摘要:
A structured interleaving/de-interleaving scheme enables efficient implementation of encoding/decoding based on two-dimensional product codes (2D PC). An encoder has an integrated architecture that performs structured interleaving and PC coding in an integrated manner in which locations in the interleaved data stream are related to row and column indices for the 2D PC coding based on closed-form expressions. In one embodiment, a corresponding decoder implements two-stage low-density parity-check (LDPC) decoding based on the same relationships between locations in the interleaved data stream and row and column indices for the LDPC decoding.
摘要:
A structured interleaving/de-interleaving scheme enables efficient implementation of encoding/decoding based on two-dimensional product codes (2D PC). In one embodiment, an encoder has an integrated architecture that performs structured interleaving and PC coding in an integrated manner in which locations in the interleaved data stream are related to row and column indices for the 2D PC coding based on closed-form expressions. A corresponding decoder implements two-stage low-density parity-check (LDPC) decoding based on the same relationships between locations in the interleaved data stream and row and column indices for the LDPC decoding.
摘要:
A structured interleaving/de-interleaving scheme enables efficient implementation of encoding/decoding based on two-dimensional product codes (2D PC). An encoder has an integrated architecture that performs structured interleaving and PC coding in an integrated manner in which locations in the interleaved data stream are related to row and column indices for the 2D PC coding based on closed-form expressions. In one embodiment, a corresponding decoder implements two-stage low-density parity-check (LDPC) decoding based on the same relationships between locations in the interleaved data stream and row and column indices for the LDPC decoding.
摘要:
A structured interleaving/de-interleaving scheme enables efficient implementation of encoding/decoding based on two-dimensional product codes (2D PC). In one embodiment, an encoder has an integrated architecture that performs structured interleaving and PC coding in an integrated manner in which locations in the interleaved data stream are related to row and column indices for the 2D PC coding based on closed-form expressions. A corresponding decoder implements two-stage low-density parity-check (LDPC) decoding based on the same relationships between locations in the interleaved data stream and row and column indices for the LDPC decoding.
摘要:
A first PHY may be coupled to a second PHY via a network link. The first PHY may transition from a role of timing master for the network link to a role of timing slave for the network link. During a first time interval subsequent to the transition, the PHYs may communicate half-duplex over the link while the first PHY synchronizes to a transmit clock of the second PHY. During a second time interval, the PHYs may communicate full-duplex while the second Ethernet PHY synchronizes to a transmit clock of the first PHY. Also during the second time interval, the first PHY may determine that the first PHY and the second PHY are synchronized. Subsequent to the determination, the PHYs may begin full-duplex communication of data on the network link.
摘要:
Aspects of a method and system for physical-layer handshaking for timing role transition are provided. Prior to changing the timing role of a first Ethernet device, the first Ethernet device may communicate over an Ethernet link to a second Ethernet PHY utilizing a first set of one or more PCS code-groups. In response to a determination to change the timing role of the first Ethernet device, the first Ethernet device may communicate one or more IDLE symbols over the Ethernet link to the second Ethernet device. The IDLE symbol(s) may be generated utilizing a second set of one or more PCS code-groups. The first set of PCS code-group(s) may be mutually exclusive with the second set of PCS code-group(s). In response to detecting a received Ethernet physical layer symbol corresponding to the second set of PCS code-groups, the second Ethernet device may make a determination to change its timing role.
摘要:
Embodiments of the invention include a method and apparatus for encoding data and a system for transmitting and/or storing data, in which the data is encoded and precoded in a manner that does not violate previously established data constraints, such as modulation encoding constraints. The method includes the steps of modulation encoding the data using a modulation code defined by at least one modulation constraint, parity encoding the modulation encoded information, and preceding the encoded information. The preceding step either partially precodes information bits and precodes parity bits, precodes information bits but not parity bits, or precodes both information bits and parity bits in such a manner that does not violate modulation constraints. Also, the parity encoding step can be performed in such a manner that does not violate modulation code constraints.
摘要:
Embodiments of the present invention enable robust and quick parallel detection of the remote LPI request signal (rem_lpi_req) and SEND ZERO mode (SEND_Z) defined in the Energy Efficient Ethernet (EEE) standard. Embodiments do not rely on energy detection for detecting SEND_Z. Therefore, SEND_Z can be detected reliably and with minimal latency. In addition, since SEND_Z and rem_lpi_req are detected in parallel, embodiments are not concerned with the false detection of rem_lpi_req (before SEND_Z is detected) or the need to disable detection of rem_lpi_req (after SEND_Z is detected).
摘要:
A data-dependent noise predictive (DDNP) adaptation module operable to support Viterbi branch metric calculations within a hard disk drive (HDD) controller is provided. This DDNP adaptation module includes a DDNP filter tap coefficient adaptation module, a DDNP filter gain scaling module, and a DDNP bias compensation module. The combination of the DDNP filter tap coefficient adaptation module, the DDNP filter gain scaling module, and the DDNP bias compensation module is operable to receive an error signal and a NRZ pattern and produce tap coefficients. A whitened error signal calculation module coupled to the DDNP filter tap coefficient adaptation module, the DDNP filter gain scaling module, and the DDNP bias compensation module, the whitened error signal calculation module operable to calculate a whitened error signal based on the error signal, NRZ pattern, and tap coefficients. This whitened error signal is used to support the Viterbi branch metric calculations.
摘要:
An interleaver employs a generalized method of generating a mapping. The mapping is generated for interleaving bits of a data block and associated error detection/correction information. The data block is of length N, and the length of the error detection/correction information is P. An (N+P)×(N+P) square matrix is formed and divided into sub-blocks, where one portion of the matrix is associated with error detection/correction information and another portion is associated with data of the data block. New positions in the matrix are generated in a time sequence on a sub-block by sub-block basis based on a generator seed pair and an original position seed pair. The time sequence also corresponds to positions in an output interleaved block. Once the new position sequence is generated, the matrix is populated with data and error detection/correction information based on the corresponding time sequence. A de-interleaver performs the inverse mapping of the interleaver.