《数字电路》是通信、电子、控制、电气等专业自学考试必考的专业基础课,是一门理论性和实践性都较强的课程。广大自考生普遍感觉是好学,不好考,其根本原因是本课程应用性、实践性、灵活性强,同学们不易把握。数字电路内容多而且烦琐,但从整体上来讲,数字电路可分为组合逻辑电路和时序逻辑电路两大类。本文拟就这两大部分的重点及难点 “Digital circuit” is a basic course for compulsory self-study examinations in the fields of communication, electronics, control, electrical and so on. It is a course with strong theoretical and practical characteristics. The majority of self-test students generally feel studious, not test, the fundamental reason is the course of practicality, flexibility, students are not easy to grasp. Digital circuit content and more cumbersome, but on the whole, the digital circuit can be divided into combinatorial logic and sequential logic circuits in two broad categories. This article intends to focus on these two major and difficult