1. A method for controlling a system clock, the method comprising the steps of:

monitoring the power-on state in real time;

if the power-on state exists, acquiring a first clock signal generated by a first clock source and acquiring a second clock signal generated by a second clock source;

updating the pre-clock signal according to the first clock signal and the second clock signal;

and controlling the system clock according to the preposed clock signal.

2. The system clocking method of claim 1, after said step of monitoring the power-on state in real time, further comprising:

and if the power-down state is detected, acquiring a first clock signal generated by a first clock source, and controlling the front-end clock by the first clock signal or acquiring a second clock signal generated by a second clock source.

3. The method of claim 1, wherein the step of obtaining the first clock signal generated by the first clock source and obtaining the second clock signal generated by the second clock source if the power-on state is asserted comprises:

controlling the first clock source to interrupt at regular time after the first clock source passes a first preset time length so as to generate a first clock source interrupt point;

updating the count value of a first counter at each first clock source interrupt point and accumulating a first preset time length;

acquiring the first clock source interrupt point and the first counter count value;

controlling the second clock source to be interrupted at regular time after the second clock source passes a second preset time length so as to generate a second clock source interruption point;

updating the count value of a second counter at the interruption point of each second clock source and accumulating a second preset time length;

and acquiring the interruption point of the second clock source and the count value of the second counter.

4. The system clock control method of claim 3, wherein the step of updating the preamble clock signal based on the first clock signal and the second clock signal comprises:

judging whether the count value of the second counter is accumulated for a second preset time length at each first clock source interrupt point;

if the count value of the second counter is accumulated for a second preset time, judging whether the count value of the first counter is greater than a preset lower limit value;

and if the count value of the first counter is greater than the preset lower limit value, updating the count value of the preposed clock and accumulating a third preset time length, and updating the count value of the first counter to be cleared.

5. The method of system clock control of claim 3, wherein the step of updating the preamble clock signal based on the first clock signal and the second clock signal further comprises:

monitoring whether the count value of the first counter is greater than a preset upper limit value in real time;

and if the count value of the first counter is greater than a preset upper limit value, controlling the count value of the preposed clock to accumulate a third preset time length, and subtracting a preset value from the count value of the first counter.

6. The system clocking method of claim 1, after said step of monitoring the power-on state in real time, further comprising:

if the electrical instrument is in a power-on state, judging whether the second clock signal meets a preset condition or not according to preset time intervals of the preposed clock signal;

if the second clock signal meets a preset condition, synchronizing the front-end clock according to the second clock signal;

and if the second clock signal does not meet the preset condition, recording the times that the second clock signal does not meet the preset condition.

7. The system clocking method of claim 1, after said step of monitoring the power-on state in real time, further comprising:

if the power failure state exists, monitoring whether the electrical instrument is powered on in real time;

and if the electrical instrument is electrified, controlling the front-end clock to synchronize according to an electrifying synchronization scheme.

8. The method according to claim 7, wherein the step of controlling the front-end clock to synchronize according to a power-on synchronization scheme if the electrical instrument is powered on comprises:

if the electrical instrument is powered on, judging whether the second clock source meets a preset condition;

if the second clock source meets the preset condition, synchronizing the preposed clock according to the second clock source;

if the second clock source does not meet the preset condition, judging whether a backup clock source meets the preset condition or not;

and if the backup clock source meets the preset condition, synchronizing the second clock source and the preposed clock according to the backup clock source.

9. A processing apparatus comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, the computer program when executed by the processor implementing the steps of the system clocking method of any of claims 1 to 8.

10. A readable storage medium, having stored thereon a computer program which, when executed by a processor, carries out the steps of the system clocking method according to any one of claims 1 to 8.

Background

The system clock is a source power and metronome for driving the whole chip system to work in order, and is the heart of the whole chip system. Once the system clock fails and stops working, the whole chip system is directly hung up; the stability and reliability of the system clock are also very important, which affects whether the whole chip can work normally. The traditional system clock usually adopts a single clock source, so that the operation of the system clock is not stable and reliable enough.

Disclosure of Invention

The invention provides a control method of a system clock, aiming at solving the technical problem that the operation of the system clock is not stable and reliable enough.

In order to achieve the above object, the present invention provides a method for controlling a system clock, comprising the steps of:

monitoring the power-on state in real time;

if the power-on state exists, acquiring a first clock signal generated by a first clock source and acquiring a second clock signal generated by a second clock source;

updating the pre-clock signal according to the first clock signal and the second clock signal;

and controlling the system clock according to the preposed clock signal.

Optionally, the first clock signal generated by the first clock source is obtained, and the front-end clock is controlled by the first clock signal, or the second clock signal generated by the second clock source is obtained, and the front-end clock is controlled by the second clock signal.

Optionally, the first clock source is controlled to perform timed interrupt after each first preset time duration passes, so as to generate a first clock source interrupt point;

updating the count value of a first counter at each first clock source interrupt point and accumulating a first preset time length;

acquiring the first clock source interrupt point and the first counter count value;

controlling the second clock source to be interrupted at regular time after the second clock source passes a second preset time length so as to generate a second clock source interruption point;

updating the count value of a second counter at the interruption point of each second clock source and accumulating a second preset time length;

and acquiring the interruption point of the second clock source and the count value of the second counter.

Optionally, at each first clock source interrupt point, determining whether the count value of the second counter is accumulated for a second preset time period;

if the count value of the second counter is accumulated for a second preset time, judging whether the count value of the first counter is greater than a preset lower limit value;

and if the count value of the first counter is greater than the preset lower limit value, updating the count value of the preposed clock and accumulating a third preset time length, and updating the count value of the first counter to be cleared.

Optionally, monitoring whether the count value of the first counter is greater than a preset upper limit value in real time;

and if the count value of the first counter is greater than a preset upper limit value, controlling the count value of the preposed clock to accumulate a third preset time length, and subtracting a preset value from the count value of the first counter.

Optionally, if the electrical instrument is in a power-on state, whether the second clock signal meets a preset condition is judged according to preset time intervals of the front clock signal;

if the second clock signal meets a preset condition, synchronizing the front-end clock according to the second clock signal;

and if the second clock signal does not meet the preset condition, recording the times that the second clock signal does not meet the preset condition.

Optionally, if the power failure state is detected, whether the electrical instrument is powered on or not is monitored in real time;

and if the electrical instrument is electrified, controlling the front-end clock to synchronize according to an electrifying synchronization scheme.

Optionally, if the electrical instrument is powered on, determining whether the second clock source meets a preset condition;

if the second clock source meets the preset condition, synchronizing the preposed clock according to the second clock source;

if the second clock source does not meet the preset condition, judging whether a backup clock source meets the preset condition or not;

and if the backup clock source meets the preset condition, synchronizing the second clock source and the preposed clock according to the backup clock source.

To achieve the above object, the present application also proposes a processing apparatus including a memory, a processor, and a computer program stored on the memory and executable on the processor, the computer program implementing the system clock control method when executed by the processor.

To achieve the above object, the present application also proposes a readable storage medium having stored thereon a computer program which, when executed by a processor, implements the system clock control method.

In the technical scheme of the invention, the power-on state of the system clock is monitored in real time, if the system clock is in the power-on state, the clock signals generated by the two clock sources are obtained, the preposed clock signal is updated according to the two clock signals, and the system clock is controlled according to the preposed clock signal. The method provided by the invention utilizes the two clock signals to control the system clock together, thereby improving the stability and reliability of the system clock.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic block diagram of a control method of a system clock according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a method for controlling a system clock according to an embodiment of the present invention;

fig. 3 is a detailed flowchart of step S200 according to the present invention.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, fig. 1 is a schematic diagram of a hardware structure of a processing device according to various embodiments of the present invention. The processing device comprises an execution module 01, a memory 02, a processor 03 and the like. Those skilled in the art will appreciate that the processing device shown in fig. 1 may also include more or fewer components than those shown, or combine certain components, or a different arrangement of components. The processor 03 is connected to the memory 02 and the execution module 01, respectively, and the memory 02 stores a computer program, which is executed by the processor 03 at the same time.

The execution module 01 may receive the clock signal, update the timer and the pre-clock, collect the above information, and send the information to the processor 03.

The memory 02 may be used to store software programs and various data. The memory 02 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function, and the like; the storage data area may store data or information created according to the use of the terminal, or the like. Further, the memory 02 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

The processor 03, which is a control center of the processing platform, connects various parts of the entire terminal by using various interfaces and lines, and performs various functions of the terminal and processes data by operating or executing software programs and/or modules stored in the memory 02 and calling data stored in the memory 02, thereby integrally monitoring the vehicle. Processor 03 may include one or more processing units; optionally, the processor 03 may integrate an application processor and a modem processor, wherein the application processor mainly handles operating systems, user interfaces, application programs, and the like, and the modem processor mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 03.

It will be appreciated by those skilled in the art that the processing platform arrangement shown in figure 1 does not constitute a limitation of the processing apparatus and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

Various embodiments of the method of the present invention are presented in terms of the above-described hardware architecture.

Referring to fig. 2, in a first embodiment of the method for controlling a system clock of the present invention, the method for controlling a system clock includes:

step S100, monitoring the power-on state in real time;

in the invention, the system clock is widely applied to a plurality of electrical instruments, the electrical instruments have higher requirements on the stability and the reliability of the system clock, the system clock is required to run in a power-on or power-off state of the electrical instruments, and for convenience of description, the following embodiments take the case that the system clock is installed in the electrical instruments as an example for explanation. For example, when the system clock is applied to an intelligent electric energy meter, the stability and reliability of the system clock are important to accurately implement the time-sharing metering function of the intelligent electric energy meter.

However, when the power-on states are different, the running states of the electrical instruments are different, and when a plurality of electrical instruments are in the power-on states, the electrical instruments run in the normal power consumption state; in the power-down state, the electrical instrument operates in a low power consumption state. Accordingly, the system clock in the electrical instrument may be affected by the normal power consumption state and/or the low power consumption state to operate in different modes.

Step S200, if the power-on state exists, acquiring a first clock signal generated by a first clock source, and acquiring a second clock signal generated by a second clock source;

in this embodiment, if the electrical apparatus is in the power-on state, the system clock in the electrical apparatus is controlled by the clock signals input by the dual clock sources, the first clock source generates the first clock signal, the second clock source generates the second clock signal, the first clock signal and the second clock signal control the front end clock of the system clock together, and the front end clock generates the front end clock signal to control the system clock. The clock source can be a clock generated by an internal timer of a CPU of the electrical instrument, and can also be a pulse signal input by an external real-time clock. In one embodiment, the first clock signal is a clock signal generated by an internal timer of the CPU of the electrical instrument, and the second clock signal is a clock signal input by an external real-time clock.

And if the power-down state is detected, acquiring a first clock signal generated by a first clock source, and controlling the front-end clock by the first clock signal or acquiring a second clock signal generated by a second clock source.

In this embodiment, when in the power-down state, the electrical apparatus operates in the low power consumption state, and at this time, in order to reduce power consumption, the front-end clock may be set to receive only the first clock signal or the second clock signal, the front-end clock is changed to be controlled by the clock signal input by the single clock source, and at this time, the updating of the front-end clock is controlled according to the signal parameter of the first clock signal or the signal parameter of the second clock signal. In one embodiment, the front-end clock receives only the first clock signal if the electrical instrument is powered down, the first clock signal is interrupted every 2 seconds, and the front-end clock accumulates two seconds every time the first clock signal is interrupted.

Step S300, updating a preposed clock signal according to the first clock signal and the second clock signal;

the clock signal is the basis of sequential logic, which determines when the state in a logic cell is updated, and is a semaphore with a fixed period and which is independent of operation. The clock signal may be an internal clock signal generated by an internal clock, and the internal clock signal may be a digital signal. The clock signal may also be an external clock signal generated by an external clock, the external clock signal being a pulse signal having only two levels, one being a high level and the other being a low level. The external clock signal is an electric signal determined according to the inherent period of the clock source, and has inherent signal parameters such as clock frequency, duty ratio and the like, and the signal parameters are irrelevant to the running state of the clock source. The first clock signal and the second clock signal are independent clock signals. And controlling the updating of the prepositive clock signal according to the first clock signal and the second clock signal.

In this embodiment, the pre-clock signal may be updated according to the clock interrupt of the first clock signal and the clock interrupt of the second clock signal. The clock interrupt can be triggered by internal interrupt, and the internal interrupt does not need to depend on the transmission of pulse signals; the clock interrupt is also triggered by the detection of an external interrupt, which generates a clock signal interrupt when a rising or falling edge of the pulse signal is detected. For example, if the first clock signal is interrupted every 10ms and the second clock signal is interrupted every second, the preamble clock is accumulated for one second when the first clock signal and the second clock signal are interrupted simultaneously.

And step S400, controlling the system clock according to the preposed clock signal.

In this embodiment, the pre-clock of the system is a soft clock, and the pre-clock outputs a pulse signal to control the operation of the system clock after being updated according to the first clock signal and the second clock signal.

Referring to fig. 3, based on the first embodiment, in the second embodiment of the method for controlling a system clock according to the present invention, step S200 includes:

step S210, controlling the first clock source to interrupt at regular time after the first clock source passes through a first preset time length so as to generate a first clock source interrupt point;

the first clock source may be an external clock source or an internal clock source. In this embodiment, the first clock source is an internal clock inside a CPU of the electrical instrument, and the timer interrupt of the first clock source is an internal interrupt. The internal interrupt is the interrupt caused when the CPU of the electrical instrument executes the first clock source code, the interrupt signal is not required to be sent through the interrupt signal line, but the process of the first clock source code is executed according to the program in the CPU, and a first clock source interrupt point is generated when the first clock source is interrupted once.

Step S220, updating the count value of a first counter at each first clock source interrupt point and accumulating a first preset time length;

in order to complete the control of the front-end clock, a first counter is arranged in the electrical instrument CPU, and in the embodiment, the first counter is a millisecond counter. The first counter corresponds to the first clock source, and each time the CPU receives an interrupt signal input by the first clock source once, the first counter is controlled to accumulate a first preset time length, which is set in advance by a person skilled in the art according to a certain rule and is different according to a different frequency of the first clock source interrupt signal. For example, if the first clock source outputs 20 interrupt signals per second, the first counter accumulates 50 milliseconds every time it receives one interrupt signal, that is, the first preset time duration is 50 milliseconds; if the first clock source outputs 10 interrupt signals per second, the first counter accumulates 100 milliseconds every time it receives one interrupt signal, i.e. the first preset time length is 100 milliseconds.

Step S230, acquiring the first clock source interrupt point and the first counter count value;

in this embodiment, the initial count value of the first counter is preset by a person skilled in the art, and may be 0, or may be any other value. The initial count value of the counter is added with the accumulated count value to be the real-time count value of the first counter, namely the count value of the first counter.

Step S240, controlling the second clock source to be interrupted at regular time after the second preset time length passes, so as to generate a second clock source interruption point;

the second clock source may be an external clock source or an internal clock source. In this embodiment, the second clock source is an external clock source of the electrical device processor, the timer interrupt of the second clock source is an external interrupt, the second clock source sends an interrupt signal to the electrical device processor at a certain frequency, and when the processor receives the interrupt signal once, an interrupt point of the second clock source is generated.

Step S250, updating the count value of a second counter at the interruption point of each second clock source and accumulating a second preset time length;

in order to complete the control of the front-end clock, a second counter is arranged in the CPU of the electrical instrument, in this embodiment, the second counter is a second counter, the second counter corresponds to the second clock source, and the second counter is controlled to accumulate a second preset time length each time the second clock source generates an interruption point, where the second preset time length is preset according to a certain rule by a person skilled in the art and is different according to the different frequencies generated by the interruption point of the second clock source. For example, if the second clock source outputs 1 interrupt signal per second, the second counter accumulates 1 second at the interrupt point of each second clock source, that is, the second preset time length is 1 second; if the second clock source outputs 1 interrupt signal every two seconds, the second counter accumulates 2 seconds at the interrupt point of each second clock source, that is, the second preset time is 2 seconds.

Step S260, obtaining the interruption point of the second clock source and the count value of the second counter.

In this embodiment, the initial count value of the second counter is preset by a person skilled in the art, and may be 0, or may be any other value. The initial count value of the counter is added with the accumulated count value, namely the real-time count value of the second counter, namely the count value of the second counter.

In one embodiment, step S300 includes:

judging whether the count value of the second counter is accumulated for a second preset time length at each first clock source interrupt point;

in this embodiment, it is known that at each first clock source interrupt point, the first counter accumulates a first preset time period, and at each second clock source interrupt point, the second counter accumulates a second preset time period. The step of determining whether the second counter count value is accumulated for a second predetermined time period at each first clock source interrupt point is substantially determining whether each first clock source interrupt point is also exactly the second clock source interrupt point.

If the count value of the second counter is accumulated for a second preset time, judging whether the count value of the first counter is greater than a preset lower limit value;

and if the count value of the first counter is greater than the preset lower limit value, updating the count value of the preposed clock and accumulating a third preset time length, and updating the count value of the first counter to be cleared.

And if the count value of the first counter is smaller than or equal to the preset lower limit value, the count values of the front-end clock, the first counter and the second counter are not updated.

In this embodiment, the preset lower limit value is preset by a person skilled in the art according to a certain rule, the front-end clock is a soft clock inside the CPU of the electrical instrument, and the front-end clock updates the count value according to the first clock signal and the second clock signal. In one embodiment, the first predetermined time period is 10ms, the second predetermined time period is 1 s, and the predetermined lower limit is 800 ms. The initial count value of the first counter and the initial count value of the second counter are both 0 and start to work simultaneously, so that when the first clock source is interrupted for 100 th time, the first counter accumulates for one second, the second clock source is also interrupted just, the count value of the second counter accumulates for 1 second, whether the count value of the first counter is greater than the preset lower limit value of 800 milliseconds or not is judged at the moment, obviously, the count value of the first counter is greater than the preset lower limit value of 800 milliseconds, the count value of the front clock is accumulated for 1 second, and the count value of the first counter is cleared.

In another embodiment, step S300 further comprises:

monitoring whether the count value of the first counter is greater than a preset upper limit value in real time;

and if the count value of the first counter is greater than a preset upper limit value, controlling the count value of the preposed clock to accumulate a third preset time length, and subtracting a preset value from the count value of the first counter.

And if the count value of the first counter is smaller than or equal to the preset upper limit value, the count values of the front-end clock, the first counter and the second counter are not updated.

In this embodiment, the preset upper limit value is preset by a person skilled in the art according to a certain rule, and is set to improve the fault tolerance of the clock control scheme.

In an embodiment, after step S100, the method further includes:

if the electrical instrument is in a power-on state, judging whether the second clock signal meets a preset condition or not according to preset time intervals of the preposed clock signal;

in this embodiment, the determining whether the second clock signal satisfies the preset condition is to perform a validity check on the second clock signal. The validity check scheme may be to determine whether the year, month, week, hour, minute, and second of the second clock signal data matches a daily time value. If yes, the clock is legal, otherwise, the clock is illegal. Specifically, the validity check scheme is to sequentially judge whether the year is 0-99, whether the month is 1-12, whether the day is 1-the maximum number of days in the month, whether the hour is 0-23, whether the minute is 0-59, and whether the second is 0-59. If the year is 0-99, the month is 1-12, the day is 1-the month maximum number of days, the hour is 0-23, the minute is 0-59, and the second is 0-59, the result is that the clock passes the validity check, that is, the second clock signal satisfies the preset condition.

If the second clock signal meets a preset condition, synchronizing the front-end clock according to the second clock signal;

in this embodiment, if the system is always kept in the power-on state, the front-end clock is synchronized every fixed time interval to ensure the accuracy and reliability of the system clock. And if the second clock signal meets the preset condition, namely passes the validity check, synchronizing the front-end clock with the second clock source clock, wherein the clock synchronization can be frequency synchronization or time synchronization. The frequency synchronization means that the changing frequencies of the front-end clock and the soft clock are the same or keep a fixed proportion, but the phases of the two clock signals can be inconsistent and the frequencies can also be inconsistent; time synchronization means that the absolute time of the preamble clock and the second clock source are kept consistent.

And if the second clock signal does not meet the preset condition, recording the times that the second clock signal does not meet the preset condition.

In this embodiment, if the electrical instrument is in the power-on state, it is detected at fixed time intervals whether the second clock source meets the preset condition, that is, the second clock source is subjected to validity check at fixed time intervals. In one embodiment, the validity check is performed at a 30 second position with an absolute time of every minute to avoid the integer point crossing problem caused by the clock synchronizing at the integer point position, and the integer point crossing problem may be skipping the integer point or repeating the integer point crossing. In an embodiment, the number of times of the second clock source being illegal within a period of time is recorded, and if the number of times reaches a preset illegal upper limit value, the event is reported.

In another embodiment, after step S100, the method further includes:

if the power failure state exists, monitoring whether the electrical instrument is powered on in real time;

and if the electrical instrument is electrified, controlling the front-end clock to synchronize according to an electrifying synchronization scheme.

In this embodiment, if the system is in a power-down state, when the electrical instrument is powered on again, the front-end clock also needs to be synchronized, so as to ensure the accuracy and reliability of the system clock.

In an embodiment, if the electrical instrument is powered on, the step of controlling the front-end clock to synchronize according to a power-on synchronization scheme includes:

if the electrical instrument is powered on, judging whether the second clock source meets a preset condition;

if the second clock source meets the preset condition, synchronizing the preposed clock according to the second clock source;

if the second clock source does not meet the preset condition, judging whether a backup clock source meets the preset condition or not;

and if the backup clock source meets the preset condition, synchronizing the second clock source and the preposed clock according to the backup clock source.

In this embodiment, before the clock synchronization when the electrical instrument is powered on again, it is also necessary to determine whether the second clock source is legal. If the judgment result is that the second clock source is legal, synchronizing the preposed clock according to the second clock source; if the judgment result is that the second clock source is illegal, continuously judging whether the backup clock source is legal, and if the judgment result is that the backup clock source is legal, synchronizing the second clock source and the preposed clock according to the backup clock source. In one embodiment, the backup clock comprises a RAM backup clock, an EEPROM power-down backup clock and an EEPROM periodic backup clock. The RAM backup clock is an RAM interval for backing up the second clock source to the MCU every second, the EEPROM power-down backup clock is used for backing up the second clock source to the EEPROM clock backup interval at the power-down occurrence moment of the electric meter, the EEPROM periodic backup clock is used for periodically backing up the second clock to the EEPROM backup interval in the running process of the electric meter, the priority sequence for carrying out the validity check of the backup clock is the RAM backup clock, the EEPROM power-down backup clock and the EEPROM periodic backup clock, and when the second clock source is illegal, the second clock source and the preposed clock are synchronized according to the backup clock with the highest priority in the legal backup clock.

The invention also proposes a processing device comprising a memory, a processor, and a computer program stored on said memory and executable on said processor for performing the method according to the various embodiments of the invention.

The invention also proposes a readable storage medium on which the computer program is stored. The computer-readable storage medium may be the Memory in fig. 1, and may also be at least one of a ROM (Read-Only Memory)/RAM (Random Access Memory), a magnetic disk, and an optical disk, and the computer-readable storage medium includes several instructions for enabling a terminal device (which may be a mobile phone, a computer, a server, a terminal, or a network device) having a processor to execute the method according to the embodiments of the present invention.

In the present invention, the terms "first", "second", "third", "fourth" and "fifth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, and those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although the embodiment of the present invention has been shown and described, the scope of the present invention is not limited thereto, it should be understood that the above embodiment is illustrative and not to be construed as limiting the present invention, and that those skilled in the art can make changes, modifications and substitutions to the above embodiment within the scope of the present invention, and that these changes, modifications and substitutions should be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.