数据选择器级联系统的简化

数据选择器级联系统的简化 THE SIMPLIFICATION OF DATA SELECTOR CASCADE SYSTEMS 卢孝先 Lu Xiaoxian first-author 本文将逻辑函数的依序展开【1】推广到变序展开,并给出一种图解定序法和一种整序方法,为简化逻辑函数的分组展开式提供了依据和具体途径;而且,将这些结果应用于执行组合逻辑的DST（数据选择器）级联系统时,能使统系简化,大量地节省DST组件。本文在给出图解定序法时,首次将变量环等概念引入卡诺图,对经典的卡诺图化简法作了较大修改,使得由它所得到的简化式不仅可以用来给变量定序,而且还可以用它来直接画出简化的DST级联系统的逻辑图。有些作者提出过一些简化DST级联系统的方法【2】、【4】,这些方法不是比较复杂、就是有一些附加条件。本文给出的方法,对所有能用卡诺图表示的逻辑函数都有效,并比其它方法简便。 In this paper the orderly expansion of logic function is extended to the changeable order expansion, a graphical method for arranging the order is given. All the above provide the mathematical foundation and the actual way for simplifying the expansion formula of logic function with respect to groupvariables. And what is more, when all these results are used in DST（Data Selector）cascade systems which implement combinationl logic, we can simplify the systems and may avoid using DST modules in large quantities. When giving the graphical method in ths paper, some conceptions, such as variable loop, etc., are introduced into Karnaugh map for the first time, and the classical Karnaugh methed is modified a lot so that the resultant simplified expression can be used not only for arranging the order of the variables, but also for directly drawing the logic diagram of the simplified DST cascade system. Several authors have put forward some methods to simplify DST cascade systems, but these methods are either complicated or conditionl. The methed given in this paper is valid for any logic function that can be represented on a Karnangh map, and is simpler than other methods. 1981-04-01 2021-04-01 4