JPH0424834A - Switching device - Google Patents

Abstract

PURPOSE:To reduce the load for development of a pseudo system by providing a switch circuit to decide the connection between a simulation circuit and a peripheral circuit or the connection between a circuit to be simulated and a peripheral circuit. CONSTITUTION:A microprocessor 102 is connected to a peripheral circuit 103 via a switch circuit block 104. The block 104 is kept in an ON state when a function is attained by a system substrate 101 only. Then the substrate 101 is connected to a simulation system 111 via a connector 121 at development of the system 111. Therefore the block 104 is turned off and the microprocessor 102 is electrically separated from the circuit 103. Then the system 111 is connected to the circuit 103. As a result, a developing stage is easily shifted to the final product and the result of evaluation obtained at development is reflected on the final product.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electrical circuit, This invention relates to a switching device.

[Prior art] Electrical signal lines [Conventional technology] In electrical systems equipped with complex circuits, as the scale of the circuits increases, the integration of each circuit makes the system lighter, smaller, and lower in cost. This has become a major factor in achieving this goal.

However, in the process of developing an electrical system, it is important to check and evaluate the operation of the designed product, and to make the system lighter and smaller, it is important to quickly discover and correct defects during the development of the electrical system. , impeding rapid reconsideration, evaluation, and early development of electrical systems.

For example, if a complex circuit configuration is integrated into a single semiconductor device, if a problem occurs, it is almost impossible to trace each signal within the semiconductor device in order to investigate the cause. Therefore, it is almost impossible to modify this semiconductor device.

Therefore, in most cases, the semiconductor device must be manufactured again.

In addition, when measures are taken to achieve miniaturization, such as mounting multiple circuit components at high density, if a problem occurs, it is necessary to trace each signal line during high-density mounting in order to investigate the cause. This makes it difficult to investigate the cause.

For this reason, currently we are developing a pseudo system equivalent to the final system, and checking and evaluating the circuit operation.

[Problem to be solved by the invention] However, differences between the pseudo system and the real system will inevitably occur, and even if the pseudo system operates correctly, it will not work correctly when replaced with the real system. It is often not possible to obtain it.

In addition, the pseudo system is developed not only for the circuit system to be integrated, but also for the peripheral circuits connected around it, and the development of the peripheral circuits for the pseudo system is also a heavy burden. For this reason, the differences between the pseudo system and the real system are increasing (and are trending).

Therefore, an object of the present invention is to significantly reduce the burden of developing a pseudo system by eliminating the differences between the pseudo system and the real system as much as possible and providing peripheral circuits that can be used in common.

[Means for Solving the Problems] A switching device of the present invention includes an electrical circuit system and a circuit system that simulates at least one circuit in the electrical circuit system, wherein the electrical circuit system is configured to simulate a simulated circuit. a circuit, a peripheral circuit connected to the simulated circuit or the simulated circuit,
The present invention is characterized by comprising a switching circuit that determines whether to connect the simulation circuit and the peripheral circuit or to connect the simulated circuit and the peripheral circuit.

[Function 1] In an electrical circuit system, a switching circuit couples a simulated circuit with its peripheral circuits. During the development of an electrical circuit system, a switching circuit couples the simulation circuit with the peripheral circuit described above.

[Embodiment] FIG. 1 is a block diagram showing a case where the present invention is applied to a system using a microprocessor.

Reference numeral 101 indicates a circuit board to which a microprocessor is applied, and when this system is used, certain functions can be achieved only with the system board 101. 6 102 is a microprocessor, and 103 is connected to the microprocessor. This figure shows the peripheral circuit blocks. Reference numeral 104 indicates a switch circuit block, and all connections between the microprocessor 102 and the peripheral circuits 103 pass through this switch. When accomplishing a function with only the 101 system, the switch remains on.

Reference numeral 111 indicates a system for simulating the microprocessor 102. 5 111 has a circuit configuration equivalent to the microprocessor 102, but the program built into the microprocessor 102 is stored in a read-only memory (hereinafter referred to as ROM). ), whereas the 111 program is
Read/write memory (hereinafter referred to as RAM)
It consists of This is because, while 102 is in the form of a final product, 111 makes it possible to check and evaluate operations while rewriting the program during system development.

During system development, the simulation system 111 and the system board 101 are connected through a connector 121. As a result, the switch circuit block 104 is turned off, and the microprocessor 102 and the switch circuit block 104 are turned off.
The peripheral circuit 03 is electrically disconnected, and the newly connected simulation system 111 and the peripheral circuit 103 are connected.

As a result, at the final product stage, only 101 circuit boards can execute programs stored in the ROM of 102 microprocessors, and during system development,
RA of newly connected 111 simulation systems
Both functions of executing the program stored in M can be accomplished using the same peripheral circuit board.

FIG. 2 is a circuit diagram showing the switching circuit block 104 of FIG. 1.

201 to 204 indicate analog switches, here 4
Can be switched about the main signal line. 205 is 201~
An analog switch control signal line 204 is shown, and when this signal line is at a low level, the switch is turned on, and when this signal line is at a high level, the switch is turned on.

The switch control line 205 is connected to the pull-down resistor circuit 206 when no external simulation circuit is connected.
A low level signal is input and the switch is in the on state.

As a result, the microprocessor 102 and the peripheral circuit 103 are connected.

Also, if a simulation circuit is connected externally, 111
A high level signal input is supplied from the simulation circuit to the analog switch control signal line 205, and
All analog switches No. 4 are in the off state. As a result, the microprocessor 102 and the peripheral circuit 103 are separated, and only the microprocessor simulation system 111 and the peripheral circuit 103 are connected.

[Effects of the Invention] According to the present invention, since the peripheral circuit configurations of the final product and the development stage are made the same, the evaluation results during system development and the evaluation results of the final product can be made similar, and the final product can be improved from the development stage. It is possible to easily transition to the next generation, and it is also possible to utilize the evaluation results during development in the final product.

Further, it is not necessary to develop pseudo circuits for peripheral circuits during system development, and the development of the developed system can be completed in a short period of time.

Furthermore, this system can also be used when you want to improve an integrated semiconductor device, and you can migrate to a new, improved system by simply adding a circuit board, etc., without changing the circuit board. It is also easy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a case where the present invention is applied to a system using a microprocessor. FIG. 2 is a circuit diagram showing a switching circuit in the present invention. 101...Circuit board to which a microprocessor is applied 102...Microprocessor 103...
... Peripheral circuit block 104 ... Switch circuit block 111 ... Microprocessor simulation system 121 ... Connectors 201 to 204 ... Analog switch 205 ... ...
...Analog switch control signal line 206...Pull-down resistor Fig. 2 12]

Claims (1)

[Claims] An electrical circuit system, and a circuit system that simulates at least one circuit in the electrical circuit system, wherein the electrical circuit system is connected to a simulated circuit, the simulated circuit, or the simulated circuit. 1. A switching device comprising: a peripheral circuit that performs a simulation; and a switching circuit that determines whether to connect the simulation circuit and the peripheral circuit or to connect the simulated circuit and the peripheral circuit.