Abstract: Techniques are provided to allow users of Electronic Design Automation (EDA) tools to define constraint template types for efficiently associating constraints with design objects to specify design intent. Processes for creating and validating the constraints are provided by user-defined plug-ins, thereby allowing users to annotate circuit designs with constraints for proprietary layout and fabrication processes without exposing the constraints to tool vendors or competitors. The constraints are re-created from the template types whenever the circuit design is loaded into the EDA tool, so that the constraints are based upon the latest version of the template type. The constraints are also re-created when validation fails. Constraint groups are reusable in different designs, technology nodes, and processes because they automatically expand to provide the specific constraints to achieve a goal.

Abstract: A method and apparatus for determining the propagation delay of a selected net in a circuit design is described. In one exemplary embodiment, a selected net is received, where the selected net includes a plurality of characteristics that represent the physical and/or parasitic parameters of the net. A net is a set of one or more wires that connects a set of circuit junctions between a pair of endpoints of that net. In addition, a simulation is performed on the selected net using the plurality of characteristics. The circuit design system computes the propagation delay for the selected net based on the simulation and makes available the propagation delay of that net. The propagation delay for a net is the delay for a signal traveling between the endpoints of the net.

Abstract: A method comprises estimating power consumption of an electronic circuit. The estimating includes assigning a first gate of the at least one gate into a priority queue based on a levelized result of the electronic circuit for a full circuit calculation and assigning a second gate of the at least one gate into the priority queue which fan-out gate is directly connected to a fan-in gate of a resized gate for an incremental circuit calculation. The estimating includes, for each gate from the priority queue, performing the following operations. Latest and earliest signal arrival times at an output net of the gate are determined by static timing analysis and calculating a glitch window as difference, and a transition metric is calculated for the output net based on the glitch window. The operations include determining an upper bound of signal transitions, and estimating the power consumption based on the upper bound.

Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.

Abstract: Individual mode timing constraints associated with a set of netlists are combined into merged mode timing constraints. An initial merged mode constraint is generated by combining timing constraints from individual modes. The initial merged mode includes the union of all timing constraints from individual modes that add timing relationships and the intersection of all timing constraints from the individual modes that remove timing relationships. Extraneous timing relationships are identified in the merged mode and eliminated by introducing timing constraints in the merged mode. Equivalence between the merged mode and the individual modes is verified by comparing timing relationships in the merged mode with timing relationships in the individual modes. The merged mode is considered equivalent to the individual modes if every timing relationship present in an individual mode is present in the merged mode and every timing relationship present in the merged mode is present in any of individual modes.

Abstract: A method for constructing delay rules which include the effects of MIS simulations for static timing analysis with reduced cost. The present method includes constructing skew windows for applying MIS penalties purely from SIS data, and scales the MIS penalties during rule use based upon how closely the skews in the use case approach the edge of the skew window. The method applies both to timing rule construction for a library of circuits and to timing rule construction for macros where only part of the circuits in the macro may be sensitive to skew between macro inputs.

Abstract: A high-level synthesis device, which converts a behavior description file describing a function of an integrated circuit using a high-level language without timing description, into a hardware description file describing the integrated circuit including timing description, has: a processor; a high-level synthesis unit in which the processor converts a behavior description file having a functional portion describing the function and a control portion controlling timing, into a first hardware description file; a variable extraction unit; a loop information generation unit; a static latency extraction unit; a latency calculation circuit generation unit in which the processor generates a second hardware description file describing a latency calculation circuit which generates the latency information based on loop count and static latency; and an insertion unit in which the processor inserts the second hardware description file into the first hardware description file to generate a third hardware description file.

Abstract: In one embodiment, a method of constructing an equivalent waveform model for static timing analysis of integrated circuit designs is disclosed. The method includes fitting time point coefficients (qk) and known time delay values from a delay and slew model of a receiving gate from a timing library; determining waveform values (Ikj) for input waveforms from the timing library; determining timing values (dj) from a timing table in the timing library in response to the input waveforms of the timing library; and determining coefficients (qk) by minimizing a residual of a delay equation.

Abstract: Methods and systems for excluding library cells are described. Some embodiments receive a generic logical effort value and optionally a generic parasitic delay value for a timing arc of a library cell type. Next, library cells of the library cell type are excluded whose specific logical effort values for the timing arc are greater than the generic logical effort value by more than a first threshold and/or optionally whose specific parasitic delay values for the timing arc are greater than the generic parasitic delay value by more than a second threshold. A new generic logical effort value and optionally a new generic parasitic delay value can be determined based on at least some of the remaining library cells. The process of excluding library cells and determining new generic logical effort values and optionally new generic parasitic delay values can be performed iteratively.

Abstract: Systems and methods are provided for designing integrated circuits using configurable delay cell (CDC) circuits that serve to expedite timing closure for an integrated circuit (IC) design by eliminating the need to iteratively repeat various design steps such as placement, signal distribution network synthesis, and routing. CDC circuits include footprint compatible circuits having different delay characteristics, which may be included as part of a standard cell library for designing integrated circuits. A CDC circuit can be used in an IC design to add a desired delay to a given clock path or data path, and then replaced with another footprint compatible CDC circuit to increase or decrease the delay in the given clock or data path to meet one or more timing requirements and achieve timing closure without having to repeat placement, signal distribution network synthesis or routing steps.

Abstract: In one embodiment of the invention, a method of analyzing a circuit design is disclosed. In the method of analyzing a circuit design, a circuit is levelized into multiple levels. Circuit simulations of elements at a level are determined using circuit simulators, one for each element and in parallel in level order. Topological circuit loops may be removed from the circuit. Circuit simulation of the circuit may be performed on the circuit using the circuit simulations determined by the circuit simulators at each level of the circuit.

Abstract: Systems, apparatus, and methods of static timing analysis for an integrated circuit design in the presence of noise are disclosed. The integrated circuit design may be partitioned into a plurality of circuit stages. A timing graph including timing arcs is constructed to represent the timing delays in circuit stages of the integrated circuit design. A model of each circuit stage may be formed including a model of a victim driver, an aggressor driver, a victim receiver, and a victim net and an aggressor net coupled together. For each timing arc in the timing graph, full timing delays may be computed for the timing arcs in each circuit stage.

Abstract: An integrated circuit includes a clock-tree with a plurality of clock buffers, a plurality of clocked storage elements, and a plurality of logic circuits. Each clocked storage element has a clock input terminal connected to one of the plurality of clock buffers and a weight. Each of the logic circuits is associated with two of the plurality of clocked storage elements and is characterized as having a logic depth. The weight of each clocked storage element is equal to a sum of an inverse of a logic depth of each of the plurality of logic circuits associated therewith. A first clocked storage element which has a highest weight and is adjacent to and interacts with a second clocked storage element via one of the plurality of logic circuits. A first clock buffer provides a common clock signal to the first and second clocked storage elements.

Abstract: A method for designing a system on a target device includes merging a netlist for a first partition of the system generated from a bottom-up design flow with a netlist for a second partition of the system from a top-down design flow to form a combined netlist, and performing fitting on the combined netlist.

Abstract: An approach for performing device-based random variability modeling in timing analysis of a digital integrated circuit having a gate-level design and a device-level custom design is described. In one embodiment, an algorithm is derived from results of simulating the operational behavior of a representative digital integrated circuit. A timing analysis is performed on the device-level custom design part of the digital integrated circuit to obtain device-level random variability sensitivity values. A gate-level characterization is performed on the gate-level design part of the digital integrated circuit to obtain logic gate random variability sensitivity values. A timing analysis is performed on the digital integrated circuit as a function of both the device-level random variability sensitivity values and the logic gate random variability sensitivity values.

Abstract: Systems and techniques are described for determining a transition-effect model for a timing arc of a library cell. A transition-effect model can be determined for each library cell that is used during an optimization process. The transition-effect models enable an optimization system to estimate the impact of a change in the transition at an output of a driver gate on the delays of downstream gates without requiring to propagate the change in the transition to the downstream gates. Once determined, the transition-effect models can be used to compute one or more transition-induced penalties during circuit optimization. An optimization system can then use the one or more transition-induced penalties to determine whether or not to accept an optimizing transformation, or to discretize a solution obtained from a numerical solver.

Abstract: A system that simulates an integrated circuit is formed of a plurality of devices. The system initially performs a fundamental circuit simulation run using original parameters for the plurality of devices and an initial time step. The system generates one or more fundamental time steps from the fundamental circuit simulation run. The fundamental time steps are generated when changes that indicate state time derivatives during two or more successive integration steps are within a predetermined range. The system stores the one or more fundamental time steps as fundamental circuit events in an events queue, and updates the parameters for the plurality of devices based on the fundamental circuit events to generate one or more derivative circuits. The system then performs one or more derivative circuit simulation runs using the derivative circuits.

Abstract: An apparatus for monitoring timing of a plurality of critical paths of a functional circuit includes a plurality of canary circuits, each configured to be coupled to a critical path of a functional circuit for detecting and outputting critical timing events. Each canary circuit includes an adjustable delay element and an analyser circuit for receiving a count of the critical timing event output from at least one of the plurality of canary circuits for a predetermined time interval for a plurality of delay values of the adjustable delay elements and for determining a probability distribution of critical timing events of the at least one of the plurality of critical paths for the predetermined time interval for the plurality of delay values.

Abstract: A method and apparatus for designing an integrated circuit to operate at a desired clock frequency range reduces process variation by estimating the value of removable pessimism from a static timing analysis. The pessimism includes, for example, at least one of the removable on-chip-variation (OCV) margin from clock paths, removable OCV margin from data paths, removable IR drop margin from clock paths, and removable interconnects margin. At the timing analysis stage of a design flow, the method and apparatus determines the value of pessimism in the timing critical paths based on timing correlation between adjacent timing critical paths. In response to the determination, the value of pessimism may be reduced in the static timing analysis of the adjacent timing critical paths to optimize the timing performance of the integrated circuit at its desired clock frequency range.

Abstract: Systems and techniques for optimizing a circuit design are described. When a selected gate is transformed during optimization, it causes a slack value at a pin of the transformed gate to change. The change in the slack value, called the delta-slack, is then propagated through a transitive fanin cone and a transitive fanout cone of the transformed gate to compute the new slack values at all the affected pins of the design. Some embodiments update slack values without propagating arrival and required times, and also without repeatedly evaluating timing arcs to compute gate delays. The updated slack values can be used to compute timing metrics. The timing metrics can be used to decide whether or not to commit the gate transformation to the circuit design.

Abstract: A computer-implemented method includes a processor identifying, within the netlist, at least one strongly connected components (SCCs) that has a reconvergent fanin input with at least two input paths from the reconvergent fanin input having a different propagation delay to the SCC. The method then computes an additive diameter for the netlist comprising at least one SCC, where the additive diameter includes a fanin additive diameter determined based on a propagation delay difference of the at least two input paths to a SCC and a number of complex feed-forward components within at least one input path. In response to the reconvergent fanin input to the SCC providing a binate function, the method computes a multiplicative diameter for the SCC utilizing a least common multiple (LCM) derived from one or more propagation delay differences across each reconvergent fanin input leading to the SCC.

Abstract: Computing accurately and effectively the impact of clock skew on statistical slack in the presence of statistically variable timing quantities that accounts for both common path credit in the common portion of the clock tree, and RSS credit in the non-common of the clock tree. The clock skew is measured on a per launch and capture path-pair basis as a function of on the post-CPPR path-specific slack (including RSS credit), total mean value of latch-to-latch delay, RSS value of random latch-to-latch delay, test guard time and test adjust. The method includes: performing an initial block-based SSTA including CPPR analysis; selecting at least one launch and capture path-pair for skew analysis; for the at least one path pair, recording post CPPR slack, total mean value of latch-to-latch delay, RSS value of latch to latch delay, test guard time and test adjust; and quantifying the impact of clock skew on statistical slack thereof.

Abstract: A method, system and computer program product are provided for implementing multiple mask lithography timing variation mitigation for a multiple mask polysilicon (PC) process. An application specific integrated circuit (ASIC) library includes at least one circuit device for a first mask, and at least one circuit device for a second mask. Critical hold time paths and critical setup time paths are identified in a circuit design. For critical hold time paths, circuit devices in the critical hold time paths are placed on a single mask of either the first mask or the second mask. For critical setup time paths, path delays are reduced by providing a mixture of circuit devices on the first mask and the second mask.

Abstract: Methods and apparatuses to design and analyze digital circuits with time division multiplexing. In one embodiment, the method for designing a digital circuit comprises determining signal timing for a portion of the digital circuit, and automatically replacing nets for a plurality of connections in the digital circuit with a Time Division Multiplexing (TDM) channel in response to a determining of routing congestion.

Abstract: A timing verification support device includes: a storage device to store first circuit data of a semiconductor integrated circuit; a search unit to identify, in the first circuit data, a plurality of circuit elements including a designated circuit element designated as a timing verification target and at least one circuit element included in a path traced when performing timing verification at a boundary between the designated circuit element and a portion other than the designated circuit element; and a generation unit to generate second circuit data for the timing verification including circuit data of the plurality of circuit elements.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A method of timing analysis of an integrated circuit (IC) design with a partition block including an original clock signal with a pair of clock paths having an external common point outside the block boundary is disclosed, including receiving a netlist of the partition block of a hierarchical IC design, analyzing a pair of clock paths having the external common point to determine first and second clock ports at the boundary of the partition block; and for the first and second clock ports, creating launch and capture clocks, making exclusive clock groups of the launch clock and the capture clock for opposing clock ports to avoid the launch and capture clocks for each port affecting other internal data paths within the partition block, and associating common path pessimism removal information with a source latency of the capture clock to adjust timing at an end point of the internal data path.

Abstract: A Hardware Description Language (HDL) utilizing a Term Rewriting System (TRS) is provided that simplifies handling of clocks, and signaling between various clock domains of a multi-clock domain circuit specification. A specific clock data type is supplied for use with clock signals. Using the clock data type, and other requirements of a circuit specification, clock domain crossing between domains of clocks of the same clock family is handled implicitly. For clock domain crossing between clock domains driven by clocks of different clock families, a “hardware approach” and a “linguistic approach” are provided. A “hardware approach” provides facilities to explicitly specify a synchronizer, using, in part, TRS rules. A “linguistic approach” allows a designer to abstracts the instantiation of synchronizers and instead specify a circuit specification in terms of differently clocked interfaces.

Abstract: A method for designing a system including optimizing path-level skew in the system and analyzing path-level skew in the system. Other embodiments are also disclosed.

Abstract: A method of integrated circuit (IC) disposition includes the steps of determining one or more disposition criteria based at least in part on statistical timing of a given IC design; and determining whether a given IC according to the given IC design satisfies the one or more disposition criteria based at least in part on one or more measurements of at least one test structure.

Abstract: A mechanism is provided for increasing the scalability of transformation-based formal verification solutions through enabling the use of phase abstraction on logic models that include memory arrays. The mechanism manipulates the array to create a plurality of copies of its read and write ports, representing the different modulo time frames. The mechanism converts all write-before-read arrays to read-before-write and adds a bypass path around the array from write ports to read ports to capture any necessary concurrent read and write forwarding. The mechanism uses an additional set of bypass paths to ensure that the proper write data that becomes effectively concurrent through the unfolding inherent in phase abstraction is forwarded to the proper read port. If a given read port is disabled or fetches out-of-bounds data, the mechanism applies randomized data to the read port data output.

Abstract: A system and method are provided for actuating static and dynamic analysis tools in parametrically intercoupled manner for synergistic optimization of an electronic system design. The system and method execute a timing designer process for selectively actuating the static analysis tool to conduct timing analysis based on at least one predetermined timing model and generate a plurality of estimated values for certain signal parameters to be in compliance with predetermined timing constraints. A signal exploration process is executed to receive the estimated values from the timing designer process and configure the resources of the dynamic analysis tool responsive thereto. The signal exploration process actuates the dynamic analysis tool to conduct electrical integrity analysis based on transient simulation and generate a plurality of simulated values for signal parameters. The simulated values are back annotated to the timing designer process for timing closure.

Abstract: A method and apparatus are provided for using a memory timing database. A plurality of characterization memories are defined, which can be mapped to a memory resource. Each characterization memory has different memory parameters. A plurality of variants of tiling each characterization memory to the memory resource are also defined. Timing characteristics of each tiling variant of each characterization memory are stored in the memory timing database for the memory resource based on sets of input ramptimes and output loads.

Abstract: Modifying a hierarchical circuit design includes accessing hierarchical circuit data in the hierarchical circuit design; performing timing analysis and modifications on a selected portion of the hierarchical circuit data to achieve inter-block timing closure; and performing timing analysis and modifications on the hierarchical circuit data, while accounting for a modification made on the selected portion of the hierarchical circuit data, to achieve intra-block timing closure.

Abstract: System and method for effectively detecting small delay defects is disclosed. The method first loads layout information of an integrated circuit. Then, the nets and paths of the integrated circuit are partitioned into two groups based upon their physical information. The physical information comprises the length of each path and net and the number of vias at each path and net. A timing-aware automatic test pattern generator is configured to generate test patterns for the first group having paths and nets susceptible to small delay defects. A traditional transition delay fault test pattern generator is configured to generate test patterns for the second group.

Abstract: Searching for desired clock frequency for integrated circuit-based design may receive timing result of a hardware synthesis job executed based on a code specifying hardware design. One or more different timing constraints specifying respective one or more different clock frequencies than used in the hardware synthesis job may be automatically generated without modifying the code. One or more instances of the hardware synthesis job to run with the respective one or more different timing constraints may be automatically spawned. The automatic generation and spawning may repeat until a termination criterion is met, and/or a desired successful timing constraint is identified for the hardware design from the different timing constraints based on whether the one or more instances of the hardware synthesis job met their respective timing constraints.

Abstract: A timing analysis program for performing analysis condition generation processing which generates a first analysis condition in which the variation width of a first delay value of a first circuit cell is shifted on the basis of a first variation coefficient and a second analysis condition in which the variation width of a second delay value of a second circuit cell is shifted on the basis of a second variation coefficient.

Abstract: In one embodiment of the invention, a physical layout wire-load algorithm is used to generate a wire-load model based on physical data including aspect ratio and wire definitions defined in a physical library. The physical layout estimator is utilized to dynamically produce the physical layout wire-load model and to calculate net length and delay for each optimization iteration.

Abstract: Systems and methods for statistical clock cycle computation and closing timing of an integrated circuit design to a maximum clock cycle or period. The method includes loading a design and timing model for at least one circuit path of an integrated circuit or a region of the integrated circuit into a computing device. The method further includes performing a statistical static timing analysis (SSTA) of the at least one circuit path using the loaded design and timing model to obtain slack canonical data. The method further includes calculating a maximum circuit clock cycle for the integrated circuit or the specified region of the integrated circuit in linear canonical form based upon the slack canonical data obtained from the SSTA.

Abstract: A method for designing an electronic circuit including determining at least one hold violation in a net routing; inserting a routing blockage associated with each at least one hold violation; de-routing the determined net-routing and re-routing the determined net-routing dependent on at least the routing blockage.

Abstract: Timing Constraints are crucial to meet timing requirements of an Integrated Circuit (IC). Timing exceptions are specified so that certain paths of the design of the IC are not timed as they are not relevant for the speed of the IC. If a path is specified as an exception but it is indeed a timing-relevant path then the design may functionally fail due to timing violations ignored by the timing analysis tools. It is therefore extremely important to ensure that all timing exceptions are correctly specified. The Hybrid Timing Exceptions Verification uses static verification as well as dynamic verification to effectively verify correctness of such timing exceptions. The solution pin-points the errors in the exceptions specification with very low number of false errors that would require significant designer inputs and time to manually waive them.

Abstract: In one embodiment, the invention is a method and apparatus for variation enabling statistical testing using deterministic multi-corner timing analysis. One embodiment of a method for obtaining statistical timing data for an integrated circuit chip includes obtaining deterministic multi-corner timing data for the integrated circuit chip and constructing the statistical timing data from the deterministic multi-corner timing data.

Abstract: Searching for desired clock frequency for integrated circuit-based design may receive timing result of a hardware synthesis job executed based on a code specifying hardware design. One or more different timing constraints specifying respective one or more different clock frequencies than used in the hardware synthesis job may be automatically generated without modifying the code. One or more instances of the hardware synthesis job to run with the respective one or more different timing constraints may be automatically spawned. The automatic generation and spawning may repeat until a termination criterion is met, and/or a desired successful timing constraint is identified for the hardware design from the different timing constraints based on whether the one or more instances of the hardware synthesis job met their respective timing constraints.

Abstract: The invention provides a method for performing statistical static timing analysis using a novel on-chip variation model, referred to as Sensitivity-based Complex Statistical On-Chip Variation (SCS-OCV). SCS-OCV introduces complex variation concept to resolve the blocking technical issue of combining local random variations, enabling accurate calculation of statistical variations with correlations, such as common-path pessimism removal (CPPR). SCS-OCV proposes practical statistical min/max operations for random variations that can guarantee pessimism at nominal and targeted N-sigma corner, and extends the method to handle complex variations, enabling graph-based full arrival/required time propagation under variable compaction. SCS-OCV provides a statistical corner evaluation method for complex random variables that can transform vector-based parametric timing information to the single-value corner-based timing report, and based on the method derives equations to bridge POCV/SSTA with LOCV.

Abstract: The timing verification method for deterministic and stochastic networks and circuits is a computerized method that includes a non-enumerative path length analysis algorithm for deterministic and stochastic directed acyclic graphs (DAGs) with applications to timing verification of circuits, the algorithm computing statistical measures of path lengths without storing and/or manipulating the paths in such networks. The timing verification method is able to compute deterministic or probabilistic costs assigned to edges, vertices, or both.

Abstract: A computer-implemented method of determining an attribute of a circuit includes using a computationally expensive technique to simulate the attribute (such as timing delay or slew) of a portion of the circuit, at predetermined values of various parameters (e.g. nominal values of channel length or metal width), to obtain at least a first value of the attribute. The method also uses a computationally inexpensive technique to estimate the same attribute, thereby to obtain at least a second value which is less accurate than the first value. Then the computationally inexpensive technique is repeatedly used on other values of the parameter(s), to obtain a number of additional second values of the attribute. Applying to the additional second values, a function obtained by calibrating the at least one second value to the at least one first value, can yield calibrated estimates very quickly, which represent the attribute's variation relatively accurately.

Abstract: A circuit design is partitioned for hardware-accelerated functional verification using a directed hypergraph with edge weights that are a function of slack. Slack may be computed as the difference between the early and late ranks for the source of an edge. The weight may further be computed as the difference between the edge's slack and a maximum slack value. In a preferred implementation each vertex also has multiple weights associated with resource requirements of different node types, and the partitioning is constrained to prevent vertex movement that would result in vertex weights for a given partition exceeding a partition resource capacity based on the accelerator architecture. Edge and vertex weights can be recomputed for the next level of partitioning. The partitioning process can be repeatedly iteratively until a termination criterion is met, the termination criterion being based in part on the number of directed cuts in each of the partitions.

Abstract: The invention concerns a computer implemented method of circuit conception of a clock tree (200) comprising: a plurality of pulse generators (202) each being coupled to the input of one or more pulsed latches and being arranged to generate a pulsed signal (PS); and a tree of buffers (204) for supplying a clock signal (CLK) to the pulse generators, the method comprising: the conception of the clock tree without pulse generators based on a timing analysis by the computer of the propagation of clock edges in the clock tree; and replacing by the computer in the clock tree at least one buffer, coupled to the input of each pulsed latch, by a pulse generator.

Abstract: An efficient method for selecting a minimal and statistically relevant set of SER sensitive logic devices critical to the SER robustness for a design, through identification by device type, identification nomenclature, connectivity and context. The minimal set of devices comprise the set of fault injection test points using a conventional fault injection test verification environment to establish an SER induced failure rate a logic design. The selection method affords a design independent means to evaluate any design regardless of the origin, source language or documentation by working at the common logic device level “gate-level” netlist format for the design data. The selected set of devices is distilled from the design data by successively filtering the design through a series of heuristic rule-based device identifier computer programs that group and annotate the devices into specific database records.

Abstract: Methods and software for determining one or more boundary conditions for nets in a signal path are disclosed. The method generally includes determining an expected characteristic for at least one net in the signal path and determining a boundary characteristic for that net. Determining a boundary characteristic for the net may include multiplying the expected characteristic by a scaling factor to produce a scaled characteristic for the net, performing timing analysis of the signal path in accordance with the scaled characteristic (e.g., by calculating timing while assuming that the net has the scaled characteristic), determining if the signal path violates a timing constraint when the net has the scaled characteristic, and repeating the determination with a new scaled characteristic if timing is violated. Advantageously, maximum and/or minimum values may be determined for characteristics of signal path nets that still satisfy timing constraints.