Patents Assigned to Xilinx, Inc.
  • Patent number: 6897663
    Abstract: A wafer of integrated circuits under test (ICUT) is tested by supplying power to the ICUTs using power and ground traces that extend between rows of the ICUTs in scribe streets. Test information is supplied to each ICUT by transmitting the test information optically onto the entire wafer. A diode on each ICUT receives the optical test information. The ICUT uses the test information to perform a self-test. Each ICUT has a diode for transmitting optical test information. All ICUTs on the wafer transmit results of the self-tests at the same time. A test device receives the optical test information and identifies the information from each of the many ICUTs, one from another. An entire wafer of ICUTs is therefore tested simultaneously without using a probe card either to power an ICUT or to supply test information to or receive test information from an ICUT.
    Type: Grant
    Filed: September 15, 2004
    Date of Patent: May 24, 2005
    Assignee: Xilinx, Inc.
    Inventor: Robert O. Conn
  • Patent number: 6897676
    Abstract: A programmable logic device (PLD) includes columns of block memory interposed between columns of configurable logic blocks (CLBs). Each column of block memory includes a plurality of random access memories (RAMs) that share common configuration address lines that do not allow the RAMs in block memory column to be individually addressed. For some embodiments, each RAM in the column includes interface logic that selectively enables the RAM during configuration operations in response to a configuration enable bit, which may be provided to the PLD in a configuration bitstream and stored in a shadow register associated with the RAM.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: May 24, 2005
    Assignee: Xilinx, Inc.
    Inventor: Raymond C. Pang
  • Patent number: 6898776
    Abstract: A method for concurrently programming a series of in-system devices by grouping the devices into sequentially-programmed groups, wherein a best possible grouping of devices is determined that achieves a minimum total configuration time. When a system includes multiple devices, it is sometimes more efficient (i.e., requires less total configuration time) to program the devices in two or more groups, as compared to programming all of the devices at the same time (i.e., as a single group). The method utilizes device information to identify an optimal or best grouping by comparing the total configuration times of several possible groupings, and selecting the grouping having the lowest total configuration time. Once a best grouping is determined, programming is performed by selecting a first group from the grouping and programming the first group while bypassing devices all other groups. Once the first group is programmed, a next group is programmed, and so on.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: May 24, 2005
    Assignee: Xilinx, Inc.
    Inventors: Neil G. Jacobson, Emigdio M. Flores Jr., Sanjay Srivastava, Bin Dai, Sungnien Jerry Mao
  • Patent number: 6894527
    Abstract: A security circuit for a reprogrammable logic IC includes an evolved circuit that ties the performance of the security circuit to the physical properties of that particular reprogrammable logic IC. The security circuit can be a decryption and/or encryption circuit that decrypts and/or encrypts, respectively, a configuration bitstream for the IC. Because of the link between the performance of the security circuit and the physical properties of the IC, the security circuit cannot be used in other ICs. For example, an encrypted bitstream that can be decrypted by the security circuit in a first IC will typically not be decrypted by the same security circuit in a second IC, since the physical properties of the two ICs will typically be different. The evolved circuit can comprise a portion of the security circuit, such as a security key generator, or it can comprise the full security circuit.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: May 17, 2005
    Assignee: Xilinx, Inc.
    Inventors: Adam P. Donlin, Stephen M. Trimberger
  • Patent number: 6895566
    Abstract: Test methods and circuits isolate thermal effects from AC effects on circuit performance. Critical paths for a failing programmable logic device (PLD) are identified and tested. This testing minimizes the impact of power-supply flicker and noise by eliminating or inactivating circuitry not required to test the critical paths. DC thermal energy generators are instantiated on the PLD adjacent the critical paths to heat the critical paths to one or more test temperatures. The critical paths are then tested over an appropriate range of temperatures and supply-voltages.
    Type: Grant
    Filed: November 19, 2002
    Date of Patent: May 17, 2005
    Assignee: Xilinx, Inc.
    Inventors: Siuki Chan, Steven H. C. Hsieh
  • Patent number: 6891258
    Abstract: Structures that provide decoupling capacitance to packaged IC devices with reduced capacitor and via parasitic inductance. A capacitive interposer structure is physically interposed between the packaged IC and the PCB, thus eliminating the leads and vias that traverse the PCB in known structures. A capacitive interposer is mounted to a PCB and the packaged IC is mounted on the interposer. The interposer has an array of lands on an upper surface, to which the packaged IC is coupled, and an array of terminals on a lower surface, which are coupled to the PCB. Electrically conductive vias interconnect each land with an associated terminal on the opposite surface of the interposer. Within the interposer, layers of a conductive material alternate with layers of a dielectric material, thus forming parallel plate capacitors between adjacent dielectric layers. Each conductive layer is either electrically coupled to, or is electrically isolated from, each via.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: May 10, 2005
    Assignee: Xilinx, Inc.
    Inventors: Mark A. Alexander, Robert O. Conn, Steven J. Carey
  • Patent number: 6891384
    Abstract: An interface structure includes first and second portions. The first portion has physical dimensions that are compatible with the docking area of an associated device tester, and includes a first socket configured to receive a first BGA package. The second portion, which is adjacent to and contiguous with the first portion, extends laterally beyond the docking area of the device tester to provide additional testing area that may include one or more additional sockets. In one embodiment, the second portion includes a second socket configured to receive a second BGA package, wherein the second size and configuration of second BGA package are different from the size and configuration of the first BGA package.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: May 10, 2005
    Assignee: Xilinx, Inc.
    Inventors: Mohsen Hossein Mardi, Joseph Macabante Juane
  • Patent number: 6891395
    Abstract: Disclosed are methods for utilizing programmable logic devices that contain at least one localized defect. Such devices are tested to determine their suitability for implementing selected designs that may not require the resources impacted by the defect. If the FPGA is found to be unsuitable for one design, additional designs may be tested. The test methods in some embodiments employ test circuits derived from a user's design to verify PLD resources required for the design. The test circuits allow PLD vendors to verify the suitability of a PLD for a given user's design without requiring the PLD vendor to understand the user's design.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: May 10, 2005
    Assignee: Xilinx, Inc.
    Inventors: Robert W. Wells, Zhi-Min Ling, Robert D. Patrie, Vincent L. Tong, Jae Cho, Shahin Toutounchi
  • Patent number: 6891397
    Abstract: Apparatus for network and system on a single programmable logic device is described. The programmable logic includes port modules. The port modules have configurable logic configured to process communications for routing communications. The port modules are configured to the process communications for at least one of a plurality of protocols.
    Type: Grant
    Filed: April 21, 2003
    Date of Patent: May 10, 2005
    Assignee: Xilinx, Inc.
    Inventor: Gordon J. Brebner
  • Patent number: 6889266
    Abstract: An existing field of a descriptor is used to store metadata associated with a block of data to be transferred. The metadata is sent to a device using a special command when transferring the block of data from a memory to the device. The metadata is sent to the device using an existing bus. The metadata is sent to the device from the field of the descriptor. The metadata may carry packet boundary information, transmit status information, or receive status information.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: May 3, 2005
    Assignee: Xilinx, Inc.
    Inventor: Laurent Stadler
  • Patent number: 6889368
    Abstract: Method and apparatus for localizing faults within an integrated circuit is described. For example, a programmable logic device (PLD) is configured with a test pattern. A test stimulus is applied to the test pattern. State data responsive to the test pattern is obtained. The state data may be obtained from a readback datastream generated by the PLD. The expected state data may be generated by a second PLD that is known to contain no faults. The state data is compared with expected state data to produce difference information. The difference information is used, or more particularly is iteratively generated, to localize a fault or faults within a unit under test.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: May 3, 2005
    Assignee: Xilinx, Inc.
    Inventors: David Mark, Randy J. Simmons, Min Luo
  • Patent number: 6886152
    Abstract: A delay optimization algorithm has four major steps: (1) selecting signal connections to target for delay improvement; (2) unrouting all signals containing those candidate connections; (3) rerouting those signals, using a “load-balancing”heuristic; and (4) during rip-up and re-try routing, protecting wiring to all signal loads routed by the heuristic, including non-timing critical loads. Load balancing includes (a) applying a branching penalty on logic cell output wire segments, and (b) encouraging all non-route critical loads to route through a single buffered wire segment.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: April 26, 2005
    Assignee: Xilinx, Inc.
    Inventor: Raymond Kong
  • Patent number: 6886092
    Abstract: A method and apparatus for processing data within a programmable gate array begins when a fixed logic processor that is embedded within the programmable gate array detects a custom operation code. The processing continues when the fixed logic processor provides an indication of the custom operational code to the programmable gate array. The processing continues by having at least a portion of the programmable gate array, which is configured as a dedicated processor, performing a fixed logic routine upon receiving the indication from the fixed logic processor.
    Type: Grant
    Filed: November 19, 2001
    Date of Patent: April 26, 2005
    Assignee: Xilinx, Inc.
    Inventors: Stephen M. Douglass, Ahmad R. Ansari
  • Publication number: 20050084076
    Abstract: Method and apparatus for a wireless local area network programmable logic device is described. More particularly, a field programmable gate array (FPGA) is coupled to memory having programming instructions for configuring the FPGA with a medium access layer selected from more than one type of medium access layers. A physical layer is hardwired or embedded on the FPGA, or a separate integrated circuit for the physical layer is used. Additionally, the memory comprises programming instructions for a baseband controller, and may include programming instructions for a baseband processor, for configuring the FPGA in accordance therewith. In this manner, a single physical layer may be used with an FPGA to provide a multi-platform application specific standard product (ASSP). This is especially advantageous for providing multi-platform devices for use in countries or applications where one or more standards may be employed.
    Type: Application
    Filed: December 3, 2001
    Publication date: April 21, 2005
    Applicant: Xilinx, Inc.
    Inventors: Amit Dhir, Krishna Rangasayee
  • Patent number: 6882182
    Abstract: A tunable clock distribution system is used to minimize the power dissipation of a clock distribution network in an integrated circuit. The tunable clock distribution system provides a tunable inductance on the clock distribution network to adjust a resonant frequency in the tunable clock distribution system. The inductance is tuned so that the resonant frequency of the tunable clock distribution system approaches the frequency of the clock signal on the clock distribution network. As the resonant frequency of the tunable clock distribution system approaches the frequency of the clock signal, the power dissipation of the clock distribution network decreases. Some embodiments also provide a tunable capacitance on the clock distribution network to adjust the resonant frequency of the tunable clock distribution system.
    Type: Grant
    Filed: September 23, 2003
    Date of Patent: April 19, 2005
    Assignee: Xilinx, Inc.
    Inventors: Robert O. Conn, Gary R. Lawman, Christopher H. Kingsley, Austin H. Lesea
  • Patent number: 6883147
    Abstract: Method and system for generating an electronic circuit design. A first logic block is instantiated in the design in response to user input controls. The first logic block includes parameters that specify its interface requirements. Bus interface blocks, which are parameterizable to connect a logic block to a bus, are provided in a library. Bus interface blocks that connect the first logic block to the bus are instantiated in the design, and the bus interface blocks are parameterized in response to the requirements of, the first logic block. The bus interface blocks are connected to the first logic block in such a way that the first logic block is extended into a peripheral that can communicate with the bus.
    Type: Grant
    Filed: November 25, 2002
    Date of Patent: April 19, 2005
    Assignee: Xilinx, Inc.
    Inventors: Jonathan B. Ballagh, Roger Brent Milne, Jeffrey D. Stroomer, Eric R. Keller, L. James Hwang, Philip B. James-Roxby
  • Patent number: 6882224
    Abstract: A data receiver having a transfer function that exhibits peaking at high frequencies is provided to compensate an input signal provided on a transmission channel having a low pass transfer function. The data receiver includes first and second differential input terminals, which receive the differential input signal from the transmission channel. The first differential input terminal is coupled to the source of a first common gate transistor in a first self-biased common gate amplifier. The second differential input terminal is coupled to the source of a second common gate transistor in a second self-biased common gate amplifier. A differential output signal is provided from the drain terminals of the first and second common gate transistors. The first and second differential input terminals are not directly connected to any transistor gates in the data receiver, thereby enabling these differential input terminals to be safely connected directly to the transmission channel.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: April 19, 2005
    Assignee: Xilinx, Inc.
    Inventors: Michael J. Gaboury, Eric D. Groen
  • Patent number: 6882571
    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.
    Type: Grant
    Filed: October 24, 2003
    Date of Patent: April 19, 2005
    Assignee: Xilinx, Inc.
    Inventor: Kevin T. Look
  • Patent number: 6879202
    Abstract: A digital frequency synthesizer (DFS) circuit adds little additional delay on the clock path. True and complement versions of an input clock signal are provided to a first and second passgates, respectively. Under the direction of a control circuit, the passgates pass selected rising edges of the true clock signal, and selected falling edges of the complement clock signal, to an output clock terminal of the DFS circuit. When neither the true nor the complement clock signal is passed, a keeper circuit retains the value already present at the output clock terminal. In some embodiments, both passgates can be disabled and a ground or power high signal can be applied to the output terminal. Other embodiments include PLDs in which the DFS circuits are employed to allow individual clock control for each programmable logic block.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: April 12, 2005
    Assignee: Xilinx, Inc.
    Inventor: Andy T. Nguyen
  • Patent number: 6878561
    Abstract: Described are mask-alignment detection structures that measure both the direction and extent of misalignment between layers of an integrated circuit using resistive elements for which resistance varies with misalignment in one dimension. Measurements in accordance with the invention are relatively insensitive to process variations, and the structures using to take these measurements can be formed along with other features on an integrated circuit using standard processes. One embodiment of the invention may be used to measure misalignment between two conductive layers. Other embodiments measure misalignment between diffusion regions and conductors and between diffusion regions and windows through which other diffusion regions are to be formed. A circuit in accordance with one embodiment includes row and column decoders for independently selecting mask-alignment detection structures to reduce the number of test terminals required to implement the detection structures.
    Type: Grant
    Filed: October 7, 2003
    Date of Patent: April 12, 2005
    Assignee: Xilinx, Inc.
    Inventors: Kevin T. Look, Shih-Cheng Hsueh