Analysis and improvement of task schedulability in hardware/software codesign

Many real time systems have timing requirements that are difficult to fulfil if the system is implemented by software running on a microprocessor. One way to remedy this problem is to implement the most time critical parts in application specific integrated circuits instead. Hardware/software codesign aims at providing support for the designer of such a heterogeneously implemented system, and especially at finding ways to determine what parts should be implemented in what technology. We discuss an approach to codesign which has as its objective to find an implementation of a real time system, which allows the deadlines to be met. The main result presented is a schedulability evaluation method, and we describe how this can be used to guide the partitioning of the system behaviour onto the different components of a hardware architecture