JPH03250334A - Data processor - Google Patents

Abstract

PURPOSE:To shorten the time needed for switch of tasks and to improve the overall system performance by saving only the register that is used in an unswitched task based on the information on a register information store part in a task switch state. CONSTITUTION:A register storage part 15 is provided for storage of the contents of registers 10 together with a register information store part 16 which stores the information showing whether each register 10 is used or not, a saving register deciding means 13 which decides one of registers 10 that should be saved, and a register saving means 12 which stores the contents of the register 10 decided by the means 13 in the resister storage part 15. When the tasks are switched, only the register 10 used by an unswitched task is saved. Thus it is possible to shorten the time needed for switch of tasks and to improve the overall system performance.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a data processing device that operates using a multitasking operating system that performs task switching.
In particular, it relates to task switching in multitasking control.

[Prior Art] Conventionally, in this type of data processing device, when switching tasks in response to the occurrence of an interrupt factor, it first saves all registers that each task may use, and then switches to a new task. It is designed to perform switching processing.

[Problem to be solved by the invention] In other words, in conventional data processing devices, when switching to a new task, all registers that can be used by each task are saved, so task switching takes time and reduces the overall system efficiency. This is causing a decline in performance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a data processing apparatus that eliminates such drawbacks, reduces the time required for task switching, and improves the performance of the entire system.

(Means for Solving the Problems) The present invention provides a data processing device that operates by a multitasking operating system that performs task switching and that includes a plurality of registers used by each task, which stores the contents of the registers. a register storage section for storing information indicating whether or not each of the registers is used; and a register information storage section storing information indicating whether or not each of the registers is used; , comprising a save register determining means for determining which register should be saved among the registers, and a register saving means for storing the contents of the register determined by the save register determining means to be saved in the register storage section. Features.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an example of a portion related to task switching processing of a data processing apparatus according to the present invention. This data processing device operates by a multitasking operating system that performs task switching, and includes a register group [O] used by each task, a register storage section 15 for storing the contents of the register group 10, and a register storage section 15 for storing the contents of the register group 10. A register information storage section 16 stores information indicating whether or not each register is used, and which registers should be saved among the registers 10 based on the information stored in this register information storage section 16 at the time of task switching. A task comprising a save register determining means 13 for determining a register, and a register saving means 12 for storing the contents of the register determined to be saved by the save register determining means 13 in a register storage section 15, and further for switching tasks. A switching means 14 is provided. The main processing required for task switching is performed by the register saving means 12. Save register determination means 13. This is also performed by the task switching means 14, which constitutes the task switching main processing section 11.

Next, the operation will be explained using the flowchart shown in FIG. When the task switching main processing unit II is activated due to the occurrence of an interrupt factor, etc., the save register format and foot means 1 are
3 determines which register is used by the current task among the register group 10 based on the information stored in the register information storage section 16, and notifies the register saving means 12 as the register to be saved (step 20). ).

The register saving means 12 stores the contents of the notified register in the register storage section I5 (step 21). Thereafter, the task switching means 14 executes task switching processing (
Step 22).

As described above, in the data processing device of the present invention, when performing task switching, only the registers used by the task before switching are saved, so the time required for task switching can be shortened, and the performance of the entire system can be improved. I can do it.

〔Effect of the invention〕

As described above, the present invention provides a data processing device that operates on a multitasking operating system that performs task switching and is equipped with a plurality of registers used by each task. , a register information storage section that stores information indicating whether each register is used or not, and a register that should be saved among the registers based on the information stored in this register information storage section at the time of task switching. The save register determining means makes a determination, and the register saving means stores the contents of the register that the save register determining means determines to be saved in a register storage section.

Therefore, in the data processing device of the present invention, when performing task switching, only the registers used by the task before switching are saved, so the time required for task switching can be shortened, and the performance of the system as a whole can be improved. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a portion related to task switching of a data processing apparatus according to the present invention, and FIG. 2 is a flowchart showing the operation of the data processing apparatus. ]0... 11... 12... 13... 14... Engineering 5... 16... ・Register group・Task switching main processing unit・Register saving means・Saving register determination means ・Task switching means ・Register storage unit ・Register information storage unit

Claims (1)

[Claims] (1) In a data processing device that operates on a multitasking operating system that performs task switching and is equipped with a plurality of registers used by each task, a register storage unit for storing the contents of the register, and each of the registers. A register information storage section stores information indicating whether or not the register is used, and at the time of task switching, a register to be saved is determined based on the information stored in this register information storage section. A data processing device comprising: save register determining means; and register saving means for storing the contents of the register determined by the save register determining means to be saved in the register storage section.