Abstract:Energy efficient embedded systems consist of a heterogeneous collection of very specific building blocks, connected together by a complex network of many dedicated busses and interconnect options. The trend to merge multiple functions into one device makes the design and integration of these "systemson-chip" (SOC's) even more challenging. Yet, specifications and applications are never fixed and require the embedded units to be programmable. The topic of this chapter is to give the designer architectures and design techniques to find the right balance between energy efficiency and flexibility. The key is to include programmability (or reconfiguration) at the right level of abstraction and tuned to the application domain. The challenge is to provide an exploration and programming environment for this heterogeneous architecture platform.