AUTOMOTIVE ELECTRONIC DESIGN
Application space Application instance
System platform (hardware and software)
Platform design space export
Platform instances Architectural space
Figure 3. Platform-based design.
Programming model: models or estimators
Kernels or benchmarks
Cycle speed, power, area
Functional blocks, interconnect
Silicon implementation platform
Delay, variation, Spice models
Basic device and interconnect structures
Figure 4. Platform stack.
design process is the stepwise refinement of a specification into a lower-level abstraction chosen from a restricted library, or platform, of available components. Components are computational blocks and interconnections.
In this view, a platform is a design family, not a single design. A platform defines the explorable design space. Once we select a par- ticular collection of platform components, we obtain a platform instance. As Figure 3 shows, we can obtain multiple platform instances in refining a platform. The choice of the plat- form instance and the mapping of the speci- fication components defining the application of interest into the platform instance compo- nents constitute the top-down process. This process maps constraints accompanying the specification into constraints on the platform instance components. Platform mapping often involves budgeting because we might have to distribute a global constraint among a set of components.
Stepwise refinement continues by defining the selected platform instance as a specifica- tion and using a lower-level platform to march toward implementation. When a component is fully instantiated, stepwise refinement stops, because the designer then has an implemen- tation for that component.
In selecting a platform instance and map- ping constraints using budgeting, it is impor- tant to guide the selection with parameters that summarize the platform component charac- teristics. Dela , power consumption, size, and cost are examples of such parameters. When selecting a platform instance, the designer must quickly and accurately evaluate the design’s potential performance. Thus, the selection of the guiding parameters is a critical part of plat- form-based design. In Figure 3, this process is called platform design space export.
It is possible to automate the selection of components and the verification of consisten- cy between the specification behavior and the platform instance behavior. To do so, design- ers must find a common semantic domain between the behavior and the platform so that the selection process becomes a covering prob- lem—that is, the selection of platform com- ponents is an effort to cover the entire design functionality with one or more platform ele- ments. The concepts of platform-based design can apply to the entire design process, even