Scalable asynchronous hardware protocol verification for compositions with relative timing

Correct interaction of asynchronous hardware protocols requires verification. Performance and power of asynchronous hardware circuits and protocols can be vastly improved by modifying them with judicious application of timing constraints. A methodology is presented for verifying larger asynchronous protocols through compositional model checking with symbolic methods. This approach uses Relative timing constraints for modeling timed asynchronous hardware protocols and hence is generic for timed and untimed protocols. This paper illustrates the modeling technique for interleaving and simultaneous models with relative timing, which helps in pruning state space. Properties which are verified for ensuring correctness of composed models are explained. Case studies of a linear pipeline controller and CElement are discussed by applying BDD and SAT methods. The simultaneous model yields better execution times when compared to interleaving for large number of compositions. In the simultaneous model, SAT methods tend to find a counter example in lesser time than BDD methods. Automatic model and property generation, leading to push button solution will enable verification of larger control planes.