JPS60144821A - Electronic disk device - Google Patents

Abstract

PURPOSE:To allow information to be written double and to improve its reliability by providing two sets of disk control parts and electronic disk parts and performing simultaneous writing operation in write mode, and switching one set to the other in case of incorrectable reading operation. CONSTITUTION:A control part switching circuit 5 once receiving an instruction from a channel sends an instruction to control circuits 11 and 21 of disk control parts 1 and 2. The circuits 11 and 21 decode the instruction and when the instruction is a write instruction, address information on a necessary disk is received from the channel and converted into a memory address, which is sent out to write/read circuits 31 and 41 through an electronic disk switch circuit 12 or 22 together with write information, thereby writing the information simultaneously. Error correction codes read by the circuits 31 and 41 at the same time are used to detect whether an error occurs or not in read mode, and if there is an incorrectable error, it is reported to control parts 1 and 2. At this time, the circuit 5 selects the control part 1, so it is switched to the side of the control part 2.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a disk device in a data processing device, and more particularly to a highly reliable electronic Dinuk device.

Description of the Prior Art Conventionally, this type of data processing device has used a magnetic disk device as a high-speed, large-capacity external storage device, but when the information stored in the magnetic disk device is extremely important, it is necessary to use a magnetic disk device to improve reliability. We have been duplicating information. That is, the same information is written to two magnetic disk drives, and when information cannot be read correctly from one magnetic disk drive, it is normally controlled by software so that it is read from the other magnetic disk drive. Therefore, when performing double writing of information in this way, not only are two Ifim disk devices required, but the same process is performed twice on different devices at the time of writing, which inevitably causes a significant drop in performance. Ta.

Object of the Invention The present invention 8A has been made in view of the above-mentioned conventional circumstances, and therefore, the object of the present invention is to provide a combination of an electronic disk section composed of a semiconductor memory, a magnetic bubble, etc., and a disk control section that controls the electronic disk section. , write information simultaneously to the electronic disk unit through the two sets of disk control units, select one set of the disk control unit and the electronic disk unit at the time of reading,
By adopting a configuration that allows information to be read by selecting a different set of disk control unit and electronic disk unit when the data cannot be read correctly, the above-mentioned drawbacks can be removed and information can be read out without deteriorating performance. An object of the present invention is to provide a highly reliable new disk device that can perform overwriting.

Structure of the Invention In order to achieve the above object, an electronic disk drive according to the present invention has a memory circuit and a function of controlling writing of information to the memory circuit at the time of writing and adding error correction information. Two electronic disk units consisting of a write/read circuit that controls the output of the information written in the memory circuit at the time of reading and also has error detection and correction functions for the read information, and deciphers commands from the channel. and an electronic disk switching circuit that switches the connection with the two electronic disk units according to a switching instruction from the control circuit.
two disk control units, a synchronization circuit that controls synchronization so that the two disk control units perform the same operation at the same time, an error detection circuit that detects an error in the two Dinuk control units, and the error detection circuit. The device is configured to include a control section switching circuit that switches the connection between the two disk control sections and the channel in response to a switching instruction from the circuit.

Next, a preferred embodiment of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, reference numbers 1 and 2 indicate disk control units, and the disk control units 1 and 2 are each comprised of a control circuit 11.21 and an electronic Dinuk switching circuit 12.22.

3 and 4G-j are electronic disk units, each consisting of a write/read circuit 31.41 and a memory circuit 32.42.

5F1 shows a control unit switching circuit, which is connected to the five channels of the control unit switching circuit by a signal line 101, and is connected to the control circuits 11 and 2.
1 through signal lines 102 and 103-, respectively.

Control circuit 11 and 211I′i electronic disk switching circuit ν
and 22 by signal lines 105 and 106, respectively, and further connected by switching instruction signal lines 114 and 115, respectively. The write/read circuit 31 is connected to the electronic digital switching circuit 12 and η via a signal line 107, and further connected to the memory circuit section via a signal line 109. Similarly, the write/read circuit 41 is connected to the electronic disk switching circuits 12 and 22 by a signal line 108, and further connected to the memory circuit 42 by a signal line 110.

6 indicates a synchronization circuit, and the synchronization circuit 6 is connected to the signal line 104.
The error detection circuit 7' is connected to the control circuits 11 and 21, and the error detection circuit 7' is for the control circuit 11 and the signal line.
2 are connected respectively to the control section switching circuit 5 and the signal line 11.
Connected by 3.

Next, the operation of the present invention will be explained step by step.

The disk controllers 1 and 2 are given the same reset signal and the same clock signal by the synchronization circuit 6, and are controlled to operate in exactly the same way. Now, the disk control section 1 is assumed to be a main disk control section, the disk control section 2 is assumed to be a sub-disk control section, the electronic disk section 3 is assumed to be a main electronic disk section, and the electronic disk section 4 is assumed to be a sub-electronic denulter section. It is assumed that the control section switching circuit 5 normally selects the main disk control section 1 side and can send only the received information from the channel to the sub-dinuk control section 2.

When the control unit switching circuit 5 receives a command from the channel,
When the control circuits 11 and 21, which send the command to the control circuits 11 and 21 of the disk control units 1 and 2, receive the command, they decode it and, if it is a write command, send the required disk from the channel. Receive address information, such as cylinder number, trunk number, code number, etc., convert it into a memory address using a predetermined conversion method, and write the memory address through the electronic disk switching circuit 12 or 22; The write information sent from the channel is sent to the read circuits 31 and 41, and the write information sent from the channel is sent to the read circuit 31.
and 41 in sequence. At this time, the electronic disk switching circuit 12 of the king dinuk control section 1 selects the main electronic dinuk section 3, and the electronic disk switching circuit 12 of the sub disk control section 2 selects the main electronic dinuk section 3.
2 HmJJ fi child disk section 4 is selected. The write and read circuits 31 and 41 tl'i address the n memory circuits 32 and 42, respectively, using the received memory address, and then sequentially insert the received write information into the memory circuits 32 and 42. At this time, an error correction code is simultaneously created and added to the write information and written.

When the control circuits 11 and 21 receive a read command from the channel, they receive the necessary address information from the channel in the same way as when writing, convert it into a memory address,
Write and read circuits 31 and 4 respectively write the memory address.
Send to 1. The write and read circuits 31 and 41 address the memory circuits 32 and 42, respectively, with the received memory address, output information, and send it to the electronic disk switching circuits 12 and 22, respectively. At this time, the write and read circuits 31 and 41 check the presence or absence of an error using the error correction code read out at the same time, correct the error information if there is a correctable error, and indicate that if there is an uncorrectable error. Notification is made to the nDinuku control units 1 and 2, respectively. The Dinuk control units 1 and 2 each send the received read information to the control unit switching circuit 5, but since the control unit switching circuit 5 is currently selecting the main Dinuk control unit 1, the read information from the Dinuk control unit 1 is sent to the control unit switching circuit 5. At this time, when an uncorrectable error is notified from the convolution/readout circuit 31, the control circuit 11 performs a retry operation, reads the same information again, and if it receives an uncorrectable error again, the control circuit 11 performs a retry operation. The number of times the trial operation is repeated and retried is predetermined, and when the predetermined number of retries is reached, the occurrence of an uncorrectable read error is notified to the software through the channel, and the controller is switched through the error detection circuit 7. The circuit 5 is switched to the sub disk control section selection side.

Generally, the software that receives the notification of the uncorrectable read error makes a retry, but the control section switching circuit 5tI'
Since the i secondary disk control unit 2 is selected and the secondary disk control unit 2 selects the secondary electronic tinook unit 4, correct read information from the secondary electronic disk unit 4 is not obtained even after a retry by the software. can be sent to the channel.

In the above explanation, when an uncorrectable read error is detected, the system of the main disk control unit and the main electronic disk unit is switched to the system of the sub disk control unit and the sub electronic disk unit, but the error cannot be corrected by the main disk control unit. When the number of retries due to read error detection reaches the predetermined number, the electronic disk switching circuit is switched to the sub electronic disk section selection. It is also possible to send information to a channel.

In addition, in the above explanation, the switching function for uncorrectable read errors from the electronic disk unit was described, but even in the case that loading and reading operations cannot be performed due to a failure in the main disk control unit, the error detection circuit By switching the control section switching circuit to the sub-Dinuk control section side through the control section, operation from the host device becomes possible.

Effects of the Invention As explained above, the present invention has two sets of the disk control section and the electronic disk section, writes the same information simultaneously at the time of writing, and when an uncorrectable read error is detected, the disk control section and the electronic disk section By adopting a configuration that allows retry by switching the set of

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 1.2...Disk control unit, 3.4...Electronic disk cover, 5...Control unit switching circuit, 6...Synchronization circuit,
7...Error detection circuit, 11.21...Control circuit,
12.22...Electronic disk section switching circuit, 31.41
...Writing, reading circuit, 32.42...Memory circuit Patent applicant: Nichifu Kuuki Co., Ltd. Representative: Patent attorney Yutabe Kumagai

Claims (1)

[Claims] It has a function of controlling the input of information into the memory circuit when writing to the memory circuit and adding error correction information, and when reading, it controls the reading of the information written to the memory circuit and corrects errors in the read information. Two electronic disk units consisting of write and read circuits with detection and correction functions, a control circuit that decodes commands from the channel and converts disk information addresses into memory addresses, and switching instructions from the control circuit. and a synchronization control unit that controls synchronization so that the two notisque control units perform the same operation at the same time. an error detection circuit that detects an error in the two disc control units; and a control unit switching circuit that switches the connection between the two disk control units and the channel in response to a switching instruction from the error detection circuit. An electronic disk device characterized by: