Abstract: Described are fast synchronous counters with reduced combinatorial logic. In one embodiment, a four-bit shift register is configured in a ring and preset with a data pattern (e.g., 1000). The register is then rapidly shifted into any of four unique states. Combinatorial logic connected to the shift register converts the four unique states into a two-bit binary signal representative of the four states. In the general case, counters in accordance with this embodiment represent N-bit binary numbers using 2N synchronous storage elements. Two or more counters can be combined to produce larger synchronous counters. An up/down counter in accordance with yet another embodiment is connected to a multi-path delay line to create a variable delay circuit. The switching speed of the delay circuit is independent of the number of delay settings. Also advantageous, the delay circuit scales linearly, in terms of power consumption and area, with changes in delay granularity.

Abstract: A method and apparatus for managing an optical transceiver includes processing that begins by transceiving management data with modules external to the optical transceiver. The processing then continues by converting the management data transceived with the external modules between a 1st data format (e.g., MDIO interface compatible) and a generic data format (e.g., a format convenient for reading data to and writing data from a random access memory). The processing continues by transceiving management data with modules internal to the optical transceiver. The processing continues by converting the management data transceived with the internal modules between the generic data format and a 2nd data format (e.g., I2C). The processing continues by arbitrating access to a shared memory, which stores the management data in the generic format, between requests from internal modules via the second controller and requests from external modules via the first controller.

Abstract: A high-speed optical transceiver for an integrated circuit (IC) includes a serializer-deserializer (SERDES) and a vertical cavity surface emitting laser (VCSEL) combined with a detector array. By covalently bonding the SERDES die to the IC, the two components can be processed simultaneously to produce a tightly aligned, high-speed data interface. The SERDES can be coupled to the VCSEL/detector array using a flex interconnect, or the VCSEL/detector array can also be covalently bonded to the IC or SERDES to maximize data bandwidth. The SERDES and VCSEL/detector array can also be produced in a single die using a process technology appropriate for both to maximize manufacturing efficiency.

Abstract: A memory device having single event upset (SEU) resistant circuitry includes a first inverter having an input and an output, a second inverter having an input and an output, a first transistor having a gate coupled to the input of the first inverter and having source and drain regions coupled to the output of the second inverter, and a second transistor having a gate coupled to the input of the second inverter and having source and drain regions coupled to the output of the first inverter.

Abstract: Described are high-speed differential flip-flops. A flip-flop in accordance with one embodiment incorporates some combinational logic, eliminating the need for separate combinational logic when the flip-flop is employed in certain circuit configurations. A flip-flop in accordance with another embodiment includes differential input and output stages, each of which includes a transistor connected across its differential output terminals. The transistors are clocked to short the differential output terminals between expressions of logic levels, thereby limiting the maximum amount of voltage swing required to express subsequent logic levels.

Abstract: Method for configuring a routing program for routing connections between an integrated circuit device and an embedded core is described. More particularly, horizontal and a vertical pitch are obtained for the integrated circuit device and the embedded core. A horizontal or a vertical pitch is selected from the embedded core to define pitch for the integrated circuit device to accommodate difference in pitch between the two. Additionally, an integrated circuit having interconnect layers using this compromise pitch are described.

Abstract: A method for customization of the software of an FPGA-based SoC includes the steps of selecting (380) a system component used for customizing the FPGA-based SoC, configuring (382) the selected system component with parameters for use with the FPGA-based SoC and propagating (384) the parameters used to configure the selected system component to peer system components. The method further includes the step of configuring (388) the peer system components using the propagated parameters during customization of the FPGA-based SoC and creating (401) a software interface to the selected system components and to the peer system components.

Abstract: A serially programmable integrated circuit (IC) includes a memory array and multiple data registers daisy-chained by bypass logic. Each of the data registers is associated with a primary column grouping or redundant column grouping in the memory array. If a data register is associated with a primary column grouping that includes a defective column, the bypass logic bypasses that data register and incorporates one of the data registers associated with a redundant column grouping into the serial programming path of the IC. Therefore, when a programming bitstream is shifted into this serial programming path, defective columns in the memory array are automatically bypassed during the subsequent programming operation. To read a word from the memory array, any data stored in the redundant columns is first read out, and then the data from the primary columns is read out, bypassing the previously identified defective column groupings.

Abstract: A voltage generation circuit for generating a read-back voltage in response to a supply voltage and a reference voltage. The voltage generation circuit includes a comparator configured to receive the supply voltage and the reference voltage. The voltage generation circuit activates a select signal if the supply voltage has a predetermined relationship with respect to the reference voltage, and de-activates the select signal if the supply voltage does not exhibit the predetermined relationship with respect to the reference voltage. An adjustable voltage divider circuit is coupled to receive the supply voltage and the select signal. The adjustable voltage divider circuit is configured in response to the select signal to provide an output voltage that is a first percentage of the supply voltage if the select signal is activated, and provide an output voltage that is a second percentage of the supply voltage if the select signal is de-activated.

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.

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.

Abstract: In modular design flow, logic designers are able to partition a top-level logic design for a PLD into modules and implement any module independently from other modules. Modules are mapped, placed, and routed using selected information derived at the time the top-level logic design is partitioned. Finally, the modules are integrated into the top-level logic design using a guided process. Specifically, the information generated during the partitioning of the top-level design and the implementation of each module is used to guide the implementation of the associated logic in the top-level design. In this manner, the implementation of all modules can proceed in any order or in parallel and the integration of the modules into the top-level design can be done quickly and in any order.

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: 8b/10b encoding begins when an input running disparity is received. The processing then continues by receiving an 8-bit digital input that includes a 5-bit digital input portion and a 3-bit digital input portion. The processing then continues by determining, in parallel, a 6-bit running disparity and a 4-bit running disparity. The processing then continues by determining a 6-bit digital output based on the 6-bit running disparity and the 5-bit digital input portion. The processing then continues by determining a 4-bit digital output based on the 4-bit running disparity and the 3-bit digital input portion. The resulting 10-bit encoded digital output is the combination of the 6-bit digital output and the 4-bit digital output.

Abstract: Structures and methods for generating high reliability designs for PLDs on which single event upsets have minimal impact. When standard triple modular redundancy (TMR) methods are used in PLDs, a single event upset can short together two module output signals and render two of the three voting circuit input signals invalid. The invention addresses this issue by providing quintuple modular redundancy (QMR) for high-reliability circuits implemented in PLDs. Thus, a single event upset that inadvertently shorts together two PLD interconnect lines can render invalid only two out of five module output signals. The majority of the five modules still provide the correct value, and the voting circuit is able to correctly resolve the error. In some embodiments, a user selects a high-reliability circuit implementation option and/or a PLD particularly suited to a QMR implementation, and the PLD implementation software automatically implements the QMR structure for the user circuit.

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: 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.

Abstract: Method and apparatus for partial reconfiguration of a programmable logic device (PLD). In one embodiment, a configuration store is arranged for storage of configuration data for a selected subset of the reconfigurable resources of the PLD. A modification store is configured with addresses and associated data values. Each address in the modification store references an address in the configuration store, and each associated data value indicates a configuration state for one of the reconfigurable resources of the PLD. A controller is coupled to the configuration and modification stores and to the PLD. In response to a reconfiguration signal, the controller reads an address and associated data value from the modification store, updates the configuration store at the address read from the modification store with the associated data value, and downloads configuration data from the configuration store to the PLD.

Abstract: A method and apparatus for testing parasitic effects on conducting paths in high-speed systems using a test package which allows for very accurate measurements of the parasitic effects to be taken. The test package is designed to be nearly identical to the actual IC package and has an external connector to allow measurements to be taken through the package, instead of at a point close to the package.

Abstract: Method and apparatus are described for providing memory cells enhanced for resistance to single event upsets. In one embodiment, transistors are coupled between cross coupled inverters of a latch, thus in a small area providing both single-event-upset resistivity most of the time, and high speed during writing to the memory cell. Alternatively, inductors coupled between inverters of a latch may be used.