JPS6390072A - Initializing system for magnetic disk - Google Patents

Abstract

PURPOSE:To set up an optional sector format by selecting two types of sector formats in which the numbers of sectors and gap positions are different each other and executing an error test. CONSTITUTION:Formats A, B indicate sector formats to be used for error tests. The format A consists of 1100 bytes (B) in 9 sectors and the format B consists of 1996B in 5 sectors. The initial gaps g1 of both the formats A, B are 29B1 and gaps g3 between sectors are 30B. In both the formats A, B, the contents of respective sectors are constituted of an identification area ID consisting of 8B, a gap g2 consisting of 18B, a data area DA consisting of 1072B in the format A and a data area DA consisting of 1968B in the format B. Test data are written in both the sectors of the formats A, B to execute an error test. Since all gaps other than g1 and g2 are located on different positions, one gap corresponds to the other sector position at the time of executing two kinds of tests to detect an error, and a similar error can be detected in the other gap. Thus, an optional sector format can be set up.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an initialization method for setting a sector format on a magnetic disk.

[Prior Art] Magnetic disks, which are often used in computer systems, have a large number of circular tracks in the radial direction, which are divided into a plurality of sectors at equal angles in the circumferential direction, and data is stored in each sector. It is something that will be done. In this case, the number of tracks and the number of sectors can be configured in various ways depending on the application, etc., but as an example, the hard magnetic disk with a diameter of 3.5 inches or 5 inches, which is currently widely used, as shown in Fig. 4 is used. The configuration is shown below.

In the figure, a magnetic disk 1 is provided with a plurality of tracks 2, and each track 2 is provided with a track reference point (or line) 3 by hard means. A gap gl that is not used for data or the like is provided at the beginning of the scanning direction indicated by an arrow R with the reference point 3 as the starting point i. Subsequently, 32 sectors 4 are provided from the first sector [00]S to the 32nd sector [31coS, and a similar gap g3 is inserted between each sector. A gap gQ is provided after the last sector [31]. The number of bytes in each gap and sector is gI 29
B (hereinafter bytes will be referred to as B), g3 is 30B1, each sector 4 is all the same, 284B%, gq is 369B, and the total of these is 10°416B, which constitutes one track. Furthermore, as for the contents of each sector, as shown in the developed diagram, I+) for sector identification is 8B1 gap g2 is 1
The I)T for storing 8B1 data consists of 256 B, and the CRC as an error check code consists of 2 B. Although not shown, clock pulses are also recorded along the track 2.

When manufacturing the magnetic disk 1, the first step is to inspect the magnetic disks 711 in an analog manner for the quality of the magnetic medium, and the second step is to assemble a plurality of magnetic disks into a disk driver. , Again, an analog sector middle error test is performed. In this case, the sector format is fixed as described above.

However, users of magnetic disks do not necessarily limit their use to the fixed format set above, and users are free to set sector formats other than the above. In fact, this kind of thing is often done. In such a case, the error test for sector qL described above has a drawback. In other words, in the first-level error test, it is checked only whether an error has occurred in the sector, but it does not go so far as to identify and indicate the byte or bit in error in the sector. Not done. Further, since no test data is written to all the gaps gt x g', g3 and g//, the error test is omitted. Therefore, if the cause of the error exists in one of the gaps,
When setting a sector format different from the initial one, it may happen that the gap corresponds to the sector position of the used standard format and cannot be used. Also, all gaps are free of defects that cause errors, but even when they are present in any sector, the byte or bit position of the error is unknown, so this can be avoided and the error does not exist. It is difficult to use only sectors.

It is desirable to have an initialization method that eliminates these drawbacks and allows a simple and reliable error test to be performed on the entire circumference of a track or a required portion, and to set an arbitrary sector format.

[Object of the Invention] In view of the shortcomings of the conventional magnetic disk initializer described in -, the present invention provides a simple digital method.
It is an object of the present invention to provide a method for initializing a magnetic disk in which a predetermined sector format is set after an error test has been performed over a sufficient track range to apply an arbitrary sector format.

[Means for Solving the Problems] The present invention provides a format initializer for a magnetic disk that sets sectors for storing a plurality of pieces of information at equal angles to circumferential tracks on the magnetic disk. The number of sectors in the sector formats differed from each other, and gaps immediately after the reference point of the track and gaps within the first sector were excluded. Select two sector formats in which all gap positions differ from each other, first set one of the formats, write test data, perform an error test using a phase margin window, and then set the other format. Set the format and perform an error test on the test data in the same way. After performing two error tests like this, a predetermined sector format is set.

In both of the above two error tests, the sector number to which the byte in which the error occurred belongs and the position of the byte from the reference point of the track are output.

[Operations] The conventional error testing method using a phase margin window only checks errors within a sector, but does not check errors caused by gap defects. On the other hand, in the error test described in "-", the positions of all the gaps in the two sectors are different from each other, except for the gap immediately after the reference point of the intra-sector track, the gap in the first sector, and the final gap. Since two types of sector formats are used and tested twice, - gaps in one type correspond to the position of the other sector and errors are detected, and vice versa. is detected 111 in one sector, and both perform error checking over the range of tracks necessary to set and use an arbitrary sector format.

In this case, among the gaps in the sector formats of various formats, the gap gt immediately after the track reference point and the gap g2 in the first sector are at the same position in each format, so there is no problem even if an error exists. It's something that doesn't exist.

Next, in the above error test, for the byte in which the error occurred, the sector number to which the byte belongs and the position (number of bytes) from the track reference point are output. When set and used, it becomes possible to specify sector numbers whose use is prohibited.

[Embodiment] FIG. 1 shows two sector formats A and B used for error testing in an embodiment of the magnetic disk initialization method according to the present invention.

In format A, the number of bytes in each sector is the same, 1100.
B, and consists of nine sectors from [00koS to [08koS]. In the B format, each sector is 1998B, and is composed of five sectors from [00S to [04S]. For both A type and B type, the first gap gl
is 29B1, and the gap g3 between each sector is 30B.

Next, for the contents of each sector, the ID for sector identification is 8B1 in both A format and B format, and the gap g2 following this is 18B1.
Also, the error check code CRC at the end of the sector
is 2B, which is the same as in the case of the 32 sector format explained in FIG.

However, the A format has a data DT of 1072B,
The B format is 1968B.

Now, in this invention, error tests are performed by writing test data to each of the two sector formats described in 1-1. No checks are done. However, in the two types described in 1-, except for the first gap gI and the gap g2 in the first sefter, all the other gaps are at different positions, so when performing the test twice using these, In one gap, an error is detected corresponding to the position of the other sector, and similarly, in the other gap, an error is detected in one sector. Regarding the difference in the position of the gap between the two, Figure 2 shows the number of bytes from the track reference point (expressed in kilobytes with one decimal place) for each of the A format and B format in kilobyte order. Shown in a numerical table. As is clear from the table, the positions of the gaps g2 and g3 do not match at all. However, regarding the last gap gq, although the position and length are slightly different, the error test is not performed on the gap gq that has a narrower range. On the other hand, the 32 sector format gq shown in Figure 4 is A format,
It is larger than any of the B-type gqs, and there is no problem as long as an error test is performed. When using any sector format, it is safe to exclude sectors included in this untested portion.

Note that the sector formats of format A and format B described in item 1 are just examples, and it goes without saying that other formats may be used as long as the gap positions are different from each other as described above. be. However, in principle, it is a good idea to select one of the two formats in which the number of sectors is not an integer ratio and the number of sectors is small.

Next, an error test performed in the magnetic disk initialization method according to the present invention will be described. Errors that occur in bytes or bits stored in a track include missing errors, overflow errors, and phase shifts due to jitter of code pulses relative to clock pulses. Since there is a certain margin for phase shift, a phase margin window for detecting bits with a phase shift within that margin is provided to check for missing and emerging errors.

FIG. 3 shows an embodiment of the processing routine for the magnetic disk initialization method according to the present invention. The processing starts at start (2), the A format is written at (2), and appropriate test data is written at (2). ■
According to the phase margin window described in 1.
The test data is read out, and the read data is compared with the reference data (the above-mentioned test data) in (2), and if there is no error, it is determined to be good. If there is an error, count the position of the error byte and [
output at [phase]. If ■ is good, move on to the next other format and perform the following steps in the same way as above: ■ B format writing, ■ writing test data, ■ reading test data using the phase margin window, and ■ comparing read data and reference data. It will be done. If it is bad, the position of the error byte is output in [phase], if it is good, the specified sector format is written in [phase], the format is checked in O, and if it is good, the process ends. do. If there is an error in the format, the defective position is also output in [phase].

[Effects of the invention] In the conventional magnetic disk initialization method,
Since there is no error checking for gaps within sectors and between sectors, there was a risk of errors occurring when using a sector format other than the one set in the initializer.However, with this invention, magnetic disk initialization In the method, the first gap, which is common to all sector formats,
Except for the gap in the first sector and the last gap, all other gaps are tested for errors, so
This has the effect that the user can freely use the magnetic disk by setting any sector format. Furthermore, this method can be easily implemented using a conventional initializer by simply selecting sector formats and performing two error tests using them. Furthermore, by applying this initialization method, it is possible to omit the conventional second-stage analog method error test mentioned at the beginning, which has a great effect.

[Brief explanation of the drawing]

FIG. 1 is a byte configuration diagram in an embodiment of two sector formats used in the magnetic disk initialization method according to the present invention, and FIG. 2 is an explanatory diagram of a numerical table showing the gap positions of the sector format of FIG. 1. , FIG. 3 is a flow diagram showing an embodiment of the initialization processing routine in the magnetic disk initialization method according to the present invention, and FIG. 4 is an explanatory diagram showing an example of the byte structure of a track of a hard magnetic disk. . 1...Magnetic disk, 2...Track, 3...
...Reference point (line), 4...Sector, ■~[Phase]・
...The code of the initialization processing routine.

Claims (2)

[Claims] (1) In a magnetic disk format initializer that sets a plurality of information storage sectors at equal angles to a circumferential track provided on a magnetic disk, the number of sectors in the sector format is different from each other, and the track standard is Select two sector formats in which the positions of both gaps, excluding the gap immediately after the point and the gap in the first sector, are different from each other, set one of the two formats, and Write test data to a sector in the sector format, perform a data error test using the phase margin window, set the other format, write test data to the sector in the sector format, and perform a data error test using the phase margin window. A magnetic disk initialization method that is characterized by setting a predetermined sector format after performing a data error test. (2) In the above error test, the magnetic disk according to claim 1 is characterized in that the sector number to which the byte in which the error occurs and the position of the byte from the reference point of the track are output. initialization method.