A Refinement Approach to Design and Verification of On-Chip Communication Protocols

Abstract

Abstract-Modern computer systems rely more and more on on-chip communication protocols to exchange data. To meet performance requirements these protocols have become highly complex, which usually makes their formal verification infeasible with reasonable time and effort.We present a new refinement approach to on-chip communication protocols that combines design and verification together, interleaving them hand-in-hand. Our modeling framework consists of design steps and design transformations formalized as finite state machines. Given a verified design step, transformations are used to extend the system with advanced features. A design transformation ensures that the extended design is correct if the previous system is correct. This approach is illustrated by an arbiter-based master-slave communication system inspired by the AMBA High-performance Bus architecture. Starting with a sequential protocol design, it is extended with pipelining and burst transfers. Transformations are generated from design constraints providing a basis for correctness-by-design of the derived system.

A symbolic execution framework for algorithm-level modelling

“…Using AsmL as a starting point, we have designed and implemented a protoype ASL environment that supports native symbolic execution and a rich collection of language constructs. We have exercised our system, and driven its design through a series of case studies, including the μop scheduler, a model of the AMBA protocol [21], and Lamport's bakery mutex protocol. We are planning to scale up our case studies and focus our efforts on methodology for ALM refinement down to design models.…”

Towards a formally verified network-on-chip

“…Regarding buses, the recent work of Böhm and Melham is the only effort trying to fill the gap between abstract specifications and low level implementations [3]. Previous efforts concentrate on proving properties on low-level implementations using model-checking [11] or combination of model-checking with theorem proving [1].…”