JP5986026B2 - Host device, host device control method, and semiconductor device - Google Patents

Description

  The present invention relates to a host device, a host device control method, and a semiconductor device, and can be suitably used for, for example, a host device that charges a device device, a host device control method, and a semiconductor device.

  In recent years, electronic devices compatible with the USB (Universal Serial Bus) standard have become widespread. In USB, a USB host (also referred to as a host device or simply a host) and a USB device (also referred to as a device device or simply a device) are directly connected via a USB cable or a USB plug receptacle. Note that a USB device refers to a USB device whose function is provided to a user by connecting to a USB host.

  In USB, input / output is performed between a USB host and a USB device using signal lines D + / D− / VBUS / GND in a USB plug receptacle (and USB cable) (each signal line is simply D + / D−). / VBUS / GND). D + / D− is a differential data signal line, and VBUS / GND is a power supply line. USB functions include data communication using D + / D− and power supply using VBUS. This power supply is performed from the host or hub toward the device. The number of products that use USB as a power supply mode for portable devices driven by a battery or the like continues to increase, and charging accessories for converting from an AC power source to a VBUS power source are often attached.

  In recent years, as the battery capacity of devices has increased, the need for high-speed charging has increased, and products equipped with USB downstream ports capable of high-speed charging, which are unique to device vendors, and charging accessories have been developed and spread throughout the world. The application of the high-speed charging function to the USB installed in the host side system such as PC (Personal Computer) is still under development, and the USB Implementers Forum has newly established the Battery Charging Specification that adds the high-speed charging function to the USB. . According to this specification, the portable device can perform high-speed charging by drawing current more than the previous (conventional) USB standard (500 mA) by handshaking with the downstream port for high-speed charging of the connected host.

  Note that the previous (conventional) USB charging is charging performed using a current of 500 mA or less defined by USB 2.0 before the establishment of Battery Charging Specification. The high-speed charging is charging performed at a higher speed (rapidly) than usual by using a current larger than 500 mA defined by USB 2.0 (for example, a current defined by Battery Charging Specification). There are also semiconductor products that switch between the USB downstream port capable of high-speed charging and the USB downstream port of the previous USB standard.

  For example, Non-Patent Documents 1 and 2 and Patent Documents 1 and 2 are known as conventional techniques. Non-Patent Document 1 is a standard for the above-mentioned Battery Charging Specification. Non-Patent Document 1 describes Charging Downstream Port (CDP) that can charge a device at high speed without hindering the USB communication function of the previous USB standard, and Dedicated Charging Port (only for high-speed charging of the device). DCP) specifications are described.

  FIG. 16 shows the configuration of the CDP described in Non-Patent Document 1. As shown in FIG. 16, the CDP 904 connects D + / D− of the plug receptacle 901 and D + / D− of the USB host controller 903. When charging with CDP, the device receives the handshake signal sent from the upstream host controller 903 via the CDP 904, and notifies the upstream side via the CDP downstream port 904 that high-speed charging is possible. . At the stage where the handshake is completed, the connected device draws a current exceeding the previous USB standard (500 mA) from the VBUS supply circuit 902 via the VBUS and performs high-speed charging.

  In Non-Patent Document 1, a downstream port of USB 2.0, which is the previous USB standard, is defined as a Standard Downstream Port (SDP). Similarly to the CDP 904 in FIG. 16, the SDP is configured to connect D + / D− of the plug receptacle 901 and D + / D− of the USB host controller 903.

  FIG. 17 shows the configuration of the DCP described in Non-Patent Document 1. As shown in FIG. 17, the DCP 905 has a short-circuit resistance R901, conducts the differential data signal D + / D− of the plug receptacle 901 through the short-circuit resistance R901, and loops back the handshake signal from the device side. . Thus, the device has a hardware configuration that can complete handshaking in a self-contained manner. Hereinafter, a configuration in which D + / D− is short-circuited and a handshake signal from the device is looped back like DCP is referred to as a D + / D− loop type. When performing high-speed charging with the D + / D− loop type, D + / D− is short-circuited, so data communication cannot be performed between the host and the device via D + / D−.

  As shown in FIGS. 16 and 17, although CDP and DCP have different hardware configurations, they are standardized so that high-speed charging is possible with either DCP or CDP if the device conforms to this specification. In addition to the DCP, there are D + / D-circular type high-speed charging ports in the world, and if they do not satisfy the specifications of Non-Patent Document 1, the D + / D-circular type DCP is used. Charges fast, but not with CDP.

  In addition to Non-Patent Document 1, there are products on the market that switch between a downstream port capable of high-speed charging and a previous USB standard downstream port. For example, in the USB host charge identification analog switch of Non-Patent Document 2, it can be inferred that detecting a certain fixed voltage from the USB differential signal D + / D− is used as a high-speed charging handshaking method. Hereinafter, a configuration in which handshaking is performed by setting D + / D− to a predetermined fixed voltage is referred to as a D + / D− fixed voltage output type.

  FIG. 18 shows a configuration of a D + / D− fixed voltage output type downstream port assumed from Non-Patent Document 2 or the like. As shown in FIG. 18, the D + / D− fixed voltage output type downstream port 906 includes voltage dividing resistors R911 and R912 connected in series and voltage dividing resistors R921 and R922 connected in series, and the voltage dividing resistor R911. And the intermediate node of R912 is connected to D + of the plug receptacle 901, and the intermediate node of the voltage dividing resistors R921 and R922 is connected to D− of the plug receptacle 901. By using these voltage dividing resistors, a handshake is realized by supplying a fixed voltage to the device. When fast charge is performed with the D + / D− fixed voltage output type, since a fixed voltage is output to D + / D−, data communication cannot be performed between the host and the device via D + / D−.

  Patent Document 1 has a configuration in which a USB host can select an effective power supply mode for a connected USB device, and can wake up from the connected USB device when the system is not operating. Is described. Patent Document 2 describes that an external device is charged while the display device is in a standby mode.

USB Implementers Forum, "Battery Charging Specification Rev1.2", December 7, 2010 Maxim Integrated Products, “USB Host Charger Identification Analog Switch”, [online], [Search March 1, 2013], Internet <URL: http://datasheets.maximintegrated.com/jp/ds/MAX14550E_en.pdf>

JP 2010-257493 A JP 2012-120433 A

On the other hand, when a host-side system such as a PC is in a power saving state, returning the PC to a normal state with a signal from a USB device is called a wake-up function, and is performed by the following three types of triggers.
-Remote wakeup: Trigger USB devices connected to the system (mouse click, keyboard input, etc.)
・ Wake on connect: Connect a USB device to an unconnected USB downstream port ・ Wake on disconnect: Disconnect a connected USB device

  These functions cannot be used unless the host system can perform USB data communication in a power saving state.

  In recent years, when a USB downstream port capable of high-speed charging as described above is installed in a host side system, when the host side system is in normal operation, the USB downstream port (SDP) capable of data communication of the previous USB standard is used. When the setting is made and the host-side system is in the power saving state, a method of switching the function to the high-speed charging downstream port as shown in FIGS. 17 and 18 is general.

  However, in the case of this method, the wake-up function by the USB device cannot be used from the high-speed charging downstream port when the host-side system transitions to the power saving state. In other words, the downstream port for charging such as the D + / D-circular type of FIG. 17 and the D + / D-fixed voltage output type of FIG. 18 uses the wake-up function because data communication with the device is not performed during charging. There was a problem that could not be done.

  Other problems and novel features will become apparent from the description of the specification and the accompanying drawings.

  According to an embodiment, the host device includes a connection connector, a power supply unit, a charging downstream port, a connection state detection unit, and a wakeup control unit. The connection connector is a connector for connecting a device device. The power supply unit supplies power to the device device via the power supply terminal of the connection connector. The charging downstream port is a port that does not perform data communication with the device device via the data terminal of the connection connector when the device device is being charged by the power supply unit. The connection state detection unit detects the connection state of the device device via the charging downstream port. The wakeup control unit performs wakeup processing according to the detected connection state of the device device.

  According to the embodiment, the wake-up function can be realized even in a charging downstream port that does not perform data communication with a device during charging.

It is a block diagram which shows the main characteristics of the host apparatus which concerns on embodiment. 2 is a configuration diagram illustrating a configuration of a USB host according to Embodiment 1. FIG. 4 is an explanatory diagram for explaining a configuration and an operation of a high-speed charging downstream port according to Embodiment 1. FIG. 4 is an explanatory diagram for explaining a configuration and an operation of a high-speed charging downstream port according to Embodiment 1. FIG. 4 is an explanatory diagram for explaining a configuration and an operation of a high-speed charging downstream port according to Embodiment 1. FIG. 6 is a waveform diagram showing a device connection state detection method according to Embodiment 1. FIG. FIG. 6 is a configuration diagram illustrating a configuration of a USB host according to a second embodiment. 6 is an explanatory diagram for explaining a configuration and an operation of a high-speed charging downstream port according to Embodiment 2. FIG. 6 is an explanatory diagram for explaining a configuration and an operation of a high-speed charging downstream port according to Embodiment 2. FIG. 6 is an explanatory diagram for explaining a configuration and an operation of a high-speed charging downstream port according to Embodiment 2. FIG. 6 is a waveform diagram illustrating a device connection state detection method according to Embodiment 2. FIG. FIG. 10 is a configuration diagram illustrating a configuration of a USB host according to a third embodiment. 10 is a flowchart showing a wake-up operation according to the third embodiment. 12 is a comparison table for explaining the effects of the USB host according to the third embodiment. FIG. 10 is a configuration diagram illustrating a configuration of a USB host according to a fourth embodiment. It is a block diagram which shows the structure of the conventional downstream port for high-speed charge. It is a block diagram which shows the structure of the conventional downstream port for high-speed charge. It is a block diagram which shows the structure of the conventional downstream port for high-speed charge.

(Outline of the embodiment)
First, the outline of the main features of the embodiment will be described with reference to FIG. As illustrated in FIG. 1, the host device 10 according to the embodiment includes a connection connector 11, a power supply unit 12, a charging downstream port 13, a connection state detection unit 14, and a wakeup control unit 15.

  The connection connector 11 is a connector for connecting the device device 20. The power supply unit 12 supplies charging power to the device device 20 via the power supply terminal of the connection connector 11. The charging downstream port 13 is a port that does not perform data communication with the device device 20 via the data terminal of the connection connector 11 when the device device 20 is being charged by the power supply unit 12. The connection state detection unit 14 detects the connection state of the device device 20 via the charging downstream port 13. The wakeup control unit 15 performs a wakeup process according to the detected connection state of the device device 20.

  As described above, in the embodiment, the connection state of the device is detected through the charging downstream port, and the wake-up process is performed according to the detected connection state. Thereby, even if it is a downstream port for charging which does not perform data communication with the device during charging, the connection state of the device can be detected, and the wake-up function can be reliably realized.

(Embodiment 1)
The first embodiment will be described below with reference to the drawings. This embodiment is an example in which a D + / D-circular downstream port is used as a high-speed charging downstream port.

  FIG. 2 shows the configuration of the USB host according to the present embodiment. As shown in FIG. 2, the USB host 100 includes a plug receptacle 101, a VBUS supply circuit 102, a USB host controller 103, a host side system 104, and a D + / D-circular downstream port 110.

  The plug receptacle (connector connector) 101 is a USB connector that conforms to the USB standard. The plug receptacle 101 is a VBUS terminal (power supply terminal) / GND terminal / D + terminal (positive data terminal) / D− terminal (negative data) which is a terminal for each signal line of VBUS / GND / D + / D−. Terminal). A USB cable or a USB plug on the USB device side is inserted into the plug receptacle 101 and the USB host 100 and the USB device 200 are connected.

  The VBUS supply circuit (power supply unit) 102 is connected to the VBUS terminal of the plug receptacle 101 and supplies power to the USB device 200 via the VBUS. The VBUS supply circuit 102 receives the control signal S1 from the USB host controller 103, and generates power to be supplied to the USB device 200 based on, for example, 5V power. The VBUS supply circuit 102 can charge the USB device 200 at a high speed by supplying the USB device 200 with a current defined by Battery Charging Specification, that is, a current of at least 500 mA defined by USB 2.0.

  The USB host controller 103 is a control circuit that realizes a USB host function compliant with the USB standard. The USB host controller 103 is connected to the D + / D− terminal of the plug receptacle 101 directly or via the D + / D− circulating downstream port 110 and performs data communication with the USB device 200 via D + / D−. Also, the USB host controller 103 receives the wakeup trigger signal S2 from the D + / D-circular downstream port 110, and outputs a wakeup request signal S3 to the host side system 104 in response to the wakeup trigger signal S2. . For example, it can be said that the USB host controller 103 is a wakeup control unit that performs a wakeup process in accordance with the connection state of the USB device 200 detected by the D + / D-circular downstream port 110. The wakeup trigger signal S2 may be notified using D + / D− or may be notified using a dedicated signal line. The USB host 100 may be a USB hub and the USB host controller 103 may be a USB hub controller.

  The host side system 104 is a block that realizes a main function of the USB host 100 such as a PC, and is, for example, a CPU or various chip sets. The host-side system 104 performs data communication with the USB device 200 via the USB host controller 103 and the plug receptacle 101, and performs processing using functions provided by the USB device 200.

  When the USB device 200 is charged (during high-speed charging), the D + / D-circular downstream port 110 is short-circuited with the D + / D- as in DCP defined by Battery Charging Specification. A downstream port for charging that loops back a signal. That is, the D + / D-circular downstream port 110 is a high-speed charging downstream port in which data communication is impossible between the USB host controller 103 and the USB device 200 when the USB device 200 is being charged. The D + / D-circular downstream port 110 includes a port unit 111 and a connection state detection unit 112.

  The port unit 111 is a port that realizes a D + / D-circular connection when the USB device 200 is charged. The port unit 111 is connected to the D + / D− terminal of the plug receptacle 101, and shorts D + / D− via the short-circuit resistor R1 when the USB device 200 is charged. The port unit 111 connects D + / D− of the plug receptacle 101 and D + / D− of the USB host controller 103 during normal times when charging is not performed.

  The connection state detection unit 112 detects the connection state of the USB device 200 via the port unit 111 when the USB device 200 is charged. Since the D + / D− of the plug receptacle 101 is not connected to the USB host controller 103, the USB port cannot be detected and the disconnection of the USB device 200 cannot be detected. Therefore, the connection state detection unit 112 detects whether or not the connected USB device 200 is disconnected, that is, whether or not the USB device 200 is removed from the plug receptacle 101. The connection state detection unit 112 detects a connection state of the USB device 200 by outputting a connection test signal to the port unit 111 and monitoring a response signal input from the port unit 111 according to the connection test signal.

  In this embodiment, a pulse signal is used as the connection test signal. That is, the connection state detection unit 112 includes a pulse output circuit 113, a trigger output circuit 114, and a trigger determination circuit 115 in order to check whether or not a USB device is connected. The pulse output circuit 113 periodically generates a detection pulse signal P 1 and outputs it to the port unit 111. The trigger determination circuit 115 monitors the pulse level (signal state such as signal level) of the response pulse signal P2 input from the port unit 111 according to the detection pulse signal P1, and determines the presence or absence of a wakeup trigger. When the trigger determination circuit 115 detects a wakeup trigger, the trigger output circuit 114 generates a wakeup trigger signal S2 and outputs it to the USB host controller 103.

  Next, a connection state detection operation of the USB device of the USB host according to the present embodiment will be described with reference to FIGS.

  FIG. 3 shows the state of the D + / D− circulating downstream port 110 when the host-side system 104 is in a normal state. The port portion 111 of the D + / D-circular downstream port 110 includes a short circuit resistor R1, switches SW1a and SW1b, and switches SW2a and SW2b.

  The switches SW1a and SW1b are switches for switching the connection between the D + / D− of the plug receptacle 101 and the short-circuit resistor R1 or the USB host controller 103. From the downstream port capable of USB data transfer such as SDP / CDP, D + / D -Switch to circular type. The switches SW2a and SW2b are switches that switch connection / disconnection between the port unit 111 and the connection state detection unit 112, and switch transmission / reception of the connection state detection pulse signals P1 and P2 on / off. Switching of the switches SW 1 a and SW 1 b and the switches SW 2 a and SW 2 b is controlled by a control signal from the USB host controller 103.

  As shown in FIG. 3, in the normal state, the switch SW1a connects D + of the plug receptacle 101 and D + of the USB host controller 103, and the switch SW1b connects D− of the plug receptacle 101 and D− of the USB host controller 103. And connected. Thereby, the USB host controller 103 can perform data communication with the USB device 200 via the D + / D−, and can realize the SDP / CDP function.

  4 and 5 show the state of the D + / D-circular downstream port 110 when the host-side system 104 is in the power saving state. As shown in FIG. 4, when the host-side system 104 is in the power saving state, the connection of the switches SW1a and SW1b is switched by the control from the USB host controller 103. For example, the switches SW1a and SW1b may be switched when the host-side system 104 transitions to a power saving state or when the D + / D-circular USB device 200 is connected to the plug receptacle 101.

  That is, in order to enable D + / D-circular handshaking, the switch SW1a connects D + of the plug receptacle 101 and one end of the short-circuit resistor R1, and the switch SW1b connects D- of the plug receptacle 101 and the short-circuit resistor R1. Connect the other end of the. As a result, D + / D− are short-circuited and connected so that the handshake signal from the USB device 200 loops back (circulates).

  In the state of FIG. 4, the USB device 200 performs a high-speed charging handshake via the D + / D− circular downstream port 110, and therefore waits for a certain period of time until the handshaking is completed. After a certain period of time, the switches SW2a and SW2b are turned on by the control from the USB host controller 103 as shown in FIG. That is, in order to detect the connection state of the USB device 200, the switch SW2a connects the output of the pulse output circuit 113 to one end of the D + and the short-circuit resistor R1, and the switch SW2b connects the input of the trigger determination circuit 115 to the D− and The other end of the short-circuit resistor R1 is connected.

  FIG. 6 shows the relationship between the detection pulse signal P1 and the response pulse signal P2 and the connection state of the USB device. When the connection is switched as shown in FIG. 5, the pulse output circuit 113 immediately and periodically outputs the detection pulse signal P1, as shown in FIG. 6, and the trigger determination circuit 115 always observes the level of the response pulse signal P2. . That is, the pulse output circuit 113 outputs the detection pulse signal P1 to one end (and D +) of the short-circuit resistance R1, and the trigger determination circuit 115 determines the other end (and D−) of the short-circuit resistance R1 according to the detection pulse signal P1. The connection / disconnection of the USB device 200 is determined based on the signal level of the response pulse signal P2 output from the device.

  When the USB device 200 is connected to the plug receptacle 101, since the termination resistors R2 and R3 of the USB device 200 are connected, the level of the response pulse signal P2 is determined by the coupling resistance of the termination resistors R2 and R3, D +, and D−. Then, the voltage drops to the divided voltage as indicated by L1 in FIG. On the other hand, when the USB device 200 is disconnected from the plug receptacle 101, the terminating resistors R2 and R3 are disconnected, so that the level of the response pulse signal P2 is almost the same as when the detection pulse signal P1 is output, as indicated by L2 in FIG. It becomes the same voltage.

  Therefore, the trigger determination circuit 115 detects that the USB device 200 is connected when the level of the response pulse signal P2 is about L1 (for example, smaller than a predetermined threshold), and the level of the response pulse signal P2 is about L2. In the case of (for example, larger than a predetermined threshold), it is detected that the USB device 200 is disconnected. Then, it is determined that the USB device 200 is disconnected as a wakeup trigger, and the trigger output circuit 114 outputs a wakeup trigger signal S2 to the USB host controller 103. Thereafter, the USB host controller 103 returns the switches SW1a and SW1b to the direction where D + / D− is connected to the USB host controller 103, and sends a wake-up request signal S3 to the host-side system 104 to put the host-side system 104 in a power saving state. To return to the normal state.

  As described above, conventionally, when a USB device is charged at high speed with a D + / D-circular downstream port such as DCP, the host side system cannot wake up from the power saving state even if the USB device is disconnected. On the other hand, in the present embodiment, since the connection state of the USB device can be detected via the D + / D-circular downstream port that does not perform data communication, the disconnection of the USB device is detected. But you can definitely wake up the host system.

(Embodiment 2)
The second embodiment will be described below with reference to the drawings. This embodiment is an example in which a D + / D− fixed voltage output type downstream port is used as a high-speed charging downstream port.

  FIG. 7 shows the configuration of the USB host according to the present embodiment. The USB host 100 in FIG. 7 includes a D + / D− fixed voltage output downstream port 120 instead of the D + / D− circulating downstream port 110 as compared with the first embodiment. Other configurations are the same as those in the first embodiment.

  The D + / D− fixed voltage output downstream port 120 is a charging downstream port that performs handshaking by setting D + / D− to a predetermined fixed voltage when the USB device 200 is charged. The D + / D− fixed voltage output type downstream port 120 includes a port unit 121 and a connection state detection unit 122.

  The port unit 121 is a port that realizes a D + / D− fixed voltage output type connection when the USB device 200 is charged. The port unit 121 is connected to the D + / D− terminal of the plug receptacle 101, and outputs a fixed voltage to D + / D− by the voltage dividing resistors R11 and R12, R21 and R22 when the USB device 200 is charged. The port unit 121 connects D + / D− of the plug receptacle 101 and D + / D− of the USB host controller 103 during normal times when charging is not performed.

  The connection state detection unit 122 detects the connection state of the USB device 200 via the port unit 121 when the USB device 200 is charged. As in the first embodiment, the connection state detection unit 122 detects whether or not the connected USB device 200 is disconnected, that is, whether or not the USB device 200 is disconnected from the plug receptacle 101. The connection state detection unit 122 detects a connection state of the USB device 200 by outputting a connection test signal to the port unit 121 and monitoring a response signal input from the port unit 121 according to the connection test signal.

  In this embodiment, a pulse signal is used as the connection test signal. That is, the connection state detection unit 122 includes a pulse output circuit 123, a trigger output circuit 124, and a trigger determination circuit 125 in order to confirm whether or not a USB device is connected, as in the first embodiment. The pulse output circuit 123 periodically generates a detection pulse signal P11 and outputs it to the port unit 121. The trigger determination circuit 125 monitors the falling or rising time (signal state such as signal timing) of the response pulse signal P12 input from the port unit 121 according to the detection pulse signal P11, and determines the presence or absence of a wakeup trigger. . When the trigger determination circuit 125 detects a wakeup trigger, the trigger output circuit 124 generates a wakeup trigger signal S2 and outputs it to the USB host controller 103.

  Next, the connection state detection operation of the USB device of the USB host according to the present embodiment will be described with reference to FIGS.

  FIG. 8 shows the state of the D + / D− fixed voltage output type downstream port 120 when the host system 104 is in a normal state. The port portion 121 of the D + / D− fixed voltage output type downstream port 120 includes voltage dividing resistors R11 and R12, voltage dividing resistors R21 and R22, a resistor R31, a gate circuit TR1, a capacitor C1, and switches SW11a and SW11b. Yes.

  The voltage dividing resistors R11 and R12 are connected in series, and an intermediate node thereof is connected to D + of the plug receptacle 101 to output a fixed voltage to D +. The voltage dividing resistors R21 and R22 are connected in series, and an intermediate node thereof is connected to D− of the plug receptacle 101 to output a fixed voltage to D−.

  The gate circuit TR1 is connected between the voltage dividing resistors R11 and R12, the detection pulse signal P11 is input from the pulse output circuit 123 to the control terminal, and the voltage between the voltage dividing resistors R11 and R12 (pull-down) according to the detection pulse signal P11. ON / OFF. In the present embodiment, the detection pulse signal is a pulse signal for instantaneously disconnecting the pull-up on either of the D + / D− signal lines, and the gate circuit TR1 instantaneously disconnects the pull-up according to the pulse signal. It can be said that it is a break circuit. The resistor R31 is connected between the pulse output circuit 123 and the control terminal of the gate circuit TR1, and constitutes an instantaneous interruption circuit together with the gate circuit TR1. The capacitor C1 is a capacitor for generating a time constant connected between the gate circuit TR1 and the trigger determination circuit 125, and may be a parasitic capacitor.

  The switches SW11a and SW11b are switches for switching the connection between the D + / D− of the plug receptacle 101 and the voltage dividing resistors R11 and R12, R21 and R22, or the USB host controller 103, and are capable of transferring USB data such as SDP / CDP. Switch from the stream port to the D + / D− fixed voltage output type. Switching of the switches SW11a and SW11b is controlled by a control signal from the USB host controller 103.

  As shown in FIG. 8, in the normal state, the switch SW11a connects D + of the plug receptacle 101 and D + of the USB host controller 103, and the switch SW11b connects D− of the plug receptacle 101 and D− of the USB host controller 103. And connected. Thereby, the USB host controller 103 can perform data communication with the USB device 200 via the D + / D−, and can realize the SDP / CDP function.

  9 and 10 show the state of the D + / D− fixed voltage output downstream port 120 when the host-side system 104 is in the power saving state. As shown in FIG. 9, when the host-side system 104 is in the power saving state, the connections of the switches SW11a and SW11b are switched by the control from the USB host controller 103. For example, the switches SW11a and SW11b may be switched when the host-side system 104 transitions to the power saving state or when the D + / D− fixed voltage output type USB device 200 is connected to the plug receptacle 101.

  That is, in order to enable D + / D− fixed voltage output type handshaking, the switch SW11a connects D + of the plug receptacle 101 and the intermediate node of the voltage dividing resistors R11 and R12, and the switch SW11b is connected to the plug receptacle 101. D− is connected to the intermediate node of the voltage dividing resistors R21 and R22. As a result, a fixed voltage is output from the intermediate node of the voltage dividing resistors R11 and R12 to the USB device 200 via D +, and a fixed voltage is output from the intermediate node of the voltage dividing resistors R21 and R22 to the USB device 200 via D−. Then, when the USB device 200 detects the voltage D + / D−, the handshake is realized.

  In the state of FIG. 9, the USB device 200 performs a high-speed charging handshake via the D + / D− fixed voltage output type downstream port 120, and thus waits for a predetermined time until the handshaking is completed. As shown in FIG. 10, the pulse output circuit 123 immediately and periodically outputs the detection pulse signal P11 under the control of the USB host controller 103 after a predetermined time has elapsed, and the trigger determination circuit 125 sets the response pulse signal P12 to rise. Always observe the downtime. That is, the pulse output circuit 123 outputs the detection pulse signal P11 that cuts the voltage dividing resistors R11 and R12 to the gate circuit TR1 (cutting path), and the trigger determination circuit 125 outputs the voltage dividing resistor R11 according to the detection pulse signal P11. The connection / disconnection of the USB device 200 is determined based on the signal timing of the response pulse signal P12 output from R12 (D +).

  FIG. 11 shows the relationship between the detection pulse signal P11 and the response pulse signal P12 and the connection state of the USB device. As shown in FIG. 11, the pulse output circuit 123 periodically outputs a detection pulse signal P11 and applies the detection pulse signal to the pull-up gate circuit TR1 (instantaneous interruption gate). The trigger determination circuit 125 always observes the fall time of the voltage of the response pulse signal P12 when the pull-up is momentarily interrupted. In this embodiment, the detection pulse signal P11 is output to the gate circuit TR1 provided in the D + side voltage dividing resistors R11 and R12, but the gate circuit TR1 is provided in the D− side voltage dividing resistors R21 and R22. Thus, the connection state of the USB device may be detected by outputting the detection pulse signal P11.

  When the USB device 200 is connected to the plug receptacle 101, since the voltage dividing resistors R11 and R12 and the terminal resistor R2 of the USB device 200 are connected, the response pulse signal P12 is at a low level from the rise of the detection pulse signal P11. The time until becomes T1 in FIG. For example, the trigger determination circuit 125 holds this T1.

  For example, the pull-up / pull-down resistors (R11 and R12) for fixed voltage output are several tens of kΩ, whereas the termination resistor R2 is about 45 to 50Ω. For this reason, when the USB device 200 is disconnected from the plug receptacle 101, the voltage dividing resistors R11 and R12 and the termination resistor R2 are disconnected, so that the discharge of the capacitor C1 is delayed, and the response pulse signal is shown as T2 in FIG. The fall time of the level of P12 becomes later than T1.

  Therefore, the trigger determination circuit 125 detects that the USB device 200 is connected when the falling time of the response pulse signal P12 is earlier than the predetermined time, and the falling time of the response pulse signal P12 is determined in advance. If it is later than the time, it is detected that the USB device 200 is disconnected. Then, it is determined that the USB device 200 has been disconnected as a wakeup trigger, and the trigger output circuit 124 outputs a wakeup trigger signal S2 to the USB host controller 103. Thereafter, the USB host controller 103 returns the switches SW11a and SW11b to the direction in which D + / D− is connected to the USB host controller 103, and sends a wakeup request signal S3 to the host side system 104 to put the host side system 104 in a power saving state. To return to the normal state.

  As described above, when the USB device is charged at high speed with the D + / D- fixed voltage output type downstream port, the host system could not wake up from the power saving state even if the USB device was disconnected. On the other hand, in this embodiment, since it is possible to detect the connection state of the USB device via the D + / D- fixed voltage output type downstream port that does not perform data communication, disconnection of the USB device is detected. Even in this case, it is possible to wake up the host side system without fail.

(Embodiment 3)
The third embodiment will be described below with reference to the drawings. The present embodiment is an example including a plurality of high-speed charging downstream ports. In other words, this embodiment can smoothly perform a handshake in which a USB device draws a VBUS current higher than the previous USB standard (500 mA) in a USB downstream port installed in a system capable of managing power saving. In addition, it is possible to provide both a USB downstream port for high-speed charging that is configured with a simple circuit and a USB wake-up function that allows a system in a power saving state to be restored from a USB device to a normal state. In this embodiment, the downstream port is automatically switched according to the power control state of the system, the connection state of the downstream port, and the type of the connected device, and the USB communication is impossible. The downstream port for high-speed charging is also characterized in that it detects connection / disconnection of a device, determines that it is a wake-up trigger, and notifies the host controller.

  FIG. 12 shows the configuration of the USB host according to the present embodiment. The USB host 100 of FIG. 12 includes a downstream port group 150 including a plurality of downstreams and a handshake function switching control circuit 105 as compared with the first and second embodiments. Other configurations are the same as those in the first and second embodiments.

  The downstream port group 150 includes the D + / D− circulating downstream port 110 according to the first embodiment, the D + / D− fixed voltage output downstream port 120 according to the second embodiment, the CDP 130, and the SDP 140. The CDP 130 includes a CDP handshake control circuit 131 that performs a CDP handshake. The D + / D-circular downstream port 110, the D + / D-fixed voltage output downstream port 120, the CDP 130, and the SDP 140 are connected between the plug receptacle 101 and the USB host controller 103, and are supplied from the handshake function switching control circuit 105. Can be switched according to the switching signal S4.

  The handshake function switching control circuit 105 switches the downstream port connected to the plug receptacle 101 and the USB host controller 103. The handshake function switching control circuit 105 selects a downstream port to be used based on the state notification signal S5 input from the USB host controller, and outputs a switching signal S4 for switching to the selected downstream port. It can be said that the handshake function switching control circuit 105 is a selection unit that selects a downstream port connected to the USB device 200 from a plurality of downstream ports in accordance with the USB device 200 connected to the plug receptacle 101. For example, the status notification signal S5 notifies or refers to the power status of the host-side system 104, the connection status of the downstream port, and the type of the connected USB device 200. Note that the handshake function switching control circuit 105 may be included in the USB host controller 103.

  The USB device 200 has been expanded in the history of the USB standard so far, and is generally classified according to the communication speed. In the USB 1.1 standard, an LS (Low-Speed) device capable of communicating at a maximum of 1.5 Mbps and an FS (Full-Speed) device capable of communicating at a maximum of 12 Mbps are defined. An HS (Hi-Speed) device capable of communicating at a maximum of 480 Mbps has been added. Generally, LS / FS devices are used for human interface devices such as a mouse and a keyboard. One of the LS device, FS device, and HS device USB device 200 is connected to the plug receptacle 101.

  Next, the wake-up operation of the USB host according to the present embodiment will be described using the flowchart of FIG. This flowchart shows the operation of grasping the type of USB device connected to the downstream port and providing wake-up means corresponding to each USB device when the host-side system shifts from the normal state to the power saving state. Show.

  As shown in FIG. 13, first, the host-side system 104 transitions from the normal state to the power saving state (S101). In the normal state, the downstream port is the SDP 140 or the CDP 130 that is a port capable of USB communication. The handshake function switching control circuit 105 is notified via the USB host controller 103 of the transition to the power saving state.

  Next, the handshake function switching control circuit 105 determines the connection state of the downstream port (S102). Since the USB host controller 103 recognizes the connection state of the downstream port, the handshake function switching control circuit 105 acquires information on the USB device 200 that is connected to the downstream port from the USB host controller 103. For example, the handshake function switching control circuit 105 sets the downstream port according to the transfer speed (transfer mode) of the connected USB device 200, that is, whether the USB device 200 is an LS / FS / HS device. select.

  If the LS / FS device is connected to the downstream port when the host side system 104 is in the normal state, the handshake function switching control circuit 105 can perform USB communication even if the host side system transitions to the power saving state. The port (SDP / CDP) is not switched to a high-speed charging function circuit (D + / D-circular type, D + / D-fixed voltage output type) incapable of USB communication (S103). Similarly, when the downstream port is in the OPEN state (not connected) and the host-side system 104 transitions to the power saving state, the handshake function switching control circuit 105 similarly uses a port (SDP) that can communicate with the downstream port as a USB port (SDP). / CDP) is not switched (S103).

  When the downstream port is SDP140 or CDP130 in S103, the USB host controller 103 notifies the host side system 104 of the wakeup on connect wakeup request signal S3 when the connection of the USB device 200 is detected (S104). When the wake-up request is received from the USB device 200, a wake-up request signal S3 for remote wake-up is notified to the host-side system 104 (S105). When the USB device 200 is disconnected (removed), A wake-up request signal S3 for connection is notified to the host system 104 (S106).

  On the other hand, when an HS device is connected to the downstream port when the host-side system 104 is in a normal state, the handshake function switching control circuit 105 switches to a high-speed charging port that is compatible with the connected USB device (S108). ). When there is no high-speed charging port corresponding to the USB device, or when the USB device does not support high-speed charging, the handshake function switching control circuit 105 does not switch the downstream port (S103).

  Here, the connection status of the USB device 200 and the type of the connected USB device 200 can be confirmed, for example, by the handshake function switching control circuit 105 or the USB host controller (hub controller) 103 referring to the descriptor.

  An example of a unit that determines and switches the high-speed charging dedicated downstream port supported by the connected USB device 200 in S108 will be described. For example, when the host-side system 104 transitions to the power saving state, the host-side system 104 is first switched to the D + / D− fixed voltage output type downstream port 120 to determine the voltage level of D +. If the USB device 200 charges at high speed with the D + / D− fixed voltage output type downstream port 120, the voltage does not change, and if the USB device 200 is compatible with the D + / D− loop type downstream port 110, In order to issue a handshake signal, the voltage at D + is lower than the fixed voltage level. When the D + / D− fixed voltage output type and the D + / D− loop type are not applicable, the D + of the normal HS device is pulled up to 3.3V, and thus becomes higher than the fixed voltage level. The handshake function switching control circuit 105 switches to the D + / D− circulating downstream port 110 (S109) and the D + / D− fixed voltage output downstream port 120 (S110) according to the fixed voltage level of D +.

  Further, it is possible to make a determination by directly observing the current value of VBUS. For example, the current is normally 500 mA or less, and the device draws current from 1.0 to 1.5 A during high-speed charging. Therefore, it can be determined that the device is compatible with high-speed charging based on the current value of VBSU.

  In S109 and S110, when switching to the D + / D-circular downstream port 110 and the D + / D- fixed voltage output downstream port 120, USB communication cannot be performed, so the disconnect detection function of the USB device 200 is turned on. In step S111, the connection state of the USB device 200 is detected as in the first and second embodiments. That is, the pulse output circuit 113/123 periodically outputs a detection pulse (S112), and the trigger determination circuit 115/125 determines Disconnect based on the response pulse (S113).

  When the USB device 200 is connected, S112 and S113 are repeated, and when the USB device is disconnected (removed), the trigger output circuit 114/124 notifies the USB host controller 103 of the wakeup trigger signal S2. The USB host controller 103 notifies the host side system 104 of a wake-up request signal S3 for wake-up on disconnection.

  When the host-side system 104 receives the wake-up request signal S3 in S104 to S106 and S114, it returns from the power saving state to the normal state (S107).

  The effect of this embodiment will be described. If no USB device is connected to the downstream port, when the host-side system is in a power saving state, the downstream port is still capable of USB communication without switching to the downstream port for high-speed charging that cannot be used for USB communication. By doing so, system recovery (Wakeup on Connect) triggered by the USB device connection becomes effective. Since the USB device is not connected, there is no need for high-speed charging in the first place.

  In addition, when an LS / FS device is connected, it is assumed that a human interface device such as a mouse or a keyboard is connected, and even when the host-side system is in a power saving state, USB communication is impossible and the downstream for high-speed charging By switching to a downstream port capable of USB communication without switching to a port, system recovery (Remote Wakeup) by a human interface device becomes effective. Since devices that support high-speed charging with LS / FS devices are extremely rare and uncommon, it is not necessary to use a downstream port for high-speed charging when the LS / FS device is connected.

  When the HS device is connected, the USB device is switched to the downstream port for high-speed charging, and when the USB device is not compatible with high-speed charging, the USB port is not switched from the downstream port. When switching to the high-speed charging downstream port, the differential data line D + / D- is disconnected from the USB host controller. Each high-speed charging port has a circuit for detecting the disconnection of the USB device, thereby disconnecting the USB device. Detection is possible. When the USB device is disconnected, the downstream port detects the device disconnection and notifies the USB host controller of a trigger, thereby enabling system recovery (Wakeup on Disconnect) by disconnecting the USB device. When the connected HS device does not support high-speed charging, Wakeup on Disconnect is effective when the device is disconnected as in the prior art because switching is not performed from a downstream port capable of USB communication.

  As described above, in this embodiment, it is possible to realize a downstream port capable of high-speed charging while always enabling the system wakeup function by the USB device.

  FIG. 14 shows a comparison table comparing the prior art and the present embodiment. In Patent Literature 1, in order to realize this function, it is necessary to construct complex hardware and perform information processing. Further, in Patent Document 1, after confirming all power supply modes for connected devices, information is stored in the ROM, and a setting is made based on the information, and the processing time is very long. . Further, according to FIG. 5 of Patent Document 1, the USB wake-up permission setting is a flow that is permitted only when there is no valid power supply mode, and normal USB communication can be performed when the USB device is in the power supply mode. The system cannot wake up from the USB device.

  In the SDP of Non-Patent Document 1, high-speed charging cannot be performed. The CDP of Non-Patent Document 1 needs to spontaneously drive a circuit and return a response to the upstream side in response to a handshake signal sent from the upstream side. For this reason, the CDP requires a circuit for detecting and judging a handshake signal and a circuit for outputting a response signal, which complicates the configuration. For applications limited to device charging, extra hardware must be implemented. In addition, devices other than those conforming to the specifications of Non-Patent Document 1 cannot be charged at high speed.

  In the downstream port of D + / D-circular type such as DCP of Non-Patent Document 1 or D + / D- fixed voltage output type of Non-Patent Document 2, D + / D- of the differential data line is a host controller or a hub controller. Is not connected, and USB communication with the connected device is not possible. For this reason, the system cannot be woken up. Further, devices other than those conforming to the specifications of Non-Patent Document 1 or 2 cannot be charged at high speed.

  As described above, since there are various high-speed charging ports in the current world, there are various means and methods for handshaking. If the downstream port and the device do not support the same fast charging method, the device cannot be fast charged. In addition, the downstream port for high-speed charging developed by device vendors for its own portable devices is specialized for charging accessories and has a demerit that it cannot communicate with the previous USB standard due to its simple configuration. . Therefore, if the above-described high-speed charging downstream port is applied to a USB downstream port mounted on a host-side system such as a PC, USB communication becomes impossible at that port. On the other hand, in the present embodiment, since the downstream port is switched according to the connected USB device, any standard USB device can be charged at high speed, and further, the downstream incapable of USB communication. Even the port can detect the connection state of the USB device and reliably wake up.

(Embodiment 4)
The fourth embodiment will be described below with reference to the drawings. The present embodiment is an example in which a plurality of functions of the third embodiment are realized with a single semiconductor device.

  FIG. 15 shows the configuration of the USB host according to the present embodiment. In FIG. 15, the USB host controller 103 according to the third embodiment is mounted on a single semiconductor device (LSI) including the handshake function switching control circuit 105 and the downstream port group 150. Other configurations are the same as those of the third embodiment.

  As described above, even when the USB host controller 103, the handshake function switching control circuit 105, and the downstream port group 150 are mounted on a single semiconductor device, the downstream port is set according to the type of device as in the third embodiment. Can be switched, and wakeup can be performed even in a downstream port where USB communication is impossible.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

DESCRIPTION OF SYMBOLS 10 Host apparatus 11 Connector 12 Power supply part 13 Charging downstream port 14 Connection state detection part 15 Wakeup control part 20 Device apparatus 100 USB host 101 Plug receptacle 102 VBUS supply circuit 103 USB host controller 104 Host side system 105 Handshaking function Switching control circuit 110 D + / D-circular downstream port 111 port unit 112 connection state detection unit 113 pulse output circuit 114 trigger output circuit 115 trigger determination circuit 120 fixed voltage output type downstream port 121 port unit 122 connection state detection unit 123 Pulse output circuit 124 Trigger output circuit 125 Trigger determination circuit 130 CDP
131 CDP handshake control circuit 140 SDP
150 Downstream port group 200 USB device C1 Capacitance P1, P11 Detection pulse signal P2, P12 Response pulse signal R1 Short-circuit resistance R11, R12, R21, R22 Voltage division resistance R2, R3 Termination resistance R31 Resistance S1 Control signal S2 Wake-up trigger signal S3 Wake-up request signal S4 Switching signal S5 Status notification signal SW1a, SW1n, SW2a, SW2b, SW11a, SW11b Switch TR1 Gate circuit

Claims (20)

A connector for connecting the device device;
A power supply unit for supplying power to the device device via a power supply terminal of the connection connector;
When the device device is being charged by the power supply unit, a charging downstream port that does not perform data communication with the device device via the data terminal of the connection connector;
A connection state detection unit for detecting a connection state of the device device via the downstream port for charging;
A wakeup control unit that performs a wakeup process according to the detected connection state of the device device;
A host device comprising: The connection state detection unit
An output circuit for outputting a connection test signal to the downstream port for charging;
A determination circuit that determines connection / disconnection of the device device based on a response signal generated from the charging downstream port according to the connection test signal.
The host device according to claim 1. The output circuit outputs a detection pulse as the connection test signal,
The determination circuit determines connection / disconnection of the device device based on a response pulse corresponding to the detection pulse as the response signal;
The host device according to claim 2. The determination circuit determines connection / disconnection of the device device based on a signal level or signal timing of the response pulse.
The host device according to claim 3. The charging downstream port is a circular downstream port that short-circuits a positive data terminal and a negative data terminal of the connection connector.
The host device according to claim 1. The circular downstream port has a short-circuit resistance that short-circuits a positive data terminal and a negative data terminal of the connector,
The connection state detection unit
An output circuit for outputting a detection pulse to one end of the short-circuit resistor;
A determination circuit that determines connection / disconnection of the device device based on a response pulse output from the other end of the short-circuit resistor in response to the detection pulse,
The host device according to claim 5. The determination circuit determines connection / disconnection of the device device based on a signal level of the response pulse.
The host device according to claim 6. The charging downstream port is a fixed voltage output type downstream port that outputs a predetermined fixed voltage to a positive data terminal and a negative data terminal of the connection connector.
The host device according to claim 1. The fixed voltage output type downstream port is:
A voltage dividing resistor that outputs a divided voltage to the positive data terminal or the negative data terminal of the connector;
A cutting circuit for cutting the voltage dividing resistor in response to an input signal,
The connection state detection unit
An output circuit for outputting a detection pulse for cutting the voltage dividing resistor to the cutting circuit;
A determination circuit that determines connection / disconnection of the device device based on a response pulse output from the voltage dividing resistor in response to the detection pulse,
The host device according to claim 8. The determination circuit determines connection / disconnection of the device device based on a signal timing of the response pulse;
The host device according to claim 9. A plurality of downstream ports including the charging downstream port;
A selection unit that selects a downstream port to be connected to the device apparatus from the plurality of downstream ports according to the device apparatus connected to the connection connector;
The host device according to claim 1. The selection unit selects the downstream port based on a transfer rate of the device device.
The host device according to claim 11. The selection unit selects a downstream port capable of data communication when the device device is a low speed device or a full speed device.
The host device according to claim 12. When the device device is a high-speed device, the selection unit selects the charging downstream port corresponding to the handshaking method of the device device.
The host device according to claim 12. A connection connector for connecting the device device, a power supply unit for supplying power to the device device via a power supply terminal of the connection connector, and when the device device is being charged by the power supply unit, A control method of a host device comprising: a downstream port for charging that does not perform data communication with the device device via a data terminal,
Detecting a connection state of the device device via the downstream port for charging;
Wake-up processing is performed according to the detected connection state of the device device.
Host device control method. In the detection of the connection state,
Output a connection test signal to the downstream port for charging,
Determining connection / disconnection of the device device based on a response signal generated from the charging downstream port according to the connection test signal;
The host device control method according to claim 15. In the output of the connection test signal, a detection pulse is output as the connection test signal,
In the connection / disconnection determination, the connection / disconnection of the device device is determined based on a response pulse corresponding to the detection pulse as the response signal.
The host device control method according to claim 16. In the connection / disconnection determination, the connection / disconnection of the device device is determined based on the signal level or signal timing of the response pulse.
The host device control method according to claim 17. The host device includes a plurality of downstream ports including the charging downstream port,
Selecting a downstream port to be connected to the device apparatus from the plurality of downstream ports according to the device apparatus connected to the connection connector;
The host device control method according to claim 15. When the device device is being charged, a charging downstream port that does not perform data communication with the device device via a data terminal of a connection connector that connects the device device;
A connection state detection unit for detecting a connection state of the device device via the downstream port for charging;
A wakeup control unit that performs a wakeup process according to the detected connection state of the device device;
A semiconductor device comprising:

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