A real time operating system for DSP applications

Usually, real-time software applications consist of periodic and sporadic tasks queued/activated/stopped by a scheduler which ensures a minimum task-switching overhead. The scheduler policy should optimise determinism and predictability in order to allow analysis and simulation activities leading to forecast the software behaviour, upon each internal/external event/exception, with proper accuracy. In particular, the implementation of control algorithms requires a scheduler strategy based on a robust cyclic scheduling engine running on the basis of a timeline table. On the other hand, the necessity to handle sporadic events requires the scheduler capability to manage asynchronous tasks. RTE21020, object of this paper, is a real time operating system developed for DSP21020, whose task management has the characteristics listed before.