Abstract: In one embodiment, a circuit element is described in text representation in a HDL source code file. The text representation is provided to a synthesis compiler for compilation. The text representation contains multiple expressions describing the logic circuits. During synthesis compilation, object names are selected for each expression in the text representation. The object names are derived from local counters and from the expressions depending on the context of the expressions such that a revision of one section of the source HDL text only affects the object names of the expressions local to the revised section. The object names of other sections of the source HDL text are not affected and remain the same.

Abstract: Methods and apparatuses for designing an integrated circuit (IC). In one exemplary method, a hardware description language (HDL) code is compiled to produce a representation of logic, and a portion of this representation of logic is allocated to a first physical portion of an area of the IC. This portion is reallocated automatically, according to machine determined parameters, such that a modified portion of the representation is allocated to the first physical portion. Examples of this reallocating include moving logic between regions on the IC, replicating logic based on the regions of the IC, decomposing RTL instances into elements based on information concerning the regions, reducing logic path crossings of a region's boundaries, and assuring that the original allocation or the result of a reallocation can be accommodated by the first physical portion of the IC.

Abstract: Methods and systems for designing integrated circuits. In one exemplary method, a first plurality of points in a first representation of a circuit are identified, and the first representation is modified to produce a second representation for which a second plurality of points are identified. The first representation is compared to the second representation at the first plurality and second plurality of points to determine whether the first representation is equivalent to the second representation. Other features and embodiments are also described.

Abstract: Methods and systems for designing integrated circuits. In one exemplary method, matched registers between the two netlists are determined. The matched registers become cut off points to generate primary inputs and outputs. When there are one or more unmatched registers between the first netlist and the second netlist, the unmatched registers are pushed to the primary inputs or outputs using retiming. At the primary inputs, a subspace generator is used to generate subspaces. The subspaces are used to identify non-equivalences between the first and second netlists. Other features and embodiments are also described.

Abstract: Methods and apparatuses for designing a plurality of integrated circuits (ICs) from a language representation of hardware. In one example of a method, a technology independent RTL (register transfer level) netlist is partitioned between representations of a plurality of ICs. In a typical example of the method, a hardware description language (HDL) code is written and compiled without regard to splitting the design among multiple ICs. After compilation, a partition of the technology independent RTL netlist, obtained from the compilation, is performed among the multiple ICs. After a partition, the technology independent RTh netlist is mapped to a particular target technology (e.g. a particular IC vendor's architecture for implementing logic circuitry), and place and route tools may be used to create the design in multiple ICs (e.g. field programmable gate arrays). Other examples of methods and apparatuses are described.

Abstract: One embodiment of the present invention includes a technique for a gated clock conversion for a circuit which includes a gating circuit and a sequential element. The gating circuit has a gated clock net that drives a clock input of the sequential element. The sequential element receives a first input net at a data input and generates an output net. The gating circuit has a user-defined clock net. The technique includes determining the gating circuit and transforming the gating circuit to provide a second input net to the sequential element based on a cofactor condition of the gating circuit.

Abstract: Techniques and systems for analysis, diagnosis and debugging fabricated hardware designs at a Hardware Description Language (HDL) level are described. Although the hardware designs (which were designed in HDL) have been fabricated in integrated circuit products with limited input/output pins, the techniques and systems enable the hardware designs within the integrated circuit products to be comprehensively analyzed, diagnosed, and debugged at the HDL level at speed. The ability to debug hardware designs at the HDL level facilitates correction or adjustment of the HDL description of the hardware designs.

Abstract: One embodiment of the present invention identifies a circuit having a loop structure and a tri-state element. The circuit provides a circuit output. The loop structure contains at least a loop element in a feedback connection. The tri-state element receives first tri-state inputs. The circuit is transformed so that the tri-state element is moved across the loop structure to provide the circuit output.

Abstract: Techniques and systems for analysis, diagnosis and debugging fabricated hardware designs at a Hardware Description Language (HDL) level are described. Although the hardware designs (which were designed in HDL) have been fabricated in integrated circuit products with limited input/output pins, the techniques and systems enable the hardware designs within the integrated circuit products to be comprehensively analyzed, diagnosed, and debugged at the HDL level at speed. The ability to debug hardware designs at the HDL level facilitates correction or adjustment of the HDL description of the hardware designs.

Abstract: In one embodiment, a circuit element is described in text representation in a HDL source code file. The text representation is provided to a synthesis compiler for compilation. The text representation contains multiple expressions describing the logic circuits. During synthesis compilation, object names are selected for each expression in the text representation. The object names are derived from local counters and from the expressions depending on the context of the expressions such that a revision of one section of the source HDL text only affects the object names of the expressions local to the revised section. The object names of other sections of the source HDL text are not affected and remain the same.

Abstract: Methods and apparatuses for designing an integrated circuit. In one example of a method, a hardware description language (HDL) code is compiled to produce a technology independent RTL (register transfer level) netlist. A portion of an area of the IC is allocated to a specific portion of the technology independent RTL netlist. In a typical implementation of this method, the allocation restricts circuitry created from the specific portion to the portion of the IC.

Abstract: Methods and apparatuses for designing a plurality of integrated circuits (ICs) from a language representation of hardware. In one example of a method, a technology independent RTL (register transfer level) netlist is partitioned between representations of a plurality of ICs. In a typical example of the method, a hardware description language (HDL) code is written and compiled without regard to splitting the design among multiple ICs. After compilation, a partition of the technology independent RTL netlist, obtained from the compilation, is performed among the multiple ICs. After a partition, the technology independent RTL netlist is mapped to a particular target technology (e.g. a particular IC vendor's architecture for implementing logic circuitry), and place and route tools may be used to create the design in multiple ICs (e.g. field programmable gate arrays).

Abstract: A method and apparatus that maintains the correspondence between a text representation of a circuit element and the corresponding schematic representation of the element after optimization of the circuit containing the element. In one example of a method of the invention, a circuit containing element is described in text representation. A first tag is assigned to the text representation. The text representation is synthesized to produce a first schematic representation of the circuit element. A second tag corresponding to the first tag is assigned to the first schematic representation of the circuit element. The circuit containing the circuit element is optimized to produce a second schematic representation of the circuit element. A third tag corresponding to the first tag is assigned to the second schematic representation. Other methods and apparatuses are described.

Abstract: Methods and apparatuses for designing a plurality of integrated circuits (ICs) from a language representation of hardware. In one example of a method, a technology independent RTL (register transfer level) netlist is partitioned between representations of a plurality of ICs. In a typical example of the method, a hardware description language (HDL) code is written and compiled without regard to splitting the design among multiple ICs. After compilation, a partition of the technology independent RTL netlist, obtained from the compilation, is performed among the multiple ICs. After a partition, the technology independent RTL netlist is mapped to a particular target technology (e.g. a particular IC vendor's architecture for implementing logic circuitry), and place and route tools may be used to create the design in multiple ICs (e.g. field programmable gate arrays).

Abstract: A method comprising determining a state machine design point from a plurality of state machine design point options, where one of the plurality of state machine design point options corresponds to a safe design point. Then, forming a safe state machine model, if the safe design point is the determined state machine design point; where the safe state machine model has valid state logic separated from invalid state logic. Another method comprising detecting an invalid state of a state machine with invalid state logic. Then, setting a state machine register to a valid state with the invalid state logic. Then, continuing valid state operation of the state machine with valid state logic, where the valid state logic is separated from the invalid state logic.

Abstract: A method and apparatus which automatically extract finite state machine circuits from a circuit design. Typically, the circuit design is specified by a hardware description language which is compiled to a level of description which shows logic and interconnections in the circuit. A circuit region which includes a register is automatically defined from this description. The circuit region is defined as the register and the group of logic gates within a feedback path from the output of the register to the input of the register. The circuit region is analyzed to define a finite state machine. For each finite state machine, the next state function of the state machine is determined. The next state function is derived by determining a next state from a current state of the state machine and a set of possible input values to the state machine.