JPH05257875A - Method for evading interruption processing start delay - Google Patents

Abstract

PURPOSE:To start interruption processing without any delay by a software system which is placed in an interruption inhibition period. CONSTITUTION:If an interruption processing request is generated at optional timing during the execution of processing 1 including the interruption inhibition period, the start of interruption processing 5 is delayed if the current processing position 2 is in the interruption inhibition period (between 3 and 4). For the purpose, temporary interruption processing is performed before main interruption processing to absorb the delay of the processing start in the interruption inhibition period by the temporary interruption processing and the real interruption processing start is set in the temporary interruption processing to eliminate the delay of the processing start.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to execution and control of interrupt processing in software including an interrupt prohibition period.

[0002]

2. Description of the Related Art Interrupt processing has an interrupt level (priority), and interrupt prohibition also gives an interrupt enable / disable according to the interrupt level.

When there is an interrupt processing execution request, during the interrupt disabled period or during another interrupt processing, it is determined whether the interrupt processing is executed or delayed depending on the interrupt level. In order to execute the interrupt processing instantly without delay, the interrupt level may be increased. With this interrupt level, interrupt processing is executed without delay.

[0004]

When it is desired to execute the corresponding interrupt processing without delay, the interrupt level may be set to the highest, but the interrupt level of interrupt inhibition is equal to or higher than the interrupt level of the interrupt processing. If the interrupt level is higher than the above, and the interrupt processing start cannot be delayed in some cases.

An object of the present invention is to avoid the delay in starting the corresponding interrupt processing in such a software system.

[0006]

First, the length (time interval) of the interrupt prohibition period is known.

Next, a tentative interrupt processing execution request is issued before the time interval from the time when the true interrupt processing execution request that does not want to delay the processing start occurs.

The interrupt level is set to "real interrupt process> temporary interrupt process>other".

Then, by making a real interrupt processing execution request during the temporary interrupt processing, the interrupt prohibition period is avoided.

[0010]

The provisional interrupt process executed prior to the actual interrupt process to be executed is such that the true interrupt process does not fall within the interrupt disable period at the time of execution request.

Even if the start of the temporary interrupt processing is delayed and the start of the temporary interrupt processing is delayed, the temporary interrupt processing is started before the time (interval) of the interrupt disable period from the time when the real interrupt processing execution request is generated. Since the interrupt processing execution request is generated, the temporary interrupt processing is in progress when the true interrupt processing execution request is generated, and the real interrupt processing can be executed instantaneously.

During the temporary interrupt processing, execution of other processing including the interrupt prohibition period is prohibited depending on the interrupt level, and only a true interrupt processing execution request can be accepted.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the process flow (FIG. 1), a comparison between (a) conventional and (b) the present invention is shown.

The timing chart (FIG. 2) also shows a comparison between (a) conventional and (b) the present invention.

Conventionally, an execution request for the interrupt processing 5 is generated at an arbitrary timing during the processing 1. Current processing position 2
However, in the interrupt prohibition period (between 3 and 4), the start of interrupt processing is delayed. Therefore, in the present invention, the temporary interrupt process is executed prior to the true interrupt process to be executed. At this time, the current processing position 2 is the interrupt prohibition period (3-4
In case of (interval), the start of provisional interrupt processing is delayed. When the interrupt is released and the temporary interrupt process starts and a true interrupt process execution request occurs, the current processing position 2 is in the temporary interrupt process and the interrupt disable period is not reached. Runs without delay.

In order to prevent the true interrupt processing from falling within the interrupt prohibition period, the temporary interrupt processing need not be in progress. For example, while a task called from a temporary interrupt process is being executed, the interrupt level is taken into consideration so that a true interrupt process execution request can be accepted, and timing is designed so that other interrupt processes are not executed. May be. Further, the interrupt level may be taken into consideration so that even if another interrupt process is executed during the temporary interrupt process, the real interrupt process execution start is not delayed.

[0018]

The OS (operating system) generally has a part in which interrupts are prohibited within the OS in order to protect the resources managed by the OS, but the problem is that the period is as short as several tens (μs). Does not mean However, unless the excitation & sampling of the flow rate signal is performed periodically accurately as in the case of an electromagnetic flow meter, an error occurs in the counter value from the A / D converter obtained by sampling, and the counter value is obtained. The flow rate value will also be inaccurate. When the OS is adopted as the software of this electromagnetic flow meter, the sampling cycle of the excitation & flow rate signal can be accurately maintained by the present invention.

Further, according to the present invention, since an existing OS can be used without modifying the OS, it is economical,
And the reliability of the software is improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a process flow in a program.

FIG. 2 is a timing chart of processing in a program.

[Explanation of symbols]

1 ... Processing, 2 ... Current processing position, 3 ... Interrupt disabled, 4 ...
Interrupt disable release, 5 ... Interrupt processing.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Saito 882, Ige, Katsuta-shi, Ibaraki Hitachi Ltd. Measuring Instruments Division

Claims (1)

[Claims] 1. A program comprising an interrupt process that must start processing instantly when an event occurs and a processing part that disables the interrupt, and the event occurs during the interrupt disable period. When there is an interrupt processing execution request, in order not to delay the interrupt processing start,
A method for avoiding an interrupt processing start delay, characterized in that provisional interrupt processing execution is provided before the interrupt processing.