JPH06230998A - Electronic equipment - Google Patents

Abstract

PURPOSE:To easily test operation by performing switching between normal operation and a test mode by connecting the opposite side to a connecting side of the connector hood of an interface cable in normal time. CONSTITUTION:This equipment consists of a circuit 1 where an I/O part 8 such as a dip switch 6 for making test operation effective and unused pins in a main body part connector 4 are connected on a wired-OR basis and the interface cable 3 having the same connector shape at both its ends where the main body part connector 4 and an external device connector 5 are connected differently. Then the interface cable 3 has its side A connected to the main body part connector 4 and its side B connected to the external device connector 5 in normal operation. In test mode, the side B is connected to the main body part connector 4 and the side A is connected to the external device connector 5. Therefore, the test mode and normal operation can be switched by one interface cable 3 without setting the dip switch and without connecting any dedicated connector hood.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having an external I / O connector as means for connecting a main body device such as a personal computer and a word processor to an external device such as a printer and a monitor.

[0002]

2. Description of the Related Art A personal computer, a word processor, etc. usually perform a test operation at the time of factory shipment or process inspection in addition to the operation as a device function, such as a memory test or an individual function test (hereinafter referred to as a test mode).
I do. In this test mode, in order to make it invisible to the user during normal operation, in order to enter the test mode during the inspection process, a specific switch (DIP switch) inside the main unit is switched or an unused pin of the external connector is used. In order to enter the test mode, a special connector in which the test bit and the ground are connected inside the connector is added and switching is performed in the same manner as the switch.

[0003]

However, in the method of switching a specific switch inside the main body in the above-mentioned conventional technique, it is necessary to switch the switch again to perform the normal normal operation after the factory inspection is completed. If you forget, there will be a problem that the device that operates in the test mode will be shipped to the market and users. In addition, it has become difficult to arrange a switch on a printed circuit board because of the downsizing of the device.

Next, in the method of adding a dedicated connector to enter the test mode, it is necessary to separately manufacture the dedicated connector, and if the dedicated connector is not at hand, the test mode cannot be entered.

In view of this point, an object of the present invention is to provide an electronic device whose operation can be easily tested.

[0006]

In order to solve this problem, the present invention provides a circuit in which an I / O port such as a DIP switch which enables a test operation and an unused pin in a main body connector are wired-OR connected, The main body connector and the external device connector are connected to each other, and they are configured by an interface cable having the same connector shape at both ends with different wirings.

[0007]

With this configuration, the switching between the normal operation of the device and the test mode for inspection is performed during normal operation of the connector hood of the interface cable without switching the switches arranged on the board or connecting a dedicated connector. The test mode can be entered by connecting the side opposite to the side to be connected by the signal connected in the connector hood.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An electronic device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the electronic equipment of this embodiment. In FIG. 1, 1 is a main body device such as a personal computer, 2 is an external device such as a printer connected to the main body device 1, and an interface cable 3 is used to connect them. Reference numeral 4 denotes a main body connector provided in the main body device 1, and 5 denotes an external device connector provided in the external device 2, which have the same shape. Reference numeral 6 is a DIP switch provided in the main unit 1 for switching between a test mode and a normal operation mode, one side is connected to the ground, the other is pulled up by a resistor 7, and one pin from the main body connector 4 is wired-OR connected. (* TEST) Configure signal a. The (* TEST) signal a is connected to the data bus b of the CPU 9 via the I / O port 8 and input to and read from the CPU 9 by the I / O read signal c.

FIG. 2 is a diagram showing the connection of the interface cable 3 in this embodiment. Here, using a 9-pin connector, the signals required for the interface are sig
It is shown as nal1 to signal7. An example of a test operation setting method for the electronic device configured as described above will be described with reference to FIG.

When the power is turned on, the CPU 9 reads the state of the (* TEST) signal a through the I / O port 8 controlled by the I / O read signal c and the data bus b.

For example, when the DIP switch 6 is OFF and the interface cable 3 is not connected to the main body connector 4 or the A side of the interface cable 3 is connected (* TEST), the signal a is set to the "High" level by the resistor 7. Become. At this time, the normal operation is C
PU9 recognizes and does not enter the test mode. Next, when the DIP switch 6 is ON, the signal a becomes "Low" regardless of the connection state of the main body connector 4 and the CPU 9 enters the test mode. Similarly, when the B side of the interface cable 3 is connected to the body connector 4, regardless of the state of the DIP switch 6 (* TES
T) The signal a becomes "Low". At this time, the test mode is entered.

In normal operation, the interface cable 3 is connected to the main body connector 4 on the A side and is connected to the external device connector 5 on the B side. In the test mode, the B side is connected to the main body connector 4 and the A side is connected to the external device connector 5.

[0014]

As described above, according to the present invention, by designating the connection direction of the interface cable, it is possible to switch between the test mode and the normal operation without the troublesome setting of the DIP switch and the connection of the dedicated connector hood. You can do it with the interface cable for normal operation,
It is possible to realize an excellent electronic device which is highly reliable and inexpensive without having to forget to switch the DIP switch after the inspection or make a dedicated connector hood.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electronic device according to an embodiment of the present invention.

FIG. 2 is a connection diagram of an interface cable 3 of an electronic device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Main unit 2 External unit 3 Interface cable 4 Main unit connector 5 External unit connector 6 DIP switch 7 Resistance 8 I / O port 9 CPU a (* TEST) signal b Data bus c I / O read signal

Claims (2)

[Claims] 1. A CPU and an I / O which is connected to the CPU via a local data bus and is readable by the CPU.
A port, a main body connector provided to connect to an external device, a test signal in which an arbitrary signal of the I / O port and an arbitrary signal of the main body connector are connected by wired OR, and the main body portion An external device connector having the same shape as the connector and provided in the external device, and an interface cable or an interface connector hood for connecting the main body connector and the external device connector. An electronic device characterized by being able to easily perform test operations and initial operations that differ from normal device operations without changing the switches, etc. 2. A connector hood at the cable end on the side connected to the main body connector and a connector hood on the other end connected to the external device connector are configured so as to have different wires, and both connector hoods are physically the same shape. The electronic device according to claim 1, further comprising an interface cable having no directivity.