JPH0729321A - Method mechanism for controlling positioning head and method therefor - Google Patents

Abstract

PURPOSE:To reduce a reading error of position information caused by damage or noise on a medium and to perform highly accurate positioning control by generating an error correcting code from data of a cylinder code and using this code and cylinder. CONSTITUTION:A detecting circuit 5 detects servo data out of reproduced data, reads out a cylinder code and generates a sample gate of burst data. A microprocessor 8 performs positioning control. In this case, the cylinder code performs positioning control by servo data constituted with data indicating the number of cylinders and an error correcting code generated from this data. Also, when an error is detected in position information from the error correcting code, writing is prohibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head positioning control mechanism mounted on a magnetic disk device and a head positioning control method.

[0002]

2. Description of the Related Art Conventionally, servo data in an embedded servo used for a magnetic disk, for example, is composed of a cylinder code indicating the number of cylinders and burst data. FIG. 3 shows an example of conventional servo data. In the cylinder code, a numerical value representing the number of cylinders is recorded in gray code.

However, the cylinder code recorded in the Gray code determines wrong data, that is, wrong position if any bit judgment is wrong, and if seek occurs during speed control, it causes increase in seek time. Met. In addition, there is a problem in that the positioning accuracy is deteriorated during position control.

[0004]

As described above, in the cylinder code recorded by the conventional Gray code,
If there is an error in the arbitrary bit judgment, the wrong position is judged, and if it occurs during speed control, it will increase the seek time. In addition, the positioning accuracy is deteriorated during the position control.

The present invention has been made in consideration of the above circumstances, and a head positioning control mechanism capable of realizing high-precision positioning control by reducing reading errors of position information due to damage on a medium or noise. Another object of the present invention is to provide a head positioning control method.

[0006]

In order to achieve the above object, the present invention provides a head positioning control mechanism in which servo data includes a cylinder code indicating the number of cylinders and burst data, wherein the cylinder code indicates the number of cylinders. A head positioning control mechanism is characterized in that positioning control is performed by servo data composed of data shown and an error correction code generated from this data.

In order to achieve the above object, the present invention provides a servo data composed of a cylinder code indicating the number of cylinders and burst data, and head positioning control is performed by this data, wherein the cylinder code is a cylinder. A head positioning control method is characterized in that positioning is controlled by servo data composed of data indicating a number and an error correction code generated from this data.

Further, in order to achieve the above object, the present invention is such that servo data is composed of a cylinder code indicating the number of cylinders and burst data, and head positioning control is performed by this data, and the cylinder code is a cylinder. Servo data composed of data indicating the number and an error correction code generated from this data, wherein when an error is detected in the position information from the error correction code, writing is controlled to be prohibited. It is in the head positioning control mechanism.

[0009]

According to the present invention, the servo data is servo data having a cylinder code composed of an error correction code generated from the cylinder code data and the generated error correction code and the cylinder data.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 shows an example of servo data when parity is used as an error correction code.

In FIG. 1, reference numeral 1 denotes a medium, that is, a magnetic disk, on which data to be recorded / reproduced and servo data are recorded. 2 is a magnetic head, and the magnetic disk 1
Data recording / reproduction and servo data reproduction are performed for. A head amplifier 3 has a function of amplifying the data reproduced by the magnetic head 2. Reference numeral 4 denotes a peak detection circuit, which converts the signal output from the head amplifier 3 into digital data. A servo data detection circuit 5 detects servo data from the reproduced data, reads the cylinder code, and generates a sample gate for burst data. Reference numeral 6 denotes a sample hold circuit, which holds burst data. 7 is an A / D conversion circuit, which converts burst data into digital
It has a function of transmitting it to the microprocessor 8. The microprocessor 8 is equipped with control program information for executing an instruction from a hard disk controller (not shown) and performs positioning control. A program memory 9 stores various program information to be executed by the microprocessor 8. A D / A conversion circuit 10 converts the head positioning signal from the microprocessor 8 into an analog signal. Reference numeral 11 denotes a driver, which converts the positioning control signal from voltage to current. Reference numeral 12 is a voice coil motor, which is a moving means for positioning the head. A data reproducing circuit 13 demodulates the data recorded in the data field. A hard disk controller 14 controls the magnetic disk device.

The operation of the above structure will be described with reference to FIG. That is, the servo data in FIG. 2 is an example in which parity data is added as an error correction code. The parity bit is set to "1" when there is an odd number of "1" data in the cylinder code. By doing so, the number of data of "1" in the data string is all even.

In reproduction, the number of "1" s in the read data string is checked, and if it is an odd number, it can be detected that an error has occurred. In short, the servo data in the embedded servo system is servo data having a cylinder code composed of an error correction code generated from the cylinder code data and the generated error correction code and cylinder data.

[0014]

As described above, according to the present invention, a servo data read error can be detected and corrected, the position information read error due to damage or noise on the medium can be reduced, and highly accurate positioning control can be performed. It has an excellent effect that

[Brief description of drawings]

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

FIG. 2 is a diagram schematically showing servo data including an error correction code according to the same embodiment.

FIG. 3 is a diagram schematically showing conventional servo data.

[Explanation of symbols]

1 ... Magnetic disc, 2 ... Magnetic head, 3 ... Head amplifier, 4 ... Peak detection circuit, 5 ... Servo data detection circuit,
6 ... Sample and hold circuit, 7 ... A / D conversion circuit, 8 ...
Microprocessor, 9 ... Program memory, 10 ... D
/ A conversion circuit, 11 ... Driver, 12 ... Voice coil motor, 13 ... Data reproduction circuit, 14 ... Hard disk controller.

Claims (3)

[Claims] 1. A head positioning control mechanism in which servo data comprises a cylinder code indicating the number of cylinders and burst data, wherein the cylinder code comprises data indicating the number of cylinders and an error correction code generated from this data. A head positioning control mechanism characterized in that the positioning is controlled by the servo data. 2. The servo data is composed of a cylinder code indicating the number of cylinders and burst data, and head positioning control is performed by this data. The cylinder code is generated from this data and the data indicating the number of cylinders. A head positioning control method, characterized in that positioning control is performed by servo data composed of the error correction code. 3. Servo data is composed of a cylinder code indicating the number of cylinders and burst data, and head positioning control is performed by this data, and the cylinder code is generated from the data indicating the number of cylinders and this data. The head positioning control mechanism is characterized in that it is servo data composed of the above-mentioned error correction code, and is controlled so as to prohibit writing when an error is detected in the position information from the error correction code.