JPS60181947A - Memory diagnosing system - Google Patents

Abstract

PURPOSE:To execute exactly a diagnosis of a memory without breaking down the contents of a memory to be diagnosed, by providing an area for shunting a data stored in a storage area of a memory for executing a check, on a diagnostic device itself. CONSTITUTION:A CPU1 reads a data stored in a storage area of a RAM13 corresponding to a memory address of a test object. The read data is shunted to a data register 1 (11). When a diagnosis which has used a check data of four patterns A-D to the same address is ended (normal end), the CPU1 writes a memory data shunted to the register 11 to the address concerned, and returns it to its original state. After a check data has been written, its write data is read out and compared with the original check data, and if dissidence of both the data is detected, a displsy part 5 outputs a message of abnormality of a memory to a printer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (al) Technical Field of the Invention The present invention provides the following features when diagnosing a memory performed by a processing device (hereinafter referred to as CPU), etc.: 1. It is possible to check the operation of the memory without destroying the contents of the memory. Concerning memory diagnostic methods.

(bl) Prior Art and Problems Conventionally, in a data processing device in which a CPU and a memory are connected, a memory operation check is performed when an error occurs or when the power is turned on.In other words, a predetermined pattern of check data is used to A read/write check is performed on the memory. Therefore, after performing a memory diagnosis, the previously saved data in the memory will be destroyed. Therefore, when an operator performs a memory diagnosis, the memo It was necessary to confirm whether or not the contents could be destroyed.

In addition, in devices that log error information when an error occurs, memory diagnosis cannot be performed until the logged information is temporarily saved in external memory, etc., which complicates error handling work. It was also one of the causes.

(C) Purpose of the Invention The purpose of the present invention is to provide a memory diagnosis method that can accurately diagnose a memory without destroying the contents of the memory to be diagnosed, in order to eliminate the above-mentioned conventional drawbacks. .

fd+ Structure of the Invention In order to achieve the above object, the present invention provides the diagnostic device itself with an area for saving data stored in the storage area of the memory to be checked, and a function for restoring the saved data after memory diagnosis. It was added. The present invention will be explained in detail below using Examples.

(El Embodiment of the Invention Figure 1 shows an embodiment of the present invention, and Figure 2 is a flowchart of its operation.The device shown in Figure 1 is a portable hand belt terminal, and is used for inventory management, etc. The data for is processed. In the figure, ■ is CP
'U, and index register 10. as an internal register. It has data registers 11, 12, etc. CPtJ
l according to the clock signal given from the oscillator 13,
It executes the program. 2 is a ROM (a non-volatile memory), which stores the control program (not shown) that should be executed by the CPU, as well as various check programs to be described later; 3 is a RAM (a readable/writable volatile memory); ), and is used as the work area and data area of the CPUI. 4 is a clock, and R
Battery support is provided by an auxiliary battery 16 along with AM3. 5 is a display unit used for processing results by the CPUI, input data monitor, etc. 6 is a buzzer used for error notification etc. 7 is a printer, 8 is a keyboard for data input, 9 is an external unit An interface section 15 with a device (for example, a host processing device to which this terminal can be connected) is a main battery, which can be charged by a charger 14 by being connected to a commercial power source.

Hereinafter, the memory diagnostic operation in the embodiment device will be explained based on FIG.

First, activation of memory diagnosis for the CPU is achieved by turning on the main battery 15 while pressing a predetermined key on the keyboard 8. C by starting the memory diagnosis 11i.
PUI executes (7) RAM check program on ROM Z. That is, the CPUI stores the memory address to be tested specified by this RAM check program in the index register 10. next,
RAM3 according to the address set in register 10.
access. In other words, the RA corresponding to that address
Read the data stored in the storage area of M3.

The read data is saved in data register 1 (11). This read data is, for example, 1 hide (8 bits)
It is data. Next, the CPUI sets pattern data (hereinafter referred to as check data) specified by the RAM check program in the data register 2 (12). For this check data, for example, four patterns A to D are prepared in advance by a program. If this pattern A-D is to be checked every 8 bits, then the binary ri i i i 1111j, r
ololololJ, rlolololo”, and ro
0000000J is defined.

Therefore, the CPU 1 first stores check data of pattern A into the register 12. Then, for the memory address stored in index register 10,
Write this check data.

After writing the check data, the CPU reads the memory contents from the address and compares the read data with the check data stored in the register 12. Specifically, the data in register 12 and the read data are subtracted, and the result is stored in register 12.
to cents. As is clear from the above operation, if the memory being diagnosed is operating normally, the check data and the read data match. Therefore, if the value of the register 12 becomes "0", it means that the product is genuine.

If the comparison result is normal, similar write/read and comparison operations are performed for that address using the next pattern B check data.

Similarly, the check data of patterns C and D are also used for diagnosing the same address.

Then, when the diagnosis using the check data of the four patterns A to D for this address is completed (normally completed), the CPUI stores the memory data saved in the register 11 by 1 into the address and restores the original data. Return to When the restoration of this saved data is completed, the CPUI increases the address value of the index register 10 by 1 and performs diagnosis on the next memory address. On the other hand, assume that a mismatch between the two pieces of data is detected at the stage of reading out the written data and comparing it with the original check data after writing the check data. In this case, the CPtJ 1 outputs the meso-save of the memory abnormality to the display unit 5 or printer together with the address value stored in the index register 10.

In addition to the above-mentioned RAM check program, the ROM 2 stores an I10 check program for the buzzer 6, printer 7, etc., or a normal processing program.

As described above, in this embodiment, one of the internal registers of the CPUI is
One is allocated as a save area for the data stored at the memory address to be checked. This makes it possible to diagnose all areas of the RAM 3 without destroying the data stored in the RAM 3.

(, fl) Effects of the Invention As described above, according to the present invention, the contents of the memory to be diagnosed are not destroyed, in other words, the contents of the memory are not saved to another device, etc. , it becomes possible to quickly and accurately diagnose memory.This makes it possible to check the operation of memory, especially for memories whose contents are retained by batho-thermal ports, etc.
Its practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart showing its operation. ■ is the processing unit CPU, 2
3 is a ROM, 3 is a RAM, 5 is a display section, 10 is an index register, and 11.12 is a data register. 1st ν”

Claims (1)

[Claims] The system includes a memory and a diagnostic device that diagnoses the memory, the diagnostic device writes data in a predetermined pattern to the memory, reads the written data, and compares the read data with the predetermined pattern data. In a memory diagnostic device that diagnoses a memory by comparing the data in a predetermined pattern, 1. e
A save area for saving data stored in the area, a record on the memory where the data saved to the save area was stored, and a diagnosis for each storage area while saving data stored in each storage area of the memory. Memory diagnosis method with 49 symptoms.