JPH03292604A - Data recording method for data recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent drop-out of data by recording and reproducing data of recording frequency on each track together with recording data. CONSTITUTION:A write count data indicating the frequency in recording outputted from a microcomputer 2 for system control is recorded on recording tape 4 together with recording data from an external computer 1 by recording heads Wa and Wb. Write count data recorded on the magnetic tape 4 is repro duced by reproducing heads Ra and Rb, and this reproduced data and data outputted from the microcomputer 2 are compared with each other by a compa rator 6 and if they do not coincide with each other, recording data and write count data are recorded again. Thus, drop-out of data is prevented because failure of data recording is detected with one track as the unit at the time of overwrite to re-write data.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a data recording method in a sequential access type data recording/reproducing apparatus such as a digital audio tape recorder (hereinafter referred to as rDATJ).

<Prior Art> In a sequential access type data recording and reproducing apparatus that reads out target recorded data according to the recording order, data is generally recorded on, for example, a magnetic tape used as the recording medium as shown in FIG. This is done as shown in .

That is, FIG. 4 is a schematic diagram showing the arrangement of data recorded on a magnetic tape by the data recording/reproducing apparatus. Each data file F(i −1), F(i), F(
i+1) indicates a collection of related data,
Between the recording area of each data file and the recording area of the next data file, there is provided a recording area of file marks (not shown) indicating the separation of these data files.

Each data file is composed of a plurality of data blocks, each consisting of a data block (hereinafter referred to as a "data block") to which error detection/correction parity is added. For example, the data file F(i) is
6 data blocks Di O, Di 1. Di2.
Di 3. Di4. Di 5, and are recorded on the magnetic tape in this order.

<Problems to be Solved by the Invention> Additionally, during this recording, in order to improve reliability, the data written by the recording head is read by a playback head that follows this recording head, and it is checked whether the data is written correctly. This is sometimes done by checking read-after-write recording, but in this read-after-write recording, parity for error detection/correction is added to every track, so when overwriting, all data on one track is rewritten. If this is not possible, there is a problem in that error detection checks, so-called ECC checks, alone cannot detect the error.

For example, data blocks Di O to Di 5 of data file F(i) in FIG.
When attempting to rewrite to 5, if all the data Di2 of one track is not rewritten as shown in FIG. 5 due to some reason, such as clogging of the recording head, the ECC check will: It will be determined that there is no error.

The present invention has been made in view of the above points, and when data is not recorded in units of one track during overwriting, it can be detected and rewritten, thereby preventing data loss. The purpose is to

Means for Solving the Problems> In order to achieve the above-mentioned object, in the present invention, each time record data is recorded on a magnetic tape, recording number data indicating the number of recording times for each track is recorded together with the recorded data. Recording is performed by a recording head, and a reproducing head that follows and reproduces the recording head reproduces the recording number data recorded on the magnetic tape, and the reproduced recording number data and the recording number data recorded by the recording head are reproduced. If the two recording count data do not match, the recorded data and the recording count data are re-recorded.

<Function> In the above configuration, each time recording data is recorded, the recording head records the recording number data indicating the number of recordings for each track along with the recording data, and the recording head is reproduced by the reproduction head that follows and reproduces the recording head. Compare the recording count data with the recorded recording count data, and if the two recording count data do not match, it is assumed that the recording has not been done correctly.
The recorded data and recording count data are re-recorded, so if data is not recorded in l-track units during override,
Since both recording count data do not match, this can be detected and rewritten.

<Examples> Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic block diagram of a DAT as a data recording/reproducing apparatus to which the recording method of the present invention is applied.

In the figure, 1 is an external computer such as a personal computer, 2 is a system control microcomputer that controls each part of the DAT, and 3 is a digital recording data that performs predetermined processing such as adding error correction parity to the recording head. A recording signal processing circuit outputs signals to Wa and Wb, 4 is a magnetic tape, and 5 is a playback head Ra and Rb. The playback signals are subjected to predetermined processing such as error detection (ECC check) and correction, and output to an external computer! 6 is a comparator that compares write count data indicating the number of recordings, which will be described later.

In the data recording method of this embodiment, an external computer
The write count data indicating the number of recordings output from the system control microcomputer 2 is recorded on the magnetic tape 4 by the recording heads Wa and Wb along with the recording data from the system control microcomputer 2, and the recording heads Wa and Wb are used to play back the recording head. Reproducing the write count data recorded on the magnetic tape 4 by the heads Ra and Rb,
A comparator 6 compares the reproduced write count data with the write count data output from the system control microcomputer 2, and if the two count data do not match, it is assumed that the data was not recorded correctly and the recorded data is and the write count data is recorded again.

That is, when a recording command and recording data are input from the external computer 1 to the system control microcomputer 2 and the recording signal processing circuit 3,
The microcomputer 2 for system control is
The write count data recorded in the reference area at the beginning of the magnetic tape 4 is read by the playback head Ra,
Rb and read through the reproduction signal processing circuit 5, and outputs write count data obtained by adding, for example, 1 to the data to the recording signal processing circuit 3.

In the reference area, the write count data written during the previous recording is recorded, and in the case of an unrecorded magnetic tape where no data has been recorded, no write count data is recorded. , At this time, the microcomputer 2 for system control
outputs, for example, "0" to the recording signal processing circuit 3 as write count data.

The recording signal processing circuit 3 inputs the recording data from the external computer 1 into the data area of the magnetic tape 4, writes the write count data from the system control microcomputer 2 into the subcode area of the magnetic tape 4, and sends the recording head Wa, Record by Wb.

A reproducing head Ra that reproduces data recorded on the magnetic tape 4 by following the recording by the recording heads Wa and Wb.
, Rb is subjected to an FCC check by the reproduction signal processing circuit 5 in the same manner as before, and when it is normal, the reproduced write count data and the write count data from the system control microcomputer 2 are combined. is compared by the comparator 6, and based on the comparison output, the system control microcomputer 2 determines that if both write count data match, it is recorded normally and continues recording.
If both write count data do not match, it is assumed that the data has not been recorded normally, and the g2 recording data and write count data are recorded again.

FIG. 2 is a schematic diagram showing data recorded on the magnetic tape 4 by this data recording method, in which (A) shows data blocks and (B) shows data recorded in the subcode area of each track. It shows the write count data.

In the reference area RE and each data block OGI to OG7 at the beginning of the magnetic tape 4, "0" is recorded as write count data.

The data of data block OG4 of this magnetic tape 4 is
If a command to rewrite the data NG4 is given from the external computer l, the system control microcomputer 2 transfers the write count data rOJ recorded in the reference area RE at the beginning of the magnetic tape 4 to the playback head Ra, Rh and read through the reproduction signal processing circuit 5, and the data "0" is set to l.
The write count data rlJ with added data NG4
The write count data is output to the recording signal processing circuit 3 as write count data.

The recording signal processing circuit 3 transfers the recording data NG4 from the external computer 1 to the data area of the corresponding track of the magnetic tape 4, and transfers the write count data rlJ from the microcomputer 2 for system control to the data area of the corresponding track of the magnetic tape 4. is recorded in the subcode area by the recording heads Wa, (wb).

Reproduction heads Ra, (Rb
) is subjected to an FCC check by the playback signal processing port gg5 in the same manner as before, and if it is normal, the playback write count data and the write count data rlJ from the system control microcombinator are processed. The comparator 6 compares the data with the write count data, and the system control microcomputer 2 determines based on the comparison output that if both write count data match, recording has ended, and finally, the reference area R is
The write count data "0" of data E is replaced with "2", which is the write count data "1" of data NG4 plus 1. As a result, the maximum write count data recorded on the magnetic tape 4 is recorded in the reference area RE.

Figure 3 shows the magnetic tape 4 rewritten in this way.
FIG. 2 is a schematic diagram corresponding to FIG. 2 showing data of FIG.

In this way, write count data is recorded for each track of the magnetic tape 4, and during follow-up playback, the reproduced write count data and the recorded write count data are compared. If data is not recorded on a track-by-track basis due to some reason such as Wb clogging, this can be detected and rewritten since the write count data does not match, and data loss can be prevented. It becomes possible.

<Effects of the Invention> As described above, according to the present invention, each time recording data is recorded, the recording head records the recording number data indicating the number of recordings for each track along with the recording data, and the recording head is used to track the recording data. Compare the recording number data played back by the playback head and the recorded recording number data, and if the two recording number data do not match, it is determined that the recording is not performed correctly and the recorded data and recording number data are re-recorded. Therefore, when data is not recorded in units of one track during overwriting, it can be detected and rewritten, and data loss as in the conventional example can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a DAT to which the recording method of the present invention is applied, FIGS. 2 and 3 are schematic diagrams showing data recorded on a magnetic tape by the method of the present invention, and FIGS.
The figure is a schematic diagram showing data recorded on a magnetic tape using a conventional method. 2... Microcomputer for system control, 4... Magnetic tape, 6... Comparator, Wa, Wb
. . . Recording head, Ra, Rb . . . Reproduction head. Figure 2 (schematic diagram showing data recorded by the method of the present invention)

Claims (1)

[Claims] (1) Each time recording data is recorded on a magnetic tape, a recording head records recording number data indicating the number of recording times for each track along with the recorded data, and a reproducing head that follows this recording head and reproduces the recorded data The recording number data recorded on the magnetic tape is reproduced, and the reproduced recording number data is compared with the recording number data recorded by the recording head. If the two recording number data do not match, the recorded data and the recording number are A data recording method in a data recording/reproducing device characterized by re-recording data.