JPH04337564A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To prevent an erroneous reproduction accident, to improve the reliability of a reproduced data and to expand an applicable field as an external storing device by adding a control data, lowering the amplitude of a digital signal and simultaneously recording doubly an input data in two tracks. CONSTITUTION:The input data D1 from a computor 4 is converted into a digital signal DA1 by an input/output device 2 and recorded successively to a digital audio tape recorder DAT 3. In a reproducing mode, the data DA2 of the DAT 3 is converted to the original data by the device 2 and outputted to the computer 4. At this time, a word data is generated by applying a prescribed control data DC to the upper bits of an input D1 so as to lower the amplitude of the input data DA1 and thee accident at the time of outputted erronesously to an audio equipment is prevented. Further, adding to this, by assigning and recording a repeating input data to respective even numbered and odd numbered word data to two tracks to record and add a code for an error correcting processing, the reliability is improved.

Description

[Detailed description of the invention]

0001

[Table of Contents] The present invention will be explained in the following order. Industrial application field Conventional technology Problems to be solved by the invention Means for solving the problem (Figs. 1 and 7) Effect (Fig. 1
and FIG. 7) Example (FIGS. 1 to 7) (1) Overall configuration (FIG. 1) (2) Format of digital signals DA1 and DA2 (
Figures 2 to 4) (3) Input/output circuit (Figures 5 to 7) (3-1) Recording mode (3-2) Playback mode (4) Effects of embodiments (5) Effects of other embodiments of the invention

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording device, and is particularly suitable for use when a digital audio tape recorder is used as an external storage device for a computer, for example.

0003

2. Description of the Related Art Conventionally, in this type of magnetic recording device, recording tracks are sequentially formed diagonally on a magnetic tape so that digital audio signals can be recorded and reproduced (hereinafter referred to as a digital audio tape recorder). There is.

[0004] In this type of digital audio tape recorder, after converting an audio signal into a digital signal, interleaving processing is performed at a predetermined period.
Recording is done by adding an error detection and correction code,
This effectively avoids the effects of dropout, etc.
It is designed to record high-quality audio signals at high density.

Furthermore, this type of digital audio tape recorder is capable of inputting and outputting digital audio signals of a predetermined format (IEC-458 standard) via a predetermined interface circuit, so that digital audio signals of a predetermined format (IEC-458 standard) can be input and output from, for example, a compact disc player. By directly recording the output digital audio signal, it is possible to effectively avoid deterioration in sound quality caused by analog-to-digital conversion processing and digital-to-analog conversion processing.

[0006]

However, it would be convenient if this type of digital audio tape recorder could be used as an external storage device for a computer or the like. In other words, switch the connection of the digital audio tape recorder connected to the audio device,
If the digital audio tape recorder can be used as an external storage device as needed, it is thought that the field of application of the digital audio tape recorder can be expanded and the usability can be improved.

However, when the magnetic tape is used as an external storage device in this way, there is a risk that the recorded magnetic tape may be erroneously reproduced on the audio device side, and in this case, there is a risk that an accident such as damage to the speaker may occur.

[0008] Furthermore, when the data is used as an external storage device in this way, there is a possibility that the recorded data may not be reproduced correctly due to error detection and correction processing performed by the digital audio tape recorder.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a magnetic recording device that can be used as an external storage device for computers and the like.

0010

[Means for Solving the Problems] In order to solve the above problems, in the first invention, recording tracks TA and TB are sequentially formed diagonally on a magnetic tape, and word data of a predetermined bit length is repeated. In a magnetic recording device 1 that sequentially records a signal DA1 on recording tracks TA and TB, input data D1 that is input sequentially is converted into a digital signal D.
It has a conversion circuit 2 that converts the digital signal DA1 into A1, and the conversion circuit 2 generates word data by adding predetermined control data DC to the upper part of the input data D1 so that the amplitude of the digital signal DA1 becomes small.

Furthermore, in the second invention, first and second recording tracks TA and TB having different azimuth angles are sequentially formed obliquely on a magnetic tape, and a digital signal is produced by repeating word data of a predetermined bit length. Of DA1, odd-numbered word data is assigned to the first recording track TA, even-numbered word data is assigned to the second recording track TB, and error detection and correction processing is performed for each of the first and second recording tracks. A magnetic recording device 1 that records data with a code attached thereto has a conversion circuit 2 that converts input data D1 that is input sequentially into a digital signal DA1. Predetermined control data DC is added to the upper part of the data D1, and the input data D1 is converted into even-numbered and odd-numbered word data so as to double-record the input data D1 on the first and second recording tracks TA and TB. is repeatedly assigned to generate word data.

0012

[Operation] When converting input data D1 that is input sequentially into digital signal DA1 and recording it, digital signal DA1
If word data is generated by adding predetermined control data DC to the upper part of the input data D1 so that the amplitude of the input data D1 is small, accidents such as damage to speakers can be prevented even if the data is played by mistake on the audio device side. be able to.

Furthermore, in conjunction with this, the input data D1 is applied to the first and second recording tracks TA and TB, which are recorded with codes for error detection and correction processing, respectively.
If the word data is generated by repeatedly assigning the input data D1 to the even and odd word data so as to perform double recording, the reliability of the reproduced data can be improved accordingly.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Overall configuration In FIG. 1, 1 indicates a computer system as a whole, and data is input and output between a digital audio tape recorder (DAT) 3 and a computer 4 via an input/output device 2. A digital audio tape recorder 3 is used as an external storage device for a computer 4. That is, the computer 4 inputs and outputs desired data to and from the input/output device 2 via the bus BUS.

The input/output device 2 converts the input data D1 inputted from the computer 4 into a digital signal DA1 according to the format standardized by IEC-458.
The digital signal DA1 is output to the digital audio tape recorder 3.

The digital audio tape recorder 3 receives the digital signal DA1 in place of the digital audio signal, records the digital signal DA1 sequentially, and thereby easily records the data D1 of the computer 4. There is.

Further, in the digital audio tape recorder 3, by switching the operation mode to the playback mode, the playback data is converted into a digital signal DA2 according to the IEC-458 standard and then sequentially output.

When the digital audio tape recorder 3 enters the playback mode, the input/output device 2 converts the digital signal DA2 outputted from the digital audio tape recorder 3 into original data D2 according to the IEC-458 standard. The data D2 is output to the computer 4.

[0020] With this, the computer 4 can connect the digital audio tape recorder 3 as necessary, and
The digital audio tape recorder 3 can be used as an external storage device.

(2) Format of digital signals DA1 and DA2 As shown in FIG. 2, according to the IEC-458 standard, digital signals DA1 and DA2 are formed by consecutive frame data from frame 0 to frame 191. In the digital audio tape recorder 3 (FIG. 2A), two recording tracks are formed at a cycle of 0 to 191 frames corresponding to the digital signals DA1 and DA2.

The frame data (FIG. 2(B)) is formed by subframe data of two consecutive channels, and in the digital audio tape recorder 3, each subframe data is assigned to the right and left channels, respectively, and the data shown in FIG. The data are recorded sequentially in the format shown.

That is, in the digital audio tape recorder 3, each recording track is divided into two recording areas in the longitudinal direction, and thereby one interleave period (
(corresponding to the period from frame 0 to frame 191), four recording areas are formed.

For these four recording areas, the digital audio tape recorder 3 records frames 0 to 191 for each recording track TA with a positive azimuth angle.
Among the frame data up to the frame, the even-numbered frame data of the first channel is sequentially recorded in the first recording area, and then the odd-numbered frame data of the second channel is recorded in the second recording area. Further, the digital audio tape recorder 3 records the even-numbered frame data of the second channel in the first recording area for the subsequent recording track TB with a negative azimuth angle, and then records the odd-numbered frame data of the first channel in the second recording area. Record in the recording area.

Furthermore, at this time, in the digital audio tape recorder 3, after interleaving the subframe data within each recording track TA, TB,
The data is recorded with an error detection and correction code attached thereto, so that the reproduced data can be subjected to error correction processing for each recording track.

[0026] As a result, in the digital audio tape recorder 3, during playback, after changing the arrangement of the playback data in the opposite manner to that during recording, the playback data that could not be error corrected is interpolated based on the previous and succeeding playback data. By doing so, for example, one of the recording tracks TA or T of the pair is
Even if dropout occurs in B, the generation of abnormal noise can be effectively avoided.

In each subframe data (FIG. 2(
C)) The first 4 bits are allocated to a synchronization preamble, the following 4 bits are allocated to transmitting auxiliary data, and the following 20 bits are used to transmit desired transmission data.

Therefore, in the digital audio signal of the IEC-458 standard, audio data is assigned to the transmission data DX, and the digital audio tape recorder 3 extracts the audio data from the transmission data DX and converts it into a recording signal. This makes it possible to record digital audio signals.

On the other hand, the first 1 bit V of the following 4 bits is assigned to a validity flag indicating the validity or invalidity of the audio data, and in the digital audio tape recorder 3, when the playback data is interpolated, the flag is is set to "1".

The following 1 bit U is assigned to a user bit flag.

The following 1 bit C is allocated to channel status data, and the remaining 1 bit P is allocated to parity bit. As a result, in the digital audio tape recorder 3,
By sequentially detecting user bits U and channel status C for frame data from frame 0 to frame 191, information regarding transmission data can be detected.

That is, as shown in FIG. 4, in channel status C, control data is transmitted from frame 0 to frame 5. For example, when transmitting 2 channels of pre-emphasized audio data, the control data is set to "0x100". ” and
When copying is prohibited, "X" is set to "0". Furthermore, in channel status C,
The next 6 and 7 frames of frame data represent the mode, and the next 8 to 15 frames of frame data transmit the category code.

In the digital audio tape recorder 3, user bits U, channel status C, etc. are allocated and recorded in a subcode recording area and a subdata recording area according to their contents, for example, sampling frequency, etc. Regarding the information, the operation is changed depending on the content.

Furthermore, the digital audio tape recorder 3 is designed to detect bit errors in the input digital signal DA1 based on the parity bit P.

(3) Input/output circuit (3-1) Recording mode As shown in FIG.
PU) 8 converts input data D1 and digital signal DA2 in accordance with the IEC-458 standard.

At this time, in the central processing unit 8,
Control data DCN output from the computer 4 is taken in via the control bus BUS, and the operation of the entire input/output device 2 is switched based on the control data DCN.

That is, when input data D1 is to be recorded on the digital audio tape recorder 3, the central processing unit 8 sets the digital audio tape recorder 3 to the recording mode, and then controls the digital audio tape recorder 3 from the computer 4 in response to keyboard operations. When data DCN is output, the operation mode of the input/output device 2 is switched to recording mode.

When input data D1 is input from the computer 4 in this state, the central processing unit 8 outputs a control signal to the buffer memory 10, and stores the input data D1 in the buffer memory 10.

At this time, the central processing unit 8 stores the predetermined control code DC in the buffer memory 10 in advance together with the synchronization preamble data, the user bit U, the channel status C data, etc., and converts the data stored in the buffer memory 10 into the input data D1. It is also sequentially output to the parallel-to-serial conversion circuit 11.

[0040] Here, the parallel-serial conversion circuit 11 is
After converting the output data DP1 of the buffer memory 10 into serial data, it is outputted via the output circuit 13.

As a result, the input/output device 2 assigns the input data D1 to the transmission data DX and converts it into a digital signal DA1, and then outputs the digital signal DA1 to the digital audio tape recorder 3.

At this time, the central processing unit 8 sets the control data to "0" for the channel status C.
1100'' (that is, the same as when transmitting two channels of pre-emphasized audio data).

Furthermore, the central processing unit 8 sets the mode data to "00" and sets the remaining channel status C data to predetermined values. Further, the central processing unit 8 stores "0" data as the validity flag V data. This allows input/output device 2
The input data D1 is recorded in the same format as the digital audio signal.

[0044] According to the IEC-458 standard, when the 0 frame of channel status C is "1", the digital audio tape recorder 3 determines that the signal is a digital signal other than a digital audio signal and stops recording. ing.

Furthermore, even in the case of a digital audio signal, recording is stopped in the digital audio tape recorder 3 when the next frame is "0".

Therefore, as in this embodiment, the input data D1 of the computer 4 can be recorded by converting the input data D1 of the computer 4 into the digital signal DA1 by adding a category code in the same format as the digital audio signal. can.

Furthermore, at this time, in the input/output device 2,
The same “0110” as in the case of two-channel audio data with pre-emphasized control data
0", the pre-emphasis processing and de-emphasis processing in the digital audio tape recorder 3 can be omitted, and the input data D1 can be reliably processed accordingly.
can be recorded and played.

Furthermore, the central processing unit 8 processes the upper 4 bits of the transmission data DX (hereinafter referred to as upper data).
And data "0000" is stored as auxiliary data. Furthermore, the central processing unit 8 outputs control codes DC such as "00000001", "00000000", and "11".
Four types of data are stored: "111111" and "11111110" (hereinafter expressed in hexadecimal numbers as "01", "00", "FF", and "FE", respectively).

As a result, as shown in FIG. 6, the central processing unit 8 adds 4-bit ``0000'' upper-order data and a control code DC to the 8-bit input data D1 to form transmission data DX. .

In the audio data of the digital audio signal, the portion corresponding to the upper data is ignored, and the amplitude of the audio signal is expressed by the remaining data expressed in two's complement.

Therefore, in the digital signal DA1,
By setting the control code DC to the above four types, even if the audio device accidentally reproduces the signal, the amplitude of the reproduced signal can be reduced, and damage to the speaker can be effectively avoided.

That is, in the digital audio signal, when the lower 16 bits of the transmission data DX are all "1" or "0", the maximum amplitude HMAX is reached. If a control code DC is attached to this, the transmission data DX
The maximum amplitude H of is given by the following formula

It can be seen that the maximum amplitude H can be reduced to 1/64 while keeping the maximum amplitude H within the range of .

Therefore, even when this type of digital audio tape recorder is used as an external storage device for a computer or the like, it is possible to effectively avoid damage to the speakers, and the field of application of the digital audio tape recorder can be expanded. .

Furthermore, when reading data from the buffer memory 10, the central processing unit 8 is configured to repeatedly read the same data in a predetermined order, thereby recording the same input data D1 twice on the magnetic tape. There is.

That is, as shown in FIG. 7, the central processing unit 8 inputs "00" as the control code DC during the period after starting the input/output device 2 into the recording mode until the output data D1 is input. Select the control code DC
The transmission data DX is formed by adding data "00" to the data.

As a result, the input/output device 2 outputs the output data D
For the portion without 1, the lower 16 bits of the transmission data DX are set to "0000" and the transmission data DX is recorded.

On the other hand, when the output data D1 is input, the central processing unit 8 outputs "F" as the control code DC.
E" is selected, and data "01" is added to the control code DC to form transmission data DX. As a result, the input/output device 2 records the transmission data DX whose lower 16 bits are "FE01" at the recording start part, and thereby, during playback,
The beginning of the data can be easily detected.

Furthermore, at this time, the central processing unit 8 sets the lower 16 bits of the transmission data DX to "0000" and "FE01", respectively, for the even-numbered frame data, and then sets the lower 16 bits of the transmission data DX to "0000" and "FE01", respectively, for the even-numbered frame data, and then sets
Repeatedly outputs transmission data with the same content.

Therefore, in the digital audio tape recorder 3, by repeating the same content in the even-numbered and odd-numbered frame data, "" is written in the first and second recording areas of the recording track TA in FIG. 3, respectively.
After the data of "0000" and "FE01" are assigned,
Data “FE01” and “0000” are recorded in the first and second recording areas of the subsequent recording track TB, respectively.
Data with the same content is recorded redundantly on different recording tracks.

At this time, in the digital audio tape recorder 3, by performing error detection and correction processing on each recording track TA and TB, data of the same content can be recorded redundantly on different recording tracks in this way. Even if correct data cannot be reproduced from one recording track, correct data can be reproduced from the remaining recording tracks, and the reliability of the reproduced data can be improved accordingly.

In response to this, the central processing unit 8 subsequently starts converting the input data D1, and at this time, it sequentially and cyclically converts the control code DC to "01", "01", and "FF".
, select the "FF" data.

Further, the central processing unit 8 maintains an interval of one cycle and reads out the same input data D1 twice from the buffer memory 10, thereby adding the input data D1 having the same content to the odd and even frame data.
Assign repeatedly. As a result, in the digital audio tape recorder 3, the input data D1 having the same content can be assigned to different recording tracks TA and TB and recorded in duplicate, similar to the beginning part of the recording start.
The reliability of reproduced data can be improved accordingly.

Furthermore, at this time, in the input/output device 2,
"01", "01", "FF", "FF" sequentially and cyclically
By selecting the data and assigning it to the control code, it is possible to easily detect a pair of double-recorded data on the basis of the control code DC at the time of reproduction. Therefore, during reproduction, the input/output device 2 can select correctly reproduced transmission data from paired data based on the control code DC, convert the transmission data into its original format, and output it. This makes it possible to improve the reliability of reproduced data.

On the other hand, when the input of the input data D1 is stopped and the control data DCN indicating the completion of output is output from the computer 4, the central processing unit 8 outputs "FE01" and "0000", contrary to the time when recording was started. After repeating the transmission data DX of ``, the output of the digital signal DA1 is stopped.

(3-2) Reproduction mode On the other hand, in the reproduction mode, the central processing unit 8
outputs a control signal to start up the operation of the input circuit 16 and the serial-parallel conversion circuit 18. As a result, the input/output device 2 receives the IEC-458 standard digital signal DA output from the digital audio tape recorder 3.
2 is converted into parallel data in 8-bit units by the serial-parallel conversion circuit 18, and then sequentially stored in the buffer memory 10.

At this time, the central processing unit 8 detects the control code DC of each transmission data DX, and detects the beginning and end of the actual data. Further, the central processing unit 8 detects the double recorded data pair based on the control code DC. As a result, the central processing unit 8
The lower 8 bits of data D2 are extracted from one of the transmission data DX of the pair, and the data D2 is output to the computer 4.

At this time, the central processing unit 8 detects the validity flag V for each subframe, and detects interpolated subframe data. As a result, the central processing unit 8 outputs data D2 from the remaining paired subframe data for the interpolated subframe data. As a result, the input/output device 2 detects the double recorded data based on the control code DC, and selectively outputs the detected data based on the validity flag V, thereby selectively outputting the correct reproduction data D2. can be output to.

Therefore, even when the digital audio tape recorder 3 performs interpolation processing, the input/output device 2 can output correct playback data that is not affected by the interpolation process, and the reliability of the playback data can be improved accordingly. In this way, the digital audio tape recorder 3 is connected to the computer 4.
It can be used as an external storage device to improve the field of application.

(4) Effects of the Embodiment According to the above configuration, by adding predetermined control data to the upper part of the input data to form frame data, even if the audio device accidentally plays the data, the playback will continue. The amplitude of the signal can be reduced, and damage to the speaker can be effectively avoided accordingly.

Furthermore, the digital audio tape recorder 3 can repeat the input data D1 with the same content to form the digital signal DA1, and double record the input data D1 with the same content on different recording tracks TA and TB.
Even when interpolation processing is performed, correct playback data that is not affected by the interpolation process can be output, and the reliability of the playback data can be improved accordingly, thereby improving the field of application of the digital audio tape recorder.

(5) Other Embodiments In the above embodiments, the case where input data outputted from a computer is recorded sequentially is described.
The present invention is not limited to this. For example, when forming transmission data, data "0000" inserted at the start of recording may be inserted to adjust the timing of input data and digital signals.

Furthermore, in the above embodiment, the case where the control data is set to "01100" has been described, but the present invention is not limited to this, but can also be used when recording in place of audio data set to various values. Can be widely applied.

Further, in the above embodiment, the case where the same data is recorded twice is described, but the present invention is not limited to this, but can be widely applied to cases where multiple recording is performed.

Furthermore, in the above embodiment, a case was described in which data outputted from a computer was recorded, but the present invention is not limited to this, and can be applied to recording data outputted from various measuring devices, image data, etc. It can be widely applied when

[0075]

As described above, according to the present invention, predetermined control data DC is added to the top of sequentially input input data so that the amplitude becomes small, and the digital signal is converted into a digital signal. By sequentially recording data, it is possible to prevent accidents such as damage to speakers even when the audio device plays back the data. Furthermore, by converting input data by repeatedly assigning input data to even-numbered and odd-numbered word data so that the same input data is recorded twice on different recording tracks, the influence of interpolation processing can be reduced. Therefore, the reliability of the reproduced data can be improved accordingly, and the field of application can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a computer system according to one embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining the digital signal.

FIG. 3 is a schematic diagram showing a recording format.

FIG. 4 is a chart for explaining channel status.

FIG. 5 is a block diagram showing an input/output device.

FIG. 6 is a schematic diagram showing transmission data.

FIG. 7 is a chart for explaining data conversion.

[Explanation of symbols]

1...computer system, 2...input/output device, 3...
... Digital audio tape recorder, 4 ... Computer, 8 ... Central processing unit, 10 ... Buffer memory, 11 ... Parallel-serial conversion circuit, 18 ... Serial-parallel conversion circuit.

Claims (2)

[Claims] 1. A magnetic recording device in which recording tracks are sequentially formed diagonally on a magnetic tape and a digital signal formed by repeating word data of a predetermined bit length is sequentially recorded on the recording tracks, wherein the input data is sequentially input. The conversion circuit includes a conversion circuit that converts the digital signal into the digital signal, and the conversion circuit generates the word data by adding predetermined control data to the top of the input data so that the amplitude of the digital signal is small. Features of magnetic recording device. 2. First and second recording tracks having different azimuth angles are sequentially formed obliquely on a magnetic tape, and odd-numbered word data of a digital signal formed by repeating word data of a predetermined bit length is recorded. Magnetic recording in which even-numbered word data is assigned to the first recording track, and even-numbered word data is assigned to the second recording track, and each of the first and second recording tracks is recorded with a code for error detection and correction processing. The apparatus includes a conversion circuit that converts sequentially input input data into the digital signal, and the conversion circuit adds predetermined control data to the top of the input data so that the amplitude of the digital signal becomes small. In addition, the word data is generated by repeatedly assigning the input data to the even-numbered and odd-numbered word data so that the input data is double-recorded on the first and second recording tracks. magnetic recording device.