JPH04134688A - Storage device - Google Patents

Abstract

PURPOSE:To start an address retrieval immediately after detecting a track position by detecting the one rotation of a track by either a number of read times of address or the lapse time of the address retrieval. CONSTITUTION:An address coincidence detecting circuit 31 compares sector address information with address information held in an instruction register 28, and in the case of a coincidence, a coincident signal is generated. When a sector counter 32 counts a sector number constituting one track, the coincident signal indicating the one rotation of the track is outputted from a coincidence detecting circuit 38. A timer counter 39 counts the lapse time of the address retrieval by counting the clock of a timer clock generating circuit 33. A coincidence detecting circuit 34 compares the coincidence between the counted value of the counter 39 and a time set value stored in the instruction register 28. A completion detecting circuit 35 generates a completion signal when the coincidence detection of either of the coincidence detecting circuits 31, 34 and 38 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a storage device using a rotating storage medium such as a magnetic or magneto-optical disk, and a track rotation detection circuit for detecting one rotation of a track of this storage medium.

[Prior Art] FIG. 7 shows the internal structure of a rotating magnetic disk memory. In FIG. 7, the rotating magnetic disk memory 1 is provided with track groups in the circumferential direction of rotation from the rotation center 6, and each track 2 is mainly composed of an index mark 4 and a sector group 3. The remaining space between the index mark 4 and the sector group 3 is filled with delimited data called gaps. The magnetic head 5 (hereinafter referred to as head) moves on the rotating magnetic memory 1 in the direction of the arrow in FIG. 1, then stops at a desired track position, and reads and writes (accesses) information to that track.

The head 5 that has stopped at the track position to be accessed detects the reference position of the track by detecting index mark information 8 from the read information. In addition,
Apart from this method, an apparatus is also known in which a detection section other than the head 5, such as an optical sensor, is provided, and the reference position of the track is detected by using this detection section to detect the pressure of a plurality of index holes provided in the disk.

FIG. 8 is an explanatory diagram in which the configuration on the track in FIG. 7 is redrawn on a straight line in time series.

In FIG. 8, the first index mark 4a is the seventh
The figure shows the time point at which the index mark 4 is first detected, and the second index mark 4b shows the time point at which the track 1 circumferential index mark 4 is detected. Each sector 3
Inside is a sector address mark (not shown) followed by a sector address mark (not shown).
an address section 8 consisting of a sector address (not shown);
Data mark (not shown) and following data (not shown)
It consists of a data section 9 consisting of and a gap 10 connecting these sections.

In the rotating magnetic disk memory 1, data reading and writing operations are basically performed in sector units, but in order to perform data reading and writing operations in sector units, immediately before this,
It is necessary to confirm (check) that the head 5 is at the sector position (address) to be accessed.

The following methods are known as conventional sector address check methods. That is, (1) after moving a certain track to a desired position along the circumference, first, an index hole is detected, and from there until several index holes on the same circumference are detected, the access target is The most common method is to position the head by continuously comparing the detected sector address with the detected current sector address.

(2) After moving the track to a desired position along the circumferential direction, first, an index mark is detected, and sector addresses that are sequentially recognized as the desired sector address from here until several index marks are detected. Continuously performs matching comparisons.

In conventional devices, the sector position to be accessed on the track is searched in this way, but if the address information stored in this sector position is destroyed, the address match determination always results in a negative determination. The storage medium will continue to rotate. Therefore, in the conventional device, after detecting the reference position on the track in the track rotation detection circuit, when the reference position is detected again, the address of the predetermined position is not found and it is determined that the track has rotated once. At this time, the track rotation detection circuit generates an abnormality signal for terminating the address search for access.

[Problems to be Solved by the Invention] However, the conventional device has a problem in that if the index mark or index hole indicating the reference position of the track is destroyed during the address search, one revolution of the track cannot be detected. Ta. Therefore, in view of the above points, an object of the present invention is to detect the end of one rotation of a rotary storage medium even if a reference position mark provided on the rotary storage medium is destroyed during an address search. An object of the present invention is to provide a rotation detection circuit for a storage device that can perform the following functions.

[Means for Solving the Problem] In order to achieve such an object, the present invention continuously reads each sector address stored on a track of a rotating storage medium and compares it with a specified address. In a storage device that searches for the position of a specified address on the track, a first detection means detects one rotation of the track by counting the number of times the sector address on the track is read; a second detection means for detecting one rotation of the track by measuring the elapsed time from the start of the position search; and when receiving a detection signal from either the first detection means or the second detection means; The present invention is characterized in that it includes detection signal generating means for generating a rotation detection signal indicating that the track has made one rotation.

[Function] The present invention detects one rotation of the track based on either the number of address readings or the elapsed time of address search, so even if one rotation of the track cannot be detected due to a failure in reading the address, it can be detected based on the elapsed time. Rotation can be detected. Furthermore, since one rotation of the track is detected based on the number of times the address is read, there is no need to detect a reference position mark on the track as in the conventional method, and address search can be started immediately after the track position is detected.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a system configuration for reading data from a rotating magnetic disk memory.

In FIG. 1, a CPU control device 20 stores various data (described later) necessary for address retrieval of a rotating magnetic disk memory.
is sent to the write data bus 24, and the write selection signal 23 specifies a register for data storage.

Also, CPU! lI@device 20 uses read selection signal 25
specifies a register in the controller 21, and reads out the contents stored in that register via the read data bus 26.

The rotating magnetic disk device 22 has a disk rotating mechanism and a head scanning mechanism, receives various signals such as write data signals, step signals, ready signals, etc. from the controller 21, and not only drives the rotation of the rotating disk memory but also drives the head. By scanning, the head is positioned at an access position on the rotating disk memory.

The controller 21 performs operational control to position the head at an address position on the rotating magnetic disk monolith instructed by the CPU control device 20. CPU control device 20
Since the rotating magnetic disk device 22 and the rotating magnetic disk device 22 can be the same as conventional ones, a detailed explanation will be omitted.
Only the configuration related to No. 1 of the present invention will be explained.

The command register 28 stores address information and read/write instructions for read/write data received from the CPU control device 20, as well as various information for address search in the following internal registers. Register 40 stores the number N of sectors constituting one track. register 4
1 stores address information of data to be accessed.

The register 43 stores the time required for one rotation of the track under normal conditions as a numerical value M.

Further, each of the register groups is selected by a write selection signal 23, and the selected register stores information on the write data bus 24, so that it can be variably set. The sector address detection circuit 30 recognizes address marks and the like from the bit string of the read data 27 actually read from the rotating magnetic disk memory, and extracts sector address information from the read data.

The address/number configuration circuit 31 compares this sector address information with the address information held in the instruction register 28, and when both address information match, the address to be accessed on the magnetic disk memory is detected. generates a match signal indicating that the

Sector counter 32 is sector address detection circuit 30
Count the number of address detections. The counter number configuration circuit 38 calculates the count value of the sector counter 32 and the sector address of the access data, that is, the instruction register 28.
A match comparison is made with the address stored in .

When the sector counter 32 counts the number of sectors constituting one track, a coincidence signal indicating one rotation of the track is outputted from the coincidence detection circuit 38. The timer counter 39 registers the start instruction register 4 at the start of address search.
The timer clock generation circuit 3 is activated by the hold signal of 2.
The elapsed time of the address search is measured by counting the clocks of 3. - The number output circuit 34 is a timer counter 3
A comparison is made between the count value of 3 and the time setting value stored in the instruction register 28.

The completion detection circuit 35 generates a completion signal when one address search is completed. Specifically, the completion detection circuit 35
is a one-number output signal from one of the -number output circuits 3I, 34. A completion signal is generated when any one revolution is detected.

The read register 29 stores various information related to address retrieval of the rotating magnetic disk memory, which will be described later, to the internal register group 36.
．． 37. The address information recording register 36 is
The sector addresses sequentially detected by the sector address detection circuit 30 are recorded.

The status register 37 includes a plurality of register groups 45 to 48.
It stores information indicating the read status of the rotating disk memory. In this embodiment, the following information is stored.

Flag information (address match flag) indicating the comparison determination result of the address-number configuration circuit 38 is stored in the register 46.

The address match flag is turned on when the set address of the comparison address register 41 and the detected address of the sector address detection circuit 30 match, that is, when the head is located at the address to be accessed, for example, and turned off at other times.

The timer count end flag is stored in register 48. This flag information corresponds to the level of the output signal of the coincidence detection circuit 34, and is turned on when the timer counter 39 counts up, and turned off at other times.

The count value of the sector counter 32 until the end of the address check, that is, until the address to be accessed is searched, is stored in the register 45. This count value is used to determine whether the address search has ended normally.

End flag information indicating whether or not the address check has ended is stored in the register 47.

The end flag information is on when a completion signal is output from the completion detection circuit 35, and off otherwise.

As described above, the information stored in the address information record register 36 and the status register 37 is sent to the read data bus 26 by the register designation of the read selection signal 25 of the CPU control device 20, and is read out by the CPU control device 20. Ru.

Based on this information, the CPU control device 20 detects the position of the address to be accessed in the rotating disk memory and determines whether there is an abnormality in the detection.

The address retrieval operation of the rotating magnetic disk memory in such a circuit will be explained with reference to FIG. In addition, the second
The figure shows the generation timing of each signal in FIG.

In this example, the first index mark 4a (eighth index mark) of a certain track is
The case where data in the second sector is accessed from (see figure) will be explained.

(A) Normal operation In FIG. 1, the controller 21 is the CPU control device 2.
When an access command and its address are received from 0, the received information is stored in each register in the command register 28. At this time, the register 40 has "N" as the number of sectors in one track, and the register 41 has the set address value "
2", and "M+α" is set and stored in the register 43 as a set comparison value for the timer counter. M represents the time for one rotation of the track. α is the waiting time for confirming the detection of one revolution. It's time.

Next, after the track position is detected using the conventional method,
When an address search start command is sent from the CPU control device 20 to the start command register 42 (at timing T in FIG.
l) The sector address detection circuit 30 and timer counter 39 each start operating.

The sector address detection circuit 30 collates the data read from the head of the rotating magnetic disk drive 22, and detects the address information of each sector (timings T2, T4, etc. in FIG. 3) every time the address information of each sector is detected. The address information is output to the address/number output circuit 31 and the sector counter 32.

The sector counter 32 counts the number of times address information is read each time address information is received.

On the other hand, the timer counter 39 indicates the address search start time T1.
It continues to measure the elapsed time.

Next, when address information indicating "2" is read from the rotating magnetic disk memory at timing T5 in FIG. As a result, the completion detection circuit 35 determines that the address search has ended, stops each of the above operations of the address search, and sets each circuit to an initial state in preparation for the next address search.

As a result, the status register 37 stores the number of sectors counted since the start of reading, the match flag "on," the end flag on, and the timer count end flag off.

The CPU control device 20 reads the register information mentioned above at a fixed period, and determines that the search was successful by turning on the match flag, by turning off the timer count flag, and by the relationship between the number of sectors and the number of sectors in one track, which is "N". 1
It can be confirmed that the magnetic disk memory has not rotated twice.

(B) Abnormal Operation Next, a case in which a specified address position cannot be detected on a certain track of the rotating magnetic disk memory will be explained using the timing chart of FIG.

In FIG. 3, first, a designated track is detected at timing Tll, and address search is started.

The sector address detection circuit 30 generates an address detection signal every time it detects that the read data 27 is address information. If noise occurs when reading the same address information as the designated address from the magnetic disk memory and the read data is distorted, then the determination result of the address-number output circuit 31 will be "inconsistent".

As a result, the rotating magnetic disk memory continues to rotate, and when the timer counter 39 measures the set time M+α, a coincidence detection signal is output from the minus number output circuit 34 (timing 14 in FIG. 3).

As a result, the information stored in the read register 29 becomes "coincidence flag off," end flag on, and timer count end flag on. At this time, the -number output circuit 34 operates as the second detection means of the present invention.

In the CPU control device 20, it is possible to know that one search process has been completed by turning on the end flag, and it is possible to know that the specified address could not be detected by turning on the match flag.

On the other hand, the address search fails and the number of times the address information is read is 1 before the timer counter 39 counts up.
When the number of sectors of the track reaches "N", a coincidence signal of "ON" is outputted from the counter-multiple sector output circuit 38, and the end flag is set to ON by the completion detection circuit 35. At this time, the match flag is "off" and the index count end flag is also "off". In this case, the counter number configuration circuit 38 operates as the first detection means of the present invention, and the completion detection circuit 35 operates as the detection signal generation means.

In this way, when either the number of times the address information has been read or the elapsed time of the address search reaches the corresponding specified value, it is determined that the magnetic disk memory has completed one rotation. Even if a reading failure occurs, the rotation of the magnetic disk memory can be reliably detected.

As explained above, in this embodiment, the address information matching process can be started immediately after the track position is detected, so compared to the conventional example in which address information matching is started after the reference position mark is detected. It is clear that the search processing time is reduced.

[Second example] FIG. 4 shows a circuit configuration of a second embodiment of the present invention.

This embodiment shows an example in which the track rotation detection function executed by the controller 21 in the first embodiment is achieved by software processing of the CPLI control device. In Figure 4,
The main control device 60 includes (: PU 63, read-only memory (ROM) 64, random access memory (RA)
M) 65, a timer (TIMER) 66, and an interface (Ilo) 67.
RAM6 according to the microcode written in
5. It exchanges information with the TIMER 66, 11067, etc., generates control commands, and controls the processing of information while reading and writing information in the data section on the rotating magnetic disk memory of the rotating magnetic device 22.

A demodulation circuit 61 is provided between the main control device 60 and the rotating magnetic disk device 22, and the demodulation circuit 61 demodulates the modulated read data 27 into a binary bit string.

Furthermore, in reality, various signals for driving the rotating magnetic memory 22 are connected between the main controller 60 and the rotating magnetic disk device 22, but for controls other than address check control, Since it is not important for the present invention, it will be omitted.

FIG. 7 is an explanatory diagram showing the configuration on the RAM 65.

The RAM 65 is composed of a command information memory area 70, a status flag memory area 72, and a work memory area 71. The instruction information memory area 70 stores a comparison address counter value (CAC) and a comparison address (CA).
, comparison timer counter value (CT), and address check start (CR). The status flag memory area 72 contains a sector counter match flag (ACR).
, a sector address match flag (AR), a timer counter match flag (TR), an area for storing a completion flag (ER), and an information storage memory area 75. The work memory 71 also has a sector counter (!IAC), a timer counter (IT(:)), and a sector address (WA). FIGS. 6(A) and 6(B) show the address check control. A processing sequence is shown.The processing sequence in this figure is a software sequence that directly replaces the address search operation of the controller in the first embodiment.

The CPU 63 detects and collates address information, counts the number of times the address information is detected, and detects one rotation of the track by executing the processing procedures shown in FIGS. 6(A) and 6(B).

[Effects of the Invention] As explained above, according to the present invention, address search can be started immediately after track detection.
The data read time is shortened by the time required for conventional reference position detection, and the rotation of the track 1 can be reliably detected even if an address read failure occurs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of the first embodiment of the present invention, FIG. 2 is a timing chart showing the timing of each signal generation during normal reading operation of the first embodiment of the present invention, and FIG. 3 is the embodiment of the present invention. 4 is a block diagram showing the circuit configuration of the second embodiment of the present invention. FIG. 5 is an explanatory diagram showing the storage area and storage contents of the RAM 65 in FIG. 4. , FIGS. 6A and 6B are flowcharts showing the processing procedure for address search and abnormality detection executed by the CPU 63 in FIG. FIG. 8 is an explanatory diagram showing accesses to a memory area of a rotating magnetic disk memory in a conventional example. DESCRIPTION OF SYMBOLS 1... Rotating magnetic disk, 2... Track, 3... Sector 4... Index mark, 4a... First index mark, 4b... Second index mark, 5... Read/write head, 6... Center of rotation, 7... Head movement direction, 8... Address section, 9... Part of data, 10... Gap section, 20... CPU control device, 21. ...Controller, 22...Rotating magnetic disk device, 23...Write selection signal, 24...Write data bus, 25...Read selection signal, 26...Read data bus, 27...Read Data, 28... Instruction register, 29... Read register, 30... Sector address detection circuit, 31... Address match detection circuit, 32... Sector counter, 33... Timer clock generation circuit, 34... Timer counter coincidence detection circuit, 35... Completion detection circuit, 36... Address information recording register, 37... Status register, 38... Counter coincidence detection circuit, 39... Timer counter, 40...Register for comparison sector counter, 41.
...Comparison address register, 42...Start instruction register, 43...Comparison index mark counter register, 45...Sector count register, 46...Address match flag register, 47... End flag register, 48... Timer count end flag register, 60... Main controller, 61... Read data demodulator, 62... Demodulated signal, 63... CPU. 64...ROM. 65...RAM, 66...TIMER, 67...Ilo, 70...Instruction information memory 71...Work memory 72...Status flag memory 75...Address information recording memory FIG. A4 Indian Soccer Mark Figure 7

Claims (1)

[Claims] 1) A storage device that searches for the position of a designated address on a track by successively reading out each sector address stored on a track of a rotating storage medium and comparing it with a designated address. a first detection means for detecting one revolution of the track by counting the number of times a sector address on the track is read; a second detection means for detecting one revolution of the track; and generating a rotation detection signal indicating that the track has made one revolution when receiving a detection signal from either the first detection means or the second detection means. A storage device comprising: a detection signal generating means;