JPH11273242A - Magnetic disk drive - Google Patents

Abstract

(57) [Summary] An object of the present invention is to reduce the overhead time related to crossing tracks by starting repositioning operation to the next target track immediately after the end of the last sector access. In a case where a target sector has already been detected and user data has been read, 3. By starting the repositioning operation to the adjacent physical track N + 1 without waiting for the normal end confirmation of the last data sector access in the track N, the overhead due to crossing tracks is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, which has a high-speed track switching process when an access request over a plurality of physical tracks is received or when a physical track is crossed by a pre-read process. Related to the device.

[0002]

2. Description of the Related Art In a magnetic disk drive, when an access request is received over a plurality of physical tracks, a skew corresponding to a head positioning time is provided between arbitrary tracks, and a plurality of continuous physical sectors are provided. To reduce the overhead for crossing tracks by arranging between tracks.

[0003] For example, Japanese Patent Application No. 58-232406.
As described in Japanese Patent Application No. 61-111208 and Japanese Patent Application No. 61-111208, there is a method of shortening the re-positioning time to an adjacent track by using specific positioning information.

[0004]

However, with the above-described conventional method alone, after confirming that the access on the first track for which the access request has been received has been completed normally,
The positioning to the adjacent track is performed, and the skew time is a major factor affecting the sequential access performance.

[0005] It is an object of the present invention to solve the above-mentioned problems by storing the last sector position of a physical track in a positioning control unit and, upon completion of the last sector access, adjacent track (sector position continuous to the last sector of the track). Another object of the present invention is to provide a magnetic disk drive that starts re-positioning to a track and shortens an overhead time for crossing tracks.

[0006]

According to the present invention, in order to achieve the above object, the positioning control section has information on the position of the last sector in the physical track, and at the end of access to the last sector, the read / write data control section. Without waiting for the normal end determination in step (1), the servo controller determines the last sector access in the track, and starts a re-positioning operation to the last adjacent track (the sector position following the accessed track last sector).

That is, when performing access across physical tracks, at the end of the track access before the execution of the crossing of the track, without waiting for the normal end determination by the read / write data control unit, the adjacent track (after the execution of the By starting the repositioning operation on the (track), the overhead time required for cross-track execution can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment corresponding to claims and claim 1. In this embodiment, an example will be described in which a host accesses four sectors across physical tracks N and N + 1.

The read / write control unit requests a positioning operation to the first target physical track N in response to an access request from the host. When the positioning operation by the servo control unit is completed, an access request for the sector M-1 and the sector M on the physical track N is issued to the HDC (hard disk controller). Further, in response to the detection of the target sector, an R / W Active signal is asserted, and the servo control unit is provided with means for distinguishing between a rotation waiting state (during a search of the target sector head) and a read / write operation.

The servo controller reads the completion of positioning.
After the report to the write control unit, a tracking operation for the target track is executed, and a determination is made every time servo information is detected whether or not the information is the last servo information in the target track.

When the last servo information 4 in the target track is detected, the R / W Active signal is confirmed, and the Active / Active signal is checked.
If (asserted state) is detected, preparation for starting repositioning to the adjacent physical track (physical track N + 1) is started. Further, when the head servo information (physical track N servo data 0) in the target track is detected, the re-positioning operation to the adjacent physical track is started.

In the prior art, after the last sector access 2 in a physical track is completed, an end report is received from the HDC,
Further, after confirming the normal end of access (read or write) in the track, the read / write control unit issues a request for repositioning to the adjacent track to the servo control unit.

The read / write control unit, after detecting the report of the end of repositioning to the physical track N + 1 by the servo control unit,
For the target track after the track
Execute the write operation.

[0014]

According to the present invention, in response to an access request that spans a physical track, the re-positioning activation to the next (adjacent) target track from the end of access of the last sector of each target track is performed based on the servo information. Since it is executed, it can be executed in the shortest time.

Thus, the track skew value given for the overhead of cross-track execution can be minimized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the operation of a magnetic disk according to an embodiment of the present invention.

[Explanation of symbols]

1: Servo information given at equal intervals to physical tracks, 2: Data sector for user data, 3: Last data sector in physical track N, 4: Last-1 data sector in physical track N, 5: Physical track Head data in N + 1, 6: Head data sector in physical track N + 1, 7: Second data sector in physical track N + 1.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Ohno 2880 Kozu, Odawara-shi, Kanagawa Prefecture Storage Systems Division, Hitachi, Ltd.

Claims (3)

[Claims] 1. A magnetic disk drive for performing a head positioning operation using positioning information stored on a disk storage medium and accessing data on the disk medium.
When a media access (read, write, verify) request over a plurality of physical tracks is received, at the end of access to the last sector in the physical track, the adjacent track can be read without waiting for a normal end determination by the read / write data control unit. A magnetic disk drive comprising means for starting a repositioning operation to (a sector position following an accessed track last sector). 2. The magnetic disk drive according to claim 1, wherein when a pre-read process is performed across a plurality of physical tracks in response to a read or verify execution request from a higher-level device, the last sector access in the physical track is terminated. A magnetic disk drive comprising: means for starting a repositioning operation to an adjacent track (a sector position that is continuous to the last sector of an accessed track) without waiting for a normal end determination by a read / write data control unit. 3. A magnetic disk drive which has the same means and configuration as the magnetic disk drive according to claim 1 or 2 and is used for a recording / reproducing apparatus for recording / reproducing a disk-shaped storage medium.