CN115801814A - A data transmission method, system and storage medium based on serial port double FIFO buffer structure - Google Patents

Abstract

The invention relates to a data transmission method, a system and a storage medium based on a serial port double FIFO buffer area structure, wherein the method comprises the following steps: at least one physical memory is respectively distributed in a monitoring system of a cloud platform and an automatic driving system of a vehicle end, an idle memory pool and a working memory pool are respectively established for the physical memories in the two systems through a bidirectional linked list, and at least one serial port double FIFO buffer area and a corresponding read-write pointer are established in the two systems; t2: and sending data requests with different priorities based on the automatic driving system of the vehicle end, acquiring the memory of a free memory pool of the automatic driving system of the vehicle end and filling the data requests, adding the memory filled with the data requests into a working memory pool of the automatic driving system of the vehicle end, and outputting the physical initial address and the size of the data requests. The invention not only reduces the probability of priority reversal caused by the problem of buffer area occupation, but also improves the real-time response performance of the system.

Description

A data transmission method, system and memory based on serial port double FIFO buffer structure storage medium

technical field

The invention relates to the technical field of data transmission, in particular to a data transmission method, system and storage medium based on a serial port double FIFO buffer structure.

Background technique

In the embedded system, the serial port is a kind of data transmission interface that is widely used. When transmitting data, the serial port driver generally uses the interrupt method to receive or send a single byte. For the application layer, it should provide a comparison Common interfaces, such as directly sending a byte array, or directly receiving a byte array, instead of sending and receiving a single byte, in order to achieve this goal, it is usually considered to add data buffer management in the serial port driver.

Commonly used serial port transceiver buffer management is generally to set two buffers, one is the sending buffer TxBuf, the other is the receiving buffer RxBuf, and set two pointers for each buffer, one records the bytes that the interrupt service program will process , another records the bytes that will be processed by the upper-level program that uses the serial port service. Take serial port transmission as an example, the two pointers are inTxBuf and outTxBuf respectively. outTxBuf points to the data to be sent by the sending interrupt, and inTxBuf points to the starting position where the upper layer program puts the data into the buffer. This approach is called the method of using a double-buffered queue. When the buffer is large enough, the upper layer program can put all the data to be sent into the buffer at one time instead of sending one byte at a time. When sending, first send the byte pointed to by outBuf, and point outBuf to the next byte to be sent. After the current byte is sent, a sending interrupt is generated, and then the interrupt is used to judge whether the buffer is empty or not. If it is empty, continue to fetch bytes and send until all bytes are sent.

The above serial port send buffer method allows the application layer to store a whole packet of data in the buffer to be sent in the form of an array. If there is no problem in a single-threaded application call, but if in a multi-threaded, multi-tasking system , when multiple application tasks with different priorities use the serial port to send their respective data packets at the same time, there will be a buffer competition problem, and even cause task priority inversion. The main reason is that there is only one inBuf pointer pointing to the beginning of the buffer to be written. For example, when a low-priority task A is using inBuf to copy its data packets to be sent into the buffer, a high-priority task B also uses inBuf to write its own data packets into the buffer, but At this time, task A has occupied the inBuf pointer, and high-priority task B must wait for A to finish copying its entire data packet before releasing inBuf to task B. This copying process cannot be preempted, otherwise it will disrupt each task. The data packets to be sent by the application layer cause data confusion, and the high-priority task B must wait for the low-priority task A to copy all the data packets before copying its own application data, which causes a certain priority inversion. If there are many application tasks in the entire system that need to use the serial port buffer to send data packets, the probability of priority inversion will increase, which will eventually lead to a decrease in the real-time performance of the system.

Contents of the invention

In view of the above deficiencies in the prior art, the present invention provides a data transmission method, system and storage medium based on a serial port double FIFO buffer structure, which not only reduces the priority inversion probability caused by the buffer occupation problem, but also improves the system Real-time responsive performance.

In order to achieve the above object and other related objects, the technical solutions provided by the present invention are as follows:

A data transmission method based on a serial port double FIFO buffer structure, comprising:

T1: Allocate at least one piece of physical memory in the monitoring system of the cloud platform and the automatic driving system of the car, respectively establish a free memory pool and a working memory pool for the physical memory in the two systems through a doubly linked list, and simultaneously create a free memory pool and a working memory pool in both systems. Establish at least one serial port double FIFO buffer and its corresponding read and write pointers;

T2: Based on the data requests with different priorities sent by the automatic driving system at the vehicle end, obtain the memory in the free memory pool of the automatic driving system at the vehicle end and fill in the data request, and add the memory filled with the data request to the vehicle In the working memory pool of the terminal automatic driving system, the physical start address and size of the output data request;

T3: Write the physical start address and size of the data request into the serial port double FIFO buffer of the autopilot system at the vehicle end, and output the data requests with high priority and those with low priority according to the priorities of the data requests data requests;

T4: Send the high-priority data request and the low-priority data request to the monitoring system of the cloud platform, and the monitoring system of the cloud platform sends the feedback data request to the vehicle through the serial port double FIFO buffer advanced automatic driving system.

Further, in step T3, the successively outputting data requests with high priority and data requests with low priority includes:

T31: inputting data requests with different priorities into the serial port double FIFO buffer, and the serial port double FIFO buffer copies the data requests according to the priority;

T32: If the low-priority data request is using the serial port dual FIFO buffer to write data, the high-priority data request is input to the serial port dual-FIFO buffer, and the low-priority data request is written into the process to interrupt , complete the priority data request, and then complete the low priority data request.

Further, the serial port double FIFO buffer includes a write pointer, a read pointer and at least one inter-buffer unit.

Further, the write pointer points to the first unused inter-buffer unit.

Further, the read pointer points to the first inter-buffer unit to be sent.

Further, when a data request is input into the serial port double FIFO buffer, a corresponding inter-buffer unit is selected according to the write pointer, and the write pointer points to the next free inter-buffer unit.

Further, when the data requests with high priority are input into the same serial port double FIFO buffer, the data requests with high priority occupy idle buffer inter-units for data copying, and the data requests with low priority stop copying data, Wait for data requests with high priority to complete data copying.

In order to achieve the above purpose and other related purposes, the present invention also provides a data transmission system based on a serial port double FIFO buffer structure, including computer equipment, which is programmed or configured to perform any one of the serial port dual FIFO based data transmission systems. The steps of the data transfer method of the buffer structure.

In order to achieve the above object and other related objects, the present invention also provides a computer-readable storage medium, which is programmed or configured to perform any one of the serial port double FIFO buffer structure-based Computer programs for data transfer methods.

The present invention has the following positive effects:

1. The present invention can reduce the priority inversion probability caused by the buffer occupation problem by adding a serial port double FIFO buffer.

2. The present invention improves the real-time response performance of the system by setting a serial port double FIFO buffer in the control system of the cloud platform and the vehicle-mounted automatic driving system.

Description of drawings

Fig. 1 is a schematic flow sheet of the method of the present invention;

Fig. 2 is a schematic diagram of the structure of the serial port double FIFO buffer in the present invention.

Detailed ways

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative efforts.

Embodiment 1: as shown in Figure 1, a kind of data transmission method based on serial port double FIFO buffer structure, comprises:

T1: Allocate at least one piece of physical memory in the monitoring system of the cloud platform and the automatic driving system of the car, respectively establish a free memory pool and a working memory pool for the physical memory in the two systems through a doubly linked list, and simultaneously create a free memory pool and a working memory pool in both systems. Establish at least one serial port double FIFO buffer and its corresponding read and write pointers;

T2: Based on the data requests with different priorities sent by the automatic driving system at the vehicle end, obtain the memory in the free memory pool of the automatic driving system at the vehicle end and fill in the data request, and add the memory filled with the data request to the vehicle In the working memory pool of the terminal automatic driving system, the physical start address and size of the output data request;

T3: Write the physical start address and size of the data request into the serial port double FIFO buffer of the autopilot system at the vehicle end, and output the data requests with high priority and those with low priority according to the priorities of the data requests data requests;

T4: Send the high-priority data request and the low-priority data request to the monitoring system of the cloud platform, and the monitoring system of the cloud platform sends the feedback data request to the vehicle through the serial port double FIFO buffer advanced automatic driving system.

In this embodiment, as shown in FIG. 2, in step T3, the successively outputting data requests with high priority and data requests with low priority includes:

T31: inputting data requests with different priorities into the serial port double FIFO buffer, and the serial port double FIFO buffer copies the data requests according to the priority;

T32: If the low-priority data request is using the serial port dual FIFO buffer to write data, the high-priority data request is input to the serial port dual-FIFO buffer, and the low-priority data request is written into the process to interrupt , complete the priority data request, and then complete the low priority data request.

In this embodiment, the serial port double FIFO buffer includes a write pointer, a read pointer and at least one inter-buffer unit.

In this embodiment, the write pointer points to the first unused inter-buffer unit.

In this embodiment, the read pointer points to the first inter-buffer unit to be sent.

In this embodiment, when a data request is input into the serial port double FIFO buffer, a corresponding inter-buffer unit is selected according to the write pointer, and the write pointer points to the next free inter-buffer unit.

In this embodiment, when the data requests with high priority are input into the same serial port double FIFO buffer, the data requests with high priority occupy the idle buffer unit for data copying, and the data requests with low priority stop Data copying, waiting for data requests with high priority to complete data copying.

In order to achieve the above purpose and other related purposes, the present invention also provides a data transmission system based on a serial port double FIFO buffer structure, including computer equipment, which is programmed or configured to perform any one of the serial port dual FIFO based data transmission systems. The steps of the data transfer method of the buffer structure.

In order to achieve the above object and other related objects, the present invention also provides a computer-readable storage medium, which is programmed or configured to perform any one of the serial port double FIFO buffer structure-based Computer programs for data transfer methods.

Embodiment 2: On the basis of the data transmission method, system and storage medium based on the serial port double FIFO buffer structure in Embodiment 1, the present invention will be further described below.

As shown in Figure 2, in a multitasking system, if multiple tasks with different priorities use the serial port to send data at the same time, for example, task A with low priority is using the buffer to write data, it first gets the write pointer, that is Occupy the buffer pointed to by the write pointer, and then immediately point the write pointer to the next free buffer. At this time, a high-priority task B also uses the serial port to send data, because the write pointer already points to the free buffer Interval, task B does not need to wait for task A to complete the copy data action, immediately interrupt task A, occupy the buffer space pointed by the write pointer, and then complete the data copy, after task B is completed, return to the breakpoint of task A to continue execution, Complete the data copy of task A. From this point of view, the double fifo buffer structure of the serial port can reduce the time for the high-priority task B to wait for the low-priority task A to complete the data copy, and improve the real-time response performance of the system.

To sum up, the present invention not only reduces the priority inversion probability caused by the buffer occupation problem, but also improves the real-time response performance of the system.

The specific implementation manners described above do not limit the protection scope of the present disclosure. It should be apparent to those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made depending on design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims (9)

1. A data transmission method based on a serial port double FIFO buffer area structure is characterized by comprising the following steps:

t1: respectively allocating at least one physical memory in a monitoring system of a cloud platform and an automatic driving system of a vehicle end, respectively establishing an idle memory pool and a working memory pool for the physical memories in the two systems through a bidirectional linked list, and simultaneously establishing at least one serial port double FIFO buffer area and a corresponding read-write pointer in the two systems;

t2: based on the data requests with different priorities sent by the automatic driving system of the vehicle end, acquiring the memory of a free memory pool of the automatic driving system of the vehicle end and filling the data requests, adding the memory filled with the data requests into a working memory pool of the automatic driving system of the vehicle end, and outputting the physical initial address and the size of the data requests;

t3: writing the physical initial address and the size of the data request into a serial port double FIFO buffer area of an automatic driving system of the vehicle end, and outputting a data request with high priority and a data request with low priority in sequence according to different priorities of the data requests;

t4: and sending the data request with high priority and the data request with low priority to a monitoring system of the cloud platform, and sending the feedback data request to an automatic driving system of the vehicle end by the monitoring system of the cloud platform through a serial port double FIFO buffer area.

2. The data transmission method based on the serial port double-FIFO buffer structure according to claim 1, wherein in step T3, the outputting the data request with high priority and the data request with low priority successively comprises:

t31: inputting data requests with different priorities into the serial port double FIFO buffer area, and copying the data requests by the serial port double FIFO buffer area according to the priorities;

t32: and if the data request with low priority is writing data by using the serial port double FIFO buffer area, the data request with high priority is input into the serial port double FIFO buffer area, the writing process of the data request with low priority is interrupted, the data request with high priority is completed, and then the data request with low priority is completed.

3. The data transmission method based on the serial port double FIFO buffer area structure according to claim 2, characterized in that: the serial port double FIFO buffer area comprises a write-in pointer, a read-out pointer and at least one buffer area unit.

4. The data transmission method based on the serial port double FIFO buffer zone structure according to claim 3, characterized in that: the write pointer points to the first unused buffer interval unit.

5. The data transmission method based on the serial port double FIFO buffer zone structure according to claim 3, characterized in that: the read pointer points to the first buffer interval unit to be sent.

6. The data transmission method based on the serial port double FIFO buffer area structure according to claim 2, characterized in that: and when a data request is input into the serial port double FIFO buffer area, selecting a corresponding buffer interval unit according to the write pointer, wherein the write pointer points to the next idle buffer interval unit.

7. The data transmission method based on the serial port double FIFO buffer area structure according to claim 6, characterized in that: when the data request with high priority is input into the same serial port double FIFO buffer area, the data request with high priority occupies the idle buffer area unit for data copying, the data request with low priority stops data copying, and the data request with high priority is waited to finish data copying.

8. A serial port double FIFO buffer structure based data transmission system comprising a computer device, characterized in that the computer device is programmed or configured to perform the steps of the serial port double FIFO buffer structure based data transmission method according to any one of claims 1 to 7.

9. A computer-readable storage medium having stored thereon a computer program programmed or configured to perform the method for data transmission based on a serial dual FIFO buffer structure according to any of claims 1 to 7.

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