JP3444277B2 - Playback device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus capable of reproducing data such as music from a disc-shaped recording medium.

[0002]

2. Description of the Related Art A CD player is known as a reproducing apparatus capable of reproducing music data and the like from an optical disk, and a data rewritable magneto-optical disk which allows a user to record music data and the like is used. A mini disk player is known as a reproducing device. In a reproducing device using such a disk medium, a device having an improved anti-vibration function is realized especially by using a buffer RAM.

That is, at the time of reproduction, the audio data read from the disk is intermittently written into the buffer RAM at a high speed, while the audio data is continuously read from the buffer RAM at a low speed and demodulated as an audio reproduction signal. To go. At this time, a certain amount of data is constantly stored in the buffer RAM, so even if a track jump occurs due to external vibration, etc., and data reading from the disk is temporarily interrupted, the buffer RAM will not The audio data can be continuously read, and the reproduced audio is output without interruption.

Taking the minidisc system as an example, the recording tracks on the magneto-optical disc are shown in FIG.
As shown in (a) and (b), 4 sectors (1 sector = 235
2 bytes sub data area and 32 sectors (SC0-S
Cluster CL (= C31) main data area
36 sectors) are continuously formed, and one cluster is the minimum unit for recording. This 1 cluster is 2
Corresponds to 3 rounds of tracks. The address is recorded for each sector. The sub-sector area of 4 sectors is used as sub-data and linking area.
Recording of TOC data, audio data, etc. is performed in the main data area of 32 sectors.

The area of the music data recorded in each sector is further subdivided into sound groups, and two sectors are divided into 11 sound groups. That is,
The even sectors (SC0, SC2,
..) are configured as shown in FIG. 18C, and odd-numbered sectors (SC1, SC3, S in FIG.
..) is configured as shown in FIG. As shown in FIGS. 18 (c) and 18 (d), each sector is provided with a header in which the synchronization pattern SYNC and the address AD are recorded, followed by a sub-header. Then, actual audio data is recorded following the subheader. A sound frame SF of 212 bytes is used as the minimum data unit for recorded audio data, and 1 is set for each sector.
Contains one sound frame. One sound frame is data obtained by compressing an audio signal for 11.6 msec for the L or R channel.

Here, in the even-numbered sectors, the L channel sound frame SF _(L0) , the R channel sound frame SF _(R0) , the L channel sound frame SF _(L1) ,. , R channels are recorded alternately, and sound frames S of L channel are recorded.
Up to F _(L5) is recorded. On the other hand, the odd-numbered sectors are recorded alternately with the R-channel sound frame SF _(R5) , the L-channel sound frame SF _(L6) , and the R-channel sound frame SF _(R6). Sound frames up to SF _(R10) are recorded.

Then, one sound group (SG0 to SG10) is constituted by the pair of L and R sound frames. Therefore, the first half of the sound groups SG0 to SG4 and the sound group SG5 are recorded in the even-numbered sector, and the second half of the sound group SG5 to the sound group 10 are recorded in the odd-numbered sector. Will be recorded.

When the data recorded in such a format on the disc is recorded / reproduced through the buffer RAM, the buffer RAM stores the data in sector units. That is, the sector address and the byte address in the sector (0 to 2351 bytes) are combined to generate an access address, and writing and reading are executed.

[0009]

By the way, the data once stored in the buffer RAM is read out again in sector units and supplied to the decoder in the subsequent stage, and for example, the decoding process for the audio compression process is executed and the two channels of L and R channels are processed. Although it is output as reproduced audio, as can be seen from the above-mentioned sector format, when the even sector data is transferred to the decoder, it is transferred in order from the L channel data (sound frame SF _(L0) ). , When the data of the odd sector is transferred to the decoder, the data of the R channel (sound frame SF _(R5) ) is transferred in order, that is, the transfer order of L and R is reversed between the even sector and the odd sector. It has become.

Buffer RAM in each sector in the correct order
When writing / reading is performed and the read data is being transferred to the decoder, L and R data are always transferred alternately in sound frame units. There is no. In other words, the decoder performs decoding processing for expanding the compressed data into audio data of 11.6 msec for each captured sound frame, and outputs the data alternately as L channel data / R channel data. If the sound frames are correctly and alternately supplied, the L channel sound frame is used as it is as the L channel audio data, and
A channel sound frame can be output as R channel audio data.

However, due to errors such as mistakes in the reading and writing of sector data in the buffer RAM, and errors in processing during transfer, for example, even sector data is transferred subsequent to even sector data. When such a situation occurs, a transfer error occurs that the data of the L channel is continuous. For example, when the alternate transfer state of the L and R sound frames cannot be maintained due to such a situation, the decoder outputs the decoded data of the L channel sound frame data as the R channel audio data, and vice versa. The decoded data of the sound frame data of the R channel is output as the sound data of the L channel. That is, a phase change of the reproduced sound LR occurs, and so-called stereo sound localization shift occurs.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a reproducing apparatus which eliminates the occurrence of localization deviation of output sound.

For this reason, the digital signal is divided into blocks of a predetermined length to form sectors, and an odd number of sound groups are formed by even-numbered and odd-numbered sectors in the sector and recorded on the recording medium. In a reproducing device for reproducing a signal, reproducing means for reproducing a digital signal from the recording medium, memory means for temporarily storing the digital signal reproduced by the reproducing means in sector units, and once stored in the memory means Demodulating means for reading and demodulating the digital signal in the sector unit,
Discriminating means for discriminating whether the sector stored in the memory means is an even-numbered sector or an odd-numbered sector when the digital signal is written in the memory means in the sector unit, and the memory means based on the discrimination result of the discriminating means. And a memory control means for storing in the memory means by adding an identifier for identifying an even sector or an odd sector to the sector stored in.

Further, when the digital signal is read from the memory means in units of the sector, the identifier is read from the memory means, and it is determined whether the sector read from the memory means is an even sector or an odd sector based on the identifier. And a control means for controlling the demodulation timing of the demodulation means based on the discrimination result of the discrimination means.

Further, digital data of a plurality of channels is time-division multiplexed and recorded in each sector,
It is assumed that the head of the even sector starts from the digital data of one of the plurality of channels, and the head of the odd sector starts from the digital data of the other of the plurality of channels. Further, the sound group is assumed to be composed of 2-channel digital audio data.

[0016]

If the demodulating means can identify whether the sector supplied from the memory means is an even sector or an odd sector, it can identify whether the leading digital data of the sector is the L channel or the R channel. Therefore,
The decoded data in the data unit of the L channel can be output as the L channel without error, and the decoded data in the data unit of the R channel can be output as the R channel.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording / reproducing apparatus using a magneto-optical disk as a recording medium will be described below as an example of the reproducing apparatus of the present invention with reference to FIGS. 1. 1. Configuration of recording / reproducing apparatus P-TOC sector 3. U-TOC sector 4. Data sector 5. Area configuration of buffer RAM 6. Configuration of memory controller 7. 7. Write / read operation for buffer RAM 8. Operation of supplying channel identification signal from memory controller to decoder Various embodiments as channel identification signals

<1. Configuration of Recording / Reproducing Apparatus> FIG. 1 is a block diagram of a main part of the recording / reproducing apparatus. In FIG. 1, reference numeral 1 denotes a magneto-optical disk on which audio data is recorded, for example, which is rotationally driven by a spindle motor 2. An optical head 3 irradiates the magneto-optical disk 1 with a laser beam during recording / reproduction, which provides a high level laser output for heating the recording track to the Curie temperature during recording, and the magnetic Kerr effect during reproduction. It provides a relatively low level laser power for detecting data from reflected light.

Therefore, the optical head 3 is equipped with a laser diode as a laser output means, an optical system including a polarization beam splitter and an objective lens, and a detector for detecting reflected light. The objective lens 3a is held by the biaxial mechanism 4 so as to be displaceable in the disc radial direction and the direction in which the disc moves toward and away from the disc.

Reference numeral 6a denotes a magnetic head for applying a magnetic field modulated by the supplied data to the magneto-optical disk, and is arranged at a position facing the optical head 3 with the magneto-optical disk 1 interposed therebetween. The entire optical head 3 and the magnetic head 6a are movable in the disk radial direction by the sled mechanism 5.

Information detected from the magneto-optical disk 1 by the optical head 3 by the reproducing operation is supplied to the RF amplifier 7. The RF amplifier 7 calculates the supplied information by reproducing RF signals, tracking error signals, focus error signals, and absolute position information (absolute position information recorded as pregrooves (wobbling grooves) on the magneto-optical disk 1). Address information, focus monitor signal, etc. are extracted. Then, the extracted reproduction RF signal is supplied to the encoder / decoder unit 8. The tracking error signal and the focus error signal are supplied to the servo circuit 9, and the address information is supplied to the address decoder 10. Further, the absolute position information and the focus monitor signal are supplied to the system controller 11 configured by, for example, a microcomputer.

The servo circuit 9 generates various servo drive signals according to the supplied tracking error signal, focus error signal, track jump command, seek command from the system controller 11, rotational speed detection information of the spindle motor 2, etc. Shaft mechanism 4 and sled mechanism 5
To perform focus and tracking control, and control the spindle motor 2 to a constant angular velocity (CAV) or a constant linear velocity (CLV).

The reproduced RF signal is sent to the encoder / decoder unit 8
After the EFM demodulation and the decoding process such as CIRC are performed by the memory controller 12, the buffer RAM 13 is temporarily processed by the memory controller 12.
Written in. The reading of data from the magneto-optical disk 1 by the optical head 3 and the transfer of reproduced data in the system from the optical head 3 to the buffer RAM 13 are performed.
It is 1.41 Mbit / sec and is performed intermittently.

The data written in the buffer RAM 13 is read out at the timing when the reproduction data is transferred at 0.3 Mbit / sec, and is supplied to the encoder / decoder section 14. Then, a reproduction signal process such as a decoding process for the audio compression process is performed, an analog signal is formed by the D / A converter 15, and the analog signal is supplied from a terminal 16 to a predetermined amplification circuit section and reproduced and output. For example, it is output as L and R audio signals.

Here, writing / reading of data to / from the buffer RAM 13 is carried out by being addressed by the memory controller 12 under the control of the write pointer and the read pointer, and the write pointer (write address) has been described above. As described above, the read pointer (read address) is incremented at a timing of 1.41 Mbit / sec, while the read pointer (read address) is 0.3 Mbit / se.
Since it is incremented at the timing of c, due to the difference between the bit rates of writing and reading, the buffer RA
A certain amount of data is stored in M13.
When the full capacity of data is accumulated in the buffer RAM 13, the increment of the write pointer is stopped, and the data read operation from the magneto-optical disk 1 by the optical head 3 is also stopped. However, since the read pointer R is continuously incremented, the reproduced voice output is not interrupted.

Thereafter, only the read operation is continued from the buffer RAM 13, and at some point the buffer RAM 13
Assuming that the amount of data stored in the memory becomes less than a predetermined amount, the data read operation and the write pointer W by the optical head 3 are performed again.
Is restarted and the buffer RAM 13 is restarted.
Data is being accumulated.

By outputting the reproduced sound signal via the buffer RAM 13 as described above, the reproduced sound output is not interrupted even if the tracking is missed due to a disturbance or the like, and the data accumulation remains. By accessing the correct tracking position and restarting the data reading, the operation can be continued without affecting the reproduction output. That is, the vibration resistance function can be remarkably improved.

In FIG. 1, address information output from the address decoder 10 and subcode data used for control operation are supplied to the system controller 11 via the encoder / decoder section 8 and used for various control operations. Further, the lock detection signal of the PLL circuit that generates the bit clock for the recording / reproducing operation and the monitor signal of the missing state of the frame synchronization signal of the reproduction data (L and R channels) are also supplied to the system controller 11.

Further, the system controller 11 outputs a laser control signal S _LP for controlling the operation of the laser diode in the optical head 3 to control the output of the laser diode on / off, and at the time of on control, the laser It is possible to switch between an output at the time of reproduction in which the power is at a relatively low level and an output at the time of recording in which the power is at a relatively high level.

When the recording operation is performed on the magneto-optical disk 1, the recording signal (analog audio signal) supplied to the terminal 17 is converted into digital data by the A / D converter 18, and then the encoder. / It is supplied to the decoder unit 14 and subjected to audio compression encoding processing. The recording data compressed by the encoder / decoder unit 14 is temporarily buffered by the memory controller 12 in the buffer RAM 1
3 is read out at a predetermined timing and sent to the encoder / decoder unit 8. Then, the encoder / decoder unit 8 performs encoding processing such as CIRC encoding and EFM modulation, and then supplies the magnetic head driving circuit 6.

The magnetic head drive circuit 6 supplies a magnetic head drive signal to the magnetic head 6a in accordance with the encoded recording data. That is, the magnetic head 6a applies an N or S magnetic field to the magneto-optical disk 1. At this time, the system controller 11 also supplies a control signal to the optical head so as to output a laser beam of a recording level.

Reference numeral 19 denotes an operation input section provided with keys used for user operation, and 20 denotes a display section composed of a liquid crystal display, for example. The operation input unit 19 is provided with a record key, a play key, a stop key, an AMS key, a search key, etc. so that the user can operate them.

When the recording / reproducing operation is performed on the disc 1, the management information recorded on the disc 1, that is, P-TOC (pre-mastered TOC) and U-T.
The OC (user TOC) is read out, and the system controller 11 determines the address of the segment to be recorded on the disc 1 and the address of the segment to be reproduced according to the management information. It is held in the buffer RAM 13. For this reason, the buffer RAM 13 is divided into the above-mentioned recording data / playback data buffer area and the area for holding these management information.

Then, the system controller 11 reads out these management information by executing a reproducing operation on the innermost circumference side of the disc on which the management information is recorded when the disc 1 is loaded, and stores it in the buffer RAM 13. It is possible to refer to the recording / reproducing operation for the disc 1 thereafter.

The U-TOC is edited and rewritten in response to the recording and erasing of data, but the system controller 11 performs this editing process at each recording / erasing operation in the U-TOC stored in the buffer RAM 13. The TOC information is written and the U-TOC area of the disc 1 is rewritten at a predetermined timing according to the rewriting operation.

<2. P-TOC Sector> Now, as the audio data sector recorded in the sector data form on the disc 1, and the management information for managing the recording / reproducing operation of the audio data, the P-TOC sector will be described first. As the P-TOC information, area designation such as a recordable area (recordable user area) of the disc and management of the U-TOC area are performed. When the disc 1 is a premastered disc which is a read-only optical disc, it is possible to manage the music recorded in the ROM by the P-TOC.

The P-TOC format is shown in FIG.
FIG. 2 shows P-recorded repeatedly in an area for P-TOC (for example, ROM area on the innermost side of the disc).
One sector (sector 0) of TOC information is shown. The P-TOC format is prepared from sector 0 to sector 4, but sector 1 and later are optional.

The data area of the sector of P-TOC (4 bytes x 588, 2352 bytes) has all 0s at the head position.
Alternatively, a 12-byte synchronization pattern consisting of 1-byte data of all 1s is formed, and then 4 bytes of an address indicating a cluster address and a sector address are added, and the header is a P-TOC area. Shown.

Further, an identification ID by an ASCII code corresponding to the character "MINI" is added at a predetermined address position following the header. Furthermore, the disc type, recording level, song number of the first song recorded (First TNO), song number of the last song (Last TNO), lead-out start address RO _A , power cal area start address PC _A. , U-TOC (U of FIG. 3 described later)
The start address UST _{A of} the TOC sector 0 data area) and the start address RST _A of the recordable area (recordable user area) are recorded.

Subsequently, a correspondence table instruction data section having table pointers (P-TNO1 to P-TNO255) for making each recorded music piece correspond to a parts table in a management table section described later is prepared.

Then, in the area subsequent to the correspondence table instruction data portion, (01h) to (FF) corresponding to the table pointers (P-TNO1 to P-TNO255) in the correspondence table instruction data portion.
A management table section provided with up to 255 parts tables up to (h) is prepared (herein, "h"
Numerical values with are so-called hexadecimal notation). Each part table can record a start address as a starting point, an end address as an ending point, and mode information (track mode) of the segment (track) for a certain segment.

The mode information of the track in each parts table is, for example, information indicating whether the segment is set to overwrite inhibition or data copy inhibition,
Whether or not it is audio information, monaural / stereo type, etc. are recorded.

In each part table from (01h) to (FFh) in the management table section, the contents of the segment are indicated by the table pointers (P-TNO1 to P-TNO255) in the corresponding table instruction data section. That is, for the first piece of music, a certain parts table (for example, (01h) is used as the table pointer P-TNO1. However, the table pointer is actually the byte position in the P-TOC sector 0 by the predetermined arithmetic processing. Is recorded), in which case the start address of the parts table (01h) is the start address of the recording position of the first piece of music, and similarly the end address is The end address is the position where the first piece of music is recorded. Further, the track mode information becomes information about the first music piece.

Similarly, for the second music piece, the parts table indicated by the table pointer P-TNO2 (eg (02h))
The start address, end address, and track mode information of the recording position of the second tune are recorded in. Similarly, since the table pointers up to P-TNO255 are prepared, it is possible to manage up to the 255th song on the P-TOC. Then, by forming the P-TOC sector 0 in this way, a predetermined music piece can be accessed and reproduced, for example, during reproduction.

In the case of a recordable / reproducible magneto-optical disk, since there is no so-called pre-mastered music area, the above-mentioned correspondence table instruction data section and management table section are not used (these are U-described later). TO
(It is managed by C), so each byte is all "00h". However, in the case of a hybrid type disc having both a ROM area and a magneto-optical area as areas where music and the like are recorded, the correspondence table instruction data section and the management table section are used to manage the music in the ROM area. .

<3. U-TOC sector> followed by UT
The OC will be explained. FIG. 3 shows a format of one sector of the U-TOC, and is mainly data in which management information is recorded about a song recorded by the user and an unrecorded area (free area) in which a new song can be recorded. It is considered as an area. Note that the U-TOC also has formats from sector 0 to sector 4, but sector 1 and later are optional. For example, when trying to record a certain piece of music on the disc 1, the system controller 11 can search for a free area on the disc from the U-TOC and record audio data there. ing. Further, at the time of reproduction, the area in which the music to be reproduced is recorded is discriminated from the U-TOC, and that area is accessed to perform the reproduction operation.

As in the P-TOC, the U-TOC sector (sector 0) shown in FIG. 3 is first provided with a header, and then, at a predetermined address position, a manufacturer code, a model code, and a song number of the first music piece. (First TNO), song number (Last TNO) of the last song, sector usage, disc serial number, disc ID, and other data are recorded. Various table pointers (P-DFA, P-EMPTY, P-
An area for recording FRA, P-TNO1 to P-TNO255) is prepared.

Then, 255 parts tables of (01h) to (FFh) are provided as management table parts to be associated with the table pointers (P-DFA to P-TNO255) of the corresponding table instruction data part, respectively. 2, the start address as the starting point, the end address as the ending point, and the mode information (track mode) of the segment are recorded as in the P-TOC sector 0 of FIG. This U-TO
In the case of C sector 0, the segment shown in each parts table may be connected to another segment subsequently, so link information indicating the parts table in which the start address and end address of the connected segment are recorded. Can be recorded.

In this type of recording / reproducing apparatus, for example, the data of one music piece is physically discontinuous, that is, a plurality of segments (here, a segment is a track portion on which physically continuous data is recorded. Even if it is recorded over multiple segments, the playback operation will not be hindered by playing while accessing between segments.Therefore, for songs etc. recorded by the user, multiple segments may be used for the purpose of efficient use of the recordable area. It may be recorded separately. Therefore, link information is provided, for example, numbers (01h) to (FFh) given to each parts table (actually indicated by a numerical value which is a byte position in the U-TOC sector 0 by a predetermined calculation process). The parts tables can be connected by specifying the parts table to be connected. (Note that since prerecorded music pieces are not usually segmented, the link information is all "(00h)" in the P-TOC sector 0 as shown in FIG.

That is, in the management table section in the U-TOC sector 0, one part table represents one segment, and, for example, a music piece formed by connecting three segments is linked by link information. The segment position is managed by the three parts tables.

Each of the parts tables (01h) to (FFh) in the management table section of the U-TOC sector 0 has a table pointer (P-DF) in the corresponding table instruction data section.
A, P-EMPTY, P-FRA, P-TNO1 to P-TNO255)
The contents of that segment are shown below.

The table pointer P-DFA is shown for a defective area on the magneto-optical disk 1, and a track portion (= segment) which is a defective area due to a scratch or the like is shown.
One part table or the first part table in multiple part tables is specified. In other words, if there is a defective segment in the table pointer P-DFA
Any one of (01h) to (FFh) is recorded, and the defective segment is indicated by the start and end addresses in the parts table corresponding thereto. Further, when there is another defective segment, another part table is designated as the link information in the part table, and the defective segment is also shown in the part table. Then, if there is no other defective segment, the link information is, for example, "(00h)", and thereafter there is no link.

The table pointer P-EMPTY indicates the top parts table of one or a plurality of unused parts tables in the management table section. If an unused parts table exists, the table pointer P-EMPTY is used as a table pointer P-EMPTY. , (01h) to (FFh) is recorded.
If there are multiple unused part tables, the part tables specified by the table pointer P-EMPTY are used to sequentially specify the part tables by link information, and all the unused part tables are linked on the management table section. To be done.

The table pointer P-FRA indicates the writable free area (including the erased area) of the data on the magneto-optical disk 1, and 1 or the track portion (= segment) which becomes the free area is indicated. The first part table in multiple part tables is specified. In other words, if there is a free area, the table pointer P-
In the FRA, any one of (01h) to (FFh) is recorded, and in the parts table corresponding to that, the segment which is the free area is indicated by the start and end addresses. Further, when there are a plurality of such segments, that is, when there are a plurality of parts tables, the parts table with link information of "(00h)" is sequentially specified by the link information.

FIG. 4 schematically shows the management state of the segment serving as the free area by using the parts table. This is the correspondence table instruction data when segment (03h) (18h) (1Fh) (2Bh) (E3h) is set as free area.
Continuing from P-FRA, parts table (03h) (18h) (1Fh) (2Bh)
The state represented by the link (E3h) is shown. The defective area and the unused parts table management mode described above are the same.

By the way, in the case of a magneto-optical disk in which no audio data such as music is recorded and there is no defect,
Parts table (01h) by table pointer P-FRA
Is designated, which indicates that the entire recordable user area of the disc is an unrecorded area (free area). And it remains in this case (02h) ~ (FFh)
Since the parts table of will not be used,
The part table (02h) is specified by the above-mentioned table pointer P-EMPTY, the part table (03h) is specified as the link information of the part table (02h), and the part table is specified as the link information of the part table (03h).
(04h) is specified, and so on.Parts table (FFh)
Are linked up to. In this case, the link information of the parts table (FFh) is set to "(00h)" indicating that there is no connection thereafter. At this time, in the parts table (01h), the start address of the recordable user area is recorded as the start address, and the address is recorded immediately before the lead-out start address as the end address.

Table pointers P-TNO1 to P-TNO255 indicate music pieces recorded by the user on the magneto-optical disk 1. For example, in the table pointer P-TNO1, one or a plurality of pieces of data in which the first music piece is recorded are recorded. A parts table indicating the temporally first segment of the segments is specified.

For example, the first music piece is not divided into tracks on the disc (that is, one segment).
When recorded, the recording area of the first music piece is recorded as the start and end addresses in the parts table indicated by the table pointer P-TNO1.

Further, for example, when the second music piece is discretely recorded in a plurality of segments on the disc, each segment is designated in chronological order to indicate the recording position of the music piece. In other words, from the parts table specified by the table pointer P-TNO2, further parts tables are sequentially specified by the link information according to the temporal order, and the parts table whose link information is "(00h)" is linked. (The above-mentioned form similar to FIG. 4). Thus, for example, all the segments in which the data constituting the second music is recorded are sequentially designated and recorded, so that the data of the U-TOC sector 0 is used to reproduce the second music or the second music. When overwriting the area (1), it becomes possible to access the optical head 3 and the magnetic head 6 to take out continuous music information from discrete segments, and to perform recording using the recording area efficiently.

As described above, the area management on the disk is P
-Music recorded by the TOC and recorded in the recordable user area, free areas, etc.
Performed by OC. These TOC information are read into the buffer RAM 13 so that the system controller 11 can refer to them.

<4. Data sector> The format of the sector in which audio data is recorded next is set as shown in FIG. In this sector (2352 bytes), the first 12 bytes are used as synchronization data, the next 3 bytes are set for the cluster address and the sector address, the next 1 byte is set as the mode, and the 16 bytes so far are used as the header. .

4 bytes following the header are used as a sub-header, and the bytes following the sub-header, that is, the second sector
2332 bytes from the 1st byte to the 2352nd byte are used as a data area (Data0 to Data2331). A sound frame of 212 bytes (refer to FIG. 18) is recorded in 11 units in this data area of 2332 bytes, so that a sound group of 5.5 units is recorded in one sector, and the sector address is even (the LSB of the address is 0) even sector and the next sector, that is, the sector address is odd (the LSB of the address is 1)
A sound group of 11 units will be recorded in two sectors of odd-numbered sectors.

<5. Area Configuration of Buffer RAM> In order to store these sectors (P-TOC sector, U-TOC sector, and data sector), the buffer RAM 13 is used in this embodiment as shown in FIG. 6, for example. It is assumed that the buffer RAM 13 has a storage capacity of 4 Mbits and is set to hold 8 sectors of TOC information. Then the first 12 bytes (address 0000
h ~ 000Ch) is an empty area, and the following address 000Ch
18944 bytes from ~ 4A0Bh are used for TOC. That is, the eight areas from area 00 to area 07 each hold the TOC sector. Each area has 2368 bytes. Therefore, in addition to 2352 bytes of data for one sector (see FIGS. 2 and 3), 16 bytes of additional data can be stored.

Further, addresses 4A0Ch to 07FC4Bh are used for audio data, that is, area 08 to area DC, which are 2368 bytes each, are used for storing and reading audio data sectors, and the shock proof function described above is achieved. Has been realized. Here, each area is 2368
In addition to 1 sector data (see FIG. 5) of 2352 bytes, 16 bytes of additional data can be stored. In addition, address 07
FC4Ch to 07FFFFh are vacant areas.

Here, 000Ch to 07F30Ch shown as the head address of each area of area 00 to area DC is calculated based on the count value of the sector to be written / read. That is, when the sector count value is N _S , the sector address is 940h × NS + 0Ch. "+ 0Ch" is the offset for the first free area. Therefore, for example, the start address of the area 08 is calculated as 940h × 08h + 0Ch = 4A0Ch.

The structure within each area of 2368 bytes is shown in FIG. 7 by taking area 09 as an example. Area 09 stores audio data, that is, the data sector shown in FIG. In this area 09, 534Ch is the start address,
2368 bytes starting from this and up to address 5C8Bh
(000h to 93Fh) is used as illustrated.

That is, since the writing of the sector is executed according to the sync detection, the cluster address, the sector address and the mode are first stored, then the 4-byte sub-header is stored, and then the data Data0 to Data2331 are sequentially stored. It will be remembered. Then, after that, the sync is written and one sector (2352 bytes) is stored. Here, 16 bytes are left in the area after the sector is stored, and a sector parameter storage area (additional area 09add) is provided so that additional data can be stored in the 16 bytes (930h to 93Fh). To be done. (Hereinafter, the additional data means various information stored in this 16-byte area corresponding to the sector.) The address of each byte is the start address (sector address) of the area. It is obtained by adding byte addresses. For example, the address of Data0 in area 09 is (940h × 09h + 0Ch) + 008h = 534Ch + 008h = 5354h
Becomes

As described above, in each area (area 00 to area DC) in the buffer RAM 13, the additional area (00) capable of storing the additional data corresponding to the sector data is stored.
add to DCadd) are set so that the track number, the traveling time, the track mode, the link information, the error information and the like associated with the sector can be held in association with the sector. When the sector data is read, the additional data accompanying it is also read and used for various operation management.

By storing the additional data in the buffer RAM 13 in association with the sector data, the system controller 11 can store the additional data in the buffer RAM 13.
When the data is read from, various information about the read sector is obtained, which is convenient for the system operation processing. For example, by reproducing through the buffer RAM 13, the information such as the performance progress time in a certain sector may deviate from the time when it is read from the disk 1 and the time when it is actually reproduced and output. The progress time information can be read at the time when the data of the sector is read from the buffer RAM 13.

In addition, the track number (song number),
The track change information, the track mode information such as stereo / monaural distinction, emphasis, and copyright, the link information before and after the audio data management information, the error information, and the like are also written to the buffer RAM 13 in the sector data. Sometimes write at the same time,
Further, the data of the sector can be read when it is read from the buffer RAM 13, and can be used for various operation control. As will be described later, in this embodiment, the memory controller 12 to the encoder / decoder unit 1
The channel identification signal SLR that is output when the data is transferred to No. 4 is generated using this additional data.

<6. Configuration of memory controller> Next,
The configuration and operation of the memory controller 12 for using the buffer RAM 13 in such a form will be described.

FIG. 8 is a block diagram showing the internal structure of the memory controller 12. Reference numeral 30 denotes a disk drive interface section, which is the disk drive side, that is, the recording / reproducing data Dt for the encoder / decoder section 8,
And, the TOC information TDt and the like are held and given.

A RAM data interface unit 31 writes / reads data to / from the buffer RAM 13 and holds these data. The data to be written / read are the recording / reproducing data Dt and the TOC information T.
It becomes Dt. Reference numeral 32 denotes an audio compression interface unit, which holds and sends the recording / reproducing data Dt and the like to the audio compression unit, that is, the encoder / decoder unit 14.

A controller interface unit 33 serves as an interface to the system controller 11. Here, the TOC information TDt is transferred to and from the system controller 11, the control signal is input from the system controller 11, and the data thereof is held.

Reference numeral 34 is an address counter, which is address specification data supplied via the controller interface unit 33, mode information, sync data of a sector detected by the disk drive interface unit 30 or the audio compression interface unit 32, and RAM. A write address / read address (M _Ad ) is generated by an operation described later based on the byte count signal supplied from the data interface unit 31 and the like, and is output to the buffer RAM 13.

Reference numeral 35 is a control section for controlling the operation of each section of the memory controller 12. The control unit 35 controls the write / read operation for the buffer RAM 13 and the transmission / reception operation of data and the like for the encoder / decoder unit 8 and the encoder / decoder unit 14 in response to a command from the system controller 11. It also controls the output operation of the channel identification signal S _LR to the encoder / decoder unit 14, which will be described later. B indicates a control bus connecting the respective units.

Here, the configuration of the address counter 34 is shown in FIG. Reference numeral 40 denotes a write sector counter that performs a count operation based on a sector sync to obtain an address for writing data to the buffer RAM 13.
Reference numeral 1 is a read sector counter that performs a count operation based on a sector sync to obtain an address for reading data from the buffer RAM 13. When writing the sector data read from the disk to the buffer RAM, one of a cyclic mode, a straight advance mode, and a retry mode is given as the write operation, and the write sector counter 40 counts according to the mode. Is controlled.

Reference numeral 42 is an adder / subtractor circuit that can increment or decrement the count value of the write sector counter 40, and 43 is an adder / subtractor circuit that is capable of increment or decrement the count value of the read sector counter 41. 44 is a selection circuit,
Write sector counter 40, read sector counter 4
1. Select one of the count values from the adder / subtractor circuits 42 and 43 and output it. The selection operation is executed by a control signal supplied from the system controller 11 via the controller interface unit 33, for example.

Reference numeral 45 denotes a sector address operation unit, which performs N _S × 940h + 0Ch on the sector count value N _S output from the selection circuit 44. That is, FIG.
The start address (start address of the sector unit in the buffer RAM 13) for the areas 00 to DC described in 1. is calculated.

46 is reset based on the sector sync to obtain a byte address (what byte of the sector) for writing data to the buffer RAM 13, and R
Reference numeral 41 is a write byte counter that performs a count operation by the byte count signal CT from the AM data interface unit 31, and 41 is a byte address for reading data from the buffer RAM 13 (what byte of the sector).
Reset based on sector sync to get
It is a read byte counter that performs a counting operation in response to the byte count signal CT from the RAM data interface unit 31.

Reference numeral 48 is a 16-byte additional area (00ad) provided in each area (area 00 to area DC) in the buffer RAM 13 as described above.
This is a parameter offset generation unit that generates a predetermined parameter offset for accessing d to DCadd). The parameter offset generating unit 48 is configured to be capable of generating parameter offsets of "930h" to "93Fh" for accessing the additional area in FIG.

A selection circuit 49 selects the output of the write byte counter 46, the read byte counter 47, or the parameter offset generator 48 as byte address data and outputs it. An address generation / output unit 50 calculates an access address by adding the byte address output from the selection circuit 49 to the sector address output from the sector address calculation unit 45.
This is output to the buffer RAM 13.

<7. Writing / reading operation to / from buffer RAM> Since the address counter 34 is configured in the memory controller 12 as described above, sector data read from the disk 1 is stored in the buffer RAM 13 during the reproducing operation from the disk 1. Sector counters 40 and 4 for generating sector addresses at the time of storing and reading sector data from the buffer RAM 13 and outputting this to the encoder / decoder unit 14 as reproduction data.
By using the value of 1 and the output of the parameter offset generator 48, the access address of the additional area can be obtained, and the additional data can be written / read. Hereinafter, various examples of the access method of the additional area will be described.

The writing / reading to / from the additional area is performed by the buffer RAM 13 when the input data is stored in the buffer RAM 13 during recording in the recording / reproducing apparatus.
This is also possible when data is read from 13 and supplied as recording data, but in this case as well, the address counter 3
The access address of the additional area can be obtained by almost the same processing as that described below in No. 4, and the description in this case will be omitted.

First, an example of the operation of recording the additional data when writing the data read from the disc in the buffer RAM 13 will be described. Therefore, during the reproduction of the recording / reproducing apparatus, the data read from the disc is stored in the buffer RAM 13. The operation according to the mode at the time of writing is shown in FIG.
Will be explained using.

When the sector data read from the disk is written in the buffer RAM 13 as described above, one of the cyclic mode, the straight advance mode and the retry mode is given as the writing operation. This is a mode control for writing the target sector in a predetermined area (any one of area 08 to area DC), and when the writing is started, the cyclic mode is first set. In the cyclic mode, the write sector counter 40 holds the count value at that time even if the sector sync is input.

Therefore, when the area 08 is addressed in the cyclic mode, the sector address calculated by the sector address calculator 45 is always the address 4A0Ch, and based on the count value of the write byte counter 46,
A write access is executed in area 08.

Then, when there is a sector sync interrupt, the data of the sector is written into each byte, and it is determined whether the written sector is the target sector. If the sector is not the target sector, the sector data input in response to the sector sync interrupt is written to each byte in the area 08 in accordance with the cyclic mode. That is, overwriting is executed in the cyclic mode until the target sector is written.

For example, when the target sector is written in the area 08, the straight advance mode is set at that time. In the straight advance mode, the write sector counter 40 counts up according to the sector sync. Therefore, the access address becomes an address indicating the area 09 by the sector sync of the next sector.
The sector data will be written into each byte of area 09.

Thereafter, if there is no write error, the sector data is sequentially written in each area in the straight advance mode until the writing is completed (end of one writing operation in the intermittent writing operation).

However, it is determined whether or not there is a write error in the sector written immediately before the shift to the straight-ahead mode or when the straight-ahead mode is continued and moves to the next area. For example, writing is performed again in the retry mode.

For example, when entering area 0A, area 0
When the write error in 9 is detected, the retry mode is set and the count value of the write sector counter is decremented by 1, that is, the access address is set to the address in the area 09. Then, in area 09, in the cyclic mode, writing is continued according to the sector sync, and when the target sector is written, the mode is returned to the straight advance mode.

When writing sector data in this way, when writing additional data corresponding to the sector to the additional area, an address is generated as follows.

For example, in the example of FIG. 10, while the straight mode is set and the area 09 is being written, appropriate sector data has already been written in the area 08. Additional area 08ad in 08
It is preferable that additional data for the written sector can be written in d. That is, the additional area 08
All you have to do is get the access address of add.

Therefore, since the count value of the write sector counter 40 is a value indicating the area 09, the addition / subtraction circuit 42 performs -1 against this and the selection circuit 44.
Selects and outputs the output of the adder / subtractor circuit 42 so that the sector address for the area 08 can be obtained.

At the same time, a parameter offset corresponding to the byte to be written in the additional area is output from the parameter offset generator 48 via the selection circuit 49. For example, if additional data is to be written as the parameter PRM20 at the 938th byte in the sector in FIG. 7, a parameter offset of "938h" is generated.

As a result, the address generation / output unit 50
Then, the parameter offset 938h is added and combined with the sector address 4A0Ch of the area 08, and the parameter PRM2
An address indicating the position of 0 will be generated and output.

In addition, when it is desired to write additional data corresponding to the sector to be written in the area in the cyclic mode, a predetermined parameter offset is output from the parameter offset generating section 48 as it is and selected. If selected and output by the circuit 49, an access address to a predetermined byte in the additional area 09add in the area 09 will be generated.

Next, when the sector data is read from the buffer RAM 13 and transferred as reproduction data, it is normally read in order as areas 08, 09, 0A ... When reading and transferring this, it is preferable that the additional data for the next sector (that is, the sector stored in area 0A) be read.

In this case, the addition / subtraction circuit 43 adds +1 to the count value of the read sector counter 41.
The selected value is selected and output by the selection circuit 44. At the same time, a predetermined parameter offset is output from the parameter offset generation unit 48, and the selection circuit 49 selectively outputs it.

Then, the sector address calculator 45 sends an address 64BC indicating the area 0A as a sector address.
Since h is obtained and the parameter offset value is added to this, the address of a certain byte in the additional area 0Aadd in the area 0A is obtained. Therefore, desired additional data can be read by the address.

Hereinafter, regarding various cases during the reproducing operation in the recording / reproducing apparatus, the address calculation operation processing will be collectively illustrated by taking the case of accessing the parameter PRM00 of the first byte in the additional area as an example. The write sector counter value at each time point is WSC, the read sector counter value is RSC, and the generated address is _Mad . The +1 or -1 arithmetic process for WSC or RSC is the process of the adder / subtractor circuit 42 or 43, and is a value obtained by the selection circuit 44 selecting and outputting the output of the adder / subtractor circuit 42 or 43. is there. Further, the calculation of (× 940h + 0Ch) represents the processing in the sector address calculation unit 45 as described above. The parameter PRM00 is 930 in the sector.
It is located at the byte corresponding to the offset position of h.

* When the sector data read from the disk is recorded in the buffer RAM, the parameter PRM
Address generation method for writing additional data as 00 a. While writing an area in the straight-ahead mode or the patrol mode, additional data (PRM0
When writing 0). Mad = (WSC-1) × 940h + 0Ch + 930h b. Additional data (PRM00) for a sector of a certain area during writing in a certain area in the straight-ahead mode or patrol mode
When writing. Mad = WSC × 940h + 0Ch + 930h c. When writing additional data (PRM00) for a sector to be written in the next area during writing in a certain area in the straight advance mode or the patrol mode. Mad = (WSC + 1) × 940h + 0Ch + 930h

* Address generation method for reading the additional data stored as the parameter PRM00 when the sector data is read from the buffer RAM and output as the reproduction data a. When reading additional data (PRM00) related to sector data in the area next to the area being read. Mad = (RSC + 1) × 940h + 0Ch + 930h b. When reading additional data (PRM00) related to the sector data of the area being read. Mad = RSC × 940h + 0Ch + 930h c. When reading additional data (PRM00) related to the sector data of the area before the area being read. Mad = (RSC-1) × 940h + 0Ch + 930h

Parameters PRM01 to PRM33
To obtain the access address for
The addition term of “30h”, that is, the parameter offset is “9
31h ”to“ 93Fh ”. Whether the address is generated by the above-described method a, b, or c during writing and reading is determined by the system controller 11
Needless to say, it is determined by the output selection control of the selection circuits 44 and 49 by the control unit 35.

Since the address counter 34 is configured as described above, it is not necessary for the system controller 11 to calculate the address when accessing the additional data, and the sector offset is automatically set only by specifying the parameter offset. The access byte position of can be an additional area. Further, the sector accessing the additional area can also be designated by using the value of the sector counter or the value obtained by adding +1 and -1 to it.

Further, by obtaining the access address of the additional area by using the value of the sector counter, the system controller 11 can manage the buffer written in the buffer RAM 13 without managing the relationship between the sector and the additional data corresponding thereto and the address position. In the RAM 13, the additional information is held in the same area corresponding to the sector,
Also during reading, additional data corresponding to the sector can be read according to the reading operation.

The addition / subtraction circuits 42 and 43 are not always necessary if the additional data is read and written for the sector currently counted. In any case, various information as information corresponding to the sector data can be held as additional data in the buffer RAM 13, and when the sector data is transferred, this additional data can be read and used for various controls.

<8. Supplying Channel Identification Signal from Memory Controller to Decoder> In the recording / reproducing apparatus configured as described above, the memory controller 1
The channel identification signal S _LR supplied from 2 to the encoder / decoder unit 14 will be described. Audio compression interface unit 32 in the memory controller 12
And an encoder / decoder unit 14 between the buffer R
Sector data read from AM13 (compressed audio data read from disk 1)
At the time of transferring Dt, signals are exchanged as shown in FIG.

At the time of reproducing operation, the encoder / decoder unit 14 side takes in audio data in sound frame units, decodes it and outputs it as a 16-bit digital signal, so that the memory controller 12 sends the data fetch request signal RQ. Then, the memory controller 12 transmits voice data in sound frame units in response to the request signal RQ. Then, the encoder / decoder section 14 takes in the transferred audio data Dt based on the clock CK and the latch signal LATCH, and performs a decoding process.

ER-FG is an error flag, which is a signal indicating whether or not there is an error in the audio data Dt to be transferred. Further, the memory controller 12 transmits a channel identification signal S _LR so that the encoder / decoder unit 14 can identify the L channel and the R channel with respect to the audio data transmitted in units of sound frames.

FIG. 12 shows the transfer state of the request signal RQ and the audio data Dt, and the channel identification signal S _LR . In addition, in FIG. 12, (a-1) and (a-2) show the continuous request signal RQ in a divided manner. Similarly, (b-1) and (b-2) are audio data, and (c-1). ) (C
2) shows the channel identification signal S _LR in a divided form.

As described with reference to FIG. 18, since one sound group is audio data of 11.6 msec of L and R audio, the encoder / decoder section 14 sets the L channel sound frame and the R channel of every 5.8 msec. Request signal RQ so that the sound frame of
Is being output. Then, the memory controller 12 reads from the buffer RAM 13 in units of sectors,
The audio data is supplied to the encoder / decoder unit 14 in units of sound frames according to the request signal RQ.

Therefore, in the period corresponding to the even sectors, the sound frames SF _(L0) , SF _(R0) , SF _(L1) , and SF _(R1) are every 5.8 msec as shown in FIG. 12 (b-1 _).
, And L and R channels are alternately output, and in the period corresponding to the odd sector following the even sector, as shown in FIG. 12B-2, the sound frame SF _(R5) , The output is SF _(L6) , SF _(R6) , SF _(L7) ...

Here, in the present embodiment, the memory controller 12 causes the encoder / decoder unit 14 to identify that the sound frame is data of the L channel once in every two sectors, so that the channel identification signal S is used. Outputs _LR . For example, at the output timing of the first sound frame SF _(L0) in the even-numbered sector, the channel identification signal S _LR is output as shown in FIG.
It is made to recognize that the sound frame is the L channel. (Once every two sectors L
In this embodiment which outputs the channel identification signal S _LR , which is a pulse indicating that the channel is a channel, in FIG.
As can be seen from 2), the pulse as the channel identification signal S _LR is not output in the odd sector. )

Therefore, in the encoder / decoder section 14,
The sound frame captured when the pulse as the channel identification signal S _LR is supplied can be identified as the first sound frame SF _(L0) of the even sector, that is, the sound frame of the L channel data, and the sound that is captured thereafter. By processing as R channel, L channel, R channel, ... For each frame, it is possible to avoid processing and outputting L / R in error.

Even if an error occurs, even-numbered sectors are read from the buffer RAM 13 twice in succession. For example, after the last L-channel sound frame SF _(L5) of the even-numbered sector, the L-channel sound frame SF is read again. _{Even when (L0)} is transferred, the channel identification signal S _LR indicating the L channel is supplied corresponding to the sound frame SF _(L0) ,
It is possible to prevent this from being erroneously processed with the R channel (that is, the first sound frame SF _{(R5) of the} odd sector ₎ .

As described above, in order to output the channel identification signal S _LR as a pulse indicating the L channel, the memory controller 12 determines whether the sector read from the buffer RAM 13 is an even sector or an odd sector. Must. The processing for this is shown in FIGS.

The data read from the disk 1 is written into the buffer RAM 13 in units of sectors by the memory controller 12 as described above. When writing to the buffer RAM 13, the control unit 35 in the memory controller 12 is used. Performs the processing of FIG.

First, if the sector data is imported (F10
0), the sync pattern in the header is detected, but if the sync pattern is correctly obtained, the process proceeds from step F101 to F102, and it is determined whether or not there is an error as header data. If there is no error as the header data, the sector data has been correctly captured.

When the sector data is correctly captured,
The LSB of the sector address is confirmed, and it is determined whether the value is "0" or "1" (F103). If the LSB of the sector address is "0", it is an even sector.
(F104), the even sector flag Feven prepared for discrimination of even / odd sectors is set to "1" (F105).

If the sync detection is not appropriate, if the header data has an error, or if it is determined that the LSB of the sector address is "1" and the sector is an odd sector, the even sector flag Feven is set to It is regarded as "0" (F106).

The even sector flag Feven is prepared as the above-mentioned additional data, and when writing the sector data into any of the areas 05 to DC in FIG. 6, which of the additional data areas (05add to DCadd) is written. ) Parameter (PRM00-PRM3)
Written as one of 3). As the additional data corresponding to the sector data, various types are additionally generated as described above, and the parameters (PRM00 to PRM) are respectively generated.
33) will be written. And
These processes are performed within the sector data and fetch operation described with reference to FIG.

By doing so, the buffer RAM 1
Since the additional data indicating the even / odd sector is stored corresponding to the sector data in 3,
Encoder / decoder unit 1 by reading sector data
When transferring to No. 4, it is only necessary to confirm the parameter that becomes the even sector flag Feven.

That is, the memory controller 12 uses the buffer R
When the sector data is read from the AM 13, the additional data can be read in correspondence with the sector data (the additional data read timing can be set variously as described above. (Additional data will be read out before the start of data transfer.) When each parameter as additional data is read (F201), various settings such as error flags are set according to those additional data (F202). Even sector flag Feven for generating the channel identification signal S _LR
Check (F203).

If the even sector flag Feven = 1, it is an even sector. Therefore, the L channel is used as the channel identification signal S _LR in synchronization with the transfer timing of the head sound frame SF _(L0) for the data of the corresponding sector. The setting process is performed so that the pulse indicating is output (F204). On the other hand, if the even sector flag Feven = 0, it is an odd sector. Therefore, when the data of the corresponding sector is transferred, the setting process is performed so that the pulse indicating the L channel is not output as the channel identification signal S _LR. It becomes (F205).

When the control unit 35 performs the above operation, the channel identification signal S _LR pulse is normally output once every two sectors as shown in FIG. 12, and the encoder / decoder unit 14 outputs the L / R signal. Can be confirmed. The processes of FIGS. 13 and 14 may be executed not only by a hard logic circuit in the control unit 35 of the memory controller 12 but also by software operation means of the system controller 11, for example.

<9. Various Embodiments as Channel Identification Signal> The channel identification signal S _LR is output as a pulse corresponding to the sound frame SF _(L0) as described above, and various modes are conceivable. These are shown in FIG. FIG. 15A shows the sound frame transfer timing for four sectors, and FIG. 15B shows the channel identification signal S _LR in the above-described embodiment.

As a modified example of FIG. 15B, FIG.
(C) has different pulse widths. That is, in the above-described embodiment, the channel identification signal S _LR is a signal having a pulse width that becomes a high level in accordance with the transfer period of the sound frame SF _(L0) , but this need not always be the case. A pulse as shown in FIG. 15C may be used to indicate that _(L0) is the L channel.

FIG. 15D shows the channel identification signal S
_This is an example in which _LR is a pulse indicating the R channel, and the pulse is output corresponding to the first sound frame SF _(R5) in the odd sector.

Further, FIG. 15E shows an example in which the identification pulse of the L channel is output as the channel identification signal S _LR for each sector, and is output in the period corresponding to the sound frames SF _(L0) and SF _(L6). It is something. Furthermore, FIG.
(F) is an example in which the R channel identification pulse is output as the channel identification signal S _LR for each sector, which is output during the period corresponding to the sound frames SF _(R0) and SF _(R5) .

When the channel identification signal is generated as a pulse for identifying the L channel or the R channel as described above, the output timing of which sector is output, and which sound frame is output are output. The output timing is as shown in FIG.
Various other than those shown in (b) to (f) are conceivable.

FIG. 15G shows the channel identification signal S _LR.
Is an example in which a pulse corresponding to a sound frame of the L or R channel as described above is output instead of a pulse corresponding to each sound frame as an L / R channel clock. FIG. 16 shows an output waveform in the embodiment in which the channel identification signal S _LR is used as a channel clock in the same format as that of FIG.

In this case, as can be seen from FIG. 16, the channel identification signal S _LR is a clock that is inverted when the transfer of each sound frame is completed. Therefore, the encoder / decoder unit 14 is supplied with the sound frames SF _(R0) , SF _(R1) , SF _(R2), ... Of the R channel during the R period of this channel identification signal S _LR . During the L period in the identification signal S _LR , the sound frames SF _(L0) , SF of the L channel
_It can be recognized that _(L1) , SF _(L2), ... Are supplied, and the occurrence of L / R processing errors can be prevented.

In this case, it is assumed that an error occurs such that the data of the even sector is output twice in succession as shown in FIG. That is, the sound frame SF _(L0) is transferred next to the sound frame SF _{(L5) to} the encoder / decoder unit 14.

However, in the memory controller 12, for example, the even / odd determination of the sector is performed by the above-described means, and the channel identification signal S _LR as the LR clock is at the L channel period at the beginning of the even-numbered sector. The signal S _LR is output as shown in FIG. 17B, and the encoder / decoder unit 14 side accurately identifies and decodes the L and R channels of the captured sound frame data based on the channel identification signal S _LR. Processing can be performed. Therefore, L / R is not inverted in the output of the reproduced sound, and the localization deviation of the stereo sound does not occur.

Although the above embodiment has been described as an example applied to the recording / reproducing apparatus for the magneto-optical disk 1, it may of course be a reproduction-only apparatus. Further, various types of channel identification signal generation methods, channel identification signal waveform modes, and the like are possible. Further, the memory controller 12
Alternatively, the system controller 11 or the like may generate and output a channel identification signal.

[0138]

As described above, in the reproducing apparatus of the present invention, the demodulation means can identify whether the sector supplied from the memory means is an even sector or an odd sector. Therefore, the digital data to be decoded can be processed by accurately identifying the L channel and the R channel, and even if a sector read error or the like occurs from the memory means, the L channel decoded data is output as the L channel without error. Also, the decoded data of the R channel can be used as the output of the R channel. Therefore, there is an effect that it is possible to eliminate the occurrence of localization deviation in reproduced stereo sound.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a P-TOC sector of a disc.

FIG. 3 is an explanatory diagram of a U-TOC sector of a disc.

FIG. 4 is an explanatory diagram of a U-TOC management form of a disc.

FIG. 5 is an explanatory diagram of a data sector of a disc.

FIG. 6 is a buffer RAM in the recording / reproducing apparatus of the embodiment.
3 is an explanatory diagram of a storage area of FIG.

FIG. 7 is a buffer RAM in the recording / reproducing apparatus of the embodiment.
3 is an explanatory diagram of a storage area of FIG.

FIG. 8 is a block diagram of a memory control device and a peripheral circuit unit according to an embodiment.

FIG. 9 is a block diagram of an address generation circuit and a peripheral circuit unit according to an embodiment.

FIG. 10 is an explanatory diagram of a write operation to the buffer RAM according to the embodiment.

FIG. 11 is a memory controller and encoder / of the embodiment.
FIG. 4 is an explanatory diagram of input / output signals between decoder units.

FIG. 12 is an explanatory diagram of a channel identification signal as an L channel pulse according to the embodiment.

FIG. 13 is a flowchart of a process at the time of writing to a buffer RAM for sector even / odd determination by the memory controller of the embodiment.

FIG. 14 is a flowchart of a process at the time of reading a buffer RAM for sector even / odd determination by the memory controller of the embodiment.

FIG. 15 is an explanatory diagram of various channel identification signals as an example.

FIG. 16 is an explanatory diagram of a channel identification signal as an LR channel clock according to the embodiment of this invention.

FIG. 17 is an explanatory diagram of a channel identification signal as an LR channel clock according to the embodiment of this invention.

FIG. 18 is an explanatory diagram of a data format of a disc.

[Explanation of symbols]

1 disk, 3 optical heads, 8 encoder / decoder section, 11 system controller, 12 memory controller, 13 buffer RAM, 14 encoder / decoder section, 30 disk drive interface section, 31 RAM data interface section, 32
Audio compression interface unit, 33 controller interface unit, 34 address counter, 35 control unit, 40 write sector counter, 41 read sector counter, 42, 43 adder / subtractor circuit, 44, 49
Selection circuit, 45 sector address calculation unit, 46 write byte counter, 47 read byte counter, 48
Parameter offset generator, 50 address generator / outputter

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-150560 (JP, A) JP 4-232663 (JP, A) JP 59-231709 (JP, A) JP 4- 40724 (JP, A) JP 4-349269 (JP, A) JP 5-89601 (JP, A) JP 5-74047 (JP, A) JP 64-49166 (JP, A) Actual Development Sho 64-24564 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 20/10-20/16 351

Claims (4)

(57) [Claims] 1. A digital signal recorded on a recording medium in which a digital signal is divided into blocks of a predetermined length to form a sector, and an odd number of sound groups are formed by a pair of even and odd sectors in the sector. A reproducing device for reproducing a digital signal from the recording medium, a memory device for temporarily storing the digital signal reproduced by the reproducing device in sector units, and a digital device once stored in the memory device. Demodulation means for reading out a signal in the sector unit and demodulating, and discrimination means for discriminating whether the sector stored in the memory means is an even sector or an odd sector when writing the digital signal in the memory unit in the sector unit. If the sector stored in the memory means is an even sector, based on the determination result of the determination means. By adding an identifier identifying whether several sectors, reproducing apparatus characterized by comprising and a memory control means for storing in said memory means. 2. When the digital signal is read from the memory means in units of the sector, the identifier is read from the memory means, and whether the sector read from the memory means is an even sector or an odd sector is determined based on the identifier. The reproducing apparatus according to claim 1, further comprising: a discriminating unit for controlling the demodulation timing of the demodulating unit based on a discrimination result of the discriminating unit. 3. Digital data of a plurality of channels is time-division-multiplexed and recorded in each sector, the even sector starts at the digital data of one of the channels, and the odd sector starts at the plurality of channels. The reproducing apparatus according to claim 1, wherein the reproducing apparatus starts from digital data of the other channel of the above. 4. The reproducing apparatus according to claim 1, wherein the sound group is composed of 2-channel digital audio data.