JPS6129462A - Control circuit of information recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize improvement of reliability of effective information, selection control or improvement of information recording reproducing device by increasing bit numbers of effective information or error detection information recordable in an information recording medium. CONSTITUTION:When the error detection circuit 46 detects coincidence, an output signal of an AND circuit 54 goes to a level 1, an information read circuit 32 or an information write circuit 33 records/reproduces the effective information to a magnetic disc device 21. Thus, a cylinder number as ID information and a check bit to head numbers and sector numbers are recorded on an ID information recording area. Then the share of the ID information to all information is decreased and the recording area of the effective information excluding the ID information is increased relatively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a control circuit for an information recording/reproducing apparatus using a magnetic disk or a floppy disk as an information recording medium.

[Technical Background of the Invention] In an information recording and reproducing device, for example, a magnetic disk device that uses a magnetic disk as an information recording medium, selection control information called ID information is used as effective information when recording and reproducing information. It is used as index information.

By the way, as is well known, as shown in FIG. 3, a magnetic disk is constructed by stacking a plurality of disks 12 on which a plurality of recording tracks 11 are set concentrically on the surface. One recording cylinder is composed of corresponding recording tracks. Further, one disk 12 is divided into, for example, 32 unit information storage areas (sectors) at equal angles, and each disk 12 is further provided with a head (not shown) for recording and reproducing information. Each sector on the magnetic disk 12 is distinguished by a combination of numbers assigned to the cylinder, head, and sector.

In conventional magnetic disk devices, the above selection control information (ID
Control is performed by mutually transferring information (as shown in FIG. 4) to and from the control circuit. This ID information consists of cylinder number, head number, sector number information, and CRC (cyclic redundancy check) or FCC (error correction code) check information for these. Conventionally, this information was used as index information. recorded on a magnetic disk. That is, when formatting a magnetic disk, the above ID information is written on the disk to secure the sector location, and when writing or reading information, the above ID information is read from the disk and checked to see if it matches the corresponding ID information. A control circuit determines whether or not there is a match, and writes/reads information regarding the effective information portion of the matched sector.

[Problems of the Background Art] Conventional magnetic disk drives record the above-mentioned various types of information as ID information, so this ID information occupies a large proportion of the total information. As a result, the recording area for effective information other than ID information is relatively reduced, especially the number of sectors within one track is reduced, and the disc has a gap area called a margin area that takes into account rotational unevenness. is set, and this gap area decreases and the disk margin decreases.
The number of bits for error detection/correction check hits for zero information or effective information is relatively reduced and reliability is lowered, and the disk has an area for recording synchronization information for synchronizing information. is set, and there are drawbacks such as the area of this synchronization information decreases and the synchronization operation becomes unstable.

The ratio of ID information to the total information is, for example, if the size of one sector is m bytes and the number of bits of ID information, which is an index representing the number of all sectors, is n bits, then the amount occupied by the effective information is: is m×2n. At this time, 10
The capacity occupied by information Vr is 2nxn/8 (bytes) T
- Yes, if ID information is separated by byte, 2nx
([n/8]+1). However, [n/8] is n/
Represents the integer closest to 8 and smaller than n/8. For example, if one sector is 256 bytes, m=2
In a magnetic disk having a capacity of I G (1-09) bytes, n is 22 bits, and the capacity Vi occupied by the ID information is approximately 11.5 Mbytes. Another 100M
In a (10B) byte magnetic disk, n is 19 bits, and the capacity Vl occupied by the ID information is 1.6M bytes, and each ■! occupies a non-negligible capacity.

[Purpose of the Invention] This invention has been made in consideration of the above circumstances, and its purpose is to increase the number of bits of effective information that can be recorded on an information recording medium, or to increase error detection information. By increasing the number of bits of the selection control information,
It is an object of the present invention to provide a control circuit for an information recording and reproducing device that can improve the reliability of the information recording and reproducing device by either improving the reliability of effective information or increasing the number of bits of synchronization information.

[Summary of the Invention] To achieve the above object, the present invention generates error detection angle information from ID information indicating a block address of effective information, and records this error detection information instead of the block address itself. I am trying to record it on the media.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of a magnetic disk device in which the control circuit of the information recording/reproducing apparatus according to the present invention is implemented. In the figure, 21 is a magnetic disk device. This magnetic disk device 21 records and reproduces information on a magnetic disk, and its operation is controlled by a control circuit 22. Reference numeral 23 denotes a host device such as a computer. Information D1 is supplied from the host device 23 to the control circuit 22, and information D2 is supplied from the control device 22 to the host device 23. Furthermore, information D is sent from the magnetic disk device 21 to the control device 22.
3 is supplied from the control circuit 22 to the magnetic disk device 21.
is supplied with information D4.

The control circuit 22 includes 10 control circuits 3 as shown in the figure.
1. Information reading circuit 32 and information writing circuit 33
It is composed of etc. When formatting a magnetic disk, the ID control circuit 31 generates check information from the ID information included in the information D1 supplied from the host device 23 and writes it to the magnetic disk, or writes the ID information itself to the magnetic disk. Write to disc. Roughly, the ID control circuit 31 reads information from the magnetic disk,
At the time of writing, the sector is determined from the check information or ID information of the information D3 read from the magnetic disk device 21, and the operations of the information read circuit 32 and the information write circuit 33 are controlled according to the result of this determination.

The information reading circuit 32 is connected to the magnetic disk device 21.
This is for reading information D3 from .

The information writing circuit 33 writes information D to the magnetic disk device 21.
This is for writing 4. In addition, the control circuit 2
A command signal @C is supplied from 2 to the magnetic disk device 21, a status signal $1 is supplied from the magnetic disk device 21 to the control circuit 22, and a status signal s2 is supplied from the control circuit 22 to the host device @23. There is. The command signal C includes a signal corresponding to the head number for selecting a magnetic head (not shown) provided in the magnetic disk device 21.

Further, the cylinder number, head number, and sector number in the ID information are supplied to the magnetic disk device 21 as electrical signals from the control circuit 22 in a separate system from the ID information.

Figure 1 shows IDi! in Figure 2 above. 1IJI [1 circuit 3
FIG. 1 is a circuit diagram showing a specific configuration of FIG. The host device 2
The cylinder number and head number of the information D1 supplied from No. 3 are stored in storage circuits 41 and 42, respectively. Furthermore, sector August is stored in the storage circuit 43.

The cylinder number and head number stored in the memory circuits 41 and 42 are stored in a comparison circuit 44 and a check bit generation circuit 45.
and the error detection circuit 46, and the sector number stored in the storage circuit 43 is supplied in parallel to the check focus generation circuit 45 and the error detection circuit 46.

The check pit generation circuit 45 is connected to the memory circuit 41゜4.
CRC or E for these information from the cylinder number, sector number and head number stored in 2.43.
A check bit for CC is generated, and this check bit is supplied to the magnetic desulfur device 21 via the OR circuit 47 and the information writing circuit 33 as part of the information D4. Furthermore, the cylinder number and sector number stored in the storage circuits 41 and 42 are part of the information D4.
The signal is supplied to the magnetic desulfur device 21 via the AND circuit 48, the OR circuit 47, and the information writing circuit 33.

Of the information D3 read from the magnetic disk when writing and reading information in the magnetic disk device 21, the check bit is stored in the storage circuit 49, and the read cylinder number and read head number of the information D3 are stored. are stored in circuits 50 and 51, respectively. The information stored in the storage circuit 49 is then supplied to the error detection circuit 46, and the information stored in the storage circuit 50 is supplied to the error detection circuit 46.
．． The information stored in 51 is respectively supplied to the comparison circuit 44.

The comparison circuit 44 includes memory circuits 41.42 and 50.51.
The stored cylinder numbers and sector numbers are compared for coincidence, and the comparison result signal is supplied to the AND circuit 52. The output signal of this AND circuit 52 is supplied to an AND circuit 54 via an OR circuit 53.

The error detection circuit 46 detects errors from the check bit read from the magnetic disk and the cylinder number, head number, and sector number stored in the storage circuits 41, 42, 43, and the detection result signal is output from the AND is supplied to circuit 54.

Further, an index signal corresponding to the reference position of rotation of the magnetic disk included in the status signal S1 is detected by an index detection circuit 55, and a detection output signal of this index detection circuit 55 is transmitted to the AND circuit 48. It is supplied directly to the AND circuit 52 and also to the OR circuit 53 via the inverter 56.

Next, the operation of the circuit configured as described above will be explained. Basically, the operation of this circuit is as follows: Information D1 is sent from the host device 23.
an information write operation in which information is received and written to the magnetic disk device 21; an information read operation in which information D3 is read from the magnetic disk device @21 and sent to the host device 23; It consists of formatting operations for writing data, allocating sectors to magnetic disks, and other operations.

During the formatting operation, the check pit generation circuit 45 generates CRC or ECC check bits for these pieces of information from the cylinder number, head number, and sector number stored in the storage circuits 41, 42, and 43. Therefore, the check bit generated here is OR circuit 4
7 to the magnetic disk device 21 as part of the information D4, and then recorded in the corresponding ID information recording area of the magnetic disk.

On the other hand, when the index signal is detected by the index detection circuit 55, the AND circuit 48 is opened, so in this case, the memory circuit 41.
The cylinder number and head number themselves stored in 42 are supplied to the magnetic disk device 21 as part of the information D4, and are then recorded in the corresponding ID information recording area of the magnetic disk.

The above index signal is generated once every rotation of the magnetic disk, so for 32 sectors in one track of one magnetic disk, the information recording area after the index signal contains the cylinder number and ID information as ID information. The head number is recorded, and the ID information recording area of 32 sectors contains the I
A check bit is recorded as D information.

When writing or reading information, the error detection circuit M4B detects the memory circuit 41 before writing or reading effective information.
．． Error detection is performed from the cylinder number, head number, and sector number stored in the memory circuit 42.
42. It is detected whether or not they match the sectors corresponding to the cylinder number, head number, and sector number stored in 43.

If they match, the AND circuit 54 outputs #I
An I+ level signal is supplied. At this time, the index detection circuit 55 detects the index signal and its output signal is set to the "0" level, so the output signal of the inverter 5G is set to the "1" level. Therefore, when the output signal of the error detection circuit 46 is set to ``1'' level, the output signal of the AND circuit 54 is set to ``1'' level.
Become a rubel.

That is, in this case, the correct sector is selected in the magnetic disk device 21, and when the output signal of the AND circuit 54 is at the 1 level, the information reading circuit 32 and the information writing circuit 33 are enabled to operate. teeth,
The information reading circuit 32 or the information writing circuit 33 records and reproduces effective information on the magnetic disk device 21 .

If sector matching is not detected during error detection in the error detection circuit 46, the next ID from the magnetic disk is detected.
The check bit recorded in the information recording area is extracted and error detection is performed in the same manner. If the index signal is detected by the index detection circuit 55 while no coincidence is being detected, the AND circuit 52 is opened. Since the cylinder number and head number themselves are recorded in the information recording area after the index signal is detected, the cylinder number and head number are read from the magnetic disk and stored in the storage circuits 50 and 51. Next, the comparison circuit 44 compares the cylinder number and head number stored in the memory circuits 41 and 42 with the memory circuit 5.
The cylinder number and head number stored in 0.51 are compared. If the two numbers match, the comparison circuit 44 outputs a signal of level 1111+ to the AND circuit 52. At this time, the index detection circuit 55
Since the output signal of the comparator circuit 44 is set to the "1" level, the AND circuit 54 is opened.
If the comparison results match, the check bit recorded in the ID information recording area of the next sector is read from the magnetic disk and stored in the storage circuit 49. Then, in the same manner as described above, error detection is performed by the error detection circuit 4G. If a match is detected during this error detection, the output signal of the AND circuit 54 is set to the 111 II level, and after this, the information reading circuit 32 or the information writing circuit 33 records the effective information on the magnetic disk device 21. Playback occurs.

Further, if the comparison results in the comparison circuit 44 do not match, or if no match is detected in the subsequent error detection operation, the second index signal is sent to the index detection circuit 44.
5, the IDllilJtll circuit 31 sends a status signal $2 meaning that the sector cannot be detected from the control unit (not shown) to the host device 23, and performs the next process such as retry.

In this way, most of the circuits in the above embodiment (1 track 3
2 sectors, including 31 sectors) ID information recording area.
Check pits for cylinder numbers, head numbers, and sector numbers are recorded as D information.

Therefore, the proportion of ID information in all information can be made smaller than in the past, and as a result, the recording area of effective information other than ID information can be relatively increased.

In particular, it is possible to increase the number of sectors within one track. Furthermore, instead of increasing the number of sectors, the gap area can be increased, and the margin of the disk can be improved. Furthermore, it is possible to relatively increase the number of bits of error detection/correction check pits for LD information or effective information, thereby improving reliability and increasing the area of the synchronization information. This also makes it possible to stabilize the synchronous operation.

By the way, in this example circuit, the check bits recorded on the magnetic disk are used to detect sector coincidence, but it should be noted that the probability of mistakenly detecting a different sector as correct is extremely small. We are using. The reason for this will be outlined below. The FCC generator polynomial G(X) is defined as G(x)=(x21+1)(xll+x2
+1) indicates that the probability that another sector will be mistakenly selected and several check bits will be read incorrectly during detection and coincidentally coincide with each other is extremely small. The polynomial of the difference between the correct check bit and the incorrectly read check bit is R(X), and I of the correct sector is
The polynomial of the difference between D information and ID information of another sector is expressed as P(x
), then the following equation must hold true in the event of a malfunction in which another sector is treated as a correct sector by chance.

x3z−P(x) =G (X) Q (X) +R, (X)= (X32
+X23 +X21 +X11+x2+1 )Q (
x)'+R(x)... 1 In the above equation 1, R(
X) is the remainder indicating the difference in check bits, and this R(
Even if x) is a few bits and has a short width, the bit width represented by P(x) contains many items and a wide range of information, which indicates that there is a large difference between another sector and the sector.

For example, when R(x)=x, P (x) =x +x2s +xi 9 +x9+
1... 2, and when R(X)=X31, P(x)=x31+x22+x +x +x...
3, and the bit width indicated by P(x) becomes larger.

Therefore, the probability of mistakenly detecting another sector as correct is extremely small.

Furthermore, in this example circuit, the cylinder number and head number are recorded in the information recording area after the index signal is detected among the 32 sectors, so that the comparison can be made with a probability of 1'2 when the first sector is detected. Thereby, reliability can be improved.

It goes without saying that the present invention is not limited to the above-mentioned embodiment and can be modified in various ways. For example, in the above embodiment, the present invention is applied to a control circuit of a floppy disk drive, but it can also be applied to a control circuit of a floppy disk drive.

[Effects of the Invention] As explained above, according to the present invention, by increasing the number of bits of effective information recordable on an information recording medium or increasing the number of bits of error detection information, selection control information and effective information can be The present invention provides a control circuit for an information recording and reproducing device that can either improve the reliability of the information recording or reproducing device by increasing the number of bits of synchronization information or by increasing the number of bits of synchronization information.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a control circuit of an information recording/reproducing apparatus according to the present invention, and FIG. 2 is a block diagram showing the configuration when the control circuit of the information recording/reproducing apparatus according to the present invention is implemented in a magnetic disk device. , FIG. 3 is a diagram showing a schematic configuration of a magnetic disk, and FIG. 4 is a diagram showing the selection control information (ID) in a conventional circuit.
FIG. 2 is a diagram showing the configuration of information. 21... Magnetic disk device, 22... Control circuit, 2
3...Hoss 1~device, 31...TD control circuit, 32
... Information reading circuit, 33... Information writing circuit, 41.42.43.49°50, 51... Memory circuit, 44... Comparison circuit, 45... Check bit generation circuit, 46. ...Error detection circuit, 55... Index detection circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (3)

[Claims] (1) Effective information for each block and selection control information indicating the block address at which this effective information should be recorded are recorded in a recording medium as a pair, and when accessing information, the effective information of the block address corresponding to the selection control information is accessed. In the control circuit of the information recording and reproducing apparatus, the error detection information is generated from the selection control information indicating the block address, and the error detection information is recorded on the recording medium as the selection control information indicating the block address. A control circuit for an information recording/reproducing device, characterized in that the control circuit is configured as follows. (2) Effective information for each block and selection control information indicating the block address at which this effective information should be recorded are recorded in a recording medium as a pair, and when information is accessed, the effective information of the block address corresponding to the selection control information is accessed. In the control circuit of the information recording and reproducing apparatus, the control circuit includes a first storage means for storing selection control information indicating a block address supplied from the host device, and an error detection method based on the selection control information stored in the first storage means. a second storage means for storing the error detection information recorded on the recording medium and read out when accessing the effective information; 1. A control circuit for an information recording/reproducing apparatus, comprising block address detection means for detecting a block address by detecting an error from information stored in a storage means. (3) Effective information for each block and selection control information indicating the block address at which this effective information should be recorded are recorded in a recording medium as a pair, and when information is accessed, the effective information of the block address corresponding to the selection control information is accessed. In the control circuit of the information recording and reproducing apparatus, the control circuit includes a first storage means for storing selection control information indicating a block address supplied from the host device, and an error detection method based on the selection control information stored in the first storage means. a first control means for generating information for use in the recording medium and recording it on the recording medium; and a first control means for recording the block address itself supplied from the host device in at least one recording area of the selection control information indicating the block address in the recording medium. A second control means for recording, a second storage means for storing the error detection information recorded on the recording medium and read out when accessing the effective information, and information stored in the first and second storage means. block address detection means for detecting a block address by performing error detection; third storage means for storing the block address itself recorded on the recording medium and read out when accessing effective information; and the first and third memories. 1. A control circuit for an information recording and reproducing apparatus, comprising block address comparing means for detecting a block address by comparing information stored in the means.