System-Level Design:Predicting System Characteristics

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Predicting System Characteristics

In system-level design, early prediction gives designers the freedom to make numerous high-level choices (such as die size, package type, and latency of the pipeline) with confidence that the final implementation will meet power and energy as well as cost and performance constraints. These predictions can guide power budgeting and subsequent synthesis of various system components, which is critical in synthesizing systems that have low power dissipation, or long battery life. The use by synthesis programs of performance and cost lower bounds allows smaller solution spaces to be searched, which leads to faster computation of the optimal solution.

System cost, performance, power consumption, and design time can be computed if the properties of each system module are known. System design using existing modules requires little prediction. If system design is performed prior to design of any of the contained system modules, however, their properties must be predicted or estimated. Owing to the complexities of prediction techniques, describing these techniques is a subject worthy of an entire chapter. A brief survey of related readings is found in the next section.

The register-transfer and subsequent lower level power prediction techniques such as gate- and transistor- level techniques are essential for validation before fabricating the circuit. However, these techniques are less efficient for system-level design as a design must be generated before prediction can be done.

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