Patent application number | Description | Published |
20080256497 | Scan compression circuit and method of design therefor - A scan-based circuit includes a selector that is implemented by multiple observation logics. Each observation logic is coupled to a scan chain to receive data to be supplied to a combinational compressor. Each observation logic is also coupled to a single input line in a corresponding group of input lines of the combinational compressor, to selectively supply data from the coupled scan chain. Each observation logic may be coupled to additional input lines (if present) in the corresponding group. The selector is operable on a per-shift basis in (a) transparent mode wherein data is supplied to all input lines and (b) several direct modes wherein data from only one scan chain is supplied at each compressor output without overlap. | 10-16-2008 |
20080294955 | Dynamically Reconfigurable Shared Scan-In Test Architecture - A low overhead dynamically reconfigurable shared scan-in test architecture is provided. This test architecture advantageously allows for changing scan inputs during the scan operation on a per shift basis. The flexibility of reconfiguring the scan input to scan chain mapping every shift cycle can advantageously reduce both test data volume and test application time. | 11-27-2008 |
20080301510 | Dynamically Reconfigurable Shared Scan-In Test Architecture - A low overhead dynamically reconfigurable shared scan-in test architecture is provided. This test architecture advantageously allows for changing scan inputs during the scan operation on a per shift basis. The flexibility of reconfiguring the scan input to scan chain mapping every shift cycle can advantageously reduce both test data volume and test application time. | 12-04-2008 |
20090235133 | SLACK-BASED TRANSITION-FAULT TESTING - A system that generates test patterns for detecting transition faults in an integrated circuit (IC). During operation, the system receives slack times for each net in the IC. Note that a slack time for a net is the minimum amount of delay that the given net can tolerate before violating a timing constraint. For each possible transition fault in the IC, the system uses the slack times for nets in the IC to generate a test pattern which exposes the transition fault by producing a transition that propagates along the longest path to the transition fault. | 09-17-2009 |
20090271673 | Dynamically Reconfigurable Shared Scan-In Test Architecture - A low overhead dynamically reconfigurable shared scan-in test architecture is provided. This test architecture advantageously allows for changing scan inputs during the scan operation on a per shift basis. The flexibility of reconfiguring the scan input to scan chain mapping every shift cycle can advantageously reduce both test data volume and test application time. | 10-29-2009 |
20090313514 | Dynamically Reconfigurable Shared Scan-In Test Architecture - A low overhead dynamically reconfigurable shared scan-in test architecture is provided. This test architecture advantageously allows for changing scan inputs during the scan operation on a per shift basis. The flexibility of reconfiguring the scan input to scan chain mapping every shift cycle can advantageously reduce both test data volume and test application time. | 12-17-2009 |
20100017760 | TEST DESIGN OPTIMIZER FOR CONFIGURABLE SCAN ARCHITECTURES - Roughly described, a scan-based test architecture is optimized in dependence upon the circuit design under consideration. In one embodiment, a plurality of candidate test designs are developed. For each, a plurality of test vectors are generated in dependence upon the circuit design and the candidate test design, preferably using the same ATPG algorithm that will be used downstream to generate the final test vectors for the production integrated circuit device. A test protocol quality measure such as fault coverage is determined for each of the candidate test designs, and one of the candidate test designs is selected for implementation in an integrated circuit device in dependence upon a comparison of such test protocol quality measures. Preferably, only a sampling of the full set of test vectors that ATPG could generate, is used to determine the number of potential faults that would be found by each particular candidate test design. | 01-21-2010 |
20100031101 | Dynamically Reconfigurable Shared Scan-In Test Architecture - A low overhead dynamically reconfigurable shared scan-in test architecture is provided. This test architecture advantageously allows for changing scan inputs during the scan operation on a per shift basis. The flexibility of reconfiguring the scan input to scan chain mapping every shift cycle can advantageously reduce both test data volume and test application time. | 02-04-2010 |
20100192030 | METHOD AND APPARATUS FOR IMPLEMENTING A HIERARCHICAL DESIGN-FOR-TEST SOLUTION - Embodiments of the present invention provide methods and apparatuses for implementing hierarchical design-for-test (DFT) logic on a circuit. The hierarchical DFT logic implements DFT circuitry that can be dedicated to a module, and which can configure DFT circuitry for multiple modules to share a sequential input signal and/or to share a sequential output signal. During operation, the DFT circuitry for a first module can propagate a bit sequence from the sequential input signal to the DFT circuitry of a second module, such that the bit sequence can include a set of control signal values for controlling the DFT circuitry, and can include compressed test vectors for testing the modules. Furthermore, the DFT circuitry for the second module can generate a sequential response signal, which combines the compressed response vectors from the second module and a sequential response signal from the DFT circuitry of the first module. | 07-29-2010 |
20100223516 | Dynamically Reconfigurable Shared Scan-In Test Architecture - A low overhead dynamically reconfigurable shared scan-in test architecture is provided. This test architecture advantageously allows for changing scan inputs during the scan operation on a per shift basis. The flexibility of reconfiguring the scan input to scan chain mapping every shift cycle can advantageously reduce both test data volume and test application time. | 09-02-2010 |
20110040528 | Systemic Diagnostics For Increasing Wafer Yield - A method of performing systemic diagnostics for a wafer includes selecting a design for manufacturability (DFM) rule for analysis. For each IC chip on the wafer, two sets of IC features adjacent the rule can be extracted based on the chip's layout design. Upconverted diagnostics can be run to generate computed numbers associated with combination categories for each set. Zonal analysis can be run on the two sets using the computed numbers to derive metrics for the two sets. A report can be generated based on the zonal analysis. | 02-17-2011 |
20110258498 | Test Architecture Including Cyclical Cache Chains, Selective Bypass Scan Chain Segments, And Blocking Circuitry - A test architecture is described that adds minimal area overhead and increases encoding bandwidth by using one or more cyclical cache chains for a set of the test patterns provided to the scan chains of the design. A multiplexer associated with a scan chain can be used to bypass a segment of the scan chain that includes unknown values. Blocking circuitry can be programmed to completely block one or more scan chains including unknown values. | 10-20-2011 |
20110301907 | Accelerating Automatic Test Pattern Generation in a Multi-Core Computing Environment via Speculatively Scheduled Sequential Multi-Level Parameter Value Optimization - Systems and methods provide acceleration of automatic test pattern generation in a multi-core computing environment via multi-level parameter value optimization for a parameter set with speculative scheduling. The methods described herein use multi-core based parallel runs to parallelize sequential execution, speculative software execution to explore possible parameter sets, and terminate/prune runs when the optimum parameter value is found at a previous level. The present invention evaluates the design prior to the implementation of the compression IP so that it can define the configuration of DFT and ATPG to maximize the results of compression as measured by test data volume and test application time. | 12-08-2011 |
20140032156 | LAYOUT-AWARE TEST PATTERN GENERATION AND FAULT DETECTION - Methods and apparatuses to generate test patterns for detecting faults in an integrated circuit (IC) are described. During operation, the system receives a netlist and a layout for the IC. The system then generates a set of faults associated with the netlist to model a set of defects associated with the IC. Next, the system determines a set of likelihoods of occurrence for the set of faults based at least on a portion of the layout associated with each fault in the set of faults. The system subsequently generates a set of test patterns to target the set of faults, wherein the set of test patterns are generated based at least on the set of likelihoods of occurrence associated with the set of faults. | 01-30-2014 |
20140059399 | TEST DESIGN OPTIMIZER FOR CONFIGURABLE SCAN ARCHITECTURES - Roughly described, a scan-based test architecture is optimized in dependence upon the circuit design under consideration. In one embodiment, a plurality of candidate test designs are developed. For each, a plurality of test vectors are generated in dependence upon the circuit design and the candidate test design, preferably using the same ATPG algorithm that will be used downstream to generate the final test vectors for the production integrated circuit device. A test protocol quality measure such as fault coverage is determined for each of the candidate test designs, and one of the candidate test designs is selected for implementation in an integrated circuit device in dependence upon a comparison of such test protocol quality measures. Preferably, only a sampling of the full set of test vectors that ATPG could generate, is used to determine the number of potential faults that would be found by each particular candidate test design. | 02-27-2014 |
20140281777 | Localizing Fault Flop in Circuit by Using Modified Test Pattern - A method for localizing at least one scan flop associated with a fault in an integrated circuit. A first test pattern, including a first scan-in data and first control data, is generated. Based on the first control data of the first test pattern, a first fault data is generated by applying the first scan-in data of the first test pattern to scan flops in a test circuit of the integrated circuit. If the first fault data indicates that a fault may be present in the integrated circuit, a second test pattern, including a second scan-in data and a second control data is generated. | 09-18-2014 |
20140289579 | Reordering or Removal of Test Patterns for Detecting Faults in Integrated Circuit - A method for reordering a test pattern set for testing an integrated circuit is disclosed. A productivity index is computed for each test pattern in a test pattern set. The productivity index of a first test pattern and the productivity index of a second test pattern are compared. If the productivity index of the second test pattern is larger than the productivity index of the first test pattern, the location of the first test pattern and the second test pattern are swapped. | 09-25-2014 |
20140304672 | Hierarchical Testing Architecture Using Core Circuit with Pseudo-Interfaces - A core circuit that can be connected in a hierarchical manner, and configured to test a multiple circuits is disclosed. The core circuit includes at least one real input for receiving scan-in data for controlling operation of the core circuit. The core circuit further includes an input register coupled to the at least one real input and configured to store data. The core circuit further includes at least one scan chain coupled a subset if registers of the register chain and configured to generate scan-out data representing the presence of faults in an circuit. Furthermore, the core circuit includes at least one control pseudo-output coupled to the input register and configured to route at least a subset of the data to another register chain in the core circuit or to another core circuit. | 10-09-2014 |
20140317463 | Scheme for Masking Output of Scan Chains in Test Circuit - Operating a scan chain of a test circuit of an integrated circuit to have either a single fanout or multiple fanout to a compressor. The test circuit receives a fanout control signal for configuring the fanout of the scan chain. If the fanout control signal indicates configuring of the scan chain with a single fanout, the output of the scan chain is sent to one input of a compressor. If the fanout control signal indicates configuring of the scan chain with multiple fanout, the output of the scan chain is sent to multiple inputs of the compressor. | 10-23-2014 |
20140372822 | Scheme for Masking Output of Scan Chains in Test Circuit - A method for masking scan chains in a test circuit of an integrated circuit is disclosed. A test pattern to be fed into the test circuit of the integrated circuit is generated. The generated test pattern can be used for detecting a primary fault, one or more secondary faults, and one or more tertiary faults. A mask to mask the output of the scan chains of the test circuit is generated. If a condition is not met, a mask that increases the total number of detectable faults is generated. If the condition is met, a mask that protects the primary fault of the test pattern is generated. | 12-18-2014 |
20150025819 | Handling of Undesirable Distribution of Unknown Values in Testing of Circuit Using Automated Test Equipment - A method for masking scan chains in a test circuit of an integrated circuit is disclosed. The test circuit includes multiple mask banks. Different mask patterns are stored in each of the mask banks. A first mask bank of the multiple mask banks is selected and the mask pattern stored in the selected first mask bank is used for masking the output of the scan chains of the test circuit during a first portion of a test cycle. A second mask bank of the multiple mask banks is selected and the ask pattern stored in the selected second mask bank is used for masking the output of the scan chains of the test circuit during a second portion of the test cycle. | 01-22-2015 |