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CSP (Communicating Sequential Processes) is a useful algebraic notation for creating a hierarchical behavioural specification for concurrent systems, due to its formal interprocess synchronization and communication semantics. CSP specifications are amenable to simulation and formal verification by model-checking tools. To overcome the drawback that CSP is neither a full-featured nor popular programming language, an approach called "selective formalism" allows the use of CSP to be limited to specifying the control portion of a system, while the rest of its functionality is supplied in the form of C++ modules. These are activated through association with abstract events in the CSP specification. The target system is constructed using a framework called CSP++, which automatically translates CSP specifications into C++, thereby making CSP directly executable. Thus a bridge is built that allows a formal method to be combined with a popular programming language. It is believed that this methodology can be extended to hardware/software codesign.

To help programmers of high-performance computing (HPC) systems avoid communication-related errors, we employ a formal process algebra, Communicating Sequential Processes (CSP), which has a strict semantics for interprocess communication and synchronization. Verification tools are available for CSP-specified programs to prove the absence of failures such as deadlock, and to explore potential multiprocess interactions. By introducing a CSP abstraction layer on top of the popular MPI message-passing primitives, we create a framework, called CSP4MPI, designed to largely hide the complexity of parallel programming for HPC.CSP4MPI is comprised of a C++ class library that provides a CSP-based process model, and a "cookbook" of candidate solutions for HPC programmers not trained in CSP. Developers can prototype their systems using CSP, and use verification tools to examine possible points of failure before implementing via the CSP4MPI library. Alternatively, they may choose an existing, verified solution from a number of common parallel application archetypes. By using CSP4MPI, HPC developers leverage the benefits of formal specification and verification in their work, in addition to obtaining an alternate method to developing HPC applications.

CSP (communicating sequential processes) is a useful algebraic notation for creating a hierarchical behavioral specification for concurrent systems, due to its formal interprocess synchronization and communication semantics. CSP specifications are amenable to simulation and formal verification by model-checking tools. A translator has been created to synthesize C++ code from CSP for execution with an object-oriented framework called CSP++, thereby making CSP specifications directly executable. To overcome the drawback that CSP is neither a full-featured nor popular programming language, an approach called "selective formalism" allows the use of CSP to be limited to specifying the control portion of a system, while the rest of its functionality is supplied in the form of C++ modules. These are activated through association with abstract events in the CSP specification. This is a new means of bringing convergence between a formal method and a popular programming language. It is believed that this methodology can be extended to hardware/software codesign for embedded systems.

The Canadian Microelectronics Corporation' has developed and distributed a Rapid Prototyping Board (RPB) to facilitate research in iYardware/Software (HW/SW) Codesign, case studies, applications and prototyping of projects in embedded systems. This research develops a series of layers between hardware and software, exploiting the dynamically reconjigurable hardware of the RPB and creating the connection to host processes and software layers in general, both on the board itself; and between a HW/SW system downloaded to the board and its host workstation. In this paper we describe a new approach which uses 'This work is supported by research grants from NSERC (Natural Science and Engineering Research Council) and equipment loans from CMC (Canadian Microelectronics Corporation). CMC is the primary govemment agency fostering microelectronics research in Canadian universities.object oriented technology as the basis for the system design methodology, the specijications and the implementation, providing a jlexible and dynamic foundation, lending itself to further expansion and research in HW/SW codesign.