JPS61234415A - Board mounting type computer unit - Google Patents

Abstract

PURPOSE:To simplify the circuit constitution of a computer unit and to miniaturize board by providing the board for maintenance attachably and detachably to the computer unit. CONSTITUTION:A terminal board 42 to be coupled with an internal bus 16 is provided to the board on which the computer unit 10 is mounted. The maintenance board 40 is connected attachably and detachably to the terminal board 42. Then a serial input/output circuit and its peripheral circuit are mounted on the maintenance board 40. A test use terminal device 32 is connected via the maintenance board 40. Thus, the serial input/output circuit for the maintenance is eliminated from the computer unit 10, the unit constitution is simplified and the board is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a board-mounted computer unit, also called a single-board computer or intelligent board.

B1 Summary of the Invention This invention provides a board-mounted computer unit that includes, in addition to a terminal section for connecting an internal bus of the computer unit to an external system bus, a second terminal section for connecting an upper internal bus and other circuits. A maintenance board having a serial input/output circuit and its peripheral circuits mounted on a printed circuit board for maintaining the computer unit is configured to be removably connected to the second terminal part Ic layer. The circuit configuration on the computer unit side can now be changed to a dark system.

C0 Conventional technology An intelligent board (referring to a board-mounted unit) with a built-in microcomputer is equipped with serial input/output circuits for terminal connection and ROM (read-only memory) data, with the main purpose of maintaining the board. A backing tool (program) has been implemented.

FIG. 3 shows this type of board-mounted computer unit and its peripheral system configuration. The part 10 surrounded by the dotted line is a computer unit mounted on one printed circuit board, and is 0PU12. A bus interface 2 that connects the memory 14, internal bus t6, and external system bus 18.
0. Not only is an external tIii controller 24 connected to an external control object 22 mounted thereon, but also a serial input/output circuit 26 and a debugging tool ROM 28 are mounted for maintenance as described above. The serial input/output circuit 26 has a terminal section 30 for external connection, and a test terminal device 32 is connected to this terminal section 30 when performing maintenance.

D0 Problems to be Solved by the Invention The serial input/output circuit 26 and debugging tool ROM 28 in the conventional configuration described above are used during maintenance, but of course they are used less frequently. Serial input/output circuit 2 that is only used very rarely
6 on the unit board leads to problems not only in terms of cost but also in increasing the size of the unit board.

This invention was made in view of the above-mentioned conventional listening point, and its purpose is to simplify the circuit configuration of the unit by providing a circuit outside the board that does not need to be integrally provided on the board of the unit. Furthermore, it is an object of the present invention to provide a board-mounted computer unit that does not impair maintainability.

Means for Solving the E8 Problem Therefore, in the present invention, in addition to the terminal section for the system bus, a second terminal section is provided on the board of the unit to connect the internal bus and other circuits.
A maintenance board, in which a serial input/output circuit and its peripheral circuits for maintaining the computer unit are mounted on a printed circuit board, is configured to be removably connected to the second terminal part. .

71 Operation Only when maintenance is to be performed, the maintenance board is coupled to the second terminal portion, and the computer unit and the test terminal are coupled via this maintenance board.

G. Embodiment FIG. 1 shows a board-mounted computer unit and peripheral system configuration according to an embodiment of the present invention. Third
Similar to the conventional example shown in the figure, the 10 parts surrounded by dotted lines are computer unit units mounted on one printed circuit board, C
! PU 12, memory 14, Hass interface 20, external device controller 24, and debugging tool R
Although the OM 28 is installed, the serial output circuit 26 in the conventional example is not installed in the device of the present invention. In place of the serial output circuit 26, a terminal section 42 (the aforementioned second terminal section) for connecting the main and maintenance board 40 to the internal bus 16 is provided on the board of the unit 10.

FIG. 2 shows a schematic appearance of the computer unit 10 with the maintenance board 40 coupled thereto. In FIG. 2, 20a is a terminal section for connecting the bus interface 20 and the system bus 18, and 245L is a terminal section for connecting the external device controller 24 and the controlled object 22. In addition to these terminal parts 20a and 24a, the terminal part 42 of the present invention is provided, and the terminal part 40 of the maintenance board 40 is provided in this terminal part 42.
a is detachably connected.

A serial input/output circuit and its peripheral circuits are mounted on the maintenance board 40, and functions as an intelligent serial input/output circuit, and is connected to the test terminal device 32 through a terminal section 401) and a cable 4004.

When performing maintenance on this computer unit 10, as shown in FIGS. 1 and 2, the maintenance board 40 is connected to the terminal portion 42 of the unit 10,
A test terminal device 32 is further coupled through this. Then, activate debugging tool ROM 4 and unit 1
Maintenance is performed by exchanging information between 0 and the terminal device 32 via a maintenance board sum.

In addition, in the above embodiment, the debugging tool ROM28
Although the present invention is not limited to this, all or part of the debugging tool (extension program, etc.) is mounted on the maintenance board 4.
It may be installed in 0. In that case, maintenance board 4
0's intelligence further increases, unit 10
The configuration becomes even simpler.

H0 Effects of the invention As explained in detail above, according to the invention, the serial input/output circuit for maintenance, which is rarely used, is eliminated from the board-mounted computer unit, the unit configuration can be further simplified, and costs can be reduced. This can be reduced and the board can be made smaller.

In addition, since the maintenance board is configured separately from the unit, it can be shared, and since it can be shared, there will be no cost problems even if the intelligentness of this board is made higher and maintainability is improved. .

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram of a board-mounted computer unit and its surroundings according to an embodiment of the present invention, Fig. 2 is an overview diagram of the same unit and a maintenance board combined, and Fig. 3 is a conventional system. FIG. 10... Board-mounted computer unit, 40...
Maintenance board, 42... second terminal section, 32.
・Test terminal device. Figure 1 Figure 2

Claims (1)

[Claims] (1) In a board-mounted computer unit in which a CPU and peripheral circuits are mounted on a printed circuit board that has a terminal section that connects an external system bus and an internal bus, a terminal section that connects the internal bus and other circuits to the printed circuit board. A maintenance board having a serial input/output circuit and its peripheral circuits mounted on a printed circuit board for maintaining the computer unit is configured to be detachably connected to the second terminal part. A board-mounted computer unit characterized by: