JPH0229883A - Handy terminal - Google Patents

Abstract

PURPOSE:To make it possible to restored a firmware program in a handy terminal by loading a firmware program saved in a backup memory space even if a firmware program stored in a RAM is destroyed. CONSTITUTION:A loader program stores a routine for judging whether firmwares exist in the RAM 6 and the backup memory 8 or not and the routine to instruct the loading of the firmware is stored. When the firmwares exist in both the RAM 6 and the backup memory 8, both the contents are checked, and if the contents are noncoincident each other, the normality of a program is judged by check sum or the like and the corrent contents are copied to the other. Then control is transferred to the firmware stored in the RAM 6. Consequently, the firmware can be restored in the handy terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a handy terminal with a built-in microprocessor.

(Prior Art) Conventionally, a handy terminal has been configured as shown in FIG. In the figure, by operating the power on switch,
The power switch circuit of the power control circuit 202 is turned on, and power is supplied to all components. The microprocessor unit 205 uses a loader program stored in the ROM 207 to load a firmware program from the personal computer into the RAM 206 via the interface circuit 209, and the firmware program controls the entire handy terminal. R.A.
The firmware program stored in the M206 will continue to use the secondary battery 2 even if the handheld terminal is turned off.
04, its contents are retained.

(Problem to be Solved by the Invention) In the above-mentioned handy terminal, if the microprocessor section 205 goes out of control for some reason, the RAM 20
The program stored in the computer 6 would be destroyed and the firmware program would have to be loaded again from the personal computer.

The present invention has been made in view of the above circumstances, and even if the firmware program stored in the RAM is destroyed due to a runaway of the microprocessor unit, the firmware program saved in advance in the backup memory space can be loaded. The purpose of this invention is to provide a handy terminal that enables firmware program restoration within the handy terminal.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a means for controlling the entire device using a microprocessor as a core and a program stored in a ROM or RAM, and a memory space that is different from the RAM. a backup memory; a backup memory control circuit that permits writing to the backup memory only when a write permission command is given to the backup memory; and prohibits writing to the backup memory when a write prohibition command is given; It consists of a ROM that stores a loader program that is executed when the power is turned on, compares the programs stored in the RAM and the backup memory, and copies the correct program to the other if they do not match. .

(Operation) In the above configuration, the loader program stores a routine that determines whether firmware exists in the RAM and backup memory and instructs to load the firmware. Further, when firmware exists in the RAM and the startup memory, both are checked, and if they do not match, it is determined whether the program is normal based on a checksum or the like, and the correct one is copied to the other. and control R
Transfer to the firmware stored in AM.

This makes it possible to restore firmware within the handy terminal.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, 1 is a keyboard for inputting data manually;
2 supplies power to each component by operating the power on switch, and supplies power to each component by operating the power off switch.
This is a power control circuit that turns off the power to components other than M6 and backup memory 8. 3 is a main battery that is a power source for each component, and 4 is a sub battery that is a power source for retaining the stored contents of the RAM 6 and backup memory 8 when the power is turned off. 5 is a microprocessor unit that controls the entire handy terminal using a firmware program stored in ROM 9 or RAM 6;
6 is a RAM in which the firmware program and entered input data are stored; 7 is a backup memory 8
This is a backup memory control circuit (BM-CNT) that permits writing to the backup memory 8 in response to a write permission command, and prohibits writing to the backup memory 8 in response to a write prohibition command. 8 is a backup memory for saving the firmware program stored in the RAM 6; 9 is a ROM that stores a loader program for loading the firmware program into the handy terminal; 10 is a keyboard 1
11 is a liquid crystal display (LCD) for displaying and confirming input data; 11 is for loading firmware programs into RAM 6 and backup memory 8;
This is an interface circuit (IF) for outputting entry data stored in the RAM 6 to the main body of the personal computer.

Hereinafter, the operation of the embodiment of the present invention will be explained in detail. First, when the power is turned on, the microprocessor section 5 is loaded into the ROM.
Execute the loader program stored in 9. The loader program is programmed to perform the following operations, and the microprocessor section controls the entire handy terminal according to its contents. That is, first, it is determined whether or not the program exists in the RAM 6 and the backup memory 8. If the program does not exist, the computer waits for the firmware program to be loaded from the personal computer via the interface circuit 11. When the firmware program is transferred from the personal computer, it is loaded into the RAM 6 and backup memory 8. Note that before loading the firmware program into the backup memory 8, a write permission command to the backup memory 8 is output to the backup memory control circuit 7. When the loading of the firmware program is completed, checksum data and information indicating that the firmware program exists are written to a specific address, and a write prohibition command to the backup memory 8 is output to the backup memory control circuit 7. When these operations are completed, control is transferred to the firmware program loaded in the RAM 6, and the entire handy terminal is controlled by this firmware program.

Next, a case where the firmware program exists in the RAM 6 and the backup memory 8 will be described. RAMb
and the program stored in the backup memory 81, and if they are the same, control is transferred to the firmware program saved in the RAM 6. If they are not the same, it is determined by checksum etc. which program is normal, and the correct program is copied to the other. In addition, when copying the contents of RAM 6 to backup memory 8, in advance,
A write permission command to the backup memory 8 is output to the backup memory control circuit 7. When the copying of the program is completed, checksum data and information that the firmware program exists are written to a specific address, and if a write permission command to the backup memory 8 is output to the backup memory control circuit 7, the backup memory control circuit 7 A command to inhibit writing to the backup memory 8 is output to the circuit 7.

When these operations are completed, control is transferred to the firmware program saved in the RAM 6.

If the firmware program is retained using the method described above, even if the firmware program stored in the RAM 6 is destroyed due to a runaway of the microprocessor unit 5, the firmware program will not be loaded from the computer itself. Can be restored.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects are achieved.

(1) Destruction of entry data is prevented by executing the firmware program while it is destroyed.

(2) Even if the firmware program is destroyed due to a runaway of the microprocessor, etc., it can be restored without loading the firmware program from the computer itself.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of the configuration of a conventional example. 5...Microprocessor, 6...RAM, 9...
・ROM, 7... Backup memory control circuit, 8.
・Backup memory. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A microprocessor is used as the core, and a means for controlling the entire device by a program stored in ROM or RAM, a backup memory existing in a memory space different from the RAM, and a write permission instruction to the backup memory are provided. A backup memory control circuit that allows writing to the backup memory only when the power is turned on and prohibits writing to the backup memory when a write inhibit command is given;
and a ROM storing a loader program that compares the program stored in the backup memory with the program stored in the backup memory and copies the correct program to the other when there is a discrepancy.