Abstract: Integrated circuits may communicate with off-chip memory. Such types of integrated circuits may include memory interface circuitry that is used to interface with the off-chip memory. The memory interface circuitry may be calibrated using a procedure that includes read calibration, write leveling, read latency tuning, and write calibration. Read calibration may serve to ensure proper gating of data strobe signals and to center the data strobe signals with respect to read data signals. Write leveling ensures that the data strobe signals are aligned to system clock signals. Read latency tuning serves to adjust read latency to ensure optimum read performance. Write calibration may serve to center the data strobe signals with respect to write data signals. These calibration operations may be used to calibrate memory systems supporting a variety of memory communications protocols.

Abstract: A programmable logic region on a programmable integrated circuit may include a first set of look-up tables that receive programmable logic region input signals and a second set of look-up tables that produce programmable logic region output signals. Multiplexer circuitry may be interposed between the first and second sets of look-up tables. The multiplexer circuitry may receive the programmable logic region input signals in parallel with the output signals from the first set of look-up tables and may provide corresponding selected signals to the second set of look-up tables. The programmable logic region input signals may be shared by the first and second sets of look-up tables. Logic circuitry may be coupled to outputs of the first and second sets of look-up tables. The logic circuitry may be configured to logically combine output signals from the first and second sets of look-up tables.

Abstract: A method for designing a system on a target device includes entering the system. The system is synthesized. The system is mapped. The system is placed on the target device. The system is routed. Physical synthesis is performed on the system immediately after more than one of the entering, synthesizing, mapping, placing and routing procedures.

Abstract: A method for designing a system on a target device includes synthesizing the system. The system is mapped. The system is placed on the target device. Physical synthesis is performed on the system by identifying a plurality of register retiming solutions for each register in the system, performing combinational resynthesis on each of the register retiming solutions, and selecting a combinational resynthesis solution for the system.

Abstract: A method for optimizing a system on a target device is disclosed. A LUT is unpacked to form a plurality of LUTs of a smaller size upon determining that the unpacking can satisfy one or more predefined objectives. The plurality of LUTs are repacked such that the design for the system is improved. Other embodiments are disclosed.

Abstract: A universal memory interface on an integrated circuit includes an external memory interface unit operable to perform data rate conversion for a data signal between a first rate associated with the integrated circuit and a second rate associated with a memory system. The universal memory interface also includes a sequencer unit operable to calibrate at least one of a delay for the data signal and a delay for a strobe for the data signal by executing a calibration procedure instruction.

Abstract: A method for designing a system on a target device is disclosed. A system is synthesized by converting a high level description of the system into gates, registers, and reset circuitry. An analysis is performed to identify and remove redundant reset circuitry. The system is optimized after the redundant reset circuitry has been removed. Other embodiments are disclosed.

Abstract: A method for designing a system on a target device includes entering the system. The system is synthesized. The system is mapped. The system is placed on the target device. The system is routed. Physical synthesis is performed on the system immediately after more than one of the entering, synthesizing, mapping, placing and routing procedures.

Abstract: Systems and methods are provided for mapping logic functions from logic elements (“LEs”) into synchronous embedded memory blocks (“EMBs”) of programmable logic devices (“PLDs”). This technique increases the amount of logic that can fit into the PLD. Where area savings are significant, smaller PLDs may be selected to implement a particular circuit. One aspect of the invention relates to methods for identifying sequential cones of logic that may be mapped into synchronous EMBs. After the sequential logic cones are identified for mapping into a synchronous EMB, the logic cone may be selected, expanded, restructured, and retimed, as necessary, to implement the mapping. Another aspect of the invention relates to techniques for handling architectural restrictions of synchronous EMBs, such as the inability to implement the asynchronous behavior of synchronous logic.

Abstract: A method for designing a system on a target device includes synthesizing the system. The system is placed on the target device. Optimizing placement of the system for routing is performed after placing the system. The system is routed after optimizing placement.

Abstract: A method for designing a system on a target device utilizing field programmable gate arrays (FPGAs) includes identifying a group of components associated with a critical signal in the system. A first copy and a second copy of the group of components are generated where the first copy is driven by a first signal at a first state and the second copy is driven by a second signal at a second state. The system is configured to select an output of one of the first copy and the second copy in response to the critical signal.

Abstract: The disclosed invention is a technology for configuring a programmable logic device to perform a computation using carry chains. A computation having multiple input values can be decomposed into sub-computations that have a few input values each. The sub-computations may be organized into a tree topology that includes a chain of sub-computations. The chain of sub-computations can be associated with a carry chain in the programmable logic device. Logic elements in the carry chain can be configured to perform the sub-computations using the carry chain logic in the logic elements.

Abstract: A method for designing a system on a field programmable gate array (FPGA) includes using binary decision diagrams (BDDs) to perform functional decomposition on a design for the system after placement.

Abstract: A method for designing a system on a target device includes synthesizing the system. The system is mapped. The system is placed on the target device. The system is routed. Physical synthesis is performed on the system where a first descendant thread is spawned to run in parallel with an existing thread where the first descendant thread is executing a different optimization strategy than the existing thread but on a same netlist as the existing thread.

Abstract: Systems and methods are provided for mapping logic functions from logic elements (“LEs”) into synchronous embedded memory blocks (“EMBs”) of programmable logic devices (“PLDs”). This technique increases the amount of logic that can fit into the PLD. Where area savings are significant, smaller PLDs may be selected to implement a particular circuit. One aspect of the invention relates to methods for identifying sequential cones of logic that may be mapped into synchronous EMBs. After the sequential logic cones are identified for mapping into a synchronous EMB, the logic cone may be selected, expanded, restructured, and retimed, as necessary, to implement the mapping. Another aspect of the invention relates to techniques for handling architectural restrictions of synchronous EMBs, such as the inability to implement the asynchronous behavior of synchronous logic.

Abstract: Reducible registers are determined to optimize a sequential circuit. A screening method tests one or more sets of registers where the registers of each set are assumed to satisfy a logic condition. The tests determine if the logic condition holds. If the logic condition of a set is found to be violated, the registers may be moved to another set having a different logic condition or removed completely. The registers remaining are potentially reducible. The reducibility of the registers is verified via Boolean analysis by verifying the logic conditions of a register set for each register. If a register does not pass verification, it then may be moved to a different set having a different logic condition or removed completely. The sets that pass verification are reducible.

Abstract: A method for designing a system on a target device utilizing field programmable gate arrays (FPGAs) includes identifying registers on near-critical paths. The registers are moved to shorten lengths of one or more near-critical paths.

Abstract: A method for designing a system on a target device utilizing field programmable gate arrays (FPGAs) includes synthesizing a design for the system. Components in the design are mapped onto resources on the target device. Placement locations are determined for the components on the target device. The design for the system is restructured after placement locations for the components are determined to improve timing for the system.

Abstract: A method for designing a system on a target device utilizing field programmable gate arrays is disclosed. A design is synthesized for the system. Components in the design are mapped onto resources on the target device. Placement locations are determined for the components on the target device. Components to replicate are identified in response to criticality determined from the placement locations.