Well-foundedness in Credit-Based Flow-Control Systems

Formal verification of liveness properties of practical communication fabrics are generally intractable with present day bit-level verification tools. We focus on a particular type of liveness called response. We show that a well-founded relation can be extracted from a high-level design of a communication fabric. This well-founded relation yields a set of local safety assertions, which are more easily provable, and lead to a formal proof of response. Our target systems are credit-based flow-control networks. Preliminary results are encouraging. We present case studies taken from this family and experimental results of response verification of large networks using a bit-level formal verifier.