| 摘要 |
<p>PURPOSE:To make a timer for clock usable as an interval timer also by constituting the timer block of the timer of an m-bit and n-bit timers and providing enable flags for controlling each timer. CONSTITUTION:A timer block 100 has an m-bit and n-bit timers 140 and 150 and enable flags 110 and 120 respectively designate the counting operations of the timers 140 and 150. The timer 140 inputs a clock signal 341 and outputs a frequency dividing signal 142 from an x-bit stage and the timer block 100 operates as an interval timer which generates an interruption requesting signal 391 to a CPU at the 2<x>-frequency dividing intervals of the clock signal 341. In addition, the block 100 operates as a timer for clock by setting an overflow flag 380 to '1' at the 2<(m+n)>-frequency dividing time intervals of the clock signal 341. Therefore, the timer block of the timer for clock can be used as an interval timer also.</p> |
