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Explain Half Adder and Full Adder with Truth Table

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableAn adder is a digital logic circuit in electronics that implements addition of numbers. In many computers and other types of processors, adders are used to calculate addresses, similar operations and table indices in the ALU and also in other parts of the processors. These can be built for many numerical representations like excess-3 or binary coded decimal. Introduction

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableAdders Are Classified Into Two TypesHalf Adder and Full Adder .

The half adder circuit has two inputs: A and B.

It add two input digits and generate a carry and sum.

The full adder circuit has three inputs: A, B and C.

It add the three input numbers and generate a carry and sum.

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableAdders Are Classified Into Two Types

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableWhat is Half Adder and Full Adder CircuitThe half adder adds two binary digits called as augend and addend.

Half adder produces two outputs as sum and carry.

XOR is applied to both inputs to produce sum.

OR gate is applied to both inputs to produce carry.

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableWhat is Half Adder and Full Adder CircuitThe full adder adds 3 one bit numbers.

Where two can be referred to as operands.

One can be referred to as bit carried in.

It produces 2-bit output, and these can be referred to as output carry and sum.

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf AdderUsing Half Adder, you can design simple addition with the help of logic gates.

Lets see an addition of single bits.

0+0 = 0 0+1 = 1 1+0 = 1 1+1 = 10

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf AdderThese are the least possible single-bit combinations. But the result for 1+1 is 10, the sum result must be re-written as a 2-bit output. Thus, the equations can be written as

0+0 = 00 0+1 = 01 1+0 = 01 1+1 = 10

The output 1of 10 is carry-out. SUM is the normal output and CARRY is the carry-out.

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth Table

Half Adder

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf Adder Truth Table

1-bit adder can be easily implemented with the help of the XOR Gate for the output SUM and an AND Gate for the Carry.

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf Adder Truth TableWhen we need to add, two 8-bit bytes together, it can be done with the help of a full-adder logic.

The half-adder is useful when you want to add one binary digit quantities.

A way to develop a two-binary digit adders would be to make a truth table and reduce it.

When you want to make a three binary digit adder, do it again.

When you decide to make a four digit adder, do it again.

The circuits would be fast, but development time is slow.

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf Adder Truth Table

Image Of Half Adder Logic Circuit

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf Adder Truth TableThe simplest expression uses the exclusive OR function

Sum=AB

An equivalent expression in terms of the basic AND, OR, and NOT is

SUM=A|.B+A.B

http://www.elprocus.com/Explain Half Adder and Full Adder with Truth TableHalf Adder Truth TableVHDL Code For half Adder:

entity ha isPort (a: in STD_LOGIC;b : in STD_LOGIC;sha : out STD_LOGIC;cha : out STD_LOGIC);end ha;

Architecture Behavioral of ha is

beginsha