Contract-based system-level composition of analog circuits

Efficient system-level design is increasingly relying on hierarchical design-space exploration, as well as compositional methods, to shorten time-to-market, leverage design re-use, and achieve optimal performances. However, in analog electronic systems, circuit behaviors are so tightly dependent on their interface conditions that accurate system performance estimations based on characterizations of individual stand-alone circuits is a hard task. Since there is no general solution to this problem, analog system integration has traditionally used ad-hoc solutions heavily dependent on designers´ experience. In this paper, we build upon the analog platform-based design methodology by exploiting contracts to enforce correct-by-construction system-level composition. Contracts intuitively capture the thought process of a designer, who aims at guaranteeing circuit performance only under specific assumptions (e.g. loading and dynamic range) on the interface properties. Our approach allows automatic detection and composition of compatible components in a given library. We apply our methodology to an ultra-wide band receiver front-end to show that contracts allow pre-designed IP components to be smoothly integrated and design decisions to be reliably made at a higher abstraction level, both key factors to improve designer productivity.