Fault-diagnosis-based technique for establishing RTL and gate-level correspondences

In this paper, we address an important problem associated with hierarchical design flows (termed the mapping problem): identifying correspondences between a signal in a high-level specification and a net in its lower level implementation. Conventional techniques use shared names to associate a signal with a net whenever possible. However, given that a synthesis flow may not preserve names, such a solution is not universally applicable. This work provides a robust framework for establishing register-transfer level (RTL) signal to gate-level net correspondences for a given design. Our technique exploits the observation that circuit diagnosis provides a convenient means for locating faults in a gate-level network. Since our problem requires locating gate-level nets corresponding to RTL signals, we formulate the mapping problem as a query whose solution is provided by a circuit diagnosis engine. Our experimental work with industrial designs for many mapping cases shows that our solution to the mapping problem is 1) fast and 2) precise in identifying the gate-level equivalents (the number of nets returned by our mapping engine for a query is typically one or two even for designs with tens of thousands of VHDL lines)