Explain about 4-bit adder-subtractor circuit, Computer Engineering

Assignment Help:

Q. Explain about 4-bit adder-subtractor circuit?

Subtraction operation on binary numbers can be obtained by succession of addition operations only it implies that to achieve subtraction A-B we can find 2's complement of B. This can be computed by 1's complemented and then adding 1 to it. So a common circuit can carry out addition and subtraction operation. A 4-bit adder subtraction circuit is displayed in figure below that is formed by employing XOR gate with each full adder. XOR gate with output 0 is for inspecting overflow.

2153_Explain about 4-bit adder-subtractor circuit.png

Figure: 4-bit adder-subtractor circuit

Control input 'x' controls operations it implies that if x =0 then circuit acts as an adder and if x =1 then circuit acts as a subtractor. The operation is summarized as below:

a. When x = 0, c = 0, output of all XOR gates would be same as corresponding input Bi where i = 0 to 3. So Ai and Bi are added by full adders providing Sum Si and carry Ci .

b. When x = 1 output of all XOR gates will be complement of input Bi where i =0 to 3 to that carry C0=1 is added. So circuit finds A plus 2's complement of B which is equal to A-B.


Related Discussions:- Explain about 4-bit adder-subtractor circuit

Write the html code to web page to insert an image, Write the HTML code to ...

Write the HTML code to accomplish the web page to insert an image onto a page using good.gif as image and having "welcome" as the ALT text. The HTML code to accomplish the web

Define the emphasis on object structure, Define the Emphasis on Object Stru...

Define the Emphasis on Object Structure Emphasis on Object Structure, not on Operation Implementation In object orientation the importance is on specifying the qualities

What is time out mechanism, What is time out mechanism. If one unit is ...

What is time out mechanism. If one unit is faulty the data transfer will not be done. Such an error can be detected using time out mechanism which makes an alarm if the data tr

Subprogram to output the result, Input a list of positive numbers (terminat...

Input a list of positive numbers (terminated by 0) into an array. Find the largest number in the array, and into the result. Use a subprogram to input the numbers, a function to fi

What is mother board, What is mother board? Mother Board is a main syst...

What is mother board? Mother Board is a main system printed circuit board which having the processor. It will occupy an unacceptably large amount of space on the board.

Which process is used for page reference, Locality of reference implies tha...

Locality of reference implies that the page reference being made by a process is Ans. Locality of reference means that the page reference being made through a process is proba

What are the advantages of interviewing, What are the Advantages of Intervi...

What are the Advantages of Interviewing - Opportunity to motivate interviewee to give open and free answers to analyst's questions    -  allows analyst to probe for more f

What is called all exceptions in java, Al l exceptions in Java are subclass...

Al l exceptions in Java are subclasses of built in class called? Each exception in Java are subclasses of make in class termed as Throwable.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd