分析由触发器构成的同步计数器的一种新方法

A new technique for analysis of synchronous counters constructed with flip-flops

为了简化由触发器构成的同步计数器的分析过程,提出一种简单、有效的方法.采用该方法,由计数器的逻辑电路图获得状态转移方程后,将其化成标准与或表达式,通过推导得出标准与或表达式中逻辑函数取值的规律,按照该规律,状态转移方程中次态值可直接由标准与或表达式得到,而不需要进行任何逻辑运算.通过对1个3变量计数器的分析表明,该方法省去了烦琐的计算,使得次态值的求取和真值表的创建更加快捷、方便.

In order to simplify the process for analysis of synchronous counters constructed with flip-flops,a simple and effective method is proposed.With this method,the state transition equations obtained from logic diagram of counter are converted to standard sum-of-products forms（SOPs）.By finding out the logic principle for achieving the value of logic function based on the standard SOPs,the values of next state can be directly obtained without any Boolean calculation.Analysis for a 3-bits counter shows that this method eliminates complex calculations,and makes the process of obtaining next state value and developing truth table more rapid and convenient.