Verifying Pipelines with BAT∗

In this chapter, we show how to use the Bit-level Analysis Tool (BAT) [21, 22, 20, 4] for hardware verification. The BAT system has been used in the analysis of systems ranging from cryptographic hash functions to machine code to biological systems to large component-based software systems [24, 13, 19], but here we focus on one application: verification of pipelined hardware systems. This chapter brings together results from previous work in a self-contained way, and is intended as a starting point for someone who is interested in using automatic formal verification tools to prove the correctness of hardware or low-level software. The structure and examples in this chapter are based on previous work by the authors that showed how to use the ACL2 theorem proving system [8] to model and verify pipelined machines [12]. Hardware systems are ubiquitous and are an integral part of safety-critical and security-critical systems. Ensuring the correct functioning of hardware is therefore of paramount importance as failure of deployed systems can lead to loss of life and treasure. A well known example is the bug that was found in the floating point division (FDIV) unit of the Intel Pentium processor and that led to a 475 million