JPS61133433A - Defective sector alternate processing system in unrewritable data recording medium - Google Patents

Abstract

PURPOSE:To omit transmission/reception of a redundant command or status byte during verification by providing a status buffer memory storing sequentially information of a defective sector found out during the verification to the inside of a drive controller. CONSTITUTION:A CPU 1 verifies data by comparing the data written on a medium. When an error is found out in a write data during verification and all spare sectors in the same track of the sector having the error are in use, the CPU 1 sets a flat representing the defective sector to the erroneous sector. Then the CPU 1 stores a sector number of the defective sector to a status buffer 9 and continues the verification from the next sector. When the verification is finished, the end of verification is informed to the CPU 1 by the interruption from a DMA circuit 3. The CPU 1 check s the content of the status buffer 9 transmitted from a drive controller 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for replacing bad sectors in a data management system KTh using a non-rewritable data recording medium.

(Prior Art) In a data management system using a non-rewritable data recording medium, if it is found during post-writing verification that incorrect data has been written due to a defect in the medium or an error during data transfer, For example, it was impossible to retry writing data to the same sector. For this reason, a bad sector replacement method is known in which, instead of prohibiting future access, the error sector is treated as a bad sector and another sector on the medium is used as a replacement sector.

Such defective sector replacement methods include a method in which a fixed number of spare sectors provided on each data track are used as replacement sectors, and a method in which sectors inside a fixed number of spare tracks provided on the medium are used. be. However, normal bad sector replacement processing first uses a spare sector inside the same track as the error-occurring sector, and then replaces it with a sector inside the spare track after all the spare sectors are used. Both methods were used together in the form of processing.

In this case, the process of replacing each data track with an internal spare sector can be performed by only the device-side device under the control of the drive control device. However, in the process of replacing spare tracks, the number of spare tracks and the position on the medium differ depending on the medium depending on the individual differences in the good/bad condition at the time of shipment, and accessing the spare tracks involves a seek of the head. Therefore, it is necessary to perform software management on the host device side.

(Problem to be Solved by the Invention) However, since the spare track needs to be set at a physically separate location from the normal data recording track, the time required for accessing the spare sector within the same track is It has the disadvantage that it is longer than .

Furthermore, when simultaneously replacing multiple sectors with sectors inside a spare track, and when reading the replaced sectors, the reciprocating sheet movement of the head to the spare track is performed each time a bad sector is discovered. This increases the time it takes to complete the access request.

Furthermore, there is a drawback that the transmission and reception of commands and status bytes between the device side and the host device side becomes redundant.

An object of the present invention is to provide a device side with a function of notifying a higher-level data management device of replacement information for bad sectors for one track at a time every time a track-by-track data access to a non-rewritable data recording medium is completed. By adding this to the drive control device of An object of the present invention is to provide a defect sector replacement processing method for a data recording medium that cannot be rewritten by memory, and is configured so that the seek operation of the head can be limited to one round trip.

(Means for Solving the Problems) A defective sector replacement processing method in a non-rewritable data recording medium according to the present invention comprises a device-side device consisting of a non-rewritable recording medium drive device and a drive control device, and at least a CPU, data This is an improvement of a structure in which a buffer memory and a higher-level data management device having a DMA circuit are interconnected, so that data can be transferred between the device-side device and the higher-level data management device.

In the above, the drive control device is equipped with a status buffer memory for sequentially storing replacement information for a defective sector when a defective sector is discovered on the recording medium.

The above-mentioned status buffer memory is provided with a formatting means for collectively notifying the upper data management device of the replacement information in the track upon completion of data access on a track-by-track basis.

(Example) Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the bad sector replacement processing method according to the present invention. In Figure 1, 1 is the CPU, 2 is the data buffer, and 3 is the DM.
A circuit, 4 is an interface circuit, 5 and 6 are signal lines, 7 is a recording medium drive device, 8 is a drive control unit ff, 9 is a status buffer, 10 is a signal line by an interface cable, 100 is upper side data management It is a device.

The upper data management device 100 in FIG. 1 is 0PUI.
The data buffer memory 2 and an interface circuit 4 including a DMA circuit 3 are connected via a data bus signal line 5, and read data and write data are transferred between the data buffer memory 2 and the device under the control of the DMA circuit 3. The data is transferred to and from the drive control device ii8 on the side. The completion of writing and reading is notified to 0PU1 via interrupt signal line 5 at the end of DMA.

On the device side, a data recording medium drive device f7 is connected to the same drive control device 8, and a drive control device f7 is connected to the drive control device 8 under the management of the upper-level data management device 100.
8 controls the operations of the recording medium drive device #7, such as data reading, writing, verifying, and head seeking.

The device side and the upper data management unit #100 are connected by an interface cable 10, which is used to send and receive commands necessary for operating the device side, parameters such as status, and write data and read data. be done.

Next, the operation when a defective sector is discovered during verification after data writing in this embodiment will be described.

0PUi of the upper data management device 100 prepares write data in the data buffer memory 2 and sends it to the DMA circuit 3.
After setting the internal start address and data length of the write data in the buffer memory 2, a command is issued to instruct the recording medium drive unit 7 on the device side to write data through the interface circuit 4, and data writing on the medium is started. Sends the track, selector number, and number of sectors in which data will be written.

The write data is transferred to the device side under the control of the DMA circuit 3 and written onto the medium under the control of the drive control device 8. The end of data writing is notified to CPU 1 by an interrupt from DMA circuit 3 at the end of data transfer.

Verification after writing is started by setting the same parameters in the DMA circuit 3 as before the start of writing, and sending a command for instructing device individual package #busy to verify and the same parameters as above. The drive control device 8 is used for controlling the DMA circuit 3 and transmitting and receiving parameter data transferred thereto, as well as write data and read data.

Next, an example of the operation of replacement processing when a defective sector is discovered during verification will be described.

The 0PUI of the upper-level data management device 100 performs data write preparation operations as follows. That is, CPU1
prepares the write data in the data buffer memory 2, and sends the start address of the write data to the DMA circuit 3 inside the interface circuit 4 inside the data buffer memory 2;
and set the write data length. Thereafter, 0PU1 sends a command to write data to the recording medium drive device 7 on the device side through the interface circuit 4, and parameters such as the data write start track and sector number on the medium. On the other hand, after initializing the status buffer memory 9, the drive control device 8 writes the write data transferred to the medium under the control of the DMA circuit 3. Data writing is completed using DMA
This is notified to 0PU1 by an interrupt from circuit 4. Therefore, 0PUI prepares for a verify operation to confirm that the data has been written normally. First, 0PUI
Verifies the data by comparing the data written on the media. If an error is found in the write data being verified and all spare sectors in the same track as the error sector are in use, the CP
U1 writes a flag indicating that the error sector is a bad sector. After that, 0PUI is status no (
The sector number of the defective sector is stored in buffer 9, and verification continues from the next sector.

21 is an explanatory diagram showing an example of a storage format of bad sector information stored in the 21st M status buffer 9. FIG.

In FIG. 2, 11 is an end code field, 12
is a bad sector number field, and 13 is a bad sector number field. The number of bad sectors indicates the number of bad safeters found during verification, and the number of bad sectors field 12
The sector numbers of the defective sectors are sequentially stored in the defective sector number field 13 following . The completion code is a parameter that indicates whether or not the verify operation has ended normally, and the completion code field 11 contains a value that indicates whether the verification is normal or abnormal when the verification ends, and if it is abnormal, the type of abnormality. Stored.

When the verify operation is completed as explained above,
Similar to the end of writing, the end of 0PULK verification is notified by an interrupt from the DMA circuit 3. ○PUI
Then, a request is made to send the contents of the device side button status buffer 9, and the contents of the status buffer 9 sent from the drive control device 8 are checked. End; - If the end code in field 11 indicates normal end and the number of defective sectors is O, there is no need to replace the track with a spare track. However, if the number of bad sectors shows a value of 1 or more, after the head seeks to the spare track, the data that should have been written to the bad sector indicated in the bad sector number field 13 is written. By sequentially writing to the internal sectors of the spare track, it is possible to complete the replacement process for all defective sectors.

(Effects of the Invention) As explained above, in the present invention, by providing a status buffer memory inside the drive control device to sequentially store information on bad sectors found during verification, the information can be saved all at once at the end of verification. It is possible to perform track replacement processing, thereby omitting redundant command and status byte transmission/reception operations during verification, and limiting the head seek operation to the spare track only once. There is. In addition, when reading data, the same effect can be obtained by sequentially storing bad sector information in the status buffer memory and reading from the spare track all at once. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the method for replacing bad sectors in a non-rewritable data recording medium according to the present invention. FIG. 2 is an explanatory diagram showing the storage format of the status buffer memory shown in FIG. 1. 1...OPU z...Data buffer memory 3
... DMA circuit 4 ... I/FACE circuit 7 ... Data recording medium drive device 18 ... Drive control device 9 ... Status buffer memory 5, 6, 10 ... Signal lines 11 to 13 ···field

Claims (1)

[Claims] A device-side device consisting of a non-rewritable recording medium drive device and a drive control device, and at least a CPU.
, a data buffer memory, and a higher-level data management device having a DMA circuit are interconnected, and data can be transferred between the device-side device and the higher-level data management device. and a status buffer memory for sequentially storing replacement information for the bad sector when the drive control device discovers a bad sector on the recording medium, and the status buffer memory completes data access in units of tracks. 1. A bad sector replacement processing method, comprising: a formatting means for collectively reporting the replacement information in a track to the upper data management device.