A method and apparatus includes receiving at a sink node a path signal frame and a modified set of idle character 64B/66B blocks. The path signal frame includes encoded client data signal 64B/66B blocks, path overhead 64B/66B data blocks and a control 64B/66B block. The link bit rate is measured. The number of idle character 64B/66B blocks is determined. The data blocks of the CBR client signal are extracted from the encoded client data signal 64B/66B blocks and the CBR client signal is regenerated from the extracted data blocks. A bit rate of the CBR client signal is determined using the measured link bit rate and the number of idle character 64B/66B blocks. The rate of a CBR signal clock is adjusted for transmitting the CBR client signal at the determined bit rate.
H04L 69/324 - Protocoles de communication intra-couche entre entités paires ou définitions d'unité de données de protocole [PDU] dans la couche liaison de données [couche OSI 2], p. ex. HDLC
One or more examples relate to an on-chip protocol analyzer provided at a physical layer of a communication interface to receive information about link control process data carried by a communication system to or from a protocol control logic of the communication interface.
H04L 69/00 - Dispositions, protocoles ou services de réseau indépendants de la charge utile de l'application et non couverts dans un des autres groupes de la présente sous-classe
H04L 47/32 - Commande de fluxCommande de la congestion en supprimant ou en retardant les unités de données, p. ex. les paquets ou les trames
One or more examples relate to an on-chip protocol analyzer provided at a physical layer of a communication interface to receive information about link control process data carried by a communication system to or from a protocol control logic of the communication interface.
H04L 69/323 - Protocoles de communication intra-couche entre entités paires ou définitions d'unité de données de protocole [PDU] dans la couche physique [couche OSI 1]
4.
Apparatus for adapting a constant bit rate client signal into the path layer of a telecom signal
A source node for rate adapting a constant bit rate client signal into a signal stream in a 64B/66B-block telecom signal communication link includes a GMP engine; a FIFO buffer coupled to receive a 64B/66B encoded client data stream; a clock rate measuring circuit; a source of 64B/66B path overhead blocks; a source of 64B/66B pad blocks; a source of 64B/66B idle blocks; a multiplexer; and a multiplexer controller. A control 64B/66B block is encoded into an ordered set block-designator and a count of data blocks to be sent in a next path signal frame is encoded into a plurality of path overhead 64B/66B data blocks. The multiplexer controller is responsive to a count of data blocks to be sent in a next path signal frame from a previous GMP window frame to selectively pass data to a data output so as to fill a GMP window frame.
H04L 69/324 - Protocoles de communication intra-couche entre entités paires ou définitions d'unité de données de protocole [PDU] dans la couche liaison de données [couche OSI 2], p. ex. HDLC
A method for rate adapting a constant bit rate (CBR) client signal into a signal stream in a telecom signal communication link includes at a source node encoding into a control block a control block header, and an ordered set block-designator, encoding into a plurality of path overhead data blocks a data block header and a count of data blocks to be encoded in a signal block, encoding into each of a plurality of signal blocks a data block header, the data blocks from the CBR signal equal to the count and pad blocks, assembling the blocks into a path signal frame, appending a set of idle character blocks following the end of the path signal frame to match a link bit rate of a first link segment, and transmitting the path signal frame and idle character blocks into the first link segment at the link bit rate.
A method switches master/slave timing in a communication network without traffic disruption. The method includes a master device informing a slave of timing loss. The master device additionally begins transmitting with timing from a local reference clock and begins receive timing recovery. The slave freezes its receive timing recovery and locks its transmit clock. The master device transitions its transmit timing to use the recovered receive clock. The slave gradually switches to transmitting using its local clock signal. The method may be used in synchronous Ethernet networks.
H04L 12/437 - Isolement de la défaillance de l'anneau ou reconfiguration
H04L 7/033 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière en utilisant les transitions du signal reçu pour commander la phase de moyens générateurs du signal de synchronisation, p. ex. en utilisant une boucle verrouillée en phase
7.
Method and apparatus for multimode wideband oscillator
A multimode, multicore inductor-capacitor (LC) oscillator having an increased oscillation frequency tuning range, and related method, are provided. The oscillation frequency tuning range of existing oscillators is limited. LC oscillators are known to have very low phase noise but a narrow frequency tuning range. The present oscillator has at least two LC oscillator cores and is capable of operating in multiple different modes of oscillation thereby increasing its overall oscillation frequency tuning range. A set of programmable amplifier pairs is used to force particular relative oscillation phases at the nodes of the multiple cores of the oscillator to realize one or more additional modes of oscillation for the oscillator. The additional oscillation mode increases the frequency tuning range of the oscillator.
H03B 5/12 - Éléments déterminant la fréquence comportant des inductances ou des capacités localisées l'élément actif de l'amplificateur étant un dispositif à semi-conducteurs
H03B 5/00 - Production d'oscillation au moyen d'un amplificateur comportant un circuit de réaction entre sa sortie et son entrée
H03B 27/00 - Générateurs fournissant plusieurs oscillations de même fréquence, mais de phases différentes, autres qu'en simple opposition de phase
H01L 29/94 - Dispositifs à métal-isolant-semi-conducteur, p.ex. MOS
8.
Method and apparatus for scatter gather processing engine in a storage controller for caching applications
The disclosure relates generally to improvements in caching operations in storage controllers, including caching operations utilizing direct memory access (DMA) systems, and related devices. Rather than the firmware running on the processor of the storage controller having to traverse a dirty cache sector bitmap and manipulate an original scatter-gather (SG) list in order to generate the two separate SG lists, namely one for the cache and one for the storage device, these operations are offloaded onto new specialized hardware referred to herein as a smart DMA engine in order to free up the processor of the storage controller.
G06F 13/28 - Gestion de demandes d'interconnexion ou de transfert pour l'accès au bus d'entrée/sortie utilisant le transfert par rafale, p. ex. acces direct à la mémoire, vol de cycle
G06F 12/0804 - Adressage d’un niveau de mémoire dans lequel l’accès aux données ou aux blocs de données désirés nécessite des moyens d’adressage associatif, p. ex. mémoires cache avec mise à jour de la mémoire principale
G06F 12/0891 - Adressage d’un niveau de mémoire dans lequel l’accès aux données ou aux blocs de données désirés nécessite des moyens d’adressage associatif, p. ex. mémoires cache utilisant des moyens d’effacement, d’invalidation ou de réinitialisation
9.
System and method for controlling the performance of serial attached SCSI (SAS) target devices
A system and method for controlling the performance of one or more target devices. A connection request for a target device of a plurality of target devices is received at a serial attached SCSI (SAS) Expander from an SAS initiator device, wherein a maximum performance availability value is associated with the target device. If the current performance availability value of the target device indicates that the target device does have availability to service the connection request, the connection request from the SAS initiator device is accepted and a connection is established between the SAS initiator device and the target device. Alternatively, if the current performance availability value of the target device indicates that the target device does not have availability to service the connection request, the connection request from the SAS initiator device is rejected and a connection is not established between the SAS initiator device and the target device. Traffic flow between the devices is measured and the current performance availability value of the target device is updated to control the performance of the target device.
A PHY constituted of: a clock arranged to generate a time signal indicative of the current time; and an egress stamp functionality arranged to: receive a data packet on the egress side, extract data from a predetermined section of the received data packet, and responsive to the extracted data, perform one of a plurality of predetermined timestamp operations, the plurality of predetermined timestamp operations comprising: generating a timestamp signal responsive to the generated time signal; not generating a timestamp signal; or modifying a timestamp written in the received data packet.
A system and method for decision feedback equalizer (DFE) tap adaptation. An input signal is received at a DFE of a receiver, wherein the input signal comprises a serial bit stream of encoded symbols. Data samples and error samples are taken from the input signal and the data samples and the error samples are aligned establish a plurality of pairs of data samples and error samples, wherein the data sample and error sample of each of the plurality of pairs of data samples and error samples are from locations in the serial bit stream of encoded symbols that are known to be uncorrelated with each other. The DFE tap weights are then adjusted based upon the plurality of pairs of data samples and error samples.
A system and method for block-code transcoding. An input signal is analyzed to determine if the input signal includes multiple control words, multiple data words and a single control word or only data words. If the input signal comprises multiple control words, the method includes, generating a control word location map and mapping the control codes and any data words to a block-code encoded transmission signal. If the input signal comprises a single control word and multiple data words, the method includes, generating a control word location address indicating a location of the single control word and mapping the control code and the multiple data words to a block-code encoded transmission signal. If the input signal comprises only data words, the method includes, mapping the data words sequentially into the block-code encoded transmission signal. Accordingly, the bandwidth efficiency of the transmission signal is improved by varying the encoding technique used dependent upon the contents of the input signal.
A method and system are provided for error correction. After row encoding and column encoding, additional codeword data (ACD) and modified parity (P′) may be concurrently created, for each of a plurality of modified column codewords (CCW′), by multiplying initial calculated parity P by a generator matrix G. Each CCW′ may include an ACD portion and a P′ portion such that each bit in the P′ portion of a selected CCW′ is present in the ACD portion for one of the other CCW′. In contrast to known approaches, the method and system may provide modified column codewords such that all data and parity bits are present in two codewords while using only two types of codewords, and without using extra parity-on-parity bits. In a set of modified column codewords, each bit in the modified parity in one modified codeword is present in another codeword.
H03M 13/29 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes combinant plusieurs codes ou structures de codes, p. ex. codes de produits, codes de produits généralisés, codes concaténés, codes interne et externe
H03M 13/11 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source utilisant un codage par blocs, c.-à-d. un nombre prédéterminé de bits de contrôle ajouté à un nombre prédéterminé de bits d'information utilisant plusieurs bits de parité
H03M 13/25 - Détection d'erreurs ou correction d'erreurs transmises par codage spatial du signal, c.-à-d. en ajoutant une redondance dans la constellation du signal, p. ex. modulation codée en treillis [TMC]
A setup test method for scheduled networks, the method constituted of: transmitting a frame to at least one network switch; responsive to the transmitted frame arriving at a first time gate of the at least one network switch, timestamping the transmitted frame with a first time stamp; responsive to the transmitted frame traversing a second time gate of the at least one network switch, additionally timestamping the transmitted frame with a second time stamp; reading the first time stamp; responsive to the read first time stamp, determining the time of arrival of the transmitted frame at the first time gate; reading the second time stamp; and responsive to the read first time stamp, determining the time of traversal of the transmitted frame through the second time gate.
Various transmission systems may benefit from techniques to improve the quality of the transmission. For example, certain full duplex transmission systems may include a virtual hybrid coupler. A circuit can include a first feedback resistor. The circuit can also include a second feedback resistor coupled to the first feedback resistor. The circuit can further include a first set of M transistors coupled to the first feedback resistor. The circuit can additionally include a second set of N transistors coupled to the second feedback resistor and to the first set of M transistors. The circuit can be configured to cancel a transmitted signal at a receiver input based on a ratio of resistance values of the first feedback resistor and the second feedback resistor, and based on a ratio of M to N.
G06F 7/501 - Semi-additionneurs ou additionneurs complets, c.-à-d. cellules élémentaires d'addition pour une position
G06F 5/01 - Procédés ou dispositions pour la conversion de données, sans modification de l'ordre ou du contenu des données maniées pour le décalage, p. ex. la justification, le changement d'échelle, la normalisation
H03K 17/687 - Commutation ou ouverture de porte électronique, c.-à-d. par d'autres moyens que la fermeture et l'ouverture de contacts caractérisée par l'utilisation de composants spécifiés par l'utilisation, comme éléments actifs, de dispositifs à semi-conducteurs les dispositifs étant des transistors à effet de champ
H04L 5/14 - Fonctionnement à double voie utilisant le même type de signal, c.-à-d. duplex
The voltage applied to an integrated circuit is scaled so as to account for variations in the manufacturing processes, temperature, and the like, and to allow for power/performance optimization of the integrated circuit. The integrated circuit may characterized during a manufacturing test or anytime thereafter. The characterization data, which reflects the performance and power consumption of the integrated circuit, is used to determine an associated processing/speed bin, which in turn, defines the voltage that will be applied to the integrated circuit during normal operation. Optionally, a number of different supply voltages are applied to different circuit blocks disposed in the same integrated circuit. Each such circuit block may have a different characterization data associated with a different supply voltage.
An asymmetric cross-connect system, constituted of: a cross-connect circuitry; and a control circuitry, wherein the cross-connect circuitry comprises a plurality of adaptive equalizers and a plurality of fixed equalizers, wherein the plurality of adaptive equalizers are in electrical communication with a multi-purpose port of a user device and each of the plurality of fixed equalizers are in electrical communication with a respective output of a processor of the user device, and wherein the cross-connect circuitry is arranged, responsive to the control circuitry, to provide a communication path between one of the outputs the processor and the multi-purpose port.
A system for sampling an RF signal comprises a plurality of capacitors, a plurality of resistors, and a sampling circuit. A first port of each capacitor of the plurality of capacitors is coupled to the RF signal. A first port of each resistor of the plurality of resistors is coupled to one of a plurality of reference levels. A second port of each resistor of the plurality of resistors is coupled to a second port of a corresponding capacitor of the plurality of capacitors. The sampling circuit produces a plurality of digital outputs by sampling the second port of each resistor of the plurality of resistors.
H03K 5/24 - Circuits présentant plusieurs entrées et une sortie pour comparer des impulsions ou des trains d'impulsions entre eux en ce qui concerne certaines caractéristiques du signal d'entrée, p. ex. la pente, l'intégrale la caractéristique étant l'amplitude
H03M 1/20 - Augmentation de la résolution par l'utilisation d'un système à n bits pour obtenir n+m bits, p. ex. par addition d'un signal aléatoire
A line of data is read from a line of memory. Intended data is specified by a random location and a random size within the line of memory. The line of data is moved into temporary storage. The line of data and a zero are multiplexed using a control signal to output a line of adjusted data which is automatically aligned to an initial point in an XOR buffer. A starting index of the intended data within the line of adjusted data corresponds to the initial point within an XOR buffer. An XOR operation is performed on the line of adjusted data and a line of data read from the XOR buffer to obtain a modified line of XOR data. The modified line of XOR data is written back to the XOR buffer at the same buffer locations as the line of data read from the XOR buffer.
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
G06F 11/20 - Détection ou correction d'erreur dans une donnée par redondance dans le matériel en utilisant un masquage actif du défaut, p. ex. en déconnectant les éléments défaillants ou en insérant des éléments de rechange
G06F 3/06 - Entrée numérique à partir de, ou sortie numérique vers des supports d'enregistrement
20.
Memory controller and integrated circuit device for correcting errors in data read from memory cells
An integrated circuit device for correcting errors in data read from memory cells includes a decoder, an encoder and a data management module. The data management module is configured to select a correctable raw bit error rate limit from a plurality of raw bit error rate limits by changing a code-rate used by the encoder, wherein a virtual change to the decoder and the encoder occur to change the code rate.
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
G06F 11/10 - Détection ou correction d'erreur par introduction de redondance dans la représentation des données, p. ex. en utilisant des codes de contrôle en ajoutant des chiffres binaires ou des symboles particuliers aux données exprimées suivant un code, p. ex. contrôle de parité, exclusion des 9 ou des 11
G11C 29/52 - Protection du contenu des mémoiresDétection d'erreurs dans le contenu des mémoires
H03M 13/11 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source utilisant un codage par blocs, c.-à-d. un nombre prédéterminé de bits de contrôle ajouté à un nombre prédéterminé de bits d'information utilisant plusieurs bits de parité
21.
Method and apparatus for converting analog radio frequency (RF) signals to the digital domain in a multiband and multicarrier wireless communication system
A method and system are provided for converting wideband analog radio frequency (RF) signals to a digital domain. In an implementation, the system comprises: an amplifier for receiving and amplifying a first wideband analog RF signal comprising one or more first narrowband analog RF signals, each first narrowband analog RF signal occupying a distinct non-overlapping spectral band within a spectrum of the first wideband analog RF signal; N down converter modules; N analog-to-digital converters (ADCs); and a cross-connect for connecting any one of the N down converter modules to one or more of the N ADCs to analog-to-digital convert only the first narrowband analog RF signals occupying the distinct non-overlapping spectral bands. The method and system of the present disclosure track the occupied bandwidth of the narrowband analog RF signals that make up a wideband analog RF signal rather than a total bandwidth of the wideband analog RF signal.
H04L 27/26 - Systèmes utilisant des codes à fréquences multiples
H04B 1/707 - Techniques d'étalement de spectre utilisant une modulation par séquence directe
H04B 1/00 - Détails des systèmes de transmission, non couverts par l'un des groupes Détails des systèmes de transmission non caractérisés par le milieu utilisé pour la transmission
H04B 1/7115 - Combinaison constructive de signaux à trajets multiples, c.-à-d. récepteurs en râteau [récepteurs RAKE]
H04L 25/03 - Réseaux de mise en forme pour émetteur ou récepteur, p. ex. réseaux de mise en forme adaptatifs
H04L 27/233 - Circuits de démodulationCircuits récepteurs utilisant une démodulation non cohérente
22.
Electro-mechanical oscillator and method for generating a signal
An oscillator and method for generating a signal are provided. The oscillator comprises an electro-mechanical resonator and a reconfigurable oscillator driver. The reconfigurable oscillator driver starts the oscillator in single-ended mode to avoid latching and transitions the oscillator to differential mode in such a manner as to sustain oscillations therein. The reconfigurable oscillator driver comprises two back-to-back banks of inverters and an adjustable feedback resistor. In single-ended mode, one bank is disabled and the other bank is enabled. To transition to differential mode and improve the quality of the signal, the number of enabled inverters is equalized in both banks.
H03B 5/36 - Production d'oscillation au moyen d'un amplificateur comportant un circuit de réaction entre sa sortie et son entrée l'élément déterminant la fréquence étant un résonateur électromécanique un résonateur piézo-électrique l'élément actif de l'amplificateur comportant un dispositif semi-conducteur
H03B 5/06 - Modifications du générateur pour assurer l'amorçage des oscillations
An oscillator and method for generating a signal are provided. The oscillator comprises an electro-mechanical resonator and a reconfigurable oscillator driver. The reconfigurable oscillator driver starts the oscillator in single-ended mode to avoid latching and transitions the oscillator to differential mode in such a manner as to sustain oscillations therein. The reconfigurable oscillator driver comprises two back-to-back banks of inverters and an adjustable feedback resistor. In single-ended mode, one bank is disabled and the other bank is enabled. To transition to differential mode and improve the quality of the signal, the number of enabled inverters is equalized in both banks.
H03B 5/06 - Modifications du générateur pour assurer l'amorçage des oscillations
H03B 5/36 - Production d'oscillation au moyen d'un amplificateur comportant un circuit de réaction entre sa sortie et son entrée l'élément déterminant la fréquence étant un résonateur électromécanique un résonateur piézo-électrique l'élément actif de l'amplificateur comportant un dispositif semi-conducteur
A cross-coupled complementary balanced voltage-controlled oscillator and a method for operating same. The oscillator comprises an electro-mechanical resonator, and an oscillator core. The oscillator core comprises capacitively cross-coupled complementary inverters and a resistor network. The oscillator may comprise a frequency tuning network having inductors for increasing the tuning range. The capacitance inhibit the inverters from latching to a static direct current state. The resistor network forms a high pass filter with the capacitance to inhibit relaxation oscillations. The method comprises enabling the resistor network to form a high pass filter and starting balanced oscillations in the oscillator, the capacitance of the high pass filter for inhibiting latching, and the high pass filter for inhibiting relaxation oscillations. The method may comprise tuning the frequency by varying the capacitance of the oscillator.
H03K 3/36 - Générateurs caractérisés par le type de circuit ou par les moyens utilisés pour produire des impulsions par l'utilisation, comme éléments actifs, de dispositifs à semi-conducteurs, non prévus ailleurs
An Interleaved Radio Frequency Digital-to-Analog Converter (RF DAC) suitable for use in cellular base stations and optimized to give both a wide RF tuning range and a wide RF bandwidth is disclosed. The RF DAC uses two levels of interleaving, the first providing a direct conversion path from Base Band (BB) to RF, and the second providing a variable interleaving factor through the use of summation to optimize the output bandwidth as a function of the RF center frequency. Digital Interpolation, including an arbitrary sample rate conversion filter, allows the RF DAC to operate from a wide range of possible BB sample rates and the DAC sample rate is a fixed ratio of the RF center frequency. As a result, the spurious outputs from the RF DAC are in known locations that are relatively easy to filter out, minimizing the frequency planning tasks required for a complete RF system design.
H04L 27/06 - Circuits de démodulationCircuits récepteurs
H04B 1/00 - Détails des systèmes de transmission, non couverts par l'un des groupes Détails des systèmes de transmission non caractérisés par le milieu utilisé pour la transmission
26.
System and method for lifetime specific LDPC decoding
A nonvolatile memory storage controller is provided for delivering log likelihood ratios (LLRs) to a low-density parity check (LDPC) decoder for use in the decoding of an LDPC encoded codeword. The controller includes read circuitry for reading an LDPC encoded codeword stored in a nonvolatile memory storage module using a plurality of soft-decision reference voltages to provide a plurality of soft-decision bits representative of the codeword. The controller further includes a plurality of lifetime specific LLR look-up tables representative of the lifetime threshold voltage distribution of the memory storage module, wherein each of the plurality of lifetime specific LLR look-up tables comprises a plurality of LLRs representative of a specific point in the lifetime of the memory storage module for each of the plurality of soft-decision bits. The controller provides the LLRs from the appropriate LLR look-up table to an LDPC decoder for the subsequent decoding of the codeword.
H03M 13/37 - Méthodes ou techniques de décodage non spécifiques à un type particulier de codage prévu dans les groupes
H03M 13/11 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source utilisant un codage par blocs, c.-à-d. un nombre prédéterminé de bits de contrôle ajouté à un nombre prédéterminé de bits d'information utilisant plusieurs bits de parité
G06F 11/10 - Détection ou correction d'erreur par introduction de redondance dans la représentation des données, p. ex. en utilisant des codes de contrôle en ajoutant des chiffres binaires ou des symboles particuliers aux données exprimées suivant un code, p. ex. contrôle de parité, exclusion des 9 ou des 11
A method and system are provided for reducing mismatch between oscillators in an LC VCO array. In an implementation, a method comprises measuring the mismatch between the driver strengths, by measuring the corresponding oscillation amplitudes, and a mismatch between the resonance frequency of each LC VCO in the array of VCOs, and adjusting each LC VCO to reduce the measured amplitude and frequency mismatches. In an implementation, the measuring and adjusting is performed once to calibrate the array of VCOs. In another implementation, the system measures and adjusts the array of VCOs repeatedly. In another implementation, the LC VCO array has a master VCO and a plurality of slave VCOs connected to the master VCO by slave PLLs to reduce phase noise caused by mismatches.
H03B 25/00 - Production simultanée, au moyen d'un oscillateur non synchronisé, d'oscillations de fréquences différentes
H03L 7/06 - Commande automatique de fréquence ou de phaseSynchronisation utilisant un signal de référence qui est appliqué à une boucle verrouillée en fréquence ou en phase
H03B 5/12 - Éléments déterminant la fréquence comportant des inductances ou des capacités localisées l'élément actif de l'amplificateur étant un dispositif à semi-conducteurs
28.
Method and apparatus for baseband processing an analog signal in a direct conversion radio receiver
A method and apparatus are provided for reducing aliasing in a direct conversion (or zero-IF) radio receiver having high and low frequency paths. According to an implementation, a non-transitory machine-readable memory stores aliasing correlation response data that associates a measured non-aliased signal in a high frequency path and a measured aliased residual of the signal in a low frequency path. A compensator is in communication with the memory to apply aliasing compensation to received signals based on the stored aliasing correlation response data. In an example implementation, the low and high frequency paths are independently optimized for low and high frequency performance, respectively, and have transfer functions that overlap with one another to create a calibration zone used to calibrate the first and second transfer functions.
Apparatus and methods reduce channel-dependent phase detector offset and/or gain errors. A conventional Mueller-Muller phase detector places a main cursor at the midpoint of a pre-cursor and a post-cursor. However, for example, when the impulse response of an associated transmission line is not symmetric, the main cursor can be misaligned by conventional Mueller-Muller techniques. By providing a replica clock and data recovery path, trial and error experiments on the phase detector offset and/or gain can be performed, and relatively good values found for the phase detector offset and/or gain without disturbing the reception of data by the phase detector that is being used to receive data. These settings can then be used by the phase detector that is being used to receive data, which can improve the bit error rate of the phase detector.
H04L 7/00 - Dispositions pour synchroniser le récepteur avec l'émetteur
H04L 7/033 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière en utilisant les transitions du signal reçu pour commander la phase de moyens générateurs du signal de synchronisation, p. ex. en utilisant une boucle verrouillée en phase
H04L 7/04 - Commande de vitesse ou de phase au moyen de signaux de synchronisation
30.
Sampling threshold detector for direct monitoring of RF signals
IF (intermediate frequency), to minimize in-band intermodulation products. The sampler produces kickback intermodulation products that are positioned out-of-band, or are of low enough power in-band so as to be inconsequential. Samples are taken for a statistically significant period of time, and the status is used to adapt the threshold to systematically determine the peak amplitude of the signal being observed.
A physical layer communication device (PHY) transmits and receives signal to and from a communication link using a synchronous protocol. The PHY communicates with a higher-layer device using a packet protocol. Timestamp values contained in timing-related messages in some packets are written or modified by the PHY. Delays incurred in transmitting and receiving the packets are predicted and used in setting the timestamp values.
A number of methods and clock generator units are disclosed to produce low Phase Noise clocks for use in Radio Frequency systems. The methods and clock generator units all use two reference clocks: a frequency-accurate reference that has comparatively high Phase Noise, and a frequency-inaccurate reference such as that from a BAW or MEMS clock source that has comparatively low Phase Noise. By combining multiple Phase-Locked Loops and a mixer, it is possible to produce flexible output frequencies whose frequency accuracy is derived from the first reference clock but whose Phase Noise level is derived from the second reference clock, all in a readily-integrated and relatively low-cost system.
H03L 7/18 - Synthèse de fréquence indirecte, c.-à-d. production d'une fréquence désirée parmi un certain nombre de fréquences prédéterminées en utilisant une boucle verrouillée en fréquence ou en phase en utilisant un diviseur de fréquence ou un compteur dans la boucle
H03L 7/093 - Détails de la boucle verrouillée en phase concernant principalement l'agencement de détection de phase ou de fréquence, y compris le filtrage ou l'amplification de son signal de sortie utilisant des caractéristiques de filtrage ou d'amplification particulières dans la boucle
H03L 7/07 - Commande automatique de fréquence ou de phaseSynchronisation utilisant un signal de référence qui est appliqué à une boucle verrouillée en fréquence ou en phase utilisant plusieurs boucles, p. ex. pour la génération d'un signal d'horloge redondant
H03L 7/087 - Détails de la boucle verrouillée en phase concernant principalement l'agencement de détection de phase ou de fréquence, y compris le filtrage ou l'amplification de son signal de sortie utilisant au moins deux détecteurs de phase ou un détecteur de fréquence et de phase dans la boucle
H03L 7/099 - Détails de la boucle verrouillée en phase concernant principalement l'oscillateur commandé de la boucle
H03L 7/197 - Synthèse de fréquence indirecte, c.-à-d. production d'une fréquence désirée parmi un certain nombre de fréquences prédéterminées en utilisant une boucle verrouillée en fréquence ou en phase en utilisant un diviseur de fréquence ou un compteur dans la boucle une différence de temps étant utilisée pour verrouiller la boucle, le compteur comptant entre des nombres variables dans le temps ou le diviseur de fréquence divisant par un facteur variable dans le temps, p. ex. pour obtenir une division de fréquence fractionnaire
33.
System and method for synchronizing local oscillators
Provided is a method and apparatus for aligning a first local oscillator (LO) clock generated by a controllable LO clock generator in a first radio frequency (RF) path with a second LO clock in a second RF path. The apparatus includes a synchronization channel configured to exchange a synchronization clock between the first and second RF paths, a phase detector configured to measure a phase alignment between the first and second LO clocks, and a loop filter configured to drive the controllable LO clock generators using the phase alignment. Also provided is a time to digital converter. The time to digital converter includes a D flip-flop for sampling first and second input clocks with a third clock, and a counter configured to synchronously increment the resulting samples and create a digital proportional value representing the delay between the first and second clocks.
H04L 7/033 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière en utilisant les transitions du signal reçu pour commander la phase de moyens générateurs du signal de synchronisation, p. ex. en utilisant une boucle verrouillée en phase
Provided is a method and apparatus for aligning a first local oscillator (LO) clock generated by a controllable LO clock generator in a first radio frequency (RF) path with a second LO clock in a second RF path. The apparatus includes a synchronization channel configured to exchange a synchronization clock between the first and second RF paths, a phase detector configured to measure a phase alignment between the first and second LO clocks, and a loop filter configured to drive the controllable LO clock generators using the phase alignment. Also provided is a time to digital converter. The time to digital converter includes a D flip-flop for sampling first and second input clocks with a third clock, and a counter configured to synchronously increment the resulting samples and create a digital proportional value representing the delay between the first and second clocks.
H04L 7/033 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière en utilisant les transitions du signal reçu pour commander la phase de moyens générateurs du signal de synchronisation, p. ex. en utilisant une boucle verrouillée en phase
G06F 1/12 - Synchronisation des différents signaux d'horloge
H03L 7/08 - Détails de la boucle verrouillée en phase
35.
Low-noise flexible frequency clock generation from two fixed-frequency references
A number of methods and clock generator units are disclosed to produce low Phase Noise clocks for use in Radio Frequency systems. The methods and clock generator units all use two reference clocks: a frequency-accurate reference that has comparatively high Phase Noise, and a frequency-inaccurate reference such as that from a BAW or MEMS clock source that has comparatively low Phase Noise. By combining multiple Phase-Locked Loops and a mixer, it is possible to produce flexible output frequencies whose frequency accuracy is derived from the first reference clock but whose Phase Noise level is derived from the second reference clock, all in a readily-integrated and relatively low-cost system.
H03L 7/18 - Synthèse de fréquence indirecte, c.-à-d. production d'une fréquence désirée parmi un certain nombre de fréquences prédéterminées en utilisant une boucle verrouillée en fréquence ou en phase en utilisant un diviseur de fréquence ou un compteur dans la boucle
H03L 7/093 - Détails de la boucle verrouillée en phase concernant principalement l'agencement de détection de phase ou de fréquence, y compris le filtrage ou l'amplification de son signal de sortie utilisant des caractéristiques de filtrage ou d'amplification particulières dans la boucle
H04L 7/033 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière en utilisant les transitions du signal reçu pour commander la phase de moyens générateurs du signal de synchronisation, p. ex. en utilisant une boucle verrouillée en phase
H04L 7/00 - Dispositions pour synchroniser le récepteur avec l'émetteur
36.
Low-noise flexible frequency clock generation from two fixed-frequency references
A number of methods and clock generator units are disclosed to produce low Phase Noise clocks for use in Radio Frequency systems. The methods and clock generator units all use two reference clocks: a frequency-accurate reference that has comparatively high Phase Noise, and a frequency-inaccurate reference such as that from a BAW or MEMS clock source that has comparatively low Phase Noise. By combining multiple Phase-Locked Loops and a mixer, it is possible to produce flexible output frequencies whose frequency accuracy is derived from the first reference clock but whose Phase Noise level is derived from the second reference clock, all in a readily-integrated and relatively low-cost system.
H03L 7/18 - Synthèse de fréquence indirecte, c.-à-d. production d'une fréquence désirée parmi un certain nombre de fréquences prédéterminées en utilisant une boucle verrouillée en fréquence ou en phase en utilisant un diviseur de fréquence ou un compteur dans la boucle
H03L 7/093 - Détails de la boucle verrouillée en phase concernant principalement l'agencement de détection de phase ou de fréquence, y compris le filtrage ou l'amplification de son signal de sortie utilisant des caractéristiques de filtrage ou d'amplification particulières dans la boucle
H04L 7/033 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière en utilisant les transitions du signal reçu pour commander la phase de moyens générateurs du signal de synchronisation, p. ex. en utilisant une boucle verrouillée en phase
37.
Method and apparatus for mapped I/O routing in an interconnect switch
A system and method are disclosed for a flexible routing engine in a PCIe switch. The system may include a switch manager that is enabled, through firmware, to configure one or more routing tables associated with a switch stack of a PCIe switch. To enable non-transparent bridging and non-standard routing, such as mapped I/O routing, the method may include receiving a transaction layer packet at a mapped I/O routed port of a PCIe switch, and performing translation of the requester ID of the packet utilizing tables that are updated by the firmware of the switch manager to route the packet through the switch.
Disclosed is a high-swing voltage-mode transmitter or line driver. The transmitter can operate over a wide range of supply voltages. Increasing the available output swing merely involves increasing the supply voltage; the circuit adapts to maintain the desired output impedance. This allows for a tradeoff between output amplitude and power consumption. Another advantage of the proposed architecture is that it compensates for process, voltage, and temperature (PVT) and mismatch variations so as to keep rise and fall times matched. This feature reduces common-mode noise and hence EMI in systems in which the transmitter is used.
H03K 19/094 - Circuits logiques, c.-à-d. ayant au moins deux entrées agissant sur une sortieCircuits d'inversion utilisant des éléments spécifiés utilisant des dispositifs à semi-conducteurs utilisant des transistors à effet de champ
H03K 19/0175 - Dispositions pour le couplageDispositions pour l'interface
H03K 19/003 - Modifications pour accroître la fiabilité
39.
Apparatus and method for adjusting a correctable raw bit error rate limit in a memory system using strong log-likelihood (LLR) values
Apparatuses and methods for correcting errors in data read from memory cells of an integrated circuit device includes an encoder. The encoder is configured from a single parity check matrix and the encoder is configured to be virtually adjustable by setting a number of bits in the encoder to zero. A decoder is configured from the single parity check matrix and the decoder is configured to be virtually adjustable by setting a log-likelihood ratio (LLR) for a number of bits in the decoder to a strong value. A code-rate that the encoder and decoder uses can be changed by adjusting the number of bits in the encoder that are set to zero and the number of bits in the decoder that are set to the strong LLR value.
G11C 29/00 - Vérification du fonctionnement correct des mémoiresTest de mémoires lors d'opération en mode de veille ou hors-ligne
G06F 11/10 - Détection ou correction d'erreur par introduction de redondance dans la représentation des données, p. ex. en utilisant des codes de contrôle en ajoutant des chiffres binaires ou des symboles particuliers aux données exprimées suivant un code, p. ex. contrôle de parité, exclusion des 9 ou des 11
40.
Scrambler with built in test capabilities for unary DAC
An apparatus comprising a scrambler having a plurality of scrambler inputs and 2N scrambler outputs, and a unary-weighted digital to analog converter (DAC) connected to scrambler to generate an analog output signal based on the 2N scrambler outputs. The scrambler has N unique scrambling stages arranged in order between the scrambler inputs and the scrambler outputs from a first scrambling stage to a last scrambling stage. Each of the N unique scrambling stages has a plurality of stage inputs and outputs, with the stage inputs of the first scrambling stage connected to the scrambler inputs, the stage outputs of each scrambling stage except the last scrambling stage connected to the stage inputs of a next scrambling stage, and the stage outputs of the last scrambling stage connected to the scrambler outputs. Each of the N unique scrambling stages is operable to pass signals at the inputs to the outputs in either an unscrambled or scrambled state under control of a control bit provided by an N-bit entropy signal. When an N+1 bit input signal is applied to the scrambler inputs and the N-bit entropy signal is randomized the analog output signal from the DAC has improved linearity compared to the analog output signal generated from a non-scrambled input, and when a test input signal is applied to the scrambler inputs and the entropy signal is swept through 2N orthogonal values the analog output signal from the DAC indicates whether a fault exists in one of the scrambler and the DAC.
G01R 31/3167 - Tests de circuits analogiques et numériques combinés
H03M 1/06 - Compensation ou prévention continue de l'influence indésirable de paramètres physiques
H03M 7/02 - Conversion en, ou à partir de codes pondérés, c.-à-d. le poids donné à un chiffre dépendant de sa position dans le bloc ou dans le mot-code
41.
Low-noise flexible frequency clock generation from two fixed-frequency references
A number of methods and clock generator units are disclosed to produce low Phase Noise clocks for use in Radio Frequency systems. The methods and clock generator units all use two reference clocks: a frequency-accurate reference that has comparatively high Phase Noise, and a frequency-inaccurate reference such as that from a BAW or MEMS clock source that has comparatively low Phase Noise. By combining multiple Phase-Locked Loops and a mixer, it is possible to produce flexible output frequencies whose frequency accuracy is derived from the first reference clock but whose Phase Noise level is derived from the second reference clock, all in a readily-integrated and relatively low-cost system.
H03L 7/06 - Commande automatique de fréquence ou de phaseSynchronisation utilisant un signal de référence qui est appliqué à une boucle verrouillée en fréquence ou en phase
H03L 7/087 - Détails de la boucle verrouillée en phase concernant principalement l'agencement de détection de phase ou de fréquence, y compris le filtrage ou l'amplification de son signal de sortie utilisant au moins deux détecteurs de phase ou un détecteur de fréquence et de phase dans la boucle
H03L 7/07 - Commande automatique de fréquence ou de phaseSynchronisation utilisant un signal de référence qui est appliqué à une boucle verrouillée en fréquence ou en phase utilisant plusieurs boucles, p. ex. pour la génération d'un signal d'horloge redondant
42.
Apparatus and method based on LDPC codes for adjusting a correctable raw bit error rate limit in a memory system
Systems and methods for correcting errors in data read from memory cells include a memory controller, which includes an encoder, and a decoder. The memory controller is configured to adjust a correctable raw bit error rate limit to correct different bit error rates occurring in data read from the memory cells. The correctable raw bit error rate limit is adjusted by switching the decoding between hard-decision decoding and soft-decision decoding, wherein a number of soft bits allocated for message values can be changed during soft-decision decoding. The correctable raw bit error rate is adjusted by changing the code-rate within the memory system while making virtual adjustments to the same encoder and decoder.
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
G06F 11/10 - Détection ou correction d'erreur par introduction de redondance dans la représentation des données, p. ex. en utilisant des codes de contrôle en ajoutant des chiffres binaires ou des symboles particuliers aux données exprimées suivant un code, p. ex. contrôle de parité, exclusion des 9 ou des 11
H03M 13/45 - Décodage discret, c.-à-d. utilisant l'information de fiabilité des symboles
H03M 13/11 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source utilisant un codage par blocs, c.-à-d. un nombre prédéterminé de bits de contrôle ajouté à un nombre prédéterminé de bits d'information utilisant plusieurs bits de parité
H03M 13/29 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes combinant plusieurs codes ou structures de codes, p. ex. codes de produits, codes de produits généralisés, codes concaténés, codes interne et externe
A device that performs Quantization Noise-Shaping and operates at high clock rates. The device can be implemented in parallel with large parallelization factors to produce extremely high throughput. The device has two feed-forward filters that can be implemented using standard parallel Digital Signal Processing techniques. The device can be used in various systems such as Digital-to-Analog Converter (DAC) system and Fractional-N frequency synthesis systems.
H03M 1/06 - Compensation ou prévention continue de l'influence indésirable de paramètres physiques
H03M 1/68 - Convertisseurs numériques/analogiques à conversions de sensibilités différentes, c.-à-d. qu'une conversion se rapportant aux bits les plus significatifs et une autre aux bits les moins significatifs
H03M 1/82 - Convertisseurs numériques/analogiques avec conversion intermédiaire en intervalle de temps
An oscillator and method for generating a signal are provided. The oscillator comprises an electro-mechanical resonator and a reconfigurable oscillator driver. The reconfigurable oscillator driver starts the oscillator in single-ended mode to avoid latching and transitions the oscillator to differential mode in such a manner as to sustain oscillations therein. The reconfigurable oscillator driver comprises two back-to-back banks of inverters and an adjustable feedback resistor. In single-ended mode, one bank is disabled and the other bank is enabled. To transition to differential mode and improve the quality of the signal, the number of enabled inverters is equalized in both banks.
H03B 5/36 - Production d'oscillation au moyen d'un amplificateur comportant un circuit de réaction entre sa sortie et son entrée l'élément déterminant la fréquence étant un résonateur électromécanique un résonateur piézo-électrique l'élément actif de l'amplificateur comportant un dispositif semi-conducteur
H03B 5/30 - Production d'oscillation au moyen d'un amplificateur comportant un circuit de réaction entre sa sortie et son entrée l'élément déterminant la fréquence étant un résonateur électromécanique
H03B 5/06 - Modifications du générateur pour assurer l'amorçage des oscillations
Apparatus and methods calibrate and control detector gain in a Mueller-Muller timing detector. A Mueller-Muller circuit obtains timing information for a received signal in which the receiving device samples the signal once per baud period.
A system and method are disclosed for a flexible routing engine in a PCIe switch. The system may include a switch manager that is enabled, through firmware, to configure one or more routing tables associated with a switch stack of a PCIe switch. The method may include receiving a configuration transaction layer packet at the switch manager of a PCIe switch, running firmware at the switch manager to identify a desired behavior of a switch stack of the switch and updating one or more routing tables associated with switch stack.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
H04J 3/24 - Systèmes multiplex à division de temps dans lesquels l'attribution est indiquée par une adresse
G06F 13/00 - Interconnexion ou transfert d'information ou d'autres signaux entre mémoires, dispositifs d'entrée/sortie ou unités de traitement
H04L 12/24 - Dispositions pour la maintenance ou la gestion
47.
Enabling RX signal path synchronization and alignment signals in a highly integrated TX RFIC
A transmit (TX) signal path circuit in a multiple-input, multiple-output (MIMO) transceiver responsive to a digital front end (DFE) for generating receive (RX) path phase alignment signals is disclosed. A digital up-conversion block uses a first numerically-controlled oscillator (NCO) for generating digital intermediate frequency (IF) signals for ordinary TX signal generation, and a different, second NCO for generating digital IF signals for RX phase alignment signal generation. An RF up-conversion block uses a TX local oscillator (LO) for generating analog RF signals for ordinary TX signal generation, and a different feedback (FB) LO for generating analog RF signals for RX phase alignment signal generation. Thus, phase alignment of the circuitry used for ordinary TX signal generation is left undisturbed by RX phase alignment signal generation.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
H04L 5/16 - Systèmes semi-duplexCommutation duplex-simplexTransmission de signaux de rupture
H04L 7/02 - Commande de vitesse ou de phase au moyen des signaux de code reçus, les signaux ne contenant aucune information de synchronisation particulière
48.
Post-distortion filter for reducing sensitivity to receiver nonlinearities
Methods and apparatus for reducing sensitivity to nonlinearities in the receiver of a digital communications system are disclosed. One aspect can be referred to as a Post-Distortion Decision Feedback Equalizer (PDFE). A gain stage is often implemented as a variable gain amplifier (VGA), and can introduce significant nonlinearities, a problem exacerbated by signals with a large peak-to-average ratio (PAR). One embodiment provides feed forward information from the VGA regarding its status to a DFE, and the DFE adjusts its filtering based on the provided information. The advantages are also applicable to fixed-gain amplifiers and to transversal filters.
A system and method are disclosed for a flexible routing engine in a PCIe switch. The system may include a switch manager that is enabled, through firmware, to configure one or more routing tables associated with a switch stack of a PCIe switch. To enable non-transparent bridging and non-standard routing, the method may include receiving a transaction layer packet at a translated routing port of a PCIe switch, and performing translation of the address and requester ID of the packet utilizing tables that are updated by the firmware of the switch manager to route the packet through the switch.
Apparatus and methods mitigate a problem of equalizing communications signals that have been distorted by severe non-linearities such as clipping or harsh compression. For example, severe non-linearity occurs when signal compression or signal clipping occurs at rates above 20% of the data transmission interval. Severe non-linearities may significantly reduce system performance. Disclosed techniques selectively apply DSP equalization based on the detection of non-linearity for a present sample or one or more samples prior to the present sample. These techniques can be implemented in relatively low-cost high-speed SerDes designs to improve eye openings and reduce sensitivity to InterSymbol Interference (ISI) and to improve bit error rate (BER).
Methods and circuits for equalizing a linear response in an observation path of a digital pre-distorter. A method comprises generating observed signals in an observation path based on observing a transmit signal; down-converting the observed signals into intermediate frequencies using different LO frequencies; calculating a ratio using the intermediate frequencies; and equalizing the linear response of the observation path on the observed signals using the ratio. An apparatus comprises a directional coupler for observing a transmit signal and generating observed signals; a down-converter for converting the observed signals into intermediate frequencies using different LO frequencies; and an adaptive estimator for calculating a ratio using the intermediate frequencies and using the ratio to equalize a linear response from the observation path on the observed signals.
A method for estimating a carrier frequency offset over a dispersive but spectrally flat channel comprises determining an autocorrelation of a received oversampled complex baseband digital signal, and estimating the carrier frequency offset based on an angle of the determined autocorrelation.
A low-density parity check (LDPC) decoder is provided for decoding low-density parity check (LDPC) encoded data wherein a layer specific attenuation factor is provided for each layer of the LDPC parity check matrix. An attenuation factor matrix comprising a plurality of coefficients specifies the specific attenuation factor for each layer and each iteration of the decoding process. A check node processor performs check node processing for each layer of the parity check matrix associated with the LDPC encoded codeword utilizing the normalized layered min-sum algorithm wherein the attenuation factor of the min-sum algorithm is determined by the coefficients of the attenuation factor matrix.
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
Disclosed is a high-swing voltage-mode transmitter or line driver. The transmitter can operate over a wide range of supply voltages. Increasing the available output swing merely involves increasing the supply voltage; the circuit adapts to maintain the desired output impedance. This allows for a tradeoff between output amplitude and power consumption. Another advantage of the proposed architecture is that it compensates for process, voltage, and temperature (PVT) and mismatch variations so as to keep rise and fall times matched. This feature reduces common-mode noise and hence EMI in systems in which the transmitter is used.
A low-density parity check (LDPC) decoder is provided that eliminates the need to calculate customized check node codeword estimates by considering the check node processor and the variable node processor as a single processer having a shared memory for storing common variables to be used during both the check node processing and the variable node processing of the iterative decoding method.
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
H03M 13/11 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source utilisant un codage par blocs, c.-à-d. un nombre prédéterminé de bits de contrôle ajouté à un nombre prédéterminé de bits d'information utilisant plusieurs bits de parité
56.
System and method for avoiding error mechanisms in layered iterative decoding
A low-density parity check (LDPC) decoder is provided for decoding low-density parity check (LDPC) encoded data wherein the processing order of the layers of the LDPC parity check matrix are rearranged during the decode process in an attempt to avoid error mechanisms brought about by the iterative nature of the LDPC belief propagation decoding process, such as stopping sets and trapping sets.
H03M 13/03 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
H03M 13/29 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes combinant plusieurs codes ou structures de codes, p. ex. codes de produits, codes de produits généralisés, codes concaténés, codes interne et externe
57.
Background calibration of aperture center errors in analog to digital converters
A method of background calibration of aperture center errors in a data communication system is provided. In an implementation, in response to detection of a low sampler output (“0”) in between two high sampler outputs (“1”), the method includes: determining a direction of an ADC output signal at the time of the detected low output; and adjusting timing at a selected sampler based on the determined signal direction. In an example implementation, the method includes watching for bubbles in the thermometer code output, and estimating the first derivative of the signal at the time of the bubble, then estimating the sign of the errors. In an example implementation, the errors are used in a control loop to reduce the aperture center error.
Methods and apparatus improve the signal integrity of high-speed integrated circuits. Disclosed is a passive network for an input to a receiver. One embodiment of the passive network has two coupled inductors to improve both return loss and insertion loss characteristics. A shunt inductor is connected in series with the termination resistance, while a series inductor is placed in series between the pad and receiver circuitry. By exploiting deliberately-introduced mutual coupling between these two inductors, an area-efficient passive network is created that improves both the return loss and input bandwidth.
A method and apparatus to digitally remove in-band non-linear signal distortion caused by a radio frequency (RF)/intermediate frequency (IF) receiver circuit that has non-linearities, which are further affected by low-IF ADC sample aliasing.
H04L 25/08 - Modifications pour réduire les perturbationsModifications pour réduire les effets des défauts de ligne
H04L 25/49 - Circuits d'émissionCircuits de réception à conversion de code au transmetteurCircuits d'émissionCircuits de réception à pré-distorsionCircuits d'émissionCircuits de réception à insertion d'intervalles morts pour obtenir un spectre de fréquence désiréCircuits d'émissionCircuits de réception à au moins trois niveaux d'amplitude
60.
Parallel replica CDR to correct offset and gain in a baud rate sampling phase detector
Apparatus and methods reduce channel-dependent phase detector offset and/or gain errors. A conventional Mueller-Muller phase detector places a main cursor at the midpoint of a pre-cursor and a post-cursor. However, for example, when the impulse response of an associated transmission line is not symmetric, the main cursor can be misaligned by conventional Mueller-Muller techniques. By providing a replica clock and data recovery path, trial and error experiments on the phase detector offset and/or gain can be performed, and relatively good values found for the phase detector offset and/or gain without disturbing the reception of data by the phase detector that is being used to receive data. These settings can then be used by the phase detector that is being used to receive data, which can improve the bit error rate of the phase detector.
A transparent clock may be provided between edge nodes of a non-precision time protocol network, with an arrival time of a packet at an edge of the non-precision time protocol network carried in a reserved field of a packet.
A low-density parity check (LDPC) decoder is provided for decoding low-density parity check (LDPC) encoded data wherein an adaptive check node approximation is performed at the check node processor utilizing the smallest magnitude log-likelihood ratio (LLR) and the second smallest magnitude log-likelihood ratio (LLR) to adapt to the current conditions at the check node.
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
A system and method are disclosed for aggregated non-transparent requester ID translation in a PCIe switch. The system may include a first switch that is enabled to receive a request from a non-transparent port of a second switch at an aggregated downstream port of the first switch and translating the requester ID of the request at the first switch using the aggregated switch number and the captured bus number of the requester ID. The method may include receiving a request from a non-transparent port of a second switch at an aggregated downstream port of a first switch and translating the requester ID of the request at the first switch using the aggregated switch number and the captured bus number of the requester ID.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
H04L 12/54 - Systèmes de commutation par mémorisation et restitution
Methods and devices generate cyclic redundancy check (CRC) values for a sequence of parallel words of data. The data words may have only some of the bits enabled. The input words are preconditioned, and then a common block generates a CRC remainder value. A specific preconditioning is selected based on the number of enabled bits. Additional post-processing may be performed to the CRC remainder.
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
H04L 1/00 - Dispositions pour détecter ou empêcher les erreurs dans l'information reçue
H03M 13/09 - Détection d'erreurs uniquement, p. ex. utilisant des codes de contrôle à redondance cyclique [CRC] ou un seul bit de parité
G06F 11/10 - Détection ou correction d'erreur par introduction de redondance dans la représentation des données, p. ex. en utilisant des codes de contrôle en ajoutant des chiffres binaires ou des symboles particuliers aux données exprimées suivant un code, p. ex. contrôle de parité, exclusion des 9 ou des 11
65.
System and method for reducing spectral pollution in a signal
A system and a method for modulating an input signal are provided. The system includes a fractional-N phase locked loop (PLL) for frequency multiplying the input signal by a multiplication factor to generate an output signal. The fractional-N PLL includes an input signal path and a feedback signal path. The system includes a controllable delay line for inserting a linearizing tone into the input signal path or the feedback signal path of the fractional-N PLL.
H03L 7/06 - Commande automatique de fréquence ou de phaseSynchronisation utilisant un signal de référence qui est appliqué à une boucle verrouillée en fréquence ou en phase
H03L 7/08 - Détails de la boucle verrouillée en phase
66.
System and method for accumulating soft information in LDPC decoding
A system and method reading, accumulating and processing soft information for use in LDPC decoding. In accordance with the present invention, an LDPC decoder includes accumulation circuitry to receive soft reads of a cell of the nonvolatile memory storage module and to produce an accumulated soft read that can be used to identify an appropriate LLR for the cell. The accumulation circuitry of the present invention may include, an accumulation RAM, an arithmetic logic unit (ALU) and a soft accumulation control and sequencing module for accumulating and processing soft information for use in LDPC decoding.
H03M 13/11 - Détection d'erreurs ou correction d'erreurs transmises par redondance dans la représentation des données, c.-à-d. mots de code contenant plus de chiffres que les mots source utilisant un codage par blocs, c.-à-d. un nombre prédéterminé de bits de contrôle ajouté à un nombre prédéterminé de bits d'information utilisant plusieurs bits de parité
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
G06F 11/00 - Détection d'erreursCorrection d'erreursContrôle de fonctionnement
G06F 11/10 - Détection ou correction d'erreur par introduction de redondance dans la représentation des données, p. ex. en utilisant des codes de contrôle en ajoutant des chiffres binaires ou des symboles particuliers aux données exprimées suivant un code, p. ex. contrôle de parité, exclusion des 9 ou des 11
H03M 13/37 - Méthodes ou techniques de décodage non spécifiques à un type particulier de codage prévu dans les groupes
67.
Method and apparatus to control the effective gain of a statistically calibrated analog to digital converter
A method and apparatus for controlling the effective gain of an ADC when the ADC is occasionally or continuously calibrated using the statistics of the input signal and when the statistics are not stationary.
A method of background calibration of aperture center errors in a data communication system is provided. In an implementation, in response to detection of a low sampler output (“0”) in between two high sampler outputs (“1”), the method includes: calculating a signal derivative of an ADC output signal at the time of the detected low output; and adjusting timing at a selected sampler based on the calculated signal derivative. In an example implementation, the method includes watching for bubbles in the thermometer code output, and estimating the first derivative of the signal at the time of the bubble, then estimating the sign of the errors. In an example implementation, the errors are used in a control loop to reduce the aperture center error.
The present invention is directed at a method and apparatus for determining a distributed Serial Attached Small computer system interface (SAS) topology in a storage network system. Once a SAS storage network element, such as a SAS Expander, receives notification that a downstream SAS topology has changed, the SAS Expander queries all downstream SAS Expanders to update its route table.
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
G06F 13/14 - Gestion de demandes d'interconnexion ou de transfert
70.
Background calibration of threshold errors in analog to digital converters
A method of background calibration of threshold errors in a data communication system is provided. In an implementation, the method uses sampler statistics just after foreground calibration as the reference signal in a control loop method to remove individual sampler offsets. In an implementation in which an analog to digital converter (ADC) includes a plurality of sub-ADCs, gain, offset, and individual threshold errors across parallel, time-interleaved sub-ADCs are minimized by establishing individual comparator statistics for the average sub-ADC after an initial foreground calibration, then forcing each individual comparator to maintain its statistics over time, in the background, by continuously adjusting its threshold.
A method and apparatus for interleaving high-speed, delta-sigma based over-sampled DACs. A delta-sigma modulator is decomposed into a parallel poly-phase block-filter running at a lower rate. The generated parallel digital data is then fed directly to the analog DAC output stage where it is directly combined to form the full-rate signal using a 1-hot-of-N output stage. By using a poly-phase implementation, the complexity of the high-speed parallel digital-analog timing interface is simplified, along with the timing requirements of the delta-sigma modulator which normally would have to run at the full-oversampled rate. The 1-hot-of-N signal encoding is directly generated from the parallel delta-sigma modulator, and efficiently encodes the data in such a way to minimize signal-dependent supply noise. The architecture disclosed is advantageous for the practical implementation of high-speed over-sampled DACs, such as those used in stringent wireless applications.
Precision Timing Protocol (PTP) related functions for use in packet communications carried in part by a microwave communications link include setting of time of day values across the microwave link and providing transparent clock functions. The PTP functions may be used for synchronizing radio base stations in a cellular network. The transparent clock can bridge Ethernet switches associated with microwave stations providing the microwave communications link.
This invention discloses circuit and methods to decouple and pipeline block decision feedback multiplexer (MUX) loop in parallel processing decision feedback circuits. In one embodiment of this invention, a block decision feedback MUX loop consists of a pipelined intra-block decision feedback MUX stage and an inter-block decision feedback MUX stage to handle intra-block decision feedback selection and inter-block decision feedback selection separately. In the pipelined intra-block decision feedback stage, inter-block dependency is eliminated to enable pipelining. In another embodiment of this invention for moderately timing-critical parallel processing decision feedback circuits, a block decision feedback MUX loop is piecewise split into multiple series connected segments that each segment contains parallel branches. The intra-segment decision feedback selections of different segments are decoupled and processed in parallel. The selections of final decision signals of different branches in a segment are parallelized.
Apparatus and methods calibrate and control detector gain in a Mueller-Muller timing detector. A main signal path includes a Mueller-Muller based timing error detector (MM TED). The main signal path generates a main error signal for clock recovery. A secondary signal path that includes a secondary MM TED. Each signal path samples soft symbols from a received signal. The sampling of the secondary MM TED is deliberately offset in time. A scale factor applied to the main error signal and to a secondary error signal is adaptively adjusted based on a comparison between the main error signal and the secondary error signal.
An integer-N phase-locked loop based clock generator for generating an output clock signal with a frequency N multiples of a reference clock signal, and a method for same, wherein N is a positive integer. The integer-N clock phase-locked loop based generator comprises a reference clock, a voltage controlled oscillator, a clock divider, a first and second phase generator for generating a plurality of phases of the reference clock signal and divided down output clock signal, a plurality of phase frequency detectors and charge pumps. The method comprises generating a reference clock and an output clock signals, generating a plurality of phases of a divided down output clock signal and reference clock signal, comparing the plurality of phases, and changing the frequency of the output clock signal based on the comparison.
H03L 7/06 - Commande automatique de fréquence ou de phaseSynchronisation utilisant un signal de référence qui est appliqué à une boucle verrouillée en fréquence ou en phase
A data storage device stores a data unit in a memory page of a storage block along with an error correction code unit for the data unit. Additionally, the data storage device stores an error correction code unit for the data unit in a memory page of another storage block. In various embodiments, one or both of the error correction code units form an error correction code for correcting data bit errors in the data unit. Because the memory page containing the data unit does not have a storage capacity for simultaneously storing the error correction code and the data unit, the data storage device is capable of correcting a greater number of data bit errors in the data unit by using the error correction code in comparison to using an error correction code that would fit in the memory page.
H03M 13/00 - Codage, décodage ou conversion de code pour détecter ou corriger des erreursHypothèses de base sur la théorie du codageLimites de codageMéthodes d'évaluation de la probabilité d'erreurModèles de canauxSimulation ou test des codes
A system and method for measuring a propagation delay in a point to multipoint network. The system includes a central timing module which provides a timing signal to a plurality of line cards. Each of the line cards includes a local clock that is frequency locked to a 1588 clock and is configured to generate a return timing signal to the central timing module after a predetermined number of clock cycles. The central timing module measures the propagation delay based on the clock cycles of the local clock counted before the return signal is generated and the period of the local clock.
A physical layer device provides for synchronization of clocks in a communication network. A place holder for an alignment marker is inserted into a frame to be transmitted. Once the placeholder alignment marker is inserted into the frame, no additional data is added to the frame. Transmission of the frame including the placeholder alignment marker may also be delayed to allow data processing in subsequent blocks within a transmit block to complete prior to further processing of the frame including the placeholder alignment marker (e.g., timestamping, MACSec, etc.) to improve timing accuracy with a multi lane distribution environment.
A method for accessing data in a storage area network is provided. The method initiates with receiving a request for a list of targets on the storage area network. All the targets on the storage area network are exposed to the requestor and authentication requiring a password is requested from the requestor to grant access to the targets on the storage are network. Access to the targets is granted if the password is acceptable, and access to the targets is refused if the password is unacceptable.
H04L 29/00 - Dispositions, appareils, circuits ou systèmes non couverts par un seul des groupes
H04L 29/06 - Commande de la communication; Traitement de la communication caractérisés par un protocole
G06F 21/80 - Protection de composants spécifiques internes ou périphériques, où la protection d'un composant mène à la protection de tout le calculateur pour assurer la sécurité du stockage de données dans les supports de stockage magnétique ou optique, p. ex. disques avec secteurs
H04L 29/08 - Procédure de commande de la transmission, p.ex. procédure de commande du niveau de la liaison
80.
Acceleration of phase and frequency tracking for low-latency timing recovery
Circuit and methods accelerate jitter tracking and reduce or eliminate the processing delay of loop filtering in timing recovery. A timing recovery circuit incorporates a phase tracking accelerator and a frequency tracking accelerator to compute the phase and frequency variation of incoming signal during the delay period of a loop filter. In one embodiment, phase and frequency tracking accelerators are realized in direct forms. In another embodiment, pre-computed look-up tables are employed in phase and frequency tracking accelerators to ease timing closure and simplify accelerator circuit. The phase tracking accelerator and the frequency tracking accelerator together compensate the estimated phase at the output of a loop filter and eliminate the processing delay of loop filtering. The loop bandwidth and jitter tolerance of timing recovery are increased.
Apparatus and methods generate equalizer coefficients for an equalizer of a receiver. In a high-speed receiver, received symbols can be subject to inter-symbol-interference (ISI). An equalizer can compensate for ISI and improve a bit error rate (BER). However, traditional adaptive techniques to generate coefficients for equalization can generate corrupted coefficients when equalized samples used for adaptation are based on clipped or heavily compressed signals. In certain situations, the clipping rate can be relatively high, such as over 20%. Equalizer performance is improved when the equalized symbols used directly or indirectly for adaptation are selected such that equalized symbols based on clipped input samples are not used for adaptation.
Signature circuits are used during testing of an integrated circuit. Test vectors are applied as inputs to a circuit under test. A signature circuit stores a “signature” for the circuit under test based on a combination of signals from the circuit under test in response to test vectors and a previous stored state of the signature register. The value contained in the signature register at the end of the test is the signature. A fault-free circuit generates a particular signature for the applied test vectors. Faults can be determined by detecting variances from the expected signature. In one embodiment, the signature circuit uses a combination of two error detection codes.
Disclosed is a high-swing voltage-mode transmitter or line driver. The transmitter can operate over a wide range of supply voltages. Increasing the available output swing merely involves increasing the supply voltage; the circuit adapts to maintain the desired output impedance. This allows for a tradeoff between output amplitude and power consumption. Another advantage of the proposed architecture is that it compensates for process, voltage, and temperature (PVT) and mismatch variations so as to keep rise and fall times matched. This feature reduces common-mode noise and hence electromagnetic interference in systems in which the transmitter is used.
For power efficiency, it can be desirable to use a 1-bit ADC or slicer to receive a wired data transmission. A plurality of N samples per baud period are taken. N can be, for example, 4 or more. At least a portion of the samples are included in a window of samples, the size of which is based at least partly on earlier determined values of prior symbols. For example, a polynomial function or other numerical function can be embedded in a lookup table to map previously determined data bits to an address, and the address can be used to control an input of multiplexers to vary the size of the window. The value for a current symbol is determined based at least partly on one or more values within the window of samples.
A data regeneration device regenerates a digital signal in a low-speed pass-through mode of operation, performs an upstream link equalization procedure on an upstream data link in an equalization mode of operation, performs a downstream link equalization procedure on a downstream data link in the equalization mode of operation, and regenerates the digital signal in a high-speed pass-through mode of operation. The data regeneration device transitions seamlessly from the low-speed pass-through mode of operation to the equalization mode of operation in compliance with a communication protocol. Moreover, the data regeneration device synchronizes completion of the upstream link equalization procedure with completion of the downstream link equalization procedure so that the data regeneration device transitions seamlessly from the equalization mode of operation to the high-speed pass-through mode of operation in compliance with the communication protocol.
A method and apparatus, such as multi-engine controller that can be used to control multiple data processing engines in a command based IO processing system, such as a storage controller, to solve to the problem of scaling the data processing rate to match the advances in the IO interface data rates, including a method of identifying dependencies among various tasks queued up in the system and scheduling tasks out-of-order to avoid head of line blocking, a method to buffer and reorder the completed tasks such that the task output order is the same as that in the input to the system.
Precision Timing Protocol (PTP) related functions for use in packet communications carried in part by a microwave communications link include setting of time of day values across the microwave link and providing transparent clock functions. The PTP functions may be used for synchronizing radio base stations in a cellular network. The transparent clock can bridge Ethernet switches associated with microwave stations providing the microwave communications link.
Methods and apparatus for reducing sensitivity to nonlinearities in the receiver of a digital communications system are disclosed. One aspect can be referred to as a Post-Distortion Decision Feedback Equalizer (PDFE). A gain stage is often implemented as a variable gain amplifier (VGA), and can introduce significant nonlinearities, a problem exacerbated by signals with a large peak-to-average ratio (PAR). One embodiment provides feed forward information from the VGA regarding its status to a DFE, and the DFE adjusts its filtering based on the provided information. The advantages are also applicable to fixed-gain amplifiers and to transversal filters.
Disclosed is a high-swing voltage-mode transmitter or line driver. The transmitter can operate over a wide range of supply voltages. Increasing the available output swing merely involves increasing the supply voltage; the circuit adapts to maintain the desired output impedance. This allows for a tradeoff between output amplitude and power consumption. Another advantage of the proposed architecture is that it compensates for process, voltage, and temperature (PVT) and mismatch variations so as to keep rise and fall times matched. This feature reduces common-mode noise and hence EMI in systems in which the transmitter is used.
H03K 19/094 - Circuits logiques, c.-à-d. ayant au moins deux entrées agissant sur une sortieCircuits d'inversion utilisant des éléments spécifiés utilisant des dispositifs à semi-conducteurs utilisant des transistors à effet de champ
90.
Multi-client content addressable memory access control method
A method and system for controlling multiple client access to cache memory and a single CAM device. Each client has a corresponding integrity controller in communication with the CAM device and all the other integrity controllers associated with the other clients in the system. Each integrity controller monitors states of the other clients, and inhibits its respective client from executing any operation when a common lookup index is detected during a co-pending operation with a first client. Once the operations of the first client are completed, its integrity controller signals the integrity controller of other clients to exit their inhibit or hold states, thereby allowing the other clients to resume their operations. Another advantage of the integrity controller is that its algorithms also prevents multiple host memory fetches of the same key, thereby saving time and improving system performance.
A method to look at the incoming received data on a SerDes link while running in normal operation without requiring a second receive path or any defined or repeated data patterns to be able to generate statistical eye plots both before and after any internal equalization; generate trajectory eye plots both before and after any internal equalization; estimate TED characteristics (hence also estimate SJ jitter tolerance of the link); estimate complete Channel Impulse Response (hence also estimate the S-parameters of the complete channel); and estimate the decomposed jitter of the complete channel.
H04B 1/38 - Émetteurs-récepteurs, c.-à-d. dispositifs dans lesquels l'émetteur et le récepteur forment un ensemble structural et dans lesquels au moins une partie est utilisée pour des fonctions d'émission et de réception
A slave communication device may transmit a packet to the master communication device, with the packet including a transmission time field and a correction field. The transmission time field may contain a value indicative of an approximate time of transmission of the packet by the slave communication device, and the correction field may contain a value indicative of a difference between the approximate time of transmission and an actual time of transmission of the packet by the slave communication device.
Disclosed is a high-swing voltage-mode transmitter or line driver. The transmitter can operate over a wide range of supply voltages. Increasing the available output swing merely involves increasing the supply voltage; the circuit adapts to maintain the desired output impedance. This allows for a tradeoff between output amplitude and power consumption. Another advantage of the proposed architecture is that it compensates for process, voltage, and temperature (PVT) and mismatch variations so as to keep rise and fall times matched. This feature reduces common-mode noise and hence EMI in systems in which the transmitter is used.
H03K 19/094 - Circuits logiques, c.-à-d. ayant au moins deux entrées agissant sur une sortieCircuits d'inversion utilisant des éléments spécifiés utilisant des dispositifs à semi-conducteurs utilisant des transistors à effet de champ
94.
Physical layer processing of timestamps and MAC security
A physical layer device provides both timestamp processing and security processing. The timestamp processing may be PTP processing according to IEEE Std. 1588 and/or OAM processing according to ITU-T Recommendation Y.1731. The security processing may be MACsec processing according to IEEE Std. 802.1AE. The timestamp processing may delay some packets to avoid impairing accuracy of timing information. For example, the accuracy of timing information could be impaired when a packet containing the timing information is delay due to additional bits added to a preceding packet to include a security tag and integrity check value.
A physical layer device provides security processing on communication frames that may include tags or headers that are for use in a wide area network. As frames pass through the physical layer device, the frames are classified for a type of security processing. Depending on the classification a cipher is applied to the frames for integrity checking of data in the frames. Some frames are also encrypted. The security processing may exclude some of the tags or headers. The frames may also be filtered and buffered.
A peripheral component interconnect express (PCIe) switch includes non-transparent endpoints, each of which is associated with a bus hierarchy domain. A source non-transparent endpoint in a source bus hierarchy domain receives a packet including a destination address and identifies a destination bus hierarchy domain including a destination non-transparent endpoint based on the destination address. Further, the source non-transparent endpoint translates a requester identifier in the packet to a translated requester identifier and generates a translated request packet including the translated requester identifier. The PCIe switch routes the translated request packet to the destination non-transparent endpoint through a non-transparent interconnect in the PCIe switch. In this way, the PCIe switch interconnects multiple bus hierarchy domains and is non-transparent in the multiple bus hierarchy domains. In further embodiments, the PCIe switch routes multicast packets to multiple destination non-transparent endpoints in multiple destination bus hierarchy domains.
Apparatus and methods mitigate a problem of equalizing communications signals that have been distorted by severe non-linearities such as clipping or harsh compression. For example, severe non-linearity occurs when signal compression or signal clipping occurs at rates above 20% of the data transmission interval. Severe non-linearities may significantly reduce system performance. Disclosed techniques selectively apply DSP equalization based on the detection of non-linearity for a present sample or one or more samples prior to the present sample. These techniques can be implemented in relatively low-cost high-speed SerDes designs to improve eye openings and reduce sensitivity to InterSymbol Interference (ISI) and to improve bit error rate (BER).
A packet switch includes a pipeline scheduler for scheduling packets according to a credit-based flow control protocol. A credit update pipeline stage initializes available credits for egress ports of the packet switch. A request pipeline stage generates packet requests for packets based on the available credits. A grant pipeline stage selects packets based on the ports requests and the available credits, and generates port grants for the selected packets. Additionally, the credit update stage updates the available credits based on the port grants. The packet switch routes the selected packets from ingress ports of the packet switch to the egress ports based on the port grants. In some embodiments, ingress ports generate enqueue requests based on the packets, an enqueue pipeline stage generates enqueue states based on the enqueue requests, and the request pipeline stage selects packets for routing based on the enqueue states and the available credits.
A packet switch includes ingress ports, each of which contains a random access memory having a storage capacity for storing data. An ingress controller of the packet switch allocates the storage capacity of each random access memory among transaction types of packets by allocating credits to each of the transactions types for the random access memory. Each ingress port accepts packets based on the transaction types of the packets and the credits of the random access memory in the ingress port. Moreover, the ingress port stores accepted packets in the random access memory of the ingress port. In further embodiments, the ingress controller dynamically reallocates the credits of the random access memory in the ingress port during operation of the packet switch.
H04L 1/00 - Dispositions pour détecter ou empêcher les erreurs dans l'information reçue
H04L 12/26 - Dispositions de surveillance; Dispositions de test
H04L 12/28 - Réseaux de données à commutation caractérisés par la configuration des liaisons, p. ex. réseaux locaux [LAN Local Area Networks] ou réseaux étendus [WAN Wide Area Networks]
A method of communicating count value information in an Optical Transport Network (OTN) signal frame. The method comprises determining a count value indicating a number of payload bytes to be sent in a next OTN signal frame; determining that a change in the count value (Δ) with respect to a current count value is within a predetermined range; selecting an inversion pattern indicating the change in the count value; determining a cyclic redundancy check (CRC) code associated with the inversion pattern; and, inserting the inversion pattern and the CRC code in a Generic Mapping Procedure (GMP) overhead of the OTN signal frame.
brevets
