JP5113670B2 - Recording modulation circuit, recording modulation method, optical disc apparatus, and optical disc recording method - Google Patents

Description

  The present invention relates to a recording modulation circuit and a recording modulation method used when recording digital data on an optical disc, and a technique effective when applied to an optical disc apparatus equipped with the recording modulation circuit.

  In Japanese Patent Laid-Open No. 2003-59184 (Patent Document 1), in order to perform additional recording on a recordable optical disc medium such as a DVD-R or a DVD-RW, the amount of misalignment is detected and included in the recording data accordingly. A method for controlling the sync width is disclosed. This method prevents the newly recorded data from being played back correctly when recording is stopped at a midway position of the sync frame and the next data is newly recorded in a discontinuous manner from the recording interruption position. ing. In addition, a waste area when writing dummy data in additional recording is reduced.

  Japanese Patent Application Laid-Open No. 2002-111513 (Patent Document 2) describes an ECC (Error Collection Code) block structure having a high burst error correction capability. A burst error is an error that occurs in continuous data, and is mainly caused by scratches or dirt. In DVD, an error correction code using a product code is employed. A unit of a predetermined size used for error correction is called an ECC block. As in Patent Document 2, when two ECC blocks used in a DVD are arranged side by side, the burst error correction capability is doubled as compared with the ECC structure in a conventional DVD.

  If there is a burst error in the reproduced data due to scratches or dirt on the medium, the burst error will be doubled if the recording linear density is increased twice. For example, if the bit length of DVD-RAM is 0.28 μm and the bit length of HD DVD (registered trademark) is 0.13 μm, the maximum correctable burst error length is 2741 bytes (about 6 mm) for DVD. In the HD DVD according to the configuration, it is 5904 bytes (about 6 mm). Since an actual HD DVD has an interleave configuration, it is more resistant to burst errors.

  FIG. 27 of Japanese Patent Application Laid-Open No. 2004-241044 (Patent Document 3) describes an ECC block in HD DVD. FIG. 34 of Patent Document 3 describes the data structure of the ECC block. One ECC block is composed of 32 sectors, and one sector is composed of 26 sync frames. Further, FIG. 29 of Patent Document 3 describes a sector structure. The sync 24 bits are inserted every 1092 bits of data. Since the order of the four types of syncs (SY0 to SY3) is determined, if sync is detected, it is possible to know what sync frame data.

FIG. 42 of Patent Document 3 describes a rewritable data recording method. Data recording on the HD DVD disc is performed in units of recording clusters. The physical address is embedded in the wobble surface in units of physical segment blocks.
JP2003-59184A (FIGS. 1 to 5a, b) JP 2002-111513 A (FIGS. 1 and 17) Japanese Patent Laying-Open No. 2004-241044 (FIGS. 27, 29, 34, and 42)

  As described in Patent Document 2, since error correction is performed in units of ECC blocks at the time of reproducing a disc, the data recorded on the disc needs to be continuous data. If the data order is increased, normal reproduction becomes difficult.

  For this reason, generally, when continuous data cannot be recorded, the recording operation is stopped, and the additional recording method described in Patent Document 1 is adopted. Causes of recording interruption include out-of-tracking in which the laser spot deviates from the control range in the track direction due to external vibration and impact on the optical head, defocusing in which the position in the focus direction of the objective lens deviates from the control range, laser degradation, buffering There are external factors such as underrun (automatically stop writing when the buffer is empty).

  On the other hand, as a cause of recording interruption in the circuit, if the transfer data from the memory controller to the recording modulation circuit is not in time for the recording clock, a transfer error is output to prevent incorrect data from being recorded on the disk. Recording operation may be stopped.

  In general, in an optical disc apparatus, a scramble process and a correction code addition process are performed using a DRAM in order to generate an ECC block as shown in Patent Document 2. The memory controller is used for data input control via the ATAPI interface, DRAM data output control to the recording modulation circuit, scramble processing, and correction code addition processing. A master clock using a crystal oscillator is used as a clock of a circuit around the memory controller.

  When the processing in the memory controller suddenly increases, or when many interrupts are received from the microcomputer, a transfer error may occur once or accidentally. In an optical disc apparatus, after a request for data input from the recording modulation circuit to the memory controller, data larger than the amount of data that can be transferred can be held during the waiting time until data is input to the memory controller. The number of buffers is determined.

  However, if an unexpected interrupt occurs, the memory controller processing increases, and data is input from the memory controller to the recording modulation circuit in a time longer than the processing time defined by the number of buffers. In such a state, since the output of the NRZI (Non Return to Zero Invert) signal synchronized with the recording clock is interrupted, a transfer error is output.

  FIG. 10A is a diagram showing the write gate and NRZI at the time of normal output in the conventional optical disc apparatus, and FIG. 10B is a diagram showing the write gate and NRZI at the time of transfer error in the conventional optical disc apparatus. As shown in FIG. 10 (2), in the conventional optical disc apparatus, when a transfer error occurs even once, the modulation process is stopped, the write gate is disabled, and the NRZI signal is not output to the laser drive circuit. . Thereafter, the transfer error is canceled by the reset, and rewriting is started from the location where the transfer error has occurred.

  Recently, there are cases in which operation is performed at 20 times speed, which is said to be the limit of DVD discs, at 16 times speed or more, and the performance limit of circuits and drives is being used. The higher the speed, the shorter the recording time, so the user's recording disk creation time is reduced. For example, in the case of data that took 60 minutes when recorded at 1 × speed, recording at 20 × speed would take 3 minutes. Such high-speed recording is strongly demanded by users not only for data but also for high-speed dubbing with a DVD recorder.

  However, as described above, there is a problem that high-speed recording becomes difficult once a transfer error is output. Further, the higher the recording speed, the more severe the memory controller processing, and the higher the possibility that a single or accidental transfer error will occur due to an unexpected factor.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide high-speed recording even when a single or accidental transfer error occurs when data is input from a memory to a recording modulation circuit in an optical disc apparatus, and to provide a margin for memory processing. It is an object of the present invention to provide an optical disc device and a recording modulation circuit thereof. In particular, it is an object to cope with high-speed recording in streaming recording in which an image is directly recorded on an optical disc.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The optical disk apparatus according to the representative embodiment of the present invention counts the number of transfer errors in units of sync frames after a transfer error occurs because the transfer data from the memory controller to the recording modulation circuit is not in time for the recording clock processing. When the transfer error is less than n times (n: positive integer), the modulation and recording operation is continued as it is, and the NRZI output operation is performed by adding a sync from the correct position. When the transfer error is n times or more The recording operation is interrupted, and additional recording is performed from the interrupted location again.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  According to the representative embodiment of the present invention, even when a single or accidental transfer error occurs when data is input from the memory to the recording modulation circuit, it supports high-speed recording and has a margin for memory processing. Can be made.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

<Embodiment 1>
Hereinafter, an optical disk apparatus according to Embodiment 1 of the present invention will be described.

  FIG. 1 is a block diagram of the optical disc apparatus according to the present embodiment. In FIG. 1, an optical disc apparatus 100 includes a laser drive circuit 110, an optical head (PU) 120, an I / V conversion circuit 130, a wobble processing circuit 140, a sample hold circuit 150, a correction code addition processing circuit 160, a memory controller 170, a scrambler. The configuration includes a processing circuit 180, a memory 190, an ATAPI 200, an ATAPI interface (ATA I / F) 210, a CPU 220, and a recording modulation circuit 300. Further, the wobble processing circuit 140 has an address decoder 141.

  Here, the recording modulation circuit 300 performs modulation in accordance with a modulation method in which an i-bit (i is a positive integer) data word is modulated into a j-bit (j is a positive integer) code word, and between the code words. This circuit outputs modulation output data in a format in which sync codes are inserted at equal intervals. The wobble processing circuit 140 is a circuit that extracts a wobble signal corresponding to a wobble groove (recording guide groove) periodically wobbling on the optical disc 400 and outputs a recording clock as a binary signal synchronized with the wobble signal. It is.

  The address decoder 141 is a circuit for determining whether the address extracted from the wobble groove is a recording position address and outputting a recording position detection signal indicating the recording position to the recording modulation circuit 300. The laser drive circuit 110 is a circuit for controlling laser light in order to record the modulated output data on the optical disc 400. The memory 190 is for temporarily storing the data word, and the memory controller 170 reads the data word from the memory 190 and outputs it to the recording modulation circuit 300.

  The recording modulation circuit 300 includes a memory controller (RAMCON) interface 301, a code word conversion circuit 302, a concatenation processing circuit 303, a DSV (Digital Sum Value) processing circuit 304, a synchronous code processing circuit 305, a transfer error detection circuit 306, and a transfer error. The configuration includes a count circuit 307, a transfer data count circuit 308, a dummy data output circuit 309, a switching circuit 310, and a recording clock synchronization processing circuit 311.

  Here, the recording clock synchronization processing circuit 311 is a circuit that converts the modulated code word into code data such as NRZI and outputs it as a laser driving signal in synchronization with the recording clock. The transfer error detection circuit 306 is a circuit that detects a transfer error when the data word input from the memory controller 170 deviates from the timing requested by the recording clock synchronization processing circuit 311. The transfer error count circuit 307 is a circuit that counts the number of transfer errors detected by the transfer error detection circuit 306 for each sync frame. The transfer data count circuit 308 is the data word input from the memory controller 170. It is a circuit which counts.

  Each circuit constituting the recording modulation circuit 300 may be a single circuit or a combination of a plurality of independent circuits. It is also possible to adopt a configuration in which processing in each circuit is executed by software processing in the CPU 220.

  As shown in FIG. 1, the optical disc apparatus 100 is connected to a host computer 500 such as a personal computer or a workstation. Instructions and information data from the host computer 500 are input to the CPU 220, and under the control of the CPU 220, the optical head 120 is moved to an information recording / reproducing operation for the optical disc 400 such as an HD DVD-R / RW and a target track. A seek operation is performed. Hereinafter, each operation content of the optical disc apparatus 100 of the present embodiment having the above-described configuration will be described.

[Playback operation]
First, the reproducing operation in the optical disc apparatus 100 of the present embodiment will be described.

  The optical disk 400 is rotationally driven by a spindle motor. The semiconductor laser in the optical head 120 emits laser light for reproducing information. The optical system in the optical head 120 forms light emitted from the semiconductor laser as a light spot on the surface of the optical disk 400. Further, the photodetector in the optical head 120 converts the reflected light from the optical disc 400 into an electrical signal. Using the converted electrical signal, light spot control such as focus control and tracking control and information reproduction are performed.

[Recording operation]
Next, a recording operation in the optical disc apparatus 100 of the present embodiment will be described.

  First, a recording start instruction is input from the host computer 500 to the CPU 220. Next, the reproduction operation described above is executed, and an electrical signal based on the reflected light of the optical disc 400 is output from the optical head 120. This electric signal is subjected to current-voltage conversion by the I / V conversion circuit 130 and input to the wobble processing circuit 140.

  The wobble processing circuit 140 extracts a wobble signal corresponding to the wobble groove provided on the recording surface of the optical disc 400. The binarized signal synchronized with the wobble signal is output to the recording clock synchronization processing circuit 311 in the recording modulation circuit 300 as a recording clock. In addition, the address decoder 141 in the wobble processing circuit 140 detects the wobble address from the wobble signal. When the recording target address on the optical disc 400 set by the CPU 220 is detected, a gate signal indicating the recording position is output to the recording clock synchronization processing circuit 311.

  Thereafter, data subjected to processing such as ID addition processing, scramble processing, and correction code addition processing by the memory 190, scramble processing circuit 180, and correction code addition processing circuit 160 is output from the memory controller 170 to the recording modulation circuit 300. FIG. 2 (1) shows the configuration of a scramble frame in HD DVD, and FIG. 2 (2) shows the configuration of an ECC block in HD DVD. The ECC block has an interleaved configuration that is scrambled so that the same data does not continue, so that even if there is a random error or burst error, it can be corrected by PO (Parity of Outer-code), PI (Parity of Inner-code ) Is added.

  The memory controller 170 outputs the data in the memory 190 to the code word conversion circuit 302 in the recording modulation circuit 300 as a data word every 8 bits (= 1 byte) via the RAMCON interface 301. The data word is input to the code word conversion circuit 302, and 8-12 modulation is performed to convert the code word into 12 bits according to a predetermined modulation rule. After that, the concatenation processing circuit 303 also performs processing (concatenation rule processing) for reducing the data arrangement of “01” in the code word to 5 consecutive times or less based on the replacement rule.

  When there is a DSV (Digital Sum Value) control bit # in the code word output from the concatenation processing circuit 303, the DSV processing circuit 304 sets the DSV control bit # in the code word to “0” so that the DSV approaches 0. "Or" 1 "is given. DSV control is control performed to suppress a low frequency component of a modulation signal. “1” in a code word is set to +1, “0” is set to −1, and a cumulative addition value is close to 0. It is something to control.

  The 12-bit code word subjected to DSV processing by the DSV processing circuit 304 is converted into NRZI by the recording clock synchronization processing circuit 311 via the switching circuit 310 in accordance with the timing of the recording position detection signal supplied from the address decoder 141. And input to the sample and hold circuit 150.

  A predetermined laser irradiation length control is performed for each NRZI mark space width by the sample hold circuit 150, and an output signal is output to the laser drive circuit 110 together with a recording clock. The laser drive circuit 110 supplies a drive current to the laser in the optical head 120. Digital data is recorded on the optical disc 400 by laser light emitted from the laser. The laser driving circuit 110 may be provided in the optical head 120.

[Circuit operation related to transfer error detection]
Next, a circuit operation related to transfer error detection in the optical disc apparatus 100 of the present embodiment will be described.

  In order to output the NRZI from the recording clock synchronization processing circuit 311 to the sample and hold circuit 150 without interruption, the memory controller 170 controls the timing of output data to the RAMCON interface 301.

  The RAMCON interface 301 has several stages of buffers. After issuing a request for data input from the RAMCON interface 301 to the memory controller 170, processing with the data in the buffer is possible for a number of clocks longer than the waiting time until data is input from the memory controller 170. The number of buffers is determined so that

  This waiting time is determined by the processing status of the memory controller 170. When processing having a higher priority than the request from the recording modulation circuit 300 is included, the data input waiting time in the recording modulation circuit 300 becomes long. In addition, if the processing has a lower priority than the request from the recording modulation circuit 300, the data input waiting time in the recording modulation circuit 300 is shortened. If the number of clocks of this waiting time is longer than the number of clocks determined by the number of buffers in the RAMCON interface 301, the NRZI output synchronized with the recording clock is interrupted, resulting in a transfer error.

  At this time, the transfer error detection circuit 306 transfers the modulation effective (enable) signal output from the memory controller 170 to the transfer error detection circuit 306 in the recording modulation circuit 300 by changing the signal from “H” to “L”. Detect errors. A transfer error count circuit 307 in the recording modulation circuit 300 counts the number of transfer errors by counting the transfer error detection signal output from the transfer error detection circuit 306 at a predetermined timing.

  Note that the higher the recording speed of the optical disc apparatus 100, the less the processing of the memory controller 170 is.

[Input / output data of recording modulation circuit]
Next, input / output data of the recording modulation circuit 300 in the optical disc apparatus 100 of the present embodiment will be described.

  The memory controller 170 controls input / output to / from the correction code addition processing circuit 160, the scramble processing circuit 180, the memory 190, the recording modulation circuit 300, etc., and from the recording clock synchronization processing circuit 311 in the recording modulation circuit 300. In response to the request, data is input to the recording modulation circuit 300 via the RAMCON interface 301 in the order shown in FIG.

  When data is input from the memory controller 170 to the RAMCON interface 301 within a predetermined timing, the RAMCON interface 301 inputs a data word for every 8 bits (1 byte before modulation) to the codeword conversion circuit 302. Thereafter, a predetermined modulation method is applied by the codeword conversion circuit 302, and predetermined processing is performed by the concatenation processing circuit 303, the DSV processing circuit 304, and the synchronous code processing circuit 305, and every 12 bits (one byte after modulation). Data is input to the recording clock synchronization processing circuit 311 via the switching circuit 310.

  The synchronization code processing circuit 305 inserts 2 bytes (24 bits) of synchronization code (sync code) every 91 bytes (1092 bits) into the modulated data. FIG. 3 (2) shows the configuration of a recording frame in which a sync code is inserted into an ECC block. The recording frame is composed of 32 sectors, including an even physical sector and an odd physical sector.

  Thereafter, a signal DSV-controlled by the DSV processing circuit 304 is input to the recording clock synchronization processing circuit 311 every 12 bits via the switching circuit 310.

[Operation when transfer error is not detected]
Next, an operation when a transfer error is not detected in the optical disc apparatus 100 of the present embodiment will be described.

  If no transfer error is detected by the transfer error detection circuit 306, the write clock is normally output from the recording clock synchronization processing circuit 311. At this time, the address decoder 141 outputs a recording start position detection signal to the recording clock synchronization processing circuit 311, and the recording clock synchronization processing circuit 311 outputs the write gate to the sample hold circuit 150 at a predetermined timing.

  FIG. 4A is a diagram showing the write gate and NRZI at the time of normal output. NRZI is output when the write gate indicating the recording operation is “H”. After N (N: positive integer) data segments continue, a guard is finally output. The recording frame corresponds to the Data field in FIG.

[Operation when a transfer error is detected]
Next, an operation when a transfer error is detected in the optical disc apparatus 100 of the present embodiment will be described.

  FIG. 4B is a diagram showing the write gate and NRZI when a transfer error occurs. When a transfer error occurs, the transfer error detection signal output from the transfer error detection circuit 306 becomes “H”. The transfer error count circuit 307 counts the number of transfer errors from the transfer error occurrence to the end of one sync frame. If the count is less than n (n: positive integer), the transfer error shown in FIG. As shown in the generation (a) timing, the write gate is not set to “L” but remains “H”.

  At this time, the dummy data is output as the output NRZI from the time when the transfer error occurs. The dummy data is obtained by inputting the dummy data output from the dummy data output circuit 309 to the recording clock synchronization processing circuit 311 via the switching circuit 310 and converting it into the output NRZI. By outputting unique dummy data that is not used in the actual data portion or sync code but can be identified from these, it is easy to identify the location of the error.

  Here, the unique dummy data may be a 12T repeating pattern in the case of HD DVD, for example. The 12T repetitive pattern is a pattern in which “0” continues for 12 consecutive clocks and then “1” continues for 12 consecutive clocks.

  The maximum channel bit length T in HD DVD is 13T included only in the sync code. The maximum T of the data portion is 11T, and the modulation scheme is defined so as to satisfy the run length rule RLL (1, 10). At this time, in NRZ (Non Return to Zero), the number of “0” sandwiched between “1” is 1 or more and 10 or less, so in NRZI, the signal is composed of 2T to 11T signals. Therefore, the 12T repetitive pattern signal is neither data nor sync code, and is identifiable unique data. Further, since the 12T repeat pattern has a DSV of 0, it can be detected by a PLL (Phase Locked Loop) without any problem during reproduction.

  Even in the case of a unique pattern other than the 12T repetitive pattern, for example, in the case of HD DVD, the signal conforms to the 8-12 modulation system so that it can be normally reproduced. Although not shown in the figure, a PLL is used during reproduction and a reproduction clock is generated by controlling the DSV to be 0. Therefore, if the signal conforms to the 8-12 modulation method, the reproduction clock is normally generated by the PLL. Because it can. For example, the dummy data may be the same 4T repeating pattern as the guard portion. The 4T repeating pattern is a pattern in which 4 clocks “0” are continuous (“0000”) and then 4 clocks “1” are continuous (“1111”) in NRZI.

  In addition, although the example at the time of setting unique dummy data based on the modulation system in HD DVD was demonstrated above, it corresponds also to the present DVD, Blu-ray (Blu-ray (trademark): BD), etc., respectively. Similarly, unique dummy data can be set based on the modulation method.

  On the other hand, the transfer error count circuit 307 counts the number of transfer errors from the transfer error occurrence to the end of one sync frame, and when the count number is n (n: a positive integer) or more, FIG. As shown in the timing of the transfer error occurrence (b), dummy data is output during the transfer error count, and then the write gate is set to “L” to interrupt the NRZI output and stop the recording operation.

  FIG. 5 is a flowchart of the operation when a transfer error is detected. After the start of recording (step 501), it is detected whether a transfer error from the memory controller 170 to the recording modulation circuit 300 has occurred (step 502). Transfer error detection is performed from the start of recording to the end of recording. If no transfer error is detected, the write gate is enabled (step 508), and data is written to the disk up to the recording end position (step 509).

  When a transfer error is detected (step 502), NRZI output to the sample hold circuit 150 is output as dummy data until the end of one sync frame (step 503). It is detected how many times a transfer error has occurred in one sync frame (step 504). If the number of transfer errors has exceeded the set number (n times), the write gate is disabled and NRZI is not output (step 507). .

  If the number is less than the set number (n times), the write gate is continuously enabled (step 505). After that, the NRZI to which a synchronization code (sync code) is added is output from the correct position based on the transfer error (error in which data cannot be input within a predetermined timing from the memory controller 170) and the number of transfer data from the memory controller 170 to the RAMCON interface 301. Recording is performed on the optical disc 400 via the sample hold circuit 150 (step 506).

  Thereafter, it is determined whether or not it is the recording end position (step 510). If it is not the recording end position, the process returns to step 502 and the processing is continued. If it is the recording end position, the recording is ended (step 511).

  The set number n (n: positive integer) of the number of transfer errors may be stored in a register, a memory, or the like, and may be changed by an external operation.

[effect]
Conventionally, when one transfer error occurs, the recording operation is once interrupted, and writing is performed again from the recording position. FIG. 6A is a diagram showing the relationship between the writing time and the linear velocity at the time of CAV (Constant Angular Velocity). FIG. 6B is a diagram showing the relationship between the writing time and the angular velocity at CLV (Constant Linear Velocity).

  In the conventional example, when a transfer error is detected once, the writing speed is increased because the linear velocity or angular velocity is made the same or the velocity is once reduced and then writing is performed again. With the optical disc apparatus 100 according to the present embodiment, when writing from the inner circumference to the outer circumference, if a transfer error is detected once, writing can be continued at a high speed, and the writing time is shortened compared to the conventional example. it can.

  As described above, the optical disc apparatus 100 according to the present embodiment has a circuit configuration suitable for high-speed recording modulation processing. When a transfer error from the memory 190 to the recording modulation circuit 300 occurs unexpectedly, a sync frame is used. By checking the number of transfer errors in units, if it is smaller than the predetermined number of times, the data of one sync frame where the transfer error has occurred is recorded on the optical disc 400 as dummy data, enabling high-speed recording.

  During reproduction, the dummy data portion is processed as a burst error. In the current DVD, even if a burst (continuous) error of 2714B (29 sync frames) occurs, the error can be corrected and reproduced normally. HD DVD can correct at least 5904B (63 sync frames) burst error. By doing this, at least one sync frame data becomes incorrect dummy data, but the dummy data portion can be restored by error correction during reproduction, so that high-speed recording is possible.

  When using a device equipped with the optical disc device 100, for example, stream data such as a recorder or a video camera is not effective for re-shooting, and real-time performance is required. It is. When mounted on a device such as a PC that requires data reliability, the high-speed recording function as described in this embodiment is not applied, and is mounted on a device such as a recorder or a camera. It is also possible to adopt a configuration in which switching can be set so that it can be applied in some cases. Further, according to this configuration, even in a PC or the like, when it is desired to write data at a high speed, it is naturally possible to use a high-speed recording function by switching the setting.

  In the optical disc apparatus 100 of the present embodiment, the configuration using the HD DVD disc has been described. However, in the case of a DVD or BD, the same configuration as described above can be obtained by simply changing the configuration of the modulation processing in the recording modulation circuit 300. Processing can be performed.

<Embodiment 2>
Hereinafter, an optical disk apparatus according to Embodiment 2 of the present invention will be described.

  The block diagram of the optical disk apparatus of the present embodiment is the same as that of FIG. 1 of the first embodiment. The optical disc apparatus 100 according to the present embodiment outputs dummy data for one ECC block from the recording modulation circuit 300 to the sample hold circuit 150 when the transfer error for each sync frame is greater than a predetermined number of times. The correct data is output from the next ECC block in the.

  At this time, the correct code word is converted to the next ECC at the timing determined by the data count value of the transfer data count circuit 308 and the transfer error count value of the transfer error count circuit 307, which is the number of times of normal data transfer from the memory controller 170. The data is switched from the block by the data switching circuit 309 and output.

  FIG. 7 is a diagram showing a write gate and NRZI in the present embodiment. As shown in FIG. 7 (2), when a transfer error occurs at a predetermined number n or more in sync frame units, the transfer error period is a period during which normal data is not recorded for one ECC block where the transfer error occurs. Provide. During this period, the write gate is not set to “L”, and a unique pattern similar to that described in the first embodiment is output as dummy data. Thereafter, data having normal timing is output from the beginning of the next ECC block.

  In the memory 190, as shown in the memory address map of FIG. 7 (3), a plurality of ECC blocks are configured. For example, when the data of the ECC block (1) is a transfer error, the data is output to the recording modulation circuit 300 from the head of the ECC block (2). The number of data of one ECC block is determined, and the memory arrangement of data is also determined. Therefore, since the head position of each ECC block is known in advance, it is easy to output data from the head position of the ECC block to the recording modulation circuit 300.

  Also, since the physical segment block length and the data segment length are the same, if the start position of the physical segment block is known by the address decoder 141, the alignment with the NRZI can be performed again. You can start writing.

  According to the optical disc apparatus 100 of the present embodiment, since one ECC block is crushed, the portion cannot be normally reproduced. However, the data is not recorded more than when the reset is newly performed and the transfer error is additionally recorded. Don't waste it. In particular, stream data such as a video camera is effective because re-shooting does not work.

<Embodiment 3>
Hereinafter, an optical disk apparatus according to Embodiment 3 of the present invention will be described.

  In the optical disc device according to the first embodiment and the second embodiment, dummy data is output without dropping the write gate when a transfer error is detected. However, the optical disc device 100 according to the present embodiment When the transfer error is detected, the write gate is dropped, and the recording modulation circuit 300 does not output NRZI, but does not record.

  FIG. 8 is a diagram showing the write gate and NRZI in the present embodiment. When a transfer error is detected by the transfer error detection circuit 306, the write gate output from the recording clock synchronization processing circuit 311 is dropped, and NRZI is not output and recording is not performed. After that, when no transfer error occurs, the write gate may be started at the head of the next sync frame.

  According to the optical disc apparatus 100 of the present embodiment, the dummy data output circuit 309, the switching circuit 310, and the like are not required, the circuit configuration is simplified, and the LSI can be easily realized. When NRZI becomes a fixed value of “0” or “1” when recording is not performed, the PLL at the time of reproduction needs a function of detecting and holding this area as an unrecorded area.

<Embodiment 4>
Hereinafter, an optical disc apparatus according to Embodiment 4 of the present invention will be described.

  In the optical disk apparatus according to the present embodiment, the transfer error count circuit 307 that counts the number of transfer errors for each sync frame in the optical disk apparatus 100 of FIG. 1 is configured to count the number of transfer errors for each sector. The transfer error count circuit 307 may be configured to switch the count of the number of transfer errors for each sync frame or for each sector by setting.

  FIG. 9 is a flowchart of the operation when a transfer error is detected. Step 904 is the same as the flowchart shown in FIG. 5 of the first embodiment except that the data transfer check is performed in units of sectors.

  As described above, in the current DVD, error correction is possible even if a burst (continuous) error of 2714B (29 sync frames) occurs, and in HD DVD, a burst of at least 5904B (63 sync frames) is possible. Even errors can be corrected. Since one sector has 26 sync frames, even if one sector becomes dummy data, it can be restored by error correction during reproduction, and high-speed recording is possible.

<Embodiment 5>
Hereinafter, an optical disc apparatus according to Embodiment 5 of the present invention will be described.

  In the above-described first to fourth embodiments, examples of the optical disk apparatus targeting DVD and HD DVD have been described. In the present embodiment, an example of an optical disk apparatus targeting BD format will be described.

  FIG. 11 (1) shows the structure of the BD format write gate and NRZI after modulation, and FIG. 11 (2) shows the configuration of an ECC block (error correction block) in the BD format. In Embodiments 1 to 4 described above, ECC blocks and sync frames in HD DVD have been described, but names and the like differ in BD.

  In FIG. 11 (1), a one-segment data portion including one ECC data corresponding to one data segment of the HD DVD shown in FIG. 4 (1) is called one recording unit block (RUB) in the BD. . The Data field indicating the data part in HD DVD is called Physical Cluster in BD. The physical cluster is composed of 16 units, and 1 unit is composed of 31 sync frames. Note that 1 wobble (denoted as wbs in the figure) corresponds to 69 channel bits.

  As shown in FIG. 11 (2), in the ECC block of BD, the Picket Code method is adopted to enhance the burst error detection capability. The main data is protected by the Reed-Solomon code as in the DVD. Picket is protected by a second Reed-Solomon code separate from the main data. The picket sequence is corrected at the time of decoding, and the presence or absence of a burst error in the main data is predicted in the correction process. In the BD, 64 KB of user data is stored in one ECC block. In addition, four picket rows are arranged at equal intervals in one ECC block. The leftmost S is a synchronization pattern indicating the start of a row. One ECC block of BD is composed of 175 bytes (B) × 496 rows.

  In this way, the point that the picket code is inserted into the ECC block in BD is greatly different from HD DVD, but ECC block data is generated using the memory 190, memory controller 170, etc. in FIG. 1, and predetermined modulation processing is performed. And is similar to HD DVD in that NRZI is output in synchronization with the recording clock. In order to output NRZI seamlessly in synchronization with the recording clock, data input / output control is performed by the memory controller 170 as in the first to fourth embodiments.

  FIG. 12 shows a block diagram of the optical disc apparatus of the present embodiment. The optical disc apparatus 100 of the present embodiment is configured so that the processing after the RAMCON interface 301 is performed by a recording clock or recording clock frequency division processing. Except for this point, processing similar to that of the optical disc apparatus 100 having the configuration shown in FIG. 1 is performed. By dividing the clock system, the setting for changing the master clock for each double speed becomes unnecessary, and the design can be facilitated.

  In the case of the BD format, 17PP (Parity Preserve) modulation is performed by the modulation circuit 312 to generate a recording unit block (RUB) shown in FIG. The switching circuit 310 switches the modulated data or dummy data, and outputs the NRZI and the write gate to the sample hold circuit 150. In addition, since BD performs strong error correction for burst errors, the number of transfer errors set to n (n: a positive integer) compared with the count of transfer error count circuit 307 is compared to the case of HD DVD. It is also possible to set a large value.

  With this configuration, even if the number of accesses to the CPU 220 or ATAPI 200 suddenly increases, the transfer error count is checked by the transfer error detection circuit 306 and the transfer error count circuit 307. Can be recorded without interruption, and high-speed recording can be realized. Further, at the time of reproduction, the dummy data portion is processed as a burst error, so that correct data can be reproduced.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  INDUSTRIAL APPLICABILITY The present invention can be used for a recording modulation circuit and a recording modulation method used when recording digital data on an optical disc, and an optical disc apparatus equipped with the recording modulation circuit.

1 is a block diagram of an optical disc apparatus that is Embodiment 1 of the present invention. FIG. (1) is a diagram showing a scramble frame in HD DVD, and (2) is a diagram showing a configuration of an ECC block in HD DVD. (1) is an ECC block after PO insertion in HD DVD, and (2) is a diagram showing a configuration of a recording frame in HD DVD. (1) is a diagram showing a write gate and NRZI at the time of normal output in Embodiment 1 of the present invention, and (2) is a diagram showing a write gate and NRZI at the time of occurrence of a transfer error in Embodiment 1 of the present invention. 6 is a flowchart of an operation when a transfer error is detected in the first embodiment of the present invention. (1) is the relationship between writing time and linear velocity at CAV, and (2) is a diagram showing the relationship between writing time and angular velocity at CLV. (1) is the write gate and NRZI at the time of normal output in the second embodiment of the present invention, (2) is the write gate and NRZI at the time of occurrence of the transfer error in the second embodiment of the present invention, and (3) is the present invention. FIG. 9 is a diagram showing a memory address map in the second embodiment. It is the figure which showed the write gate and NRZI in Embodiment 3 of this invention. It is a flowchart of operation | movement when the transfer error in Embodiment 4 of this invention is detected. (1) is a diagram showing a write gate and NRZI at the time of normal output in the conventional optical disc apparatus, and (2) is a diagram showing a write gate and NRZI at the time of occurrence of a transfer error in the conventional optical disc apparatus. (1) is a BD format write gate and NRZI after modulation in Embodiment 5 of the present invention, and (2) is a diagram showing the configuration of an ECC block in the BD format. It is a block diagram of the optical disk apparatus which is Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Optical disk apparatus, 110 ... Laser drive circuit, 120 ... Optical head (PU), 130 ... I / V conversion circuit, 140 ... Wobble processing circuit, 141 ... Address decoder, 150 ... Sample hold circuit, 160 ... Correction code addition process Circuit: 170 ... Memory controller, 180 ... Scramble processing circuit, 190 ... Memory, 200 ... ATAPI, 210 ... ATAPI interface (ATA I / F), 220 ... CPU, 300 ... Recording modulation circuit, 301 ... Memory controller (RAMCON) interface , 302 ... code word conversion circuit, 303 ... concatenation processing circuit, 304 ... DSV processing circuit, 305 ... synchronous code processing circuit, 306 ... transfer error detection circuit, 307 ... transfer error count circuit, 308 ... transfer data count circuit, 309 ... Dummy data output times , 310 ... switching circuit, 311 ... recording clock synchronous processing circuit, 312 ... modulation circuit, 400 ... optical disk, 500 ... host computer.

Claims (19)

In an optical disc apparatus that records digital data on an optical disc by light irradiation, modulation is performed in accordance with a modulation method that modulates an i-bit (i is a positive integer) data word into a j-bit code word (j is a positive integer). A recording modulation circuit for outputting a signal obtained by converting the obtained modulation output data into code data and a write gate indicating a recording range of the modulation output data on the optical disc,
Means for detecting a transfer error for the data word read from the memory in the optical disk device by the memory controller in the optical disk device and input to the recording modulation circuit;
When the transfer error is detected, dummy data is output to continue without interrupting the recording modulation operation. After that, when the transfer error is not detected, the modulation output data is output from the next sync frame. Recording modulation circuit, The recording modulation circuit according to claim 1,
The number of times that the transfer error is detected is counted for each sync frame, and if the counted number of transfer errors is less than n (n: a positive integer), the recording modulation operation is continued without interruption, and the counted transfer The recording modulation circuit, wherein the write gate is disabled so that the modulation output data is not output when the number of errors becomes equal to or greater than n. The recording modulation circuit according to claim 2,
When the counted number of transfer errors is not less than n and the write gate is invalidated, and the transfer error is not detected after that, the invalidated write gate is validated and the modulation is performed. A recording modulation circuit which resumes output of output data. The recording modulation circuit according to claim 2,
When the counted number of transfer errors is equal to or more than n, the dummy data for the ECC block in which the transfer error is detected is output with the write gate being enabled, and then the transfer error is determined. A recording modulation circuit characterized by restarting the output of the modulation output data from the head of the next ECC block when it is no longer detected. The recording modulation circuit according to claim 1,
The recording modulation circuit according to claim 1, wherein the dummy data is data having a unique arrangement that can be identified from a user data portion and a sync code portion in the modulation output data. The recording modulation circuit according to claim 5,
The dummy data is NRZI code data in accordance with the modulation method on an optical disc to be recorded by the recording modulation circuit, and is data in an arrangement such that DSV is 0. . The recording modulation circuit according to claim 6, wherein
The dummy data is a repetitive pattern data of a channel bit length not corresponding to the range of the channel bit length used in the user data portion and the sync code portion in the format of the code data on the optical disc to be recorded by the recording modulation circuit, Alternatively, a recording modulation circuit characterized in that it is data of a repetitive pattern having the same channel bit length as that used in the guard portion. The recording modulation circuit according to claim 2,
A recording modulation circuit comprising means for holding the value of n, wherein the value of n can be changed by an external setting. The recording modulation circuit according to claim 2,
A recording modulation circuit, wherein the number of times the transfer error is detected is counted for each sector. The recording modulation circuit according to claim 9, wherein
A recording modulation circuit, wherein the number of times that the transfer error is detected is counted for each sync frame or for each sector, can be switched by an external setting. In an optical disc apparatus that records digital data on an optical disc by light irradiation, modulation is performed in accordance with a modulation method that modulates an i-bit (i is a positive integer) data word into a j-bit code word (j is a positive integer). A recording modulation circuit for outputting a signal obtained by converting the obtained modulation output data into code data and a write gate indicating a recording range of the modulation output data on the optical disc,
Means for detecting a transfer error for the data word read from the memory in the optical disk device by the memory controller in the optical disk device and input to the recording modulation circuit;
When the transfer error is detected, the recording modulation operation is continued without interruption, the write gate is disabled so that the modulation output data is not output, and then the transfer error is not detected. A recording modulation circuit, wherein the invalidated write gate is validated and the output of the modulation output data is restarted from the next sync frame. The recording modulation circuit according to claim 1 or 11,
A recording modulation circuit, wherein whether or not to enable the function of the recording modulation operation when the transfer error is detected can be switched by an external setting. An optical disc apparatus for recording digital data on an optical disc by light irradiation,
A signal obtained by modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word and modulating the resulting modulated output data into code data A recording modulation circuit that outputs a write gate indicating a recording range of the modulation output data to the optical disc;
A memory controller that reads the data word from the memory and outputs the data word to the recording modulation circuit;
The recording modulation circuit includes:
Means for detecting a transfer error of the data word from the memory controller to the recording modulation circuit;
When the transfer error is detected, dummy data is output to continue without interrupting the recording modulation operation. After that, when the transfer error is not detected, the output of the modulation output data is resumed. An optical disc device characterized. An optical disc apparatus for recording digital data on an optical disc by light irradiation,
A signal obtained by modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word and modulating the resulting modulated output data into code data A recording modulation circuit that outputs a write gate indicating a recording range of the modulation output data to the optical disc;
A memory controller that reads the data word from the memory and outputs the data word to the recording modulation circuit;
The recording modulation circuit includes:
Means for detecting a transfer error of the data word from the memory controller to the recording modulation circuit;
When the transfer error is detected, the recording modulation operation is continued without interruption, the write gate is disabled so that the modulation output data is not output, and then the transfer error is not detected. An optical disc apparatus, wherein the invalidated write gate is validated, and the output of the modulated output data is resumed from the next sync frame. A signal obtained by modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word and modulating the resulting modulated output data into code data A recording modulation circuit that outputs a write gate indicating a recording range of the modulation output data on the optical disc;
A recording modulation method in an optical disc apparatus having a memory controller that reads the data word from a memory and outputs the data word to the recording modulation circuit,
The optical disc apparatus is
Detecting a transfer error of the data word from the memory controller to the recording modulation circuit;
When the transfer error is detected, a procedure of outputting dummy data from the recording modulation circuit and continuing without interrupting the recording modulation operation;
Thereafter, when the transfer error is no longer detected, a procedure for resuming the output of the modulation output data from the recording modulation circuit from the next sync frame is executed. A signal obtained by modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word and modulating the resulting modulated output data into code data A recording modulation circuit that outputs a write gate indicating a recording range of the modulation output data on the optical disc;
A recording modulation method in an optical disc apparatus having a memory controller that reads the data word from a memory and outputs the data word to the recording modulation circuit,
The optical disc apparatus is
Detecting a transfer error of the data word from the memory controller to the recording modulation circuit;
When the transfer error is detected, the recording modulation operation is continued without interruption, and the write gate is disabled so that the modulation output data is not output from the recording modulation circuit.
Thereafter, when the transfer error is no longer detected, the recording modulation method is characterized in that the invalidated write gate is validated and the output of the modulated output data is restarted from the next sync frame. . By light irradiation, the digital data to a disc apparatus that records on an optical disk,
A signal obtained by modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word and modulating the resulting modulated output data into code data When the recording modulation circuit for outputting a write gate indicating a recording range to the optical disc of the modulated output data,
Reading said data word from memory have a memory controller to be output to the recording modulation circuit,
In the recording modulation circuit, upon detecting transmission errors of the data word from the memory controller to the recording modulation circuit, to record dummy data, as well as continue without interrupting the recording modulation operation, then, the when no longer detects a transfer error, the optical disk apparatus characterized that you resume recording of the modulated output data. An optical disc apparatus for recording digital data on an optical disc by light irradiation,
A signal obtained by modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word and modulating the resulting modulated output data into code data A recording modulation circuit that outputs a write gate indicating a recording range of the modulation output data to the optical disc;
A memory for temporarily storing an error correction block in which parity is added to data; and
A memory controller that controls generation of the error correction block, reads the error correction block from the memory, and outputs the block to the recording modulation circuit;
When the processing of the memory controller is occupied, the generation of the error correction block detects a transfer error in time for the generation of the modulation output data output in synchronization with the recording clock in the recording modulation circuit. ,
The recording modulation circuit outputs dummy data when the delay time of the output of the error correction block from the memory controller is within a range in which burst error correction is possible during reproduction of the optical disc, or The write gate is disabled so that no modulation output data is output, and the recording modulation operation continues without interruption, and when the transfer error is not detected, the modulation output data is output from the next sync frame. An optical disk device characterized by resuming the process. In order to perform modulation in accordance with a modulation method for modulating an i-bit (i is a positive integer) data word into a j-bit (j is a positive integer) code word, and to record the resulting modulated output data on an optical disc A recording modulation circuit for output;
A memory for temporarily storing an error correction block in which parity is added to data; and
An optical disc recording method in an optical disc apparatus comprising: a memory controller that controls generation of the error correction block, reads the error correction block from the memory, and outputs the error correction block to the recording modulation circuit;
When the processing of the memory controller is occupied, the generation of the error correction block detects a transfer error in time for the generation of the modulation output data output in synchronization with the recording clock in the recording modulation circuit. ,
The recording modulation circuit outputs dummy data when the delay time of the output of the error correction block from the memory controller is within a range in which burst error correction is possible during reproduction of the optical disc, or The write gate is disabled so that no modulation output data is output, and the recording modulation operation continues without interruption, and when the transfer error is not detected, the modulation output data is output from the next sync frame. An optical disc recording method characterized by restarting the recording.

Images