Jens Rettkowski: Design and Programming Methods for Reconfigurable MPSoCs using a NoC-centric Approach (PhD Defense)

29.11.2021, 14:15 pm

Invitation to the PhD defense of Mr. Jens Rettkowski

Topic: Design and Programming Methods for Reconfigurable MPSoCs using a NoC-centric Approach

Supervisor: Prof. Dr.-Ing. Diana Göhringer

Abstract: A lot of applications gain performance advantages by executing parallel tasks on Multiprocessor Systems-on-Chip (MPSoCs) due to inherent parallelism. Moreover, heterogeneous structures provide high performance/energy efficiency, since application-specific processing elements (PEs) can be exploited. The increasing number of PEs in MPSoCs leads to challenging communication requirements. To overcome this challenge, Networks-on-Chip (NoCs) have emerged as scalable on-chip interconnects. Nevertheless, NoCs have to deal with many design parameters such as virtual channels, routing algorithms and buffering techniques to fulfill the system requirements. 

In the following, the major contributions of this work are introduced. As a first major contribution, a novel router concept is presented that efficiently utilizes communication times by performing sequences of arithmetic operations on data that is transferred. The internal input buffers of the routers are exchanged with processing units that are capable of executing operations. Two different architectures of such processing units are presented. The first architecture provides multiply and accumulate operations which are often used in signal processing applications. The second architecture introduced as Application-Specific Instruction Set Router (ASIR) contains processing units capable of executing any operation that can be developed in C/C++ and synthesized using high-level synthesis. 

Furthermore, two applications using an ASIR-based MPSoC are implemented and evaluated on a Xilinx Zynq SoC. The first application is an image processing algorithm consisting of a Sobel filter, an RGB-to-Grayscale conversion, and a threshold operation. The second application is a system that helps visually impaired people by navigating them through unknown indoor environments. A Light Detection and Ranging (LIDAR) sensor scans the environment, while Inertial Measurement Units (IMUs) measure the orientation of the user to generate an audio signal that makes the distance as well as the orientation of obstacles audible. This application consists of multiple parallel tasks that are mapped to an ASIR-based MPSoC. Both applications show the performance advantages of ASIRs compared to a conventional NoC-based MPSoC. Moreover, dynamic partial reconfiguration in terms of relocation and security aspects are investigated. The third major contribution refers to development and programming methodologies of NoC-based MPSoCs. A software-defined approach is presented that combines the design and programming of heterogeneous MPSoCs. In addition, a Kahn-Process Network (KPN) –based model is designed to describe parallel applications for MPSoCs using ASIRs. The KPN-based model is extended to support not only the mapping of tasks to NoC-based MPSoCs but also the mapping to ASIR-based MPSoCs.