JPH07117885B2 - Storage device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to data transfer of an apparatus including a storage unit and a control unit for controlling the storage unit, and particularly to data transfer from the control unit to the storage unit during a reproducing operation. The present invention relates to a method of sending a command signal and transferring data reproduced in a storage unit to a control unit in synchronization with a reproduction clock at a timing in response to this signal. Also,
The present invention relates to a storage device that handles a storage medium having a large number of medium defects as compared with an ordinary magnetic disk such as an optical disk or a magneto-optical disk.

[Prior Art and Problems Thereof] Generally, a storage device such as a magnetic disk includes a storage unit main body in which a storage medium is mounted, and a control unit that controls and manages the storage unit main body.

When reproducing data on a storage medium that has many medium defects such as dust and scratches, the frequency of the reproduction clock may fluctuate drastically or the reproduction clock may be extremely chipped. When trying to reproduce data in such a state, a state occurs in which the predetermined number of data is not transferred within one sector of the number of data transferred to the control unit. As a result, there are problems that the address of the next succeeding sector cannot be detected and the timing of the operation of the control unit and the sector of the storage unit cannot be synchronized, or a malfunction occurs during data transfer.

[Means for Solving Problems] In view of the problems of the above-described conventional techniques, an object of the present invention is that the frequency of the reproduction clock may fluctuate significantly or the reproduction clock may be extremely lacking. However, it is still another object of the present invention to provide a storage device capable of stable and reliable data transfer by detecting the state and taking a predetermined measure without causing malfunction.

The object as described above has a storage unit for storing information and a control unit for controlling the storage unit, and a control signal for instructing data transfer is provided from the control unit between the storage unit and the control unit. In a storage device in which a clock signal output to the storage unit and synchronized with data according to the control signal is output from the storage unit to the control unit, the control unit substantially matches the clock signal. It is achieved by a storage device comprising a basic clock having a frequency, and detecting an abnormality of the clock signal by comparing the basic clock with the clock signal.

It should be noted that the comparison means may be a counter or the like that detects a state in which a predetermined number of clocks are not transferred even if the clock signal has passed a predetermined time.

[Operation] According to the storage device as described above, since the state of the reproduction clock can be constantly monitored by the basic clock, an operation based on a data transfer error can be immediately performed when an abnormality occurs, and stable and reliable data transfer can be performed. It is possible to provide a storage device that can be used.

[Embodiment] Hereinafter, the storage device of the present invention will be described in detail based on a specific embodiment.

FIG. 1 is a schematic block diagram of the apparatus of the present invention.

In FIG. 1, reference numeral 1 is a control unit for instructing recording, reproduction, etc. in the storage unit, and management of recording and reproduction data, 2 is a storage unit containing a storage medium, and recording is performed according to an instruction from the control unit 1. Perform playback operation. For convenience of explanation, only four types of signal lines related to this embodiment are shown between the control unit 1 and the storage unit 2.

FIG. 2 is a schematic block diagram showing the structure of the most important part of the storage device of the present invention.

In the figure, 3 is an R-CLK counter for counting the clock (R-CLK) reproduced from the storage medium, and 4 is R-CL.
It is an abnormality detection counter that counts a basic clock (that is, INT-CLK) made to have a frequency almost equal to that of the K signal, and outputs a signal T-ERR when a predetermined number is counted. The T-ERR signal is a signal that is output when the R-CLK signal has not been transferred for the predetermined number of clocks even after the predetermined time, that is, the counting time by the abnormality detection counter 4, has passed, and indicates a data transfer error. There is. The counting time by the abnormality detection counter 4 is set so that it is completed within one sector. Reference numeral 5 is a memory for temporarily storing the data reproduced from the storage unit 2.

FIG. 3 is a diagram showing the timing of each signal of FIG. 2, and description will be given below with reference to this timing diagram. In FIG. 3, the solid line indicates normal operation and the broken line indicates abnormal operation. SCT is used as a signal name representing a sector mark, and is output when the sector mark recorded at the beginning of each sector is detected.

First, when the sector to be played back is detected, the sequence controller (not shown) composed of CPU etc.
-ENB signal is output to each counter 3,4. The R-CLK counter 3 and the abnormality detection counter 4 are brought into a countable state by the CNT-ENB signal. At the same time, the R-CLK counter 3 outputs an R-GATE signal to the storage unit 2 and commands the output of the reproduction clock (R-CLK) and the reproduction data (R-DATA).

In the normal operation, when the R-CLK counter 3 counts a predetermined number of R-CLK signals, the R-GATE signal is dropped to instruct the storage unit 2 to end the reproduction and stop the reproduction operation of the storage unit 2. As a result, R-DATA and R-CL from the storage unit 2
The K signal stops and the playback operation is completed.

On the other hand, when the count signal of the R-CLK counter 3 takes longer than the predetermined count time due to a defect in the storage unit 2 causing the playback signal to fluctuate significantly or an abnormal operation in which the playback clock is not transferred. (The broken line in FIG. 3 indicates that the reproduction time increases if the frequency of the reproduction clock slows during reproduction or if there is a dropout in the reproduction clock). It ends quickly and the T-ERR signal is generated. This T-ERR signal prohibits the transfer of reproduction data to the memory 5, and the R-CLK counter 3
Stop the operation and drop the G-GATE signal. Therefore, the storage unit 2 detects that the R-GATE signal is in the inoperative state and stops the reproducing operation. The abnormality detection counter 4 is set so that the counting time is always completed within one sector and has a time longer than the normal operation time. This is so that even if the recording area to the sector becomes long due to the fluctuation of the rotation of the spindle motor at the time of data recording, the transfer error can be surely detected at the time of reproduction.

The T-ERR signal is also connected to a sequence control (not shown), and when the sequence controller detects the T-ERR signal, an operation based on a data transfer error is performed.

The present invention is not limited to the above embodiment, and various modifications and applications are possible.

As described above, the present invention is characterized in that the control unit is provided with the basic clock having a frequency substantially equal to the reproduction clock signal, and the abnormality of the reproduction clock signal is detected by comparing the basic clock and the reproduction clock signal. Therefore, the configuration of the counter is not always essential, and various substitutions are possible.

[Effects of the Invention] As described above, according to the storage device of the present invention, the control unit is provided with the basic clock having a frequency almost equal to the reproduction clock, and the abnormality of the reproduction clock is detected by comparing with the reproduction clock. Since the configuration is adopted, the state of the reproduction clock can be constantly monitored, and when an abnormality occurs, the operation based on the data transfer error can be immediately performed, and the data can be stably and reliably transferred.

Further, as an embodiment of the present invention, when the counter is adopted as the comparing means, the counting time is set so as to be completed within one sector. It is possible to efficiently perform the reproducing operation by eliminating the adverse effect that it also spreads to.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of the apparatus of the present invention. FIG. 2 is a schematic block diagram showing the structure of the most important part of the storage device of the present invention. FIG. 3 is a diagram showing the timing of each signal in FIG. 1: Control part 2: Storage part 3: R-CLK counter 4: Abnormality detection counter 5: Memory

Claims (3)

[Claims] 1. A storage unit for storing information, and a control unit for controlling the storage unit. A control signal for instructing data transfer is provided between the storage unit and the control unit from the control unit. In a storage device in which a clock signal synchronized with data according to the control signal is output from the storage unit to the control unit, in the control unit, A storage device comprising a basic clock, and detecting an abnormality of the clock signal by comparing the basic clock with the clock signal. 2. The memory according to claim 1, wherein the comparing means is a counter for detecting a state in which a predetermined number of clocks is not transferred even after a predetermined time elapses of the clock signal. apparatus. 3. The counter according to claim 2, wherein the counting time by the counter is completed within one sector of the storage medium and has a time corresponding to an area longer than the recording area in the sector. Storage device.