Abstract: A system for a fiber-optic network includes a transceiver. The transceiver includes a fiber-optic interface unit and a host unit. The host unit includes a low-complexity error correction decoder and a high-complexity error correction decoder. One or both from the low-complexity error correction decoder and the high-complexity error correction decoder are selected to decode input data from the fiber-optic interface unit, the input data including codewords.

Abstract: The present disclosure provides a method for checking a to-be-checked signal and related products. The method is applied in a checking device and includes: a first obtaining module, configured to obtain a to-be-checked signal carrying first control information, wherein the first control information is generated based on original control information; a second obtaining module, configured to obtain original checking information; a determining module, configured to determine the first control information according to the to-be-checked signal; and a checking module, configured to check correctness of the first control information according to the original checking information. The present disclosure can be used to enable reliability and functional safety on devices originally designed without features intended to support those functions.

Abstract: An electronic system includes circuitry to detect errors in logic state in the system and to initiate corrective action when one or more errors are detected. In some embodiments, redundant information is stored within a system that is associated with an operational state of the system. If the operational state of the system is subsequently corrupted as a result of an electrical or mechanical overstress condition, resulting errors may be detected by comparing or otherwise processing the stored operational state information and the redundant information.

Abstract: A method may be performed at a data storage device that includes a memory and a controller. The method includes providing user data to a variable-bit error correction coding (ECC) encoder. The ECC encoder generates a first set of parity bits. A first number of parity bits in the first set of parity bits is determined based on stored counts of read errors. The method also includes storing the user data and the first set of parity bits to a memory of the data storage device.

Abstract: For detecting an error of an A/D converter, which is designed to generate at least one digital output signal, which includes a quantity of output data bits, based on at least one analog input signal, and during a conversion, to generate a thermometer code which includes a quantity T of output data values, the detection method includes: ascertaining a first parity directly for the output data bits of the output signal; making a prediction for the output data bits on the basis of the T output data values of the thermometer code; ascertaining a second parity, which is a reverse of the first parity, for the predicted output data bits; and detecting an error for the A/D converter when both the first and second parities are identical.

Abstract: Systems and methods are provided for encoding data based on an LDPC code using various inversion mechanisms to obtain parity bits. In some embodiments, an LDPC encoder may compute parity bits using a speculative recursion and correction mechanism. In these embodiments, the LDPC encoder may initiate a recursion using at least one speculative value in place of the actual value for a parity component. The speculative values may then be corrected using a correction factor. In other embodiments, an LDPC encoder is provided that can perform a blockwise inversion mechanism. This mechanism may be used on LDPC codes with parity check matrices having a parity portion composed partially of a large triangular matrix. In still other embodiments, a generic LDPC encoder is provided. The generic LDPC encoder can implement a variety of different encoding techniques, such as different inversion mechanisms, and may be processor-based or finite state machine-based.

Abstract: The subject matter hereof relates to error detection. Various example embodiments for error defection are disclosed. In an example method of error detection in a Module UnderTest (MUT), a parity signal representing the parity of an MUT output is compared to a parity signal representing the parity of an errorless MUT output. In an example system, an Actual Parity Generator provides a parity signal representing the parity of on MUT output, a State Parity Generator provides a parity signal representing the parity of an errorless MUT output, and a comparator compares these two parity signals.

Abstract: LDPC codes robust to non-stationary narrowband ingress noise. Particularly designed LDPC codes are adapted to address deleterious noise-effects incurred within LDPC coded signals that propagate via a communication channel (such as from a transmitting communication device to a receiving communication device). Such LDPC matrices employed for encoding and/or decoding such LDPC coded signals are composed of sub-matrices (e.g., all-zero values sub-matrices and/or CSI (Cyclic Shifted Identity) sub-matrices). The sub-matrices are generally uniform in size and square in shape. Based on certain operational conditions, such as communication channel noise, various operations within a communication device are adaptively modified (e.g., signaling, modulation, demodulation, symbol mapping, metric generation, decoding, etc.).

Abstract: A predictor configured to predict a parity value of a Carry-Less multiplication result of a multiplicand data string and a multiplier data string being two data strings in which q (q is a natural number) data units being p-bit (p is a natural number equal to two or above) data, includes a unit configured to predict a parity value of a first data unit from lower order in a result data string representing the multiplication result based on a value and a parity value of a first data unit from lower order in each of the two data strings; and a unit configured to predict a parity value for data at a high-order p?1 bit of the result data string based on a value and a parity value for a q-th data unit from lower order in each of the two data strings.

Abstract: An apparatus, system, and method are disclosed for ensuring data validity in a data storage process. A data receiver module receives a storage block and existing parity information. An ECC generation module generates error correcting code (“ECC”) check bits for the data of the storage block in response to receiving the storage block and the existing parity information. The ECC check bits for the storage block are generated using a block code, a convolutional code, etc. A pre-storage consistency module uses the data of the storage block, the existing parity information, and the ECC check bits to determine if the data of the storage block, the existing parity information, and the ECC check bits are consistent. A data storage module stores the data of the storage block and the ECC check bits the data storage device without storing the existing parity information.

Abstract: In order to generate a parity of output data from a priority encoder without increasing processing time or making the circuitry complex, the present invention a first level generator having a plurality of first component circuits arranged in parallel, into each of which one of a plurality of sets of a specific number of bits of the binary data in sequence from the most significant bit is input and each of which generates and outputs a first signal for parity generation of bit data of the specific number of bits and a second signal representing whether or not the entire bit data of the specific number of bits is “0s” or “1s”; and a second level generator generating the parity of the binary data based on the first signal and the second signal from each of said first component circuits of said first level generator.

Abstract: A method of recovering data in a line signal which is predicted to be subjected to repetitive noise impulses, the line signal comprising a series of data frames, the method comprising the steps of: predicting a group comprising one or more frames in said line signal which are expected to be corrupted by a noise signal; blanking said group of one or more frames which are predicted to be corrupted; determining the preceding and succeeding frames adjacent to said group; and including in each said group of one or more frames one or more parity blocks wherein if said noise signal deviates from its predicted timing interval or duration and corrupts the data carried in one or more of said frames adjacent to said group, the corrupted data is recovered using one or more of said parity blocks of said group of blanked frames and the other one of said adjacent frames.

Abstract: An encoding apparatus includes a systematic encoder that generates information bits and parity bits, both of which are transmitted selectively to a decoding apparatus. At certain points, sufficient bit data are transmitted to identify the state of the systematic encoder. The decoding apparatus partitions the received bits at these identifiable points, and processes each partition separately by predicting the information bits, modifying the predicted information bits according to the received information bits, and using the parity bits to correct errors in the resulting information bits. In video coding, this partitioning scheme can deal flexibly with multiple image formats without requiring extra decoding circuitry. With a parallel decoding apparatus, the number of decoding units operating concurrently can be changed flexibly. The error correcting capability of the decoding apparatus is also improved.

Abstract: A method of transmitting data by transmitting apparatus, that includes controlling generation of bit sequences to adjust an occupation rate of systematic bits in a first data block including systematic bits and parity bits, which is obtained by encoding first data in a first encoding process, and is equal or closer to an occupation rate of systematic bits in a second data block including systematic bits and parity bits, which is obtained by encoding second data in a second encoding process, and to adjust an occupation rate of parity bits in the first data block that is closer to an occupation rate of parity bits in the second data block, in regard to first bit positions of the bit sequences generated using bits included in the first and second data blocks and performs multi-level modulation for transmission based on the generated bit sequences.

Abstract: Algebraic method to construct LDPC (Low Density Parity Check) codes with parity check matrix having CSI (Cyclic Shifted Identity) sub-matrices. A novel approach is presented by which identity sub-matrices undergo cyclic shifting, thereby generating CSI sub-matrices that are arranged forming a parity check matrix of an LDPC code. The parity check matrix of the LDPC code may correspond to a regular LDPC code, or the parity check matrix of the LDPC code may undergo further modification to transform it to that of an irregular LDPC code. The parity check matrix of the LDPC code may be partitioned into 2 sub-matrices such that one of these 2 sub-matrices is transformed to be a block dual diagonal matrix; the other of these 2 sub-matrices may be modified using a variety of means, including the density evolution approach, to ensure the desired bit and check degrees of the irregular LDPC code.

Abstract: A method and system for instruction address parity comparison are provided. The method includes calculating an instruction address parity value for an instruction, and distributing the instruction address parity value to one or more functional units in processing circuitry. The method also includes receiving the distributed instruction address parity value from the one or more functional units, and calculating a completing instruction address (CIA) parity value associated with completing the instruction. The method further includes generating an error indicator in response to a mismatch between the received instruction address parity value and the CIA parity value.

Abstract: A semiconductor memory device includes a memory cell array and an error correction code (ECC) engine. The memory cell array stores bits of normal data and parity data therein. The ECC engine performs a masking operation in a masking mode, the ECC engine calculating the parity data using the normal data. The normal data includes a first section that is to be updated and a second section that is to be saved by the masking operation.

Abstract: A system and method for operating a collection of memory cells includes storing binary data values and parity data values by associating binary values with a common adjustable characteristic parameter of a memory cell collection. Probability distribution functions for values of the characteristic parameter of the memory cell collection are read and constructed. Binary data values and parity data values stored in the memory cell collection are retrieved. Parity data for error detection and error correction is evaluated in the binary data values.

Abstract: A system includes an encoder that manipulates postcoded data and produces parity bits, and a parity bit encoder that produces encoded parity bits by inserting into the parity bits one or more flags with polarities, or states, that are selected to produce, after precoding, precoded parity bits that meet predetermined modulation constraints.

Abstract: Methods and apparatus are provided for soft decision decoding using reliability values based on a log base two function. A signal is processed to determine one or more reliability values for a soft decision decoder by computing one or more log-likelihood ratio (LLR) values using a log base two function. The soft decision decoder may employ, for example, a belief propagation algorithm. The soft decision decoder can decode, for example, Low-Density Parity Check codes or turbo codes.

Abstract: A Forward Error Correction (FEC) code compatible with the self-synchronized scrambler used by the 64B/66B encoding standard for transmission on Serializer/Deserializer (SerDes) communications channel links. The FEC code allows encoding and decoding to occur before and after scrambling, respectively, so as to preserve the properties of the scrambling operation on the transmitted signal. The code allows the correction of any single transmission error in spite of the multiplication by three of all transmission errors due to the 64B/66B scrambling process. A Hamming code is combined with a Bit Interleaved Parity code of degree n (BIP-n). These two codes provide for protection both for an error anywhere in the maximum length of the packet as well as for an error replicated two or three times by the descrambling process. All single bit errors, whether multiplied or not, have unique syndromes and are therefore easily correctable.

Abstract: A decoder for decoding low-density parity-check codes includes a first calculator that calculates ??rRml, for each parity check equation, at iteration i?1. A second calculator calculates ??rQ?m, for each parity check equation, at iteration i. ??rQ?m represents information from bit node I to equation node m, one for each connection. ??rRml represents information from equation node m to bit node I, one for each connection. The first calculator is responsive to the second calculator.

Abstract: A computer system including: at least one host computer, a storage system for storing data used in the host computer, and a managing computer for managing storing the data in the storage system which are connected to each other with a network. The managing computer monitors the journal volume which is a storing destinations of the journal, in a case that the journal is stored in the journal volume in parallel, when it is detected that the storing destination of the journal changes from one of the groups into which the journal is just stored to another group, transmits an instruction to the storage system to change the storing destination of the journal to another group.

Abstract: A method and system for instruction address parity comparison are provided. The method includes calculating an instruction address parity value for an instruction, and distributing the instruction address parity value to one or more functional units in processing circuitry. The method also includes receiving the distributed instruction address parity value from the one or more functional units, and calculating a completing instruction address (CIA) parity value associated with completing the instruction. The method further includes generating an error indicator in response to a mismatch between the received instruction address parity value and the CIA parity value.

Abstract: The invention provides a channel coding method for encoding systematic data for transmission in a communication channel. The systematic data has a runlength constraint. In the method, data words are permuted. Error codes are generated based upon the permuted data words. The error codes are appended to original data words to form channel input for serial transmission in the communication channel. The number of error code bits is limited to ensure the channel input meets the runlength constraint. The error code can be a parity check bit.

Abstract: A system includes an encoder that manipulates postcoded data and produces parity bits, and a parity bit encoder that produces encoded parity bits by inserting into the parity bits one or more flags with polarities, or states, that are selected to produce, after precoding, precoded parity bits that meet predetermined modulation constraints.

Abstract: A decoder for decoding low-density parity-check codes comprises a first calculator to calculate LLrRml, for each parity check equation, at iteration i?1. A detector detects LLrRml, at iteration i, in response to the first calculator. A second calculator calculates LLrQLm, for each parity check equation, at iteration i in response to the detector. LLrQLm represents information from bit node l to equation node m, one for each connection. LLrRml represents information from equation node m to bit node l, one for each connection. The first calculator is responsive to the second calculator.

Abstract: A system and method for operating a collection of memory cells includes storing binary data values and parity data values by associating binary values with a common adjustable characteristic parameter of a memory cell collection. Probability distribution functions for values of the characteristic parameter of the memory cell collection are read and constructed. Binary data values and parity data values stored in the memory cell collection are retrieved. Parity data for error detection and error correction is evaluated in the binary data values.

Abstract: Disclosed are an error-detecting encoding apparatus for creating parity bits by error-detecting encoding processing, appending the parity bits to an input data string and encoding the data string, and an error-detecting decoding apparatus for detecting error using these parity bits. Data segmenting means segments an input data string, which is to undergo error-detecting encoding, into a plurality of sub-data strings, dividing means divides the segmented sub-data strings by a polynomial, which is for generating an error-detecting code, and calculates remainders, converting means applies conversion processing, which conforms to a segmentation position of the sub-data strings, to the remainders on a per-remainder basis, and combining means combines converted values, which have been obtained by the conversion processing, and outputs parity bits. An encoder appends this parity to a data string, and a decoder detects error using this parity.

Abstract: A storage system for storing data on a storage medium includes an encoder, a linear block encoder, a write circuit, a read circuit, a channel decoder, and a soft linear block code decoder. In a first iteration, the channel decoder decodes data read by the read circuit. In succeeding iterations, the channel decoder decodes the data read by the read circuit and utilizes information decoded by the soft linear block decoder from an immediately preceding iteration. The storage system includes a threshold check circuit to select (i) an output of the soft linear block code decoder if the number of parity-check violations has a first relationship with respect to a threshold, or (ii) an output of the channel decoder if the number of violations has a second relationship with respect to the threshold. The storage system includes a decoder to decode an output of the threshold check circuit.

Abstract: A dynamic parity distribution system and technique distributes parity across disks of an array. The dynamic parity distribution system includes a storage operating system that integrates a file system with a RAID system. In response to a request to store (write) data on the array, the file system determines which disks contain free blocks in a next allocated stripe of the array. There may be multiple blocks within the stripe that do not contain file system data (i.e., unallocated data blocks) and that could potentially store parity. One or more of those unallocated data blocks can be assigned to store parity, arbitrarily. According to the dynamic parity distribution technique, the file system determines which blocks hold parity each time there is a write request to the stripe. The technique alternately allows the RAID system to assign a block to contain parity when each stripe is written.

Abstract: A method uses an outer code that is a concatenation of code words generated by a parity check encoder. The outer code word is permuted by an interleaver. The high rate coding provides good performance with a simple structure. A parity check bit is generated for each data word of received systematic dates. Code words are formed by adding a generated parity bit to each data word. Groups of code words are permuted to form encoded input for transmission in a communication channel. The invention further includes encoding to maintain a runlength-limiting (RLL) constraint at the channel input. Interleaved runlength encoded system data is used to generate error code bits. Insertion of error code bits in the system data at the channel input is controlled. This guarantees that the channel input stream comprised of the runlength-limited system data and inserted error code bits meets the runlength constraints.

Abstract: Architectures for decoding low density parity check codes permit varying degrees of hardware sharing to balance throughput, power consumption and area requirements. The LDPC decoding architectures may be useful in a variety of communication systems in which throughput, power consumption, and area are significant concerns. The decoding architectures implement an approximation of the standard message passing algorithm used for LDPC decoding, thereby reducing computational complexity. Instead of a fully parallel structure, this approximation permits at least a portion of the message passing structure between check and bit nodes to be implemented in a block-serial mode, providing reduced area without substantial added latency.

Abstract: A data coder includes a combined parallel concatenated convolution coder (PCCC) and a parallel concatenated zigzag (PCZZ) coder, where PCCC functional blocks are re-used in the PCZZ coder for coding at high coding rates. The PCZZ coding rate (R) may be changed by re-partitioning at least one interleaver pattern. A second interleaver for the PCZZ coder is obtained by a transform of an initial interleaving vector. Alternatively, the PCZZ coder re-uses a PCCC interleaver. The PCZZ coder may also use a multi-dimensional concatenation of zigzag codes, and it is shown one may add additional code dimensions (and relevant parity check symbols) by using properties of already specified interleaver(s), and without adding more interleaver(s).

Abstract: A method uses an outer code that is a concatenation of code words generated by a parity check encoder. The outer code word is permuted by an interleaver. The high rate coding provides good performance with a simple structure. An odd parity check bit is generated for each data word of received systematic dates. Code words are formed by adding a generated parity bit to each data word. Groups of code words are permuted to form encoded input for transmission in a communication channel. The invention further includes encoding to maintain a runlength-limiting (RLL) constraint at the channel input. Interleaved runlength encoded system data is used to generate error code bits. Insertion of error code bits in the system data at the channel input is controlled. This guarantees that the channel input stream comprised of the runlength-limited system data and inserted error code bits meets the runlength constraints.

Abstract: Stopping or reducing oscillations in Low Density Parity Check (LDPC) codes. A novel solution is presented that completely eliminates and/or substantially reduces the oscillations that are oftentimes encountered with the various iterative decoding approaches that are employed to decode LDPC coded signals. This novel approach may be implemented in any one of the following three ways. One way involves combining the Sum-Product (SP) soft decision decoding approach with the Bit-Flip (BF) hard decision decoding approach in an intelligent manner that may adaptively select the number of iterations performed during the SP soft decoding process. The other two ways involve modification of the manner in which the SP soft decoding approach and the BF hard decision decoding approach are implemented. One modification involves changing the initialization of the SP soft decoding process, and another modification involves the updating procedure employed during the SP soft decoding approach process.

Abstract: A method and apparatus for characterizing frequency response of a device under test (DUT) is disclosed. A repeated base bit pattern is received, the base bit pattern including a first transition from a 0-bit to a 1-bit. Then, using bit error rate distribution, multivalue voltage along the first transition is determined. Finally, the multivalued voltages are converted into frequency domain using fast Fourier transform. The apparatus includes a processor and storage with instructions for the processor to perform these operations. Using the present inventive technique, the frequency response of the DUT can be determined using an error performance analyzer such as a BERT.

Abstract: A system and method for checking and correcting soft errors in a next instruction pointer is described. In one embodiment, a parity bit is generated for a next instruction pointer that is produced in a front end of a processor. The next instruction pointer and the parity bit are staged from the front end of the processor to a back end of the processor. Another next instruction pointer is generated in the back end of the processor when an instruction corresponding to the next instruction pointer generated in the front end executes. The next instruction pointer generated in the back end is also parity protected. The next instruction pointer generated in the front end is checked for a parity error. The next instruction pointer generated in the back end is also checked for the parity error. Finally, both next instruction pointers are compared to determine if both are equal.

Abstract: A system and method for detecting unchanged parity in a random data block write operation to a disk array, and for acting upon such detection is provided. A direct memory access and exclusive-OR (DMA/XOR) engine transfers data between the host processor, a cache memory and the disk array, which can be configured as a redundant array of independent disks (RAID) having a stripe storage block structure across multiple drives and separate parity blocks. The DMA/XOR engine reads the states of the original stored data block, the new data block to-be-written and the original parity, and performs XOR operations, combining the data to derive the data difference. If the data difference result is zero, indicating no data difference, then the write of new parity and new data to respective blocks is omitted, and/or other optimizing functions are performed.

Abstract: A mechanism for decoding linear shifted codes employs two shift registers. The shift registers are independently controlled by an associated control unit. Initially, the received parity bits are stored in a first shift register and the global syndrome bits are stored in a second shift register. While the right-most cell in the first shift register contains a logical “0”, both shift registers are shifted right one position. When the right-most cell of the first shift register contains a “1”, the content of the right-most cell of the second shift register is recorded as a first bit of a syndrome code which identifies the position of an error with any groups with an error. If the value recorded is a “1”, a bit-wise exclusive OR operation is then performed on the values in the first and second shift registers, and the result is stored in the second shift register. Subsequently, the contents of the second shift register are shifted by one position.

Abstract: A method and apparatus are provided for detecting virtual address parity error for a translation lookaside buffer in a computer system. The computer system includes a processor unit, a cache coupled to the processor unit, a main memory, and a storage control unit including a translation lookaside buffer (TLB) and a segment lookaside buffer (SLB). A virtual address parity (VAP) is generated for each entry written in the segment lookaside buffer (SLB). A virtual address parity (VAP) is generated for each virtual address entry written in the translation lookaside buffer (TLB). The SLB virtual address parity (VAP) and the TLB virtual address parity (VAP) are utilized for identifying a translation miss condition.

Abstract: A shifting structure and method which separates a shifting operation into partial shifts which may be executed in different pipeline staged is described herein. In a first pipe stage, an operand is read out and at least one partial shift is accomplished by placing the operand or parts thereof into registers coupled to a shift unit. The shift unit, in a second pipe stage, finalizes the shifting operation executing the remaining partial shifts, thereby reducing the time required for the total shifting operation. A control string is derived in the shift unit based on the shift amount to correct the output of the shifted result as well as providing for parity prediction therefor.