A program state machine based virtual processing model in SystemC

Abstract

The Program State Machine (PSM) Model of Computation offers a rich set of modeling elements to describe behavioral and structural hierarchy, concurrency, synchronization, state transitions and timing. With the rising software complexity of today's embedded systems, the use of Real-Time Operating Systems (RTOS) has become state-of-the-art for nearly all System-on-Chip designs. Regrettably, the PSM model itself has insufficient support for the specification of the preemptive dynamic scheduling behavior of an RTOS. In this paper, we propose a model for dynamically dispatching PSM models on a virtual processing element. Our model aims to abstract from the targeted RTOS and the processor core through execution time annotations and a flexible preemptive scheduler model. Mapping a PSM model to a set of scheduled virtual processing elements only requires minor model transformation and enables early exploration of different processing element mappings and scheduling policies. Our virtual processing model for PSMs is realized on top of the SystemC library. We evaluate the proposed virtual processing model using a Canny edge detection filter.