JP5136678B2 - How to record or play - Google Patents

Description

The present invention relates to a method capable record or reproduce be applied to an optical disk or the like.

  A disc-shaped recording medium, such as a DVD, has two types of media, a rewritable (rewritable) medium (DVD + RW) and a read-only medium (DVD-ROM), depending on its characteristics. Both are of a similar physical format, and it is preferable that a DVD + RW can be reproduced by a DVD-ROM drive. A method for acquiring a spindle servo signal and a position signal (address) on a medium differs between a DVD + RW drive and a DVD-ROM drive. The DVD + RW has a wobbling groove that has been engraved on the disk in advance as an emboss, and a spindle servo signal and a position signal are obtained from the wobbling groove reproduction signal. On the other hand, a DVD-ROM does not have such a wobbling groove, and obtains a position signal from a frame synchronization signal and an address signal separated from reproduction data of the disc.

  In order to reproduce DVD + RW with a DVD-ROM drive, a frame synchronization signal and a position signal are also inserted in the DVD + RW data. However, it is difficult to reproduce a DVD + RW with an unrecorded part before or after recorded data by a DVD-ROM drive. Specifically, since the frame synchronization signal cannot be reproduced, the spindle servo cannot be stably applied, and a seek operation for reading a desired sector is impossible.

  The seek operation is performed by combining a coarse servo that jumps a large number of tracks and a fine servo that captures a desired sector near the target position. Due to the eccentricity of the disc, even when jumping to the target track, a deviation of several tens to several hundreds of tracks usually occurs, and if the jump destination position on the disc is an unrecorded area , You will not be able to reach the target track. Therefore, in the seek operation, data including a frame synchronization signal and a position signal needs to be recorded around the target sector.

  As described above, in order to enable the DVD + RW to be reproduced by the DVD-ROM drive, it is necessary to set the dummy data to be recorded before or after the recorded data of the DVD + RW. The process for this is called finalization. The following two methods can be considered as a method for finalization.

  One method is based on file system analysis. In general, a file system has a space bitmap for user area allocation, and a UDF used in a DVD has a space bitmap and information on whether each entry of each file is recorded / unrecorded. Yes. Therefore, by analyzing the file system, it is possible to know where user data is written and where dummy data should be written. This method is performed by application software of a host computer.

  Another method is a method by blank detection. In this method, all the blocks of DVD + RW are actually read, and if they can be read, they are recorded. If it is not readable, the drive hardware determines whether there is no RF signal (ie, it is not recorded) or whether it is recorded but cannot be reproduced. If the RF signal cannot be obtained, it is clearly unrecorded, so dummy data is recorded. When the RF signal is obtained but cannot be read, it is determined whether to leave it as it is or to overwrite the dummy data in consideration of the amount of ECC error or the like. This process is performed inside the drive.

  The file system analysis method is efficient when the number of directories / files is small, but is inefficient when the number of directories / files reaches thousands. . In addition, since the file system other than UDF cannot use this method because only allocation information is available, the possibility of using this method is limited by the file system. The method by blank detection does not choose a file system. However, since all the blocks on the disk are read, there is a disadvantage that the processing time is long.

  In addition to the two methods described above, it may be possible to require certification at the time of formatting. In the certification, a certification pattern is recorded on the entire surface of the disc, and this data is reproduced to inspect the presence or absence of defects on the disc. Therefore, if the certification pattern is recorded on the entire surface, there is no unrecorded area, so that finalization itself becomes unnecessary. However, since DVD + RW has a large recording capacity, it requires about one hour of certification, which is not efficient, and there is a problem in requiring this certification from the user.

Accordingly, an object of the invention is independent of the file system and quickly is to provide a method capable of record or reproduction by performing finalization.

The present invention is a method of recording user data on a recordable recording medium having a user data area in which user data is recorded and a management area in which management data is recorded, or reproducing user data from the recording medium. The user data area has a first zone area and a second zone area, and a first bitmap and a second bitmap are recorded in the management area, and the first bitmap is Including information indicating the first zone area and information indicating whether or not recording has been performed for each recording / reproduction data unit in the first zone area, and the second bitmap is information indicating the second zone area If, includes information indicating whether recorded or not each recording reproduction data unit in the second zone area, data units of said recording corresponds to the ECC block, the first Bit Mac consists of a first ECC block, the second bit map is a method which is characterized in that it consists of the second ECC block.

  For each block that is a recording / reproducing data unit, a bit map, which is a set of bits indicating whether the block has been recorded or not recorded, is recorded in a management area on the disc. Therefore, finalization data (dummy data) can be recorded by referring to this bitmap when finalizing. It does not depend on the file system, can be finalized quickly, and does not require users to be certified.

  Since the present invention has a bitmap indicating recorded / unrecorded, finalization can be performed on the drive itself as compared to the method of analyzing the file system, and finalization independent of the file system is performed. In addition, even if the number of directories and files is large, finalization can be performed efficiently.

  Also, the present invention can perform finalization more quickly than the method of actually reading all blocks and checking recorded / unrecorded. Furthermore, there is no need to require certification. Since the time taken for finalization is much shorter than that of certification, it is an efficient specification for users.

By forming the WBBM in the present invention into a ring structure, the number of times of writing the WBBM to the same block can be reduced, and deterioration of the medium can be reduced. Furthermore, the area following the recorded area is read in advance in the background, etc., and it is checked first that it has not been recorded, and in response to a write command to that area, avoid read-modify-write, Performance can be improved. In particular, this is very effective when a flash cache is used, or when a write cache is disabled or a FUA flag is used (a flag that requests a write immediately without caching).
In the present invention, since the WBBM having exactly the same content is multiplex-recorded, the reliability can be improved.

It is a block diagram which shows the structure of the drive of one Embodiment of this invention. It is a basic diagram which shows the structure of each area of the disc-shaped recording medium which can apply this invention. It is a basic diagram which shows the wobbling groove of the disk-shaped recording medium which can apply this invention. It is a basic diagram for demonstrating the frame structure of the wobbling groove of the disc-shaped recording medium which can apply this invention. It is a basic diagram which shows the sector format of the disk-shaped recording medium which can apply this invention. It is a basic diagram which shows the format of 32K bytes of the disk-shaped recording medium which can apply this invention. It is a basic diagram which shows the state which interleaved the outer code | symbol in the format of 32K bytes of the disc-shaped recording medium which can apply this invention. It is a basic diagram which shows the structure of the block of the disk-shaped recording medium which can apply this invention. It is a basic diagram used for description of finalization. It is a basic diagram used for description of the recording position of WBBM. It is a basic diagram used for description of the data structure of WBBM. It is a basic diagram used for description of the multiple writing of WBBM. It is a basic diagram used for description of the ring structure of WBBM. It is a basic diagram used for description of WBBM which has the bit map regarding user data. It is a flowchart used for description of the process performed when a medium is inserted in a drive. It is a flowchart used for description of the process performed when executing a write command. It is a flowchart used for description of the process which updates WBBM. It is a flowchart used for description of the process of finalization. It is a basic diagram used for description of read modify write.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a phase change type disk is used as a rewritable optical disk. More specifically, a two-sheet bonded disk having a diameter of 120 mm and a disk thickness of 0.6 mm is used. On the disc, a wobbling groove is formed in advance as an emboss (uneven shape). As will be described later, the wobbling groove is wobbled by a signal obtained by FM-modulating an address (position signal), and a spindle servo signal and an absolute address on the disk can be extracted from the reproduction signal of the wobbling groove.

Further, the disk is rotated at CAV (constant angular velocity), and the address included in the groove becomes CAV data accordingly. The data is recorded in the groove. Also, the data is constant linear density (CLD) on the disk.
) Is recorded. The linear density is 0.35 μm / bit. However, a certain width is set as the linear density range, the rewritable area on the disc is divided into a large number of zones, and the linear density is defined in each zone. Such a disc is called DVD + RW. However, the present invention is not limited to such a DVD + RW, and can be applied to an optical disk such as a disk for recording on a groove and a land, a magneto-optical recording (MO) disk, or the like.

  With reference to FIG. 1, an outline of a drive of a rewritable optical disc such as a DVD + RW will be described. In FIG. 1, 1 indicates, for example, a phase change type optical disk. The optical disk 1 is rotationally driven by a spindle motor 2 at CAV. An optical pickup 3 is provided for recording data on the optical disc 1 and reproducing the data from the optical disc 1.

  Data from the external host processor 10 is supplied to the drive via the interface 4. A controller 5 is connected to the interface 4, and a buffer memory 6 is connected to the controller 5. The buffer memory 6 holds write data or read data. Write data is supplied from the controller 5 to the encoder 7. In the encoder 7, the write data is converted into the sector structure, the error correction code is encoded for each ECC block of 16 sectors, and the frame synchronization signal and the linking section are added to the frame. Converted to structured data.

  Frame structure data is supplied to the recording system 8. In the recording system 8, processing such as digital modulation is performed. Recording data from the recording system 8 is supplied to the laser drive 9. In the laser drive 9, a drive waveform having a predetermined level relationship for recording record data on the optical disc 1 is generated. The output of the laser drive 9 is supplied to the optical pickup 3 and data is recorded.

  Data on the optical disc 1 is reproduced by the optical pickup 3, and a signal detected by the photodetector is supplied to the amplifier circuit 11. An output signal of the amplifier circuit 11 is supplied to the reproduction system 12 and the servo system 14. The amplifier circuit 11 calculates the detection signal of the photodetector, and generates an RF signal, a tracking error signal, and a focus error signal. An RF signal is supplied to the reproduction system 12, and a tracking error signal and a focus error signal are supplied to the servo system 14.

  The reproduction system 12 performs processing such as digital demodulation processing. Also, the reproduction signal of the wobbling groove is processed to demodulate the address. The separated frame synchronization signal and address are supplied to the servo system 14. The servo system 14 performs tracking servo and focus servo for the optical pickup 3, performs spindle servo, and further performs sled servo for controlling movement of the optical pickup 3 in the disk radial direction.

  Reproduction data from the reproduction system 12 is supplied to the decoder 13. The decoder 13 performs processing such as decoding of error correction codes (that is, error correction), decomposition of reproduced data into sector structures, and the like. The reproduction data of the decoder 13 is supplied to the controller 5 and stored in the buffer memory 6. When a read command from the host processor 10 is received, read data is transferred to the host processor 10 via the interface 4.

  A CPU 21 is provided to control the operation of the entire drive. A RAM 23 and a ROM 24 for storing programs are connected to the CPU 21 via a bus 22. In addition, a reproduction address from the reproduction system 12 is supplied to the bus 22. Further, the controller 5 is connected to the bus 22.

  An example of the rewritable optical disc 1 will be described. FIG. 2 shows an area structure from the inner circumference side (lead-in) to the outer circumference side (lead-out) of the disk. The radial position is added to the left side of the structure diagram, and the absolute address value is added to the right side in hexadecimal notation (this notation is expressed by adding h).

  The hatched portions on the innermost circumferential side (radius position 22.6 mm to 24.0 mm) and the outermost circumferential side (radius position 58.00 mm and later) are areas where embossed pits are recorded. In this embossed area (also referred to as ROM area), in addition to all “00h” data, a reference code is recorded for 2 ECC blocks from the position of the absolute address “2F000h”, and control data is recorded from the position of the absolute address “2F200h”. 186 blocks are recorded. An ECC block is a unit that constitutes an error correction block, and is formed by adding a parity of an error correction code to each 32 Kbyte (= 2 Kbyte × 16) data.

  The control data and the reference code are recorded at the time of cutting for manufacturing the master disc, and become pit data dedicated for reading. In the control data, physical management information of the optical disc is recorded.

  An area from the radial position 24.0 mm to 58.0 mm, that is, an area other than the embossed area is a rewritable area (groove area) in which tracks by grooves are formed. Among these, the user area that can be used for data recording by the user is an area having a radial position of 24.19 mm to 57.9 mm, and the absolute address is 31000h to 1A0EBFh.

  A guard zone, a disk test zone, a drive test zone, and a DMA (defect management area) are provided on the inner and outer rewritable areas of the user area. The guard zone is provided as an area for synchronizing the write clock when writing to the disk test zone or DMA. The disc test zone is provided for checking the disc condition. The drive test zone is used for checking the recording / reproducing drive status.

  As the DMA, DMA1 and DMA2 are provided on the inner peripheral side of the disk, and DMA3 and DMA4 are provided on the outer peripheral side of the disk. The same contents are recorded in each of DMA1 to DMA4. In this DMA, the detection result of the defect state on the recordable area and the information of the alternate sector are recorded. By performing the recording / reproducing operation with reference to the contents of the DMA, recording / reproducing can be performed while avoiding the defective area. A lead-in area as a management area is configured by an inner peripheral area of the rewritable area excluding a user area and an innermost embossed area.

  In the optical disc 1, in a groove area other than the embossed area, a track is previously formed by a wobbling groove, and the wobbling groove expresses an absolute address. Therefore, the recording / reproducing apparatus can obtain information such as an absolute address from the reproduction signal of the groove.

  FIG. 3 shows an example of the groove structure of the optical disc 1. As shown in FIG. 3A, in the groove area of the optical disc 1, a pre-groove 1a is previously formed in a spiral shape from the inner periphery to the outer periphery. Of course, the pregroove 1a can also be formed concentrically.

  In addition, as shown in FIG. 3B, a part of the pre-groove 1a is enlarged, and the left and right side walls are wobbled corresponding to the address information. That is, wobbling is performed at a predetermined period corresponding to the wobbling signal generated based on the address. A land 1b is formed between the groove 1a and the adjacent groove 1a, and data is recorded in the groove 1a. Therefore, the track pitch is the distance from the center of the groove 1a to the center of the adjacent groove 1a, and the track pitch is set to 0.8 μm, for example. The groove width (the width of the bottom surface of the groove 1a) is, for example, 0.48 μm, and the groove 1a is wider than the land 1b.

  The wobbling amount of the groove 1a is defined as the value of the wobble amplitude WW. For example, the wobble amplitude WW is 12.5 nm. On the groove, the wobble amount is instantaneously increased at a certain cycle interval, and this is used as a fine clock mark. In this portion, the wobble amplitude is, for example, about 25 to 30 nm.

  One track (one round track) has a plurality of wobbling address frames. The wobbling address frame is divided into eight in the rotation direction of the disk, and each is a servo segment (segment 0 to segment 7). One servo segment (hereinafter simply referred to as a segment) includes 48-bit information mainly including an absolute address, and wobbling per segment is 360 waves.

  Further, fine clock marks are formed on the wobbling groove at equal intervals. This clock mark is used to generate a reference clock at the time of data recording by a PLL circuit. 96 fine clock marks are formed per rotation of the disk, and therefore 12 fine clock marks are formed per segment.

  Each wobbling address frame as each segment (segment 0 to segment 7) has the configuration shown in FIG. In the 48-bit wobbling address frame, the first 4 bits are a synchronization signal (Sync) indicating the start of the wobbling address frame. The 4-bit synchronization pattern is bi-phase data that forms 4-bit data with 8 channel bits. The next 4 bits are layer information (Layer) indicating which layer of the plurality of recording layers or the layer structure of the disc is.

  The next 20 bits are a track address (track number) as an absolute address on the disk. The next 4 bits represent the segment number. The segment number value is a value from “0” to “7” corresponding to segment 0 to segment 7, that is, the segment number is a value representing the circumferential position of the disc. The next 2 bits are reserved, and an error detection code (CRC) code is added as the last 14 bits of the wobbling address frame. As described above, fine clock marks are formed at equal intervals in the wobbling address frame.

  Data read / write is performed in units of ECC blocks. One sector is, for example, 2 Kbytes, and one block is 32 Kbytes in size. FIG. 5 shows the structure of one sector. In one sector, data ID (4 bytes), IED (2 bytes), reserved area (6 bytes), user data (2048 bytes = 2K bytes), EDC (4 bytes) are arranged in order from the head, totaling 2064 bytes. Have a size of

  The data ID includes an address corresponding to the address by the wobbling groove, that is, a track number and a sector number. IED is a parity (for example, CRC) for error detection with respect to the data ID. The EDC is a parity (for example, CRC) for error detection that is reproduced from the optical disc 1 and finally checks whether there is an error in the user data after completion of processing such as error correction.

  Sixteen sectors having the configuration shown in FIG. 5 are collected to form the ECC block shown in FIG. One sector is 2064 bytes, which is a data size of (172 bytes × 12). Therefore, as shown in FIG. 6, a data array of (172 bytes × 192 (= 12 × 16)) is formed by arranging 16 sectors each rearranged to 172 bytes × 12. The product code is encoded for the user data of 192 × 172 bytes. That is, an inner code (for example, Reed-Solomon code) is encoded for 172 bytes of data in each row, a parity (PI) of 10 bytes of inner code is generated, and for 192 bytes of data in each column Then, the outer code (for example, Reed-Solomon code) is encoded to generate a 16-byte outer code parity (PO).

  Further, among the data that is blocked into 182 bytes × 208 (= (172 + 10) × (192 + 16)), the parity (PO) of the 182 bytes × 16 outer code is divided into 16 182 bytes × 1 data. Then, as shown in FIG. 7, the data is interleaved so that one is added below each of the 16 sector data of number 0 to number 15 (size of 182 bytes × 12). After product code encoding, data of 13 (= 12 + 1) × 182 bytes including the parity PO of the outer code is handled as data of one sector.

  Further, when data of 182 bytes × 208 shown in FIG. 7 is recorded on the disc, the transmission frame structure is as shown in FIG. That is, 182 bytes of each row are divided into two equal parts of 91 bytes, and the data is 208 (row) × 2 (frame). A linking section (link area data) of 13 (row) × 2 (frame) is added to the head of each data of 208 × 2 frames. More precisely, a part of the data of the linking section for 26 frames is recorded at the end of the previous block, and the rest is recorded at the beginning of the current block.

  A 2-byte frame synchronization signal (FS) is further added to the head of the 91-byte frame data. As a result, as shown in FIG. 8, the data of one frame is a total of 93 bytes, and the total is 221 (row) × 93 × 2 bytes, that is, the data of a block of 442 frames. This is data for one block (unit of recording / reproduction). The size of the actual data part excluding the overhead part is 32 Kbytes (= 2048 × 16/1024 Kbytes).

  As described above, in this embodiment, one block is composed of 16 sectors, and one sector is composed of 26 frames. A linking section is disposed between the blocks. The linking section functions as an area for clock synchronization when data is recorded or reproduced.

  The present invention relates to a finalization process required for reproducing an optical disk (for example, DVD + RW) recorded by the above-described drive by a ROM drive (for example, DVD-ROM drive). FIG. 9 shows the concept of finalization according to the present invention. In FIG. 9, data is recorded in block units in the user area in the rewritable area where the wobbling groove is formed.

  When the DVD-ROM drive accesses to read DVD + RW, coarse seek and fine seek are repeated several times to reach the target track. In order to know the position information (data ID of each sector), when the spindle servo is applied and this ID is read, if it is not recorded, a frame synchronization signal as servo information cannot be obtained. Since the spindle servo is in a runaway state and no ID exists, position information cannot be obtained. Therefore, it is always necessary to enter the recorded area when seeking. Even when jumping to the expected track from the current track when seeking due to disk eccentricity, etc., it will deviate to some extent from the expected track, so the range is filled with dummy data (referred to as finalization data) in advance. It is necessary to keep it. The finalization data is data that has no meaning (for example, all zero data), but the sector structure and block structure are the same as the user data described above. Therefore, the finalization data includes servo information (frame synchronization signal) and position information (ID).

  In the example of FIG. 9, as a result of finalization, the final area is recorded before and after the recorded area in the user area, the rewritable area (test zone, DMA, etc.) in the lead-in area, and the rewritable area (DMA) in the lead-out area. Indicates the state in which the application data is recorded. The amount of finalization data recorded depends on the seek performance of the drive, the amount of disk eccentricity, etc., but is generally recorded over a width of several hundred tracks.

  In order to perform the above-described finalization, it is necessary to know which blocks have been recorded and which blocks have not been recorded. For every block in the rewritable area, a bit map table in which 1 bit is associated with each block is created and defined as, for example, recorded (logical value 1) or unrecorded (logical value 0). By changing the corresponding bit of the recorded block to 1 (recorded) each time a write command is executed, information on the written block can be left. This bit map is referred to as WBBM (Written Block Bit Map).

  In the configuration of FIG. 1, the CPU 21 receives information corresponding to the write command from the controller 5, and a WBBM is formed in the RAM 23 under the control of the CPU 21. At a predetermined timing as will be described later, the WBBM is read from the RAM 23 by the CPU 21, is subjected to a recording process similar to user data via the controller 5, and is recorded in a predetermined area of the lead-in area of the optical disc 1. The In addition, when the user instructs execution of finalization in the host processor 10 (or drive), this instruction is sent to the CPU 21, and a predetermined amount of finalization is recorded before and after the recorded block based on the latest WBBM. The CPU 21 controls the drive so as to write data.

  As shown in FIG. 10, the WBBM is placed in the lead-in area together with the test zone, DMA, and the like. The recording position can be appropriately set as long as it is between 30000h and 31000h in the lead-in area. Preferably, guard zones are arranged before and after the WBBM. In principle, it works with one WBBM, but it is very effective to provide multiple WBBMs (WBBM-1 to WBBM-N) to improve reliability and reduce the number of writes to the same area. is there. In the case of a phase change type disk medium, there is a limit to the number of writes (about 100,000 times), and if a write operation is performed only on the same area, there is a problem of shortening the life of the medium.

  Details of an example of the structure of the WBBM will be described below. As described above, since one block is 16 sectors (32 Kbytes), there are 90,000 to 100,000 blocks in DVD + RW having a capacity of about 3 Gbytes. If 1 bit corresponds to 1 block, a bitmap of about 12 Kbytes is required. Management information is added to this bitmap to form one WBBM. When the WBBM is recorded on the disc, the encoding process using the product code and the framing process are performed as in the case of user data. That is, one ECC block is composed of one WBBM.

  As shown in FIG. 11, in one WBBM, a WBBM identifier, a ring number, an update counter, and zone information are added as management information to bitmap data. The bitmap is arranged in units of bytes, and the upper right corner of the bitmap is a bit related to the block whose ECC block number is 1. Then, each bit is arranged so that the ECC block number sequentially increases toward the left side in each byte and the ECC block number sequentially increases toward the lower side of the bitmap. FIG. 11 shows an enlarged view of the byte at the Nth position from the top. This byte includes bits from ECC block number 8N to bits 8N + 7. A bit of 0 indicates that the ECC block has not been recorded, and a bit of 1 indicates that the ECC block has been recorded.

  Each piece of management information is 1 byte and has the following contents.

  WBBM identifier: A numerical value indicating that the ECC block is a WBBM, for example, a value such as 0C0Ch.

  Ring number: Indicates how many WBBMs are treated as a set among a plurality of WBBMs, and what number is among them.

  Update counter: A numerical value that is incremented each time the WBBM is updated, and the one having the maximum update counter value in the set of WBBM groups is determined as the latest WBBM. When updating, the WBBM having the smallest update counter value is updated to the latest WBBM. Thereby, concentration of writing to a specific WBBM can be prevented and deterioration of the disk medium can be prevented. Even if data destruction occurs in the latest WBBM, the destroyed WBBM can be almost compensated by the information of the WBBM having the largest update counter value among the remaining WBBMs.

  Zone information: Since it is not efficient to check all bits when actually finalizing, when all areas of the rewritable area are divided into multiple zones and writing of all blocks belonging to each zone is completed For that zone, a flag indicating that all blocks have been recorded is set. Once this flag is reached, the zone is excluded from finalization.

  In order to improve reliability, a plurality of WBBMs having exactly the same contents may be written as shown in FIG. In this case, all WBBMs are rewritten every time they are updated.

  FIG. 13 shows a ring structure with a plurality of WBBMs (WBBM-1, WBBM-2,..., WBBM-N). The update counter of each WBBM is initialized to a value of 0, for example. First, when WBBM-1 is updated, only the value of the update counter is set to 1. Next, when WBBM is updated, WBBM-2 is updated and only the value of the update counter of WBBM-2 is set to 2. Further, the next time WBBM is updated, WBBM-3 is updated and only the value of the update counter of WBBM-3 is set to 3. Thus, when updating the WBBM, the WBBM having the smallest update counter value is updated. If there is a WBBM with the same update counter value, the one with the smallest WBBM number is updated. As a result, the largest update counter value can be determined as the latest WBBM.

  Even if the WBBM is not the latest, that is, even if the recorded bits are slightly missing, it can be effective information. That is, a check is made before writing finalization data to an ECC block that has been determined to be unrecorded by the WBBM. Therefore, even if the bit relating to the ECC block is incorrect, the finalization data is written and recorded. There is no destruction of the data. Therefore, if a plurality of WBBMs are provided and rewritten from the old WBBM at the time of update, a plurality of the latest WBBMs remain. If the update counter is defined to be larger as the value of the update counter is larger, the latest WBBM can be determined when the drive reads the WBBM during spin-up.

  Advantages of the WBBM having a ring structure will be described below.

  Since the number of times of writing to a specific WBBM can be reduced to 1 / (number of WBBM rings), deterioration of the medium can be reduced.

  Even if an abnormality such as power-off of the drive occurs during WBBM writing, the previous WBBM remains, so that it can be used as the latest WBBM.

  Also, a method of generating a plurality of WBBMs having the same content (multiple writing (see FIG. 12)) is possible. This method is the simplest power outage countermeasure. In this method, in general, the update counter should be the same for all WBBMs. However, if there is a different counter, it can be estimated that the power supply has been turned off during the update. In this case, the WBBM having the largest update counter value is the latest. Furthermore, a ring structure and multiple writing methods may be used in combination.

  Another example of WBBM will be described with reference to FIG. In the example shown in FIG. 14A, a user data map (referred to as user WBBM) is paired with the above-described WBBM. The WBBM indicates recorded / unrecorded in block units, and cannot distinguish whether the data recorded in the recorded block is user data or finalization data. The user WBBM is formed so as to set 1 bit to the block in which user data is written. Therefore, the bit regarding the block in which the finalization data is written is 0.

  Having a user WBBM is advantageous when a DVD + RW that has been finalized once is reproduced by a DVD-ROM drive and then written again by a DVD + RW drive. In this case, finalization is required again in order to use the DVD + ROM drive again. Since the WBBM is a combination of the bitmap of user data and the bitmap of finalization data, that is, indicates all recorded blocks, the user data and the finalization data cannot be distinguished from the WBBM. As a result, the finalization data is further written around the finalization data unnecessarily. By having users WBBM and WBBM, recording of unnecessary finalization data can be avoided.

The method of holding the user WBBM is not limited to the method of having the user WBBM and WBBM as a pair as shown in FIG. 14A, and there are two portions corresponding to one block on the bitmap as shown as WBBM ′ in FIG. 14B. Bits may be used to distinguish unrecorded blocks, user data recording blocks, and finalization data recording blocks. Thus, by having a bitmap that can distinguish user data and finalization data, more efficient finalization is possible.

  The WBBM is first written to a predetermined area of the DVD + RW lead-in area when the medium is formatted. When the blank medium is formatted, when the certification is not performed, all the user areas are unrecorded, and when the certification is performed, all the user areas are recorded. When reformatting, since recorded data remains in the user area, the existing WBBM is continuously used.

  When DVD + RW is inserted into the drive, WBBM is read into the drive memory (RAM 23 in FIG. 1). FIG. 15 is a flowchart of processing when a medium is inserted. In step S1 of FIG. 15, when a medium is inserted into the drive, and spins up in step S2, the DMA and WBBM in the lead-in area are reproduced. The first WBBM is read (step S3), and the ring number which is management information in the WBBM is checked (step S4). In the case where the WBBM has a ring structure, since there are a plurality of WBBMs, all WBBMs are read, and update counters in all WBBMs are read (step S5). Then, the values of the update counters of all WBBMs are compared, and the one having the maximum update counter value is left in the memory (step S6). If the certification has been completed or the entire area has already been written, there is no need to leave the WBBM in the memory or update the WBBM. This determination is performed by the CPU of the drive, and the flag is controlled in accordance with the determination result.

  Next, a process of rewriting the WBBM on the memory when executing a write command will be described with reference to the flowchart of FIG. Here, for the sake of simplicity, the processing when there is no user WBBM will be described. This process is performed for a medium that is determined to require WBBM management at the time of spin-up. When a write command is accepted (step S11) and execution of the write command is completed in step S12 (when it is determined that recording has been performed on the entire block), the WBBM bit corresponding to the written block is viewed. (Step S13). It is determined whether this bit is 0 (step S14).

  If the bit is 1, it means that the block has been recorded, and it is unnecessary to update the bit, so the processing ends. If the bit corresponding to the block is 0 (that is, unrecorded), the bit corresponding to the block of WBBM on the memory is set to 1 (step S15). Then, a flag (referred to as a WBBM update request flag) indicating that the WBBM has been updated in the memory is set (that is, this flag is set to 1). The WBBM on the medium is sometimes updated at a predetermined timing (at the time of ejecting the medium, at the time of flash cache, or at the background), and the WBBM update request flag is cleared after the end of the update. The flash cache is a process in which when a write command comes, data is temporarily stored in a write cache and a plurality of write commands are executed collectively. The background is a state where the CPU of the drive is not relatively busy.

  FIG. 17 is a flowchart showing processing for updating the WBBM, which is executed at a predetermined timing. Here, WBBM has a ring structure. When the WBBM update request flag is 1, the WBBM is updated (step S21). First, the value of the update counter of WBBM on the memory is incremented by 1 (step S22).

  In step S23, the WBBM on the medium next to the previously read WBBM is updated by the WBBM on the memory. This process sets a ring number corresponding to the WBBM having the smallest update counter value among a plurality of WBBMs on the medium, and replaces the WBBM having the smallest update counter value with the latest WBBM in the memory. is there. Since the update process has ended, the WBBM update request flag is cleared in step S24.

  When the written DVD + RW medium can be reproduced by the DVD-ROM drive, the user instructs execution of finalization. Processing when the drive receives this finalization command will be described with reference to the flowchart of FIG. In step S31, when the finalization command is received, the WBBM on the disk is updated by the WBBM on the memory, so the WBBM on the memory indicates the latest state. Of course, the latest WBBM may be read from the medium.

  In the next step S32, all unrecorded blocks (bit = 0) in a certain range before and after the already recorded (bit = 1) portion, for example, the number of blocks corresponding to 300 tracks, are listed with reference to the WBBM on the memory. Up. Assume that the listed blocks are B (0), B (1), B (2) B (N-1). In step S32, the variable I is set to an initial value (0).

  The next step S33 is to check (I = N?), And in the case of (I = N), it means that finalization data has been recorded for all unrecorded blocks, so WBBM is updated. Processing (step S34) is performed. The WBBM update process is as described above with reference to FIG.

  Finalization data is recorded in the vicinity from block B (0) where variable I is 0 to B (N-1) in order. In this case, it is checked whether or not the area where finalization data determined from WBBM is to be recorded is actually unrecorded. Even in a portion that is not recorded (bit = 0) on the WBBM, there is actually no possibility of recording because of a trouble such as power-off. If it is already recorded, the recorded user data is destroyed by overwriting the finalization data. In order to avoid this, a read operation is performed on the area where finalization data is to be recorded (step S35).

  In step S36, it is determined whether or not the data can be read by the read operation (OK) or not (or no recording is required). If the data can be read or no recording is required, the finalization data is not recorded because the block B (I) is a recorded (or no recording required) block. When the data cannot be read, finalization data (dummy data) is recorded in the unrecorded block B (I) (step S37). In step S38, I is incremented. In the next step S39, the bit on the WBBM corresponding to the recorded block is set to 1.

  The above-described reading for unrecorded check, recording of finalization data for a block in which unrecorded data has been confirmed, increment of I, and processing of setting the corresponding bit on the WBBM to 1 are all listed. This is done for the recording block. Thereafter, in step S34, the bit on the WBBM corresponding to the recorded block or the block confirmed to be recorded is set as recorded (bit = 1), and the WBBM on the memory is written to the medium.

  In the flowchart shown in FIG. 18, one block of a plurality of listed blocks is processed. However, after all the listed blocks are read and checked for recording, finalization is performed collectively. Data may be written. This process is more efficient and suitable for implementation.

  As described above, WBBM is used for efficient finalization. Furthermore, WBBM can be used for improving the efficiency of read-modify-write. The DVD-RW is accessed from the host processor in units of 2K bytes (sectors). The buffer memory of the drive is accessed similarly. On the other hand, the access that the drive makes to the medium is in units of 32 Kbytes in the ECC block. For example, when a read command of 2 Kbytes is received, the drive reads a block (32 Kbytes) including the sector, sends 2 Kbytes requested by the host to the host, and discards the remaining 30 Kbytes. .

  On the other hand, lights are more complex. As shown in FIG. 19, when 2K bytes are to be written, if data is already recorded in the corresponding block, the block is read once, and 2K bytes of the corresponding sector is used as write data from the host. It is necessary to replace and write 32 Kbytes back to the original block. This is referred to as read modify write. In this case, in order to write 2K bytes, 32K byte read and 32K byte write are performed. In general, in order to avoid this read-modify-write, when the drive receives a write command, it temporarily stores the write data in the buffer memory (buffer memory 6 in FIG. 1) and terminates the command. This is called a write cache.

  In general, since the host computer often writes consecutive sectors, data for one block may be gathered as write data is stored. In this case, the data can be collectively set to 32 Kbytes and can be written without a read operation. Of course, batch writing of multiple blocks is also possible. However, there are many cases where 2K bytes are written alone, and long data needs to be read modified at the beginning and end.

  Now, when read-modify-write, the block may not be recorded. In general, when the block is read, if it cannot be read, it is confirmed that it has not been recorded based on information such as the signal level. If not recorded, the portion other than the write data from the host is generally filled with all 0 data. In this case, if it can be confirmed in advance that there is no recording, writing can be executed without reading. Simply put, the performance is doubled. WBBM can be used to improve the efficiency of such read-modify-write.

  For a block already recorded on the WBBM, read modification write should be performed when writing some sectors such as 2 Kbytes. On the other hand, in the case of an unrecorded block (bit = 0) on the WBBM, there is no possibility that the recorded part will be unrecorded due to power off or the like, but in most cases it is unrecorded. If this is utilized, the read-modify-write is not performed, and the data other than the write data can be filled with all 0s and written.

  In many file systems, the medium is usually used in ascending order of LBA (logical block address). Therefore, there is a very high possibility that writing will be performed for an area following the range in which writing has been performed so far. Further, in a medium used without certification, there is a very high possibility that the area following the written range is unrecorded.

  Therefore, in the WBBM, if the area adjacent to the written area is read in advance and it is confirmed that it has not been recorded, the read modify write is not performed when a write command to that area is received. Can light up instantly. When there is no access from the host, the drive checks the WBBM, reads the part following the recorded area, and confirms that it has not been recorded. This may be a relatively narrow range where the next write command is likely to come.

  When a write command to this area is received (possible after cache), if it has been confirmed that the data has not been recorded, read-modify-write is not performed, and all 0 or the like is set in a portion other than the write data. Write. Of course, the WBBM is updated after writing. As a result, a check is made as to whether or not there is an unrecorded area in the subsequent area.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the present invention can be applied to a rewritable or WO (write-once) recording medium other than DVD + RW. The present invention can also be applied to a disc that records address information in a form other than a wobbling groove. Further, the servo information may be information for either CAV or CLV. Furthermore, the finalization data may be recorded before or after the recorded block.

DESCRIPTION OF SYMBOLS 1 ... Rewritable optical disk, 1a ... Pre-groove, 2 ... Spindle motor, 3 ... Optical pick-up, 6 ... Buffer memory, 21 ... CPU, 23 ... RAM

Claims (1)

A method of recording user data on a recordable recording medium having a user data area in which user data is recorded and a management area in which management data is recorded, or reproducing user data from the recording medium,
The user data area has a first zone area and a second zone area;
In the management area, a first bitmap and a second bitmap are recorded,
The first bitmap includes information indicating the first zone area and information indicating whether or not recording has been performed for each data unit of recording / reproduction in the first zone area,
The second bitmap includes information indicating the second zone area and information indicating whether or not recording has been performed for each data unit of recording / reproduction in the second zone area,
The recording / playback data unit corresponds to an ECC block ,
The first ECC block is configured by the first bitmap, and the second ECC block is configured by the second bitmap .

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