Abstract: A defect area management method of an optical recording medium is disclosed. The present method is capable of managing a defective areas by storing information of defective blocks in the user block upon formatting as well as information of defective replacement blocks by extension of the user area by slipping.

Abstract: In a data recovery processing, the conventional overhead, primarily, latency due to a rotational recording media is removed. Secondary, in a signal processing or in a recording and reproducing apparatus, reliability of data reproduction is improved by repeatedly processing data. These processing are achieved that input signal, i.e., raw analog signal read from the recording media is digitized to be stored in a secondary storage such as a memory or a FIFO memory. The apparatus includes a signal processing circuit to repeatedly process the stored digital signal in the secondary storage. When detecting data, operation of the circuit is efficiently controlled by a change over detector parameters, in which characteristics for the detecting performance. Resultantly, data recovery processing speed is increased and reliability of data reproduced is improved.

Abstract: A sampled amplitude read channel is disclosed for writing data to and reading data from a disk storage medium. A first channel encoder encodes a first j-k bits of a j-bit data block to generate first encoded data, and an ECC encoder encodes the first encoded data and a remaining k-bits of the data block to generate ECC redundancy symbols comprising a plurality of bits. A second channel encoder encodes the remaining k-bits of the data block and the ECC redundancy symbols to generate second encoded data. The first encoded data and the second encoded data are then output as channel data written to the disk storage medium.

Abstract: Disclosed herein is a disk drive in which servo-sector addresses are reproduced from a disk, a target data sector to be accessed is specified, and data is read from or written in the target data sector. The servo-sector addresses are recorded on the disk and randomized in accordance with a specific translation rule, thus arranged in an order different from the order they should be arranged in the same cylinder. The disk drive has a read head and a CPU. The head reads the randomized servo-sector addresses from the disk. The CPU refers to a back translation table, translating the servo-sector addresses back to the original servo-sector addresses. The CPU then checks the continuity of each servo-sector address with respect to the adjacent ones. If the servo-sector address has have no continuity, the CPU determines that the servo-sector address has an error.

Abstract: In playing back data in an optical disk device, to perform high-speed data playback with a low number of playback retries even if an error occur when data is being read. In reading data composed of ECC blocks, if a data error occurs during a read operation, the data from sectors for which PI error correction can be performed is left alone. Playback retries using different playback conditions are performed just on the sectors for which PI error correction can be performed. Thus, the playback retry count can be reduced.

Abstract: A method of checking for errors in a set associative cache array, by comparing a requested value to values loaded in the cache blocks and determining, concurrently with this comparison, whether the cache blocks collectively contain at least one error (such as a soft error caused by stray radiation). Separate parity checks are performed on each cache block and if a parity error occurs, an error correction code (ECC) is executed for the entire congruence class, i.e., only one set of ECC bits are used for the combined cache blocks forming the congruence class. The cache operation is retried after ECC execution. The present invention can be applied to a cache directory containing address tags, or to a cache entry array containing the actual instruction and data values. This novel method allows the ECC to perform double-bit error as well, but a smaller number of error checking bits is required as compared with the prior art, due to the provision of a single ECC field for the entire congruence class.

Abstract: Where a recording medium recorded on at a slave side apparatus is reproduced, it has been made possible to perform on cite modification processing identical to that conducted at a master side apparatus, by reproducing, at the master side apparatus, the primary information added with parity symbol for error correction from the recording medium on which the primary information is recorded, correcting the symbol error of primary information reproduced at the reproducing means using the reproduced parity symbol, producing the flag which indicates the production of an uncorrectable symbol error in one unit of a block of a specified amount of information and thus outputting the modification information corresponding to the primary information and the flag and forming, at the slave side, the parity symbol for correction of error of primary information output at the master side apparatus and recording the primary information with the parity symbol and modification information, on the same recording medium.

Abstract: The present invention provides an error correction circuit for receiving and decoding a trellis-encoded signal of a series of data Zq, Zq−1, . . . ,Z1 which comprises convolutional-encoded bits and unencoded bits, the convolutional-encoded bits being obtained by convolutional-encoding lower t bits Xt, Xt−1, . . . ,X1 of an input p-bit series of data Xp, Xp−1, . . . , X1 (where p≧2, q≧p, and p>t≧1), and the unencoded bits being obtained by not convolutional-encoding upper (p-t) bits thereof. The circuit includes: a maximum likelihood decoder for preselecting one of m parallel paths of transition from state x at time k to state y at time k+1.

Abstract: Data integrity is increased on mass-storage devices through a scheme whereby, a frame-based cyclic redundancy code (CRC) for each sector is recorded. A frame-based CRC is generated from the CRCs of the frames that compose a sector of data. In recording data, a CRC is generated from each frame, later, a master CRC is generated from the frame CRCs, then sector and master CRC are recorded on the mass-storage device medium. In retrieving data, the sector composed of frames and a master CRC are read, a plurality of CRCs are generated from each of the frames, a second master CRC is generated from the frame CRCs, and the master CRCs are compared to determine data integrity. In another embodiment, an input/output error detection and correction checksum (IOEDC), an error correction code (ECC) and a CRC are generated from a sector of data, and the IOEDC, ECC and CRC are stored on disc with the data sector.

Abstract: In the event that during write to a storage device such as a DVD, data does not fill up a unit of generation of an error correction code (ECC), an increase in the data transfer amount caused by reading a shortage of data from a storage medium can be prevented. Controlling is carried out such that write data is not immediately written to the storage medium but write operation is deferred until an amount of data of ECC generation unit is complete in a buffer memory. As a result, the ECC can be generated and written to the storage medium by using only the write data without resort to read of the shortage of data from the storage medium.

Abstract: Disclosed is method and apparatus for error code correction using product code. The method includes: (a) reading a data frame and associated check bytes from a media; (b) generating an error correction model for the data frame and associated check bytes, where the error correction model is defined by non-zero syndromes in the check bytes of Q dimension code words and P dimension code words of the data frame; (c) examining the generated error correction model; and (d) correcting the data frame using a combination of error correction systems that are selected based on the examining of the generated error correction model.

Abstract: A method and apparatus for convolution encoding and Viterbi decoding utilizes a flexible, digital signal processing architecture that comprises a core processor and a plurality of re-configurable processing elements arranged in a two-dimensional array. The core processor is operable to configure the re-configurable processing elements to perform data encoding and data decoding functions. A received data input is encoded by configuring one of the re-configurable processing elements to emulate a convolution encoding algorithm and applying the received data input to the convolution encoding algorithm. A received encoded data input is decoded by configuring the plurality of re-configurable processing elements to emulate a Viterbi decoding algorithm wherein the plurality of re-configurable processing elements is configured to accommodate every data state of the convolution encoding algorithm.

Abstract: A method and apparatus for detecting and correcting errors and erasures in product-coded data arrays by iterative syndrome processing array data in row major order and column major order. A first dense map is formed for classifying each row containing location indicia of random errors, their correction patterns, and pointers to rows containing erasure errors. This map is used to effectuate row array random error corrections in place in memory. A second dense map is formed of location indicia and correction patterns for each pair adjacent position within a column containing erasure errors as indexed by a counterpart row pointer. The second map is used to effectuate column array erasure corrections and random error corrections in place in memory.

Abstract: A method for detecting the location of falsely detected “good” data, or “rogue”, packets in a data buffer is presented. A segment-level CRC is generated over, and associated with, a buffer segment, and recorded along with the segment data onto a storage medium. During data recovery, only packets that pass a packet-level error detection test are allowed in the data buffer. Once a data segment is complete, a segment-level CRC test is performed over the recovered segment-level CRC and the entire recovered segment data. The segment contains a rogue packet if the segment-level CRC test fails. Reed-Solomon syndromes are generated and used to locate and optionally correct the rogue packets.

Abstract: The error correcting decoder using an erasure flag process for a digital signal, according to the present invention, comprises: a row code word corrector for correcting errors in each row; a column code word corrector for correcting errors in each column; a first counter for counting the respective numbers of the uncorrectable rows and of the error corrected rows; a second counter for counting the number of error corrected symbols in each column; a storage device for storing the states of the corrected symbols; and an erasure flag selector for appropriately setting erasure flags for each column, based on the count results and the stored data.

Abstract: Disclosed is a method and apparatus for increasing the reliability of a disk drive. A block of information is read from a storage medium to provide a first sample, which is stored. The method determines whether an uncorrectable error occurred during the reading, and when the error is determined to have occurred, the block of information is reread from the storage medium to provide an averaged sample, and the average sample is decoded. Further disclosed is a storage unit, which includes a reader for reading a block of information from a storage medium to provide a first sample and for storing said first sample. An error determining mechanism determines whether an uncorrectable error occurred during the reading and issues a command to the reader to re-read the block of information to provide a second sample when the uncorrectable error is determined. A processor receives and averages the first sample and the second sample and produces an averaged sample. A decoder decodes the average sample.

Abstract: A method, apparatus and computer system for correcting errors and defects in a storage device. The storage device includes media for storing data. A periodic read scan is performed to test the data. If a repeatable error is found, the data is moved to a new sector from a pool of available sectors. Defects are counted and identified in a defect list for reporting to the host. The storage device is scannable is small segments to minimize impact on performance.

Abstract: A method, disc drive, and data handling system for optimizing the data writing/transmitting process are disclosed. The disc drive implemented method involves detecting at a current burst whether data written to a previous wedge is recoverable and making the disc drive's buffer space holding that data available for holding other data when the written data is recoverable. The disc drive implemented method also involves detecting at the current burst whether data to be written to a following wedge will encroach upon data written in adjacent tracks and allowing the data to be written in the following wedge when the encroachment is not too severe.

Abstract: A system and method for data error recovery uses a plurality of error correction routines in an attempt to provide data that can be used by the end user. In some situations the user is prompted for additional information and in some situations the data is provided with the errors highlighted. This system minimizes the amount of data that is unrecoverable. The system will work with CD discs or other storage media as well as with data lost by communication failures.

Abstract: A mass data storage device (10) and method for operating it are disclosed. The mass data storage device has a rotating disk memory (14) which has a number of sectors for containing data. A FIFO memory (30) has three memory sections (40-42), each for containing an entire sector of data associated with respective sectors of the rotating disk memory. An ECC unit (34) has random access to any data contained in the FIFO memory (30). The ECC unit (34) is operated to perform error correction on data while the data is contained in the FIFO memory (34).

Abstract: A data transmission system for transmitting information data with a parity of an error correcting code for correcting an error in the information data. A read-out controller controls a transmitter to transmit information data and a parity so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are transmitted at intervals along each sector having a sector address. The sector is defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.

Abstract: The present invention provides a decoding system and method for an optical disk storage device to receive and decode the data of the disk. The present invention does not need to increase the clock frequency and the bus width of the decoding system, it can effectively decrease the access times to the data buffer and the system response time by changing the structure of the conventional decoding system, in this way the present invention increases the parallel processing capability and the decoding speed of the system, thus, it can enhance the entire device to become a high speed optical storage device.

Abstract: A data decoder for decoding digital data in a high frequency signal in an optical storage device. A carrier signal derived from the high frequency passed through a zonal bandpass filter and a limiter is multiplied by the high frequency signal passed through a high pass filter. The resulting product is filtered and passed through a comparator forming a digital data stream.

Abstract: The storage unit of the present invention registers a plurality of data read conditions set in a plurality of parameters, an MPU reads data read conditions from the storage unit to an IC for read/write (R/W) in order and the MPU reads data from a magnetic disk according to these data read conditions. Then, a retry is repeated until normal data are obtained, the normal data are read, the frequency of data read conditions in the case where an error is recovered from, is accumulated, and the data read conditions are replaced when the accumulated value exceeds a certain threshold. By setting data read conditions whose probability of error recovery is high, in a higher order, the frequency of the retrying is reduced, and thereby a data error correction device and the correction method thereof can be provided such that data can be read from a magnetic disk in a short time.

Abstract: An apparatus and method for error correction in an optical disk system are described. An optical disk reproducing system calculates syndromes for each codeword to set an eraser flag during EFM demodulation. Error-correction-coding is performed using the eraser flag after completion of EFM-demodulation to reduce the access time for a data memory in error correction, thus reducing the time of error correction. The system includes a data memory for storing the EFM signals and the EFM-demodulated signals in the unit of an error correction block, an EFM demodulation and syndrome calculator for EFM-demodulating the EFM signals to output the EFM-demodulated signals to the data memory, and for calculating syndromes of the EFM-demodulated signals in the unit of the first codeword and outputting a flag indicating errors.

Abstract: Apparatus is provided for implementing high-speed and area efficient architectures for Viterbi detection of generalized partial response signals including two-way add/compare/select for improved channel speed. The two-way add/compare/select includes a two-way compare for comparing first and second state metric input values and a pair of two-way adds in parallel with the two-way compare for respectively adding the first and second state metric input values with a second input value. The second input value includes a time varying term or a constant term. The time varying terms are expressed as outputs Zn of a partial matched filter or as outputs Wn of a matched filter. A multiplexer is coupled to the pair of two-way adds, the multiplexer receiving a selectable input controlled by the two-way compare. A pair of shifts coupled between the pair of two-way adds and the multiplexer receive a shift control input for providing metric bounding to avoid underflow.

Abstract: Disclosed is a disc drive system that includes a digital signal processor for processing information sectors read from a CD media. The digital signal processor is configured to parse the information sectors into data frames and subcode frames. A data auto-start unit for triggering a data transfer to a buffer memory when a desired data frame is detected. A subcode auto-start unit for triggering a subcode transfer to the buffer memory when a desired subcode frame is detected. Preferably, the desired data frame and the desired subcode frame have a same MSF. The disc drive system further includes a buffer manager having a plurality of counters that are configured to track the number of data frames and the number of subcode frames being transferred to the buffer memory, and releasing a block including one of the data frames and one of the subcode frames when the counters indicate that the block is complete.

Abstract: A method for logically rejecting previously recorded track residue from magnetic media is presented. A session ID unique to a given recording session is encoded into track packet error check and error correction codes but is not itself actually written to tape. During a data recovery session, a reference session ID for the original recording session is acquired by reconstructing the packet session ID from the first few track packets and verifying that a predetermined number of consecutive track packets have identical packet session IDs. Once the reference packet session ID is acquired, it is preloaded into error detection and correction hardware. When a residue track encoded with a previously recorded session ID is recovered by the tape drive track packet detection circuitry, it is inherently rejected because the error detection and correction hardware detects an error and it is therefore never allowed into the data buffer.

Abstract: A multi-level error correction technique for maintaining data integrity in a data recording/recovery device is presented. Data is stored in buffer packets in a segment of a data buffer before being recorded to a storage medium. Error correction codes are generated over a plurality of instances of a plurality of buffer packet patterns in the segment, and are recorded along with all of the buffer packets onto a storage medium. During data recovery from the storage medium, recovered error correction code packets are used to perform multi-level segment correction on the recovered data packets.

Abstract: A device for detecting and correcting errors in error correction coded (ECC) data blocks that are read sequentially from a DVD medium is disclosed. Each ECC data block is defined as a two dimensional block of a plurality of columns and rows. Each of the ECC data blocks is read from the DVD medium sequentially in rows. The device includes row correction circuitry, a buffer, column correction circuitry, and repeat correction circuitry. The row correction circuitry is configured to sequentially receive the rows of an ECC data block for detecting and correcting up to a first predetermined number of errors in each of the received rows. The buffer is coupled to the row correction circuitry for receiving the error corrected rows of the ECC data block as a receiving buffer. The buffer also stores the ECC data block as a correction buffer when all the rows of the ECC data block have received.

Abstract: A method and apparatus for efficiently encoding an ECC block for improving writing performance of a storage device using an ECC block format having a linear code such as a Reed-Solomon code is described. When the data f1 of a part of data sectors among a plurality of data sectors which form an ECC block F1 having a PO portion q1 formed with a linear code such as a Reed-Solomon code is updated with data f2 to obtain the ECC block F2 having the updated PO portion q2, the ECC block F1+F2 of the exclusive OR of the source data part of the ECC block F1 before updating and the ECC block F2 after updating is taken, so that the XOR of f1 and f2 (i.e. f1+f2) of the data f1 to be updated and the updated data f2 is obtained. The XOR of non-updated data sectors is 0. Then, when the ECC block F1+F2 of the XOR is encoded, the PO portion in the form of the XOR q1+q2 is obtained in accordance with the linearity of the Reed-Solomon code.

Abstract: Data recording/reproduction is carried out in a disc format such that error correction codes interleaved with respect to the direction of data on a disc are collectively blocked into an error correction unit and that the input/output order of user data in an ECC block as an error correction unit is made coincident with the direction of processing of the error correction codes. Thus, coding can be started at the time when necessary data for generating one code is transmitted, without waiting for transmission of data for one ECC block. Also, transmission of user data can be started at the time when correction of one code is completed, without waiting for completion of correction operation for one ECC block. Also, since the direction of correction codes is the same as the direction of user data, no memory for rearrangement of data is required and the hardware structure can be minimized.

Abstract: A code error correcting apparatus, which can be used in a CD digital audio system, reads data stored on a disc, performs error correction, and transfers the error corrected data to another device, such as a computer, at an increased playback speed. The apparatus includes a digital processor which receives and processes (EFM demodulation) the data read from the disc, and a latch circuit connected to the processor for receiving the processed data. A memory is connected to the latch circuit by way of an input interface circuit, for storing the latched data. An error correction circuit connected to the memory reads the stored data, performs error correction on the data, and stores the error corrected data back in the memory. An output interface circuit is connected to the memory and provides an interface to the memory for external devices. The digital processor, the latch circuit, the input interface and the error correction circuit are all formed on a single substrate.

Abstract: Data recording/reproduction is carried out in a disc format such that error correction codes interleaved with respect to the direction of data on a disc are collectively blocked into an error correction unit and that the input/output order of user data in an ECC block as an error correction unit is made coincident with the direction of processing of the error correction codes. Thus, coding can be started at the time when necessary data for generating one code is transmitted, without waiting for transmission of data for one ECC block. Also, transmission of user data can be started at the time when correction of one code is completed, without waiting for completion of correction operation for one ECC block. Also, since the direction of correction codes is the same as the direction of user data, no memory for rearrangement of data is required and the hardware structure can be minimized.

Abstract: A digital signal processing method and apparatus that provide a mechanism for controlling the output of digitally processed data in an optical disc player so as to reduce the probability of error and lost data during such output. In one aspect, an apparatus for processing information on an optical disc comprises a signal processor for processing a digital signal corresponding to an analog signal read from the optical disc to generate output data, a memory unit, operatively associated with the signal processor, for temporarily storing the output data in predetermined units under the control of the signal processor, and an output unit, operatively connected to the signal processor, for processing the output data based on the type of optical disc. The output unit generates a request signal that causes the signal processor to retrieve output data from the memory unit and transmit the retrieved output data to the output unit in parallel.

Abstract: An error correcting apparatus includes a storing means for storing product code with n2 rows and n1 columns, an error correcting unit 5 that performs error correction for four code sequences simultaneously in parallel, and a bus control unit 2 for reading codes on four rows from the buffer memory 1 and transferring the codes to the error correcting unit 5. The bus control unit 2 reads and transfers four consecutive codes on each of four rows in order before shifting the reading position by four codes in the row direction.

Abstract: A digital data recording channel which uses variable rate encoding. The encoder monitors an input bit stream for sequences associated with selected readback characteristics, and inserts one or more bits where desirable to improve the characteristics of the stored bit stream.

Abstract: An execution unit that performs both Reed-Solomon Error Correction Code (R-S ECC) encoding and R-S ECC syndrome generation within a combinational circuit coupled between an input buffer and an output buffer.

Abstract: A method and apparatus for processing data read from a DVD media containing stored data is described. The apparatus includes a DVD media reader for reading data and error information stored on a DVD media, an error processor for determining the number of errors in the read data, and a display means for displaying the number of errors. The method includes the steps of reading actual data from a DVD media, computing a first correction code for the actual data, reading a second correction code from the DVD media, the second correction code pertaining directly to said stored data, and comparing the first and second correction codes to determine whether said actual data needs to be corrected. The method further includes the steps of determining whether the number of errors in the actual data exceeds the number of errors that can be corrected, correcting the actual data if possible, and counting the number of errors that are corrected.

Abstract: In a system recording compressed video and audio signals or computer user data on a disk in the sector unit, to reproduce the data in a simple fashion at a high speed, data to be recorded on the disk is divided into data in a predetermined unit so as to add a first error correction (C1) code to each of the resultant data, which form (C1) correction blocks. Sectors are produced each including a plurality of (C1) correction blocks. Added to each (C1) correction block is a code enabling identification of a sector. To all data in the plural (C1) correction blocks, a second error correction (C2) code is added to record the resultant data on the disk to allow interleaving or deinterleaving completing in a block. The capacity of each sector is set to be substantially equal to that of a plurality of transport packets.

Abstract: The present invention relates to an apparatus for detecting a signal received from a channel signal and for transforming this signal into a binary code sequence. More particularly the invention refers to a signal processing apparatus, which can perform a maximum likelihood detection of the reproduced data from an optical disk.

Abstract: A method and system that map the defects on the storage media of a disc drive. The method and system calculate the position of the defect and from that position determine the sector that must be flagged as unusable. The method and system also detect the distance the defect lies from an adjacent sector and flags the adjacent sector as unusable if the defect is too close because the defect may grow over time and eventually invade the adjacent sector. Also a method and system that efficiently utilize the space between all of the servo bursts by filling the space with sectors during the defect mapping process and marking the sectors with defects and those too close to the defect as unusable rather than shifting the sectors within the track area to avoid the defect.

Abstract: A CD-ROM decoder that reduces the load on a microcomputer temporarily stores in a buffer memory in sector units digital data having a predetermined number of bytes and a predetermined format. The CD-ROM decoder also processes the digital data by selectively correcting and detecting code errors included in the digital data. A sector information conversion circuit identifies a mode of a sector of the digital data based on header information and compares former four bytes and latter four bytes of sub-header information to identify a form of the sector of the digital data.

Abstract: In a disk array system of RAID (level 5) improving the system performance by distributing data, duplicated fields are allocated in a parity group in order to reduce an overhead of data write. In the data write process, write data is tentatively and duplicately written in the duplicate fields. At this time, a write completion is reported to CPU. The parity is generated later at a proper timing and written in a SCSI drive. Generating a parity and writing data can be efficiently scheduled.

Abstract: A Reed-Solomon type error correction device carries out correction passes, and includes a first memory containing DVD type data, as well as CD type data after a first correction pass, for deinterleaving of the CD type data before a second correction pass. Additionally, a second memory of smaller capacity than the first memory, is provided for containing CD type data before correction, as well as deinterleaved CD type data. The invention concerns the error correction device and an optical disk reader containing such a device.

Abstract: A method for retrying a read operation upon detecting a read error of a disk drive is disclosed. The method includes the steps of decreasing the revolution rate of a disk until the read error is corrected; and if the read error is corrected, gradually increasing the revolution rate of the disk while a data read operation is performed.

Abstract: A disk drive that includes a disk defining a multiplicity of sectors operates in accord with a method comprising the steps of providing a firmware-controlled state machine which can be in any of a plurality of states including an off-line in-progress state. While the state machine is in the off-line in progress state; a firmware-controlled scan of the multiplicity of sectors is performed. While performing the firmware-controlled scan, steps are performed to maintain a list of sector identifiers such that each sector identifier in the list points to a sector that has failed, preferably repeatedly, to provide valid data on the fly. While the state machine is not in the offline in-progress state; the drive responds to a request to write data at a specified sector by determining whether the specified sector matches a sector identifier in the list, and if so, autonomously performing a read-verify-after-write operation.

Abstract: A recording apparatus includes a plurality of ECC units operating selectively and independently. A medium access unit reads data from a recording medium in a read mode, and writes data from a host device to the recording medium in a write mode. The data read out from the recording medium contains a reproduction data and a medium reproduction check symbol added to the reproduction data, and data written contains a recording data and a medium recording check symbol added to the recording data. The reproduction data or the recording data is stored in a buffer. In a read mode, the reproduction data from the medium access unit is transferred to the host device through the buffer and in the write mode, the recording data from the host device is transferred to the medium access unit through the buffer.

Abstract: In an optical data storage device for storing data on a removable optical disk in a continuous sequence of sectors or blocks, the input data buffer includes an ECC process. A padding provider is disclosed which is responsive to an under-run indication for providing padding characters for formatting the storage into sectors. The sectors may be provided with headers indicating the “padding sectors”. A reading device for reading the data sectors and providing the data to a host detects padding and prevents the padding data from being transmitted to the host.

Abstract: In the event that during write to a storage device such as a DVD, data does not fill up a unit of generation of an error correction code (ECC), an increase in the data transfer amount caused by reading a shortage of data from a storage medium can be prevented. Controlling is carried out such that write data is not immediately written to the storage medium but write operation is deferred until an amount of data of ECC generation unit is complete in a buffer memory. As a result, the ECC can be generated and written to the storage medium by using only the write data without resort to read of the shortage of data from the storage medium.