JP2604490B2 - Magnetic disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive accompanied by magnetic disk defect processing.

2. Description of the Related Art In a conventional magnetic disk drive, the phase relationship between an index signal inside the drive and an index signal output to a host device is fixed.

FIG. 2 is a timing chart showing the relationship between index signals and sectors in a conventional magnetic disk drive.

As shown in FIG. 2, the phase relationship between the index signal (internal index signal) 21 inside the device and the index signal (output index signal) 22 output to the host device is fixed, and the defect of the magnetic disk is Are (n-1) cylinders, a, (n) in sector 1
In the case of c and d in sector 1 in +1) cylinder, sector 1 of (n-1) cylinder and (n + 1) cylinder is not used.

[Problems to be Solved by the Invention] As described above, in the conventional magnetic disk device, since the phase relationship between the index signal inside the device and the index signal output to the host device is fixed, the magnetic disk medium (magnetic If there is one defect on the cylinder of the disc), the defective sector must be used instead of using the defective sector, and there is a disadvantage that the actual storage capacity is reduced.

[Means for solving the problem]

A magnetic disk device according to the present invention includes a defect position register that stores a position of a defect of a magnetic disk, a cylinder position register that stores a current cylinder position of a magnetic head,
A delay value calculating circuit for calculating an index signal delay value from the values of the defect position register and the cylinder position register; and an index signal delay for outputting an output index signal obtained by delaying an internal index signal by the index signal delay value to a host device. And a circuit.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

 FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, a defect position register 1 stores the position of a defect on a magnetic disk. The cylinder position register 2 stores the position of the cylinder where the magnetic head is currently positioned. The delay value calculation circuit 3 calculates an index signal delay value from the values of the defect position register 1 and the cylinder position register 2. Index signal delay circuit 4
Outputs an index signal obtained by delaying the index signal inside the device by the index signal delay value calculated by the delay value calculation circuit 3 to the host device.

FIG. 3 is a timing chart showing the relationship between the index signal and the sector in the embodiment of FIG.

As shown in FIG. 3, the index signal (output index signal) 12 to be output to the host device is different from the index signal (internal index signal) 11 in the apparatus in that the defect position of the magnetic disk is located at a in sector 1. There is (n-
1) The delay value A is output in the cylinder, the delay value B is output in the (n) cylinder having no defect, and the delay value C is output in the (n + 1) cylinder in which the position of the defect is located in c and d in the sector 1. You. The delay value calculation circuit 3 calculates these delay values from the position of the cylinder where the magnetic head is currently positioned and the position of the defect on the magnetic disk, and outputs the result to the index signal delay circuit 4. The time relationship between the position of the defect on the magnetic disk and the output index signal is set so that the index signal is output immediately after the position of the defect on the magnetic disk. A constant delay value B is set for a cylinder having no defect. If there are two adjacent defects in the same sector like (n + 1) cylinder,
The delay value C is set so as to output the index signal immediately after the rear defect d. By delaying the output index signal in this way, the position of the defect enters the gap and no unusable sector is left.

〔The invention's effect〕

As described above, the magnetic disk drive of the present invention
By calculating a delay value from the position of the cylinder where the magnetic head is currently positioned and the position of a defect on the magnetic disk, and outputting an output index signal obtained by delaying the internal index signal by the calculated value to a host device, This has the effect of eliminating the sectors that cannot be used due to the defect described above, and thus has the effect of increasing the substantial storage capacity of the magnetic disk drive.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a timing chart showing the relationship between an index signal and a sector in a conventional magnetic disk drive, and FIG.
6 is a timing chart showing a relationship between an index signal and a sector in the embodiment shown in FIG. 1 ... Defect position register, 2 ... Cylinder position register, 3 ... Delay value calculation circuit, 4 ... Index signal delay circuit, 11/21 ... Internal index signal, 12/22 ...
Output index signal.

Claims (1)

(57) [Claims] 1. A defect position register for storing a position of a defect on a magnetic disk, a cylinder position register for storing a current cylinder position of a magnetic head, and an index signal delay based on values of the defect position register and the cylinder position register. A magnetic disk drive comprising: a delay value calculation circuit for calculating a value; and an index signal delay circuit for outputting an output index signal obtained by delaying an internal index signal by the index signal delay value to a host device.