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

Constant voltage sources, Constant Voltage Sources An ideal constant v...

Constant Voltage Sources An ideal constant voltage source maintains a given voltage across its load regardless of the current drawn from it .Most 'every-day' power supplies a

Quantifiers and variables - propositional model, Quantifiers and Variables ...

Quantifiers and Variables - propositional model: There is one question is arrives that 'What do sentences containing variables mean?' In other way of words, how does a first-o

Explain ip address structure, Q. Explain IP Address Structure? Internet...

Q. Explain IP Address Structure? Internet addresses are divided in five types of classes. Classes were designated A through E. class A address space enables a small number of n

Labels in the sub trees, A sorting method which uses the binary tree concep...

A sorting method which uses the binary tree concept such that label of any node is larger than all  the labels in the sub trees, is called A Sorting method which uses the binar

What guarantees the integration of all application modules, What guarantees...

What guarantees the integration of all application modules? The R/3 basis system guarantees the integration of all application modules.  The R/3 basis s/w gives the run time e

Differentiate the latch and flip-flop, Differentiate the latch and flip-flo...

Differentiate the latch and flip-flop? The major difference between latch and FF is which latches is level sensitive whereas FF is edge sensitive. They both need the use of clo

What is socket, A socket is one end-point of a two-way communication link a...

A socket is one end-point of a two-way communication link among two programs running on the network. Socket classes are used to show the connection among a client program and a ser

What is replacement policy in cache, Q.What is Replacement Policy in cache?...

Q.What is Replacement Policy in cache? When a new block has to be fetched in cache the other block may have to be replaced to make room for new block. Replacement policy determ

How many address bits are required to represent 4K memory, How many address...

How many address bits are required to represent 4K memory ? Ans. 12 address bits are required for representing 4K memory, as 4K = 2 2 x 2 10   = 2 12 Therefore 1K = 1024

Speed up factor, Remember, the value of α is between 0 and 1. Now, let us p...

Remember, the value of α is between 0 and 1. Now, let us put some values of α and compute the speed up factor for increasing values of number of processors.  We get that the S(N) k

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