| 摘要 |
<p>PURPOSE:To improve the accuracy of a timer interruption by producing an interruption of high priority when no interruption is accepted for a fixed time or longer. CONSTITUTION:When a timer part 3 is started by a processor 1, the timer 3 holds the timer value set by the processor 1. When this timer valve reaches a fixed level with subtraction, a timer control part 2 applies an interruption signal 7 of a low level to the processor 1. At the same time, an interruption waiting time count circuit 4 included in the part 2 starts a counting action. If the circuit 4 counts a fixed value before the signal 7 is not received by the processor 1, an interruption signal switch part 5 produces an interruption signal of a high level. Then an interruption acceptance signal 8 is produced when the processor 1 accepts an interruption signal. Thus the part 3 is updated. As result, the timer interruption accuracy is improved.</p> |
