This paper presents a new verification methodology to prove that a high level HDL description of a synchronous sequential circuit satisfies certain desired behavior or that it is free of certain malicious behavior. The correctness specifications are modeled as state machines with some transitions having unspecified inputs. We show that this suffices for specification of a large class of properties, including both safety and liveness properties. The properties are described as VHDL programs to enable the designer to simulate them for sample inputs and gain some measure of confidence in their correctness. Experimental results are presented for the Viper microprocessor.