JP3898736B2 - system - Google Patents

Description

  The present invention comprises a host and an optical disc apparatus that records and reproduces data with respect to an optical disc such as a CD-R (data writable CD) or CD-R / E (data writable and erasable CD). About the system.

The recording format of optical discs such as CD-R and CD-R / E is defined in the Orange Book, and in the Orange Book, rules for data writing seam, that is, data writing start and write end are clearly determined. Yes.
Also, redundant sectors such as a link (Link), run-in (RunIn), and run-out (RunOut) are always added to the data sector, which is a data writing unit.

  This is based on the assumption that data is interrupted at the joint, and is necessary for synchronization and interleaving. The assumption that the data is interrupted at the joint is that encoding including previously written data and data to be written in the future is impossible, and it is very important to start writing data accurately so that synchronization is not lost Presumably because it is difficult.

By the way, in the optical disc, the unit of data writing is somewhat large due to the nature of the recording format.
In conventional optical disk devices, data is not paused during data writing. If data is not sent from the host at a transfer rate higher than the writing speed of the optical disk device, writing is interrupted and data is then added. I can't write, and writing fails. This is called buffer underrun.

  That is, in the conventional optical disc apparatus, it is necessary to form a track or an optical disc by one writing, and the writing method name is also a name such as Track at once or Disc at once. ing.

  This becomes more severe as data is written at a higher speed, and data writing failure becomes a very serious problem for the user. This is because, for example, in the case of a CD-R, write-once causes a loss of the disk, and there is always a risk of loss of an expensive optical disk or data written in the past.

  One of the reasons for not pausing the writing of the data is that the encoder chip does not consider the pausing, so the dummy data is inserted and written at the beginning of the data where the data of the previous sector originally enters, The continuity of data was lost.

  Therefore, it is preferable that data can be continuously read out normally after the pause and restart of data writing.

  Even if the continuity of logical data is ensured in the format at the seam between the end point and the start point of data writing, normal data reproduction is not possible if the seam is not exactly the same. I can't do it.

  Normally, a frame sync deviation of about ± 2 bits is allowed and data can be reproduced normally. However, as in the conventional optical disk device, writing start depending on the rotation control from the wobble synchronization signal is not allowed. Since the repetitive error reaches several tens of bits, there is a problem that synchronization is lost at this portion and data of several frames is lost.

  Therefore, it is preferable that the end of the previously written data can be accurately detected in order to make the data writing seam at a level where there is no problem in reproduction.

  Furthermore, it is preferable that the end of the previously written data can be accurately detected at low cost.

Further, in the conventional optical disc apparatus, since one track must be written at a time, data transfer from the host is slow, or if there is a pulsation of transfer that cannot be absorbed by the buffer RAM, the writing fails.
Therefore, when writing data to the optical disc, the host must always send data stably at a faster transfer rate than the disc.

However, there are actually hosts with a fast transfer rate and hosts with a slow transfer rate, and the above-mentioned restrictions on data transfer are a major obstacle to the use of optical discs.
Therefore, a test mode is provided in the host software, and this type of writing failure is reduced by performing simulated writing.
However, this software has a problem that it takes twice as much time to write data, and the multitask OS is not completely safe because the machine status changes every moment.

The present invention has been made in view of the above points, and an object of the present invention is to prevent a data write failure due to a lack of data transfer from a host in time.
Furthermore, it is preferable to improve the reliability of data writing when data transfer from the host is not in time.

In order to achieve the above object, the present invention provides the following system.
(1) A host and an optical disk device that records data on the optical disk are provided, the host transfers a write command and data to the optical disk device, and the optical disk device transmits the write command and a predetermined amount of data. When data is received, data writing is started with the user data block in which the link block and the run-in block are provided on the optical disc and the run-out block is provided later as a writing unit. A system that temporarily suspends writing without writing a run-out block during data recording to the optical disc when transfer is not in time.

(2) In the system as described above, when resuming data writing, the optical disc apparatus performs writing to maintain data continuity by CIRC demodulation at the end point and start point of data writing without writing the link block. System to do.

(3) In the system as described above, the optical disc apparatus includes a buffer RAM, and the predetermined amount of data is data that fills the buffer RAM.

(4) In the system as described above, the optical disc apparatus writes the runout block after the data has been written to a predetermined length.

(5) In the system as described above, the optical disc apparatus, when the encoder that encodes the data received from the host and the writing is temporarily interrupted, interrupts the encoding operation by the encoder and resumes the data writing during the encoding. A system comprising a RAM for storing data to be written to the optical disc sometimes at times.

  The system according to the present invention can prevent a data write failure due to a lack of data transfer from the host.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment of the present invention. The optical disk apparatus includes an optical disk 1, a spindle motor 2, a motor driver 3, a servo 4, an optical pickup 5, a read amplifier 6, a CD decoder 7, a CD-ROM decoder 8, a buffer manager 9, a buffer RAM 10, an ATPI / SCSI interface 11, It comprises a D / A converter 12, an ATIP decoder 13, a CD encoder 14, a CD-ROM encoder 15, a laser control circuit 16, a CPU 17, a ROM 18, and a RAM 19.

In this optical disk apparatus, an optical disk 1 is driven to rotate by a spindle motor 2. The spindle motor 2 is controlled by the motor driver 3 and the servo 4 so that the linear velocity is constant. The linear velocity can be changed in stages.
The optical pickup 5 includes a semiconductor laser, an optical system, a focus actuator, a track actuator, a light receiving element, and a position sensor (not shown), and irradiates the recording surface of the optical disc 1 with the laser light L.

  The optical pickup 5 can be moved in the sledge direction by a seek motor. These focus actuators, track actuators, and seek motors are controlled by the motor driver 3 and the servo 4 so that the laser spot is positioned at a target location on the optical disk 1 based on signals obtained from the light receiving element and the position sensor.

  In the case of data read (data reproduction), the reproduction signal obtained by the optical pickup 5 is amplified by the read amplifier 6 and binarized, and then input to the CD decoder 7 to perform deinterleaving and error correction processing. Further, the data after the deinterleaving and error correction processing is input to the CD-ROM decoder 8 to perform error correction processing for improving data reliability.

Thereafter, the data processed by the CD-ROM decoder 8 is temporarily stored in the buffer RAM 10 by the buffer manager 9 and transferred to the host at once by the ATAPI / SCSI interface 11 when it is prepared as sector data.
In the case of music data, the data output from the CD decoder 7 is input to the D / A converter 12 to extract an analog audio signal.

  Next, in the case of data write (data write), when data transferred from the host by the ATAPI / SCSI interface 11 is received, the data is temporarily stored in the buffer RAM 10 by the buffer manager 9.

  Writing starts when a certain amount of data is accumulated in the buffer RAM 10, but before that, the laser spot is positioned at the writing start point. The writing start point is obtained by a wobble signal preliminarily carved on the optical disc 1 by meandering tracks. The wobble signal includes absolute time information called ATIP, and the ATIP decoder 13 extracts ATIP information.

The synchronization signal generated by the ATIP decoder 13 is input to the CD encoder 14 so that data can be written at an accurate position.
The data in the buffer RAM 10 is recorded on the optical disc 1 through the laser control circuit 16 and the optical pickup 5 by adding an error correction code and interleaving with the CD-ROM encoder 15 and the CD encoder 14.

  The CPU 17 and the like perform the functions according to the present invention. Also, means for recording and reproducing data on an optical writable optical disc, writing means for maintaining data continuity by CIRC demodulation at the end and start points of data writing on the optical disc, and writing on the optical disc the previous time It functions as a means for counting the PLL of channel bits that take the timing to start writing accurately from the end of the data.

It also functions as a means for counting the frame sync signal that takes the timing to start writing accurately from the end of the previously written data on the optical disc.
Further, when the data transfer from the host is not in time during the writing of data to the optical disc, the data writing is temporarily stopped, and the data writing is resumed when the data is sufficiently sent from the host.

  Furthermore, when data transfer from the host is not in time during data writing to the optical disk, the data writing is temporarily stopped, and the function of means for restarting data writing after reducing the data writing speed to the optical disk is achieved.

  FIG. 2 is a diagram showing a format of a data writing unit of CD-R and CD-R / E defined in Orange Book. Usually, because of data interleaving and synchronization pull-in, it is not possible to read the data completely just by writing the data in the user data block (User Data blocks). Therefore, the user data block is protected by providing 5 blocks and 2 redundant blocks before and after the user data block, respectively, so that data can be surely read even by a normal optical disk apparatus.

  That is, as shown in FIG. 2, before the user data block, a link block (Link block), a run-in block 1 (Run-in block 1), a run-in block 2 (Run-in block 2), and a run-in block 3 ( Run-in block 3), run-in block 4 (Run-in block 4), run-in block 5 (Run-in block 5), 5 redundant blocks, run-out block 1 (Run-out block 1), run-out block 2 ( Two redundant blocks of Run-out block 2) are provided.

  FIG. 3 is a diagram showing an example of a format when data is written in a plurality of times for the user data block shown in FIG. The optical disk apparatus of this embodiment receives data from the host, and executes start write (Start Write) when the buffer RAM 10 is filled with the data.

  When the user data block starts to be written and the remaining data in the buffer RAM 10 becomes small, a pause write is executed to temporarily stop the writing. Thereafter, data transfer from the host is waited, and when the buffer RAM 10 is full of data, a restart write is executed, and data writing is started from the position where the data writing is paused by the pause write.

  As described above, when the data in the buffer RAM 10 decreases, the data write is temporarily stopped by pause write, and when the data is full in the buffer RAM 10, the process of restarting the data write by restart write is appropriately repeated, and all the data from the host is stored. After writing, the writing is completed with a stop write (Stop Write).

  By the way, the reason why the above-mentioned data is not written in the conventional optical disk apparatus is that there are the following two points of failure as well as not being defined in the Orange Book.

The first point stems from the fixed idea that the host (file system) determines the data write unit and it must be written once.
Certainly, the data write unit of the host cannot be changed due to a format peculiar to an optical disc such as a CD that cannot be reproduced only by the user data block.

However, if data continuity is maintained, there is no problem even if the host data write unit is divided and written.
Therefore, in the optical disc apparatus of this embodiment, control is performed so that data continuity is maintained and data write units from the host are written separately.

  In other words, the logical data writing unit according to the rules defined in the Orange Book is divided from the physical data writing unit when data is actually written to the optical disc. Since the host always sends data continuously, it is easy to divide the physical write unit of data if the encoder pauses.

Next, the data write control will be described.
FIG. 4 is a block diagram showing a circuit configuration example for performing the data write control.
When a pause signal is input to this circuit, the clock to the CD-ROM encoder 15 and the CIRC encoder 20 is interrupted, so that the CD-ROM encoder 15 and the CIRC encoder 20 interrupt the encoding operation, The output of the write data (Write Data) is stopped.

Further, since the write gate is also masked by the pause signal, data writing to the optical disc is also interrupted.
However, since the RAM 21 and 22 store the data in the middle of encoding, the data is continuously output as write data by releasing the pause signal, and writing to the optical disk is resumed when the mask of the write gate is released. However, the pause signal is highly synchronized with the pause and restart of data writing.

In this way, since writing is performed to maintain data continuity by CIRC demodulation at the end point and start point of data writing on the optical disc, data writing to the optical disc is paused and then resumed and written. Later, the data can be read out accurately and continuously.
In other words, data can be continuously and normally read out even if data writing is paused and resumed.

  Next, the second failure point is that the beam position at the start of data writing cannot be determined by the error level of the bit clock in the writing control of the conventional optical disk apparatus.

FIG. 5 is a diagram showing the positional relationship between the end of writing data and the start of writing on the optical disc defined in the Orange Book.
As shown in this format, a considerably large data overlap of 4 EFM frames (4 EFM Frames) is allowed. This is not presupposed from the beginning, but with this, even with an optical disc such as a CD having a high correction capability, frame synchronization is lost and normal reproduction cannot be performed.

  The reason why such an allowable value is allowed is to absorb the control error of the spindle motor, and the data write start position is determined by the ATIP of the wobble signal regardless of the already written data. Because.

Therefore, when the frame synchronization protection window width is taken into consideration in order to reproduce data without losing synchronization at the data recording seam, the format shown in FIG. 6 is obtained.
FIG. 6 is a diagram showing an example of forming a seam on the optical disc by the optical disc apparatus shown in FIG.

  That is, as shown in the figure, it is necessary to form a seam with a deviation of about ± 2 bit clock. As described above, it is difficult to determine an accurate data writing position by writing control based on the control accuracy of the spindle motor as in the conventional optical disk apparatus.

  Therefore, in the optical disk device of this embodiment, the end of the data written immediately before on the optical disk is found, specifically, the end position calculated based on the clock synchronized with the data written immediately before is obtained, and the end position is determined. The data write position is determined based on the above.

  Next, a description will be given of a writing process in which the PLL of channel bits is counted to take a writing timing and the writing is started accurately from the end of the data written on the optical disk.

  FIG. 7 is a block diagram showing a circuit configuration example for creating the write timing of the seam formation shown in FIG. 6 of the optical disc apparatus shown in FIG. 1, and FIG. 8 is a timing chart of the circuit shown in FIG.

  The circuit shown in FIG. 7 counts channel bits PLL and creates a write start timing. First, the channel bit offset register 30 inputs the number of channel bit clocks from the subcode sync clock to the write start position.

Thereafter, the address of the write start sector 1 is detected by the ATIP or SubQ code, and the value of the channel bit offset register is loaded into the 16-bit DOWN counter 31 at the first subcode sync, that is, the subcode sync of the write start sector.
When the 16-bit DOWN counter 31 is decremented by the channel bit PLL and becomes “0”, RC, that is, write start (write start) is output.

  In this way, it is possible to start writing accurately from the end of the last written data on the optical disc at a timing based on the count of the PLL of the channel bits, and the channel is the signal with the smallest error with respect to the written data. A write seam with small deviation can be formed with high accuracy by the PLL of the bit, and writing at the time of resumption after pausing data writing can be performed with high accuracy.

  Next, a description will be given of a write control process in which the frame sync signal is counted and the write timing is taken to start writing accurately from the end of the data written on the optical disc.

  FIG. 9 is a block diagram showing a circuit configuration example for creating a write timing based on the frame sync signal of the optical disc apparatus shown in FIG. 1, and FIG. 10 is a timing chart of the circuit shown in FIG.

  The circuit shown in FIG. 9 generates a write start timing by counting the frame sync clock. First, the frame offset register 40 inputs the number of frame sync clocks from the subcode sync clock to the frame sync of “Fr25”. The clock offset register 41 inputs the number of write reference clocks from the frame sync clock of “Fr25” to the write start position.

  After that, the address of the write start sector 1 is detected by the ATIP or SubQ code, and the value of the frame offset register is loaded into the 5-bit DOWN counter 42 at the first subcode sync, that is, the subcode sync of the write start sector. The value of the offset register is loaded into the 16-bit DOWN counter 31.

  Further, when the 5-bit DOWN counter 42 is decremented by the frame sync clock to “0”, the value of the clock offset register 41 is loaded into the 11-bit DOWN counter 43. When the 11-bit DOWN counter 43 is decremented by the write reference clock and becomes “0”, RC, that is, write start (write start) is output.

  In this way, it is possible to accurately start writing from the end of the data previously written to the optical disc at a timing based on the count of the frame sync signal, and the frame sync signal can be obtained by an inexpensive general-purpose decoder LSI. Therefore, the cost of the optical disk device can be reduced.

Next, a write control process when data transfer from the host is not in time for the optical disc apparatus of this embodiment will be described.
First, a description will be given of the processing when the data transfer from the host is not in time during data writing, and the writing is interrupted and the writing is resumed after receiving a sufficient amount.

FIG. 11 is a flowchart showing the data write control process.
In this process, start writing is performed at step (indicated by “S” in FIG. 1), the process proceeds to step 2, the disk is written, the process proceeds to step 3, the data is received from the host, the process proceeds to step 4, and the host data (host It is determined whether or not the amount of data transferred from (1) is small.

  If it is determined in step 4 that the amount of data from the host is not small, the process proceeds to step 5 to determine whether or not the data writing is completed. If the data writing is not completed, the process returns to step 2 to continue the data writing. If the writing is completed, the process proceeds to step 6 to stop write, and the process is terminated.

  If it is determined in step 4 that the amount of data from the host is small, the process proceeds to step 7 to pause write to interrupt writing to the optical disc, and proceeds to step 8 to receive data from the host and proceeds to step 9. It is determined whether or not the host data (data transferred from the host) has become full. If not, the process proceeds to step 8 and data reception from the host is continued. Restart writing is performed to resume writing to the optical disk, and the process returns to step 3 to continue the data writing process.

  Further, this process will be described. First, when the optical disk apparatus receives a write command and a certain amount of data from the host, it starts data writing (start writing). The start light is a normal write sequence starting from a link block, and repeats a predetermined length for writing to the optical disk and receiving data from the host.

  During data writing, if the data transfer speed is slower than the writing speed to the optical disk, the data in the buffer will decrease quickly and writing will not be continued. If it is determined that there is no, the pause light is executed. The pause light is a write sequence in which writing is temporarily suspended without writing a runout block.

  After that, sufficient data is received from the host and a restart write is executed. The restart write is a write sequence in which the continuity of the previous data is maintained without writing the link block, and the write is accurately written at the end of the previous data pit so as not to lose synchronization.

When a predetermined length is written, stop light is executed. The stoplight is a normal write sequence for writing a runout block.
In other words, this optical disc apparatus monitors the data amount of the buffer during the write sequence, and repeats pause write and restart write as needed to prevent writing failure due to buffer underrun.

  In this way, when the data transfer from the host is not in time during the writing of data to the optical disc, the data writing is temporarily stopped, and the data writing is resumed when the data is sufficiently sent from the host.

Therefore, even if the data transfer from the host is interrupted for a moment or the transfer rate is somewhat reduced, the data can be normally written to the optical disc in a plurality of times, and data writing failure can be prevented.
In addition, the capacity of the buffer RAM that absorbs the pulsation of data transfer can be reduced, and the cost of the optical disk can be reduced.

  Next, a description will be given of processing for interrupting writing when data transfer from the host is not in time during data writing, and restarting writing after reducing the writing speed.

FIG. 12 is a flowchart showing the data write control process.
In this process, start writing is performed at the maximum speed or the speed set by the host in step (indicated by “S” in FIG. 11), the process proceeds to step 12, the disk is written, the process proceeds to step 13, and data is received from the host. Proceeding to step 14, it is determined whether or not the host data (data transferred from the host) is small.

  If it is determined in step 14 that the amount of data from the host is not small, the process proceeds to step 15 to determine whether or not the data writing is completed. If the data writing is not completed, the process returns to step 12 to continue the data writing. If the writing is completed, the process proceeds to step 16 to stop write, and this process is terminated.

  If it is determined in step 14 that the amount of data from the host is small, the process proceeds to step 17 to pause write to interrupt writing to the optical disc, and proceeds to step 18 to receive data from the host and proceeds to step 19. It is determined whether or not the host data (data transferred from the host) is full.

  If it is not full at step 19, the process proceeds to step 18 and data reception from the host is continued. If it is full, the process proceeds to step 20 and if it is not the minimum speed, the speed is decreased by one step. The process proceeds to, restart writing to resume writing to the optical disk, and the process returns to step 13 to continue the data writing process.

Further, this process will be described.
First, when the optical disk device receives a write command and a certain amount of data from the host, it starts data writing (start write). At this time, at the speed set by the host or if there is no setting, the optical disk device has the maximum speed. Run the start light. The start light is a normal write sequence starting from a link block, and repeats a predetermined length for writing to the optical disk and receiving data from the host.

  During data writing, if the data transfer speed is slower than the writing speed to the optical disk, the data in the buffer will decrease quickly and writing will not be continued. If it is determined that there is no, the pause light is executed. The pause light is a write sequence in which writing is temporarily suspended without writing a runout block.

  When the data writing is interrupted, if the speed is not the minimum speed, the writing speed is lowered by one step, data is received from the host, and a restart write is executed. The restart write is a write sequence in which the continuity of the previous data is maintained without writing the link block, and the write is accurately written at the end of the previous data pit so as not to lose synchronization.

Thereafter, when the data transfer from the host is not in time again, the data writing is interrupted, the data writing speed is further reduced, and the restart writing is performed.
When a predetermined length is written, stop light is executed. The stoplight is a normal write sequence for writing a runout block.

  In this way, when data transfer from the host is not in time during the writing of data to the optical disk, the data writing is temporarily stopped, and the data writing is resumed after the data writing speed to the optical disk is reduced.

Therefore, this optical disk device automatically changes to the data writing speed suitable for the data transfer from the host and continues writing. Therefore, to prevent writing failure due to buffer underrun, pause and restart writes are performed many times. Repetitive writing processing can be prevented from taking a long time.
In addition, it is not necessary for the user to constantly check the data transfer capability of the host and the writing speed of the optical disk apparatus, so that the operability can be improved, and data writing can be performed making the best use of the capability of the host.

In the optical disk device of this embodiment, buffer underrun can be avoided, and data can be written so that write data can be normally read as continuous data. Therefore, the reliability of data writing can be improved.
Further, the user can safely write data to the optical disc without worrying about the performance of the host. Therefore, the operability at the time of data writing can be improved.

1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment of the present invention. It is a figure which shows the format of the data writing unit of CD-R and CD-R / E prescribed | regulated by the orange book. FIG. 3 is a diagram showing an example of a format when data is written in a plurality of times for the user data block shown in FIG. 2. FIG. 2 is a block diagram showing a circuit configuration example for performing data write control according to the present invention of the optical disc apparatus shown in FIG. 1.

It is a figure which shows the positional relationship of the writing end of data on the optical disk prescribed | regulated to the orange book, and a writing start. It is a figure which shows the example of formation of the joint on the optical disk by the optical disk apparatus shown in FIG. FIG. 7 is a block diagram showing a circuit configuration example for creating the joint formation write timing shown in FIG. 6 of the optical disc apparatus shown in FIG. 1. FIG. 8 is a timing chart of the circuit shown in FIG. 7.

FIG. 2 is a block diagram showing a circuit configuration example for creating a write timing based on a frame sync signal of the optical disc apparatus shown in FIG. 1. FIG. 10 is a timing chart of the circuit shown in FIG. 9. 3 is a flowchart showing a data write control process when data transfer from a host is not in time for the optical disc apparatus shown in FIG. 10 is a flowchart showing another data write control process when data transfer from the host is not in time for the optical disc apparatus shown in FIG.

Explanation of symbols

1: Optical disk 2: Spindle motor 3: Motor driver 4: Servo 5: Optical pickup 6: Read amplifier 7: CD decoder 8: CD-ROM decoder 9: Buffer manager 10: Buffer RAM 11: ATPI / SCSI interface 12: D / A converter 13: ATIP decoder 14: CD encoder 15: CD-ROM encoder 16: Laser control circuit 17: CPU 18: ROM 19, 21, 22: RAM 20: CIRC encoder 30: Channel bit offset register 31: 16-bit DOWN counter 40: Frame offset register 41: Clock offset register 42: 5-bit DOWN counter 43: 11-bit DOWN counter Unta

Claims (5)

A host and an optical disk device for recording data on the optical disk;
The host transfers a write command and data to the optical disk device,
When the optical disk apparatus receives the write command and a predetermined amount of data, the optical disk apparatus writes data in a user data block in which a link block, a run-in block, a run-out block and a run-out block are respectively provided to the optical disk. The system is characterized in that, when data transfer from the host is not in time during data writing, the writing is temporarily suspended without writing a run-out block during data recording on the optical disc.   2. The optical disc apparatus according to claim 1, wherein when resuming data writing, the data writing is performed without maintaining the continuity of data by CIRC demodulation at the end point and the start point of the data writing without writing the link block. system.   3. The system according to claim 1, wherein the optical disk device includes a buffer RAM, and the predetermined amount of data is data that fills the buffer RAM.   The system according to any one of claims 1 to 3, wherein the optical disc apparatus writes the run-out block after data has been written to a predetermined length.   The optical disk device stores an encoder that encodes data received from the host and, when the writing is temporarily interrupted, interrupts the encoding operation by the encoder and continues to write data to the optical disk when resuming data writing during encoding. 5. The system according to claim 1, further comprising:

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