Abstract: Methods of optimizing the use of routing resources in programmable logic devices (PLDs) to minimize test time. A set of routing resources is identified that are not used in most designs, and a device model is provided to the user that prevents the use of these resources. Because the routing resources will never be used, they need not be tested by the PLD manufacturer, significantly reducing the test time. For example, each PLD within a PLD family is typically designed using a different number of similar tiles. Thus, smaller PLDs in the family include an unnecessarily large number of routing resources. These excessive routing resources can be disabled during implementation of a design. In another example, each tile along the edges of an array includes routing resources designed primarily to provide access to tiles that are not present. These redundant routing resources can be disabled during implementation of a design.

Abstract: Optimal routing line segments and associated buffers are pre-engineered for each family of ASIC chips by simulating wires segments of various lengths using distributed resistance and capacitance wire models, and by estimating crosstalk from neighboring line segments. During ASIC design, space is reserved on the ASIC substrate for fabricating the buffers, which are selectively connected by local metal and diffusion structures to form long distance interconnections. Signals are passed from an ASIC circuit structure to a selected long distance interconnection by connecting an output terminal of the ASIC structure either to the input terminal of a buffer located at one end of the interconnection, or by connecting the output terminal directed to a line segment of the interconnection.

Abstract: Bit-Edge Zero Forcing Equalizer. A novel solution is presented by which a BE-ZFE (Bit-Edge Zero Forcing Equalizer) is employed to drive an error term within a data signal to an essentially zero value. This new BE-ZFE looks at values of data that occur at the bit edges of a data signal and drives the associated error term to zero. The new BE-ZFE is appropriately implemented within communication systems that are phase (or jitter) noise limited. Some examples of such communication systems include high-speed serial links one type of which serviced using a SERDES (Serializer/De-serializer) where data that is originally in a parallel format is serialized into a serial data stream and then subsequently de-serialized back into a parallel data stream.

Abstract: The invention provides an interface that can facilitate integration of user specific proprietary cores and commercially available cores during customization of an FPGA-based SoC. A selected hardware or software system component (380) used for customizing the FPGA-based SoC can be configured (382) using parameters that can be automatically propagated (384) and used to configure peer system components. During configuration (388) of the peer system components, other parameters used to configure those peer system components can also be propagated (400) and used to configure other system components during customization of the FPGA-based SoC.

Abstract: A circuit according to an embodiment of the present invention can load data in parallel to a barrel shifter, and output data to a pipelined multiplexer stage. The multiplexer is used to direct data from predetermined barrel slots to a predetermined number of output data slots. A control logic circuit will determine which of the barrel shifter entries are the oldest, and will drive the selects of the multiplexer to direct them to the output. The second stage of the multiplexer will drive the four 16-bit outputs to generate the 64-bit user data path. Methods for implementing the embodiments of the invention are also disclosed.

Abstract: A method of partially reconfiguring an IC having programmable modules that includes the steps of reading a frame of configuration information from the configuration memory array; modifying at least part of the configuration information, thereby creating a modified frame of configuration information; and overwriting the existing frame of configuration information in the configuration memory array with the modified frame, thereby partially reconfiguring the IC.

Abstract: A memory cell comprises a multilayer gate heating structure formed over a channel region between source and drain regions. The multilayer gate heating structure comprises polysilicon and metal silicide layers stacked over a similarly shaped gate oxide. When a programming voltage is applied across the metal silicide layer, there is intense localized heating. The heating causes segregation of the channel dopant atoms towards the source and drain regions, lowering the threshold voltage of the device. The heating causes carrier activation in the polysilicon layer and dopant penetration through the oxide layer into the channel region, thereby increasing the threshold voltage of the device.

Abstract: A system for gray-code counting in an integrated circuit such as a programmable logic device uses a binary adder coupled to a binary counter output and to a selected binary offset value. The binary adder provides a binary sum that is converted to a gray code value by a binary-to-gray converter. The gray code value represents the binary sum output.

Abstract: Structures enabling the efficient testing of interconnect in programmable logic devices (PLDS), and methods utilizing these structures. A PLD includes a non-homogeneous array of programmable logic blocks and an array of standardized interconnect blocks, where the same interconnect block is used for different types of logic blocks. Coupled between each of the interconnect blocks and the associated logic block is a standardized test structure, allowing the same test configuration to be used for each interconnect block even though the interconnect blocks are associated with logic blocks of different types. In some embodiments, one or more types of logic blocks are not associated with standardized test structures. These logic blocks are coupled directly to their associated interconnect blocks, and are preferably of a type that can be configured to emulate the standardized test structure. Thus, by a correct application of configuration data all of the interconnect blocks display the same behavior.

Abstract: Method to determine path timing to and from an embedded device is described. More particularly, clock-to-output delays, interconnects and interconnect logic delays, and setup and hold times for input and output paths from a microprocessor core and a memory controller are obtained and determined, as applicable. These times are assembled in a spreadsheet for associating with respective signals. Times for each of the signals are totaled to determine respective path delays for comparison with a target clock period.

Abstract: An integrated circuit having an embedded first-in, first-out (“FIFO”) memory system uses an embedded block random access memory (“BRAM”). Counters operate in both the read and write clock domains. A binary adder adds a first selected offset value and to a first pointer address, and the sum is converted to a first gray code value. The first gray code value is compared to a second gray code value that represents a second pointer address. If the first gray code value equals the second gray code value, the output of the comparator is provided to a logic block that produces a status flag (e.g. ALMOST FULL or ALMOST EMPTY) in the correct clock domain.

Abstract: An interconnect assembly to electrically interconnect one or more integrated circuits to an electronic device may comprise a base package to couple to a circuit board of the electronic device. A terminal mezzanine package may support the integrated circuit(s) above the base package. A first set of conductors of a first material and design carry low-frequency signals between the base and terminal connector packages. A second set of conductors of a second material and design carry high-frequency signals. In particular embodiments the base package may comprise a base mezzanine integrating one or more additional integrated circuits and intermediate mezzanines supporting one or more additional integrated circuits each and enabling multi-story modular interconnection structures. In particular embodiments, the second set of conductors may comprise columns of compressible polymer compound embedded with metallized particles, and the columns may be dispersed amongst pins and sockets of a pin-grid array.

Abstract: Described are high-speed parallel-to-serial converters. The converters include data combiners with differential current-steering circuits that respond to parallel data bits by producing complementary current signals representing a differential, serialized version of the parallel data bits. One embodiment includes inductive and resistive loads to equalize the gain over the frequency of interest to reduce data-deterministic jitter.

Abstract: The invention provides an interface that can facilitate integration of user specific proprietary cores and commercially available cores during customization of an FPGA-based SoC. A selected hardware or software system component used for customizing the FPGA-based SoC can be configured using parameters that can be automatically propagated and used to configure peer system components. During configuration of the peer system components, other parameters used to configure those peer system components can also be propagated and used to configure other system components during customization of the FPGA-based SoC.

Abstract: To prevent copying of a design implemented in a programmable logic device (PLD), the PLD itself stores a decryption key or keys loaded by the designer, and includes a decryptor for decrypting an encrypted configuration bitstream as it is loaded into the PLD. The PLD also includes logic for reading header information that indicates whether the bitstream is encrypted, and can accept both encrypted and unencrypted bitstreams. The encryption keys may be stored in non-volatile memory or backed up with a battery so that they are retained when power is removed.

Abstract: A memory cell comprises a multilayer gate heating structure formed over a channel region between source and drain regions. The multilayer gate heating structure comprises polysilicon and metal silicide layers stacked over a similarly shaped gate oxide. When a programming voltage is applied across the metal silicide layer, there is intense localized heating. The heating causes segregation of the channel dopant atoms towards the source and drain regions, lowering the threshold voltage of the device. The heating causes carrier activation in the polysilicon layer and dopant penetration through the oxide layer into the channel region, thereby increasing the threshold voltage of the device.

Abstract: An FPGA includes a programmable interconnect structure in which the interconnect resources are divided into two groups. A first subset of the interconnect resources are optimized for high speed. A second subset of the interconnect resources are optimized for low power consumption. In some embodiments, the transistors of the first and second subsets have different threshold voltages. Transistors in the first subset, being optimized for speed, have a lower threshold voltage than transistors in the second subset, which are optimized for low power consumption. The difference in threshold voltages can be accomplished by using different doping levels, wells biased to different voltage levels, or using other well-known means. In some embodiments, the first subset of the interconnect resources includes buffers coupled to a higher voltage level than the second subset. In some embodiments, the first subset includes buffers manufactured using larger transistors than those in the second subset.

Abstract: The invention provides an interface that can facilitate integration of user specific proprietary cores and commercially available cores during customization of an FPGA-based SoC. A selected hardware or software system component used for customizing the FPGA-based SoC can be configured using parameters that can be automatically propagated and used to configure peer system components. During configuration of the peer system components, other parameters used to configure those peer system components can also be propagated and used to configure other system components during customization of the FPGA-based SoC.

Abstract: A low power LVDS driver includes a switchable current module, a source termination circuit, a transistor section, and a load current source. The switchable current module is operably coupled to produce a first current when a differential input signal is in a first state and to produce a second current when the differential input signal is in a second state. The source termination circuit is operably coupled in parallel with a load. The transistor section is operably coupled to receive the first and second currents from the switchable current module via at least one of the source termination circuit and the load, wherein the transistor section produces an LVDS output signal based on the first and second currents, the differential input signal, and the source termination circuit. The load current source is operably coupled to sink the first and second currents from the transistor section.

Abstract: Method and apparatus for a nonlinear current circuit element are described, and method and apparatus using the nonlinear current circuit element in current-source self-biasing circuits are described. In one embodiment, a transistor is provided having source and drain terminals coupled together. This transistor has a significant gate tunneling current used beneficially to provide a nonlinear current circuit element. This nonlinear current circuit element is used in a plurality of current-source self-biasing circuits.