JPH10241289A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an erroneous writing at the abnormality of sector pulse by performing time monitoring from a servo data till an object sector at the time of write-in to a recording medium in a magnetic disk device using an ID-less format. SOLUTION: In a write-in to a recording medium 7, a microcontroller 3 instructs the number of sectors from the servo data till the object sector to a formator control 2. A window pulse generating counter 8 generates a window pulse at a timing when the sector pule of the object sector is to be detected. A sector pulse monitoring part 1 releases the mask of a write gate only in the case it detects the sector pulse when the window pulse is '1', to permit the write-in to the recording medium. The part 1 blocks the write-in to the medium in the case it detects the sector pulse when the window pulse is '0'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive using an ID-less format and having a function of preventing erroneous writing.

[0002]

2. Description of the Related Art A magnetic disk device has ID information for each data sector as means for identifying a target sector, and writes and reads data when the ID information on a recording medium matches the ID information expected as the target sector. Was allowed.

[0003] Today, as a method of increasing the recording capacity and improving the performance of a magnetic disk device, there is an IDless format system in which the ID information is omitted to improve the recording density and the transfer rate. This is a method of indirectly specifying the address of a target sector by means such as ID information of a servo data portion or counting of the number of sector pulses in a servo data section.

In the IDless format method, there is no means for direct ID matching between a target sector and a sector to be actually accessed.
When generating the CC byte, calculate including the ID information,
If writing to or reading from an erroneous sector is performed, there is a method of reporting an ECC error at the time of reading.

Further, as described in Japanese Patent Application Laid-Open No. 8-321142 (Japanese Patent Application No. 7-126729), an erroneous sector due to an erroneous detection of a servo sector (servo data portion) or an undetectable address is detected. There is a method of preventing the destruction of user data due to writing to the host and the transfer of erroneous data to the host computer due to reading from an incorrect sector.

[0006]

However, in the above-described conventional method alone, for example, the address of the servo data portion is guaranteed, and even if the address is in the correct servo data section,
When there is an abnormality in the sector pulse, the arrival at the target sector is detected at an incorrect position, and writing to the wrong sector may be performed. As for the erroneously written sector, it is possible to detect that the written data is incorrect due to ECC data guarantee or the like at the time of reading. However, the writing was not performed for the target sector that was supposed to be written. Cannot be detected.

Further, since the means for guaranteeing ECC data and the like are executed at the time of reading, a write failure cannot be reported for a write command from the host computer in which erroneous writing has been performed. The loss of the original data of the sector cannot be prevented.

In order to solve the above-mentioned problems, the present invention should further prevent erroneous detection of a data sector after arriving at a correct servo data section, destroy data due to erroneous writing to an erroneous sector, and write data. The purpose of the present invention is to prevent the loss of data.

[0009]

According to the present invention, in order to attain the above object, the number of sector pulses which reach the servo data section of the target sector and are expected as the target sector at the time of writing to the disk-type medium are obtained. A means for detecting and monitoring the time until the data is detected, and a means for suppressing data writing when the time is out of a prescribed range.

Further, one of the generation means for generating the sector pulse and the definition means for defining the time required to detect the expected number of sector pulses as the target sector is a hardware circuit using a logic circuit. The output is created by software, and the other means is created by software by a microprogram. Furthermore, by using different or contradictory means, methods, styles, forms, parts, configurations, design ideas, etc. for both means of the generating means and the defining means,
Both means can be monitored and detected simultaneously without failure.

According to the present invention comprising such means, before writing to a recording medium,
Since an abnormality in the sector pulse can be detected, writing can be suppressed, and an error can be reported, it is possible to prevent loss of data written to the target sector from the viewpoint of the host computer.

Since writing to the wrong sector is not performed, it is possible to prevent the original data of the wrong sector from being lost.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 are views showing an embodiment according to the present invention.

FIG. 1 is a schematic configuration diagram of the present embodiment. In the figure, 1 is a sector pulse monitoring unit, 2 is a formatter controller, 3 is a microcontroller, 4 is a sector pulse generation counter, 5 is a servo data detection unit,
Reference numeral 6 denotes a signal processing unit, 7 denotes a recording medium, and 8 denotes a window pulse generation counter. The above configuration will be described with reference to FIG.

A track or a cylinder of a recording medium such as a hard disk according to the embodiment of the present invention has a plurality of data sectors without an ID, and a tracking servo is performed for an appropriate number of data sectors. A servo data part necessary for the operation is formed. As an example, according to FIG. 2, a servo data section having one servo data section includes three data sectors.

To search for a target sector, first, a corresponding track or cylinder is selected based on the ID data in the servo data section, and a specific servo data section within the track or cylinder is selected. Next, the target sector in the servo data section is specified by searching the number of sectors in the section and searched.

When writing data to the recording medium 7,
The microcontroller 3 instructs the formatter controller 2, which is one component of the HDC, with the number of sector pulses from the servo data in the servo data section including the target sector to the target sector. When the servo data detection unit 5 detects the target servo data based on the reproduction data from the recording medium (see (1) in FIG. 2), it starts the sector pulse generation counter 4 (see (2) in FIG. 2). ), And generates a sector pulse (see (3) in FIG. 2).

At this time, the section of the data sector is designed to correspond to an appropriate count number of the generation counter 4. Therefore, the falling edge of some number of the generation counter becomes the start time of the next sector, and at this time the sector pulse (see (3) in FIG. 2) rises. In other words,
A timer, which is hardware called the generation counter 4, generates a sector pulse indicating the head position of the target sector.

In general, the formatter controller 2 counts the number of sector pulses. When the number of sector pulses reaches the specified number, the formatter controller 2 determines that the target sector has been reached and permits writing. As a result, the formatter controller 2 asserts (stands up or validates) the write gate and executes data writing on the recording medium.

On the other hand, in the present embodiment, the time until the front edge of the sector pulse of the target sector is detected in the above is uniquely determined from the track format, so that the servo data detecting section 5 detects the target servo data. Is reported to the microcontroller 3, and based on the servo data, the microcontroller 3 starts and operates a microprogram counter (counts by executing the created program) (see (4) in FIG. 2). ), A window pulse is generated at a specified timing at which the leading edge of the sector pulse of the target sector is to be detected (see (5) in FIG. 2). In other words, the time at which the sector pulse from the hardware sector pulse generation counter 4 should indicate the head position of the target sector is the window pulse from the software window pulse generation counter 8 (see (5) in FIG. 2). Is set within the range of “1”.

When detecting the leading edge of the sector pulse of the target sector while the window pulse is "1", the sector pulse monitoring unit 1 releases the mask of the write gate (FIG. 2).
(6)), the write gate signal generated by the formatter controller 2 is validated. Here, the write gate 1 from the formatter controller 2 automatically outputs the write gate 1 when the number of sector pulses from the servo data corresponds to the appropriate number of sectors for the target sector. Even when an error occurs and a sector pulse is missing, the write gate 1 is output when the number of sectors reaches an appropriate number.

If a sector pulse is present during the window pulse "1", the mask outputs "1", and the write gate 1 is ANDed with this mask to create a write gate 2, thereby producing a write gate 2. It is determined whether or not writing to the recording medium 7 is executed.

If the leading edge of the sector pulse of the target sector is detected when the window pulse is "0", the mask of the write gate is not released (the mask is "0"). Even when the gate 1 is asserted (valid), writing to the recording medium is suppressed.

As described above, in the embodiment of the present invention, I
As a means of monitoring the time required to detect the expected number of sector pulses as the target sector in the D-less format method, the time from the detection of servo data to the leading edge of the sector pulse of the target sector is executed on the microcontroller. The write gate is masked by a logic circuit as one means for suppressing writing of data when the time is out of a specified range, defined by a window pulse generated by a microprogram.

Although not particularly shown in FIG. 1, the exclusive OR of the write gate signal 1 generated by the formatter controller 2 and the write gate signal 2 output via the sector pulse monitoring unit 1 is calculated. By reporting the fact that writing to the recording medium has not been executed to the microcontroller 3 as an error, a write failure status can be returned to a write command from the host computer.

Further, by starting the retry from the microcontroller 3, normal writing to the recording medium can be expected.

As described above, even if an abnormality occurs in a sector pulse and a sector pulse is generated at a timing different from that of an actual target sector, writing to a recording medium is not performed, so that irrelevant sectors are prevented from being destroyed. In addition, normal writing to the target sector can be expected by means such as retry.

Further, in the above embodiment, the window pulse generating means for defining the time from the detection of the servo data to the leading edge of the sector pulse of the target sector as one means for detecting the abnormality of the sector pulse of the target sector. A certain “window pulse generation counter 8” and a “sector pulse generation counter 4” which is a means for generating sector pulses are different from each other (the counters 3 and 4 are different).
And a different method (the former is software and the latter is hardware). Thus, by realizing the generation of the pulse defining the time to the target sector and the generation of the sector pulse by completely different or contradictory means, methods, styles, forms, parts, configurations, design ideas, etc. , Which can lead to simultaneous occurrence of abnormalities.

In the configuration shown in FIGS. 1 and 2, for example, the sector pulse generation counter 4 is configured in hardware by a logic circuit such as an integrated circuit, and generates a window pulse for detecting abnormality of the sector pulse. If the window pulse generation counter 8 to be generated is constituted by a logic circuit incorporated in the same integrated circuit or the like, if an abnormality occurs in the sector pulse, it is sufficient that the integrated circuit itself is in an abnormal operation. The window pulse may not be generated correctly.

In the present embodiment, the sector pulse generation counter 4 is configured in hardware by a logic circuit such as an integrated circuit, and a window pulse generation counter 8 for generating a window pulse for detecting an abnormality of the sector pulse is provided.
By executing a microprogram on the microcontroller, the function is realized in software. Thus, even if an abnormal sector pulse is generated due to a hardware failure of an integrated circuit or the like, it is possible to reduce the possibility that the generation of the abnormality detection window pulse is simultaneously affected by the failure.

In this embodiment, the generation of the sector pulse is performed by hardware means, and the generation of the window pulse for abnormality detection is performed by software means. The generation of the abnormality detection window pulse may be performed by hardware means.

Although the generation of the sector pulse and the generation of the abnormality detection window pulse are both performed by hardware means, it is also possible to incorporate each logic circuit into a different integrated circuit.

Although the generation of the sector pulse and the generation of the abnormality detection window pulse are both performed by software means, the respective microprograms are executed on different microprocessors, and the memories for storing the microprograms are provided separately. Means of making parts may be used.

Further, regarding the two means, a means for generating a sector pulse and a means for monitoring the time until the expected number of sector pulses are detected as a target sector, if the former is generated by a logic circuit, the latter is controlled by a microprogram. Monitoring, or conversely, if the former is generated by a microprogram, the latter is monitored by a logic circuit,
Furthermore, if the former is generated by a logic circuit, the latter is monitored by a logic circuit composed of components different from the former, or conversely, if the former is generated by a microprogram, the latter executes the former. Monitoring by a microprogram executed by a microcontroller separate from the microcontroller that is running, or, if the former is generated by a microprogram, the latter is separate from the memory that stores the former microprogram. Monitoring and detection by different or contradictory means, methods, methods, styles, forms, parts, configurations, design ideas, etc., such as configurations monitored by microprograms stored in memory, and some functions May be hardly affected by the abnormal state.

In the present invention, a disk-type recording medium other than a magnetic disk, for example, a magneto-optical disk or a write-once optical disk may be used.

[0037]

According to the present invention, in a magnetic disk drive using an ID-less format, erroneous writing due to abnormal sector pulses can be prevented before writing to a recording medium. The data in the sector that should have been lost is protected.

Further, since erroneous writing can be detected during processing of a write command from the host computer, normal writing can be expected by retry or the like. Even if writing cannot be performed, a write failure status is given to the host computer. , The host computer has an opportunity to perform error processing and perform recovery processing such as rewriting to another sector.

Further, by using means, methods, styles, forms, parts, configurations, design ideas, and the like that are different or contradictory to the generation of the sector pulse and the generation of the window pulse for abnormality detection, the abnormality detection can be performed. The certainty is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a signal waveform and an operation description in the configuration of the present invention in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sector pulse monitoring part 2 Formatter controller 3 Microcontroller 4 Sector pulse generation counter 5 Servo data detection part 6 Signal processing part 7 Recording medium 8 Window pulse generation counter

Claims (6)

[Claims] 1. A magnetic disk drive for writing and reading data to and from a target sector of a disk-type recording medium using a format having no ID information for each data sector, comprising: A servo I for positioning the magnetic head on the cylinder where the target sector exists.
D, identifying that the servo data section including the target sector has been reached by the detection of the servo ID, starting a counter with the servo data section as a base point, and locating a data sector existing in the servo data section. By generating a sector pulse indicating the number of sector pulses, the address of the target sector on the cylinder is specified.When writing to the recording medium, after reaching the servo data section including the target sector, A time period until a number of sector pulses expected as a target sector is detected, and when the expected sector pulse is not detected at the specified time, data writing is suppressed. Disk device. 2. A magnetic disk drive for writing and reading data to and from a target sector of a disk-type recording medium using a format having no ID information for each data sector, comprising: A servo I for positioning the magnetic head on the cylinder where the target sector exists.
D, identifying that the servo data section including the target sector has been reached by the detection of the servo ID, starting the counter with the servo data section as a base point, and locating the data sector existing in the servo data section. By generating a sector pulse indicating the number of sector pulses, the address of the target sector on the cylinder is specified.When writing to the recording medium, after reaching the servo data section including the target sector, A window pulse is generated at the time of detecting the expected number of sector pulses as a target sector, and whether to permit data writing is determined depending on whether or not the expected sector pulse exists within the pulse width of the window pulse. A magnetic disk drive for determining whether to suppress. 3. The magnetic disk drive according to claim 1, wherein the generating means for generating the sector pulse and the defining means for defining a time until a number of sector pulses expected as a target sector are detected are: A magnetic disk drive characterized in that one of the means creates its output by hardware using a logic circuit and the other creates its output by software based on a microprogram. 4. The magnetic disk drive according to claim 1, wherein: the generating means for generating the sector pulse; and the defining means for defining a time until detecting a number of sector pulses expected as a target sector, A magnetic disk drive comprising different components. 5. The magnetic disk drive according to claim 2, wherein the generation means for generating the sector pulse generates its output by hardware using a logic circuit, and the generation means for generating the window pulse includes a micro-program. A magnetic disk drive, wherein the output is generated by software according to (1). 6. The magnetic disk drive according to claim 1, wherein, when an abnormal state occurs in which data writing is inhibited, the abnormal state is reported to a higher-level device. Characteristic magnetic disk drive.