JPH05341065A - Clock circuit - Google Patents

Abstract

PURPOSE:To lessen the correcting frequency for manual operations and generate correction at a low cost with no use of any high precision oscillation source by determining the corrective interval from the error time and cumulative time, and performing time correction automatically every time the corrective interval has elapsed. CONSTITUTION:A new time is entered from a key entry device 4 and set in a memory 5, and a start key is pushed when the new time is attained. In response thereto, a control part 1 retreats the time data stored in the memory 5 and stores new time data. As a result, the error till the time is corrected, and a correct time indication is given on a display 3. The control part 1 determines the error through computation from the new time data in the memory 5 and the time data immediately before the correction which has been retreated, and determines the corrected total time from the elapsed time and the corrective interval data. Further the suns of the error and corrected total time is determined to calculate the total error, and setting of the polarity is performed. When the automatic correcting time is reached, the stored polarity data is read, and judgement is made whether the clock is to get or lose, and processing of automatic correction is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clock circuit for automatically correcting an error at a predetermined cycle.

[0002]

2. Description of the Related Art Recent electronic devices have a built-in clock function and are used not only for time display but also for timer control. In general, a crystal clock that uses a crystal oscillator as a clock source is used, and a clock circuit with a small error is built up.However, even if the error is small, if the time is not set for a long time, the error accumulates. There is a considerable error. Therefore, as a method of correcting the error, a method of manually correcting it by a person who is aware of the error or a method of automatically correcting by receiving a reference time signal (see, for example, Japanese Patent Publication No. 63-22276).

[0003]

As the above-described correction method, when a person manually performs the correction operation, the error becomes large if the correction operation is forgotten, and if the correction operation is attempted to be accurate, it is necessary to frequently perform the correction operation. However, when a reference time signal is received and automatically corrected, on the other hand, an accurate time can always be obtained, but on the other hand, a circuit for receiving the reference time signal and automatically correcting the time is separately required, which is expensive. There was a problem of becoming.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. Means for accumulating elapsed time from time correction to the next time correction, and correction It is composed of a means for obtaining an error from the time and the time immediately before the correction, a means for obtaining a correction interval time from the obtained error time and the integrated time, and a means for automatically adjusting the time each time the obtained correction interval time elapses. It is a thing.

[0005]

Since the present invention is configured as described above, since the correction is automatically performed at every correction interval calculated and calculated, the number of manual corrections can be reduced and the oscillation source with such a high accuracy can be obtained. It is possible to configure at low cost without the need for.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

(1) is a control circuit composed of a microprocessor, which outputs a time signal by counting clock pulses from a clock pulse oscillation circuit (2) composed of a crystal oscillator. (3) is a display that displays the current time based on the time signal output from the control unit (1).
(4) is a key input device provided with a time setting key,
The key signal is output to the control unit (1). (5) is a memory for storing the data processed by the control section (1), and is composed of an area for storing various data as shown in FIG. The area (5A) of the memory (5) stores the current time data obtained by counting the clock pulses from the clock pulse oscillator circuit (2) by the control unit (1).
(5B) is an area in which data for accumulating the elapsed time from the time when the time is corrected is stored. (5C) is an area in which the correction interval data of the time calculated by the control unit (1) is stored. (5D) is an area for storing correction polarity data for advancing or delaying when correcting the time. When advancing, "1" data is stored, and when deferring, "0" data is stored. It (5E) is an area for storing time data for automatically performing the next time correction calculated by the control unit (1). Area (5F) is an area in which data indicating the immediately preceding time is transferred from area (5A) and stored when the time is adjusted. (5G) is an area where the integrated time data of area (5B) is transferred and stored. (5H) is an area where the new time data input from the key input device (4) is set, and the data is transferred to the area (5A) by the start operation of the new time and the time is corrected.

Next, the operation of the present invention having such a configuration will be described with reference to the flow charts of FIGS.

First, when setting the time for the first time in the initial state, after setting the time correction mode by operating a predetermined key of the key input device (4), time data is input from the key input device (4) in step (S1). Then, the input time data is set in the area (5H) of the memory (5). Then, when the start key is operated, the control unit (1) which has detected the key signal receives the area (5) of the memory (5) in step (S2).
The time data of A) is transferred to the area (5F) and saved, and the elapsed time data of the area (5B) is transferred to the area (5G) and saved. In this case, the data in the areas (5A) and (5B) is random and meaningless data is transferred and saved. At the same time, the control unit (1) controls the area (5
The data of H) is transferred to the area (5A) and the time starts. The value of the area (5A) is updated by the control unit (1) every one second, and the current time is displayed by displaying the data of the area (5A) on the display (3). Simultaneously with the start of time, the control unit (1) clears the area (5B) of the memory (5) and then starts counting elapsed time. Subsequently, the control section (1) proceeds to step (S3) to determine whether or not the automatic correction mode is set. However, since the automatic correction mode is not yet set, the control section (1) proceeds to step (S12) to automatically After setting the flag instructing the correction mode, the process proceeds to step (S14) to clear the correction interval time data in the area (5C) of the memory (5), and then in step (S15) the memory (5).
The next automatic correction time data in the area (5E) is cleared and the processing of the time correction mode is finished. Even after the time adjustment mode ends, the control unit (1) continues counting the current time, the data in the area (5A) of the memory (5) is updated every second, and the display (3) shows the current time. At the same time that the time data is displayed, the elapsed time in the area (5B) of the memory (5) is integrated. The accuracy of the clock depends on the accuracy of the crystal oscillator of the clock pulse oscillation circuit (2), and an error occurs in the display time with the passage of time. Normally, an error of about ± 15 seconds per month occurs.

Next, an operation of correcting an error that has occurred after a predetermined period has passed will be described.

In the same manner as described above, the key input device (4) is used to set the time correction mode, and the new time is input and set in the area (5H) of the memory (5). When the start key is operated at the time when the new time is reached by the time signal or the like, the control unit (1) which has detected the key signal displays the time data in the area (5A) of the memory (5) in the area (5F) in step (S2). ), And the elapsed time data in the area (5B) is transferred to and saved in the area (5G). Then the area (5
The new time data set in H) is transferred to the area (5A). As a result, the error up to that point is corrected and the time is started from the new time, and the accurate time is displayed on the display (3). At the same time, the control unit (1) starts after clearing the elapsed time data in the area (5B) of the memory (5). Subsequently, the control unit (1) proceeds to step (S3) to determine whether or not the automatic correction mode is set. However, since the automatic correction mode has been set by the processing of step (S12) described above, the step (S4) is performed. An error is calculated from the new time data set in the area (5H) of the advance memory (5) and the time data immediately before correction saved in the area (5F). Next, in step (S5), the total time corrected is obtained from the elapsed time saved in the area (5G) and the correction interval data stored in the area (5C).
Since no correction interval data has been set in C), the total time becomes zero as a result of this processing. Next, the control unit (1) proceeds to step (S6) and steps (S4) (S
The total error is calculated by obtaining the sum of the error obtained in 5) and the corrected total time. Then, the process proceeds to step (S7) to set the polarity to be corrected from the error obtained in steps (S4) (S5) (S6). Set "1" to correct to advance, and set "0" to delay. Subsequently, the control unit (1) proceeds to step (S8) and divides the elapsed time stored in the area (5G) of the memory (5) by the total error time obtained in step (S6) to obtain an error per second. The elapsed time is calculated and used as the correction interval time. Next, in step (S9), it is determined whether the calculated correction interval time is appropriate. If the correction interval time is not appropriate, the step (S1
After proceeding to step 3) to clear the automatic correction mode, the procedure proceeds to steps (S14) and (S15) to clear the data in the areas (5C) and (5E) and terminate. On the other hand, if the correction interval time is appropriate, the process proceeds to step (S10) and the correction interval time data is stored in the area (5C) of the memory (5). Subsequently, the control unit (1) proceeds to step (S11), and the area (5C) is added to the new time data of the area (5H) of the memory (5).
The correction interval time data stored in is added, and the time at which the automatic correction is to be performed next is calculated and stored in the area (5E) of the memory (5). Thus, the time is automatically corrected.

When the automatic correction state is set in this way, the control unit (1) proceeds to the memory (5) in step (S20).
The automatic correction time stored in the area (5E) is compared with the current time in the area (5A) to determine whether it is the automatic correction time. If it is not the automatic correction time, proceed to other processing. If the automatic correction time is reached, the step (S
In step 21), the polarity data stored in the area (5D) of the memory (5) is read, and it is determined whether to advance or delay. Then, in case of advancing, the data of the area (5A) is changed so as to advance to 1 second by advancing to step (S22),
If it is delayed, the process proceeds to step (S23) so that it is delayed by 1 second. When the automatic correction process is completed, the control unit (1) proceeds to step (S24) to add the correction interval time data of the area (5C) to the data of the area (5E) of the memory (5) and then perform the automatic correction. The time is obtained and written in the area (5E) of the memory (5).

Therefore, at the next automatic correction time written in the area (5E), the correction is performed in the same manner as described above. Thus, the error is automatically corrected every time a predetermined time elapses.

Then, when a new time is set and the time is corrected next, the control unit (1) performs the process shown in FIG. 3 in the same manner as described above, but when performing the process of step (S5). Since the automatic correction is being performed, the elapsed time is divided by the correction interval time to find out how many times the automatic correction has been carried out, and the total time of the correction is calculated.
In 6), the total error is obtained by adding the error time and the corrected total time. Thereafter, the correction interval time is obtained in the same manner as described above, the data in the memory (5) is updated, and when the time to be corrected is reached, the correction is automatically performed.

[0015]

As described above, the timepiece circuit of the present invention is configured so that, when the time is adjusted, the time at which an error of 1 second occurs is calculated, and the time is automatically corrected. It is possible to configure a timepiece in which the error is not accumulated with the passage of time and the error is small.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a clock circuit of the present invention.

FIG. 2 is a schematic diagram showing a storage state of the memory of FIG.

FIG. 3 is a flowchart showing an operation state of FIG.

FIG. 4 is a flowchart showing the operating state of FIG.

5 is a flow chart showing the operation state of FIG. 1. FIG.

[Explanation of symbols] 1 control unit 2 clock pulse oscillation circuit 3 indicator 4 key input device 5 memory

Claims (1)

[Claims] 1. A means for accumulating the elapsed time from one time adjustment to the next time adjustment, a means for obtaining an error from the adjustment time and the time immediately before the adjustment, and the obtained error time and integration. A means for obtaining the correction interval time from the time,
A clock circuit comprising a means for automatically adjusting the time each time the calculated correction interval time elapses.