Error detection/correction and fault detection/recovery – Pulse or data error handling – Digital data error correction
Reexamination Certificate
1999-09-22
2003-04-22
Decady, Albert (Department: 2133)
Error detection/correction and fault detection/recovery
Pulse or data error handling
Digital data error correction
C369S059240
Reexamination Certificate
active
06553532
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method of recording and reproducing information on and from a disk-shaped recording medium such as an optical disk, a magnetic disk, or a magneto-optical disk. This invention also relates to an apparatus for recording and reproducing information on and from a disk-shaped recording medium such as an optical disk, a magnetic disk, or a magneto-optical disk.
2. Description of the Related Art
Japanese published unexamined patent application 6-19767 discloses a magnetic disk controller with a file restoration function. The magnetic disk controller in Japanese patent application 6-19767 includes an output control means, an output data storage means, an output control information storage means, an output state storage means, and a file restoration means. The output data storage means stores data to be outputted to the magnetic disk which is fed from a host device. The output data storage means can hold the data even when power supply is interrupted. The output control means is informed by the host device of a designated output position and an output-data length. The output control means writes the information of the designated output position and the output-data length into the output control information storage means. The output control information storage means can hold the information even when power supply is interrupted. The output control means writes a signal representative of a state of output processing into the output state storage means. The output state storage means can hold the signal even when power supply is interrupted.
The magnetic disk controller in Japanese patent application 6-19767 records data on the magnetic disk as follows. The output control means accesses a region of the magnetic disk which agrees with the designated output position. The output control means transfers the data from the output data storage means to the magnetic disk, and records the data into a file on the accessed region of the magnetic disk. The amount of the data recorded into the file corresponds to the output-data length. When the data is recorded into the file, the output control means writes a signal, which represents a state where the data is being outputted, into the output state storage means. After the recording of the data into the file has been completed, the output control means writes a signal, which represents a state where the data has been outputted, into the output state storage means. In the output state storage means, the signal representing the state where the data has been outputted replaces the signal representing the state where the data is being outputted. If power supply is interrupted before the recording of the data into the file is completed, the signal representing the state where the data is being outputted remains in the output state storage means.
In Japanese patent application 6-19767, when the magnetic disk controller is restarted, the file restoration means inspects the state represented by the signal stored in the output state storage means. If the state means that the data is being outputted, the file restoration means provides the output control means with a data re-recording request. The output control means implements a data re-recording process in response to the data re-recording request as follows. The output control means reads out the information of the designated output position and the output-data length from the output control information storage means. The output control means accesses the region of the magnetic disk which agrees with the designated output position. The output control means transfers the data from the output data storage means to the magnetic disk again, and re-records the data into the file on the accessed region of the magnetic disk. After the re-recording of the data into the file has been completed, the output control means writes a signal, which represents a state where the data has been outputted, into the output state storage means. Accordingly, in the case where power supply is interrupted during the recording of data into a file on the magnetic disk, data in the file on the magnetic disk can be restored after the interruption of power supply terminates.
A typical recording disk has a recording track divided into sectors to which different addresses are assigned respectively. Every sector corresponds to a minimum unit of data in recording and reproducing information on and from the recording disk. In general, data on a recording disk includes user data and correction-code (ECC) information. The data on the recording disk is divided into blocks (ECC blocks) each having a set of a user data piece and an ECC information piece. During playback, error correction of the user data is implemented block by block. An ECC information piece in every block is predetermined depending on a user data piece in the same block to permit error correction thereof.
In some recording disks, every ECC block of recorded data extends over a plurality of sectors. During the updating of data on such a recording disk, old data is replaced by new data in every ECC block. It is assumed that power supply is interrupted during the replacement of old data by new data in an ECC block. In this case, portions of the new data are recorded on former sectors in the ECC block while portions of the old data remain on latter sectors therein. As a result, there is a discrepancy between a user data piece and an ECC information piece in that ECC block. It is difficult to correctly reproduce a user data piece from such a wrong ECC block since an ECC information piece therein is inconsistent with the user data piece. Thus, it is also difficult to update a portion of the user data piece in a specified sector among sectors of the wrong ECC block.
SUMMARY OF THE INVENTION
It is a first object of this invention to provide a method of recording and reproducing information on and from a disk-shaped recording medium which is less adversely affected by interruption of power supply.
It is a second object of this invention to provide an apparatus for recording and reproducing information on and from a disk-shaped recording medium which is less adversely affected by interruption of power supply.
A first aspect of this invention provides a method of recording and reproducing information on and from a disk ECC-block by ECC-block. Every ECC block is composed of plural sectors. The method comprises the steps of generating a recording command containing information of a recording position on the disk; storing the information of the recording position into a nonvolatile memory; recording data on the disk in response to the recording command; in cases where power supply is turned on after interruption of power supply terminates, detecting a specified ECC block from the information stored in the nonvolatile memory, the specified ECC block being adversely affected by the interruption of power supply during the recording of data on the disk; generating one of a reproducing command and a verify command for at least one sector of the specified ECC block; reproducing data from the specified ECC block on the disk in response to the one of the reproducing command and the verify command; deciding whether or not the reproduction of data from the specified ECC block succeeds or fails; and in cases where it is decided that the reproduction of data from the specified ECC block fails, recording data on a whole of the specified ECC block to convert the specified ECC block into a normal ECC block.
A second aspect of this invention provides a method of recording and reproducing information on and from a disk ECC-block by ECC-block. Every ECC block is composed of plural sectors. The method comprises the steps of generating a recording command for a specified ECC block on the disk, the recording command containing information of a recording position on the disk and information of a recording size, the specified ECC block having sectors designated by the recording command and sectors undesignated by the recording comman
Lamarre Guy
Matsushita Electric - Industrial Co., Ltd.
Woo Louis
LandOfFree
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