Storage device with the ability to check for defects in same

• US 6,233,108 B1
• Filed: 04/07/1997
• Issued: 05/15/2001
• Est. Priority Date: 04/08/1996
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Inoue, Sunao
• Primary Examiner(s): YOUNG, WAYNE R
• Application Number:
  US08/826,690
• Time in Patent Office: 1,499 Days
• Field of Search: 360/48-49, 360/54, 360/61, 360/47, 360/53, 369/48, 369/54, 369/59, 369/124, 369/124-1-1, 710/5, 710/7, 710/8, 714/710, 714/718, 714/719, 714/769, 714/770
• US Class Current: 360/53
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 20/1883 Methods for assignment of alternate areas for defective areas
• CPC Class Codes: G11B 2020/183 wherein at least one additional attempt is made to read or write the data when a first attempt is unsuccessful
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers

Abstract

All storage areas constituting a storage medium are checked for defects by successively reading and writing data. If an error that has occurred owing to the checking operation is an error for which retry is possible, the number of times this occurs is accumulated in a retrial-count storage area of a memory. A faulty storage area is detected based upon the type of error that has occurred by checking and/or the number of occurrences that have been accumulated.

Claims

1. A storage device equipped with a storage medium, comprising:

checking means for checking for defects in storage areas by performing reading and writing of data over all storage areas constituting the storage medium, periodically at predetermined intervals;

accumulating means which, when an error that has been discovered by checking performed by said checking means is an error which can be recovered from by performing a retry, is for accumulating the number of times a recovery has occurred;

detecting means for detecting fault locations in the storage areas based upon (1) the type of error that has occurred by checking performed by said checking means, or (2) upon the number of occurrences accumulated by said accumulating means, or both; and

control means for inhibiting instructions from elsewhere during execution of a set of reading and writing of data over a single storage area by said checking means and for allowing execution of the instructions from elsewhere after execution of each set of reading and writing of data over a respective one of storage areas.

2. The device according to claim 1, further comprising substitution means for substituting another storage area for a storage area having a defect detected by said detecting means.

3. The device according to claim 1, wherein said detecting means detects a storage area under examination as being a defective location if the number of occurrences accumulated by said accumulating means exceeds a predetermined number or if the error that has been discovered by checking performed by said checking means is an error which cannot be recovered from by performing a retry.

4. The device according to claim 1, wherein the storage device has a control instruction for inhibiting instructions from elsewhere during execution of a set of reading and writing of data over a single storage area by said checking means;

and

wherein said control means controls the storage device by using the control instruction.

5. The device according to claim 1, further comprising memory means for holding data read out by said checking means,

said checking means checking for defects of the storage areas by re-reading data out of a storage area after the data has been written to the storage area by said checking means and comparing the read data and the data held by said memory means.

6. A storage system equipped with a plurality of storage devices, comprising:

checking means for checking for defects in storage areas by performing reading and writing of data over all storage areas constituting a storage medium, periodically at predetermined intervals, provided in each storage device of said plurality of storage devices;

accumulating means which, when an error that has been discovered by checking performed by said checking means is an error which can be recovered from by performing a retry, is for accumulating the number of times a recovery has occurred;

detecting means for detecting fault locations in the storage areas based upon (1) the type of error that has occurred by checking performed by said checking means, or (2) upon the number of occurrences accumulated by said accumulating means, or both;

monitoring means for monitoring status of detection of each storage device of said plurality of storage devices by said detecting means;

substitution means for substituting one storage device for another in dependence upon status of detection monitored by said monitoring means; and

control means for inhibiting instructions from elsewhere during execution of a set of reading and writing of data over a single storage area by said checking means and for allowing execution of the instructions from elsewhere after execution of each set of reading and writing of data over a respective one of storage areas.

7. A method of controlling a storage device equipped with a storage medium, comprising:

a checking step, of checking for defects in storage areas by performing reading and writing of data over all storage areas constituting the storage medium, periodically at predetermined intervals;

an accumulating step, which, when an error that has been discovered by checking performed at said checking step is an error which can be recovered from by performing a retry, is a step of accumulating the number of times a recovery has occurred;

a detecting step, of detecting fault locations in the storage areas based upon (1) the type of error that has occurred by checking performed in said checking step, or (2) upon the number of occurrences accumulated in said accumulating step, or both; and

a control step, of inhibiting instructions from elsewhere during execution of a set of reading and writing of data over a single storage area in said checking step and of allowing execution of the instructions from elsewhere after execution of each set of reading and writing of data over a respective one of storage areas.

8. The method according to claim 7, further comprising a substitution step, of substituting another storage area for a storage area having a defect detected at said detecting step.

9. The method according to claim 7, wherein said detecting step includes detecting a storage area under examination as being a defective location if the number of occurrences accumulated in said accumulating step exceeds a predetermined number or if the error that has occurred by checking performed in said checking step is an error for which retry is impossible.

10. The method according to claim 7, wherein the method has a control instruction for inhibiting instructions from elsewhere during execution of checking in said checking step;

and

wherein said control step includes controlling the storage device by using the control instruction.

11. The method according to claim 10, further comprising a data holding step, of holding data read out at said checking step,

wherein said checking step includes checking for defects of the storage areas by re-reading data out of a storage area after it has been checked in said checking step and comparing the read data and the data held in said data holding step.

12. A method of controlling a storage system equipped with a plurality of storage devices, comprising:

a checking step, of checking for defects in storage areas by performing reading and writing of data over all storage areas constituting a storage medium, periodically at predetermined intervals, provided in each storage device of the plurality of storage devices;

an accumulating step, which, when an error that has been discovered by checking performed in said checking step is an error which can be recovered from by performing a retry, is a step of accumulating the number of times a recovery has occurred;

a detecting step, of detecting fault locations in the storage areas based upon (1) the type of error that has occurred by checking performed in said checking step, or (2) upon the number of occurrences accumulated in said accumulating step, or both;

a monitoring step, of monitoring status of detection of each storage device of the plurality of storage devices in said detecting step;

a substitution step, of substituting one storage device for another in dependence upon status of detection monitored at said monitoring step; and

a control step, of inhibiting instructions from elsewhere during execution of a set of reading and writing of data over a single storage area by said checking step, and of allowing execution of the instructions from elsewhere after execution of each set of reading and writing of data over a respective one of storage areas.

13. A computer readable memory storing program code control processing for controlling a storage device equipped with a storage medium, the program code comprising:

program code for a checking step, of checking for defects in storage areas by performing reading and writing of data over all storage areas constituting the storage medium, periodically at predetermined intervals;

program code for an accumulating step, which, when an error that has been discovered by checking performed in said checking step is an error which can be recovered from by performing a retry, is a step of accumulating the number of times a recovery has occurred;

program code for a detecting step, of detecting fault locations in the storage areas based upon (1) the type of error that has occurred by checking performed in said checking step, or (2) upon the number of occurrences accumulated in said accumulating step, or both; and

program code for a control step, of inhibiting instructions from elsewhere during execution of a set of reading and writing of data over a single storage area in said checking step, and of allowing execution of the instructions from elsewhere after execution of each set of reading and writing of data over a respective one of storage areas.