CN115643126A

CN115643126A - Communication method, device and protocol stack based on SPI bus

Info

Publication number: CN115643126A
Application number: CN202211192689.3A
Authority: CN
Inventors: 阙秋根; 何天翼
Original assignee: BDstar Intelligent and Connected Vehicle Technology Co Ltd
Current assignee: BDstar Intelligent and Connected Vehicle Technology Co Ltd
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2023-01-24

Abstract

The communication method based on the SPI bus receives command messages sent by functional application through an application layer and calculates corresponding command lengths according to the command messages; calling a first sending interface of the transmission layer, and carrying out frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data; the first frame start symbol and the first check code are added to at least one frame of data through the second sending interface of the data link layer to obtain first communication data, and the first communication data are sent to the opposite end through the driving layer and the physical layer.

Description

Communication method, device and protocol stack based on SPI bus

Technical Field

The invention relates to the technical field of communication, in particular to a communication method, a communication device and a protocol stack based on an SPI bus.

Background

An SPI (Serial Peripheral Interface) bus is a high-speed full-duplex communication bus, which operates in a master-slave manner, generally includes a master device and one or more slave devices, and is widely used for data transmission between System On Chips (SOCs) of Advanced Driving Assistance System (ADAS) domain controllers (SOCs). Usually, the SPI bus only defines the communication specification related to the physical layer, and does not have the definition of the upper layer message format and the guarantee of the transmission protocol, and cannot provide reliable connection management.

Disclosure of Invention

The invention aims to provide an SPI bus-based communication method, an SPI bus-based communication protocol stack, an SPI bus-based communication device, a terminal device and a readable storage medium.

In a first aspect, the present invention provides a communication method based on an SPI bus, the method comprising:

receiving a command message sent by functional application through an application layer, and calculating a corresponding command length according to the command message;

calling a first sending interface of a transmission layer, and carrying out frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data;

and adding a first frame start symbol and a first check code to the at least one frame data through a second sending interface of the data link layer to obtain first communication data, and sending the first communication data to an opposite end through a driving layer and a physical layer.

In an alternative embodiment, the method further comprises:

receiving second communication data sent by an opposite terminal through the data link layer, and checking the second communication data based on a second frame start symbol and a second check code;

after the second communication data passes the verification, caching the second communication data through a first receiving interface of the transmission layer, and packaging the second communication data after receiving a tail frame of the second communication data to obtain a data packet;

and sending the data packet to a corresponding functional application according to the functional command ID of the data packet based on a second receiving interface of the application layer.

In an alternative embodiment, the method further comprises:

and after the second communication data fails to be checked, sending an error response to the opposite terminal.

In an alternative embodiment, said calculating the corresponding command length according to the command message includes:

filling out corresponding function command ID and time stamp based on the command message, and calculating corresponding command length.

In an optional embodiment, the performing, by the first sending interface, frame processing on the command message according to the command length to obtain at least one frame data includes:

determining a frame mode corresponding to the command message according to the command length through the first sending interface, wherein the types of the frame mode comprise a single frame mode and a continuous frame mode;

when the type of the frame mode is the continuous frame mode, splitting the command message into at least one fixed-length data, and encapsulating the at least one fixed-length data according to a transport layer protocol to obtain at least one frame data.

In an optional embodiment, the determining, by the first sending interface and according to the command length, a frame mode corresponding to the command message includes:

when the command length is smaller than or equal to a preset length, selecting the single-frame mode;

and when the command length is greater than the preset length, selecting the continuous frame mode.

In a second aspect, the present invention provides a communication protocol stack based on an SPI bus, the communication protocol stack comprising an application layer, a transport layer and a data link layer;

the application layer is used for receiving a command message sent by the functional application and calculating a corresponding command length according to the command message;

the transmission layer is used for carrying out frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data;

the data link layer is used for adding a first frame start symbol and a first check code to the at least one frame data through a second sending interface of the data link layer to obtain first communication data, and sending the first communication data to an opposite end through the driving layer and the physical layer.

In a third aspect, the present invention provides an SPI bus based communication device, comprising:

the receiving module is used for receiving the command message sent by the functional application through the application layer and calculating the corresponding command length according to the command message;

the fragmentation module is used for calling a first sending interface of a transmission layer and carrying out frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data;

and the sending module is used for adding a first frame start character and a first check code to the at least one frame data through a second sending interface of the data link layer to obtain first communication data, and sending the first communication data to an opposite end through the driving layer and the physical layer.

In a fourth aspect, the present invention provides a terminal device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer program executes any one of the SPI bus based communication methods when running on the processor.

In a fifth aspect, the present invention provides a readable storage medium storing a computer program, which when run on a processor, performs any of the SPI bus based communication methods described herein.

The embodiment of the invention has the beneficial effects that:

the embodiment of the application provides a communication method based on an SPI bus, which receives a command message sent by functional application through an application layer and calculates a corresponding command length according to the command message; calling a first sending interface of the transmission layer, and carrying out frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data; the first frame start character and the first check code are added into at least one frame of data through the second sending interface of the data link layer to obtain first communication data, and the first communication data are sent to the opposite end through the driving layer and the physical layer.

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention. Like components are numbered similarly in the various figures.

Fig. 1 is a schematic structural diagram illustrating a communication protocol stack based on an SPI bus according to an embodiment of the present application;

fig. 2 is a first flowchart illustrating a SPI bus based communication method according to an embodiment of the present application;

fig. 3 is a schematic flowchart illustrating a process of determining frame data in an SPI bus-based communication method according to an embodiment of the present application;

fig. 4 shows a second flowchart in the SPI bus based communication method according to the embodiment of the present application;

fig. 5 shows a schematic structural diagram of a communication device based on an SPI bus according to an embodiment of the present application.

Description of the main element symbols:

10-SPI bus based communication device; 11-a receiving module; 12-a slicing module; 13-sending module.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present invention, are only intended to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.

Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present invention belong. The terms (such as terms defined in a commonly used dictionary) will be construed to have the same meaning as the contextual meaning in the related art and will not be construed to have an idealized or overly formal meaning unless expressly so defined in various embodiments of the present invention.

Example 1

In the present Application, as shown in fig. 1, a communication protocol stack based on an SPI bus includes a Master node (Master node) and a Slave node (Slave node), where the Master node and the Slave node each include a hardware portion and a Data Link Layer (Data Link Layer), a Transport Layer (Transport Layer) and an Application Layer (Application Layer), the hardware portion includes a Physical Layer (Physical Layer) and a Driver Layer (SPI Driver), and the Physical Layer is implemented by SPI controller hardware of a chip; the driver layer is a driver portion of the chip, and is mainly used for providing SPI frame transceiving of the bottom-layer SPI and an interrupt notification mechanism of a related GPIO (General-purpose input/output). The data link layer is used for realizing SPI communication protocol management and adopts SPI frames with fixed length; the transmission layer is responsible for data slicing operation of the function application and is used for transmitting variable-length data blocks with the application layer; the application layer is used for realizing the protocol transmission of the SPI message of the functional application definition data, and the application layer and the functional application interact data distribution through interprocess communication.

Referring to fig. 2, the embodiment of the present application provides an SPI bus based communication method, which exemplarily includes steps S100 to S300.

Step S100: and receiving the command message sent by the functional application through the application layer, and calculating the corresponding command length according to the command message.

It is understood that the application layer adopts a common data format, such as xml format and JSON format, and the protocols of the application layer can be DNS domain name system, HTTP hypertext transfer protocol, FTP file transfer protocol, etc., and different protocols correspond to different protocol IDs. The command message is composed of an Msg Header and an Msg Content, the message Header includes a functional command ID, a command length, a protocol ID and a timestamp, the message Content is data defined by a functional application, is not limited in length, and splits the message data sent by the application layer through the transport layer. Illustratively, the application layer format is shown in table 1 and the message header definition is shown in table 2.

Byte0-15	Byte16-x
		Msg Header	Msg Content

TABLE 1

TABLE 2

In the application, the functional application sends a command message to the application layer through inter-process communication, the application layer receives the command message, determines that the functional command ID and the supplementary timestamp are filled in the application layer according to the command message, and calculates the corresponding command length. The message header of the command message comprises a protocol ID, a function command ID, a time stamp and the like, after the command message is received, the corresponding function command ID and the corresponding time stamp are filled in the application layer according to the message header, and the corresponding command length of the command message is calculated.

Step S200: and calling a first sending interface of the transmission layer, and carrying out frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data.

It can be understood that the transport layer is used to implement a fixed-length fragmentation mechanism, that is, long data is split into a plurality of fixed-length data and then sent, and then the split data is sent, and during sending, the data split by the application layer is encapsulated according to a transport layer protocol, and after encapsulation is completed, the data is sent through a data link layer, and when sending is completed, a notification that the sending is successful is received.

The command message is divided into a single frame mode and a continuous frame mode according to the data length received by the application layer, and is distinguished by Mask, namely, the first byte of the transmission layer. The Mask is described as shown in table 3, and includes a last frame flag, a consecutive frame flag, a first frame flag, a reserved portion, and the like. The format of the single frame mode is shown in table 4, the multi-frame mode is a continuous frame mode, the continuous frame mode is divided into a first frame and a non-first frame, the format of the first frame is the same as that of the single frame mode, the format of the non-first frame is shown in table 5 and comprises a fragmentation Mask, a fragmentation serial number, fragmentation data and the like, and in the application, the message data is distinguished as the first frame or the non-first frame through the Mask.

TABLE 3

TABLE 4

Byte0	Byte1	Byte2～251
			Mask (slicing Mask)	Count (number of segments)	Data (slicing Data)

TABLE 5

The transmission layer comprises a first sending interface, after the command length is obtained, the first sending interface of the transmission layer is called, and corresponding frame processing is carried out on the command message through the first sending interface according to the command length to obtain at least one frame data.

In one embodiment, as shown in fig. 3, the frame processing of the command message according to the command length through the first transmission interface to obtain at least one frame data includes substeps S210 to S220.

Substep S210: and determining a frame mode corresponding to the command message according to the command length through the first sending interface, wherein the types of the frame mode comprise a single frame mode and a continuous frame mode.

In the present application, at the first sending interface of the called transport layer, a corresponding frame mode is selected according to the command length of the command message, where the frame mode is a single frame mode or a continuous frame mode. When the command length is smaller than or equal to the preset length, selecting a single-frame mode; when the command length is greater than the preset length, the continuous frame mode is selected. For example, when the application data needing to be transmitted by the transmission layer does not exceed 248Bytes, the single frame mode is selected, and when the application data needing to be transmitted by the transmission layer is larger than 248Bytes, the continuous frame mode is selected.

Substep S220: when the type of the frame mode is a continuous frame mode, splitting the command message into at least one fixed-length data, and encapsulating the at least one fixed-length data according to a transport layer protocol to obtain at least one frame data.

After the corresponding frame mode is determined, when the type of the frame mode is a continuous frame mode, data fragmentation is carried out on the command message, namely the command message is divided into at least one piece of fixed-length data, the obtained at least one piece of fixed-length data is packaged according to a transport layer protocol, so that corresponding at least one piece of frame data is obtained, and the at least one piece of frame data is sent through a data link layer.

Step S300: and adding a first frame start symbol and a first check code to at least one frame data through a second sending interface of the data link layer to obtain first communication data, and sending the first communication data to an opposite end through the driving layer and the physical layer.

It is understood that the data link layer will provide services to the transport layer based on the services provided by the physical layer, and mainly includes adding and identifying a start symbol and an end symbol of each frame, checking by a corresponding checking mechanism, such as CRC (Cyclic Redundancy Check) and cheksum Check, and the like, and performing diagnostic processing on the data by a corresponding error diagnosis mechanism and error processing mechanism, where the specific format of the data link layer is shown in table 6. Wherein, sync occupies 8 bits, which represents synchronization; RC occupies 8bit and represents a rolling counter and is mainly used for monitoring whether a data link layer loses frames or not; CRC16/Checksum16 occupies 16 bits, represents a cyclic verification code and is mainly used for error checking; data represents useful Data for transmission by the Data link layer.

Byte0	Byte1	Byte2～3	Byte4～255
				Sync	RC	CRC16/Checksum16	Data

TABLE 6

In the application, the data link layer includes a second sending interface, a first frame start symbol and a first check code are added to at least one obtained frame of data through the called second interface of the data link layer to ensure the integrity and accuracy of the data, and first communication data obtained after the first frame start symbol and the first check code are added is sent to a corresponding opposite end through the driving layer and the physical layer.

In one embodiment, as shown in FIG. 4, the method further includes steps S400-S600.

Step S400: and receiving second communication data sent by the opposite terminal through the data link layer, and checking the second communication data based on the second frame start character and the second checking code.

In this application, the data link layer will also receive second communication data sent by the peer end, where the second communication data includes a second frame start and a second check code. After the data link layer receives the second communication data, delimitation is carried out according to the second frame start symbol to find out the start of one frame, and then the second check code in the second communication data is checked through a corresponding checking method, such as checking methods of CRC (cyclic redundancy check) and CHECKSUM (check code division multiple access), so that the integrity and the accuracy of the second communication data are ensured. If the second communication data fails to be checked, step S700 is executed: an error response will be sent to the peer. If the second communication data passes the verification, step S500 is executed. The first communication data bit is used for sending data, and the second communication data bit is used for receiving data.

Step S500: and caching the second communication data through a first receiving interface of the transmission layer, and packaging the second communication data after receiving a tail frame of the second communication data to obtain a data packet.

The transmission layer comprises a first receiving interface, and after the data frame passes the verification, the first receiving interface of the transmission layer is called back, received by the first receiving interface, and the received second communication data is cached. The second communication data includes a corresponding end frame flag, and when the end frame flag is recognized by the first receiving interface of the transport layer, the transport layer receives the corresponding end frame. And after receiving the tail frame of the second communication data, sending a response notice to the opposite terminal, and packing according to a transport layer protocol to obtain a corresponding data packet. The application layer comprises a second receiving interface, and the second receiving interface of the application layer is called back after the transmission layer packet is completed.

Step S600: and the second receiving interface based on the application layer sends the data packet to the corresponding function application according to the function command ID of the data packet.

It can be understood that the data packet obtained by the packet packaging includes corresponding message content, command length, function command ID and other content, each function command ID corresponds to one function application, and the data packet is sent to the corresponding function application through the second receiving interface of the application layer according to the function command ID in the data packet.

The application solves the problem that the SPI bus only defines the relevant communication standard of a physical layer, does not have upper layer message format definition and transmission protocol guarantee, and cannot provide reliable connection management, and the application can provide more reliable connection management.

Based on the communication method based on the SPI bus of the embodiment, the communication protocol stack based on the SPI bus is provided, and comprises an application layer, a transmission layer and a data link layer.

It is understood that the method steps of the present embodiment correspond to the corresponding functions of the SPI bus based communication method in the above embodiment, wherein the alternatives of the SPI bus based communication method described above are also applicable to the method of the present embodiment and will not be described repeatedly here.

Based on the communication method based on the SPI bus in the foregoing embodiment, fig. 5 shows a schematic structural diagram of the SPI bus-based communication device 10 according to the embodiment of the present application. The SPI bus based communication device 10 includes:

a receiving module 11, configured to receive, through an application layer, a command message sent by a function application, and calculate a corresponding command length according to the command message;

the fragmentation module 12 is configured to invoke a first sending interface of a transport layer, and perform frame processing on the command message through the first sending interface according to the command length to obtain at least one frame data;

a sending module 13, configured to add a first frame start symbol and a first check code to the at least one frame of data through a second sending interface of the data link layer to obtain first communication data, and send the first communication data to an opposite end through the driver layer and the physical layer.

The SPI bus-based communication device 10 of this embodiment is used to execute the SPI bus-based communication method of the above embodiment, and the implementation and beneficial effects related to the above embodiment are also applicable in this embodiment, and are not described again here.

The embodiment of the present application further provides a terminal device, which includes a memory and a processor, where the memory stores a computer program, and the computer program executes the SPI bus-based communication method when running on the processor.

An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed on a processor, the computer program implements the SPI bus-based communication method.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus embodiments described above are merely illustrative and, for example, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, each functional module or module in each embodiment of the present invention may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention or a part of the technical solution that contributes to the prior art in essence can be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a smart phone, a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk, and various media capable of storing program codes.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and shall cover the scope of the present invention.

Claims

1. A method for communicating based on an SPI bus, the method comprising:

and adding a first frame start character and a first check code to the at least one frame data through a second sending interface of the data link layer to obtain first communication data, and sending the first communication data to an opposite terminal through a driving layer and a physical layer.

2. The SPI bus based communication method according to claim 1, further comprising:

3. The SPI bus based communication method according to claim 2, further comprising:

4. An SPI bus based communication method according to any one of claims 1 to 3, wherein said calculating a corresponding command length from said command message comprises:

5. The SPI bus based communication method according to claim 1, wherein said framing said command message according to said command length through said first transmission interface to obtain at least one frame data, comprises:

6. The SPI bus based communication method according to claim 5, wherein said determining a frame mode corresponding to said command message according to said command length by said first transmission interface comprises:

7. A communication protocol stack based on SPI bus is characterized in that the communication protocol stack comprises an application layer, a transmission layer and a data link layer;

8. An SPI bus based communication device, the device comprising:

and the sending module is used for adding a first frame start symbol and a first check code into the at least one frame data through a second sending interface of the data link layer to obtain first communication data, and sending the first communication data to an opposite end through the driving layer and the physical layer.

9. A terminal device comprising a memory and a processor, the memory storing a computer program which, when run on the processor, performs the SPI bus based communication method of any one of claims 1 to 6.

10. A readable storage medium, characterized in that it stores a computer program which, when run on a processor, performs the SPI bus based communication method of any one of claims 1 to 6.