JPH04351752A - Magnetic disk driving device - Google Patents

Abstract

PURPOSE:To contrive cost reduction, miniaturization, high speed access and high reliability of the device by realizing a servo system of a spindle motor rotating system and a magnetic head positioning system by means of software. CONSTITUTION:Data is written in advance in a shipping area of a magnetic disk 4, while a DC erasing part is formed. A start-up control of a spindle motor and an operation control of a magnetic head are performed by a control device 1. The rotation at a constant speed of the magnetic disk 4 is confirmed by a servo timing circuit 11 based on the read-out of the data in the shipping area by the magnetic head 7 and the detection of the DC erasing part, and a pseudo index signal is sent to the control device 1.

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 device, and more particularly to start-up control of the device when power is turned on.

0002

2. Description of the Related Art Magnetic disk drives are used in external storage devices for computer systems, etc., and read data by positioning a magnetic head at a desired data position on a rapidly rotating magnetic disk at high speed. /Write.

In order to position the magnetic head, conventional magnetic disk drive devices have mainly adopted a servo surface servo method.

[0004] In this servo surface servo method, special servo information necessary for positioning the magnetic head is written in advance on one side of a single magnetic disk, and when the device is operating,
In this method, the servo information is read out using a dedicated servo magnetic head to perform positioning, and at the same time, data is read/written using a data-only magnetic head on the remaining surface that has been positioned.

Although this method has been widely adopted, since servo information is written on the entire surface of the magnetic disk, data storage efficiency is poor, especially in devices with a small number of magnetic disks. That was a drawback.

On the other hand, in the sector servo method, information for positioning is simultaneously written on the data surface of the magnetic disk, so as mentioned above, the magnetic head dedicated to positioning and the magnetic head dedicated to data are separated. This method does not require any preparation, and has been adopted in many recent magnetic disk drives.

[0007]

However, recent magnetic disk drive devices are increasingly required to be lower in price, smaller in size, and faster in access. For example, in the past, a Hall IC built into the spindle motor generated an index signal, which is a signal for one rotation of the spindle, but in order to reduce costs, there is a tendency to not build it in. Instead, it is necessary to create the index signal on the equipment side. There is.

[0008] Furthermore, the access motor requires a position detector for high-speed positioning of the magnetic head. For example, in order to form an optical encoder of the position detector, a glass slit disk having an optical pattern, a light emitting diode, and a light receiving device are used. A phototransistor, etc. was required, but in order to achieve miniaturization and high-speed access, there is a trend toward not adding a position detector. Instead, positioning information for the magnetic head is written on the magnetic disk in advance, and the magnetic head This positioning information read out is calculated by a control device, and the calculation result calculated as a position error is used for positioning control of the magnetic head.

[0009] As described above, the configurations of recent magnetic disk drives are considerably different from those of the conventional ones in terms of hardware and software, and various proposals have therefore been made for control methods for the drives.

The present invention adds a new improvement to the start-up control of such a magnetic disk drive device.
In particular, the servo system for the spindle motor rotation system and magnetic head positioning system is configured with a sampling control system realized by software based on a μCPU, reducing and simplifying the amount of control circuitry, and making the system more flexible with software servo. The purpose of the present invention is to improve performance/versatility, and to achieve lower costs, smaller size, faster access, and higher reliability in order to be compatible with the recent magnetic disk drive devices mentioned above.

[0011]

Means for Solving the Problems In order to solve the above problems, the present invention provides a magnetic disk drive in which a shipping area is formed on a magnetic disk in which servo sectors having servo information and data sectors having data are alternately divided and arranged. In the device, special data is written in advance in a data sector corresponding part in the shipping area, and a magnetic disk having a DC erase part for generating a pseudo index signal in an arbitrary data sector corresponding part and a spindle motor are activated and controlled. A control means that controls the rotation of the magnetic disk at a constant speed and controls the operation of the magnetic head, and a controller that confirms that the magnetic disk is rotating at a constant speed based on the result of reading the dedicated data by the magnetic head, and controls the DC erase section. and an input/output circuit that sends a pseudo index signal to the control means upon reading, and after receiving the pseudo index signal, the control means sends a rotation ready signal of the magnetic disk to the input/output circuit, and selects the first data sector to be detected. After receiving the rotation ready signal, the input/output circuit sends the first sector signal generated based on reading of servo information by the magnetic head to the control means as an index signal, and also sends the data in the shipping area. This is to mask the sector corresponding portion.

0012

[Operation] First, the control means starts and controls the spindle motor to rotate the magnetic disk up to a specified rotation speed. The magnetic head reads the dedicated data written in the data sector corresponding portion of the shipping area, and based on the read result, the input/output circuit confirms that the magnetic disk is rotating at a constant speed. After confirmation, a pseudo index signal is sent to the control means using a DC erase detection signal from the magnetic head. When the control means receives the pseudo index signal, it sends a rotation ready signal to the input/output circuit, and sets the first data sector detected after passing through the DC erase section as the first data sector.

When the input/output circuit receives the rotation ready signal, it sends the first sector signal generated by reading servo information from the magnetic head to the control means as an index signal, and also masks the data sector corresponding portion of the shipping area. .

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. Note that elements common to each drawing are given the same reference numerals.

FIG. 1 is a control block diagram showing a magnetic disk drive device according to an embodiment of the present invention.

In FIG. 1, the magnetic disk drive device according to this embodiment includes a control device 1 composed of a one-chip microcomputer or the like, which controls the entire device. The control device 1 generates a spindle control signal S1, which is a first control signal that instructs the spindle motor 2 to start and stop rotation.
It also has a function of outputting a second control signal S2 that instructs the access motor 5 to rotate or stop.

The first control signal S1 includes a spindle motor enable signal S11, which is a signal for instructing whether to enable or disable the spindle motor driver 3, which is the first driving means;
and a signal S12 instructing the rotation of the spindle motor 2.

The spindle motor driver 3 cooperates with the control device 1 to start and control the spindle motor 2 based on a rotor position signal as described later, and further starts and controls the spindle motor 2 based on an index signal which is a one-rotation signal.
This is a circuit that controls constant speed rotation drive.

One or more magnetic disks 4 are attached to the spindle motor 2.

The second control signal S2 of the control device 1 consists of an access motor enable signal S21, which is a signal that instructs the access motor driver 6 to be enabled or disabled, and a signal S22, which instructs the access motor 5 to rotate. .

Furthermore, on the second control signal S2 side, there is a second driving means 8 equipped with a plurality of magnetic heads 7, which moves the plurality of magnetic heads 7 simultaneously to desired data positions on the magnetic disk 4. can be done.

The access motor driver 6 receives this signal S.
21, and drives the access motor 5 based on the rotation command value of the signal S22.

Further, the analog data read from the magnetic disk 4 by the magnetic head 7 is amplified by the first stage amplifier 9 and then sent to the pulse detector 1 as shown by SR.
Sent to 0.

The pulse detector 10 converts this analog data SR into a pulse-like signal and sends a read pulse SG to the servo timing circuit 11. The servo timing circuit 11 samples this read pulse SG and generates various timing signals SGT, SBT,
SSE and SX are created and sent to the control device 1.

At this time, the pulse detector 10 sends a 2-7 RLL code pulse-like signal DR from the analog data SR to an interface controller (not shown). Note that DW and SW are write data.

The control device 1 also calculates the position of the magnetic head 7 based on the servo information obtained through the servo timing circuit 11, and sends the calculation result to the access motor driver 6 as a rotation command value signal S22 for the access motor 5. Output. In this manner, the control device 1 reads servo information, which is positioning information, and controls the position of the magnetic head 7.

Second driving means 8 equipped with magnetic head 7
is rotated by this position control operation, and the magnetic head 7 reaches the target track at high speed. After the settling operation is completed on the target track, the magnetic disk drive enters a state in which data read/write operations are possible.

FIG. 2 is an explanatory diagram showing the format of the magnetic disk of this embodiment.

In FIG. 2, the magnetic disk 4 of this embodiment
The data surface is divided into a plurality of data sectors 41, and between each data sector 41 there is a servo sector 42 in which servo data is recorded.

Furthermore, on the inner and outer peripheries of the magnetic disk 4,
There is a shipping area 43 in either one or at an arbitrary position. In this embodiment, dedicated data 431 is written in advance in this shipping area 43, and the data 431 is used to control the startup of the device after power is turned on.

FIG. 3 is an explanatory diagram showing the relationship between shipping areas and sectors, and shows the case where the shipping area is on the inner circumferential side.

In FIG. 3, 411 is the data sector 41
This is a sector within the , and data is written here. Inside the servo sector 42 is a minute DC erase section 42.
1 has been created. Further, dedicated data 431 is written in a portion corresponding to the data sector 41 of the shipping area 43. A DC erase section 44 is formed at an appropriate position in one data area corresponding section within the shipping area 43.

FIG. 4 is an explanatory diagram showing the shipping area and the recording format of each track.

That is, FIG. 4 shows one data track among a plurality of data tracks in the data area 410 and the recording format in the shipping area 43 that corresponds to the data track in rotation angle. show.

The data track is formed by formatting data sectors 41 and servo sectors 42 repeatedly a plurality of times.

The data sector 41 is divided into an address and data, and each address records identification information such as a cylinder, and each address is located at the beginning of the data.

FIG. 5 is a detailed explanatory diagram showing a servo sector. In the figure, 420 is a sync, 421 is the DC erase section mentioned above, 422 is a gray code indicating track identification information, 423 is a servo burst, and 424 is a sync. , 41 are data sectors.

Next, the operation of this embodiment having the above structure will be explained. 6 and 7 are flowcharts showing the control operation of the control device 1 when starting the spindle motor, and the operation of the control device 1 will first be explained according to this flowchart.

When DC power is supplied to the magnetic disk drive device, the control device 1 performs initial settings such as port set and system register set (step 1), and then RO
M, perform self-diagnosis such as RAM check (Step 2)
). Then, it outputs a spindle start signal S11 (step 3), and when the spindle motor driver 3 operates in response to this signal, the spindle motor 2 and the above-mentioned magnetic disk 4 fixed thereto start rotating, and the rotational speed gradually increases. speed up.

The control device 1 detects a rotor position signal ST of the spindle motor 2 sent from the spindle motor driver 3. This position signal ST is created, for example, from the excitation voltage of each excitation winding and the back electromotive force from the coil starting point of the spindle motor 2. The control device 1 measures this signal ST (step 4) and internally calculates the rotation speed from the period of the signal ST. Furthermore, the rotation speed error, which is the difference between this measured speed and the target rotation speed, is calculated, and the rotation speed is adjusted each time so that the spindle motor 2 reaches the specified rotation speed.
PWM (pul
(se width modulation) output to the spindle motor driver 3.

The spindle motor driver 3 drives the spindle motor 2 at a duty ratio corresponding to the sent PWM signal. As a result, the spindle motor 2 gradually increases its rotational speed and approaches the specified rotational speed due to the above-mentioned PWM control.

Whether or not the spindle motor 2 is within the specified rotation speed is determined by determining whether the period of the signal ST measured as described above is within the specified period (step 5). Ru.

After determining that the specified rotation speed has been reached, the control device 1 determines whether or not the pseudo index signal created by the DC erase section detection characteristic of the present invention is being sent out from the servo timing circuit 11. (Step 6).

When the pseudo index signal is detected, the control device 1 measures the period of the signal ST again (step 7), and determines whether the signal ST is within the specified period (step 8). After determining that the rotation is at the specified rotation speed, the control device 1 sends a spindle ready signal indicating that the spindle motor 2 has reached the specified rotation speed to the servo timing circuit 11 (step 9).

Next, the control device 1 receives an index signal S sent from the servo timing circuit 11 as described later.
Wait for X. Index signal SX sent here
is a one-rotation signal of the spindle motor 2, and the control device 1
receives this index signal SX and activates a PLL (phase-lock) to rotate the spindle motor 2 at a constant speed.
ked loop ) control (step 10)
.

In this way, when the spindle motor 2 is pulled into PLL control by the control device 1,
Next, the access motor 5 is driven to control the position of the magnetic head 7 on the track (step 11).

First, the control device 1 takes in the servo burst 423 shown in FIG. 5 from the magnetic head 7 through the servo timing circuit 11. This servo burst 423 is
For example, it is a signal in which a plurality of phases are symmetrically shifted from the center of the track by a fixed pitch in the radial direction, and the plurality of phases are written in phase with each other in time.

In this example, when the magnetic head 7 causes a slight positional deviation from the track center, the analog values of the multi-phase servo burst 423 change slightly in response to this positional deviation. The servo timing circuit 11 processes this as appropriate, the burst peak hold circuit 12 holds the peak, and the position information SBT is AD converted and taken into the control device 1.

The control device 1 performs servo calculation based on this position information SBT, and as described above, outputs the calculation result to the access motor driver 6 as the rotation command value signal S22 of the access motor 5, and outputs the calculation result to the access motor driver 6. The position of the magnetic head 7 is corrected and controlled at high speed to accurately position the magnetic head 7.

As will be described later, the position correction control of the magnetic head 7 is performed during the time after the sector count value is counted up until the next servo section 42 comes. If the position correction control does not end within the specified time, the position correction control is continued over the plurality of sectors 41.

The control device 1 then performs a rezero operation (step 12). This is an operation in which the magnetic head 7 starts a recalibration operation toward track zero.

After reaching track zero, if there is no abnormality in the device at that position, it enters the state of waiting for a command from the higher-level device, receives a request from the higher-level device, decodes the command,
A monitor routine (step 13) for executing/instructing commands is entered.

As described above, the start-up control after turning on the power of the device is completed, and the control of this control device 1 is performed by various signals sent from the servo timing circuit 11, which will be described in detail below. In response, various signals are sent to the servo timing circuit 11, and control proceeds sequentially.

Next, the control operation of the servo timing circuit 11 will be explained according to the flowcharts shown in FIGS. 8 to 12.

When the device is not in operation, the magnetic head 7
is located in the above shipping area 43, so even when the power is turned on, the magnetic disk 4 is located in the shipping area 43.
sliding contact in the circumferential direction. Then, as the rotational speed increases thereafter, the magnetic head 7 flies up from the magnetic disk 4.

In the present invention, the magnetic head 7 starts reading data from the dedicated data area 431 in the shipping area 43 on the magnetic disk 4 before the magnetic disk 4 reaches a specified rotational speed.

This dedicated data is data written at the same frequency, and whether or not the magnetic disk 4 has reached the desired rotational speed can be determined by reading this dedicated data and checking the above-mentioned first stage amplifier 9 and pulse detector. The servo timing circuit 11 monitors the period and number of read pulses SG obtained through the read pulses 10 and 10, thereby easily determining the period and number of read pulses SG.

When the spindle motor 2 starts rotating, the magnetic head 7 starts reading data and sends the analog data SR amplified by the first stage amplifier 9 to the pulse detector 10. The pulse detector 10 converts this analog data SR into a pulsed read pulse SG.
and sends it to the servo timing circuit 11.

As the first stage of processing in the servo timing circuit 11, it is first confirmed that the spindle start signal S11 is being sent from the control device 1 (step 21). Once confirmed, the servo timing circuit 11 then detects the period of this read pulse SG (step 22). At first, the read pulse is irregular and picks up noise, but as the rotation increases, it approaches a read pulse with a uniform period. Then, confirm that the period of the read pulse SG is within the specified time (
Step 23), and when it is confirmed that the read pulses SG that have entered within the specified time are continuously sent out a specified number of times (step 24), the process enters the next second stage.

In the second step, the DC erase section 44 necessary for generating the index signal characteristic of the present invention is searched for. That is, the servo timing circuit 11 detects the read pulse SG, which is the result of reading dedicated data written at a specified frequency and in a specified pattern (step 25), at one point per revolution in the signal. The DC erase section 44 located at an appropriate position is detected. This DC erase section 44 is an area in which no signals are written.

Detection of the DC erase section 44 is achieved by measuring whether the read pulse SG remains undetected for a predetermined period of time (step 26). Next, it is determined whether the spindle is ready (step 27). Naturally, at this stage, since the control device 1 has not detected the pseudo index signal (step 6), it is not in the spindle ready state. Therefore, a timer for the pseudo index signal is started (step 28), and when this timer reaches a specified value (step 29), the servo timing circuit 11 sends out a pseudo index signal (step 30).

Thereafter, as shown in the figure, control shifts to step 22 of the first stage.

Now, the index signal is a signal that is generated once per rotation, and is a signal that determines the starting point of a track, and is mainly used for disk formatting and the like.

In this embodiment, a method is adopted in which the servo timing circuit 11 generates a pseudo index signal by detecting the DC erase portion 44 in the data pattern written on the magnetic disk 4.

As described above, after detecting this pseudo index signal generated by the servo timing circuit 11 (step 6), the control device 1 detects the spindle ready signal S indicating that the spindle motor 2 is in a constant speed rotation state.
Send the SR (step 6). As a result, the servo timing circuit 11 determines that the spindle is ready in the second step (step 27), exits the second step of generating a pseudo index signal, and jumps to the next third step.

The third and subsequent stages are exclusively signal processing and control in the servo section. As shown in FIGS. 3 and 5, DC
Next to the erase section 44, the magnetic head 7 moves to the servo sector 42.
rush inside. In the servo sector 42, the preceding sync 420 is first detected. The sink 420 is also written at a specified frequency and in a specified pattern, and in this third stage regular read pulses SG can be detected (step 31).

Next, it is confirmed that the cycle of the read pulses SG is within a specified time (step 32), and furthermore, it is confirmed that the read pulses SG that have entered within the specified time are continuously sent out a specified number of times. Confirm (step 33). Next, in order to detect the DC erase section 421, the read pulse SG is detected again (step 34), and the read pulse SG is detected again (step 34).
Confirm that the condition has continued for the specified time (Step 3)
5) After that, start the sample/hold timer (
Step 36). This timer is used as a time reference point for various signal processing in the servo section.

In the fourth step, the Gray code 422 is first read out (step 37). The gray code 422 is a code for track identification, and is a code for identifying the servo timing circuit 11.
Based on the track identification information SGT sent to the control device 1 (step 38), the control device 1 determines in which track on the magnetic disk 4 the magnetic head 7 is located.

After reading the Gray code 422, the servo burst 423 is read (step 39).

The servo burst 423 is, for example, a signal in which a plurality of phases are symmetrically shifted from the center of the track by a fixed pitch in the radial direction, and the plurality of phases are written in phase with each other in time.

Therefore, if the magnetic head 7 slightly deviates from the track center, the servo burst 4
23 is processed by the servo timing circuit 11. And the processing result is burst peak hold circuit 1
2 (step 40), is AD converted and taken into the control device 1 as position information SBT (step 4
1). The control device 1 performs servo calculation based on this position information SBT, and outputs the calculation result to the access motor driver 6 as the rotation command value signal S22 for the access motor 5, as described above. Through such control, the position of the magnetic head 7 is corrected and controlled at high speed.

Next, it is checked whether the sample/hold timer value has reached the specified value (step 42).
When the specified value is reached, the sample/hold timer is cleared (step 43). At this point, the magnetic head 7 is connected to the sink section 424 preceding the data section 41 shown in FIG.
The signal processing in the servo sector 42 preceding the data sector 1 is completed.

A mask timer is then started (step 44), and it is checked whether the sector count value is a specified number (step 45). If it is the specified number, an index signal SX is sent to the control device 1 (step 46), and the sector count value is cleared (step 47). If the sector count value has not reached the specified number, the sector signal SSE is sent to the control device 1 (step 48
).

Start the mask timer (step 44)
After that, a mask is set until the servo sector 42 preceding the next data sector 2 arrives (step 50). By setting this mask, the dedicated data section of the shipping area can no longer be detected.

Next, it is checked whether the mask timer value is a specified value (step 51). When the timer value reaches the specified value, the magnetic head 7 has entered the sink portion 420 of the servo sector 42 preceding the next data sector 2, and the servo timing circuit 11 resets the mask (step 52). The sector count value is increased (step 53). Signal processing and control then move to the third stage again.

At this stage until the next servo unit 42 arrives, the control device 1 enters control to correct the position of the magnetic head 7 on the track as described above. Basically, this position correction control is performed during the time until the next servo section 42 comes, but if the position correction does not end within this time, the position correction control is continued over multiple sectors 41. .

As described above, the servo timing circuit 11
The control device 1 receives and appropriately processes various signals sent from the servo timing circuit 11, and the control device 1 appropriately sends various signals to the servo timing circuit 11. Startup control will proceed and end.

[0078]

[Effects of the Invention] As explained in detail above, according to the present invention, a servo system for a spindle motor rotation system and a magnetic head positioning system is realized by software based on a control device and a dedicated servo timing circuit. Since it is configured with a sampling control system, the amount of control circuitry can be reduced and simplified, and the flexibility and versatility of the system with software servo increases.

At the same time, lower costs, smaller size, faster access, and higher reliability can be achieved.

Furthermore, it is not necessary to provide the spindle motor with a circuit for generating a one-rotation signal, and the reliability of the device is improved at a low cost.

Furthermore, in order to control the positioning of the magnetic head based on dedicated data written in advance on the magnetic disk and servo information, as in the past, a signal generator such as an optical encoder is used on the access motor side. There is no need to prepare a separate section or a circuit to drive it, resulting in low cost and improved reliability of the device.

[Brief explanation of drawings]

FIG. 1 is a control block diagram showing an embodiment according to the present invention.

[Fig. 2] Explanatory diagram showing the format of the magnetic disk of the embodiment

[Figure 3] Explanatory diagram showing the relationship between shipping areas and sectors

[Figure 4] Explanatory diagram showing the shipping area and the recording format of each track

[Figure 5] Detailed explanatory diagram showing servo sectors

[Figure 6] Flowchart showing the operation of the control device

[Figure 7] Flowchart showing the operation of the control device

[Figure 8] Flowchart showing the operation of the servo timing circuit

[Figure 9] Flowchart showing the operation of the servo timing circuit

[Figure 10] Flowchart showing the operation of the servo timing circuit

[Figure 11] Flowchart showing the operation of the servo timing circuit

[Figure 12] Flowchart showing the operation of the servo timing circuit

[Explanation of symbols]

1 Control device 2 Spindle motor 4 Magnetic disk 5 Access motor 7 Magnetic head 11 Servo timing circuit

Claims (5)

[Claims] 1. In a magnetic disk drive device in which a shipping area is formed on a magnetic disk in which servo sectors having servo information and data sectors having data are alternately divided and arranged, dedicated data is stored in a portion corresponding to a data sector in the shipping area. D for writing in advance and generating a pseudo index signal in an arbitrary data sector corresponding part
A magnetic disk having a C erase section formed thereon, a control means for starting and controlling a spindle motor to control the rotation of the magnetic disk at a constant speed, and controlling the operation of the magnetic head, based on the result of reading the dedicated data by the magnetic head. An input/output circuit is provided which confirms that the magnetic disk is rotating at a constant speed and sends a pseudo index signal to the control means by reading the DC erase section, and after receiving the pseudo index signal, the control means determines whether the magnetic disk is ready for rotation. The signal is sent to the input/output circuit, and the first data sector to be detected after passing through the DC erase section is set as the first data sector. After the input/output circuit receives the rotation ready signal, the magnetic head reads the servo information. What is claimed is: 1. A magnetic disk drive device characterized in that a sector signal generated first based on the index signal is sent to a control means as an index signal, and a data sector corresponding portion of a shipping area is masked. 2. The magnetic disk drive device according to claim 1, wherein the shipping area is formed on the inner or outer circumference of the magnetic disk. 3. The magnetic disk drive device according to claim 1, wherein the dedicated data is written in the data sector corresponding portion at the same frequency. 4. The control means, after sending out the rotation ready signal,
2. The magnetic disk drive device according to claim 1, wherein PLL control for constant speed rotation of the spindle motor is performed by measuring the period of the index signal obtained from the input/output circuit. [Claim 5] After the input/output circuit receives the rotation ready signal,
2. The magnetic disk drive device according to claim 1, wherein a data sector corresponding portion of the shipping area is masked and a servo sector portion is unmasked.