JP3294004B2 - Dual clock system for information equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is suitable for use in various information devices (hereinafter simply referred to as information devices) such as personal computers and time recorders which perform data processing using time information of a built-in system clock. It concerns a dual clock system.

[0002]

2. Description of the Related Art A general information device has a built-in system clock equipped with a crystal oscillator, and performs various data processing using time information sent from the system clock. System clocks used in information equipment have poor crystal oscillation accuracy and have an error of about 30 seconds per week. Therefore, there is a problem that various data processing is performed based on the incorrect time information. Was.

Therefore, a system clock having a built-in high-precision crystal oscillator is used, or the built-in clock is corrected based on a standard frequency (JJY) or a time signal of a television / radio, and furthermore, By using a clock system configured to correct a built-in clock by receiving a standard time supply using a telephone line, the built-in clock is made highly accurate and the reliability of time data is increased.

[0004]

However, in the case of a system clock equipped with a high-precision crystal oscillator, since the clock is incorporated in an information device in an independent state, the clock data is corrupted by the occurrence of some kind of trouble. When this occurs, it is not possible to monitor or correct this time data error,
There was a problem that data processing was continued without knowing the wrong clock data.

In the case of the above-mentioned timepiece system in which the built-in timepiece is corrected on the basis of a standard frequency or a time signal, the accuracy of the timepiece can be ensured, but the system as a whole is very complicated and expensive, There is a problem that it cannot be used in a local area, and the above-mentioned clock system that corrects the built-in clock using a telephone line is also very complicated and expensive as a whole system. There was a problem that it could not be used.

Accordingly, a technical object of the present invention is to make it possible to accurately monitor and correct a clock incorporated in an information device by a simple device, thereby improving clock accuracy and high reliability of time data in the information device. That is, it can be obtained at a relatively low cost.

[0007]

Means taken by the present invention to solve the above-mentioned technical problems are as follows.

In an information device configured to perform various data processing using time information of a built-in system clock,

(1) A master clock configured with high accuracy, clock comparing means for comparing the time of the master clock with the time of the system clock, and a result of comparison by the clock comparing means,
Clock reset means for correcting the system clock to match the master clock when the error between the two clocks is within a specified range;
Similarly, as a result of the comparison by the clock comparing means, when the error between the two clocks exceeds the specified range , and when the master
Even if there is an error within the specified range between the
The clock reset means resets the system clock.
And reset alarm means for outputting an alarm for clock correction in the case where the alarm is not known.

(2) At power-on and at regular time intervals,
It is configured to compare the time by the clock comparing means and to correct the system clock based on the time comparison or to output a clock correction alarm.

[0011]

The respective means described in the above (1) and (2) operate as follows.

According to the means described in the above (1), even if the accuracy of the system clock built in the information equipment is poor, another high-precision clock can be added to this and used as a master clock. The system clock, which had been single until now, is monitored by the master clock to correct the deviation.If the deviation is large, it is considered that one of the clocks has gone out of control, and an alarm is output. In order to enable the correction, the reliability of the clock data and the clock accuracy can be easily realized by means that can be implemented relatively simply and at low cost simply by adding a master clock.

Further, according to the means described in the above (1),
There is an error within the specified range between the star clock and the system clock.
The clock comparison means detects that
Re-set to manual stage match the system clock to the master clock
If the processing is not performed, it is regarded as CPU runaway and immediately
In any case, the alarm for resetting the clock is output.
To ensure high clock accuracy and high reliability of time data
Enable .

According to the means described in the above (2), the system clock and the master clock are automatically compared when the power is turned on or at regular time intervals according to a program. To perform correction or alarm output,
It is possible to always secure the clock accuracy of information devices and to further enhance the reliability of time data.

[0015] As described above, the above-mentioned technical problems can be solved by the above-mentioned means, and the problems of the conventional technology can be solved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the dual timepiece system for information equipment according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram clearly showing a dual timepiece system for information equipment according to the present invention, and FIG. 2 is a block diagram showing an electrical configuration of the present invention. In FIG.
Denotes an entire information device such as a personal computer or a time clock; 1 denotes a CPU constituting a center of a control unit built in the information device T; 2 denotes a ROM in which a system program is stored; and a RAM in which various data are filed. 3 is a keyboard used when inputting / outputting various information, 4 is a display for displaying various information or an alarm described later, 5 is a printer for printing out various information and data, and 6 is a CPU 1 Various peripheral devices to be connected, 7 is a system clock built in the main body of the information device 1 in advance, and 8 is a unique master clock added to the extension board. It is configured with higher precision than that.

The information device T performs various data processing based on time data transmitted from the system clock 7, while the CPU 1 turns on a power supply (not shown) according to a program in the memory 2, and When the time information is received from the master clock 8 at regular time intervals and the error (inconsistency) of the system clock 7 is adjusted, if the error exceeds a specified range (for example, 10 minutes), either of the clocks 7 or Assuming that the clock 8 is in a runaway state, a clock correction message is displayed on the display 4 to prompt an operator or the like to reset the clocks 7 and 8.

Next, the processing procedure of the clock correction according to the present invention will be described with reference to the flowchart shown in FIG.

In the first step S1, it is determined whether or not the present time is the clock check timing, that is, whether or not the power is turned on, or whether or not it is the preset clock check time. If the answer is NO, the process proceeds to step S2, and the process proceeds to the clock data access process. If NO, the process proceeds to step S1
The routine proceeds to 0, where normal processing such as a personal computer or a time clock is executed.

In the next step S3, the time of the master clock 8 is read out. Then, the process proceeds to step S4, in which the time of the system clock 7 is read out. In step S5, the times of both clocks 7, 8 are compared. In step S6, it is determined whether or not the error between the two clocks 7, 8 is within a specified range (for example, within 10 minutes). If YES (within the specified range), the process proceeds to step S7; Is exceeded), it is considered that one of the clocks 7 and 8 is running away, and the process proceeds to step S11.

In step S7 described above, the time content of the master clock 8 is read again, and then, in step S8
After correcting the error of the system clock 7 with the time content of the master clock 8 and proceeding to the normal process of step S9, the process returns to step S1 and repeats the above process.

On the other hand, in step S11 described above, it is determined that the master clock 8 or the system clock 7 is defective. Then, the flow proceeds to step S12, where a reset alarm is displayed on the display 4, and then the flow proceeds to step S13. The processing operation of T is suspended, and thereafter, step S14
When manual correction of each of the clocks 7 and 8 is performed by the operator or the like, the process returns to step S1 to repeat the above-described processing.

In the above-described embodiment, the alarm for correcting the clock is displayed on the screen of the display 4 to inform the user of the alarm. However, the alarm is activated by operating a sound generator (not shown). And the selection is optional.

In the present invention, steps S6 and S7 described above are executed, and the master clock 8 and the system clock 7 are executed.
If the clock correction process in step S8 is not executed, although it is clear that there is an error within the specified range between the step S1 and
The process 2 is executed, that is, the reset alarm output process is executed, and a mechanism for notifying the operator or the like of the process is established.

[0026]

As described above, according to the dual clock system for information equipment according to the present invention, it is possible to monitor and correct the deviation of the system clock built in the information equipment only by adding a high-precision master clock. It can be used for various information devices, such as personal computers and time clocks, because it can achieve high clock accuracy and high reliability of clock data, and can be implemented at a very simple and low cost. It is suitable for Jun.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram clearly showing a dual timepiece system for information equipment according to the present invention.

FIG. 2 is a block diagram illustrating an electrical configuration of the present invention.

FIG. 3 is a flowchart illustrating a clock correction processing procedure according to the present invention.

[Explanation of symbols]

T Information devices such as personal computers and time clocks 1 CPU 4 Display 7 System clock 8 Master clock

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G04G 3/00 G04G 5/00

Claims (2)

(57) [Claims] 1. An information device configured to perform various data processing using time information of a built-in system clock, comprising: a master clock configured with high accuracy; a time of the master clock and a time of the system clock. And a clock resetting means for correcting the system clock to the master clock when the error between the two clocks is within a specified range as a result of the comparison by the clock comparing means.
As a result of the comparison, when the error between the two clocks exceeds the specified range , and between the master clock and the system clock
Clock resetting means despite the error within the specified range
A reset alarm means for outputting an alarm for clock correction when the system clock is not reset. 2. The system according to claim 1, wherein at power-on and at fixed time intervals, the clock comparison means compares the time and corrects the system clock based on the time comparison or outputs a clock correction alarm. The dual clock system for information equipment according to claim 1, wherein