Fujitsu Corporation

Liang Zhang

Indradeep Ghosh

Koichiro Takayama

Propagating an error through a network includes receiving a network having propagation paths and nodes, where a propagation path has one or more nodes and a node is associated with a variable operable to have a value during simulation. A tag of a tag set is assigned to the value. The tag set includes at least two signed tags, positive tag representing a positive error and a negative tag representing a negative error, and an unsigned tag representing an error having an unknown sign. The tag is propagated along the propagation path to yield intermediate tags, where at least one intermediate tag is an unsigned tag formed from at least two signed tags. A final tag is determined in accordance with the intermediate tags in order to propagate an error through the network.

Propagating an error through a network

Generating a test environment includes accessing initial test environments for a network of nodes, where a test environment specifies a propagation or justification path for a node. The following are repeated until satisfactory coverage is achieved or until a predetermined number of iterations is reached. A coverage for each test environment is calculated, and at least two of the test environments are mated to generate next test environments, where the coverage of the at least two test environments is greater than the coverage of the other test environments.

Generating a test environment for validating a network design

Evaluating a validation vector includes receiving a network having nodes and a target set that includes one or more nodes of the network. The following steps are repeated until the nodes of the target set have been selected. A node is selected from the target set, and a tag is assigned to the node, where the tag represents an error of a value of a variable corresponding to the node. A test environment specifying a propagation path from an input, through the node, and to an output is generated. The test environment is translated into a validation vector, and the tag is propagated to the output according to the validation vector. After repeating the steps, coverage for the validation vectors is determined in accordance with the propagation to evaluate the one or more validation vectors.

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Blacksburg, VA, United States of America

Liang Zhang