The logic functions of MSI counter 74161 was analysed. It could be taken as a universal sequential module to realize any synchronous sequential circuits.
分析了MSI计数器74161的逻辑功能，它作为通用的时序部件可以实现任意同步时序电路。
2
But the problem with this configuration is that it does not provide sequential count from 1 to 20 because the first counter begins to count over again once it has reached 10.
但是这个结构一旦第一个计数器达到10，就开始重新计数，不能提供1到20的连续计数。
3
The counter is the most commonly used one of the sequential circuits, they not only can be used to count on pulse, still can separate frequency, timing, produce beats pulse and other clock signal etc.