Ethernet data link layer unvarnished transmission method and device based on secure digital input / output interface
By using a secure digital input/output interface in embedded devices to pass through Ethernet frames at the data link layer, the problem of the lack of Ethernet interfaces in embedded devices is solved, achieving efficient local area network communication and simplified module design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANGZHOU YUETAI TECHNOLOGY CO LTD
- Filing Date
- 2026-01-19
- Publication Date
- 2026-04-28
AI Technical Summary
Embedded devices lack traditional Ethernet interfaces, resulting in inconvenient and inefficient production and testing operations. Furthermore, existing network communication solutions consume a lot of hardware resources, increasing design complexity and hindering miniaturization and cost reduction.
By using the Secure Digital Input/Output Interface (SDIO) to directly transmit Ethernet frames at the data link layer, bypassing the network layer and TCP/IP protocol stack, and utilizing direct memory access and custom extension headers to manage data, high-speed communication between the main control microcontroller unit and the Ethernet module is achieved.
It enables direct connection between embedded devices and devices within a local area network, reducing latency, simplifying module design, reducing hardware resource consumption, and improving production testing efficiency.
Smart Images
Figure CN121940438A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of embedded device technology, and in particular to a method and apparatus for Ethernet data link layer pass-through based on a secure digital input / output interface. Background Technology
[0002] With the widespread application of embedded devices in smart homes, industrial control, and consumer electronics, some embedded devices, due to design or cost limitations, are not equipped with traditional Ethernet interfaces. When these devices enter the production testing phase, using 4G or other wireless communication methods for local area network testing presents problems such as inconvenience in operation and low testing efficiency, making it impossible to effectively complete the production testing work. Currently, the industry typically uses a solution of Network Address Translation (NAT) at the network layer (L3) to achieve network forwarding for embedded devices without traditional Ethernet interfaces. However, this solution suffers from problems such as limited local area network communication, high transmission latency, and poor real-time performance. Furthermore, traditional solutions that rely on a complete TCP / IP or LWIP protocol stack will consume a significant amount of hardware resources in embedded devices, increase module design complexity, and hinder device miniaturization and low-cost design.
[0003] Therefore, the existing technology still needs further improvement and enhancement. Summary of the Invention
[0004] This invention aims to solve the above-mentioned technical problems and provides an Ethernet data link layer pass-through method based on a secure digital input / output interface, applicable to a system including a main control microcontroller unit and an Ethernet module, wherein the pass-through method includes: A communication connection is established between the main control microcontroller unit and the Ethernet module through the secure digital input / output interface; The main control microcontroller generates Ethernet frames that conform to the Ethernet data link layer protocol specification, and sends the Ethernet frames to the Ethernet module through the secure digital input / output interface; The Ethernet module receives external Ethernet frames through the physical layer chip and transmits the Ethernet frames to the main control microcontroller through the secure digital input / output interface; wherein, the main control microcontroller and the Ethernet module directly interact with each other through the Ethernet data link layer frames.
[0005] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.
[0006] As a preferred technical solution, the method, wherein sending the Ethernet frame to the Ethernet module through the secure digital input / output interface includes: The main control microcontroller writes the Ethernet frame to be sent into the secure digital input / output interface transmission queue; The data in the transmission queue is moved to the buffer of the Ethernet module via the direct memory access controller; The media access control module of the Ethernet module reads the buffer data and sends it to the Ethernet physical interface through the physical layer chip.
[0007] As a preferred technical solution, the method wherein the step of the Ethernet module transparently transmitting Ethernet frames to the main control microcontroller unit includes: The Ethernet module receives data streams through the physical layer chip, and the media access control module extracts complete Ethernet frames. The Ethernet frames are moved to the Secure Digital Input / Output Interface receive queue via the Direct Memory Access Controller; The Ethernet module triggers a receive completion interrupt, notifying the main control microcontroller to read the data in the receive queue.
[0008] As a preferred technical solution, the method wherein, when transmitting data through the secure digital input / output interface, a custom secure digital input / output interface extension header is used for data management; The custom extension header includes at least one of the following fields: frame type, packet identifier, packet sequence number, data length, queue identifier, and checksum.
[0009] As a preferred technical solution, the method further includes: When the amount of Ethernet frame data to be sent exceeds the single transmission limit, the main control microcontroller unit divides the data into packets according to the packet division rules and marks the packet sequence number in the custom extension header; The receiving end reassembles the received data according to the packet sequence number in the custom extension header, and submits it to the application layer after reassembly.
[0010] As a preferred technical solution, in the method described, the main control microcontroller unit operates a secure digital input / output interface slave driver and an Ethernet driver; the secure digital input / output interface slave driver is responsible for managing transmission timing, and the Ethernet driver is responsible for controlling the working state of the media access control module and the physical layer chip, and the two work together to ensure the stable transmission and reception of data link layer frames.
[0011] As a preferred technical solution, the method further includes, after the system is powered on: The main control microcontroller unit is equipped with a secure digital input / output interface with a high transmission rate and data bit width. Configure the operating mode of the Ethernet module to support at least one of broadcast, multicast, or promiscuous modes; Initialize the transmit and receive queues of the secure digital input / output interface, and configure direct memory access addresses and interrupt enable.
[0012] Secondly, an Ethernet data link layer transparent transmission device based on a secure digital input / output interface, comprising: The main control microcontroller unit is used to generate or process Ethernet data link layer frames; Ethernet module, including media access control module and physical layer chip, is used to send and receive Ethernet signals; A secure digital input / output interface is used to connect the main control microcontroller unit to the Ethernet module to enable transparent transmission of Ethernet frames.
[0013] As a preferred technical solution, the device further includes: A direct memory access controller is used to directly transfer data between the main control microcontroller unit and the Ethernet module; An interrupt controller is used to send an interrupt notification to the main microcontroller unit after data transmission is completed.
[0014] Thirdly, a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the method described above.
[0015] Beneficial effects: Compared with existing technologies, this invention allows embedded devices to directly connect to other devices within a local area network (LAN) through data link layer pass-through, meeting the needs of production testing and LAN debugging. Bypassing the network layer and the TCP / IP protocol stack, it achieves high-speed transmission through direct memory access acceleration and secure digital input / output interfaces, reducing data processing steps, lowering latency, and adapting to applications with large data volumes such as video frames. Furthermore, this invention eliminates the need to integrate a complete protocol stack into the module, achieving data management through a custom secure digital input / output interface extension header, simplifying module design and reducing the hardware resource consumption of embedded devices. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the system architecture in an embodiment of the present invention; Figure 2 This is a schematic diagram of SDIO data encapsulation in an embodiment of the present invention; Figure 3 This is a schematic diagram of the Ethernet data link layer transparent transmission method based on a secure digital input / output interface provided by the present invention; Figure 4 This is a schematic diagram of the communication process between the main control microcontroller unit and the local area network in an embodiment of the present invention; Figure 5 This is a schematic diagram of the Ethernet data link layer transparent transmission device based on a secure digital input / output interface in an embodiment of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Experimental methods in the following embodiments, unless otherwise specified, are performed according to conventional methods and conditions, or as selected in the product specification. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.
[0018] Please refer to Figure 1 The core architecture of this invention consists of a main control microcontroller unit (MCU), an Ethernet module, and a secure digital input / output interface (SDI) connecting the two. The MCU establishes a bidirectional communication connection with the Ethernet module via the SDI, which provides a high-speed data transmission channel to meet the needs of large data volume transmission. The Ethernet module includes a media access control module and an externally connectable physical layer chip. The media access control module is responsible for the encapsulation, decapsulation, and transmission / reception control of Ethernet frames at the data link layer (L2). The physical layer chip is responsible for converting digital signals into Ethernet physical layer signals to achieve connection with external network cables. At the hardware level, a direct memory access controller (DMI) and an interrupt controller are integrated. DMI enables direct data transfer between the MCU and the Ethernet module without consuming central processing unit resources, improving transmission efficiency. The interrupt controller triggers an interrupt after data reception or transmission is completed, notifying the MCU to perform subsequent processing and avoiding polling resource consumption. In this embodiment, the secure digital input / output interface data encapsulation is as follows: Figure 2 As shown, the SDIO frame encapsulation includes: an SDIO frame header and an Ethernet frame. The SDIO frame header includes: interface type (4 bits), interface number (4 bits), flags (1 byte), data length (2 bytes), data offset (2 bytes), checksum (2 bytes), packet sequence number (2 bytes), and reserved bytes (1 byte). The Ethernet frame includes: Ethernet frame header, data, and CRC.
[0019] Please refer to Figures 3 to 4Based on the above core architecture, the Ethernet data link layer transparent transmission method based on a secure digital input / output interface provided in this embodiment of the invention includes the following steps: S101. Establish a communication connection between the main control microcontroller unit and the Ethernet module through the secure digital input / output interface; S102. The main control microcontroller generates an Ethernet frame that conforms to the Ethernet data link layer protocol specification, and sends the Ethernet frame to the Ethernet module through the secure digital input / output interface. S103. The Ethernet module receives external Ethernet frames through the physical layer chip and transmits the Ethernet frames to the main control microcontroller through the secure digital input / output interface; wherein, the main control microcontroller and the Ethernet module directly interact with the Ethernet data link layer frames.
[0020] Specifically, the runtime data pass-through process in this embodiment is divided into two directions: "master control sends Ethernet frames" and "master control receives Ethernet frames," covering the entire data link from generation to transmission, reception, and processing. The specific steps are as follows: (1) Master control Ethernet frame transmission process: The application layer of the master control microcontroller generates a complete Ethernet data link layer (L2) frame. The frame structure includes the destination media access control address, the source media access control address, the frame type field, and the data payload, ensuring compliance with the Ethernet data link layer (L2) protocol specification. The master control writes the complete Ethernet frame into the Secure Digital Input / Output (SDI) interface transmission queue. If the Ethernet frame data volume exceeds the single transmission limit, it is packetized according to the packetization rules of the custom SDI extension header, and the packet sequence number and total number of packets are marked in the extension header. After the Direct Memory Access Controller (DMI) detects data in the transmission queue, it automatically moves the data from the master control buffer to the Ethernet module's receive buffer. The media access control module of the Ethernet module reads the data in the buffer. If it is packetized data, it temporarily stores it and reassembles it according to the sequence number. After reassembly, the data is sent to the Ethernet physical interface (such as a network cable) through an external physical layer chip. After the data is sent to the physical interface, the Ethernet module triggers the SDI transmission completion interrupt, notifying the master control microcontroller that the transmission queue is currently idle and can continue to write the next frame of data. (2) Ethernet Frame Reception Process: The Ethernet module receives the data stream from the Ethernet physical interface through the physical layer chip. The media access control module decapsulates the data stream and extracts the complete Ethernet data link layer (L2) frame. If the received data is in packet form, the media access control module reassembles it according to the packet sequence number in the custom secure digital input / output interface extension header. The media access control module transmits the complete Ethernet frame (or the reassembled complete frame) to the module buffer. The direct memory access controller moves the data from the module buffer to the secure digital input / output interface receive queue and updates the data length information of the receive queue. After the data is written to the receive queue, the Ethernet module triggers the secure digital input / output interface receive completion interrupt and sends a notification to the main control microcontroller unit that there is new data to be processed. The main control responds to the interrupt, reads the Ethernet frame in the secure digital input / output interface receive queue, and verifies the data integrity through the check field of the custom secure digital input / output interface extension header. After successful verification, the Ethernet frame is transmitted to the application layer for subsequent service processing (such as parsing the data payload and executing the corresponding control logic).
[0021] In this embodiment, communication between the main control microcontroller and the Ethernet module does not rely on the Transmission Control Protocol / Internet Protocol (TCP / IP) or Lightweight Internet Protocol (LwIP) stacks. Instead, it directly transmits data based on Layer 2 (L2) Ethernet frames, reducing protocol processing steps and latency. The Secure Digital Input / Output (SDI) interface slave driver and the Ethernet driver work together. The SDIOS slave driver manages the transmission timing and data interaction of the SDIOS interface, while the Ethernet driver controls the operating status of the Media Access Control (MAC) module and the physical layer chip. Together, they ensure stable transmission and reception of L2 frames. The custom SDIOS extension header includes frame type (data frame / control frame), packet identifier, packet sequence number, data length, queue identifier (send queue / receive queue), and checksum (e.g., Cyclic Redundancy Check 16 (CRC16)). This extension header enables packet management, data length identification, transmission queue differentiation, and data integrity verification, preventing data loss or errors.
[0022] For example, a gateway in an external local area network sends an ARP request broadcast packet. This packet appears as an electrical signal flow conforming to the IEEE 802.3 standard on the physical line.
[0023] The physical layer chip of the Ethernet module performs differential-to-single-ended signal conversion and synchronizes the bit stream to the media access control module via the RMII interface. The MAC module performs preamble recognition and start-of-frame delimiter location.
[0024] The MAC module identifies the destination address of the ARP packet as FF:FF:FF:FF:FF:FF based on the hardware-preset broadcast enable bit, and determines that it meets the reception conditions.
[0025] The interrupt controller inside the module is activated. At this time, the module does not directly report the data, but instead activates the direct memory access controller.
[0026] The protocol packaging machine reserves 8 bytes of space in the module's SRAM buffer and constructs a custom SDIO extension header: Set Frame Type to 00 (data frame); Since ARP request packets are typically 64 bytes, which is less than the SDIO block length, Frag Info is set to 00 (complete frame). The Payload Len should be filled with the actual length of the captured Ethernet frame (including MAC header, ARP payload, and FCS). Calculate CRC16 and fill the header.
[0027] The module triggers a receive interrupt to the main microcontroller unit by pulling the SDIO_DATA1 pin low.
[0028] Furthermore, the interrupt service routine (ISR) of the main microcontroller unit is activated.
[0029] SDIO reads the SDIO status register from the device driver to confirm the length of the data to be processed.
[0030] The Ethernet driver on the MCU side requests a contiguous block of memory (such as a pbuf structure) from the memory pool. The starting address (Addr_Start) of this memory block is directly configured to the direct memory access controller.
[0031] DMA initiates multiple read operations via the SDIO bus. The data stream is pumped directly from the Ethernet module's buffer into the MCU's SRAM.
[0032] During the data transfer process described above, the memory address is a pre-mapped application-layer cache address by the driver layer. After the DMA transfer is complete, the data is ready for processing and does not require the CPU to perform a second memcpy operation.
[0033] Furthermore, after the data transfer is complete, the SDIO slave device driver first parses the first 8 bytes of the extended header.
[0034] The driver verifies HCS and CRC16. If the verification passes, the driver executes pointer offset logic: shifting the valid data pointer (Data Pointer) in the buffer forward by 8 bytes. At this point, the pointer points to the Destination MAC Address of the original Ethernet frame. The MCU's Ethernet driver submits this pbuf structure to the upper-layer protocol stack (or directly to the application layer parsing logic). Because NAT translation is bypassed, the application layer directly obtains the complete L2 frame, achieving a pass-through effect completely equivalent to the native network interface.
[0035] In this invention, before transparent transmission, the core architecture initialization process (state preparation) must be completed after the system powers on or restarts to determine the initial state of data transmission and ensure accurate execution of subsequent log storage. The specific steps are as follows: The main control microcontroller initializes the Secure Digital Input / Output (SDI) interface, configuring parameters such as transmission rate and data bit width. Simultaneously, it initializes the media access control module of the Ethernet module, setting its operating mode (e.g., supporting broadcast, multicast, and promiscuous modes) and physical layer chip connection parameters to ensure the module can send and receive Ethernet frames correctly. The direct memory access controller is initialized, setting the source address (e.g., main control transmit buffer / module receive buffer), destination address (e.g., module receive buffer / main control receive buffer), and transmission length threshold for data transmission. The interrupt controller is configured to enable transmit completion and receive completion interrupts for the SDI interface, ensuring timely feedback of data transmission status to the main control. SDI interface transmit and receive queues are created to temporarily store Ethernet frames to be sent and processed. The parsing rules for the custom SDI interface extension header are initialized, defining fields such as packet identifier, data length, and checksum, providing a basis for subsequent data processing. like Figure 5 As shown, the present invention also provides an Ethernet data link layer pass-through device based on a secure digital input / output interface, comprising: a master microcontroller unit 100 for generating or processing Ethernet data link layer frames; an Ethernet module 200, including a media access control module and a physical layer chip, for transmitting and receiving Ethernet signals; a secure digital input / output interface 300 for connecting the master microcontroller unit and the Ethernet module to realize the pass-through of Ethernet frames; a direct memory access controller 400 for directly transferring data between the master microcontroller unit and the Ethernet module; and an interrupt controller 500 for sending an interrupt notification to the master microcontroller unit after data transmission is completed.
[0036] Based on the same inventive concept, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described above.
[0037] The following explanation will further illustrate the technical solutions provided by this invention by applying them to three specific scenarios.
[0038] Example 1: High-precision synchronous control for industrial automation In high-performance multi-axis motion control systems, the MCU needs to receive synchronization messages (such as EtherCAT frames) from industrial Ethernet in real time. Using the L2 pass-through method of this invention, the MCU does not need to establish complex socket connections; it can directly intercept control frames with specific MAC addresses at the data link layer. Combined with the interrupt aggregation mechanism described in step five, control commands can be directly mapped to the MCU's task cycle, ensuring that timing jitter is less than 10 microseconds, meeting the stringent synchronization requirements of precision machining equipment.
[0039] Example 2: Data Fast Lane of High-Definition Video Stream Monitoring Equipment In intelligent security modules, the H.265 video stream data captured by the Ethernet module is extremely large. Employing the DMA zero-copy mechanism of this solution, video frames, after entering from the MAC layer, are directly pumped into the memory of the hardware video decoder associated with the MCU via the SDIO bus. This process bypasses L3 protocol stack filtering, effectively avoiding frame drop caused by protocol stack buffer overflow, and achieving smooth pass-through of 1080P@60fps video streams.
[0040] Example 3: Portable LAN Protocol Analyzer In this embodiment, the MCU is configured in Promiscuous Mode. Using the transparent transmission method of this invention, all LAN packets captured by the Ethernet module (including ARP, RARP, and other non-IP frames) are losslessly submitted to the MCU via the SDIO interface. Developers can directly perform Layer 2 protocol analysis or network security auditing on the MCU side. Due to its complete L2 transparency, this device can simulate the network behavior of any host within the LAN, enabling automated network function testing on production lines.
[0041] In summary, this invention provides a method and apparatus for Ethernet data link layer pass-through based on a Secure Digital Input / Output (SDI) interface. The pass-through method includes: establishing a communication connection between the main control microcontroller unit (MCU) and the Ethernet module through the SDI interface; the MCU generating Ethernet frames conforming to the Ethernet data link layer protocol specification and sending the Ethernet frames to the Ethernet module through the SDI interface; the Ethernet module receiving external Ethernet frames through a physical layer chip and pass-through the Ethernet frames to the MCU through the SDI interface; wherein the MCU and the Ethernet module directly interact with the Ethernet data link layer frames. Because this invention performs pass-through directly at the L2 layer, it completely bypasses the complex TCP / IP protocol stack processing flow, significantly shortening the data dwell time within the MCU. Combined with DMA hardware acceleration, it can support efficient, non-blocking transmission of video streams in 100M mode, meeting the needs of applications with extremely high real-time requirements. The Ethernet module does not need to integrate a large protocol stack, only requiring the implementation of simple MAC / PHY control logic and custom extension header parsing. This not only simplifies the module's circuit design but also frees up valuable SRAM and Flash resources for the MCU, reducing overall system power consumption and cost. By supporting promiscuous mode and broadcast forwarding, this invention enables embedded devices to exhibit protocol performance completely consistent with native network interface devices within a local area network. This allows functions such as ARP scanning, network packet capture analysis, and automatic LAN device discovery to be perfectly implemented on non-native network interface devices, greatly improving the efficiency of production testing and engineering maintenance. Simultaneously, the verification mechanism and packet reassembly logic provided by the custom extension header ensure the integrity of data frames in a high-speed SDIO transmission environment, effectively avoiding the risk of data packet out-of-order delivery or loss due to hardware signal interference.
[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for Ethernet data link layer pass-through based on a secure digital input / output interface, applied to a system including a main control microcontroller unit and an Ethernet module, characterized in that, The transparent transmission method includes: A communication connection is established between the main control microcontroller unit and the Ethernet module through the secure digital input / output interface; The main control microcontroller generates Ethernet frames that conform to the Ethernet data link layer protocol specification, and sends the Ethernet frames to the Ethernet module through the secure digital input / output interface; The Ethernet module receives external Ethernet frames through the physical layer chip and transmits the Ethernet frames to the main control microcontroller through the secure digital input / output interface; wherein, the main control microcontroller and the Ethernet module directly interact with each other through the Ethernet data link layer frames.
2. The method according to claim 1, characterized in that, Sending the Ethernet frame to the Ethernet module via the secure digital input / output interface includes: The main control microcontroller writes the Ethernet frame to be sent into the secure digital input / output interface transmission queue; The data in the transmission queue is moved to the buffer of the Ethernet module via the direct memory access controller; The media access control module of the Ethernet module reads the buffer data and sends it to the Ethernet physical interface through the physical layer chip.
3. The method according to claim 1, characterized in that, The steps of the Ethernet module transparently transmitting Ethernet frames to the main control microcontroller unit include: The Ethernet module receives data streams through the physical layer chip, and the media access control module extracts complete Ethernet frames. The Ethernet frames are moved to the Secure Digital Input / Output Interface receive queue via the Direct Memory Access Controller; The Ethernet module triggers a receive completion interrupt, notifying the main control microcontroller to read the data in the receive queue.
4. The method according to claim 2 or 3, characterized in that, When transmitting data through the secure digital input / output interface, a custom secure digital input / output interface extension header is used for data management; The custom extension header includes at least one of the following fields: frame type, packet identifier, packet sequence number, data length, queue identifier, and checksum.
5. The method according to claim 4, characterized in that, The method further includes: When the amount of Ethernet frame data to be sent exceeds the single transmission limit, the main control microcontroller unit divides the data into packets according to the packet division rules and marks the packet sequence number in the custom extension header; The receiving end reassembles the received data according to the packet sequence number in the custom extension header, and submits it to the application layer after reassembly.
6. The method according to claim 1, characterized in that, The main control microcontroller unit runs a secure digital input / output interface slave driver and an Ethernet driver; the secure digital input / output interface slave driver is responsible for managing transmission timing, and the Ethernet driver is responsible for controlling the working state of the media access control module and the physical layer chip. The two work together to ensure the stable transmission and reception of data link layer frames.
7. The method according to claim 1, characterized in that, After the system is powered on, the method further includes: The main control microcontroller unit is equipped with a secure digital input / output interface with a high transmission rate and data bit width. Configure the operating mode of the Ethernet module to support at least one of broadcast, multicast, or promiscuous modes; Initialize the transmit and receive queues of the secure digital input / output interface, and configure direct memory access addresses and interrupt enable.
8. An Ethernet data link layer transparent transmission device based on a secure digital input / output interface, characterized in that, include: The main control microcontroller unit is used to generate or process Ethernet data link layer frames; Ethernet module, including media access control module and physical layer chip, is used to send and receive Ethernet signals; A secure digital input / output interface is used to connect the main control microcontroller unit to the Ethernet module to enable transparent transmission of Ethernet frames.
9. The apparatus according to claim 8, characterized in that, Also includes: A direct memory access controller is used to directly transfer data between the main control microcontroller unit and the Ethernet module; An interrupt controller is used to send an interrupt notification to the main microcontroller unit after data transmission is completed.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method described in any one of claims 1-7.