This paper presents a practical approach to communication synthesis for hardware/software system specified as tasks communicating through lossless blocking channels. It relies on a limited set of templates that characterize the way data are exchanged between tasks realized either in software or in hardware. The templates are highly portable because their software part is implemented using the POSIX thread functions, and their hardware part is a hand crafted synthesizable module with a System VCI interface. These interface modules allow simple virtual component reuse since they not only implement protocol compatibility through the use of the System VCI/OCB standard but also system level communications through semantics widely accepted in the design community.