Patents Assigned to Xilinx, Inc.
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Publication number: 20050144216Abstract: Described are arithmetic circuits divided logically into a product generator and an adder. Multiplexing circuitry logically disposed between the product generator and the adder supports conventional functionality by providing partial products from the product generator to addend terminals of the adder. The multiplexing circuitry can also be controlled to direct a number of external added inputs to the adder. The additional addend inputs can include inputs and outputs cascaded from other arithmetic circuits.Type: ApplicationFiled: December 21, 2004Publication date: June 30, 2005Applicant: Xilinx, Inc.Inventors: James Simkins, Steven Young, Jennifer Wong, Bernard New, Alvin Ching
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Publication number: 20050144211Abstract: Described is a programmable logic device (PLD) with columns of DSP slices that can be combined to create DSP circuits of varying size and complexity. DSP slices in accordance with some embodiments includes programmable operand input registers that can be configured to introduce different amounts of delay, from zero to two clock cycles, for example, to support pipelining. In one such embodiment, each DSP slice includes a partial-product generator having a multiplier port, a multiplicand port, and a product port. The multiplier and multiplicand ports connect to the operand input port via respective first and second operand input registers, each of which is capable of introducing from zero to two clock cycles of delay. In another embodiment, the output of at least one operand input register can connect to the input of an operand input register of a downstream DSP slice so that operands can be transferred among one or more slices.Type: ApplicationFiled: December 21, 2004Publication date: June 30, 2005Applicant: Xilinx, Inc.Inventors: James Simkins, Steven Young, Jennifer Wong, Bernard New, Alvin Ching
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Patent number: 6912646Abstract: Prior art storage techniques have certain limitations, including requiring additional external resources to implement and not making use of all of the available storage space. A method and apparatus using a header table and, in some cases, an alternative access interface are described which allow for more efficient use of available memory space, permit an arbitrary number of data streams to be stored and accessed with a minimal interface, and provide for a simple serial connection to chain multiple memory devices together.Type: GrantFiled: January 6, 2003Date of Patent: June 28, 2005Assignee: XILINX, Inc.Inventor: Arthur H. Khu
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Patent number: 6911730Abstract: The invention provides multi-chip modules (MCMs) that utilize transistors embedded in an active substrate to provide various desirable functions, optionally including programmable functions. In some embodiments, the MCM includes an active substrate having a field-programmable universal structure. The active substrate includes a regular grid pattern of lands separated by a programmable interconnect structure similar to those used in field programmable gate arrays (FPGAs). Interconnections within the programmable interconnect structure are controlled by values stored in configuration memory cells. The regular pattern of lands on the surface of the substrate permits the use of a single programmable active substrate to mount die of various sizes by means of solder bumps positioned to correspond to the land grid on the active substrate.Type: GrantFiled: March 3, 2003Date of Patent: June 28, 2005Assignee: Xilinx, Inc.Inventor: Bernard J. New
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Patent number: 6912698Abstract: Integrated circuits, key components in thousands of products, frequently include thousands and even millions of microscopic transistors and other electrical components. Because of difficulties and costs of fabricating these circuits, circuit designers sometimes ask fabricators to produce skew lots for testing and predicting manufacturing yield. However, conventional skew lots for CMOS circuits, which are based on increasing or decreasing transistor transconductance, are not very useful in testing certain types of analog circuits, such as oscillators. Accordingly, the present inventors developed a new type of skew lot, based on increasing or decreasing gate-to-source capacitance of transistors, or more generally a transistor characteristic other than transconductance. This new type of skew lot is particularly suitable for simulating, testing, and/or making yield predictions for oscillators and other CMOS analog circuits.Type: GrantFiled: May 23, 2002Date of Patent: June 28, 2005Assignee: Xilinx, Inc.Inventors: Brian T. Brunn, Brian K. Seemann
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Patent number: 6911842Abstract: A programmable logic device (PLD) is provided that supports multi-gigabit transceivers (MGTs). The PLD includes one or more pairs of shared clock pads for receiving one or more high-quality differential clock signals. Dedicated clock traces couple each pair of shared clock pads to one or more MGTs on the PLD. Each MGT includes a clock multiplexer circuit, which allows one of the high-quality differential clock signals to be routed as a reference clock signal for the MGT. The clock multiplexer circuits are designed such that no significant jitter is added to the high-quality clock signals. The clock multiplexer circuits can also route general-purpose clock signals received by the PLD as lower quality reference clock signals for the MGTs. The reference clock signal routed by the clock multiplexer circuit can be stepped down to provide a reference clock for a physical coding sublayer of the MGT.Type: GrantFiled: March 1, 2002Date of Patent: June 28, 2005Assignee: Xilinx, Inc.Inventors: Atul V. Ghia, Vasisht M. Vadi, Adebabay M. Bekele, Philip D. Costello, Hare K. Verma
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Patent number: 6911840Abstract: An integrated circuit with overclocked embedded logic circuitry is described. In an example, a programmable logic device includes programmable logic blocks operable using a first clock signal having a first frequency. A dedicated logic circuit embedded within the programmable logic device is operable using a second clock signal synchronized with the first clock signal and having a second frequency, the second frequency being a multiple of the first frequency. An interface coupled between one or more of the programmable logic blocks and the dedicated logic circuit includes multiplexer circuitry to multiplex output signals produced by the one or more programmable logic blocks among input terminals of the dedicated logic circuit.Type: GrantFiled: June 6, 2003Date of Patent: June 28, 2005Assignee: Xilinx, Inc.Inventors: Roger B. Milne, Jonathan B. Ballagh
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Patent number: 6912706Abstract: A method and arrangement for executing instructions of a computer program using a programmable logic device to perform selected functions of the program. Profile data for code segments of the computer program are generated during program execution. Based on the profile data, a code segment is selected for transformation to a hardware implementation. The functionality of the selected code segment is transformed into a configuration bitstream, and the PLD is configured with the configuration bitstream. During program execution, the PLD is activated in lieu of executing the code segment.Type: GrantFiled: August 15, 2001Date of Patent: June 28, 2005Assignee: Xilinx, Inc.Inventors: Reto Stamm, Ciaran McGloin, David McNicholl
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Publication number: 20050134339Abstract: A data density independent clock and data recovery system includes a lock phase adjust charge pump operably coupled to receive phase information and transition information from a phase detector and to produce a current signal, responsive to the phase information and transition information, to a loop filter that converts the current signal to a control voltage signal operably coupled to a voltage controlled oscillator that produces a clock signal to the phase detector based on the control voltage signal. The lock phase adjust charge pump includes a phase charge pump, a transition charge pump, a programmable DC bias current sink, and two programmable offset bias current sinks. The transition charge pump includes a programmable transition current sink. The control logic operates under external control to adjust the currents conducted by the transition charge pump, the programmable DC bias current sink, and the two programmable offset bias current sinks.Type: ApplicationFiled: February 17, 2005Publication date: June 23, 2005Applicant: Xilinx, Inc.Inventors: Ahmed Younis, Firas Abughazaleh
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Patent number: 6910002Abstract: In one embodiment, a method for specifying addressability in a memory-mapped device is disclosed. A data access primitive is used to model addressablity for the memory-mapped device. Addressability comprises an address matching function, a lane matching function and one or more bus connections. A first starting address for the memory-mapped device is specified. A first set of addressing matching function, lane matching function and one or more bus connections for the memory-mapped device is generated using the data access primitive and the first starting address.Type: GrantFiled: August 23, 2000Date of Patent: June 21, 2005Assignee: Xilinx, Inc.Inventors: Bart Reynolds, Cheng-I Chuang, Chukwuweta Chukwudebe, Sridhar Krishnamurthy, Damon McCormick, Tom Shui, Kai Zhu
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Patent number: 6908340Abstract: A method and system for configuring the transmit and receive elements or structures in connector such that crosstalk can be reduced. The connector connects serdes modules in first PCB to serdes modules in one or more second PCBs via a backplane. The connector includes: first and second transmit connection positions in a first direction; first and second receive connection positions; and a ground shield positioned in the first direction between the first and second transmit connection positions and the first and second receive connection positions, wherein the first and second transmit connection positions do not have an interposing ground shield in another direction.Type: GrantFiled: September 11, 2003Date of Patent: June 21, 2005Assignee: Xilinx, Inc.Inventor: Matthew S. Shafer
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Patent number: 6907595Abstract: A programmable logic device, such as a field programmable gate array, is partially reconfigured using a read-modify-write scheme that is controlled by a processor. The partial reconfiguration includes (1) loading a base set of configuration data values into a configuration memory array of the programmable logic device, thereby configuring the programmable logic device; (2) reading a first frame of configuration data values from the configuration memory array; (3) modifying a subset of the configuration data values in the first frame of configuration data values, thereby creating a first modified frame of configuration data values; and (4) overwriting the first frame of configuration data values in the configuration memory array with the first modified frame of configuration data values, thereby partially reconfiguring the programmable logic device. The steps of reading, modifying and overwriting are performed under the control of a processor.Type: GrantFiled: December 13, 2002Date of Patent: June 14, 2005Assignee: Xilinx, Inc.Inventors: Derek R. Curd, Punit S. Kalra, Richard J. LeBlanc, Vincent P. Eck, Stephen W. Trynosky, Jeffrey V. Lindholm, Trevor J. Bauer
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Patent number: 6907584Abstract: Method, apparatus, and computer readable medium for producing an interface description for an electronic design of an integrated circuit is described. By example, the electronic design includes a plurality of circuit descriptions representing the behavior of circuit elements. One or more circuit descriptions from the electronic design are selected to produce interface description. The one or more selected circuit descriptions include a subset of the plurality of circuit descriptions of the electronic design. A processor for modifying the electronic design is obtained. The electronic design is then processed using the processor with the interface description as parametric input.Type: GrantFiled: March 14, 2003Date of Patent: June 14, 2005Assignee: Xilinx, Inc.Inventors: Roger B. Milne, Jeffrey D. Stroomer
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Patent number: 6906571Abstract: Phased clock generator circuits and methods that use counters to define the desired positions of the phased output clock edges. A plurality of counters are each clocked by a count clock relatively much faster than the input clock. A first counter counts for one input clock period, and the counted value is stored. The stored value is then divided and added to provide the number of counts in various fractions of the input clock period. The divided and/or added values are provided to a second counter that counts from zero and generates various pulses at desired times throughout the input clock period. The pulses from the second counter are used (sometimes in combination with the input clock signal) to provide phased output clock signals at predetermined times during the input clock cycle. Some embodiments include a duty cycle correction feature. In some embodiments, duty cycle correction is optional.Type: GrantFiled: October 28, 2003Date of Patent: June 14, 2005Assignee: Xilinx, Inc.Inventor: Andy T. Nguyen
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Patent number: 6906562Abstract: Clock multiplier circuits and methods use counters to define the positions of the output clock edges. A plurality of counters are each clocked by a count clock relatively much faster than the input clock. A first counter counts for one input clock period, and the counted value is stored. The stored value is then divided and added to provide the number of counts in various fractions of the input clock period. The divided and/or added values are provided to a second counter that counts from zero and generates various pulses at desired times throughout the input clock period. The pulses from the second counter are used (sometimes in combination with the input clock signal) to provide output clock edges at predetermined times during the input clock cycle.Type: GrantFiled: August 29, 2003Date of Patent: June 14, 2005Assignee: Xilinx, Inc.Inventor: Andy T. Nguyen
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Patent number: 6904527Abstract: Individual IP vendors can directly license their IP modules to PLD users. Each PLD has a unique device identifier (UDI). If a user obtains a license to use an IP module on a particular PLD, then the IP vendor issues the user an authorization code (AC). The user supplies the AC to a license manager. The license manager decrypts the AC and checks that the UDI of the supplied AC matches the UDI of the PLD. If the two match, then the license manager encrypts a key, and sends the encrypted key to the PLD. The PLD uses a private key to decrypt the key. When the configuration bitstream for the design is later sent to the PLD, the license manager encrypts the IP module portion of the bitstream with the key. The PLD receives the bitstream and uses the decrypted key to decrypt the IP module portion.Type: GrantFiled: March 14, 2000Date of Patent: June 7, 2005Assignee: Xilinx, Inc.Inventors: David B. Parlour, Richard S. Ballantyne
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Patent number: 6904375Abstract: A bridge circuit disposed between a device under test (DUT) and conventional automatic test equipment (ATE) extends the performance of the ATE. The bridge circuit allows the ATE to test ICs capable of operating at frequencies above the ATE's normal performance limits. In some embodiments, the bridge circuit also extends ATE functionality, providing frame alignment and automatic test-vector generation, for example, and can increase the number of available test channels.Type: GrantFiled: January 22, 2003Date of Patent: June 7, 2005Assignee: Xilinx, Inc.Inventors: Sabih Sabih, Jari Vahe
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Patent number: 6903571Abstract: Programmable systems and devices that include programmable multiplexers designed to minimize the impact of single event upsets (SEUs) on triple modular redundancy (TMR) circuits. In a programmable routing multiplexer, each path through the multiplexer is controlled by a different configuration memory cell. A unidirectional buffer is included on each routing path through the multiplexer. Therefore, an SEU changing the state of any single memory cell does not short together any two input terminals of the multiplexer. Hence, when a TMR circuit is implemented using the multiplexer, an SEU affecting the multiplexer causes no more than one TMR module to become defective. The other two TMR modules together provide the correct output signal, outvoting the defective module, and the circuit continues to operate correctly.Type: GrantFiled: November 18, 2003Date of Patent: June 7, 2005Assignee: Xilinx, Inc.Inventor: Stephen M. Trimberger
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Patent number: 6904574Abstract: Method and apparatus for automatically eliminating inferred latches created by hardware design language (HDL) source code is described. A node tree is built from the HDL source code based on the HDL's Language Reference Manual. The node tree is scanned to identify one or more conditional logic constructs that are sources for creation of inferred latches. A modified node tree is generated by automatically adding and/or modifying sub-productions of the conditional language constructs that create the inferred latches.Type: GrantFiled: September 10, 2002Date of Patent: June 7, 2005Assignee: Xilinx, Inc.Inventor: Andrew M. Bloom
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Patent number: 6904397Abstract: A system and method for developing a reusable electronic circuit design module are presented in various embodiments. In one embodiment, the functional design elements comprising a design module are entered into a database along with documentation elements that describe the design elements. The functional design elements are linked with selected ones of the documentation elements in the database. A testbench is simulated with the design module, and the generated results are stored in a database and linked with the functional design elements. By linking the simulation results, documentation, and design elements, the characteristics of the design module are easily ascertained by a designer who is reusing the design module.Type: GrantFiled: February 22, 2000Date of Patent: June 7, 2005Assignee: Xilinx, Inc.Inventors: Carol A. Fields, Anthony D. Williams