Examples of solved problems for chapter3,5,6,7,and8. The logic is just as before combining the two selector lines, we have four different combinations. In digital circuit design, the selector wires are of digital value. Combinational logic circuits boolean laws and theorems, sumofproducts method, truth table to karnaugh map, pairs, quads, and octets, karnaugh simplifications, dont care conditions, productofsums method, productofsums. The single pole multiposition switch is a simple example of nonelectronic circuit of multiplexer, and it is widely used in many electronic circuits. Implementation of combinational logic using mux, rom, pal and pla.
Digital logic design, holdsworth, brian, woods, clive. Implementing simple logic with a multiplexer youtube. Digital logic designers build complex electronic components that use both electrical and computational characteristics. Multiplexers combinational logic functions electronics. Show the table that you applied in the design procedure as the table 2. Combinational logic circuits boolean laws and theorems, sumofproducts method, truth table to karnaugh map, pairs, quads, and octets, karnaugh simplifications, dont care conditions, productofsums method, productofsums simplification, simplification by. In essence it all starts with true and false or 0 and 1. Comparators, ic 7485, 5 bit comparator, 8 bit comparator, multiplexer, and other topics. For each possible input combination there is one and only one possible output combination, a combinational circuit can be. Vhdl for fpga design wikibooks, open books for an open world. Spring 2011 ece 331 digital system design 30 using a 2ninput multiplexer use a 2ninput multiplexer to realize a logic circuit for a function with 2n minterms. Multiplexers can be used as lookup tables to perform logic functions.
June 23, 2003 basic circuit design and multiplexers 12 building a multiplexer here is a truth table for the multiplexer, based on our description from the previous page. From the truth table above, we can see that when the data select input, a is low at logic 0. A multiplexer of inputs has select lines, which are used to select which input line to send to the output. I only tested this circuit with a few of the possible inputs since. The multiplexer is one of the most important components in communications networking. Dandamudi for the book, fundamentals of computer organization and design.
Later, we will study circuits having a stored internal state, i. University, faizabad area of reversible logic is attracting much attention of researchers nowadays. The multiplexer is used to perform highspeed switching and is constructed by electronic components multiplexers are capable of handling both analog and digital applications. This means that one output z will be selected from any of the eight inputs i 0 to i 7 by a set of 3 bit binary selectors s 0 to s 2 in combination with enable.
Multiplexer and demultiplexer circuit diagrams and applications. Foundation of digital electronics and logic design index of. Digital electronics part i combinational and sequential. As with a lot of logical circuits, making gates using mux also does not have a method written in stone. In general, a 2 ninput multiplexer can be programmed to perform any ninput. Download it once and read it on your kindle device, pc, phones or tablets. Multiplexers a multiplexers mux is a combinational logic component that has several inputs and only one output. Design using conventional logic gates, encoder, decoder, multiplexer, demultiplexer, modular design using ic chips, mux realization of switching functions parity bit generator, codeconverters, hazards and hazard free realizations. Multiplexerdecoder implementation of logic functions. When the enable input is active, the circuit mux in this case works normally when the enable input has the inactive value, the circuits outputs are all inactive. Choose one of two inputs based on a control input sel.
I was forced to getting this book as it was required for my course, for some concepts its comprehensible but for most of the time its gibberish full of equations which are not explained. Very good book covering all theoretical and practical aspects of digital design. Since the logic gates we study are generally with two inputs and have one output, we can take it up as a logical challenge to design all logic gates using a 2. A multiplexer, like many other circuits, can have additional enable inputs. Multiplexer handle two type of data that is analog and digital. Using an 2n1input multiplexer use a 2n1input multiplexer to realize a logic circuit for a function with 2n minterms. Multiplexer can act as universal combinational circuit. A multiplexer has n control inputs 2n data inputs 1 output a multiplexer routes or connects the selected data input to the output. The implementation of not gate is done using n selection lines. Multiplexers can be used for generating any logic function. For my 4to1 multiplexer, i combined eight singlebit 4to1 multiplexers, merging their outputs into a 8bit bus output. The main function of a multiplexer is to route only one selected data input to its single output. A multiplexer, abbreviated mux, is a device that has multiple inputs and one output.
In this lesson we will study digital multiplexing in which the number of inputs is a power of two 2, 4, 8, 16, and there is one output. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. Now at this point, the important points are the functional unitssubsystems that refer to some hardware which is made up of lower level building blocks. Multiplexers operate like very fast acting multiple position rotary switches connecting or controlling multiple input lines called. This book contains information obtained from authentic and highly regarded sources.
A combinational circuit consists of input variables n, logic gates, and output variables m. Dandamudi, fundamentals of computer organization and design, springer, 2003. For n input variables there are 2n possible combinations of binary input values. For analog application, multiplexer are built of relays and transistor switches. It does not replace a course in logic design, nor will it enable you to design signi.
Digital logic gate functions include and, or and not. Digital logic is rooted in binary code, a series of zeroes and ones each having an opposite value. Digital logic design, holdsworth, brian, woods, clive, ebook. Computer science students learn skills in analysis, design and debugging. The input a of this simple 21 line multiplexer circuit constructed from standard nand gates acts to control which input i 0 or i 1 gets passed to the output at q. This book requires that you first read digital circuits.
Given that we have 2 2 inputs, we need two selector lines. Switching theory and logic design pdf notes stld pdf notes sw. Practice problems on digital electronics and logic design. The only drawback should be with little emphasis that because the book covers extensively the fundamentals of logic design, it dedicates less efforts to more complex.
Target audience this text will be geared toward computer science students. Logic equations show the logic equations for the logic functions, d, e, and f, described in the previous example. Kinney, fundamentals of logic design, sixth edition, cengage learning. Flip flops sr, jk, t, d and master slave characteristic table and equation application table edge triggering level triggering realization of one flip flop using other flip flops asynchronous ripple counters synchronous counters modulo n. Thorough and clear explanations of theoretical foundations. We also see that there are two additional control pins. It comprehensively covers all the basics of digital electronics, its logic and design. In digital logic, a multiplexer is the logical implementation of a single pole, n position switch. In this project, well be using the 74ls174 multiplexer, a 1 of 8 multiplexer. How do i design a sequential logic circuit if i am only given a timing diagram that. Ch1 ch2 ch3 ch4 ch5 ch6 ch7 ch8 ch9 ch10 ch11 ch12 problem. Logic gates in cmos indepth discussion of logic families in cmosstatic and dynamic, passtransistor, nonran tioed and ratioed logic n optimizing a logic gate for area, speed, energy, or robustness lowpower and highperformance circuitdesign techniques 6. Spring 2011 ece 301 digital electronics 21 using a 2ninput multiplexer use a 2ninput multiplexer to realize a logic circuit for a function with 2n minterms.
In the case of a 2to1 multiplexer, a logic value of 0 would connect to the output while a logic value of 1 would connect to the output. Basic circuit design and multiplexers howard huang. Use features like bookmarks, note taking and highlighting while reading digital logic design. When designing logic circuits, one can sometimes come up with a clever idea which leads to a superior implementation. The multiplexer used for digital applications, also called digital multiplexer, is a circuit with many input but only one output.
Each pair of rows represents a product term of n 1 variables. Despite the fact that many of these devices are tremendously complex and require vast amounts of engineering in their design, they all share the ubiquitous bit as their fundamental unit of data. First, we inspect the combinational portion of the multiplexer circuit without the. Multiplexer is a circuit to selectively pass one of two inputs to the output depending on a. Its central function, from the network managers viewpoint, is to concentrate many users or information channels on to a single transmission channel in order to maximise the efficiency of that channel. The multiplexer, shortened to mux or mpx, is a combinational logic circuit designed to switch one of several input lines through to a single common output line by the application of a control signal. In analog circuit design, a multiplexer is a special type of analog switch that connects one signal selected from several inputs to a single output. Multiplexer and demultiplexer circuit diagrams and. For digital application, they are built from standard logic gates. This appendix provides a brief discussion of the basics of logic design. Consequently the output is solely a function of the current inputs. Mux directs one of the inputs to its output line by using a control bit word selection line to its select lines. If you have little or no exposure to logic design, however, this appendix will provide suf. Because of its unique structure, a multiplexer can also be used to implement a logic function.
Come prepared with circuit diagrams, writing materials and calculator. All the standard logic gates can be implemented with multiplexers. Its output is a twobit number x1x0, representing that count in binary. And so the next chapter starts with the simplest of. Multiplexer multiplexing is the property of combining one or more signals and transmitting on a single channel. Design and implementation of boolean functions using. Switching theory and logic design notes pdf stld notes pdf book starts with the topics philosophy of number systems, map method, prime implicants, encoder, decoder, multiplexer, demultiplexer, modular design using ic chips.
We can build a simple 2line to 1line 2to1 multiplexer from basic logic nand gates as shown. The value of the control inputs determines the data input that is selected. The schematic symbol for multiplexers is the truth table for a 2to1 multiplexer is using a 1to2 decoder as part of the circuit, we can express this circuit easily. A detailed account of fords accomplishments can be found in the book. Multiplexers are used as one method of reducing the number of integrated circuit packages required by a particular circuit design.
These characteristics may involve power, current, logical function, protocol and user input. This decomposition leads to the circuit in figure 6. Digital logic overview of basic gates and universal logic gates and andorinvert gates, positive and negative logic, introduction to hdl. These are mostly used to form a selected path between multiple sources and. The computer logical organization is basically the abstraction which is below the operating system and above the digital logic level. Page 2 outline introduction multiplexers and demultiplexers. Its central function, from the network managers viewpoint, is to concentrate many users or information channels on to a single transmission channel in order to maximise the efficiency of that. The multiplexer routes one of its data inputs d0 or d1 to the output q, based on the value of s. Wikiversity has learning materials about ee 215 vhdl for fpga design.
Sep 04, 2015 multiplexer handle two type of data that is analog and digital. Whatever logic value is on the selected input will be presented on the q output. Modeling, synthesis, and simulation using vhdl book. Digital logic design is foundational to the fields of electrical engineering and computer engineering. Way more information than you ever wanted on how to fell a tree. Digital electronics and logic design tutorials geeksforgeeks. Laboratory manual digital systems and logic design. This article explains different types of demultiplexers. Mar 11, 2017 pre book pen drive and g drive at teacademy. Design a circuit that counts the number of 1s present in 3 inputs a, b and c. On the right is an example of a singlebit 4to1 multiplexer i used in my circuit. This book is designed to meet the syllabus requirement of the b. Multiplexers are mainly used to increase the amount of data that can. Multiplexers operate like very fast acting multiple position rotary switches connecting or controlling multiple input lines called channels one at a time to the output.
The three selection inputs, a, b, and c are used to select one of the eight d0 to d7 data inputs. What is the best book to master digital logic design and also which book. It is a process of taking information from one input and transmitting over one of many outputs. Digital logic design bibasics combinational circuits sequential circuits pujen cheng adapted from the slides prepared by s. Demux are used to implement generalpurpose logic systems. Design a 5to1 multiplexer circuit, minimizing the circuit as much as possible. Introduction to digital logic with laboratory exercises. A multiplexer performs the function of selecting the input on any one of n input lines and feeding this input to one output line. Now that weve created the simplest of multiplexers, lets get on with the 4to1 multiplexer.
A multiplexer is the most frequently used combinational circuits and important building block in many in digital systems. July 31, 2008 digital logic fundamentals 9 ports of a multiplexer a, b, sel are input ports out is an output port internal nodes are declared as wire provide design description. Using a 1to2 decoder as part of the circuit, we can express this circuit easily. This system facilitates the design of electronic circuits that convey information, including logic gates. The resulting gatelevel circuit of the multiplexer in figure 6. Twoinput multiplexer design the input a of this simple 21 line multiplexer circuit constructed from standard nand gates acts to control which input i0 or i1 gets passed to the output at q. J hoolan, in telecommunications engineers reference book, 1993. The multiplexer data inputs are connected to 0 or 1 according to the corresponding row of the truth table. Multiplexers can also be expanded with the same naming conventions as demultiplexers. This book proposes the reversible logic multiplexer and also demarcates between reversible and irreversible logic multiplexers. For power reduction in future computing technologies, reversible logic is a very productive approach of logic synthesis. In the case of a 2to1 multiplexer, a logic value of 0 would connect. Digital logic design kindle edition by holdsworth, brian, woods, clive.
635 768 615 1364 144 1069 20 1391 1272 671 1067 409 1084 1210 544 1409 890 1450 1266 704 676 1067 763 912 1410 682 1355 1032 321 768 1379 62