Abstract: Method and apparatus for doubling the throughput rate of data transmission on a logic path comprising providing two latches that alternately receive successive bits of the data stream to be transmitted and a multiplexer having data transmission paths that are alternately clocked by two separate clocks, which clocks are substantially 180 degrees out of phase.

Abstract: One or more columns of multi-function tiles are positioned between CLB tiles of the FPGA array. Each multi-function tile includes multiple function elements that share routing resources. In one embodiment, a multi-function tile includes a configurable, dual-ported RAM and a multiplier that share routing resources of the multi-function tile. The RAM includes first and second input ports coupled to first and second input data buses, respectively, and includes first and second output ports coupled to first and second output data buses, respectively. The multiplier includes first and second operand ports coupled to receive operands from the first and second input data buses, and in response thereto provides a product. In one embodiment, the most significant bits (MSBs) of the product are selectively provided to the first output data bus using bus multiplexer logic, and the least significant bits (LSBs) of the product are selectively provided to the second output data bus using bus multiplexer logic.

Abstract: A fast, space-efficient lookup table (LUT) for programmable logic devices (PLDs) in which the write decoder, read decoder and memory block of the LUT are modified to improve performance while providing a highly efficient layout. Both the write decoder and the read decoder are controlled by LUT input signals, and data signals are transmitted directly to each memory circuit of the memory block (i.e., without passing through the write decoder). The read decoder includes a multiplexing circuit made up of a series of multiplexers that are directly controlled by the input signals received from the interconnect resources of the PLD. In one embodiment, a configurable logic block is provided with a single write decoder that is shared by a first LUT and a second LUT.

Abstract: Interconnecting logic provides connectivity of an embedded fixed logic circuit, or circuits, with programmable logic fabric of a programmable gate array such that the fixed logic circuit functions as an extension of the programmable logic fabric. The interconnecting logic includes interconnecting tiles and may further include interfacing logic. The interconnecting tiles provide selective connectivity between inputs and/or outputs of the fixed logic circuit and the interconnects of the programmable logic fabric. The interfacing logic, when included, provides logic circuitry that conditions data transfers between the fixed logic circuit and the programmable logic fabric.

Abstract: Structures and methods for selectively applying a well bias to only those portions of a PLD where such a bias is necessary or desirable, e.g., applying a positive well bias to transistors on critical paths within a user's design. A substrate for an integrated circuit includes a plurality of wells, each of which can be independently and programmably biased with the same or a different well bias voltage. In one embodiment, FPGA implementation software automatically determines the critical paths and generates a configuration bitstream that enables positive well biasing only for the transistors participating in the critical paths, or only for programmable logic elements (e.g., CLBs or lookup tables) containing those transistors. In another embodiment, negative well biasing is selectively applied to reduce leakage current.

Abstract: A fast, space-efficient lookup table (LUT) for programmable logic devices (PLDs) in which the write decoder, read decoder and memory block of the LUT are modified to improve performance while providing a highly efficient layout. Both the write decoder and the read decoder are controlled by LUT input signals, and data signals are transmitted directly to each memory circuit of the memory block (i.e., without passing through the write decoder). The read decoder includes a multiplexing circuit made up of a series of multiplexers that are directly controlled by the input signals received from the interconnect resources of the PLD. In one embodiment, a configurable logic block is provided with a single write decoder that is shared by a first LUT and a second LUT.

Abstract: An FPGA architecture and method enables partial reconfiguration of selected configurable logic blocks (CLBs) connected to an address line without affecting other CLBs connected to the same address line. Partial reconfiguration at a memory cell resolution is achieved by manipulating the input voltages applied to the address and data lines of an FPGA so that certain memory cells are programmed while other memory cells are not programmed. In addition, partial reconfiguration at a CLB resolution can be achieved by hardwiring the FPGA to enable selection of individual CLBs for reconfiguration.

Abstract: Method and apparatus for doubling the throughput rate of data transmission on a logic path comprising providing two latches that alternately receive successive bits of the data stream to be transmitted and a multiplexer having data transmission paths that are alternately clocked by two separate clocks, which clocks are substantially 180 degrees out of phase.

Abstract: A data processing system having a user configurable memory controller, one or more block RAMS, and a processor core can be configured in a single field programmable gate array (FPGA). The address depth of the block RAMs and the number of wait states can be selected by a user, and they can be set either prior to configuration of the FPGA or programmed using instructions of the processor core. An algorithm that can optimize the address depth and the number of wait states to achieve a performance level is also disclosed. The present invention can be applied to designs having separate instruction and data sides.

Abstract: A valve, such as a gate valve, includes a housing having a fluid conduit and defining a valve seat and a support surface, a seal plate, a counter plate, an actuator for moving the seal plate and the counter plate between an open position and a closed position, and a coupling mechanism operatively coupled between the seal plate, the counter plate, and the actuator. The seal plate is in sealed engagement with the valve seat, and the counter plate is in engagement with the support surface in the closed position. The coupling mechanism retracts the counter plate from the support surface subsequent to retraction of the seal plate from the valve seat as the valve is opened.

Abstract: An FPGA architecture and method to reduce the size of the bitstream used in configuring or reconfiguring the FPGA. To facilitate features of the compression process, an FPGA is modified to implement an addressable data register in place of a conventional shift register. This allows data frames to be arranged in order of similarity, and a bitstream formed from one full data frame along with an address into which the frame is to be loaded, and subsequent partial data frames including only changed words along with the row address of the changes and the column address into which modified frames are to be loaded, rather than shifting in entire frames of data for subsequent frames.

Abstract: An improved CLB architecture, wherein the use of dedicated AND gates to generate a carry chain input signal facilitates low latency multiplication and makes efficient use of four-input function generators. In one embodiment of the invention, when multiplication using a binary addition tree algorithm is used, AND gates to implement single-bit multiplication are provided within the available function generators and duplicated in a dedicated AND gate accessible outside the corresponding function generator as a carry-chain input signal. In another embodiment, carry chain multiplexers can be selectively configured as AND or OR gates to facilitate certain arithmetic or comparison functions for the outputs of a plurality of function generators.

Abstract: Method and apparatus for doubling the throughput rate of data transmission on a logic path comprising providing two latches that alternately receive successive bits of the data stream to be transmitted and a multiplexer having data transmission paths that are alternately clocked by two separate clocks, which clocks are substantially 180 degrees out of phase.

Abstract: A clock routing circuit is coupled to receive a primary clock signal, a secondary clock signal, and a select signal, all of which may be asynchronous with respect to one another. When the select signal is in a first state, the clock routing circuit passes the primary clock signal as an output clock signal. At time TA, the select signal transitions to a second state, thereby indicating that the secondary clock signal should be routed as the output clock signal. The first clock signal is prevented from being routed as the output clock signal at time TB, wherein time TB is the first time that the first clock signal has a predetermined logic state after time TA. The output clock signal is held at the predetermined logic state at time TB. The second clock signal is then routed as the output clock signal the first time that the second clock signal transitions to the predetermined logic state after time TB.

Abstract: The invention provides an FPGA interconnect structure preferably included in an array of identical tiles. A combination of single-length lines connecting to adjacent tiles and intermediate-length lines connecting to tiles several tiles away creates an interconnect hierarchy which allows any logic block to be connected to any other logic block, yet also allows for fast paths to both adjacent tiles and tiles some distance away. Longer interconnect lines may be included as a third level of hierarchy to permit interconnection of widely separated tiles. In a preferred embodiment, from a given tile an intermediate-length line connects to the tile three tiles away, then continues and connects to the tile six tiles away. In this embodiment, the intermediate-length line does not connect to the intervening tiles one, two, four, and five tiles away.

Abstract: The invention comprises an FPGA having a plurality of input reference voltages and/or output voltage supplies. In one embodiment, two or more differential amplifiers in the same configurable input buffer use different input reference voltages. According to a second aspect of the invention, the I/O pad line is configurably connected to the input reference voltage line, so that any configurable Input/Output Block (IOB) can be used to supply the input reference voltage. According to a third aspect of the invention, the reference input of an I/O is configurably connected to any of two or more input reference voltage lines. According to another aspect of the invention, a single input reference voltage and/or a single output voltage supply is applied to each IOB, with the IOBs grouped into sets. Each set of IOBs has a separate input reference voltage and/or a separate output voltage supply.

Abstract: A fast, space-efficient lookup table (LUT) for programmable logic devices (PLDs) in which the write decoder, read decoder and memory block of the LUT are modified to improve performance while providing a highly efficient layout. Both the write decoder and the read decoder are controlled by LUT input signals, and data signals are transmitted directly to each memory circuit of the memory block (i.e., without passing through the write decoder). The write decoder includes NOR gates that generate select signals used to address individual memory circuits during write operations. For dynamic latching during reading or shifting, each memory circuit includes an inverter circuit connected between the memory cell and the output terminal of the memory circuit. The read decoder includes a multiplexing circuit made up of a series of 2-to-1 multiplexers that are directly controlled by the input signals received from the interconnect resources of the PLD.

Abstract: A clock routing circuit is coupled to receive a primary clock signal, a secondary clock signal, and a select signal, all of which may be asynchronous with respect to one another. When the select signal is in a first state, the clock routing circuit passes the primary clock signal as an output clock signal. When the select signal transitions to a second state, the clock routing circuit waits for the primary clock signal to transition in a predetermined direction (i.e., rising edge or falling edge). Upon detecting the transition of the primary clock signal, the clock routing circuit holds the state of the output clock signal. The clock routing circuit then waits for the secondary clock signal to transition in the predetermined direction. Upon detecting the transition of the secondary clock signal, the clock routing circuit passes the secondary clock signal as the output clock signal.

Abstract: An improved CLB architecture, wherein the use of dedicated AND gates to generate a carry chain input signal facilitates low latency multiplication and makes efficient use of four-input function generators. In one embodiment of the invention, when multiplication using a binary addition tree algorithm is used, AND gates to implement single-bit multiplication are provided within the available function generators and duplicated in a dedicated AND gate accessible outside the corresponding function generator as a carry-chain input signal. In another embodiment, carry chain multiplexers can be selectively configured as AND or OR gates to facilitate certain arithmetic or comparison functions for the outputs of a plurality of function generators.

Abstract: An apparatus for implementing fast sum-of-products logic in an FPGA is disclosed. The apparatus includes a CLB including a plurality of slices and a second-level logic circuit to combine the outputs of the slices. Typically, the second-level logic circuit is an OR gate or its equivalent that implements the sum portion of the sum-of-products expression. Alternatively, a combining gate may be included within the slice to combine the output of one slice with the output of another slice. In this case the combing gates of each of the slices are connected in series to sum the result of the product operation of a given slice with the product operations from preceding slices. The slice may also include a dedicated function generator to increase the performance of each slice to implement wide functions, particularly sum-of-products functions. The dedicated function generator may include an AND gate and an OR gate with a multiplexer as a selector.