JPH0395660A - System time setting method for plural central processing unit method - Google Patents

Abstract

PURPOSE:To secure the synchronization with much higher accuracy when the internal time has an error and the system time is set again by providing a time setting request acceptance means, a time transmission means, a time reception means and an internal time setting means. CONSTITUTION:A time setting request acceptance means 110 accepts a system time setting request produced in a 1st central processing unit (CPU) 100 and starts a time transmission means 120. The means 120 secures the internal time data clocked in the CPU 100 as the system time data. Then the means 120 sends the system time data to a bus so as to send them in a batch to the CPU 100 and a 2nd CPU 200. A time reception means 130 of the CPU 100 and a time reception means 230 of the CPU 200 receive the system time data received from the means 120 via a bus 300 at the same time under the execution right of the highest priority that can be set in its own CPU and start the internal time setting means 140 and 240 respectively. At the same time, the system time data are sent to both means 140 and 240.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a system in which a plurality of central processing units are connected by a bus bar (hereinafter referred to as a multiple central processing unit system), and in particular, to a system in which a plurality of central processing units are connected by a bus bar. This invention relates to a system time setting method in a multiple central processing unit system for synchronization.

[Conventional technology]

In a multiple central processing unit system consisting of multiple central processing units in which each central processing unit independently measures internal time, errors may occur over time between the internal times measured in each central processing unit. It is inevitable that it will occur. For this reason, in the conventional system time setting method in this type of multiple central processing unit system, internal time data kept in a specific central processing unit in the multiple central processing unit system is transmitted to other central processing units via the bus line. The central processing unit that transmitted the internal time data and received the internal time data from the bus set the internal time data as its own internal time, thereby synchronizing the internal times of the plurality of central processing units.

FIG. 2 is a block diagram showing an example of a multiple central processing unit system to which a conventional system time setting method is applied. This multiple central processing unit system includes a first central processing unit 400 including internal time securing means 410 and internal time transmitting means 420, and a second central processing unit including internal time receiving means 510 and internal time setting stage 520. 500, the first central processing unit 400, and the second central processing unit 50
0 and a bus bar 600 that connects the Next, the operation when synchronizing the internal time between each central processing unit using the conventional system time setting method will be described with reference to the example shown in FIG.

The first central processing unit 4 where the system time setting request occurred
00, the internal time securing means 410 first secures the internal time data TI in the first central processing unit 400, activates the internal time transmitting means 420, and transmits the internal time data T.
Hand over 1. The internal time transmitting means 420 transmits the internal time data TI passed from the internal time securing means 410 to the bus line 6.
00 to the second central processing unit 500 which receives the internal time data T1.

Internal time receiving means 510 within second central processing unit 500
receives internal time data Tl from bus 600, activates internal time setting means 520, and delivers the internal time data. The internal time setting stage 520 sets the internal time data T1 passed from the internal time receiving means 5'IO to the second stage.
is set as the internal time of the central processing unit 500.

[Problem to be solved by the invention]

In the system time setting method in the conventional multiple central processing unit system described above, from the time when the internal time securing means 410 within the first central processing unit 400 secures the internal time data TI, the internal time within the second central processing unit 500 The time Tx that has passed until the time setting means 520 sets the internal time data T1 becomes an error between the internal time in the first central processing unit 400 and the internal time in the second central processing unit 500. There are drawbacks.

In view of the above-mentioned points, an object of the present invention is to send a signal from a time transmitting means to a bus line in response to a system time setting request arbitrarily generated at an arbitrary time in a multiple central processing unit system in which a plurality of central processing units are connected by a bus line. The system time data sent by the simultaneous transmission function is received by each central processing unit that wants to set the system time among the multiple central processing units at the same time, and the internal time of each central processing unit is set at the same time. An object of the present invention is to provide a system time setting method in a multiple central processing unit system that synchronizes the time.

[Means to solve the problem]

The system time setting method in the multiple central processing unit system of the present invention connects a plurality of central processing units, each of which measures time independently, through a bus bar, and requests system time setting from any central processing unit in the system. In a multiple central processing unit system that has a simultaneous transmission function that can simultaneously send the information to all central processing units including the originating central processing unit, the system time setting that occurs in any central processing unit. a time setting request receiving means for accepting a request; a time transmitting means activated by the time setting request receiving means to send system time data of the own central processing unit to the bus line by a simultaneous transmission function; a time receiving means for receiving the system time data that has been sent; and a time receiving means for setting the system time data activated by the time receiving means and passed from the time receiving means as the internal time within the own central processing unit, and for setting the internal time within a predetermined time. and internal time setting means for monitoring whether the setting is completed.

[Effect]

In the system time setting method in the multiple central processing unit system of the present invention, the time setting request receiving means receives a system time setting request generated in any central processing unit,
The time transmitting means is activated by the time setting request receiving means and sends the system time data of the own central processing unit to the bus line by a simultaneous transmission function, the time receiving means receives the system time data sent to the bus line by the time transmitting means, The internal time setting means is activated by the time receiving means, sets the system time data passed from the time receiving means as the internal time within its own central processing unit, and monitors whether the setting of the internal time is completed within a predetermined time.

(Example) Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing a multiple central processing unit system to which a system time setting method according to an embodiment of the present invention is applied. This multiple central processing unit system includes a first central processing unit 100 including a time setting request receiving means 110, a time transmitting means 120, a time receiving means 130, and an internal time setting means 140;
a second central processing unit 200 including time transmitting means 220, time receiving means 230 and internal time setting means 240;
First central processing unit 100 and second central processing unit 200
It is composed of a bus bar 300 that connects the . Next, the operation of the system time setting method in the multiple central processing unit system of the present embodiment configured as described above will be explained.

The time setting request receiving means 110 is a first central processing unit l.
When a system time setting request generated within 00 is received, the time transmitting means 120 is activated. The time transmitting stage 120 activated by the time setting request receiving means 110 secures the internal time data measured within the first central processing unit 100, which is its own central processing unit, as system time data, and transmits the system time. In order to simultaneously transmit data to two central processing units, the first central processing unit 100 and the second central processing unit 200, which are coupled to the bus 300, the system time data can be transmitted simultaneously to the two central processing units (not shown). ) to the bus 300. Time receiving means 1 in the first central processing unit 100 where the system time setting request has occurred
30 and the time receiving means 230 in the second central processing unit 200 receive the system time data transmitted to the bus line 300 by the time transmitting means 120 under the execution right of the highest priority that can be set within the own central processing unit. received at the same time,
The internal time setting means 140 and 240 are activated and the system time data is delivered to the internal time setting means 140 and 240.

The internal time setting means 140 and 240 activated by the time receiving means 130 and 230 receive the time under the execution right of the highest priority that can be set within the first central processing unit 100 and the second central processing unit 200. The system time data received from means 130 and 230 is set as internal time data of first central processing unit 100 and second central processing unit 200. As a result, the internal times of each central processing unit of the first central processing unit 100 and the second central processing unit 200 are synchronized with extremely high precision. Internal time setting means 1 activated by time receiving means 130
40 is the system time data received from the time receiving means 130 under the execution authority of the highest priority that can be set within the first central processing unit if 1 0 0 and the first central processing unit!
Compare it with the internal time data currently being measured at 100,
If the error is within a predetermined range, the system time data received from the time receiving stage 130 is set as the internal time data of the first central processing unit 100, and the system time setting request issuer is notified. Returns illumination that the system time setting was successful. Further, if the comparison result is outside the predetermined error range, the internal time setting means 140 restarts the time setting request receiving means 110 in the first central processing unit 100 and restarts the time setting request receiving means 110. Count the number of times.

Time setting request receiving means 11 in internal time setting means 140
If the number of restarts relative to 0 exceeds a predetermined value, the internal time setting means 140 returns a notification of failure to set the system time to the system time setting request issuer.

In the above embodiment, the operation when the system time setting request is generated within the first central processing unit 100 has been described, but also when the system time setting request is generated within the second central processing unit 200, the operation is completely different. Needless to say, the operation will be similar.

Further, in the above embodiment, a multiple central processing unit system in which two central processing units are connected by a bus bar was explained as an example, but a multiple central processing unit system with m (an integer greater than or equal to 3) central processing units is explained. iI1, of which n(
≦m positive integer) When setting the system time between central processing units, each time receiving unit in the n central processing units receives the system time data sent by the time transmitting unit, and each internal It goes without saying that the present invention can be similarly implemented by setting the time as internal time data by the time setting means.

[Effects of the Invention] As explained above, the present invention provides a time setting request receiving means,
By providing a time transmitting means, a time receiving means, and an internal time setting means, in a multiple central processing unit system, an error occurs in the internal time measured in each central processing unit, making it necessary to reset the system time. In this case, it is possible to synchronize the internal times in each central processing unit with much higher precision than in the prior art.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a multiple central processing unit system to which a system time setting method according to an embodiment of the present invention is applied, and FIG. 2 is a block diagram showing a multiple central processing unit system to which a conventional system time setting method is applied. FIG. 2 is a block diagram showing an example. In the figure, 100...first central processing unit, 200...
- Second central processing unit, 110, 210 - Time setting request receiving means, 120, 220 - Time transmitting means, 130, 230 - Time receiving means, 140, 240 - Internal time setting means, 300...Bus line It is. Figure 1

Claims (1)

[Scope of Claims] A plurality of central processing units whose individual central processing units measure time independently are connected by a bus bar, and includes a central processing unit that sends a system time setting request from any central processing unit in the system. In a multiple central processing unit system having a simultaneous transmission function that can send data to all central processing units at the same time, a time setting request receiving means that accepts a system time setting request generated in any central processing unit; , a time transmitting means that is activated by the time setting request receiving means and transmits the system time data of its own central processing unit to the bus line by a simultaneous transmission function; and a time at which the system time data transmitted to the bus line by this time transmitting means is received. and a receiving means, which sets the system time data activated by the time receiving means and passed from the time receiving means as an internal time within its own central processing unit, and monitors whether or not the setting of the internal time is completed within a predetermined time. 1. A system time setting method in a multiple central processing unit system, comprising: internal time setting means.