Nmultiplexer and demultiplexer in digital logic design pdf

In fact, decoder and demultiplexer are two of the basic concepts of digital circuits. Multiplexing is the generic term used to describe the operation of sending one or more analogue or digital signals over a common transmission line at different times or speeds and as such, the device we use to do just that is called a multiplexer the multiplexer, shortened to mux or mpx, is a combinational logic circuit designed to switch one of several input lines through to a. Lab 4 lmp model multiplexer and demultiplexer in embedded system implemented by fpgas a multiplexer is a device that acts like a selector switch for digital signals. The output to which the input signal is to be passed is decided by the control logic. The input is e3 one input and depending on the values of a0, a1, a2 control lines, the value of e3 is routed to one of the y outputs many outputs. Different inputoutput configuration demultiplexers are. Dandamudi, fundamentals of computer organization and design, springer, 2003. The common channel select logics include two digital select inputs s0. Sep 23, 2017 multiplexer and demultiplexer definition. Apr 18, 2017 1x4 dmux demultiplexer digital electronics demultiplexer is defined and designed using basic gates. Dld lecture no 29 multiplexer, demultiplexer 06 dec 2016. This analog multiplexer and demultiplexer controls. Multiplexing and demultiplexing are used when data from several sources are to be transmitted over one line to a distant location and redistributed to several destinations.

For example, if n 2 then the demux will be of 1 to 4 mux with 1 input, 2 selection line and 4 output as shown below. The difference may appear subtle at first glance but is a very important one. Demultiplexer performs the reverse operation of the multiplexer i. Following figure illustrate the general idea of a demultiplexer with. Demultiplexer demux digital decoder tutorial electronics.

The 74lv4052 is a dual 4channel analog multiplexerdemultiplexer with a common select logic. Both demultiplexers and multiplexers have similar names, abbreviations, schematic symbols and circuits, so confusion is easy. So, each combination will select only one data input. The selected line decides which ip is connected to the op, and also increases the amount of data that can be sent over an nw within a certain time. Enhanced diminishing manufacturing sources analog voltages that may vary across the. The multiplexer mux the operation of sending one or more analog or digital signals over a common transmission line at different times or speeds is known as multiplexing, and the device used to do this is known as multiplexer. Few types of demultiplexer are 1to 2, 1to4, 1to8 and 1to 16 demultiplexer.

Shown here is a multiplexer and a demultiplexer, each using a multipleposition switch symbol to indicate the selection functions inside the respective circuits. Multiplexers in digital logic it is a combinational circuit which have many data inputs and single output depending on control or select inputs. The outputs of upper 1x4 demultiplexer are y 7 to y 4 and the outputs of lower 1x4 demultiplexer are y 3 to y 0. Mc14551b quad 2channel analog multiplexerdemultiplexer. Sep 04, 2015 multiplexer handle two type of data that is analog and digital. The select inputs are used to specify the input channel that is to be connected to the output pins. Multiplexer is a combinational circuit that has maximum of 2 n data inputs, n selection lines and single output line. Unused inputs must always be tied to an appropriate logic voltage level e. Page 2 outline introduction multiplexers and demultiplexers. A demultiplexer or demux is a device that takes a single input line and routes it to one of several digital output lines. The multiplexer is a combinational logic circuit designed to switch one of. Khan department of computer science and engineering, east west university, 43 mohakhali, dhaka 1212, bangla desh.

A multiplexer is often used with a complementary demultiplexer on the receiving end. The definition of multiplexer and demultiplexer is simply an apparatus used to choose a particular input and then channeled to a particular output through a single channel. For analog application, multiplexer are built of relays and transistor switches. The demultiplexer demux is a logic circuit that switches digital data from one input line to several output lines in a specified time sequence. Multiplexer and demultiplexer circuit diagrams and. Cd74hc4051ep analog multiplexer and demultiplexer datasheet. A demultiplexer of 2 n outputs has n select lines, which are used to select which output line to send the input. These ssi chips allow us to specify our design at a higher level, thus focusing on the function of a circuit and not its basic implementation. Design of reversiblequantum ternary multiplexer and demultiplexer mozammel h. As with a lot of logical circuits, making gates using mux also does not have a method written in stone. It is used to carry out the essential arithmetic, not only in computers and calculators, but also in navigation systems, robots and many other types of automatic machinery.

Multiplexing and demultiplexing logic functions for computing. Although they appear similar, they certainly perform di. These are combinational circuits built from the basic logic gates, which are and, or, not, and xor. Here is an abbreviated truth table for the demultiplexer. A demultiplexer is a circuit with one input and many output. In electronics, a multiplexer also known as a data selector, is a device that selects between. Demultiplexers combinational logic functions electronics. Show a graphical representation of the designed logic circuit as figure 2. Since there are n selection lines, there will be 2 n possible combinations of zeros and ones. This description sounds similar to the description given for a decoder, but a decoder is used to select among many devices while a demultiplexer is used to send a. Test circuit for measuring offstate leakage current. The multiplexer used for digital applications, also called digital multiplexer, is a circuit with many input but only one output.

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. One of these data inputs will be connected to the output based on the values of selection lines. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output. Data labeled typ is not to be used for design purposes, but is intended as an indication of the ics potential performance. The output data lines are controlled by n selection lines. Difference between decoder and demultiplexer difference. Lab 4 lmp model multiplexer and demultiplexer in embedded. Mux directs one of the inputs to its output line by using a control bit word selection line to its select lines.

The multiplexer is used to perform highspeed switching and is constructed by electronic components multiplexers are capable of handling both analog and digital applications. By applying control signal, we can steer any input to the output. 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. Digital electronics multiplexer demultiplexer this presentation will demonstrate the basic function of the multiplexer mux. Multiplexer mux and multiplexing tutorial electronicstutorials. Gate cmos the mc74hc238a is identical in pinout to the ls238. A multiplexer or mux is a device that has many inputs and a single output. The single pole multiposition switch is a simple example of nonelectronic circuit of multiplexer, and it is widely used in many electronic circuits. I have a question regarding the use of an and gate in a demultiplexer 1x4 circuit such as a demultiplexer truth table shows you can output a 1 signal on the zero line, if your input is 1, and both. Multiplexers and demultiplexers are often confused with one another by students. Multiplexers, or muxs, can be either digital circuits made from high speed logic gates.

The device has two independent decoders, each accepting two inputs and providing four mutuallyexclusive activelow outputs. In digital circuit design, the selector wires are of digital value. Definition of decoder and demultiplexer the key difference between a decoder and a demultiplexer is that the former is a logic circuit that decrypts an encoded bit stream from one format into another, while the latter is a combination circuit that routes a single input line to multiple digital output lines. Dual 1of4 decoderdemultiplexer general description the acact9 is a highspeed, dual 1of4 decoder demultiplexer. Each decoder has an activelow enable input which can be used as a data input for a 4output. For digital application, they are built from standard logic gates. For n input lines, log n base2 selection lines, or we can say that for 2 n input lines, n selection lines are required. Mar 12, 2018 demultiplexer demux select one output from the multiple output line and fetch the single input through selection line. It is used to send a signal to one of the many devices. A demultiplexer works in the opposite direction by taking a digital.

Multiplexerdecoder implementation of logic functions. That is,a demultiplexer distributor distributes its input signal to one of its several outputs in fact, a decoder with an enable input can be used as demultiplexer. Multiplexers combinational logic functions electronics. Multiplexer and demultiplexer circuits and apllications.

Demultiplexer demultiplexing is the reverse of multiplexing. Multiplexers can also be expanded with the same naming conventions as demultiplexers. Multiplexers a multiplexers mux is a combinational logic component that has several inputs and only one output. So, biological implementation of logic gates is definitely a powerful resource to design modular gene networks inspired to digital electronic circuits 3, 6. It is used when a circuit intends to send a signal to one of many devices. 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. Multiplexer handle two type of data that is analog and digital. Introduction to logic design panupong sornkhom, 20052 17 2. Demultiplexers can be used to implement general purpose logic.

The device inputs are compatible with standard cmos outputs. Digital logic design is foundational to the fields of electrical engineering and computer engineering. The demultiplexer is a combinational logic circuit designed to switch one common input line to one of several seperate output line. Digital logic is the basis of electronic systems, such as computers and cell phones. Pdf design of reversiblequantum ternary multiplexer and. 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. In analog applications, multiplexers are made up of of. Demultiplexers are mainly used in boolean function generators and decoder circuits. We can implement 1x8 demultiplexer using lower order multiplexers easily by considering the above truth table. Combinational logic has many uses in electronic systems. A demultiplexer, sometimes abbreviated dmux, is a circuit that has one input and more than one output.