摘要:
A method and apparatus for recording or reproducing data in which high performance encoding and a high efficiency decoding are realized to lower the decoding error rate. A magnetic recording and/or reproducing apparatus 50 includes, in a recording system, a modulation encoder 52 for modulation encoding input data in a predetermined fashion and an interleaver 53 for interleaving data supplied from the modulation encoder 52 to re-array the data sequence. The magnetic recording and/or reproducing apparatus 50 also includes, in a reproducing system, a first deinterleaver for interleaving the input data for re-arraying the data sequence so that the bit sequence of data re-arrayed by the interleaver 53 will be restored to its original bit sequence, a modulation SISO decoder for modulation decoding data supplied from the first deinterleaver and a second deinterleaver for interleaving data corresponding to a difference value between data output by the modulation SISO decoder and data output by the first deinterleaver to re-array the data sequence of the difference data.
摘要:
A method and apparatus for encoding a plurality of successive m-bit binary data words to produce a plurality of successive of n-bit binary code words, where n and m are positive integers and n is greater than m, for supply to a magnetic recording channel. Each m-bit binary data word is partitioned into a plurality of blocks of bits, and at least one said blocks of bits in each m-bit binary data word is encoded in accordance with a finite-state coding scheme to produce a plurality of successive n-bit binary code words. At least one stage of violation correction which transforms the plurality of successive n-bit binary code words. Violation correction includes detecting the occurrence of any of a plurality of prohibited bit patterns at one or more predetermined locations within each n-bit binary coded word, and replacing any prohibited bit pattern so detected by a corresponding substitute bit pattern. The finite-state coding scheme, the prohibited bit patterns, and corresponding substitute bit patterns are predetermined such that in a serial bit-steam comprising the successive n-bit binary code words, the maximum number of consecutive bits of a first value is limited to a first predetermined number j, where b greater or equal to 2, and the maximum number of consecutive bits of the a second value is limited to a second predetermined number k.
摘要:
An apparatus for encoding digital data for storage on a data storage medium includes a non-deterministic randomizer code generator. The randomizer code generator may select different randomizer codes for different portions of the data to be stored. The randomizer code used to randomize a given portion of the data may be stored on the media for use in subsequent data retrieval.
摘要:
A high density optical disk that includes a plurality of tracks and a format marking. The tracks are arranged in a predetermined number of zones. Each track is divided into a plurality of sectors. The number of sector is different in each zone and is increased as it is moving outwardly on the optical disk. The format marking includes a sector field for each sector. The format marking is erasable recorded.
摘要:
An apparatus for encoding digital data for storage on a data storage medium includes a non-deterministic randomizer code generator. The randomizer code generator may select different randomizer codes for different portions of the data to be stored. The randomizer code used to randomize a given portion of the data may be stored on the media for use in subsequent data retrieval.
摘要:
An apparatus for encoding digital data for storage on a data storage medium includes a non-deterministic randomizer code generator. The randomizer code generator may select different randomizer codes for different portions of the data to be stored. The randomizer code used to randomize a given portion of the data may be stored on the media for use in subsequent data retrieval.
摘要:
An 8/9 coding apparatus which suppresses the DC component of input data to be recorded on a magnetic tape by converting the 8-bit input data to 9-bit coded data, provided with a CDSc table for the CDSc data, that is, the data of the complement of 2 of the cumulative value of bits in a symbol included in coded data based on the input data. In a DSVc adder, CDSc data is cumulatively added by a polarity in accordance with polarity data, DSVc data indicating the complement of 2 of the cumulative value of the bits for every sector is generated, and an MSB bit thereof is output as MSB data to a table selector. The table selector outputs a table switching signal generated based on the polarity data and the MSB data to a data table, a polarity table, and the CDSc table. The tables are selectively used based on this switching signal.
摘要:
A data encoding method and apparatus are provided for implementing a predefined rate code, such as a 16/17 rate code for a data detection channel in a direct access storage device. A binary data stream is received and sequential symbols of the received binary data stream are identified. Sequential alternate symbols of the binary data stream are encoded into first codewords. Sequential alternate other symbols are encoded into second codewords. The alternating first and second codewords are sequentially combined. For a rate 16/17 rate code, the first codewords include 9-bit codewords and the second codewords include 8-bit codewords. The second 8-bit codewords are either raw symbols of the received binary data stream or remapped symbols of the received binary data stream. All likely error events are limited to within three consecutive bytes in a user data stream with a 16/17 rate code of the preferred embodiment.
摘要:
A first write encoder encodes digital data in a first high density format. A second write encoder encodes digital data in a second low density, i.e. ANSI format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first encoder is connected between a source of digital data and the read/write head, and the first decoder is connected between the read/write head and utilizing apparatus. In a second mode, the second encoder is connected between the source and the read/write head, and the second decoder is connected between the read/write head and the utilizing apparatus. Control electronics switches between the first and second modes, depending upon the format in which data is recorded on the disk received by the disk drive. An 8/9 GCR encoder and a laser pulse generator are used in the first write encoder to record data on the optical media to increase the storage capacity. Improvement in timing is accomplished with write compensation and signal equalization.
摘要:
Rate 24/25 modulation encoding methods and apparatus improve efficiency in a PRML magnetic recording channel. The rate 24/25 code word uses rate 8/9 RLL encoding of one byte of user data, combined with interleaved unencoded bytes to achieve improved code rates with reasonable global run length constraint. Use of the the rate 8/9 RLL (0,3) subcode results in a rate 24/25 RLL (0,11) code, while a rate 8/9 (0,6/5) subcode results in a rate 24/25 RLL (0,14/13) code.