JPS63262739A - Device with cpu - Google Patents

Abstract

PURPOSE:To change a program started by the same absolute address, in an unmanned state, by providing plural pieces of ROMs, and resetting a CPU by selecting the ROM corresponding to set information from the outside. CONSTITUTION:In ROMs 3-5, each different program is stored from an absolute address 0000H. Also, address lines A0-A15 are connected to other memory system, as well. A control circuit 2 is a circuit for selecting the ROMs 3-5, and constituted of an EEPROM 10 and a one-chip microcomputer 11. In this state, OR of set information from an external apparatus or a front panel operating part, and the address line A15 is taken, and a chip selecting signal for selecting the ROMs 3-5 is generated. Accordingly, in case of changing a control program, when the set information is inputted to the control circuit 2, a desired ROM can be selected automatically by the control circuit 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies to CPU, ROM, RAM 1F! , relates to an apparatus having.

[Conventional technology]

Conventionally, there is a limit to the program area that can be allocated by the CPU, and in devices where the control program occupies most of the program area, it is difficult to create a large-scale device operation test program or a large-scale program that uses the same hardware but is completely different. If it was necessary to operate the device, the ROM had to be replaced.

[Problem that the invention attempts to solve]

In order to operate the above-mentioned conventional device with a large-scale device operation test program or a separate program, it is necessary to turn off the power of the device, remove the unit with the ROM installed, and replace the unit after replacing the ROM. It has the disadvantage that it cannot be unmanned because it requires the steps of returning it to the device and turning on the power to the device.

(Means for Solving the Problems) The CPU-equipped device of the present invention inputs setting information from a plurality of ROMs and an external interface, resets the CPU, and selects one of the plurality of ROMs corresponding to the setting information. It has a control circuit that selects 0rl1 on one day.

[Effect]

Therefore, if different programs are stored in advance in these ROMs from the same starting address, the device M can be operated with different programs without replacing the ROMs.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a CPU-equipped embodiment of the present invention, and FIG. 2 is a detailed diagram of the control circuit 2 and external interface 9 in FIG.

This embodiment is a communication line switching device that monitors and switches communication lines, and includes a CPU 1, a control circuit 2, and ROMs 3 to 3.
5 (address space 0000)-1 to 7FFFH),
It is composed of a data bus 7, an address bus 8, an external interface 9, etc. Among address lines A0 to AI5 of address bus 8, address line AI5 is connected to control circuit 2, and addresses A0 to A14 are connected to ROMs 3 to 5. Furthermore, ROM3 to 5 are at absolute address 0000.
Different programs have been stored since H. Maasa,
Address lines A0-AI5 are also connected to other memory systems (address spaces 8000H-FFFFH, not shown). The control circuit 2 is a circuit for selecting ROMs 3 to 5, and is composed of an EEPROMIO and a one-chip microcomputer 11, and performs the logical sum of setting information from an external device 14 or front panel operation unit 13 via a communication interface 12 and an address line AIs. and ROM3~5
Chip select signal to select C3I, C32, C
S3 is generated, and then a reset signal RESET% is output to the CPU1. In addition, the setting information is EEPRO
It is stored in the MIO, and its contents are retained even when the power is turned off.

Therefore, when changing the control program, if the setting information is input to the control circuit 2 from the external device 14 or the front panel operation section 13, the control circuit 2 selects the desired ROM.
is automatically selected.

(Effects of the Invention) As explained above, the present invention has a plurality of ROMs.
Select the ROMG that corresponds to the setting information from the outside, and then
By resetting U, a program starting at the same absolute address can be changed unattended, and the ROM
This has the effect of reducing the number of personnel required for replacement.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the CPIJ attached device of the present invention, and FIG. 2 is a diagram showing the configuration of the control circuit 2 and external interface 9 in FIG. 1. 1...CPU, 2...Control circuit, 3.
4.5-ROM, 7...data bus, 8...
address bus, 9... external interface, 10... EEPROM, 11... one-chip microcomputer, 12...
・Communication interface, 13...Front panel operation unit, 14...External device,
A0 ~ A Is "" Address line, CSI ~ CS3-...Chip select signal, RESE
T--Reset signal.

Claims (1)

[Claims] In a device having a CPU, a plurality of ROMs and a control for inputting setting information from an external interface, resetting the CPU, and selecting one ROM corresponding to the setting information from the plurality of ROMs. A CPU-equipped device characterized by having a circuit.