JPH0831258B2 - Magnetic recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a magnetic recording apparatus represented by R-DAT, and in particular, error correction cannot be performed when recording a transmitted digital signal. The present invention relates to a magnetic recording device that prevents subcode data from being recorded.

[Outline of Invention]

In the present invention, when the error of the data to be recorded is uncorrectable, the data is recorded as substantially no information data.

[Conventional technology]

In R-DAT, subcode data is recorded together with PCM audio data. The subcode data is recorded in two areas (SUB-1, SUB-2) of one track.
The subcode data of each area is composed of eight blocks of data, one block being 32 symbols (one symbol is 8 bits).
It consists of the data of. Addresses from 0 to F (hexadecimal number) are assigned to each block, and one set of odd symbols and one set of even symbols in two blocks of even-numbered blocks and odd-numbered blocks larger by 1 Error correction is performed as a unit. Assuming that the odd symbols are error correction A blocks and the even symbols are error correction B blocks,
Two blocks of error corrections A and B exist in the two blocks. Each error correction block is composed of 32 symbols, 28 symbols are data, and 4 symbols are parity.

Program time, absolute time, TOC information, etc. can be recorded as a pack in this subcode data. The head azimuth is different, and the subcode is not updated in one frame composed of two consecutive tracks. For example, a time code at the same time is recorded on the two tracks. Each pack is composed of a 4-bit item (ITEM), 60-bit data and parity, and the item represents the content (item) of the data. For example, item (0001) represents program time, (0010) represents absolute time, and (0000) represents no information (all data is 0).

[Problems to be solved by the invention]

For example, when a signal reproduced by the first device is recorded by the second device, even if the error of the data input as the signal recorded in the second device cannot be corrected, the conventional device is The subcode data was recorded as it was. As a result, the device may malfunction (perform erroneous processing) based on newly recorded erroneous data.

[Means for solving problems]

In order to solve the above problems, the present invention provides a magnetic recording device for recording subcode data to which a flag indicating an error correction status is added to a recording medium together with main information, including the following. To do.

(A) Judging means for judging a flag included in the input sub-code data and indicating whether or not the error correction is possible.

(B) A memory for storing the input subcode data.

(C) Data conversion means for converting the subcode data stored in the memory into a specific data string indicating no information when the determination means determines that the error correction of the subcode data is impossible .

(D) Control means for recording the specific data string converted by the data converting means on the recording medium as subcode data to be added to the main information.

[Action]

According to the magnetic recording device of the present invention, each component operates as follows.

The determination means determines a flag indicating whether or not the error correction of the subcode data which is reproduced from another reproduction device or the like and is input, can be performed.

 The memory also stores the subcode data.

The data conversion means, when the determination means determines that the error correction of the subcode data cannot be performed, the data conversion means stores a data string indicating that the subcode data recorded in the memory is non-information (for example, “0000”). )).

Then, the control means records the specific data sequence converted by the data conversion means on a recording medium (for example, an R-DAT magnetic tape) as subcode data to be added to the main information.

〔Example〕

FIG. 1 is a block diagram when the magnetic recording apparatus of the present invention is applied to an R-DAT. In the figure, 1 is a PLL circuit, which separates and extracts a clock component from an input digital signal. The extracted clock is supplied to the extraction circuit 2. The extraction circuit 2 uses this clock to separate and extract subcode data and PCM audio data from the input signal. Signal processing circuit 8 for PCM audio data
After being input to the memory, processed, and stored in a predetermined address (PCM data area) of the memory (external RAM) 9.

Assuming that the first mode is set and input by operating the input means 5, the control circuit 4 including a microcomputer controls the signal processing circuit 8 and the subcode data input from the extraction circuit 2 is input. Are processed and stored as they are in a predetermined address (subcode data area) of the memory 9.

On the other hand, when the second mode is set and input by the input means 5, the determination circuit 3 determines the flag indicating the error correction status from the subcode signal output by the extraction circuit 2.

That is, the input subcode data is configured as shown in FIG. 4, for example. That is, on the magnetic tape, as shown in the 0th and 1st blocks, 24 symbols up to the 32nd symbol of the even block and the 23rd symbol of the odd block
A total of 56 symbols are used as data, and among the 8th symbol from the 24th symbol to the 31st symbol of the odd block, the even symbol is the parity of the error correction block A.
Pa, the odd symbol is the parity of the error correction block B
While recorded as Pa, the input (transmitted) data is structured as shown in the second and third blocks. 32 symbols for even blocks and
It is similar that a total of 56 symbols of 24 symbols are used as data, but parity Pa and Pb are not input (transmitted), and C1 correction flags Fa and Fb indicating the error correction status are input (transmitted) instead. It Flags Fa and Fb are flags of error correction blocks A and B, respectively.

The determination circuit 3 determines a flag regarding the sub-code data for two blocks stored in the memory 9 via the signal processing circuit 8. The control circuit 4 has a good flag. When it can be corrected (for example, it can be corrected), the next two blocks of data are stored in the memory 9 via the signal processing circuit 8. Further, when the flag is not good (for example, uncorrectable), the control circuit 4 controls the memory 9 via the signal processing circuit 8 and the stored sub-code data of two blocks is substantially non-information. Data (for example, all data is set to 0).

The above processing is performed for one frame of data, that is, for 32 blocks of data after the detection of the frame sync. This operation is shown in a flow chart in FIG.

The subcode data stored in the memory 9 is sequentially read as needed and recorded on a magnetic tape (not shown). Therefore, this prevents uncorrectable subcode data from being recorded and prevents a device that reproduces it from malfunctioning.

Next, when the third mode is set and input by the input means 5, the operation shown in the flowchart of FIG. 3 is performed. That is, when two blocks of subcode data are stored in the memory 9 via the signal processing circuit 8, the determination circuit 3 determines the corresponding flag.

The flag is better than a predetermined criterion (for example, the criterion is good when the number of errors per 2 blocks is 2 or less, whereas the number of errors of 2 blocks this time is 1) If, the control circuit 4 reads, for example, the item (ITEM) of the pack data from the input data. When the item means no information (when it is 0000), the control circuit 4 stores the next two blocks of subcode data in the memory 9 and repeats the same processing.

When the item means other than non-information (when it is not 0000), the control circuit 4 stores the data of two blocks in the memory (two block buffer) 6 and then repeats the above operation.

When the flag is not better, the control circuit 4
Stores the address of the block in the memory 7 such as a register, and then repeats the above-described operation.

When the above operation is performed for one frame of data, the control circuit 4 reads the block address stored in the memory 7, and the subcode data of the block address stored in the memory 9 is stored in the memory 6. Rewrite the stored data. Since the memory 6 stores the data of a block that has meaningful information and is capable of error correction, and the memory 7 stores the block address of a block in which the data is not reliable,
After all, the bad block data is replaced with the good two blocks of data. The subcode data stored in the memory 9 is sequentially read out as needed and recorded on the magnetic tape, so that the same subcode data is written in a maximum of eight times in one track (16 times in one frame). Will be. This prevents uncorrectable subcode data from being recorded, and prevents a device that reproduces the subcode data from malfunctioning.

Since the maximum number of packs that can be recorded in two blocks is seven, for example, one magnetic tape has seven or more packs.
Frame 16 Overwriting creates lost packs. Therefore, the control circuit 4 reads the subcode data and displays it on the display means.
Make 10 display a predetermined number (for example, display the number of packs). The user looks at this display and operates the input means 5,
The desired mode described above can be selected and input.

〔effect〕

As described above, the magnetic recording apparatus according to the present invention comprises the determination means for determining the flag included in the input subcode data, which indicates whether or not the error correction is possible, the memory for storing the input subcode data, and the determination means. When it is determined that the error correction of the subcode data is impossible, the data conversion means for converting the subcode data stored in the memory into a specific data string indicating no information, and the data conversion means. Since the control means for recording the converted specific data sequence as subcode data to be added to the main information on the recording medium is provided, the subcode data with many errors is recorded on the recording medium such as a magnetic tape. Can be prevented. Therefore, when reproducing this recording medium, it is possible to solve the problem that the reproducing device may malfunction due to incorrect contents of the subcode data.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic recording apparatus of the present invention, FIGS. 2 and 3 are flowcharts thereof, and FIG. 4 is an explanatory diagram of its subcode data. 1 ... PLL circuit 2 ... extraction circuit 3 ... judgment circuit 4 ... control circuit 5 ... input means 6,7 ... memory 8 ... signal processing circuit 9 ... memory 10 ... display means

Claims (1)

[Claims] 1. A magnetic recording device for recording subcode data to which a flag indicating an error correction status is added together with main information on a recording medium, in which a flag indicating whether or not an error correction is included in the input subcode data is set. Determination means for determining, a memory for storing the input sub-code data, and a sub-memory stored in the memory when the determination means determines that error correction of the sub-code data is impossible Data conversion means for converting code data into a specific data string indicating no information, and the recording medium as sub-code data to be added to the main information with the specific data string converted by the data conversion means. A magnetic recording device comprising: