Abstract: A method for implementing physical optimizations includes performing physical optimizations on a first reference version of a design, maintaining a computer-readable list of the physical optimizations, and during a subsequent compile for a second version of the design: identifying matching cells, nets, or both between the first reference version of the design and the second version of the design; and restoring at least a subset of the physical optimizations in the second version of the design by reading the computer-readable list of the physical optimizations and applying the subset to a computer-readable description of the second version of the design.

Abstract: A method for implementing physical optimizations includes performing physical optimizations on a first reference version of a design, maintaining a computer-readable list of the physical optimizations, and during a subsequent compile for a second version of the design: identifying matching cells, nets, or both between the first reference version of the design and the second version of the design; and restoring at least a subset of the physical optimizations in the second version of the design by reading the computer-readable list of the physical optimizations and applying the subset to a computer-readable description of the second version of the design.

Abstract: A method for designing a system on a target device includes generating a first netlist for a first version of the system after performing synthesis in a first compilation. Optimizations are performed on the first version of the system during placement and routing in the first compilation resulting in a second netlist. A third netlist is generated for a second version of the system after performing synthesis in a second compilation. A hybrid netlist is generated from the first, second, and third netlists. Incremental placement and routing are performed on portions of the hybrid netlist that are new to the first compilation.

Abstract: A method for designing a system on a target device includes identifying candidate portions in the system to preserve based on similarities between the system and another system. Preservation criteria are applied on the candidate portions in the system to preserve to identify portions of the system to preserve. Design results from the another system are reused for portions in the system that are preserved.

Abstract: A programmable logic device (PLD) includes a plurality of logic array blocks (LAB's) connected by a PLD routing architecture. At least one LAB includes a logic element (LE) configurable to arithmetically combine a plurality of binary input signals in a plurality of stages. The LE comprises look-up table (LUT) logic having K inputs (a “K-LUT”). The K-LUT is configured to input the binary input signals at respective inputs of the K-LUT logic cell and to provide, at a plurality of outputs of the K-LUT logic cell, respective binary result signals indicative of at least two of the plurality of stages of the arithmetic combination of binary input signals. An input line network includes a network of input lines, the input lines configurable to receive input signals from the PLD routing architecture that represent the binary input signals and to provide the input signals to the K-LUT.

Abstract: A programmable logic device (PLD) includes a plurality of logic array blocks (LAB's) connected by a PLD routing architecture. At least one LAB includes a logic element (LE) configurable to arithmetically combine a plurality of binary input signals in a plurality of stages. The LE comprises look-up table (LUT) logic having K inputs (a “K-LUT”). The K-LUT is configured to input the binary input signals at respective inputs of the K-LUT logic cell and to provide, at a plurality of outputs of the K-LUT logic cell, respective binary result signals indicative of at least two of the plurality of stages of the arithmetic combination of binary input signals. An input line network includes a network of input lines, the input lines configurable to receive input signals from the PLD routing architecture that represent the binary input signals and to provide the input signals to the K-LUT.

Abstract: A system for parallelizing software in computer-aided design (CAD) software for circuit design includes a computer. The computer is configured to form or optimize a plurality of clusters in parallel. Each cluster in the plurality of clusters includes a set of nodes in a netlist in a design. The computer is configured to determine placements for blocks in a netlist in parallel, based on iterative improvement, partitioning, or analytic techniques.

Abstract: A method for designing a system on a target device includes generating a first netlist for a first version of the system after performing synthesis in a first compilation. Optimizations are performed on the first version of the system during placement and routing in the first compilation resulting in a second netlist. A third netlist is generated for a second version of the system after performing synthesis in a second compilation. A hybrid netlist is generated from the first, second, and third netlists. Incremental placement and routing are performed on portions of the hybrid netlist that are new to the first compilation.

Abstract: A method for designing a system on a target device includes identifying candidate portions in the system to preserve based on similarities between the system and another system. Preservation criteria are applied on the candidate portions in the system to preserve to identify portions of the system to preserve. Design results from the another system are reused for portions in the system that are preserved.

Abstract: A programmable logic device (PLD) includes a plurality of logic array blocks (LAB's) connected by a PLD routing architecture. At least one LAB includes a logic element (LE) configurable to arithmetically combine a plurality of binary input signals in a plurality of stages. The LE comprises look-up table (LUT) logic having K inputs (a “K-LUT”). The K-LUT is configured to input the binary input signals at respective inputs of the K-LUT logic cell and to provide, at a plurality of outputs of the K-LUT logic cell, respective binary result signals indicative of at least two of the plurality of stages of the arithmetic combination of binary input signals. An input line network includes a network of input lines, the input lines configurable to receive input signals from the PLD routing architecture that represent the binary input signals and to provide the input signals to the K-LUT.

Abstract: A method for designing a system on a target device includes identifying candidate portions in the system to preserve based on similarities between the system and another system. Preservation criteria are applied on the candidate portions in the system to preserve to identify portions of the system to preserve. Design results from the another system are reused for portions in the system that are preserved.

Abstract: A method for generating a design for a system to be implemented on a target device includes compiling the design. Information used to make a compilation decision on the design is stored. A strategy to improve timing closure on a signal path on the design is derived using the information.

Abstract: Systems and techniques are described for optimizing placement and routing by providing global information during early stages of a computer aided design (CAD) flow to produce better place and route solutions. Moreover, the systems and techniques described herein use natural connectivity information inherently provided in a design hierarchy.

Abstract: A method for designing a system on a target device includes identifying candidate portions in the system to preserve based on similarities between the system and another system. Preservation criteria are applied on the candidate portions in the system to preserve to identify portions of the system to preserve. Design results from the another system are reused for portions in the system that are preserved.

Abstract: Techniques are provided for grouping circuits in a user design for a programmable integrated circuit into logic blocks. A packing tool separates each circuit element into individual abstract blocks and groups the abstract block into logic blocks. A determination is made whether placement information indicates that a design goal would be improved by rearranging at least a portion of the user design. The user design can be rearranged by moving one or more of the abstract blocks into different logic blocks than the ones they were previously grouped with. Circuit elements in the same logic block can be separated and placed into different logic blocks to improve routability of the user design and signal timing.

Abstract: A system for parallelizing software in computer-aided design (CAD) software for logic design includes a computer. The computer is configured to identify dependencies among a set of tasks. The computer is also configured to perform the set of tasks in parallel such that a solution of a problem is identical to a solution produced by performing the set of tasks serially.

Abstract: A method of performing placement of resources in a computer-aided design (CAD) tool includes performing a first congestion analysis, proposing a placement move, and evaluating the placement move. The method further includes incrementally updating information used for performing another congestion analysis.

Abstract: A programmable logic device (PLD) includes a plurality of logic array blocks (LAB's) connected by a PLD routing architecture. At least one LAB includes a logic element (LE) configurable to arithmetically combine a plurality of binary input signals in a plurality of stages. The LE comprises look-up table (LUT) logic having K inputs (a “K-LUT”). The K-LUT is configured to input the binary input signals at respective inputs of the K-LUT logic cell and to provide, at a plurality of outputs of the K-LUT logic cell, respective binary result signals indicative of at least two of the plurality of stages of the arithmetic combination of binary input signals. An input line network includes a network of input lines, the input lines configurable to receive input signals from the PLD routing architecture that represent the binary input signals and to provide the input signals to the K-LUT.

Abstract: A method for technology mapping user logical RAM on a programmable logic device is provided. The method preferably includes clustering non-RAM functional block types in the programmable logic device. Following synthesis of a user design, the method then includes determining the number of physical RAM locations available on the selected device. Also, the method includes determining the number of physical RAM locations available in the PLD and the number of Look-Up-Table (LUT) RAM locations available in the PLD. Finally, the method includes determining a combination of physical RAM locations and LUT RAM locations for implementation of the user logical RAM. The combination preferably represents a beneficial combination of physical RAM and LUT RAM with respect to a predetermined metric.

Abstract: The process of designing an integrated circuit (“IC”) to implement a generalized circuit design includes a signoff between a front-end part of the process and a back-end part of the process. This signoff preferably takes place after at least some global routing has been done for the IC implementation, but before all final detailed routing is done for that implementation.