Abstract: Structures and methods of including processor capabilities in an existing PLD architecture with minimal disruption to the existing general interconnect structure. In a PLD including a column of block RAM (BRAM) blocks, the BRAM blocks are modified to create specialized logic blocks including a RAM, a processor, and a dedicated interface coupled between the RAM, the processor, and the general interconnect structure of the PLD. The additional area is obtained by increasing the width of the column of BRAM blocks. Because the interconnect structure remains virtually unchanged, the interconnections between the specialized logic blocks and the adjacent tiles are already in place, and the modifications do not affect the PLD routing software. In some embodiments, the processor can be optionally disabled, becoming transparent to the user. Other embodiments provide methods of modifying a PLD to include the structures and provide the capabilities described above.

Abstract: A configurable logic element (CLE) for a field programmable gate array (FPGA) includes “expanders”, i.e., connectors that allow fast signal communication between logic blocks. Expanders allow the configurable interconnection of a plurality of logic blocks, or portions thereof, to form a single logical entity that can implement large user circuits such as PALs, lookup tables, multiplexers, tristate buffers, and memories. One embodiment includes a configurable logic block. In a first mode, the logic block provides two N-input LUTs having N shared inputs and two separate outputs. The outputs are then combined using an expander to generate an (N+1)-input function. In a second mode, the logic block provides two N-input LUTs having M unshared inputs. An optional third mode provides a plurality of product term output signals based on the values of the N input signals.

Abstract: A configurable logic element (CLE) for a field programmable gate array (FPGA) includes “expanders”, i.e., connectors that allow fast signal communication between logic blocks. Expanders allow the configurable interconnection of a plurality of logic blocks, or portions thereof, to form a single logical entity that can implement large user circuits such as PALs, lookup tables, multiplexers, tristate buffers, and memories. One embodiment includes a configurable logic block. In a first mode, the logic block provides two N-input LUTs having N shared inputs and two separate outputs. The outputs are then combined using an expander to generate an (N+1)-input function. In a second mode, the logic block provides two N-input LUTs having M unshared inputs. An optional third mode provides a plurality of product term output signals based on the values of the N input signals.

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.

Abstract: An FPGA is described using optical waveguides for routing signals through the FPGA. The routing is controlled electrically. Either coupling waveguides or resonant disks can be used for routing the optical signals. Lookup tables convert optical input signals to electrical signals for selecting values in the lookup table.

Abstract: A method for implementing a large multiplexer with FPGA lookup tables. Logic that defines a multiplexer is detected and implemented according to the number of inputs and the target FPGA architecture. In one situation, a large multiplexer is implemented in two stages. The first stage implements wide AND functions of each of the input signals using lookup tables and carry logic. In a second stage, the resulting decoded input signals are combined in a wide OR gate again formed from lookup tables and a carry chain. In another situation, the multiplexer is implemented as a tree structure using lookup tables that implement 2:1 multiplexers in combination with other 2:1 multiplexers provided by configurable logic blocks of the FPGA.

Abstract: A memory array having a read mode and a write mode is addressed using separate read and write decoders. The write decoder is used to write bit values to one column of the array. A hard-wired read decoder is utilized to further increase the operating speed during the memory read mode. In one embodiment, a separate read bit line is provided to facilitate faster read operations. In an exemplary embodiment, the write decoder receives two input signals and generates four write address signals on write word lines that are transmitted to the columns of programmable elements of a logic/memory array. The hard-wired read decoder also receives the same two input signals, and generates eight read address signals on two read word lines, two read address signals being transmitted to each column of the logic/memory array.

Abstract: The invention provides parametric modules called Self Implementing Modules (SIMs) for use in programmable logic devices such as FPGAS. The invention further provides tools and methods for generating and using SIMs. SIMs implement themselves at the time the design is elaborated, targeting a specified FPGA according to specified parameters. In one embodiment, a SIM references or includes one or more floorplanners each of which may employ one or more placement algorithms. Such placement algorithms might include, for example: a linear ordering algorithm that places datapath logic bitwise in a regular linear pattern; a rectangular mesh algorithm that implements memory in a grid pattern in distributed RAM; a columnar algorithm for counters and other arithmetic logic; or a simulated annealing algorithm for random logic such as control logic. Therefore, a design including more than one SIM can utilize a plurality of placement algorithms at the same or different levels of hierarchy.

Abstract: A configurable logic element (CLE) for a field programmable gate array (FPGA) includes “expanders”, i.e., connectors that allow fast signal communication between logic blocks. Expanders allow the configurable interconnection of a plurality of logic blocks, or portions thereof, to form a single logical entity that can implement large user circuits such as PALs, lookup tables, multiplexers, tristate buffers, and memories. One embodiment includes a configurable logic block. In a first mode, the logic block provides two N-input LUTs having N shared inputs and two separate outputs. The outputs are then combined using an expander to generate an (N+1)-input function. In a second mode, the logic block provides two N-input LUTs having M unshared inputs. An optional third mode provides a plurality of product term output signals based on the values of the N input signals.

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.

Abstract: A configurable logic element (CLE) for a field programmable gate array (FPGA) includes “expanders”, i.e., connectors that allow fast signal communication between logic blocks. Expanders allow the configurable interconnection of a plurality of logic blocks, or portions thereof, to form a single logical entity that can implement large user circuits such as PALs, lookup tables, multiplexers, tristate buffers, and memories. One embodiment includes a configurable logic block. In a first mode, the logic block provides two N-input LUTs having N shared inputs and two separate outputs. The outputs are then combined using an expander to generate an (N+1)-input function. In a second mode, the logic block provides two N-input LUTs having M unshared inputs. An optional third mode provides a plurality of product term output signals based on the values of the N input signals.

Abstract: A configurable logic element (CLE) for a field programmable gate array (FPGA) includes “expanders”, i.e., connectors that allow fast signal communication between logic blocks. Expanders allow the configurable interconnection of a plurality of logic blocks, or portions thereof, to form a single logical entity that can implement large user circuits such as PALs, lookup tables, multiplexers, tristate buffers, and memories. One embodiment includes a configurable logic block. In a first mode, the logic block provides two N-input LUTs having N shared inputs and two separate outputs. The outputs are then combined using an expander to generate an (N+1)-input function. In a second mode, the logic block provides two N-input LUTs having M unshared inputs. An optional third mode provides a plurality of product term output signals based on the values of the N input signals.

Abstract: A logic element for a programmable logic device (PLD) can be configured as a shift register of variable length. An array of memory cells in the logic element is divided into two or more portions. The memory cells of each portion supply values to a corresponding output multiplexing circuit, thereby enabling the logic element to function as a lookup table by combining the outputs of the multiplexing circuits. However, each portion is also configurable as a shift register. The portions can function as separate shift registers, or can be concatenated to function as a single shift register. In some embodiments, the portions can also be concatenated with shift registers in other logic elements. Because two or more output multiplexing circuits are available, two or more taps are provided, one from each portion of the memory array.

Abstract: A method for implementing wide gates and tristate buses using FPGA carry logic. Wide gate logic functions and tristate buses are detected and implemented with a plurality of LUTs and carry multiplexers. The wide gate functions are of the form: Ff=((( . . . (f0 $ f1) $ f2) $ f3) . . . ) $ fm, where $ represents a logic operator such as AND, OR or XOR. Thus the method includes the commonly used functions FAND=i1 AND i2 AND i3 AND . . . in; and FOR=i1 OR i2 OR i3 . . . in.as well as many mixed functions. The LUTs implement the respective portions of functions f0 through fm and the carry multiplexers implement the logic operators that connect the functions in a cascaded manner. A tristate bus definition includes a plurality of bus input signals and a plurality of bus select signals, each of the bus input signals associated with one or more of the bus select signals.

Abstract: A configurable logic element (CLE) for a field programmable gate array (FPGA) includes “expanders”, i.e., connectors that allow fast signal communication between logic blocks. Expanders allow the configurable interconnection of a plurality of logic blocks, or portions thereof, to form a single logical entity that can implement large user circuits such as PALs, lookup tables, multiplexers, tristate buffers, and memories. One embodiment includes a configurable logic block. In a first mode, the logic block provides two N-input LUTs having N shared inputs and two separate outputs. The outputs are then combined using an expander to generate an (N+l)-input function. In a second mode, the logic block provides two N-input LUTs having M unshared inputs. An optional third mode provides a plurality of product term output signals based on the values of the N input signals.

Abstract: A memory array having a read mode and a write mode is addressed using separate read and write decoders. The write decoder is used to write bit values to one column of the array. A hard-wired read decoder is utilized to further increase the operating speed during the memory read mode. In one embodiment, a separate read bit line is provided to facilitate faster read operations. In an exemplary embodiment, the write decoder receives two input signals and generates four write address signals on write word lines that are transmitted to the columns of programmable elements of a logic/memory array. The hard-wired read decoder also receives the same two input signals, and generates eight read address signals on two read word lines, two read address signals being transmitted to each column of the logic/memory array.

Abstract: The invention provides parametric modules called Self Implementing Modules (SIMs) for use in programmable logic devices such as FPGAs. The invention further provides tools and methods for generating and using SIMs. SIMs implement themselves at the time the design is elaborated, targeting a specified FPGA according to specified parameters that may, for example, include the required timing, data width, number of taps for a FIR filter, and so forth. SIMs are called “self implementing” because they encapsulate much of their own implementation information, including mapping, placement, and (optionally) routing information. Therefore, implementing a SIM-based design is significantly faster than with traditional modules, since much of the implementation is already complete and incorporated in the SIM.

Abstract: A memory array having a read mode and a write mode is addressed using separate read and write decoders. The write decoder is used to write bit values to one column of the array. A hard-wired read decoder is utilized to further increase the operating speed during the memory read mode. In one embodiment, a separate read bit line is provided to facilitate faster read operations. In an exemplary embodiment, the write decoder receives two input signals and generates four write address signals on write word lines that are transmitted to the columns of programmable elements of a logic/memory array. The hard-wired read decoder also receives the same two input signals, and generates eight read address signals on two read word lines, two read address signals being transmitted to each column of the logic/memory array.

Abstract: The invention provides parametric modules called Self Implementing Modules (SIMs) for use in programmable logic devices such as FPGAs. The invention further provides tools and methods for generating and using SIMs. SIMs implement themselves at the time the design is elaborated, targeting a specified FPGA according to specified parameters. In one embodiment, a SIM automatically places and interconnects child SIMs in a mesh pattern. The mesh is a 2-dimensional object corresponding to an array of CLBs on an FPGA. In essence, this embodiment allows a SIM to reserve routing resources on a target device (e.g., an FPGA), and allocate these resources to its child SIMs. Using a defined protocol, each child SIM can request and reserve routing resources, as well as placement resources (such as flip-flops and function generators in the CLBs) through the parent SIM. The routing resources are not necessarily limited to local or nearest neighbor routing.

Abstract: A high-pressure discharge lamp includes a ceramic discharge vessel which encloses a discharge space containing two electrodes and an ionizable filling including a metal halide. The discharge vessel includes a central cylindrical part with an end, and an end part closing the cylindrical part at the end in a gastight manner. The discharge vessel also has a projecting plug connected to the end part in a gastight manner for enclosing a feedthrough conductor. The end part is monolithic and its outside surface includes an angle A with the longitudinal axis of the discharge vessel at the projecting plug, where the angle A is between 30 and 60 degrees. The outside surface of the end part may be shaped like a truncated cone with a base extending radially outward. Alternatively, the end part includes two concentric tubular portions which are interconnected in a gastight manner.