JPS6211918A - Checking system for memory back-up battery - Google Patents

Abstract

PURPOSE:To prevent the program runaways and the destruction of the check data due to the program logic conflict without using any exclusive device, by providing the battery check data on a memory with a space of a fixed piece of data or more. CONSTITUTION:When an address (a) is used as a battery check memory X for memory back-up, the address (b) of the 2nd check memory Y is set at a place away from the address (a) of the memory X by (c) bytes or more. In other words,the memory contents show X(AA) in the address (a) together with the memory contents showing Y(SS) in the address (b) respectively. Thus it is avoided that both the check data X and check data Y are destructed at a time by a single instruction. Furthermore, the contents of the address (b) are secured as long as a back-up batter 5 is normal even in case the logic conflict occurs during the operation of a system 1 and the contents of the address (a) are destructed. This improves the reliability with the system restart processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] In order to check whether the backup battery of the memory is depleted or not, a plurality of pieces of check data are arranged on the memory at a distance of a certain address or more.

[Industrial application field]

The present invention relates to a system having a memory equipped with a microprocessor and a backup battery, and more particularly to a memory backup battery check system that does not require a dedicated checking device and has higher reliability than the conventional system.

Among conventional memory and amplifier battery check methods, those that rely on software have the disadvantage that check data may be destroyed due to runaway programs or inconsistencies in program logic. Improvement was strongly desired.

[Conventional technology]

Normal memory naturally loses its memory contents when there is a power outage. In order to prevent memory contents from being erased even in the event of a power outage, there are two methods: using special memory such as ROM, and using memory operated by a dedicated battery.

When using a memory powered by such a dedicated battery, it is necessary to check whether the battery is operating normally, that is, whether the battery is depleted.

As this memory backup battery checking method, there are two methods: one has a dedicated check device and notifies a check signal on the hardware memory, and the other uses a program to check a fixed value written in advance at a specific address in the memory.

[Problem that the invention seeks to solve]

However, the system having a dedicated checking device has the drawbacks of being expensive and increasing the space of the system.

Furthermore, the system using a program has the disadvantage that if the fixed value of the address is destroyed due to a program runaway or a contradiction in the program logic, it may be mistaken as a battery depletion.

An object of the present invention is to provide a check method that does not require any special equipment for checking a memory backup battery and is resistant to destruction of check data due to program runaway or contradiction in program logic.

[Means for Solving the Problems] The above problem is that in a system having a memory 3 equipped with a microprocessor 2 and a backup battery 5, a plurality of This problem can be solved by arranging check data X, Y, etc. to check the quality of the backup battery 5.

[Effect]

According to the present invention, in consideration of the instruction function provided by the microprocessor, data for battery checking, such as data X and Y, is provided at an address that is far away from the maximum consecutive memory area of addresses that can be simultaneously destroyed by an instruction. This has the effect of strengthening protection against runaway programs and inconsistencies in program logic.

〔Example〕

FIG. 1 is a diagram showing an embodiment of a memory backup battery checking method according to the present invention.

FIG. 2 is an explanatory diagram of the arrangement of check data according to the present invention.

In the figure, 1 is a system having a memory with a microprocessor and a backup battery, 2 is a microprocessor, 3 is a memory, 4 is a memory that does not require a backup battery, 5 is a backup battery for the memory 3, and 6 is a main power source. be.

The system 1 shown in Fig. 1 is always powered by an external main power source 6, but the Memo+J 3 is powered by a backup battery 5 so that its memory contents will not be lost even in the event of a power outage. has been done. Note that the memory 4 is a memory that does not require a backup battery.

When the main power supply 6 loses power, the microprocessor 2 stops its operation.

However, since the memory 3 is powered by the backup battery 5, its stored contents are retained without being lost even if the main power supply 6 is interrupted.

If the main power supply 6 is restored after a certain period of time after a power outage,
The microprocessor 2 immediately resumes operation and the restart processing program R for the system 1 can be activated.

FIG. 2 shows a memory arrangement in the case of an address/memory management system using a segment system, which is found in, for example, the Intel 8086 microprocessor.

That is, taking the Intel 8086 microprocessor as an example, one segment of memory specified by one data transfer instruction is at least 16 bytes as shown in segment A.
It consists of a maximum of 65,536 bytes, and data transfer commands are executed in units of segments.

Therefore memory backup battery check memory
When address a [memory content AA] is used for the second check memory Y, address b [memory content S
S] is 655 from the address of the first check memory
Set the address at a location more than 37 bytes away.

That is, b-a > 65537 Hyde-C Hyde If address a of check data X and address b of check data Y are separated by more than C bytes like this, check data There are no words to be said.

When the power is restored and the main power supply 6 is activated, the microprocessor 2 immediately resumes operation and starts the restart processing program R for the system 1.

The restart processing program R is stored in a memory 4 that does not require a battery, and the memory 4 normally uses a read-only memory ROM or the like.

The microprocessor 2 reads the restart processing program R from the memory 4 and starts the restart processing program R.

The restart processing program R first starts at address a of the memory 3.
The contents of check data X1 and check data Y of address b are checked, and if the contents of check data X and check data Y are both destroyed, it is determined that the backup battery 5 is exhausted, and the memory 3 Initialize all data in the file.

In other cases, the backup battery 5 is assumed to be normal, and only the minimum necessary area in the memory 3 is initialized.

Next, suppose that a program logic contradiction occurs while system 1 is operating, and as a result, the contents of address a are destroyed, but there is no problem with system operation.

Even if the main power supply 6 of the system 1 is turned off/on in this state, the contents of address b in the memory 3 will be retained as long as the backup battery 5 is normal, so it is not considered that the bank-up battery 5 is depleted. Memory 3
Only the minimum necessary area within the system is initialized, and other data can be preserved, thus increasing the reliability of the system restart process.

It is necessary to reset the contents of the puncture-up bath battery check memories X and Y before starting operation.

In addition, FIGS. 1 and 2 illustrate a method for separating check data by C bytes or more, taking as an example the address/memory management method that uses the segment method found in the Intel 8086 microprocessor, etc. This is merely one embodiment of the present invention, and the effects of the present invention remain the same even in the case of an address/memory management system using a different type of microprocessor.

〔Effect of the invention〕

As explained in detail above, according to the present invention, system reliability is improved because protection against false recognition of memory hack-up battery depletion check in the event of memory corruption due to program runaway or inconsistency in program logic is strengthened. There is a big effect.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a memory backup battery checking method according to the present invention. FIG. 2 is an explanatory diagram of the arrangement of check data according to the present invention. In the figure, 1 is a system having a memory including a microprocessor and a backup battery, 2 is a microprocessor, 3 is memory, 4 is memory that does not require a backup amplifier battery, 5 is a backup battery for memory 3, and 6 is a main power supply It is.

Claims (1)

[Claims] In a system having a memory (3) equipped with a microprocessor (2) and a backup battery (5), a plurality of microprocessors located at a certain address (C) or more apart on the memory (3) are provided. A memory backup battery checking method characterized in that the quality of the backup battery (5) is checked by arranging check data.