2 input multiplexer using nand gates pdf

Also, give the realization using only two input nand gates. The 8 input or gate also has to be replaced with a nor gate to invert the input back, so the output would be correct. 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 from the truth table above, we can see that when the data select input, a is low at logic 0, input i 1 passes its data through the nand gate multiplexer circuit to the output, while input i 0 is blocked. When any of the one input is zero output is always zero or same as. We can build a simple 2line to 1line 2to1 multiplexer from basic logic nand gates as shown. Twolevel logic using nand gates cont d z or gate with inverted inputs is a nand gate. When the control signal is 0, the first channel is selected and the2 nd channel is selected when the control signal is 1. The extra to the m control lines input to each gate is connected to one of the n inputs. Mar 25, 2017 a multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output. Ors into 4 input nand 7 20, 0 0 0 0 0 exclusiveor f unctio ns xn2 xn2a xn2t xn3 2 inout 2 input 2 input 3 input 4 xnor or, 2 input nand into 2 input nand 3 xnor using tpts, nand minimumarea 5 input nand 6 input nand 8 input nand 4 3 5 6 10, 6, 11, 15, 0 0, 0 1 0 nand gates nand nand using rlt nand nand and gates or nand gates. For the love of physics walter lewin may 16, 2011 duration. Basic logic gates using nand gate not, or, and gates. Physically, a multiplexer has n input pins, one output pin, and m control pins. Enable input is 1, then the selected input either i0 or i 1 is allowed through.

Static characteristics voltages are referenced to gnd ground 0 v symbol parameter conditions 74hc157 74hct157 unit min typ max min typ max vcc supply voltage 2. Implementing twolevel logic using nor gate requires the boolean expression to be in product of sum pos form. How a nand gate can be used to replace an and gate, an or gate, or an inverter gate. To implement a boolean function using nor gate, there are basically three step. In general, there are 2n input lines and n selection lines whose bit combinations determine which input is selected. A multiplexer is a device that selects one of several input signals and forwards the selected input to the output. A universal gate is a gate which can implement any given logic function. How a logic circuit implemented with aoi logic gates can be reimplemented using only nand gates. How can i design 41 multiplexer using 2 multiplexers designed as in the title of the question using only nands plus as many nor gates as i need.

For the breadboard part of this step, the blue wire represents input 1 a, wire 2 represents input 2 b, and the led represents the final output. Nor gates, like all the other multipleinput gates seen thus far, can be manufactured with more than two inputs. Heres how you might make a 2to1 multiplexer out of logic gates. Universal gate nand i will demonstrate the basic function of the nand gate. A nand gate is smaller, areawise and faster than other circuits. Design a combinational circuit with three inputs, x, y and z, and the three outputs, a, b, and c. A flipflop with a clock input will usually only perform an operation on the rising edge of a clock signal. Hi im trying to learn logic gates and im trying to solve this problem is this correct using nand gates with 2 inputs only, construct a three input nor gate any advice would be awsome im stuck. Oct 28, 2015 as mentioned earlier, a nand gate is one of the universal gates and can be used to implement any logic design. These features allow the use of these devices in a mixed 3. Hi im trying to learn logic gates and im trying to solve this problem is this correct using nand gates with 2 inputs only, construct a three input nor gate. The extra to the m control lines input to each gate is. When any of the one input is zero output is always zero or same as that input.

If the enable input is 0, neither i 0 nor i 1 get through. Jk flipflop circuit diagram, truth table and working explained. Similarly, you could in theory build a car using only basic lego blocks. The 8input or gate also has to be replaced with a nor gate to invert the input back, so the output would be correct.

The nand gates is implemented by three input majority gate with inverters. Normally, there are 2n input lines and n selection lines whose. There is also an enable bit used for enablingdisabling the circuit. As you might have suspected, the nor gate is an or gate with its output inverted, just like a nand gate is an and gate with an inverted output. In product of sum form, 1st level of the gate is or gate and 2nd level of the gate is and gate. In this post, we will discuss how we can use nand gates to build a 4x1 mux.

As mentioned earlier, a nand gate is one of the universal gates and can be used to implement any logic design. Logic nand gate tutorial with nand gate truth table. There are three main ways of constructing a multiplexer. Since a multiplexers job is to select one of the data input lines and send it to the output, it is also known as data selector. Normally, a multiplexer has an even number of 2 n data input lines and a number of control inputs that correspond with the number of data inputs. If you must use 8x and gates to design your mux, then youd have to invert the inputs before entering the and gates. Oct 09, 2018 physically, a multiplexer has n input pins, one output pin, and m control pins. Multiplexer mux and multiplexing tutorial electronics tutorials. The circuit of full adder using only nand gates is shown below. Generally, the selection of each input line in a multiplexer is controlled by an. Hence the nand gate is made up of and gate which is followed by an inverter.

If you are designing a printed circuit board pcb using simple logic devices, like dualinline dil packaged integrated circuits ics containing six not gates or four 2input and, or, nand, or nor gates, it may be that you end up short of something like an and gate, but you happen to have a nand and a not gate going spare or perhaps an or. Let the 2 input and gate has the inputs a and b, and output as y. By replacing those 2 input and gates with a 3 input variety, we can add a clock input to the jk flipflop. The nandbased derivation of the or gate is shown in figure 1. A multiplexer, in a sense, can also be termed as a universal gate, since, you can realize any function by using a mux as a lookuptable structure. The circuits operation is best understood by dividing it into the three parts that are shown in the. Thus y1 when either input is 0 requires parallel pmos rule of conduction complements pullup network is complement of pulldown parallel series, series parallel 10 cmos logic gates1 inverter input output a a v dd gnd pulldown pullup path path 2input nand gnd vdd a b a b pulldown pullup tree tree a b z z 0 0 z. In this post, we will be discussing the implementation of 2input and, or, nand, nor, xor and xnor gates using a 2input mux. The cd54hc00, cd54hct00, cd74hc00 and cd74hct00 logic gates utilize silicon gate cmos technology to achieve operating speeds similar to lsttl gates with the low power consumption of standard cmos integrated circuits. Thus, comparing the three input and two input nand gate truth table and applying the inputs as given in jk flipflop truth table the output can be analysed. Half adder and full adder circuits using nand gates.

As we know that a 4x1 mux can be structurally built from 2x1 muxes as shown in figure 1 below. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output. Twolevel logic using nand gates twolevel logic using nand. May 08, 2015 for the love of physics walter lewin may 16, 2011 duration. The clock input can be used in many ways, for instance multiple flip flops can be synchronized by sharing a clock input. The nand gate is just a combination of the expression not gate as well as and gate. Combinational logic implementation implementations of two level logic.

Laboratory manual digital systems and logic design. Nand gate based qca 2to1 line multiplexer semantic scholar. Finally, from the results, we can conclude that the derived configuration of the nand gates is correct and indeed is equivalent to an. How can i design a 21 multiplexer with enable using only. Design an 8to1 mux using a 3to8 decoder and and gates and. If we want to perform n bit addition, then n number of 1 bit full adders should be used in the. Logic diagram for an 8 input multiplexer using gates and a decoder. If you will write down the logic equations for a 4 to 1 multiplexor, then the logic will become obvious. The selection of a particular input line is controlled by a set of selection lines. Cse 370 spring 1999 combinational implementation 2. Taking a circuit described using and and or gates in either a sumofproducts or a productofsums format and converting it into an alternative representation using only nand gates, only nor gates, or a mixture of nand and nor gates is a great way to make sure you understand how the various gates work. Using the kmap minimize the function in the sum of products form. All devices have the ability to drive 10 lsttl loads. The working of these gate is like that we get binary 1 at the output of the gate if and only is both the input is at the binary low state i.

The output of a logic gate is 1 when all its input are at logic 0. Thus, in the same way, we can arrange the 2input nand. The nand based derivation of the or gate is shown in figure 1. M u lt i p l e x e r s a multiplexer is a combinational circuit that. From truth table we can write the output equation as y a. Previous gate questions on kmap, sop and pos expressions. High speed cmos logic quad 2 input nand gates datasheet. Design a 3input nand gate using only 2input nand gates and not gates. Nand and nor gates are basically known as universal gates, since you can implement any logic function with these. That using a single gate type, in this case nand, will reduce the number of integrated circuits ic required. General description the 74lvc1g00 provides the single 2input nand function. How to design a 4 by 1 multiplexer using nand or nor gates. In this paper we propose a new design of 2to1 line multiplexer using three nand gates in.

As with the and function seen previously, the nand function can also have any number of individual inputs and commercial available nand gate ics are available in standard 2, 3, or 4 input types. A 2input nand is equivalent to oring two inverted inputs. If the enable input is 1, then the selected input gets through to the or gate. Using tristate gates to implement an economical multiplexer. Cd54hc00, cd74hc00, cd54hct00, cd74hct00 datasheet rev. The circuit diagram for the mux with the enable is. When the binary input is 4, 5, 6, or 7, the binary output is one less than the input. Sep 07, 2015 the nand gate is just a combination of the expression not gate as well as and gate. Design an 8to1 mux using a 3to8 decoder and and gates. From the truth table above, we can see that when the data select input, a is low at logic 0, input i 1 passes its data through the nand gate multiplexer circuit to the output. It is therefore could be regarded as the building block of all digital circuits. Cse 370 spring 2000 combinational implementation 2. It would be more elegant to design with nand gates as suggested by.

This, works like sr flipflop for the complimentary inputs and the advantage is that this has toggling function. The outputs from the existing and gates now enter two additional and gates. The implementation of a fulladder using two halfadders and one nand gate requires fewer gates than the twolevel network. The design uses three majority and gates and three inverters. For example, a 21 mux with select line s, output y, and inputs a and b might be y s and a or not s and b and the obvious implementation. We can refer to a multiplexer with the terms mux and mpx too. In other words, the rotary switch is a manual switch that you can use to select. Route one of many inputs to a single output multiplexer.

If additional inputs are required, then the standard nand gates can be cascaded together to provide more inputs for example. The nand function is obtained by combining a diode and gate with an inverting buffer amplifier. In the post 2x1 mux using nand gates, we discussed how we can use nand gates to build a 2x1 multilexer. When using tristate logic 1 make sure never more than one driver for a wire at any one time pulling high and low at the same time can severely damage circuits 2 make sure to only use value on wire when its being driven using a floating value may cause failures.

Multipleinput gates logic gates electronics textbook. How do i construct a 4x1 mux using only 2 input nand gates. The commercially available 8input multiplexer integrated circuit in the ttl family is. These features allow the use of these devices in a. Ors into 4input nand 7 20, 0 0 0 0 0 exclusiveor f unctio ns xn2 xn2a xn2t xn3 2inout 2 input 2 input 3 input 4 xnor or, 2 input nand into 2 input nand 3 xnor using tpts, nand minimumarea 5 input nand 6 input nand 8 input nand 4 3 5 6 10, 6, 11, 15, 0 0, 0 1 0 nand gates nand nand using rlt nand nand and gates ornand gates. A and b are the two inputs, x is the select input, and y is the output. That using a single gate type, in this case nand, will reduce the number of integrated circuits ic required to implement a logic circuit. Twolevel logic using nand gates twolevel logic using.