A DP switching device with fast switching and an audio-video data transmission system

Abstract

The present invention discloses a DP switching device with fast switching and an audio-video data transmission system. The device includes a virtual DP AUX receiver, an AUX parser including several hardware parts and an AUX controller including software parts. The AUX parser corresponds to the AUX controller and the DP source device respectively one by one, and is used to receive the AUX signal in the AUX request signal sent by the DP source device, parse the AUX signal to obtain AUX request information, and then send the AUX request information to the AUX controller. The AUX controller is used to generate AUX response information according to the AUX request information, and the AUX response information is sent to the DP source device via the AUX parser, so as to complete the previous AUX communication and data path training process and achieve the task of negotiating the number and rate of data transmission lines. The present invention uses a software and hardware combination solution to give full play to the respective advantages of software and hardware.

Description

Technical Field

[0001] The present invention relates to the technical field of audio - video data transmission, and particularly to a DP switching device with fast switching and an audio - video data transmission system. Background Art

[0002] A DP switching device is a tool for switching the connection between a DP (DisplayPort) signal source and a display among multiple devices, enabling a set of keyboards, mice or displays to control multiple computers or video devices.

[0003] The DP switching device is characterized by multiple DP interfaces for input. After multiple selections, the selected DP input data is output. Before data transmission through the DP interface, the DP source device and the DP receiving device need to perform Training to negotiate the number of data lines and the rate of data transmission to ensure the correctness of data transmission. This process takes a certain amount of time. Therefore, if the Training process starts only after the DP interface is switched, there will be no video data output during this period, resulting in a phenomenon of no display on the monitor, that is, a bad display such as a black screen or snowflakes for a relatively long time.

[0004] If, before switching, each DP source device and the DP receiving device have already negotiated the inherent number of data lines and the rate through the Training process respectively, when switching is required, the input data of the selected DP source device can be directly switched. Existing technical solutions to enable each DP source device to complete the Training process in advance are as follows:

[0005] 1) Each DP source device is docked with an independent DP receiver. The independent DP receiver includes an independent DP AUX receiver and a DP data receiver, which can perform AUX communication and data transmission with each DP source device respectively. Each DP data receiver will independently receive and parse the DP data. The selector inside the DP switching device outputs the data output by the DP receiver corresponding to the selected path as the selected data. The disadvantages of this technical solution are: a) The independent DP receiver will occupy a large amount of logic resources, increasing the production cost; b) Each independent DP receiver will consume power during operation. Even if this channel is not selected as the selected channel, it will still consume power in the normal working mode.

[0006] 2) Each DP source device is docked with an independent DP AUX receiver, while there is only one DP data receiver. To reduce the logical resources occupied by each independent DP receiver in the existing technical solution 1 of the DP switching device, an independent DP AUX receiver is used to dock with each DP source device, so as to achieve the purpose of negotiating the number and rate of data transmission data lines in advance through the Training training process. The DP data receiver can be shared. The selector inside the DP switching device selects the selected DP data and inputs it into the DP data receiver for data parsing, and then outputs it to the subsequent device. The disadvantage of this technical solution is that each independent DP AUX receiver contains a DPCD hardware table and may also contain a local EDID hardware table, and these hardware tables will occupy a large amount of RAM or register resources, resulting in an increase in production costs.

[0007] 3) Each DP source device is docked with a software virtual DP AUX receiver, while there is only one DP data receiver. To reduce the logical resources occupied by each independent DP receiver, a software virtual DP AUX receiver is used to dock with each DP source device, so as to achieve the purpose of negotiating the number and rate of data transmission data lines in advance through the Training training process. The DP data receiver can be shared. The selector inside the DP switching device selects the selected DP data and inputs it into the DP data receiver for data parsing, and then outputs it to the subsequent device. The software virtual DP AUX receiver, that is, the MCU inside the DP switching device, realizes AUX communication with the DP source device through software via the GPIO pins. In this case, a powerful MCU support is required inside the DP switching device, and an additional GPIO interface is required to support the software virtual DP AUX receiver. The internal MCU receives the AUX signal through the GPIO pins, then analyzes the AUX signal according to the protocol to obtain the parameters of the AUX Request. Then it replies with the corresponding AUX Reply, converts it into an AUX signal, and sends it out through the GPIO pins. The disadvantages of this technical solution are: a) Inside the DP switching device, a powerful MCU support is required, which will increase the production cost; b) At the same time, an additional GPIO interface is required to support the software virtual DP AUX receiver, increasing the GPIO resources, which will also increase the production cost. Summary of the Invention

[0008] The object of the present invention is to provide a fast-switching DP switching device and an audio-video data transmission system in view of the deficiencies of the existing technology.

[0009] To achieve the above object, in the first aspect, the present invention provides a fast-switching DP switching device, including:

[0010] A virtual DP AUX receiver, including an AUX parser in several hardware parts and an AUX controller in a software part running on a processor. The AUX parser corresponds to the AUX controller and the DP source device respectively, and is used to receive the AUX signal in the AUX request signal sent by the DP source device, parse the AUX signal to obtain AUX request information, and then send the AUX request information to the AUX controller. The AUX controller is used to generate AUX response information according to the AUX request information. The AUX parser generates an AUX response signal according to the AUX response information and sends the AUX response signal to the corresponding DP source device, so as to complete the preliminary AUX communication and data path training process and achieve the task of negotiating the number and rate of data transmission lines;

[0011] A DP source configuration module, used to receive and identify an externally sent DP source configuration command, and output a control signal for selecting the corresponding DP source device according to the DP source configuration command;

[0012] A DP source selector, used to receive the control signal sent by the DP source configuration module, and select the corresponding DP source device according to the control signal, so as to send the DP input data sent by the selected DP source device to the DP receiver;

[0013] An AUX information copying module, used to send the parameters inconsistent with the default parameters in the AUX controller corresponding to the selected DP source device to the DP receiver;

[0014] A DP receiver, including a DP AUX receiver and a DP data receiver. The DP AUX receiver is used to receive the DP AUX data and the parameters sent by the AUX information copying module in the DP input data sent by the DP source selector, initialize according to the received parameters, and then perform AUX interaction according to the received DP AUX data. The DP data receiver is used to receive the DP data in the DP input data sent by the DP source selector, parse the DP data to obtain audio and video data, and then send the audio and video data to the display device.

[0015] Further, the AUX parser includes:

[0016] An AUX signal receiving module, used to receive the AUX signal in the AUX request signal and receive the valid data in the AUX signal by identifying the synchronization code;

[0017] An AUX data decoding module, used to decode the valid data in the AUX signal into AUX training data;

[0018] An AUX data parsing module, which is used to parse the AUX training data to obtain AUX request information and write the AUX request information into the corresponding register;

[0019] An interrupt sending module, which is used to send an interrupt signal after the AUX data parsing module writes the AUX request information into the register, so as to notify the AUX controller that the AUX request information is ready;

[0020] The AUX controller includes:

[0021] An interrupt receiving module, which is used to receive the interrupt signal sent by the interrupt sending module;

[0022] An AUX request information reading module, which is used to read the AUX request information from the register when the interrupt receiving module receives the interrupt signal;

[0023] An AUX state machine control module, which is used to control the AUX state machine to jump according to the read AUX request information;

[0024] An AUX response information preparation module, which is used to prepare AUX response information according to the current state of the AUX state machine;

[0025] An AUX response information writing module, which is used to write the AUX response information prepared by the AUX response information preparation module into the corresponding register;

[0026] An AUX response information start sending module, which is used to write an enable into the corresponding register after the AUX response information writing module writes the AUX response information prepared by the AUX response information preparation module into the register;

[0027] The AUX parser further includes:

[0028] An AUX response information obtaining module, which is used to obtain AUX response information from the corresponding register;

[0029] An AUX response data packetizing module, which is used to packetize the AUX response information obtained by the AUX response information obtaining module into AUX response data;

[0030] An AUX data encoding module, which is used to encode the AUX response data into an AUX response signal;

[0031] An AUX signal sending module, which is used to send out the AUX response signal encoded by the AUX data encoding module.

[0032] Furthermore, the data writing and reading of the register are performed based on the I2C interface or the APB interface or the AHB interface.

[0033] Further, the processor is an MCU.

[0034] Further, the DP source selector is a data selector.

[0035] Further, the AUX parser is also used to monitor the correctness of the training bit sequence data used in the training process in the data path.

[0036] In a second aspect, the present invention provides an audio - video data transmission system, including the above - mentioned fast - switching DP switching device.

[0037] Beneficial effects: 1. By designing the virtual DP AUX receiver as an AUX parser in the hardware part and an AUX controller in the software part, the present invention makes full use of the respective advantages of software and hardware through a software - hardware combination scheme, simplifying the system design;

[0038] 2. The present invention saves the use of logic resources to the greatest extent, achieving the design purpose of low cost and low power consumption;

[0039] 3. The scheme of implementing the controller by software in the present invention also overcomes the disadvantage that the hardware controller cannot be modified, making the system have better system flexibility and can be optimized according to the application scenario by optimizing the controller code. Description of the Drawings

[0040] Figure 1 is the principle block diagram of the fast - switching DP switching device according to an embodiment of the present invention;

[0041] Figure 2 is the schematic diagram of the data flow of the fast - switching DP switching device according to an embodiment of the present invention;

[0042] Figure 3 is the principle block diagram of the virtual DP AUX receiver according to an embodiment of the present invention. Detailed Embodiments

[0043] The following further clarifies the present invention in conjunction with the drawings and specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0044] As Figures 1 to 3 shown, an embodiment of the present invention provides a fast - switching DP switching device, including a virtual DP AUX receiver 1, a DP source configuration module 2, a DP source selector 3, an AUX information replication module 4, and a DP receiver 5.

[0045] Among them, the virtual DP AUX receiver 1 includes an AUX parser 11 of several hardware parts and an AUX controller 12 of a software part running on the processor 6. The processor 6 is preferably an MCU (Microcontroller Unit). The AUX parser 11 corresponds to the AUX controller 12 and the DP source device 100 respectively. The AUX parser 11 is used to receive the AUX signals in the AUX request signals sent by the DP source device 100, including the signals used for data path training and the signals used for preliminary communication to prepare for training. The above AUX signals are sent by the DP source device 100 through the AUX interface (auxiliary interface). After receiving the AUX signals, the AUX parser 11 analyzes the received AUX signals to obtain AUX request information, and then sends the parsed AUX request information to the AUX controller 12. The AUX controller 12 is used to generate AUX response information according to the received AUX request information. The AUX parser 11 generates an AUX response signal according to the AUX response information generated by the AUX controller 12, and sends the AUX response signal to the corresponding DP source device 100, so as to complete the preliminary AUX communication and data path training process, and then realize tasks such as negotiating the number and rate of data lines (lanes) for data transmission.

[0046] The DP source configuration module 2 is used to receive and identify the externally sent DP source configuration commands, and output a control signal for selecting the corresponding DP source device 100 according to the DP source configuration commands. The above DP source configuration module 2 is preferably a software module in the processor 6.

[0047] The DP source selector 3 is used to receive the control signal sent by the DP source configuration module 2, and select the corresponding DP source device 100 according to the received control signal, so as to send the DP input data sent by the selected DP source device 100 to the DP receiver 5. The DP source selector 3 is a multiple-choice MUX (data selector), which can select one output from multiple DP source devices 100.

[0048] The AUX information copying module 4 is used to send the parameters inconsistent with the default parameters in the AUX controller 12 corresponding to the selected DP source device 100 to the DP receiver 5. For example, the default is the 4lane mode, but the negotiated mode through the training process is the 2lane mode, so the parameters are different from the default. Similarly, the rate negotiated through the training process may also be different from the default. In this case, the parameters inconsistent with the default parameters need to be sent to the DP receiver 5. The AUX information copying module 4 is also preferably a software module in the processor 6.

[0049] The DP receiver 5 includes a DP AUX receiver 51 and a DP data receiver 52. Among them, the DP AUX receiver 51 is used to receive the DP AUX data and the parameters sent by the AUX information replication module 4 in the DP input data sent by the DP source selector 3. The DP AUX receiver 51 is initialized according to the received parameters. Since the previous AUX communication and data path training process has been completed by the virtual DP AUX receiver 1, the DP AUX receiver 51 can directly perform AUX interaction according to the received DP AUX data, including subsequent HDCP or other AUX interactions according to the scenario requirements. The DP data receiver 52 is used to receive the DP data in the DP input data sent by the DP source selector 3, parse the DP data to obtain audio-visual data, and then send the audio-visual data to the display device 200. The display device 200 can then control the playback of the received audio-visual data.

[0050] It should be further noted that since the completion of the previous AUX communication and data path training process by the virtual DP AUX receiver 1 will not affect the operation of the DP source selector 3 and the DP receiver 5, during the period when a certain DP source device 100 sends audio-visual data to the display device 200 through the DP source selector 3 and the DP receiver 5, the virtual DP AUX receiver 1 can normally complete the AUX communication and data path training processes in all / part of the other DP source devices 100. The parameters such as the number and rate of data lines (lanes) for data transmission negotiated respectively are controlled and stored by the corresponding AUX controllers 12. When the DP source selector 3 is controlled to select the corresponding DP source device 100, the AUX information replication module 4 simultaneously sends the parameters inconsistent with the default parameters in the AUX controller 12 corresponding to the selected DP source device 100 to the DP receiver 5, so that the switching and initialization operations of the DP source device 100 are carried out simultaneously.

[0051] See Figure 3 , the AUX parser 11 of the embodiment of the present invention includes an AUX signal receiving module 111, an AUX data decoding module 112, an AUX data parsing module 113, an interrupt sending module 114, an AUX response information obtaining module 115, an AUX response data packet assembling module 116, an AUX data encoding module 117, and an AUX signal sending module 118.

[0052] Among them, the AUX signal receiving module 111 is used to receive the AUX signal in the AUX request signal and receive the valid data in the AUX signal by identifying the synchronization code.

[0053] The AUX data decoding module 112 is used to decode the valid data in the AUX signal into AUX training data.

[0054] The AUX data parsing module 113 is used to parse the AUX training data to obtain AUX request information and write the AUX request information into the corresponding register. The register is a data interaction medium between the AUX parser 11 in the hardware part and the AUX controller 12 in the software part. The writing and reading of register data are based on the i2c interface or the APB interface or the AHB interface or other bus interfaces.

[0055] The interrupt sending module 114 is used to send an interrupt signal after the AUX data parsing module writes the AUX request information into the register, so as to notify the AUX controller 12 that the AUX request information is ready.

[0056] The AUX controller 12 of the embodiment of the present invention includes an interrupt receiving module 121, an AUX request information reading module 122, an AUX state machine control module 123, an AUX response information preparation module 124, an AUX response information writing module 125 and an AUX response information start sending module 126.

[0057] The interrupt receiving module 121 is used to receive the interrupt signal sent by the above interrupt sending module 114. Receiving the interrupt signal means that it is known that the AUX request information is ready.

[0058] The AUX request information reading module 122 is used to read the AUX request information from the register when the interrupt receiving module 121 receives the interrupt signal.

[0059] The AUX state machine control module 123 is used to control the jump of the AUX state machine according to the read AUX request information.

[0060] The AUX response information preparation module 124 is used to prepare the AUX response information according to the current state of the AUX state machine.

[0061] The AUX response information writing module 125 is used to write the AUX response information prepared by the AUX response information preparation module 124 into the corresponding register.

[0062] The AUX response information start sending module 126 is used to write an enable into the corresponding register after the AUX response information writing module 125 writes the AUX response information into the register, that is, the AUX controller 12 notifies the AUX parser 11 to start the operation of reading the AUX response information.

[0063] The AUX response information obtaining module 115 is used to obtain the AUX response information from the corresponding register.

[0064] The AUX response data packet assembling module 116 is used to assemble the AUX response information obtained by the AUX response information obtaining module 115 into AUX response data.

[0065] The AUX data encoding module 117 is used to encode the AUX response data into an AUX response signal.

[0066] The AUX signal sending module 118 is used to send out the AUX response signal encoded by the AUX data encoding module. The above AUX data decoding module 112 and AUX data encoding module 117 preferably perform decoding and encoding operations according to the Manchester encoding algorithm specified in the protocol. Through the above data interaction mode between each module of the AUX parser 11 and the AUX controller 12, the preliminary AUX communication and data path training process can be completed.

[0067] The AUX parser 11 of the embodiment of the present invention is further used to monitor the correctness of the training bit sequence (TPS, Training Pattern Sequence) data for the training process in the data path.

[0068] Based on the above embodiments, those skilled in the art can easily understand that the present invention also provides an audio - video data transmission system, which includes the above - mentioned DP switching device with fast switching.

[0069] The above description is only a preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, other parts not specifically described belong to the prior art or common knowledge. Without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A fast switching DP switching device, characterized in that: include: A virtual DP AUX receiver includes an AUX parser of several hardware parts and an AUX controller of the software part running on the processor. The AUX parser corresponds to the AUX controller and the DP source device respectively, and is used to receive the AUX signal in the AUX request signal sent by the DP source device, and parse the AUX signal to obtain AUX request information, and then send the AUX request information to the AUX controller. The AUX controller is used to generate AUX response information according to the AUX request information. The AUX parser generates an AUX response signal according to the AUX response information generated by the AUX controller, and sends the AUX response signal to the corresponding DP source device, thereby completing the early AUX communication and data path training process and realizing the task of negotiating the number of data lines and rate of data transmission; A DP source configuration module, configured to receive and identify an externally sent DP source configuration command, and output a control signal for selecting a corresponding DP source device according to the DP source configuration command; a DP source selector, configured to receive a control signal sent by the DP source configuration module and select a corresponding DP source device according to the control signal, so as to send the DP input data sent by the selected DP source device to the DP receiver; An AUX information copy module is used to send parameters in the AUX controller corresponding to the selected DP source device that are inconsistent with the default parameters to the DP receiver; The DP receiver includes a DP AUX receiver and a DP data receiver. The DP AUX receiver is used to receive the DP AUX data in the DP input data sent by the DP source selector and the parameters sent by the AUX information copy module, and is initialized according to the received parameters, and then performs AUX interaction according to the received DP AUX data. The DP data receiver is used to receive the DP data in the DP input data sent by the DP source selector, parse the DP data to obtain audio and video data, and then send the audio and video data to the display device.

2. The fast switching DP switching device according to claim 1, characterized in that: The AUX parser includes: An AUX signal receiving module is used to receive the AUX signal in the AUX request signal and receive valid data in the AUX signal by identifying the synchronization code; AUX data decoding module, used to decode the valid data in the AUX signal into AUX training data; An AUX data parsing module is used to parse the AUX training data to obtain AUX request information and write the AUX request information into a corresponding register; an interrupt sending module, configured to send an interrupt signal after the AUX data parsing module writes the AUX request information into the register, so as to notify the AUX controller that the AUX request information is ready; The AUX controller includes: An interrupt receiving module, configured to receive an interrupt signal sent by the interrupt sending module; An AUX request information reading module, configured to read the AUX request information from the register when the interrupt receiving module receives an interrupt signal; AUX state machine control module, used to perform AUX state machine jump control according to the read AUX request information; AUX response information preparation module, used to prepare AUX response information according to the current state of the AUX state machine; An AUX response information writing module, used to write the AUX response information prepared by the AUX response information preparing module into a corresponding register; An AUX response information starting sending module is configured to write an enable signal into a corresponding register after the AUX response information writing module writes the AUX response information prepared by the AUX response information preparing module into the register; The AUX parser also includes: AUX response information acquisition module, used to obtain AUX response information from the corresponding register; An AUX response data packaging module, configured to package the AUX response information acquired by the AUX response information acquisition module into AUX response data; An AUX data encoding module, configured to encode the AUX response data into an AUX response signal; The AUX signal sending module is used to send the AUX response signal encoded by the AUX data encoding module.

3. The fast switching DP switching device according to claim 2, characterized in that: The data writing and reading of the register are performed based on the i2c interface, the APB interface or the AHB interface.

4. The fast switching DP switching device according to claim 1, characterized in that: The processor is an MCU.

5. The fast switching DP switching device according to claim 1, characterized in that: The DP source selector is a data selector.

6. The fast switching DP switching device according to claim 1, characterized in that: The AUX parser is also used to monitor the correctness of the training bit sequence data used in the training process in the data path.

7. An audio and video data transmission system, characterized in that: A fast-switching DP switching device comprising the device described in any one of claims 1-6.

Images