This paper presents a knowledge based approach to computer aided specification of analog and digital components. It provides support and control for the development of requirement specifications and environment descriptions as well as for high level system description. As this approach is intended to support micrcsystem designs, it provides 8 unique specification model for analog, digital, optoelectronical, actuator and sensor components. Object-oriented data representation and rule-based 'consistency checking enable the management of requirements and design results as well as early and simulation independent evaluation. The development is part of the DEBYS (DEsign BY Specification) project for an integrated specification, estimation, design, analysis and test system.
lntroductlonThe increasing complexity of integrated systems, especially the integration of mixed analog/digital, components on one chip demand computer support for high level design phases as well as an integrated design, analysis and test environment Computer support has to be extended towards feasibility study, environment description and requirement specification. Extaordinary marginal conditions have to be considered during design and verification. Furthermore, adequate test strategies, test methods and test systems have to be developed.The integration of analog and digital components into one ASIC offers high demands to a computer aided design process. As the design processes for each of these component types differ crucially, specific design, analysis and test tools have to be combined within a common specification, estimation and design management environment. Although the state of analog synthesis tools is quite primitive in comparison with digital synthesis tools, a number of new analog design tools (for example /SED88/, PEG89/, /CAR89/, /BER89/) promise essential progress in analog design, at least for designs that do not stress the limits of technology or performance. For the design of mixed analog/digitaI systems these mls together with digital design aids have to be embedded into a design environment that provides acquisition and checking of requirements and environment descriptions as well as partitioning and hierarchical organization of components. This environment provides an interface between the component specific design processes and therefore serves as a requirement transformation and evaluation medium.Many present day computer-aided systems for designing analog as well as digital components are based on an algorithmic approach to information transformation between different levels of abstraction. Although this proved to be a powerful approach for the lower level design phases, the early design phases of feasibility study, requirement specification and early design estimation, characterized by uncertainty, incompleteness and temporal inconsistency mandate flexible, knowledge based approaches.DEBYS (DEsign BY Specification) is an integrated specification, design, verification and test system for microsystem (analog, digital, optoe...
