Open Access

Martin Frieb

• The requirements for today's embedded hard real-time systems are high: They should deliver high performance, be energy-efficient and always react in time. This leads to the use of processors with several cores. However, when the cores are connected via a shared memory, static timing analysis suffers from high pessimism. We see distributed memory many-core processors as a solution where cores communicate via messages. One of them is the Reduced Complexity Many-Core (RC/MC) architecture. It was developed with the goal of high timing predictability. In our thesis, we present an approach to estimate the Worst-Case Execution Time (WCET) of programs running on this platform. Furthermore, we extend the RC/MC to improve its timing predictability and its worst-case performance. Our first step is the introduction of ready synchronization, which avoids buffer overflows. Second, we design hardware support for broadcasts and multicasts. Third, the RC/MC is extended with hardware supportedThe requirements for today's embedded hard real-time systems are high: They should deliver high performance, be energy-efficient and always react in time. This leads to the use of processors with several cores. However, when the cores are connected via a shared memory, static timing analysis suffers from high pessimism. We see distributed memory many-core processors as a solution where cores communicate via messages. One of them is the Reduced Complexity Many-Core (RC/MC) architecture. It was developed with the goal of high timing predictability. In our thesis, we present an approach to estimate the Worst-Case Execution Time (WCET) of programs running on this platform. Furthermore, we extend the RC/MC to improve its timing predictability and its worst-case performance. Our first step is the introduction of ready synchronization, which avoids buffer overflows. Second, we design hardware support for broadcasts and multicasts. Third, the RC/MC is extended with hardware supported barriers. Each of these techniques is evaluated for its impact. We carry out timing analyses of the hardware operations for broadcasts/multicasts and barriers and compare them with their variants without hardware support. Finally, we present three case studies, where we analyze benchmarks taken from the NAS parallel benchmark suite to evaluate the worst-case performance of our extensions in the context of real use cases.…