Heterogeneous and runtime parameterizable Star-Wheels Network-on-Chip

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.