Patent application number | Description | Published |
20080215943 | Generating test sets for diagnosing scan chain failures - Embodiments of the disclosed technology comprise software-based techniques that can be used to improve scan chain test pattern generation and scan chain failure diagnosis resolution. For example, certain embodiments can be used to generate high quality chain diagnosis test patterns that are able to isolate a scan chain defect to a single scan cell. Such embodiments can be used to generate a “complete” test set—that is, a set of chain diagnosis test patterns that is able to isolate any scan chain defect in a faulty scan chain to a single scan cell. | 09-04-2008 |
20090235134 | TEST PATTERN GENERATION FOR DIAGNOSING SCAN CHAIN FAILURES - Embodiments of the disclosed technology comprise techniques that can be used to generate scan chain test patterns and improve scan chain failure diagnosis resolution. For example, certain embodiments can be used to generate high quality chain diagnosis test patterns that are able to isolate a scan chain defect to a single scan cell. At least some embodiments can be used to locate faults over multiple capture cycles in the scan chain. | 09-17-2009 |
20100293422 | Method And System For Scan Chain Diagnosis - Scan chain diagnosis techniques are disclosed. Faulty scan chains are modeled and scan patterns are masked to filter out loading-caused failures. By simulating the masked scan patterns, failing probabilities are determined for cells on a faulty scan chain. One or more defective cells are identified based upon the failing probability information. A noise filtering system such as the one based upon adaptive feedback may be adopted for the identification process. | 11-18-2010 |
20110191643 | Detection And Diagnosis Of Scan Cell Internal Defects - A diagnosis technique to improve scan cell internal defect diagnostic resolution using scan cell internal fault models. | 08-04-2011 |
20110307751 | Profiling-Based Scan Chain Diagnosis - Profiling-based scan chain diagnosis techniques are disclosed. With various implementations of the invention, unloading masking information for each of scan patterns is first determined. A tester then applies the scan patterns to a circuit under test and collects test response data according to the unloading masking information. A profiling-based analysis is performed to determine failing scan cell information based on the test response data. | 12-15-2011 |
20120210184 | Compound Hold-Time Fault Diagnosis - Aspects of the invention relate to techniques for diagnosing compound hold-time faults. A profiling-based scan chain diagnosis may be performed on a faulty scan chain to determine observed scan cell failing probability information and one or more faulty segments based on scan pattern test information. Calculated scan cell failing probability information may then be derived. Based on the calculated scan cell failing probability information and the observed scan cell failing probability information, one or more validated faulty segments are verified to have one or more compound hold-time faults. Finally, one or more clock defect suspects may be identified based on information of the one or more validated faulty segments. | 08-16-2012 |
20120216088 | GENERATING TEST SETS FOR DIAGNOSING SCAN CHAIN FAILURES - Embodiments of the disclosed technology comprise software-based techniques that can be used to improve scan chain test pattern generation and scan chain failure diagnosis resolution. For example, certain embodiments can be used to generate high quality chain diagnosis test patterns that are able to isolate a scan chain defect to a single scan cell. Such embodiments can be used to generate a “complete” test set—that is, a set of chain diagnosis test patterns that is able to isolate any scan chain defect in a faulty scan chain to a single scan cell. | 08-23-2012 |
20120233512 | Two-Dimensional Scan Architecture - Aspects of the invention relate to techniques of using two-dimensional scan architecture for testing and diagnosis. A two-dimensional scan cell network may be constructed by coupling input for each scan cell to outputs for two or more other scan cells and/or primary inputs through a multiplexer. To test and diagnose the two-dimensional scan cell network, the two-dimensional scan cell network may be loaded with chain patterns and unloaded with corresponding chain test data along two or more sets of scan paths. Based on the chain test data, one or more defective scan cells or defective scan cell candidates may be determined. | 09-13-2012 |
20130080849 | TEST PATTERN GENERATION FOR DIAGNOSING SCAN CHAIN FAILURES - Embodiments of the disclosed technology comprise techniques that can be used to generate scan chain test patterns and improve scan chain failure diagnosis resolution. For example, certain embodiments can be used to generate high quality chain diagnosis test patterns that are able to isolate a scan chain defect to a single scan cell. At least some embodiments can be used to locate faults over multiple capture cycles in the scan chain. | 03-28-2013 |
20130145213 | Dynamic Design Partitioning For Diagnosis - Aspects of the invention relate to techniques for fault diagnosis based on dynamic circuit design partitioning. According to various implementations of the invention, a sub-circuit is extracted from a circuit design based on failure information of one or more integrated circuit devices. The extraction process may comprise combining fan-in cones of failing observation points included in the failure information. The extraction process may further comprise adding fan-in cones of one or more passing observation points to the combined fan-in cones of the failing observation points. Clock information of test patterns and/or layout information of the circuit design may be extracted and used in the sub-circuit extraction process. The extracted sub-circuit may then be used for diagnosing the one or more integrated circuit devices. | 06-06-2013 |
20130166976 | Diagnosis-Aware Scan Chain Stitching - Aspects of the invention relate to techniques for determining scan chains that could be diagnosed with high resolution. A circuit design and the information of scan cells for the circuit design are analyzed to determine information of potential logic relationship between the scan cells. The information of potential logic relationship between the scan cells may comprise information of fan-in cones for the scan cells. Based at least in part on the information of potential logic relationship between the scan cells, scan chains may be formed. The formation of scan chains may be further based on layout information of the circuit design. The formation of scan chains may be further based on compactor information of the circuit design. | 06-27-2013 |
20130219216 | Hybrid Memory Failure Bitmap Classification - Aspects of the invention relate to techniques for classifying memory failure bitmaps using both rule-based classification and artificial neural network-based classification methods. The rule-based classification method employs classification rules comprising those for global failure patterns. The artificial neural network-based classification method classifies local failure patterns. One of the artificial neural network models is the Kohonen self-organizing map model. The input vector for a failure pattern may contain four elements: pattern aspect ratio, failing bit ratio, dominant failing column number and dominant failing row number. | 08-22-2013 |
20130246869 | ENHANCED DIAGNOSIS WITH LIMITED FAILURE CYCLES - Chain or logic diagnosis resolution can be enhanced in the presence of limited failure cycles using embodiments of the various methods, systems, and apparatus described herein. For example, pattern sets can be ordered according to a diagnosis coverage figure, which can be used to measure chain or logic diagnosability of the pattern set. Per-pin based diagnosis techniques can also be used to analyze limited failure data. | 09-19-2013 |
20140115413 | FAULT DICTIONARY BASED SCAN CHAIN FAILURE DIAGNOSIS - A dictionary-based scan chain fault detector includes a dictionary with fault signatures computed for scan cells in the scan chain. Entries in the fault dictionary are compared with failures in the failure log to identify a faulty scan cell. In one embodiment a single fault in a scan chain is identified. In another embodiment, a last fault and a first fault in a scan chain are identified. | 04-24-2014 |
20140164859 | Dynamic Design Partitioning For Scan Chain Diagnosis - Aspects of the invention relate to techniques for chain fault diagnosis based on dynamic circuit design partitioning. Fan-out cones for scan cells of one or more faulty scan chains of a circuit design are determined and combined to derive a forward-tracing cone. Fan-in cones for scan cells of the one or more faulty scan chains and for failing observation points of the circuit design are determined and combined to derive a backward-tracing cone. By determining intersection of the forward-tracing cone and the backward-tracing cone, a chain diagnosis sub-circuit for the test failure file is generated. Using the process, a plurality of chain diagnosis sub-circuits may be generated for a plurality of test failure files. Scan chain fault diagnosis may then be performed on the plurality of chain diagnosis sub-circuits with a plurality of computers. | 06-12-2014 |
20140237310 | Test Architecture for Characterizing Interconnects in Stacked Designs - Aspects of the invention relate to ring-oscillator-based test architecture for characterizing interconnects in stacked designs. The disclosed ring-oscillator-based test architecture comprises a plurality of boundary scan cells coupled to a plurality of interconnects. Each of the plurality of boundary scan cells can be configured to operate as, based on control signals, a conventional boundary scan cell or any bit of an asynchronous counter. The control signals are supplied by control circuitry. | 08-21-2014 |
20150040087 | IDENTIFICATION OF POWER SENSITIVE SCAN CELLS - Aspects of the disclosed techniques relate to techniques for identifying power sensitive scan cells. Signal probability values for signal lines in a circuit design are first computed, wherein the signal lines comprise signal lines associated with scan cells in the circuit design. Toggling probability values are then computed based on the signal probability values, wherein the toggling probability values comprise toggling rate values for the scan cells. Toggling rate reduction values are then computed based on the toggling probability values, wherein the toggling rate reduction values comprise toggling rate reduction values for the scan cells. Finally, scan cells having high toggling rate reduction values are identified. | 02-05-2015 |