14 research outputs found
Specification, Simulation, and Verification of Timing Behavior
Temporal behavior needs to be formally specified, validated, and verified, if systems that interface with the outside world are to be synthesized from high-level specifications. Due to the high level of abstraction, the work presented in this thesis applies to systems that ultimately can be implemented using hardware, software, or a combination of both. In the area of specification, a generalization of the event-graph specification paradigm is presented. The model supports the expression of complex functionalty using an operational semantics and cleanly integrates structure into the event-based paradigm. Temporal relationships between systems events are specified using a denotational semantics that relies on both chronological and causal relationships to identify the discrete event occurrences bei..
Symbolic Time Separation of Events
We extend the TSE [14] timing analysis algorithm into the symbolic domain, that is, we allow symbolic variables to be used to specify unknown parameters of the model (essentially, unknown delays) and verification algorithms which are capable of identifying not just failure or success, but also the constraints on these symbolic variables which will ensure successful verification. The two main contributions are 1) an iterative algorithm which continuously narrows down the domain of interest and 2) a practical method for reducing the representation of symbolic expressions containing minimizations and maximizations defined for a given domain. We report experimental results for several asynchronous circuits to demonstrate that symbolic analysis is feasible and that the output provided is what a designer (or perhaps a synthesis tool) would often want to know. 1. Introduction This paper presents a novel approach to timing analysis based on a new paradigm we refer to as "symbolic timing verif..
Non-stochastic Analysis of Manufacturing Systems using Timed Event Graphs
Using automated methods to analyze the temporal behavior of manufacturing systems has proven to be essential and quite beneficial
Simplifying Formulas of Linear Inequalities with Boolean Connectives
this paper, we present a methodology for simplifying these formulas in both the Integer and Real domains. Our primary focus will be on the Integer domain (such formulas are commonly known as quantifier-free Presburger formulas) although some simple extensions to our theory and tools enable handling the Real domain as well. Our methodology supports many different formal definitions of simplification. Our primary motivation is to simplify for human readability which encompasses many different formal definitions of simplification (e.g., people have different opinions about how algebraic expressions should be specified and the same is true with regards to expression
Specification and Verification of Temporal Information Using Presburger Formulas
We present a novel set of tools for performing symbolic timing verification of timing diagrams. The tools are multi-purpose with uses in verification, derivation of synthesis constraints, and design evaluation. Our methodology is based on techniques for manipulating Presburger formulas. We demonstrate via examples that Presburger formulas are very expressive and our verification results argue that complexity concerns should not prohibit their use. We also present a novel methodology for simplifying quantifier-free Presburger formulas using logic minimization algorithms thus greatly improving efficiency as well as yielding more readable results. 1 Introduction With regards to temporal behavior and design automation, there are many different problems to be considered. For example, ffi implementation verification -- which confirms that an implementation of a design and its associated delays will meet the constraints in the original specification, ffi interface verification -- which con..
Making Complex Timing Relationships Readable: Presburger Formula Simplification Using Don't Cares
Solutions to timing relationship analysis problems are often reported using symbolic variables and inequalities which specify linear relationships between the variables. Complex relationships can be expressed using Presburger formulas which allow Boolean relations to be specified between the inequalities. This paper develops and applies a highly effective simplification approach for Presburger formulas based on logic minimization techniques
Timing Analysis of Concurrent Systems -- An Algorithm for . . .
A fundamental problem in the synthesis and optimization of concurrent systems is the determination of the separation time between system events. We present a theoretical framework for solving this problem for arbitrary process graphs without conditional behavior and develop an efficient and exact algorithm based on this theoretical foundation. Examples are used to demonstrate the operation and generality of the algorithm