JPS6344362A - Disk memory device - Google Patents

Abstract

PURPOSE:To decrease a recording capacity loss by counting the physical address of a fault-free sector based upon an address and fault sector information in the device equipped with a formatting means. CONSTITUTION:An area to record fault sector information DI is set to a special place in a disk 2 surface, and at the time of the formatting of the disk 2, a physical serial sector number, a head number, a sector number, etc., are written as the fault sector information DI into the special area by a formatting means 30. At the time of the actual reading and writing of information, for the address such as a logical serial sector number to designate the reading/writing information with an address converting means 40, a disk 2 is accessed by the physical address while the fault sector information is referred to.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a disk storage device such as a fixed disk device in which information is read and written in sectors that are formatted in a predetermined manner.

[Prior art and its problems]

A disk as a magnetic recording medium of a disk storage device is
In recent years, the recording capacity has been significantly improved, but...
It is quite difficult to guarantee that all of the extremely large number of storage areas, ranging from several megabytes to several tens of megabytes, are completely defect-free. The cause of defects varies depending on the type of media and the manufacturing method of the disc, but in terms of bytes it is 10-'. In bit units, it is inevitable that defects will occur with a probability of about 101 due to non-uniformity of the disk substrate surface or the media attached to it; for a disk with a storage capacity of several tens of megabytes on one side, there will be 10 to 20 defects. Those that do have these are used as good quality products for economic reasons. Of course, the defective area cannot be used as a storage area, so
Conventionally, efforts have been made to avoid these defective areas when formatting a disk so that only the defect-free areas can be used as a recording medium. An example of conventional means for formatting while avoiding such defective locations will be described with reference to FIG. In the figure, the horizontal lines indicate the tracks T set on the disk surface, for example, from the outer diameter side of the disk to the inner diameter side as shown on the left side of the figure. Sector numbers i (+=0 to p) are assigned to them. In addition, a spare track indicated by 3 in the figure is prepared in advance, for example, on the inner diameter side of the disk.Assume that the i-th track has a defect as indicated by the X mark in the figure. In conventional means, this i including defects
One row in the spare track is used instead of the th track, and the serial sector numbers are changed as shown on the right side of the figure. The serial sector number on the left side of the above diagram is the physical serial sector number for the disk surface, but the serial sector number on the right side is the software or logical serial sector number, and in this way, the serial sector number on the left side is the serial sector number on the disk surface. By assigning logical sequential sector numbers,
Formatting is performed so that only healthy recording areas are used. Of course, a comparison table between the physical serial sector number and the logical serial sector number is recorded at an appropriate location on the disk surface, and when the disk storage device is used, this table is attached to the disk storage device. The track where the information is actually recorded is accessed after the serial sector number specified from the outside is converted from the logical serial sector number to the physical serial sector number. . According to such conventional means, even if there is a defect on the disk surface, it is possible to access the disk in the same way as if it were a completely defect-free disk when viewed from the outside, and the logical serial sector number can be converted to the physical serial number required for actual access. This can be easily converted into a sector number, but as can be easily seen, it is necessary to set up spare tracks for the number of defects on the disk, which has the disadvantage that the forward recording capacity of the disk decreases accordingly. Of course, strictly speaking, there may be defects in the same track, so it may not be necessary to have as many spare tracks as there are defects, but as a system, it is necessary to prepare for the worst case. Even if it is possible that not all of the tracks will be used as spares, in reality, the recording capacity of the tracks will be taken up by the number of defects that occur. For example, if the number of defects per disk is 20 and the number of effective tracks is If it is about 500, about 4% of the recording capacity will be wasted.

[Purpose of the invention]

According to the present invention, even if the disk has a defect, the recording capacity is not substantially sacrificed, and 1! ! The aim is to obtain a disk storage device that is simply accessible.

[Key points of the invention]

The present invention was made by focusing on the fact that in many disk storage devices, information is written in units of sectors, which are constituent elements of tracks. For example, when formatting a disk, the disk storage device's matting means stores defective sector information in that specific area, for example, the physical information of the sector containing the defect. In addition to writing the standard serial sector number, head number, sector number, etc., the disk storage device is equipped with a simple address conversion means, and when actually reading and writing information, the read/write information is The above object is achieved by accessing the disk using a physical address while referring to the defective sector 1n report for an address such as the above-mentioned logical serial sector number that specifies the defective sector. As will be seen from the explanation of the embodiment described below, the amount of defective sector information to be written in a specific area is usually small enough to fit within one sector, so in reality, the specific area is also one sector 1. Therefore, in the present invention, the number of sectors required to exclude sectors containing defects in formatting is at most one defective sector.
Normally, one track contains about 32 sectors, so in formatting, one extra track should be set in addition to the track required for no defects. As mentioned above, when the number of defects is 20 and the number of effective tracks is 500, according to the present invention, only about 0.2% of the recording capacity is lost due to the elimination of defects. Additionally, it is advantageous to include a serial sector number for the entire physical disk surface of each defective sector in the defective sector information that should be recorded in a specific area, in order to simplify the configuration of the address conversion means. It is.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an example of the overall configuration of a disk storage device embodying the present invention in terms of hardware. In the figure, the drive unit of the disk storage device is denoted by 100, and the controller attached to or integrated with it is denoted by 100. Although they are shown separately at 200 for convenience, they together constitute a disk storage device according to the present invention. This disk storage device is, for example, a 5C3I type (Small Comp
uter 5ystesInterface) bus 3
00, it is connected to a host computer (not shown) which is the user. The drive unit 100 on the upper side of the figure is a fixed disk device, and two disks I and 2 are schematically shown inside thereof, and these are driven at a constant speed in the direction of the arrow in the figure by a so-called spindle motor 3. being driven. On the other hand, a head 4 for reading and writing information on the disk is operated by a head operation motor 5 in the radial direction of the disk as shown by double arrows in the figure. A drive circuit 5a that receives a head operation command 1 (C) and drives the head operation motor 5 is shown below it.A large number of tracks T are set on each disk surface, but they are not shown in the figure. Only one of the outermost tracks and one of the inner tracks is shown as a representative.Each track T includes a plurality of sectors S, usually 32, but the inner track A sector containing a defect is illustrated with an x mark. Defective sector information regarding the sector containing this defect jlJDI
In the illustrated example, it is assumed that the data is recorded in a specific area that is hunted in the figure, which is the first sector of the outermost track. Incidentally, on this disk surface, an area in which so-called servo information Sl is written is indicated by a fan-shaped part. As is well known, this servo information is for detecting the deviation of the head 4 from its normal position on the track T, and this servo information SI is synchronized with the index pulse IDX from the pulse generator 3a of the spindle motor 3. The information is read by the head 4, and the deviation from the normal position is corrected, and then information is written to or written to the track. The head 4 is connected to a read/write circuit 6, and as usual, this read/write circuit 6 receives a head selection command HS.
puts the head designated by R into a reading or writing state according to the read/write command R-;
A read signal R5 from the read output R is modulated into a signal such as a known MFM signal by a demodulation circuit 7, and is then applied to the controller 200. On the other hand, the MFM type write signal -3 from the controller 200 is applied to the write input W of the read/write circuit 6 as is. After receiving the index pulse TDX, the mask signal generation circuit 8 receives the above-mentioned servo information Il! After the time for reading s+ has elapsed, an external index pulse IDXe is issued to the controller 200. Moreover, the processor IO incorporated in the drive unit 100 is! f For controlling the operation of the drive section, the above-mentioned head operation command HC, head selection command H5° read/write command l? In addition to issuing a signal, a seek completion signal SC is issued to the controller 200 to confirm that the head has been correctly sought to the correct position on the track. On the other hand, a processor 20 is also included in the controller 200, and a formatting means 3 according to the present invention is included therein.
0 and address conversion means 40 are included as software in the manner illustrated in FIGS. 2 and 3. An interface circuit 21 is placed at the connection point of the controller 200 with the bus 300, but the main bus within the controller is also shown as being the same as the bus 300 from the outside, and the internal bus 300 is connected to the aforementioned processor 20 and data. A control circuit 22 is connected. The data control circuit 22 converts, for example, information data on an 8-bit parallel bus into a serial signal of, for example, a known NRZ system, or vice versa. The signal conversion circuit 23 shown above converts the aforementioned M F M signal into this N
Convert to RZ or perform the inverse conversion. Further, the aforementioned processor 20 is connected to the data control circuit 22 and the processor 10 in the drive unit 100 via separate buses 24 and 25, respectively. In addition, controller 2
The hardware configuration of the processor 20 is not particularly different from the conventional one, and the feature of the present invention is that the processor 20
formatting means 30 and address conversion means 4 within
0 and exists. Next, before going into a description of these two means, an example of how defective sector information is written in a specific area will first be described with reference to FIGS. 4 and 5. Figure 4 shows the sectors in which information is recorded within the entire disk surface included in the disk storage device, and the long rectangles or horizontal lines indicate the track T.
However, one sector is shown in a small section within a rectangle.The variable i in the vertical direction in the 0 figure indicates the serial sector number of p+1 tracks starting with O and ending with p on each disk surface. The direction variable j (j-0 to q) is the number length on the disk surface,
This indicates the yarn head number. As mentioned above, the value of p is usually 500 or more, and as shown in FIG. 1, when there are two disks, there are four disk surfaces, so q=3. Also, the variable k shown in the left and right direction of the figure within one track
(k-Q=r) indicates the sector number within the track, which is usually r-31 as described above. As can be easily understood, 1 is a unit for reading and writing information.
A physical address for specifying a sector is expressed as a three-dimensional matrix combining these three variables t, j, and k. Furthermore, the numbers shown above each track in FIG. Let the number be represented by a variable n starting from 0. In case a shown in FIG. 4, the specific area in which defective sector information is recorded is one sector, as in the previous FIG. is variable 1. j. It is set in the first sector where k is all 0. Of course, this physical serial sector number n is also 0, but it may preferably be set over a plurality of consecutive sectors if necessary. The numbers shown at the bottom of each track are logical serial sector numbers for calling a specific sector when implementing the present invention, and the series of serial numbers starting from 0 is the beginning of the specific area. The numbers on the bottom of the track shown are less than the numbers on the top because they are marked from one sector to the next. A track containing sectors of 1 is shown.
As shown in the figure, the logical serial sector number is assigned by skipping the defective sector, so the logical serial sector number is Although n-2 is one less than that, the logical serial sector number for the sector next to the defective sector is n-1, which is two less than its physical serial sector number n+l. Similarly, when a defective sector appears, logical serial sector numbers are assigned to skip over that sector. Figure 5 (5) shows an example of the allocation of information records in one sector, and the substance is normally a 256-byte data section DT and an error check code section EC, but before that, each sector is The aforementioned variable 1 + J indicating the physical address
+ A collation unit [0 is placed there to record the actual value of k, etc. As is well known, a synchronization signal section SYN is placed before the collation section 10 and the data section OT, and a gap section G is placed at the end of the sector. The defective sector information is written in the data section DT in the first sector, which is a specific area, and the situation is shown in the figure fbl.
is shown. The solid line part in this figure) corresponds to one defective sector, and the actual values of three variables '+ J+ k that constitute the physical address of the defective sector, and the physical serial sector number. This includes n. Note that it is not necessarily necessary to record both the 3 variables 1 + J + k and the 1 variable n, and it is possible to record only one of them. Even if all these variables are recorded, about 8 bytes per defective sector. Since the amount of data is enough, 1
Defective sector information regarding about 32 defective sectors can be stored in the data portion of a sector, which is a specific area. Next, referring to FIG. 2, the formatting means 30
Among the variables described in each step in the illustrated flow, the variables i and j contain the serial sector number 1 that constitutes the physical address of the sector as described above.
The head number and sector number are respectively represented, and the variable n represents the physical serial sector number.The sector in which defective sector information is recorded is the first sector in which the variables '+J+k are all 0. It is assumed that the defect has been verified and confirmed. In the first step s1 as a formatting means, 0 is entered into the serial sector number variable n.In the sixth step s2, 0 is entered into both the track number variable i and the head number variable j to designate the first head of the first track. The following step S3 instructs a so-called seek operation to place the Helad device on the track specified by the variable i. This command is given to the processor 10 in the drive 100 previously shown in FIG. 1, for example via the bus 25. In response, the processor IO gives a head operation command HC to the drive circuit 5a of the head operation motor 5 to place the head at the specified position. When the head is fixed at a predetermined position, the processor IO issues a seek completion signal SC, and after receiving this, the formatting means 30 in the processor 20 of the controller 200 performs step S4 shown in the upper right corner of FIG. There are many sheep in the flow. Steps S4 to 51 shown on the right side of FIG.
The flow up to step 2 detects the presence or absence of defects in all sectors in l track specified by two variables i and j, and
If there is a defect, the defective sector information is stored in the formatting means and then a formatting operation is performed. In the first step S4, test data 1, for example, hexadecimal F, is written uniformly within the track. This data is given from the processor 20 to the data control circuit 22 via, for example, a bus 24, and a write signal WS corresponding to this data is issued from the signal conversion circuit 23 to the read/write circuit 6. At the same time, a write command is issued to processor 2.
0 to the processor 10, and the processor 10 issues a read/write command R to the read/write circuit 6 to place the head in a writing state. In step S5 after the writing is completed, 0 is set in the sector number variable k to designate the first sector in the track, and the operation is entered into a loop for detecting defects starting from step S6. In the first step S6 in the loop, a read command is issued to the processor 10 to switch the read/write command RW to a read designation, and the read/write circuit 6. Signal conversion circuit 2
3 and the data control circuit 22, the test data written in step S4 is read out, and the presence or absence of a defect is detected based on whether the written data is as written. Note that the operations in the previous step s4 and the current step S6 are performed using the external index pulse IDX given from the mask signal generation circuit 8.
This is done in synchronization with e. If the detection result in step S6 is that there is no defect in the sector in the variable, the operation jumps to step S9 from the next judgment step s7, but if there is a defect in that sector, the operation goes to step S8 and the current 4 variables 011・The value of ``j'' is stored in the formatting means 30.The serial sector number n is incremented by one in step S9 regardless of the presence or absence of a defect.The following step S10 and step Sll are sector number variables. When the presence or absence of defects in all sectors of the track has been detected and the variable k reaches its maximum number r, the flow of operation moves from step S10 to step 512 to format the entire track. The actual hardware operation of this step 312 is the same as the previous step S4, except that formatting data is output from the processor 20 instead of the test data.The operation of step 512 After completion, the flow returns to the left column in Figure 2 and returns to step 513.
to go into. This step 513 and the next step 514 are for incrementing the head number variable j, and unless the value of the variable j reaches its maximum (direction q), a head switching command is issued to the processor 10 in step S14, and the head switching command issued by it is Selection command F
After switching the IS to the incremented head number j, the above step S4 is performed without performing a head seek operation.
The operation from to step S12 is repeated and performed. When this operation has been completed for all heads for a certain serial sector number l, the flow of the operation starts from step S13 to incrementing the serial sector number variable from step S15 to
The process goes to step S16. After the serial sector number i is incremented in step S16, the flow returns to the previous step S3, and the head is operated to seek a position corresponding to the new serial sector number. When the above operations are completed for all serial sector numbers i, head numbers j, and sector numbers k in this way, the flow moves from step 315 to the final step SIT as the formatting means 30. Since defective sector information regarding all sectors in which defects have been detected is stored in the means, in this step 517, these defective sector information are written in the specific area in the manner shown in the fifth [ill].
Of course, in this case, the head is operated to seek to the position of the serial sector number in which the specific area is set, and then the write operation is performed. At this time, it is convenient to write the value obtained by adding 1 to the last value of the variable n in the specific area in order to simplify the operation of the address conversion means. In the above-described operation of the formatting means 30, the presence or absence of defects is detected in all sectors on all disk surfaces, but in reality, after the disk is manufactured and before it is assembled into a disk storage device, the disk is The inspection level at this time is often more rigorous than that by the formatting means 30 described above, and the defects detected by this preliminary inspection are likely to deteriorate during use. Defects may also be included. Therefore, if there is data from this pre-inspection, the physical address of the defect data is stored in advance in the formatting means, and when the defect detection point in step s6 above coincides with this memory address, it is unconditionally It is desirable to determine in step S7 that there is a defect in the disk.Of course, new defects may have occurred in the disk during the assembly work of the disk storage device of the disk after this preliminary inspection. Step s for sectors that passed inspection
6 defect detection is always required. Next, the operation of the address conversion means 40 will be explained with reference to FIG. 3. The flow shown in the figure is an example of reading and writing information using the serial sector number n in defective sector information written in a specific area. It is assumed that, before the address conversion means 40 receives a read/write command, the value of this serial sector number n is read in advance from a specific area on the disk and stored in the means. Read/write commands to the disk storage device are sent from the host combinator side via bus 3.
00 to the controller 200, but if the bus 300 is for the above-mentioned SC3I, the address of the read/write information is usually given in the form of a serial sector number along with a command specifying read/write in the so-called command phase, so the following It is assumed that addressing is done in this form. Now, the address set in this way is originally a physical serial sector number assuming that the disk is defect-free, but in reality there may be defects within the disk, so the disk storage system The 1 side must accept this specified address as a logical serial sector number.0 In the figure, this specified logical serial sector number is the variable i.
It is indicated by n. In the first step S18 as the address conversion means 40, 1 is added to the variable in. This corresponds to one starting sector being set as a specific area. Continued step 519 and step S2
0 is a loop operation, and in step S19 the variable i
It is determined whether the value of n is smaller than the physical serial sector number value n stored within the specific area. If not, the variable in is incremented in the next step S20, and the magnitude relationship with the next physical serial sector number value n is determined again in step S19. When the serial sector number value n gradually increases and becomes larger than the value of the variable in, the operation exits the loop from step S19, but as can be easily seen, the value of the variable In at this time is not specified. The logical serial sector number is converted into a corresponding physical serial sector number value. The flow in the column on the right side of FIG. 3 is the same as the flow in the prior art, and in step 521, as described above, from the value of the variable in which is the physical serial sector number, the corresponding serial sector number i and the head number Calculate the values of j and sector number. In step S22, information can be read or written as instructed by the host computer using these three values as physical addresses. This is the same as what was described about the means, so it will be omitted. The host computer may specify the values of three variables i and j instead of the serial sector number values. In this case, it is possible to change the flow in the left column of FIG. 3 from that shown, but the simplest way is to convert it into a serial sector number value using the following equation. n −1−qirl+j −rl′, where ql−q+i, rl=r+l. Normally, the values of ql and rl are each 32.4, for example, and both are powers of 2, so the q included in the above equation
Multiplication of l and rl can be easily accomplished by shifting the 2a number by 5 digits and 2 digits. Note that step S2 in the above
The operation in 1 is the inverse calculation of the above equation, and the division included therein can be easily performed by shifting in the opposite direction to multiplication. Therefore, the address conversion means 40 shown on the left side of FIG.
The operation is based on three variables i. Even if information is specified in j and , it actually takes a very short time, and can be completed within the command phase of the above-mentioned SC3I method, for example. The present invention is not limited to the embodiments described above, and can be implemented in various modified forms.For example, the defective sector information written in a specific area may be the serial sector number of the sector containing the defect, or the track number. It is clear from the above equation that a physical address that is a combination of a head number and a sector number may also be used. Furthermore, the serial sector number does not necessarily have to be a physical serial sector number as in the embodiment, and although the operation flow of the address conversion means is slightly complicated, it is a logical serial sector number for the disk storage device. It is also possible to use a sector number. Regarding the location where the specific area is provided, it is not limited to the first sector in the embodiment, but may be provided at the end sector or intermediate sector, and the flow and constants in the formatting means and address conversion means may be changed as appropriate. This makes it easy to implement. Also, it is of course possible to set the specific area over multiple sectors if necessary.For example, if the specific area is set in multiple intermediate sectors, all such sectors are considered to be defective. If the serial sector number or physical address is written in the area, there is no need to significantly change the flow of both methods.

【Effect of the invention】

Conventionally, recording capacity is lost track by track to compensate for a single defect in a disk, and at the current defect occurrence probability level, this takes up several percent of the total recording capacity. As described in detail, by implementing the present invention, it is possible to compensate for each defect by one sector, and therefore the loss of recording capacity can be reduced to 1710 or less compared to the conventional technology. However, one or two sectors are consumed to set up a specific area for writing defective sector information, but this is negligible among the tens of thousands of sectors in the entire disk storage device. In addition, it was thought that replenishing defects on a sector-by-sector basis would be a heavy burden on the software, but as can be seen from the example of Kamiyu, formatting means can be used to write defective sector information. It only requires adding a few operation steps, and since the address conversion means can be performed using a very simple flow including the same number of steps, the burden on the software is also light. The reading and writing operations are no different from the conventional ones. As described above, the present invention is expected to make a substantial contribution to improving the storage capacity of disk storage devices.

[Brief explanation of the drawing]

1 to 5 are for explanation of the present invention, of which FIG. 1 is a block circuit diagram showing an example of a disk storage device embodying the present invention from a hardware perspective, and FIG. 2 is a block circuit diagram of a disk storage device embodying the present invention. A flowchart illustrating the operation of the matting means from a software perspective; FIG. 3 is a flowchart illustrating the operation of the address conversion means in the apparatus of the present invention from a software perspective;
Fig. 4 is a layout diagram showing the sector arrangement within the entire disk surface of the device of the present invention, and Fig. 5 shows an example of the allocation of the recording area within the sector, and the allocation of the recording area of defective sector information within the sector as a specific area. The diagram shows an example layout. FIG. 6 is a track layout diagram showing the procedure for replenishing defects in track units in the prior art. In FIG. 0, 1.2: disk, 4: head, 5: head operation motor, 6: read/write circuit, 7: demodulation circuit, 8: mask signal generation circuit, to, 2o: processor, 21: interface circuit, 22: data control circuit, 23: signal conversion circuit, 24, 25: bus, 30: formatting means, 40 near address conversion Means, 100: disk storage device or its drive unit, 200; controller attached to the disk storage device, 300: bus, D: defect, Dl
: defective sector information, HC: head operation command, R3: head selection m command, IDX: interior. index pulse, IDXe: external index pulse,
+ (= O~p): Variable representing the serial sector number, j (
0 to q): Variable representing the head number, K (= Q − r
): Variable representing the sector number, it: Variable representing the logical serial sector number, n: @y Variable representing the logical serial sector number, R3: Read signal, R11: Read/write command, S: Sector, 31 ~517: Operation step as formatting means, 518~S20 Operation step as near address conversion means, -8: Write signal, first
Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1) In a disk storage device in which information is read and written in sector units, and is equipped with formatting means for setting the sectors in a predetermined format within the disk surface, An area for recording defective sector information regarding sectors containing defects is set at a specific location within the disk surface, and the formatting means includes means for writing defective sector information in the specific area, and an address specifying information to be read and written. Address conversion means is provided for calculating the physical address within the disk surface of the non-defective sector in which the addressed information should be read or written based on the received address and the defective sector information recorded in the specific area. Disk storage. 2) A disk storage device according to claim 1, characterized in that the defective sector information recorded in the specific area by the formatting means includes the track number, head number, and sector number of the sector containing the defect. Device. 3) A disk storage device according to claim 1, wherein the specific area in which defective sector information is recorded is a non-defective sector. 4) In the apparatus according to claim 3, the defective sector information recorded in the specific area includes a continuous sector for defect-free sectors excluding a specific area on the entire disk surface of the defect-free sectors following each sector containing a defect. A disk storage device characterized in that a number is included.