This paper gives an overview of a transaction level modeling (TLM) design flow for straightforward embedded system design with SystemC. The goal is to systematically develop both application-specific HW and SW components of an embedded system using the TLM approach, thus allowing for fast communication architecture exploration, rapid prototyping and early embedded SW development. To this end, we specify the lightweight transaction-based communication protocol SHIP and present a methodology for automatic mapping of the communication part of a system to a given architecture, including HW/SW interfaces.