CN116938195A - Clock synchronization and self-adaptive switching circuit and method, and clock circuit - Google Patents

Clock synchronization and self-adaptive switching circuit and method, and clock circuit Download PDF

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Publication number
CN116938195A
CN116938195A CN202310970276.1A CN202310970276A CN116938195A CN 116938195 A CN116938195 A CN 116938195A CN 202310970276 A CN202310970276 A CN 202310970276A CN 116938195 A CN116938195 A CN 116938195A
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voltage
signal
crystal oscillator
control
controlled crystal
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Inventor
戴怡飞
吴光勋
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Chongqing Changan Automobile Co Ltd
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Chongqing Changan Automobile Co Ltd
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Priority to CN202310970276.1A priority Critical patent/CN116938195A/en
Publication of CN116938195A publication Critical patent/CN116938195A/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/353—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of field-effect transistors with internal or external positive feedback
    • H03K3/356—Bistable circuits
    • H03K3/356069—Bistable circuits using additional transistors in the feedback circuit
    • H03K3/356078—Bistable circuits using additional transistors in the feedback circuit with synchronous operation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
    • G06F1/04—Generating or distributing clock signals or signals derived directly therefrom
    • G06F1/12—Synchronisation of different clock signals provided by a plurality of clock generators

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Oscillators With Electromechanical Resonators (AREA)

Abstract

The invention relates to the technical field of clock synchronization, and discloses a clock synchronization and self-adaptive switching circuit and method, and a clock circuit, wherein the clock circuit comprises the following components: the control module obtains a first voltage signal based on the control signal and a feedback signal of the voltage-controlled crystal oscillator, wherein the first voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator in an automatic operation mode; the resistance adjusting module is used for outputting a second voltage signal after adjusting the resistance value based on the adjusting signal, wherein the second voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator in a manual operation mode; the control module is used for transmitting the first voltage signal or the second voltage signal to the voltage-controlled crystal oscillator by controlling the on-off state of the switch module according to the preset priority. The control module of the invention realizes the switching between the automatic mode and the manual mode according to the preset priority, thereby solving the problem that the clock is required to be manually switched when the external input is changed in the prior art.

Description

Clock synchronization and self-adaptive switching circuit and method, and clock circuit
Technical Field
The invention relates to the technical field of clock synchronization, in particular to a clock synchronization and self-adaptive switching circuit and method and a clock circuit.
Background
In contemporary electronic systems, the system interior is made up of a plurality of sub-modules, typically with independent internal clock circuits within the sub-modules. When they are combined to form a system, a unified external clock is required for synchronization, so that the clock synchronization circuit almost forms a necessary part of each sub-module of the electronic system.
The clock synchronization technology commonly used at present is usually implemented by a separate chip, for example, a phase-locked loop is combined with a crystal oscillator to implement crystal oscillator taming, or an external input clock is directly selected as a module local clock through a radio frequency switch. When external input is changed, a clock is required to be manually switched, or an additional amplifier and triode detection circuit are added to realize automatic switching, so that the cost and the power consumption are additionally increased, and the miniaturization development of the system is not facilitated.
Disclosure of Invention
One of the purposes of the present invention is to provide a clock synchronization and adaptive switching circuit, so as to solve the problem in the prior art that when external input changes, a clock needs to be manually switched; the second objective is to provide a clock synchronization and adaptive switching method; a third object is to provide a clock circuit.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a clock synchronization and adaptive switching circuit, comprising: the device comprises a switch module, a resistance adjusting module and a control module, wherein the input end of the control module is input with various control signals, the input end of the control module is also connected with the output end of the voltage-controlled crystal oscillator, the first output end of the control module is connected with the first input end of the switch module, the second output end of the control module is connected with the control end of the switch module, the control module is used for obtaining a first voltage signal based on the control signals and feedback signals of the voltage-controlled crystal oscillator, and the first voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator in an automatic operation mode; the second input end of the switch module is connected with the output end of the resistance adjusting module, and the output end of the switch module is connected with the input end of the voltage-controlled crystal oscillator; the input end of the resistance adjusting module is input with an adjusting signal, and the resistance adjusting module is used for outputting a second voltage signal after adjusting the resistance value based on the adjusting signal, wherein the second voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator in a manual operation mode; the control module is used for transmitting the first voltage signal or the second voltage signal to the voltage-controlled crystal oscillator by controlling the on-off state of the switch module according to the preset priority.
According to the technical means, the control module of the invention realizes the switching between the automatic mode and the manual mode according to the preset priority, and the control module can detect whether external input exists or not through an internal algorithm, and can be adaptively switched to other modes for control when no external input signal exists, and the priority of each synchronizing signal can be customized in a program according to the actual application.
Further, the switch module includes: the first input end of the analog switch is connected with the first output end of the control module, the second input end of the analog switch is connected with the output end of the resistance adjusting module, the output end of the analog switch is connected with the input end of the voltage-controlled crystal oscillator, and the control end of the analog switch is connected with the second output end of the control module.
Further, the control module includes: the device comprises a programmable controller and a digital-to-analog converter, wherein the input end of the programmable controller is input with various control signals, the input end of the programmable controller is also connected with the output end of a voltage-controlled crystal oscillator, the first output end of the programmable controller is connected with the input end of the digital-to-analog converter, the second output end of the programmable controller is connected with the control end of a switch module, and the programmable controller is used for obtaining a first digital voltage signal based on the control signals; according to the preset priority, the on-off state of the switch module is controlled so that the first voltage signal or the second voltage signal is transmitted to the voltage-controlled crystal oscillator; the output end of the digital-to-analog converter is connected with the first input end of the switch module and is used for converting the first digital voltage signal into a first voltage signal.
According to the technical means, under the condition that only two devices of a digital-to-analog converter and an analog switch are added, multiple signal synchronization and self-adaptive switching functions are realized, the adaptability of a circuit is increased, the circuit functions are enriched, and the circuit cost is simplified.
Further, the resistance adjustment module includes: the first voltage dividing resistor, the second voltage dividing resistor and the potentiometer, wherein the first end of the potentiometer is connected with an external power supply through the first voltage dividing resistor, the second end of the potentiometer is grounded through the second voltage dividing resistor, the third end of the potentiometer outputs a second voltage signal, and the resistance value of the potentiometer is changed due to the rotation of the external knob.
A clock synchronization and self-adaptive switching method includes: judging whether a control signal is input or not in real time; when at least one control signal is input, according to a preset priority, a first voltage signal is obtained based on the control signal and a feedback signal of the voltage-controlled crystal oscillator; and controlling the first voltage signal to be transmitted to the voltage-controlled crystal oscillator.
Further, the clock synchronization and self-adaptive switching method further comprises the following steps: when no control signal is input, the second voltage signal is controlled to be transmitted to the voltage-controlled crystal oscillator.
Further, when the control signal is a second pulse input signal or an external clock input signal, a process of obtaining the first voltage signal includes: dividing the frequency of the feedback signal of the voltage-controlled crystal oscillator to obtain a frequency-divided signal of the feedback signal; comparing the second pulse input signal or the external clock input signal with the feedback signal frequency division signal; filtering the comparison result to obtain a first voltage digital signal; and D, performing digital-to-analog conversion on the first voltage digital signal to obtain a first voltage signal.
Further, when the control signal is an external control input signal, the external control input signal including a frequency control word, the process of obtaining the first voltage signal includes: comparing the frequency control word with a reference frequency control word; based on the comparison result, a first voltage digital signal is obtained; and D, performing digital-to-analog conversion on the first voltage digital signal to obtain a first voltage signal.
According to the technology, the invention supports a plurality of synchronous modes, and can simultaneously support knob adjustment, second pulse synchronization, clock synchronization and control instruction adjustment.
Further, when a plurality of control signals are input, according to a preset priority, a process of obtaining a first voltage signal based on the control signals and feedback signals of the voltage-controlled crystal oscillator includes: according to the preset priority, a first voltage signal is obtained based on a control signal with the highest priority and a feedback signal of the voltage-controlled crystal oscillator; or when the mode switching signal is received, obtaining a first voltage signal based on a control signal corresponding to the mode to be switched and a feedback signal of the voltage-controlled crystal oscillator.
A clock circuit, comprising: the device comprises a clock synchronization and self-adaption switching circuit and a voltage-controlled crystal oscillator, wherein the output end of the clock synchronization and self-adaption switching circuit is connected with the input end of the voltage-controlled crystal oscillator; the clock synchronization and self-adaptive switching circuit controls the output frequency of the crystal oscillator by the method of the embodiment.
The beneficial effects of the invention are as follows:
(1) The control module obtains a first voltage signal based on the control signal and a feedback signal of the voltage-controlled crystal oscillator, wherein the first voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator in an automatic operation mode; the resistance adjusting module is used for outputting a second voltage signal after adjusting the resistance value based on the adjusting signal, wherein the second voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator in a manual operation mode; the control module is used for transmitting the first voltage signal or the second voltage signal to the voltage-controlled crystal oscillator by controlling the on-off state of the switch module according to the preset priority. The control module of the invention realizes the switching between the automatic mode and the manual mode according to the preset priority, thereby solving the problem that the clock is required to be manually switched when the external input is changed in the prior art.
(2) The programmable controller is an inherent device in the system, is not additionally added, the voltage-controlled crystal oscillator is a necessary device for clock generation, the potentiometer is a necessary device for knob adjusting function, and under the condition that only two devices of a digital-analog converter and an analog switch are added, the synchronous and self-adaptive switching functions of various signals are realized, the adaptability of a circuit is increased, the circuit function is enriched, and the circuit cost is simplified.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a block diagram of a clock synchronization and adaptive switching circuit according to the present invention;
FIG. 2 is a block diagram of another clock synchronization and adaptive switching circuit according to the present invention;
FIG. 3 is a block diagram of a clock synchronization and adaptive switching circuit according to another embodiment of the present invention;
FIG. 4 is a block diagram of a clock synchronization and adaptive switching circuit according to another embodiment of the present invention;
FIG. 5 is a flow chart of a clock synchronization and adaptive switching method of the present invention;
fig. 6 is a block diagram of the clock circuit of the present invention.
Wherein, 1-clock synchronization and self-adaptive switching circuit; 2-voltage-controlled crystal oscillator; 11-a switch module; 12-a resistance adjustment module; 13-a control module; 111-analog switch; 131-a programmable controller; 132-digital-to-analog converter; r1 is a first voltage dividing resistor; r2 is a second voltage dividing resistor; w1-a potentiometer; VCC-external power supply.
Detailed Description
Further advantages and effects of the present invention will become readily apparent to those skilled in the art from the disclosure herein, by referring to the accompanying drawings and the preferred embodiments. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be understood that the preferred embodiments are presented by way of illustration only and not by way of limitation.
It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.
The present embodiment provides a clock synchronization and adaptive switching circuit, as shown in fig. 1, including: a switch module 11, a resistance adjusting module 12 and a control module 13.
As shown in fig. 1, the control module 13 has an input end for inputting various control signals, an input end connected to the output end of the voltage-controlled crystal oscillator 2, a first output end connected to the first input end of the switch module 11, and a second output end connected to the control end of the switch module 11, and is configured to obtain a first voltage signal based on the control signal and a feedback signal of the voltage-controlled crystal oscillator 2, where the first voltage signal is used to control the output frequency of the voltage-controlled crystal oscillator 2.
Specifically, the various control signals of the present embodiment may include a pulse-per-second input signal, an external clock input signal, an external control input signal, and the like. The control module 13 selects different automatic operation modes according to the type of the control signal, and based on the feedback signal of the voltage-controlled crystal oscillator 2, adopts a closed-loop control method, and synchronizes the output frequency of the voltage-controlled crystal oscillator 2 with the control signal by adjusting the parameter of the first voltage signal.
Specifically, the automatic operation modes of the control module 13 include: second pulse mode, external clock mode, external control mode, etc., when a plurality of control signals are input, based on preset priority, select corresponding mode, adjust first voltage signal. For example: if the second pulse mode is the highest level and the control module 13 receives the second pulse input signal, the external clock input signal and the external control input signal at the same time, the control module 13 switches to the second pulse mode, and obtains the first voltage signal based on the second pulse input signal and the feedback signal of the voltage-controlled crystal oscillator 2.
As shown in fig. 1, the resistor adjusting module 12 has an input terminal for inputting an adjusting signal, and is configured to output a second voltage signal after adjusting the resistance value based on the adjusting signal, where the second voltage signal is configured to control the output frequency of the voltage-controlled crystal oscillator 2.
Specifically, the present embodiment also sets the manual operation mode, and the user manually inputs an adjustment signal to the resistance adjustment module 12, the adjustment signal causing the resistance value of the resistance adjustment module 12 to be changed, thereby causing the parameter of the second voltage signal to be changed.
As shown in fig. 1, the second input end of the switch module 11 is connected with the output end of the resistance adjusting module 12, and the output end of the switch module is connected with the input end of the voltage-controlled crystal oscillator 2. When the control signal is changed, the control module 13 controls the on-off state of the switch module 11 according to the preset priority, so that the first voltage signal or the second voltage signal is transmitted to the voltage-controlled crystal oscillator 2.
Specifically, the switch module 11 in this embodiment is actually a gating switch, and since the clock synchronization and adaptive switching circuit in this embodiment has an automatic operation mode and a manual operation mode, when a control signal is input, the control module 13 switches to the automatic operation mode, and by controlling the operation state of the switch module 11, the control module 13 is connected to the voltage-controlled crystal oscillator 2, so that only the first voltage signal is transmitted as the voltage-controlled signal to the voltage-controlled crystal oscillator 2; when no control signal is input, the control module 13 is switched to a manual operation mode, and the resistance adjustment module 12 is connected with the voltage-controlled crystal oscillator 2 by controlling the operation state of the switch module 11, so that only the second voltage signal is transmitted as the voltage-controlled signal to the voltage-controlled crystal oscillator 2.
It should be noted that, the priority levels of the automatic operation module and the manual operation mode and the priority levels of the various control signals in the present embodiment may be set as required, which is not limited herein.
In this embodiment, after the voltage-controlled crystal oscillator 2 outputs a clock signal, the control module 13 may further obtain a required output signal based on the clock signal through an internal frequency divider or a phase-locked loop, where the output signal may be a pulse-per-second after synchronization, an external synchronous clock output, and the like.
In this embodiment, as shown in fig. 2, the switch module 11 includes: the first input end of the analog switch 111 is connected with the first output end of the control module 13, the second input end of the analog switch is connected with the output end of the resistance adjusting module 12, the output end of the analog switch is connected with the input end of the voltage-controlled crystal oscillator 2, and the control end of the analog switch is connected with the second output end of the control module 13.
Specifically, the analog switch 111 is a gate switch, and a plurality of channels are arranged in the analog switch and controlled by the control module 13; the control module 13 controls the on state of the analog switch 111, so that the control module 13 is connected with the voltage-controlled crystal oscillator 2, or the resistance adjusting module 12 is connected with the voltage-controlled crystal oscillator 2.
In this embodiment, as shown in fig. 3, the control module 13 includes: a programmable controller 131 and a digital-to-analog converter 132.
As shown in fig. 3, the programmable controller 131 has an input end for inputting various control signals, an input end connected to the output end of the voltage-controlled crystal oscillator 2, a first output end connected to the input end of the digital-to-analog converter 132, and a second output end connected to the control end of the switch module 11, and is configured to obtain a first digital voltage signal based on the control signals; according to the preset priority, the first voltage signal or the second voltage signal is transmitted to the voltage-controlled crystal oscillator 2 by controlling the on-off state of the switch module 11.
Specifically, the programmable controller 131 of the present embodiment employs a type of programmable memory for storing programs therein, executing instructions for users such as logic operations, sequence control, timing, counting, and arithmetic operations, and controlling various types of machines or production processes through digital or analog input/output.
Specifically, the programmable controller 131 of this embodiment not only can realize the switching between multiple automatic operation modes, but also can realize the switching between the automatic operation mode and the manual operation mode by controlling the on state of the switch module 11, and even the programmable controller 131 embeds a logic algorithm to obtain the first digital voltage signal based on the control signal and the feedback signal when the automatic operation mode is operated.
As an example, in the programmable controller 131 of the present embodiment, a digital phase detector is built in, and when the control signal is a second pulse input signal or an external clock input signal, the programmable controller 131 can divide the frequency of the feedback signal of the voltage controlled crystal oscillator 2 to obtain a frequency division signal of the feedback signal; the digital phase discriminator compares the second pulse input signal or the external clock input signal with the feedback signal frequency division signal; the digital filtering algorithm built in the programmable controller 131 filters the comparison result to obtain a first voltage digital signal.
It should be noted that, the programmable controller 131 not only can adjust the first voltage digital signal based on the second pulse input signal and the feedback signal to realize synchronization of the voltage-controlled crystal oscillator 2 with the control signal, but also can realize synchronization of the voltage-controlled crystal oscillator 2 with the control signal based on various types of control signals in the related art, which is only used as an example and not limited thereto.
As shown in fig. 3, the output terminal of the digital-to-analog converter 132 is connected to the first input terminal of the switch module 11, and is used for converting the first digital voltage signal into a first voltage signal.
In this embodiment, as shown in fig. 4, the resistance adjustment module 12 includes: the first voltage dividing resistor R1, the second voltage dividing resistor R2 and the potentiometer W1, wherein the potentiometer W1 is connected with the external power supply VCC through the first voltage dividing resistor R1 at the first end, is grounded through the second voltage dividing resistor R2 at the second end, and outputs a second voltage signal at the third end, and the resistance value of the potentiometer W1 is changed due to the rotation of the external knob.
Specifically, the potentiometer W1 of the embodiment is provided with an external knob, and a user rotates the knob to change the resistance of the potentiometer W1, thereby realizing manual adjustment of the output frequency of the voltage-controlled crystal oscillator 2.
The embodiment also provides a clock synchronization and adaptive switching method, as shown in fig. 5, including:
step S11: and judging whether a control signal is input or not in real time.
Step S12: when at least one control signal is input, a first voltage signal is obtained according to a preset priority based on the control signal and a feedback signal of the voltage-controlled crystal oscillator.
Specifically, depending on the clock synchronization and adaptive switching circuit of the above embodiment, the clock synchronization and adaptive switching method of the present embodiment includes: switching between a plurality of automatic operation modes, switching between an automatic operation mode and a manual operation mode. The control module 13 is switched to an automatic operation mode by judging whether a control signal is input in real time, and the control module 13 is connected with the voltage-controlled crystal oscillator 2 by controlling the operation state of the switch module 11 when the control signal is input, so that only a first voltage signal is transmitted to the voltage-controlled crystal oscillator 2 as a voltage-controlled signal; when no control signal is input, the control module 13 is switched to a manual operation mode, and the resistance adjustment module 12 is connected with the voltage-controlled crystal oscillator 2 by controlling the operation state of the switch module 11, so that only the second voltage signal is transmitted as the voltage-controlled signal to the voltage-controlled crystal oscillator 2.
Specifically, the various control signals may include a second pulse input signal, an external clock input signal, an external control input signal, and the like, and the automatic operation mode includes: a second pulse mode, an external clock mode, an external control mode, and the like. When a plurality of control signals are input, a corresponding mode is selected based on a preset priority, and the first voltage signal is adjusted. For example: if the second pulse mode is the highest level and the control module 13 receives the second pulse input signal, the external clock input signal and the external control input signal at the same time, the control module 13 switches to the second pulse mode, and obtains the first voltage signal based on the second pulse input signal and the feedback signal of the voltage-controlled crystal oscillator 2.
Step S13: and controlling the first voltage signal to be transmitted to the voltage-controlled crystal oscillator.
It should be noted that, the priority levels of the automatic operation module and the manual operation mode and the priority levels of the various control signals in the present embodiment may be set as required, which is not limited herein.
In this embodiment, when the control signal is a second pulse input signal or an external clock input signal, the process of obtaining the first voltage signal includes: (1) Dividing the frequency of the feedback signal of the voltage-controlled crystal oscillator 2 to obtain a feedback signal frequency division signal; (2) Comparing the second pulse input signal or the external clock input signal with the feedback signal frequency division signal; (3) Filtering the comparison result to obtain a first voltage digital signal; (4) And D, performing digital-to-analog conversion on the first voltage digital signal to obtain a first voltage signal.
Specifically, in the embodiment, the digital phase discriminator is built in the programmable controller 131, and when the control signal is a second pulse input signal or an external clock input signal, the programmable controller 131 can divide the frequency of the feedback signal of the voltage controlled crystal oscillator 2 to obtain a frequency division signal of the feedback signal; the digital phase discriminator compares the second pulse input signal or the external clock input signal with the feedback signal frequency division signal; the digital filtering algorithm built in the programmable controller 131 filters the comparison result to obtain a first voltage digital signal.
Illustratively, the voltage-controlled crystal oscillator 2 has a frequency of 40MHz and a pulse-per-second input signal of 1pps, and the frequency division ratio is 40 MHz/1 hz=4×104. When the control signal is an external clock input signal, the frequency division ratio is the frequency of the voltage-controlled crystal oscillator 2.
In this embodiment, when the control signal is an external control input signal, the external control input signal includes a frequency control word, and the process of obtaining the first voltage signal includes: (1) (2) comparing the frequency control word with a reference frequency control word; (3) Based on the comparison result, a first voltage digital signal is obtained; (4) And D, performing digital-to-analog conversion on the first voltage digital signal to obtain a first voltage signal.
Specifically, the reference frequency control word in this embodiment may be preset in the editable controller, or the current automatic operation mode is the external control mode, and the current automatic operation mode is also the external control operation mode, where the difference between the two is only the frequency control word, and the reference frequency control word is the frequency control word of the previous automatic operation mode, but this is merely taken as an example and not a limitation.
In this embodiment, when a plurality of control signals are input, a process of obtaining a first voltage signal based on the control signals and feedback signals of the voltage-controlled crystal oscillator 2 according to a preset priority includes: (1) According to the preset priority, a first voltage signal is obtained based on a control signal with the highest priority and a feedback signal of the voltage-controlled crystal oscillator 2; (2) Or when the mode switching signal is received, the first voltage signal is obtained based on the control signal corresponding to the mode to be switched and the feedback signal of the voltage-controlled crystal oscillator 2.
Specifically, in this embodiment, the switching between the operation modes may be performed according to a preset priority, or may be performed by user control, which is not limited herein.
The embodiment can also utilize the characteristic of high short-term frequency stability of the voltage-controlled crystal oscillator 2, and can optimize the random error of the second pulse. The pulse per second signal can also play a role in maintaining when the pulse per second signal is lost in a short time, so that the pulse per second optimization and the pulse per second loss maintaining function are realized.
The present embodiment also provides a clock circuit, as shown in fig. 6, including: the device comprises a clock synchronization and self-adaption switching circuit 1 and a voltage-controlled crystal oscillator 2, wherein the output end of the clock synchronization and self-adaption switching circuit 1 is connected with the input end of the voltage-controlled crystal oscillator 2; the clock synchronization and adaptive switching circuit 1 outputs a first voltage signal or a second voltage signal to the voltage-controlled crystal oscillator 2.
Specifically, the clock synchronization and adaptive switching circuit 1 of the present embodiment realizes the functions of switching between the above modes, and the like, and will not be described herein.
The above embodiments are merely preferred embodiments for fully explaining the present invention, and the scope of the present invention is not limited thereto. Equivalent substitutions and modifications will occur to those skilled in the art based on the present invention, and are intended to be within the scope of the present invention.

Claims (10)

1. A clock synchronization and adaptive switching circuit, comprising: a switch module (11), a resistance adjusting module (12) and a control module (13), wherein,
the control module (13) is used for inputting various control signals into the input end of the control module, the input end of the control module is also connected with the output end of the voltage-controlled crystal oscillator (2), the first output end of the control module is connected with the first input end of the switch module (11), the second output end of the control module is connected with the control end of the switch module (11), and the control module is used for obtaining a first voltage signal based on the control signal and the feedback signal of the voltage-controlled crystal oscillator (2), and the first voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator (2) in an automatic operation mode;
the second input end of the switch module (11) is connected with the output end of the resistance adjusting module (12), and the output end of the switch module is connected with the input end of the voltage-controlled crystal oscillator (2);
the input end of the resistance adjusting module (12) is input with an adjusting signal, and the resistance adjusting module is used for outputting a second voltage signal after adjusting the resistance value based on the adjusting signal, wherein the second voltage signal is used for controlling the output frequency of the voltage-controlled crystal oscillator (2) in a manual operation mode;
the control module (13) enables the first voltage signal or the second voltage signal to be transmitted to the voltage-controlled crystal oscillator (2) by controlling the on-off state of the switch module (11) according to the preset priority.
2. The clock synchronization and adaptive switching circuit according to claim 1, wherein the switching module (11) comprises:
the first input end of the analog switch (111) is connected with the first output end of the control module (13), the second input end of the analog switch is connected with the output end of the resistance adjusting module (12), the output end of the analog switch is connected with the input end of the voltage-controlled crystal oscillator (2), and the control end of the analog switch is connected with the second output end of the control module (13).
3. The clock synchronization and adaptive switching circuit according to claim 1, wherein the control module (13) comprises: a programmable controller (131) and a digital-to-analog converter (132), wherein,
the programmable controller (131) is provided with input ends for inputting various control signals, the input ends of the programmable controller are also connected with the output ends of the voltage-controlled crystal oscillator (2), the first output ends of the programmable controller are connected with the input ends of the digital-to-analog converter (132), and the second output ends of the programmable controller are connected with the control ends of the switch module (11) and are used for obtaining a first digital voltage signal based on the control signals; according to a preset priority, the first voltage signal or the second voltage signal is transmitted to the voltage-controlled crystal oscillator (2) by controlling the on-off state of the switch module (11);
and a digital-to-analog converter (132) whose output is connected to the first input of the switching module (11) for converting the first digital voltage signal into a first voltage signal.
4. The clock synchronization and adaptive switching circuit according to claim 1, wherein the resistance adjustment module (12) comprises: a first voltage dividing resistor (R1), a second voltage dividing resistor (R2) and a potentiometer (W1), wherein,
the potentiometer (W1) is connected with an external power supply (VCC) through the first voltage dividing resistor (R1) at the first end, is grounded through the second voltage dividing resistor (R2) at the second end, outputs the second voltage signal at the third end, and changes the resistance value due to the rotation of the external knob.
5. A clock synchronization and adaptive switching method, characterized in that it is based on a clock synchronization and adaptive switching circuit according to any one of claims 1-4, said method comprising:
judging whether a control signal is input or not in real time;
when at least one control signal is input, according to a preset priority, a first voltage signal is obtained based on the control signal and a feedback signal of the voltage-controlled crystal oscillator (2);
and controlling the first voltage signal to be transmitted to the voltage-controlled crystal oscillator (2).
6. The method for clock synchronization and adaptive switching according to claim 5, further comprising:
and when no control signal is input, controlling a second voltage signal to be transmitted to the voltage-controlled crystal oscillator (2).
7. The method of claim 5, wherein the step of obtaining the first voltage signal when the control signal is a second pulse input signal or an external clock input signal comprises:
dividing the frequency of the feedback signal of the voltage-controlled crystal oscillator (2) to obtain a feedback signal frequency division signal;
comparing the second pulse input signal or the external clock input signal with the feedback signal frequency division signal;
filtering the comparison result to obtain a first voltage digital signal;
and D, performing digital-to-analog conversion on the first voltage digital signal to obtain a first voltage signal.
8. The method of claim 5, wherein when the control signal is an external control input signal, the external control input signal includes a frequency control word, and the process of obtaining the first voltage signal includes:
comparing the frequency control word with a reference frequency control word;
based on the comparison result, a first voltage digital signal is obtained;
and D, performing digital-to-analog conversion on the first voltage digital signal to obtain a first voltage signal.
9. The method for clock synchronization and adaptive switching according to claim 5, wherein the step of obtaining the first voltage signal based on the control signal and the feedback signal of the voltage controlled crystal oscillator (2) according to a preset priority when a plurality of control signals are input, comprises:
according to the preset priority, a first voltage signal is obtained based on a control signal with the highest priority and a feedback signal of the voltage-controlled crystal oscillator (2);
or when the mode switching signal is received, a first voltage signal is obtained based on a control signal corresponding to the mode to be switched and a feedback signal of the voltage-controlled crystal oscillator (2).
10. A clock circuit, comprising: the clock synchronization and adaptive switching circuit (1), voltage controlled crystal oscillator (2) of any one of claims 1-4, wherein,
the output end of the clock synchronization and self-adaptation switching circuit (1) is connected with the input end of the voltage-controlled crystal oscillator (2);
the clock synchronization and adaptive switching circuit (1) adjusts the output frequency of the voltage controlled crystal oscillator (2) by using the method of any of claims 5-9.
CN202310970276.1A 2023-08-02 2023-08-02 Clock synchronization and self-adaptive switching circuit and method, and clock circuit Pending CN116938195A (en)

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CN202310970276.1A CN116938195A (en) 2023-08-02 2023-08-02 Clock synchronization and self-adaptive switching circuit and method, and clock circuit

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CN202310970276.1A CN116938195A (en) 2023-08-02 2023-08-02 Clock synchronization and self-adaptive switching circuit and method, and clock circuit

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