One embodiment of the present invention provides a method and a system
that facilitates structural coverage of a design during a design
verification process. During operation, the system receives a hardware
description of the design, which contains one or more module instances
and a set of structural coverage targets for a set of structures in the
design. The system then extracts a control flow, the set of structural
coverage targets, and a set of structural coverage metrics for the
hardware description, and creates a shadow module with the same control
flow as the hardware description. This shadow module contains a set of
parallel structures that correspond to the set of structural coverage
targets in the control flow of the hardware description and serve as
targets for formal methods used to analyze the design. The system also
generates a set of cross-module references to link the set of parallel
structures in the shadow module with signals from the set of structures
in the hardware description. The system then applies a formal
verification tool to the design, including the shadow module and the
cross-module references in an attempt to achieve the desired structural
coverage.