JPH0273440A - Evaluating method for memory - Google Patents

Abstract

PURPOSE:To shorten the time required for diagnosis and at the same time to detect the abnormality of a connection bus in addition to the abnormality of a RAM by using the control program data stored previously in a ROM. CONSTITUTION:It is confirmed whether a significant program is stored or not in the entire area of a ROM 1 which stores a program for the total control of an information processor, etc. In case an insignificant prescribed pattern is detected, the random number data is written over the entire area of the RAM 1. Then the data stored in the ROM 1 is sent to a RAM 2, and the data stored in the ROM 1 and the RAM 2 are compared with each other via a verifying part 3. A coincidence signal is produced when the coincidence is obtained between both data. Thus the self-diagnosing time is shortened. If no coincidence is obtained, a 2nd prescribed pattern is written into the RAM 2 and at the same time stored in another appropriate memory. Then the coincidence is confirmed again between the RAM 2 and another memory. If no coincidence is obtained, the abnormality of the RAM 2 is decided. While a connection bus, for example, has the abnormality except the RAM 2 in case the coincidence is confirmed between the RAM 2 and another memory.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for evaluating storage devices, and particularly relates to a method for evaluating storage devices, and is particularly applicable to not only read/write storage devices such as RAM, which are subject to self-diagnosis within a short period of time, but also CPU The present invention relates to an evaluation method for a storage device that also performs self-diagnosis of the connection parts such as data nodes and boxes between the ROM and the ROM.

"Prior art" For example, in information processing devices such as copying machines and facsimile machines, RAM (random access memo storage) and ROM
(read-only memory) is used as a storage device, and a microcomputer (CPU) is connected to these to perform various controls.

What is shown in FIG. 4 is a typical configuration in such a case,
A program for controlling the entire Mako device is stored in the ROM I0I, and is read out as appropriate in response to instructions from the CPU I02. RAM10
3 temporarily stores processing data coming from other components (not shown). This is a readable and writable storage device for storing the information and processing it in accordance with instructions from the CPU 102.

"Problem to be Solved by the Invention" By the way, for example, during an initial check when starting the operation of an information processing device, or during maintenance work at regular intervals, a self-diagnosis (Diagnostics) is used to check the basic functions of the RAM.
Gnostic).

Self-diagnosis here refers to checking the functions of RAM, etc. using devices and functions installed in the device itself, without using external devices.
It means to do Mn. In the case of such self-diagnosis, for example, 00H (000
00000) 55 H (01010101)
, A A H (10101010) F F H (1
1111111) were sequentially written into all memory areas of the RAM, and verified by comparison means such as a CPU for self-diagnosis.

However, the conventional method has the following drawbacks: (1) It takes too much time to write and check four types of data such as OOH.

(2) In the case of Fig. 4, although the memory function of the ROM 10.l itself has been diagnosed in advance using a checksum etc., the connection between the ROM 10.l and the CPU 102 (that is, the connection bus, etc.) I was unable to make a diagnosis.

(3) It is necessary to create diagnostic data such as the above-mentioned 0OH155H and store it, for example, inside the CP port, which requires an extra memory area.

(4) For example, as shown in FIG. 5, when the entire area of the RAM 103 is to be diagnosed, it is assumed that the most significant bit of the address bus is erroneously connected.

Then, although the upper half of the RAM 103 is read and written twice, resulting in a double check, the lower half is not read or written, resulting in an undiagnosed state. In other words, although the upper half is checked, the lower half is not checked, and even after verification, the RA
It was not possible to discover any abnormality in M.

This invention was made in view of such circumstances, and
The aim is to provide a storage device evaluation method that eliminates the above-mentioned drawbacks.

"Means for Solving the Problem" When there is a predetermined pattern of data that does not function as a program in a ROM that stores a program that controls the entire device such as an information processing device, random number data is inserted in advance into this predetermined pattern portion. A first step of writing, and a second step of transferring and writing all the data stored in the ROM to a read/write storage device such as a RAM that temporarily stores the processed data.
a third step of confirming the match between the data stored in the transfer source ROM and the data stored in the transfer destination storage device; and a third step in which the data stored in the ROM is checked. @A fourth step of generating a match signal if the data stored in the device match; and a second step of generating second predetermined pattern data in which the data stored in RO~D and the data stored in the storage device do not match in the third step. is written to the storage device and stored in an appropriate other storage device, and after confirming that the storage device matches the other storage device again, if they match, it is determined that there is an abnormality in a member other than the storage device, and a match is made. If not, it is determined that there is an abnormality in the storage device.

"Example" Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a flowchart showing the operation of the present invention, and FIG. 2 is a block diagram showing the main parts of a storage device to which the operation of the present invention is applied.

The ROMI shown in Figure 2 stores a program that controls the entire device (not shown) such as an information processing device, and random number data is stored in the remaining area that is not necessary for the original program. has been done.

In other words, the original program area of this ROM l contains "
0 and 1. The program data that appears to be randomly arranged is stored in the number 1 shift, and the random number data is stored in areas other than the original program area, so in the end, the random number data is arranged perfectly in the entire area. This means that data consisting of ``0's and 1'' is stored.

ROMI is a RAM that temporarily stores various data.
2 is connected, and data read from ROM 1 is stored therein.

The data transferred from ROM1 to RAM2 is C
The verification unit 3, which includes a PU, etc., compares the data.

Next, the operation of the storage device configured as described above will be explained with reference to the flowchart shown in the 11th ffl.

First, it is checked in advance whether a "meaningful program" is stored in the entire area of the ROMI (step 2).

Here, a "meaningful program" refers to a program for controlling an information processing device, whereas a "meaningless (meaningless) program" is, for example, '00000000.
This means that a predetermined pattern of all j and rQ is formed, such as =. Then, if there is a meaningless predetermined pattern such as "0OJ", random number data is written across the entire area of the predetermined pattern (step ■), and if there is no meaningless predetermined pattern, random number data is written in particular. No (step ■; N).

Next, the data stored in the ROMI is transferred to the RAM according to instructions from the CPU.
Step 2). At this time, if the area of ROMI is narrower than the area of RAM 2, the contents stored in ROM 1 (meaningful programs) are stored in the first area 2a to fifth area 2e of RAM 2, as shown in FIG. The data is transferred repeatedly until the meaningful data is temporarily stored in all the storage areas in the RAM 2 (step 2).

Furthermore, when the data transfer is completed as described above, the verification unit 3 verifies whether or not the data stored in the ROMI and RAM 2 respectively match (step 2: 2).

If they match, "Match (OK> Output signal (step ■)". In this way, the previous steps ■ ~ ■
Since this method does not use a predetermined pattern (for example, 00H1, to, toH, etc.), it is possible to reduce the time spent on self-diagnosis, and even in the case of maintenance etc., steps
Most of the time it ends with.

Also, if the contents of ROMI and RAM 2 do not match, use the conventional diagnostic method as described above.
Enter J etc. one after another and check while verifying (
Step ■). In this case, the CPU performs rooooooooo
cl J etc. may be created.

If they match (step ■; Y), there is no problem with the RAM itself, so components other than the RAM (for example, the bus)
It is determined that there is an abnormality in the RAM (Step O), and if they do not match (Step ■; N), it is determined that there is an abnormality in the RAM (Step ■).

In this way, it is possible to perform not only self-diagnosis of the RAM but also self-diagnosis of the connected parts at the same time.

Note that in this embodiment, in the case of RAMO as a storage device, i
As mentioned above, the present invention can of course be applied to any readable/writable storage device such as a floppy disk or a hard disk.

Effects of the Invention As described above, according to the present invention, since the control program area (random data) stored in advance in the ROM is used, the time required for diagnosis can be shortened.
Furthermore, it is possible to detect not only an abnormality in the RAM but also an abnormality in the connection bus, for example.

Furthermore, there is no need to create or store new diagnostic data such as ``Oo'', rAAJ, etc. using already completed data in the ROM as diagnostic data.

Further, even in the case shown in FIG. 5, different random number data are stored in the upper half and the lower half, making it possible to easily determine whether double checking is being performed.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the operation of the storage device evaluation method of the present invention, FIG. 2 is a diagram showing the main part of a storage device to which the evaluation method of the present invention is applied, and FIG. 3 is a ROM area. More RA
A conceptual diagram of repeated data transfer when the area of M is large, FIG. 4 is a block diagram showing the main parts of a conventional storage device, and FIG. 5 is a conceptual diagram showing an inconvenient state in conventional self-diagnosis. . l...ROM, 2...RAM. 3...Verify section. Representative of Fuji Xerox Co., Ltd. Patent attorney Kai Yamauchi

Claims (1)

[Scope of Claims] When there is data of a predetermined pattern that does not function as a program in a ROM that stores a program that controls the entire device such as an information processing device, a first method for writing random number data in advance into the predetermined pattern portion. A second step of transferring and writing all the data stored in the ROM to a read/write storage device such as a RAM that temporarily stores the processing data, and a second step of transferring and writing all the data stored in the ROM as the transfer source. a third step of confirming a match with the data stored in the destination storage device; and a fourth step of generating a match signal if the data stored in the ROM and the data stored in the storage device match in the third step.
If the data stored in the ROM and the data stored in the storage device do not match in the third step, write the second predetermined pattern data to the storage device and store it in another appropriate storage device. After confirming again whether the storage device matches the other storage device, if they match, it is determined that there is an abnormality in a member other than the storage device, and if they do not match, it is determined that there is an abnormality in the storage device. A method for evaluating a storage device, comprising the steps of: