Spi bus communication method and apparatus for a measuring instrument, spi interface

Abstract

The application discloses an SPI bus communication method and device and an SPI interface for a measuring instrument, comprising a transmission frequency setting process for dynamically adjusting the data transmission frequency of communication between a master device and a slave device. Firstly, a transmission data response result in a data communication process between the master device and the slave device on the SPI bus is acquired, and the data transmission frequency of communication between the master device and the slave device is set according to the transmission data response result; and when the transmission data response result is a failure, the data transmission frequency of communication between the master device and the slave device is reduced. Since the data transmission frequency of the SPI bus is set in a dynamic switching mode, the reliability and stability of SPI communication can be maintained under different use environments or in the case of device aging.

Description

Technical Field

[0001] This application relates to the field of measuring instrument technology, specifically to an SPI bus communication method and device for measuring instruments, and an SPI interface. Background Technology

[0002] SPI (Serial Peripheral Interface) is a high-speed, full-duplex, synchronous serial communication bus protocol, mainly used in EEPROM, FLASH, real-time clock, AD converter, and communication between multiple MCUs. The SPI bus communication mode can work in a multi-master device environment. Each master device can be used as a communication master device or a communication slave device. Full-duplex communication can be achieved using only four wires. Because it is compatible with master-slave mode and is simple and flexible, it is widely used in various measuring instruments, such as digital oscilloscopes and network analyzers.

[0003] The communication process of the SPI bus includes:

[0004] 1. The master device initiates communication.

[0005] The master device pulls the target slave device's CS line low (enabled) to notify the slave device that it is ready to communicate.

[0006] 2. Synchronous data transmission.

[0007] The master device begins generating clock pulses on its SCLK pin, and within each clock cycle, it simultaneously performs the transmit and receive processes:

[0008] The transmission process involves the master device sending 1 bit of data via the MOSI line. Simultaneously, the slave device samples the data bit on the MOSI line at the clock edge (rising or falling edge, depending on configuration) and shifts it into an internal shift register. The reception process involves the slave device sending 1 bit of data via the MISO line. Simultaneously, the master device samples the data bit on the MISO line at the same clock edge (or the opposite edge, depending on configuration) and shifts it into an internal shift register. This achieves full-duplex communication, allowing simultaneous bidirectional data transmission between the master and slave devices.

[0009] 3. Data transmission process.

[0010] Data is typically transmitted in 8-bit or 16-bit (or other length) units (frames). Both the master and slave devices have an internal shift register. Driven by a clock, data is shifted out bit by bit through the MOSI lines from the most significant bit (MSB) or least significant bit (LSB) of the master's shift register, while simultaneously being shifted into the slave's shift register. Similarly, data is shifted out bit by bit through the MISO lines from the most significant bit (MSB) or least significant bit (LSB) of the slave's shift register, while simultaneously being shifted into the master's shift register.

[0011] After a fixed number of clock cycles (equal to the number of data bits), a complete data frame is transmitted. At this point, the content of the master device's shift register is the data it received from the slave device, and the content of the slave device's shift register is the data it received from the master device.

[0012] 4. End communication.

[0013] The master device pulls the CS line high (invalid) to indicate the end of the communication. After the slave device detects that CS has gone high, it will usually stop driving the MISO line (becoming a high-impedance state) and reset its internal state.

[0014] SPI is a high-efficiency, flexible, and widely used point-to-point or master-slave serial communication interface. Although the protocol itself is simple, it is essential to ensure that the SPI modes of the master and slave devices are consistent, and to select the appropriate connection method (independent CS or daisy chain) based on the application scenario (speed requirements, number of slave devices). Its high speed and simplicity make it one of the preferred solutions for connecting peripherals in various measuring instruments. Summary of the Invention

[0015] The main technical problem addressed in this application is how to improve and ensure the communication quality of the SPI bus used in measuring instruments and equipment.

[0016] According to the first aspect, one embodiment provides an SPI bus communication method for a measuring instrument, including a transmission frequency setting process for dynamically adjusting the data transmission frequency for communication between a master device and a slave device;

[0017] The transmission frequency setting process includes:

[0018] Obtain the data transmission response results during the data communication process between the master device and the slave device on the SPI bus, and set the data transmission frequency between the master device and the slave device based on the data transmission response results;

[0019] When the data transmission response result is a failure, the data transmission frequency between the master device and the slave device is reduced.

[0020] In one embodiment, when the data transmission response result is successful, the transmission lifetime of communication between the master device and the slave device at the current data transmission frequency is obtained; wherein, the transmission lifetime is used to identify the duration of successful communication between the master device and the slave device at the current data transmission frequency;

[0021] When the transmission lifetime is greater than a preset lifetime limit, the data transmission frequency between the master device and the slave device is increased.

[0022] When the master device and slave device perform their first data communication at the increased data transmission frequency, and the data transmission response result of the first data communication is a failure, the data transmission frequency of the master device and slave device before the increase is restored, and the transmission lifetime is reset and / or the lifetime limit is extended.

[0023] In one embodiment, the transmission frequency setting process further includes:

[0024] When the master device and the slave device perform their first data communication at the increased data transmission frequency, and the data transmission response result of the first data communication is successful, the master device and the slave device perform data communication at the increased data transmission frequency and reset the transmission lifetime.

[0025] In one embodiment, the transmission frequency setting process further includes:

[0026] When the master device and the slave device communicate for the first time, the set value of the data transmission frequency is set to the preset maximum value;

[0027] When the data transmission response result is successful, and the data transmission frequency between the master device and the slave device is the preset maximum value, the current data transmission frequency between the master device and the slave device is maintained.

[0028] When the data transmission response result is a failure, and the data transmission frequency between the master device and the slave device is a preset minimum value, the current master device and slave device are shut down and fault information is fed back.

[0029] In one embodiment, the method for obtaining the transmission lifetime includes:

[0030] The transmission lifetime is obtained based on the number of successful communications between the master device and the slave device at the current data transmission frequency.

[0031] Methods for extending the survival time limit include:

[0032] Each time the survival time limit is extended, the survival time limit is increased exponentially.

[0033] In one embodiment, obtaining the data transmission response result during data communication between the master device and the slave device on the SPI bus includes:

[0034] The CRC algorithm is used to obtain the response result of the transmitted data.

[0035] In one embodiment, the transmission frequency setting process further includes:

[0036] When the master device communicates with different slave devices, a data transmission frequency is set for each.

[0037] According to a second aspect, one embodiment provides a computer-readable storage medium storing a computer program that can be executed by a processor to implement the SPI bus communication method as described in the first aspect.

[0038] According to a third aspect, one embodiment provides an SPI interface, including a transmission frequency setting module for dynamically adjusting the data transmission frequency for communication between a master device and a slave device.

[0039] The transmission frequency setting module includes a response result acquisition unit, a lifetime acquisition unit, and a frequency setting unit;

[0040] The response result acquisition unit is used to acquire the data transmission response result during the data communication process between the master device and the slave device on the SPI bus;

[0041] The lifetime acquisition unit is used to acquire the transmission lifetime, which is used to identify the duration of successful communication between the master device and the slave device at the current data transmission frequency.

[0042] The frequency setting unit is used to set the data transmission frequency between the master device and the slave device based on the data transmission response result.

[0043] When the data transmission response result is a failure, the data transmission frequency between the master device and the slave device is reduced;

[0044] When the data transmission response is successful and the current transmission lifetime is greater than a preset lifetime limit, the data transmission frequency between the master device and the slave device is increased.

[0045] According to a fourth aspect, one embodiment provides an SPI bus communication device for a measuring instrument, including the SPI interface as described in the third aspect.

[0046] According to the SPI bus communication method of the above embodiments, since the data transmission frequency of the SPI bus is set by dynamically switching, the reliability and stability of the SPI communication can be maintained even under different operating environments or when the components are aging. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating the transmission frequency setting process in one embodiment.

[0048] Figure 2 This is a functional block diagram of a transmission frequency setting module in one embodiment;

[0049] Figure 3 This is a schematic diagram illustrating the parameter setting process for the transmission frequency in one embodiment. Detailed Implementation

[0050] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0051] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0052] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0053] Currently, the communication transmission rate of the SPI bus used in measuring instruments is a preset value (the factory default value), which remains unchanged after the measuring instrument is powered on. However, given the complex industrial environment and significant differences in device manufacturing processes, a single fixed transmission frequency (especially for measuring instruments) cannot avoid noise interference in the communication path. Furthermore, when connecting external devices with different equipment, environments, and varying degrees of device aging, a single fixed transmission frequency is even less able to guarantee communication efficiency and quality.

[0054] In this embodiment, the data transmission frequency of the SPI bus is set by dynamically switching, which can ensure that the measuring instrument maintains the reliability and stability of SPI communication under different usage environments or when components are aging.

[0055] Example 1:

[0056] In this embodiment, the measuring instrument uses an SPI interface as a communication interface. The SPI interface uses the SPI bus communication method for data communication. The SPI bus communication method includes a transmission frequency setting process to dynamically adjust the data transmission frequency between the master device and the slave device.

[0057] Please refer to Figure 1 This is a flowchart illustrating a transmission frequency setting process in one embodiment, which includes:

[0058] Step 101: Obtain the data transmission response result.

[0059] This document describes how to obtain the data transmission response results during data communication between a master and slave device on the SPI bus. In one embodiment, the CRC-8 algorithm is applied to obtain the data transmission response results. Each data frame sent by the transmitting end includes a CRC8 checksum. The receiving end recalculates the CRC for verification. If the verification is successful, the data transmission response result is considered successful; otherwise, it is considered unsuccessful. In one embodiment, after successful CRC verification, the slave device sends a success confirmation data to the master device to inform it that the data transmission response result is successful. For example, if the master device receives 4 bits of data 'b1010' from the slave device, it confirms success; if it receives 4 bits of data 'b1111', it confirms failure.

[0060] Step 102: Adjust the data transmission frequency.

[0061] Based on the data transmission response results, the data transmission frequency between the master and slave devices is set, specifically including:

[0062] When the data transmission response fails, reduce the set value of the data transmission frequency between the master device and the slave device.

[0063] When the data transmission response is successful, the transmission lifetime value for communication between the master and slave devices at the current data transmission frequency is obtained. The transmission lifetime is used to identify the duration of successful communication between the master and slave devices at the current data transmission frequency. In one embodiment, considering the communication idle time during actual communication (when the master and slave devices have no communication needs), the transmission lifetime is obtained based on the number of successful communication transactions between the master and slave devices at the current data transmission frequency.

[0064] In one embodiment, when the transmission lifetime exceeds a preset lifetime limit, the data transmission frequency between the master and slave devices is increased. When the master and slave devices perform their first data communication at the increased data transmission frequency, and the data transmission response result of the first data communication fails, the data transmission frequency before the increase is restored, and the transmission lifetime is reset or the lifetime limit is extended. In one embodiment, each time the lifetime limit is extended, the lifetime limit is increased exponentially.

[0065] In one embodiment, when the set value of the data transmission frequency for communication between the master device and the slave device is decreased or increased, the decreased or increased set value is a multiple of the current set value of the data transmission frequency. In one embodiment, when the master device and the slave device communicate for the first time, the set value of the data transmission frequency is set to a preset maximum or minimum value. In one embodiment, when the data transmission response result is successful, and the data transmission frequency for communication between the master device and the slave device is the preset maximum value, the current data transmission frequency for communication between the master device and the slave device is maintained.

[0066] Step 103: Set the data transmission frequency respectively.

[0067] When a master device communicates with different slave devices, a separate data transmission frequency is set for each. In practical applications, the hardware connection environments of the SPI interfaces between multiple slave devices and the master device differ (e.g., different levels of interference in hardware lines and different degrees of aging of slave device interface hardware). Therefore, in this embodiment, a separate data transmission frequency is set for each slave device to adapt to different slave devices. Traditional SPI interface connections involve one master device and multiple slave devices. The data transmission frequency of SPI interface communication is generally a preset fixed value, which limits the maximum communication rate of the SPI interface to the minimum of the maximum rates of each slave device. However, in one embodiment of this application, the data transmission frequency is set according to the transmission lifetime and lifetime limit of each slave device. The lifetime limit and current data transmission frequency of each slave device can be stored in a lookup table or latched in a register. This allows both the master device and each slave device to find and execute the maximum data transmission frequency of the current slave device.

[0068] Step 104: Feedback on fault information.

[0069] When the data transmission response result is a failure, and the data transmission frequency between the master device and the slave device is at the preset minimum value, the current master device and slave device are shut down and fault information is reported.

[0070] In one embodiment of this application, an SPI interface is also disclosed for applying the SPI bus communication method described above. The SPI interface includes a transmission frequency setting module for dynamically adjusting the data transmission frequency between the master device and the slave device.

[0071] Please refer to Figure 2 The diagram below illustrates the functional structure of a transmission frequency setting module in one embodiment. The transmission frequency setting module includes a response result acquisition unit 10, a lifetime acquisition unit 20, and a frequency setting unit 30. The response result acquisition unit 10 acquires the transmission data response result during data communication between the master and slave devices on the SPI bus. The lifetime acquisition unit 20 acquires the transmission lifetime, which indicates the duration of successful communication between the master and slave devices at the current data transmission frequency. The frequency setting unit 30 sets the data transmission frequency between the master and slave devices based on the transmission data response result. When the transmission data response result is a failure, the set value of the data transmission frequency between the master and slave devices is decreased. When the transmission data response result is a success and the current transmission lifetime is greater than a preset lifetime limit, the set value of the data transmission frequency between the master and slave devices is increased.

[0072] In one embodiment of this application, an SPI bus communication device for measuring instruments is also disclosed, including the SPI interface as described above.

[0073] To facilitate understanding of the application of the transmission frequency setting process in the embodiments of this application, a specific embodiment is described below, including:

[0074] Please refer to Figure 3 This is a schematic diagram of the parameter setting process for the transmission frequency in one embodiment, specifically including:

[0075] Step 201: Power on the SPI interface. The SPI bus communication device of the measuring instrument is powered on, initiating the transmission frequency setting process.

[0076] Step 202: Set initial parameters. Set the data transmission frequency of the SPI interface to the preset maximum value (and simultaneously set the corresponding maximum transmission lifetime) to initiate the first communication between the master and slave devices.

[0077] Step 203: Obtain the data response result. Apply the CRC-8 algorithm to verify the data communication. If the verification is successful, the data transmission response result is successful; if the verification fails, the data transmission response result is unsuccessful.

[0078] Step 204: Compare the lifetime limit. If the data response result indicates successful verification, determine whether the transmission lifetime is greater than the lifetime limit. If it is, increase the data transmission frequency. However, if the current data transmission frequency is already at its maximum value, the frequency increase operation is not performed.

[0079] Step 205, reduce frequency upon verification failure. The data response result is a set value for reducing the data transmission frequency when verification fails. In one embodiment, the data transmission frequency (Hz) is reduced sequentially in the order of 20M, 10M, 5M, 2M, 1M, 500K, 200K, and 100K.

[0080] Step 206: Modify the lifetime limit. When the master and slave devices perform their first data communication at the increased data transmission frequency, and the initial data communication response fails, the master and slave devices resume timing based on the transmission lifetime at the previous data transmission frequency, and the lifetime limit is extended exponentially. If the transmission lifetime at the current data transmission frequency is greater than the preset lifetime limit, the frequency is increased. If increasing the frequency fails, it reverts to the previous frequency and the lifetime limit is increased. If each frequency increase fails, both the transmission lifetime and the lifetime limit will continuously increase. The lifetime limit is set to increase exponentially by 2. If increasing the frequency fails and reverts to the current frequency, the lifetime limit is increased again to prevent excessively high frequency increases. However, if the response at the current frequency is incorrect, the lifetime limit is reset to the initial preset value. The main purpose of this setting is to extend the dwell time at the most suitable maximum frequency without affecting the continued upward adjustment of the frequency in this segment. For example: The current frequency is 5MHz, and the lifetime limit at this frequency is 2 seconds. If the transmission lifetime exceeds 2 seconds, the frequency is increased to 10MHz. However, the first communication fails after increasing the frequency, so it is necessary to return to the 5MHz frequency for data communication. At this time, the lifetime limit is increased to 4 seconds. If communication also fails at the 5MHz frequency, the frequency is immediately reduced to 1MHz, and the lifetime limit at 5MHz is reset to the preset 2 seconds.

[0081] Step 207: Shut down the device and report an error. If the data transmission frequency drops to the preset minimum value and the data response result is still a verification failure, then shut down the device and report an error message.

[0082] The parameter setting process in the above embodiments can dynamically set the transmission rate of the SPI interface, and applies the transmission lifetime and exponentially increasing lifetime algorithm, which can ensure that the SPI interface transmits at the highest possible frequency, and also ensure that the duration of the SPI interface at the current appropriate transmission frequency is continuously extended, thereby reducing the frequency switching process.

[0083] The SPI bus communication method disclosed in this application includes a transmission frequency setting process. First, the transmission data response result during data communication between the master and slave devices on the SPI bus is obtained. Then, the data transmission frequency between the master and slave devices is set based on the transmission data response result. If the transmission data response result is a failure, the set value of the data transmission frequency between the master and slave devices is reduced. Because the data transmission frequency of the SPI bus is set using a dynamic switching method, the reliability and stability of SPI communication can be maintained even under different operating environments or when components are aging.

[0084] Those skilled in the art will understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer programs, the program can also be stored in a server, another computer, disk, optical disk, flash drive, or external hard drive, etc., and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0085] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A method for SPI bus communication of a measuring instrument, characterized in that, The transmission frequency setting process comprises a transmission frequency setting process for dynamically adjusting the data transmission frequency of the communication between the master device and the slave device; The transmission frequency setting process comprises: Obtaining the transmission data response result in the data communication process between the master device and the slave device on the SPI bus, and setting the data transmission frequency of the communication between the master device and the slave device according to the transmission data response result; When the transmission data response result is failure, reducing the data transmission frequency of the communication between the master device and the slave device; When the transmission data response result is success, obtaining the transmission survival time of the communication between the master device and the slave device under the current data transmission frequency; wherein the transmission survival time is used to identify the duration of the successful communication between the master device and the slave device under the current data transmission frequency; When the transmission survival time is greater than a preset survival limit time, increasing the data transmission frequency of the communication between the master device and the slave device; When the master device and the slave device perform the first data communication at the increased data transmission frequency, and the transmission data response result of the first data communication is failure, restoring the data transmission frequency of the master device and the slave device before the increase, and resetting the transmission survival time and / or prolonging the survival limit time; The transmission frequency setting process further comprises: When the master device communicates with different slave devices, respectively setting the data transmission frequency; When the master device and the slave device perform the first data communication at the increased data transmission frequency, and the transmission data response result of the first data communication is success, the master device and the slave device perform data communication at the increased data transmission frequency, and reset the transmission survival time.

2. The SPI bus communication method of claim 1, wherein, The transmission frequency setting process further comprises: When the master device and the slave device perform the first communication, setting the setting value of the data transmission frequency as a preset maximum value; When the transmission data response result is success, and the data transmission frequency of the communication between the master device and the slave device is the preset maximum value, maintaining the current data transmission frequency of the communication between the master device and the slave device; When the transmission data response result is failure, and the data transmission frequency of the communication between the master device and the slave device is the preset minimum value, shutting down the current master device and slave device and feeding back the failure information.

3. The SPI bus communication method of claim 1, wherein, The method for obtaining the transmission survival time comprises: Obtaining the transmission survival time according to the number of successes of the communication between the master device and the slave device under the current data transmission frequency; The method for prolonging the survival limit time comprises: Each time the survival limit time is prolonged, the survival limit time is increased by an exponential factor.

4. The SPI bus communication method of claim 1, wherein, The method for obtaining the transmission data response result in the data communication process between the master device and the slave device on the SPI bus comprises: Applying the CRC algorithm to obtain the transmission data response result.

5. A computer readable storage medium, characterized in that, The medium stores a computer program, and the computer program can be executed by the processor to implement the SPI bus communication method according to any one of claims 1-4.

6. An SPI interface, characterized in that The transmission frequency setting module is configured to dynamically adjust the data transmission frequency of the communication between the master device and the slave device. The transmission frequency setting module comprises a response result acquisition unit, a survival time acquisition unit and a frequency setting unit. The response result acquisition unit is configured to acquire a transmission data response result in the data communication process between the master device and the slave device on the SPI bus. The survival time acquisition unit is configured to acquire a transmission survival time, which is used to identify the duration of successful communication between the master device and the slave device at the current data transmission frequency. The frequency setting unit is configured to set the data transmission frequency of the communication between the master device and the slave device according to the transmission data response result. When the transmission data response result is failure, the data transmission frequency of the communication between the master device and the slave device is reduced. When the transmission data response result is success and the current transmission survival time is greater than a preset survival limit time, the data transmission frequency of the communication between the master device and the slave device is increased. When the master device and the slave device perform the first data communication at the increased data transmission frequency, and the transmission data response result of the first data communication is failure, the data transmission frequency of the master device and the slave device before the increase is restored, and the transmission survival time is reset and / or the survival limit time is extended. When the master device communicates with different slave devices, the data transmission frequency is set respectively. When the master device and the slave device perform the first data communication at the increased data transmission frequency, and the transmission data response result of the first data communication is success, the master device and the slave device perform data communication at the increased data transmission frequency, and the transmission survival time is reset.

7. An SPI bus communication device for a measuring instrument, characterized in that The SPI interface as claimed in claim 6 is provided.

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