International Business Machines Corporation

Viresh Paruthi

Jason Raymond Baumgartner

Hari Mony

Robert Lowell Kanzelman

Geert Janssen

Christian Jacobi

Kai Oliver Weber

Jiazhao Xu

Ali S El-Zein

Wolfgang Roesner

Bradley Donald Bingham

Stephen Gerard Shuma

Krishnan Kunjunny Kailas

Mark A Williams

Udo Krautz

Brian Chan Monwai

Fadi A Zaraket

Derek E Williams

Jun Sawada

Peter Anthony Sandon

Fady Copty

Michael L Case

Andreas Kuehlmann

Alvan Wing Ng

Benedikt Geukes

Robert J Shadowen

Gadiel Auerbach

Stephen J Barnfield

Klaus-Dieter Schubert

Sujeet Kumar

Travis Wellington Pouarz

Anand B Arunagiri

Jason Raymond Baumgarter

Fadi Z Zaraket

Chung-Lung K Shum

Luis Alfonso Lastras-Montano

Harry S Barowski

Robert Alan Cargnoni

Michael H Wood

Barry Marshall Trager

Praveen S Reddy

Arun Joseph

Alexey Y Lvov

Shmuel Winograd

Yee Ja

Louise Helen Trevillyan

Nicolas Maeding

Tobias Gemmeke

Mitra Purandare

Matthias Pflanz

Spandana V Rachamalla

Matyas A Sustik

Shiladitya Ghosh

Klaus Keuerleber

Steven Mark German

David J Levitt

J Adam Butts

Florian Karl Krohm

Barinjato Ramanandray

Birgit Schubert

Edward Armayor McQuade

Gradus (Geert) Janssen

Nico Gulden

Malay Kumar Ganai

Abrar Polani

A first plurality of hardware description language (HDL) files describe a hierarchical integrated circuit design utilizing a simplified HDL syntax that omits specification of logical clock connections for at least some entities in the hierarchical integrated circuit design. The hierarchical integrated circuit design as described by the first plurality of HDL files is processed to automatically add logical clock connections for entities in the hierarchical integrated circuit design for which specification of logical clock connections are omitted in the first plurality of HDL files. Based on the processing, a second plurality of HDL files defining the hierarchical integrated circuit design is generated.

Logical clock connection in an integrated circuit design

Based on a directive in a control file, a processor pre-routes, within a hierarchical integrated circuit design, a signal through one or more levels of design hierarchy between a signal source at a higher level of the design hierarchy and an entity instance at a lower level of the design hierarchy. The processor processes entity instances in the design hierarchy in a bottom-up manner to insert technology-specific structures into the hierarchical integrated circuit design. During the processing, the processor inserts into a particular entity instance of the design hierarchy a technology-specific structure and connects the technology-specific structure to the signal pre-routed to the particular entity instance by the pre-routing.

Signal pre-routing in an integrated circuit design

A method, a computer system, and a computer program product for detection of unintended dependencies between hardware design signals from pseudo-random number generator (PRNG) taps is provided. Embodiments of the present invention may include identifying one or more tap points in a design as an execution sequence. Embodiments of the present invention may include sampling the tap points by propagating the tap points in the design with different delays. Embodiments of the present invention may include defining observation points to identify tap collisions based on the tap points. Embodiments of the present invention may include identifying tap collisions. Embodiments of the present invention may include identifying one or more sources of the tap collisions in the design. Embodiments of the present invention may include eliminating the one or more sources of uninteresting tap collisions out of the tap collisions and filtering one or more of the tap collisions.

Detection of unintended dependencies in hardware designs with pseudo-random number generators

A method, computer program product, and/or system is disclosed for testing integrated circuits, e.g., processors, that includes: generating a software design prototype of the functional behavior of an integrated circuit to be tested; creating a lab All-Events-Trace (AET) normalized model of the integrated circuit, wherein the normalized model captures the functions of the integrated circuit and not the non-functional aspects of the integrated circuit; generating a lab scenario using the software design prototype and the AET normalized model of the integrated circuit for a particular cycle of interest, wherein the lab scenario contains initialization for all signals that have hardware information; and generating a replayed lab normalized AET for the particular cycle of interest.

Methods and systems for identifying flaws and bugs in integrated circuits, for example, microprocessors

Techniques include configuring a sequential circuit monitor having been generated by applying a quantifier elimination to each random bit position of random inputs associated with a formal verification driver and selecting a value for random inputs to drive a next stage logic of sequential circuit simulation monitor, a state of the next stage logic being used by sequential circuit simulation monitor to generate sequential inputs to match those permitted by formal verification driver, formal verification driver being specified for a DUT input interface. An equivalence check between sequential circuit simulation monitor and original formal driver matches the same set of sequential inputs permitted original formal driver. The sequential circuit simulation monitor is coupled to a simulation environment and the DUT in simulation environment, sequential circuit simulation monitor being configured to flag an input sequence from the simulation environment not permitted by formal verification driver based on the sequential inputs.

Converting formal verification testbench drivers with nondeterministic inputs to simulation monitors

A processor receives, as input, a first hardware description language (HDL) file defining an entity of a modular circuit design. The first HDL file instantiates, by a storage element declaration in a hardware description language, a storage element within the entity. The first HDL file omits a port map for the storage element. Based on the first HDL file, the processor automatically fully elaborates a port map for the storage element. The processor stores, in data storage, a derived second HDL file defining the entity and including the port map.

Clock mapping in an integrated circuit design

A method, system and computer program product for appending abstractions to a testbench used for verifying the design of an electronic circuit. According to an embodiment of the invention, a method comprises identifying a set L of one or more support properties l for a set P of one or more properties p for a given electronic circuit; computing a plurality of hardware signals s of the given electronic circuit; and creating a plurality of abstract signals ABS, including declaring a fresh abstract signal abs_s for each of the hardware signals s, and creating a fresh abstract signal abs_l for each of the support properties l of the set L; for each of the properties p of the set P, creating an abstract property version abs_p; and appending the abstract signals ABS and the abstract property abs_p to the testbench to form an appended testbench.

Scalable model checking in functional verification by integrating user-guided abstraction

A method and/or system is disclosed for pre-silicon verification of a first integrated circuit design modified to a second integrated circuit design to avoid a hit of property P where property P has a known counterexample. The method/system includes applying a first implication check in an equivalence testbench on the first integrated circuit and on the second integrated circuit to determine whether the second integrated circuit hits property P in the same way as the first integrated circuit hits property P. Additionally or alternatively applying a second implication check to determine whether the second integrated circuit hits property P at a different timestep than the first integrated circuit hits property P. Additionally or alternatively applying a third implication check to determine whether the second integrated circuit hits property P further along a path than the first integrated circuit hits property P.

Methods and systems to verify correctness of bug fixes in integrated circuits

Embodiments of the present invention provides methods, computer program products, and a system for processing hierarchical references for a formal equivalence check. In certain embodiments, hierarchical references of a first design are identified as functionally equivalent to hierarchical references of a second design. Value outputs of the first design can be compared to the value outputs of the second design to determine whether the value outputs of the respective designs match.

Equivalency verification for hierarchical references

A tool for formally verifying forwarding paths in an information pipeline. The tool creates two logic design copies of the pipeline to be verified. The tool retrieves a first and a second instruction, which have previously been proven to compute a mathematically correct result when executed separately. The tool defines driver input functions for issuing instructions to the two logic design copies. In accordance with the driver input functions, the tool issues instructions to the two logic design copies. The tool abstracts data flow of the two logic design copies to isolate forwarding paths for verification. The tool adjusts for latency differences between the first and second logic design copies. The tool checks a register for results, and when results from of two logic design copies become available in the register, the tool verifies the results to conclusively prove the correctness of all states of the information pipeline.

Verifying forwarding paths in pipelines

Embodiments include dividing source code for an application into multiple program fragments by generating a control flow graph for the multiple program fragments. The control flow graph represents a graph structure with nodes representing the multiple program fragments and edges representing an execution order of the program fragments. Aspects include searching for a chosen assertion statement within a program fragment, wherein the chosen assertion statement must be satisfied for correct execution of the chosen program fragment. Aspects also include identifying an immediate parent program fragment for the chosen program fragment using the control flow graph and calculating an immediate parent assertion statement for the immediate parent program fragment using the chosen assertion logic statement. The immediate parent assertion statement is an over-approximate pre-condition of the chosen program fragment. The computation of the over-approximate pre-condition is performed by computing a precondition that satisfies the chosen assertion statement and the particular-precondition.

Calculating an immediate parent assertion statement for program verification

A computer-implement method, computerized apparatus and computer program product for formal verification of an arbiter design. The method comprising: performing formal verification of an arbiter design, wherein the arbiter design is based on an original arbiter design comprising a fairness logic and an arbitration logic, wherein the arbiter design comprising the arbitration logic and a portion of the fairness logic; and wherein the formal verification is performed with respect to a multi-dimensional Complete Random Sequence (CRS) having two or more dimensions.

Formal verification of arbiters

A random number generator includes a fairness checker and correction module that ensures that a complete random sequence within a predetermined period of time will be output by the random number generator.

Method and structure for provably fair random number generator

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Austin, TX, United States of America

Viresh Paruthi