JPH04130917A - Electronic disk device - Google Patents

Abstract

PURPOSE:To confirm the storage of the same data in both of duplicated storage parts by reading out data stored in both the duplicated storage parts and mutually comparing the read data. CONSTITUTION:When a write instruction is generated from a CPU, a control part 100 simultaneously selects both the storage parts 200, 300 through respective lines 201, 301 and stores data sent from the CPU in both the storage parts 200, 300 through a line 101. When a signal is sent from a timer 400 to the control part 100, the control part 100 selects the storage part 200, reads out and stores a certain fixed volume of data stored in the storage part 200, reads out the fixed volume of data stored in the storage part 300 from the same address as the storage part 200, and compares the read data with the data read out from the storage part 200. When both the data coincide with each other as the result of comparison, a certain fixed volume of data read out from the succeeding address are compared based upon a signal outputted from the timer 400. When the compared data are mutually different as the result of comparison, the control part 100 informs discrepancy of data to the CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electronic disk device, and more particularly, to an electronic disk device in which a storage section composed of semiconductor memories is duplicated.

[Conventional technology]

Conventionally, when this kind of electronic disk device performs dual storage, when writing data to the storage, the data is written to the dual storage, first and second, and the data is read from the storage. In this case, the data was read from the first or second storage unit.

[Problem to be solved by the invention]

When the above-mentioned conventional electronic disk device performs duplex storage, data is written to the first and second duplex storage units when writing data, and data is written to the first and second duplex storage units when data is read from the first or second storage unit. Since the data is read only from the second storage section, there is a drawback that even if erroneous data is stored in the duplicated first and second storage sections, it cannot be confirmed.

[Means to solve the problem]

The electronic disk device of the present invention stores input data simultaneously in the duplicated first and second storage units in response to a write command, and outputs the stored data in the first or second storage unit in response to a read command. In an electronic disk device, the electronic disk device has a control unit that outputs a signal at predetermined time intervals, and a timer that outputs a signal at predetermined time intervals, and a predetermined amount of data at the same address in the first and second storage units is sequentially read out by the signal and compared. It is characterized by notifying the higher-level device when there is a mismatch.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.

In this embodiment, input data is simultaneously duplicated in first and second storage units 20 based on a write command from a central processing unit.
0,300 and outputs the stored data to the first or second storage unit 200, 300 in response to a read command from the central processing unit; and a timer 400 that outputs a signal at predetermined time intervals; A predetermined amount of data at the same address in the first and second storage units 200 and 300 is sequentially read out and compared based on a signal from the timer 400, and when the comparison results do not match, the central processing unit is notified.

Next, the operation will be explained.

When a write command is issued from the central processing unit, the control unit 1
00 is the line 201. The first and second storage units 200 and 300 are simultaneously selected through the line 301, and the data sent from the central processing unit through the line 101 is transferred to the first and second storage units 2.
00,300.

When a read command is issued from the central processing unit, the control unit 1
00 selects the first storage unit 200 through the line 201, reads data stored in the first storage unit 200 through the line 101, and transfers it to the central processing unit.

Further, when a signal is sent from the timer 400 to the control section 100 through the line 401 when no command is issued from the central processing unit, the control section 100 selects the first storage section 200 through the line 201 and stores it on the line 101. A certain amount of data is read out and held, then the second storage unit 300 is selected through line 301, and the data stored in the second storage unit 300 is transferred through line 101 to the first storage unit. 2
A certain amount of data is read from the same address as 00 and compared with the data read from the first storage unit 200.

If the comparison results match, then a certain amount of data from the next address is compared in response to a signal from the timer 400.

When the comparison result is a mismatch, the control unit 100 notifies the central processing unit that the data do not match.

〔Effect of the invention〕

As explained above, the present invention has the advantage that by reading and comparing the data stored in the duplicated storage units, it is possible to confirm that the same data is stored in both of the duplicated storage units. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. 0...control unit, 200...first storage section, O... second storage section, 400...Timer.

Claims (1)

[Claims] 1. Input data is simultaneously stored in the duplicated first and second storage units by a write command, and the stored data is outputted to the first or second storage unit by a read command. In an electronic disk device, the electronic disk device has a control unit that outputs a signal at predetermined time intervals, and a timer that outputs a signal at predetermined time intervals, and a predetermined amount of data at the same address in the first and second storage units is sequentially read out by the signal and compared. An electronic disk device characterized by notifying a host device when there is a mismatch. 2. The electronic disk device according to claim 1, wherein the comparison operation is performed when data is not transferred to the host device.