CN117978785A - A communication method between MCU and SOC based on SPI communication protocol and protocol construction method - Google Patents

Abstract

The application discloses an MCU and SOC communication method based on SPI communication protocol and a protocol construction method. The MCU and SOC communication method based on the SPI communication protocol comprises the following steps: an SPI communication system data path based on an SPI communication protocol is established between the MCU end and the SOC end; and the SOC end generate data according to the SPI communication protocol and mutually send the data. The communication mode adopted by the MCU and SOC communication method based on the SPI communication protocol is SPI communication, the SPI protocol supports a full duplex communication mode, and the communication method based on the SPI communication protocol has the characteristics of simplicity in communication, high transmission rate and the like.

Description

A communication method between MCU and SOC based on SPI communication protocol and protocol construction method

Technical Field

The present application relates to the field of automotive SPI communication technology, and in particular to a method for communicating between an MCU and a SOC based on an SPI communication protocol and a method for constructing an SPI communication protocol.

Background technique

The automotive instrument system mostly adopts the MCU+SOC architecture, in which the MCU side is responsible for receiving CAN signals and hard-wire signals and determining the display results at the same time, while the SOC side receives the results from the MCU side and displays them. Therefore, ensuring the accuracy, reliability and efficiency of data transmission between the MCU and SOC is the key to ensuring the normal display of the instrument.

Traditional instrument communication methods mostly use UART and I2C. The UART communication data frame supports a maximum of 9 bits of data and has a slow transmission speed. In serial communication, additional information bits are required to send a character, such as the start bit, check bit, and stop bit. These additional information bits are not valid information itself, but belong to additional communication overhead. At the same time, I2C also has the characteristic of low transmission rate.

Therefore, it is hoped that a technical solution can be provided to solve or at least alleviate the above-mentioned deficiencies of the prior art.

Summary of the invention

The object of the present invention is to provide a communication method between MCU and SOC based on SPI communication protocol to at least solve one of the above technical problems.

One aspect of the present invention provides a method for communicating between an MCU and a SOC based on an SPI communication protocol, the method comprising:

The MCU side and the SOC side establish an SPI communication system data path based on the SPI communication protocol;

The SOC end and the SOC end generate data according to the SPI communication protocol and send the data to each other.

Optionally, the data includes a heartbeat packet. When the data is a heartbeat packet and is uplink data, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC generates and sends a heartbeat packet to the MCU periodically based on the SPI communication protocol. The heartbeat packet includes a LiveCounter field and the heartbeat message is in a single sending mode.

The MCU side obtains the heartbeat packet and notifies the watchdog on the MCU side to update.

Optionally, when the data is a heartbeat packet and is uplink data, the MCU and SOC communication method based on the SPI communication protocol further includes:

When the MCU does not receive a valid heartbeat packet within the preset time, the SOC restart is triggered through EcuM.

Optionally, the data includes a periodic message. When the data is a periodic message and is uplink data, the MCU and SOC communication method based on the SPI communication protocol includes:

The MCU side periodically generates a periodic message to be sent according to the operation cycle, wherein the periodic message includes a LiveCounter field and a checksum field;

The MCU sends periodic messages to the SOC.

The SOC end receives the periodic message and verifies the LiveCounter field and the checksum field in the periodic message. If the verification is successful, the SOC end distributes the data.

Optionally, when the data is a periodic message and is uplink data, the MCU and SOC communication method based on the SPI communication protocol further includes:

The SOC receives the periodic message and verifies the LiveCounter field and the checksum field in the periodic message. If the LiveCounter field verification fails or times out, the SOC communication process is restarted.

Optionally, when the data is a periodic message and is uplink data, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC receives the periodic message and checks the LiveCounter field and the checksum field in the periodic message. If the checksum is abnormal, the message data is discarded.

Optionally, the data includes an event-type message. When the data is an event-type message and is uplink data, the MCU and SOC communication method based on the SPI communication protocol includes:

The MCU generates an event message to be sent, wherein the event message includes a LiveCounter field and a checksum field;

The MCU sends the event message to be sent to the SOC;

The SOC end receives the event-type message and verifies the LiveCounter field and the checksum field in the event-type message. If the verification is successful, the SOC end distributes the data.

Optionally, when the data is an event-type message and is uplink data, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC receives the event-type message and verifies the LiveCounter field and the checksum field in the event-type message. If the checksum field verification fails, the NACK data is recorded and inserted into the to-be-sent linked list.

Optionally, when the data is an event-type message and is uplink data, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC receives the event-type message and verifies the LiveCounter field and the checksum field in the event-type message. If the LiveCounter field verification fails, an exception is recorded.

The present application also provides a SPI communication protocol construction method for constructing an SPI communication protocol, wherein the SPI communication protocol is used for the MCU and SOC communication method based on the SPI communication protocol as described above, and the SPI communication protocol construction method includes:

Set up the interface, application layer, session layer, transport layer, data link layer, and driver layer;

Define the protocol format;

Design a state machine.

Beneficial Effects

The communication method adopted by the MCU and SOC communication method based on the SPI communication protocol of the present application is SPI communication. The SPI protocol supports full-duplex communication and has the characteristics of simple communication and fast transmission rate. The present application is based on the SPI communication method, designs the communication protocol within the protocol, and formulates a timeout retransmission mechanism and a response detection mechanism to ensure the stability and reliability of data transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a method for communicating between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

FIG. 2 is a schematic diagram of an uplink path establishment process of a communication method between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

FIG3 is a schematic diagram of an abnormal process of establishing an uplink path in a communication method between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

FIG4 is a flow chart of a normal uplink heartbeat packet transmission process of a communication method between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

FIG5 is a flow chart of an uplink heartbeat packet process (abnormal) of a communication method between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

FIG6 is a schematic diagram of an uplink periodic message generation process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

FIG. 7 is a schematic diagram of an uplink periodic message sending process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

FIG8 is a schematic diagram of an uplink periodic message triggering process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

9 is a schematic diagram of an abnormal process of an uplink periodic message checksum in a method for communicating between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

10 is a schematic diagram of an abnormal flow of an uplink periodic message LiveCounter of a communication method between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

11 is a schematic diagram of the TimeOut exception process of the uplink periodic message of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

12 is a schematic diagram of the SOC-side distribution process of the uplink periodic message of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

FIG. 13 is a schematic diagram of the uplink event message generation process of the MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

FIG. 14 is a schematic diagram of the uplink event message sending process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

15 is a schematic diagram of an uplink event message checksum exception process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

16 is a schematic diagram of an abnormal flow of an uplink event-type message LiveCounter of a communication method between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

17 is a schematic diagram of an uplink event-type message timeout exception process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

18 is a schematic diagram of the SOC-side distribution process of the uplink event-type message of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

FIG. 19 is a schematic diagram of an uplink ACK data flow of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

FIG. 20 is a schematic diagram of an uplink NACK data flow of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

FIG. 21 is a schematic diagram of a process for generating periodic message downlink data in a method for communicating between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

FIG. 22 is a schematic diagram of the periodic message downlink data sending process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

23 is a schematic diagram of a periodic message downlink data checksum exception process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

24 is a schematic diagram of the LiveCounter exception process of the downlink data periodic message of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

FIG. 25 is a schematic diagram of the downlink data event message generation process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

FIG. 26 is a schematic diagram of the downlink data event message sending process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

27 is a schematic diagram of a downlink data event message checksum exception process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

28 is a schematic diagram of the LiveCounter exception process of the downlink data event message of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

29 is a schematic diagram of a downlink data event-type message timeout exception process of an MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

FIG. 30 is a schematic diagram of the downlink data ACK sending process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

FIG. 31 is a schematic diagram of the downlink data NACK sending process of the MCU and SOC communication method based on the SPI communication protocol in an embodiment of the present application.

Figure 32 is a schematic diagram of the MCU data sending process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

Figure 33 is a schematic diagram of the MCU data receiving process of the MCU and SOC communication method based on the SPI communication protocol in one embodiment of the present application.

FIG34 is a schematic diagram of data transmission between MCU and SOC in one embodiment of the present application.

Figure 35 is a schematic diagram of the protocol format definition in an embodiment of the present application.

Figure 36 is a schematic diagram of the state machine design in one embodiment of the present application.

Detailed ways

In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

FIG1 is a flow chart of a method for communicating between an MCU and a SOC based on the SPI communication protocol in an embodiment of the present application.

The MCU and SOC communication method based on the SPI communication protocol as shown in Figure 1 includes:

The MCU side and the SOC side establish an SPI communication system data path based on the SPI communication protocol;

The SOC end and the SOC end generate data according to the SPI communication protocol and send the data to each other.

The communication method adopted by the MCU and SOC communication method based on the SPI communication protocol of the present application is SPI communication. The SPI protocol supports full-duplex communication and has the characteristics of simple communication and fast transmission rate. The present application is based on the SPI communication method, designs the communication protocol within the protocol, and formulates a timeout retransmission mechanism and a response detection mechanism to ensure the stability and reliability of data transmission.

In this embodiment, the data includes a heartbeat packet. When the data is a heartbeat packet, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC generates and sends a heartbeat packet to the MCU periodically based on the SPI communication protocol. The heartbeat packet includes a LiveCounter field, and the heartbeat message is in a single sending mode.

The MCU side obtains the heartbeat packet and notifies the watchdog on the MCU side to update.

In this embodiment, when the data is a heartbeat packet, the MCU and SOC communication method based on the SPI communication protocol further includes:

When the MCU does not receive a valid heartbeat packet within the preset time, the SOC restart is triggered through EcuM (state management).

In this embodiment, the data includes a periodic message. When the data is a periodic message, the MCU and SOC communication method based on the SPI communication protocol includes:

The MCU generates a periodic message to be sent according to the operation cycle, and the periodic message includes a LiveCounter field and a checksum field;

The MCU sends periodic messages to the SOC.

The SOC end receives the periodic message and verifies the LiveCounter field and the checksum field in the periodic message. If the verification is successful, the SOC end distributes the data.

In this embodiment, when the data is a periodic message, the MCU and SOC communication method based on the SPI communication protocol further includes:

The SOC receives the periodic message and verifies the LiveCounter field and the checksum field in the periodic message. If the LiveCounter field verification fails or times out, the SOC communication process is restarted.

In this embodiment, when the data is a periodic message, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC receives the periodic message and checks the LiveCounter field and the checksum field in the periodic message. If the checksum is abnormal, the message data is discarded.

In this embodiment, the data includes an event-type message. When the data is an event-type message, the MCU and SOC communication method based on the SPI communication protocol includes:

The MCU generates an event message to be sent, wherein the event message includes a LiveCounter field and a checksum field;

The MCU sends the event message to be sent to the SOC;

The SOC end receives the event-type message and verifies the LiveCounter field and the checksum field in the event-type message. If the verification is successful, the SOC end distributes the data.

In this embodiment, when the data is an event-type message, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC receives the event message and verifies the LiveCounter field and the checksum field in the event message. If the checksum field verification fails, NACK (no acknowledgement) data is recorded and inserted into the to-be-sent linked list.

In this embodiment, when the data is an event-type message, the MCU and SOC communication method based on the SPI communication protocol includes:

The SOC receives the event-type message and verifies the LiveCounter field and the checksum field in the event-type message. If the LiveCounter field verification fails, an exception is recorded.

The present application also provides a SPI communication protocol construction method for constructing an SPI communication protocol, wherein the SPI communication protocol is used for the MCU and SOC communication method based on the SPI communication protocol as described above, and the SPI communication protocol construction method includes:

Set up the interface, application layer, session layer, transport layer, data link layer, and driver layer;

Define the protocol format;

Design a state machine.

The present application is further described in detail below by way of examples. It should be understood that the examples do not constitute any limitation to the present application.

Referring to FIG. 34 , in this embodiment, the MCU and the SOC A-core communicate via the SPI communication system, and the MCU and the M-CORE communicate via the UART.

See Figure 35, which is a use case diagram of the SPI communication protocol of the present application.

In this embodiment, the SPI communication protocol of the present application requires setting up an interface, an application layer, a session layer, a transport layer, a data link layer and a driver layer.

See Table 1 below:

Referring to FIG. 35 , the SPI communication protocol of the present application requires a protocol format definition, and the specific definition is shown in FIG. 35 .

In this embodiment, the protocol format is specifically described as follows:

In this embodiment, the SPI communication protocol of the present application requires a state machine design, and the specific design is shown in Figure 36.

In this embodiment, each state in the state machine shown in FIG. 36 is described as follows:

State transition description:

The communication protocol designed in this application ensures the stability of data transmission through a timeout retransmission mechanism and a response detection mechanism. Different processes are set between various levels to ensure stable and reliable data transmission. After verification by actual vehicle project, the communication method designed based on this protocol meets the real-time requirements and can ensure stable and error-free data transmission between the MCU and SOC. It can run continuously for one month without downtime, and its stability and accuracy meet the technical requirements.

In this embodiment, the MCU and SOC communication method based on the SPI communication protocol of the present application includes:

The MCU side and the SOC side establish an SPI communication system data path based on the SPI communication protocol;

The SOC end and the SOC end generate data according to the SPI communication protocol and send the data to each other.

In this embodiment, data sent from the MCU end to the SOC A end is called uplink data, and data sent from the SOC A end to the MCU end is called downlink data.

In this embodiment, it is first necessary to establish an SPI communication system data path based on the SPI communication protocol between the MCU end and the SOC end.

In this embodiment, the communication system data path establishment process: communication interaction establishment is initiated after the SOC-side service is started, and the MCU-side responds to the handshake message in a single-sending mode, without the need for ACK (acknowledgement)/NACK, LiveCounter/CheckSum and other communication mechanisms to ensure that the handshake stage message is triggered by the MCU every 10ms. If there is no handshake response or the message does not match during the period, the message content is obtained again.

For the convenience of description, the following description will be made from the MCU side and the SOC side respectively.

Specifically, see Figure 2, which describes the MCU side:

The MCU_VehicleInterface (communication protocol interface on the MCU side) on the MCU side is first started and waits for the SOC side to start. After receiving the GPIO (chip IO pin interface) notification sent by the SOC side, the communication mode is turned on, and the A-Core on the SOC side is periodically obtained to determine whether a handshake message is obtained. If so, a handshake response message is sent to the A-Core on the SOC side, and the message sent by the SOC side is obtained to determine whether the obtained message is a handshake completion message. If so, the handshake is determined to be completed and the normal communication state is entered.

See Figure 2, which describes the SOC side:

After the SOC is started, it sends a GPIO notification to the MCU and starts handshaking. The SOC sends a handshake message to the MCU, obtains the handshake response message sent by the MCU, and determines whether it is a handshake response. If so, it sends a handshake completion message and enters the normal communication state.

It is understandable that sometimes there may be abnormalities in the establishment of the uplink channel. At this time, the SOC service is started and the timing begins. If the handshake cannot be completed within 5 seconds, the service needs to be restarted and the handshake needs to be reinitiated. On the MCU side, the timing starts after the task is started. If the handshake cannot be completed within 10 seconds, the SOC communication service needs to be restarted and the handshake needs to be reinitiated.

See Figure 3, which describes the MCU side:

The MCU sets a timer to determine whether the handshake is completed within a preset time (e.g., 10 seconds). If not, the GPIO notifies the SOC to restart the communication service.

See Figure 3, which describes the SOC side:

The SOC sets a timer to determine whether the handshake is completed within a preset time (eg, 5 seconds). If not, the communication service is restarted.

In this embodiment, the data of the present application includes heartbeat packet data.

When it is heartbeat packet data, the application is as follows:

After the communication interaction is established, the SOC service sends a heartbeat packet at a fixed period (1s). The heartbeat packet needs to contain the LiveCounter field (0-0xF). The heartbeat message is a single-send mode and does not require ACK/NACK, LiveCounter/CheckSum and other communication mechanisms to ensure. If the LiveCounter of the heartbeat packet is wrong, the link layer does not need to record the error and restart.

Referring to FIG. 4 , in this embodiment, the MCU side is used for description:

When MCU_VehicleInterface is in normal communication state, it provides the common communication state to the MCU watchdog and starts the communication mode, periodically obtains the A-Core data of the SOC, and determines whether the obtained A-Core data is a heartbeat packet. If so, it notifies the MCU watchdog and the MCU watchdog resets the timer.

Referring to FIG. 5 , in this embodiment, the SOC end is used for description:

The A-Core of the SOC sends the normal communication status to the watchdog of the A-Core.

When the watchdog of the SOC's A-Core starts sending a heartbeat message, the SOC's A-Core updates the LiveCounter field in the heartbeat packet and sends it to the MCU.

Referring to FIG. 5 (when describing, only the differences from FIG. 4 are described), in this embodiment, if the SPI communication system heartbeat packet process (abnormal), for example, the MCU end does not receive a valid heartbeat packet for 30 seconds (no communication, or LiveCounter does not change), the SOC end is triggered to restart through EcuM.

In this embodiment, when the data is a periodic message and is uplink data, each module of the MCU calls the SPI communication system interface to update the periodic message data. The periodic message is a static fixed size buffer, which is overwritten and filled after the interface is called. There is no need to judge whether the old data has been sent. The interface needs to implement data change judgment and interface call count management. The periodic message protocol needs to include a data change field and an interface call Counter field to confirm the calling relationship between the APP and this system.

See Figure 6, which describes the MCU side:

MCU_Modules (MCU module scheduling) periodically packages data and calls the data update interface according to the operating cycle;

MCU_VehicleInterface updates the interface call count counter to determine whether the data is the same as the last time. If not, it sets the data change flg to TRUE and updates the periodic message data buff and management data.

In this embodiment, the periodic message is released periodically according to the designed sending cycle (static design). The periodic message needs to have two attributes: initial sending time and periodic sending time. When sending for the first time, the initial sending time is used as an identifier to determine whether the sending cycle has been reached. After sending once, it is reloaded as the periodic sending time for fast sending of periodic messages at startup. Through static design, the average sending time interval of each periodic message is used. At the same time, when two or more periodic messages meet the issuance requirements, the sending order is arbitrated according to the message ID. If the message is not sent, it will be sent when the link layer schedules the next time. Inside the SPI driver, when sending, it is necessary to mirror the release buffer (DI when copying data) to ensure that the data buffer is not updated during data transmission.

Referring to FIG. 7 , in this embodiment, the MCU side is used for description:

After MCU_VehicleInterface establishes communication with SOC, it traverses the periodic message to confirm whether the sending cycle is reached. If so, it updates the checksum field in the data, sends the sorted data (periodic message) to A_Core of SOC, and updates the sending time and sending status.

Referring to FIG. 7 , in this embodiment, the SOC end is used for description:

After the SOC obtains the periodic message, it performs data verification. If the verification is successful, the periodic data timing is reset and the first data distribution is performed.

In this embodiment, the uplink data sending process of the SPI communication system (triggered by periodic message event): periodic messages with larger periods are allowed to be set as periodic event types. After the event is triggered, it is treated as a period in the next transmission cycle, and the cycle timing is restarted after the sending is completed.

See Figure 8. The content in Figure 8 is a combination of Figure 7 and Figure 6.

Referring to FIG. 9 , in this embodiment, when the checksum is abnormal, the message data is discarded.

In this embodiment, when the LiveCounter is abnormal, the communication process on the SOC side is restarted.

Specifically, see FIG. 10 (only the LiveCounter determination at the SOC end is described).

The SOC determines whether the LiveCounter has changed. If not, it determines whether the LiveCounter has no change record for more than 5 times. If so, it restarts.

The SOC determines whether the LiveCounter has changed. If so, it determines whether the change is less than 3 times. If not, it records the LiveCounter exception and repeats this judgment. If the LiveCounter exception is recorded more than 5 times, it restarts.

The SOC determines whether the LiveCounter has changed. If so, it determines whether the change is less than 3 times. If so, it determines that the LiveCounter has no abnormality and the data is valid.

Referring to FIG. 11 , in this embodiment, when a TimeOut exception occurs, a restart is performed.

Referring to FIG. 12 (only describing the parts different from FIG. 8 ), in this embodiment, when the SOC side performs the first data distribution, the VehicleInterface of A_Core of the SOC side is distributed to the Modules of A_Core of the SOC side through the inter-process communication mechanism.

In this embodiment, the data of the present application includes event-type messages. When the data is an event-type message and is uplink data, after the communication interaction is established, each module calls the data update interface as needed and performs linked list management according to the attributes of each event message.

Referring to FIG. 13 , in this embodiment, the Modules on the MCU side call the data update interface according to the business logic. The VehicleInterface on the MCU side updates the interface call count counter to determine whether it is allowed to overwrite the unsent data. If so, the same ID event message is checked in the to-be-sent data linked list. If it is determined that there is an event message with the same ID to be sent, the same ID event message is updated in the linked list and the to-be-sent data linked list is updated.

Referring to FIG. 14 , in this embodiment, the communication system uplink data transmission process (event-type message) is specifically as follows:

Take the MCU side as an example:

After the VehicleInterface handshake on the MCU side is completed, a detection is performed periodically, and the to-be-sent linked list is searched to determine whether there is data to be sent. If so, the LiveCounter field and checksum field in the to-be-sent data are updated, and the sorted data (i.e., event-type message) is sent to the SOC and the message ID is put into the sent to-be-verified linked list.

Take the SOC end as an example:

The SOC verifies the LiveCounter field and the checksum field. If the verification succeeds, the second data distribution is performed.

Referring to FIG. 15 (only describing the difference from FIG. 14 ), in this embodiment, if the checksum of the event-type message is abnormal, the checksum abnormality record NACK data is inserted into the to-be-sent linked list.

Refer to Figure 16 (only the differences from Figure 14 are described). In this embodiment, if the event-type message LiveCounter is abnormal, the SOC determines whether the LiveCounter has changed. If not, it determines whether the LiveCounter has no change record for more than 5 times. If so, it restarts.

The SOC determines whether the LiveCounter has changed. If so, it determines whether the change is less than 3 times. If not, it records the LiveCounter exception and repeats this judgment. If the LiveCounter exception is recorded more than 5 times, it restarts.

The SOC determines whether the LiveCounter has changed. If so, it determines whether the change is less than 3 times. If so, it determines that the LiveCounter has no abnormality and the data is valid.

Referring to FIG. 17 , in this embodiment, when an ACK/NACK timeout exception occurs, a restart is performed.

Referring to FIG. 18 , in this embodiment, the SPI communication system uplink data A-CORE distributes data to other module processes (event-type messages).

Referring to FIG. 18 , in this embodiment, when the SOC side performs the second data distribution, the VehicleInterface of the A_Core of the SOC side is distributed to the Modules of the A_Core of the SOC side through the inter-process communication mechanism.

Referring to FIG. 19 , in this embodiment, the uplink data transmission process (ACK) of the SPI communication system is as follows:

Take the MCU side as an example:

Get the message type transmitted by the SOC end;

Determine whether there is an ACK response. If so, traverse the verification linked list to find the element with the same ID and remove the element from the linked list.

Referring to FIG. 20 , in this embodiment, the uplink data transmission process (NACK) of the communication system is specifically as follows:

Take the MCU side as an example:

Get the message type transmitted by the SOC and determine whether a NACK response is obtained. If so, traverse the verification linked list to find the element with the same ID and update the retry count. If the retry count exceeds 3 times, restart the communication. If the retry count does not exceed 3 times, clear the element from the linked list and append it to the linked list to be sent.

Referring to Figures 21 to 30, in this embodiment, the above-mentioned periodic messages and event-type messages also include processes such as sending and distributing downlink data. The sending process is generally the same as that of uplink data, except that the sender and the receiver are opposite to those of uplink data. For example, when the periodic message is uplink data, what the SOC side needs to do is done by the MCU side in downlink data, and what the MCU side does in uplink data is done by the SOC side in downlink data. For details, please refer to Figures 21 to 32.

Referring to FIG. 32 , in this embodiment, an MCU data transmission SOC is also included, as follows:

Before sending a message, you need to add Checksum and Livecounter to the packet. Livecounter uses 4 bits, and each group uses an independent Livecounter number. 0 is invalid, and 1 to 15 are valid. The number starts from 1 and is used cyclically.

The checksum uses 16 bits and the algorithm is the standard algorithm.

In addition, the data needs to be sent repeatedly in a period of 10ms, and the Livecounter needs to be updated in each new period.

Referring to FIG. 33 , in this embodiment, MCU data reception is also included, specifically as follows: for data that needs to be sent via SPI/UART, the received data is processed in an interrupt manner, and the data is moved from DMA to the system content. The message processing thread needs to process the data in a cycle of 10ms.

This application designs and implements a complete set of communication protocols, which ensures the stability of data transmission by formulating data priority mechanism, timeout retransmission mechanism, and response detection mechanism. In order to ensure stable and reliable data transmission, different processes are set between various levels. After verification by actual vehicle project, the communication method designed based on this protocol meets the real-time requirements, and can ensure the stable transmission of data between MCU and SOC without errors. It can run continuously for one month without downtime, and its stability and accuracy meet the technical requirements.

The present application designs and implements a communication message format, which includes a data header, a message ID, a message type, a packet ID, a message communication count, a trigger count, a data length, and a data packet CRC8 check algorithm.

This application clarifies the responsibilities and functions of each level through hierarchical division, so that each level can perform its duties without interfering with each other, so as to achieve stable data transmission.

This application ensures the stability and reliability of data transmission by formulating data priority mechanism, timeout retransmission mechanism, and response detection mechanism, so as to prevent problems such as instrument erroneous display caused by data transmission errors.

In addition, it is obvious that the word "comprising" does not exclude other units or steps. Multiple units, modules or devices stated in the device claims can also be implemented by one unit or the overall device through software or hardware.

Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims (10)

1. The MCU and SOC communication method based on the SPI communication protocol is characterized by comprising the following steps of:

an SPI communication system data path based on an SPI communication protocol is established between the MCU end and the SOC end;

and the SOC end generate data according to the SPI communication protocol and mutually send the data.

2. The SPI communication protocol-based MCU and SOC communication method of claim 1, wherein the data includes a heartbeat packet, and when the data is a heartbeat packet and is uplink data, the SPI communication protocol-based MCU and SOC communication method includes:

the SOC end generates and sends a heartbeat packet to the MCU end based on the SPI communication protocol period, wherein the heartbeat packet comprises LiveCounter fields, and the heartbeat packet is in a single sending mode;

and the MCU end acquires the heartbeat packet and informs the watchdog of the MCU end to update.

3. The SPI communication protocol-based MCU and SOC communication method of claim 2, wherein when the data is a heartbeat packet and is uplink data, the SPI communication protocol-based MCU and SOC communication method further comprises:

And triggering the SOC to restart through EcuM when the MCU end does not receive the effective heartbeat packet within the preset time.

4. The method for communicating with an MCU and an SOC based on an SPI communication protocol according to claim 3, wherein the data includes a periodic message, and when the data is a periodic message and is uplink data, the method for communicating with an MCU and an SOC based on an SPI communication protocol includes:

The MCU end periodically generates a periodic message to be sent according to the operation period, wherein the periodic message comprises LiveCounter fields and a checksum field;

the MCU end sends a periodic message to the SOC end;

And the SOC end receives the periodic message and checks LiveCounter fields and checksum fields in the periodic message, and if the check is successful, the SOC end distributes data.

5. The method for communicating with an MCU and an SOC based on an SPI communication protocol according to claim 4, wherein when the data is a periodic message and is uplink data, the method for communicating with an MCU and an SOC based on an SPI communication protocol further comprises:

and the SOC end receives the periodic message and checks LiveCounter fields and a checksum field in the periodic message, and if LiveCounter fields fail to check or are overtime, the SOC communication process is restarted.

6. The method for communicating with an MCU and an SOC based on an SPI communication protocol according to claim 5, wherein when the data is a periodic message and is uplink data, the method for communicating with an MCU and an SOC based on an SPI communication protocol comprises:

And the SOC end receives the periodic message and checks LiveCounter fields and checksum fields in the periodic message, and if the checksum is abnormal, the message data is discarded.

7. The method for communicating with an MCU and an SOC based on an SPI communication protocol according to claim 6, wherein the data includes an event type message, and when the data is an event type message and is uplink data, the method for communicating with an MCU and an SOC based on an SPI communication protocol includes:

The method comprises the steps that an MCU end generates an event type message to be sent, wherein the event type message comprises LiveCounter fields and a checksum field;

the MCU end sends an event type message to be sent to the SOC end;

and the SOC receives the event type message, checks LiveCounter fields and checksum fields in the event type message, and distributes data if the check is successful.

8. The method for communicating with an MCU and an SOC based on an SPI communication protocol according to claim 7, wherein when the data is an event type message and is uplink data, the method for communicating with an MCU and an SOC based on an SPI communication protocol comprises:

And the SOC end receives the event type message and checks LiveCounter fields and checksum fields in the event type message, and if the checksum fields fail to check, the NACK data is recorded and inserted into a linked list to be sent.

9. The method for communicating with an MCU and an SOC based on an SPI communication protocol according to claim 8, wherein when the data is an event type message and is uplink data, the method for communicating with an MCU and an SOC based on an SPI communication protocol comprises:

and the SOC end receives the event type message and checks LiveCounter fields and checksum fields in the event type message, and if LiveCounter fields fail to check, the record is abnormal.

10. A method for constructing an SPI communication protocol for use in the MCU and SOC communication method based on the SPI communication protocol according to any one of claims 1 to 9, the method comprising:

Setting an interface, an application layer, a session layer, a transmission layer, a data link layer and a driving layer;

Defining a protocol format;

The state machine is designed.