Top 39 digital electronics interview questions javatpoint. Combinational logic has many uses in electronic systems. A multiplexer of inputs has select lines, which are used to select which input line to send to the output. The multiplexer acts like an electronic switch that selects one from. In several reports, both digital and analog circuits have been. It is a combinational digital circuit and generally called a data selector as well. Since the mux demux also works with digital signals, you can use it to pipe ttllevel serial data to or from multiple devices. Digital electronics course offered by mtu noida and gbtu lucknow. A demultiplexer performs the reverse process of multiplexer. The 1180 is designed to insert analog or digital audio signals onto a single.
It is used to send a signal to one of the many devices. 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. Digital logic and computer systems based on lecture notes by dr. Text book fundamentals digital electronics by rp jain, tmg. 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 third pin serves as a digital output whose signal then can be redirected to up to four external peripheral components by toggling the address pins into one of four states including 00, 01, 10, and 11. A multiplexer takes inputs from multiple devices, selected using the microcontrollers address pins, and routes the desired components output to a single input pin on the microcontroller. Implementation of combinational logic using mux, rom, pal and pla. This means you can hook up multiple serial devices like a gps tx pin, and a xbee dout pin to one rx pin on a microcontroller. Preface this book has been written primarily to serve as a textbook in accordance with the syllabus of digital electronics course offered by mtu noida and gbtu lucknow. Concept on digital signal, logic levels, active high, active low signals, switching characteristic of semiconductor diode. Apr 18, 2017 1x4 dmux demultiplexer digital electronics demultiplexer is defined and designed using basic gates. In electronics, a multiplexer or mux is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. We can have n control bits to select from 2n input bits.
The book has been organised accordance to the syllabus of mtu. It is intended to provide a student with clear understanding of the fundamentals of digital electronics with an emphasis on solving large number of numerical problems that generally ask in their examinations. Although they appear similar, they certainly perform di. The main difference between a multiplexer and a demultiplexer is that a multiplexer takes two or more signals and encodes them on a wire, whereas a demultiplexer does reverse to what the multiplexer does. A multiplexerencoder mux is a selector device that has 2i data inputs, and i select inputs. A multiplexer of 2 n inputs has n select lines, which are used to select which input line to send to the output. 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. Thus, demultiplex is reconverting a signal containing multiple analog or digital signal streams back into. The demultiplexer converts a serial data signal at the input to a parallel data at its output. R1 ch5 encoder decoder mux demux free download as powerpoint presentation. Dandamudi for the book, fundamentals of computer organization and design. J hoolan, in telecommunications engineers reference book, 1993. A demultiplexer or demux is a device that takes a single input line and routes it to one of several digital output lines.
A digital device capable of selecting one input out of its multiple input lines and forwarding it on a common output line is called a multiplexer. 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. Physically, a multiplexer has n input pins, one output pin, and m control pins. A multiplexers mux is a device that allows digital information from several sources to be routed onto a single line for transmission over that line to a common destination. A list of top frequently asked digital electronics interview questions and answers are given below. The demultiplexer is the inverse of the multiplexer, in that it takes a single data input and n address inputs. Multiplexers are also known as data n selector, parallel to serial convertor, many to one circuit, universal logic circuit. Demultiplexer digital circuits electronics teacher. Apr 15, 2017 multiplexer data selector digital electronics english. Sep 04, 2015 multiplexer handle two type of data that is analog and digital. In other words, the rotary switch is a manual switch that you can use to select. A multiplexer mux is a circuit that has data inputs control inputs an output the control inputs select which data inputs to be connected to the output figure 9. Multiplexer mux data selectordigital electronicsenglish. We can refer to a multiplexer with the terms mux and mpx too.
For analog application, multiplexer are built of relays and transistor switches. The demultiplexer is a combinational logic circuit that performs the. For example, in telecommunications, several telephone calls may be carried using one wire. Demultiplex demux is the reverse of the multiplex mux process combining multiple unrelated analog or digital signal streams into one signal over a single shared medium, such as a single conductor of copper wire or fiber optic cable. Kaushik and others published digital electronics find, read and cite all. As we know multiplexer is a device or chip which selects one output of multiple input lines. Here the basic concept of mux is explained with truth table and circuit is also designed. In simple words, it is the reverse of demultiplexer demux. Multiplexer mux and multiplexing tutorial basic electronics. The muxdemux also works with digital signals like serial, i2c, spi. The demultiplexer is a combinational logic circuit designed to switch one common input line to one of several seperate output line the data distributor, known more commonly as a demultiplexer or demux for short, is the exact opposite of the multiplexer we saw in the previous tutorial. The 1180 is a very reliable product for the demanding user. For digital application, they are built from standard logic gates.
The board also breaks out the chips enable pin, which when driven high, will completely disconnect the common pin all switches off. A single output corresponding to that code becomes true. 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. Demultiplexer can route a data output pin to different components based on address pins. The multiplexer, shortened to mux or mpx, is a combinational logic circuit designed to. In latches level triggered means that the output of the latches changes as we change the input and edge triggered means that. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output. Pdf highspeed multiplexers, demultiplexers, and static frequency dividers are key electronic components in. The term multiplexing can have multiple interpretations. A multiplexer or mux is a device that has many inputs and a single output. So, biological implementation of logic gates is definitely a powerful resource to design modular gene networks inspired to digital electronic circuits 3, 6. 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. Multiplexers are mainly used to increase the amount of data that can.
The book digital electronics contains twelve chapters with comprehensive. The multiplexer routes one of its data inputs d0 or d1 to the output q, based on the value of s. The single pole multiposition switch is a simple example of nonelectronic circuit of multiplexer, and it is widely used in many electronic circuits. R1 ch5 encoder decoder mux demux computer engineering. A demultiplexer of 2 n outputs has n select lines, which are used to select which output line to send the input. Multiplexer data selectordigital electronicsenglish. It is a combinational circuit which have many data inputs and single output depending on control or select inputs. Sep 06, 2017 with a demultiplexer we can take two of the microcontrollers io pins and turn them into address pins for example a1 and a0. The address input determine which data output is going to have the same value as the data input. Its output is a twobit number x1x0, representing that count in binary. Since a multiplexer s job is to select one of the data input lines and send it to the output, it is also known as data selector.
A decoder takes address pins as inputs and raises the corresponding pin to a logic high. Aug 28, 2015 a multiplexer or mux is a device that selects one of several analogs or digital input signals. Multiplexer and demultiplexer electronics circuits elprocus. A general overview of multiplexer and demultiplexer. The multiplexer is used to perform highspeed switching and is constructed by electronic components multiplexers are capable of handling both analog and digital applications. 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. Shown here is a multiplexer and a demultiplexer, each using a multipleposition switch symbol to indicate the selection functions inside the respective circuits. The multiplexer is one of the most important components in communications networking. In most cases a digital multiplexer is a digital selector. In telecommunications and computer networks, multiplexing sometimes contracted to muxing is a method by which multiple analog or digital signals are combined into one signal over a shared medium.
Multiplexing originated in telegraphy in the 1870s, and is now. Again the output line is selected using an address. The difference between latches and flipflop is that the latches are level triggered and flipflops are edge triggered. Ones complement uses an endaround carry if the carry bit is 1, which. Jul 19, 2017 the term multiplexing can have multiple interpretations. Multiplexer handle two type of data that is analog and digital. And then it forwards the selected input into a single line. The mux output is a single bit, which is one of the 2n data inputs. Demultiplexer is also a device with one input and multiple output lines. Multiplexing and demultiplexing logic functions for computing. Since all input variables are complemented in this expression, we can directly derive the pullup network as having parallelconnected pmos transistors controlled by x1 and x2, in series with parallelconnected transistors controlled by x3 and x4, in series with a transistor controlled by x5.
Computer architectures digital circuits demultiplexer. This page on muxmultiplexer vs demuxdemultiplexer covers basics of mux and demux and also mention difference between muxmultiplexer and demuxdemultiplexer. A multiplexer or mux is a device that selects one of several digital input signals and directs it to a single output. Muxdemux components i would also like a more detailed report even though this reports scope was clearly defined and quite interesting. In analog applications, multiplexers are made up of of.
This circuit, along with the corresponding pulldown network, is shown in figure 3. Multiplexers and demultiplexers are often confused with one another by students. Digital logic design bibasics combinational circuits sequential circuits pujen cheng adapted from the slides prepared by s. A demultiplexerdecoder demux is a selector device that has some i select inputs and 2i outputs. Pdf 46 gbs demux, 50 gbs mux, and 30 ghz static frequency. The 1180 is a highquality multiplexer demultiplexer for embedding and deembedding analog or aes audio onto the sdi signal. Since the muxdemux also works with digital signals, you can use it to pipe ttllevel serial data to or from multiple devices. There are three main ways of constructing a multiplexer. The ic can control analog voltages that vary across the voltage supply range. A 2nto1 multiplexer sends one of 2n input lines to a single output line. T here are two data inputs d0 and d1, and a select input called s.
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. For n input lines, log n base2 selection lines, or we can say that for 2 n input lines, n selection lines are required. Electronics tutorial about the multiplexer mux and digital multiplexers used in. The multiplexer used for digital applications, also called digital multiplexer, is. The mux demux also works with digital signals like serial, i2c, spi. Lecture notes for digital electronics university of oregon. Introduction to digital electronics lab nomenclature of digital ics, specifications, study of the data sheet, concept of v1 cc and ground, verification of the truth tables of logic gates using ttl ics. The data distributor, known more commonly as a demultiplexer or demux for short, is the exact opposite of the multiplexer we saw in the previous tutorial the demultiplexer takes one single input data line and then switches it to any one of a number of individual output lines one at a time. Examples of solved problems for chapter3,5,6,7,and8. 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. The value on the output of such a device is the value nth data input, where n is the binary number on the select inputs. Design a circuit that counts the number of 1s present in 3 inputs a, b and c.101 309 996 725 858 123 917 1035 649 1247 1401 693 642 529 1207 194 400 1295 1420 787 446 1023 965 1375 1326 204 169 1389 222 807 479 273 782 1389 1270 327 237 402 1391 1331 675 373 1282 240 625 813 647