JPH0793145A - Remote changing system for program - Google Patents

Abstract

PURPOSE:To perform the change of a program mounted on a device from a service base through an error free MODEM while utilizing a network for maintenance or the like by making the non-used area of a ROM writable, loading the program stored in the ROM to a RAM and executing the program on the RAM. CONSTITUTION:Program change information is loaded to the non-used area of a ROM 2 by a loader inside a debugger program while performing error free transmission from a personal computer 6 to a MODEM 4. Then, when the initial start of a microprocessor 1 is performed, an application program is loaded to a RAM 3 by a loader mounted on the basic part program of the ROM 2. At the same time, the change information of the program loaded in the non-used area of the ROM 2 is loaded to the RAM 3 and operated so as to be overwritten onto the original application program on the RAM 3, and the change of the program is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote program changing method for changing a program from a remote place by using a communication line or the like in an electronic device which operates a microprocessor or the like by an embedded program.

[0002]

2. Description of the Related Art Conventionally, in order to change a program mounted on an apparatus, a read-only memory (hereinafter referred to as EPROM) that can be erased by ultraviolet rays is mounted on a printed circuit board as an element for storing the program by using an IC socket. ， It was general to do this by replacing it.

Therefore, in order to change the program of the device delivered to the spectators, it is necessary to send a person to the place where the device is installed and replace the EPROM, no matter how small the change. There is a problem that the cost and time increase as the number of deliveries increases.

In order to solve such a problem, an attempt to rewrite a program from the outside by using a partially electrically rewritable memory (hereinafter referred to as E ² PROM) has not been made. However, the fact that E ² PROM is expensive and can be easily rewritten from the outside means that
There is a risk of destroying the program stored in the E ² PROM due to program runaway due to external noise, etc., and there was a problem in practical use.

In recent years, with the rapid development of personal computer communication, so-called error-free modems having a highly reliable error correction function have become available at a low price. In addition, a system that is configured with a maintenance network so that the operation status of the device can be remotely monitored is becoming popular.

The monitoring of the operation status of the device is generally performed by storing a log obtained based on the operation result of the program in a random access memory (hereinafter referred to as RAM) and reading the log from a remote place via a modem. It is the one.

[0007]

The first object of the present invention is to utilize the above-mentioned maintenance network or the like,
The purpose is to allow a program installed in the device to be changed from a service base or the like via an error-free modem. A second object of the present invention is to provide a highly reliable device that does not cause the program to be destroyed or become unrecoverable even when the program runs away due to external noise or the like.

[0008]

As a method of changing the program, there are a method of changing the source program and compiling, and a method of changing the object program partially.

According to the former method, even if only one line at the beginning of the source program is changed, the program stored in the ROM will be close to a complete change due to the movement of the address. It is difficult to transmit because there is too much information to change.

On the other hand, in the latter method, the address of the original program is not moved, and the patch method is used to change the original program, so that only the changed portion requires a small amount of information. The present invention is directed to the latter, and as shown in FIG.
In an electronic device having a basic configuration of a ROM, a RAM and a modem, and loading a program from the ROM to the RAM at the time of initial start and executing the program on the RAM, a part of the ROM is a recordable ROM. The change information of the program is loaded into the ROM from the outside by a write-once method via the modem, and after the loading is completed, the initial start command is input from the outside via the modem and the original program and the change information are stored in the ROM.
To the RAM, and the change information is overwritten on the original program on the RAM to update the program code.

As the additionally recordable ROM, the above-mentioned EPRO is used.
Although M is possible, a flash memory that is easy to write onboard is suitable for this purpose.

[0012]

1 is a block diagram showing the overall structure of the present invention. In the figure, 1 is a microprocessor, 2 is an RO
M and 3 are RAMs, 4 is a modem, 5 is a network, and 6 is a personal computer such as a service base. Figure 2
Is an embodiment of the memory configuration of the present invention, in which the ROM 2 and the RAM 3 are arranged in the memory space of the microprocessor 1.

The ROM 2 is composed of a basic part program, an application program and an unused area. The basic part program includes an operating system and a loader for loading the program from the ROM to the RAM. The application program is a program for operating the device.

In this operation, first, when the power of the apparatus is turned on, the basic part program first operates to load the application program into the RAM. R when loading is completed
The basic program on the OM and the application program loaded on the RAM are combined to start the operation.

Next, the operation for changing the program will be described. The exchange of program change information is performed by a communication program and a debugger program, which are installed in the basic part program or the application program and control the modem. These are designed to operate multiplex in the background of the main operation of the device.

Personal computer 6 at service base
To call the modem 4 via the network 6 to connect the line. When the connection is completed, the program change information is error-free transmitted from the personal computer 6 to the modem 4, and loaded in the unused area of the ROM 2 by the loader in the debugger program.

When the loading is completed, the personal computer 6 issues a command to initially start the microprocessor 1. When the microprocessor 1 is initially started, the application program is loaded into the RAM 3 by the loader installed in the basic part program, and the change information of the program loaded in the unused area of the ROM 2 is loaded into the RAM 3 to be loaded into the RAM 3. The program is modified by operating as if overwriting the original application program.

When the loading to the RAM 3 is completed in this way, the basic program and the RAM 3 are loaded as described above.
The application program that has been loaded into and modified has been combined to start the operation.

The unused area of the ROM 2 is a memory such as a flash memory that can be additionally written, and if a necessary and sufficient capacity is secured in advance, the program change information can be sequentially written by the additional writing method, It can handle many program changes.

Next, a means for preventing the program from being destroyed even if the program runs away due to external noise or the like will be described. Regarding the loader for loading the change information of the program from the modem 4 to the unused area of the ROM 2, the loader in the debugger installed in the basic program or the application program of the ROM 2 has been described in the above embodiment. When the loader is made to reside in the ROM 2 in this way, the program may run away due to external noise or the like, the loader may be mistakenly started, and the contents of the recordable ROM may be destroyed and the function may stop. There is.

In order to prevent this, the loader for loading the program into the additionally recordable area of the ROM 2 does not reside in the memory but is transmitted to the personal computer 6 before the program change information is transmitted. R
The AM3 is loaded in advance, then the program change information is transmitted, and the loader is used to perform additional writing to the unused area of the ROM2.

If the loader loaded in the RAM 3 is automatically erased when the microprocessor 1 performs an initial start, the dangerous situation caused by the malfunction of the loader can be completely prevented. be able to.

The network 5 connecting the personal computer 6 and the modem 4 at the service base or the like is generally an NTT telephone network, but if there is a PBX switch at the product installation site, the NTT subscriber line is dedicated. PB without borrowing to
Only one X extension line is required, and in the case of a communication system in which the product itself constitutes a certain type of network, the network can be shared, and there are few practical problems.

Further, the original program and the change information are stored in the ROM, and the RAM is stored at the initial start.
When the program is loaded and executed in combination with a watchdog timer that is widely used in microprocessor-embedded devices at present, even if there is an abnormality in the operation of the program, the watchdog timer works. Since the microprocessor is reset and the initial start is performed, automatic recovery can be achieved.

[0025]

As described above, according to the present invention,
Since it is possible to easily change programs from remote locations, it is possible to significantly reduce the cost and time required for changing programs after product delivery, and to make it easier to change programs. It is possible to provide a highly reliable device that does not have a risk of recovery ability deterioration.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of the present invention.

FIG. 2 is a diagram showing a memory configuration of an embodiment of the present invention.

[Explanation of symbols]

1 ... Microprocessor 2 ... ROM 3 ... RAM 4 ... Modem 5 ... Network 6 ... Personal computer

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Claims (2)

[Claims] 1. A control device such as a microprocessor and an unused area are basically composed of at least a recordable ROM, a RAM and a modem, a program stored in the ROM is loaded into the RAM, and the program is executed on the RAM. A method for remotely changing a program in an electronic device, wherein after the change information of the program is externally added and loaded into the additionally writable ROM via a modem, the RA is added.
A remote program changing method characterized in that a changed portion is overwritten on the original program on M to change the program and the changed program is executed. 2. The remote change system for a program according to claim 1, wherein a loader for loading the change information of the program into the recordable ROM is not resident in the memory but the change information of the program is loaded. A remote program changing method, characterized in that it is loaded into the RAM from outside and executed immediately before the execution, and is erased after the execution is completed.