JPH02211543A - Task control system - Google Patents

Abstract

PURPOSE:To simplify system design by storing the current situation of a control system, and controlling the execution of a module by means of a scheduler in each task. CONSTITUTION:For example in an automatic vending machine, when cash is inputted, a coin mechanism 32 detects it, a serviceman cannot operate a keyboard until the sale of a commodity thereafter is completed or the cash is returned, then which commodity is sold is determined, and the commodity is carried. Simultaneously change is calculated, and paid out from a mechanism 32. When a series of the operations is completed, the serviceman can operate the keyboard, and the machine is restored to a waiting state. The operating state of the vending machine is stored into a state information means 4. In the module in each task, whether a program described in the own module is executed is determined beforehand based on the state information of the means 4, and the execution start of each module is controlled by the scheduler. Thus the system design can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a system in which one task constitutes a plurality of subsystems, and furthermore, those subsystems are combined in a complex manner to constitute one system, and This invention relates to a task management method for an embedded microcomputer system whose functions are frequently changed.

Here, built-in type refers to devices that are built into various products such as air conditioners and rice cookers.

[Conventional technology]

In such conventional embedded microcomputer systems, programs are often stored in read-only memory (ROM), and the system is configured on the premise that once the system is built, it will not be changed thereafter.

However, in recent years, the demands on such microcomputer systems have been diversifying along with the products into which they are incorporated, and there have been increasing demands for later changes in functionality and addition of optional functionality.

On the other hand, a function consisting of a plurality of tasks is treated as one subsystem, and a management task is provided to manage the task group of these subsystems. A request communication means and a status communication means are provided for communication between each management task that manages each subsystem. A method was proposed for increasing the independence of subsystems as modules by communicating between management tasks through their management tasks, and a patent application was filed as Japanese Patent Application No. 1981-281301. There is.

[Problem to be solved by the invention]

However, with this method, when changes that span subsystems occur, the management task that manages each task must also be modified at the same time, making the modification process complicated and making it difficult to decide which part to modify. The problem was that it took a lot of time to consider. In addition, the effects of modifications may occur in unexpected areas, making it difficult to maintain the quality of the embedded microcomputer.

An object of the present invention is to provide a task management method that is useful for realizing an embedded microcomputer that can be easily and easily modified to change or add functions later on, and with less deterioration in quality. It's about doing.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a microcomputer control system comprising a system including a plurality of processing tasks and a state information storage means for storing the state of the system. In this method, each processing task is provided with a required number of modules as program units that realize a set of functions, and is provided with a scheduler as an execution planning means for starting execution of each module.

[Effect]

The scheduler refers to the state information storage means to search (determine) which processing module in the self-processing task is executable, and causes the executable module to start execution. Each module starts processing the program written in advance in the module in response to an execution start request from the scheduler, and when it finishes, writes the resulting new state of the system into the state information storage means to update the state information. do. The scheduler searches for executable modules again based on the updated state information.

In this way, each task has a processing module and a scheduler, and the scheduler executes the processing operations of the module within each task and manages the module. To absorb changes in a program within a task, eliminate the influence on other tasks, and only need to replace the task.

〔Example〕

FIG. 1 is a block diagram showing a task management system as an embodiment of the present invention. In the same figure, l(1a, 1
b) is a task, 2 (2a, 2b) is a scheduler, 3
(3a, 3b) are modules, 4 is state information storage means, and 5 is storage means.

This embodiment will be explained by taking a control system in a vending machine as an example. A vending machine consists of the following three subsystems.

■ A cash processing subsystem that performs things such as inserting money and dispensing change; ■ A sales processing subsystem that selects products and carries them out; ■ Various operations performed by service personnel (setting product prices,
A settings processing subsystem for calculating sales amounts, sales numbers, etc.

FIG. 2 shows the task structure of this embodiment. The second money management task includes an input amount detection module that checks whether money has been input, an input amount calculation module that calculates the input amount, a change calculation module that calculates change, and a refund processing module that returns change. It will be done. The sales control task 22 includes a sellable product setting module that searches for products that can be sold for the amount invested, a button press detection module that detects the button pressed to determine the product to sell, and a button press detection module that detects the button pressed to determine the product to sell. It includes a product delivery module and a sales termination module that performs product sales termination processing. The setting processing task 23 includes a keyboard operation detection module that detects the use of a keyboard operated by a service person, a keyboard processing module that processes data input from the keyboard (such as setting a product price), and a keyboard operation module that completes the keyboard operation. Contains a keyboard termination processing module.

First, we will briefly explain the operation of a vending machine.

FIG. 3 is a configuration diagram of a control system in a vending machine. In the figure, 31 is a main control device, 32 is a coin mechanism, 33 is a device control device, and 34 is a keyboard control device. It is a multiprocessor system consisting of a control device with a microcomputer, memory, and input/output device for each function, and each control device (31
~34) are connected by communication lines.

Generally, when money (including cards) is inserted into a vending machine, it is detected by a coin mechanism (C/M), and the service is maintained until the sale of the product ends or the refund lever is pressed and the money is returned. prevent Man from using the keyboard, then decide which products to sell,
(Checking which button on the front of the vending machine was pressed, etc.) Based on that decision, the product is delivered. At the same time, change is calculated and paid out from the coin mechanism (C/M). When this series of operations is completed, the service person is enabled to operate the keyboard and the machine returns to the standby state.

FIG. 4 shows the stored contents of the status information storage means 4 representing the operating status of the vending machine as described above. have. For each module in each task shown in FIG. The scheduler controls the start of execution.

FIG. 5 shows the execution start conditions for each module and the state information set when the module finishes execution. The inserted amount detection module starts execution when it is on standby, and when it detects that money has been inserted, it resets the waiting state and sets it to the depositing state. Further, the refund processing module starts execution when "on sale" is set, and sets "end of refund" when processing is completed. Input amount calculation, change calculation.

This indicates that each module of the sellable product setting is repeatedly executed while the payment in progress is set.

Figure 6 shows a processing flowchart of the money management task.
Since other tasks have a similar structure, an example of the money management task will be explained below.

Step 61 indicates the waiting time required for other tasks to operate. Step 62 is the state information storage means 4
This process searches for executable modules.

For example, if the status information is set to Waiting, this indicates that the inserted amount detection module is executable. Also, if the status information is set to ``Depositing'', it is checked that the two modules, the input amount calculation module and the change calculation module, are executable, and since it is not possible to execute both modules at the same time, one of these modules is selected first. choose,
There are various methods for this selection, but in this embodiment, it is assumed that both modules are selected to be executed alternately. This has flags in the scheduler that indicate the execution of both, and sets the flag of the one that issued the execution request and resets the other. By checking this flag, execution requests are issued alternately in step 63 and step 62.
Starts execution of the module selected by .

Steps 64 and 65 are input amount detection modules, step 66 is an input amount calculation module, step 67 is a change calculation module, and steps 68 and 69 are refund processing modules. Here, in step 65, when it is detected in step 64 that money has been deposited, the state information is reset to "waiting" and "depositing" is set. Further, in step 69, when the refund processing in step 68 is completed, the state information is set to the end of refund.

If the above explanation is applied to FIG. 1, the money management task corresponds to 1a, for example, and the input amount detection module,
It goes without saying that the input amount calculation module, the change calculation module, and the refund processing module correspond to 3a, the scheduler corresponds to 2a, and the state information storage means corresponds to 4.

〔Effect of the invention〕

According to the present invention, in a control system composed of a plurality of tasks, a state information storage means for storing the current state of the control system, and a scheduler (referring to the state information storage means) disposed within each task are provided. Since the execution of the module is controlled by executing the executable module within the task, the judgment whether the module is executable is made only based on the state information, and there is no need to consider interference with other tasks. (This has the effect of simplifying system design.

Also, when making system changes such as adding or deleting modules, the startup timing between tasks and modules is determined only by the state information and the scheduler and does not depend on the program structure, so refer to the state information and scheduler for the impact of changes. By doing so, you can obtain the effect of being able to investigate in a unified manner.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a system configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an example of a task configuration, FIG. 3 is a block diagram showing an example of a hardware configuration of a vending machine, and FIG. 5 is an explanatory diagram showing an example of the storage contents of the state information storage means, FIG. 5 is an explanatory diagram of the relationship between each module in a task, its execution start condition, and the state information to be operated. FIG. 3 is a chart showing a processing flow of management tasks. Explanation of symbols 1 (1a, lb) --- task, 2 (
2a, 2b)...Scheduler, 3 (3a, 3b)
...Module, 4...Status information storage means, 5...
- Data, 31... Main control device, 32... Coin mechanism, 33... Equipment control device, 34... Keyboard control device, 21... Money management task, 22...
Sales control task, 23...setting processing task fig.

Claims (1)

[Scope of Claims] 1) In a microcomputer control system comprising a system including a plurality of processing tasks and a state information storage means for storing the state of the system, each processing task has the state information storage means for storing the state of the system. an execution planning means that determines which processing module in the self-processing task is executable by referring to the means and starts execution of the executable module; 1. A task management method comprising: the processing module which writes a new state of the system resulting from the start and completion of execution of a predetermined process into the state information storage means.