当前位置:网站首页>Fundamentals of digital circuit (IV) data distributor, data selector and numerical comparator
Fundamentals of digital circuit (IV) data distributor, data selector and numerical comparator
2022-07-06 14:34:00 【ブリンク】
Fundamentals of digital circuits ( Four ) Data distributor 、 Data selector and numeric comparator
One 、 Data distributor
In the process of data transmission , The data selector can allocate the data of a certain way to different data channels , This circuit is called a data distributor . abbreviation DEMUX, Generally, there are already input and multiple outputs . The following figure shows the chip integration diagram of a four-way data selector :
It can be D Send to the channel selected by the data variable , The following figure is the truth table of the data selector :
You can see , A A A and B B B The two digits represent the binary code of the output circuit , It is called selection input . The function expression of each path is :
W 0 = D A B ‾ W_0=D\overline{AB} W0=DAB
W 1 = D A ‾ B W_1=D\overline{A}B W1=DAB
W 2 = D A B ‾ W_2=DA\overline{B} W2=DAB
W 0 = D A B W_0=DAB W0=DAB
Two 、 Data selector
Data selector abbreviation MUX. Its logic function is under the control of address selection signal , Select one output from multiple data .
74153 It is a data selector of one out of four , The following figure shows its chip pin distribution :
among A 0 A_0 A0, A 1 A_1 A1 Is the address selector , E ‾ \overline{E} E Is the enable end , Only if it is entered as 0 when , Data selector can work , Otherwise, the two outputs will output 0.
74151 It is a one out of eight data selector , The following figure shows its chip pin distribution :
E E E The end is the enabling end , Only if it is 0 when , Data selector will work , Otherwise, the output end outputs 0; Because it is an eight bit selector , So we need A 0 A_0 A0 A 1 A_1 A1 A 2 A_2 A2 Three bit selector ( 2 3 = 8 2^3=8 23=8) The picture below is 74151 My menu :
The output logic function of the data selector is in the form of and or of the sum of the minimum terms , So we can use data selector to realize any logic function .
3、 ... and 、 Numerical comparator
The function of numerical comparator is to compare the size of two binary numbers .
How does the numerical comparator realize comparison ? Suppose there are two four bit binary numbers A = A 3 A 2 A 1 A 0 A=A_3A_2A_1A_0 A=A3A2A1A0 and B = B 3 B 2 B 1 B 0 B=B_3B_2B_1B_0 B=B3B2B1B0, To compare the size of these two numbers, start from the highest order , If the highest order is not equal , Then it can be said that the number with the largest highest position is larger , The number with the smaller highest position is smaller ; If the highest order is equal , Compare the next , Again , If this bit is not equal , It means that the larger one is , This means that the smaller number is smaller , If this one is also equal , Then continue to compare the next , Until we can distinguish the size of these two numbers .
1. One digit value comparator
First, the truth table of a one digit numerical comparator is given :
You can write an expression according to the truth table :
( A i = B i ) = A i ⊕ B i ‾ (A_i=B_i)=\overline{A_i\oplus B_i} (Ai=Bi)=Ai⊕Bi
( A i < B i ) = A i ‾ B i (A_i<B_i)=\overline{A_i}B_i (Ai<Bi)=AiBi
( A i > B i ) = A i B i ‾ (A_i>B_i)=A_i\overline{B_i} (Ai>Bi)=AiBi
Connect the logic diagram according to the expression .
2. Four digit value comparator
The following figure is the truth table of the four digit numeric comparator :
No 2-3 Line description as long as the highest order is not equal , Then you can judge the size
In the table 4-9 Row is the case when the highest bits are equal , At this time, it is relatively low , Finally, you can also compare the size
The last three rows in the table are the cases where each of the two numbers is equal , The result at this time is determined by the state of the cascade input , Which cascade input is 1, Then the output of the corresponding output end is 1.
first draft 2022/5/7
边栏推荐
- Harmonyos application development -- address book management system telmanagesys based on listcontainer [phonebook][api v6]
- Web vulnerability - File Inclusion Vulnerability of file operation
- Proceedingjoinpoint API use
- 外网打点(信息收集)
- Binary search tree concept
- Intranet information collection of Intranet penetration (4)
- 《统计学》第八版贾俊平第二章课后习题及答案总结
- 函数:求1-1/2+1/3-1/4+1/5-1/6+1/7-…+1/n
- XSS unexpected event
- The United States has repeatedly revealed that the yield of interest rate hiked treasury bonds continued to rise
猜你喜欢
《统计学》第八版贾俊平第四章总结及课后习题答案
Wu Enda's latest interview! Data centric reasons
Chain team implementation (C language)
Attack and defense world misc practice area (simplerar, base64stego, no matter how high your Kung Fu is, you are afraid of kitchen knives)
Intranet information collection of Intranet penetration (3)
JDBC read this article is enough
Statistics 8th Edition Jia Junping Chapter XIII Summary of knowledge points of time series analysis and prediction and answers to exercises after class
Intranet information collection of Intranet penetration (5)
How to earn the first pot of gold in CSDN (we are all creators)
Xray and Burp linked Mining
随机推荐
{1,2,3,2,5}查重问题
The United States has repeatedly revealed that the yield of interest rate hiked treasury bonds continued to rise
Statistics, 8th Edition, Jia Junping, Chapter 11 summary of knowledge points of univariate linear regression and answers to exercises after class
Ucos-iii learning records (11) - task management
Which is more advantageous in short-term or long-term spot gold investment?
浙大版《C语言程序设计实验与习题指导(第3版)》题目集
Internet Management (Information Collection)
Intranet information collection of Intranet penetration (I)
Low income from doing we media? 90% of people make mistakes in these three points
Intranet information collection of Intranet penetration (5)
This article explains in detail how mockmvc is used in practical work
New version of postman flows [introductory teaching chapter 01 send request]
Tencent map circle
攻防世界MISC练习区(gif 掀桌子 ext3 )
AQS details
JDBC事务、批处理以及连接池(超详细)
Statistics 8th Edition Jia Junping Chapter 10 summary of knowledge points of analysis of variance and answers to exercises after class
Statistics, 8th Edition, Jia Junping, Chapter VIII, summary of knowledge points of hypothesis test and answers to exercises after class
Realize applet payment function with applet cloud development (including source code)
Load balancing ribbon of microservices