JPH0679419B2 - Magnetic recording device - Google Patents

Description

The present invention relates to a magnetic recording device represented by R-DAT.

[Outline of the Invention] In the present invention, a flag relating to an error in data to be recorded is determined, and good data is multiple-written.

[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 consists of 8 blocks of data, one block is 32 symbols (1 symbol is 8 bits)
It is composed 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. If the odd symbol is the error correction A block and the even symbol is the error correction B block,
There are two blocks of error correction A and B in the two blocks. Each error correction block consists 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, the time code of the same time is recorded on the two tracks. Each pack consists of 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]

According to the present invention, in a magnetic recording device for recording information inputted with a flag indicating an error state on a magnetic recording medium in block units, a determination circuit for determining an error state of the information by the flag, and the determination circuit It is characterized in that it is provided with a storage circuit for storing information determined to be good by the circuit, and a processing circuit for multiplex-recording the information stored in the storage circuit in a plurality of blocks.

[Action]

The decision circuit decides a flag included in the input signal and indicating an error correction situation. The input signal is processed by the processing circuit and then stored in the second memory. On the other hand, the first memory stores the input signal corresponding to the output of the determination circuit. The data stored in the second memory is controlled by the control circuit, and is substantially changed into the signal stored in the first memory according to the determination result of the determination circuit.

〔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, a total of 56 symbols of 32 symbols in the even block and 24 symbols up to the 23rd symbol in the odd block are used as data, and from the 24th symbol in the odd block. The 8 symbols up to the 31st symbol are
The even symbol is the parity Pa of the error correction block A,
The odd symbol is recorded as the parity Pa of the error correction block B, whereas the input (transmitted) data is configured as shown in the second and third blocks. 32 symbols in even blocks and 24 in odd blocks
It is similar that a total of 56 symbols are used as data, but the parities Pa and Pb are not input (transmitted), and C1 correction flags Fa and Fb indicating the error correction status are input (transmitted) instead. . 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. When this flag is good (for example, correctable), the control circuit 4 stores the next two blocks of data in the memory 9 via the signal processing circuit 8. When the flag is not good (for example, it is uncorrectable), the control circuit 4 controls the memory 9 via the signal processing circuit 8 and the stored sub-code data for 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 the data of one frame, 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 can be error-corrected, and the memory 7 stores the block address of a block in which the data is not reliable, the block of the unsatisfactory block is eventually stored. The data is replaced by two good 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, when a magnetic tape having seven or more packs is written 16 times in one frame, some packs are lost. Therefore, the control circuit 4 reads the subcode data and displays it on the display unit 10.
To display a predetermined display (for example, display the number of packs). The user can operate the input means 5 while viewing this display to select and input the desired mode described above.

〔effect〕

As described above, the present invention provides a determination circuit for determining the error state of the information by the flag in the magnetic recording apparatus for recording the information inputted with the flag indicating the error state on the magnetic recording medium in block units. Since a storage circuit that stores information that is determined to be good by the determination circuit and a processing circuit that multiplex-records information stored in the storage circuit in a plurality of blocks are provided, It is possible to prevent erroneous data from being recorded on the magnetic tape and the device that reproduces it from malfunctioning.

[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 information inputted with a flag indicating an error state on a magnetic recording medium in block units, a determination circuit for determining an error state of the information by the flag, A magnetic recording device comprising: a storage circuit that stores information that is determined to be good by a determination circuit; and a processing circuit that multiplex-records information stored in the storage circuit into a plurality of blocks. apparatus.