JPS61131049A - System for preserving contents in storage device from being swept out - Google Patents

Abstract

PURPOSE:To quickly perform the trial operations of resisting while preserving fault information even when a state where the saving to an external device cannot be made occurs, by continuously operating a primary storage device as a storage device while preserving its content. CONSTITUTION:A condition where a CPU 11 can make access to a memory 67 and another memory 8 memory bank 1) is considered as an example. When a trigger input I1 is turned on against a control circuit 1 under such a condition, the control circuit 1 reads out the time of a clock 4 and writes the time in a time register 2 corresponding to the memory bank 1 and, at the same time, a trigger factor in a register 3. In addition, the control circuit 1 switches a switching circuit 5 from the memory bank 1 to another memory bank 2 (memory 9). As a result, the CPU 11 can make access to the memories 9 and 6. Since the trigger factor, the switched time, and the content of the memory when the factor I1 occurs are preserved in the memory bank 1 in such a way, the resising can be performed quickly by using the memory bank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method for a storage device, and more particularly to a storage content preservation method when a failure occurs.

[Conventional technology]

Conventionally, as a countermeasure against equipment failure, a method has been adopted in which necessary portions of memory contents are saved in an external storage device such as a magnetic disk device.

[Problem that the invention seeks to solve]

This is usually a reliable method, but it takes time to save because it uses an external storage device, and when saving the contents immediately before restarting the device, it takes a long time from the time a failure occurs until the restart is completed. It took. Furthermore, since the CPU is involved in saving, there are cases where the memory contents cannot be saved if the basic software is damaged.

The present invention solves the above-mentioned drawbacks and saves information when a situation occurs where it is impossible to save data to an external storage device, or when a failure occurs in a device without an external storage device, so that restart attempts can be made quickly. The purpose of this invention is to provide a device that makes it possible to perform the following tasks.

[Failure to solve the problem]

The present invention is made non-volatile by battery backup etc.
Regarding a specific area in a storage device, n (n≧2) memory banks for the same storage area, a memory bank switching circuit that allows the CPU to access any one of the memory banks, and all A read circuit for reading the contents of the memory bank, a state holding register corresponding to the memory bank, a clock indicating the time, and a control circuit for controlling the state holding register and the clock, and the control circuit includes: This is a method for purging and saving the contents of a storage device, which is characterized in that the type and time of the trigger are written in a state holding register by a trigger input, a switching circuit is activated, and the storage bank can be switched.

〔Example〕 Next, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, the device of the present invention has switching trigger inputs ■1 to X.
4, a clock 4, three sets of time registers 2 corresponding to memory banks that hold the time of trigger input, and a trigger factor register 3 that indicates whether any one of trigger input crabs 1 to r4 has been input. , a switching circuit 5 for switching memory banks, a bank selection circuit 7 for selecting a bank for memory access, and three memory banks 8.9.10. , a memory 6 without a switching function, and a readout circuit 12 for reading out the contents of the time register 2, trigger factor register 3, and 8.9.10. Here, one of the three sides of the memory 6 and the memo IJ 8.9.10 can be accessed from the CPU II.

Next, the operation of the embodiment will be explained.

Currently, memory 6 and memory 8 (bank 1) are
It can be accessed from I. In this state, when the trigger input crab 1 is turned on for the control circuit 1, the control circuit 1 reads the time from the clock 4 and writes the time to the time register 2 corresponding to bank 1. Also, it is displayed that there is a trigger input r1 in the trigger cause register 3 corresponding to bank 1.

At the same time, control circuit 1 instructs switching circuit 5 to switch from memory bank 1 to memory bank 2. The switching circuit 5 makes the memory bank 1 not in use and makes the memory bank 2 in use. As a result, the CPU 11 uses the memory (bank 2).
)9 and memory 6 become accessible. C.P.U.I.
When viewed from I, memory bank 1 and memory bank 2 have the same address space of the memory.

Through the above operations, the cause of switching from memory bank 1 to bank 2 is displayed, the time of switching is displayed, and the contents of memory bank 1 are saved when the cause of switching 1 occurs. It becomes possible. Then, it is possible to restart using memory bank 2. Trigger input 11-I4
By assigning failure factors to failure causes, both recovery and failure analysis become easier.

〔Effect of the invention〕

As explained above, the present invention has the effect of enabling early recovery and discovery of failures by allowing the device to continue operating while preserving the contents of the primary storage device. It is something.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention in a block diagram.

Claims (1)

[Claims] (1) A switching circuit that allows at least two memory banks in the storage device to be made nonvolatile by battery backup, etc., and one memory bank that is always accessible from the CPU, and also switches the memory bank that can be accessed from this CPU. , a reading circuit that can read the contents of the memory bank at any time, a clock that shows the time, a register for holding the state, and a control circuit that controls the clock and the register. The switching circuit is operated by a trigger or an input such as a trigger from the CPU, rotates and switches the memory bank, records the switching time and input trigger factor in the state holding register corresponding to the memory bank, and then switches the memory bank. 1. A system for purging and saving the contents of a storage device, characterized in that it is possible to later read the time when the switching occurred, the cause thereof, and the contents of a storage bank that is separated from a CPU and stores the contents.