JP2000209238A - Method and apparatus for electronic equipment control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic equipment control method by which an electronic equipment controller can make communication with a host or a device, depending on whether a connected electronic equipment to the controller is the host or the device and to provide the electronic equipment controller using this method. SOLUTION: This electronic equipment controller, to which an electronic/ equipment as a host or a device is connected and making communication with the electronic equipment, is provided with connecting means (111, 112), which are separate connectors connected to the electronic equipment as the host and the electronic equipment as the device, with a 1st communication means that makes communication acting as a device with the electronic equipment as the host connected by the connection means, and with a 2nd communication means that makes communication acting as a host with the electronic equipment as the device connected by the connection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a USB (Universa)
l Serial Bus) as an interface.

[0002]

2. Description of the Related Art In recent years, USB has attracted attention as a means for easily connecting peripheral devices to a personal computer (hereinafter, PC). As shown in FIG. 11, the connection of peripheral devices using USB is in a star shape (tree shape). A USB host (usually a PC) is the center, and a mouse is connected via a repeater called a hub. Many peripheral devices such as printers, scanners, and modems can be easily connected.

Electronic devices such as a mouse and a printer having a USB as a connection interface (hereinafter, referred to as USB devices) are easy to plug and play (PnP), and can be attached and detached while the USB host is turned on. Yes, and automatically when connected
The control software of the B device (a program such as a driver or a utility, hereinafter simply referred to as control software) is selected so that the USB device can be used immediately.

A conventional electronic device having a USB interface is divided into a USB host (usually a PC) and a USB device (for example, a peripheral device of a PC). Only a PC has a USB host function.

In a USB connection structure as shown in FIG. 11, a hub has one upstream port for connecting to an upper layer (another hub or USB device near the center of the star structure) and a lower layer (star structure for a star structure). It has multiple downstream ports for connecting to other hubs or USB devices near the periphery.

FIG. 12 shows an external configuration of a hub having one upstream port and four downstream ports.

[0007] By passing through a hub, one USB
The number of USB devices that can be connected to the host can be easily increased.

[0008] In the USB, one connection structure has a USB connection.
There is only one host, and data is transmitted and received between the one USB host and another USB device.

[0009] The details are outlined in the USB standard.

[0010]

As described above, the conventional U
An electronic device having an SB interface has only one of a USB host function and a USB device function for each electronic device. If there is no USB host, communication between USB devices cannot be performed. There was a problem that it was limited and lacked convenience. For example, digital cameras are typically USB devices. This can be connected to a personal computer (PC) as a USB host having a USB interface to transfer image data to the PC.
It cannot be used to directly print image data stored in a digital camera by connecting to an SB device printer.

The above problem is not limited to the USB, but an electronic device as a single host controls electronic devices as other plural devices, and performs communication between these plural electronic devices. The same applies to other methods.

Accordingly, the present invention provides an electronic device control method capable of connecting an electronic device as a host and an electronic device as a device, and performing communication with the electronic device as a host or a device according to the connected electronic device. It is an object of the present invention to provide an electronic device control device using the same.

[0013]

(1) An electronic device control method according to the present invention is an electronic device control method for connecting and communicating with an electronic device as a host or a device. Electronic devices are connected by separate connectors, and when the electronic device as a host is connected, communication is performed as a device, and when the electronic device as a device is connected, communication is performed as a host. And

According to the present invention, an electronic device as a host and an electronic device as a device can be connected, and communication with the electronic device can be performed as a host or a device according to the connected electronic device.

(2) The electronic device control method of the present invention is an electronic device control method for performing communication by connecting an electronic device as a host or a device, wherein the electronic device as a host and the electronic device as a device are connected. Selectively using one common connector terminal and performing communication as a device when an electronic device as a host is connected, and performing communication as a host when an electronic device as a device is connected It is characterized by.

According to the present invention, an electronic device as a host and an electronic device as a device can be connected, and communication with the electronic device can be performed as a host or a device according to the connected electronic device.

(3) An electronic equipment control apparatus according to the present invention is an electronic equipment control apparatus for performing communication by connecting an electronic equipment as a host or a device, wherein the electronic equipment as a host and the electronic equipment as a device are separately provided. Connection means for connecting with the connector of the above, a first communication means for performing communication as a device with respect to an electronic device as a host connected with the connection means, and an electronic device as a device connected with the connection means And second communication means for performing communication as a host.

According to the present invention, an electronic device as a host and an electronic device as a device can be connected, and communication with the electronic device can be performed as a host or a device according to the connected electronic device. In addition, since the connector for connecting the electronic device as the host and the connector for connecting the electronic device as a device are separate from each other, the user does not make a wrong connection.

Preferably, when the electronic device as a host and the electronic device as a device are connected by the connection means, the first and second electronic devices are connected in accordance with a given instruction.
One of the communication means is selected. Thus, even when the electronic device is connected to both connectors, the user can switch the mode of the host / device without changing the connection, and the operability and usability are improved.

(4) An electronic equipment control apparatus according to the present invention is an electronic equipment control apparatus for performing communication by connecting an electronic equipment as a host or a device. A connection means for selectively using a terminal of a common connector for connection, a first communication means for performing communication as a device with respect to an electronic device as a host connected by the connection means, and a connection means connected by the connection means; Second communication means for communicating as a host to an electronic device as a device.

According to the present invention, an electronic device as a host and an electronic device as a device can be connected, and communication with the electronic device can be performed as a host or device according to the connected electronic device. Further, the connector for connecting the electronic device as a host and the connector for connecting the electronic device as a device are common, and only one such connector needs to be mounted. Can be reduced.

Preferably, when the electronic device control device is connected by the connection means, the one electronic device control device that has obtained the host right becomes the host. Thereby, even when the electronic device control devices are connected, one can be a host and the other can be a device, and can communicate with each other.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, taking the case of USB as an example. (First Embodiment) FIG. 1 shows a USB according to this embodiment.
It shows a configuration example of a main part of an electronic device control device having an interface (hereinafter simply referred to as an electronic device), and mainly includes a CPU 101, a ROM 102, a RAM 103, and a US.
It is configured by connecting a B interface unit 114 via a system bus 115.

The CPU 101 controls the entire electronic device.

The ROM 102 is a non-volatile memory that stores various programs and data for controlling the operation of functions unique to electronic devices and processing USB signals.

The RAM 103 is a volatile memory for temporarily storing data used for operation control of functions unique to electronic equipment and processing of USB signals.

When a device is connected to both the connector (# 1) 111 and the connector (# 2) 112 with respect to the mode controller of the USB interface unit 114, the mode setting switch 113 switches between the host mode and the device mode. Is a switch for the user to instruct whether or not to operate.

The USB interface 114 is a USB interface.
It processes signals.

The USB interface unit 114 includes a mode controller 104 and a bus interface unit (BUS
I / F) 105, SIE (Serial Interface Engin)
e) 107, DPLL (Digital Phased Lock Loop) 1
08, a transceiver / receiver (XCVR) 109, and a changeover switch 110.

The mode controller 104 operates according to the contents set by the mode setting switch 113 or
From the connection state between the connector (# 1) 111 and the connector (# 2) 112, the entire USB interface unit 114 is set to the host mode or the device mode.

The bus interface unit 105 is a circuit that controls the interface between the USB interface unit 114 and the system bus 115.
Depending on whether the mode 14 is the host mode or the device mode, an operation necessary for each mode is performed. In addition, an endpoint, that is, a plurality of buffers assigned to each endpoint, that is, a FIFO (Fi
rst In First Out) 106 is controlled. For example, S
The control for storing the signal processed by the IE 107 in an appropriate FIFO 106, the reverse processing, and the FIFO 1
Also includes an interface portion with the circuit after 06.

SIE (Serial Interface Engine) 1
07 executes protocol processing for data transfer with the USB host, and the USB interface unit 11
Depending on whether the mode 4 is the host mode or the device mode, an operation necessary for each mode is performed.

A DPLL (digital PLL) 108 generates a reference clock from a USB signal as a PLL in the device mode, and synchronizes a phase of a received sync signal with an internal clock.
In the host mode, it functions not as a PLL but as a reference clock generation circuit (oscillation circuit).

Transceiver / Receiver (XCVR) 10
9 has the characteristics according to the USB electrical standard,
It comprises a transmission driver circuit for transmitting and receiving a USB operation signal via a B standard cable, and a reception driver circuit. In addition, processing such as detection of attachment / detachment of a USB device and detection of speed is also performed.

The changeover switch 110 receives an instruction from the mode controller 104 to set the mode to one of the host mode and the device mode, and
109 is connected to the connector (# 1) 111 or to the connector (# 2) 112 (when in the host mode,
Connect the XCVR 109 and the connector (# 1) 111,
In device mode, XCVR109 and connector (#
2) Connect 112).

The connector (# 1) 111 is a connector that conforms to the electrical characteristics of the USB. When the USB interface unit 114 functions in the host mode, another USB connector 114 is used.
This is a host function connector for connecting an upstream port of a device or a hub.

The connector (# 2) 112 is a connector according to USB electrical characteristics, and is used to connect a downstream port of another USB host or hub when the USB interface unit 114 functions as a device mode. Device function connector.

Here, the USB standard defines
A general USB electrical interface will be described.

FIG. 2 schematically shows a circuit configuration around a connector of a USB device.

In FIG. 2, the USB cable has four lines: a power line (5 V), a data line (D + line), a data line (D- line), and a ground line (GND).
It is a wick.

The USB interface of a USB host device and a downstream port of a hub (hereinafter, these may be collectively referred to as a host side) include a power supply line (5V (OUT) line), a data line (D + line), It consists of a data line (D-line) and a ground line (GND line).

The USB interface of a USB device and an upstream port of a hub (hereinafter, these are collectively referred to as a device side) are connected to a power receiving line (5).
V (IN) line), a data line (D + line), a data line (D- line), and a ground line (GND line).

On the host side, two data lines (D +
Line, D- line) are each about 15 kΩ resistance and G
On the device side, the D + line is pulled up to a 3.3 V power supply with a resistance of about 1.5 kΩ for the high speed device and hub, and the D− line for the low speed device and hub. . In addition, USB
There are two types of devices, high speed devices are 12M
The low-speed device can perform data communication up to 1.5 Mbps.

When the device is not connected, the two data lines (D + line and D- line) are in the reception mode on both the host side and the device side, and are not driven by the USB transceiver. Therefore, in the unconnected state, the potential of the two data lines (D + line and D- line) is at the GND level due to the pull-down resistor.

When a high-speed device or hub is connected to the host, the D + line is set to about 3.0 V by a pull-up resistor, so that the host can detect that the high-speed device or hub is connected. Given P
An nP (Plug And Play) operation starts. Similarly, when a low-speed device is connected, the D- line becomes approximately 3.0 V, so that the host can detect that the low-speed device is connected.

Next, the connectors 111 and 112 shown in FIG.
The configuration of the main part around the part will be described in more detail.

FIG. 3 shows in detail the connector 111 which is a connector for the host function and the essential parts around it. As shown in FIG. 3, in the connector 111, pull-down resistors 122a and 122b of about 15 kΩ are connected to two data lines (D + line and D− line), respectively. On the other hand, as described above, one of the two data lines on the USB device device side has about 1.
5kΩ pull-up resistor is connected (high-speed US
In the case of the B device, the D + line is pulled up, and in the case of the low-speed USB device, the D- line is pulled up.)

The potential detecting unit 121
When the SB device or the upstream port of the hub is connected, it detects which of the D + line and the D- line is pulled up (detects a voltage of about 3 V),
Identify the speed of the lower connected device.
If both lines are at the GND level, it is determined that no device is connected to the lower level. Potential detector 121
Notifies the mode controller 104 of the determination result.

FIG. 4 shows in detail the connector 112 which is a connector for a device function and the essential parts around it. Note that the connector 112 shown in FIG. 4 shows a case of a high-speed device. Therefore, a pull-up resistor 132b of about 1.5 kΩ is connected to the D + line.

The potential detecting section 131 connects the U
When the SB host device or the downstream port of the hub is connected, the voltage of the power supply line (5V (IN) line) is detected. For this purpose, the power supply line is, for example, about 10
It is pulled down to GND by a resistor 132a of 0 kΩ. Therefore, in the unconnected state, the power supply line (5 V (I
N) line) is a pull-down resistor, and the potential is GND.
Level. The potential detecting unit 121 notifies the mode controller 104 of the result of the determination.

Next, the operation of the electronic apparatus of FIG. 1 will be described with reference to the flowchart shown in FIG.

The initial state at power-on is a mode according to the state of the mode setting switch 113 (step S1). (1) First, an upstream port of a USB device or a hub is connected to the connector 111 of FIG.
When nothing is connected to the connector 112, that is, as shown in FIG.
A case will be described in which, for example, a printer is connected as a device, and the electronic apparatus in FIG. 1 is set to the host mode.

The power line (5) of the connector (# 2) 112
V (IN) line) because nothing is connected
The potential is 0 V (Step S2). On the other hand, when a USB device or a hub is connected to the connector (# 1) 111, about 3.0 V is detected on the D + line or the D- line by their pull-up resistors (step S).
6). Therefore, the mode controller 104 sets the changeover switch 110, the DPLL 108, the SIE 107, and the bus interface unit 105 to the host mode (Step S7). Thereafter, as described above, the connection of the low-speed / high-speed device is detected as the USB host, and a predetermined operation such as PnP or the control of the device is performed (step S8).

(2) When the downstream port of the USB host or hub is connected to the connector 112 of FIG. 1 and nothing is connected to the connector 111, that is, as shown in FIG. U to connector 112
As the SB host, for example, a personal computer (P
C) is connected and the electronic apparatus of FIG. 1 is set to the device mode.

When a USB host or hub is connected to the connector (# 2) 112, a voltage is supplied to the power supply line (5V (IN) line) of the connector 112, and this is detected (step S2). Meanwhile, the connector (#
1) Since nothing is connected to the D + line and D- line of 111, the potential is 0 V (step S3). Therefore, the mode controller 104
0, the DPLL 108, the SIE 107, and the bus interface unit 105 are set to the device mode (step S
5). Then, as a USB device,
A predetermined process is performed for the request from the B host (step S8).

(3) A case where a USB host or hub is connected to the connector (# 2) 112 and a USB device or hub is also connected to the connector (# 1) will be described.

When a USB host or hub is connected to the connector (# 2) 112, a voltage is supplied to the power supply line (5V (IN) line) of the connector 112, and this is detected (step S2). Meanwhile, the connector (#
1) When a USB device or a hub is connected to 111, about 3.0 V is detected on the D + line or the D- line by their pull-up resistors (step S).
3). At this time, the mode controller 104 operates the changeover switch 11 according to the setting of the mode setting switch 113.
0, the DPLL 108, the SIE 107, and the bus interface unit 105 are set to the host mode or the device mode. Thereafter, predetermined processing is performed as a USB device or USB host (step S8). (Second Embodiment) FIG. 7 shows a USB according to this embodiment.
It shows a configuration example of a main part of an electronic device control device having an interface (hereinafter, simply referred to as an electronic device), and mainly includes a CPU 201, a ROM 202, a RAM 203, and a US.
The B interface unit 214 is connected by a bus.

The CPU 201 controls the entire electronic device.

The ROM 202 is a non-volatile memory that stores various programs and data for controlling the operation of functions unique to electronic devices and processing USB signals.

The RAM 203 is a volatile memory for temporarily storing data used for operation control of functions unique to electronic equipment and for processing USB signals.

The USB interface unit 214
It processes signals.

The USB interface 214 has a mode controller 204 and a bus interface (BUS).
I / F) 205, SIE (Serial Interface Engin)
e) 207, DPLL (Digital Phased Lock Loop) 2
08, and a transceiver / receiver (XCVR) 209.

The mode controller 204 has a connector 2
10, the entire USB interface unit 214 is set to the host mode or the device mode.

The bus interface unit 205 is a circuit that manages the interface between the USB interface unit 214 and the system bus 215.
Depending on whether the mode 14 is the host mode or the device mode, an operation necessary for each mode is performed. In addition, an endpoint, that is, a plurality of buffers assigned to each endpoint, that is, a FIFO (Fi
rst In First Out) 206 is controlled. For example, S
The control of storing the signal processed by the IE 207 in an appropriate FIFO 206, the reverse processing, and the FIFO2
Also includes an interface portion with the circuit after 06.

SIE (Serial Interface Engine) 2
07 executes a protocol process for data transfer with the USB host.
Depending on whether the mode 4 is the host mode or the device mode, an operation necessary for each mode is performed.

A DPLL (digital PLL) 208 generates a reference clock from a USB signal as a PLL in the device mode, and synchronizes a phase of a received sync signal with an internal clock.
In the host mode, it functions not as a PLL but as a reference clock generation circuit (oscillation circuit).

Transceiver / Receiver (XCVR) 20
9 has the characteristics according to the USB electrical standard,
It comprises a transmission driver circuit for transmitting and receiving a USB operation signal via a B standard cable, and a reception driver circuit. In addition, processing such as detection of attachment / detachment of a USB device and detection of speed is also performed.

A connector 210 connects to another USB device or an upstream port of a hub in the host mode, and connects to another USB device in the device mode.
This is a connector for connecting a downstream port of a host or hub.

FIG. 8 shows the connector 210 and its peripheral circuits in more detail.

5 V (IN), 5 V
(OUT), D +, D-, and ground (GND).
Has two connector terminals. As shown in FIG. 8, when connecting an upstream port of another device or hub, for example, 5 V (OUT), D +, D-, and ground (GN) of the connector terminals of the connector 210 are connected.
D) is used to connect other device devices or the upstream port of the hub via the connector 213a and the cable 213a for connecting to these connector terminals. When connecting to a downstream port of another host device or a hub, 5V (IN), D +, D-, and GND of the connector terminals of the connector 210 are used, and cables for connecting to these connector terminals are used. 213b, and a downstream port of another host device or hub via a connector 212b.

When connecting electronic devices having the configuration shown in FIG. 7, the 5V (IN) terminal of one connector 210 is connected to the 5 V (OU) terminal of the other connector 210 as shown in FIG.
T) 5V of one connector 210
(OUT) terminal is connected to 5 V (I
N) The one electronic device is connected to the other electronic device via a cable 213c for connecting to a terminal and a connector 212c.

Returning to the description of FIG. 8, the power receiving line (5V (IN) line) of the connector 210 and the data line (D
+ Line) and the data line (D- line) are connected to GND by resistors 235 to 237 of about 100 kΩ, for example.
Has been pulled down to Therefore, when nothing is connected to these connector terminals, the potential is at the GND level due to the pull-down resistor.

In order that the electronic apparatus of FIG. 7 can correspond to a high-speed device when in the device mode, the D + line is
A pull-up resistor of about 1.5 kΩ is connected via a switch (SW # 1) 222. In order to enable the electronic device of FIG. 7 to be compatible as a low-speed device when in the device mode, the D-line should be used instead of the D + line.
A pull-up resistor of about 1.5 kΩ may be connected via the switch (SW # 1) 222.

When the electronic device of FIG. 7 is in the host mode,
In order to determine whether the connected USB device is a low-speed device or a high-speed device, the D + line and the D- line
About 15k each via switch (SW # 2) 232
Ω pull-down resistors 233 and 234 are connected.

When the electronic device of FIG. 7 is in the device mode,
The switch (SW # 1) 222 is turned on (the pull-up resistor 223 is connected to the D + line), and the switch (SW # 1) is turned on.
2) 232 is turned off (the pull-down resistors 233 and 234 are disconnected from the D + line and D- line, respectively), and in the host mode, the switch 222 is turned off (D +
The pull-up resistor 223 is disconnected from the line), and the switch 232 is turned on (the pull-down resistors 233 and 234 are connected to the D + line and the D- line, respectively).

The potential detecting unit 221 connects the U
When the downstream port of the SB host device or hub is connected, the voltage of the 5V (IN) line is detected.
Therefore, the 5V (IN) line is, for example, about 100 kΩ.
Is pulled down to GND by the resistor 235. Therefore, in the unconnected state, the potential of the 5V (IN) line is at the GND level due to the pull-down resistor. The potential detection unit 221 notifies the mode controller 204 of the determination result.

When the electronic device shown in FIG. 7 is in the host mode and the USB device device or the upstream port of the hub is connected to the connector 210 when the electronic device shown in FIG.
It detects whether the D + line or the D- line is pulled up (detects a voltage of about 3 V), and determines the speed of the device connected below. If both lines are at the GND level, it is determined that no device is connected to the lower level. The potential detecting unit 231 notifies the mode controller 204 of the result of the determination.

Next, the operation of the electronic device of FIG. 7 will be described with reference to the flowchart shown in FIG.

Initial state at power-on and connector 21
When nothing is connected to 0, the device mode is set (step S11). That is, the mode controller 204 turns on the switch (SW # 1) 222 (connects the pull-up resistor 223 to the D + line) and turns off the switch (SW # 2) 232 (the pull-down resistor 233 from the D + line and the D- line, respectively). , 234 are disconnected), and the DPLL 208, the SIE 207, and the bus interface unit 205 are set to the device mode. (1) First, when a USB device or an upstream port of a hub is connected to the connector 210 of FIG. 7, that is, as shown in FIG.
A case will be described in which, for example, a printer is connected to USB device 0 as a USB device, and the electronic device in FIG. 7 is set to the host mode.

When an upstream port of a USB device or hub is connected to the connector 210, about 3.3 V is detected on the D + line or the D- line by their pull-up resistors. On the other hand, since nothing is connected to the 5V (IN) line, the potential is 0 V (step S12). Therefore, the process proceeds to step S13, in which the mode controller 204
22 is turned on, the switch 232 is turned off, and the DPLL 20
8, set the SIE 207 and the bus interface unit 205 to the host mode (step S13). After that, as described above, the connection of the low-speed / high-speed device is detected as the USB host, and a predetermined operation such as PnP and the control of the device are performed (step S19). (2) When the downstream port of the USB host or the hub is connected to the connector 210 of FIG. 7, that is, as shown in FIG.
As the B host, for example, a personal computer (P
C) is connected, and the electronic apparatus of FIG. 7 is set to the device mode.

When a downstream port of a USB host or hub is connected to the connector 210, 5V (I
N) Since a voltage is supplied to the line, it is detected (step S12), and the process proceeds to step S14. The potential of the D + line and the D- line is 0 V due to the pull-down resistance of the downstream port of the host or the hub (step S14). Therefore, the process proceeds to step S15,
The mode controller 204, as it is,
0, the switch 222 is turned on, the switch 232 is turned off, and the DPLL 208, the SIE 207, and the bus interface unit 205 are set to the device mode (step S1).
5). Then, as a USB device,
A predetermined process is performed for the request from the host B (step S19). (3) A case where nothing is connected to the connector 210 will be described.

Since nothing is connected to the 5V (IN) line of the connector 210, the potential is 0V. Also, D
Since neither the + line nor the D- line is connected, the potential is 0 V (step S12, step S14).
Therefore, the process proceeds to step S15, and the mode controller 2
04, the switch 222 of the connector 210 is turned on, the switch 232 is turned off, and the DPLL 208, S
The IE 207 and the bus interface unit 205 are set to the device mode (step S15). Thereafter, as a USB device, predetermined processing is performed in response to a request from the connected USB host (step S19). (4) A description will be given of a case where the electronic devices having the configuration shown in FIG. 7 are connected to each other, that is, a case where the electronic device having the configuration shown in FIG. 7 is connected to the connector 210 as shown in FIG.

Before the connection, neither electronic device should be connected to anything, and thus the device mode is set.

5 V of connector 210 of both electronic devices
Since a voltage is supplied to the (IN) line, it is detected (step S12), and the process proceeds to step S14. Since the connected device is a USB device, about 3.0 V is detected on the D + line or the D- line of the connectors 210 of both electronic devices (step S4). Therefore, the process proceeds to step S16, where both electronic devices wait for a predetermined time (preferably a random time different from each other for each of the electronic devices) (step S16), and then return to the respective electronic devices again. Connector 210
Whether a voltage is supplied to the 5V (IN) line of
Further, when it is not supplied, it is checked whether about 3.0 V has been detected on the D + line or the D- line of the connector 210 (step S17). When one of the two electronic devices previously determines that the connected electronic device is not in the host mode, that is, does not detect a voltage on the 5V (IN) line of the connector 210, and , D + line of connector 210 or D−
When about 3.0 V is detected on the line, the mode controller 204 of the electronic device sets the electronic device to the host mode (step 18). At this time, the other electronic device can determine that one of the connected electronic devices is already in the host mode in step S17 (step S17).
17), remains in device mode. Thereafter, both electronic devices perform predetermined processing as USB devices or USB hosts (Step S19).

As described above, when connecting the electronic devices having the configuration shown in FIG. 7, the shorter one of the predetermined random waiting times first acquires the host right and becomes the host, and the longer one becomes the host. Becomes a device, and mutual communication becomes possible.

[0086]

As described above, according to the present invention,
Both an electronic device as a host and an electronic device as a device can be connected, and communication with the electronic device can be performed as a host or a device according to the connected electronic device.

[Brief description of the drawings]

FIG. 1 is an exemplary view showing a configuration example of a main part of an electronic device control device (electronic device) according to a first embodiment.

FIG. 2 shows a general US defined in the USB standard
FIG. 4 is a diagram for describing an electrical interface B, and schematically shows a circuit configuration around a connector of a USB device.

FIG. 3 is a diagram showing in detail a connector 111 serving as a host function connector and a main part around the connector 111;

FIG. 4 shows a connector 112 which is a connector for a device function.
FIG. 3 is a diagram showing in detail a main part of the apparatus and its periphery.

FIG. 5 is a flowchart for explaining the operation of the electronic device of FIG. 1;

FIG. 6 is an exemplary view showing a connection form between the electronic device of FIG. 1 and another electronic device having a USB interface.

FIG. 7 is a view showing an example of a configuration of a main part of an electronic device control device (electronic device) according to a second embodiment of the present invention.

FIG. 8 is a diagram showing the connector 210 and its peripheral circuits in more detail.

FIG. 9 is a diagram schematically illustrating a cable configuration in a case where electronic devices having the configuration illustrated in FIG. 7 are connected to each other;

FIG. 10 is a flowchart for explaining the operation of the electronic device in FIG. 7;

FIG. 11 illustrates an example of a USB connection structure.

FIG. 12 is a diagram showing an example of an external configuration of a hub having one upstream port and four downstream ports.

[Explanation of symbols]

 101 CPU 102 ROM 103 RAM 104 Mode Controller 105 Bus Interface Unit (BUS I / F) 106 FIFO (First In First Out) 107 SIE (Serial Interface Engine) 108 DPLL (Digital Phased Lock Loop) 109: Transceiver / Receiver (XCVR) 110: Changeover Switch 111: Host Function Connector (# 1) 112: Device Function Connector (# 2) 113: Mode Setting Switch 114: USB Interface Unit 115: System Bus 201: CPU 202 ... ROM 203 ... RAM 204 ... Mode controller 205 ... Bus interface unit (BUS I / F) 206 ... FIFO (First In First Out) 207 ... SIE (Serial Interface Engine) 208 ... DPLL (Digital Phased Lock Loop) 209 ... Transceivers / receiver (XCVR) 210 ... 214 ... USB connector interface unit 215 ... system bus

Claims (6)

[Claims] An electronic device control method for performing communication by connecting an electronic device as a host or a device, wherein the electronic device as a host and the electronic device as a device are connected by separate connectors, respectively. An electronic device control method comprising: performing communication as a device when the electronic device is connected, and performing communication as a host when the electronic device as a device is connected. 2. An electronic device control method for performing communication by connecting an electronic device as a host or a device, wherein the electronic device as a host and the electronic device as a device are selectively connected to one common connector terminal. An electronic device control method comprising: performing communication as a device when an electronic device serving as a host is connected, and performing communication as a host when an electronic device serving as a device is connected. 3. An electronic device control apparatus for performing communication by connecting an electronic device as a host or a device, wherein the connecting device connects the electronic device as a host and the electronic device as a device with separate connectors, respectively. A first communication unit that communicates as a device with the electronic device as a host connected by the connection unit; and a second communication that communicates as a host with the electronic device as a device connected by the connection unit. An electronic device control device, comprising: means. 4. When an electronic device as a host and an electronic device as a device are connected by the connection means,
4. The electronic device control device according to claim 3, wherein one of the first and second communication units is selected in accordance with a given instruction. 5. An electronic device control device for performing communication by connecting an electronic device as a host or a device, wherein the electronic device as a host and the electronic device as a device are selectively used by terminals of one common connector. A first communication means for communicating as a device with respect to an electronic device as a host connected by the connection means, and a host device for communicating with the electronic device as a device connected by the connection means. An electronic device control apparatus, comprising: a second communication unit that performs communication as: 6. The electronic device control device according to claim 5, wherein, when the electronic device control device is connected by the connection unit, one of the electronic device control devices that has obtained the host right becomes a host. The electronic device control device according to claim 5.