JP2017224219A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus that can detect connection to a connector of a device (for example, USB device) even when power supply to a controller (for example, USB host controller) is completely stopped.SOLUTION: An electronic apparatus 10 comprises: a connector 30 to which a device 20 is detachably attached; a voltage monitoring part 40a that is electrically connected to a host via a voltage line L5 and monitors a voltage state of the voltage line L5; and a device attachment determination part 40b that determines whether or not the device 20 is attached to the connector 30 on the basis of the voltage state of the voltage line L5 monitored by the voltage monitoring part 40a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device, and in particular, an electronic device that can detect attachment of a device (for example, a USB device) to a connector even when power supply to a controller (for example, a USB host controller) is completely stopped. About.

  2. Description of the Related Art Conventionally, a USB device is provided with a connector to which a USB device is detachably attached and a USB host controller that transmits and receives data between the USB device that is attached (connected) to the connector. If not, there is an electronic device that stops the function of the USB host controller (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2000-10907

  However, in the above-described conventional electronic device, in order to detect the attachment of the USB device to the connector, the USB host controller must detect a change in the D + / D− signal. There is a problem that power supply to the host controller cannot be completely stopped.

  The present invention has been made in view of the above circumstances, and even when the power supply to a controller (for example, a USB host controller) is completely stopped, the device (for example, a USB device) is attached to a connector. It is an object of the present invention to provide an electronic device that can detect the above.

  To achieve the above object, according to one aspect of the present invention, there is provided a connector for detachably mounting a device and a voltage that is electrically connected to a host via a voltage line and monitors a voltage state of the voltage line. And a device mounting determination unit that determines whether the device is mounted on the connector based on a voltage state of the voltage line monitored by the voltage monitoring unit.

  According to this aspect, it is possible to provide an electronic device that can detect attachment of a device (for example, a USB device) to a connector even when power supply to the controller (for example, a USB host controller) is completely stopped. Can do.

  This is because whether the device is mounted on the connector is determined (detected) by the device mounting determination unit, not the controller, based on the voltage state of the voltage line monitored by the voltage monitoring unit.

Further, in the above invention, a preferable aspect is that a controller that communicates with the device mounted on the connector and the controller when the device mounting determination unit determines that the device is mounted on the connector. And a power control unit that stops power supply to the controller when the device mounting determination unit determines that the device is not mounted on the connector. .

  According to this aspect, the following effects can be achieved.

  First, when the device mounting determination unit determines that the device is not mounted on the connector, the power supply to the controller can be completely stopped by the action of the power control unit.

  Second, even when the power supply to the controller is completely stopped, it is possible to determine (detect) whether or not the device is mounted on the connector by the action of the device mounting determination unit.

  Third, when the device attachment determination unit determines that the device is attached to the connector, power can be supplied to the controller by the action of the power supply control unit. As a result, the controller can be activated to communicate with the device attached to the connector.

  Fourth, when the device is not attached to the connector, the power supply to the controller can be completely stopped as described above, so compared to the conventional technology in which the power supply to the controller cannot be completely stopped. Power saving can be realized.

  In the above invention, a preferable aspect is that the device includes at least a device-side first terminal and a device-side second terminal electrically connected to the device-side first terminal, and the connector includes: At least a host-side first terminal and a grounded host-side second terminal, wherein the device electrically connects the host-side first terminal and the device-side first terminal, and The host side second terminal and the device side second terminal are electrically connected to be attached to the connector, and the voltage monitoring unit is electrically connected to the host side first terminal via the voltage line. It is characterized by that.

  According to this aspect, the voltage state of the voltage line can be made different between when the device is not attached to the connector and when the device is attached. Therefore, it is possible to determine (detect) whether or not the device is attached to the connector based on the voltage state of the voltage line monitored by the voltage monitoring unit.

  In the above invention, a preferable aspect is that the device is a USB device, the device-side first terminal is a device-side GND terminal, the device-side second terminal is a device-side metal shell, The host-side first terminal is a host-side GND terminal, the host-side second terminal is a host-side metal shell, and the controller is a USB host controller.

  According to this aspect, it is possible to provide an electronic device that can detect the attachment of the USB device to the connector even when the power supply to the USB host controller is completely stopped.

  This is because whether the USB device is attached to the connector is determined (detected) by the device attachment determination unit, not by the USB host controller, based on the voltage state of the voltage line monitored by the voltage monitoring unit. is there.

  In the above invention, a preferred aspect is further characterized by further comprising a circuit for pulling up the voltage of the voltage line.

  According to this aspect, the voltage state of the voltage line can be made different between when the device is not attached to the connector and when the device is attached. Therefore, based on the voltage state of the voltage line monitored by the voltage monitoring unit, it can be determined whether or not the device is attached to the connector.

1 is a schematic configuration diagram of a printer 10. FIG. This is an example of the printer 10 in which the USB device 20 is attached to the USB connector 30. 4 is a flowchart for explaining an example of an operation of the printer 10 of the present embodiment. It is a schematic block diagram of printer 10A which is a 1st modification. It is a schematic block diagram of the printer 10B which is a 2nd modification.

  Hereinafter, a printer 10 to which an electronic apparatus of the present invention is applied will be described with reference to the accompanying drawings. In each figure, corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram of the printer 10. FIG. 2 is an example of the printer 10 in which the USB device 20 is attached to the USB connector 30.

  As shown in FIG. 1, the printer 10 of the present embodiment includes a USB connector 30 (connector) to which a USB device 20 (device) is detachably attached, a control unit 40, and the like as hardware configurations. The printer 10 actually includes a printing mechanism and the like, but is omitted in each drawing.

  The USB device 20 is, for example, a USB memory and includes a device-side metal shell 22 and device-side terminals 24a to 24d. The device-side metal shell 22 and the device-side terminal 24d (No. 4 pin) are electrically connected. Specific USB device. The device side metal shell 22 corresponds to the device side second terminal of the present invention, and the device side terminal 24d corresponds to the device side first terminal (device side GND terminal) of the present invention.

  The USB connector 30 is a general USB connector to which the USB device 20 is detachably attached, and includes a host-side metal shell 32, host-side terminals 34a to 34d, and the like. The host side metal shell 32 corresponds to the host side second terminal of the present invention, and the host side terminal 34d corresponds to the host side first terminal (host side GND terminal) of the present invention.

  In the USB device 20, the host side terminals 34a to 34d and the device side terminals 24a to 24d are electrically connected, and the host side metal shell 32 and the device side metal shell 22 are electrically connected. The USB connector 30 is attached.

The host side metal shell 32 is connected to the ground GND via a ground line L1 (GND signal line). The host side terminal 34a is electrically connected to the VBUS line L2. The host side terminal 34b is electrically connected to the D + line L3. The D + line L3 electrically connects the host side terminal 34b and the USB host controller 44. The host side terminal 34c is electrically connected to the D-line L4. The D-line L4 electrically connects the host side terminal 34c and the USB host controller 44. The host side terminal 34d is electrically connected to the voltage line L5. The voltage line L5 electrically connects the host side terminal 34d and the monitoring port 42.

  A pull-up resistor R (a circuit that pulls up the voltage of the voltage line L5) is connected to the voltage line L5. Therefore, when the USB device 20 is not attached to the USB connector 30 (see FIG. 1), the voltage of the voltage line L5 is pulled up by the pull-up resistor R and becomes H level (for example, 3.3 V).

  On the other hand, when the USB device 20 is attached to the USB connector 30 (see FIG. 2), the voltage of the voltage line L5 becomes L level (for example, 0 V). This is because when the USB device 20 is attached to the USB connector 30, the voltage line L5 is electrically connected to the ground GND. That is, when the USB device 20 is attached to the USB connector 30, the device side metal shell 22 and the host side metal shell 32 are electrically connected as shown by the dotted arrows in FIG. 24d and the host-side terminal 34d are electrically connected, so that the voltage line L5 becomes the host-side terminal 34d, the device-side terminal 24d, the device-side metal shell 22, the host-side metal shell 32, and the ground line L1. This is because it is electrically connected to the ground GND via the pin.

  The control unit 40 includes a monitoring port 42, a USB host controller 44 (controller), and although not shown, a SoC (System-On-a-) in which a CPU, RAM, ROM, and the like are integrated (mounted) on one semiconductor chip. Chip).

  The monitoring port 42 is a port capable of detecting an interrupt, and is used for monitoring the voltage state of the voltage line L5 electrically connected thereto.

  The USB host controller 44 communicates with the USB device 20 attached to the USB connector 30 via the D + line L3 and the D- line L4. The USB host controller 44 is electrically connected to the host side terminals 34b and 34c of the USB connector 30 via the D + line L3 and the D- line L4. The USB host controller 44 is supplied with power (electric power) by a power supply control unit 40c described later, or power supply (electric power) supply is completely stopped.

  As shown in FIG. 1, the printer 10 includes a voltage monitoring unit 40a, a device attachment determination unit 40b, a power supply control unit 40c, and the like as functional configurations. The voltage monitoring unit 40a, the device attachment determination unit 40b, and the power supply control unit 40c are realized by the control unit 40 (CPU) executing a control program (firmware).

  The voltage monitoring unit 40a monitors the voltage state of the voltage line L5 input to the monitoring port 42. The voltage monitoring unit 40a is electrically connected to the host side terminal 34d through the voltage line L5. The voltage monitoring unit 40a is electrically connected to the USB device 20 (host) via the voltage line L5.

  The device attachment determination unit 40b determines whether or not the USB device 20 is attached to the USB connector 30 based on the voltage state of the voltage line L5 monitored by the voltage monitoring unit 40a.

As described above, when the USB device 20 is not attached to the USB connector 30 (see FIG. 1), the voltage of the voltage line L5 is pulled up by the pull-up resistor R and becomes H level (for example, 3.3 V). Become. On the other hand, when the USB device 20 is attached to the USB connector 30 (see FIG. 2), since the voltage line L5 is electrically connected to the ground GND, the voltage of the voltage line L5 is L level (for example, 0V). Become. Thus, the voltage state of the voltage line L5 differs depending on whether the USB device 20 is not attached to the USB connector 30 or not. Accordingly, it can be determined (detected) whether or not the USB device 20 is attached (connected) to the USB connector 30 based on the voltage state of the voltage line L5 monitored by the voltage monitoring unit 40a.

  The power supply control unit 40 c supplies power to the USB host controller 44 when the device mounting determination unit 40 b determines that the USB device 20 is mounted on the USB connector 30. On the other hand, when the device attachment determination unit 40b determines that the USB device 20 is not attached to the USB connector 30, the power supply controller 40c completely stops supplying power to the USB host controller 44.

  Next, an example of the operation of the printer 10 of this embodiment will be described with reference to FIG.

  FIG. 3 is a flowchart for explaining an example of the operation of the printer 10 of the present embodiment.

  The following processing is mainly realized by the control unit 40 (CPU) executing a control program (firmware).

  First, when a power switch (not shown) of the printer 10 is turned on, the control unit 40 is activated (step S10).

  Next, the voltage monitoring unit 40a monitors the voltage state of the voltage line L5 input to the monitoring port 42 (step S12).

  Next, based on the voltage state of the voltage line L5 monitored by the voltage monitoring unit 40a, the device attachment determination unit 40b determines whether or not the voltage of the voltage line L5 input to the monitoring port 42 is L level (step). S14). That is, it is determined whether or not the USB device 20 is attached to the USB connector 30.

  Here, when the USB device 20 is not attached to the USB connector 30 (see FIG. 1), an H level (for example, 3.3 V) is input to the monitoring port 42 as the voltage state of the voltage line L5.

  In this case, the device attachment determination unit 40b determines that the voltage state of the voltage line L5 input to the monitoring port 42 is not at the L level (step S14: No). That is, it is determined that the USB device 20 is not attached to the USB connector 30.

  When it determines with the voltage state of the voltage line L5 input into the monitoring port 42 not being L level (step S14: No). That is, when it is determined that the USB device 20 is not attached to the USB connector 30, the power supply control unit 40c completely stops the power supply (power) supply to the USB host controller 44 (step S16). At that time, the control unit 40 (CPU or the like) may shift to a power saving state depending on its own state.

  Next, it is assumed that the USB device 20 is attached to the USB connector 30 with the power supply to the USB host controller 44 completely stopped (see FIG. 2). In this case, since the voltage line L5 is electrically connected to the ground GND, an L level (for example, 0 V) is input to the monitoring port 42 as the voltage state of the voltage line L5.

  In this case, even if the control unit 40 shifts to the power saving state, the device attachment determination unit 40b determines (detects) the voltage change of the voltage line L5 input to the monitoring port 42 by interruption. Specifically, the device attachment determination unit 40b determines that the voltage state of the voltage line L5 input to the monitoring port 42 is L level (step S14: Yes). That is, it is determined that the USB device 20 is attached to the USB connector 30.

  When it is determined that the voltage state of the voltage line L5 input to the monitoring port 42 is L level (step S14: Yes), that is, when it is determined that the USB device 20 is attached to the USB connector 30, the power control unit 40c Starts supplying power (electric power) to the USB host controller 44 (step S18).

  Next, the USB host controller 44 executes a mutual authentication process called enumeration as a pre-process for establishing a connection with the USB device 20 that is activated by power supply and attached (connected) to the USB connector 30 ( Next, communication (USB communication) is performed with the USB device 20 attached to the USB connector 30 (step S22).

  As described above, according to the present embodiment, the printer 10 that can detect the mounting (connection) of the USB device 20 to the USB connector 30 even when the power supply to the USB host controller 44 is completely stopped. Can be provided.

  This is based on the voltage state of the voltage line L5 monitored by the voltage monitoring unit 40a, not by the USB host controller 44, but by whether or not the USB device 20 is mounted on the USB connector 30 ( Is detected).

  Moreover, according to this embodiment, the following effects can be produced.

  First, when the device attachment determining unit 40b determines that the USB device 20 is not attached to the USB connector 30, the power supply to the USB host controller 44 is completely stopped by the action of the power control unit 40c. Can do.

  Second, even when the power supply to the USB host controller 44 is completely stopped, it is determined (detected) whether or not the USB device 20 is mounted on the USB connector 30 by the action of the device mounting determination unit 40b. can do.

  Third, when the device attachment determination unit 40b determines that the USB device 20 is attached to the USB connector 30, power can be supplied to the USB host controller 44 by the action of the power supply control unit 40c. As a result, the USB host controller 44 is activated and communication (USB communication) can be performed with the USB device 20 attached to the USB connector 30.

  Fourth, when the USB device 20 is not attached to the USB connector 30, the power supply to the USB host controller 44 can be completely stopped as described above, so that the power supply to the USB host controller is completely stopped. Compared with the prior art that cannot be stopped, power saving can be realized.

  Next, a modified example will be described.

  FIG. 4 is a schematic configuration diagram of a printer 10A that is a first modification.

  As shown in FIG. 4, the printer 10 </ b> A of this modification example is different from the printer 10 of the above embodiment in that the USB host controller 44 is provided outside the control unit 40 (that is, the control unit 40 and the USB host controller). 44 is configured as a separate chip), the control unit 40 includes a control terminal 46, the control terminal 46 and the USB host controller 44 are electrically connected by a control line L6, The control unit 40c is different in that it supplies power (or completely stops power supply) directly to the USB host controller 44 via the control terminal 46 (and the control line L6). It is a configuration.

  Also by this modification, the same effect as the above-mentioned embodiment can be produced.

  FIG. 5 is a schematic configuration diagram of a printer 10B that is a second modification.

  As shown in FIG. 5, the printer 10B according to the present modification is different from the printer 10A according to the first modification in that a load switch SW is provided between the control terminal 46 and the USB host controller 44, and the power control unit 40c. However, by controlling the load switch SW via the control terminal 46 (and the control line L6), the difference is that the power is supplied to the USB host controller 44 (or the power supply is completely stopped). It is the structure similar to a form.

  Also by this modification, the same effect as the above-mentioned embodiment can be produced.

  In the above-described embodiment, the example in which the electronic device of the present invention is applied to the printer 10 has been described. However, the present invention is not limited to this, and the electronic device of the present invention is also applied to electronic devices other than the printer 10, for example, personal computers. Of course, you can do it.

  In the above-described embodiment, the example in which the USB device 20 is used as a device, the USB connector 30 is used as a connector, and the USB host controller 44 is used as a controller is not limited thereto. A connector other than the USB connector 30 may be used, and a controller other than the USB host controller 44 may be used.

  Moreover, although the said embodiment demonstrated the example which pulls up the voltage of the voltage line L5, you may pull down not only this but the voltage of the voltage line L5.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited by the description of the above embodiment. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  10, 10A, 10B ... Printer, 20 ... USB device, 22 ... Device side metal shell, 24a ... Device side terminal, 24b ... Device side terminal, 24c ... Device side terminal, 24d ... Device side terminal, 30 ... USB connector, 30b ... Device mounting determination unit, 30c ... Power source control unit, 32 ... Host side metal shell, 34a to 34d ... Host side terminal, 40 ... Control unit, 40a ... Voltage monitoring unit, 40b ... Device mounting determination unit, 40c ... Power source control unit , 42 ... monitoring port, 44 ... USB host controller, 46 ... control terminal, GND ... ground, L1 ... ground line, L2 ... VBUS line, L3 ... D + line, L4 ... D- line, L5 ... voltage line, L6 ... Control line, R ... pull-up resistor, SW ... load switch.

Claims (5)

A connector to which the device is detachably mounted;
A voltage monitoring unit that is electrically connected to the host via a voltage line and monitors the voltage state of the voltage line;
An electronic apparatus comprising: a device attachment determination unit that determines whether the device is attached to the connector based on a voltage state of the voltage line monitored by the voltage monitoring unit. A controller for communicating with the device attached to the connector;
When it is determined that the device is mounted on the connector by the device mounting determination unit, power is supplied to the controller, and when the device mounting determination unit determines that the device is not mounted on the connector, The electronic device according to claim 1, further comprising: a power control unit that stops power supply to the controller. The device includes at least a device-side first terminal and a device-side second terminal electrically connected to the device-side first terminal,
The connector includes at least a host-side first terminal and a grounded host-side second terminal,
The device electrically connects the host-side first terminal and the device-side first terminal, and electrically connects the host-side second terminal and the device-side second terminal. Attached to the connector,
The electronic device according to claim 2, wherein the voltage monitoring unit is electrically connected to the host-side first terminal through the voltage line. The device is a USB device;
The device side first terminal is a device side GND terminal;
The device side second terminal is a device side metal shell,
The host side first terminal is a host side GND terminal;
The host-side second terminal is a host-side metal shell;
The electronic device according to claim 3, wherein the controller is a USB host controller.   The electronic device according to claim 1, further comprising a circuit that pulls up a voltage of the voltage line.

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