Altera Corporation

Xilinx, Inc.

Tabula, Inc.

Christopher D Ebeling

Andrew Edward Caldwell

Steven L Teig

Kent R Townley

Scott J Weber

Shangzhi Sun

Hung Q Nguyen

Shilpa V Yeole

Timothy J Callahan

Michael Glenn Wrighton

Steven P Young

Trevor J Bauer

Trevis Chandler

Hamish T Fallside

Jason R Bergendahl

Nicolas J Camilleri

Arthur Behiel

Prasun K Raha

Martin L Voogel

David P Schultz

Michael Alan Baxter

Peter H Alfke

David Bruce Parlour

For an integrated circuit (IC) that is designed to execute user defined operations after initialization, a sequencing circuitry in the IC that delays the start of the user design execution until a set of initial condition has been computed and propagated is provided. The sequencing holds the first group of circuits at an initial state while a second group of circuits computes and propagates a set of initial conditions based at least partly on the initial state of the first group of circuits. The circuits in the first group when being held disregard their inputs and do not change their outputs. The first group of circuits is released from its initial state after the second group of circuits has completed computation and propagation of the set of initial conditions. The circuits in the first group when released are freed to store or clock-in new inputs and produce new outputs in order to perform the user defined operations in conjunction with the second group of circuits.

Delaying start of user design execution

A novel integrated circuit (IC) that configurably distributes clocks from multiple clock sources to multiple sets of circuits is described. The IC includes multiple clock sources and multiple clock domains. Each clock domain includes a clock signal and a control signal. The clock signal is configurably selected from one of the multiple clock sources. The control signal is synchronized to the clock signal. The IC also includes multiple configurable circuits. A configurable circuit can configurably operate in one of the clock domains by selecting and using the control signal and the clock signal of the clock domain.

Clock management block

An integrated circuit (IC) that includes multiple clock domains is provided. Each clock domain operates at a user specified data rate, and the data rates of at least two of the clock domains are related by a common base clock. The specified data rate of each clock domain is controlled by a modulating signal. Each clock domain includes reconfigurable circuits that operate on the common base clock, and the modulating signal controls the data rate of the clock domain by modulating reconfiguration of the reconfigurable circuits. The reconfigurable circuits reconfigure when the modulating signal enables the reconfiguration.

Implementation of related clocks

A structure for a parallel cyclic redundancy check (CRC) structure in which the number of cycles in the loopback can be arbitrarily extended is provided. The parallel CRC structure includes a reweighting module in the feedback loop that is pipelined into multiple stages. The parallel CRC structure also includes multiple feed forward reweighting modules that correspond to the multiple pipeline stages in the feedback loop. The reweighting module in the feedback loop accumulates and reweights the contribution of all symbols in the message, while the N reweighting modules in the N parallel feed-forward paths provide the contributions of the symbols that are 'in-flight' within the feedback loop to the final CRC checksum.

CRC circuits with extended cycles

A novel method for designing an integrated circuit ('IC') by rescaling an original set of circuits in a design of the IC is disclosed. The original set of circuits to be rescaled includes sequential nodes, combinational nodes, and interconnects. Each sequential node is associated with a phase of a clock. The method generates a rescaled set of circuits that includes multiple replica sets of the circuits. Each replica set of circuits includes sequential nodes, combinational nodes, and interconnects that are identical to nodes and interconnects in the original set of circuits. Each sequential node is associated with a phase of a clock that is at a fraction of the phase of its corresponding sequential element in the original set. The method connects nodes in each replica set of circuits to a logically equivalent node in another replica set. The method replaces the original set of circuits with the rescaled set of circuits.

Rescaling

A low power sub-cycle reconfigurable conduit is provided. The low power reconfigurable conduit is a clocked storage element that consumes less power when performing low-throughput operations that do not require sub-cycle rate. The low power conduit includes a first configurable routing multiplexer that is reconfigurable to select one of several inputs at a first clock rate. The low power conduit also includes an array of storage elements for storing output data from the configurable routing multiplexer at the first clock rate. Each storage element in the array of storage elements operate at a second clock rate that is slower than the first clock rate. Each storage element receives a different phase of a clock that operates at the second clock rate. The low power conduit also includes a second configurable routing multiplexer that is reconfigurable to select from the array of storage elements at the first clock rate.

Configurable storage elements

A cyclic redundancy check (CRC) bit-slice circuit including a plurality of AND gates coupled with configuration data is described. The configuration data may enable the plurality of AND gates to provide a set of CRC input data and feedback polynomial data meeting a plurality of CRC protocols. The CRC bit-slice circuit accepts a generator polynomial as an input design parameter to build a CRC module. The modularity of the design then allows a larger CRC design to be constructed from multiple CRC modules such that wider data width may be accommodated. Several CRC modules can be cascaded to accommodate various data widths and to meet a plurality of CRC protocols.

Method and apparatus for implementing a cyclic redundancy check circuit

Queuing and ordering data is described. Data is stored or queued in concatenated memories where each of the memories has a respective set of data out ports. An aligner having multiplexers arranged in a lane sequence are coupled to each set of the data out ports. A virtual-to-physical address translator is configured to translate a virtual address to provide physical addresses and select signals, where the physical addresses are locations of at least a portion of data words of a cell stored in the concatenated memories in successive order. The multiplexers are coupled to receive the select signals as control select signaling to align the at least one data word obtained from each of the concatenated memories for lane aligned output from the aligner.

Queuing and aligning data

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.

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San Jose, CA, United States of America

Christopher D Ebeling