A high-precision LIN communication automatic baud rate matching circuit and matching method

Abstract

The invention discloses a high-precision LIN communication automatic baud rate matching circuit and matching method, comprising an adaptive filter module, a dynamic baud rate correction module, a controller, a temperature compensation module and a voltage monitoring module, wherein the input end of the adaptive filter module is connected to the RX signal of LIN_IN, the output end of the adaptive filter module is connected to the input end of the dynamic baud rate correction module, the output end of the dynamic baud rate correction module is connected to a data transmitter, the adaptive filter module, the dynamic baud rate correction module, the temperature compensation module and the voltage monitoring module are all connected to the controller and controlled by the controller, and the output ends of the temperature compensation module and the voltage monitoring module are connected to the baud rate controller. The invention uses a dynamic adjustment mechanism of the baud rate to maintain high-precision baud rate matching under different working environments.

Description

Technical Field

[0001] The invention relates to a baud rate matching circuit and a matching method, in particular to a high-precision LIN communication automatic baud rate matching circuit and a matching method, belonging to the technical field of semiconductor integrated circuits. Background Art

[0002] As a low-cost serial communication network, LIN bus is widely used in data exchange between sensors and control units inside automobiles. The master node is responsible for sending synchronization signals and command frames, and the slave node responds to data frames. To ensure the accuracy and reliability of communication, accurate baud rate matching is essential. The existing LIN communication baud rate matching method is affected by factors such as hardware clock drift, temperature changes, and power supply voltage fluctuations, which may cause baud rate deviation and affect communication quality. Therefore, it is of great practical significance to design a circuit to improve the accuracy of automatic baud rate matching in LIN communication. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-precision LIN communication automatic baud rate matching circuit and matching method, which can maintain high-precision baud rate matching under different working environments through a dynamic adjustment mechanism.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A high-precision LIN communication automatic baud rate matching circuit comprises an adaptive filter module, a dynamic baud rate correction module, a controller, a temperature compensation module and a voltage monitoring module, wherein the input end of the adaptive filter module is connected to the RX signal of LIN_IN, the output end of the adaptive filter module is connected to the input end of the dynamic baud rate correction module, the output end of the dynamic baud rate correction module is connected to a data transmitter, the adaptive filter module, the dynamic baud rate correction module, the temperature compensation module and the voltage monitoring module are all connected to the controller and controlled by the controller, and the output ends of the temperature compensation module and the voltage monitoring module are connected to the baud rate controller.

[0006] Furthermore, the adaptive filter module includes a signal acquisition module, a filter parameter adjustment module and a filter output module. The signal acquisition module is used to collect the RX signal of LIN_IN. The filter parameter adjustment module dynamically adjusts the filter parameters based on the quality of the RX signal to adapt to different communication environments. The filter output module provides a filtered RX signal according to the filter parameters provided by the filter parameter adjustment module.

[0007] Furthermore, the dynamic baud rate correction module includes an adaptive baud rate operation unit and a baud rate controller. The adaptive baud rate operation unit monitors the signal changes in the LIN communication link in real time, and calculates the baud rate of the new frame signal in real time based on the frame header agreed in the protocol. The baud rate controller dynamically adjusts the baud rate of the data transmitter according to the baud rate of the new frame signal provided by the adaptive baud rate operation unit.

[0008] Furthermore, the temperature compensation module includes a temperature monitoring module, a temperature clock drift model and a first clock adjustment unit. The temperature monitoring module continuously monitors the ambient temperature. The temperature clock drift model calculates the temperature compensation coefficient of the clock frequency based on real-time temperature data. The first clock adjustment unit dynamically adjusts the baud rate of the baud rate controller in the dynamic baud rate correction module according to the temperature compensation coefficient calculated by the temperature clock drift model.

[0009] Furthermore, the voltage monitoring module includes a power monitoring module, a voltage clock drift model and a second clock adjustment unit. The power monitoring module monitors the power supply voltage in real time. The voltage clock drift model calculates the voltage compensation coefficient of the clock frequency according to the real-time power supply voltage. The second clock adjustment unit dynamically adjusts the baud rate of the baud rate controller in the dynamic baud rate correction module according to the voltage compensation coefficient calculated by the voltage clock drift model.

[0010] A matching method for a high-precision LIN communication automatic baud rate matching circuit comprises the following steps:

[0011] The adaptive baud rate module collects the RX signal of LIN_IN and filters it and outputs it to the dynamic baud rate correction module. The dynamic baud rate correction module analyzes the baud rate in the RX signal and calculates the new baud rate Bd1;

[0012] The temperature compensation module collects the ambient temperature in real time, calculates the temperature compensation coefficient Tc of the clock frequency according to the real-time temperature data, and transmits the temperature compensation coefficient Tc to the dynamic baud rate correction module;

[0013] The voltage detection module monitors the power supply voltage in real time, calculates the voltage compensation coefficient Tv of the clock frequency according to the real-time power supply voltage, and transmits the voltage compensation coefficient Tv to the dynamic baud rate correction module;

[0014] The dynamic baud rate correction module calculates the corrected baud rate BD2 = Tc*Tv*Bd1 according to the new baud rate Bd1, the temperature compensation coefficient Tc and the voltage compensation coefficient Tv, and completes the automatic baud rate matching.

[0015] Furthermore, the calculation process of the temperature compensation coefficient Tc is:

[0016] Collect multiple sets of clock frequency f data corresponding to different temperatures T, and then use a computer program to obtain a fitting formula for the relationship between temperature T and clock frequency f based on the collected multiple sets of temperature T and its corresponding clock frequency f data:

[0017] f=fa*[1-k1*(T-Ta) 2 ];

[0018] Where Ta is the temperature at the last baud rate match, fa is the frequency value corresponding to temperature Ta, and k1 is a constant;

[0019] Then the temperature compensation coefficient Tc=f / fa=1-k1*(T-Ta) 2 .

[0020] Furthermore, the calculation process of the voltage compensation coefficient Tv is:

[0021] Collect multiple sets of clock frequency f data corresponding to different voltages V, and then use a computer program to obtain a fitting formula for the relationship between voltage V and clock frequency f based on the collected multiple sets of voltage V and its corresponding clock frequency f data:

[0022] f=k2*V+fb;

[0023] Where k2 is a constant, and fb is the frequency value corresponding to the voltage V being 0V;

[0024] Assume that the voltage at the last baud rate match is V1, the current voltage is V2, the clock frequency corresponding to voltage V1 is f1, and the clock frequency corresponding to voltage V2 is f2.

[0025] f2-f1=k2*(V2-V1);

[0026] Then we get f2= k2*(V2-V1)+f1;

[0027] Then the voltage compensation coefficient Tv=f2 / f1= k2*(V2-V1) / f1+1.

[0028] Compared with the prior art, the present invention has the following advantages and effects: the present invention provides a high-precision LIN communication automatic baud rate matching circuit and matching method, and compensates for the baud rate error caused by temperature and voltage changes through a dynamic baud rate adjustment mechanism, thereby maintaining high-precision baud rate matching under different working environments; the present invention significantly improves the baud rate matching accuracy of LIN communication, reduces communication errors caused by hardware clock drift, temperature changes and power supply voltage fluctuations, enhances the system's anti-interference ability and stability, and maintains good communication performance; and the present invention simplifies the system debugging process, reduces the need for manual intervention, and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a schematic diagram of a high-precision LIN communication automatic baud rate matching circuit. DETAILED DESCRIPTION

[0030] In order to elaborate on the technical scheme adopted by the present invention to achieve the predetermined technical purpose, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without paying creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0031] like Figure 1 As shown, a high-precision LIN communication automatic baud rate matching circuit of the present invention comprises an adaptive filter module, a dynamic baud rate correction module, a controller, a temperature compensation module and a voltage monitoring module, the input end of the adaptive filter module is connected to the RX signal of LIN_IN, the output end of the adaptive filter module is connected to the input end of the dynamic baud rate correction module, the output end of the dynamic baud rate correction module is connected to the data transmitter, the adaptive filter module, the dynamic baud rate correction module, the temperature compensation module and the voltage monitoring module are all connected to the controller and controlled by the controller, and the output ends of the temperature compensation module and the voltage monitoring module are connected to the baud rate controller.

[0032] The adaptive filter module includes a signal acquisition module, a filter parameter adjustment module and a filter output module. The signal acquisition module is used to collect the RX signal of LIN_IN. The filter parameter adjustment module dynamically adjusts the filter parameters based on the quality of the RX signal to adapt to different communication environments. The filter output module provides a filtered RX signal according to the filter parameters provided by the filter parameter adjustment module.

[0033] The dynamic baud rate correction module includes an adaptive baud rate operation unit and a baud rate controller. The adaptive baud rate operation unit monitors the signal changes in the LIN communication link in real time, and calculates the baud rate of the new frame signal in real time based on the frame header agreed in the protocol. The baud rate controller dynamically adjusts the baud rate of the data transmitter according to the baud rate of the new frame signal provided by the adaptive baud rate operation unit.

[0034] The temperature compensation module includes a temperature monitoring module, a temperature clock drift model and a first clock adjustment unit. The temperature monitoring module continuously monitors the ambient temperature. The temperature clock drift model calculates the temperature compensation coefficient of the clock frequency based on real-time temperature data. The first clock adjustment unit dynamically adjusts the baud rate of the baud rate controller in the dynamic baud rate correction module according to the temperature compensation coefficient calculated by the temperature clock drift model.

[0035] The voltage monitoring module includes a power monitoring module, a voltage clock drift model and a second clock adjustment unit. The power monitoring module monitors the power supply voltage in real time. The voltage clock drift model calculates the voltage compensation coefficient of the clock frequency according to the real-time power supply voltage. The second clock adjustment unit dynamically adjusts the baud rate of the baud rate controller in the dynamic baud rate correction module according to the voltage compensation coefficient calculated by the voltage clock drift model.

[0036] A matching method for a high-precision LIN communication automatic baud rate matching circuit comprises the following steps:

[0037] The adaptive baud rate module collects the RX signal of LIN_IN and filters it and outputs it to the dynamic baud rate correction module. The dynamic baud rate correction module analyzes the baud rate in the RX signal and calculates the new baud rate Bd1.

[0038] The temperature compensation module collects the ambient temperature in real time, calculates the temperature compensation coefficient Tc of the clock frequency according to the real-time temperature data, and transmits the temperature compensation coefficient Tc to the dynamic baud rate correction module.

[0039] The voltage detection module monitors the power supply voltage in real time, calculates the voltage compensation coefficient Tv of the clock frequency according to the real-time power supply voltage, and transmits the voltage compensation coefficient Tv to the dynamic baud rate correction module.

[0040] The dynamic baud rate correction module calculates the corrected baud rate BD2 = Tc*Tv*Bd1 according to the new baud rate Bd1, the temperature compensation coefficient Tc and the voltage compensation coefficient Tv, and completes the automatic baud rate matching.

[0041] The calculation process of temperature compensation coefficient Tc is:

[0042] Collect multiple sets of clock frequency f data corresponding to different temperatures T, and then use a computer program to obtain a fitting formula for the relationship between temperature T and clock frequency f based on the collected multiple sets of temperature T and its corresponding clock frequency f data:

[0043] f=fa*[1-k1*(T-Ta) 2 ];

[0044] Where Ta is the temperature at the last baud rate match, fa is the frequency value corresponding to temperature Ta, and k1 is a constant;

[0045] Then the temperature compensation coefficient Tc=f / fa=1-k1*(T-Ta) 2 .

[0046] The calculation process of the voltage compensation coefficient Tv is:

[0047] Collect multiple sets of clock frequency f data corresponding to different voltages V, and then use a computer program to obtain a fitting formula for the relationship between voltage V and clock frequency f based on the collected multiple sets of voltage V and its corresponding clock frequency f data:

[0048] f=k2*V+fb;

[0049] Where k2 is a constant, and fb is the frequency value corresponding to the voltage V being 0V;

[0050] Assume that the voltage at the last baud rate match is V1, the current voltage is V2, the clock frequency corresponding to voltage V1 is f1, and the clock frequency corresponding to voltage V2 is f2.

[0051] f2-f1=k2*(V2-V1);

[0052] Then we get f2= k2*(V2-V1)+f1;

[0053] Then the voltage compensation coefficient Tv=f2 / f1= k2*(V2-V1) / f1+1.

[0054] The present invention provides a high-precision LIN communication automatic baud rate matching circuit and matching method. Through a dynamic baud rate adjustment mechanism, the baud rate error caused by temperature and voltage changes is compensated, thereby maintaining high-precision baud rate matching under different working environments; the present invention significantly improves the baud rate matching accuracy of LIN communication, reduces communication errors caused by hardware clock drift, temperature changes and power supply voltage fluctuations, enhances the system's anti-interference ability and stability, and maintains good communication performance; and the present invention simplifies the system debugging process, reduces the need for manual intervention, and reduces maintenance costs.

[0055] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A high-precision LIN communication automatic baud rate matching circuit, characterized in that: It comprises an adaptive filter module, a dynamic baud rate correction module, a controller, a temperature compensation module and a voltage monitoring module, wherein the input end of the adaptive filter module is connected to the RX signal of LIN_IN, the output end of the adaptive filter module is connected to the input end of the dynamic baud rate correction module, the output end of the dynamic baud rate correction module is connected to the data transmitter, the adaptive filter module, the dynamic baud rate correction module, the temperature compensation module and the voltage monitoring module are all connected to the controller and controlled by the controller, and the output ends of the temperature compensation module and the voltage monitoring module are connected to the baud rate controller in the dynamic baud rate correction module; The voltage monitoring module includes a power monitoring module, a voltage clock drift model and a second clock adjustment unit. The power monitoring module monitors the power supply voltage in real time. The voltage clock drift model calculates the voltage compensation coefficient of the clock frequency according to the real-time power supply voltage. The second clock adjustment unit dynamically adjusts the baud rate of the baud rate controller in the dynamic baud rate correction module according to the voltage compensation coefficient calculated by the voltage clock drift model.

2. A high-precision LIN communication automatic baud rate matching circuit according to claim 1, characterized in that: The adaptive filter module includes a signal acquisition module, a filter parameter adjustment module and a filter output module. The signal acquisition module is used to collect the RX signal of LIN_IN. The filter parameter adjustment module dynamically adjusts the filter parameters based on the quality of the RX signal to adapt to different communication environments. The filter output module provides a filtered RX signal according to the filter parameters provided by the filter parameter adjustment module.

3. A high-precision LIN communication automatic baud rate matching circuit according to claim 1, characterized in that: The dynamic baud rate correction module includes an adaptive baud rate operation unit and a baud rate controller. The adaptive baud rate operation unit monitors the signal changes in the LIN communication link in real time and calculates the baud rate of the new frame signal in real time based on the frame header agreed in the protocol. The baud rate controller dynamically adjusts the baud rate of the data transmitter according to the baud rate of the new frame signal provided by the adaptive baud rate operation unit.

4. A high-precision LIN communication automatic baud rate matching circuit according to claim 1, characterized in that: The temperature compensation module includes a temperature monitoring module, a temperature clock drift model and a first clock adjustment unit. The temperature monitoring module continuously monitors the ambient temperature. The temperature clock drift model calculates the temperature compensation coefficient of the clock frequency based on real-time temperature data. The first clock adjustment unit dynamically adjusts the baud rate of the baud rate controller in the dynamic baud rate correction module according to the temperature compensation coefficient calculated by the temperature clock drift model.

5. A matching method for a high-precision LIN communication automatic baud rate matching circuit according to any one of claims 1 to 4, characterized in that The following steps are involved: The adaptive baud rate module collects the RX signal of LIN_IN and filters it and outputs it to the dynamic baud rate correction module. The dynamic baud rate correction module analyzes the baud rate in the RX signal and calculates the new baud rate Bd1; The temperature compensation module collects the ambient temperature in real time, calculates the temperature compensation coefficient Tc of the clock frequency according to the real-time temperature data, and transmits the temperature compensation coefficient Tc to the dynamic baud rate correction module; The voltage detection module monitors the power supply voltage in real time, calculates the voltage compensation coefficient Tv of the clock frequency according to the real-time power supply voltage, and transmits the voltage compensation coefficient Tv to the dynamic baud rate correction module; The dynamic baud rate correction module calculates the corrected baud rate BD2 = Tc*Tv*Bd1 according to the new baud rate Bd1, the temperature compensation coefficient Tc and the voltage compensation coefficient Tv, and completes the automatic baud rate matching.

6. The matching method according to claim 5, characterized in that: The calculation process of the temperature compensation coefficient Tc is: Collect multiple sets of clock frequency f data corresponding to different temperatures T, and then use a computer program to obtain a fitting formula for the relationship between temperature T and clock frequency f based on the collected multiple sets of temperature T and its corresponding clock frequency f data: f=fa*[1-k1*(T-Ta) 2 ]; Where Ta is the temperature at the last baud rate match, fa is the frequency value corresponding to temperature Ta, and k1 is a constant; Then the temperature compensation coefficient Tc=f / fa=1-k1*(T-Ta) 2 .

7. The matching method according to claim 5, characterized in that: The calculation process of the voltage compensation coefficient Tv is: Collect multiple sets of clock frequency f data corresponding to different voltages V, and then use a computer program to obtain a fitting formula for the relationship between voltage V and clock frequency f based on the collected multiple sets of voltage V and its corresponding clock frequency f data: f=k2*V+fb; Where k2 is a constant, and fb is the frequency value corresponding to the voltage V being 0V; Assume that the voltage at the last baud rate match is V1, the current voltage is V2, the clock frequency corresponding to voltage V1 is f1, and the clock frequency corresponding to voltage V2 is f2. f2-f1=k2*(V2-V1); Then we get f2= k2*(V2-V1)+f1; Then the voltage compensation coefficient Tv=f2 / f1= k2*(V2-V1) / f1+1.

Images