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

Quick sort , Write Quick sort non recursive program

Write Quick sort non recursive program

Explain switch statement, Switch This is another form of the multi way ...

Switch This is another form of the multi way decision. It is well structured, but can only be used in certain cases where; Only one variable is tested, all branches must

What is the linkage section used for, The linkage section is used to pass d...

The linkage section is used to pass data from one program to one more program or to pass data from a PROC to a program.

What is persistence, What is Persistence When you make an object, it e...

What is Persistence When you make an object, it exists for so long as you need it, but under no circumstances object exist when program terminates. While this makes sense at s

Explain wait for graph-resource request and allocation graph, Explain Wait ...

Explain Wait for graph (WFG) with Resource request and allocation graph (RRAG). WFG with RRAG: A graph G = (V,E) is termed as bipartite if V can be decomposed in two

What is block started by symbol, What is BSS(Block Started by Symbol)? ...

What is BSS(Block Started by Symbol)? A data showing at the machine level, that has initial values when a program begins and tells about how much space the kernel assigns for t

Explain register marker, Explain Register marker. Register marker: St...

Explain Register marker. Register marker: Strowger selectors doing searching and counting. Conversely, the crossbar switch has no 'intelligence'. Something external to the

Describe about second generation computers, Q. Describe about Second Genera...

Q. Describe about Second Generation Computers? Silicon brought advent of second generation computers. A two state device termed as a transistor was created from silicon. Transi

Compares a pair of characters entered by keyboard, Program: This program c...

Program: This program compares a pair of characters entered by keyboard. ; Registers used: AX, BX, CX, DX DATA SEGMENT                          XX DB?

What is a screen group, What is a screen group? How it is useful? Scre...

What is a screen group? How it is useful? Screen group is a field in the Screen Attributes of a screen.  Here we can explain a string of up to four characters which is availa

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