JPH03269633A - Terminal program rewriting system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding a program rewriting method for a terminal connected to a host computer via a communication line,
The purpose is to make it possible to change the program of this terminal without replacing the ROM card or ROM card, by storing a program including a program rewriting processing program in a rewritable read-only memory, and allowing the program to be rewritten from the host. When the operation is started, the program in the read-only memory is rewritten by the program transmitted from the host.

[Industrial application field]

The present invention relates to a program rewriting method for a terminal connected to a host computer via a communication line.

[Conventional technology]

Systems in which a large number of terminals are connected to a host computer via communication lines are in practical use, but recently systems have been developed in which these terminals are installed in ordinary homes and the like to conduct commercial transactions.

The terminal of such a system has only one memory (
Various programs are stored in recording media such as ROM (hereinafter referred to as ROM) and ROM cards, and these programs execute communication control, data processing, data exchange, etc. with the host.

[Problem to be solved by the invention]

However, when changing programs due to service expansion, etc., even though it is easy to change the host program, in order to change the program on the terminals in each home as mentioned above, it is necessary to do the above. It is not only necessary to replace the ROM or ROM card that stores such programs, which not only requires a lot of effort and expense, but also requires replacing the programs on certain terminals, especially in many ordinary households. It is extremely difficult to change the method.

Additionally, in order to make it easier to change programs, it is conceivable to use non-volatile RAM with battery backup in the terminal, but in terminals used for commercial transactions as mentioned above, it is difficult to store the program. This is problematic in practical use due to its low reliability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a program rewriting method for a terminal that allows the program of the terminal to be changed without replacing the ROM or ROM card in the terminal.

[Means to solve the problem]

A program including a program rewrite processing program is stored in a rewritable read-only memory, and when a program rewrite operation is started from a host, the program in the read-only memory is rewritten by the program transmitted from the host. It was configured as follows.

[For production]

As shown in the principle embodiment of FIG. 1, a rewritable ROM 2 such as an electrically erasable programmable read-only memory (EEPROM) of a terminal 1 stores processing programs for a microprocessor 4 to execute various processes. are doing.

When changing the processing program of this terminal, the ROM rewriting function of this terminal 1 is started from the host computer, and the new program transferred from the host computer is rewritten by the ROM rewriting circuit 3, for example. Write to ROM2.

Once this rewriting is completed, the terminal device 1 will begin to execute processing based on the new program.

〔Example〕

FIG. 1 shows a principle embodiment of a terminal device to which the present invention is applied.
In addition to the rewrite circuit 3 and microprocessor 4, a random access memory (RAM) 5 and a communication control circuit 6
It is equipped with

FIG. 2 is for explaining an example of the operation of the principle embodiment shown in FIG. 1, and the program rewriting operation of this embodiment will be explained with reference to these figures.

As the first step in rewriting the program, the host combicoater communicates with this terminal 1, and then
As shown in (1) in the figure, this terminal is set to program rewrite mode by setting a ROM rewrite mode flag set in a part of the storage area of the RAM 5, for example.

When terminal 1 is set to program rewrite mode, the second
As shown in (2) in the figure, the programs necessary to achieve the communication control function and ROM rewrite control function in the ROM2 are transferred to the RAM5, and the control of the microprocessor 4 is transferred to the RAM.
Switch to the program on M5.

The microprocessor 4 receives a new program from the host computer using the communication control program stored in the RAM 5, and as shown in (3) in FIG. Store this new program in the area. Note that this new program may relate to any of the programs necessary to achieve the communication control function and ROM rewriting control function shown in the ROM of FIG. 2, or to other programs.

Once the above new program has been stored in RAM5,
According to the rewriting control program, the ROM rewriting circuit 3 erases the program to be rewritten with this new program in the rewritable ROM 2, and then transfers this new program from the RAM 5 as shown in (4) in FIG. Transfer and write to ROM2.

When this writing is completed, the rewriting control program reads out this newly written program from ROM2 and displays the new program stored in RAM5 as shown in FIG.
Compare as shown in 5) and notify the host computer of the results. If the result of the above comparison does not match, the microprocessor 4 re-attempts writing from the RAM 5 to the ROM 2 within the terminal using the rewrite program.

If the comparison results match, the host computer resets the ROM rewriting mode flag and switches the microprocessor to perform processing according to the program stored in ROM 2, thereby ending the program rewriting operation. .

In the above embodiment, when executing the rewriting operation, the programs necessary to achieve the communication control function and the ROM rewriting control function are transferred from the ROlvl 2 to the RAM 5, but these programs are not transferred to the host computer. It may also be sent from . Also, if the programs used when executing these rewrites are implemented as a separate ROM,
Even if there is a rewriting failure, there is a high possibility that rewriting will be possible by retrying, but there is a problem in that the amount of hardware will increase.

In addition, in the above embodiment, a new program is temporarily stored in RAM 5.
Although the new program received from the host computer may be written directly to the ROM 2 after being stored in the ROM 2. In this case R
Although the storage capacity of the AM5 can be reduced, if there is a failure in writing, it is necessary to repeatedly request and send a new program to the host computer until the writing is successful.

〔Effect of the invention〕

According to the present invention, when changing the program of a terminal device, not only is there no need for transportation or labor to replace the ROM of the terminal device, but also it is possible to change the program of a large number of terminal devices in a short time. Moreover, the special effect of being able to change the program without the user or installer knowing it can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a basic embodiment of a terminal device according to the present invention, and FIG. 2 is a diagram for explaining a program rewriting operation. Principle example Fig. 1

Claims (1)

[Claims] A program including a program rewrite processing program is stored in a rewritable read-only memory, and when a program rewrite operation is started from a host, the program in the read-only memory is rewritten by the program transmitted from the host. A terminal program rewriting method characterized by the following.