JPH02126477A - Digital data recording and reproducing device - Google Patents

Abstract

PURPOSE:To select a stepwise recording and reproducing from high reliability to high speed with a large capacity by changing the capacity of system data or external digital data and changing the redundancy data length of a 3rd error correction code as well. CONSTITUTION:Selecting information among redundancy data lengths from control information given by an external device via a communication part 3 is recognized by a control part 8 to issue a selecting command to a data management part 5. One of plural steps of the redundancy data lengths including zero which have previously set according to the selecting command is selected by the management part 5. On the other hand, M-number of rows of two-dimensional group data is selected by the management part 5 in order to make a code length constant corresponding to the selected redundancy data length P. An enhanced code processing corresponding to the selected redundancy data length is executed by an enhanced code processing part 6. In the case of demanding extremely high reliability, when the redundancy data length is raised, the frame portion on a tape is conformed in proper quantities accordingly. In other words, the system data capacity can be set as large enough without deteriorating the reliability, and at the same time, data can be recorded without uselessness, so that the high recording capacity and high data transfer speed can be compatible.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a digital data recording and reproducing apparatus that uses a tape as a recording medium and records or reproduces data in a group area that is a predetermined area on the tape. It is.

BACKGROUND ART In recent years, digital data recording and reproducing technology using a magnetic recording and reproducing method has made rapid progress, and its application development has progressed particularly in the field of digital audio, and DAT (digital audio tape recorder) has come into practical use. DAT rotates heads with different azimuth angles to form continuous diagonal tracks on the magnetic tape.
A pair of tracks formed by both heads constitutes a frame, and digitized audio data is recorded or reproduced frame by frame. At this time, error correction code processing is performed using a double-Solomon code combined with interleaving that completes one frame, and this correction ability achieves sufficient reliability for audio use.

On the other hand, attempts have been made to apply DAT as an external storage device for computers.

This is an attempt to realize a digital data recording and reproducing apparatus by recording and reproducing digital data transferred from a computer instead of digitized audio data. In these devices, a group area consisting of a plurality of frames is formed on a tape, and digital data such as computer code data and ASCII data is recorded and reproduced using the group area as a unit of recording and reproduction. At this time, the data that can be recorded in the group area is divided into two, and one is used to record digital data from the computer as external digital data, and the other is used as system data to record data management information related to records, files, etc., and the data to manage it. The structure includes a management department.

In addition, the configuration includes an enhanced code processing unit that adds a third error correction code that is completed within the group area, realizing the data management function and reliability required for recording and reproducing computer code data, ASCII data, etc. are doing.

Problems to be Solved by the Invention However, in the above conventional configuration, there is no means for changing the capacity of system data or external digital data,
Since there is no means to change the code length of the third error correction code, there are cases where a larger system data capacity is required, conversely there are cases where a smaller system data capacity is required, or the reliability is on the same level as audio DAT. Whether a larger data storage capacity or higher data transfer rate with the computer is required, or even a lower capacity or data transfer rate but very high reliability, certain However, this method has a problem in that reliability, data recording capacity, and data transfer speed cannot be changed depending on the application because redundant data and system data of a certain capacity are added to each group data.

In view of the above-mentioned problems, the present invention provides a recording and reproducing method that achieves high reliability and a recording and reproducing method that achieves large capacity and high speed recording and reproducing in stages, allowing the user to select the recording and reproducing method that is suitable for the application. The present invention provides a digital data recording and reproducing device that realizes the present invention.

Means for Solving the Problems In order to solve the above problems, the digital data recording and reproducing apparatus of the present invention includes a data recording and reproducing means for recording or reproducing digital data by forming diagonal frames on a tape, and a data recording and reproducing means for recording or reproducing digital data by forming diagonal frames on a tape. and storage means for temporarily storing the group data recorded and reproduced in the group area as two-dimensional data, the group data is divided into external digital data and system data, and the system data capacity or external A data management means that allows the capacity of digital data to be selected from a plurality of preset values, and a Reed-Solomon code encoding process whose code sequence is in the column direction of group data, which is two-dimensional data, are provided. an enhanced code processing means that can select the redundant data length from a plurality of preset values; and a bidirectional system that distributes the system data to a plurality of tracks on the tape between the data recording and reproducing means and the storage means. The configuration includes a transfer means for transferring data.

According to the above-described configuration, the present invention switches the overall data storage capacity and data transfer speed by switching the capacity of system data or external digital data, and improves reliability and reliability by switching the redundant data length of the third error correction code. Switch the data transfer speed.

Embodiments Hereinafter, embodiments of the digital data recording/reproducing apparatus of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a digital data recording/reproducing apparatus according to an embodiment of the present invention.

In FIG. 1, 1 is a tape which is a recording medium, and 2 is a recording medium for forming a frame on the tape 1 and recording a digital signal, or for reproducing the digital signal from the tape 1.
A recording/reproduction processing unit performs encoding processing and interleaving processing consisting of <C1 series and 02 series based on the standard; 3 is a communication unit that transmits and receives control information and external digital data to and from an external device; 4 is a communication unit that transmits and receives control information and external digital data to and from an external device; 5 is a memory for temporarily storing the above-mentioned external digital data exchanged with an external device, system data generated in internal processing, and redundant data, and 5 is a group in which a group area consisting of a plurality of frames is a unit, and is recorded and reproduced in the group area. Data is divided into external digital data and system data, formed on the memory 4 as two-dimensional data, and has a system data capacity selection procedure, an external digital data capacity selection procedure, and a group data capacity adjustment procedure for selecting each capacity. This is the management department. Reference numeral 6 denotes an enhanced code processing unit that performs enhanced code processing on the group data formed on the memory 4 and stores redundant data in the memory 4. Reference numeral 7 refers to a recording/reproduction processing unit that transfers the group data and the redundant data to the memory 4. 8 is a communication unit 3 that transfers data bidirectionally between 2 and 3.
The data management information is transferred to the data management unit 5 according to the control information input via the control procedure set in advance, and the operating state of the data management unit 5, the operating state of the enhanced code processing unit 6, and data transfer are This is a control unit that controls the operating state of the unit 7.

FIG. 2 shows the internal configuration of the data management section 5. As shown in FIG. In FIG. 2, 9 is the number of rows of group data, the code length of the third error correction code, the number of columns of external digital data,
This is a register for setting the number of columns of group data in several stages, and 10 to 13 are switches for selecting one of the above setting values in accordance with the selection signal of the control unit 8 in FIG. be. 14 is a row address counter corresponding to a two-dimensional data string position and whose initial value is set by the control unit 8;
corresponds to the row position of two-dimensional data, and is a row address counter whose initial value is set by the control unit 8. Reference numeral 16 compares the value of the column address counter 14 with the number of columns of group data selected by the switch 10, and when the two are equal, outputs a clear signal of the column address counter 14 and an increment signal of the row address counter 15. 17 is the value of the column address counter 14 and the switch 11.
This is a comparator that compares the number of columns of the group data selected by the column address counter 14 and outputs a switching output for switching the data to be stored in the memory 4 between external digital data and system data depending on the size of the column address counter 14. A comparator 18 compares the value of the row address counter 15 with the code length selected by the switch 12, and outputs an end signal indicating that the two-dimensional data is completed on the memory 4 when the two are equal. , 19 compares the value of the row address counter 15 with the number of columns of group data selected by the switch 13, and outputs a switching signal to switch the data to be stored in the memory 4 between redundant data and group data depending on the magnitude. It is a comparator that Reference numerals 20 to 22 designate changeover switches that change over the data to be stored in the memory 4 in accordance with the changeover signals output from each of the comparators. 23 is an address arithmetic unit that calculates the address of the memory 4 from the values of the row address counter 15 and the column address counter 14.

The operation of the digital data recording/reproducing apparatus of this embodiment configured as above will be explained below by dividing it into basic operation and practical operation.

First, basic operations such as data recording and reproduction will be explained. When the control information given from the external device via the communication unit 3 indicates recording, the control unit 8 activates the enhanced code processing unit 6.
and instruct the data transfer unit 7 to perform a recording operation, respectively.

In the recording operation, the control unit 8 generates system data from the control information and transfers it to the data management unit 5.
transfers the system data to the memory 4 and controls external digital data transfer from an external device to the memory 4 via the communication section 3. When the transfer of the external digital data in M rows and N columns and the system data in M rows and Q columns as shown in FIG. Start. As shown in FIG. 3, the redundant data has a structure of P rows and (N+Q) columns.

At this time, the encoding sequence is in the column direction of the two-dimensional data as shown by arrow A in Figure 3, and the Reed-Solomon code with code length (M + P) bytes and intercode distance (P + 1) is transferred from the sequence of arrow A to the sequence of arrow B. Generate up to (N+Q) sequences. After the encoding process is completed, the data transfer section 7 sequentially transfers the group data to the recording/reproducing processing section 2 in the row direction of the two-dimensional data as shown by arrow C in FIG.
Based on the T standard, the C1 series and C2 series are encoded and interleaved, and a digital signal, which is a recording signal, is generated frame by frame and recorded on the tape 1. The data transfer unit 7 distributes the system data to a plurality of tracks by sequentially transferring the two-dimensional data in the row direction. Following the completion of the transfer of the group data, redundant data is similarly transferred in the row direction as shown by arrow E to the recording/reproducing processing unit 2, and frames are continuously formed on the tape 1, thereby completing the recording operation.

In the playback operation, the operation is completely reversed to the above recording operation.
The recording/reproduction processing unit 2 reproduces the group area formed on the tape 1, performs deinterleaving processing, C1 series decoding processing, and C2 series decoding processing, and the data transfer unit 7 stores the two-dimensional data shown in FIG. 3 on the memory 4. restore. Enhanced code processing unit 8
performs error correction processing for the series shown from arrow A to arrow B in FIG.
The data transfer of the memory 4 is controlled according to instructions from the control section 8, and the necessary external digital data is transferred to the external device via the communication section 3 to complete the playback operation.

Next, practical operations such as selection of system data capacity will be explained. First, the selection of system data capacity that determines the form of group data will be explained.

The control unit 8 recognizes system data capacity selection information from control information given from an external device via the communication unit 3 and issues a selection command to the data management unit 5.

In response to the selection command, the data management unit 5 follows the system data capacity selection procedure to determine the number of columns Q of the two-dimensional system data.
Select one from a plurality of preset column numbers including zero. A similar procedure is used to select the external digital data capacity, and the number N of columns of two-dimensional external digital data is selected.

Further, when the capacity of the group data is to be constant, the data management unit 5 selects the number of columns Q of the two-dimensional system data from among the number of columns set in advance in a plurality of stages according to the selection command, and also Adjust the number of columns of external digital data according to the number of columns of system data according to the capacity adjustment procedure.

In the recording/reproducing operation after the selection, the data management section 5 transfers the system data to a predetermined position on the memory 4 according to the selected number of columns, and also transfers the system data from the external device to the memory 4 via the communication section 3. The external digital data to be transferred to the memory 4 is controlled to be transferred to a predetermined position on the memory 4 according to the selected number of columns.

Further, the enhanced code processing unit 6 executes enhanced code processing for the number of code sequences corresponding to the selected number of columns.

Next, the selection of redundant data length that determines reliability will be explained. The control unit 8 recognizes redundant data length selection information from control information given from an external device via the communication unit 3 and issues a selection command to the data management unit 5. The data management unit 5 selects one from among a plurality of preset redundant data lengths including zero in response to the selection command.

On the other hand, the data management unit 5 selects the number of rows M of the two-dimensional group data in accordance with the selected redundant data length P so that the code length is constant. The recording and reproducing operation after selection is the same as explained in the basic operation, but the enhanced code processing unit 6 executes enhanced code processing according to the selected redundant data length.

Now, the selection of the number of columns of system data or the number of columns of external digital data, and the selection of redundant data length will be explained using some examples. Figure 4 shows external digital data in 32 rows and 4096 columns, and system data in 32 rows and 4 columns.
This is a standard example with 4 columns and a redundant data length of 4. The third error correction code is a Reed-Solomon code with a code length of 36 and an inter-code distance of 5, the external digital data capacity is 128 bytes, and the system data capacity is 1408 bytes. In the case of two-dimensional data with the above capacity, the capacity of the group data is 132,480 bytes, which exactly matches 23 frames on the tape as shown in Figure 5 (one frame of DAT data is 5,760 bytes). be). In other words, maximum recording efficiency is achieved for only group data.

If very high reliability is required, this can be achieved by increasing the redundant data length of the standard example.

In this example, redundant data and group data are prevented from coexisting in the same frame, and the area for redundant data is formed independently on the tape, so the recording area for redundant data shown in Figure 5 is The compatibility of tapes can be easily ensured by simply increasing or decreasing the number.

FIG. 6 is an example in which only the system data in FIG. 4 is changed to 32 rows and 64 columns to increase the capacity of the system data. In this case, the total capacity of the group data and redundant data is 149,760 bytes, which exactly matches 26 frames on the tape as shown in FIG. In other words, it is possible to increase the system data capacity without deteriorating reliability, and at the same time record data without wasting a single byte in 26 frames, making it possible to achieve both high recording capacity and high data transfer speed. It is possible.

In Figure 8, the total capacity is constant in the group data in Figure 4, the system data is set to zero, and the number of columns Q is set to zero), and by setting the redundant data length to zero, the storage capacity,
This is an example of improving data transfer speed. In this case, the reliability is on the same level as audio DAT, and the maximum recording capacity and data transfer rate are achieved. At the same time, as shown in Fig. 9, external digital data is recorded without wasting 1 byte in 23 frames, and redundant data is not recorded, so it is possible to realize the same data recording state on the tape as audio DAT. .

As described above, according to this embodiment, the data management unit 5 includes a system data capacity selection procedure, an external digital data capacity selection procedure, a group data capacity M adjustment procedure, and an enhanced code includes a redundant data length selection procedure. A processing unit 8, a recording/reproduction processing unit 2, and a memory 4 are provided, and by setting a plurality of columns and redundant data lengths for system data and external digital data treated as two-dimensional data, and selecting the above-mentioned number of columns, a group can be created. The ratio of external digital data to the total data changes, and as a result, the data transfer speed of external digital data exchanged with an external device can be varied in stages. On the other hand, by changing the redundant data length, the third error correction capability can be changed, and the capacity of redundant data that is always added to the group data can be changed, so that the data transfer rate can be varied.

Also, the number of columns of system data, external digital data,
By combining the redundant data lengths, it is possible to set various characteristics including the recording format on the tape.

In the present embodiment, the data management unit 6 divides the group data on the memory 4 in the column direction into system data and external digital data as shown in FIG. 3, but the data management unit 6 may divide the group data in the row direction. . In this case, the external digital data is M rows and N columns, the system data is Q rows and N columns, and the number of columns is N.
The capacity of the external digital data and system data is selected by selecting the number of rows M and Q with M being constant.

Effects of the Invention As described above, the digital data recording/reproducing apparatus of the present invention includes a data recording/reproducing means for recording or reproducing digital data by forming diagonal frames on a tape;
A storage means for temporarily storing digital data, and storing the group data recorded in the group area as two-dimensional data in the storage means, dividing the group data into external digital data and system data, and dividing the group data into external digital data and system data. A data management means capable of selecting a digital data capacity from a plurality of preset values, and encoding and decoding processing of a Reed-Solomon code whose code sequence is in the column direction of group data, which is two-dimensional data, The system data is distributed to a plurality of tracks on the tape between the enhanced code processing means that can select the redundant data length of the Reed-Solomon code from a plurality of preset values, the data recording and reproducing means, and the storage means. By providing a transfer means that transfers data in both directions, it is possible to select in stages between a recording and reproducing method that achieves high reliability and a recording and reproducing method that achieves large capacity and high-speed recording and reproducing. It is possible. Further, since various recording formats on the tape can be set depending on the set combinations, it is possible to realize a recording/reproduction method most suitable for the application. Moreover, these can be easily realized with the same hardware, and the effects are great in practical and industrial terms.

[Brief explanation of the drawing]

A structural diagram of two-dimensional data formed on memory 5 in the example, FIG. 4 is a structural diagram of two-dimensional group data in a standard example, and FIG. 5 is a frame on tape 1 in the group data structure of FIG. 4. , Figure 6 is a diagram of the structure of two-dimensional group data in an example where the system data capacity has been changed, Figure 7 is a diagram of the frame configuration on tape 1 in the group data structure of Figure 6, and Figure 8 is the system diagram. FIG. 9 is a structural diagram of two-dimensional group data in an example in which the data capacity and redundant data capacity are set to zero. FIG. 9 is a structural diagram of frames on tape 1 in the group data structure of FIG. 8. 1... Tape, 2... Recording/playback processing section, 3
...Communication section, 4.Memory, 5.Data management section, 6.Enhanced code processing section, 7.Data transfer section, 8.Control section. Name of agent: Patent attorney Shigetaka Awaka One person speaking! - UJ player - 9 External part 91 Renargu + statement L take happy figure figure figure 7i' long teta mixed play

Claims (7)

[Claims] (1) data recording and reproducing means for recording or reproducing digital data by forming diagonal frames on the tape; and storage means for temporarily storing digital data;
data management means for storing group data, which is a unit of recording and reproduction and is recorded and reproduced in a group area consisting of a plurality of continuous frames on the tape, in the storage means; and between the data recording and reproduction means and the storage means. The data management means transfers the group data into external digital data input from the outside and system data used for recording management information of the external digital data. 1. A digital data recording and reproducing apparatus comprising: a system data capacity selection procedure for selecting a system data capacity from a plurality of preset values; (2) The data management means includes an external digital data capacity selection procedure for selecting the capacity of external digital data from a plurality of preset values in place of the system data capacity selection procedure. The digital data recording and reproducing device described above. (3) The data management means includes a group data capacity adjustment procedure for increasing or decreasing the capacity of external digital data and keeping the capacity of the group data constant according to the capacity of the system data selected by the system data capacity selection procedure. A digital data recording/reproducing apparatus according to claim 1. (4) The data management means stores external digital data in M rows and N columns, system data in M rows and Q columns, and a total of M rows (N
+Q) It is stored in the storage means as two-dimensional group data with a capacity of columns, and the number of columns of two-dimensional data is selected in the system data capacity selection procedure, external digital data capacity selection procedure, and group data capacity adjustment procedure. 4. A digital data recording and reproducing apparatus according to claim 1, 2 or 3. (5) The digital data recording and reproducing apparatus according to claim 1, 2 or 3, wherein the transfer means includes a transfer processing procedure for transferring the system data so as to be distributed over a plurality of tracks on the tape. (6) A data recording and reproducing means for recording and reproducing digital data by forming diagonal frames on the tape, a storage means for temporarily storing digital data, and a plurality of frames on the tape. The group data to be recorded and played back in the group area, which is the unit of playback, is
a data management means for storing the two-dimensional data in the storage means; an enhanced code processing means for encoding and decoding a Reed-Solomon code whose code sequence is the column direction of the two-dimensional data; The reinforcement code processing means includes a transfer means for performing bidirectional data transfer of group data between the storage means and the data recording and reproducing means, and the reinforcement code processing means includes a redundant redundancy code that allows the redundant data length to be selected from a plurality of preset values. 1. A digital data recording and reproducing device comprising a degree selection procedure. (7) The data management means increases or decreases the number of rows of the two-dimensional group data in accordance with the redundant data length selected by the redundancy selection procedure of the enhanced code processing means, and keeps the code length whose code sequence is in the column direction constant. 7. The digital data recording and reproducing apparatus according to claim 6, further comprising code length adjusting means.