Xilinx, Inc.

Jason R Bergendahl

Suresh M Menon

Atul V Ghia

Paul T Sasaki

Jian Tan

Steven P Young

Trevor J Bauer

Qi Zhang

Ping-Chen Liu

David P Schultz

Christopher D Ebeling

Arthur Behiel

Eunice Y D Hao

Venu M Kondapalli

Matthew H Klein

Warren E Cory

Scott O Frake

Hassan K Bazargan

Ketan Sodha

Prasad Rau

Chee Chong Chan

An integrated circuit comprises programmable resources; a plurality of hard blocks; and a programmable connector coupled to the programmable resources, the plurality of hard blocks; wherein the programmable connector is configurable to route signals between a first hard block and a second hard block in a first mode of operation and to route signals between the first hard and the programmable resources in a second mode of operation.

Circuit for and method of providing a programmable connector of an integrated circuit device

Signal distribution of a regional signal is described. An integrated circuit includes a global signal distribution network, a regional signal distribution network and a regional buffer. The regional buffer has an output coupled at an end of the regional signal distribution network. The regional signal distribution network is coupled to a configurable logic block via an interconnect tile. The regional buffer is coupled to a regional clock capable input/output block. Additionally described is a source synchronous interface for regional signal distribution.

Regional signal-distribution network for an integrated circuit

An input/output (I/O) structure includes a delay element usable for the input path, the output path, or both input and output paths in a user design. In a first mode, the delay element is included in the input path. In a second mode, the delay element is included in the output path. In a third mode, the I/O structure includes the delay in both outgoing signal paths and incoming signal paths, e.g., by utilizing an output tristate signal to control the direction of the delay line. When the output buffer is driving, the delay is inserted in the output path. When the output buffer is tristated, the delay is inserted in the input path. Thus, a single delay element is dynamically shared by both input and output signals that use the same I/O pad. In an optional fourth mode, the delay element is bypassed by both input and output signals.

Reversible input/output delay line for bidirectional input/output blocks

A data alignment and deskewing module includes a delay calibration unit, a data alignment and deskew unit, and a delay unit. The delay calibration unit is operably coupled to generate a reference signal based on a reference clock and a mirrored delay line output signal. The data alignment and deskew unit is operably coupled to determine a delay selection signal based on a delayed and deskewed representation of an input data stream and propagation delay of a line on which the input data stream is received. The delay unit is operably coupled to produce the delayed and deskewed representation of the input data stream based on the reference signal and the delay selection signal.

Data alignment and deskewing module

Method and apparatus for a bimodal source synchronous interface for a receiver module is described. A first input cell with a first delay chain and a first register block is provided for receipt of a forwarded clock signal by the first delay chain. A second input cell with a second delay chain and a second register block is provided for receipt of a data signal by the second delay chain. The second input cell is configured such that output from the second delay chain is coupled to a data input of the second register block. The first input cell and the second input cell may be operated in either a first modality or a second modality. The first modality may be for interfacing to a synchronous integrated circuit interface. The second modality may be for interfacing to a synchronous network/telecommunications interface.

Bimodal source synchronous interface

A level translator includes a programmable booster stage that augments the drive level of the level translator under certain conditions. The booster stage is programmably activated. e.g., via a memory cell or control bit, and augments operation of the pull-up stages of a cross-coupled latch within the level translator. When the voltage levels at the high voltage portion of the level translator are reduced below a threshold voltage, the booster stage is activated to maintain proper operation of the level translator despite the reduced voltage levels.

Method and apparatus for a programmable level translator

Signal distribution of a regional signal is described. A programmable logic device includes a global signal distribution network, a regional signal distribution network and a regional buffer. The regional buffer has an output coupled at an end of the regional signal distribution network. The regional signal distribution network is coupled to a configurable logic block via an interconnect tile. The regional buffer is coupled to a regional clock capable input/output block. Additionally described is a source synchronous interface for regional signal distribution.

Apparatus for signal distribution, and more particularly to a clock-distribution network in an integrated circuit, is described. A programmable logic deviceincludes an input buffer () and an input signal distribution buffer () coupled to the input buffer (). The input signal distribution buffer () is configured to distribute a clock signal () within an input/output block clock region (A,B). Signal lines (UD) extend to at least one other input signal distribution buffer ().

Clock signal-distribution network for an integrated circuit

A serializer-deserializer instantiated in configurable logic of an integrated circuit is described. The serializer-deserializer includes an input deserializer and an output serializer, which may be commonly coupled via an input/output pad. Each of the serializer and deserializer may be configured for an operating mode selected from a Single Data Rate mode and a Double Data Rate mode. The serializer-deserializer may be used as part of a synchronous interface.

Multi-purpose source synchronous interface circuitry

Method and apparatus for a bimodal serial to parallel converter is provided. A first stage of registers is clocked responsive to a clock signal, such as a forwarded clock signal of a synchronous interface. The first stage of registers is configurable in either a single serial shift chain or two serial shift chains. The former configuration is for Single Data Rate ('SDR') data, and the latter configuration is for Double Data Rate ('DDR') data. A bitslip controller is configured to provide a control select signal to selection circuitry. For DDR operation, the control signal is for selecting respective portions of outputs from the two serial shift chains for providing to a second stage of registers. For DDR operation, the second stage of registers is alternatively clocked responsive to a divided down version of the clock signal and another divided down version of the clock signal which is periodically stopped.

Bimodal serial to parallel converter with bitslip controller

Described are circuits and methods for aligning data and clock signals. Circuits in accordance with some embodiments separate incoming data into three differently timed data signals: an early signal, an intermediate signal, and a late signal. The timing of the three data signals can be collectively moved with respect to the clock signal. In addition, the temporal spacing between the three signals can be adjusted so that the early and late signals define a window encompassing the intermediate signal. The three signals are aligned with respect to the clock edge to center the intermediate data signal on the clock edge. The early and late signals can be monitored to identify changes in the relative timing of the clock and data signals. Some embodiments automatically alter the timing of the data and/or clock signals to keep the intermediate data signal centered on the clock edge.

Windowing circuit for aligning data and clock signals

Described are methods and circuits for aligning data and clock signals. Methods in accordance with some embodiments separate incoming data into three differently timed data signals: an early signal, an intermediate signal, and a late signal. The timing of the three data signals can be collectively moved with respect to the clock signal. In addition, the temporal spacing between the three signals can be adjusted so that the early and late signals define a window encompassing the intermediate signal. The three signals are aligned with respect to the clock edge to center the intermediate data signal on the clock edge. The early and late signals can be monitored to identify changes in the relative timing of the clock and data signals. Some embodiments automatically alter the timing of the data and/or clock signals to keep the intermediate data signal centered on the clock edge.

Methods for aligning data and clock signals

A low pass filter (LPF) is provided that smoothes and significantly slows any change in its input voltage. The capacitance of the LPF is provided by an NMOS transistor having its source and drain tied to ground. The resistance of the LPF is provided by a plurality of series-connected PMOS transistors. The gates of the PMOS transistors are coupled to ground and therefore these transistors are conducting. The PMOS transistors are fabricated in a floating well. Therefore, the LPF eliminates any capacitive coupling between a voltage supply and the well. Thus, any variation in the supply voltage fails to affect adversely the functioning of the PMOS transistors. Thus, the LPF of the present invention can advantageously smooth and significantly slow any change in its input voltage. In one embodiment, the input voltage is a reference voltage. In this manner, a voltage regulator, which receives the filtered reference voltage from the LPF, in turn provides a significantly more constant regulated voltage to the internal circuits of the IC. Thus, the present invention advantageously minimizes the possibility of a malfunction in a digital system due to a variation in the regulated voltage.

Low pass filter

A system for controlling the impedances of circuits on an integrated circuit chip is provided. At least one circuit is selected to operate as a p-channel reference circuit, and at least one circuit is selected to operate as an n-channel reference circuit. Other circuits are selected to operate as circuits and/or line termination circuits. A digitally controlled impedance (DCI) circuit controls the p-channel reference circuit to determine a desired configuration of p-channel transistors for use in the circuits. The DCI circuit further controls the n-channel reference circuit to determine a desired configuration of n-channel transistors for use in the circuits. The DCI circuit takes into account such factors as resistances of p-channel transistors in the p-channel reference circuit, resistances of n-channel transistors in the n-channel reference circuit, as well as temperature, voltage and process variations. The DCI circuit relays information identifying the desired configurations of the n-channel and p-channel transistors to the circuits. The circuits are then configured in response to this information.

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Sunnyvale, CA, United States of America

Jason R Bergendahl