JPH03160670A - Data reader - Google Patents

Abstract

PURPOSE:To eliminate re-reading and to speed up reading by deciding and storing an address to be read next when the reading of the address is judged to be successful, comparing the addresses whenever the address is read and defining it to be an accurate content. CONSTITUTION:A read means 2 reads the address and data of a sector in a recording medium 1. When a judgment means 3 judges that the reading of the having read address is successful, an address counting means 4 decides and stores the address which the means 2 has to be read next based on the address. Then, a comparison means 5 compares the address which the means 4 stores whenever the means 2 reads the address. When they coincide, a data decision means 6 decides that the having read address is the accurate contents. Consequently, a processing operation for re-reading is eliminated even if reading is failed and a read speed can be improved.

Description

[Detailed Description of the Invention] [Summary] It relates to a data reading device, and more specifically to a reading device that reads data recorded on a recording medium such as an optical disk. The purpose is to shorten the data reading time, increase the reading speed, and read out accurate data.At least a storage area for storing data and a storage area for storing the address of the data are configured. reading means for reading the address and data of each sector from a recording medium having a large number of consecutive sectors formed on a track; and determining means for determining success/failure of reading with respect to the address of the sector read by the reading means. , when the determining means first determines that the reading of the address is successful, the address of the sector to be read by the reading means next is determined and stored based on the address read by the reading means, and from then on, the reading means An address counting means that determines and stores the next address based on the stored address each time an address is read, and a comparison that compares the read address with the address stored by the address counting means when the address is successfully read. When it is determined by the comparing means and the comparing means that the two addresses match, it is determined that the address of the sector being read by the reading means at that time is correct, and the contents of the previous sector are determined to be correct. The present invention comprises data whose correspondence with an address has not been determined due to a failure in reading the address, and data determining means which determines the correspondence between the data and the address.

[Industrial Field of Application] The present invention relates to a data reading device, and more particularly to a reading device that reads data recorded on a recording medium such as an optical disk.

2. Description of the Related Art In reading devices that read data stored on recording media such as optical disks and magnetic disks, accurate data reading and faster reading speed are required as peripheral devices become faster.

[Prior Art] In recent years, optical discs have been proposed as one of data recording media, and various data reading devices have also been proposed.

The reading method of a data reading device that reads data recorded on this optical disk is to first read the address from the storage area (ID section) where its own address is stored in the sector, and then read the address from the sector that stores the data to be read. (target sector), and if it is the target sector, read the data stored in the data storage area (data part) following the ID part.On the other hand, if it is not the target sector or if reading of the ID part fails, The process moves on to reading the address of the next sector without reading the data stored in the data section.

[Problems to be Solved by the Invention] However, this optical disk has disadvantages in that the defect rate of the recording medium is high and the surface is not sealed, so it is easily affected by dust and the like. Therefore, reading devices that read data recorded on optical discs often fail to read their own address stored in the ID section of each sector where data is stored, and are unable to read the data. There is.

In other words, when reading data in each sector from a sector at a certain address to a sector at a certain address, if reading the address of the ID part for one sector fails and the data in that sector cannot be read, the data After the reading device completes one read operation, it performs a read processing operation to reread the data of the sector in which the reading failed.

As a result, the reading time increases accordingly, and especially in optical disk reading devices with a high rate of reading errors, there is a problem in that the processing is frequent and the reading speed is extremely reduced.

The present invention has been made to solve the above-mentioned problems, and its purpose is to omit the time required to read data again based on the read failure even if the address read fails, and to increase the read speed. Moreover, it is an object of the present invention to provide a data reading device that can read accurate data.

[Means for Solving the Problems] FIG. 1 is an explanatory diagram of the principle of the present invention, in which a recording medium 1 is composed of at least a storage area for storing data and a storage area for storing the address of the data. A large number of consecutive sectors are formed on the track. The reading means 2 reads the address and data of each sector.

The determining means 3 determines the success/failure of reading the address of the sector read by the reading means 2. The address counting means 4 determines and stores the address of the sector to be read next by the reading means 2 based on the address read by the reading means 2 when the determining means 3 first determines that the reading of the address is successful; Thereafter, each time the reading means 2 reads an address, it determines and stores the next address based on the stored address.

When the comparing means 5 successfully reads an address, it compares the read address with the address stored in the address counting means 4. When the comparison means 5 determines that the two addresses match, the data determination means 6 determines that the address of the sector being read by the reading means 2 at that time is correct, and also The correspondence between data whose correspondence with an address has not been determined due to a failure in reading a sector address and the address of that data is determined.

[Operation] When reading an address fails, the address counting means 4 determines and stores the address of the sector to be read next by the reading means 2 based on the address stored by itself, so that the sector is read next. When the address of a sector is read, the fact that the address matches the address stored in the address counting means 4 means that the address of the sector for which the address reading has failed before is the same as that of the address counting means 4. This means that it matched the address stored in 4. Therefore, in that case, the data determining means 6 determines that the data read by the reading means 2 when the address reading fails corresponds to the data when the address is correctly read. As a result, there is no need to perform the reading process again even if reading has failed.

[Example] Hereinafter, an example in which the present invention is embodied in a data reading device for reading data recorded on an optical disc will be described with reference to the drawings. Incidentally, an optical disk has a large number of sectors formed on a spiral-shaped track, and each sector has a storage area (ID section) for storing its own address and a storage area (ID section) for storing data following the address. data section)
Since this is a well-known disk configured with the following, details thereof will be omitted.

In FIG. 2, the central processing unit (hereinafter referred to as CPU) 1
1 is connected to the control program memory 1 via the system bus l2.
3 and a rewritable working memory l4, and operates according to the program stored in the control program memory l3, and temporarily stores the calculation results in the working memory l4. As shown in FIG. 3, the working memory l4 includes a storage area (hereinafter referred to as an address pointer) 14a for storing the address of the sector currently being processed by the CPU II, and a storage area for indicating that the contents of the address pointer 14a are valid. An area 14c (hereinafter referred to as an address valid flag) 14c and a storage area 14b (hereinafter referred to as an IDER flag) that indicates whether or not reading of an address stored in the ID section has failed are formed. Then, when the CPU II succeeds in reading the address, the IDER flag 14b is set to "0" by the CPU II.
”, but on the other hand, if it fails, “l” is stored.

In addition, the CPU I is connected to ■DER via the system bus 12.
A register l5 is connected as well as a format control circuit l6. IDER register l5
The address of the first sector in which the CPU II fails to read the address is stored in the CPU II. The format control circuit 16 records and reproduces addresses and data in each sector via a recording/reproducing head (not shown) based on a control signal from the CPU II.

Data buffer memory l7 is format control circuit 16
The data read and reproduced by the optical disc via the recording/reproducing head and the data to be written on the optical disc are temporarily stored.

Next, the operation of the data reading device configured as described above will be explained with reference to the flowchart of FIG. 4 showing the operation of CPUll.

Now, when those addresses are specified in order to read data in multiple sectors at consecutive addresses, in step 1 the CPU II selects the address of the sector to be read first (hereinafter referred to as the target address; in this case, the address with the smallest address value is The first address is set, and each of the flags 14b and 14c is set to "0".

In step 2, the CPU II checks via the recording/reproducing head and format control circuit 16 whether or not the head has successfully read the address of the sector. If the address of the sector on the track cannot be read, step 3 (address valid flag 14c)
It is checked whether the address of the sector currently being processed is already stored in the address pointer l4a', and since it is not stored yet, the process returns to step 2. Therefore, this operation continues until the recording/reproducing head reads the address of a certain sector on the track.

Eventually, when the address of the sector where the recording/reproducing head is successfully read, the address pointer 1 is set in step 4.
It is checked whether the address of the sector currently being processed is stored in step 4a, and since it is not stored yet, the address of the sector is stored in the address pointer 14a in step 5, and the address valid flag 14c is Set the content to "l".

Next, in step 6, it is determined whether the address stored in the address pointer 14a is the target address (start address of the sector to be read) set in step 1, and if it is not the sector of the target address, The destination address stored in the address pointer 14a in step 7 is updated to the address of the next sector following the destination sector to be read next to the previous sector, and step 2 is performed again.
Move to.

Next, the CPU 1 checks whether the recording/reproducing head successfully reads the address of the next sector adjacent to the previous sector, and if it succeeds in reading the address of the next sector, then steps In step 4, the address valid flag 14c is referenced to check whether an address is stored in the address pointer 14a, and if this is the case, the address previously updated in step 7 (the address of the sector to be read next) Since this is stored, the process moves to step 8.

In step 8, it is checked whether the address stored in the address pointer 14a and the address of the ID section in the current sector read by the recording/reproducing head match. That is, in step 8, it is checked whether the recording/reproducing head searches each sector on the track in ascending order without failing to read the address.

When the address of the sector to be read next is read by the recording/reproducing head, the IDER flag 14b is set in step 9, indicating that the address has been successfully read.
After setting the contents to rQJ, the process moves to step 6, where it is determined whether the successfully read sector is the target address. If the address of the sector found by the recording/reproducing head is not the target address sector, in step 7 the destination address stored in the address pointer 14a is updated to the value of the address of the next sector following the first sector, and the process is repeated. Move on to step 2.

Therefore, similar processing operations continue until the recording/reproducing head reads the sector at the target address. When repeating this operation, if the address of the sector on the track fails to be read in step 2, the address of the sector currently being processed is stored in the address pointer 14a, so step 3 is performed. Then, proceed to step IO.

In step IO, it is determined whether the address stored in the address pointer 14a is the target address, and if it is not the sector of the target address, step I
The address stored in the address pointer 14a at step I is updated to the value of the address of the next sector following the current sector, and the process returns to step 2.

Eventually, when the address of the sector read by the recording/reproducing head is determined to be the target address in step 6, the address corresponding to the target address is stored in the data portion of the sector currently being processed by the recording/reproducing head in step 12. The data contained in the data is read through the same head.

When the data reading of the sector at the first address from which data is to be read is completed, it is checked in step l3 whether or not there was a data reading error, and if an error has occurred, a notification that a reading error has occurred is determined in step 14. After outputting the error report to, for example, an external device, the process moves to step 15.

On the other hand, if no error has occurred, the process immediately moves to step 15.

In step 15, it is checked whether the data reading processing operation is to be continued. That is, it is determined whether reading of all data in a plurality of sectors at consecutive addresses set in step 1 has been completed. At this stage, only the data of the first sector has been read, so in step 16, the address of the next sector adjacent to the first, ie, the first address, sector is updated and set as a new target address. When the update of the target address is completed, the process moves to step 7 described above and the address pointer 14
The destination address stored in a (in this case, it will be the first address). is set as the address of the next sector to be read after the first address (that is, in this case corresponds to the updated target address), and the process returns to step 2.

Thereafter, steps 2, 4, and 4 are performed until reading of data from all the multiple sectors set in step 1 is completed
8, 9, 6, 12. Processing operations 13 to 16 and 7 are repeated.

Next, a case will be described in which, while data is being read from all of a plurality of set sectors, reading of the address of the ID part in the sector of the target address fails for some reason.

In step 2, determine if the address has failed to read,
Subsequently, in step 3, the address pointer 14a stores the address determined in step 7 and to be read next, so the process moves to step 10. In step IO, it is determined whether the address stored in the address pointer 14a and to be read next is the target address. When the data of all the set sectors is repeatedly read, the address stored in the address pointer 14a always matches the updated target address.
The process moves to step l7, and the content of the IDER flag 14b is "0".
” or “l”. At this time, since this is the first read failure and "01" was found in step 1 or step 9 of the previous processing operation, the address to be read next stored in the address pointer 14a at that time in step 18, That is, the address for which reading has failed is stored in the IDER register l5, and the content of the IDER flag 14b is set to "l", indicating that the reading of the address has failed. Therefore, this IDER register 15 stores the address for which reading failed for the first time.

Next, the process moves to step 12 described above, and the data recorded in the data portion of the sector whose address has failed to be read is read via the recording/reproducing head. That is, even if reading the address of the ID section fails, the data stored in the data section of the sector is read.

When the data reading of the data section is completed, it is determined in step l3 whether or not there was a data reading error, and if an error has occurred, an error report indicating that a reading error has occurred is output in step l4. After that, the process moves to step l5. If no error has occurred, the process immediately moves to step 15.

In step 15, it is checked whether or not to continue the data reading processing operation. Then, since data reading of all set sectors has not been completed, in step 16, the address of the next sector following the sector of the address whose reading failed is updated and set as a new target address. When the update of the target address is completed, the process moves to step 7 described above, and the destination address stored in the address pointer 14a (in this case, the address for which reading failed) is transferred to the address of the next sector (that is, the updated target address ) and move to step 2 again.

When the address of the ID part in the sector of the target address to be processed next is successfully read, step 2
, 4.8 are executed.

In step 8, the address of the address pointer 14a and the I in the current sector read by the recording/reproducing head.
It is checked whether the address of part D matches or not. If the recording/reproducing head normally searches each sector on the track in ascending order, the address of the address pointer 14a and the address of the ID section read by the recording/reproducing head match. As a result, it can be determined that the recording/reproducing head is in the correct position even when a sector whose address has previously failed to be read and whose address is stored in the IDER register 15 is processed.

Therefore, in the next step 9, the content of the IDER flag 14b is changed from "l" to "0", and first, in step l8, the IDER flag 14b is changed from "l" to "0".
After determining that the sector at the address stored in the ER register 15 has been successfully processed, the process moves to step 6, where it is determined whether the successfully read sector is the target address.

Since the recording/reproducing head searches each sector in ascending order as described above, the address of the sector read by the recording/reproducing head matches the target address.

Then, in the same manner as described above, the process moves to step I2, and the data recorded in the data section of the sector whose address was successfully read is read, and the occurrence of a data read error is checked in step l3, and if there is an error, the step After reporting an error in step 14, if there is no error, the process immediately moves to steps 15, 16, 7 and step 2.

Note that if the address reading fails consecutively, the process moves to step 10 via steps 2 and 3, but step 1
Even in step 0, when data is repeatedly read from all of the set sectors, the address stored in the address pointer 14a matches the updated target address, so step 17 is immediately followed by step 12. The data stored in the data section of the sector of the address concerned is read. Therefore, even in this case, even if reading the address of the ID section fails, the data stored in the data section of the sector is read.

When the address of the ID section in the next sector is successfully read, the data in the data section is read through steps 2, 4, 8, 9, and 6.12.

Thereafter, unless there is a reading failure, steps 2, 4. are performed until reading of data in all sectors set in step 1 is completed. 8, 9, 6, 1
Processing operations 2, 13 to 16, and 7 are repeated.

Therefore, if the data of all the set sectors is being read, even if reading of the address recorded in the ID part of the sector fails, the data stored in the data part of the sector will be read in step 12. At the same time, the address of the read sector is estimated to be the sector of the target address, and the next target address is updated and set in step 16 and step 7, and the next address to be read is predicted and the address pointer 14 is read.
If the address of the ID part of the next new sector is successfully read and the predicted address matches the address of the ID part in step 8, the address for which the previous read failed is estimated. Since the data in the sector at that address has been read in advance in the previous process, it is only necessary to continue reading the data in the remaining sector.

When it is determined in step 15 that reading of data in all set sectors has been completed, in step 19 the content of the IDER flag 14b at that time is set to "0".
” or “lJ.”

That is, when the data of the last sector is read, it is checked whether the reading is a failure or a success in reading the address of the ID part of the sector. ID
When the content of the ER flag 14b is "0", that is, when the reading is successful, the reading processing operation is immediately terminated.

On the other hand, if the reading of the address in the last sector fails, the address of the last sector is still estimated and has not been determined, so in step 20, the address stored in the address pointer 14a is transferred to the next address. After updating to the address of the sector, in step 2l, the address of the sector in which no data is to be read next to the last sector from which data is read is read, and steps 20.21 are repeated until the address is read.

When the reading is successful, in step 22, the read address of the ID section is compared with the address in the estimated state stored in the address pointer 14a. If the two addresses match, it is determined that the address of the last sector is the target address, and the read processing operation ends. On the other hand, if they do not match, an error of mismatch is reported in step 23 and the reading processing operation is terminated.

If the address of the ID section read in step 8 does not match the address stored in the address pointer 14a, it is checked in step 24 whether the content of the IDER flag 14b at that time is "0" or "lJ".

When the content of the IDER flag 14b is rlJ, in step 25, an error report indicating that reading of the ID section has failed along with the first failed reading address stored in the DER register l5 is reported, and then the reading process is immediately performed. end.

On the other hand, when the content of the IDER flag 14b is "0",
In step 26, an error report is made to the effect that the reading of the ID section has failed at the current address, and then the reading processing operation is immediately terminated.

In this way, in this embodiment, unlike the conventional method, there is no need to read data from a sector that has failed after reading data from all sectors, so the read processing time is significantly reduced. It is possible to read shortened and accurate data.

Note that the physical addresses of the target sectors do not necessarily have to be consecutive, and target sectors and non-target sectors may appear alternately.

Furthermore, the present invention is not limited to the above-mentioned embodiments, and may of course be applied to data reading devices used for other recording media such as magnetic disks other than optical disks.

[Effects of the Invention] As described in detail above, the present invention is capable of omitting the data read processing operation again based on the read failure even if an address reading fails, thereby increasing the reading speed. It has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is an electrical block circuit diagram of a data reading device embodying the invention, Fig. 3 is an explanatory diagram showing the contents of the working memory, and Fig. 4 is a data reading device. It is a flowchart for explaining the operation of the device. In the figure, 1 is a recording medium, 2 is a reading means, 3 is a determining means, 4 is an address counting means, 5 is a comparing means, and 6 is a data determining means. Fig. 2 Electrical block circuit diagram of a data reading device embodying the present invention 1/ Fig. 3 An explanatory diagram showing the contents of the working memory

Claims (1)

[Scope of Claims] A recording medium (1
); reading means (2) for reading the address and data of each sector from the reading means (2); determining means (3) for determining success/failure of reading with respect to the address of the sector read by the reading means (2); and the determining means (3). ) first determines that the reading of the address is successful, the reading means (2) determines and stores the address of the sector to be read next based on the address read by the reading means (2), and from then on, the reading means (2) determines and stores the address of the sector to read. Reading means (
2) includes an address counting means (4) that determines and stores the next address based on the stored address each time it reads an address; When the comparing means (5) compares the addresses stored in 4) and the comparing means (5) determines that both addresses match, the reading means (2) reads the addresses at that point. Data determining means (6) for determining that the address of the sector is correct, and determining the correspondence between data whose correspondence with the address has not been determined due to a failure in reading the address of the previous sector and the address of that data. A data reading device consisting of.