HW/SW Codesign and Design, Evaluation of Software Framework for AcENoCs : An FPGA-Accelerated NoC Emulation Platform

Majority of the modern day compute intensive applications are heterogeneous in nature. To support their ever increasing computational requirements, present day System-on-Chip (SoC) architectures have adapted multicore style of modeling, thereby incorporating multiple, heterogeneous processing cores on a single chip. The emerging Network-On-Chip (NoC) interconnect paradigm provides a scalable and power-efficient solution for communication among multiple cores, serving as a powerful replacement for traditional bus based architectures. A fast, robust and exible emulation platform is the key to successful realization and validation of such architectures within a very short span of time. This research focuses on various aspects of Hardware/Software (HW/SW) codesign for AcENoCs (Accelerated Emulation Platform for NoCs), a Field Programmable Gate Array (FPGA) accelerated, con gurable, cycle accurate platform for emulation and validation of NoC architectures. This work also details the design, implementation and evaluation of AcENoCs' software framework along with the various design optimizations carried out and tradeoffs considered in AcENoCs' HW/SW codesign for achieving an optimum balance between emulated network dimensions and emulation performance. AcENoCs emulation platform is realized on a Xilinx Virtex-5 FPGA. AcENoCs' hardware framework consists of the NoC built using configurable hardware library components, while the software framework consists of Traffic Generators (TGs) and their associated source queues, Traffic Receptors (TRs) along with statistics analysis module and dynamically controlled emulation clock generator. The software framework is implemented using on-chip Xilinx MicroBlaze processor. This report also describes the interaction between various HW/SW events in an emulation cycle and assesses AcENoCs' performance speedup and tradeoffs over existing FPGA emulators and software simulators. FPGA synthesis results showed that networks with dimensions upto 5x5 could be accommodated inside the device. Varying synthetic traffic workloads, generated by TGs, were used to evaluate the network. Real application based traces were also run on AcENoCs platform to evaluate the performance improvement achieved in comparison to software simulators. For improving the emulator performance, software profiling was carried out to identify and optimize the software components consuming highest number of processor cycles in an emulation cycle. Emulation testcases were run and latency values recorded for varying traffic patterns in order to evaluate AcENoCs platform. Experimental results showed emulation speedups in order of 10000-12000X over HDL (Hardware Description Language) simulators and 14-47X over software simulators, without sacri cing cycle accuracy.