| 摘要 |
PURPOSE:To remove an excessive switching time and a program step and to attain rapid processing by managing a task number indicating the top address of a task and the status of I/O units at the switching of the task. CONSTITUTION:When program starting signals are generated from a timer TIM14 at a fixed period, a counter CNT13 is updated and I/O units IOUs 1, 2 are selected. The task numbers corresponding to the IOUs 1, 2 are read out from a task number storing memory TSK6. The selected status information and the task number access an address generating part ADG8 through a gate 7. If there is no status signal of the IOUs 1, 2 at the starting of the program, a microprogram address indicated by the task number is generated. If any status signal exists, the task number is modified and a program address is generated as another task address to execute the task. |
