JPH05158680A - Rom rewrite processing system - Google Patents

Abstract

PURPOSE:To guard the writing of an electrically rewritable ROM and to make the ROM rewriting process easy for a user. CONSTITUTION:An electrically rewritable ROM 3 is stored with a utility program which rewrites a program stored in the ROM 3 and a SW9 which inhibits the writing of the ROM 3 is provided; when the program stored in the ROM 3 is corrected, the utility program and all programs in the ROM 3 are temporarily loaded in a RAM 2, a utility program stored in the RAM 2 corrects all the programs, and after the rewriting switching of the SW 9 and the input of ROM rewriting from a KB 5 are checked, all the corrected programs are written in the ROM 2 from the RAM 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ROM rewriting processing system, and more particularly to a flash EEPROM rewriting processing system.

[0002]

2. Description of the Related Art Conventionally, this type of ROM rewriting processing method has the following method when it is executed by a personal computer having the rewriting processing program installed therein.

Regarding the write guard processing to the ROM, depending on the physical switch state of the hardware,
Determines whether to disable or enable writing, and writes to ROM only under specific switch conditions.
S (Basic Input Output System)
The permission is given in m).

Regarding the rewriting process of the ROM, it is provided as a utility in the form of another medium such as a floppy disk and can be booted from the ROM BIOS.

[0005]

The conventional ROM rewriting processing system has the following problems.

Since the guard process for the ROM is a single physical switch, the ROM rewriting process may be illegally executed by the user's erroneous operation.

Further, since it is necessary to prepare a rewriting utility program in the form of another medium such as a floppy disk, a storage medium attachment for storing the utility program must be separately provided for the computer system. However, the handling of the user is troublesome.

[0008]

According to the ROM rewriting processing method of the present invention, at least the RAM, CRT,
In a ROM rewriting processing system of a computer system comprising a keyboard and an electrically rewritable ROM connected to the ROM rewriting processing system, a manual switch for making the ROM writable is provided, and the ROM is provided with a utility program for rewriting the ROM. When storing and rewriting the ROM, a first check is made as to whether the switch is in the write enabled state, and a second check is made as to whether or not a predetermined key for rewriting has been pressed from the keyboard. When the first and second checks are in the rewriting state, the utility program stored in the ROM is transferred to the RAM, all the programs stored in the ROM are transferred to the RAM, and the RA
By executing the utility program transferred to M, a new program in which all the programs stored in the ROM are modified is written in the RAM, and the new program written in the RAM is written in the ROM. It has a writing process.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a personal computer system to which an embodiment of the present invention is applied, and FIG. 2 is a flowchart showing a procedure of a ROM rewriting process of an embodiment of the present invention shown in FIG. is there.

In FIG. 1, the personal computer system of this application example has a ROM 3 in which a utility program for rewriting the ROM 3 itself is stored, and a ROM
Switch that enables rewriting of the contents of 3 (hereinafter SW)
9, a RAM 2 having a storage area for rewriting all programs stored in the ROM 3, a keyboard (hereinafter referred to as KB) 5 for inputting program rewriting data, and a program for the operating system, which stores the old program in the ROM 3. Floppy disk device (FD) 7 used for storage and C used for changing programs
An RT6, an input / output control unit (hereinafter referred to as IOC) 4 for controlling the KB5, CRT6 and FD7, and a central processing unit (hereinafter referred to as CPU) 1 for controlling the entire application example via a bus 8 are configured. There is.

Next, in this application example, the ROM of this embodiment
The rewriting processing method will be described with reference to FIGS.

First, the hardware and software conditions are checked to see if the rewriting process of the ROM 3 is possible by the inputs from the SW 9 and the KB 5 (S1).
Next, the utility program of ROM3 is copied to the empty area of RAM2 (S2), and the utility program is started on RAM2 (S3). After that, RAM3
ROM by the utility program executed on
The rewriting process of the contents of 3 is performed.

First, all programs stored in the ROM 3 are loaded into the RAM 2 (S4). The utility program stores the programs in the ROM 3 using the KB5 and the CRT 6 and edits all the programs to write them in the RAM 2 (S5). A write-protection release process for the ROM 3 is performed (S6). The new program and utility program edited in RAM2 are written in ROM3 (S7). When the writing to the ROM3 is completed, the process of prohibiting the writing to the ROM3 is performed (S
8).

After the writing of the new program to the ROM 3 is completed, the ROM 3 shifts to the normal operation. Also, SW9 is set to write-protected.

[0016]

As described above, according to the present invention, the ROM can be written in the ROM rewriting processing system of the computer system in which at least the RAM, the CRT, the keyboard and the electrically rewritable ROM are connected to the central processing unit. ROM is equipped with a manual switch to
When a ROM is rewritten, a first check is made as to whether the switch is in the writable state or not, and a predetermined key for rewriting is pressed from the keyboard. When the check is performed and the first and second checks are in the rewriting state, the utility program stored in the ROM is transferred to the RAM, all the programs stored in the ROM are transferred to the RAM, and then transferred to the RAM. By executing the executed utility program, a new program in which all the programs stored in the ROM are modified is written in the RAM, and the new program written in the RAM is written in the ROM.
Since a double card for M writing is performed, there is an effect that it is possible to reduce the possibility of contents destruction due to a user's erroneous operation as compared with the conventional case.

Further, it is possible to eliminate the need for the user to prepare another storage medium in which the ROM rewriting program is stored for the computer system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a personal computer system to which an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing a procedure of a ROM rewriting process of an embodiment of the present invention in the application example shown in FIG.

[Explanation of symbols]

 1 central processing unit (CPU) 2 RAM 3 ROM 4 input / output control unit (IOC) 5 keyboard (KB) 6 display unit (CRT) 7 floppy disk (FD) 8 bus 9 switch (SW)

Claims (1)

[Claims] 1. The central processing unit includes at least a RAM and a CR.
In a ROM rewriting method of a computer system, which is configured by connecting a T, a keyboard, and an electrically rewritable ROM, a utility that includes a manual switch that makes the ROM writable, and performs the ROM rewriting process on the ROM When the program is stored and the ROM is rewritten, whether the switch is in the writable side or the first
And a second check whether a predetermined key for rewriting is pressed from the keyboard,
When the first and second checks are in the rewriting state, the utility program stored in the ROM is transferred to the RAM, all the programs stored in the ROM are transferred to the RAM, and By executing the utility program transferred to the RAM, a new program in which all the programs stored in the ROM are modified is written in the RAM, and the new program written in the RAM is written in the ROM. R characterized by having a writing process
OM rewrite processing method.