A design approach for real-time signal processing software

The process-resource approach to system software design is described and illustrated using a simple finite-impulse response filter design example. Process-resource design is essentially an object-oriented system design approach, i.e. the system is viewed as a collection of concurrent activities called objects. The system is decomposed into processes and resources using data flow analysis techniques. Resources `source´ and `sink´ data to and from processes, respectively. Processes initiate data flow transactions to and from resources and process the data. Most resources are passive and respond to initiatives from the processes. After defining the functional specification of a system from a user requirement, a data flow analysis is performed. The first-level system analysis follows directly from the functional specification. After the processes, resources and their operations are specified and designed, coding can begin. The approach is iterative, progressively describing the system in greater detail. This enables the designer to break the system down into manageable entities and simplifies project management. The initial overhead in the earlier design stages pays for itself in the end, as it leads to well-structured, reliable and reusable software