JPH0470523A - Electronic scale - Google Patents

Abstract

PURPOSE:To prohibit driving when ROMs are erroneously installed between models A and B by providing a start data memory to which a specific address read by a microcomputer immediately after the start of driving is written. CONSTITUTION:A ROM is read in accordance with a specific address written into a memory 11, not by an address defined by a microcomputer (CPU) 1 of a printed circuit board 3a to which the start data memory 11 is installed. For example, if a specific address N is written in the memory of a model A, system software is written in a ROM 4a of the model A from the N address. Therefore, a different address M is written as a specific address in a memory 11 of a model B and system software is arranged to be written into a ROM 4b of the model B from the M address. Accordingly, if the ROM 4b of the model B is erroneously installed on the printed circuit board 3a of the model A, the CPU 1 executes read from the address N, so that the scale of the model A is never actuated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electronic scale using a microcomputer.

Conventionally, a microcomputer 1 is used in the control section 2, as shown in FIG. 2, so that the same printed wiring board can be used even in conventional electronic scales having different technical specifications. Here, model A and model B, which have different specifications, are printed wiring boards 3a and 3 using the same model number microcomputer 1.
b is built in, and the contents of the system software written in the ROM4a mounted on the printed wiring board 3a of model A, and the contents of the system software written in the ROM4b mounted on the printed wiring board 3b of model B. The contents are different.

Taking model A as an example, immediately after startup, the microcomputer 1 reads the data written in the specified address defined by the microcomputer 1 among the contents of the ROM 4a, and the system of model A Write software to RAM 5a. During operation, the microcomputer 1 reads the weighed value of the load cell 7a via the A/D converter 6a and displays the weighed value etc. via the input/output section 8a based on the system software written in the RAM 5a. 9a, and read manual key operations from the keyboard 10a.

Problems to be Solved by the Invention In such a conventional configuration, the address of the ROM 4a that the microcomputer 1 of model A reads immediately after startup, and the address of the ROM 4a that the microcomputer 1 of model B performs reading immediately after startup. Since the address of the ROM 4b is the same specified address determined by the microcomputer 1, the system software for the model B is written into the socket where the ROM 4a of the printed wiring board 3a mounted on the model A is to be installed. If the ROM 4b is installed, even if the electronic scale has the appearance of model A, it will operate according to the specifications of model B when started.

An object of the present invention is to provide an electronic scale that will not operate if a ROM is inserted incorrectly between models A and B.

Means for Solving the Problems The electronic scale of the present invention is an electronic scale in which a microcomputer executes system software written in a memory, in which a specific address from which the microcomputer reads immediately after startup is written. It is characterized by the provision of a start data memory.

Effects According to this configuration, even if the microcomputer is the same, the correct ROM can be written by differentiating the specific address written to the start data memory for each model.
If this is implemented, the system will run normally by reading the contents of the specific address specified in the start data memory.

Furthermore, if a ROM of a different model is installed by mistake, the system will not run even if the contents of the specific address specified in the start data memory are read.

Example Hereinafter, one embodiment of the present invention will be described based on FIG.

Components having the same functions as those in FIG. 2 showing the conventional example will be described with the same reference numerals.

In the electronic scale of the present invention, as shown in FIG. 1, a start data memo 1/1 is mounted on a printed wiring board 3a. Immediately after startup, the microcomputer 1 reads the ROM, but the microcomputer 1 on the printed wiring board 3a on which the start data memo IJII is mounted
reads out the ROM in accordance with a specific address written in the start data memory 11, rather than reading out a specified address defined in the microcomputer 1. Here, assuming that "N address" was written as a specific address in the start data memo January 1 of model A, "N address" is written in the ROM 4a for model A.
The system software has been written from.

Therefore, if the start data memory 11 of model B is written with "M address" which is different from "N address" as a specific address, and the system software is written into the ROM 4b for model B from "M address", Even if the ROM 4b for model B is installed in the printed wiring board 3a of model A by mistake, the microcomputer 1 will not be able to read "N" as the specific address written in the start data memory 11.
The electronic scale of model A does not work because reading is executed from the address ".

Effects of the Invention As described above, according to the present invention, in an electronic scale in which a microcomputer executes system software written in a memory, start data written with a specific address from which the microcomputer executes reading immediately after startup is used. Since a memory is provided, by setting a different specific address to be written in the start data memory for each model, it is possible to prohibit the operation of the device even if the memory in which the system software is written is incorrectly installed.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit configuration diagram of an embodiment of an electronic scale of the present invention, and FIG. 2 is an electric circuit configuration diagram of a conventional electronic scale. 1...Microcomputer, 2...Control unit, 3a
...Printed wiring board for model A, 3b...model B
Printed wiring board for 4a...ROM for model A
C memory], 4b...ROM for model B (memory)
, 11...Start data memory. Figure 1 Figure 2

Claims (1)

[Claims] 1. In an electronic scale in which system software written in memory is executed by a microcomputer,
An electronic scale equipped with a start data memory in which a specific address is written that is read by a microcomputer immediately after startup.