Real-Time Operating System Kernel for Multithreaded Processor

In embedded system development, multithreaded processors are used for further performance improvement to satisfy large-scale and sophisticated applications. PRESTOR-1, a multithreaded processor we developed, has a mechanism, a processor context buffer (PCB), that accommodates thread contexts spilt from built-in context slots. Threads/tasks located in the PCB are controlled and swapped for built-in active contexts fully by hardware control and performance of a system with many threads/tasks can be enhanced. Our RTOS kernel that is compatible with the ITRON specification is extended to utilize the PRESTOR-1 multithreaded architecture including the PCB mechanism and several extended instructions. Evaluation for execution with PCB showed higher performance than single-thread execution or multithreaded execution without PCB in spite of more cache misses