Communication apparatus

Abstract

To enable communication even if a communication error is detected in one of two communication ports.SOLUTION: A communication apparatus includes control means which performs control, when a USB Type-C cable is connected to a connection unit, for establishing communication via the USB Type-C cable connected to the connection unit. When the USB Type-C cable is connected to the connection unit in a first-side state of two sides, the communication apparatus is configured to start communication using a first communication port, and start communication using a second communication port in accordance with detecting an error of communication through the first communication port. When the USB Type-C cable is connected to the connection unit in a second-side state of the two sides, the communication apparatus is configured to start communication using the second communication port, and start communication using the first communication port in accordance with detecting an error of communication through the second communication port.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a communication device, a communication system, and a control method for a communication device. [Background technology]

[0002] USB Type-C cables can be connected upside down and have two sets of lanes, Tx1 / Rx1 and Tx2 / Rx2, for communication with USB3.2 Gen1 x 1 and USB3.2 Gen2 x 1. Communication with USB3.2 Gen1 x 1 and USB3.2 Gen2 x 1 is carried out using either Tx1 / Rx1 or Tx2 / Rx2, depending on the orientation of the cable.

[0003] The USB Type-C Tx1 / Rx1 and Tx2 / Rx2 ports are located near both ends of the connector's length, so if the connector is inserted at a slight angle, poor contact can occur in either the Tx1 / Rx1 or Tx2 / Rx2 lanes, which can cause communication problems with USB3.2 Gen1x1 or USB3.2 Gen2x1.

[0004] Patent Document 1 describes a technology that detects a connection abnormality in a USB Type-C connector from the timing of the rise of the voltage at the signal terminal and turns off the VBUS power supply. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-29451 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a method for turning off the VBUS power supply and disabling USB communication when a short circuit between terminals is detected. However, Patent Document 1 cannot improve communication failures in high-speed differential lanes such as USB3.2 Gen1×1 and USB3.2 Gen2×1 caused by poor connections in the high-speed differential lanes Tx1 / Rx1 or Tx2 / Rx2.

[0007] An object of the present disclosure is to enable communication even when a communication error is detected in one of the two communication ports. [Means for solving the problem]

[0008] The communication device has a connection unit to which a USB Type-C cable is connected, and a control means that, when the USB Type-C cable is connected to the connection unit, performs control to communicate with an external device via the USB Type-C cable connected to the connection unit, wherein the control means controls to start communication using a first communication port when the connection orientation of the USB Type-C cable connected to the connection unit is a first orientation of front or back, and to start communication using a second communication port in response to detection of an error in communication using the first communication port, and when the connection orientation of the USB Type-C cable connected to the connection unit is a second orientation of front or back, to start communication using the second communication port, and to start communication using the first communication port in response to detection of an error in communication using the second communication port. [Effects of the Invention]

[0009] According to the present disclosure, communication is possible even when a communication error is detected in either of the two communication ports. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an example of the configuration of a communication system. [Figure 2]FIG. 10 is a diagram for explaining selection of a communication port. [Figure 3] 10 is a flowchart showing a communication port selection process. [Figure 4] FIG. 1 illustrates an example of the configuration of a communication system. [Figure 5] FIG. 10 is a diagram for explaining selection of a communication port. [Figure 6] 10 is a flowchart showing a communication port selection process. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) A first embodiment will be described below. FIG. 1 is a diagram showing an example of the configuration of a communication system 100 according to the first embodiment. The communication system 100 includes a USB host device 101 and a USB device 151. The USB host device 101 and the USB device 151 are connected to each other via a USB Type-C cable 121. The USB host device 101 includes a first USB Type-C port 108. The USB device 151 includes a second USB Type-C port 158. The first USB Type-C port 108 and the second USB Type-C port 158 ​​are each a USB Type-C receptacle. One plug and the other plug of a USB Type-C cable 121 are removably connected to the first USB Type-C port 108 and the second USB Type-C port 158, respectively. The first USB Type-C port 108 and the second USB Type-C port 158 ​​can also be considered as connection portions to which the USB Type-C cable is connected. The USB host device 101, which is a communication device, communicates with a USB device 151, which is an external device connected via a USB Type-C cable 121.

[0012] The USB host device 101 includes a first CPU 102, a USB host controller 103, a first CC / mode control unit 104, a first USB SS multiplexer 105, a first communication path selection unit 106, and a first multiplexer control unit 107.

[0013] The USB device 151 includes a second CPU 152, a USB device controller 153, a second CC / mode control unit 154, a second USB SS multiplexer 155, a second communication path selection unit 156, and a second multiplexer control unit 157.

[0014] The first CPU 102 and the second CPU 152 are CPUs that respectively perform system control of the USB host device 101 and the USB device device 151. Furthermore, the first CPU 102 and the second CPU 152 control data transmission and reception to the USB host controller 103 and the USB device controller 153, respectively, for USB communication.

[0015] The USB host controller 103 and the USB device controller 153 perform communication in accordance with instructions from the first CPU 102 and the second CPU 152, respectively. The USB host controller 103 and the USB device controller 153 perform USB 2.0 communication using the D+ / D- ports. Furthermore, the USB host controller 103 and the USB device controller 153 perform USB 3.2 Gen1×1 and USB 3.2 Gen2×1 (hereinafter referred to as USB 3.1) communication using the TX / RX ports.

[0016] The first CC / mode control unit 104 and the second CC / mode control unit 154 detect whether the connected USB Type-C cable 121 is connected in a non-inverted or inverted orientation based on the CC1 / CC2 terminal voltages, and output a connection orientation determination signal. Specifically, the first CC / mode control unit 104 and the second CC / mode control unit 154 detect the connection orientation as follows.

[0017] A USB Type-C connector has CC1 and CC2 ports, but the USB Type-C cable 121 has only one CC line. Therefore, when the USB Type-C cable 121 is connected in a non-inverted orientation, the CC line is connected only to the CC1 port, and when the USB Type-C cable 121 is connected in an inverted orientation, the CC line is connected only to the CC2 port. The non-inverted orientation is one of the front and back orientations, and the inverted orientation is the other of the front and back orientations.

[0018] When a port is connected to a CC line, a current flows through the CC line, causing a change in the port voltage. Therefore, the first CC / mode control unit 104 and the second CC / mode control unit 154 can determine whether the USB Type-C cable 121 is connected in a non-inverted or inverted state based on the voltages of the CC1 port and the CC2 port.

[0019] The first CC / mode control unit 104 and the second CC / mode control unit 154 output a connection direction determination signal of '0' when the connection is non-inverted and '1' when the connection is inverted. Figure 2 shows the relationship between the CC line connection and the connection direction determination signal.

[0020] The first USB SS multiplexer 105 switches the port used for USB 3.1 communication based on the connection direction determination signal output from the first CC / mode control unit 104. The second USB SS multiplexer 155 switches the port used for USB 3.1 communication based on the connection direction determination signal output from the second CC / mode control unit 154.

[0021] Specifically, when the connection direction determination signal is '0', the first USB SS multiplexer 105 connects the TX / RX port and the Tx1 / Rx1 port, allowing the USB host controller 103 to perform USB 3.1 communication through the Tx1 / Rx1 port.

[0022] Furthermore, when the connection direction determination signal is '1', the first USB SS multiplexer 105 connects the TX / RX port and the TX2 / RX2 port, allowing the USB host controller 103 to perform USB 3.1 communication through the Tx2 / Rx2 port.

[0023] The operation of the second USB SS multiplexer 155 is similar to that of the first USB SS multiplexer 105. Figure 2 shows the relationship between the connection direction determination signal and the USB 3.1 communication port.

[0024] As described above, devices that comply with the USB Type-C standard are capable of USB 3.1 communication regardless of whether the USB Type-C cable 121 is connected in a non-inverted or inverted orientation.

[0025] In a USB Type-C connector, the Tx1 / Rx1 and Tx2 / Rx2 ports are located near the longitudinal ends of the connector, which means that if the connector is inserted at a slight angle, either the Tx1 / Rx1 or Tx2 / Rx2 port may have poor contact.

[0026] For example, if there is poor contact on the Tx1 / Rx1 port side when the connection orientation is not reversed, USB 3.1 communication will be impossible even if the Tx2 / Rx2 port is connected properly.

[0027] In this embodiment, by providing a first communication path selection unit 106, a first multiplexer control unit 107, a second communication path selection unit 156, and a second multiplexer control unit 157, it is possible to prevent USB 3.1 communication from becoming impossible due to such poor connections.

[0028] If USB 3.1 communication is not possible due to a poor connection, USB 3.1 communication is not established between the USB host controller 103 and the USB device controller 153, and a link error occurs.

[0029] When a USB 3.1 link error is detected in the USB host controller 103, the first CPU 102 outputs a communication path switching command to the first communication path selection unit 106. Then, the first CPU 102 outputs a communication path switching request to the second CPU 152 of the USB device 151 using USB 2.0 communication. The second CPU 152, having received the communication path switching request, outputs a communication path switching command to the second communication path selection unit 156.

[0030] Furthermore, because the USB port is located in the center of the length of the USB Type-C connector, poor contact is unlikely to occur even if the connector is inserted at a slight angle, and communication is often possible even if poor contact occurs with the USB 3.1 port.

[0031] Upon receiving the communication path switching command, the first communication path selection unit 106 and the second communication path selection unit 156 output a communication path switching signal. The communication path switching signal is, for example, a signal of '0' under normal circumstances and a signal of '1' when the communication path is switched.

[0032] The first multiplexer control unit 107 and the second multiplexer control unit 157 receive the communication path switching signal and the connection direction determination signal from the first CC / mode control unit 104 and the second CC / mode control unit 154, respectively, and output an inverted connection direction determination signal. Specifically, for example, the inverted connection direction determination signal can be generated by taking an exclusive OR (XOR) of the communication path switching signal and the connection direction determination signal.

[0033] Fig. 3(a) is a flowchart showing a method for controlling the USB host device 101 according to the first embodiment. Fig. 3(b) is a flowchart showing a method for controlling the USB device 151 according to the first embodiment. The processing flow of the communication system 100 according to this embodiment will be described with reference to the flowcharts of Figs. 3(a) and 3(b). The USB host device 101 and the USB device 151 are each an example of a communication apparatus.

[0034] First, in step S101, the first CC / mode control unit 104 of the USB host device 101 connects the USB Type-C cable 121 and waits for a change in the voltage at the CC1 / CC2 port. The USB Type-C cable 121 is an example of a communication cable. When a change in the voltage at the CC1 port or the CC2 port is detected, the first CC / mode control unit 104 notifies the first CPU 102 and proceeds to step S102. The CC1 port and the CC2 port are each an example of a communication port.

[0035] First, in step S151, the second CC / mode control unit 154 of the USB device 151 waits for a change in the voltage at the CC1 / CC2 port when the USB Type-C cable 121 is connected. Then, when the second CC / mode control unit 154 detects a change in the voltage at the CC1 port or the CC2 port, it notifies the second CPU 152 and proceeds to step S152.

[0036] In step S102, the first CC / mode control unit 104 of the USB host device 101 determines the connection orientation of the USB Type-C cable 121 based on the voltage of the CC1 / CC2 port, and outputs the result as a connection orientation determination signal.

[0037] Specifically, when the voltage at the CC1 port changes, the first CC / mode control unit 104 outputs a connection orientation determination signal of '0' indicating that the USB Type-C cable 121 is connected in a non-inverted orientation. Also, when the voltage at the CC2 port changes, the first CC / mode control unit 104 outputs a connection orientation determination signal of '1' indicating that the USB Type-C cable 121 is connected in an inverted orientation.

[0038] In step S152, the second CC / mode control unit 154 of the USB device 151 determines the connection orientation of the USB Type-C cable 121 based on the voltage of the CC1 / CC2 port, and outputs the result as a connection orientation determination signal.

[0039] Specifically, when the voltage at the CC1 port changes, the second CC / mode control unit 154 outputs a connection orientation determination signal of '0' indicating that the USB Type-C cable 121 is connected in a non-inverted orientation. Also, when the voltage at the CC2 port changes, the second CC / mode control unit 154 outputs a connection orientation determination signal of '1' indicating that the USB Type-C cable 121 is connected in an inverted orientation.

[0040] In step S103, the first USB SS multiplexer 105 connects either Tx1 / Rx1 or Tx2 / Rx2 of the USB Type-C port 108 to the Tx / Rx port of the USB host controller 103 based on the connection direction determination signal.

[0041] Specifically, when the connection direction determination signal in step S102 is '0', the first USB SS multiplexer 105 connects the Tx1 / Rx1 port of the USB Type-C port 108 to the Tx / Rx port of the USB host controller 103. When the connection direction determination signal in step S102 is '1', the first USB SS multiplexer 105 connects the Tx2 / Rx2 port of the USB Type-C port 108 to the Tx / Rx port of the USB host controller 103.

[0042] In step S153, the second USB SS multiplexer 155 connects either the Tx1 / Rx1 or Tx2 / Rx2 port of the USB Type-C port 158 ​​to the Tx / Rx port of the USB device controller 153 based on the connection orientation determination signal. The Tx1 / Rx1 port and the Tx2 / Rx2 port are each an example of a communication port.

[0043] Specifically, if the connection direction determination signal in step S152 is '0', the second USB SS multiplexer 155 connects the Tx1 / Rx1 port of the USB Type-C port 158 ​​to the Tx / Rx port of the USB device controller 153. Furthermore, if the connection direction determination signal in step S152 is '1', the second USB SS multiplexer 155 connects the Tx2 / Rx2 port of the USB Type-C port 158 ​​to the Tx / Rx port of the USB device controller 153.

[0044] In step S104, the first CPU 102 of the USB host device 101 functions as a communication control unit and controls the USB host controller 103 to start USB 3.1 communication with the USB device 151 using the Tx / Rx ports. Here, the USB 3.1 communication is USB 3.2 Gen1×1 or USB 3.2 Gen2×1 communication.

[0045] In step S154, the second CPU 152 of the USB device 151 functions as a communication control unit, and controls the USB device controller 153 to start communication with the USB host device 101 according to USB 3.1 using the Tx / Rx ports.

[0046] In step S105, the first CPU 102 of the USB host device 101 waits for the link processing of USB 3.1 communication to be completed in the USB host controller 103. If the link processing has been completed successfully, the first CPU 102 completes the processing and ends the processing of the flowchart in Fig. 3(a). If an error is detected in the link processing, the first CPU 102 proceeds to step S106.

[0047] In step S155, the second CPU 152 of the USB device 151 waits for the USB 3.1 link processing to be completed in the USB device controller 153. If the link processing has been completed successfully, the second CPU 152 completes the processing and ends the processing of the flowchart in Fig. 3(b). If an error has occurred in the link processing, the second CPU 152 proceeds to step S156.

[0048] Since the link processing is performed by a pair of the USB host 101 and the USB device 151, if an error occurs in one, an error also occurs in the other.

[0049] In step S106, the first CPU 102 of the USB host device 101 controls the USB host controller 103 to transmit a communication path switching request to the USB device device 151 using USB 2.0 communication via the D+ / D- ports of the USB host controller 103. The D+ / D- ports are an example of a communication port.

[0050] In step S156, the second CPU 152 of the USB device 151 waits to receive a communication path switching request from the USB host device 101. If the second CPU 152 receives a communication path switching request, the process proceeds to step S157.

[0051] In step S107, the first multiplexer control unit 107 of the USB host device 101 inverts the connection orientation determination signal of step S102 and outputs it to the first USB SS multiplexer 105. Then, the first USB SS multiplexer 105 switches the lane used for USB 3.1 communication.

[0052] Specifically, when the connection direction determination signal in step S102 is '0', the first USB SS multiplexer 105 connects the Tx2 / Rx2 port of the USB Type-C port 108 to the Tx / Rx port of the USB host controller 103. When the connection direction determination signal in step S102 is '1', the first USB SS multiplexer 105 connects the Tx1 / Rx1 port of the USB Type-C port 108 to the Tx / Rx port of the USB host controller 103.

[0053] In step S157, the second multiplexer control unit 157 of the USB device 151 inverts the connection direction determination signal of step S152 and outputs it to the second USB SS multiplexer 155. Then, the second USB SS multiplexer 155 switches the lane used for USB 3.1 communication.

[0054] Specifically, if the connection direction determination signal in step S152 is '0', the second USB SS multiplexer 155 connects the Tx2 / Rx2 port of the USB Type-C port 158 ​​to the Tx / Rx port of the USB device controller 153. Furthermore, if the connection direction determination signal in step S152 is '1', the second USB SS multiplexer 155 connects the Tx1 / Rx1 port of the USB Type-C port 158 ​​to the Tx / Rx port of the USB device controller 153.

[0055] In step S108, the first CPU 102 of the USB host device 101 uses the Tx / Rx port of the USB host controller 103 to control the USB host device 101 to start communication with the USB device 151 again according to USB 3.1.

[0056] In step S158, the USB device controller 153 of the USB device 151 uses the Tx / Rx ports of the USB device controller 153 to control the USB device 151 to start communication with the USB host device 101 again according to USB 3.1.

[0057] As described above, in this embodiment, when USB 3.1 communication is not possible in a USB Type-C connection, the communication system 100 switches the lane used for USB 3.1 communication. This allows the communication system 100 to perform USB 3.1 communication even when a connection failure occurs in either the Tx1 / Rx1 lane or the Tx2 / Rx2 lane.

[0058] In the present embodiment, an example has been shown in which the first CPU 102 of the USB host device 101 sends a communication path switching request to the USB device 151 when a link error occurs in USB 3.1 communication, but the present invention is not limited to this. The first CPU 102 may send a communication path switching request to the second CPU 152 of the USB device 151. Alternatively, after a link error occurs, the USB host device 101 and the USB device 151 may each reverse their lanes.

[0059] Although the present embodiment has been described with reference to a case where the USB Type-C connector is inserted at a slight angle, resulting in poor contact at either the Tx1 / Rx1 port or the Tx2 / Rx2 port, the present invention is not limited to this. For example, the present invention can also be applied to a case where poor contact occurs at either the Tx1 / Rx1 port or the Tx2 / Rx2 port due to a break in the USB Type-C cable 121 or damage to the connector.

[0060] As described above, according to this embodiment, the communication system 100 can avoid communication failures in high-speed differential lanes such as USB3.2 Gen1×1 or USB3.2 Gen2×1 when a connection failure occurs in either the Tx1 / Rx1 or Tx2 / Rx2 high-speed differential lanes.

[0061] (Second embodiment) In the first embodiment, a process has been described that enables USB 3.1 communication even when a connection failure occurs in either the Tx1 / Rx1 lane or the Tx2 / Rx2 lane in a USB Type-C connection.

[0062] In the second embodiment, a process will be described for avoiding a situation where video transmission is disabled due to a poor connection when transmitting video via DisplayPort in Alternate Mode of USB Type-C.

[0063] In USB Type-C, by using Alternate Mode, it is possible to interface video signals such as DisplayPort, HDMI (registered trademark), and Thunderbolt using Tx1 / Rx1 lanes or Tx2 / Rx2 high-speed differential lanes.

[0064] Devices connected via USB Type-C communicate using the CC line to recognize the supported modes and begin communication. One of these modes is one that allows USB 3.1 communication and video signal transmission simultaneously by using the Tx1 / Rx1 lanes and Tx2 / Rx2 lanes for USB 3.1 and DisplayPort, respectively.

[0065] 4 is a diagram showing an example of the configuration of a communication system 200 according to the second embodiment. The communication system 200 includes a USB host device 201 and a USB device 251.

[0066] 1, the USB host device 201 is provided with a first CPU 202 instead of the first CPU 102, and a first USB SS multiplexer 205 instead of the first USB SS multiplexer 105. Furthermore, the USB host device 201 is provided with a DP Tx 209 in addition to the USB host device 101 in FIG.

[0067] 1, the USB device 251 is provided with a second CPU 252 instead of the first CPU 152, and a second USB SS multiplexer 255 instead of the second USB SS multiplexer 155. Furthermore, the USB device 251 is provided with a DP Rx 259 in addition to the USB device 151 in FIG.

[0068] In this embodiment, the operations of the first CPU 202, the first USB SS multiplexer 205, the DP Tx 209, the second CPU 252, the second USB SS multiplexer 255, and the DP Rx 259 are different from those in the first embodiment. Other operations in this embodiment are the same as those in the first embodiment.

[0069] The DP Tx209 is a module that converts video data into serial data that conforms to the DisplayPort standard and outputs it. The DP Tx209 outputs the video serial data from two lanes, DPTx0 and DPTx1.

[0070] DP Rx259 is a module that receives serial data conforming to the DisplayPort standard and converts it into video data. DP Rx259 receives video serial data from two lanes, DPRx0 and DPRx1.

[0071] The basic operations of the first USB SS multiplexer 205 and the second USB SS multiplexer 255 of this embodiment are the same as those of the first USB SS multiplexer 105 and the second USB SS multiplexer 155 of the first embodiment.

[0072] The first USB SS multiplexer 205 of this embodiment switches between the ports used for communication between USB 3.1 and DisplayPort based on the connection direction determination signal output from the first CC / mode control unit 104.

[0073] Specifically, when the connection direction determination signal is '0', the first USB SS multiplexer 205 connects the TX / RX port to the Tx1 / Rx1 port and connects the DPTx0 / DPTx1 port to the Tx2 / Rx2 port. Also, when the connection direction determination signal is '1', the first USB SS multiplexer 205 connects the TX / RX port to the Tx2 / Rx2 port and connects the DPTx0 / DPTx1 port to the Tx1 / Rx1 port.

[0074] Similarly, the second USB SS multiplexer 255 switches the port used for communication between USB 3.1 and DisplayPort based on the connection direction determination signal output from the second CC / mode control unit 154.

[0075] Specifically, when the connection direction determination signal is '0', the second USB SS multiplexer 255 connects the TX / RX port to the Tx1 / Rx1 port and connects the DPRx0 / DPRx1 port to the Tx2 / Rx2 port. Furthermore, when the connection direction determination signal is '1', the second USB SS multiplexer 255 connects the TX / RX port to the Tx2 / Rx2 port and connects the DPRx0 / DPRx1 port to the Tx1 / Rx1 port. Figure 5 shows the relationship between the connection direction determination signal and the communication ports.

[0076] As explained in the first embodiment, when the USB Type-C connector is inserted at a slight angle, a poor connection may occur in either the Tx1 / Rx1 port or the Tx2 / Rx2 port. If the port with the poor connection is the lane selected for DisplayPort, video transmission will become impossible.

[0077] On the other hand, if the port with poor contact is the lane selected for USB3.1, USB3.1 communication will not be possible, but USB2.0 communication can be used instead of USB3.1 communication if a decrease in communication speed is acceptable.

[0078] Therefore, when a connection failure occurs in either the Tx1 / Rx1 port or the Tx2 / Rx2 port, it is considered desirable to prioritize establishing a DisplayPort connection from the viewpoint of user convenience.

[0079] Therefore, in the communication system 200, when the first CPU 202 detects a link error in DisplayPort communication via the DP Tx 209, the first CPU 202 inverts the connection orientation determination signal and controls the switching of the communication lanes used for DisplayPort and USB 3.1. Switching the communication lanes causes a link error on the USB 3.1 side. Therefore, the first CPU 202 and the second CPU 252 configure the USB host controller 103 and the USB device controller 153, respectively, to communicate using only USB 2.0.

[0080] Fig. 6(a) is a flowchart showing a method for controlling a USB host device 201 according to the second embodiment. Fig. 6(b) is a flowchart showing a method for controlling a USB device device 251 according to the second embodiment. The flow of processing in the communication system 200 according to this embodiment will be described with reference to the flowcharts of Figs. 6(a) and 6(b).

[0081] Figure 6(a) is obtained by deleting step S104 from Figure 3(a) and adding steps S204, S205, S208, and S209. Figure 6(b) is obtained by deleting step S154 from Figure 3(b) and adding steps S254, S255, S258, and S259. The processing of the other steps is the same as in the first embodiment.

[0082] The processing of the USB host device 201 in steps S101 and S102 is the same as that shown in FIG. 3(a).

[0083] In step S103, the first USB SS multiplexer 205 of the USB host device 201 switches the port used for communication between USB 3.1 and DisplayPort based on the connection direction determination signal output from the first CC / mode control unit 104.

[0084] Specifically, when the connection direction determination signal is '0', the first USB SS multiplexer 205 connects the TX / RX port to the Tx1 / Rx1 port and connects the DPTx0 / DPTx1 port to the Tx2 / Rx2 port. Furthermore, when the connection direction determination signal is '1', the first USB SS multiplexer 205 connects the TX / RX port to the Tx2 / Rx2 port and connects the DPTx0 / DPTx1 port to the Tx1 / Rx1 port. Then, the process proceeds to step S204.

[0085] The processing of the USB device 251 in steps S151 and S152 is the same as that shown in FIG. 3(b).

[0086] In step S153, the second USB SS multiplexer 255 of the USB device 251 switches the port used for communication between USB 3.1 and DisplayPort based on the connection direction determination signal output from the second CC / mode control unit 154.

[0087] Specifically, when the connection direction determination signal is '0', the second USB SS multiplexer 255 connects the TX / RX port to the Tx1 / Rx1 port and connects the DPRx0 / DPRx1 port to the Tx2 / Rx2 port. Furthermore, when the connection direction determination signal is '1', the second USB SS multiplexer 255 connects the TX / RX port to the Tx2 / Rx2 port and connects the DPRx0 / DPRx1 port to the Tx1 / Rx1 port. Then, the process proceeds to step S254.

[0088] In step S204, the first CPU 202 of the USB host device 201 controls the DPTx0 / DPTx1 port of the DP Tx 209 to start communication with the USB device 251 via DisplayPort.

[0089] In step S254, the second CPU 252 of the USB device 251 controls the DPRx0 / DPRx1 port of the DP Rx 259 to start communication with the USB host 201 via DisplayPort.

[0090] In step S205, the first CPU 202 of the USB host device 201 waits for the link processing of the DisplayPort communication to be completed in the DP Tx 209. If the link processing has been completed successfully, the first CPU 202 proceeds to step S108. If an error is detected in the link processing, the first CPU 202 proceeds to step S106.

[0091] In step S255, the second CPU 252 of the USB device 251 waits for the link process of the DisplayPort communication to be completed in the DP Rx 259. If the link process has been completed successfully, the second CPU 252 proceeds to step S158. If an error has occurred in the link process, the second CPU 252 proceeds to step S156.

[0092] Since the link processing is performed by a pair of the USB host device 201 and the USB device 251, if an error occurs in one, an error also occurs in the other.

[0093] The process of the USB host device 201 in step S106 is the same as that shown in FIG. 3(a).

[0094] In step S107, the first multiplexer control unit 107 of the USB host device 201 inverts the connection orientation determination signal of step S102 and outputs it to the first USB SS multiplexer 205. Then, the first USB SS multiplexer 205 switches the lane used for DisplayPort communication.

[0095] Specifically, when the connection direction determination signal is '0', the first USB SS multiplexer 205 connects the TX / RX port to the Tx2 / Rx2 port and connects the DPTx0 / DPTx1 port to the Tx1 / Rx1 port. Furthermore, when the connection direction determination signal is '1', the first USB SS multiplexer 205 connects the TX / RX port to the Tx1 / Rx1 port and connects the DPTx0 / DPTx1 port to the Tx2 / Rx2 port. Then, the process proceeds to step S208.

[0096] The process of the USB device 251 in step S156 is the same as that shown in FIG. 3(b).

[0097] In step S157, the second multiplexer control unit 157 of the USB device 251 inverts the connection orientation determination signal of step S152 and outputs it to the second USB SS multiplexer 255. Then, the second USB SS multiplexer 255 switches the lane used for DisplayPort communication.

[0098] Specifically, when the connection direction determination signal is '0', the second USB SS multiplexer 255 connects the TX / RX port to the Tx2 / Rx2 port and connects the DPRx0 / DPRx1 port to the Tx1 / Rx1 port. Furthermore, when the connection direction determination signal is '1', the second USB SS multiplexer 255 connects the TX / RX port to the Tx1 / Rx1 port and connects the DPRx0 / DPRx1 port to the Tx2 / Rx2 port. Then, the process proceeds to step S258.

[0099] In step S208, the first CPU 202 of the USB host 201 controls the DPTx0 / DPTx1 port of the DP Tx 209 to start communication with the USB device 251 via DisplayPort again.

[0100] In step S258, the second CPU 252 of the USB device 251 controls the DPRx0 / DPRx1 port of the DP Rx 259 to start communication with the USB host 201 via DisplayPort again.

[0101] In step S108, the first CPU 202 of the USB host device 201 uses the Tx / Rx ports of the USB host controller 103 to control the start of USB 3.1 communication with the USB device 251. After that, the process proceeds to step S105.

[0102] In step S105, the first CPU 202 of the USB host device 201 waits for the link processing of USB 3.1 communication to be completed in the USB host controller 103. If the link processing has been completed successfully, the first CPU 202 completes the processing and ends the processing of the flowchart in Fig. 6(a). If an error is detected in the link processing, the first CPU 202 proceeds to step S209.

[0103] In step S158, the second CPU 252 of the USB device 251 uses the Tx / Rx ports of the USB device controller 153 to control the start of USB 3.1 communication with the USB host device 201. Then, the process proceeds to step S155.

[0104] In step S155, the second CPU 252 of the USB device 251 waits for the link processing of USB 3.1 communication to be completed in the USB device controller 153. If the link processing has been completed successfully, the second CPU 252 completes the processing and ends the processing of the flowchart in Fig. 6(b). If an error is detected in the link processing, the second CPU 252 proceeds to step S259.

[0105] In step S209, the first CPU 202 of the USB host device 201 stops the USB 3.1 communication and instead controls the USB host controller 103 to start USB 2.0 communication in parallel with the communication in step S204, using the D+ / D- ports. The D+ / D- ports are an example of a communication port.

[0106] In step S259, the second CPU 252 of the USB device 251 stops the USB 3.1 communication and instead controls the USB device controller 153 to start USB 2.0 communication in parallel with the communication in step S254 using the D+ / D- ports.

[0107] As described above, the communication system 200 of this embodiment switches the lane used for DisplayPort communication when DisplayPort communication is not possible in the case of performing DisplayPort communication in USB Type-C Alternate Mode. This enables DisplayPort communication in the communication system 200 even when a connection failure occurs in either the Tx1 / Rx1 lane or the Tx2 / Rx2 lane.

[0108] (Other embodiments) The present disclosure can also be realized by a process in which a program that realizes one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device read and execute the program. The present disclosure can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0109] Although the present invention has been described in detail above based on preferred embodiments, it is not limited to these specific embodiments and includes various forms within the scope of the present invention. Parts of the above-described embodiments may be combined as appropriate.

[0110] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) The connector where the USB Type-C cable is connected, a control unit that performs control for communicating with an external device via the USB Type-C cable connected to the connection unit when the USB Type-C cable is connected to the connection unit, The control means When a connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, control is performed to start communication using a first communication port, and in response to detection of an error in communication using the first communication port, control is performed to start communication using a second communication port; A communication device characterized by controlling the device to start communication using the second communication port when the connection orientation of the USB Type-C cable connected to the connection unit is a second orientation between front and back, and to start communication using the first communication port when an error in communication using the second communication port is detected. (Configuration 2) The communication device described in configuration 1, characterized in that the control means controls the communication device to send a communication path switching request to the external device using a third communication port in response to the detection of the communication error. (Configuration 3) The communication device according to configuration 1 or 2, characterized in that the control means performs control to start communication using the second communication port when an error in the communication using the first communication port is detected and a request to switch the communication path is received from the external device, and to start communication using the first communication port when an error in the communication using the second communication port is detected and a request to switch the communication path is received from the external device. (Configuration 4) the first communication port is a Tx1 / Rx1 port; 4. The communication device according to any one of configurations 1 to 3, wherein the second communication port is a Tx2 / Rx2 port. (Configuration 5) 5. The communication device according to any one of configurations 1 to 4, wherein the communication is USB3.2 Gen1×1 or USB3.2 Gen2×1 communication. (Configuration 6) The connector where the USB Type-C cable is connected, a control unit that performs control for communicating with an external device via the USB Type-C cable connected to the connection unit when the USB Type-C cable is connected to the connection unit, The control means When a connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, a first communication using a first communication port is started, and a second communication using a second communication port is started in parallel with the first communication using the first communication port, and when an error in the first communication using the first communication port is detected, the first communication using the second communication port is started; a communication device configured to control the first communication using the second communication port when the connection orientation of the USB Type-C cable connected to the connection unit is a second orientation between front and back, and to start the second communication using the first communication port in parallel with the first communication using the second communication port when an error in the first communication using the second communication port is detected, thereby starting the first communication using the first communication port. (Configuration 7) The communication device described in configuration 6, characterized in that when an error is detected in the second communication using the first communication port or the second communication port, the control means stops the second communication and, instead, controls to start a third communication using a third communication port in parallel with the first communication. (Configuration 8) the first communication is a DisplayPort communication, 8. The communication device according to configuration 6 or 7, wherein the second communication is USB3.2 Gen1×1 or USB3.2 Gen2×1 communication. (Configuration 9) the first communication port is a Tx1 / Rx1 port; the second communication port is a Tx2 / Rx2 port; 8. The communication device according to configuration 7, wherein the third communication port is a D+ / D- port. (Configuration 10) the first communication is a DisplayPort communication, the second communication is USB3.2 Gen1×1 or USB3.2 Gen2×1 communication, 10. The communication device according to configuration 7 or 9, wherein the third communication is USB 2.0 communication. (Configuration 11) The communication device according to any one of configurations 1 to 10, wherein the control means detects that the connection orientation is the first orientation when the voltage of the fourth communication port changes, and detects that the connection orientation is the second orientation when the voltage of the fifth communication port changes. (Configuration 12) the fourth communication port is a CC1 port; 12. The communication device according to claim 11, wherein the fifth communication port is a CC2 port. (Configuration 13) a first communication device; a second communication device connected to the first communication device via a USB Type-C cable; the first communication device, a first connection portion to which the USB Type-C cable is connected; a first control unit that, when the USB Type-C cable is connected to the first connection unit, performs control to communicate with the second communication device via the USB Type-C cable connected to the first connection unit; The first control means When a connection orientation of the USB Type-C cable connected to the first connection unit is a first orientation among front and back orientations, control is performed to start communication using a first communication port, and in response to detection of an error in communication using the first communication port, control is performed to start communication using a second communication port; When a connection orientation of the USB Type-C cable connected to the first connection unit is a second orientation among front and back orientations, control is performed to start communication using the second communication port, and in response to detection of an error in communication using the second communication port, control is performed to start communication using the first communication port; the second communication device, a second connection portion to which the USB Type-C cable is connected; a second control unit that, when the USB Type-C cable is connected to the second connection unit, performs control to communicate with the first communication device via the USB Type-C cable connected to the second connection unit; The second control means When a connection orientation of the USB Type-C cable connected to the second connection portion is a first orientation among front and back orientations, control is performed to start communication using a third communication port, and in response to detection of an error in communication using the third communication port, control is performed to start communication using a fourth communication port; A communication system characterized by controlling the device to start communication using the fourth communication port when the connection orientation of the USB Type-C cable connected to the second connection portion is a second orientation between front and back, and to start communication using the third communication port when an error in communication using the fourth communication port is detected. (Configuration 14) a first communication device; a second communication device connected to the first communication device via a USB Type-C cable; the first communication device, a first connection portion to which the USB Type-C cable is connected; a first control unit that, when the USB Type-C cable is connected to the first connection unit, performs control to communicate with the second communication device via the USB Type-C cable connected to the first connection unit; The first control means When a connection orientation of the USB Type-C cable connected to the first connection unit is a first orientation among front and back orientations, a first communication using a first communication port is started, and a second communication using a second communication port is started in parallel with the first communication using the first communication port, and when an error in the first communication using the first communication port is detected, the first communication using the second communication port is started; when a connection orientation of the USB Type-C cable connected to the first connection unit is a second orientation between front and back, start the first communication using the second communication port and start the second communication using the first communication port in parallel with the first communication using the second communication port, and when an error in the first communication using the second communication port is detected, control is performed to start the first communication using the first communication port; the second communication device, a second connection portion to which the USB Type-C cable is connected; a second control unit that, when the USB Type-C cable is connected to the second connection unit, performs control to communicate with the second communication device via the USB Type-C cable connected to the second connection unit; The second control means When a connection orientation of the USB Type-C cable connected to the second connection portion is a first orientation among front and back orientations, a first communication using a third communication port is started, and a second communication using a fourth communication port is started in parallel with the first communication using the third communication port, and when an error in the first communication using the third communication port is detected, the first communication using the fourth communication port is started; a communication system characterized by: when the connection orientation of the USB Type-C cable connected to the second connection portion is a second orientation among front and back orientations, starting the first communication using the fourth communication port and starting the second communication using the third communication port in parallel with the first communication using the fourth communication port; and when an error is detected in the first communication using the fourth communication port, controlling to start the first communication using the third communication port. (Method 1) The connector where the USB Type-C cable is connected, a control unit that, when the USB Type-C cable is connected to the connection unit, performs control to communicate with an external device via the USB Type-C cable connected to the connection unit, When the connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, starting communication using a first communication port, and in response to detection of an error in communication using the first communication port, performing control to start communication using a second communication port; When the connection orientation of the USB Type-C cable connected to the connection unit is a second orientation between front and back, starting communication using the second communication port, and in response to detection of an error in communication using the second communication port, performing control to start communication using the first communication port. A method for controlling a communication device, comprising: (Method 2) The connector where the USB Type-C cable is connected, a control unit that, when the USB Type-C cable is connected to the connection unit, performs control to communicate with an external device via the USB Type-C cable connected to the connection unit, When a connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, starting a first communication using a first communication port and starting a second communication using a second communication port in parallel with the first communication using the first communication port, and when an error in the first communication using the first communication port is detected, performing control to start the first communication using the second communication port; when a connection orientation of the USB Type-C cable connected to the connection unit is a second orientation between front and back, starting the first communication using the second communication port and starting the second communication using the first communication port in parallel with the first communication using the second communication port, and when an error in the first communication using the second communication port is detected, performing control to start the first communication using the first communication port. A method for controlling a communication device, comprising: [Explanation of symbols]

[0111] 100 Communication system, 101 USB host device, 102 First CPU, 103 USB host controller, 104 First CC / mode control unit, 105 First USB SS multiplexer, 106 First communication path selection unit, 107 First multiplexer control unit, 108 First USB Type-C port, 121 USB Type-C cable, 151 USB device device, 152 Second CPU, 153 USB device controller, 154 Second CC / mode control unit, 155 Second USB SS multiplexer, 156 Second communication path selection unit, 157 Second multiplexer control unit, 158 Second USB Type-C port

Claims

1. A connection portion to which a USB Type-C cable is connected; a control unit that performs control for communicating with an external device via the USB Type-C cable connected to the connection unit when the USB Type-C cable is connected to the connection unit, The control means When a connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, control is performed to start communication using a first communication port, and in response to detection of an error in communication using the first communication port, control is performed to start communication using a second communication port; A communication device characterized by performing control so that, when the connection orientation of the USB Type-C cable connected to the connection portion is a second orientation among front and back orientations, communication using the second communication port is started, and communication using the first communication port is started in response to detection of an error in communication using the second communication port.

2. 2. The communication device according to claim 1, wherein the control means performs control so as to send a communication path switching request to the external device using a third communication port in response to detection of the communication error.

3. The communication device described in claim 1, characterized in that the control means controls the communication using the second communication port when an error in the communication using the first communication port is detected and a request to switch the communication path is received from the external device, and controls the communication using the first communication port when an error in the communication using the second communication port is detected and a request to switch the communication path is received from the external device.

4. the first communication port is a Tx1 / Rx1 port; 2. The communication device according to claim 1, wherein the second communication port is a Tx2 / Rx2 port.

5. 2. The communication device according to claim 1, wherein the communication is USB 3.2 Gen1x1 or USB 3.2 Gen2x1 communication.

6. A connection portion to which a USB Type-C cable is connected; a control unit that performs control for communicating with an external device via the USB Type-C cable connected to the connection unit when the USB Type-C cable is connected to the connection unit, The control means when a connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, a first communication using a first communication port is started, and a second communication using a second communication port is started in parallel with the first communication using the first communication port, and when an error in the first communication using the first communication port is detected, the first communication using the second communication port is started; a communication device configured to control the communication device so that, when the connection orientation of the USB Type-C cable connected to the connection portion is a second orientation among front and back orientations, the first communication using the second communication port is started and the second communication using the first communication port is started in parallel with the first communication using the second communication port, and, when an error is detected in the first communication using the second communication port, the communication device performs control so as to start the first communication using the first communication port.

7. The communication device described in claim 6, characterized in that the control means controls the second communication to be stopped when an error is detected in the second communication using the first communication port or the second communication port, and instead controls the second communication to be started in parallel with the first communication using a third communication port.

8. the first communication is a DisplayPort communication, The communication device according to claim 6 , wherein the second communication is USB 3.2 Gen1×1 or USB 3.2 Gen2×1 communication.

9. the first communication port is a Tx1 / Rx1 port; the second communication port is a Tx2 / Rx2 port; 8. The communication device of claim 7, wherein the third communication port is a D+ / D- port.

10. the first communication is a DisplayPort communication, the second communication is USB 3.2 Gen1×1 or USB 3.2 Gen2×1 communication, 8. The communication device according to claim 7, wherein the third communication is USB 2.0 communication.

11. The communication device according to claim 1 or 6, characterized in that the control means detects that the connection orientation is the first orientation when a voltage at a fourth communication port changes, and detects that the connection orientation is the second orientation when a voltage at a fifth communication port changes.

12. the fourth communication port is a CC1 port; 12. The communication device of claim 11, wherein the fifth communication port is a CC2 port.

13. A first communication device; a second communication device connected to the first communication device via a USB Type-C cable; The first communication device is a first connection portion to which the USB Type-C cable is connected; a first control means for performing control for communicating with the second communication device via the USB Type-C cable connected to the first connection unit when the USB Type-C cable is connected to the first connection unit, The first control means is When a connection orientation of the USB Type-C cable connected to the first connection portion is a first orientation among front and back orientations, control is performed to start communication using a first communication port, and in response to detection of an error in communication using the first communication port, control is performed to start communication using a second communication port; When a connection orientation of the USB Type-C cable connected to the first connection portion is a second orientation among front and back orientations, control is performed to start communication using the second communication port, and in response to detection of an error in communication using the second communication port, control is performed to start communication using the first communication port; The second communication device is a second connection portion to which the USB Type-C cable is connected; a second control means for performing control for communicating with the first communication device via the USB Type-C cable connected to the second connection unit when the USB Type-C cable is connected to the second connection unit, The second control means is When a connection orientation of the USB Type-C cable connected to the second connection portion is a first orientation among front and back orientations, control is performed to start communication using a third communication port, and in response to detection of an error in communication using the third communication port, control is performed to start communication using a fourth communication port; A communication system characterized by controlling the device to start communication using the fourth communication port when the connection orientation of the USB Type-C cable connected to the second connection portion is a second orientation between front and back, and to start communication using the third communication port when an error in communication using the fourth communication port is detected.

14. A first communication device; a second communication device connected to the first communication device via a USB Type-C cable; The first communication device is a first connection portion to which the USB Type-C cable is connected; a first control means for performing control for communicating with the second communication device via the USB Type-C cable connected to the first connection unit when the USB Type-C cable is connected to the first connection unit, The first control means is when a connection orientation of the USB Type-C cable connected to the first connection portion is a first orientation among front and back orientations, a first communication using a first communication port is started, and a second communication using a second communication port is started in parallel with the first communication using the first communication port, and when an error in the first communication using the first communication port is detected, the first communication using the second communication port is started; when a connection orientation of the USB Type-C cable connected to the first connection portion is a second orientation among front and back orientations, control is performed to start the first communication using the second communication port and to start the second communication using the first communication port in parallel with the first communication using the second communication port, and when an error is detected in the first communication using the second communication port, control is performed to start the first communication using the first communication port; The second communication device is a second connection portion to which the USB Type-C cable is connected; a second control means for performing control for communicating with the second communication device via the USB Type-C cable connected to the second connection unit when the USB Type-C cable is connected to the second connection unit, The second control means is when a connection orientation of the USB Type-C cable connected to the second connection portion is a first orientation among front and back orientations, a first communication using a third communication port is started, and a second communication using a fourth communication port is started in parallel with the first communication using the third communication port, and when an error is detected in the first communication using the third communication port, the first communication using the fourth communication port is started; A communication system characterized by: when the connection orientation of the USB Type-C cable connected to the second connection portion is a second orientation among front and back orientations, starting the first communication using the fourth communication port and starting the second communication using the third communication port in parallel with the first communication using the fourth communication port; and when an error is detected in the first communication using the fourth communication port, controlling to start the first communication using the third communication port.

15. A connection portion to which a USB Type-C cable is connected; a control unit that performs control for communicating with an external device via the USB Type-C cable connected to the connection unit when the USB Type-C cable is connected to the connection unit, a step of performing control so as to start communication using a first communication port when a connection orientation of the USB Type-C cable connected to the connection unit is a first orientation among front and back orientations, and to start communication using a second communication port in response to detection of an error in communication using the first communication port; a step of controlling to start communication using the second communication port when a connection orientation of the USB Type-C cable connected to the connection unit is a second orientation among front and back orientations, and to start communication using the first communication port in response to detection of an error in communication using the second communication port; 13. A method for controlling a communication device, comprising:

16. A connection portion to which a USB Type-C cable is connected; a control means for performing control for communicating with an external device via the USB Type-C cable connected to the connection unit when the USB Type-C cable is connected to the connection unit, a step of controlling to start a first communication using a first communication port when a connection orientation of the USB Type-C cable connected to the connection portion is a first orientation among front and back orientations, and to start a second communication using a second communication port in parallel with the first communication using the first communication port, and to start the first communication using the second communication port when an error in the first communication using the first communication port is detected; when a connection orientation of the USB Type-C cable connected to the connection portion is a second orientation among front and back orientations, starting the first communication using the second communication port and starting the second communication using the first communication port in parallel with the first communication using the second communication port, and when an error in the first communication using the second communication port is detected, performing control to start the first communication using the first communication port.

13. A method for controlling a communication device, comprising:

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