Abstract: A method and system for improving the fault coverage of test vectors for testing integrated circuits. The present invention also provides a method and system for reducing the number of deterministic test vectors required for testing integrated circuits by inserting test points in a cost effective manner. According to an embodiment of the present invention, a fault list having all the potential faults of an integrated circuit design is initialized and all the potential faults are marked as untestable. A set of test patterns, T, for testing several of the potential faults are generated. A fault simulation process is then performed on the integrated circuit design with the test patterns, T, to mark off untested faults. During fault simulation, fault propagation is monitored to determine the nets in the design to which faults were propagated. The nets at which fault propagation discontinues (e.g., de-sensitized) are also monitored. This information is collected over the set of test patterns, T.

Abstract: A system and method for generating gate level descriptions tables from simulation for formal verification. Implementation libraries contain table-based descriptions of user defined primitives (UDPs), various-strength primitives, hierarchical structural cells and non-functional constructs, such as timing and simulation assertion checks. In order to use the library cells for use by test-generation (ATPG) and formal verification (FV), the present invention provides a library reader and a model builder that read in the library cells and construct gate-level models usable by ATPG processes. The present invention also provides a translator that accesses the ATPG models through an API (Application Programming Interface) interface and produces FV models that are usable by FV processes. Significantly, according to the present invention, the FV models are generated based on the ATPG models. Library cell complexities that would require different ATPG and FV models are automatically detected.

Abstract: Automatic generation of gate-level descriptions from table-based descriptions within the field of electronic design automation. The gate-level and structural descriptions are used for test generation processes and some formal verification processes. For combinational table-based descriptions, ordered ternary decision diagram (OTDD) graphs are used with novel input reordering to extract prime, non-redundant cube sets that can include high level functions (e.g., XOR, XNOR, MUX). For sequential table-based descriptions, a reduced or "clock" based OTDD graph is generated from which data and clock signals are identified and characterized. Input reordering is done and a complete sequential OTDD graph is generated, followed by port separation and characterization of the sequential element. Clock and data functions are then constructed on a port-by-port basis using the prime, non-redundant cube set generation processes of the combinational logic phase.

Abstract: A system and method for generating a fault model for a logic circuit includes a data storage device for storing information relative to fault models or primitive elements in a logic circuit and for storing fault models for each level of design in a hierarchical logic circuit, a processor for processing the stored information relative to primitives and lower level fault models in the hierarchy for generating fault models for each succeeding higher level of design in the hierarchy, an input device for operator input of information to modify primitive fault models and a display subsystem for displaying various aspects of the hierarchical fault model generated in accordance with the present invention.

Abstract: A globally distributed system clock is received and selectively gated by local clock generators responsive to global control signals. The local clock generators, which are located proximately to sequential circuits having serial scan paths, produce scan and functional clock signals adapted to the sequential circuits, which may have a variety of required timing diagrams.

Abstract: An integrated circuit chip with high level logic functions formed from a pass gate logic family. The logic for each logic book includes at least one pass gate. Each book has complementary outputs and a pseudo latch attached to its outputs. If the book is of one FET type, the pseudo latch is of the opposite type. Books are placed in the logic function such that the output pseudo latches redrive opposite logic levels on alternating stages of series-connected books.