| 摘要 |
PURPOSE:To improve the system performance by suppressing the interruptions for a fixed time after the tasks are switched so that the task switching frequency caused by the interruptions is decreased. CONSTITUTION:When tasks are switched, the timer set value of a register 5 is set at a timepiece (timer) 3 and the subtraction is started in response to a clock signal 12. When the set value of the timer 3 becomes negative, a timer run-out signal 14 is turned on. The signal 14 is applied to an AND gate 4 as an output signal 15 via a gate 6 when a task executing signal 11 is kept turned off, that is, while no tasks is carried out. When an interruption factor is produced, an interruption factor signal 7 is accepted by an interruption holding circuit 1 and an interruption holding signal 8 is produced. Under such conditions, an interruption signal 9 is produced when the signal 15 is applied to the gate 4. Thus the tasks are switched by an interruption control task switching circuit 2.
|
