We present a mathematical definition of a hardware description language that admits a semantics-preserving translation to a subset of VHDL. The language is based on the VHDL model of event-driven simulation and includes behavioral and structural circuit descriptions, the basic VHDL propagation delay mechanisms, and both zero and nonzero delays. It has been formally encoded in the computational logic of Boyer and Moore, which provides a LISP implementation as well as a facility for mechanical proof-checking. We prove a number of basic properties of the simulator, which we apply to the analysis of gate-level designs of a one-bit adder and a d-flip-flop.
Full paper: ps, pdf (appeared in Formal Methods in System Design, Special Issue on VHDL Semantics, 1995)