JPH01219918A - Electronic apparatus - Google Patents

Abstract

PURPOSE:To surely and easily recognize attachment and detachment by providing a pull-up resistance connected to a power source on the main body device side and a read line provided on the extended unit side and connected to the ground. CONSTITUTION:A personal computer is provided with a main body device 1 and an extended memory board 2 which is freely attached to and detached from this device 1. The device 1 is provided with a CPU 3, and a memory 4 as the main element in the device 1, a register 5 to which the attached/ detached state of the extended memory board 2 is set, a connector 6 to which the board 2 is connected are connected by a bus 7. The extended memory board 2 is provided with an extended memory 11 connected to the connector 6 through a bus 10 and a read line 12. The register 5 and the connector 6 are connected by a signal line 9 pulled up by a pull-up resistance 8 whose one end is connected to a power source Vcc. Thus, the attached or detached state of the extended unit is recognized by the change of the inter-terminal voltage of the resistance 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to electronic equipment such as, for example, a personal computer.

(Prior Art) Generally, in an electronic device such as a personal computer, when expanding the memory area to the outside, an expansion memory board on which a memory element is mounted is attached to the main body device.

When the attachment of the extended memory board is recognized, a central processing unit (CPU) built into the main unit starts accessing the memory element of the extended memory board.

By the way, in conventional personal computers,
The installation of an extended memory board is recognized by operating a switch provided on the main device side or by executing a conversation process using a setup program.

(Problem to be Solved by the Invention) However, in the method in which the installed expansion memory board is recognized by operating a switch, if the switch is neglected or operated incorrectly, the expansion memory board cannot be used. It disappears.

Also, in the method using a setup program,
Conversation processing and the like must be performed every time an expansion memory board is installed, which is cumbersome to operate.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide an electronic device that has a simple configuration and can reliably and easily recognize attachment/detachment of an expansion unit.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an expansion unit in which a memory element is mounted and is detachably attached to a main unit;
In this electronic device, the recognition means includes a pull-up resistor provided on the main unit side and connected to the power supply, and a pull-up resistor provided on the expansion unit side and connected to the ground. The device includes a lead line and a connector that connects the lead line and a pull-up resistor, and is configured to recognize whether the expansion unit is attached or detached based on a change in the voltage between the terminals of the pull-up resistor.

(Function) In the electronic device of the present invention, the recognition means includes a pull-up resistor provided on the main device side and connected to the power supply, a lead line provided on the expansion unit side and connected to the ground, and this lead line and It has a connector for connecting a pull-up resistor, and it is possible to recognize whether the expansion unit is attached or detached by a change in the voltage between the terminals of the pull-up resistor.

(Example) Hereinafter, details of an example of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a personal computer.

As shown in the figure, the personal computer of this embodiment is equipped with a main unit 1 and an expansion memory board 2 that is detachable from the main unit 1.

The main device 1 is equipped with a CPU 3 that accesses memory and registers, which will be described later.

The CPU 3 includes a main memory 4 in the main unit 1.
, a register 5 in which the attachment/detachment state of the expansion memory board 2 is set, and a connector 6 for connecting the expansion memory board are connected via a bus 7.

Further, the resistor 5 and the connector 6 have one end connected to a power source (
Vcc) and is connected by a signal line 9 pulled up by a pull-up resistor 8 connected to Vcc).

A connector 6 is connected to the expansion memory board 2 via a bus 10.
an expansion memory 11 connected to the connector 6, and a lead line 12 connected to the connector 6 at one end and grounded at the other end.
is provided.

A case in which the expansion memory board 2 is not installed in a personal computer will be explained.

Since the signal line 9 is pulled up by the pull-up resistor 8, the old gh level data is set in the register 5. At this time, the CPU 3 reads that the old gh level is set in the register 5, and recognizes that the extended memory board 2 is not installed.

Next, add expansion memory board 2 to the personal computer.
When installed, the signal line 9 is connected to the lead line 12 of the expansion memory board 2 via the connector 6. At this time, since the lead line 12 is connected to the ground, the potential of the signal line 9 becomes Ov, and the resistor 5 is set to Low.
Level data is set. And CPU 3 is
It reads that the register 5 is set to a low level, and recognizes that the extended memory board 2 has been installed.

In this embodiment, the CPU 3 recognizes the attachment/detachment state of the expansion memory board 2 by reading the Il1gh level or Low level set in the register 5, that is, the change in the voltage between the terminals of the pull-up resistor 8. Therefore, unlike conventional personal computers, there is no need to operate switches provided on the main unit side or to execute conversation processing using a setup program.

In this embodiment, when the level set in the register 5 is Illgh, it is recognized that the expansion memory board 2 is not installed, and when the level is Low, it is recognized that the expansion memory board 2 is installed. An example of recognition has been described, but this is not limited to this example. When the level is Low, it is recognized that the extended memory board 2 is unmounted, and when the level is Old GH, the extended memory board 2 is installed. It may also be possible to recognize that it has been done.

Further, in this embodiment, an example has been described in which the attachment/detachment state of the expansion memory board 2 is recognized, but the present invention is not limited to this example, and may be applied to recognition of the attachment/detachment condition of other expansion units such as option boards.

[Effects of the Invention] As described above, the electronic device of the present invention has a simple configuration and can reliably and easily recognize attachment/detachment of an expansion unit.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention applied to a personal computer. 1... Main unit, 2... Expansion memory board, 5...
-Resistor, 6...Connector, 8...Pull-up resistor, 9...Signal line, 12...Lead line. Figure 1

Claims (1)

[Claims] (1) In an electronic device comprising an expansion unit in which a memory element is mounted and is detachable from the main body device, and a recognition means for recognizing the attachment/detachment state of the expansion unit, the recognition means is attached to the main body device side. A pull-up resistor provided and connected to a power source, a lead line provided on the expansion unit side and connected to ground, and a connector connecting this lead line and the pull-up resistor,
An electronic device characterized in that the electronic device is configured to recognize the attachment/detachment state of the expansion unit based on a change in voltage between terminals of the pull-up resistor.