Formalising the Design of an SECD chip

We describe work completed on a custom SECD chip which is powerful enough to run a LispKit compiler. The 20,000 transistor design was fabricated in 1988 and is being interfaced to a workstation so that it can run downloaded programs. We discuss the evolution of the architecture from its abstract specification and abstraction issues that arose at key levels in the verification of the design. The verification is being undertaken in Cambridge HOL. One hard issue (garbage collection) has been left over for a second iteration of the specification and verification.