JPH0982038A - Storage device and its control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the circuit scale by obtaining a data sector address by computation from a servo sector address by making use of the periodicity of the arrangement of a servo sector and a data sector on a cylinder. SOLUTION: Data sector information which is hard to be computed from a servo sector address (SSA) 25 is stored in a data sector information table 47. In conventional cases, it is required to prepare for the same number of piece of information as the number of servo sectors contained in one round of a track. However, in this case, the number of pieces of information is reduced by making use of the property of a boundary. That is to say, the arrangement pattern of a data sector and a servo sector inside one boundary is the same in any boundary. Consequently, it is sufficient to prepare by the same number of piece of information as the number of servo sectors contained inside the boundary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage device compatible with a high density recording system and a control device therefor.

[0002]

2. Description of the Related Art In recent years, as the functions and performances of personal computers and office computers have improved, the capacity of data storage devices, especially magnetic disk devices, has been increased.
There is a strong demand for higher performance. Based on this background,
Attention has been focused on a method of increasing the capacity by improving the format efficiency.

As an example of this approach, in a conventional disk device, there is a method of deleting an ID area provided for identifying a sector as described in Japanese Patent Laid-Open No. 174498/1993 (here, this method). Is defined as an "IDless format method"). FIG. 2 shows an example of a disk format when this method is used. Hereinafter, the configuration of this format will be described. The disk format includes a servo sector (SSCT) provided to control the position of the head on the recording medium for recording / reproducing data, and a data sector (DSCT) provided to store user data. Broadly divided.
The servo sector (SSCT) is, as shown in SSCT example 1 in FIG. 2, AGCG20, SVMK21, IDXM22.
/ SCTM23, CYL24, POS27, ISG28
Consists of

The AGCG 20 is an area provided for detecting the head position of the servo sector in order to adjust the read gain of the servo information and the SVMK 21.

The IDXM22 / SCTM23 is an area provided for identifying the beginning of a track or a sector, and the CYL24 is an area for storing a cylinder number (track number).

The POS 27 stores detailed head positioning information between cylinders, and performs detailed head positioning operation (settling) and follow-up operation for always positioning the head on a target cylinder. Used to control.

ISG28 is a disk rotation fluctuation and REA
This is a region provided to absorb the time for switching D / WRITE.

As described above, the servo sector SSCT16 is
The head is always used because it is used for moving the head to the target cylinder (seek), detailed positioning operation of the head (settling), and always following the positioning of the head on the target cylinder (following). It is necessary to be able to read the servo sector SSCT16. The servo sectors SSCT 16 are generally arranged at constant intervals over all cylinders on the disk and in such a manner that there is no displacement of the servo sectors between the cylinders, that is, on the magnetic disk at fan-shaped intervals. This is so that the servo sector SSCT16 can be read at the same timing regardless of the position of the cylinder of the head, and the time for the head to pass through the servo sector SSCT16 is constant.

On the other hand, when the data sector (DSCT) adopts a format in which the recording density is constant over the inner and outer circumferences of the disk, the servo sector (SSC) is included therein.
A data sector (DSCTB19) including T),
The structure is different from the data sector (DSCTA 18) when it is not included. The DSCTB may be referred to as a "split data sector".

DSCTA18 is ISG29, PLO3
0, BS31, DATA32, ECC33, PAD34
Consists of The ISG 29 is an area provided for absorbing the rotational fluctuation of the disk as described above.
The PLO 30 is an area provided for clock synchronization with the read data, and the BS 31 is an area provided for detecting the timing of conversion from serial data to parallel data. DATA32 is
This is an area for storing user data. The ECC 33 is an area provided for checking the read DATA 32 for an error, and for correcting the error if there is an error.

The DSCTB 19 is basically a DSCTA.
It is a format in which SSCTB17 is inserted in 18, but after SSCTB17, PLO30, BS again.
31 are arranged. This is the SSCT when reading
This is because the read process is interrupted once when passing through B17, and it is necessary to perform the clock synchronization and the byte synchronization again in order to perform the read process again.

When the above method is used, the data sector 18 requested by the host computer can be detected by the following procedure. Since the data sector 17 does not have an ID part storing the data sector address (DSA), the data sector address (DSA) is obtained using the sector address (SSA25) of the servo sector 16.

The servo sector address (SSA) is obtained by setting the address of the servo sector 16 including the index mark 22 to 0 and incrementing the address by one each time the sector mark 21 of the subsequent servo sector 16 is detected. You can

Once the servo sector address (SSA25) is obtained, the data sector address (DSA) corresponding to the servo sector address (SSA25) can be obtained using the address conversion table. The address conversion table stores the address of the data sector located after the servo sector, the length of one data sector (split time), and the like.

This address conversion table can be uniquely created at the time of formatting in units of tracks. This address translation table contains servo sectors 1 included in at least one track (cylinder).
It is necessary to prepare as many pieces of information as six pieces (that is, pieces of information for one track of the track).

[0016]

As described above, in the conventional IDless format method, the address conversion table used to obtain the data sector address (DSA) from the servo sector address (SSA) is the number of servo sectors per track. Only needed. For example, consider an address conversion table when the number of servo sectors per track is 64 and the number of data sectors per track is 256 (8 bits). This address conversion table has a data amount of 64 × 8 = 512 bits. In order to increase the versatility of the address conversion table, the address conversion table should have at least the number of servo sectors per track.
128, the number of data sectors per track is 512 (9 b
it) need to be prepared. In other words, this address conversion table has a data amount of 128 × 9 = 1152 bits. However, such a large-capacity (1152 bit) address conversion table is too large to be built in an IC.

In the IDless format, if the format has an ID portion, information (for example, split information) for accessing the data sector contained in the ID portion is also stored in the servo sector address (SS).
It must be generated from A).

It is conceivable to store the address conversion table in a data buffer for temporarily storing the data read from the storage medium, but this has a problem that the circuit configuration becomes complicated. That is, the data buffer is prepared mainly for temporarily storing data to be read / written to / from the R / W head and data to be read / written from the host computer. Further, in the IDless format, since there is a data sector that starts immediately after the servo sector, the data sector address must be generated after the servo sector address is read and before the servo sector ends.
Therefore, in order to store the address conversion table in this data buffer, an arbitration circuit for accessing the address conversion table and an interface circuit for inputting / outputting data between the buffer control unit and the arbitration circuit of the data buffer are used. Had to add to.

It is an object of the present invention to provide a storage device having a reduced circuit scale and its control device by suppressing the capacity of a table storing information that must be prepared in advance for control.

[0020]

The present invention calculates a data sector address or the like from a servo sector address by utilizing the fact that the array (sector array) of servo sectors and data sectors on a cylinder has periodicity. It is what you ask for.

Further, the amount of information in the table is reduced by utilizing this periodicity. That is, the table has only one cycle.

The structure of the present invention will be described in more detail below.

According to a first aspect of the present invention, at least a servo sector in which its own address is stored and a data sector in which data is stored are formed in a predetermined array (hereinafter referred to as "sector array"). In the control device of the storage device for reading information from the stored storage medium,
The information indicating the number of data sectors included in the predetermined range on the sector array and the information indicating the number of servo sectors included in the predetermined range on the sector array are separately read. Address of the above servo sector (hereinafter "servo sector address")
By performing the calculation of the following formula 4 using the above) and rounding up the decimal point of the calculation result, the first data sector starting after the servo sector indicated by the servo sector address used for the calculation of the formula 4 is rounded up on the sector array. There is provided a control device for a storage device, which is provided with a calculating means for obtaining an address (hereinafter referred to as "data sector address").

[0024]

[Formula 4] SSA / DSPB / SSPB where SSA: servo sector address DSPB: number of data sectors included in a predetermined range on the above sector array SSPB: within a predetermined range on the above sector array Number of included servo sectors The sector array allows the servo sectors to be positioned so as to divide the data sector at an intermediate position of the data sector, and separately reads the servo sector address. The data sector is divided by the servo sector next to the servo sector pointed to by the servo sector address used in the operation of the above-mentioned sector array by performing the operation of the following equation 5 and cutting off the decimal point of the operation result. It may have a second calculation means for obtaining the address of.

[0025]

[Formula 5] (SSA + 1) · DSPB / SSPB where SSA: servo sector address DSPB: number of data sectors included in a predetermined range on the sector array SSPB: predetermined on the sector array Number of Servo Sectors Included in Range As a second aspect of the present invention, at least a servo sector in which its own address is stored and a data sector for storing data are arranged in a predetermined array (hereinafter, “sector”). In a control device of a storage device that reads information from a storage medium formed by an “array”), the sector array allows the servo sector to be located so as to divide the data sector at an intermediate position of the data sector. Included in a predetermined range on the sector array The address of the servo sector (hereinafter referred to as “servo sector address”) that is separately read, is provided with information indicating the number of data sectors included and information indicating the number of servo sectors included in a predetermined range on the sector array. The following equation 6
And the fractional part of the result of the calculation is rounded down to obtain the address of the data sector divided by the servo sector next to the servo sector pointed to by the servo sector address used in the calculation of Equation 6 above. There is provided a control device for a storage device, which has two calculation means.

[0026]

[Formula 6] (SSA + 1) · DSPB / SSPB where SSA: servo sector address DSPB: number of data sectors included in a predetermined range on the sector array SSPB: predetermined on the sector array Number of Servo Sectors Included in Range In the first and second aspects described above, data sector information prepared for each servo sector, and an index indicating the position of the servo sector in the predetermined range, Storage means for storing a table in which the above-mentioned table is stored, third calculating means for obtaining the index based on the servo sector address, and data sector information corresponding to the index obtained by the third calculating means. It is obtained from the above table, and the control is performed according to the obtained data sector information. It is preferable to further include a control signal generation unit that generates and outputs a control signal.

The third calculation means converts the SSA into SS.
The index may be obtained as the remainder divided by PB.

The sector array is a repetition of a specific array pattern, and the predetermined range is preferably the specific array pattern.

It is preferable that the index and the corresponding data sector information corresponding to the index are stored in the table for one predetermined range.

Prediction means for predicting the next servo sector address is provided, and the calculation means and / or the second calculation means perform the calculation by using the servo sector address predicted by the prediction means. May be.

As a third aspect of the present invention, information is read from a storage medium in which at least a servo sector storing its own address and a data sector for storing data are formed in a predetermined arrangement. In a storage device, there is provided a storage device including a reading unit that reads out information stored in the storage medium, and the control device according to the first or second aspect.

It is preferable to further include a writing unit for writing data in the storage medium.

[0033]

The calculating means includes the number of data sectors (DSP) included in a predetermined range on the sector array.
B) and the number of servo sectors (SSPB) and the separately read servo sector address are used to perform the operation of the above-mentioned equation 4 (= equation 1). Then, by rounding up after the decimal point of the calculation result, the address of the first data sector starting after the servo sector pointed to by the servo sector address used for the calculation is obtained in the sector array.

The second calculation means is DSPB, SS.
Using the PB and the separately read servo sector address, the operation of the above-mentioned expression 5 (= expression 2 = expression 3 = expression 6) is performed. Then, by truncating the decimal point of the calculation result, the address of the data sector divided by the servo sector next to the servo sector pointed to by the servo sector address used for the calculation is obtained in the sector array.

The servo sector address used when performing such calculation does not necessarily have to be read from the storage medium. If the servo sector address predicting means is provided, the prediction result may be used.

The third calculating means obtains the data sector information prepared for each servo sector by referring to the table based on the index. This index is S
It is calculated as the remainder of SA divided by SSPB. The control signal generation means acquires the data sector information corresponding to the obtained index from the table, and generates and outputs the control signal according to the acquired data sector information.

When the sector array is a repetition of a specific array pattern, this specific array pattern is set as the above-mentioned predetermined range. In this way, when the data sector information is obtained, the same table can be reused for each of the predetermined ranges (specific array patterns). In other words, it is sufficient to prepare one table for this predetermined range (in this case, the specific array pattern).

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

In the first embodiment, the data sector address is obtained based on the servo sector address.

First, the outline of the disk device as a prerequisite will be described with reference to FIG.

As shown in FIG. 4, the disk device of this embodiment has a CPU 11, a servo controller 8, a host I / F controller 14, a buffer controller 12, a drive I / F controller 9, a data buffer 13 and an ECC. It is composed of a data processing device including a control unit 10, a signal processing device 3, an R / W amplifier 4, a motor driver 5, and a data surface recording medium 7.

The host computer 15 is the disk device 1
To READ / WRITE data to the
The AD / WRITE command is issued to the disk device 1. This issuance is performed by writing an instruction to the register of the host I / F control unit 14. WRIT to register
The instruction that has been E is interpreted and executed by the CPU 11.

If the instruction is a READ instruction, the CPU
11 issues an instruction to each block of the disk device 1 to execute this READ command. For example, drive I /
The F control unit 9 sets the data sector address of the data to be read.

Each section operates as follows in response to an instruction.

The servo controller 8 operates the motor driver 5 to move the R / W head 6 to the cylinder address (CYL) 24 where the data to be read is recorded (seek operation). After the seek operation is completed, the R / W head 6 reads the data from the data surface recording medium 7. R /
The W amplifier 4 and the signal processing device 3 perform a predetermined process on the read data. The drive I / F control unit 9
The processed data is read and the ECC control unit 10 is caused to detect an error. The ECC control unit 10 performs error correction processing when there is an error. The ECC control unit 10 causes the buffer control unit 12 to temporarily store the corrected data in the data buffer 13.

When a certain amount of data is stored in the data buffer 13 and the data is ready to be transferred to the host computer 15, the host computer 15 is notified that the transfer is ready. The host computer 15 reads the READ data stored in the data buffer 13 through the buffer control unit 12 and the host I / F control unit 14.

When the command from the host is a WRITE command, the CPU 11 issues an instruction to each block of the disk device 1 to execute the WRITE command. In response to this, each unit operates as follows.

After interpreting the WRITE command, the CPU 11 notifies the host computer 15 that the transfer is ready. In response to this, the host computer 15
Data is transferred to the host I / F control unit 14. Host I
The / F control unit 14 temporarily stores the transferred data in the data buffer 13 via the buffer control unit 12.

When the R / W head 6 completes the seek operation and reaches the head of the target data sector, the buffer controller 1
2 transfers the data stored in the data buffer 13 to the drive I / F control unit 9. The ECC control unit 10 adds an error detection and error correction code to the data transferred to the drive I / F control unit 9. Drive I / F
The control unit 9 sends this to the R / W head 6 through the signal processing device 3 and the R / W amplifier 4. The R / W head 6 records this on the target data sector of the data surface recording medium 7.

In the READ / WRITE operation described above, the cylinder address and the data sector address are required. Of these, the cylinder address is stored in the servo sector 16. On the other hand, the data sector address is generated by the servo control unit 8 using the servo sector information. The servo controller 8 will be described below with reference to FIG.

The read data pulse (RDP) 51 is input from the signal processing device 3 to the servo control unit 8. The servo control unit 8 uses the read data pulse (RDP) 5
Based on 1, the cylinder address (CYL) 24, the data sector address (DSA) 60, and various control signals (split length SPTL59, sector pulse SCTP61, index pulse IDXP62) are generated. The servo control unit 8 outputs the generated control signals and the like to the signal processing device 3 and the drive interface control unit 9.

Further, the servo control unit 8 controls the motor driver 5 based on the servo sector information, and the R /
The movement of the W head 6 and the rotation of the data surface recording medium 7 are controlled.

An outline of the operation in the servo controller 8 will be described.

The data surface recording medium 7 has a data sector 1
7 and servo sector 16 are recorded (see FIG. 2). The servo sector 16 is used for moving and positioning the R / W head 6 and generating a sector pulse (SCTP) 61.

The data read from the servo sector by the R / W head 6 is subjected to predetermined processing in the R / W amplifier 4 and the signal processing device 3, and then input to the servo control unit 8 as a read data pulse (RDP) 51. To be done.

Servo control sequencer 3 of servo control unit 8
Reference numeral 5 controls the output timing of the control signal generated and output by each unit constituting the servo control unit 8.

The servo clock generation circuit 36 generates a servo clock having a frequency necessary for the operation of each unit constituting the servo control unit 8 from an external clock 55 such as an oscillator.

The RDP detection circuit 37 synchronizes the input read data pulse (RDP) 51 with the servo clock and notifies the circuit of the subsequent stage.

Servo mark detection circuit 39, index mark detection circuit 40 and sector mark detection circuit 41
Are synchronized read data pulses (RD
P) 51 to SVMK21, IDXM2 shown in FIG.
2. Detect SCTM23. CRC52 is IDXM
22 / SCTM23, CYL24, SSA25, etc. are checked for error (see SSCT example 2 in FIG. 2).

The Gray code converter 38 also converts the Gray code (see FIG. 2) into a binary code. In the example of FIG. 2, the gray code is used as the cylinder address (CYL24) and the servo sector address (SSA25).
Although it was configured with, the head address (HD)
53 may be included.

The current servo address latch 42 temporarily stores each of these read addresses (cylinder address, servo sector address, head address). On the other hand, the servo address register 45 separately stores the address instructed to access.

The comparator 44 determines whether or not the read address is the address to be accessed, based on the match between the read address and the address stored in the servo address register 45. judge.

The read cylinder address (C
YL) 24 is also transferred from the current servo address latch 42 to the CPU 11 in order to recognize the position of the R / W head 6 on the data surface recording medium 7.

The data sector address generation circuit 49 generates a data sector address (DSA) 60 based on the servo sector address (SSA) 25 fetched in the current servo address latch 42 and outputs it to the I / F control unit 9. . Further, based on the servo sector address (SSA) 25, the data sector information table 47
Generate and output the index of. The index is information necessary to refer to the data sector information table 47 of this embodiment.

The data sector information table 47 outputs various data corresponding to the output index. Although referred to simply as the “table” 47 here, in reality, it corresponds to the memory that stores information (table) that associates the index with various data and the index that is input from the data sector address generation circuit 49. A circuit for obtaining an address where various data are stored and reading the data from the address of the memory is provided. However, these read circuits and the like may be included in the SCTP generation circuit 48.
The manner of sharing these functions is not particularly limited.

The SCTP generation circuit 48 generates a sector pulse (SCTP) 61 and an index pulse (IDXP) 62 based on the data output from the data sector information table 47, and outputs the sector pulse (SCTP) 61 and the index pulse (IDXP) 62 to the drive I / F control unit 9. SCTP61 is data sector 1
8 is a signal indicating the head position.

The split length generation circuit 50 generates a split length (SPTL) 59, and drives I
Output to the / F control unit 9. Split length (SPT
L) is a value indicating the data length of the first DATA1 (35) included in the data sector (DSCTB) 19.

The greatest feature of this embodiment is the generation of the data sector address by the data sector address generation circuit 49. It is also characterized by the data sector information table 47, the SCTP generation circuit 48 and the split length generation circuit 50. Therefore, they will be described in more detail below.

Before describing the specific configuration of each unit, first, the method of calculating the data sector address and the method of calculating the index in this embodiment will be described.

First, the periodicity of the sector arrangement used by the calculation method of the present invention will be described.

The positional relationship between the servo sector and the data sector on the cylinder of the data surface recording medium 7 is shown in FIG. As can be seen from FIG. 3, servo sectors are recorded at regular intervals in all cylinders. The servo sector address (SSA) starts from "0". The servo sector (SSCTB17) with the servo sector address (SSA) = 1 and 2 is the data sector (DSCTB1).
9) is divided. Servo sector address (SSA)
= 3 servo sectors (SSCTA16) are just data sectors (DSA = 7) and data sectors (DSA =
It is between 8). Therefore, the arrangement pattern of the servo sector and the data sector on each cylinder is one in which a range consisting of three servo sectors (SSPB = 3) and eight data sectors (DSPB = 8) is set as one cycle and is repeated. ing. Hereinafter, the repeating unit is referred to as "Boundary".

A method of calculating the data sector address will be described.

In order to calculate the data sector address (DSA), first, the following mathematical expression 7 is calculated.

[0074]

[Equation 7] SSA / DSPB / SSPB where SSA: servo sector address DSPB: number of data sectors included in one Boundary SSPB: number of servo sectors included in one Boundary The data sector address (DSA) is obtained by moving up the remainder (fractional part) of the result. For example, if the calculation result of Equation 7 is 2.3, DSA
Is 3.

Next, a method of calculating the index will be described.

The data sector information table 47 has data sector information (eg, Spli) that is difficult to calculate from the servo sector address (SSA) 25.
tTime, split length, split sector offset) are stored. Conventionally, it is necessary to prepare this data sector information for the number of servo sectors included in one track of the track. However, in the present invention, this number is reduced by utilizing the above-mentioned Boundary property. That is, the arrangement pattern of the data sector and the servo sector in one Boundary is the same for any Boundary. Therefore, it is sufficient to prepare the data sector information for the number of servo sectors included in the Boundary.

However, in this case, in order to refer to the data sector information table 47, information (index) indicating the number of the servo sector from the beginning in the Boundary is required.

The index is, as shown in the following equation 8,
It is obtained as the remainder obtained by dividing the servo sector address (SSA) 25 by SSPB.

[0079]

## EQU00008 ## Vector No. = SSA mod SSPB Vector No. : Index SSA: Servo sector address SSPB: Number of servo sectors included in one Boundary Next, a data sector address circuit 49 and a data sector for executing the above-described data sector address calculation method and index calculation method. Specific configurations of the information table 47, the SCTP generation circuit 48, and the split length generation circuit 50 will be described with reference to FIG.

The data sector address generation circuit 49
SPB register 65, multiplier 66, selector 67, SS
PB register 68, divider 69, Vector No.
It is composed of a register 71 and a data sector address DSA counter 70. These are connected so as to be able to perform the operations of the equations 7 and 8.
The DSPB register 65 stores in advance the number of data sectors (DSPB) included in the Boundary. The SSPB register 68 has a Bound
The number of servo sectors included in the directory (SSP
B) is stored in advance.

The data sector information table 47 stores a Split Time 73, a split length (SPTL), and a split sector offset (SPSO) 72. Split
Time73 is from the rear end position of the servo sector,
This is information indicating the time required to reach the head position of the first data sector after the servo sector. This is used when the SCTP generation circuit 48 generates the SCTP 61. Split sector offset (SPS
O) 72 is information indicating what number data sector after the servo sector is a split data sector (DSCTB). Split length (S
As described above, the PTL) is a value indicating the data length (bytes) of the first DATA1 (35) of the data sector (split data sector DSCTB19) divided by the servo sector next to the relevant servo sector. Yes (see Figure 2).

The information amount of the data sector information table 47 is at least (one Bound
The number of servo sectors included in ary) × (amount of information prepared for one servo sector). Actually, the Split Time can be configured as 12 bits, the split length as 10 bits, and the split sector offset as 3 bits. Further, the number of servo sectors included in one Boundary is 16 at most. Therefore, the data sector information table 47 is 400 bits (= (12 + 10 + 3) × 16)
Can be configured as information.

The SCTP generation circuit 48 uses the Split T
The IDXP 62 and the SCTP 61 are generated using the time 73. Although not clear in the figure, the SCTP6
1 is also output to the DSA counter 70. As described above, the SCTP 61 is information indicating the head position of the data sector 18 from the servo sector 17.

The split length generation circuit 50 divides the data sector (D
Drive up to SPTL59 until SCTB19)
The output to the F control unit 9 is controlled. The split length generation circuit 50 includes an SPSO counter 74 and an S
The PTL output control circuit 75. These functions will be described later together with the operation.

The term "sector array" used in the claims refers to a cylinder (track) in this embodiment.
It corresponds to the array of servo sectors and data sectors above. The "arithmetic means" and the "third arithmetic means" correspond to the servo control unit 8 (in particular, the data sector address generation circuit 49). The “predetermined range” corresponds to the above-mentioned Boundary.
The "specific array pattern" corresponds to the array pattern of the servo sector and the data sector in the Boundary. The “table” and the storage means in which it is stored correspond to the data sector information table 47. To correspond to “data sector information”, in the present embodiment, it is Split time, split length (SPTL), and SPSO. The “control signal generating means” is composed of the SCTP generating circuit 48 and the split length generating circuit 50. The “reading unit” corresponds to the signal processing device 3, the R / W amplifier 4, and the like. The “writing means” corresponds to all parts that function to write data on the recording medium 7.
The above-mentioned units operate in cooperation with each other, and the correspondence relationship described here is not strict. In particular, the SCTP generation circuit 48 and the like may have a function of reading information from the data sector information table 47.

Operations of the data sector address generation circuit 49 and the like shown in FIG. 5 will be described with reference to FIG.

Here, SSA = n, DSPB = B, S
SPB = A.

The servo sector address (SSA) 25 read from the current servo address latch 42 is input to the multiplier 66 and the selector 67.

The multiplier 66 calculates n · B. Then, the calculation result is output to the selector 67.

The selector 67 first outputs SSA (here, n) to the divider 69. The divider 69 is n
Mod A is calculated (see Eq. 8), and the remainder is Vec
tor No. It is stored in the register 71.

Next, the selector 67 outputs the multiplication result (n · B) of the multiplier 66 to the divider 69. Divider 69
Calculates (n · B) / A and outputs the calculation result (quotient and remainder) to the DSA counter 70.

The DSA counter 70 has the servo sector 16
The result of the divider 69 is fetched in synchronism with the first SCTP 61 after the above. When the calculation result input from the divider 69 has a surplus, the DSA counter 70 adds 1 to the count value of the quotient. The count value thus obtained is used as the data sector address (DS
A) 60 is output to the drive I / F control unit 9.

After this, the DSA counter 70 makes the SCTP
Each time 61 is output, the count is incremented by one. Thus, the drive I / F control unit 9 can determine whether the read data sector address matches the data sector address of the target data sector.

The SCTP generation circuit 48 uses the Split T
IDXP62 and SCTP61 are produced | generated using time73.

SPS of split length generation circuit 50
As shown in FIG. 6, the O counter 74 displays the servo sector 1
The split sector offset (SPSO) 72 is fetched in synchronization with the first SCTP 61 after the end of 7.
After that, each time the SCTP 61 is output, the countdown is performed. When the value of the SPSO counter 74 becomes “0”, the SPTL output control circuit 75 outputs the split length input from the data sector information table 47 to the I / F control unit 9 as the split length (SPTL) 59.

Normally, when the data sector is split by the servo sector, the split length (SPTL) 59 output to the drive I / F control unit 9 cannot be "0", so in this embodiment, the split length (S
When the PTL) 59 is "0", it means that the corresponding data sector has no split due to the servo sector. Therefore, as shown in FIG. 6, split length (SPTL)
59 is “from the data sector“ m ”to“ j-1 ”
0 "is output, and when the data sector is" j ", the split length value output from the data sector information table 47 is output. The output of this split length (SPTL) 59 is S shown in FIG.
It is controlled by the split generation circuit 50 including the PSO counter 74 and the SPTL output control circuit 75. In this way, the split length (SPTL) 59 value is "
When it is "0", it means that there is no split by the servo sector. Therefore, by setting the value of the corresponding split length in the data information table 47 to "0", the data sector is not split in the next servo sector. It is possible to handle cases.

As described above, in this embodiment, the presence or absence of the split of the data sector is determined by the split length (SPTL) 59.
In order to determine whether the value of is "0" or other than "0", the addition of the graph showing whether the data sector is split in the next servo sector is omitted in the data sector information table 47.

As described above, in the present embodiment, the amount of information in the data sector information table 47 can be reduced, so that the scale of the circuit that holds and uses it can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

The second embodiment is the same as the first embodiment (FIG. 5).
Compared with the above, the control method of the SPTL 59 (that is, the determination method of the data sector DSCTB) is different. In this embodiment, instead of SPSO, the SPTL 59 is controlled by comparing a predetermined calculation result, which will be described later, with the DSA 60.

Corresponding to the difference in the determination method, the specific circuit configuration is also different (see FIG. 7). That is, the data SPSO 72 is stored in the data information table 47.
Is not stored. Further, the split length generation circuit 47 is provided with a comparator 77 instead of the SPSO counter 74 in the first embodiment. The split length generation circuit 47 controls the SPTL 59 by comparing the result of the operation (described later) by the divider 69 with the DSA 60 by the comparator 77.

Next Split Data Sector (DSCT
In order to obtain the data sector address (j) of B), first, the following equation 9 is calculated. Then, it is obtained by truncating the remainder (fractional part) of the calculation result.

[0103]

(SSA + 1) -DSPB / SSPB SSA: Servo sector address SSPB: Number of servo sectors included in one Boundary DSPB: Number of data sectors included in one Boundary The operation result of Equation 9 is an integer This means that the next servo sector is located just between the data sectors and the data sector is not divided.

The servo sector address (SSA) 2
5 to data sector address 60 and index (V
vector No. ) Is performed by the first method
This is the same as the embodiment.

The "second arithmetic means" referred to in the claims corresponds to the servo control unit 8 (in particular, the data sector address generation circuit 49).

The operation of this embodiment will be described with reference to FIG.

Here, SSA = n, DSPB = B, S
SPB = A.

The multiplier 66 and the divider 69 are
Calculations of Equations 8 and 9 are performed. That is, the multiplier 66 multiplies the servo sector address (SSA) by DSPB (n · B). Then, (n + 1) · B is calculated. However, since the multiplier 66 has already performed (n · B),
It suffices to add B to this calculation result (n · B). After that, the divider 69 performs the operation of Expression 8 to obtain Vecto.
r No. Of the vector No. It is stored in the register 71. Further, the divider 69 is the multiplier 66.
Divides n · B previously obtained by A (see Eq. 7). And
The calculation result is output to the DSA counter 70. Further, the divider 69 divides (n + 1) · B by A (Equation 9).
reference). Regarding this calculation result (quotient and remainder (fractional part)), the remainder (fractional part) is truncated and the value is held. This value is the split data sector (DSCTB1
It is the address of 9).

The DSA counter 70 takes in the calculation result (quotient and remainder) input from the divider 69. In this case, if there is a remainder in this calculation result, "1" is held as the count enable 78. When there is no remainder, "0" is held in the count enable 78. And the count enable78 is "1".
If it is, the count is further increased by 1. When the count enable 78 is "0", the value taken in without holding the count up is held as it is.

After that, the count enable 78 is SC
It is set to "1" at TP61. After this, SCTP
Each time 61 is input, the DSA counter 70 is incremented by 1.
Count up one by one.

The comparator 77 compares the DSA 60 output from the DSA counter 70 with the address of the split data sector (DSCTB) held by the divider 69, and the result is sent to the SPTL output control circuit 75. It is outputting. The SPTL output control circuit 75 sends the SPT to the I / F control unit 9 when the comparison result of the comparator 77 is “match”.
L59 is output.

As described above, the data sector information table 47 of this embodiment need not store SPSO. Therefore, the amount of data can be made smaller than in the first embodiment. Therefore, the circuit scale can be further reduced.

The servo sector address input to the data sector address generation circuit 49 may not be the servo sector address read from the data recording medium 7. The servo sector address read from the data recording medium 7 may be wrong due to the influence of noise or the like. Therefore, if you can predict the servo sector address by some other method,
The prediction result may be used. Such an example will be described below as a third embodiment.

A third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, the next SSA prediction circuit 43 is arranged between the current servo address latch 42 and the data sector address generation circuit 49. Then, the servo sector address predicted by the next SSA prediction circuit 43 is set to the data sector address generation circuit 4
I am entering 9.

The next SSA prediction circuit 43 includes a servo mark SVMK21, an index mark IDXM22,
A counter that counts up with the sector mark SCTM23 or the like, or a servo sector address (SSA) of 0, 1, 2,
In the case of continuously changing in a constant relationship with 3, the servo sector address is predicted using the immediately preceding servo sector information, that is, in this case, the value obtained by adding 1 to the immediately preceding servo sector address is set as the predicted value. It is a circuit. The "prediction means" referred to in the claims is realized by the next SSA prediction circuit 43 and each unit that operates in cooperation with the next SSA prediction circuit 43.

The comparator 46 reads the servo sector address SSA and the next SSA read from the data surface recording medium 7.
The prediction result is confirmed by comparing the values of the prediction circuit 43.

As described above, in the third embodiment,
Since the next SSA prediction circuit 43 is provided, it is possible to detect a read error of the servo sector address from the data surface recording medium 7. Further, since the servo sector address is predicted in advance, there is a margin in the calculation time of the data sector address (DSA).

Data sector address DSA in CPU 11
60 and the index (Vector No. 71) may be calculated. In this way, the multiplier 66
Also, the divider 69 can be eliminated, and the circuit scale can be further reduced. However, the data sector address (DSA) 6
Since the calculation of 0 and the index (Vector No. 71) needs to be completed by the end of the servo sector, it is necessary to use a CPU with high processing capacity.

Data sector address DSA60 and Vec
tor No. A processor such as a DSP may be used for the calculation of 70.

Data sector address DSA57 and Vec
tor No. The calculation of 70 can be calculated only by integer arithmetic. Some microprocessors (microcontrollers) for embedded applications have integer multiplication instructions and integer division instructions. By using such a microprocessor, the calculation overhead can be reduced. Data sector address DSA6 by microprocessor
0 and Vector No. If the calculation of 70 is performed, it is not necessary to provide the data sector address generation circuit 49 exclusively, so that the circuit scale can be further reduced.

[0122]

As described above, the present invention does not use the conversion table when obtaining the data sector address from the servo sector address. Also, on the table, one Bo
It is sufficient to provide information as many as the number of servo sectors included in the unary. Therefore, the size of the table used in the present invention can be made significantly smaller than the conventional size. For example, a conventional conversion table for generating a data sector address DSA (9 bits), a split length (10 bits), a split sector offset (3 bits), and a Split Time (12 bits) from a servo sector address SSA is assumed to have 128 servo sectors.
It becomes 4352 bits (= (9 + 10 + 3 + 12) × 128). On the other hand, the table when the present invention is applied is 400 bits (= (10 + 3 + 12) × 16), which is about one tenth of the conventional one.

Since the table can be made small in this way,
The circuit scale of the disk device can be reduced. In particular, it is possible to suppress the cost in the case of making an IC.

[Brief description of drawings]

FIG. 1 is a servo control unit 8 according to a first embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG.

FIG. 2 is a diagram showing a configuration example of a disc format using an IDless format.

FIG. 3 is a diagram showing a positional relationship between servo sectors and data sectors.

FIG. 4 is a block diagram showing the overall system configuration of the disk device of the first embodiment.

FIG. 5 is a block diagram showing configurations of a data sector address generation circuit 49 and peripheral circuits in the first embodiment.

FIG. 6 is a diagram showing operation timing.

FIG. 7 is a block diagram showing configurations of a data sector generation circuit 49 and peripheral circuits in a second embodiment of the present invention.

FIG. 8 is a diagram showing operation timing.

FIG. 9 is a third aspect of the present invention including a next SSA prediction circuit.
3 is a configuration diagram of a servo control unit in the embodiment of FIG.

[Explanation of symbols]

1 ... Disk device, 2 ... Data processing device, 8 ... Servo control unit, 9 ... Drive I / F control unit, 16 ... Servo sector, 17 ... Data sector, 19 ... Servo mark, 20 ...
Index mark, 21 ... Sector mark, 22 ... Cylinder address, 23 ... Servo sector address, 40 ... Next SSA prediction circuit, 44 ... Data sector information table, 57 ... Data sector address, 66
... multiplier, 69 ... divider, 70 ... DSA counter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Motoyasu Tsunoda Inventor Motoyasu Tsunoda 1099, Ozenji, Aso-ku, Kawasaki, Kanagawa Inside the Hitachi, Ltd. System Development Laboratory (72) Inventor Shoichi Miyazawa 1099, Ozen-ji, Aso-ku, Kawasaki, Kanagawa Hitachi, Ltd. System Development Laboratory (72) Inventor Masatoshi Nishina 2880 Kokufu, Odawara, Kanagawa Stock Company Hitachi Storage Systems Division (72) Inventor Katsumi Yamamoto 5-20, Kamimizumoto-cho, Kodaira-shi, Tokyo Hitachi, Ltd. Semiconductor Business Division No. 1

Claims (10)

[Claims] 1. A servo sector in which at least its own address is stored and a data sector in which data is stored are read from a storage medium formed in a predetermined array (hereinafter referred to as "sector array"). In the controller of the storage device, information indicating the number of data sectors included in the predetermined range on the sector array and information indicating the number of servo sectors included in the predetermined range on the sector array are displayed. The address of the above-mentioned servo sector that is provided separately and read (hereinafter, “servo sector address”)
The following data is calculated by using the above formula (1) and the fractional part of the calculation result is rounded up to the right of the decimal point, so that the first data sector starting after the servo sector pointed to by the servo sector address used for the calculation An arithmetic means for obtaining an address (hereinafter, referred to as "data sector address") is provided. [Expression 1] SSA / DSPB / SSPB where SSA: servo sector address DSPB: included in a predetermined range on the sector array. Number of Data Sectors SSPB: Storage device controller characterized by the number of servo sectors included in a predetermined range on the sector array. 2. The sector array allows the servo sector to be positioned so as to divide the data sector at an intermediate position of the data sector, using the separately read servo sector address. The address of the data sector divided by the servo sector next to the servo sector pointed to by the servo sector address used in the calculation of the above mathematical expression 2 is rounded down by performing the mathematical operation of the following mathematical expression 2 (SSA + 1) · DSPB / SSPB where SSA: servo sector address DSPB: number of data sectors included in a predetermined range on the sector array. SSPB: A sector included in a predetermined range on the sector array. Controller of the storage device according to claim 1, wherein the number of Bosekuta. 3. A servo sector storing at least its own address and a data sector for storing data read information from a storage medium formed in a predetermined array (hereinafter referred to as "sector array"). In the control device of the storage device, the sector array allows the servo sector to be positioned so as to divide the data sector at an intermediate position of the data sector, and within the predetermined range on the sector array. The information indicating the number of included data sectors and the information indicating the number of servo sectors included in a predetermined range on the sector array is provided, and the address of the separately read servo sector (hereinafter referred to as “servo sector address”). ”
By performing the calculation of the following formula 3 by using the above) and truncating the decimal part of the calculation result, the sector is divided by the servo sector next to the servo sector pointed to by the servo sector address used for the calculation of the formula 3 above. A second arithmetic means for obtaining the address of the data sector, which is (SSA + 1) DSPB / SSPB, where SSA: servo sector address DSPB: included in a predetermined range on the sector array. Number of Data Sectors SSPB: Storage device controller characterized by the number of servo sectors included in a predetermined range on the sector array. 4. Storage means for storing a table in which data sector information prepared for each servo sector and an index indicating the position of the servo sector within the predetermined range are stored, and the servo sector. Third computing means for obtaining the index based on the address, and the data sector information corresponding to the index obtained by the third computing means is obtained from the table, and control is performed according to the obtained data sector information. 4. A control signal generating means for generating and outputting a signal, further comprising:
A control device for the storage device described. 5. The third computing means converts the SSA into SS.
The control device for a storage device according to claim 4, wherein the index is obtained as a remainder divided by PB. 6. The storage according to claim 4, wherein the sector array is a repetition of a specific array pattern, and the predetermined range is the specific array pattern. The control device of the device. 7. The storage device according to claim 6, wherein the index and the data sector information corresponding to the index are stored in the table for one predetermined range. Control device. 8. A prediction unit for predicting a next servo sector address, wherein the calculation unit and / or the second calculation unit uses the servo sector address predicted by the prediction unit,
The control device for a storage device according to claim 1, 2 or 3, wherein the control device performs the calculation. 9. A storage device for reading information from a storage medium having a servo sector storing at least its own address and a data sector for storing data, which is formed in a predetermined arrangement. A storage device comprising: a reading unit that reads out stored information; and the control device according to claim 1, 2, 3, 4, 5, 6, 7, or 8. 10. The storage device according to claim 9, further comprising writing means for writing data to the storage medium.