摘要:
A data dependent scrambler for a communications channel that receives a user data sequence including N symbols and host cyclic redundancy check (CRCU) bits comprises a data buffer that receives the user data sequence and the host CRCU bits. A seed finder generates a scrambling seed that is dependent upon the symbols in the user data sequence. A first scrambler receives the user data sequence from the data buffer and the scrambling seed from the seed finder and generates the scrambled user data sequence. A second scrambler generates a difference sequence that is based on the user data sequence and the scrambled user data sequence.
摘要:
An error correcting Reed-Solomon decoder includes an error locator polynomial generator that generates an error locator polynomial and a scratch polynomial based on an inversionless Berlekamp-Massey algorithm (iBMA). An error location finder communicates with the error locator polynomial generator and generates error locations. An error values finder communicates with the error locator polynomial generator and generates error values directly from the error locator polynomial and the scratch polynomial.
摘要:
A Reed-Solomon decoder includes an inversionless Berlekamp-Massey algorithm (iBMA) circuit with a pipelined feedback loop. An error locator polynomial generator generates error locator polynomial values. A scratch polynomial generator generates scratch polynomial values. A discrepancy generator generates discrepancy values based on the error locator polynomial values and the scratch polynomial values. Multipliers used to generate the discrepancy values are also used to generate the error locator polynomial to reduce circuit area. A first delay circuit delays the discrepancy values. A feedback loop feeds back the delayed discrepancy values to the error locator polynomial generator and the scratch polynomial generator. An error location finder circuit communicates with the iBMA circuit and identifies error locations. An error value computation circuit communicates with at least one of the error location finder circuit and the iBMA circuit and generates error values.
摘要:
Method and apparatus for detecting errors in data read from a data storage medium include an error correction step/device which receives at least one of (i) data and (ii) data with errors, from the data storage medium, and outputs an error sequence in a first order in the case where data with errors is received. A first CRC step/device receives the at least one of (i) data and (ii) data with errors from the data storage medium, and outputs a CRC checksum in a second order different from said first order. A second CRC step/device receives both the error sequence and the CRC checksum, and outputs another CRC checksum indicative of whether the correction device or step has generated a correct error sequence. Preferably, a first CRC is coupled parallel to a Reed-Soloman decoder, and a second CRC is coupled in series with the first CRC and so as to receive the output of the R-S decoder. The second CRC will thus be able to detect errors in the output of the R-S decoder, and provide an error signal which will cause the erroneous data to be reread.
摘要:
In an error correcting code encoder apparatus, a first processor generates a first subset of codeword symbols based on original symbols. The first processor includes a first serial input to receive a first subset of the original symbols. A second processor generates a second subset of the codeword symbols based on the original symbols. The second processor includes a second serial input to receive a second subset of the original symbols.
摘要:
A system-on-a-chip includes a first memory and a processor. The first memory is configured to store a boot code. The processor is configured to (i) access the first memory, and (ii) execute the boot code when booting up. The processor is configured to, while booting up, determine whether a first one-time-programmable memory has been previously programmed based on the boot code. The processor is configured to, in response to the first one-time-programmable memory not having been previously programmed based on the boot code, (i) load firmware from a second memory into a third memory, and (ii) execute the firmware loaded into the third memory. The processor is configured to, in response to the first one-time-programmable memory having been previously programmed, verify a digital signature of the firmware.
摘要:
A data dependent scrambler for a communications channel that receives a user data sequence including N symbols each with M bits includes a seed finder that selects a scrambling seed and a first scrambler that receives said user data sequence and said scrambling seed from said seed finder. The first scrambler generates a scrambled user data sequence. A first encoder identifies a string of X consecutive zeros in adjacent symbols of the scrambled used data sequence and replaces one of the adjacent symbols with an all-one symbol. The first encoder replaces the other of the adjacent symbols with first bits representing a position of the string of X consecutive zeros and second bits representing bits of the adjacent symbols that are not in the string of X consecutive zeros.
摘要:
A method and apparatus enables advanced signal processing in a wireless local area network (WLAN). First and second WLAN transceivers are provided with advanced signal processing capabilities. A maximum interframe period between data and an acknowledgement is required by the WLAN for compatibility. A duration of the interframe period is shorter than a duration that is required to perform the advanced signal processing. The first WLAN transceiver transmits a header and data. A first data field in the header is specified that enables the advanced signal processing. A second data field is specified that defines a data time period and an extension time period. The first WLAN transceiver transmits data during the data time period and dummy data during the extension time period. The second WLAN transceiver receives the header and initiates receiver processing during the extension time period.
摘要:
An error decoding system that comprises a first Reed-Solomon (RS) decoder that receives an encoded codeword and generates a decoded codeword. An inner code (IC) decoder checks the decoded codeword for uncorrected errors. A decoding control module communicates with the first RS decoder and the IC decoder, iteratively modifies a parameter of the first RS decoder if the IC decoder detects uncorrected errors in the decoded codeword, and instructs the first RS decoder to decode the encoded codeword again after modifying the parameter.
摘要:
A secure hard drive comprises a storage medium that stores encrypted digital content and corresponding encrypted content keys. A public key decryption module receives one of the encrypted content keys from the storage medium and decrypts the encrypted content key using a private key to generate a content key. A block decryption module receives the encrypted digital content corresponding to the one of the encrypted content keys from the storage medium and the content key from the public key decryption module and decrypts the encrypted content using the content key. The storage medium is a magnetic storage medium. The public key decryption module and the block decryption module are implemented by a system on chip (SOC). A content player receives the decrypted digital content from the block decryption module and generates at least one of an analog output signal and a digital output signal.