JPH0528651A - Information recorder and reproducer - Google Patents

Abstract

PURPOSE:To reduce the burden of a controller due to address calculation at the time of reading information and to operate reading at high speed by previously calculating sector length to a next defective sector at every defective sector. CONSTITUTION:An optical disk 19 is provided with a substitution sector area and is constituted in such a way that the prepared substitution sector is substituted for the defective sector when the defective sector is generated in the optical disk. At this time, sector length to the next defective sector is previously calculated at every defective sector and is stored inside the memory of MPU 13. MPU 13 detects the defective sector based on verified error result by an ECC circuit 15 so as to process the substitution of the substitution sector. When a substitution processing is generated, MPU 13 controls the operation for reading information in accordance with the information inside the memory so that the burden of the controller is reduced and reading is operated at high speed.

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 by using an information recording medium capable of rewriting information.

[0002]

2. Description of the Related Art Conventionally, since an information recording medium such as an optical disk has a relatively high error rate, it is common to prepare an alternative sector for replacing a defective sector in advance as a remedy. Is. Therefore, when data cannot be normally written in the designated sector due to a defect, the data is written in a previously prepared alternative sector, and so-called replacement processing is performed. In this case, the replacement management information that associates the defective sector with the replacement sector is registered in the memory of the controller in the apparatus every time the replacement process occurs. The replacement management information is sorted in the order of occurrence of replacement processing. On the other hand, if there is a read request from the host computer or other higher-level control device to the information recording / reproducing device,
The controller determines whether or not 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 speed up the transfer speed with the host computer, and if there is a read request, the controller continuously reads data as long as the buffer memory size allows. If there is a replaced sector within the required range, read up to the sector immediately before that and start the transfer to the host computer.
At the same time, the read head seeks to the alternative sector to read the alternative sector. When this is completed, seek is performed immediately after the sector that has been replaced again, and reading is started from the sector immediately after that. When reproducing information in this way, if there is a sector that has been replaced within the required range, the information is read by seeking to the alternative sector each time.

[0003]

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

However, in a recording device having a medium having an enormous storage capacity such as a magneto-optical medium, its address must be represented by several bytes. Therefore,
In order to perform the above calculation, addition / subtraction over several bytes must be performed, which imposes a heavy load on the CPU of the controller and adversely affects the execution speed. Further, the calculation of the above (1) and (3) may be performed once for one read request, but the calculation of (2) is required as many times as the number of replacement sectors within the request range. Therefore, the longer the read request, the larger the number of replacement sectors and the larger the number of calculations, resulting in a corresponding increase in the load on the CPU.

The present invention has been made in order to solve such a problem, and the purpose thereof 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. It is to provide a recording / reproducing apparatus.

[0006]

An object of the present invention is to provide an alternative sector area on an information recording medium, and when a defective sector occurs on the recording medium, the alternative sector provided with the defective 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 when the information is read, the information reading operation is performed according to the information in the memory. This is achieved by an information recording / reproducing device characterized by controlling.

[0007]

Embodiments of the present invention will now be described 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 is an information recording / reproducing apparatus, and 11 is a host computer which is a host controller. Information recording / reproducing apparatus 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 is a SCSI adapter that interfaces with the host computer 11, 13 is an MPU that performs overall control of the information recording / reproducing apparatus 10, 14 is a ROM that stores control programs, and 15 is an ECC circuit that performs 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 the optical disk 19 used as an information recording medium, or reproducing the recorded information, and 18 temporarily stores data transferred from the host computer 11, It is a buffer RAM for temporarily storing the reproduced data to the host computer 11.

The MPU 13 detects a defective sector based on the result of the verify error by the ECC circuit 15 and controls the replacement process to the alternative sector. Whenever replacement processing occurs, replacement management information is registered in the internal memory of the MPU 13. In this embodiment, the replacement management information is shown in FIG.
As shown in, the length (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. As shown in FIG. 3, the replacement management information is sorted and expanded in the memory in the order of the addresses of the replacement sectors.

The operation of the above information recording / reproducing apparatus when the host computer 11 requests reading will be described with reference to FIG. The host computer 11 sets the read start position to ST and the read sector number to L.
It is assumed that the reading is requested as. In FIG. 4, when a read request is transmitted from the host computer 11, the MPU 13 first searches the replacement management information registered in its internal memory (S1). When searching for the replacement management information, it is checked whether or not there is a replacement sector in the sector within the required range, and as shown in FIG. 3, the pointer PT indicates the replacement management information of the replaced sector. In FIG. 3, the two sectors are alternated and therefore the two pointers PT
The replacement management information of the replacement sector is designated by 1 and PT2. 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 request sector number L is continuously added from the request start address ST. Then, the reproduction data is read (S3), and the reproduced data is read by the host computer 11
To end the process.

On the other hand, if there is a replacement sector within the read request range, the sectors from the start of reading to the sector immediately before the replacement sector are continuously read, and the number of read sectors is subtracted from the number of requested read sectors ( S4). After that, the alternative sector indicated by the pointer PT1 is sought to read the alternative sector, and one sector is subtracted from the requested sector number (S
5). Next, the number of read request sectors is compared with the number of sectors up to the next replacement sector recorded in the replacement management information designated by the pointer PT1 (S6). If the number is less than the number of sectors, the number of requested sectors is continuously read from the sector immediately after the replacement sector indicated by the pointer PT1 (S7), and the process is terminated. If the number of requested sectors is greater than the number of sectors up to the next replacement sector, the sectors immediately after the replacement sector indicated by the pointer PT1 to the position immediately before the next replacement sector are continuously read, and the required number of sectors is read from that number. Reduce (S
8). In this case, since the number of sectors up to the next replacement sector is included in the replacement management information as described above, the MPU
13 indicates the number of sectors to be read continuously by this information. Next, the pointer PT1 is incremented (S
9) Then, the process returns to S5 and the same process as described above is executed until the requested sector becomes 0. If the number of replacement sectors is two as shown in FIG. 3, the pointer PT2 is next.
Indicates the management information of the replacement sector.

As another embodiment, all the replacement management information written on the optical disk when the apparatus is started up is read into the memory of the MPU, and from this replacement management information, the next replacement sector for all replacement sectors is read. It is also possible to calculate the sector length up to and to make a table in the same order as the replacement management information. Therefore, when there is a read request from the host computer, by controlling the read operation by the information stored in the table, the sector length up to the next replacement sector can be set as in the conventional case at the time of reading information as in the above embodiment. There is no need for calculation, and the burden 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 the replacement management information, so that the address is calculated when the information is read. This has the effect of reducing the load on the controller and speeding up the read operation.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an information recording / reproducing apparatus of 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.

[Explanation of symbols]

10 Information recording / reproducing apparatus 11 Host computer 13 MPU 15 ECC circuit 18 buffer RAM 19 optical disc

Claims (3)

[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 characterized in that, for each defective sector, a sector length up to the next defective sector is calculated in advance and stored in a memory, and when reading information, the information reading operation is controlled according to the information in the memory. 2. The information recording / reproducing apparatus according to claim 1, wherein the calculation of the sector length is performed every time replacement processing occurs, and the calculation result is stored in the 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 information is reproduced based on the replacement management information recorded on the information recording medium, and the calculation result is tabulated in the memory in the same order as the replacement management information.