JP2770917B2 - Information recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording or reproducing information using an information recording medium on which information can be rewritten.

[0002]

2. Description of the Related Art Conventionally, since an information recording medium such as an optical disk has a relatively high error rate, as a remedy, it is general to prepare an alternative sector for replacing a defective sector in advance. It is. Therefore, when data cannot be normally written to the designated sector due to a defect, data is written to a prepared alternative sector, and a so-called replacement process is performed. In this case, every time the replacement process occurs, replacement management information that associates the defective sector with the replacement sector is registered in the memory of the controller in the device. The replacement management information is sorted in the order of occurrence of the replacement process. On the other hand, when a higher-level control device such as a host computer issues a read request to the information recording / reproducing device,
The controller determines whether there is a replaced sector within the required range of the recording medium by checking the replacement management information registered in the memory. Usually, the controller has a buffer memory in order to increase the transfer speed with the host computer. When a read request is issued, the controller continuously reads data as long as the size of the buffer memory permits. If there is a replaced sector within the requested range, read up to the immediately preceding sector and start transferring it to the host computer,
At the same time, the read head is sought to the substitute sector to read the substitute sector. When this is completed, seek is performed immediately after the replaced sector, and reading is started from the sector immediately after the seek. When information is reproduced in this manner, when there is a replaced sector within the requested range, the information is read by seeking to an alternative sector each time.

[0003]

In the above-mentioned conventional information recording / reproducing apparatus, when there is a replaced sector in the read request range, the following number of sectors is calculated to determine the number of sectors that can be read continuously. I was calculating. (1) Length from the start sector of the read request to the first replacement sector within the request range (the number of sectors). (2) Length from the replacement sector to the next replacement sector. (3) Length from last replacement sector to last sector of request.

However, in a recording apparatus having a medium having a huge storage capacity such as a magneto-optical medium, its address must be expressed by several bytes. Therefore,
In order to perform the above calculation, addition and subtraction over several bytes must be performed, which places a heavy burden on the CPU of the controller and adversely affects the execution speed. The calculations in (1) and (3) may be performed only once for one read request, but the calculation in (2) is required as many times as the number of replacement sectors in the requested range. Therefore, the longer the read request, the greater the number of replacement sectors and the number of calculations, which results in a corresponding increase in the load on the CPU.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to reduce the load on the controller due to the address calculation at the time of reading information and to increase the information reading speed. An object of the present invention is to provide a recording and reproducing device.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an information recording medium with a spare sector area, and when a defective sector occurs on the recording medium, replace the defective sector with the spare sector. In the information recording / reproducing apparatus, the sector length up to the next defective sector is calculated in advance for each defective sector and stored in the memory, and the information reading operation is performed according to the information in the memory when reading the information. This is achieved by an information recording / reproducing device characterized by controlling.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the information recording / reproducing apparatus of the present invention. In FIG.
Reference numeral 10 denotes an information recording / reproducing device, and reference numeral 11 denotes a host computer which is a host control device. Information recording / reproducing device 1
0 is connected to the host computer 11, and recording or reproduction of information is performed based on an instruction from the host computer 11. Reference numeral 12 denotes a SCSI adapter for interfacing with the host computer 11, reference numeral 13 denotes an MPU for performing general control of the information recording / reproducing apparatus 10, reference numeral 14 denotes a ROM in which a control program and the like are stored, and reference numeral 15 denotes an ECC circuit for performing error correction processing. is there. 16 is an I / O control unit,
Reference numeral 17 denotes a disk R / W unit for recording information on an optical disk 19 used as an information recording medium or reproducing recorded information, and 18 temporarily stores data transferred from the host computer 11, This is a buffer RAM for temporarily storing reproduction data to the host computer 11.

The MPU 13 detects a defective sector on the basis of the result of the verify error by the ECC circuit 15 and controls the process of replacing the defective sector. Whenever the replacement process occurs, the replacement management information is registered in the internal memory of the MPU 13 each time. In the present embodiment, the replacement management information shown in FIG.
As shown in (1), the length (the number of sectors) up to the next replacement sector is registered in addition to the replacement sector (defective sector) address and the replacement sector address. The replacement management information is expanded in the memory in the order of addresses of replacement sectors as shown in FIG.

Next, the operation of the information recording / reproducing apparatus when reading is requested from the host computer 11 will be described with reference to FIG. The host computer 11 sets the read start position to ST, and sets the number of read sectors to L.
It is assumed that reading has been requested. In FIG. 4, when a read request is transmitted from the host computer 11, the MPU 13 first searches for replacement management information registered in its internal memory (S1). In searching for the replacement management information, it is checked whether or not there is a replacement sector among the sectors within the request range, and the replacement management information of the replaced sector is indicated by the pointer PT as shown in FIG. In FIG. 3, two sectors are replaced, and therefore two pointers PT
1 and PT2 indicate replacement management information of the replacement sector. Next, the MPU 13 determines whether or not there is a replacement sector within the read request range based on the search result of the replacement management information (S2). If there is no replacement sector, the MPU 13 continues the request sector number L from the start address ST of the request. And read the data (S3).
And the process ends.

On the other hand, when there is a replacement sector within the read request range, the read sector is continuously read from the sector at the start of reading to the sector immediately before the replacement sector, and the number of read sectors is subtracted from the required number of read sectors ( S4). After that, seek to the alternative sector indicated by the pointer PT1 to read the alternative sector, and subtract one sector from the requested sector number (S
5). Next, the number of sectors requested to be read is compared with the number of sectors up to the next replacement sector recorded in the replacement management information pointed to by the pointer PT1 (S6). If the number of sectors is smaller than the number of sectors, the requested number of sectors is continuously read from the sector immediately after the replacement sector indicated by the pointer PT1, and the processing (S7) is completed. If the number of requested sectors is larger than the number of sectors up to the next replacement sector, data is read continuously from the sector immediately after the replacement sector indicated by the pointer PT1 to immediately before the next replacement sector. (S
8). In this case, the number of sectors up to the next replacement sector is included in the replacement management information as described above.
Reference numeral 13 indicates the number of sectors to be continuously read based on this information. Next, the pointer PT1 is incremented (S
9) Return to S5 again and execute the same processing as described above until the requested sector becomes 0. When the number of replacement sectors is two as shown in FIG. 3, the next is the pointer PT2.
Indicates the replacement sector management information.

Further, as another embodiment, when the apparatus starts up, all the replacement management information written on the optical disk is read into the memory of the MPU, and the next replacement sector is read from the replacement management information for all the replacement sectors. May be calculated and tabulated in the same order as the replacement management information. Therefore, when there is a read request from the host computer, the read operation is controlled by the information stored in the table, so that the length of the sector up to the next replacement sector is conventionally determined at the time of reading the information as in the above-described embodiment. There is no need to calculate, and the load on the controller can be reduced.

[0012]

As described above, according to the present invention, the sector length required for reading information is calculated in advance and stored in the memory as replacement management information, so that the address calculation at the time of reading information is performed. There is an effect that the load on the controller can be reduced and the reading operation can be speeded up.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an information recording / reproducing apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing replacement management information used in the embodiment of FIG.

FIG. 3 is an explanatory diagram showing a state in which replacement management information is expanded in a memory;

FIG. 4 is a flowchart showing an operation at the time of reading information in the embodiment of FIG. 1;

[Explanation of symbols]

 Reference Signs List 10 information recording / reproducing device 11 host computer 13 MPU 15 ECC circuit 18 buffer RAM 19 optical disk

Claims (3)

(57) [Claims] 1. An information recording / reproducing apparatus wherein an alternative sector area is prepared on an information recording medium, and when a defective sector occurs on the recording medium, the defective sector is replaced with the prepared alternative sector. An information recording / reproducing apparatus which calculates a sector length up to the next defective sector for each defective sector, stores the calculated length in a memory, and controls an information reading operation in accordance with information in the memory when reading information. 2. The information recording / reproducing apparatus according to claim 1, wherein the calculation of the sector length is performed every time a replacement process occurs, and the calculation result is stored in a memory as replacement management information. 3. The calculation of the sector length is performed when the device starts up.
2. The information recording / reproducing apparatus according to claim 1, wherein the calculation is performed based on the replacement management information recorded on the information recording medium, and a calculation result is tabulated in a memory in the same order as the replacement management information.