Looking into the Crystal Ball: From Transistors to the Smart Earth

Abstraction: reduce thenumber of items by aggre-gating objects and by elimi-nating unnecessary detailswith respect to the goal athand. h Refinement: proceed froman abstract representationof the design towards animplementation by addingdetails.Complexity has been also man-aged by ‘‘construction’’: by con-straining ‘‘artificially’’ the design space (i.e.,imposing regular layout, or synchronous designs),and starting high in the abstraction layers, it ispossibletodefineanumberofrefinementstepsthat go from the initial description to the finalimplementation that can be performed automat-ically with the use of sophisticated tools. Forexample, the digital design flow in use todaymarches from a high-level description of the func-tion to be performed using appropriate languagestowards a synchronous gate-level representationobtained by logic synthesis to a transistor layout,via automatic place and route made possible byrestricting the position of transistors in regularpatterns that are stored in appropriate, fully charac-terized libraries.Figure 4. Platform-based design.Figure 3. The V-diagram.Figure 5. The swarm as a platform (courtesy ofJan Rabaey).