor by utilizing its configurability. These hardware peripherals manage tasks and interrupts in cooperation with the soft processor, while retaining the real-time responsiveness of the operating system. More specifically, the hardware peripherals perform the following power management functionalities: (1) control the on-chip clock distribution network for driving the soft processor, its hardware peripherals, and the bus interfaces between them; (2) perform task and interrupt management responsibilities of the operating system when the soft processor is turned off; and (3) selectively wake up the soft processor and its hardware components, and put them into proper activation states based on the hardware resource requirements of the tasks under execution. The implementations of two popular real-time operating systems on a state-of-the-art FPGA device are presented. Measurements on an experimental board show that the proposed power management scheme can lead to significant power savings.

Jingzhao Ou

Papers

Rapid energy estimation for hardware-software codesign using FPGAs

Design space exploration using arithmetic-level hardware--software cosimulation for configurable multiprocessor platforms

A Cooperative Management Scheme for Power Efficient Implementations of Real-Time Operating Systems on Soft Processors