Specification and design of complex digital systems

Abstract

A methodology for generating structural descriptions of complex digital devices from high-level descriptions and specifications is disclosed. The methodology uses a systematic technique to map and enforce consistency of the semantics imbedded in the intent of the original, high-level descriptions. The design activity is essentially a series of transformations operating upon various levels of design representations. At each level the intended meaning (semantics) and formal software manipulations are captured to derive a more detailed level describing hardware meeting the design goals. Important features of the methodology are: capturing the users concepts, intent, specification, descriptions, constraints and trade-offs; architectural partitioning; what-if analysis at a-high level; sizing estimation; timing estimation; architectural trade-off; conceptual design with implementation estimation; and timing closure. The methodology includes using estimators, based on data gathered over a number of realized designs, for partitioning and evaluating a design prior to logic synthesis. From the structural description, a physical implementation of the device is readily realized. The methodology further includes an automated interactive, iterative technique for creating a system-level specification in a directly-executable formal specification language. This technique makes use of formal verification and feasibility analysis techniques to iteratively refine the specification prior to implementation. This iterative refinement eliminates many ambiguities and inconsistencies from the specification, and ensures that there is at least one realizable implementation of the specification. The formal verification techniques are further employed to ensure that as the design progresses, compliance with the specification is maintained, and that any specification change is reflected and accounted for, both system-wide and implementation-wide.