Cadence Design Systems, Inc.
Method to improve testability using 2-dimensional exclusive or (XOR) grids

Abstract:

Methods and design system for generating 2-dimensional distribution architecture for testing integrated circuit design that utilizes double grid to minimize interdependencies between grid cells and the associated functional logic to facilitate the a physically efficient scan of integrated circuit designs, that simultaneously minimizes required test application time ("TAT"), test data volume, tester memory and cost associated with design for test ("DFT"), while also retaining test coverage. An additional grid parallel to a 2-dimensional XOR grid may be implemented that improves the quality of test coverage by optimally adding additional data inputs which decreases correlations between grid cells. A column spreader may feed data into column wires and row spreader may feed data into column wires. The double grid allows data to be fed into two wires, row and column, respectively, which provides twice as much stimulus data in each direction, without significantly increasing the wiring used to build the grid.