摘要 |
A method for utilizing an XOR network for testing internal nodes of a die wherein the nodes are connected to the input ports of the XOR network. The nodes are chosen by an iterative algorithm whereby the toggled, but not observed nodes, are partitioned into subsets belonging to a test hierarchy whereby the largest subset in the hierarchy is chosen. Based upon this largest subset, a first and second node set is constructed. A functional test is performed wherein the first and second node set, respectively, are inputs and outputs. The second node set serves as inputs to the XOR network. Deeper levels of hierarchies are created if the functional test on the first an second node sets do not meet a fault coverage criterion, or if the hierarchy level is too large, where the deeper test hierarchy is constructed from the largest subset associated with a less deep hierarchy. |