JPS61255421A - Time setting system for computer - Google Patents

Abstract

PURPOSE:To obtain highly accurate and stable time setting system of a computer by checking clocks by time recognized from an external read-out clock and time recognized by an internal clock. CONSTITUTION:When interruption from an external read-out clock 5 reached n times, time of the external read-out clock 5 is read from the external read-out clock 5 through an input circuit 4, and compared with the value of time tB of an internal clock 1 provided inside of a computer 7. If the result of comparison is within a specified limit, the value from the external read-out clock 5 is set to a computer 3 as external clock time tA and internal clock time tB. Thereby, internal clock time tB is corrected automatically. When the result of judgement is out of the fixed limit, the value of internal clock time tB is adopted as the value of external clock time tA.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a computer time setting method for setting the time of a computer while synchronizing the internal clock of the computer with an external clock. [Technology] In general, the time for MH of a computer is created by installing a clock inside the computer and counting interrupts from that clock using software, or by installing an external time device and calculating the time. There are things that are created by being read by a computer. FIG. 3 is a block diagram of a conventional time setting system for realizing the above functions using an internal clock. an interrupt processing circuit that notifies the program of interrupts from 3;
is a calculator. Further, FIG. 4 is a block diagram showing a conventional time setting method using an external time device. In the figure, numerals 2 and 3 are the same as those in FIG. 3. In FIG. 4, 4 is an input circuit for inputting the external time value into the computer 3, 5 is an external time device, and 6 is an external time interrupt signal line that is output every time the external time changes.

Next, the operation will be explained. First, in the case of a configuration in which the computer device is equipped with an internal clock 1t as shown in FIG. 3, the time recognized by the computer 3 is created only by the internal clock 1.
Interrupts of internal clock 1 are counted at regular intervals by a program, and the time is m seconds, 2 seconds, and 2 minutes.

It is what creates time, 1 day, 2 months, and 2 years.

On the other hand, when the time recognized by the computer 3 is generated by an external time device 5 as shown in FIG. 4, an interrupt signal from the external time interrupt signal line 6 is notified to the computer 3 by the interrupt processing circuit 2. The external time is read through the input circuit 4 and set in the computer 3.

[Problem that the invention seeks to solve]

The time setting method of conventional computers is configured as described above to set the time, so when using the internal clock, it is necessary to adjust the time to the absolute time such as Japan Standard Time in the order (unit) of seconds or less. Moreover, if the internal clock itself is extremely accurate, the computer itself will become very expensive and uneconomical.

Furthermore, when using an external time device, since it is installed outside the computer, there is a higher probability of problems with the cable before it is imported into the computer than with an internal clock, and the external time setting can be easily changed artificially. There were problems such as the wrong time being set inside the computer due to the incorrect time being set inside the computer.

This invention was made to solve the above-mentioned problems, and aims to provide a highly accurate and stable computer time setting method based on the accuracy of the external clock and the reliability of the internal clock. .

[Means for solving problems]

A time setting method for a computer according to the present invention is to set each clock based on a time recognized from an external time device and a time recognized by the internal clock in a computer device including an internal clock and an interrupt processing circuit. I decided to check it.

[For production]

The time setting method in this invention uses an internal clock to check whether there is a failure in the external time device, and periodically corrects the delay or advance of the internal clock time set inside the computer using the external time device. This allows a highly accurate time to be set inside the computer.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is an internal clock provided inside the computer device 7, 2 is an interrupt processing circuit that notifies the program of interrupts from inside and outside the computer 3, 3 is the computer, and 4
5 is an input circuit for importing an external time value into the computer 3;
6 is an external time device, and 6 is an external time interrupt signal line that is output every time the external time changes.

The processing method for the time setting method of the computer of the present invention configured as described above will be explained with reference to the drawings. FIG. 2-1 is a flowchart showing a processing method in the computer 3 of the present invention. The case where it is started every time is shown. The judgment block 10 checks whether or not the interrupt from the external time device 5 is the nth time, that is, whether a certain period of time has elapsed.If the result of this check is that the interrupt has not reached the nth time, the system is configured only with the internal clock 1. m seconds (milliseconds) using the same processing method as in the conventional example.

Seconds, minutes, two days, September, and one year are counted, and the external clock time is set inside the computer 3 (processing block 11). Here, if the result of the check has reached n times, the time of the external time device 5 is read from the external time device 5 via the input circuit 4 (processing block 12), and compared with the value of the internal clock time tB (judgment block 13). ). If the result of this comparison is within a certain range, the values from the external time device 5 are set in the computer 4 as the external clock time tA and the internal clock time 1B (processing block 14). As a result, the internal clock time tB is automatically corrected. If the determination result is outside the certain range, the value of internal clock time 1B is adopted as the value of external clock time 1 (processing block 15).

The processing in the processing block 16 sets the count value of the internal clock processing routine to zero every time this processing routine passes a certain period of time, and uses the internal clock processing routine to determine whether or not an interrupt from the external time device 5 has failed. is being created. Next, FIG. 2-2 shows a processing method when the computer 3 is activated every 10 internal clock interrupts. First, the processing block 20 changes i of the processing block 16 of FIG. Indicates that the number is to be added by 2, and a check is made in the 2nd judgment block 21 to see if the number is greater than a certain number of times.

At this time, the value of M is determined by the decision block 10 in FIG. 2-1.
By setting it slightly larger than the fixed time value of , it is possible to determine whether or not the external time device 5 is malfunctioning. Furthermore, when a failure is detected, an external clock failure mode is set in processing block 22. The release of this failure mode is the second
This is carried out in the processing block 14 of FIG. Processing block 2
3 creates the internal clock 10 time [B] using the clock from the internal clock 1.

〔Effect of the invention〕

As described above, according to the present invention, an external time device and an internal clock are provided, and the configuration takes advantage of the high accuracy of the external clock and the stability of the internal clock, so that the time of the computer can be set with good stability and precision. There is an effect that the method can obtain.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the hardware configuration of a computer time setting method according to an embodiment of the present invention, and FIG. 2-1 is a flowchart showing an example of the processing routine of the external time device in FIG. 1. 2-2 is a flowchart showing an example of the internal clock processing routine in FIG.
FIG. 3 is a block diagram showing an example of the hardware structure of a conventional computer, and FIG. 4 is a block diagram showing another hardware structure of the conventional computer. In the figure, 1 is the internal clock, 2 is the interrupt processing circuit, and 3 is the internal clock.
is a computer, 5 is an external time device, and 7 is a computer device. In each figure, the same reference numerals indicate the same or corresponding parts. Figure 1 1: Containment flow 6: 5 points? '? Pig/”Government/”Pear! Seven Toy No. 6 East 7:
Calculation Reference Figure 2-1 Figure 2-2 Figure 3, 7 Figure 4

Claims (1)

[Claims] Time setting for a computer comprising an internal clock provided inside the computer device, and an interrupt processing circuit that notifies a program of an interrupt from an external time device provided outside the computer device and an interrupt from the internal clock. In the method, an internal clock time created by counting the number of interrupts of the internal clock to the computer and the number of interrupts sent to the computer each time the external time from the external time device changes are counted. 1. A time setting method for a computer, characterized in that the internal clock time is corrected based on an external clock time created by a computer, and a time on a program inside the computer device is set.