数字电路中的时钟脉冲

Clock Pulse Transition

The movement of a trigger pulse is always from a 0 to 1 and then 1 to 0 of a signal. Thus it takes two transitions in a single signal. When it moves from 0 to 1 it is called a positive transition and when it moves from 1 to 0 it is called a negative transition. To understand more take a look at the images below.

参考链接：
Triggering of Flip Flops

总结：

1. 时钟不断地在01之间规律地周期性变化，这个周期就是时钟周期，它的倒数就是时钟频率，用于衡量时钟变化速度，单位是Hz。
2. 对于一个时钟周期，分成几个部分
   1. 上升沿：0–>1
   2. 正脉冲：1
   3. 下降沿：1–>0
   4. 负脉冲：0