Synchronous sequential circuit memory, usually consisting of flip-flops, update circuit states information All flip-flops share a common clock pulse input The clock input is not a binary value representing the time of day but rather a\synchronous\train of pulses. Synchronous memory changes its data only at certain time intervals The flip-flops can change state only on a clock pulse edge

在数字电路或系统中,常常需要各种脉冲波形,例如时钟脉冲、控制过程的定时信 号等。这些脉冲波形的获取,通常采用两种方法:一种是利用脉冲信号产生器直接产 生;另一种则是通过对已有信号进行变换,使之满足系统的要求。 本章以中规模集成电路555定时器为典型电路,主要讨论555定时器构成的施密 特触发器、单稳态触发器、多谐振荡器以及555定时器的典型应用

Let be the set of all input variables, X={, X1, .Xn} Let y be the set of all output variables, y={Y, 1 ...m} o The combinational function, F, operated on the input variable set, to produce the output variable set y. o The output is related to the input as

4.1 概述 4.2 组合逻辑电路的分析与设计 4.3 常用组合逻辑电路 4.4 用PLD实现组合电路 4.5 组合逻辑电路的竞争与冒险

Sec2.1 CMOS 反向器 • 1.CMOS逻辑电路的逻辑电平 • 2.CMOS 反向器 Sec 2.2 CMOS 逻辑门 ➢ CMOS 与非门 ➢ CMOS 或非门 ➢ CMOS 同向缓冲逻辑门 ➢ 与-或-非门 ➢ 异或门 ➢ 三态门 Sec2.3.异或门和其他逻辑门 • 1. 异或门及其应用 • 2. 传输门及其应用 • 3. 三态门 • 4. 漏极开路门 • 5. “线与”逻辑

INTRODUCTION Level five Complex Systems, Function Units from levels Two through Four Level four More complex Function Logic Units, e.g. microprocessor Third IC level (VLSI) Level three Function Logic Units, e.g. adders, Second IC level counters, multiplexers (MSI and LSI) Level two Function Logic Units, e.g. gates, NOT, AND, NAND, EX-OR First IC level (SSI)

在第一章里,我们初步认识了与、或、非三种基本逻辑运算和与非、或非、异或等常 用逻辑运算,在那里,这些运算关系都是用逻辑符号来表示的。而在工程中每一个逻辑符 号都对应着一种电路,并通过集成工艺作成一种集成器件,称为集成逻辑门电路,逻辑符 号仅是这些集成逻辑门电路的“黑匣子\。本章将逐步揭开这些“黑匣子”的奥秘,介绍集 成逻辑门电路的两种主要类型TL和MO门电路的工作原理、逻辑功能及外部特性,同 时对内部结构也作一简要介绍

(一)课程性质与学习目的 《脉冲与数字电路》课程是髙等学校应用电子技术、机电技术与计算机应用技 术专业的重要技术基础课程,它是具有实践性强、工程性强的特点而且又能自成体 系的课程。 本课程的任务是使学生能对数字电子技术的基本原理、基本知识和基本技能有 全面认识,熟悉数字电路的工作原理、工作特性,掌握数字电路的逻辑分析和设计 方法,具备正确运用数字集成电路的能力,并为后续课程准备必要的基础知识

Hazard o Boolean algebra does not account for propagation delays through signal paths of actually circuits. o The delay can cause glitches to occur. A glitch is an unwanted signal, usually short pulse caused by the transient behavior of signal path that have different delays A hazard exists any time the potential for glitches is present

Positional Number System Number system use positional notation to represent value. The position of the character(numeral) in a character string (collection of possible numerals) indicate value as well as the character itself. Radix (base) is the number of numeral characters in the character set of positional number system. Position Weiaht is a constant that represents the value of a position. Different position has different weight. It is the integer power of radix