KR20060112053A - Connection detecting method of usb device and the same processing portable terminal - Google Patents

Abstract

A method for detecting connection of a USB(Universal Serial Bus) device and a portable terminal performing the same are provided to prevent a wrong operation caused by irregular voltage supplied from a host terminal, and to protect damage of a USB port or components of connected portable terminal in case that the voltage supplied from the host terminal is higher than a reference value. A portable terminal comprises a USB connector(410), a controller(430), and a signal transmitter(440). The USB connector(410), combined with a host device via a cable, includes one and more data terminals and a ground terminal for data transmission with the host device. The controller(430) controls the USB connector(410) for the data transmission in case that the host device is combined with the USB connector(410). The signal transmitter(440), whose one end is combined with the ground terminal and whose other end is combined with the controller(430), transmits a current signal of an arbitrary size to the controller(430) if combined with the host device via the USB connector(410).

Description

Connection detecting method of USB device and the same processing portable terminal

1 is a block diagram briefly illustrating a communication method using a USB between a typical portable terminal and a host terminal.

2 is a block diagram schematically showing the configuration of a portable terminal including a USB (USB) according to an embodiment of the present invention.

3 is a circuit diagram briefly illustrating a circuit configuration of a signal transmission unit according to an exemplary embodiment of the present invention.

Figure 4 is a simplified block diagram illustrating a communication method using a USB terminal of the portable terminal and the host terminal (USB).

The present invention relates to a portable terminal, and more particularly, to a portable terminal that recognizes a connection of a universal serial bus (USB) device.

USB is a universal communication bus specification developed by seven companies: Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel. Its host terminal (e.g., personal computer) and peripherals ( For example, it is a plug and play interface between portable terminals, audio players, joysticks, keyboards, phones, scanners, and printers.

Advancing from earlier bus conventions, the main goal of USB technology is to provide easy access to peripherals, as can be seen in the USB 1.0 specification, which is extended to the concept of easily integrating up to 127 peripherals in a host terminal. It also provides scalability, low cost communication and data transfer with peripherals.

Thus, at present, USB adopts the concept of master / slave. In order to support a direct connection between a host terminal and each peripheral device or a connection through a hub, a basic serial bus (i.e. And serial bus).

For example, when a host device and a peripheral device such as a portable terminal are coupled through the USB, the combined peripheral device may receive power from the host terminal through the USB.

In general, the voltage applied to the USB device in the host terminal (for example, a computer) is specified as 5V. However, some terminal terminals such as prefabricated computers may apply different voltages (eg, 9V, 12V, etc.) or non-uniform voltages (eg, unevenly varying voltages) depending on assembly characteristics. . In such a case, the USB port of the portable terminal may be damaged or a malfunction may be caused. Of course, damage to the USB port and application of overvoltage may cause a fire to the portable terminal or damage to components.

The above-mentioned problems are not limited to portable terminals, and are common to all peripheral devices using USB as a communication means.

Accordingly, an object of the present invention for solving the above problems is to connect a USB device capable of stably recognizing whether a USB device is connected regardless of whether the voltage is applied from the host terminal and / or the magnitude of the applied voltage. A recognition method and a portable terminal for performing the method are provided.

Another object of the present invention is to provide a method for recognizing a connection of a USB apparatus and a portable terminal for performing the method, even when the voltage applied from the host terminal is irregular.

Still another object of the present invention is a method for recognizing a connection of a USB device capable of damaging a USB port or protecting a connected portable terminal component even when a voltage applied from a host terminal is greater than or equal to a reference value and a portable device performing the method. It is to provide a terminal.

Still another object of the present invention is to use a grounding terminal provided in a portable terminal as a detection pin capable of recognizing whether a USB device is connected or not, thereby reducing the unit cost of the portable terminal, and a method for recognizing the connection of a USB terminal. It is to provide a portable terminal for performing the method.

Still other objects of the present invention will be readily understood through the following description of the embodiments.

In order to achieve the above object, according to an aspect of the present invention, in the portable terminal, a USB connector coupled to the host device via a cable, including one or more data terminals and ground terminals for data transmission and reception with the host device ; A controller configured to control the USB connector for transmitting and receiving the data when the host device is coupled to the USB connector; And a signal transmission unit configured to couple one end to the ground terminal, the other end to the control unit, and the control unit and the other end to transmit a current signal having an arbitrary size to the control unit when the host device is coupled through the USB connector. Provides a portable terminal for determining whether the host device is coupled based on the detection signal.

The signal transfer unit includes one or more transistors, a first applied voltage applied to the base terminal or the ground terminal of the transistor, a second applied voltage applied to the collector terminal of the transistor, or the controller, and one or more predetermined resistors. It features.

When a current corresponding to the first applied voltage is input to the base terminal, the transistor is turned on so that a current corresponding to the second applied voltage is output to the emitter terminal of the transistor (ie, grounded through the emitter terminal. Side), and when the current corresponding to the first applied voltage is outputted (flows) to the ground terminal by being coupled with the host device through the USB connector, the transistor is turned off to correspond to the second applied voltage. The current is output to the control unit.

The transistor is an NPN transistor, and the signal transfer unit further includes a capacitor for noise bypass.

The signal transmission unit may be coupled to a general purpose input / output port (GPIO) of the controller.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the prior art will be briefly described with reference to the accompanying drawings for the convenience of understanding before describing the preferred embodiment of the present invention. In addition, numbers (eg, first, second, etc.) used in the present specification are for distinguishing the same or similar entities, but the scope of the rights or the objects thereof are not limited thereto.

The portable terminal according to the present invention may be a mobile communication terminal, a portable multimedia player, an MP3, and the like. In addition, the portable terminal may be equally applicable to any device capable of performing data communication using the USB connector 210 described below. Self-explanatory

FIG. 1 is a block diagram schematically illustrating a communication method using a USB between a general portable terminal and a host terminal.

Referring to FIG. 1, a method of recognizing whether a portable terminal 100 having a general UBS connector is connected to the host terminal 140 using UBS (USB) will be described.

As shown in FIG. 1, the portable terminal 100 includes a USB connector 110, a USB controller 120, and a controller 130.

The USB connector 110 is coupled to the host terminal 140 (eg, a personal computer) through the USB cable. In FIG. 1, a USB cable is illustrated for a 4-pin terminal, and the USB cable 110 corresponds to a power terminal (eg, VBUS (5V)) and a ground terminal (eg, VBS (5V)) receiving power from the host terminal 140. For example, GND) includes a first data terminal (eg, D +) and a second data terminal (eg, D−) for data transmission and reception.

The structure of the USB connector 110 includes a power terminal (for example, VBUS (5V)) and a ground terminal (for example, in the process of connecting the USB cable to the USB connector 110). GND) is configured to engage with a USB cable before the first data terminal (eg D +) or the second data terminal (eg D-).

The USB cable is coupled to the USB connector 110 of the portable terminal 100, and when connected to the host terminal 140, a voltage of 5V is applied to the power terminal VBUS of the USB connector 110. Is applied. Then, the USB controller 120 recognizes that the USB terminal 120 is connected to the host terminal 140 through the USB cable to the USB connector 110 when the voltage applied to the power terminal VBUS is greater than or equal to the reference voltage. can do.

However, in this case, as described above, an irregular voltage is applied to the USB controller 120 of the portable terminal 100 due to the irregular power supply from the host terminal 140, and the portable terminal 100 malfunctions. Will cause.

In addition, since an overvoltage (for example, 9V, 12V, etc.) is applied from the host terminal 140 to the power supply terminal (ie, VBUS) and consequently the overcurrent is supplied, the USB controller of the portable terminal 100 (USB controller) 120 There was also a problem that can cause a fire.

FIG. 2 is a block diagram schematically illustrating a configuration of a portable terminal including a USB device according to an exemplary embodiment of the present invention, and FIG. 3 is a schematic diagram of a circuit configuration of a signal transmission unit according to an exemplary embodiment of the present invention. 4 is a circuit diagram schematically illustrating a communication method using a USB terminal of a portable terminal and a host terminal.

As shown in FIG. 2, the portable terminal 100 according to the present invention includes a USB connector 210, a USB controller 220, a controller 230, and a signal transmitter 240. .

The USB connector 210 is connected to the host terminal 140 through a USB cable, and is a power terminal for receiving power from the host terminal 140 (for example, VBUS (5V)). , A ground terminal (eg, GND), a first data terminal (eg, D +) for data transmission and reception, and a second data terminal (eg, D−).

Here, the first data terminal and the second data terminal for data transmission and reception are connected to the USB controller 220 through a data line. The ground terminal is connected to the control unit 230 through the signal transmission unit 240.

As illustrated in FIG. 3, the signal transmitter 240 includes a power supply terminal, an NPN transistor, a plurality of resistors R1 and R2, a plurality of applied voltages VDD1 and VDD2, and a capacitor. It is connected to the control unit 230. An operation process of the signal transmitter 240 will be described below.

The USB controller 220 is connected to the data terminals D + and D- of the USB connector 210 to transmit and receive data, and serves as a data transmission / reception function with the host terminal 140. Although not shown in FIG. 2, the USB controller 220 includes a transceiver that is responsible for an electrical interface with the USB, a serial interface engine (SIE) for transmitting and receiving serial data at high speed, and a controller. Internal blocks such as an interface unit in charge of the interface with the 230 may be included. Here, most internal blocks for high speed communication may be configured as integrated circuits (ICs).

The controller 230 is connected to the ground terminal of the USB connector 210 through the signal transmission unit 240 to recognize whether the host terminal 150 is connected to the USB connector 210. In addition, when it is recognized that the controller 230 is connected to the host terminal 150, the controller 230 controls the USB controller 220 to receive data input from the host terminal 140 through the first and second data terminals.

The signal transmission unit 240 is coupled to the ground terminal of the USB connector 210 and the GPIO port of the controller 230 to correspond to whether the host terminal is coupled to the USB connector 210. Different currents corresponding to the applied voltages are transferred to the GPIO ports of the controller 230. Detailed operations of the signal transmission unit 240 will be described below.

First, as shown in FIGS. 2 and 3, the circuit operation method of FIG. 3 when the host terminal 140 is not connected to the USB connector 210 will be described.

A plurality of resistors shown in the circuit of FIG. 3 can be used for pull up, and a capacitor bypasses to remove noise components that occur when combined with a USB cable. Can be used for purposes. In addition, the NPN transistor may perform many functions such as a switch or an amplifier. In an exemplary embodiment of the present invention, the NPN transistor is described as being limited to the NPN transistor, but the same function other than the NPN transistor is performed. It is apparent that this possible transistor may be used.

In the following description, a detailed operation method of the NPN transistor is obvious to those skilled in the art, so it will be briefly described.

As shown in FIG. 2, when the USB cable is not connected, the same state as that of the infinite resistance is connected to the ground terminal (ie, GND) of the USB connector 210. Accordingly, as shown in FIG. 3, a current corresponding to the second applied voltage (ie, VDD2) flows along the path 1 to the base end of the NPN transistor. That is, a high signal is input to the base end of the NPN transistor.

That is, the NPN transistor is turned on by a current corresponding to the second applied voltage (that is, VDD2) input to the base terminal, and the collector terminal of the NPN transistor is connected. A current corresponding to the first applied voltage (that is, VDD1) input to is output along the path 2 to the emitter terminal of the NPN transistor.

Therefore, a current corresponding to the first applied voltage (ie, VDD1) is not input to the general purpose input / output (GPIO) port of the controller 230. Of course, a very small amount of current may be input by the magnitude of the resistance component. That is, the general-purpose input / output (GPIO) port of the controller 230 is in a low state. Accordingly, the controller 230 may recognize that the host terminal 140 is not connected as the GPIO port is in a low state.

In this state, as shown in FIG. 4, when the USB cable is connected through the USB connector 410, the second voltage corresponds to the second applied voltage (ie, VDD2) as shown in FIG. 3. The current flows along path 3 toward the ground terminal (ie, GND) of the USB connector 410. Therefore, a current corresponding to the second applied voltage (ie, VDD2) is not input to the base terminal of the NPN transistor, and consequently a low signal to the base terminal of the NPN transistor. ) Is entered.

That is, the NPN transistor is turned off by a low signal, and a current corresponding to the first applied voltage (ie, VDD1) is passed to the general-purpose input / output (GPIO) port of the controller 430 along the path 4. Is output. When the NPN transistor is turned on, a path is formed between the collector and the emitter so that a current corresponding to the first applied voltage (that is, VDD1) flows to the ground side like the path 2, but the NPN transistor In the turn-off state, since no path is formed between the collector and the emitter, current flows to the GPIO port as in path 4.

As a result, a current corresponding to the first applied voltage (that is, VDD1) is input to the general purpose input / output (GPIO) port of the controller 230, and the general purpose input / output (GPIO) port of the controller 430 is in a high state. Is switched. Accordingly, the controller 430 may recognize that the host terminal 140 is connected by detecting that the state of the general-purpose input / output (GPIO) port is high.

As such, the controller 430 may recognize whether the host terminal 140 is connected to the USB connector 410 by detecting whether the current is input from the signal transmission unit 440 or the magnitude of the input current. Can be.

As described above, the present invention can stably recognize whether the USB device is connected regardless of whether the voltage is applied from the host terminal and / or the magnitude of the applied voltage.

In addition, the present invention has an effect that can prevent the malfunction even when the voltage applied from the host terminal is irregular.

In addition, the present invention has the effect that even if the voltage applied from the host terminal is greater than the reference value or irregular voltage can protect the USB port or the connected portable terminal components.

In addition, the present invention has the effect of reducing the unit cost of the portable terminal by using the ground terminal provided in the portable terminal as a detection pin (detection) that can recognize the connection of the USB device.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

Claims (6)

In a portable terminal, A USB connector coupled to the host device through a cable, the USB connector including one or more data terminals and a ground terminal for data transmission and reception with the host device; A controller configured to control the USB connector for transmitting and receiving the data when the host device is coupled to the USB connector; And One end is coupled to the ground terminal, the other end is coupled to the control unit, and includes a signal transmission unit for transmitting a current signal of any size to the control unit when the host device is coupled through the USB connector, The controller determines whether the host device is coupled based on the detection signal. The method of claim 1, The signal transmission unit is a portable device including one or more transistors, a first applied voltage applied to the base terminal or the ground terminal of the transistor, a second applied voltage applied to the collector terminal of the transistor, or the controller, and one or more preset resistors. terminal. The method of claim 2, When the current corresponding to the first applied voltage is input to the base terminal, the transistor is turned on so that the current corresponding to the second applied voltage is output to the emitter terminal of the transistor, When the current corresponding to the first applied voltage is output to the ground terminal by being coupled to the host device through the USB connector, the transistor is turned off so that the current corresponding to the second applied voltage is output to the controller. Handheld terminal. The method of claim 2, The transistor is a portable terminal of the NPN transistor. The method of claim 2, The signal transmission unit further comprises a capacitor (capacitor) for noise bypass. The method of claim 1, The signal transmission unit is coupled to a general-purpose input / output (GPIO) port of the control unit.

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