An audio transmission system based on tree topology

Abstract

The present invention discloses an audio transmission system based on a tree topology structure, and relates to the field of vehicle audio technology. The system includes: a host, which is used to obtain the topology information of the audio transmission network and establish a routing table; the audio transmission network includes multiple audio transmission nodes forming a tree topology structure, the audio transmission node is used to obtain and parse the data frames sent by other audio transmission nodes, transmit the data frames to the target node according to the routing table, and is also used to generate data frames to be sent according to the acquired audio data and control information, and query the routing table to transmit the data frames to the target node; peripheral equipment, which is used to apply the target node connected thereto to process the audio data, and is used to collect audio data and control information. The present invention constructs a tree topology system, and the control information and audio data use the same routing protocol to realize the transmission of audio data and control information between any nodes, thereby improving the data transmission efficiency and system flexibility.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle-mounted audio technology, and in particular to an audio transmission system based on a tree topology structure. Background Art

[0002] In the field of in-vehicle audio, with the increasing number of audio acquisition devices and audio playback devices in the car, there is an urgent need for an efficient and low-cost transmission solution that can transmit audio data to various locations in the car for playback as needed and collect audio data from various locations in the car and transmit it to the audio processor. While transmitting audio data, the audio processor is also required to control the audio playback device and audio acquisition device accordingly as needed. This requires the transmission solution to support the transmission and response of control information at the same time. In the current system, a daisy chain topology is mainly used, which only supports half-duplex transmission. Other slave nodes can only be controlled by the audio processor docked at the master node, and the transmission efficiency is low. In the scenario of multiple audio processors, this single system topology cannot meet the control requirements. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, the present invention provides an audio transmission system based on a tree topology structure. The present invention covers the application scenarios of a daisy chain topology structure by constructing a tree topology structure. The audio data and control information adopt the same routing transmission protocol, which can realize the transmission of control information between any nodes.

[0004] The present invention provides an audio transmission system based on a tree topology structure.

[0005] Host computer, audio transmission network and peripheral devices;

[0006] The audio transmission network includes a plurality of audio transmission nodes forming a tree topology, wherein a root node is connected to the host and at least one child node, and each child node is connected to the peripheral device;

[0007] The host is used to obtain topology information of the audio transmission network, and establish corresponding routing tables in the root node and child nodes at all levels according to the obtained topology information;

[0008] The audio transmission node is used to obtain data frames sent by other audio transmission nodes, query the routing table according to the parsing result of the data frame to obtain the transmission path of the target node, and transmit the data frame to the target node according to the transmission path of the target node; and generate a data frame to be sent according to the acquired audio data and control information, query the routing table to obtain the transmission path corresponding to the target node, and transmit the data frame to be sent to the next audio transmission node according to the transmission path;

[0009] The peripheral device is used to apply the processing of the audio data by the target node according to the audio data and control information obtained by the target node connected to it; and to collect the audio data and control information and input them into the child node connected to it.

[0010] Further, the non-leaf node in the subnode includes an uplink communication interface, at least two downlink communication interfaces, a peripheral interface and a data processing and routing module;

[0011] The uplink communication interface is used to receive the downlink data frame transmitted by the upper-level audio transmission node, and send the downlink data frame to the data processing and routing module;

[0012] The downlink communication interface is used to receive the uplink data frame transmitted by the next-level audio transmission node, and send the uplink data frame to the data processing and routing module;

[0013] The data processing and routing module is used to parse the data frame, output the data in the data frame from the peripheral interface according to the setting of the control register, add the data input by the peripheral interface to the uplink data frame or the downlink data frame, and then send it to the next audio transmission node through the uplink communication interface or the downlink communication interface.

[0014] Furthermore, the data frame includes a preamble, a synchronization subframe, a plurality of data segments and a tail frame arranged in sequence;

[0015] The preamble adopts a sequence that does not conform to the Manchester coding rule, and the synchronization subframe adopts a sequence that conforms to the Manchester coding rule;

[0016] The synchronization subframe includes a synchronization control subframe and a synchronization response subframe. The root node periodically sends the synchronization control subframe at a predetermined frequency. The child node generates its own working clock based on the synchronization control subframe and the phase-locked loop sent by the root node, and sends the synchronization control subframe to the next level child node through the downlink communication interface. After the leaf node receives the synchronization control subframe, it returns the synchronization response subframe through the uplink communication interface.

[0017] Furthermore, the several data segments include simple data segments, control information data segments and routing data segments; wherein the simple data segments include transmitted audio data and a first check value; the control information data segments include segment type, source node information, target node information, control information and a second check value; the routing data segments include segment type, target node information, audio data and a third check value.

[0018] Furthermore, the data processing and routing module is also used to control which simple data segments in the received data frame are used by the current audio transmission node through the control register, and indicate which simple data segments the received audio data is stored in to be sent to the next level audio transmission node.

[0019] Furthermore, the data processing and routing module is also used to parse the received control information data segment to obtain target node information;

[0020] If the current audio transmission node is the target node, the data processing and routing module operates according to the control information, inserts the response information into the data frame of the reverse transmission according to the format of the control information data segment, and takes the current audio transmission node as the source node and the initiating node of the control information as the target node;

[0021] If the current audio transmission node is not the target node, the data processing and routing module queries the routing table to determine through which output port the control information data segment is transmitted to the next level audio transmission node.

[0022] Furthermore, the data processing and routing module is also used to parse the received routing data segment to obtain target node information;

[0023] If the current audio transmission node is the target node, the data processing and routing module outputs the audio data in the received routing data segment through the peripheral interface of the current audio transmission node;

[0024] If the current audio transmission node is not the target node, the data processing and routing module queries the routing table to determine through which output port the routing data segment is transmitted to the next level audio transmission node.

[0025] Furthermore, when the at least two downlink communication interfaces in the audio transmission node receive uplink data frames, the data processing and routing module merges the two uplink data frames and then sends them to the upper-level audio transmission node through the uplink communication interface.

[0026] Furthermore, the leaf node among the subnodes has an uplink communication interface but does not have a downlink communication interface. When the leaf node receives a synchronization control subframe, it sends a synchronization response subframe to the upper-level audio transmission node through the uplink communication interface.

[0027] Further, the root node is configured as a node having both an uplink communication interface and a downlink communication interface, and the root node is instructed to send a data frame containing a synchronization control subframe through the downlink communication interface. If a synchronization response subframe returned by the downlink communication interface is received within a predetermined time, it is determined that the downlink communication interface is connected to a next-level node;

[0028] The next level node of the root node is configured as a node having both an uplink communication interface and a downlink communication interface through a synchronization control subframe, and the next level node of the root node continues to send the synchronization control subframe transmitted from the upper level to the next level node through the downlink communication interface. If the downlink communication interface can receive the synchronization response subframe within a predetermined time, it is determined that the downlink communication interface is connected to a next level node. If the synchronization response subframe is not received within the predetermined time, it is determined that the downlink communication interface does not have a next level node.

[0029] Repeat the above steps until no lower-level nodes can be found, assign an independent number to each found node to obtain the topology information of the audio transmission network, and establish a corresponding routing table in each audio transmission node according to the obtained topology information.

[0030] The present invention provides an audio transmission system based on a tree topology structure, which has the following beneficial effects: the present invention constructs a tree topology structure audio transmission system, covers the application scenarios of a daisy chain system, adopts a full-duplex transmission mode, and upstream data frames and downstream data frames can be transmitted simultaneously, supporting a higher audio sampling frequency and a larger number of nodes; constructs a routing table for each node, introduces a routing data segment based on a simple data segment, takes into account both the efficiency and flexibility of audio data transmission, uses the same routing transmission protocol for audio data and control information, realizes the transmission of audio data and control information between any nodes, and eliminates the limitation that the audio processor in the current daisy chain system can only be docked at the master node to control other slave node peripheral devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0032] Figure 1 is a structural diagram of an audio transmission system based on a tree topology structure provided by an embodiment of the present invention;

[0033] Figure 2 It is a structural schematic diagram of an audio transmission node in an audio transmission system based on a tree topology structure provided by an embodiment of the present invention;

[0034] Figure 3 An example of an audio transmission system based on a tree topology structure provided by an embodiment of the present invention;

[0035] Figure 4 It is a routing representation diagram of an example of an audio transmission system based on a tree topology structure provided by an embodiment of the present invention;

[0036] Figure 5It is a flowchart of an audio transmission method based on a tree topology structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0039] It should be understood that although the terms first, second, third, etc. may be used to describe the acquisition modules in the embodiments of the present invention, the acquisition modules should not be limited to these terms. These terms are only used to distinguish the acquisition modules from each other.

[0040] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0041] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is formed "on" or "under" another element, it can not only be formed directly "on" or "under" another element, but also be formed "on" or "under" another element indirectly through an intermediate element.

[0042] See also Figure 1 , an embodiment of the present invention provides an audio transmission system based on a tree topology structure, the system comprising a host, an audio transmission network and peripheral devices;

[0043] The audio transmission network includes a plurality of audio transmission chips forming a tree topology structure, and the audio transmission chips serve as audio transmission nodes of the system. The audio transmission nodes are connected to each other through a transmission medium such as a coaxial cable or a twisted pair, wherein a root node is connected to the host and at least one child node, and each child node is connected to the peripheral device;

[0044] See also Figure 2 A schematic diagram of the structure of an audio transmission node, wherein a non-leaf node in a subnode includes an uplink communication interface, at least two downlink communication interfaces, a peripheral interface and a data processing and routing module, wherein the peripheral interface includes an audio data interface, which complies with the I2S / TDM / PDM protocol and is used to connect an audio device, and also includes an I2C interface for connecting a controller, and the uplink communication interface is used to receive a downlink data frame transmitted from an upper-level audio transmission node, and send the downlink data frame to the data processing and routing module; the downlink communication interface is used to receive an uplink data frame transmitted from a lower-level audio transmission node, and send the uplink data frame to the data processing and routing module; the data processing and routing module parses the data frame, obtains audio data and control information, outputs the audio data in the data frame from the corresponding audio data interface according to the setting of the control register, and plays it through an audio device such as a speaker, and adds the audio data collected by an audio device such as a microphone and the control information input by the controller to the uplink data frame or the downlink data frame, and then sends it to the next audio transmission node through the uplink communication interface or the downlink communication interface. Among them, when at least two downlink communication interfaces in the audio transmission node receive uplink data frames, the data processing and routing module merges the two uplink data frames and then sends them to the upper-level audio transmission node through the uplink communication interface. The transmission of downlink data frames and uplink data frames between audio transmission nodes uses the same transmission medium, and both directions can be transmitted simultaneously.

[0045] Among them, the data frame includes a preamble code, a synchronization subframe, several data fragments and a tail frame arranged in sequence. The preamble code adopts a sequence that does not comply with the Manchester coding rule, and the synchronization subframe adopts a sequence that complies with the Manchester coding rule. When the data frame receiver detects the preamble code sequence, it is ready to receive the synchronization subframe. The first codeword that complies with the Manchester coding rule indicates the beginning of the synchronization subframe. The synchronization subframe includes a synchronization control subframe and a synchronization response subframe. The root node periodically sends the synchronization control subframe at a predetermined frequency. The predetermined frequency is usually the audio data sampling frequency of the system. The child node generates its own working clock according to the synchronization control subframe and the phase-locked loop sent by the root node, and sends the synchronization control subframe to the next level child node through the downlink communication interface. After the leaf node receives the synchronization control subframe, it returns the synchronization response subframe through the uplink communication interface, thereby realizing the synchronization and control of the entire system. The leaf node is the last level child node with an uplink communication interface and no downlink communication interface.

[0046] The plurality of data segments include a simple data segment, a control information data segment and a routing data segment. In a data frame, each data segment is of equal size. The simple data segment includes the transmitted audio data and a first check value. Preferably, the present embodiment uses a CRC (Cyclic Redundancy Check) value as the check value. The sender calculates the CRC value when loading the audio data, and attaches the CRC value to the rear of the audio data to form a simple data segment. After receiving a simple data segment, the receiver calculates the CRC value and compares it with the received CRC value to check the data integrity. On the one hand, the data processing and routing module of the audio transmission node controls one or several simple data segments in the received data frame through the control register to be used by the current audio transmission node. On the other hand, the control register also indicates which simple data segments the received audio data needs to be placed in to be sent to the next level audio transmission node. The number of simple data segments in the data frame is fixed and can be set through the control register of the audio transmission node. Each audio transmission node in the system needs to use the same setting. Since the simple data segment only contains audio data and its corresponding CRC value, and does not contain information such as the destination node, the bandwidth utilization rate is higher and the audio data transmission efficiency is higher; however, in the tree topology system of this embodiment, the simple data segment cannot flexibly realize data transmission between any nodes, especially dynamically change the transmission path between nodes. If you want to change the target node for data transmission, you can only set it by setting the control register of the target node.

[0047] Therefore, based on the simple data segment transmission, this embodiment also introduces the control information data segment and the routing data segment to further realize the transmission of control information and audio data between any nodes, taking into account the efficiency and flexibility of audio data transmission. The control information data segment and the routing data segment are arranged after the simple data segment. After receiving the simple data segment, the audio transmission node can directly process the audio data. After receiving the control information data segment and the routing data segment, it needs to parse and obtain the segment type, and then perform corresponding processing.

[0048] The control information data segment includes a fragment type, source node information, target node information, control information, and a second check value. The control information data segment is used to transmit control information between audio transmission nodes according to a routing table. The audio transmission node requires the current audio transmission node to parse the control information data segment through a data processing and routing module to obtain source node information and target node information, and to know whether the current node is a target node. If the current node is a target node, operations are performed according to the control information, such as writing the control information into a control register for subsequent processing of the received audio data, and inserting the response information into the reversely transmitted data frame in the format of the control information data segment, with the current audio transmission node as the source node and the initiating node of the control information as the target node, and returning the response information; if the current audio transmission node is not the target node, the data processing and routing module queries the routing table to determine which output port the control information data segment is transmitted from to the next-level audio transmission node.

[0049] The routing data segment includes a fragment type, target node information, audio data and a third check value. The routing data segment is used to transmit audio data between audio transmission nodes according to a routing table. The current audio transmission node parses the routing data segment through a data processing and routing module to obtain the target node information. If the current node is the target node, the audio data in the received routing data segment is output through the peripheral interface of the current audio transmission node. If the current node is not the target node, the routing table is queried to determine which output port the routing data segment is transmitted to the next-level audio transmission node.

[0050] The host is used to obtain the topology information of the audio transmission network, and establish corresponding routing tables in the root node and child nodes at all levels according to the obtained topology information; specifically, the host starts the pre-order traversal from the root node, configures the root node as a node with both an uplink communication interface and a downlink communication interface, and enables the root node to send a data frame containing a synchronization control subframe through the downlink communication interface. If a synchronization response subframe returned by the downlink communication interface is received within a predetermined time, it is determined that the downlink communication interface is connected to a next-level node; the host then configures the next-level node of the root node as a node with both an uplink communication interface and a downlink communication interface through the synchronization control subframe. The node of the root node, the next-level node of the root node continues to send the synchronization control subframe transmitted from the upper level to the next-level node through the downlink communication interface. If the downlink communication interface can receive the synchronization response subframe within the predetermined time, it is determined that the downlink communication interface is connected to the next-level node. If the synchronization response subframe is not received within the predetermined time, it is determined that the downlink communication interface does not have a next-level node; repeat the above steps until no next-level node can be found, assign an independent number to each node that has been found to obtain the topology information of the audio transmission network, and establish a corresponding routing table in each audio transmission node according to the obtained topology information.

[0051] For example, see Figure 3 An example of an audio transmission system based on a tree topology structure is shown in FIG. The host obtains the topology information of the audio transmission network of the system, numbers the root node as master, and numbers the child nodes as slave0, slave1, slave2, slave3, and slave4, and constructs the following according to the topology information of the audio transmission network: Figure 4 The routing table of each audio transmission node shown in the figure, each node can know which interface the current node needs to use to transmit to the next node by querying the routing table, and the audio data and control information use the same routing transmission protocol, which can realize the transmission of data control information between any nodes. For example, the master sends a data frame to slave3, and each node can know the transmission path by querying the routing table: master.B0, slave0.B0, slave1.B1, slave3; for another example, slave4 sends a data frame to slave3, and each node can know the transmission path by querying the routing table: slave4.A, slave2.A, slave0.B0, slave1.B1, slave3.

[0052] The audio transmission node is used as an intermediate node for audio transmission, obtains data frames sent by other audio transmission nodes, queries the routing table according to the parsing result of the data frame to obtain the transmission path of the target node, and transmits the data frame to the target node according to the transmission path of the target node; exemplarily, after the current node slave0 obtains the data frame containing audio data and control information sent by the master, the data frame is parsed through the data processing and routing module, and the target node is known to be slave3 through the parsing result. The routing table is queried to obtain that the transmission path for the current node to transmit the data frame to the target node slave3 is slave0.B0, and The data frame is transmitted to slave1 through the communication interface B0. Similarly, slave1 transmits the data frame to slave3 through its communication interface B1 by parsing the data frame and querying the routing table. Slave3 parses the data frame to obtain the control information and audio data, and learns that the current node is the target node. The data processing and routing module transmits the audio data to the corresponding audio device through the required audio data interface according to the control information, and inserts the response information into the reversely transmitted data frame in the format of the control information data segment, with slave3 as the source node and the master as the target node, and transmits the response information back to the master.

[0053] The audio transmission node is also used as a source node for audio transmission, generates a data frame to be sent according to the acquired audio data and control information, queries the routing table to obtain the transmission path corresponding to the target node, and transmits the data frame to be sent to the next audio transmission node according to the transmission path.

[0054] Specifically, the source node obtains audio data and control information, including: 1. Obtaining control information through other nodes and locally obtaining audio data, such as the root node obtaining control information from the connected host or the child node obtaining control information from the connected controller, and then packaging the control information into a control information fragment format and transmitting it to the current audio transmission node. The current audio transmission node receives and parses the control information fragment to obtain the control information and writes it into the control register. The current audio transmission node obtains local audio data through the audio data interface, and uses the current audio transmission node as the source node. According to the control information, the control information and audio data are transmitted in a data frame format to the target node. For example, Figure 3In the system shown in the figure, the host writes the relevant control information of the command "transmit the audio data collected by the node slave4 to the target node slave3" into the master through the I2C bus. After obtaining the control information, the master transmits it to the node slave4 in the form of a control information fragment. The current node slave4 parses the control information fragment through the data processing and routing module, writes the control information into the control register, and obtains the audio data collected by the audio device such as a microphone through its audio data interface according to the control information. According to the routing table, to transmit the data frame to the target node slave3, the current node slave4 transmission path is slave4.A, and the control information and the audio data are transmitted in the form of a digital The data frame format is transmitted to the next node slave2 through its uplink communication interface A. Node slave2 parses the data frame through its data processing and routing module, and confirms that the current node slave2 is not the target node according to the target node information. According to the query of the routing table, slave2 needs to continue to transmit the data frame to the next node salve0 through its uplink communication interface A until it is transmitted to the node slave3. Slave3 parses the data frame through the data processing and routing module, and confirms that the current node slave3 is the target node according to the target node information. After processing the audio data according to the control information, it is transmitted to the designated audio playback device through the audio data interface for playback;

[0055] Second, directly obtain local control information and audio data. When the root node is used as the source node, it obtains control information and audio data through the connected host; when the child node is used as the source node, it obtains control information and audio data through the connected controller. For example, the child node slave4 is used as the source node, and the user can input commands through the controller to which it is connected. The controller directly writes the control information related to the command into the control register of salve4 through the I2C bus. After slave4 obtains the control information and the local audio data transmitted by the audio data interface, it transmits the control information and audio data in the data frame format to the target node as the source node.

[0056] The peripheral device includes an audio device and a controller. For example, the audio device includes an amplifier, a speaker, a microphone, etc. For example, the speaker is used to receive the audio data sent by the connected audio transmission node after processing and convert it into a sound signal for playback; the microphone is used to collect audio data and transmit it to the connected audio transmission node; the controller is used to write control information to the connected audio transmission node through the I2C bus.

[0057] See also Figure 5 Another embodiment of the present invention further provides an audio transmission method based on a tree topology structure, which is applied to Figure 1 The method of audio transmission based on a tree topology structure shown includes:

[0058] Step S101, the host obtains topology information of the audio transmission network, and establishes corresponding routing tables in the root node and child nodes at all levels according to the obtained topology information;

[0059] Step S102, the root node obtains audio data and control information from the host to generate a data frame to be sent, queries the routing table to obtain a transmission path corresponding to the target node, and transmits the data frame to be sent to the next audio transmission node according to the transmission path;

[0060] Step S103, the next audio transmission node parses the data frame through the data processing and routing module, queries the routing table according to the parsing result of the data frame to obtain the transmission path of the target node, and transmits the data frame to the target node according to the transmission path of the target node.

[0061] The present invention provides an audio transmission system based on a tree topology structure, which constructs a tree topology structure, covers the application scenarios of a daisy chain system, adopts a full-duplex transmission mode, and an uplink data frame and a downlink data frame can be transmitted simultaneously, supporting a higher audio sampling frequency and a larger number of nodes; constructs a routing table for each node, introduces a control information data segment and a routing data segment on the basis of a simple data segment, takes into account both the efficiency and flexibility of audio data transmission, and adopts the same routing transmission protocol for audio data and control information to realize the transmission of audio data and control information between any nodes, thereby eliminating the limitation that an audio processor in the current daisy chain system can only be docked at a master node to control peripheral devices of other slave nodes.

[0062] The above description is only a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of disclosure involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but also should cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) to form a technical solution.

Claims

1. An audio transmission system based on a tree topology structure, characterized in that: include: Host computer, audio transmission network and peripheral devices; The audio transmission network includes a plurality of audio transmission nodes forming a tree topology, wherein a root node is connected to the host and at least one child node, and each child node is connected to the peripheral device; The host is used to obtain topology information of the audio transmission network, and establish corresponding routing tables in the root node and child nodes at all levels according to the obtained topology information; The audio transmission node is used to obtain data frames sent by other audio transmission nodes, query the routing table according to the parsing result of the data frame to obtain the transmission path of the target node, and transmit the data frame to the target node according to the transmission path of the target node; And, generating a data frame to be sent according to the acquired audio data and control information, querying the routing table to obtain a transmission path corresponding to the target node, and transmitting the data frame to be sent to the next audio transmission node according to the transmission path; The peripheral device is used to apply the processing of the audio data by the target node according to the audio data and control information obtained by the target node connected thereto; and, for collecting audio data and inputting control information to the child nodes connected thereto; The non-leaf node in the subnode includes an uplink communication interface, at least two downlink communication interfaces, a peripheral interface and a data processing and routing module; The uplink communication interface is used to receive the downlink data frame transmitted by the upper-level audio transmission node, and send the downlink data frame to the data processing and routing module; The downlink communication interface is used to receive the uplink data frame transmitted by the next-level audio transmission node, and send the uplink data frame to the data processing and routing module; The data processing and routing module is used to parse the data frame, output the data in the data frame from the peripheral interface according to the setting of the control register, add the data input by the peripheral interface to the uplink data frame or the downlink data frame, and then send it to the next audio transmission node through the uplink communication interface or the downlink communication interface; The data frame includes a preamble, a synchronization subframe, a plurality of data segments and a tail frame arranged in sequence; The preamble code adopts a sequence that does not conform to the Manchester coding rule, and the synchronization subframe adopts a sequence that conforms to the Manchester coding rule; The synchronization subframe includes a synchronization control subframe and a synchronization response subframe. The root node periodically sends the synchronization control subframe at a predetermined frequency. The child node generates its own working clock based on the synchronization control subframe and the phase-locked loop sent by the root node, and sends the synchronization control subframe to the next level child node through the downlink communication interface. After the leaf node receives the synchronization control subframe, it returns the synchronization response subframe through the uplink communication interface.

2. The audio transmission system based on a tree topology structure according to claim 1, characterized in that: The several data segments include simple data segments, control information data segments and routing data segments; wherein the simple data segments include transmitted audio data and a first check value; the control information data segments include segment type, source node information, target node information, control information and a second check value; the routing data segments include segment type, target node information, audio data and a third check value.

3. The audio transmission system based on tree topology structure according to claim 2, characterized in that: The data processing and routing module is also used to control which simple data segments in the received data frame are used by the current audio transmission node through the control register, and indicate which simple data segments the received audio data is stored in to be sent to the next level audio transmission node.

4. The audio transmission system based on a tree topology structure according to claim 2, characterized in that: The data processing and routing module is also used to parse the received control information data segment to obtain target node information; If the current audio transmission node is the target node, the data processing and routing module operates according to the control information, inserts the response information into the data frame of the reverse transmission according to the format of the control information data segment, and takes the current audio transmission node as the source node and the initiating node of the control information as the target node; If the current audio transmission node is not the target node, the data processing and routing module queries the routing table to determine through which output port the control information data segment is transmitted to the next level audio transmission node.

5. The audio transmission system based on tree topology structure according to claim 2, characterized in that: The data processing and routing module is also used to parse the received routing data segment to obtain target node information; If the current audio transmission node is the target node, the data processing and routing module outputs the audio data in the received routing data segment through the peripheral interface of the current audio transmission node; If the current audio transmission node is not the target node, the data processing and routing module queries the routing table to determine through which output port the routing data segment is transmitted to the next level audio transmission node.

6. The audio transmission system based on tree topology structure according to claim 1, characterized in that: When the at least two downlink communication interfaces in the audio transmission node receive uplink data frames, the data processing and routing module merges the two uplink data frames and then sends them to the upper-level audio transmission node through the uplink communication interface.

7. The audio transmission system based on tree topology structure according to claim 1, characterized in that: The leaf node among the subnodes has an uplink communication interface but no downlink communication interface. When the leaf node receives the synchronization control subframe, it sends a synchronization response subframe to the upper-level audio transmission node through the uplink communication interface.

8. The audio transmission system based on tree topology structure according to claim 2, characterized in that: The host is further configured to: The root node is configured as a node having both an uplink communication interface and a downlink communication interface, and the root node is instructed to send a data frame containing a synchronization control subframe through the downlink communication interface. If a synchronization response subframe returned by the downlink communication interface is received within a predetermined time, it is determined that the downlink communication interface is connected to a next-level node. The next level node of the root node is configured as a node having both an uplink communication interface and a downlink communication interface through a synchronization control subframe, and the next level node of the root node continues to send the synchronization control subframe transmitted from the upper level to the next level node through the downlink communication interface. If the downlink communication interface can receive the synchronization response subframe within a predetermined time, it is determined that the downlink communication interface is connected to a next level node. If the synchronization response subframe is not received within the predetermined time, it is determined that the downlink communication interface does not have a next level node. Repeat the above steps until no lower-level nodes can be found, assign an independent number to each found node to obtain the topology information of the audio transmission network, and establish a corresponding routing table in each audio transmission node according to the obtained topology information.

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