JPH0215469A - Control system for optical disk device - Google Patents

Abstract

PURPOSE:To shorten a processing time by forming the check sum value (CSV) of data when the data are to be recorded, storing the CSV in a register, and deciding the recorded result by comparing the stored CSV with the CSV of reproduced data. CONSTITUTION:A data selector 10 selects recording data to be outputted from a system interface circuit 1 to a buffer memory 2 and transfers the selected data to the buffer memory 2 by the control of a control part 7. The recording data are transferred through the circuit 10 to a check sum circuit 11, and the CSV is formed and stored in a register 12. Next, the control part 7 transfers the data obtained by adding an error corrected code to the recording data stored in the memory 2 in a correcting circuit 4 to an optical disk driving device 5 and records the transferred data in an optical disk. When the control part 7 ends data recording, the control part 7 makes the selector 10 select the reproduced data from the circuit 4, the data from the circuit 5 are reproduced, the error of the data is corrected in the circuit 4, the reproduced data are added to the circuit 11, and the CSV is formed. The value of the formed CSV and that of the CSV read from the register 12 are compared in a comparator 13, and the recorded result is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method for an optical disc device that reproduces recorded data immediately after data recording and determines the recording result.

[Prior Art] Generally, in an optical disk device, since the data error rate of the optical disk used as a recording medium is relatively high, when recording data, the recorded data is reproduced immediately after recording, and the reproduced data is compared with the recorded data. It is determined whether there are any recording errors by
ad After Write operation).

FIG. 3 shows a conventional example of an optical disk device that performs such a RAW operation.

In the figure, a system interface circuit 1 is for exchanging data and control information between this optical disk device and an external host device (path shown), and a buffer memory 2 is for exchanging recording data and playback data. This is to temporarily store the buffer memory 3.
has the same storage capacity as the buffer memory 2 and is for storing recording data.

The error correction circuit 4 is for adding a predetermined error correction code to the recorded data and referring to the error correction code to correct data errors included in the reproduced data.

The optical disk transfer device 5 transfers recorded data to an optical disk (
The data is recorded in a designated recording area of the path shown in the figure, and data is reproduced from the designated recording area.

The comparator 6 is for comparing the stored contents of the buffer memory 3 and the reproduced data output from the error correction circuit 4 in units of bytes, and the optical disc control section 7 is notified of the comparison result.

The optical disc control unit 7 controls the operation of this optical disc device, and controls the recording and reproducing operation of the optical disc drive device 5, the storage read operation of the buffer memories 2 and 3, and the comparison operation of the comparator 6, and also controls the system Various information is exchanged with the host device via the interface circuit 1.

With the above configuration, when data recording is commanded by the host device, the optical disc control section 7 temporarily stores the recording data transferred from the host device in the buffer memory 2.3.

When the transfer of the recorded data is finished, the optical disk drive device 5
With the recording area specified, data writing is commanded, and the recorded data stored in the buffer memory 2 is transferred to the optical disk disc drive device 5 via the error correction circuit 4.

As a result, an error correction code is added to the recorded data,
In that state, the data is transferred to the optical disc drive device 5 and written on the optical disc.

When the data recording on the optical disc is completed, the optical disc control unit 7 instructs the optical disc parking device 5 to reproduce the data while specifying the recording area where the data is recorded.

As a result, data is reproduced from the optical disk moving device 5, data is corrected by the error correction circuit 4, and the reproduced data is applied to the comparator 6.

On the other hand, the optical disc control unit 6 sequentially reads the same byte of recording data from the buffer memory 3 and outputs it to the comparator 6 in synchronization with the addition of the reproduced data to the comparator 6.

The comparator 6 compares the reproduced data and the recorded data in units of bytes, and notifies the optical disk controller 7 of the comparison result.

If the optical disc control unit 7 is notified of a data match by the comparator 6 between the time when the reproduction of the recorded data is finished and the comparison of all the reproduced data with the recorded data is completed, the optical disc control unit 7 detects a recording error by informing the system interface circuit 1 of the data match.
Otherwise, the normal end of recording is notified to the host device via the system interface circuit 1.

In this way, the reproduced data and the recorded data are compared in units of bytes to determine the data recording result.

[Problems to be Solved by the Invention] However, such a conventional device requires a buffer memory for storing recorded data, resulting in an inconvenience that the cost of the device increases.

Furthermore, since data files stored on optical disks are generally large, it takes a long time to read the recorded data from the buffer memory 3 and transfer it to the comparator 6, resulting in an inconvenience that the time for data comparison becomes long.

It is also possible to compare recorded data and reproduced data on the host device side, but in this case, although it is possible to reduce the cost of the optical disk device, it would take a lot of time to compare the data. However, this causes the inconvenience that the burden on the host device is extremely large.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control method for an optical disc device that can solve the problems of the prior art and appropriately judge the data recording results.

[Means for Solving the Problems] The present invention includes a checksum circuit that forms a checksum value, and a register that stores the checksum value calculated by the checksum circuit, and the checksum value of recorded data when recording data. A checksum value of the reproduced data is generated when the data is reproduced immediately after data recording, and the recording result is determined by comparing the contents stored in the register with the checksum value of the reproduced data.

[Effects] Therefore, the number of elements required for determining data recording results is very small, and the cost of the device is reduced.

Furthermore, since the amount of data for data comparison is small, processing time is significantly reduced.

C Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an optical disc device according to an embodiment of the present invention. In this figure, the same parts and corresponding parts as in FIG. 4 are given the same reference numerals.

The data selector 10 is the system interface circuit 1
Data output from to buffer memory 2.

and one of the reproduced data outputted from the error correction circuit 4, and the selected output is outputted to the checksum circuit 11.

The checksum circuit 11 integrates the data output from the data selector 10 in 1-byte units, and outputs the lower 2 bytes of the integrated value as a checksum value. register 12
, and one input terminal of the comparator 13.

The register 12 stores the checksum value output from the checksum circuit 11, and its stored contents are output to the other input terminal of the comparator 13.

The comparator 13 compares the contents stored in the register 12 and the contents of the checksum value output from the checksum circuit 11, and the optical disc control section 7 is notified of the comparison result.

Here, the checksum value will be explained.

As mentioned above, the checksum value is obtained by dividing the data into bytes and sequentially accumulating each byte data.The checksum values of the same data file are the same, and the checksum values of different data files are the same. , differ.

That is, when the recorded data and the reproduced data match, their respective checksum values match, and when the optical disc has some kind of defect and the reproduced data differs from the recorded data, the checksum values do not match.

Therefore, by using this, it is possible to detect that a data error has occurred in the reproduced data.

With the above configuration, the optical disc control section 7 executes the processing shown in FIG. 2 when recording data. Note that this process is performed for each amount of data recorded on the optical disc at one time.

In other words, when data recording is commanded from the host device,
First, the optical disc control unit 7 selects recording data to be output from the system interface circuit 1 to the buffer memory 2 using the data selector 10 (processing 1).
01), the recording data from the host device is transferred to the buffer memory 2 (processing 102, judgment 103).

Thereby, the record data is transferred to the checksum circuit 11 via the data selector 10, and the record data is accumulated in units of bytes.

When the transfer of the recorded data is completed, a checksum value is formed in the checksum circuit 11, so the checksum value is read out and stored in the register 12 (process 10).
4).

Next, the optical disc control unit 7 instructs the optical disc movement device 5 to record data with the recording area specified.
05), the recorded data stored in the buffer memory 2 is transferred to the optical disk drive device 5 (process 4106, judgment 107).

As a result, the recorded data to which the error correction code has been added by the error correction circuit 4 is transferred to the optical disk agitating device 5 and stored in the designated recording area of the optical disk (path shown).

After completing the data recording in this manner, the optical disc control unit 7 causes the data selector 1o to select the reproduced data output from the error correction circuit 4 (processing 108).
), commands data reproduction while specifying the recording area in which data is recorded in the optical disc agitating device 5 (process 109).
.

As a result, data is reproduced from the optical disk active device 5, data is corrected by the error correction circuit 4, and the reproduced data is sequentially added to the checksum circuit 11 via the data selector 10 and accumulated in byte units. .

The optical disc control unit 7 waits until the data reproduction is completed (No loop of judgment 110). When this data reproduction is completed, since a checksum value for the reproduced data has been formed in the checksum circuit 11, the checksum value is read out.

Furthermore, the checksum value of the recording data stored in the register 12 is read out, the checksum values are compared by the comparator 13, and the comparison result is input (process 111).

At this time, if there is a defect in the recording area where the data was recorded and a data error occurs in the read data, the checksum value of the reproduced data and the checksum value of the recorded data will be different as described above. Therefore, in that case, the comparator 13 notifies the data abnormality.

On the other hand, if there is no data error in the read data, the checksum value of the reproduced data and the checksum value of the recorded data match, and in that case, it is notified that the data is normal.

In this way, when the notification of the recording result is input from the comparator 13, the optical disc control section 7 notifies the host device of the contents of the recording result via the system interface circuit 1 (process 112).

In this way, each time one data recording unit of recording data is transferred to the optical disk device, the host device is notified of the recording result. In addition, when the data recording has ended normally, the host device records the remaining data,
When data recording has ended abnormally, processing is performed to record the same data in a different recording area.

As described above, in this embodiment, DRAW during data recording
When performing an operation, the checksum value of the recorded data and the checksum value of the reproduced data are compared to determine whether the data recording was normal or not, so the circuit configuration for this determination is extremely simple. , equipment costs can be significantly reduced.

Furthermore, the length of the checksum value in the above-described embodiment is 2 bytes, and therefore the time required to compare the checksum values is very short, so the time required for data recording can be significantly reduced.

Note that since the operation of the host device is not directly related to the present invention, a detailed explanation thereof will be omitted.

By the way, in the above embodiment, the length of the checksum value is set to 2 bytes, but the length of the checksum value can also be set to 3 bytes or more.

Furthermore, in the embodiment described above, the checksum values are compared each time one data recording unit of recorded data is recorded on the optical disk device, but the checksum value is compared each time recording of one data file is completed. It is also possible to perform a comparison.

Alternatively, the checksum values may be compared each time a predetermined number of data recording units are recorded on the optical disc device.

[Effects of the Invention] As explained above, according to the present invention, the present invention includes a checksum circuit that forms a checksum value, and a register that stores the checksum value calculated by the checksum circuit,
When recording data, a checksum value of the recorded data is formed and stored in a register, and when data is reproduced immediately after data recording, a checksum value of the reproduced data is formed, and the checksum value of the reproduced data is compared with the contents stored in the register. Since the recording result is determined, the number of elements required for determining the data recording result is very small, and the cost of the apparatus is reduced.

Furthermore, since the amount of data for data comparison is small, the processing time can be significantly shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an optical disc device according to an embodiment of the present invention, FIG. 2 is a flowchart showing an example of processing of an optical disc control section, and FIG. 3 is a block diagram showing a conventional example of an optical disc device. 7... Optical disc control unit, 10... Data selector, 11... Checksum circuit, 12... Register,
13... Comparator. Figure Figure

Claims (1)

[Claims] A checksum circuit that forms a checksum value consisting of a predetermined number of lower bytes of the sum of bytes of data in a control method for an optical disk device that reproduces the recorded data immediately after recording data on an optical disk and determines the recording result. and a register for storing the checksum value calculated by the checksum circuit, and when recording data, the recorded data is also transferred to the checksum circuit to form a checksum value of the recorded data and stored in the register, During data reproduction immediately after data recording, the reproduced data is also transferred to the checksum circuit to form a checksum value of the reproduced data, and the recording result is determined by comparing the contents stored in the register with the checksum value of the reproduced data. A control method for an optical disc device characterized by the following.