Abstract: The present invention provides a method and mechanism for simulating complex digital circuits using hybrid control and data flow representations. Specifically, the invention provides a method of simulating a digital circuit in such a way that the simulation is stopped at desired functions for subsequent analysis. A hardware design code describing the digital circuit is converted to an assignment decision diagram (ADD) representation that is then annotated with one or more control nodes that are used for maintaining control flow through a simulator. In this way, one or more break points are created that allow the simulator to stop at associated points in the simulation.

Abstract: Compiler flows are provided that can produce functionally equivalent field programmable gate arrays (“FPGAs”) and structured application-specific integrated circuits (“structured ASICs”). The flows may include feeding back design transformations that are performed during either flow so that a later performance of the other flow will necessarily include the same transformations, thereby helping to ensure functional equivalence. The flows may include a comparison of intermediate results in order to prove that functional equivalence is being achieved.

Abstract: A mask-programmable logic device includes some circuitry that is electrically programmable as in conventional programmable logic devices. This allows a user to adjust certain characteristics of programmed devices whose logic functions have been proven and need not change, but which operate in an environment that changes, necessitating different characteristics, without having to redesign the programming metallization layers, and therefore without involving the device manufacturer. The programmable elements may include input/output elements, which may need adjustment because the signal characteristics of the larger system change, or clock circuitry, which may need adjustment because environmental conditions such as changes in the expected operating temperature may affect clock signals in the larger system.

Abstract: A mask-programmable logic device includes some circuitry that is electrically programmable as in conventional programmable logic devices. This allows a user to adjust certain characteristics of programmed devices whose logic functions have been proven and need not change, but which operate in an environment that changes, necessitating different characteristics, without having to redesign the programming metallization layers, and therefore without involving the device manufacturer. The programmable elements may include input/output elements, which may need adjustment because the signal characteristics of the larger system change, or clock circuitry, which may need adjustment because environmental conditions such as changes in the expected operating temperature may affect clock signals in the larger system.

Abstract: A mask-programmable logic device includes some circuitry that is electrically programmable as in conventional programmable logic devices. This allows a user to adjust certain characteristics of programmed devices whose logic functions have been proven and need not change, but which operate in an environment that changes, necessitating different characteristics, without having to redesign the programming metallization layers, and therefore without involving the device manufacturer. The programmable elements may include input/output elements, which may need adjustment because the signal characteristics of the larger system change, or clock circuitry, which may need adjustment because environmental conditions such as changes in the expected operating temperature may affect clock signals in the larger system.

Abstract: The present invention provides a method and mechanism for simulating complex digital circuits using hybrid control and data flow representations. Specifically, the invention provides a method of controlling the simulation of a digital circuit in such a way that desired functions are annotated for subsequent analysis. A hardware design code describing the digital circuit is converted to an assignment decision diagram (ADD) representation that is then annotated with one or more control nodes that are used for maintaining control flow through a simulator. In this way, one or more break points are created that allow the simulator to stop at associated points in the simulation.

Abstract: The present invention provides a method and mechanism for simulating complex digital circuits using hybrid control and data flow representations. Specifically, the invention provides a method of simulating a digital circuit in such a way that the simulation is stopped at desired functions for subsequent analysis. A hardware design code describing the digital circuit is converted to an assignment decision diagram (ADD) representation that is then annotated with one or more control nodes that are used for maintaining control flow through a simulator. In this way, one or more break points are created that allow the simulator to stop at associated points in the simulation.

Abstract: The design of logic for implementation in programmable logic array integrated circuit devices is facilitated by allowing various characteristics of modules in the logic design to be parameterized. Specific values for a parameter can be “inherited” by a logic module from other logic higher in the hierarchy of the logic design. Default values for parameters can also be provided. The user can design his or her own parameterized modules, and logic designs can be recursive, meaning that a logic module can make use of other instances of itself.

Abstract: Methods and apparatus are described for generating circuit parameters for a plurality of interconnect line circuit models. The plurality of circuit models represent a plurality of interconnect lines in a programmable logic device (PLD). Design description data corresponding to the PLD are generated at least in part from spreadsheet representations of the plurality of interconnect lines. A device model for the PLD is generated using estimated circuit parameters and a plurality of mathematical equations representing the plurality of interconnect line circuit models. Operation of the PLD is simulated using the device model and the design description data thereby generating modeled delay data corresponding to the estimated circuit parameters. The modeled delay data are compared with measured delay data corresponding to the plurality of interconnect lines.

Abstract: A technique for allowing local compilation at any level within a design hierarchy tree for a programmable logic device allows a user to compile within the context of the entire design using inherited parameter values and assignments from any parent nodes within the design hierarchy tree. A user is allowed to perform an isolated, local compilation that gives a compilation result as if the lower level node had been compiled within the context of the complete design. This local compilation is performed even though assignments, parameters, and logic options of parent nodes have not been compiled. An "action point" is specified at a node where a local compilation, timing analysis or simulation is to occur. A method compiles design source files that represent a PLD design. The design source files specify design entities that are represented as nodes in a design hierarchy tree. A first step analyzes the design source files to determine what design entities are represented in the source files.

Abstract: Methods for implementing a portion of a user's logic design in a component such as a random access memory, a read-only memory, an arithmetic logic unit, a digital signal processor, a microprocessor, or the like which is associated with programmable logic array integrated circuitry are disclosed. A candidate portion of the user's logic is identified and its logic requirements are determined and compared to the logic capabilities of the auxiliary component. If the candidate logic portion can be implemented in the auxiliary component, that may then be done. Alternatively, additional analysis may be performed prior to implementation (e.g., to make sure that it is beneficial to implement this logic portion in the auxiliary component and/or to ascertain whether it would be more beneficial to implement some other portion of the logic in the auxiliary component).