Novel rules to derive the signal flow in a VLSI-design are presented. This method is based on design-style independent logical principles, which makes it suitable for circuits that have not been checked on their electrical correctness. The use of two global principles has an important influence for more complicated designs, but also results in an efficiency penalty which may be kept reasonable by introducing graph reduction rules and heuristics. The different steps in the tagging process are explained and illustrated with examples. The dataflow rules are integrated in the overall DIALOG system to perform electrical verification, and they offer an invaluable help to break up the verification problem in subproblems and to cope with feedback in designs, by introducing the concept of intended unilateral blocks.>

This paper discusses the kernel implementation issues of a new and more formal approach to electrical verification. Rule based analysis of the transistor network is applied to derive the signal flow direction and to identify control and state nodes. Symbolic analysis of Boolean expressions, capturing all aspects of switch level networks, allows to take into account the logical structure of the network and its environment during verification and guarantees more relevant error reports. The application of the proposed strategy on real life examples, demonstrates its usefulness and allows for a realistic evaluation of the tool.