The term nor is a contraction of notor and implies an or function with an inverted output. Nand and nor gates are called as universal gates as they can be used to create all other logic gates. The nand gate as a univers al gate 1 the nand gate as a univers al gate. Lab02 basic logic gates chiachun tsai objectives understand a module of digital system and all the components on the module understand basic logic gates, not, and, or, nand, nor, xor, and xnor and their truth tables. How a logic circuit implemented with aoi logic gates could be reimplemented using only nor gates. Nor gate is used to construct the basic gates similar to and gate.
The output of this gate is high, only when all input voltages are low. In other words, the output of a nand gate is high when both of the inputs are low. As a result, we can build any logic circuit and implement any boolean expression. Logic nor gate tutorial the logic nor gate gate is a combination of the digital logic or gate and an inverter or not gate connected together in series the inclusive nor notor gate has an output that is normally at logic level 1 and only goes low to logic level 0 when any of its inputs are at logic level 1.
In this activity you will revisit the voting booth monitoring system introduced in activity 2. Logic nor gate tutorial with logic nor gate truth table. A nor gate is a logic gate which gives a positive output only when both inputs are negative like nand gates, nor gates are socalled universal gates that can be combined to form any other kind of logic gate. In this physics digital electronics video lecture in hindi for class 12 we explained why nor gate is called universal gate. Thus operation of an and gate is based on the rule. Refer the following diagram here the same input is applied to the both inputs of a nand gate. If these gates are fabricated properly other basic gates can be constructed easily. Transistors, mosfets and other devices can also be used in the construction of and gates. An inverter can be made from a nand gate by connecting all of the inputs together and creating, in effect, a single input, as shown in fig for a 2input gate. The nand gate is a universal gate because it can be used to produce the not operation, the and operation, the or operation, and the nor operation. Just as a nand gate is like an or gate for low inputs, a nor gate is like an and gate for low inputs. Now let us see how each logic gate can be created with nand and nor gates. Generally, nor gate have 2 inputs, lets say x and y, and one output z. Universal property of nor gates nor gate is also selfsufficient.
A universal gate is a gate which can implement any boolean function without need to use any other gate type. X nor gate the exclusive nor gate circuit does the opposite to the xor gate. Very quickly, below are the symbols, boolean expression and truth table of nand and nor gates. Therefore, nor is also a complete set of logic can be used to implement andornot. Nand and nor gate as universal gate or universal building blocks in hindi. The nor gate is a digital logic gate that implements logical nor it behaves according to the truth table to the right. It will give a low output if either, but not both, of its two inputs are high. The logic diagram of any boolean function can be drawn using a twolevel nand gates or twolevel nor gates. How an nor gate can be using to replace an and gate, an or gate or an inverter gate. Nand and nor are called universal gates because all the other gates like and,or,not,xor and xnor can be derived from it.
The first part is an and gate and second part is a dot after it represents a not gate. The universality of the nand and nor gates means that they can be used as an inverter and the combinations of nand nor gates can be used to implement the and, or, and all. So it is clear that during the operation of nand gate, the inputs are first going through and gate and after that, the output gets reversed, and we. Explain the logic nor gate and its operation and how it. Logic gates are the basic elements in digital world. The logic gate nor takes two or more input and works as per the following truth table. Nor is the result of the negation of the or operator. The following paragraphs describe how the circuits work. This gate still uses pfets to pull the output high and nfets to pull the output low, satisfying rule 1. Nor gates are socalled universal gates that can be combined to form any other kind of logic gate. Patel college of engineering and technology subject. These basic gates can be constructed from the universal gates.
A universal gate is a logic gate which can be used to implement any other type of logic gates. Although and,or and not are basic gates but each of their functionality can be derived using nand and not as well. Nor gate is a digital logic gate also known as universal gate which gives output 1 only and only when all of its inputs are logic low state 0. Any logic gate or, and, not, nand, xor and xnor can be constucted. Specifically, you will be implementing the nor only combinational logic circuits for the two outputs. A high output 1 results if both the inputs to the gate are low 0. Conceptually, the or gate is built from nand gates through the following diagram. Nor gates can be combined in various and sundry ways to create not, and, or, and nand gates. Basic logic gates types, functions, truth table, boolean. Universal set is a powerful concept to identify the coverage of a set of gates afforded by a given. Nor gate as universal gate pdf download, the book of esther movie free download ae94280627 marks standard handbook for mechanical engineers download pdfzechariah sitchin ebook ita download moviespdfill pdf editor crack free downloadin the light of what we know pdf downloadgrade 9 ap module 3rd quarter pdf downloadcontrassegno p principiante pdf. Nor gate is the logic gate and is one of the universal gates. Now we will look at the operation of nor gates and nand gates as universal gates nand gate as universal gate. Nand gate, we can build the three basic logic operators.
Universal logic gates nand gate nor gate gate vidyalay. Universal gates are the one, which can be used for implementing any gate like and, or and not. There are following two universal logic gates nand gate. So it is clear that during the operation of nand gate, the inputs are first going through and gate and after that. It can also in some senses be seen as the inverse of an and gate. Basic logic gates and, or, and not gates objectives.
The output of an and gate assumes 1, only if all the inputs assume 1. Nor notor gates are universal logic gates for electronics applications. Universal gates in digital electonics nand and nor. According to nand gate if a and b are two inputs than output equation will be a. Like the nand gate, the nor gate is a universal gate.
By combining not gate and or gate, nor gate can be constructed. In the previous article we have learnt about basic logic gates. As a nor gate is equivalent to an or gate leading to not gate, this automatically sees to the or part of. Digital logic basics 21 implementation using nand gates. It produces a 1 output only when even number of 1 is present at the input. Nand gate a nand gate is constructed by connecting a not gate at the output terminal of the and gate. Analene montesinesnagayo implementation of boolean function using twolevel universal gates. Logic gates not, or, and, nor, nand, xor, xnor gate, pdf. The standard symbol for the nor gate is the same as the or gate. The three gates or, and and not, when connected in various combinations, give us basic logic gates such as nand, nor gates, which are the universal building blocks of digital circuits.
From the truth table, we can say that the output of the or logic or an or gate is true or high or 1, even if either or both of a or b are 1. An inverter can be made from a nand gate by connecting all of the inputs together and creating, a single input as shown below. Universal gate nor universal gate nor this presentation will demonstrate the basic function of the nor gate. The output of nand gate is high 1 if at least one of its inputs is low 0. This basic logic gate is the combination of and and not gate. In practice, this is advantageous since nand and nor gates are economical and easier to fabricate and are the basic gates used in all ic digital logic families. The gate is either a nand or an ex or gate b nor or an ex nor gate.
When the ldr is in the light the other input is low. The basic logic gates arethe inverter or not gate, the. Creating a not gate from a nor gate is the same as creating a not gate from a. This means that if either of these things happen, i. Universal gates free download as powerpoint presentation. There are two universal gates in the digital logic. Any logic network that consists of not, and, and or gates can be recreated with just nor gates. In operation, when the x and y inputs are low, the two pfets turn on and pull the output. For example, the first embedded system, the apollo guidance computer, was built exclusively from nor gates, about 5,600 in total for the later versions. The symbol is an xor gate with a small circle on the output. To build an or gate from a nand gate, we need to use 3 of the 4 gates that a 4011 nand chip offers. The output of a logic gate is 1 when all its input are at logic 0. Taken to limit, give me as many nand gate as i want, in theory i can build a pentium processor.