Formal Design of Cache Memory Protocols in IBM

We describe the formal design techniques currently used in IBM to develop cache protocol controllers for high-end servers. In our approach to formal design, formal specification and verification methods are incorporated into the hardware design process, starting from the earliest stages of a hardware project. We describe collaborations between a formal methods expert and hardware designers on two high performance server projects. Properties of the design are verified using both manual proof techniques and model checking. We discuss the modelling and model checking techniques we have developed and indicate future directions.