Abstract: A new and convenient methodology for proving the correctness of multiplier and multiply-accumulate circuit designs in a full custom design flow. Such an approach utilizes a basic description of the implemented algorithm, which is created in early phases of the design flow and requires only little extra work for the designer who spends most of the time in full-custom optimizations. Such an approach also defines arithmetic circuit at the arithmetic bit level and allows for the generation of a gate level netlist. Given a structural similarity between the specification and design under verification, a large amount of structural similarity between the generated netlists is obtained so that a standard equivalence checker can be utilized to verify the design against the specification.

Abstract: An improved method of verifying a processor design using a processor simulation model in a simulation environment is disclosed, wherein the processor simulation model comprises at least one execution unit for executing at least one instruction of a test file. The method comprises tracking each execution of each of the at least one instruction, monitoring relevant signals in each simulation cycle, maintaining information about the execution of the at least one instruction, wherein said maintained information comprises a determination of an execution length of a completely executed instruction, matching said maintained information about said completely executed instruction against a set of trap elements provided by the user through a trap file, and collecting the maintained information about the completely executed instruction in a monitor file in response to a match found between the maintained information and at least one of the trap elements.

Abstract: The invention relates to a copper-zinc alloy, consisting of (in wt %): from 28.0 to 36.0% Zn, from 0.5 to 2.3% Si, from 1.5 to 2.5% Mn, from 0.2 to 3.0% Ni, from 0.5 to 1.5% Al, from 0.1 to 1.0% Fe, optionally also up to at most 0.1% Pb, optionally also up to at most 0.2% Sn, optionally also up, to at most 0.1% P, optionally also up to 0.08% S, remainder Cu and inevitable impurities, with mixed silicides of iron-nickel-manganese incorporated in the matrix.

Abstract: A method for performing verification is proposed. The method comprises receiving a design and building an intermediate binary decision diagram for the design containing one or more nodal binary decision diagrams. In response to a size of the intermediate binary decision diagram exceeding a size threshold, a node of the design is selected for case-splitting. A first case-splitting is performed upon the selected node of the design to generate a primary constraint for setting the selected node to a primary value. A first constraining is performed on one of the one or more nodal binary decision diagrams with the primary constraint to generate a primary final binary decision diagram, a first verification of the design is performed using the primary final binary decision diagram.

Abstract: A method for performing verification includes receiving a design and building for the design an intermediate binary decision diagram set containing one or more nodes representing one or more variables. A first case-splitting is performed upon a first fattest variable from among the one or more variables represented by the one or more nodes by setting the first fattest variable to a primary value, and a first cofactoring is performed upon the intermediate binary decision diagram set with respect to the one or more nodes using an inverse of the primary value to generate a first cofactored binary decision diagram set. A second cofactoring is performed upon the intermediate binary decision diagram set with respect to the one or more nodes using the primary value to generate a second cofactored binary decision diagram set, and verification of the design is performed by evaluating a property of the second cofactored binary decision diagram set.

Abstract: A method for performing verification includes receiving a design and building for the design an intermediate binary decision diagram set containing one or more nodes representing one or more variables. A first case-splitting is performed upon a first fattest variable from among the one or more variables represented by the one or more nodes by setting the first fattest variable to a primary value, and a first cofactoring is performed upon the intermediate binary decision diagram set with respect to the one or more nodes using an inverse of the primary value to generate a first cofactored binary decision diagram set. A second cofactoring is performed upon the intermediate binary decision diagram set with respect to the one or more nodes using the primary value to generate a second cofactored binary decision diagram set, and verification of the design is performed by evaluating a property of the second cofactored binary decision diagram set.

Abstract: A method of verifying a digital design is disclosed. The method comprises generating a reference model for a first digital design and creating an operational model for a second digital design, wherein the first digital design and the second digital design are intended to have a same logical function. A plurality of testcase types are then created by constraining one or more internal signals, and one or more test scripts representing the plurality of testcase types are produced. The method also includes verifying the second digital design with a testing simulation program by comparing results of the test scripts from the operational model and the reference model.

Abstract: A method of verifying a digital design is disclosed. The method comprises generating a reference model for a first digital design and creating an operational model for a second digital design, wherein the first digital design and the second digital design are intended to have a same logical function. A plurality of testcase types are then created by constraining one or more internal signals, and one or more test scripts representing the plurality of testcase types are produced. The method also includes verifying the second digital design with a testing simulation program by comparing results of the test scripts from the operational model and the reference model.

Abstract: A method for performing verification is proposed. The method comprises receiving a design and building an intermediate binary decision diagram for the design containing one or more nodal binary decision diagrams. In response to a size of the intermediate binary decision diagram exceeding a size threshold, a node of the design is selected for case-splitting. A first case-splitting is performed upon the selected node of the design to generate a primary constraint for setting the selected node to a primary value. A first constraining is performed on one of the one or more nodal binary decision diagrams with the primary constraint to generate a primary final binary decision diagram, a first verification of the design is performed using the primary final binary decision diagram.

Abstract: A method, a computer program product and a system for performing functional verification logic circuits. The invention enables the functional formal verification of a hardware logic design by replacing the parts that cannot be formally verified easily. In one form the invention is applied to a logic design including a multiplier circuit. The multiplier is replaced (51) by pseudo inputs. The input signal values of the multiplier circuit are determined (54) automatically from a counterexample (53) delivered (52) by a functional formal verification system for a modified design where the multiplier is replaced by pseudo signals. The input signal values are combined (55) with other known inputs to form a test case (56) file that can be used by a logic simulator to analyse the counterexample (52) on the unmodified hardware design including the multiplier.

Abstract: A method for performing verification includes receiving a design and building for the design an intermediate binary decision diagram set containing one or more nodes representing one or more variables. A first case-splitting is performed upon a first fattest variable from among the one or more variables represented by the one or more nodes by setting the first fattest variable to a primary value, and a first cofactoring is performed upon the intermediate binary decision diagram set with respect to the one or more nodes using an inverse of the primary value to generate a first cofactored binary decision diagram set. A second cofactoring is performed upon the intermediate binary decision diagram set with respect to the one or more nodes using the primary value to generate a second cofactored binary decision diagram set, and verification of the design is performed by evaluating a property of the second cofactored binary decision diagram set.

Abstract: The present invention relates to a method, a computer program product and a system for performing functional formal verification. Error detection logic is verified by injecting errors in a hardware design description without any changes to the original design description. With the present invention both permanent and transient faults can be modelled, and the complete error space can be covered for all types of fault models that can be used at the RTL. The number of detected design errors is used to determine the overall coverage in relation to the number of injected errors. The error injection is prepared by adding additional circuits to an RTL netlist representation of the hardware logic design. Signal values for selected signals related to the error detection logic are compared for a modified netlist representation and for the original netlist using a formal verification tool.

Abstract: The present invention relates to a circuit comprising a Leading Zero Counter (LZC) sub-circuit driving a second sub-circuit, like a shifter or arbiter. Shifter circuits or arbiter circuits operating with fewer stages than before have a smaller delay since every stage can select between more than two inputs. This reduces the overall delay of the shifter, arbiter, etc. But for state-of-the art binary LZC circuits this requires a complex recoding between LZC and shifter circuit. In order to provide an improved leading zero circuit having an output which allows a simpler control of a post-connected sub-circuit having two or more stages and having at least one stage with three or more inputs, it is proposed to provide a LZC circuitry providing an output consisting of two or more unary encoded substrings. This removes the requirement for a recoder between LZC and shifter.

Abstract: A method, a computer program product and a system for performing functional verification logic circuits. The invention enables the functional formal verification of a hardware logic design by replacing the parts that cannot be formally verified easily. In one form the invention is applied to a logic design including a multiplier circuit. The multiplier is replaced (51) by pseudo inputs. The input signal values of the multiplier circuit are determined (54) automatically from a counterexample (53) delivered (52) by a functional formal verification system for a modified design where the multiplier is replaced by pseudo signals. The input signal values are combined (55) with other known inputs to form a test case (56) file that can be used by a logic simulator to analyse the counterexample (52) on the unmodified hardware design including the multiplier.

Abstract: A method for performing verification is proposed. The method comprises receiving a design and building an intermediate binary decision diagram for the design containing one or more nodal binary decision diagrams. In response to a size of the intermediate binary decision diagram exceeding a size threshold, a node of the design is selected for case-splitting. A first case-splitting is performed upon the selected node of the design to generate a primary constraint for setting the selected node to a primary value. A first constraining is performed on one of the one or more nodal binary decision diagrams with the primary constraint to generate a primary final binary decision diagram, a first verification of the design is performed using the primary final binary decision diagram.

Abstract: A method for verifying a design through symbolic simulation is disclosed. The method comprises creating one or more binary decision diagram variables for one or more inputs in a design containing one or more state variables and building a binary decision diagram for a first node of one or more nodes of the design. A binary decision diagram for the initial state function of one or more state variables of the design is generated and the design is subsequently initialized. Binary decisions diagrams for one or more constraints are synthesized. A set of constraint values is accumulated over time by combining the binary decision diagrams for the one or more constraints with a set of previously generated binary decision diagrams for a set of constraints previously used in one or more previous time-steps. A binary decision diagram for the next state function of the one or more state variables in the design is constructed in the presence of the constraints.

Abstract: A method of verifying a digital design is disclosed. The method comprises generating a reference model for a first digital design and creating an operational model for a second digital design, wherein the first digital design and the second digital design are intended to have a same logical function. A plurality of testcase types are then created by constraining one or more internal signals, and one or more test scripts representing the plurality of testcase types are produced. The method also includes verifying the second digital design with a testing simulation program by comparing results of the test scripts from the operational model and the reference model.

Abstract: A method, system and computer program product for building decision diagrams efficiently in a structural network representation of a digital circuit using a dynamic resource constrained and interleaved depth-first-search and modified breadth-first-search schedule is disclosed. The method includes setting a first size limit for a first set of one or more m-ary decision representations describing a logic function and setting a second size limit for a second set of one or more m-ary decision representations describing a logic function. The first set of m-ary decision representations of the logic function is then built with one of the set of a depth-first technique or a breadth-first technique until the first size limit is reached, and a second set of m-ary decision representations of the logic function is built with the other technique until the second size limit is reached.