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

Explain control word, What is control word? A control word is a word wh...

What is control word? A control word is a word whose individual bits show the various control signals.

Define main memory and auxiliary memory, Define main memory and auxiliary m...

Define main memory and auxiliary memory? The memory unit that communicates directly with the cpu is known as main memory [RAM].Devices that give backup storage are known as aux

Find out lowest propagation delay time in logic family, Which the digital l...

Which the digital logic family has the lowest propagation delay time ? Ans. ECL is the digital logic family that has the lowest propagation delay time. In ECL lowest propagati

Explain segment registers in bus interface unit, Q. Explain Segment Registe...

Q. Explain Segment Registers in bus interface unit? These are very significant registers of CPU. Why? We will answer this later. In 8086 microprocessor memory is a byte organiz

General purpose register - assembly language, General purpose register - as...

General purpose register - assembly language: Basic ISA Classes: Accumulator: 1 address add Aacc ←acc + mem [A] Stack: 0 address add to s ←to s+ next G

Explain what the difference between the two readings, The following sentenc...

The following sentences have a (potential) scope ambiguity. Give two translations into predicate logic for each sentence (one formula for each reading), and explain in words what t

Hardware implementation for signed-magnitude data, Hardware Implementation ...

Hardware Implementation for signed-magnitude data When multiplication  is  implemented  in  digital  computer,  we  change  process lightly. Here, in place of providing registe

What is unordered lists, Q. What is Unordered Lists? First, we will bui...

Q. What is Unordered Lists? First, we will build an unordered list. Many times, these lists are also termed as bulleted lists. These lists are characterized by list items which

Explain the acceptance and request determination, Explain the Acceptance an...

Explain the Acceptance and Request Determination As we have learned, much of the overhead in client-server interaction occurs in the CSInteface, either client or server. It is

State the example of begin end, State the Example of begin end module s...

State the Example of begin end module sequential(); reg a; initial begin $monitor ("‰g a = ‰b", $time, a); #10 a = 0; #11 a = 1; #12 a = 0; #13 a = 1; #

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