JP2015035012A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device which operates in an appropriate operation mode according to power supply capability of a partner device connected with the electronic device via a USB interface.SOLUTION: An electronic device comprises: a USB interface 1; a processor unit 10 which controls units 2-1 to 2-n, respectively; power-consumption mode switching means 31 which controls at least the processor unit 10 to be in a high power-consumption mode or a low power-consumption mode; determination means 11 which determines whether a partner device that is connected with the electronic device via the USB interface 1 is a host having a USB host function or a device without the USB host function; and power control means 12 which controls the power-consumption mode switching means 31 on the basis of a determination result by the determination means 11.

Description

  The present invention relates to an electronic device that receives power supply via a USB interface.

  An electronic device that receives power supply via a USB interface can be connected to, for example, a personal computer or a television having a USB terminal. The electronic device can also be connected to an AC adapter having a USB terminal.

  In the USB standard, the power supply capability is 0.5 A, and devices that operate by power supply from the USB terminal are restricted to this standard of 0.5 A. However, an AC adapter having a USB terminal is configured with a margin so that a current exceeding the standard of 0.5 A can be passed. On the other hand, a host such as a personal computer or a television is strictly configured so that the power supply capability is 0.5 A as in the standard.

  Therefore, there is no waste if it can operate with power consumption according to the device on the power supply side, and power can be used effectively. However, there is no electronic device designed from such a viewpoint.

  As an electronic apparatus adopting a configuration close to the above example, there is known an image reading apparatus that operates in a normal mode when connected to an external power supply and operates in a power saving mode when receiving power supply via a USB cable or the like. (See Patent Document 1).

JP 2001-358908 A

  The present invention has been made in view of such a situation in electronic devices, and an object of the present invention is to provide an electronic device that can operate in an appropriate operation mode according to the power supply capability of the counterpart device connected via the USB interface. Is to provide a device.

  An electronic apparatus according to the present invention includes a USB interface, a processor unit that controls each unit, a power consumption mode switching unit that operates at least the processor unit in a high power consumption mode or a low power consumption mode, and the USB interface. Determination means for determining whether the connected partner device is a host having a USB host function or a device having no USB host function, and power for controlling the power consumption mode switching means based on a determination result by the determination means And a control means.

  In the electronic apparatus according to the present invention, the determining means determines whether the partner apparatus is a host or a device depending on whether the partner apparatus has a communication function.

  In the electronic device according to the present invention, the power consumption mode switching means changes the operation clock frequency of the processor unit to realize a high power consumption mode and a low power consumption mode.

  In the electronic apparatus according to the present invention, the power control unit causes the low power consumption mode to be executed when the determination unit determines that the host is a host, and the power control unit executes the high power consumption mode when the determination unit determines that the host is a device. It is characterized by running

  In the electronic device according to the present invention, the electronic device is an HDMI dongle.

  According to the present invention, it is determined whether the counterpart device connected via the USB interface is a host having a USB host function or a device not having a USB host function, and at least the processor unit is increased based on the determination result. Since the operation is performed in the power consumption mode or the low power consumption mode, the operation can be performed in an appropriate operation mode according to the power supply capability of the counterpart apparatus connected via the USB interface.

The block diagram which shows the function structure of embodiment of the electronic device which concerns on this invention. The block diagram which shows the structure of the HDMI dongle as embodiment of the electronic device which concerns on this invention. 6 is a flowchart for explaining the operation of the embodiment of the electronic device according to the present invention.

  Embodiments of an electronic device according to the present invention will be described below with reference to the accompanying drawings. In each figure, the same components are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 shows a functional block diagram of an embodiment of an electronic device according to the present invention. The electronic apparatus includes a USB interface 1 and a processor unit 10 that controls the units 2-1 to 2-n.

  The processor unit 10 includes a determination unit 11. The determination unit 11 determines whether the partner apparatus connected via the USB interface 1 is a host having a USB host function or a device having no USB host function. For example, the determination unit 11 determines whether the partner apparatus is a host or a device depending on whether the partner apparatus has a communication function. A power consumption mode switching means 31 is connected to the outside of the processor unit 10.

  The power consumption mode switching unit 31 operates at least the processor unit 10 in the high power consumption mode or the low power consumption mode, and is a clock generation unit 311 in this embodiment. That is, the clock generation unit 311 changes the operation clock frequency of the processor unit 10 and increases the frequency of the operation clock in the high power consumption mode, and decreases the frequency of the operation clock in the low power consumption mode. Realization of power consumption mode switching. As the power consumption mode switching means, the power given to each unit 2-1 to 2-n is increased in the high power consumption mode, and the power given to each unit 2-1 to 2-n is reduced in the low power consumption mode. It may be a power supply unit.

  The processor unit 10 includes a power control unit 12 that controls the power consumption mode switching unit 31 based on a determination result by the determination unit 11. The power control unit 12 performs control so that the low power consumption mode is set when the determination result is a host determination result, and high power consumption when the determination result is a device determination result. Control is performed so as to be in the power mode.

  The USB interface 1 performs serial / parallel conversion on the serial data of the signal line and sends it to the bus 3, and parallel / serial converts the parallel data on the bus 3 and sends it to the outside. The USB interface 1 connects the power supply line to the power supply unit 4. When a counterpart device such as a device or a host is connected to the USB interface 1, power arrives at the power supply unit 4 via the USB interface 1. The power supply unit 4 receives this and supplies it to the units 2-1 to 2-n and the processor unit 10 as necessary voltages.

  The electronic device configured as described above can configure the HDMI dongle shown in FIG.

  The HDMI dongle 40 is connected to a television (not shown) having an HDMI terminal, and includes an Android (registered trademark) as an OS and a program that enables the television to be used as a personal computer.

  The configuration is as shown in FIG. That is, the CPU 41 includes a main memory 42, a storage unit 43, a communication interface (here, Bluetooth communication) 44, an HDMI port 45, a USB port 46, and a power management IC 47. Power is supplied via the USB port 46 or the power management IC 47.

  The CPU 41 corresponds to the processor unit 10 and the clock generation unit 311 in FIG. 1, the USB port 46 corresponds to the USB interface 1 in FIG. 1, and the other corresponds to the units 2-1 to 2-n in FIG. A configuration corresponding to the power supply unit 4 of FIG. 1 is not shown.

  The operation when the electronic apparatus is connected to a host such as a personal computer or a television having a USB terminal or connected to a device that is an AC adapter having a USB terminal will be described with reference to the flowchart of FIG. . When the partner device is connected to the USB interface 1, it is determined whether the partner device is a host or a device depending on whether or not the partner device has a communication function (S11). If it has a communication function, since it is a host, the clock generator 311 is controlled to lower the frequency of the operation clock to realize the low power consumption mode (S12). On the other hand, when it does not have a communication function, it is a device and an AC adapter, so the frequency of the operation clock is increased to realize the high power consumption mode (S13). As a result, high-speed operation can be ensured when sufficient power supply is received, and stable operation can be ensured by suppressing power consumption when sufficient power supply cannot be received.

  In the above embodiment, whether the connected device is a host or a device is determined immediately after the connection, but immediately after the connection, a low power consumption mode is realized and a predetermined time (several tens of seconds to several minutes) is achieved. After the elapse of time, it may be determined whether the connected device is a host or a device. In this way, even when a host that does not perform communication using the communication function is connected immediately after the USB connection is made, it can be configured to operate in an appropriate power consumption mode without making a determination error.

DESCRIPTION OF SYMBOLS 1 USB interface 2 Patent document 2-1 to 2-n Each part 3 Bus 4 Power supply part 10 Processor part 11 Determination means 12 Power control means 31 Power consumption mode switching means 40 Dongle 42 Main memory 43 Memory | storage part 45 HDMI port 46 USB port 311 Clock generator

Claims (5)

A USB interface;
A processor unit for controlling each unit;
Power consumption mode switching means for operating at least the processor unit in a high power consumption mode or a low power consumption mode; and
Determining means for determining whether the counterpart device connected via the USB interface is a host having a USB host function or a device having no USB host function;
An electronic apparatus comprising: a power control unit that controls the power consumption mode switching unit based on a determination result by the determination unit.   The electronic apparatus according to claim 1, wherein the determination unit determines whether the partner apparatus is a host or a device depending on whether the partner apparatus has a communication function.   3. The electronic apparatus according to claim 1, wherein the power consumption mode switching means realizes a high power consumption mode and a low power consumption mode by changing an operation clock frequency of the processor unit.   The power control unit causes the low power consumption mode to be executed when the determination unit determines that the host is used, and causes the high power consumption mode to be executed when the determination unit determines that the device is a device. The electronic device according to claim 1.   The electronic device according to claim 1, wherein the electronic device is an HDMI dongle.

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