JPH06186358A - Automatic time corrector for digital timepiece - Google Patents

Abstract

PURPOSE:To enhance reliability by allowing automatic correction of time measuring error of a digital timepiece due to noise. CONSTITUTION:A main CPU 1 counts clock pulses outputted from a reference clock generating section 6 and reads out time data from a timepiece function LSI2 every predetermined reference time and stores the time data in a RAM7. A time interval data between current and previous time data is then determined and compared with the reference time and when they do not match each other, a decision is made that the time piece function LSI2 functioned erroneously. A reference time based on a reference clock is then added to the previous time data to create a current time data thus setting the current time of the timepiece function LSI2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital timepiece, and more particularly to an automatic time adjustment device for automatically correcting a time difference.

[0002]

2. Description of the Related Art A clock function LSI is built in not only a timepiece but also various electric devices and is used, for example, as a part of a time circuit of a household electric appliance or a time recording circuit of a time recorder.

[0003]

The clock function LSI incorporated in the electric device may cause a timing error due to the influence of high frequency noise propagated from other circuits. The CPU of the electric device having the built-in clock LSI controls on / off of the device and records the time based on the time data of the clock LSI. Need to be set again.

Therefore, according to the present invention, the operation of the timepiece LSI is monitored, and when an error occurs, the operation is automatically corrected to prevent the operation failure, and the setting operation by the user is not required to improve the reliability. The purpose is to improve.

[0005]

The present invention is proposed in order to achieve the above-mentioned object, and comprises a processor having a time setting function of a clock function LSI and a reference clock generator, and has a predetermined read interval. And the LSI for clock function
Means for sequentially reading and storing the time data, means for comparing the timing result of the reading interval in the clock function LSI with a reference value based on the reference clock number, and a reference time obtained from the reference value in the previous time data. For calculating the current time data, and the current time data according to the comparison result of the comparing means.
To provide an automatic time adjustment device in a digital timepiece provided with a means for setting the time.

[0006]

The processing device for controlling the time setting of the clock function LSI sequentially reads and stores the time data from the clock function LSI at a predetermined reading interval. The time measurement result of the read interval in the clock function LSI is compared with the reference value defined by the reference clock number of the reference clock generator. When it is determined that the interval time data is different from the reference value and the timekeeping operation of the clock function LSI is affected, the current time data is generated by adding the reference time based on the reference value to the previous time data, The current time data is set in the clock function LSI.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a block diagram of a time recorder. The main CPU 1 drives the display unit 3 such as an LED to display the date, the day of the week, and the time according to the time, day of the week, and date data read from the clock function LSI 2, and prints when the time card is inserted. The section 4 is driven to print the time on a predetermined date column of the time card. LSI for clock function 2
The time is set from the input unit 5 via the main CPU 1.

The main CPU 1 counts the clock pulses output from the reference clock generator 6, and writes the time and date data in the RAM 7 each time the set count is reached.
Then, when the deviation of the time data is detected according to the procedure described later, the clock function LSI is passed through the reset control unit 8.
System reset for 2 and current time data calculated based on the reference clock
Set to 2. The procedure of this automatic adjustment of the current time will be described with reference to the flowchart of FIG.

The clock counter of the main CPU 1 is preset with a clock count number corresponding to an arbitrary time. Further, when the time is set in the clock function LSI 2 via the input unit 5, the main CPU 1 writes the set time in the address DT0 of the RAM 7. Then, counting is started by the clock input from the reference clock generating unit 6 (step 101 → 102). When the set number is counted up (step 103), the counter is reset (step 104), and the data at the address DT0 is changed to D.
After transferring to T1, the current date and time data is read from the clock function LSI 2 and written to DT0 (step 1
05).

Then, the previous time data DT1 is subtracted from the current time data DT0 to calculate the interval time data (step 106), and the reference time and the interval time data obtained from the set clock count number / the reference clock frequency are calculated. To determine whether the date and time data are correct (step 107). Here, the interval time data matches the reference time, or the deviation is the reading time and the clock function L.
If it is within the allowable error range considering the performance of SI2, it is determined to be normal and the process ends, and the automatic correction program is executed again from step 101. If the deviation is out of the allowable range, the main CPU 1 drives the reset control unit 8 to reset the clock function LSI 2 and restart it (step 1).
08). Then, the reference time is added to the previous time data stored in DT1 to obtain the current date and time data T
Is calculated (step 109), the current time of the clock function LSI 2 is set (step 110), the time adjustment is completed, and the program from step 101 is executed again.

In this way, the LS for the clock function is set at regular intervals.
The elapsed time data obtained from the time data of I2 is compared with the reference time obtained from the reference clock. If the elapsed time data and the reference time do not match, the reference time is added to the previous time data to obtain the current time data. Is calculated, and this data is set in the clock function LSI 2. Therefore, the operation of the clock function LSI 2 is automatically controlled to be equal to the reference clock accuracy of the reference clock generation unit 6.

FIG. 3 shows another embodiment. Here, a clock function LSI of the type that transmits a clock pulse for operating state monitoring at a constant interval is used, and the clock pulse is used. . In the memory of the main CPU 1, the number of clock pulses of the reference clock generation unit 6 corresponding to the clock pulse interval of the clock function LSI 2 is set in advance as the reference number.

First, the main CPU 1 is an LS for clock function.
When the clock pulse of I2 is input, the reference clock starts counting, and the reference clock is counted until the next clock pulse is input from the clock function LSI 2 (step 201 → 204). When the next clock pulse is input, counting is stopped, the count number is read, and the counter is reset (step 205).

Then, the data at the address DT0 is changed to DT1.
To the current date from the clock function LSI2.
Read time data and write to DT0 (step 20)
6). Then, the number of clock pulses actually counted is compared with the reference number (step 207), and if both match or are within the allowable range, it is determined that the clock function LSI 2 is operating normally, and the process ends.

If the comparison results do not match and the deviation is outside the allowable range, it is determined that the clock pulse interval of the clock function LSI 2 indicates an abnormal operation, and it is obtained from the reference number of set reference clocks. Reference time and address D
The previous time data stored in T1 is added to calculate the current date and time data T (step 209),
Set the current time of the clock function LSI 2 (step 21
0) and the time adjustment is completed.

Incidentally, in the step 207, as in the embodiment of FIG.
The elapsed time data may be calculated by subtracting 1 and the reference time obtained from the set reference number of clock pulses may be compared with the elapsed time data. Depending on the timepiece LSI, step 108 in FIG. 2 and step 208 in FIG. 3 may be omitted and the current time data T may be set without resetting. Further, although the one embodiment has been described with respect to the time recorder, it is needless to say that it can be applied to a device having another clock function.

[0017]

As described in detail in the above embodiment, the present invention monitors the operation of the clock function LSI, and automatically detects the reference time when a deviation occurs with respect to the reference time by another reference clock. Since the time based on is reset, the accuracy of the reference clock is maintained without the user's hand, and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a time recorder showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a control procedure of the automatic time adjustment device.

FIG. 3 is a flowchart showing a control procedure of another embodiment.

[Explanation of symbols]

 1 Main CPU 2 Clock Function LSI 3 Display Section 4 Printing Section 5 Input Section 6 Reference Clock Generation Section 7 RAM 8 Reset Control Section

Claims (1)

[Claims] 1. A clock function LSI comprising a processor having a time setting function and a reference clock generator, and means for sequentially reading and storing time data from the clock function LSI at a predetermined read interval, and a clock function A means for comparing the timing result of the read interval in the LSI with a reference value based on a reference clock number; a means for adding the reference time obtained from the reference value to the previous time data to calculate the current time data; An automatic time adjustment device in a digital timepiece provided with means for setting the present time data in a timepiece LSI according to the comparison result of the means.