An algorithm that implicitly searches the flattened VLSI netlist data space without first constructing it is presented. In traditional methods, the entire search space of size n (e.g. the total number of instances) is constructed explicitly to allow a fast O(1) query time. The new algorithm uses circuit hierarchy to prune the search effectively. It is shown that the size of a hierarchical netlist is o(n), and a query can be executed in O(1) amortized time.>

A hierarchical search software package that allows an application to retrieve flattened netlist data from a hierarchical netlist database. An algorithm is presented that implicitly searches the entire VLSI CAD net list data space without first constructing it. While traditional methods construct the entire search space explicitly, which helps to achieve a fast O(1) query time but requires Omega (n) space, this method relies on the circuit hierarchy to prune the search effectively. It is shown that the hierarchical net list data space is smaller by a factor of O(n/sup epsilon /). Where O>

A design data manager is emerging as an important component of an integrated CAD system. The authors present a semantic data model and an architecture for VLSI/CAD databases. The data model provides mechanisms to represent the design entities the relationships among them in a unified way. A key feature of the system architecture is that it exploits design hierarchy to provide high performance. A data manager based on this model has been implemented and used by a set of diverse applications. In conjunction with efficient data flow, the data manager can serve to improve software productivity.>