Seagate Technology Incorporated

Tidal Systems, Inc.

Micron Technology Incorporated

Terayon Communication Systems, Inc.

Terayon Communications Systems, Inc.

Alexander Hubris

Yingquan Wu

Earl T Cohen

Yunxiang Wu

Hao Zhong

Christopher Brewer

Zhengang Chen

Robert Fanfelle

Yan Li

Ivana Djurdjevic

AbdelHakim S Alhussien

Warangkana Tepmongkol

Sanjay Dave

Robert J Fanfelle

An input file is processed according to hash algorithm that references sets of literals to preceding sets of literals to facilitate copy-offset command generation. Preceding instances are identified by generating a hash of the literal set and looking up a corresponding entry in a hash table. The hash table may be accessed by placing look-up requests in a FIFO buffer. When the FIFO buffer is full, generation of the hash chain is suspended until it is no longer full. When repeated literals are found, generation of the hash chain is likewise suspended. The hash chain is used to generate a command file, such as according to the LZ algorithm. Runs of consecutive literals are replaced by a run-length command. The command file may then be encoded using Huffman encoding.

Adaptive rate compression hash processor

A compression algorithm based on Huffman coding is disclosed that is adapted to be readily implemented using VLSI design. A data file may be processed to replace duplicate data with a copy commands including an offset and length, such as according to the LV algorithm. A Huffman code may then be generated for parts of the file. The Huffman code may be generated according to a novel method that generates Huffman code lengths for literals in a data file without first sorting the literal statistics. The Huffman code lengths may be constrained to be no longer than a maximum length and the Huffman code may be modified to provide an acceptable overflow probability and be in canonical order. Literals, offsets, and lengths may be separately encoded. The different values for these data sets may be assigned to a limited number of bins for purpose of generating usage statistics used for generating Huffman codes.

VLSI efficient Huffman encoding apparatus and method

An apparatus includes one or more error-correction decoders, a buffer, and at least one processor. The buffer may be configured to store data to be decoded by the one or more error-correction decoders. The at least one processor is generally enabled to send messages to the one or more error-correction decoders. The messages may contain datapath control information corresponding to data in the buffer to be decoded by the one or more error-correction decoders. The one or more error-correction decoders are generally enabled to decode the data read from the buffer according to the corresponding datapath control information.

Dynamic per-decoder control of log likelihood ratio and decoding parameters

A low density parity check decoder includes a variable node processor operable to generate variable node to check node messages and to calculate perceived values based on check node to variable node messages, a check node processor operable to generate the check node to variable node message vectors and to calculate checksums based on the variable node to check node messages, and a convergence detector and bit map generator operable to convergence of the perceived values and to generate at least one bit map that identifies variable nodes that are connected to check nodes with unsatisfied parity checks.

Data decoder with trapping set flip bit mapper

An NVM controller measures cell damage for wear leveling in an NVM, thus improving performance, reliability, lifetime, and/or cost of a storage sub-system, such as an SSD. In a first aspect, the controller determines that an error reading a page of NVM was caused by cell damage and/or cell leakage. The controller reprograms and immediately reads back the page, detecting that the error was caused by cell damage if an error is detected during the immediate read. In a second aspect, the cell damage is tracked by updating cell damage counters for pages and/or blocks of NVM. In a third aspect, wear leveling is performed based at least in part upon measured cell damage for pages and/or blocks of NVM.

Measuring cell damage for wear leveling in a non-volatile memory

An apparatus includes one or more error-correction decoders, a buffer, at least one direct memory access (DMA) engine, and at least one processor. The buffer may be configured to store data to be decoded by the one or more error-correction decoders. The at least one DMA engine may couple the buffer and the one or more error-correction decoders. The at least one processor may be enabled to send messages to the at least one DMA engine. The messages may be configured to deliver DMA control information and corresponding datapath control information. Data may be read from the buffer based upon the DMA control information and delivered to the one or more error-correction decoders along with the corresponding datapath control information. The one or more error-correction decoders may be enabled to decode the data read from the buffer according to the corresponding datapath control information.

A compression algorithm is disclosed in which compressibility of an input frame is determined. If a frame is found to be compressible, it is input to a compression algorithm, otherwise the frame may bypass the compression algorithm. Literals of length N bits in a frame are sorted into 2^N bins such a counter Bindicates a number of literals of value i. The maximum and minimum counter values are evaluated to estimate the compressibility of the file. For example, if Bis the maximum counter value and Bis the minimum counter value, then If B&#x3c;A*B(A being a value greater than 1, e.g. 4), the frame may be deemed to be uncompressible, otherwise the frame may be deemed to be compressible and compressed according to the DEFLATE algorithm or some other compression algorithm.

Statistical compressibility determination system and method

A method and system for constructing a generator matrix is disclosed. The method includes: receiving a parity check matrix H, wherein the parity check matrix H includes multiple circulant sub-matrices; rearranging the parity check matrix H by column and row permutations to obtain a rearranged parity check matrix H'; and constructing the generator matrix G based on the rearranged parity check matrix H&#x2032;.

Generating partially sparse generator matrix for a quasi-cyclic low-density parity-check encoder

A method for implementing adaptive error correction in a memory, comprising the steps of (A) decoding a page of data read from a memory, (B) selecting one of a plurality of histograms based on a measured code word error rate of the decoded page and (C) applying an error correction code rate based on the selected histogram. The error correction code rate allows the memory to use a minimum number of error correction bits to provide reliable operation of the memory.

Statistical adaptive error correction for a flash memory

An interleaver for any modem or transmitter which transmits digital data. The interleaver eliminates the iterative divide step of a first prior art method to calculate the final depth of each block and the divide followed by a multiply step of a second prior art method. This is done by calculating the minimum depth, i.e., number of rows, for each 2-D block of data using a divide step and retaining the remainder. The remainder is used to determine how many blocks get an extra row when the burst length and width of each row precludes all blocks from having the same number of rows.

Method and apparatus for faster block size calculations for interleaving

Memory may be partitioned into ever-sliding FIFOs. Each of the FIFOs may be stacked end-to-end in memory with the oldest data at the base offset and the newest at the end (or vice-virsa). Each symbol, the pointer may be incremented (modulo the set size) by an appropriate amount (typically J more than for the previous symbol). After each set, the pointers may be incremented by J more than the previous increment and the process starts over, wrapping around the memory if the end of the memory is reached. After a preset number of symbols, the process may restart from an increment of J. Alternatively, the pointers may be decremented rather than incremented. Thus, the newest symbol cannibalizes the memory position vacated by the oldest symbol in the current FIFO, causing the FIFOs to 'slide', providing for a very efficient and reliable use of memory for error-correcting code interleaving.

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San Jose, CA, United States of America

Alexander Hubris