Xor gate using nand gate pdf

Implementation of xorxnor and and logic gates by using. Realization of xor gate using minimum number of two inputs nand gate. For example, it is possible to build a circuit exhibiting the or function using three interconnected nand gates. Twolevel digital circuit implementations using other gates. Various researchers have proposed designs and implementation of logic functions using nand and nor gate circuits but this paper proposes a three nand gate. Today, contrary to popular belief, integrated circuits are not constructed exclusively from a single type of gate. If we look at the truth table carefully we will find that the first three results are totally satisfying the process of binary addition but in the last input sequence i. The output is low if both the inputs are high or either of the input is high fig. It produces a 1 output when any of the inputs is 0. A low 0 output results only if all the inputs to the gate are high 1.

Implementation of xorxnor and and logic gates by using mach. Here, no signal is provided at the second input terminal of mzi 1. The xor and xnor logic gates implementation consists of two mzi structures as shown in fig. An xor gate is made by connecting four nand gates as shown below. Xor gate is a digital logic gate that gives a true 1 or high output when the number of true. Note that the exact same network works if all of the nand gates are changed to nor gates, except that you get an xnor gate the output is high if the inputs are equal. The outputs of all nand gates are high if any of the inputs are low. The table of combinations for a twoinput xor gate is given in table 6. Depending on the type of logic gate being used and the. The other important ic gate type is the sum modulo two, or exclusiveor xor gate, which has a high output only when an odd number of its inputs are high. Jul 14, 2015 the exor gate is defined as, the hybrid logic gate with 2 or more inputs to perform the exclusive disjunction operation.

Xor from nand logic, nand to xor conversion, equations, circuit, minimizatio truth tables. In digital electronics, a nand gate notand is a logic gate which produces an output which is false only if all its inputs are true. A nand gate presents an and gate followed by an inverter. Export eps export svg export svgz description a xor gate using nand gates. If the four nand gates are replaced by nor gates, this results in an xnor gate, which can be converted to an xor gate by inverting the. All nor input pins connect to the input signal a gives an output a.

Drive xor from nand gate, nand to xor conversion with. Hence the nand gate is made up of and gate which is followed by an inverter. At any given moment, every terminal is in one of the two binary conditions false high or true low. Linbo 3 based waveguide at cost of higher switching voltage of 8 v 20 21. Neural representation of and, or, not, xor and xnor logic. The ability for a single gate type to be able to mimic any. Universal gate nand i will demonstrate the basic function of the nand gate.

The figure shows two ways in which a nand gate can be used as an inverter not gate. An entire processor can be created using nand gates alone. A basic cmos structure of any 2input logic gate can be drawn as follows. The exor gate is defined as, the hybrid logic gate with 2 or more inputs to perform the exclusive disjunction operation. 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.

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. Logic gates types, working principle, application, advantage. A logic gate is a building block of a digital circuit. Pdf realization of alloptical xor, nor, and nand gates in. The nand gate has the property of functional completeness, which it shares with the nor gate. The main application of the exclusive or gate is in the operation of half and full adder. Continuing the process, the nand gate can be further extended to more three inputs as well. If both the inputs are same, then the output is low. Several kinds of digital logic circuits are the basic elements that form the building blocks for such complex digital system as the.

Now lets understand how this circuit will behave like a nand gate. The following illustration and table show the circuit symbol and logic combinations for an and gate. I am trying to design a full adder just 1 bit using only 4 xor gates and 4 nand gates in other words, the 7486 and 7400 ics. If both inputs are false 0low or both are true, a false output results. For example, the, apollo guidance computer, was built exclusively from nor gates, about 5,600 in total for the later versions. The paper focuses on the description of optical switching phenomena and its efficient application to perform digital logic operations such as and, xor and xnor logic gates. Passtransistorlogic xor gate using pass transistor logic.

The output of 2 input xor gate is high only when one of its inputs are high. All the anded literals can be realized directly using a nand gate each. This table shows that the output of an xor gate with input x 1 and x 2 is given by x 1. Logic gate actually the term logic is applied to digital circuits used to implement logic functions. The and gate is so named because, if 0 is called false and 1 is called true, the gate acts in the same way as the logical and operator. Perform the following steps to obtain the minimum number of gates required. Abstract this study implements nand gate as universal gate to realize other gates xor, or, and, not using. Sep 07, 2015 the nand gate is just a combination of the expression not gate as well as and gate. Now all i need to know is how to align the transistors to make a 3input version of exactly this, lol. One nand input pin is connected to the input signal a while all other input pins are connected to logic 1. Thus, the nand gate is a universal gate since it can implement the and, or and not functions. I know the answer but how to get the gate diagram from the formula. How a logic circuit implemented with aoi logic gates can be reimplemented using only nand gates. Digital circuitsnor logic wikibooks, open books for an.

Its a fairly straightforward approach using boolean algebra as our guide, mainly making use. The diagrams below show two ways that the nand logic gate can be configured to produce a not gate. Alternatively, an xor gate is made by considering the disjunctive normal form. Aug 04, 2015 a basic cmos structure of any 2input logic gate can be drawn as follows.

The nandbased derivation of the or gate is shown in figure 1. Here you will get the articles of mechanical engineering in brief with some key points and you will get to know an enormous amount of knowledge from it. A cd4011b was used as an example of a nand gate ic. The old techinterview forum xor gate using nand gates. Gate input controls whether current can flow between the other two terminals or not. The above drawn circuit is a 2input cmos nand gate. It can also be done using nor logic gates in the same way. On pspice, ive created a transistorlevel schematic for what i mean by 2input cmos xor gate the top voltage source is simply supposed to be vdd of 5v, ignore the missing connection. Pdf alloptical multiple logic gates with xor, nor, or, and.

I just cant seem to figure out how to replace the or gate with anything other than 3 nand gates, which doesnt leave enough to replace the and gates. Logic gates and, or, not, nor, nand, xor, xnor gates. The truth table of xor gate is as shown in table below. Jan 28, 2017 realization of xor gate using minimum number of two inputs nand gate. The figure shows two ways in which a nor gate can be used as an inverter not gate. Basic logic gates using nand gate not, or, and gates. Boolean algebra and am following an example given in the text that shows the configuration of nor gates to create an xor. All nand input pins connect to the input signal a gives an output a.

In this gate if the b input is low then left nmos transistor is on and the logic value of a is copied to the output f. The nand boolean function has the property of functional completeness. The nand gate is just a combination of the expression not gate as well as and gate. Realization of alloptical xor, nor, and nand gates in single format by using semiconductor optical amplifiers article pdf available in japanese journal of applied physics 461 january 2007. In ttl ics using multipleemitter transistors, it also requires fewer transistors than a nor gate. Boolean logical algebra prove 4 nor gates to an xnor gate. Pdf realization of alloptical xor, nor, and nand gates. Xor gate can be realized with four two inputs nand gates. That using a single gate type, in this case nand, will reduce. The nand gate represents the complement of the and operation. I mean intuitively, to me, i should get this one if i do it step by step followed by the definition xor a and not b or not a and b. Implementing or using only nand gates an or gate can be replaced by nand gates as shown in the figure the or gate is replaced by a nand gate with all its inputs complemented by nand gate inverters. Architecture of nand gate threshold value is 4 net input is y in x 1x 2.

Finally, from the results, we can conclude that the derived configuration of the nand gates is correct and indeed is equivalent to an. The two input nand gate can be extended to three inputs by placing three nfets in series and three pfets in parallel as in figure 3. That is, given enough gates, either type of gate is able to mimic the operation of any other gate type. So if you find this articles helpful, please let us know in the comment box, either if any. In the previous tutorials, we saw that by using the three principal gates, the. An or gate equivalent can also be constructed using only nand gates, by putting two shorted equivalent to not nand gates each at the input of a third nand gate as shown in figure 4. The nand based derivation of the or gate is shown in figure 1. Most logic gates have two inputs and one output and are based on boolean algebra.

So today we will study the complete details on logic gates not, or, and, nor, nand, xor, xnor gate, pdf. The circuit output should follow the same pattern as in the truth table for different input combinations. The output of nor gate is high if both the inputs are low. The xor circuit with 2 inputs is designed by using and, or and not gates is shown above. Figure below shows the implementation of xor function using pass transistors. Exclusiveor gate tutorial the exclusiveor logic function is a very useful circuit that can be used in many different types of computational circuits in the previous tutorials, we saw that by using the three principal gates, the and gate, the or gate and the not gate, we can build many other types of logic gate functions, such as a nand gate. The truth table for the simple two input nand gate is given in table 6. Gate universality logic gates electronics textbook. Watch this video to learn more and see the interesting practical.

I mean intuitively, to me, i should get this one if i do it step by step followed by the definition xor a and. A nand gate is made using transistors and junction diodes. An xnor gate is made by considering the disjunctive normal form. It can beverified that the output f is always connected to either v dd or gnd, but never to both at the same time. The operation is the same as for the two input nand gate, satisfying all three basic rules. Pdf by using the cross gain modulation xgm characteristics of semiconductor optical amplifiers soas, multifunctional alloptical logic gates. Xor gate using nand gates this question was actually part of an interview i had with intel slightly over two years ago. The outputs of all anded literals are then fed into one nand gate to realize sop sum of product expression as a whole. In this paper, the working principle of machzehnder interferometer is described. Realization of logic gates using mccullochpitts neuron model. What is logic gate and, or, xor, not, nand, nor and xnor. Various researchers have proposed designs and implementation of logic functions using nand and nor gate circuits but this paper proposes a threenand gate. Kumar proposed novel way of implementing and, nand, nor, xor and xnor gate using ti.

This video takes the viewers, step by step to four different derived gates, i. Exclusiveor gate tutorial with exor gate truth table. I cannot follow the algebraic example and would like to have detailed steps filled in as i cannot match up rules i know to. Digital logic basics 21 implementation using nand gates. That using a single gate type, in this case nand, will reduce the number of integrated circuits ic required to implement a. Like nand gates, nor gates are socalled universal gates that can be combined to form any other kind of logic gate. This construction entails a propagation delay three times that of a single nand gate and uses five gates.