Patents Assigned to Verisity Ltd.
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Patent number: 7284177Abstract: Method, apparatus, and computer readable medium for functionally verifying a physical device under test (DUT) is described. In one example, verification test data is generated for the physical DUT using a constraint-based random test generation process. For example, the architecture, structure, and/or content of the verification test data may be defined in response to constraint data and an input/output data model. A first portion of the verification test data is applied to the physical DUT. Output data is captured from the physical DUT in response to application of the first portion of the verification test data. A second portion of the verification test data is selected in response to the output data. Expected output data for the physical DUT associated with the verification test data may be generated and compared with the output data captured from the DUT to functionally verify the design of the DUT.Type: GrantFiled: March 31, 2005Date of Patent: October 16, 2007Assignee: Verisity, Ltd.Inventors: Yoav Z. Hollander, Yaron E. Kashai
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Patent number: 6920583Abstract: A system and method for enabling the behavior of temporal expressions to be analyzed for the evaluation of such expressions. The process of evaluating such expressions ultimately results in the construction of a finite state machine, such that the set of non-deterministic functions for describing the behavior of dynamic and relativistic systems is reduced to such a system. The behavior of the finite state machine can then be examined and analyzed. The present invention is useful for such applications as the examination of the temporal behavior of a DUT (device under test), as well as for examining the behavior of dynamic systems.Type: GrantFiled: June 15, 2001Date of Patent: July 19, 2005Assignee: Verisity Ltd.Inventors: Matthew John Morley, Yaron Kashai
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Patent number: 6918076Abstract: A method for enabling bitwise or bit slice constraints to be provided as part of the test generation process, by providing a language structure which enables these constraints to be expressed in a test generation language such as e code for example. The language structure for such bitwise constraints is then handled in a more flexible manner, such that the test generation process does not attempt to rigidly “solve” the expression containing the constraint as a function. Therefore, the propagation of constraints in such a structure do not necessarily need to be propagated from left to right, but instead are generated in a multi-directional manner. The language structure is particularly suitable for such operators as “[:]”, “|”, “&”, “^”, “˜”, “>>” and “<<”.Type: GrantFiled: August 28, 2001Date of Patent: July 12, 2005Assignee: Verisity Ltd.Inventors: Vitaly Lagoon, Guy Barruch
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Patent number: 6907599Abstract: A method for synthesizing a verification language, and thereby enabling the verification language to be compiled into a target language. This method enables the underlying control structure of the verification language to be determined, and then used to map the dynamic behavior of the verification language onto the target language as part of a static framework. The process of synthesizing any type of verification language causes at least a portion of the implicit control structure of the software program to be constructed into the compiled output code, such that an additional scheduler or other type of runtime system may not be required. Therefore, the compiled output code should have a greater execution speed and should be operated more efficiently than the software programs which are written in the verification language itself.Type: GrantFiled: June 15, 2001Date of Patent: June 14, 2005Assignee: Verisity Ltd.Inventors: Yaron Kashai, Matthew John Morley
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Publication number: 20040216023Abstract: A method and system for managing test generation and examination of test coverage so as to most efficiently obtain maximum coverage during test generation. Therefore, in addition to achieving coverage maximization, the present invention also preferably manages test generation in order to increase the efficiency of testing to obtain such coverage maximization. The present invention also preferably provides tactics and/or strategies for generation as part of such management. Thus, coverage providing by test generation and execution is not only measured, but is also preferably obtained in a more efficient manner by enabling the coverage maximization functions to provide feedback and management to the test generation process.Type: ApplicationFiled: May 24, 2004Publication date: October 28, 2004Applicant: Verisity Ltd.Inventors: Uri Maoz, Amos Noy
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Patent number: 6684359Abstract: A system and method for testing the quality of a simulation model for the DUT (device under test) with dynamic constraint solving and test generation for the testing and verification process. The present invention provides such dynamic constraint solving through the creation of a sequence of instructions in a “generator mini-language” (GML). These instructions are then executed in order to provide a correct random solution to any given set of dynamic constraints. The process of execution is preferably performed by a constraint resolution engine, optionally and more preferably implemented as software, which manages the requirements imposed by the constraints on the execution, while simultaneously enabling a random solution to the set of constraints to be provided. Such a constraint resolution engine may optionally be viewed as a type of state machine, in which individual elements of the state machine are more preferably represented by one or more dynamic graph(s).Type: GrantFiled: March 6, 2001Date of Patent: January 27, 2004Assignee: Verisity Ltd.Inventor: Amos Noy
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Patent number: 6675138Abstract: A system and method for testing the quality of a simulation model for the DUT (device under test) through temporal coverage of the testing and verification process. Temporal coverage examines the behavior of selected variables over time, according to a triggering event. Such a triggering event could be determined according to predefined sampling times and/or according to the behavior of another variable, for example. This information is collected during the testing/verification process, and is then analyzed in order to determine the behavior of these variables, as well as the quality of the simulation model for the DUT. For example, the temporal coverage information can be analyzed to search for a coverage hole, indicated by the absence of a particular value from a family of values.Type: GrantFiled: June 8, 1999Date of Patent: January 6, 2004Assignee: Verisity Ltd.Inventors: Yoav Hollander, Lev Plotnikov, Yaron Kashai
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Patent number: 6530054Abstract: A method and apparatus are provided for functionally verifying an integrated circuit design. A hardware-oriented verification-specific object-oriented programming language is used to construct and customize verification tests. The language is extensible, and shaped to provide elements for stimulating and observing hardware device models. The invention is platform and simulator-independent, and is adapted for integration with Verilog, VHDL, and C functions. A modular system environment ensures interaction with any simulator through a unified system interface that supports multiple external types. A test generator module automatically creates verification tests from a functional description. A test suite can include any combination of statically and dynamically-generated tests. Directed generation constrains generated tests to specific functionalities. Test parameters are varied at any point during generation and random stability is supported.Type: GrantFiled: February 11, 2002Date of Patent: March 4, 2003Assignee: Verisity Ltd.Inventor: Yoav Hollander
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Patent number: 6519727Abstract: A system and method including a simulation model with at least one flexible constraint on a data structure. The term “flexible constraint” indicates that the constraint is not limited to any one type of data structures, but instead can be used for any type of data structure. The preferred data structures include an object, a list of objects and a list of scalars. An object includes at least one data element and optionally a function for operating on the data element. The data element in turn could be a scalar or another object, for example. Preferably, the data structure is not a single scalar The method of the present invention determines the constraint which should be applied to data structure, and then applies the constraint during the test generation process.Type: GrantFiled: April 3, 2001Date of Patent: February 11, 2003Assignee: Verisity Ltd.Inventor: Amos Noy
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Patent number: 6499132Abstract: A system and method for enabling the behavior of temporal expressions to be analyzed for the evaluation of such expressions. The process of evaluating such expressions ultimately results in the construction of a finite state machine, such that the set of non-deterministic functions for describing the behavior of dynamic and relativistic systems is reduced to such a system. The behavior of the finite state machine can then be examined and analyzed. The present invention is useful for such applications as the examination of the temporal behavior of a DUT (device under test), as well as for examining the behavior of dynamic systems.Type: GrantFiled: June 15, 2001Date of Patent: December 24, 2002Assignee: Verisity Ltd.Inventors: Matthew John Morley, Yaron Kashai
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Patent number: 6347388Abstract: A method and apparatus are provided for functionally verifying an integrated circuit design. A hardware-oriented verification-specific object-oriented programming language is used to construct and customize verification tests. The language is extensible, and shaped to provide elements for stimulating and observing hardware device models. The invention is platform and simulator-independent, and is adapted for integration with Verilog, VHDL, and C functions. A modular system environment ensures interaction with any simulator through a unified system interface that supports multiple external types. A test generator module automatically creates verification tests from a functional description. A test suite can include any combination of statically and dynamically-generated tests. Directed generation constrains generated tests to specific functionalities. Test parameters are varied at any point during generation and random stability is supported.Type: GrantFiled: September 21, 2000Date of Patent: February 12, 2002Assignee: Verisity Ltd.Inventor: Yoav Hollander
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Patent number: 6219809Abstract: The method of the present invention determines constraints which should be applied to data structures, and then applies the constraints during the test generation process. The constraint is applied according to an internal logical order of application. Each constraint of the sequence of constraints is defined. Then a constraint is applied to a data structure for at least reducing the range of possible values, even the possible values are not restricted to one such value. This process is then repeated for other constraints in the sequence. The first constraint in the sequence or at least an earlier constraint in the sequence, is then re-applied, in order to further restrict the range of possible values, and so forth. During this process, preferably the order of suitable application is also determined, such that a constraint which cannot be applied because it requires values which have not yet been defined, is only applied after other constraint(s) which supply the missing values.Type: GrantFiled: March 1, 1999Date of Patent: April 17, 2001Assignee: Verisity Ltd.Inventor: Amos Noy
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Patent number: 6182258Abstract: A method and apparatus are provided for functionally verifying an integrated circuit design. A hardware-oriented verification-specific object-oriented programming language is used to construct and customize verification tests. The language is extensible, and shaped to provide elements for stimulating and observing hardware device models. The invention is platform and simulator-independent, and is adapted for integration with Verilog, VHDL, and C functions. A modular system environment ensures interaction with any simulator through a unified system interface that supports multiple external types. A test generator module automatically creates verification tests from a functional description. A test suite can include any combination of statically and dynamically-generated tests. Directed generation constrains generated tests to specific functionalities. Test parameters are varied at any point during generation and random stability is supported.Type: GrantFiled: February 6, 1998Date of Patent: January 30, 2001Assignee: Verisity Ltd.Inventor: Yoav Hollander