Patent Publication Number: US-2007104053-A1

Title: Method for controlling an optical disc drive to resume interrupted recording on an optical disc, circuit thereof, and optical disc drive capable of resuming interrupted recording on an optical disc

Description:
BACKGROUND  
      The present invention relates to optical disc drives, and more particularly, to methods for controlling an optical disc drive to resume interrupted recording on an optical disc, circuits thereof, and optical disc drives capable of resuming interrupted recording on an optical disc.  
      According to the related art, resuming interrupted recording on an optical disc, for example, a Digital Versatile Disc (DVD) such as a DVD-Recordable (DVD-R) or a DVD-Rewritable (DVD-RW), is typically implemented by sync detection of a reproduced signal such as a Radio Frequency (RF) signal which represents data read from the optical disc. According to the sync detection, the number of syncs, for example, the number of frame syncs or the number of sub code syncs, can be counted to generate at least one counter value. When the counter value mentioned above matches a corresponding counter value generated during a writing procedure previously interrupted, i.e., the interrupted location is detected, the interrupted recording can be resumed. Please refer to U.S. Pat. No. 6,198,707 and U.S. Pat. No. 6,252,838 for related information.  
     SUMMARY  
      It is an objective of the claimed invention to provide methods for controlling an optical disc drive to resume interrupted recording on an optical disc, circuits thereof, and optical disc drives capable of resuming interrupted recording on an optical disc.  
      An exemplary embodiment of a method for controlling an optical disc drive to resume interrupted recording on an optical disc comprises: when the recording of a first recording unit block (RUB) is interrupted, storing an address of the first RUB and storing a first value corresponding to the number of recorded sets of data of the first RUB; according to the address of the first RUB, searching a pseudo-recording start position corresponding to a recorded set of data of a specific RUB which is either the first RUB or a second RUB that is recorded on the optical disc prior to the first RUB; re-encoding at least a portion of raw data corresponding to recorded sets of data on the optical disc and performing pseudo-recording from the pseudo-recording start position without physically writing on the optical disc until a second value corresponding to the pseudo-recording start position and a current pseudo-recording position matches a target value corresponding to the first value and the pseudo-recording start position; and physically writing on the optical disc when the second value matches the target value to resume recording the first RUB.  
      An exemplary embodiment of a circuit for controlling an optical disc drive to resume interrupted recording on an optical disc comprises: a processor for performing recording control of the optical disc drive, when the recording of a first RUB is interrupted, the processor storing an address of the first RUB and storing a first value corresponding to the number of recorded sets of data of the first RUB, wherein according to the address of the first RUB, the processor controls an optical pickup of the optical disc drive to search a pseudo-recording start position corresponding to a recorded set of data of a specific RUB which is either the first RUB or a second RUB that is recorded on the optical disc prior to the first RUB; a data encoder coupled to the processor for re-encoding at least a portion of raw data corresponding to recorded sets of data on the optical disc and performing pseudo-recording from the pseudo-recording start position until a second value corresponding to the pseudo-recording start position and a current pseudo-recording position matches a target value corresponding to the first value and the pseudo-recording start position; and a laser control circuit coupled to the data encoder for driving the laser of the optical pickup; wherein the laser control circuit controls the optical pickup to prevent physically writing on the optical disc until the second value matches the target value, and controls the optical pickup to physically write on the optical disc when the second value matches the target value to resume recording the first RUB.  
      An exemplary embodiment of an optical disc drive capable of resuming interrupted recording on an optical disc comprises: an optical pickup for accessing the optical disc; a processor for performing recording control of the optical disc drive, when the recording of a first RUB is interrupted, the processor storing an address of the first RUB and storing a first value corresponding to the number of recorded sets of data of the first RUB, wherein according to the address of the first RUB, the processor controls the optical pickup to search a pseudo-recording start position corresponding to a recorded set of data of a specific RUB which is either the first RUB or a second RUB that is recorded on the optical disc prior to the first RUB; a data encoder coupled to the processor for re-encoding at least a portion of raw data corresponding to recorded sets of data on the optical disc and performing pseudo-recording from the pseudo-recording start position until a second value corresponding to the pseudo-recording start position and a current pseudo-recording position matches a target value corresponding to the first value and the pseudo-recording start position; and a laser control circuit coupled to the data encoder for driving the laser of the optical pickup; wherein the laser control circuit controls the optical pickup to prevent physically writing on the optical disc until the second value matches the target value, and controls the optical pickup to physically write on the optical disc when the second value matches the target value to resume recording the first RUB.  
      These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc according to one embodiment of the present invention.  
       FIG. 2  is a flowchart of a method for controlling an optical disc drive to resume interrupted recording on an optical disc according to one embodiment of the present invention.  
       FIG. 3  illustrates details of Step  916  shown in  FIG. 2 .  
       FIG. 4  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc according to one embodiment of the present invention.  
       FIG. 5  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc according to one embodiment of the present invention.  
       FIG. 6  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc according to one embodiment of the present invention.  
    
    
      Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, consumer electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.  
     DETAILED DESCRIPTION  
      Please refer to  FIG. 1 .  FIG. 1  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc  1  according to one embodiment of the present invention, where the optical disc drive comprises a loader comprising an optical pickup (OPU)  2  and a spindle motor  6 , and a circuit  100 B, which is positioned in the optical disc drive and utilized for controlling the optical disc drive to resume interrupted recording on the optical disc  1 . According to the present invention, the optical disc can be a Compact Disc (CD), a Digital Versatile Disc (DVD), a High Density DVD (HD-DVD), or a Blu-ray disc (BD), and the optical disc drive can be a corresponding disc drive capable of accessing the optical disc, e.g., a CD drive, a DVD drive, a HD-DVD drive, or a BD drive. In this embodiment, the optical disc  1  is a DVD such as a DVD-Recordable (DVD-R) or a DVD-Rewritable (DVD-RW), and the optical disc drive is a DVD drive accordingly. As shown in FIG.  1 , the circuit  100 B comprises a read amplifier  3 , a data decoder  4 , a servo circuit  7 , a data encoder  14 , a laser control circuit  16 , a wobble address decoder  18 , a processor  20 , a buffer manager  22 , and a buffer RAM  24 , where the buffer manager  22  is coupled to a host  80  such as a personal computer (PC). Please note that the architecture of the processor  20  can be replaced with a plurality of processors for performing the same functionalities according to another embodiment of the present invention.  
      In a read procedure of the optical disc drive, a read channel is involved, where the read channel typically comprises the read amplifier  3  and the data decoder  4 . The read amplifier  3  is capable of amplifying a reproduced signal outputted from the OPU  2  to correspondingly generate an amplified signal, where the reproduced signal represents data read from the optical disc  1 . The data decoder  4  is capable of decoding the data according to the amplified signal, and deriving logical addresses such as sector IDs. The servo circuit  7  performs servo control for the OPU  2  and the spindle motor  6 . The wobble address decoder  18  is utilized for deriving physical addresses such as ADIP addresses.  
      In a writing procedure of the optical drive, a writing channel is involved, where the writing channel typically comprises the data encoder  14  and the laser control circuit  16 . Data to be recorded on the optical disc  1  is transferred from the host  80  through the buffer manager  22  to the buffer RAM  24  and temporarily stored in the buffer RAM  24 . In addition, the buffer manager  22  is capable of transferring the data stored in the buffer RAM  24  to the data encoder  14  if needed. The data encoder  14  encodes the data stored in the buffer RAM  24  to generate encoded data. According to the encoded data, the laser control circuit  16  may control the writing power of the laser emitted from the OPU  2  or control the OPU  2  to emit laser or not, in order to record the encoded data on the optical disc  1 .  
      During the writing procedure, if the speed that the buffer RAM  24  buffers the data from the host  80  is lower than the encoding speed of the data encoder  14 , that means the data transfer rate (which is also referred to as the data rate) between the host  80  and the buffer RAM  24  is less than the data transfer rate between the buffer RAM  24  and the data encoder  14 . In order to prevent the data in the buffer RAM  24  from being used up by the data encoder  14 , when an amount of the data in the buffer RAM  24  is less than a first predetermined value, the buffer manager  22  notifies the processor  20  that buffer under-run would occur. As a result, the processor  20  interrupts the writing procedure to prevent from a failure of the writing procedure. Additionally, when the amount of the data in the buffer RAM  24  becomes greater and reaches a second predetermined value (which is typically greater than the first predetermined value), the buffer manager  22  notifies the processor  20  that the data amount is enough for safely resuming the writing procedure. As a result, the processor  20  resumes the writing procedure.  
      Similarly, when another interruptive event such as external mechanical shock is detected, the processor  20  also interrupts the writing procedure to prevent from a failure of the writing procedure. When the interruptive event is removed, the processor  20  resumes the writing procedure.  
       FIG. 2  is a flowchart of a method  900  for controlling an optical disc drive to resume interrupted recording on an optical disc according to one embodiment of the present invention, where  FIG. 3  illustrates details of Step  916  shown in  FIG. 2 . The method  900  can be applied to the architecture shown in  FIG. 1 , and described as follows. According to this embodiment, the processor  20  performs not only the writing control comprising the recording control but also the read control of the optical disc drive mentioned above. The processor  20  controls the optical disc drive to execute Step  902 , i.e., start writing while receiving data from the host  80 , and execute Step  904  to check if any interruptive event such as buffer under-run or external mechanical shock is detected. In a normal condition, which is not completely shown in  FIG. 2  for simplicity, the writing procedure is stopped if data transfer is completed. In an abnormal condition as shown in  FIG. 2 , if any interruptive event mentioned above is detected, Step  906  is entered, so the processor  20  controls the optical disc drive to check if data transfer is completed. Here, if data transfer is completed, Step  908  is entered, so the processor  20  controls the optical disc drive to stop writing. On the other hand, if data transfer is not completed, Step  910  is entered, so the processor  20  controls the optical disc drive to execute the working flow comprising Steps  910 ,  912 ,  914 , and  916 , and then reenter Step  904 .  
      If the recording of a recording unit block (RUB) such as a sector or an Error Correction Code (ECC) block is interrupted, the RUB is also referred to as an interrupted RUB. It is important to store information related to the location where the RUB is interrupted, in order to resume writing in Step  916 . According to this embodiment, while controlling the optical disc drive to pause writing in Step  910 , the processor  20  stores an address of the interrupted RUB and may further store a value V 1  and output a target value (V 1 −L), where either the value V 1  or the target value (V 1 −L) is corresponding to the number of recorded sets of data of the interrupted RUB. The value L (which is zero for an ideal case without any signal delay) is a constant representing a hardware latency. According to the present invention, the address can be a physical address such as an ADIP address of the interrupted RUB, or a logical address such as a sector ID of the interrupted RUB. Additionally, the address stored by the processor  20  typically corresponds to the beginning of the interrupted RUB.  
      According to a loop comprising Step  912  and Step  914  shown in  FIG. 2 , the processor  20  controls the optical disc drive to wait for removal of the interruptive event. If the removal of the interruptive event is detected in Step  914 , enter Step  916 ; otherwise, reenter Step  912 .  
      In the present invention, we may call the interrupted RUB mentioned above the interrupted RUB Ri. According to the address of the interrupted RUB Ri, the processor  20  typically controls the OPU  2  to search a pseudo-recording start position corresponding to a recorded set of data of a specific RUB Rs which is either the interrupted RUB Ri or a RUB Rp that is recorded on the optical disc  1  prior to the interrupted RUB Ri. In this embodiment, to search out the pseudo-recording start position, the pseudo-recording start position is first determined according to the address of the interrupted RUB Ri and searching the pseudo-recording start position is performed later.  
      In Step  922 , as shown in  FIG. 3 , the data encoder  14  firstly clears a First In First Out (FIFO) memory therein, in order to perform re-encoding from a recorded set of data corresponding to a head position of a RUB that had been recorded onto the optical disc  1 . The outset of the re-encoding process may correspond to a head position of a recorded RUB, e.g., the specific RUB Rs, which could be either the interrupted RUB Ri or the RUB Rp that had been recorded prior to the interrupted RUB Ri.  
      In Step  924 , according to the address of the interrupted RUB Ri, the processor  20  determines the pseudo-recording start position corresponding to the recorded set of data of the specific RUB Rs (which is either the interrupted RUB Ri or the RUB Rp that is recorded on the optical disc  1  prior to the interrupted RUB Ri).  
      In Step  926 , the data encoder  14  reloads information related to the pseudo-recording start position, for example, the modulation state(s), and a DSV value corresponding to the pseudo-recording start position. Some other information such as a certain value of the rotational speed can be reloaded in this step, in order to perform pseudo-recording utilizing the same rotational speed of the optical disc  1  as that utilized before the recording of the interrupted RUB Ri was interrupted.  
      In Step  928 , the data encoder  14  re-encodes at least a portion of raw data corresponding to recorded sets of data on the optical disc  1 .  
      In Step  930 , the processor  20  controls the OPU  2  to search the pseudo-recording start position. Once the pseudo-recording start position is found, the optical disc drive may perform pseudo-recording from the pseudo-recording start position, where the pseudo-recording start position typically corresponds to the beginning of the specific RUB Rs, i.e., the beginning of the interrupted RUB Ri or the beginning of the RUB Rp. Please note that performing pseudo-recording means performing recording operations without physically writing on the optical disc. For example, the power of the laser can be temporarily turned off, disabled, or blocked, so although the recording operations is performed, no data is actually written on the optical disc and no data on the optical disc is altered during pseudo-recording.  
      In Step  932 , when the pseudo-recording start position is searched, the data encoder  14  performs pseudo-recording from the pseudo-recording start position without physically writing on the optical disc  1  until a value V 2  matches the target value (V 1 −L), where the value V 2  corresponds to the pseudo-recording start position and a current pseudo-recording position (e.g., a real position of the OPU  2 ), and more specifically, corresponds to the number of pseudo-recorded sets of data or the number of re-encoded sets of data. Additionally, the value L can be considered zero if the hardware latency is negligible. It is noted that the value L corresponds to a difference between an ideal location of the pseudo-recording start position and a real location of the OPU  2  when the data decoder  4  or the wobble address decoder  18  detects out the pseudo-recording start position. If the hardware latency is negligible, the target value (V 1 −L) can be replaced with the value V 1  in related descriptions hereafter. The laser control circuit  16  can be utilized for driving the laser of the OPU  2 . Here, in this step, the laser control circuit  16  controls the OPU  2  to prevent physically writing on the optical disc until the value V 2  matches the target value (V 1 −L).  
      In Step  934 , the laser control circuit  16  controls the OPU  2  to physically write on the optical disc  1  when the value V 2  matches the target value (V 1 −L) to resume recording the interrupted RUB Ri.  
      It is noted that the value V 1  can be the number of recorded sets of data of the interrupted RUB, and the value V 2  can be the number of pseudo-recorded sets of data or the number of re-encoded sets of data, where the number of pseudo-recorded sets of data is typically equal to the number of re-encoded sets of data. In this situation, the criterion that the value V 2  matches the target value (V 1 −L) means the number of pseudo-recorded sets of data or the number of re-encoded sets of data matches the number of recorded sets of data of the interrupted RUB Ri. Here, if the specific RUB Rs is the interrupted RUB Ri, checking whether the value V 2  matches the target value (V 1 −L) typically means checking whether the value V 2  is equal to the target value (V 1 −L). On the other hand, if the specific RUB Rs is the RUB Rp, checking whether the value V 2  matches the target value (V 1 −L) typically means checking whether the value V 2  is equal to another target value being the target value (V 1 −L) plus an offset value representing the offset between the RUB Ri and the RUB Rp. In detail, if the number of sets of data in one RUB is equal to M, and if the offset between the RUB Ri and the RUB Rp is equal to N RUB(s), where N is a positive integer, then the offset value is equal to (M*N), and therefore, checking whether the value V 2  matches the target value (V 1 −L) typically means checking whether the value V 2  is equal to the target value (V 1 +M*N−L).  
      According to the present invention, different kinds of RUBs can be involved, where each set of data within one RUB represents a sub-unit within the RUB. If the optical disc is a CD, each of the RUBs can be defined as a sector. In addition, if the optical disc is a DVD or a HD-DVD, each of the RUBs can be defined as a sector or an ECC block. Additionally, if the optical disc is a BD, each of the RUBs can be defined as a sector or a cluster.  
       FIG. 4  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc according to one embodiment of the present invention, where the data encoder  14  shown in  FIG. 1  is replaced with another data encoder  14 - 1 , and the processor  20  shown in  FIG. 1  is replaced with another processor, the recording control unit  20 - 1 . The recording control unit  20 - 1  controls the data encoder  14 - 1  to perform data encoding via the buffer manager  22 . The external encoder  32  reads data from the buffer RAM  24  under the control of the buffer manager  22  and additionally provides an ID error detection (IED) code and an error detection code (EDC), conducts a scramble operation, and provides an outer code ECC, and then writes the result on the buffer RAM  24 . The internal encoder  34 - 1  reads the data from the buffer RAM  24  under the control of the buffer manager  22  and additionally provides the inner error correction code, conducts an interleave operation, and further conducts the eight-to-sixteen modulation for the data to output. According to the present invention, the counter  36  can be positioned inside or outside the internal encoder  34 - 1 . In this embodiment, the counter  36  can be utilized for counting the value V 2  corresponding to the number of re-encoded sets of data. In particular, in this embodiment, the specific RUB Rs is the interrupted RUB Ri, the value V 1  is the number of recorded sets of data of the interrupted RUB Ri, and the value V 2  is the number of re-encoded sets of data.  
      Accordingly, the comparator  38  compares the value V 2  outputted from the counter  36  and the target value (V 1 −L) outputted from the recording control unit  20 - 1 . The FIFO memory  40 - 1  shown in  FIG. 4  is utilized for buffering encoded data C e  outputted from the internal encoder  34 - 1  together with the corresponding comparison result F e  outputted from the comparator  38 . As shown in  FIG. 4 , the encoded data C e  and the comparison result F e  are temporarily stored in the FIFO memory  40 - 1  and outputted to be the encoded data C r  and the comparison result F r , respectively. A recorder  42 - 1  is utilized for retrieving encoded data C r  from the FIFO memory  40 - 1  and converting the encoded data C r  into the non-return-to-zero-inverted (NRZI) format for recording. The recorder  42 - 1  is also utilized for performing pseudo-recording according to the comparison result F r , i.e., the comparison result F e  retrieved from the FIFO memory  40 - 1 . In this embodiment, the comparison result F r  may indicate whether the value V 2  is equal to the target value (V 1 −L), so the recorder  42 - 1  will be notified if the value V 2  is equal to the target value (V 1 −L). Therefore, the laser control circuit  16  may control the OPU  2  whether to physically write on the optical disc  1  according to the comparison result F r , i.e., the comparison result F e  retrieved from the FIFO memory  40 - 1 .  
      It is noted that in a normal condition of the writing procedure, the recording control unit  20 - 1  may control the recorder  42 - 1  through a direct connection as shown in  FIG. 4 , where the direct connection (which can be a single wire or a plurality of wires) is also utilized during the transition from the normal condition to an abnormal condition such as that shown in  FIG. 2 . For example, while controlling the recorder  42 - 1  to pause writing in Step  910 , the recording control unit  20 - 1  stores the address of the interrupted RUB Ri and stores the value V 1  corresponding to the number of recorded sets of data of the interrupted RUB Ri, where the recording control unit  20 - 1  may simply store the target value (V 1 −L) rather than the value V 1 . Additionally, in the normal condition, flags such as the comparison result F r  or the comparison result F e  shown in  FIG. 4  are not needed, so after Step  916 , the counter  36  and the comparator  38  can be disabled.  
      In a variation of the embodiment shown in  FIG. 4 , while controlling the recorder  42 - 1  to pause writing in Step  910 , the recording control unit  20 - 1  stores the address of the interrupted RUB Ri and stores a plurality of values corresponding to the number of recorded sets of data of the interrupted RUB Ri. For example, if the optical disc is a DVD and each of the RUBs is defined as an ECC block, the recording control unit  20 - 1  may store the number of recorded sectors, the number of recorded codewords (sync frames) on the optical disc posterior to the recorded sectors mentioned above, and the number of recorded bytes on the optical disc posterior to the recorded codewords (sync frames) mentioned above. In another variation similar to the variation mentioned above, if the optical disc is a DVD and each of the RUBs is defined as a sector, the recording control unit  20 - 1  may store the number of recorded codewords (sync frames), and the number of recorded bytes on the optical disc posterior to the recorded codewords (sync frames) mentioned above.  
       FIG. 5  is a diagram of an optical disc drive capable of resuming interrupted recording on an optical disc according to one embodiment of the present invention, where the data encoder  14  shown in  FIG. 1  is replaced with another data encoder  14 - 2 , the laser control circuit  16  shown in  FIG. 1  is replaced with another laser control circuit  16 - 2 , and the processor  20  shown in  FIG. 1  is replaced with another processor, the recording control unit  20 - 2 . In order to prevent confusion between what the counter  36  counts in the embodiment shown in  FIG. 4  and what the counter  36  counts in the embodiment shown in  FIG. 5 , the value V 2  outputted from the counter  36  is replaced with a value V 3 . The internal encoder  34 - 2  performs internal encoding of the RUBs according to control of the recording control unit  20 - 2 . Similar to the embodiment shown in  FIG. 4 , the FIFO memory  40 - 2  is utilized for buffering the encoded data C e  outputted from the internal encoder  34 - 2 , where the encoded data C e  is temporarily stored in the FIFO memory  40 - 2  and outputted to be the encoded data C r . The recorder  42 - 2  is utilized for performing pseudo-recording. According to the present invention, the counter  36  can be positioned inside or outside the recorder  42 - 2 . In this embodiment, the counter  36  can be utilized for counting the value V 3  corresponding to the number of pseudo-recorded sets of data. In particular, in this embodiment, the specific RUB Rs is the interrupted RUB Ri, the value V 1  is the number of recorded sets of data of the interrupted RUB Ri, and the value V 3  is the number of pseudo-recorded sets of data.  
      Accordingly, the comparator  38  compares the value V 3  outputted from the counter  36  and the target value (V 1 −L) outputted from the recording control unit  20 - 2  to output a comparison result to the laser control circuit  16 - 2 . In this embodiment, the comparison result outputted from the comparator  38  may indicate whether the value V 3  is equal to the target value (V 1 −L), so the laser control circuit  16 - 2  will be notified if the value V 3  is equal to the target value (V 1 −L). Therefore, the laser control circuit  16 - 2  may control the OPU  2  whether to physically write on the optical disc  1  according to the comparison result outputted from the comparator  38 .  
      It is noted that in a normal condition of the writing procedure, the recording control unit  20 - 2  may control the recorder  42 - 2  through a direct connection as shown in  FIG. 5 , where the direct connection is also utilized during the transition from the normal condition to an abnormal condition such as that shown in  FIG. 2 . For example, while controlling the recorder  42 - 2  to pause writing in Step  910 , the recording control unit  20 - 2  stores the address of the interrupted RUB Ri and stores the value V 1  corresponding to the number of recorded sets of data of the interrupted RUB Ri, where the recording control unit  20 - 2  may simply store the target value (V 1 −L) rather than the value V 1 . Additionally, in the normal condition, the comparison result mentioned above is not needed, so after Step  916 , the counter  36  and the comparator  38  can be disabled.  
       FIG. 6  illustrates another embodiment of the present invention, where the data encoder  14  shown in  FIG. 1  is replaced with another data encoder  14 - 3 , the laser control circuit  16  shown in  FIG. 1  is replaced with another laser control circuit  16 - 3 , and the processor  20  shown in  FIG. 1  is replaced with another processor, the recording control unit  20 - 3 . The Operations of the buffer manager  22 , the buffer RAM  24 , the recording control unit  20 - 3 , and the laser control circuit  16 - 3  are similar to those in the embodiments shown in  FIG. 4  and  FIG. 5 , and are therefore not repeated in detail here. Within the data encoder  14 - 3 , the external encoder  32  comprises an ID+IED+CPR_MAI preparer  632 , an EDC affixer  634 ,a scrambler  636 , and a PO encoder  638 , and the internal encoder  34 - 3  comprises an interleaver  612 , a PI encoder  614 , a modulator  616 , an NRZ converter  618 , and an NRZI converter  620  comprising an exclusive-OR logic  622  and a 1-T delay unit  624 , where the delay introduced by the 1-T delay unit  624  is equal to one channel clock period.  
      The ID+IED+CPR_MAI preparer  632  prepares a 4-byte ID, calculates a 2-byte IED code, and further prepares a user-defined number in a 6-byte CPR_MAI field (which can be varied depending on different implementation choices) posterior to the 2-byte IED code. The EDC affixer  634  arranges the information data (which is transferred from the host  80 ) to be main information data posterior to the CPR_MAI field, where there are  2048  bytes in each data frame of the main information data. In addition, the EDC affixer  634  calculates a 4-byte EDC according to the ID, the IED code, and the CPR_MAI number (i.e., the user-defined number in the 6-byte CPR_MAI field) prepared by the ID+IED+CPR_MAI preparer  632  and according to the main information data mentioned above. Thus, the last data frame comprises 2064 bytes, which are the 4-byte ID, the 2-byte IED, the 6-byte CPR_MAI number, the 2048-byte main information data, and the 4-byte EDC. The 4-byte ID, the 2-byte IED, the 6-byte CPR_MAI number, and the 4-byte EDC are written into the buffer RAM  24  through the buffer manager  22 . The scrambler  636  scrambles the 2048-byte main information data in order to randomize the 2048-byte main information data. As a result, 16 continuously transmitted data frames form an ECC block after being scrambled. Additionally, the PO encoder  638  utilize an ECC block as a unit to generate Parity of Outer Code, and write the Parity of Outer Code into the buffer RAM  24  through the buffer manager  22 .  
      While reading the data of each ECC block from the buffer RAM  24  through the buffer manager  22 , the interleaver  612  interleaves one of the PO rows at a time after reading every  12  rows of the ECC block. The PI encoder  614  performs PI encoding on the data outputted from the interleaver  612 , and outputs PI-encoded data bytes. The modulator  616  performs 8-16 modulation on the PI-encoded data bytes, and adds a 32-bit sync pattern prior to every 91 data bytes generated by the modulator  616 . As a result, the NRZ converter  618  and the NRZI converter  620  perform NRZ conversion and NRZI conversion, in order to output 16 channel bits NRZI converted pulses as outputs of the data encoder  14 - 3 .  
      In order to prevent confusion between what the counter  36  counts in the embodiment shown in  FIG. 4  (or  FIG. 5 ) and what the counter  36  counts in the embodiment shown in  FIG. 6 , the value outputted from the counter  36  is replaced with a value V 4  in the embodiment shown in  FIG. 6 . The internal encoder  34 - 3  performs internal re-encoding of the RUBs according to control of the recording control unit  20 - 3 . The internal encoder  34 - 3  is also utilized for performing pseudo-recording. According to the present invention, the counter  36  can be positioned inside or outside the internal encoder  34 - 3 . In this embodiment, the counter  36  can be utilized for counting the value V 4  corresponding to the number of re-encoded sets of data of any encoding stage (e.g., the interleaver  612 , the PI encoder  614 , the modulator  616 , or the NRZ converter  618 ). In particular, in this embodiment, the specific RUB Rs is the interrupted RUB Ri, the value V 1  is the number of recorded sets of data of the interrupted RUB Ri, and the value V 4  is the number of re-encoded sets of data of any encoding stage.  
      Accordingly, the comparator  38  compares the value V 4  outputted from the counter  36  and the target value (V 1 −L) outputted from the recording control unit  20 - 3  to output a comparison result to the laser control circuit  16 - 3 . In this embodiment, the comparison result outputted from the comparator  38  may indicate whether the value V 4  is equal to the target value (V 1 −L), so the laser control circuit  16 - 3  will be notified if the value V 4  is equal to the target value (V 1 −L). Therefore, the laser control circuit  16 - 3  may control the OPU  2  whether to physically write on the optical disc  1  according to the comparison result outputted from the comparator  38 .  
      It is noted that in a normal condition of the writing procedure, the recording control unit  20 - 3  may control the internal encoder  34 - 3  and the laser control circuit  16 - 3  through a direct connection as shown in  FIG. 6 , where the direct connection is also utilized during the transition from the normal condition to an abnormal condition such as that shown in  FIG. 2 . For example, while controlling the internal encoder  34 - 3  to pause encoding and recording, and the laser control circuit  16 - 3  to pause writing in Step  910 , the recording control unit  20 - 3  stores the address of the interrupted RUB Ri and stores the value V 1  corresponding to the number of recorded sets of data of the interrupted RUB Ri, where the recording control unit  20 - 3  may simply store the target value (V 1 −L) rather than the value V 1 . Additionally, in the normal condition, the comparison result mentioned above is not needed, so after Step  916 , the counter  36  and the comparator  38  can be disabled.  
      According to the present invention, even if the interrupted location is not precisely located, i.e., there exists a linking gap or a linking overlap at the linking area on the optical disc  1  after Step  916 , it will not degrade the performance of the optical disc drive. The linking gap or the linking overlap is typically smaller than one or more sub-units within a RUB, so different error correction algorithms can be utilized for covering the error(s) due to the linking gap or the linking overlap.  
      Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.