TWI536160B - Electronic Device Capable of Turning off Built-In USB Hub to Lower Electric Power Consumption - Google Patents

Description

Electronic device that can turn off the built-in USB hub to save power consumption

The present invention relates to a power-saving power-saving processing technique, and more particularly to an electronic device that can be used to save power consumption by turning off a built-in USB hub applied to a USB hub circuit and providing power saving processing.

Universal Serial Bus (USB) has been widely used in computer systems and peripherals because it has features such as hot swapping or hot plugging and Plug and Play (PNP). An input/output interface on the device connection has even been applied to mobile communication products. Therefore, the USB interface seems to have become the mainstream connector.

In addition, the industry has expanded the original input and output interface of electronic devices, and introduced USB interface expansion devices such as USB hubs or USB interface keyboards with USB hub circuits, and the USB hub circuit provided by the USB interface expansion device allows users to It can be more flexible with external peripheral devices.

However, when the USB interface expansion device does not have any peripheral devices inserted into the USB connector, the USB controller in the USB hub circuit is still consuming power, so how to provide the USB interface expansion function can also achieve energy saving effect. It is the subject of current research.

In view of the above problems of the prior art, an object of the present invention is to provide an electronic device capable of turning off a built-in USB hub to save power consumption, which has both a USB interface expansion function and a power saving function.

To achieve the above and other objects, the present invention provides an electronic device, which can couple a USB device to a host device, and the USB device outputs a first signal. The electronic device includes: a main function module, and outputs a first a second transmission line coupled to the main function module for transmitting the second signal; a connector for selectively connecting the USB device to receive the first signal; and a USB hub circuit Having a first USB downstream port, a second USB downstream port, and a USB port, the first USB downstream port is coupled to the main function module through the first transmission line to receive the second signal, the second USB The downstream port is coupled to the connector to receive the first signal; a detecting unit is disposed adjacent to the connector, and when the connector is connected to the USB device, the detecting unit outputs a trigger signal; a power supply unit, Selectively outputting electrical energy to the USB hub circuit; and a switching control circuit having a host-side transmission line connected to the host device, a bypass line connected to the main function module, and the USB hub circuit a second transmission line connected to the upstream port of the USB, and the switching control circuit is connected to the detecting unit; wherein when the detecting unit does not output the trigger signal, the power supply unit stops supplying power to the USB collecting circuit, and the switching The control circuit is configured to enable the host transmission line and the bypass line to be in an ON state; wherein when the detection unit outputs the trigger signal, the power supply unit supplies power to the USB hub circuit, and the switching control circuit causes the host end The transmission line is switched from the on state of the bypass line to the on state of the second transmission line, so that the main function module and the USB device share the USB hub circuit to process with the host device.

In the foregoing electronic device of the present invention, the switching control circuit includes: a first multiplexer having a first input port, a second input port, and an output port, wherein the first input port transmits the The bypass line is coupled to the main function module, and the second input port of the first multiplexer is coupled to the USB upstream port through the second transmission line; the output of the first multiplexer is transmitted through the host end The transmission line is coupled to the host device.

In the electronic device of the present invention, the second multiplexer includes an input 埠, a first output 埠 and a second output 埠, wherein the input 埠 is coupled to the main function module. The first output port is coupled to the bypass line, and the second output port is coupled to the first USB downstream port of the USB hub circuit. When the detecting unit does not output the trigger signal, the second The device couples the input port to the first output port, wherein when the detecting unit outputs the trigger signal, the second multiplexer couples the input port to the second output port.

Compared with the prior art, the present invention detects whether the USB interface connector for expansion is coupled to the peripheral device, so that when the USB interface connector is detected to be idle, the USB hub circuit is not powered, so The effect of energy saving. Furthermore, in addition to providing a USB interface expansion function and a power saving function, the present invention also provides a main function, and the main function can share a USB hub circuit with the expansion function, thereby effectively reducing hardware cost.

The other aspects of the present invention will be readily understood by those skilled in the art from this disclosure. The invention may also be embodied or applied by other different embodiments. The details of the present invention can be variously modified and changed without departing from the spirit and scope of the invention.

1A is a block diagram showing the basic system architecture of the electronic device of the present invention. The USB device 5 can be coupled to a host device 2, such as a USB interface device such as a USB interface mouse or a USB interface flash drive. The host device 2 is, for example, a USB interface device such as a USB interface mouse or a USB interface flash drive. A computer system such as a desktop computer or a notebook computer, or even a mobile communication device, can be connected to the main function module 15 through a single USB interface 41 by the electronic device 1 of the present invention, and can also selectively activate the USB hub. To connect an additional USB device 5.

The electronic device 1 of the present invention comprises: a main function module 15, a first transmission line 115, a connector 16, a USB hub circuit 11, a detection unit 12, and a switching control circuit 13. In the embodiment, the main function module 15 is a keyboard circuit, so a specific embodiment of the electronic device 1 of the present invention may be a USB interface keyboard 4 of the built-in USB connector 16 as shown in FIG. 2, and the connector 16 is disposed on the keyboard 4 casing, the keyboard 4 The USB device 41 can be connected to the host device 2. It should be noted that the main function module 15 is not limited to the keyboard circuit, that is, the terminal implementation mode can be replaced by different functional modules. For example, the main function module 15 can be a touch circuit. The entire electronic device 1 may be a touch panel; or the main function module 15 may be a mouse circuit, and the entire electronic device 1 may be a mouse device or the like.

The USB hub circuit 11 is generally implemented by a USB hub controller (USB Hub IC), such as a Cypress CY7C656xx USB 2.0 Hub Controller integrated circuit. Since the USB Hub controller is a well-known component in the industry, in order to simplify the drawing and description, only some of the circuits related to the present invention in the USB hub controller will be described below for the USB hub circuit 11. The USB hub circuit 11 has a plurality of USB downstream ports, a logic unit 114, and a USB upstream port. In this embodiment, the number of USB downstream ports of the USB hub circuit 11 is two. As an example, it is of course also possible to use two or more USB downstream ports. In the two USB downstream ports (110, 111) in FIG. 1A, the USB downstream port 110 is coupled to the main function module 15 through the first transmission line 115. The main function module 15 in this embodiment will be a keyboard. For example, the first transmission line 115 is configured to transmit the keyboard signal of the keyboard circuit to the USB downstream port 110; the USB downstream port 111 is coupled to the connector 16 to receive the USB interface signal output by the external USB device. . The logic unit 114 is configured to coordinate the signals received between the USB downstream ports (110, 111) to smoothly integrate the signals received by the USB downstream ports (110, 111) and pass through the USB upstream port 113. Transfer to the host device 2.

The detecting unit 12 is disposed near the connector 16. When the external USB device is connected to the connector 16, the detecting unit 12 is activated to generate a trigger signal, and the trigger signal is transmitted to the switching control circuit 13 and the power source. Unit 14 is provided. When the external USB device is not connected to the connector 16, the detecting unit 12 is activated to stop sending the signal. The detecting unit 12 controls the following actions by using the trigger signal: (1) the switching control circuit 13 performs a line switching operation, and (2) whether the power supply unit 14 outputs power to the USB hub circuit 11.

The switching control circuit 13 has a host-side transmission line 130 connected to the host device 2, a bypass line 131 connected to the keyboard circuit, and a second transmission line 132 connected to the USB upstream port 113 of the USB hub circuit 11, wherein The bypass transmission line 131 is connected to the first transmission line 115; as described in the above paragraph, the switching control circuit 13 is connected to the detection unit 12 to receive the trigger signal. Since the electronic device 1 of the present invention is mainly used to perform the transmission processing of the USB signal, the host-side transmission line 130, the bypass line 131, the first transmission line 115, and the second transmission line 132 respectively have data ends (D+, D). -).

Please refer to FIG. 2 and FIG. 3 , which are used to illustrate a specific embodiment of the detecting unit 12 shown in FIG. 1A , wherein the detecting unit 12 ′ includes: a grounding terminal 121 , a control terminal 120 , and a The touch switch 122 is adjacent to the connector 16, wherein the ground terminal 121 provides a low potential signal as a trigger signal, and the control terminal 120 is connected to the switch control circuit 13 and the power supply unit 14. When the USB device 5 is not connected to the connector 16, the touch switch 122 is disconnected, and the control terminal 120 is connected to the power source, thereby transmitting the high level signal to the switching control circuit 13 and the power supply unit 14. When the USB device is connected to the connector 16, the switch 122 is turned on, and the ground terminal 121 and the control terminal 120 are turned on, thereby transmitting a low potential signal to the switching control circuit 13 and the power supply unit 14, so The embodiment uses the low potential signal as the trigger signal. It should be noted that the control terminal 120 can also be connected to the lower side of the switch 122 adjacent to the ground terminal 121 (not shown here), so that the trigger signal can also be replaced by a high potential signal, and is not limited to low. The potential signal acts as a trigger signal.

In detail, when the connector 16 has not connected to the external USB device 5, and the detecting unit (12' or 12) outputs a high potential signal, the power supply unit 14 stops supplying power to the USB hub circuit 11, and the switching control The circuit 13 causes the host side transmission line 130 to be in an on state with the bypass line 131, i.e., the line relationship as shown in FIG. 1A. Conversely, when the connector 16' is connected to the USB device 5, and the detecting unit (12' or 12) thus outputs the low potential trigger signal, the power supply unit 14 supplies power to the USB hub circuit 11, and The switching control circuit 13 performs a line switching operation to switch the host-side transmission line 130 from the on state with the bypass line 131 to the second transmission line 132, that is, the line relationship as shown in FIG. 1B. Under the circuit switching and power supply operation, the keyboard circuit 15 and the USB device 5 can share the USB hub circuit 11 to transmit data to the host device 2.

It can be seen from the above that the electronic device of the present invention does not supply power to the USB hub circuit with high power consumption when the USB interface connector for expansion is not connected to the peripheral device; The connection state of the USB interface connector satisfies the external expansion function of the user and the main function of the local end of the electronic device, so that in addition to the power saving effect at the right time, the flexibility of the device is improved.

Referring to FIG. 4, the switching control circuit 13 in FIG. 1A can be implemented by a multiplexer 136. The switching control circuit 13' can include: a multiplexer 136 having a first An input port 133, a second input port 134 and an output port 135, the first input port 133 is coupled to the keyboard circuit function module via the bypass line 131 to receive the keyboard signal, and the multiplexer 136 The second input port 134 is coupled to the USB upstream port 113 through the second transmission line 132. The output port 135 of the multiplexer 136 is coupled to the host device 2 through the host terminal transmission line 130, and the multiplexer is coupled through the multiplexer 136 can selectively couple the output port 135 to the first input port 133 or the second input port 134.

In the same manner, when the detecting unit 12 does not connect the USB device, the power supply unit 14 stops supplying power to the USB hub circuit 11 when the detecting unit 12 does not output the trigger signal. The multiplexer 136 couples the output port 135 to the first input port 133, so that the keyboard signal outputted by the keyboard circuit does not pass through the USB hub circuit 11, but is transmitted to the host device 2 through the multiplexer 136. .

Conversely, when the detecting unit 12 outputs the trigger signal because the connector 16 is connected to the USB device, the power supply unit 14 supplies power to the USB hub circuit 11, and the multiplexer 136 couples the output port 135. The second input port 134 is received, so that the keyboard signal outputted by the keyboard circuit can be transmitted to the host device 2 through the USB hub circuit 11 and the multiplexer 136.

In addition, please refer to FIG. 5, which is a block diagram showing the basic system architecture of another embodiment of the electronic device capable of turning off the built-in USB hub of the present invention. The electronic device 1" of the present embodiment is different from the foregoing FIG. 1A or 4 in that a multiplexer 17 is provided between the main function module 15 and the switching control circuit (13 or 13'), and the multiplexer 17 has an input. The first output port 171 and the second output port 172; the multiplexer 17 selectively couples the input port 170 to the first output port 171 according to whether the detecting unit 12" issues a trigger signal. The second output is 172. The input port 170 is coupled to the main function module 15, the first output port 171 is coupled to the bypass line 131, and the second output port 172 is coupled to the USB downstream port 110 of the USB hub circuit 11.

As shown in FIG. 5, when the connector 16 is not connected to the USB device, the detecting unit 12" does not output a trigger signal, so the multiplexer 17 will connect the input port 170 to the first output port 171. And the main function module 15 communicates with the host device 2 through the bypass line 131, and the main function module 15 is completely disconnected from the USB downstream port 110, and the multiplexer 17 is disconnected. The USB downstream port 110 is prevented from drawing additional power from the bypass line 131 to make the D+/D-electric signal between the main function module 15 and the host device 2 more stable.

Conversely, if the bypass line 131 is continuously connected to the USB downstream port 110 as shown in FIG. 4, even if the USB hub circuit 11 is in the power-off state, the USB downstream port 110 of the USB hub circuit 11 may still The power is extracted from the bypass line 131, so that the data terminal D+/D-electric signal of the main function module 15 is too low by the USB downstream port 110, and the host device 2 and the main function module 15 are caused. Unable to stabilize communication.

As can be seen from the above, the multiplexer 17 of FIG. 5 provides the function of signal isolation, so that when the main function module 15 communicates with the host device 2 via the bypass line 131, it can be completely unaffected by the USB downstream of the USB hub circuit 11. The influence of 110 causes the communication between the host device 2 and the main function module 15 to be more stable.

Furthermore, please refer to FIG. 6, which is a block diagram showing the basic system architecture when the present invention is implemented inside a host device. The difference between this embodiment and the foregoing FIG. 1A, FIG. 4 and FIG. 5 is that the electronic device (1 or 1' or 1") shown in FIG. 1A, FIG. 4 or FIG. 5 is a peripheral device (for example, a keyboard and a slide). The mouse or the touchpad) is then pluggably connected to the USB connector of the electronic device such as a mobile phone, a notebook computer or a desktop computer that executes the operating system via the USB transmission line. The embodiment of FIG. 6 is the aforementioned electronic device. The (1 or 1' or 1") itself is the host device 3 (for example, an electronic device such as a mobile phone or a notebook computer that executes the operating system), and the host device 3 also has a motherboard unit 30. In addition, if the main function module 15 is a touch circuit, the host device 3 can be an electronic device such as a tablet computer or a touch smart phone. In short, the terminal function mode can be used for the main function mode. Group 15 is replaced by a different functional module.

The above embodiments are merely illustrative of the principles and effects of the invention and are not intended to limit the invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as listed in the scope of the patent application of the present invention.

1,1',1" electronic device 11 USB hub circuit 110~111 USB downstream port 113 USB upstream port 114 logic unit 115 first transmission line 12, 12', 12" detection unit 120 ground terminal 121 control terminal 122 switch 13 Switching control circuit 136, 17 multiplexer 130 host side transmission line 131 bypass line 132 second transmission line 133 first input port 134 second input port 135 output 埠D+, D- data terminal 14 power supply unit 15 main function mode Group 16 connector 170 input 埠 171 first output 埠 172 second output 埠 2 host device 3 host Counter unit 4 USB interface motherboard 30 41 USB keyboard interface

1A is a block diagram showing the basic system architecture of an electronic device of the present invention for turning off a built-in USB hub to save power consumption;

1B is a block diagram showing the basic system architecture of the switching control circuit of FIG. 1A;

2 is a product example for explaining that the electronic device capable of turning off the built-in USB hub of the present invention to save power consumption is applied to a USB interface keyboard;

3 is a diagram for explaining a specific embodiment of the detecting unit shown in FIG. 1A;

4 is a block diagram showing the basic system architecture of a specific embodiment of the above-described switching control circuit of FIG. 1A;

5 is a block diagram showing the basic system architecture of another embodiment of an electronic device capable of turning off a built-in USB hub of the present invention;

FIG. 6 is a block diagram showing the basic system architecture when the electronic device capable of turning off the built-in USB hub of the present invention to save power consumption is applied to a host device.

1 electronic device 11 USB hub circuit 110~111 USB downstream port 113 USB upstream port 114 logic unit 115 first transmission line 12 detection unit 13 switching control circuit 130 host side transmission line 131 bypass line 132 second transmission line D+, D - Data terminal 14 Power supply unit 15 Main function module 16 Connector 2 Host device

Claims (15)

An electronic device can be coupled to a host device, the USB device outputting a first signal, comprising: a main function module, outputting a second signal; a first transmission line, and the main function The module is coupled to transmit the second signal; a connector selectively connecting the USB device to receive the first signal; and a USB hub circuit having a first USB downstream port and a second USB downstream device And a USB upstream port, the first USB downstream port is coupled to the main function module to receive the second signal through the first transmission line, and the second USB downstream port is coupled to the connector to receive the first signal a detecting unit disposed near the connector, the detecting unit outputs a trigger signal when the connector is connected to the USB device; a power supply unit selectively outputting power to the USB hub circuit; a switching control circuit having a host-side transmission line connected to the host device, a bypass line connected to the main function module, and a second transmission line connected to the USB upstream port of the USB hub circuit, and the switching control The circuit is connected to the detecting unit; wherein when the detecting unit does not output the trigger signal, the power supply unit stops supplying power to the USB hub circuit, and the switching control circuit causes the host terminal transmission line to be in the bypass line An ON state; wherein when the detecting unit outputs the trigger signal, the power supply unit supplies power to the USB hub circuit, and the switching control circuit causes the host terminal transmission line to be switched from the on state of the bypass line to The second transmission line is turned on for the main function module to share the USB hub circuit with the USB device for processing with the host device. The electronic device of claim 1, wherein the electronic device is applied to a USB interface keyboard, wherein the main function module is a keyboard function provided by the USB interface keyboard, and the connector is disposed on the USB interface keyboard shell. . The electronic device of claim 1, wherein the switching control circuit comprises: a first multiplexer having a first input port, a second input port, and an output port. The first input port is coupled to the main function module through the bypass line, and the second input port of the first multiplexer is coupled to the USB upstream port through the second transmission line; the first multiplexer The output is coupled to the host device through the host-side transmission line. The electronic device of claim 1, wherein the detecting unit comprises: a grounding terminal for providing a low potential signal as a trigger signal; and a control terminal connected to the switching control circuit and the power supply unit a switch disposed adjacent to the connector to activate the switch to turn on the ground terminal and the control terminal when the USB device is connected to the second USB downstream port through the connector, thereby transmitting the trigger signal to The switching control circuit and the power supply unit. The electronic device of claim 1, wherein the detecting unit comprises: a power terminal for providing a high potential signal as a trigger signal; and a control terminal connected to the switching control circuit and the power supply unit a switch disposed adjacent to the connector to activate the switch to turn on the power terminal and the control terminal when the USB device is connected to the second USB downstream port through the connector, thereby transmitting the trigger signal to The switching control circuit and the power supply unit. The electronic device of claim 1, wherein the electronic device is built in the host device. The electronic device of claim 6, wherein the bypass transmission line is coupled to the first transmission line. The electronic device of claim 1, further comprising a second multiplexer having an input port, a first output port, and a second output port, wherein the input port and the The main function module is coupled to the first output port and coupled to the bypass line, and the second output port is coupled to the first USB downstream port of the USB hub circuit, when the detecting unit does not output the trigger signal The second multiplexer couples the input port to the first output port, wherein when the detecting unit outputs the trigger signal, the second multiplexer couples the input port to the second output port . An electronic device that couples a USB device to a host device, the USB device outputs a first signal, the electronic device includes: a main function module that outputs a second signal; and a connector that is selectively connectable The USB device is configured to receive the first signal; a first multiplexer having a first input port, a second input port, and an output port, the first input port being coupled to the main function module to receive the a second signal, the output port is coupled to the host device, the first multiplexer selectively coupling the output port to one of the first input port and the second input port; a USB hub circuit The first USB downstream port is connected to the first USB downstream port, and the first USB downstream port is coupled to the main function module to receive the second signal, and the second USB downstream port is coupled. The connector is configured to receive the first signal, the USB upstream port is coupled to the second input port of the first multiplexer; a detecting unit is disposed adjacent to the connector, when the connector is connected to the USB device The detecting unit outputs a trigger signal; and a power supply list Selectively outputting power to the USB hub circuit; wherein when the detecting unit does not output the trigger signal, the power supply unit stops supplying power to the USB hub circuit, and the first multiplexer couples the output port The first input port is configured to enable the second signal to be transmitted to the host device through the first multiplexer without passing through the USB hub circuit; wherein when the detecting unit outputs the trigger signal, the power supply unit pair The USB hub circuit is powered, and the first multiplexer couples the output port to the second input port, so that the second signal and the first signal can be transmitted through the USB hub circuit and the first multiplexer Go to the host device. The electronic device according to claim 9 is applied to a USB interface keyboard, wherein the main function module is a keyboard function provided by the USB interface keyboard, and the connector is disposed on the USB interface keyboard shell. . The electronic device of claim 9, wherein the detecting unit comprises: a grounding terminal for providing a low potential signal as a trigger signal; a control terminal, and the first multiplexer and the power supply a unit connection, a switch disposed adjacent to the connector, when the USB device is connected to the second USB downstream port through the connector, the switch is activated to turn on the ground terminal and the control terminal, and the trigger signal is further Transfer to the first multiplexer and the power supply unit. The electronic device of claim 9, wherein the detecting unit comprises: a power terminal for providing a high potential signal as a trigger signal; a control terminal, and the first multiplexer and the power supply a unit connection, a switch disposed adjacent to the connector, when the USB device is connected to the second USB downstream port through the connector, the switch is activated to turn on the power terminal and the control terminal, and the trigger signal is further Transfer to the first multiplexer and the power supply unit. The electronic device of claim 9, further comprising: a host end transmission line, a bypass line, a first transmission line, and a second transmission line, wherein the first USB downstream of the USB hub circuit The first transmission line is coupled to the main function module through the first transmission line; the first input port of the first multiplexer is coupled to the main function module through the bypass line; the second input of the first multiplexer And being coupled to the USB upstream port through the second transmission line; the output of the first multiplexer is coupled to the host device through the host-side transmission line. The electronic device of claim 13, wherein the bypass transmission line is coupled to the first transmission line. The electronic device of claim 13, further comprising a second multiplexer having an input port, a first output port, and a second output port, wherein the input port and the input device The main function module is coupled to the first output port and coupled to the bypass line, and the second output port is coupled to the first USB downstream port of the USB hub circuit, when the detecting unit does not output the trigger signal The second multiplexer couples the input port to the first output port, wherein when the detecting unit outputs the trigger signal, the second multiplexer couples the input port to the second output port .