An Algorithm for Process Partitioning and Deadline Assignment of a Dataflow Application

The design of an embedded real-time application can be divided in three phases. In the first phase, the functional aspects of the application are specified, usually by means of a dataflow-like formalism. In the second phase, the architecture of the system is specified in terms of hardware capability, RTOS to be used, etc. In the last phase, the functional specification is mapped on to the system architecture and the performance of the system is evaluated. This operation is usually done manually. Moreover, there is no automatic tool to support that permits to evaluate the correctness of the mapping and the resulting performance. In this paper, we present a general dataflow model that allows the designer to assign real-time constraints in the early phase of the design. Then we present a simple algorithm that automatically maps a dataflow specification onto a set of realtime tasks to be executed in a RTOS. The algorithm is based on the assumption that the RTOS provides EDF scheduling. A schedulability analysis is presented that permits to evaluate if the temporal constraints can be met.