JPH03157896A - Transmitter - Google Patents

Abstract

PURPOSE:To detect important information through software by inhibiting writing operation normally after the important information is written, and placing hardware television information on an EEPROM. CONSTITUTION:A transmitter is constituted principally of a memory control means 22, the EEPROM 23, and a write permitting means 24, and the EEPROM 23 is assigned in the memory space of a microprocessor 21 as well as other memories and I/O parts. When the memory space of the EEPROM 23 is accessed, the entire area is readable, but a part of the area is inhibited from being written according to the state of the write permitting means 24. Consequently, the hardware television information can be read by a program and confirmed through the software.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a transmission device, and in particular, to a transmission device, and in particular to a memory control device that normally permits only reading and prohibits writing of information such as hardware change information. The present invention relates to a transmission device configured to perform the above operations.

(Prior art) Transmission devices, unlike connected devices such as sequence controllers, cannot exist independently but are distributed within the system, and the shape of the transmission module also has several variations depending on the connected devices. have. Therefore, maintenance after system delivery is carried out for each transmission module.

Software revisions are usually stored in the firmware program and updated when the program is changed, so there is no problem. However, when it comes to hardware revision management, conventional methods require humans to visually check the 1-novision mark printed on Mogicor. , or had to have a table with the revisions of each module.

In any case, confirmation requires human work, and therefore there is a possibility that errors may occur during confirmation.

It is also possible to have a dedicated readout board 1- so that the hardware can be read out by a program, but in order to do this, an extra circuit such as a dedicated switch is required as shown in Figure 3. If no switch is provided, pattern cut 1 is required to update the modification revision.
- is required.

Furthermore, the memory of the transmission module must be capable of storing transmission control information and retaining its contents even when the power of the module is turned off. The transmission control information includes, for example, a transmission area, operation designation when starting up the system 11, transmission mode, and the like. This information must be retained even when the power is turned off. If this information is lost, it will be necessary to reset the settings in the car when the power is turned on, and it will take time for the system 11 to start up.

This information is called rough l-ware, and if it is stored in FROM, which can be erased by ultraviolet light, it is troublesome to change it. Further, a RAM with a battery requires a battery circuit, and battery maintenance is troublesome.

(Problem U to be Solved by the Invention) The present invention has been made in view of the problem described in -1-. ), which can be done using conventional means such as switches and pattern cutters, and which do not require much effort, and which also provides a means of storing important information.

[Structure of the invention]

(Means for Solving the Problem) In order to achieve the above object, the present invention provides an electronic
In a device equipped with an E P ROM, the EEFR
At least hardware revision information is stored in a part of the OM area, and this area is normally configured to be prohibited from writing and only readable.

(Function) By setting the structure in -, it becomes possible to read out hardware revision information by reprogramming, and software 1-
Confirmation using software is possible. This allows hardware management of transmission modules scattered at various locations to be performed by a central maintenance device. I also write information when modifying hardware! If it is written in lEF ROM, there is no need for extra modification such as modification to the pattern cutter 1, and the number of equipment parts such as switches can be reduced. Also, if you set it write-protected at the time of shipment, it will not be destroyed due to runaway program 11 or power failure.

(Embodiment) FIG. 1 is an embodiment diagram of a transmission module (transmission device) according to the present invention. That is, a microprocessor 21 that performs hardware control and protocol control, and a UV-erasable FROM that stores firmware for performing the control.
25 (Progera 11 Mable Read-On Memory), - RAM 26 (random access memory) that temporarily stores data, Media Access Controller 1 that controls access to the transmission path - Roller MAC 30, digital signals inside the module and information on the transmission path A transmitting/receiving circuit 31 performs signal conversion between analog signals, a bus control circuit 29 exchanges control signals on a bus 42 of the connected device to transfer data with the connected device, and stores data exchanged between the transmission module and the connected device. Dual port 1-memory DPRAM28
, a serial board such as R3-232C for connecting maintenance equipment 1-27. Electrically erasable EEPROM 23 for storing transmission information. and microbe [1
A memory control means 22 for allocating the memory space of the setter to the above-mentioned various memories and (10) generating a select signal;
It is configured to include a write permission means 24 for prohibiting/permitting writing to the - section of the ROM 23.

In the above configuration, the memory control means 22, the EEPROM
23. The write permission means 24 constitutes a main part of the present invention, and FIG. 2 shows an example of its specific circuit configuration.

This EEPROM 23 is allocated in the memory space of the microprocessor 21 like other memories and the I10 board. When the microprocessor 21 accesses the corresponding space, the memory control means 22 decodes the address signal and outputs a select signal to each corresponding circuit. EEPr
When the memory space of the 1OM 23 is accessed, reading is possible for the entire area, but writing is prohibited for some areas depending on the state of the write permission means 24. That is, as shown in FIG.
The memory space 23 is divided into area 1 and area 2, and the AT female decoder 1 outputs one of the signals ERA1 and ERA2 corresponding to the accessed areas 1 and 2.

These signals are combined into one at or game-6, and the read signal RD is confirmed at or game-1-7, and or game 1,
7EEPROM23 (7) select 1-signal SE through g
1 outputs I, 1. Therefore, in the case of reading, both area 1 and area 2 can be accessed.

Also, when area 2 is accessed, signal ERA2 output from the address decoder and signal J from the jumper circuit (1 stage of write permission) 24 are input to the controller 1-4, and the output and area 1 are activated. -1-8 are inputted, and the lie 1- signal WR is inputted to the other side.

Therefore, in the case of external input, area 1 can be executed unconditionally, but for area 2, the jumper circuit 24 signal,
Prohibit/permit is selected by .

In addition, although this embodiment shows an example in which one EEPROM area is divided into two areas, the EEPROM area 2 is dedicated to hair only.
Needless to say, it can be done as follows.

〔Effect of the invention〕

According to the present invention, after writing important information that must not be lost, such as hardware revision information and transmission control information, to a part of the FEFROM, it is possible to normally set the write-inhibited state.

Furthermore, by placing the hardware revision information in the EEPROM, the same information can be detected by software in the software 1. This allows the same information to be easily referenced from the central monitoring room, etc. In addition, when modifying, you can easily write hardware revision information to the EEPROM by connecting a jumper, and if you remove the jumper to prevent writing, there is no risk that this information will be destroyed by the microprocessor going out of control. Therefore, a transmission device with improved information storage reliability can be obtained.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the transmission device according to the present invention. Fig. 2 is a specific circuit configuration diagram of the main part of the present invention, and Fig. 3 is a diagram showing the main part for explaining the conventional example. be. ■・Address decoder 8 7.8...An] Game 1-C:, 9-・Or gate 20...Transmission device・Microprocessor 22・Memory control means - EEPROM Write fraud means

Claims (1)

[Claims] In a device equipped with an EEPROM controlled by a microprocessor via at least a bus line, at least hardware revision information is stored in a partial area of the EEPROM, and this area is normally prohibited from writing and only read. A transmission device characterized by making it possible.