Computing Delay with Coupling Using Timed Automata

Deep sub-micron circuits place new requirements on timing analysis tools: More accuracy is needed and new effects such as pattern dependent delays and cross-talk must be modeled. We propose a timed-automaton-based approach for computing delays of combinational circuits. Timed automata are used to represent delay models of circuit componentsand cross-talk effects, as well as sets of waveforms at nodes of the circuit. The uniform framework offered by timed automata has the advantage that accuracy and complexity can be traded-off without needing to change the algorithms used in the analysis. The expressiveness of timed automata is very useful for modeling deep sub-micron effects, however, analysis with timed automata has suffered from complexity problems and has been limited to systems with tens of components. To alleviate this problem, we propose a method that mimics image computation across a Boolean network and argue that by adopting a hierarchical view of combinational circuits and by using a proper set of heuristics for image computation, delay analysis with timed automata can be made practical.

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