JPH0387934A - Program monitor - Google Patents

Abstract

PURPOSE:To improve the development efficiency of a task program of large capacity by securing such a constitution where a program monitor switches a task to an address bank which stores the task program by reference to a table of address banks storing the task programs. CONSTITUTION:When a monitor acquires the executing right of a CPU, the monitor calculates a task to be started next and transfers the executing right of the CPU to this task to perform a task switching process. Then the monitor calculates the ID number of the task to be started next and acquires an address bank and an execution address via a table consisting of the address banks 2, 5 and 8 and the task execution addresses 3, 6 and 9. The monitor switches the address banks based on the acquired address bank, opens the register and the work area necessary for the task to be started to the due task, and transfers the executing right of the CPU to the task based on the acquired execution address. As a result, a task program of large capacity easily is developed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a monitor, and in particular, a table showing address banks corresponding to each task and a function to switch to an address bank containing a program for the task when starting a task. Regarding monitors including

[Conventional technology]

Conventionally, this type of monitor has not had a function to switch address banks when switching tasks.

[Problem to be solved by the invention]

The conventional monitors mentioned above did not have a function to switch address banks when switching tasks, so when using a CPU with a narrow address space or when the program capacity of a task becomes large, the task program itself has to perform tasks such as switching banks. This has the disadvantage that the amount of work increases and errors in task program production are more likely to occur.

[Means to solve the problem]

The program monitor of the present invention has a table showing address banks corresponding to each task, and means for switching to the address bank corresponding to each task when switching tasks.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

In Figure 1, each task has task ID numbers 1 and 4.
7, task address banks 2, 5, and 8, and task execution addresses 3, 6, and 9.

FIG. 2 is a flowchart of the monitor task switching process.

When the monitor obtains the right to execute the CPU, it calculates the task to be started next and gives the right to execute the CPU to that task.

At this time, task switching processing is performed (see Figure 2).

The monitor calculates the ID number of the task to be started next,
Address banks 2, 5, 8 and task execution addresses 3, 6
・Obtain the address bank and execution address from the table from 9.

Switches the address bank according to the obtained address bank, releases the registers and work area necessary for the task to be started, and executes the CPU based on the obtained execution address.
Pass execution rights to the task.

[Effects of the Invention] As explained above, the present invention provides that when a program monitor switches a task, it refers to a table of address banks in which task programs are stored, and selects an address bank in which a task program is stored. By switching to , it is possible to efficiently develop large-capacity task programs and reduce manufacturing errors.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart of address bank switching performed when switching tasks. l... ID number of task 1, 2... address bank of task 1, 3... execution address of task 1, 4...
- ID number of task 2, 5... address bank of task 2, 6... execution address of task 2, 7... LD number of task rt, 8... address bank of task n, 1-- 1 Task lθ1I)kU2--1 Task l's at L Suno V>73--1 Taz7
1 Execution Axis 4-- Task 7Z's iD permission S--1 Task Z Kaa)'L'S Eighth 1--1
Task z/) Actual f deat°゛1st 7-11 iDk u θ −11 Taz74t A1-Lzha”27da ---
Tazufusa Travelogue AtoLS 1 ■ Funeral 2

Claims (1)

[Claims] When switching tasks using the ROM system's program monitor (hereinafter referred to as the monitor), it has a table that shows the address bank where the program for the task is stored, and when starting the task, refers to the table that shows the address bank mentioned above. A program monitor comprising means for switching to an address bank containing a program for the task.