JPS63282510A - Time synchronization system - Google Patents

Abstract

PURPOSE:To make time information coincident between information processors by receiving a synchronizing signal and clock pulses that a time synchronizing device has internally by an information processor which has a high-accuracy timer circuit of the time synchronizing device becomes faulty. CONSTITUTION:If trouble occurs to the time synchronizing device 2, an auxiliary synchronizing signal 20-2 from a synchronizing signal selector 16 and auxiliary clock pulses 28-2 from a clock pulse selector 17 are received. The mus counter of a synchronous counter 13 is cleared to zero with the auxiliary synchronizing signal 20-2 and then counts up again with the auxiliary clock pulses 28-2. Then a timer readout circuit 14 reads in time data 24 from a timer register 11 and time data 25 smaller than a second from the synchronous counter 13 with a timer readout signal 26 and outputs the as time data 27 to an information processing part 30 which makes a request. This operation is carried out by plural information processors 1A and 1B which have high-accuracy timer circuits 10 synchronously, so that time information can be made completely coincident to a unit smaller than a second.

Description

Detailed Description of the Invention Technical Field The present invention relates to a time synchronization method, and more particularly to a time synchronization method for synchronizing time between a plurality of information processing devices using time information supplied from a time synchronization device. Regarding.

BACKGROUND ART When a highly reliable system is configured by a plurality of information processing devices, it is necessary to match time information among the plurality of information processing devices, and a time synchronization device is used for this purpose. In order to match the time information between the information processing apparatuses using the time information and control information supplied from the time synchronization apparatus, a high precision 31 o'clock circuit is provided in each information processing apparatus.

In such a case, the time synchronization device receives only one clock pulse and time information by a clock circuit built into the information processing device, and synchronizes the time between multiple information processing devices. There is. However, conventionally, although it is possible to synchronize time in units of seconds, it is impossible to synchronize times in units smaller than seconds (milliseconds or microseconds).

This has the problem of not being able to support high-reliability systems, such as the so-called hot standby system, which requires highly accurate time synchronization to match times smaller than seconds between multiple information processing devices. have

Furthermore, if a failure occurs in the time synchronization device, time synchronization between the information processing devices may no longer be performed, which again has the disadvantage that it cannot support a highly reliable system.

OBJECTS OF THE INVENTION It is an object of the present invention to make it possible to match time information to a unit smaller than a second between a plurality of information processing devices, and to achieve highly accurate time synchronization even when a time synchronization device fails. The purpose is to provide a time synchronization method.

Structure of the Invention According to the present invention, there is provided a time synchronization method that synchronizes time between a plurality of information processing devices using time information of seconds or more generated from a time synchronization device, The time synchronization device is provided with means for generating 1 and 11 signals and means for generating a main clock pulse having a period smaller than a second, and in each of the information processing devices, a timer register for taking in the time information. and means for generating an auxiliary clock pulse having the same period as the main D clock pulse, means for generating an auxiliary synchronization signal having the same period as the main synchronization signal, and alternatively controlling the main and auxiliary clock pulses. a counter that selects and counts the same, and means that selectively selects the main and auxiliary synchronization signals and uses them as zero clear signals for the counter, and when the time synchronization device is normal, the first If the time synchronization device is abnormal, the auxiliary synchronization signal and the auxiliary clock pulse are selected, and the time information from the timer register and the contents of the counter are selected. A time synchronization method is obtained which is characterized in that the time synchronization is performed between a plurality of information processing devices using the above method.

Example The present invention will be described in detail below using the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.
The information processing devices 1A and 1B have a common time synchronization color N2
This is an example in which mutual time synchronization is achieved using time information from the system, and is applied to a highly reliable system such as a hot standby system.

The information processing devices 1Δ and IB have the same configuration, and the diagram only shows the configuration of the information processing device 1A, which includes a high-precision time measurement circuit 10 and an information processing section 30. The high-precision clock circuit 10 includes a timer register 11. timer buffer 1
2. Synchronous counter 13, timer readout circuit 14. Clock circuit 15. It is composed of a synchronization signal selector 16 and a clock pulse selector 17.

Next, the operation of this embodiment will be explained with reference to the time chart of FIG. 2. First, the operation when the time synchronization device 2 is operating normally will be explained.

The time data 21 supplied from the time synchronization device 2 includes "year", "month", "day", "hour", and "minute".

This time data 21 is information consisting of "seconds" and is taken into the timer buffer 12 when the strobe signal 22 from the time synchronization device 2 is received.

The first strobe signal 22 provides "year" information, the next strobe signal 22 provides "month" information, and in turn "seconds".
Information up to this point will be imported. In this way, "year", "month", "
These time data are written into the timer register 11 using the timing immediately after all data of "day", "hour", "1 minute", and "1 second" are stored in the timer buffer 12.

This time data written in the timer register 11 is outputted to the timer readout circuit 14 as time data 24 at the timing of the main synchronization signal 20-1, which is supplied from the time synchronization device 2 at precise intervals of seconds. . This main synchronization signal 20-
1 is also received by the synchronization counter 13 via the synchronization signal selector 16.

Therefore, at this time, the synchronization signal selector 16 outputs the valid signal 23.
The main synchronization signal 20-1 from the time synchronization device 2 is selected by.

The synchronization counter 13 is constantly counted up using the 1H112 main clock pulse (1 so-called pulse > 28-1) from the time synchronization device 2. At this time, the clock pulse selector 17 also uses the valid signal 23 to count up the main clock pulse of 1H112 from the time synchronization device 2.
The main clock pulse 28-1 from . Therefore, the silent counter of this synchronization counter 13 is the main synchronization signal 2.
After being cleared to zero by 0-1, it is counted up again by 11 Js pulse 28-1. This same 1111
The counter 13 is used as a timing circuit that is smaller than the second (millisecond or microsecond) counted up by the 1 μs pulse 28-1, and in this way, the synchronous counter 13
outputs time data 25 smaller than seconds to the timer readout circuit 14.

When the information processing unit 30 performs a timer read operation, a timer read signal 26 is output from the information processing unit 30 to the timer read circuit 14. This timer read signal 26 causes the timer read circuit 14 to read "year", "month", "
Time data 24 consisting of "day", "hour", "minute", and "second"
and time data 25 smaller than the second from the synchronization counter 13
is read in synchronization with "Year" to the requesting information processing unit 3o.

It is output as time data 27 consisting of "month", "day", "hour", "minute", "second", and microseconds smaller than the second.

When the time synchronization device 2 is operating normally, it operates as described above, but if a failure occurs in the device 2, the main station) II] signal 20-1 and the main clock from the time synchronization device 2 are interrupted. When pulse 28-1 becomes invalid, auxiliary synchronization signals 20 to 2 from internal clock circuit 15 and auxiliary clock pulse 28-2 become valid via synchronization signal selector 16 and clock pulse selector 17, respectively.

Next, the operation when a failure occurs in the time synchronization device 2 and the auxiliary synchronization signal 20-2 and the auxiliary clock pulse 28-2 from the internal clock circuit 15 are received will be described.

When time synchronization device 2 is normal, timer buffer 1
The time data 21 captured in 2 is always stored in the timer register 11.
has been incorporated into. In this state, if a failure occurs in the time synchronization device 2, the auxiliary synchronization signal 20-2 from the synchronization signal selector 16 and the auxiliary clock pulse 28-2 from the clock pulse selector 17 are received. Timer register 11
The time data written in the auxiliary synchronization signal 20-2
The signal is clocked up in units of seconds and is constantly output to the timer read circuit 14. Further, after the so-called counter of the synchronization counter 13 is cleared to zero by the auxiliary synchronization signal 20-2, it is counted up again by the auxiliary clock pulse 28-2. This synchronous counter 13 is used as a time measurement circuit for smaller seconds (milliseconds or microseconds) counted up by the auxiliary clock pulse 28-2. It is output to 14.

In response to the timer read signal 26, the timer read circuit 14 reads the time data 24 from the timer register 11 and the synchronous counter 13.
The time data 25 that is smaller than the second is read in synchronization, and the "year", "month", and "day" are sent to the requesting information processing unit 30.
, "hour", "minute".

It is output as time data 27 consisting of "seconds" and microseconds smaller than seconds.

By performing the operations described above in synchronization with each of the plurality of information processing devices 1A and 1B each having a high-precision timekeeping circuit 10, the time information between these information processing devices can be completely matched down to the second or less. You will be able to do that.

As described in detail, according to the present invention, the synchronization signal, clock pulse, and time information are transmitted from the time synchronization device, and when the time synchronization device fails, the internal synchronization signal, clock By receiving the pulses with an information processing device having a high-precision timekeeping circuit, there is an effect that the time information among a plurality of information processing devices can be accurately matched to the second or less. These effects make it possible to construct a highly reliable system consisting of a plurality of information processing devices, such as a hot standby system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is an operation time chart of the blocks in FIG. Explanation of symbols of main parts 1A, IB... Information processing device 2... Time synchronization device 10... High precision clock circuit 11... Timer register 13 ...Synchronous counter 14...Timer readout circuit 15...Clock circuit

Claims (1)

[Claims] A time synchronization method that synchronizes time between a plurality of information processing devices using time information of seconds or more generated from a time synchronization device, wherein the time synchronization device includes a main synchronization signal. and means for generating a main clock pulse having a period less than a second;
Each of the information processing devices includes a timer register for capturing the time information, means for generating an auxiliary clock pulse having the same period as the main clock pulse, and generating an auxiliary synchronization signal having the same period as the main synchronization signal. a counter that selectively selects and counts the main and auxiliary clock pulses; and means that selectively selects the main and auxiliary synchronization signals and uses them as zero clear signals for the counter. , if the time synchronization device is normal, selecting the main synchronization signal and the main clock pulse;
When the time synchronization device is abnormal, the auxiliary synchronization signal and the auxiliary clock pulse are selected, and the time information from the timer register and the contents of the counter are used to synchronize the time between the plurality of information processing devices. A time synchronization method that is characterized in that it performs