JPH01176369A - Flag for track collation for disk storage device - Google Patents

Abstract

PURPOSE:To read a proper cylinder number even while a head is moved by obtaining a flag for collation, which is written in each track, as the set of bits in a prescribed number and causing only the contents of one bit in the set to be different between the tracks, in which the contents of the set are different in each track, to be adjacent. CONSTITUTION:A flag ID, which is written to respective tracks T0-T5 in order to mutually discriminate the tracks T0-T5 in the large number to be set in the surface of a disk, is obtained as the set of the bits in the prescribed number. Then, among the tracks T0-T5, in which the contents of the set are different in respective tracks T0-T5, to be adjacent each other, only the contents of one bit in the set are caused to be different. Thus, while a head for reading and writing information on the tracks T0-T5 is moved and operated, the flag ID can be read through the head and even when a mixing is generated among the bits to constitute the flag ID of the adjacent tracks T0-T5, there is no danger to read the abnormal contents and the flag ID can be exactly read while the head is moved and operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a method for writing information into each track in order to distinguish between a large number of tracks set within the disk surface of a disk storage device such as a fixed disk device. It is a mark for verification that can be read through the head for reading and writing information on the track during a moving operation.

[Conventional technology]

As is well known, hundreds of information recording tracks are set on each disk surface of a disk storage device, and when reading or writing information, the head must first be moved to the track where the information is recorded. There is a need to do so. Track numbers, usually called cylinder numbers, are consistently assigned to all tracks on each disk surface, for example, from the outermost track to the innermost track. moves the head by the number of tracks equal to the difference between the cylinder number of the current track and the cylinder number of the target track. For example, this cylinder number is recorded together with the sector number in the collation section in each sector of the track. When reading or writing information from that sector, first read this collation section and carefully check the cylinder number and sector number before actually reading or writing. Do this. This collation information such as the cylinder number is, of course, written in the form of numerical values expressed in binary codes of 0 and 1, usually in hexadecimal notation.

[Problem that the invention seeks to solve]

As mentioned above, a cylinder number is assigned to each track and written in a predetermined location within the track, but the recorded information of this cylinder number is originally read when the head is stationary on the track hill. It belongs to
It is not possible to read while the head is moving. but,
There are times when you want to read while the head is moving. For example, while the head is moving according to a high-speed schedule to reduce the access time of the disk storage device, the cylinder number of the track the head is passing is read and the deviation from the schedule is detected. This is a case where it is desired to control the actuator that operates the head so as to eliminate the deviation while detecting the deviation. Of course, since the cylinder number is recorded in the track, it is possible to try to read it, but as a result of the trial, it was found that the cylinder number read was unreliable. The reasons for this, revealed as a result of the investigation, are as follows.

For ease of understanding, assume that the head is now diagonally crossing between the track of cylinder number 7 and the track of cylinder number 8. The binary code for 7 is (0111) and the binary code for 8 is (1000). Of course, there are cases where these binary codes are read correctly and give 7 or 8 as the cylinder number, but both binary codes For example, (111
1) and the wrong cylinder number 1
There are cases where 5 is obtained. Since the head crosses both tracks diagonally, it is inevitable that the cylinder number read will be 7 at one time and 8 at another time, but since you get a completely different number 15, you can trust the reading result. I can't afford to do that.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a track verification mark or code for a disk storage device that allows the correct cylinder number to be read even when the head is moving.

[Means for solving problems]

According to the present invention, the purpose of this is to write the collation mark on each track as a set of a predetermined number of bits, the contents of the set are different for each track, and the contents of only one pit in the set are different between adjacent tracks. This is achieved by making them different from each other.

[Effect]

The effect of the above configuration will be explained with reference to FIG.
Tracks TO-T5 with cylinder numbers 0 to 5 are shown from top to bottom of the figure, and the range on which markings 10 are written is shown by two long vertical lines. The short vertical lines at the bottom of the figure indicate the positions of bits 81 to Bm forming [1alD], and [K6xo is a set of these m bits. A short vertical line on each track indicates that its corresponding bit has a 1 content, and bits without a vertical line have a 0 content. I'm looking forward to it
-3 and B1 is the least significant bit, as shown in the figure, track To, T1.72
The mark 10 written in each is (000),
They can be represented by (001), (011), etc., respectively. Of course, these marks are different for each track, but unlike ordinary binary codes, when the +i marks of adjacent tracks are compared, their contents differ by only one pit. Therefore, tracks TO, TI, 7
If the sign ID of 2nd grade is read as a normal binary code, it will be 0, 1°, 3, etc., and the order will be different from the cylinder number 0, 1.2, etc. In other words, with the label according to the present invention,
If the indicator can be read as 0.1 in normal binary code, the cylinder numbers are assumed to be 0 and 1, respectively, but 3
If it can be read as , it is decided that it represents cylinder number 2, and such conversion can be facilitated by creating an NHL correspondence table.

Now, the disk, that is, the track, rotates in the direction of arrow R with respect to the head 3, and the head 3 moves in the direction of arrow M. As a result, when viewed from the track side, the head looks like arrow P, for example, tracks T1 and T2. If the head passes diagonally between
), but since the contents of the indicators written in both tracks differ by only one bit, both indicators (
No matter how 001) and (011) mix together,
It cannot be read as any other mark than these two marks. As we will see below, by making a mark that is a set of a predetermined number of bits different from each other in the content of only one bit in the set between adjacent tracks, as in the above structure, the marks of both tracks can be Even if a mix-up occurs between bits, nothing other than the indicators written on both tracks will be read, thereby eliminating the conventional problem or inconvenience.

In order to further clarify the above point, an example of a marker ID according to the present invention will be explained with reference to the table of FIG.

Cylinder numbers CN are listed in the left column of the table.

Column A is the same example as in Figure 1, but here the sign ID is m.
=4, that is, a set of 4 bits, and the numerical value N when each indicator 10 is read as a normal binary code is shown. As can be easily seen, in this example A, when the mark i10 is a combination of m pi + - a, two cylinder numbers CN can be distinguished from each other. In the example shown in column B, the way in which the bit contents that make up the mark i1D are combined is slightly different from that in example A, and as can be seen from the table, the same eight cylinder numbers CN as in example A are connected to each other by a set of 3 bits. differentiated. Naturally, the numerical value N obtained by reading each mark as a normal binary code is also different from Example A.

In this example B, the indicator of the m bit set indicates m” −m
+ Two cylinder numbers can be expressed distinctly from each other. Therefore, if 512 tracks are set on the disk surface, in example A, 256 tracks are set.
Although it is necessary to use a bit set, in example B, a 24-bit set is sufficient. Although these examples of signs differ in the bits required to distinguish and represent a predetermined number of tracks from each other, all of them satisfy the above-mentioned requirements for the signs according to the present invention, and of course, signs satisfying other requirements can also be created. Is possible.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings. Second
The figure shows an example of the configuration of a disk storage device W30, which is a fixed disk device in this example, using the mark [10] according to the present invention. The disk 1 shown in the upper left of FIG. 2 is rotated at a constant speed by a spindle motor 2, and for example, 512 tracks T are set within its surface, and each sector within each track is marked. 11i1D can also be written, but in this example, for simplicity, the servo information S
It is assumed that a sign ID is written in one place next to 1.

The details of this area are shown in the previous part 1, and next to where the halves Sla and Slb of the servo information Sl are written in a staggered manner as usual, the mark file D is written via the leading part top of the mark. is written. The leading part 10p indicates that what follows is the mark filD, and a special numerical value or the like indicating this may be written therein, but the easiest way is to make it an area in which nothing is written. It is assumed that the writing range of the indicator ID in this embodiment is 24 bits, that is, 3 bytes, corresponding to the previous example B in FIG. For example, the area for the preceding part IDp may be 1 byte (
, even if this is included, the indicator only needs to have a range of 4 bytes for writing, so it can be easily written into each sector.

The head 3 for reading and writing the information recorded in the marker 10 and the track is supported at its base by a carriage 4 that is movable in the left and right directions in the figure. It is operated to move in the direction. The actuator 5 is an attached drive circuit 5
The spindle motor 2 is also driven by its drive circuit 2a which receives a clock pulse CP, and has a built-in pulse generator 2b which generates an index pulse IDX once per rotation of the disk. All the heads 3 in the disk storage device 530 are connected to the read/write circuit 6, and the head designated by the head selection command H3 received by the read/write circuit 6 is enabled to read or write depending on the state of the read/write command RW. It will be destroyed. The signal from the read output of the read/write circuit 6 is converted into a read signal R5 of a predetermined modulation method by the demodulation circuit 7 and output to the outside. On the contrary, the write signal -3 of the modulation method is directly applied to the write input W of the read/write circuit 6 from the outside. The label ID in the present invention is also written via the read/write circuit 6 and head 3 by this write signal -8.

A processor 8 is incorporated in the disk storage device 30 for comprehensive control thereof, and the processor 8 is installed in the disk storage device 30 for general control thereof.
5 and a read/write command R- are given to the read/write circuit 6, a drive signal DS is given to the drive circuit 5a of the actuator 5, and a clock pulse CP specifying the rotational speed of the disk 1 is given to the drive circuit 2a of the spindle motor 2. The index pulse IDX is supplied from the spindle motor 2, respectively, and the index pulse IDX is received from the spindle motor 2. A moving operation means 9 is incorporated in the processor 8 as software for moving the head 3 to a desired track.

For reading the sign 10, a reading circuit 10 receiving the above-mentioned reading signal R3 and reading means 20, which is software built into the processor 8, are provided.

The reading circuit 10 receives from the reading means 20 a reset pulse RP as a reading operation command and a shift pulse SP synchronized with the clock pulse CP, and accordingly reads the mark 10 and reads the above-mentioned numerical value N as a binary code. is given to the reading means 20. Reading means 20 value N
A conversion table 21 for converting the cylinder number CM from CM is provided. This conversion table 21 is set within a storage area within the processor 8.

The reading circuit IO can be configured as appropriate, and FIG. 4 shows an example thereof. The two flip-flops 11 and 12 are both reset by the aforementioned reset pulse RP received from the reading means 20, thereby starting the operation of the reading circuit 10. When the flip-flop 12 is reset by the reset pulse RP, its output enables the two AND gates 14a and 14b. As a result, the AND gate 14a outputs the read signal R.
A pulse formed by shaping S by the one-shot circuit 13 is given to the data output of the shift register 14, and this input value is transferred to the shift register one stage at a time by the shift pulse SP given to the shift register 14 via the AND gate 14b. Sent within. The Noah gate 15 is for detecting the leading part IDp of the above-mentioned label, and this leading part is, for example, 8.
When the shift register 14 is made up of blanks corresponding to bits, when all outputs from the first stage to the eighth stage of the shift register 14 become 0, it is opened and the flip-flop 11 is set.

By the cent of this flip-flop 11, the shift register 14 is cleared to zero by its Q output via the one-shot circuit 16, and the AND gate 17 is enabled, and the count of the shift pulse SP is changed to the counter 1.
Started by 8. In this embodiment, the shift register 14 is configured in 24 stages according to the number of constituent bits of the indicator ID, and the binary counter 18 is configured in 5 stages correspondingly. After the shift register 14 is cleared to zero, the contents of each bit of indicator 1[1 are sequentially changed to shift pulse S
The shift pulses SP are stored in the shift register 14 while being sent by the pulse signal P, and the counter 18 successively counts the shift pulses SP in synchronization with this. The count value of this counter 18 is 24
When , the AND gate that receives the output of the last two stages opens, and by setting the flip-flop 12, the AND gate 14a, 1 is output via the Q output.
Release the enable state of 4b. As a result, the stored value of 24 bits of the mark 11i1D in the shift register 14 is fixed, and the numerical value N is held as it is in the shift register 14 until the next time the reading circuit 10 receives the reset pulse RP.

Now that the explanation of the configuration of each part has been completed, the overall operation will finally be explained with reference to the flowchart of FIG. 5 showing the operation of the reading means 20. In the disk storage device shown in FIG. 2, when the processor 8 receives an instruction to move the head from the outside via the bus 8a, it starts the moving operation means 9 and sends a drive signal to the drive circuit 5a of the actuator 5. The head is moved by sending the OS. The flow shown in FIG. 5 is activated, for example, when servo information arrives under the head and the processor 8 receives an index pulse IDX synchronized with this, using this as an interrupt command.In the first step 521, the reading The means 20 is a reset pulse RP.
is sent to the reading circuit 10 to start its operation.

The next step S22 is to wait for the completion of the operation of this reading circuit 10, and after the time required to read the indicator IO has elapsed, the content of the indicator Ill is read as a numerical value N expressed in normal binary code in step S23. circuit 10
read from. The last step S24 is this numerical value N.
The cylinder number CN as a function f is read from the conversion table 21 and given to the moving operation means 9.

As a result, the flow of operation returns to the movement operation means 9, and the movement operation means 9 proceeds with the movement operation while referring to this cylinder number.

The present invention is not limited to the embodiments described above, and the present invention can be implemented in various embodiments. As mentioned above, the contents of the marker focus set can be selected from various options, and the locations where they are written are not limited to the embodiments, but can be distributed in the circumferential direction of the track, such as within each sector.

When a plurality of markers are distributed and provided within a truck in this way, the output of the drive signal DS by the moving operation means 9 is normally intermittently, so the reading means 2o is activated at any time between the output of this drive signal. You can call it to read the signs. The circuit configuration of the reading circuit 1o and the mode of operation of the reading means 20 should also be selected as appropriate depending on the situation.

〔Effect of the invention〕

As explained above, in the present invention, the mark written in each track to distinguish a large number of tracks set on the disk surface is a set of a predetermined number of bits, and the contents of the set are changed for each track. , and adjacent tracks are configured such that only the content of one bit in the set is different from each other, so that the l! m can be read through the head for reading and writing information on a track during a moving operation, and even if a mix-up occurs between the bits constituting the indicators of adjacent tracks during this reading, the information on both adjacent tracks This allows the markings to be read accurately during head movement operations without the risk of reading any abnormal content other than the content of the markings written on the cylinder number of the track the head is currently traversing. From this, it is possible to rationally proceed with the head movement operation by detecting deviations in the head movement from the planned schedule. Of course, the indicia according to the invention can also be read with the head held on track. By utilizing the markings according to the present invention in various ways in a disk storage device, the performance of the disk storage device can be improved by speeding up the head movement operation and shortening the access time, or by improving the read reliability. It has a remarkable effect on improving

[Brief explanation of the drawing]

All of the figures relate to the present invention; FIG. 1 is a partially enlarged developed view of the disk surface showing the procedure for writing a mark on a track in an embodiment of the track verification mark of a disk storage device according to the present invention, and FIG. A configuration circuit diagram illustrating the configuration of a disk storage device using a marker according to the invention, FIG. 3 is a table showing an example of the mode of the marker, FIG. 4 is a circuit diagram showing an example configuration of a reading circuit, and FIG. In figure 0, which is a flowchart showing an example of the operation mode of the reading means, 1: disk, 2 spindle motor, 2a drive circuit for spindle motor, 2b: pulse generator, 3: head, 4: carriage, 5: actuator, 5a: Actuator drive circuit, 6: Read/write circuit, 7: Demodulation circuit, 8: Processor, 8a: Bus, 9: Movement operation means, 10: Reading circuit, 1L12: Flinopflo 7b, 1
3: One-shot circuit, 14: Shift register, 14a
, 14b: AND gate, 15: Noah gate, 16: One yacht circuit, 17: AND game), 18: Counter, 18a: AND gate, 20: Reading means, 21: Conversion table, A, B: Examples of signs, 81- Bm: 4yA identification bit, CN number, cP: clock pulse, DS: drive signal, f: function, R3: head selection command,
■D: Label, IDp: Leading part of the label, IDX: Index pulse, M: Direction of movement of the head, N: Numeric value read from the label as a binary code, P: Transverse direction of the head,
R: Disc rotation direction, RP + reset pulse, R3
: read signal, R-: read/write command, SI: servo information, Sla, Slb: half of servo information, SP: shift pulse, T, TO to T5: track, S: write signal.

Claims (1)

[Claims] 1) Written in each track in order to distinguish between a large number of tracks set within the disk surface of a disk storage device, and readable through the head during movement of the head for reading and writing information on the track. An indicator for track matching, in which the indicator is written as a set of a predetermined number of bits, the content of the set is different for each track, and only the content of one bit in the set is different between adjacent tracks. A track verification indicator for a disk storage device, characterized in that: